linux/drivers/pci/probe.c

2744 lines
69 KiB

PCI: Add pci_bus_addr_t David Ahern reported that d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows") fails to boot on sparc/T5-8: pci 0000:06:00.0: reg 0x184: can't handle BAR above 4GB (bus address 0x110204000) The problem is that sparc64 assumed that dma_addr_t only needed to hold DMA addresses, i.e., bus addresses returned via the DMA API (dma_map_single(), etc.), while the PCI core assumed dma_addr_t could hold *any* bus address, including raw BAR values. On sparc64, all DMA addresses fit in 32 bits, so dma_addr_t is a 32-bit type. However, BAR values can be 64 bits wide, so they don't fit in a dma_addr_t. d63e2e1f3df9 added new checking that tripped over this mismatch. Add pci_bus_addr_t, which is wide enough to hold any PCI bus address, including both raw BAR values and DMA addresses. This will be 64 bits on 64-bit platforms and on platforms with a 64-bit dma_addr_t. Then dma_addr_t only needs to be wide enough to hold addresses from the DMA API. [bhelgaas: changelog, bugzilla, Kconfig to ensure pci_bus_addr_t is at least as wide as dma_addr_t, documentation] Fixes: d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows") Fixes: 23b13bc76f35 ("PCI: Fail safely if we can't handle BARs larger than 4GB") Link: http://lkml.kernel.org/r/CAE9FiQU1gJY1LYrxs+ma5LCTEEe4xmtjRG0aXJ9K_Tsu+m9Wuw@mail.gmail.com Link: http://lkml.kernel.org/r/1427857069-6789-1-git-send-email-yinghai@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=96231 Reported-by: David Ahern <david.ahern@oracle.com> Tested-by: David Ahern <david.ahern@oracle.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: David S. Miller <davem@davemloft.net> CC: stable@vger.kernel.org # v3.19+
2015-05-27 17:23:51 -07:00
PCI: Add pci_bus_addr_t David Ahern reported that d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows") fails to boot on sparc/T5-8: pci 0000:06:00.0: reg 0x184: can't handle BAR above 4GB (bus address 0x110204000) The problem is that sparc64 assumed that dma_addr_t only needed to hold DMA addresses, i.e., bus addresses returned via the DMA API (dma_map_single(), etc.), while the PCI core assumed dma_addr_t could hold *any* bus address, including raw BAR values. On sparc64, all DMA addresses fit in 32 bits, so dma_addr_t is a 32-bit type. However, BAR values can be 64 bits wide, so they don't fit in a dma_addr_t. d63e2e1f3df9 added new checking that tripped over this mismatch. Add pci_bus_addr_t, which is wide enough to hold any PCI bus address, including both raw BAR values and DMA addresses. This will be 64 bits on 64-bit platforms and on platforms with a 64-bit dma_addr_t. Then dma_addr_t only needs to be wide enough to hold addresses from the DMA API. [bhelgaas: changelog, bugzilla, Kconfig to ensure pci_bus_addr_t is at least as wide as dma_addr_t, documentation] Fixes: d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows") Fixes: 23b13bc76f35 ("PCI: Fail safely if we can't handle BARs larger than 4GB") Link: http://lkml.kernel.org/r/CAE9FiQU1gJY1LYrxs+ma5LCTEEe4xmtjRG0aXJ9K_Tsu+m9Wuw@mail.gmail.com Link: http://lkml.kernel.org/r/1427857069-6789-1-git-send-email-yinghai@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=96231 Reported-by: David Ahern <david.ahern@oracle.com> Tested-by: David Ahern <david.ahern@oracle.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: David S. Miller <davem@davemloft.net> CC: stable@vger.kernel.org # v3.19+
2015-05-27 17:23:51 -07:00
PCI: Support 64-bit bridge windows if we have 64-bit dma_addr_t Aaron reported that a 32-bit x86 kernel with Physical Address Extension (PAE) support complains about bridge prefetchable memory windows above 4GB: pci_bus 0000:00: root bus resource [mem 0x380000000000-0x383fffffffff] ... pci 0000:03:00.0: reg 0x10: [mem 0x383fffc00000-0x383fffdfffff 64bit pref] pci 0000:03:00.0: reg 0x20: [mem 0x383fffe04000-0x383fffe07fff 64bit pref] pci 0000:03:00.1: reg 0x10: [mem 0x383fffa00000-0x383fffbfffff 64bit pref] pci 0000:03:00.1: reg 0x20: [mem 0x383fffe00000-0x383fffe03fff 64bit pref] pci 0000:00:02.2: PCI bridge to [bus 03-04] pci 0000:00:02.2: bridge window [io 0x1000-0x1fff] pci 0000:00:02.2: bridge window [mem 0x91900000-0x91cfffff] pci 0000:00:02.2: can't handle 64-bit address space for bridge In this kernel, unsigned long is 32 bits and dma_addr_t is 64 bits. Previously we used "unsigned long" to hold the bridge window address. But this is a bus address, so we should use dma_addr_t instead. Use dma_addr_t to hold the bridge window base and limit. The question of whether the CPU can actually *address* the window is separate and depends on what the physical address space of the CPU is and whether the host bridge does any address translation. [bhelgaas: fix "shift count > width of type", changelog, stable tag] Fixes: d56dbf5bab8c ("PCI: Allocate 64-bit BARs above 4G when possible") Link: https://bugzilla.kernel.org/show_bug.cgi?id=88131 Reported-by: Aaron Ma <mapengyu@gmail.com> Tested-by: Aaron Ma <mapengyu@gmail.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v3.14+
2014-11-19 14:30:32 -07:00
PCI: Add pci_bus_addr_t David Ahern reported that d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows") fails to boot on sparc/T5-8: pci 0000:06:00.0: reg 0x184: can't handle BAR above 4GB (bus address 0x110204000) The problem is that sparc64 assumed that dma_addr_t only needed to hold DMA addresses, i.e., bus addresses returned via the DMA API (dma_map_single(), etc.), while the PCI core assumed dma_addr_t could hold *any* bus address, including raw BAR values. On sparc64, all DMA addresses fit in 32 bits, so dma_addr_t is a 32-bit type. However, BAR values can be 64 bits wide, so they don't fit in a dma_addr_t. d63e2e1f3df9 added new checking that tripped over this mismatch. Add pci_bus_addr_t, which is wide enough to hold any PCI bus address, including both raw BAR values and DMA addresses. This will be 64 bits on 64-bit platforms and on platforms with a 64-bit dma_addr_t. Then dma_addr_t only needs to be wide enough to hold addresses from the DMA API. [bhelgaas: changelog, bugzilla, Kconfig to ensure pci_bus_addr_t is at least as wide as dma_addr_t, documentation] Fixes: d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows") Fixes: 23b13bc76f35 ("PCI: Fail safely if we can't handle BARs larger than 4GB") Link: http://lkml.kernel.org/r/CAE9FiQU1gJY1LYrxs+ma5LCTEEe4xmtjRG0aXJ9K_Tsu+m9Wuw@mail.gmail.com Link: http://lkml.kernel.org/r/1427857069-6789-1-git-send-email-yinghai@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=96231 Reported-by: David Ahern <david.ahern@oracle.com> Tested-by: David Ahern <david.ahern@oracle.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: David S. Miller <davem@davemloft.net> CC: stable@vger.kernel.org # v3.19+
2015-05-27 17:23:51 -07:00
PCI: Support 64-bit bridge windows if we have 64-bit dma_addr_t Aaron reported that a 32-bit x86 kernel with Physical Address Extension (PAE) support complains about bridge prefetchable memory windows above 4GB: pci_bus 0000:00: root bus resource [mem 0x380000000000-0x383fffffffff] ... pci 0000:03:00.0: reg 0x10: [mem 0x383fffc00000-0x383fffdfffff 64bit pref] pci 0000:03:00.0: reg 0x20: [mem 0x383fffe04000-0x383fffe07fff 64bit pref] pci 0000:03:00.1: reg 0x10: [mem 0x383fffa00000-0x383fffbfffff 64bit pref] pci 0000:03:00.1: reg 0x20: [mem 0x383fffe00000-0x383fffe03fff 64bit pref] pci 0000:00:02.2: PCI bridge to [bus 03-04] pci 0000:00:02.2: bridge window [io 0x1000-0x1fff] pci 0000:00:02.2: bridge window [mem 0x91900000-0x91cfffff] pci 0000:00:02.2: can't handle 64-bit address space for bridge In this kernel, unsigned long is 32 bits and dma_addr_t is 64 bits. Previously we used "unsigned long" to hold the bridge window address. But this is a bus address, so we should use dma_addr_t instead. Use dma_addr_t to hold the bridge window base and limit. The question of whether the CPU can actually *address* the window is separate and depends on what the physical address space of the CPU is and whether the host bridge does any address translation. [bhelgaas: fix "shift count > width of type", changelog, stable tag] Fixes: d56dbf5bab8c ("PCI: Allocate 64-bit BARs above 4G when possible") Link: https://bugzilla.kernel.org/show_bug.cgi?id=88131 Reported-by: Aaron Ma <mapengyu@gmail.com> Tested-by: Aaron Ma <mapengyu@gmail.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v3.14+
2014-11-19 14:30:32 -07:00
PCI: Support 64-bit bridge windows if we have 64-bit dma_addr_t Aaron reported that a 32-bit x86 kernel with Physical Address Extension (PAE) support complains about bridge prefetchable memory windows above 4GB: pci_bus 0000:00: root bus resource [mem 0x380000000000-0x383fffffffff] ... pci 0000:03:00.0: reg 0x10: [mem 0x383fffc00000-0x383fffdfffff 64bit pref] pci 0000:03:00.0: reg 0x20: [mem 0x383fffe04000-0x383fffe07fff 64bit pref] pci 0000:03:00.1: reg 0x10: [mem 0x383fffa00000-0x383fffbfffff 64bit pref] pci 0000:03:00.1: reg 0x20: [mem 0x383fffe00000-0x383fffe03fff 64bit pref] pci 0000:00:02.2: PCI bridge to [bus 03-04] pci 0000:00:02.2: bridge window [io 0x1000-0x1fff] pci 0000:00:02.2: bridge window [mem 0x91900000-0x91cfffff] pci 0000:00:02.2: can't handle 64-bit address space for bridge In this kernel, unsigned long is 32 bits and dma_addr_t is 64 bits. Previously we used "unsigned long" to hold the bridge window address. But this is a bus address, so we should use dma_addr_t instead. Use dma_addr_t to hold the bridge window base and limit. The question of whether the CPU can actually *address* the window is separate and depends on what the physical address space of the CPU is and whether the host bridge does any address translation. [bhelgaas: fix "shift count > width of type", changelog, stable tag] Fixes: d56dbf5bab8c ("PCI: Allocate 64-bit BARs above 4G when possible") Link: https://bugzilla.kernel.org/show_bug.cgi?id=88131 Reported-by: Aaron Ma <mapengyu@gmail.com> Tested-by: Aaron Ma <mapengyu@gmail.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v3.14+
2014-11-19 14:30:32 -07:00
PCI: Support 64-bit bridge windows if we have 64-bit dma_addr_t Aaron reported that a 32-bit x86 kernel with Physical Address Extension (PAE) support complains about bridge prefetchable memory windows above 4GB: pci_bus 0000:00: root bus resource [mem 0x380000000000-0x383fffffffff] ... pci 0000:03:00.0: reg 0x10: [mem 0x383fffc00000-0x383fffdfffff 64bit pref] pci 0000:03:00.0: reg 0x20: [mem 0x383fffe04000-0x383fffe07fff 64bit pref] pci 0000:03:00.1: reg 0x10: [mem 0x383fffa00000-0x383fffbfffff 64bit pref] pci 0000:03:00.1: reg 0x20: [mem 0x383fffe00000-0x383fffe03fff 64bit pref] pci 0000:00:02.2: PCI bridge to [bus 03-04] pci 0000:00:02.2: bridge window [io 0x1000-0x1fff] pci 0000:00:02.2: bridge window [mem 0x91900000-0x91cfffff] pci 0000:00:02.2: can't handle 64-bit address space for bridge In this kernel, unsigned long is 32 bits and dma_addr_t is 64 bits. Previously we used "unsigned long" to hold the bridge window address. But this is a bus address, so we should use dma_addr_t instead. Use dma_addr_t to hold the bridge window base and limit. The question of whether the CPU can actually *address* the window is separate and depends on what the physical address space of the CPU is and whether the host bridge does any address translation. [bhelgaas: fix "shift count > width of type", changelog, stable tag] Fixes: d56dbf5bab8c ("PCI: Allocate 64-bit BARs above 4G when possible") Link: https://bugzilla.kernel.org/show_bug.cgi?id=88131 Reported-by: Aaron Ma <mapengyu@gmail.com> Tested-by: Aaron Ma <mapengyu@gmail.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v3.14+
2014-11-19 14:30:32 -07:00
PCI: Add pci_bus_addr_t David Ahern reported that d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows") fails to boot on sparc/T5-8: pci 0000:06:00.0: reg 0x184: can't handle BAR above 4GB (bus address 0x110204000) The problem is that sparc64 assumed that dma_addr_t only needed to hold DMA addresses, i.e., bus addresses returned via the DMA API (dma_map_single(), etc.), while the PCI core assumed dma_addr_t could hold *any* bus address, including raw BAR values. On sparc64, all DMA addresses fit in 32 bits, so dma_addr_t is a 32-bit type. However, BAR values can be 64 bits wide, so they don't fit in a dma_addr_t. d63e2e1f3df9 added new checking that tripped over this mismatch. Add pci_bus_addr_t, which is wide enough to hold any PCI bus address, including both raw BAR values and DMA addresses. This will be 64 bits on 64-bit platforms and on platforms with a 64-bit dma_addr_t. Then dma_addr_t only needs to be wide enough to hold addresses from the DMA API. [bhelgaas: changelog, bugzilla, Kconfig to ensure pci_bus_addr_t is at least as wide as dma_addr_t, documentation] Fixes: d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows") Fixes: 23b13bc76f35 ("PCI: Fail safely if we can't handle BARs larger than 4GB") Link: http://lkml.kernel.org/r/CAE9FiQU1gJY1LYrxs+ma5LCTEEe4xmtjRG0aXJ9K_Tsu+m9Wuw@mail.gmail.com Link: http://lkml.kernel.org/r/1427857069-6789-1-git-send-email-yinghai@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=96231 Reported-by: David Ahern <david.ahern@oracle.com> Tested-by: David Ahern <david.ahern@oracle.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: David S. Miller <davem@davemloft.net> CC: stable@vger.kernel.org # v3.19+
2015-05-27 17:23:51 -07:00
PCI: Support 64-bit bridge windows if we have 64-bit dma_addr_t Aaron reported that a 32-bit x86 kernel with Physical Address Extension (PAE) support complains about bridge prefetchable memory windows above 4GB: pci_bus 0000:00: root bus resource [mem 0x380000000000-0x383fffffffff] ... pci 0000:03:00.0: reg 0x10: [mem 0x383fffc00000-0x383fffdfffff 64bit pref] pci 0000:03:00.0: reg 0x20: [mem 0x383fffe04000-0x383fffe07fff 64bit pref] pci 0000:03:00.1: reg 0x10: [mem 0x383fffa00000-0x383fffbfffff 64bit pref] pci 0000:03:00.1: reg 0x20: [mem 0x383fffe00000-0x383fffe03fff 64bit pref] pci 0000:00:02.2: PCI bridge to [bus 03-04] pci 0000:00:02.2: bridge window [io 0x1000-0x1fff] pci 0000:00:02.2: bridge window [mem 0x91900000-0x91cfffff] pci 0000:00:02.2: can't handle 64-bit address space for bridge In this kernel, unsigned long is 32 bits and dma_addr_t is 64 bits. Previously we used "unsigned long" to hold the bridge window address. But this is a bus address, so we should use dma_addr_t instead. Use dma_addr_t to hold the bridge window base and limit. The question of whether the CPU can actually *address* the window is separate and depends on what the physical address space of the CPU is and whether the host bridge does any address translation. [bhelgaas: fix "shift count > width of type", changelog, stable tag] Fixes: d56dbf5bab8c ("PCI: Allocate 64-bit BARs above 4G when possible") Link: https://bugzilla.kernel.org/show_bug.cgi?id=88131 Reported-by: Aaron Ma <mapengyu@gmail.com> Tested-by: Aaron Ma <mapengyu@gmail.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v3.14+
2014-11-19 14:30:32 -07:00
PCI: Add pci_register_host_bridge() interface Make the existing pci_host_bridge structure a proper device that is usable by PCI host drivers in a more standard way. In addition to the existing pci_scan_bus(), pci_scan_root_bus(), pci_scan_root_bus_msi(), and pci_create_root_bus() interfaces, this unfortunately means having to add yet another interface doing basically the same thing, and add some extra code in the initial step. However, this time it's more likely to be extensible enough that we won't have to do another one again in the future, and we should be able to reduce code much more as a result. The main idea is to pull the allocation of 'struct pci_host_bridge' out of the registration, and let individual host drivers and architecture code fill the members before calling the registration function. There are a number of things we can do based on this: * Use a single memory allocation for the driver-specific structure and the generic PCI host bridge * consolidate the contents of driver-specific structures by moving them into pci_host_bridge * Add a consistent interface for removing a PCI host bridge again when unloading a host driver module * Replace the architecture specific __weak pcibios_*() functions with callbacks in a pci_host_bridge device * Move common boilerplate code from host drivers into the generic function, based on contents of the structure * Extend pci_host_bridge with additional members when needed without having to add arguments to pci_scan_*(). * Move members of struct pci_bus into pci_host_bridge to avoid having lots of identical copies. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
2016-11-25 11:57:09 +01:00
PCI: Add pci_register_host_bridge() interface Make the existing pci_host_bridge structure a proper device that is usable by PCI host drivers in a more standard way. In addition to the existing pci_scan_bus(), pci_scan_root_bus(), pci_scan_root_bus_msi(), and pci_create_root_bus() interfaces, this unfortunately means having to add yet another interface doing basically the same thing, and add some extra code in the initial step. However, this time it's more likely to be extensible enough that we won't have to do another one again in the future, and we should be able to reduce code much more as a result. The main idea is to pull the allocation of 'struct pci_host_bridge' out of the registration, and let individual host drivers and architecture code fill the members before calling the registration function. There are a number of things we can do based on this: * Use a single memory allocation for the driver-specific structure and the generic PCI host bridge * consolidate the contents of driver-specific structures by moving them into pci_host_bridge * Add a consistent interface for removing a PCI host bridge again when unloading a host driver module * Replace the architecture specific __weak pcibios_*() functions with callbacks in a pci_host_bridge device * Move common boilerplate code from host drivers into the generic function, based on contents of the structure * Extend pci_host_bridge with additional members when needed without having to add arguments to pci_scan_*(). * Move members of struct pci_bus into pci_host_bridge to avoid having lots of identical copies. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
2016-11-25 11:57:09 +01:00
PCI: Enable CRS Software Visibility for root port if it is supported Per PCIe r3.0, sec 2.3.2, an endpoint may respond to a Configuration Request with a Completion with Configuration Request Retry Status (CRS). This terminates the Configuration Request. When the CRS Software Visibility feature is disabled (as it is by default), a Root Complex must handle a CRS Completion by re-issuing the Configuration Request. This is invisible to software. From the CPU's point of view, an endpoint that always responds with CRS causes a hang because the Root Complex never supplies data to complete the CPU read. When CRS Software Visibility is enabled, a Root Complex that receives a CRS Completion for a read of the Vendor ID must return data of 0x0001. The Vendor ID of 0x0001 indicates to software that the endpoint is not ready. We now have more devices that require CRS Software Visibility. For example, a PLX 8713 NT bridge may respond with CRS until it has been configured via I2C, and the I2C configuration is completely independent of PCI enumeration. Enable CRS Software Visibility if it is supported. This allows a system with such a device to work (though the PCI core times out waiting for it to become ready, and we have to rescan the bus after it is ready). This essentially reverts ad7edfe04908 ("[PCI] Do not enable CRS Software Visibility by default"). The failures that led to ad7edfe04908 should be addressed by 89665a6a7140 ("PCI: Check only the Vendor ID to identify Configuration Request Retry"). [bhelgaas: changelog] Link: http://lkml.kernel.org/r/20071029061532.5d10dfc6@snowcone Link: http://lkml.kernel.org/r/alpine.LFD.0.9999.0712271023090.21557@woody.linux-foundation.org Signed-off-by: Rajat Jain <rajatxjain@gmail.com> Signed-off-by: Rajat Jain <rajatjain@juniper.net> Signed-off-by: Guenter Roeck <groeck@juniper.net> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-09-02 16:26:00 -07:00
Revert "PCI: Make sure bus number resources stay within their parents bounds" This reverts commit 1820ffdccb9b ("PCI: Make sure bus number resources stay within their parents bounds") because it breaks some systems with LSI Logic FC949ES Fibre Channel Adapters, apparently by exposing a defect in those adapters. Dirk tested a Tyan VX50 (B4985) with this device that worked like this prior to 1820ffdccb9b: bus: [bus 00-7f] on node 0 link 1 ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-07]) pci 0000:00:0e.0: PCI bridge to [bus 0a] pci_bus 0000:0a: busn_res: can not insert [bus 0a] under [bus 00-07] (conflicts with (null) [bus 00-07]) pci 0000:0a:00.0: [1000:0646] type 00 class 0x0c0400 (FC adapter) Note that the root bridge [bus 00-07] aperture is wrong; this is a BIOS defect in the PCI0 _CRS method. But prior to 1820ffdccb9b, we didn't enforce that aperture, and the FC adapter worked fine at 0a:00.0. After 1820ffdccb9b, we notice that 00:0e.0's aperture is not contained in the root bridge's aperture, so we reconfigure it so it *is* contained: pci 0000:00:0e.0: bridge configuration invalid ([bus 0a-0a]), reconfiguring pci 0000:00:0e.0: PCI bridge to [bus 06-07] This effectively moves the FC device from 0a:00.0 to 07:00.0, which should be legal. But when we enumerate bus 06, the FC device doesn't respond, so we don't find anything. This is probably a defect in the FC device. Possible fixes (due to Yinghai): 1) Add a quirk to fix the _CRS information based on what amd_bus.c read from the hardware 2) Reset the FC device after we change its bus number 3) Revert 1820ffdccb9b Fix 1 would be relatively easy, but it does sweep the LSI FC issue under the rug. We might want to reconfigure bus numbers in the future for some other reason, e.g., hotplug, and then we could trip over this again. For that reason, I like fix 2, but we don't know whether it actually works, and we don't have a patch for it yet. This revert is fix 3, which also sweeps the LSI FC issue under the rug. Link: https://bugzilla.kernel.org/show_bug.cgi?id=84281 Reported-by: Dirk Gouders <dirk@gouders.net> Tested-by: Dirk Gouders <dirk@gouders.net> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v3.15+ CC: Yinghai Lu <yinghai@kernel.org>
2014-09-19 11:08:40 -06:00
PCI: Enable CRS Software Visibility for root port if it is supported Per PCIe r3.0, sec 2.3.2, an endpoint may respond to a Configuration Request with a Completion with Configuration Request Retry Status (CRS). This terminates the Configuration Request. When the CRS Software Visibility feature is disabled (as it is by default), a Root Complex must handle a CRS Completion by re-issuing the Configuration Request. This is invisible to software. From the CPU's point of view, an endpoint that always responds with CRS causes a hang because the Root Complex never supplies data to complete the CPU read. When CRS Software Visibility is enabled, a Root Complex that receives a CRS Completion for a read of the Vendor ID must return data of 0x0001. The Vendor ID of 0x0001 indicates to software that the endpoint is not ready. We now have more devices that require CRS Software Visibility. For example, a PLX 8713 NT bridge may respond with CRS until it has been configured via I2C, and the I2C configuration is completely independent of PCI enumeration. Enable CRS Software Visibility if it is supported. This allows a system with such a device to work (though the PCI core times out waiting for it to become ready, and we have to rescan the bus after it is ready). This essentially reverts ad7edfe04908 ("[PCI] Do not enable CRS Software Visibility by default"). The failures that led to ad7edfe04908 should be addressed by 89665a6a7140 ("PCI: Check only the Vendor ID to identify Configuration Request Retry"). [bhelgaas: changelog] Link: http://lkml.kernel.org/r/20071029061532.5d10dfc6@snowcone Link: http://lkml.kernel.org/r/alpine.LFD.0.9999.0712271023090.21557@woody.linux-foundation.org Signed-off-by: Rajat Jain <rajatxjain@gmail.com> Signed-off-by: Rajat Jain <rajatjain@juniper.net> Signed-off-by: Guenter Roeck <groeck@juniper.net> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-09-02 16:26:00 -07:00
[PATCH] PCI: Avoid leaving MASTER_ABORT disabled permanently when returning from pci_scan_bridge. > On Mon, Feb 13, 2006 at 05:13:21PM -0800, David S. Miller wrote: > > > > In drivers/pci/probe.c:pci_scan_bridge(), if this is not the first > > pass (pass != 0) we don't restore the PCI_BRIDGE_CONTROL_REGISTER and > > thus leave PCI_BRIDGE_CTL_MASTER_ABORT off: > > > > int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max, int pass) > > { > > ... > > /* Disable MasterAbortMode during probing to avoid reporting > > of bus errors (in some architectures) */ > > pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl); > > pci_write_config_word(dev, PCI_BRIDGE_CONTROL, > > bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT); > > ... > > if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus) { > > unsigned int cmax, busnr; > > /* > > * Bus already configured by firmware, process it in the first > > * pass and just note the configuration. > > */ > > if (pass) > > return max; > > ... > > } > > > > pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl); > > ... > > > > This doesn't seem intentional. Agreed, looks like an accident. The patch [1] originally came from Kip Walker (Broadcom back then) between 2.6.0-test3 and 2.6.0-test4. As I recall it was supposed to fix an issue with with PCI aborts being signalled by the PCI bridge of the Broadcom BCM1250 family of SOCs when probing behind pci_scan_bridge. It is undeseriable to disable PCI_BRIDGE_CTL_MASTER_ABORT in pci_{read,write)_config_* and the behaviour wasn't considered a bug in need of a workaround, so this was put in probe.c. I don't have an affected system at hand, so can't really test but I propose something like the below patch. [1] http://www.linux-mips.org/git?p=linux.git;a=commit;h=599457e0cb702a31a3247ea6a5d9c6c99c4cf195 [PCI] Avoid leaving MASTER_ABORT disabled permanently when returning from pci_scan_bridge. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-02-14 16:23:57 +00:00
[PATCH] PCI: Avoid leaving MASTER_ABORT disabled permanently when returning from pci_scan_bridge. > On Mon, Feb 13, 2006 at 05:13:21PM -0800, David S. Miller wrote: > > > > In drivers/pci/probe.c:pci_scan_bridge(), if this is not the first > > pass (pass != 0) we don't restore the PCI_BRIDGE_CONTROL_REGISTER and > > thus leave PCI_BRIDGE_CTL_MASTER_ABORT off: > > > > int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max, int pass) > > { > > ... > > /* Disable MasterAbortMode during probing to avoid reporting > > of bus errors (in some architectures) */ > > pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl); > > pci_write_config_word(dev, PCI_BRIDGE_CONTROL, > > bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT); > > ... > > if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus) { > > unsigned int cmax, busnr; > > /* > > * Bus already configured by firmware, process it in the first > > * pass and just note the configuration. > > */ > > if (pass) > > return max; > > ... > > } > > > > pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl); > > ... > > > > This doesn't seem intentional. Agreed, looks like an accident. The patch [1] originally came from Kip Walker (Broadcom back then) between 2.6.0-test3 and 2.6.0-test4. As I recall it was supposed to fix an issue with with PCI aborts being signalled by the PCI bridge of the Broadcom BCM1250 family of SOCs when probing behind pci_scan_bridge. It is undeseriable to disable PCI_BRIDGE_CTL_MASTER_ABORT in pci_{read,write)_config_* and the behaviour wasn't considered a bug in need of a workaround, so this was put in probe.c. I don't have an affected system at hand, so can't really test but I propose something like the below patch. [1] http://www.linux-mips.org/git?p=linux.git;a=commit;h=599457e0cb702a31a3247ea6a5d9c6c99c4cf195 [PCI] Avoid leaving MASTER_ABORT disabled permanently when returning from pci_scan_bridge. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-02-14 16:23:57 +00:00
Revert "PCI: Don't scan random busses in pci_scan_bridge()" This reverts commit fc1b253141b3 ("PCI: Don't scan random busses in pci_scan_bridge()") because it breaks CardBus on some machines. David tested a Dell Latitude D505 that worked like this prior to fc1b253141b3: pci 0000:00:1e.0: PCI bridge to [bus 01] pci 0000:01:01.0: CardBus bridge to [bus 02-05] Note that the 01:01.0 CardBus bridge has a bus number aperture of [bus 02-05], but those buses are all outside the 00:1e.0 PCI bridge bus number aperture, so accesses to buses 02-05 never reach CardBus. This is later patched up by yenta_fixup_parent_bridge(), which changes the subordinate bus number of the 00:1e.0 PCI bridge: pci_bus 0000:01: Raising subordinate bus# of parent bus (#01) from #01 to #05 With fc1b253141b3, pci_scan_bridge() fails immediately when it notices that we can't allocate a valid secondary bus number for the CardBus bridge, and CardBus doesn't work at all: pci 0000:01:01.0: can't allocate child bus 01 from [bus 01] I'd prefer to fix this by integrating the yenta_fixup_parent_bridge() logic into pci_scan_bridge() so we fix the bus number apertures up front. But I don't think we can do that before v3.17, so I'm going to revert this to avoid the problem while we're working on the long-term fix. Link: https://bugzilla.kernel.org/show_bug.cgi?id=83441 Link: http://lkml.kernel.org/r/1409303414-5196-1-git-send-email-david.henningsson@canonical.com Reported-by: David Henningsson <david.henningsson@canonical.com> Tested-by: David Henningsson <david.henningsson@canonical.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v3.15+
2014-09-19 10:56:06 -06:00
PCI: Do not allocate more buses than available in parent [ Upstream commit a20c7f36bd3d20d245616ae223bb9d05dfb6f050 ] One can ask more buses to be reserved for hotplug bridges by passing pci=hpbussize=N in the kernel command line. If the parent bus does not have enough bus space available we incorrectly create child bus with the requested number of subordinate buses. In the example below hpbussize is set to one more than we have available buses in the root port: pci 0000:07:00.0: [8086:1578] type 01 class 0x060400 pci 0000:07:00.0: scanning [bus 00-00] behind bridge, pass 0 pci 0000:07:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring pci 0000:07:00.0: scanning [bus 00-00] behind bridge, pass 1 pci_bus 0000:08: busn_res: can not insert [bus 08-ff] under [bus 07-3f] (conflicts with (null) [bus 07-3f]) pci_bus 0000:08: scanning bus ... pci_bus 0000:0a: bus scan returning with max=40 pci_bus 0000:0a: busn_res: [bus 0a-ff] end is updated to 40 pci_bus 0000:0a: [bus 0a-40] partially hidden behind bridge 0000:07 [bus 07-3f] pci_bus 0000:08: bus scan returning with max=40 pci_bus 0000:08: busn_res: [bus 08-ff] end is updated to 40 Instead of allowing this, limit the subordinate number to be less than or equal the maximum subordinate number allocated for the parent bus (if it has any). Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> [bhelgaas: remove irrelevant dmesg messages] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-13 21:35:43 +03:00
PCI: lets kill the 'PCI hidden behind bridge' message Adrian Bunk wrote: > Alois Nešpor wrote >> PCI: Bus #0b (-#0e) is hidden behind transparent bridge #0a (-#0b) (try 'pci=assign-busses') >> Please report the result to linux-kernel to fix this permanently" >> >> dmesg: >> "Yenta: Raising subordinate bus# of parent bus (#0a) from #0b to #0e" >> without pci=assign-busses and nothing with pci=assign-busses. > > Bernhard? Ok, lets kill the message. As Alois Nešpor also saw, that's fixed up by Yenta, so PCI does not have to warn about it. PCI could still warn about it if is_cardbus is 0 in that instance of pci_scan_bridge(), but so far I have not seen a report where this would have been the case so I think we can spare the kernel of that check (removes ~300 lines of asm) unless debugging is done. History: The whole check was added in the days before we had the fixup for this in Yenta and pci=assign-busses was the only way to get CardBus cards detected on many (not all) of the machines which give this warning. In theory, there could be cases when this warning would be triggered and it's not cardbus, then the warning should still apply, but I think this should only be the case when working on a completely broken PCI setup, but one may have already enabled the debug code in drivers/pci and the patched check would then trigger. I do not sign this off yet because it's completely untested so far, but everyone is free to test it (with the #ifdef DEBUG replaced by #if 1 and pr_debug( changed to printk(. We may also dump the whole check (remove everything within the #ifdef from the source) if that's perferred. On Alois Nešpor's machine this would then (only when debugging) this message: "PCI: Bus #0b (-#0e) is partially hidden behind transparent bridge #0a (-#0b)" "partially" should be in the message on his machine because #0b of #0b-#0e is reachable behind #0a-#0b, but not #0c-#0e. But that differentiation is now moot anyway because the fixup in Yenta takes care of it as far as I could see so far, which means that unless somebody is debugging a totally broken PCI setup, this message is not needed anymore, not even for debugging PCI. Ok, here the patch with the following changes: * Refined to say that the bus is only partially hidden when the parent bus numbers are not totally way off (outside of) the child bus range * remove the reference to pci=assign-busses and the plea to report it We could add a pure source code-only comment to keep a reference to pci=assign-busses the in case when this is triggered by someone who is debugging the cause of this message and looking the way to solve it. From: Bernhard Kaindl <bk@suse.de> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-30 20:35:13 +02:00
[PATCH] PCI: Avoid leaving MASTER_ABORT disabled permanently when returning from pci_scan_bridge. > On Mon, Feb 13, 2006 at 05:13:21PM -0800, David S. Miller wrote: > > > > In drivers/pci/probe.c:pci_scan_bridge(), if this is not the first > > pass (pass != 0) we don't restore the PCI_BRIDGE_CONTROL_REGISTER and > > thus leave PCI_BRIDGE_CTL_MASTER_ABORT off: > > > > int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max, int pass) > > { > > ... > > /* Disable MasterAbortMode during probing to avoid reporting > > of bus errors (in some architectures) */ > > pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl); > > pci_write_config_word(dev, PCI_BRIDGE_CONTROL, > > bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT); > > ... > > if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus) { > > unsigned int cmax, busnr; > > /* > > * Bus already configured by firmware, process it in the first > > * pass and just note the configuration. > > */ > > if (pass) > > return max; > > ... > > } > > > > pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl); > > ... > > > > This doesn't seem intentional. Agreed, looks like an accident. The patch [1] originally came from Kip Walker (Broadcom back then) between 2.6.0-test3 and 2.6.0-test4. As I recall it was supposed to fix an issue with with PCI aborts being signalled by the PCI bridge of the Broadcom BCM1250 family of SOCs when probing behind pci_scan_bridge. It is undeseriable to disable PCI_BRIDGE_CTL_MASTER_ABORT in pci_{read,write)_config_* and the behaviour wasn't considered a bug in need of a workaround, so this was put in probe.c. I don't have an affected system at hand, so can't really test but I propose something like the below patch. [1] http://www.linux-mips.org/git?p=linux.git;a=commit;h=599457e0cb702a31a3247ea6a5d9c6c99c4cf195 [PCI] Avoid leaving MASTER_ABORT disabled permanently when returning from pci_scan_bridge. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-02-14 16:23:57 +00:00
PCI: Add dev->has_secondary_link to track downstream PCIe links A PCIe Port is an interface to a Link. A Root Port is a PCI-PCI bridge in a Root Complex and has a Link on its secondary (downstream) side. For other Ports, the Link may be on either the upstream (closer to the Root Complex) or downstream side of the Port. The usual topology has a Root Port connected to an Upstream Port. We previously assumed this was the only possible topology, and that a Downstream Port's Link was always on its downstream side, like this: +---------------------+ +------+ | Downstream | | Root | | Upstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ But systems do exist (see URL below) where the Root Port is connected to a Downstream Port. In this case, a Downstream Port's Link may be on either the upstream or downstream side: +---------------------+ +------+ | Upstream | | Root | | Downstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ We can't use the Port type to determine which side the Link is on, so add a bit in struct pci_dev to keep track. A Root Port's Link is always on the Port's secondary side. A component (Endpoint or Port) on the other end of the Link obviously has the Link on its upstream side. If that component is a Port, it is part of a Switch or a Bridge. A Bridge has a PCI or PCI-X bus on its secondary side, not a Link. The internal bus of a Switch connects the Port to another Port whose Link is on the downstream side. [bhelgaas: changelog, comment, cache "type", use if/else] Link: http://lkml.kernel.org/r/54EB81B2.4050904@pobox.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=94361 Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-05-21 15:05:02 +08:00
PCI: Enumerate switches below PCI-to-PCIe bridges A PCI-to-PCIe bridge (a "reverse bridge") has a PCI or PCI-X primary interface and a PCI Express secondary interface. The PCIe interface is a Downstream Port that originates a Link. See the "PCI Express to PCI/PCI-X Bridge Specification", rev 1.0, sections 1.2 and A.6. The bug report below involves a PCI-to-PCIe bridge and a PCIe switch below the bridge: 00:1e.0 Intel 82801 PCI Bridge to [bus 01-0a] 01:00.0 Pericom PI7C9X111SL PCIe-to-PCI Reversible Bridge to [bus 02-0a] 02:00.0 Pericom Device 8608 [PCIe Upstream Port] to [bus 03-0a] 03:01.0 Pericom Device 8608 [PCIe Downstream Port] to [bus 0a] 01:00.0 is configured as a PCI-to-PCIe bridge (despite the name printed by lspci). As we traverse a PCIe hierarchy, device connections alternate between PCIe Links and internal Switch logic. Previously we did not recognize that 01:00.0 had a secondary link, so we thought the 02:00.0 Upstream Port *did* have a secondary link. In fact, it's the other way around: 01:00.0 has a secondary link, and 02:00.0 has internal Switch logic on its secondary side. When we thought 02:00.0 had a secondary link, the pci_scan_slot() -> only_one_child() path assumed 02:00.0 could have only one child, so 03:00.0 was the only possible downstream device. But 03:00.0 doesn't exist, so we didn't look for any other devices on bus 03. Booting with "pci=pcie_scan_all" is a workaround, but we don't want users to have to do that. Recognize that PCI-to-PCIe bridges originate links on their secondary interfaces. Link: https://bugzilla.kernel.org/show_bug.cgi?id=189361 Fixes: d0751b98dfa3 ("PCI: Add dev->has_secondary_link to track downstream PCIe links") Tested-by: Blake Moore <blake.moore@men.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v4.2+
2017-01-11 09:11:53 -06:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Add dev->has_secondary_link to track downstream PCIe links A PCIe Port is an interface to a Link. A Root Port is a PCI-PCI bridge in a Root Complex and has a Link on its secondary (downstream) side. For other Ports, the Link may be on either the upstream (closer to the Root Complex) or downstream side of the Port. The usual topology has a Root Port connected to an Upstream Port. We previously assumed this was the only possible topology, and that a Downstream Port's Link was always on its downstream side, like this: +---------------------+ +------+ | Downstream | | Root | | Upstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ But systems do exist (see URL below) where the Root Port is connected to a Downstream Port. In this case, a Downstream Port's Link may be on either the upstream or downstream side: +---------------------+ +------+ | Upstream | | Root | | Downstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ We can't use the Port type to determine which side the Link is on, so add a bit in struct pci_dev to keep track. A Root Port's Link is always on the Port's secondary side. A component (Endpoint or Port) on the other end of the Link obviously has the Link on its upstream side. If that component is a Port, it is part of a Switch or a Bridge. A Bridge has a PCI or PCI-X bus on its secondary side, not a Link. The internal bus of a Switch connects the Port to another Port whose Link is on the downstream side. [bhelgaas: changelog, comment, cache "type", use if/else] Link: http://lkml.kernel.org/r/54EB81B2.4050904@pobox.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=94361 Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-05-21 15:05:02 +08:00
PCI: Enumerate switches below PCI-to-PCIe bridges A PCI-to-PCIe bridge (a "reverse bridge") has a PCI or PCI-X primary interface and a PCI Express secondary interface. The PCIe interface is a Downstream Port that originates a Link. See the "PCI Express to PCI/PCI-X Bridge Specification", rev 1.0, sections 1.2 and A.6. The bug report below involves a PCI-to-PCIe bridge and a PCIe switch below the bridge: 00:1e.0 Intel 82801 PCI Bridge to [bus 01-0a] 01:00.0 Pericom PI7C9X111SL PCIe-to-PCI Reversible Bridge to [bus 02-0a] 02:00.0 Pericom Device 8608 [PCIe Upstream Port] to [bus 03-0a] 03:01.0 Pericom Device 8608 [PCIe Downstream Port] to [bus 0a] 01:00.0 is configured as a PCI-to-PCIe bridge (despite the name printed by lspci). As we traverse a PCIe hierarchy, device connections alternate between PCIe Links and internal Switch logic. Previously we did not recognize that 01:00.0 had a secondary link, so we thought the 02:00.0 Upstream Port *did* have a secondary link. In fact, it's the other way around: 01:00.0 has a secondary link, and 02:00.0 has internal Switch logic on its secondary side. When we thought 02:00.0 had a secondary link, the pci_scan_slot() -> only_one_child() path assumed 02:00.0 could have only one child, so 03:00.0 was the only possible downstream device. But 03:00.0 doesn't exist, so we didn't look for any other devices on bus 03. Booting with "pci=pcie_scan_all" is a workaround, but we don't want users to have to do that. Recognize that PCI-to-PCIe bridges originate links on their secondary interfaces. Link: https://bugzilla.kernel.org/show_bug.cgi?id=189361 Fixes: d0751b98dfa3 ("PCI: Add dev->has_secondary_link to track downstream PCIe links") Tested-by: Blake Moore <blake.moore@men.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v4.2+
2017-01-11 09:11:53 -06:00
PCI: Add dev->has_secondary_link to track downstream PCIe links A PCIe Port is an interface to a Link. A Root Port is a PCI-PCI bridge in a Root Complex and has a Link on its secondary (downstream) side. For other Ports, the Link may be on either the upstream (closer to the Root Complex) or downstream side of the Port. The usual topology has a Root Port connected to an Upstream Port. We previously assumed this was the only possible topology, and that a Downstream Port's Link was always on its downstream side, like this: +---------------------+ +------+ | Downstream | | Root | | Upstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ But systems do exist (see URL below) where the Root Port is connected to a Downstream Port. In this case, a Downstream Port's Link may be on either the upstream or downstream side: +---------------------+ +------+ | Upstream | | Root | | Downstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ We can't use the Port type to determine which side the Link is on, so add a bit in struct pci_dev to keep track. A Root Port's Link is always on the Port's secondary side. A component (Endpoint or Port) on the other end of the Link obviously has the Link on its upstream side. If that component is a Port, it is part of a Switch or a Bridge. A Bridge has a PCI or PCI-X bus on its secondary side, not a Link. The internal bus of a Switch connects the Port to another Port whose Link is on the downstream side. [bhelgaas: changelog, comment, cache "type", use if/else] Link: http://lkml.kernel.org/r/54EB81B2.4050904@pobox.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=94361 Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-05-21 15:05:02 +08:00
PCI: Enumerate switches below PCI-to-PCIe bridges A PCI-to-PCIe bridge (a "reverse bridge") has a PCI or PCI-X primary interface and a PCI Express secondary interface. The PCIe interface is a Downstream Port that originates a Link. See the "PCI Express to PCI/PCI-X Bridge Specification", rev 1.0, sections 1.2 and A.6. The bug report below involves a PCI-to-PCIe bridge and a PCIe switch below the bridge: 00:1e.0 Intel 82801 PCI Bridge to [bus 01-0a] 01:00.0 Pericom PI7C9X111SL PCIe-to-PCI Reversible Bridge to [bus 02-0a] 02:00.0 Pericom Device 8608 [PCIe Upstream Port] to [bus 03-0a] 03:01.0 Pericom Device 8608 [PCIe Downstream Port] to [bus 0a] 01:00.0 is configured as a PCI-to-PCIe bridge (despite the name printed by lspci). As we traverse a PCIe hierarchy, device connections alternate between PCIe Links and internal Switch logic. Previously we did not recognize that 01:00.0 had a secondary link, so we thought the 02:00.0 Upstream Port *did* have a secondary link. In fact, it's the other way around: 01:00.0 has a secondary link, and 02:00.0 has internal Switch logic on its secondary side. When we thought 02:00.0 had a secondary link, the pci_scan_slot() -> only_one_child() path assumed 02:00.0 could have only one child, so 03:00.0 was the only possible downstream device. But 03:00.0 doesn't exist, so we didn't look for any other devices on bus 03. Booting with "pci=pcie_scan_all" is a workaround, but we don't want users to have to do that. Recognize that PCI-to-PCIe bridges originate links on their secondary interfaces. Link: https://bugzilla.kernel.org/show_bug.cgi?id=189361 Fixes: d0751b98dfa3 ("PCI: Add dev->has_secondary_link to track downstream PCIe links") Tested-by: Blake Moore <blake.moore@men.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v4.2+
2017-01-11 09:11:53 -06:00
PCI: Add dev->has_secondary_link to track downstream PCIe links A PCIe Port is an interface to a Link. A Root Port is a PCI-PCI bridge in a Root Complex and has a Link on its secondary (downstream) side. For other Ports, the Link may be on either the upstream (closer to the Root Complex) or downstream side of the Port. The usual topology has a Root Port connected to an Upstream Port. We previously assumed this was the only possible topology, and that a Downstream Port's Link was always on its downstream side, like this: +---------------------+ +------+ | Downstream | | Root | | Upstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ But systems do exist (see URL below) where the Root Port is connected to a Downstream Port. In this case, a Downstream Port's Link may be on either the upstream or downstream side: +---------------------+ +------+ | Upstream | | Root | | Downstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ We can't use the Port type to determine which side the Link is on, so add a bit in struct pci_dev to keep track. A Root Port's Link is always on the Port's secondary side. A component (Endpoint or Port) on the other end of the Link obviously has the Link on its upstream side. If that component is a Port, it is part of a Switch or a Bridge. A Bridge has a PCI or PCI-X bus on its secondary side, not a Link. The internal bus of a Switch connects the Port to another Port whose Link is on the downstream side. [bhelgaas: changelog, comment, cache "type", use if/else] Link: http://lkml.kernel.org/r/54EB81B2.4050904@pobox.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=94361 Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-05-21 15:05:02 +08:00
PCI: Tolerate hierarchies with no Root Port We should not assume any particular hardware topology. Commit d0751b98dfa3 ("PCI: Add dev->has_secondary_link to track downstream PCIe links") relied on the assumption that every PCIe hierarchy is rooted at a Root Port. But we can't rely on any assumption about what hardware we will find; we just have to deal with the world as it is. On some platforms, PCIe devices (endpoints, switch upstream ports, etc.) appear directly on the root bus, and there is no Root Port in the PCI bus hierarchy. For example, Meelis observed these top-level devices on a Sparc V245: 0000:02:00.0 PCI bridge to [bus 03-0d] Switch Upstream Port 0001:02:00.0 PCI bridge to [bus 03] PCIe to PCI/PCI-X Bridge These devices *look* like they have links going upstream, but there really are no upstream devices. In set_pcie_port_type(), we used the parent device to figure out which side of a switch port has a link, so if the parent device did not exist, we dereferenced a NULL parent pointer. Check whether the parent device exists before dereferencing it. Meelis observed this oops on Sparc V245 and T2000. Ben Herrenschmidt says this is also possible on IBM PowerVM guests on PowerPC. [bhelgaas: changelog, comment] Link: http://lkml.kernel.org/r/alpine.LRH.2.20.1508122118210.18637@math.ut.ee Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: David S. Miller <davem@davemloft.net>
2015-08-17 18:47:58 +08:00
PCI: Add dev->has_secondary_link to track downstream PCIe links A PCIe Port is an interface to a Link. A Root Port is a PCI-PCI bridge in a Root Complex and has a Link on its secondary (downstream) side. For other Ports, the Link may be on either the upstream (closer to the Root Complex) or downstream side of the Port. The usual topology has a Root Port connected to an Upstream Port. We previously assumed this was the only possible topology, and that a Downstream Port's Link was always on its downstream side, like this: +---------------------+ +------+ | Downstream | | Root | | Upstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ But systems do exist (see URL below) where the Root Port is connected to a Downstream Port. In this case, a Downstream Port's Link may be on either the upstream or downstream side: +---------------------+ +------+ | Upstream | | Root | | Downstream Port +--Link-- | Port +--Link--+ Port | +------+ | Downstream | | Port +--Link-- +---------------------+ We can't use the Port type to determine which side the Link is on, so add a bit in struct pci_dev to keep track. A Root Port's Link is always on the Port's secondary side. A component (Endpoint or Port) on the other end of the Link obviously has the Link on its upstream side. If that component is a Port, it is part of a Switch or a Bridge. A Bridge has a PCI or PCI-X bus on its secondary side, not a Link. The internal bus of a Switch connects the Port to another Port whose Link is on the downstream side. [bhelgaas: changelog, comment, cache "type", use if/else] Link: http://lkml.kernel.org/r/54EB81B2.4050904@pobox.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=94361 Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-05-21 15:05:02 +08:00
PCI: Recognize Thunderbolt devices Detect on probe whether a PCI device is part of a Thunderbolt controller. Intel uses a Vendor-Specific Extended Capability (VSEC) with ID 0x1234 on such devices. Detect presence of this VSEC and cache it in a newly added is_thunderbolt bit in struct pci_dev. Also, add a helper to check whether a given PCI device is situated on a Thunderbolt daisy chain (i.e., below a PCI device with is_thunderbolt set). The necessity arises from the following: * If an external Thunderbolt GPU is connected to a dual GPU laptop, that GPU is currently registered with vga_switcheroo even though it can neither drive the laptop's panel nor be powered off by the platform. To vga_switcheroo it will appear as if two discrete GPUs are present. As a result, when the external GPU is runtime suspended, vga_switcheroo will cut power to the internal discrete GPU which may not be runtime suspended at all at this moment. The solution is to not register external GPUs with vga_switcheroo, which necessitates a way to recognize if they're on a Thunderbolt daisy chain. * Dual GPU MacBook Pros introduced 2011+ can no longer switch external DisplayPort ports between GPUs. (They're no longer just used for DP but have become combined DP/Thunderbolt ports.) The driver to switch the ports, drivers/platform/x86/apple-gmux.c, needs to detect presence of a Thunderbolt controller and, if found, keep external ports permanently switched to the discrete GPU. v2: Make kerneldoc for pci_is_thunderbolt_attached() more precise, drop portion of commit message pertaining to separate series. (Bjorn Helgaas) Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Michael Jamet <michael.jamet@intel.com> Cc: Tomas Winkler <tomas.winkler@intel.com> Cc: Amir Levy <amir.jer.levy@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: http://patchwork.freedesktop.org/patch/msgid/0ab165a4a35c0b60f29d4c306c653ead14fcd8f9.1489145162.git.lukas@wunner.de
2017-03-10 21:23:45 +01:00
PCI: Recognize Thunderbolt devices Detect on probe whether a PCI device is part of a Thunderbolt controller. Intel uses a Vendor-Specific Extended Capability (VSEC) with ID 0x1234 on such devices. Detect presence of this VSEC and cache it in a newly added is_thunderbolt bit in struct pci_dev. Also, add a helper to check whether a given PCI device is situated on a Thunderbolt daisy chain (i.e., below a PCI device with is_thunderbolt set). The necessity arises from the following: * If an external Thunderbolt GPU is connected to a dual GPU laptop, that GPU is currently registered with vga_switcheroo even though it can neither drive the laptop's panel nor be powered off by the platform. To vga_switcheroo it will appear as if two discrete GPUs are present. As a result, when the external GPU is runtime suspended, vga_switcheroo will cut power to the internal discrete GPU which may not be runtime suspended at all at this moment. The solution is to not register external GPUs with vga_switcheroo, which necessitates a way to recognize if they're on a Thunderbolt daisy chain. * Dual GPU MacBook Pros introduced 2011+ can no longer switch external DisplayPort ports between GPUs. (They're no longer just used for DP but have become combined DP/Thunderbolt ports.) The driver to switch the ports, drivers/platform/x86/apple-gmux.c, needs to detect presence of a Thunderbolt controller and, if found, keep external ports permanently switched to the discrete GPU. v2: Make kerneldoc for pci_is_thunderbolt_attached() more precise, drop portion of commit message pertaining to separate series. (Bjorn Helgaas) Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Michael Jamet <michael.jamet@intel.com> Cc: Tomas Winkler <tomas.winkler@intel.com> Cc: Amir Levy <amir.jer.levy@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: http://patchwork.freedesktop.org/patch/msgid/0ab165a4a35c0b60f29d4c306c653ead14fcd8f9.1489145162.git.lukas@wunner.de
2017-03-10 21:23:45 +01:00
PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX) Per PCIe spec r3.0, sec 2.3.1.1, the Read Completion Boundary (RCB) determines the naturally aligned address boundaries on which a Read Request may be serviced with multiple Completions: - For a Root Complex, RCB is 64 bytes or 128 bytes This value is reported in the Link Control Register Note: Bridges and Endpoints may implement a corresponding command bit which may be set by system software to indicate the RCB value for the Root Complex, allowing the Bridge/Endpoint to optimize its behavior when the Root Complex’s RCB is 128 bytes. - For all other system elements, RCB is 128 bytes Per sec 7.8.7, if a Root Port only supports a 64-byte RCB, the RCB of all downstream devices must be clear, indicating an RCB of 64 bytes. If the Root Port supports a 128-byte RCB, we may optionally set the RCB of downstream devices so they know they can generate larger Completions. Some BIOSes supply an _HPX that tells us to set RCB, even though the Root Port doesn't have RCB set, which may lead to Malformed TLP errors if the Endpoint generates completions larger than the Root Port can handle. The IBM x3850 X6 with BIOS version -[A8E120CUS-1.30]- 08/22/2016 supplies such an _HPX and a Mellanox MT27500 ConnectX-3 device fails to initialize: mlx4_core 0000:41:00.0: command 0xfff timed out (go bit not cleared) mlx4_core 0000:41:00.0: device is going to be reset mlx4_core 0000:41:00.0: Failed to obtain HW semaphore, aborting mlx4_core 0000:41:00.0: Fail to reset HCA ------------[ cut here ]------------ kernel BUG at drivers/net/ethernet/mellanox/mlx4/catas.c:193! After 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") and 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices with a link"), we apply _HPX settings to *all* devices, not just those hot-added after boot. Before 7a1562d4f2d0, we didn't touch the Mellanox RCB, and the device worked. After 7a1562d4f2d0, we set its RCB to 128, and it failed. Set the RCB to 128 iff the Root Port supports a 128-byte RCB. Otherwise, set RCB to 64 bytes. This effectively ignores what _HPX tells us about RCB. Note that this change only affects _HPX handling. If we have no _HPX, this does nothing with RCB. [bhelgaas: changelog, clear RCB if not set for Root Port] Fixes: 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") Fixes: 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices with a link") Link: https://bugzilla.kernel.org/show_bug.cgi?id=187781 Tested-by: Frank Danapfel <fdanapfe@redhat.com> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Myron Stowe <myron.stowe@redhat.com> CC: stable@vger.kernel.org # v3.18+
2016-11-23 10:56:28 -06:00
PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX) Per PCIe spec r3.0, sec 2.3.1.1, the Read Completion Boundary (RCB) determines the naturally aligned address boundaries on which a Read Request may be serviced with multiple Completions: - For a Root Complex, RCB is 64 bytes or 128 bytes This value is reported in the Link Control Register Note: Bridges and Endpoints may implement a corresponding command bit which may be set by system software to indicate the RCB value for the Root Complex, allowing the Bridge/Endpoint to optimize its behavior when the Root Complex’s RCB is 128 bytes. - For all other system elements, RCB is 128 bytes Per sec 7.8.7, if a Root Port only supports a 64-byte RCB, the RCB of all downstream devices must be clear, indicating an RCB of 64 bytes. If the Root Port supports a 128-byte RCB, we may optionally set the RCB of downstream devices so they know they can generate larger Completions. Some BIOSes supply an _HPX that tells us to set RCB, even though the Root Port doesn't have RCB set, which may lead to Malformed TLP errors if the Endpoint generates completions larger than the Root Port can handle. The IBM x3850 X6 with BIOS version -[A8E120CUS-1.30]- 08/22/2016 supplies such an _HPX and a Mellanox MT27500 ConnectX-3 device fails to initialize: mlx4_core 0000:41:00.0: command 0xfff timed out (go bit not cleared) mlx4_core 0000:41:00.0: device is going to be reset mlx4_core 0000:41:00.0: Failed to obtain HW semaphore, aborting mlx4_core 0000:41:00.0: Fail to reset HCA ------------[ cut here ]------------ kernel BUG at drivers/net/ethernet/mellanox/mlx4/catas.c:193! After 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") and 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices with a link"), we apply _HPX settings to *all* devices, not just those hot-added after boot. Before 7a1562d4f2d0, we didn't touch the Mellanox RCB, and the device worked. After 7a1562d4f2d0, we set its RCB to 128, and it failed. Set the RCB to 128 iff the Root Port supports a 128-byte RCB. Otherwise, set RCB to 64 bytes. This effectively ignores what _HPX tells us about RCB. Note that this change only affects _HPX handling. If we have no _HPX, this does nothing with RCB. [bhelgaas: changelog, clear RCB if not set for Root Port] Fixes: 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") Fixes: 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices with a link") Link: https://bugzilla.kernel.org/show_bug.cgi?id=187781 Tested-by: Frank Danapfel <fdanapfe@redhat.com> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Myron Stowe <myron.stowe@redhat.com> CC: stable@vger.kernel.org # v3.18+
2016-11-23 10:56:28 -06:00
PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX) Per PCIe spec r3.0, sec 2.3.1.1, the Read Completion Boundary (RCB) determines the naturally aligned address boundaries on which a Read Request may be serviced with multiple Completions: - For a Root Complex, RCB is 64 bytes or 128 bytes This value is reported in the Link Control Register Note: Bridges and Endpoints may implement a corresponding command bit which may be set by system software to indicate the RCB value for the Root Complex, allowing the Bridge/Endpoint to optimize its behavior when the Root Complex’s RCB is 128 bytes. - For all other system elements, RCB is 128 bytes Per sec 7.8.7, if a Root Port only supports a 64-byte RCB, the RCB of all downstream devices must be clear, indicating an RCB of 64 bytes. If the Root Port supports a 128-byte RCB, we may optionally set the RCB of downstream devices so they know they can generate larger Completions. Some BIOSes supply an _HPX that tells us to set RCB, even though the Root Port doesn't have RCB set, which may lead to Malformed TLP errors if the Endpoint generates completions larger than the Root Port can handle. The IBM x3850 X6 with BIOS version -[A8E120CUS-1.30]- 08/22/2016 supplies such an _HPX and a Mellanox MT27500 ConnectX-3 device fails to initialize: mlx4_core 0000:41:00.0: command 0xfff timed out (go bit not cleared) mlx4_core 0000:41:00.0: device is going to be reset mlx4_core 0000:41:00.0: Failed to obtain HW semaphore, aborting mlx4_core 0000:41:00.0: Fail to reset HCA ------------[ cut here ]------------ kernel BUG at drivers/net/ethernet/mellanox/mlx4/catas.c:193! After 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") and 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices with a link"), we apply _HPX settings to *all* devices, not just those hot-added after boot. Before 7a1562d4f2d0, we didn't touch the Mellanox RCB, and the device worked. After 7a1562d4f2d0, we set its RCB to 128, and it failed. Set the RCB to 128 iff the Root Port supports a 128-byte RCB. Otherwise, set RCB to 64 bytes. This effectively ignores what _HPX tells us about RCB. Note that this change only affects _HPX handling. If we have no _HPX, this does nothing with RCB. [bhelgaas: changelog, clear RCB if not set for Root Port] Fixes: 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") Fixes: 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices with a link") Link: https://bugzilla.kernel.org/show_bug.cgi?id=187781 Tested-by: Frank Danapfel <fdanapfe@redhat.com> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Myron Stowe <myron.stowe@redhat.com> CC: stable@vger.kernel.org # v3.18+
2016-11-23 10:56:28 -06:00
PCI: Introduce new device binding path using pci_dev.driver_override The driver_override field allows us to specify the driver for a device rather than relying on the driver to provide a positive match of the device. This shortcuts the existing process of looking up the vendor and device ID, adding them to the driver new_id, binding the device, then removing the ID, but it also provides a couple advantages. First, the above existing process allows the driver to bind to any device matching the new_id for the window where it's enabled. This is often not desired, such as the case of trying to bind a single device to a meta driver like pci-stub or vfio-pci. Using driver_override we can do this deterministically using: echo pci-stub > /sys/bus/pci/devices/0000:03:00.0/driver_override echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind echo 0000:03:00.0 > /sys/bus/pci/drivers_probe Previously we could not invoke drivers_probe after adding a device to new_id for a driver as we get non-deterministic behavior whether the driver we intend or the standard driver will claim the device. Now it becomes a deterministic process, only the driver matching driver_override will probe the device. To return the device to the standard driver, we simply clear the driver_override and reprobe the device: echo > /sys/bus/pci/devices/0000:03:00.0/driver_override echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind echo 0000:03:00.0 > /sys/bus/pci/drivers_probe Another advantage to this approach is that we can specify a driver override to force a specific binding or prevent any binding. For instance when an IOMMU group is exposed to userspace through VFIO we require that all devices within that group are owned by VFIO. However, devices can be hot-added into an IOMMU group, in which case we want to prevent the device from binding to any driver (override driver = "none") or perhaps have it automatically bind to vfio-pci. With driver_override it's a simple matter for this field to be set internally when the device is first discovered to prevent driver matches. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Alexander Graf <agraf@suse.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-20 08:53:21 -06:00
PCI: Add support for multiple DMA aliases Solve IOMMU support issues with PCIe non-transparent bridges that use Requester ID look-up tables (RID-LUT), e.g., the PEX8733. The NTB connects devices in two independent PCI domains. Devices separated by the NTB are not able to discover each other. A PCI packet being forwared from one domain to another has to have its RID modified so it appears on correct bus and completions are forwarded back to the original domain through the NTB. The RID is translated using a preprogrammed table (LUT) and the PCI packet propagates upstream away from the NTB. If the destination system has IOMMU enabled, the packet will be discarded because the new RID is unknown to the IOMMU. Adding a DMA alias for the new RID allows IOMMU to properly recognize the packet. Each device behind the NTB has a unique RID assigned in the RID-LUT. The current DMA alias implementation supports only a single alias, so it's not possible to support mutiple devices behind the NTB when IOMMU is enabled. Enable all possible aliases on a given bus (256) that are stored in a bitset. Alias devfn is directly translated to a bit number. The bitset is not allocated for devices that have no need for DMA aliases. More details can be found in the following article: http://www.plxtech.com/files/pdf/technical/expresslane/RTC_Enabling%20MulitHostSystemDesigns.pdf Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: David Woodhouse <David.Woodhouse@intel.com> Acked-by: Joerg Roedel <jroedel@suse.de>
2016-03-03 15:38:02 +01:00
2015-07-17 15:05:46 -05:00
pci: do not mark exported functions as __devinit Functions marked __devinit will be removed after kernel init. But being exported they are potentially called by a module much later. So the safer choice seems to be to keep the function even in the non CONFIG_HOTPLUG case. This silence the follwoing section mismatch warnings: WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_add_device from __ksymtab_gpl between '__ksymtab_pci_bus_add_device' (at offset 0x20) and '__ksymtab_pci_walk_bus' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_create_bus from __ksymtab_gpl between '__ksymtab_pci_create_bus' (at offset 0x40) and '__ksymtab_pci_stop_bus_device' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_max_busnr from __ksymtab_gpl between '__ksymtab_pci_bus_max_busnr' (at offset 0xc0) and '__ksymtab_pci_assign_resource_fixed' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_claim_resource from __ksymtab_gpl between '__ksymtab_pci_claim_resource' (at offset 0xe0) and '__ksymtab_pcie_port_bus_type' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_add_devices from __ksymtab between '__ksymtab_pci_bus_add_devices' (at offset 0x70) and '__ksymtab_pci_bus_alloc_resource' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_scan_bus_parented from __ksymtab between '__ksymtab_pci_scan_bus_parented' (at offset 0x90) and '__ksymtab_pci_root_buses' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_assign_resources from __ksymtab between '__ksymtab_pci_bus_assign_resources' (at offset 0x4d0) and '__ksymtab_pci_bus_size_bridges' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_size_bridges from __ksymtab between '__ksymtab_pci_bus_size_bridges' (at offset 0x4e0) and '__ksymtab_pci_setup_cardbus' Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-03-26 21:53:30 -08:00
PCI ACPI: Rework PCI handling of wake-up * Introduce function acpi_pm_device_sleep_wake() for enabling and disabling the system wake-up capability of devices that are power manageable by ACPI. * Introduce function acpi_bus_can_wakeup() allowing other (dependent) subsystems to check if ACPI is able to enable the system wake-up capability of given device. * Introduce callback .sleep_wake() in struct pci_platform_pm_ops and for the ACPI PCI 'driver' make it use acpi_pm_device_sleep_wake(). * Introduce callback .can_wakeup() in struct pci_platform_pm_ops and for the ACPI 'driver' make it use acpi_bus_can_wakeup(). * Move the PME# handlig code out of pci_enable_wake() and split it into two functions, pci_pme_capable() and pci_pme_active(), allowing the caller to check if given device is capable of generating PME# from given power state and to enable/disable the device's PME# functionality, respectively. * Modify pci_enable_wake() to use the new ACPI callbacks and the new PME#-related functions. * Drop the generic .platform_enable_wakeup() callback that is not used any more. * Introduce device_set_wakeup_capable() that will set the power.can_wakeup flag of given device. * Rework PCI device PM initialization so that, if given device is capable of generating wake-up events, either natively through the PME# mechanism, or with the help of the platform, its power.can_wakeup flag is set and its power.should_wakeup flag is unset as appropriate. * Make ACPI set the power.can_wakeup flag for devices found to be wake-up capable by it. * Make the ACPI wake-up code enable/disable GPEs for devices that have the wakeup.flags.prepared flag set (which means that their wake-up power has been enabled). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-07 03:34:48 +02:00
pci: do not mark exported functions as __devinit Functions marked __devinit will be removed after kernel init. But being exported they are potentially called by a module much later. So the safer choice seems to be to keep the function even in the non CONFIG_HOTPLUG case. This silence the follwoing section mismatch warnings: WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_add_device from __ksymtab_gpl between '__ksymtab_pci_bus_add_device' (at offset 0x20) and '__ksymtab_pci_walk_bus' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_create_bus from __ksymtab_gpl between '__ksymtab_pci_create_bus' (at offset 0x40) and '__ksymtab_pci_stop_bus_device' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_max_busnr from __ksymtab_gpl between '__ksymtab_pci_bus_max_busnr' (at offset 0xc0) and '__ksymtab_pci_assign_resource_fixed' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_claim_resource from __ksymtab_gpl between '__ksymtab_pci_claim_resource' (at offset 0xe0) and '__ksymtab_pcie_port_bus_type' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_add_devices from __ksymtab between '__ksymtab_pci_bus_add_devices' (at offset 0x70) and '__ksymtab_pci_bus_alloc_resource' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_scan_bus_parented from __ksymtab between '__ksymtab_pci_scan_bus_parented' (at offset 0x90) and '__ksymtab_pci_root_buses' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_assign_resources from __ksymtab between '__ksymtab_pci_bus_assign_resources' (at offset 0x4d0) and '__ksymtab_pci_bus_size_bridges' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_size_bridges from __ksymtab between '__ksymtab_pci_bus_size_bridges' (at offset 0x4e0) and '__ksymtab_pci_setup_cardbus' Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-03-26 21:53:30 -08:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Don't restrict MPS for slots below Root Ports When booting with "pci=pcie_bus_safe", we previously limited the fabric MPS to 128 when we found: (1) A hotplug-capable Downstream Port ("dev->is_hotplug_bridge && pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT"), or (2) A hotplug-capable Root Port with a slot that was either empty or contained a multi-function device ("dev->is_hotplug_bridge && !list_is_singular(&dev->bus->devices)") Part (1) is valid, but part (2) is not. After a hot-add in the slot below a Root Port, we can reconfigure all MPS values in the fabric below the Root Port because the new device is the only thing below the Root Port and there are no active drivers. Therefore, there's no reason to limit the MPS for Root Ports, no matter what's in the slot. Test info: -+-[0000:40]-+-07.0-[0000:46]--+-00.0 Intel 82576 NIC \-00.1 Intel 82576 NIC 0000:40:07.0 Root Port bridge to [bus 46] (MPS supported=256) 0000:46:00.0 Endpoint (MPS supported=512) 0000:46:00.1 Endpoint (MPS supported=512) # echo 0 > /sys/bus/pci/slots/7/power # echo 1 > /sys/bus/pci/slots/7/power pcieport 0000:40:07.0: PCI-E Max Payload Size set to 256/ 256 (was 256) pci 0000:46:00.0: PCI-E Max Payload Size set to 256/ 512 (was 128) pci 0000:46:00.1: PCI-E Max Payload Size set to 256/ 512 (was 128) Before this change, we set MPS to 128 for the Root Port and both NICs because the slot contained a multi-function device and dev->is_hotplug_bridge && !list_is_singular(&dev->bus->devices) was true. After this change, we set it to 256. [bhelgaas: changelog, comments, split out upstream bridge check] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Jon Mason <jdmason@kudzu.us>
2013-08-22 11:24:47 +08:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Don't restrict MPS for slots below Root Ports When booting with "pci=pcie_bus_safe", we previously limited the fabric MPS to 128 when we found: (1) A hotplug-capable Downstream Port ("dev->is_hotplug_bridge && pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT"), or (2) A hotplug-capable Root Port with a slot that was either empty or contained a multi-function device ("dev->is_hotplug_bridge && !list_is_singular(&dev->bus->devices)") Part (1) is valid, but part (2) is not. After a hot-add in the slot below a Root Port, we can reconfigure all MPS values in the fabric below the Root Port because the new device is the only thing below the Root Port and there are no active drivers. Therefore, there's no reason to limit the MPS for Root Ports, no matter what's in the slot. Test info: -+-[0000:40]-+-07.0-[0000:46]--+-00.0 Intel 82576 NIC \-00.1 Intel 82576 NIC 0000:40:07.0 Root Port bridge to [bus 46] (MPS supported=256) 0000:46:00.0 Endpoint (MPS supported=512) 0000:46:00.1 Endpoint (MPS supported=512) # echo 0 > /sys/bus/pci/slots/7/power # echo 1 > /sys/bus/pci/slots/7/power pcieport 0000:40:07.0: PCI-E Max Payload Size set to 256/ 256 (was 256) pci 0000:46:00.0: PCI-E Max Payload Size set to 256/ 512 (was 128) pci 0000:46:00.1: PCI-E Max Payload Size set to 256/ 512 (was 128) Before this change, we set MPS to 128 for the Root Port and both NICs because the slot contained a multi-function device and dev->is_hotplug_bridge && !list_is_singular(&dev->bus->devices) was true. After this change, we set it to 256. [bhelgaas: changelog, comments, split out upstream bridge check] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Jon Mason <jdmason@kudzu.us>
2013-08-22 11:24:47 +08:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Set PCI-E Max Payload Size on fabric On a given PCI-E fabric, each device, bridge, and root port can have a different PCI-E maximum payload size. There is a sizable performance boost for having the largest possible maximum payload size on each PCI-E device. However, if improperly configured, fatal bus errors can occur. Thus, it is important to ensure that PCI-E payloads sends by a device are never larger than the MPS setting of all devices on the way to the destination. This can be achieved two ways: - A conservative approach is to use the smallest common denominator of the entire tree below a root complex for every device on that fabric. This means for example that having a 128 bytes MPS USB controller on one leg of a switch will dramatically reduce performances of a video card or 10GE adapter on another leg of that same switch. It also means that any hierarchy supporting hotplug slots (including expresscard or thunderbolt I suppose, dbl check that) will have to be entirely clamped to 128 bytes since we cannot predict what will be plugged into those slots, and we cannot change the MPS on a "live" system. - A more optimal way is possible, if it falls within a couple of constraints: * The top-level host bridge will never generate packets larger than the smallest TLP (or if it can be controlled independently from its MPS at least) * The device will never generate packets larger than MPS (which can be configured via MRRS) * No support of direct PCI-E <-> PCI-E transfers between devices without some additional code to specifically deal with that case Then we can use an approach that basically ignores downstream requests and focuses exclusively on upstream requests. In that case, all we need to care about is that a device MPS is no larger than its parent MPS, which allows us to keep all switches/bridges to the max MPS supported by their parent and eventually the PHB. In this case, your USB controller would no longer "starve" your 10GE Ethernet and your hotplug slots won't affect your global MPS. Additionally, the hotplugged devices themselves can be configured to a larger MPS up to the value configured in the hotplug bridge. To choose between the two available options, two PCI kernel boot args have been added to the PCI calls. "pcie_bus_safe" will provide the former behavior, while "pcie_bus_perf" will perform the latter behavior. By default, the latter behavior is used. NOTE: due to the location of the enablement, each arch will need to add calls to this function. This patch only enables x86. This patch includes a number of changes recommended by Benjamin Herrenschmidt. Tested-by: Jordan_Hargrave@dell.com Signed-off-by: Jon Mason <mason@myri.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-07-20 15:20:54 -05:00
PCI: Do not allocate more buses than available in parent [ Upstream commit a20c7f36bd3d20d245616ae223bb9d05dfb6f050 ] One can ask more buses to be reserved for hotplug bridges by passing pci=hpbussize=N in the kernel command line. If the parent bus does not have enough bus space available we incorrectly create child bus with the requested number of subordinate buses. In the example below hpbussize is set to one more than we have available buses in the root port: pci 0000:07:00.0: [8086:1578] type 01 class 0x060400 pci 0000:07:00.0: scanning [bus 00-00] behind bridge, pass 0 pci 0000:07:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring pci 0000:07:00.0: scanning [bus 00-00] behind bridge, pass 1 pci_bus 0000:08: busn_res: can not insert [bus 08-ff] under [bus 07-3f] (conflicts with (null) [bus 07-3f]) pci_bus 0000:08: scanning bus ... pci_bus 0000:0a: bus scan returning with max=40 pci_bus 0000:0a: busn_res: [bus 0a-ff] end is updated to 40 pci_bus 0000:0a: [bus 0a-40] partially hidden behind bridge 0000:07 [bus 07-3f] pci_bus 0000:08: bus scan returning with max=40 pci_bus 0000:08: busn_res: [bus 08-ff] end is updated to 40 Instead of allowing this, limit the subordinate number to be less than or equal the maximum subordinate number allocated for the parent bus (if it has any). Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> [bhelgaas: remove irrelevant dmesg messages] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-13 21:35:43 +03:00
ACPI / PCI: Set root bridge ACPI handle in advance The ACPI handles of PCI root bridges need to be known to acpi_bind_one(), so that it can create the appropriate "firmware_node" and "physical_node" files for them, but currently the way it gets to know those handles is not exactly straightforward (to put it lightly). This is how it works, roughly: 1. acpi_bus_scan() finds the handle of a PCI root bridge, creates a struct acpi_device object for it and passes that object to acpi_pci_root_add(). 2. acpi_pci_root_add() creates a struct acpi_pci_root object, populates its "device" field with its argument's address (device->handle is the ACPI handle found in step 1). 3. The struct acpi_pci_root object created in step 2 is passed to pci_acpi_scan_root() and used to get resources that are passed to pci_create_root_bus(). 4. pci_create_root_bus() creates a struct pci_host_bridge object and passes its "dev" member to device_register(). 5. platform_notify(), which for systems with ACPI is set to acpi_platform_notify(), is called. So far, so good. Now it starts to be "interesting". 6. acpi_find_bridge_device() is used to find the ACPI handle of the given device (which is the PCI root bridge) and executes acpi_pci_find_root_bridge(), among other things, for the given device object. 7. acpi_pci_find_root_bridge() uses the name (sic!) of the given device object to extract the segment and bus numbers of the PCI root bridge and passes them to acpi_get_pci_rootbridge_handle(). 8. acpi_get_pci_rootbridge_handle() browses the list of ACPI PCI root bridges and finds the one that matches the given segment and bus numbers. Its handle is then used to initialize the ACPI handle of the PCI root bridge's device object by acpi_bind_one(). However, this is *exactly* the ACPI handle we started with in step 1. Needless to say, this is quite embarassing, but it may be avoided thanks to commit f3fd0c8 (ACPI: Allow ACPI handles of devices to be initialized in advance), which makes it possible to initialize the ACPI handle of a device before passing it to device_register(). Accordingly, add a new __weak routine, pcibios_root_bridge_prepare(), defaulting to an empty implementation that can be replaced by the interested architecutres (x86 and ia64 at the moment) with functions that will set the root bridge's ACPI handle before its dev member is passed to device_register(). Make both x86 and ia64 provide such implementations of pcibios_root_bridge_prepare() and remove acpi_pci_find_root_bridge() and acpi_get_pci_rootbridge_handle() that aren't necessary any more. Included is a fix for breakage on systems with non-ACPI PCI host bridges from Bjorn Helgaas. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-01-09 22:33:37 +01:00
PCI: Add pci_register_host_bridge() interface Make the existing pci_host_bridge structure a proper device that is usable by PCI host drivers in a more standard way. In addition to the existing pci_scan_bus(), pci_scan_root_bus(), pci_scan_root_bus_msi(), and pci_create_root_bus() interfaces, this unfortunately means having to add yet another interface doing basically the same thing, and add some extra code in the initial step. However, this time it's more likely to be extensible enough that we won't have to do another one again in the future, and we should be able to reduce code much more as a result. The main idea is to pull the allocation of 'struct pci_host_bridge' out of the registration, and let individual host drivers and architecture code fill the members before calling the registration function. There are a number of things we can do based on this: * Use a single memory allocation for the driver-specific structure and the generic PCI host bridge * consolidate the contents of driver-specific structures by moving them into pci_host_bridge * Add a consistent interface for removing a PCI host bridge again when unloading a host driver module * Replace the architecture specific __weak pcibios_*() functions with callbacks in a pci_host_bridge device * Move common boilerplate code from host drivers into the generic function, based on contents of the structure * Extend pci_host_bridge with additional members when needed without having to add arguments to pci_scan_*(). * Move members of struct pci_bus into pci_host_bridge to avoid having lots of identical copies. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
2016-11-25 11:57:09 +01:00
PCI: Add pci_register_host_bridge() interface Make the existing pci_host_bridge structure a proper device that is usable by PCI host drivers in a more standard way. In addition to the existing pci_scan_bus(), pci_scan_root_bus(), pci_scan_root_bus_msi(), and pci_create_root_bus() interfaces, this unfortunately means having to add yet another interface doing basically the same thing, and add some extra code in the initial step. However, this time it's more likely to be extensible enough that we won't have to do another one again in the future, and we should be able to reduce code much more as a result. The main idea is to pull the allocation of 'struct pci_host_bridge' out of the registration, and let individual host drivers and architecture code fill the members before calling the registration function. There are a number of things we can do based on this: * Use a single memory allocation for the driver-specific structure and the generic PCI host bridge * consolidate the contents of driver-specific structures by moving them into pci_host_bridge * Add a consistent interface for removing a PCI host bridge again when unloading a host driver module * Replace the architecture specific __weak pcibios_*() functions with callbacks in a pci_host_bridge device * Move common boilerplate code from host drivers into the generic function, based on contents of the structure * Extend pci_host_bridge with additional members when needed without having to add arguments to pci_scan_*(). * Move members of struct pci_bus into pci_host_bridge to avoid having lots of identical copies. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
2016-11-25 11:57:09 +01:00
ACPI / PCI: Set root bridge ACPI handle in advance The ACPI handles of PCI root bridges need to be known to acpi_bind_one(), so that it can create the appropriate "firmware_node" and "physical_node" files for them, but currently the way it gets to know those handles is not exactly straightforward (to put it lightly). This is how it works, roughly: 1. acpi_bus_scan() finds the handle of a PCI root bridge, creates a struct acpi_device object for it and passes that object to acpi_pci_root_add(). 2. acpi_pci_root_add() creates a struct acpi_pci_root object, populates its "device" field with its argument's address (device->handle is the ACPI handle found in step 1). 3. The struct acpi_pci_root object created in step 2 is passed to pci_acpi_scan_root() and used to get resources that are passed to pci_create_root_bus(). 4. pci_create_root_bus() creates a struct pci_host_bridge object and passes its "dev" member to device_register(). 5. platform_notify(), which for systems with ACPI is set to acpi_platform_notify(), is called. So far, so good. Now it starts to be "interesting". 6. acpi_find_bridge_device() is used to find the ACPI handle of the given device (which is the PCI root bridge) and executes acpi_pci_find_root_bridge(), among other things, for the given device object. 7. acpi_pci_find_root_bridge() uses the name (sic!) of the given device object to extract the segment and bus numbers of the PCI root bridge and passes them to acpi_get_pci_rootbridge_handle(). 8. acpi_get_pci_rootbridge_handle() browses the list of ACPI PCI root bridges and finds the one that matches the given segment and bus numbers. Its handle is then used to initialize the ACPI handle of the PCI root bridge's device object by acpi_bind_one(). However, this is *exactly* the ACPI handle we started with in step 1. Needless to say, this is quite embarassing, but it may be avoided thanks to commit f3fd0c8 (ACPI: Allow ACPI handles of devices to be initialized in advance), which makes it possible to initialize the ACPI handle of a device before passing it to device_register(). Accordingly, add a new __weak routine, pcibios_root_bridge_prepare(), defaulting to an empty implementation that can be replaced by the interested architecutres (x86 and ia64 at the moment) with functions that will set the root bridge's ACPI handle before its dev member is passed to device_register(). Make both x86 and ia64 provide such implementations of pcibios_root_bridge_prepare() and remove acpi_pci_find_root_bridge() and acpi_get_pci_rootbridge_handle() that aren't necessary any more. Included is a fix for breakage on systems with non-ACPI PCI host bridges from Bjorn Helgaas. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-01-09 22:33:37 +01:00
PCI: Add pci_register_host_bridge() interface Make the existing pci_host_bridge structure a proper device that is usable by PCI host drivers in a more standard way. In addition to the existing pci_scan_bus(), pci_scan_root_bus(), pci_scan_root_bus_msi(), and pci_create_root_bus() interfaces, this unfortunately means having to add yet another interface doing basically the same thing, and add some extra code in the initial step. However, this time it's more likely to be extensible enough that we won't have to do another one again in the future, and we should be able to reduce code much more as a result. The main idea is to pull the allocation of 'struct pci_host_bridge' out of the registration, and let individual host drivers and architecture code fill the members before calling the registration function. There are a number of things we can do based on this: * Use a single memory allocation for the driver-specific structure and the generic PCI host bridge * consolidate the contents of driver-specific structures by moving them into pci_host_bridge * Add a consistent interface for removing a PCI host bridge again when unloading a host driver module * Replace the architecture specific __weak pcibios_*() functions with callbacks in a pci_host_bridge device * Move common boilerplate code from host drivers into the generic function, based on contents of the structure * Extend pci_host_bridge with additional members when needed without having to add arguments to pci_scan_*(). * Move members of struct pci_bus into pci_host_bridge to avoid having lots of identical copies. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
2016-11-25 11:57:09 +01:00
PCI: Add pci_register_host_bridge() interface Make the existing pci_host_bridge structure a proper device that is usable by PCI host drivers in a more standard way. In addition to the existing pci_scan_bus(), pci_scan_root_bus(), pci_scan_root_bus_msi(), and pci_create_root_bus() interfaces, this unfortunately means having to add yet another interface doing basically the same thing, and add some extra code in the initial step. However, this time it's more likely to be extensible enough that we won't have to do another one again in the future, and we should be able to reduce code much more as a result. The main idea is to pull the allocation of 'struct pci_host_bridge' out of the registration, and let individual host drivers and architecture code fill the members before calling the registration function. There are a number of things we can do based on this: * Use a single memory allocation for the driver-specific structure and the generic PCI host bridge * consolidate the contents of driver-specific structures by moving them into pci_host_bridge * Add a consistent interface for removing a PCI host bridge again when unloading a host driver module * Replace the architecture specific __weak pcibios_*() functions with callbacks in a pci_host_bridge device * Move common boilerplate code from host drivers into the generic function, based on contents of the structure * Extend pci_host_bridge with additional members when needed without having to add arguments to pci_scan_*(). * Move members of struct pci_bus into pci_host_bridge to avoid having lots of identical copies. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
2016-11-25 11:57:09 +01:00
PCI: optionally sort device lists breadth-first Problem: New Dell PowerEdge servers have 2 embedded ethernet ports, which are labeled NIC1 and NIC2 on the chassis, in the BIOS setup screens, and in the printed documentation. Assuming no other add-in ethernet ports in the system, Linux 2.4 kernels name these eth0 and eth1 respectively. Many people have come to expect this naming. Linux 2.6 kernels name these eth1 and eth0 respectively (backwards from expectations). I also have reports that various Sun and HP servers have similar behavior. Root cause: Linux 2.4 kernels walk the pci_devices list, which happens to be sorted in breadth-first order (or pcbios_find_device order on i386, which most often is breadth-first also). 2.6 kernels have both the pci_devices list and the pci_bus_type.klist_devices list, the latter is what is walked at driver load time to match the pci_id tables; this klist happens to be in depth-first order. On systems where, for physical routing reasons, NIC1 appears on a lower bus number than NIC2, but NIC2's bridge is discovered first in the depth-first ordering, NIC2 will be discovered before NIC1. If the list were sorted breadth-first, NIC1 would be discovered before NIC2. A PowerEdge 1955 system has the following topology which easily exhibits the difference between depth-first and breadth-first device lists. -[0000:00]-+-00.0 Intel Corporation 5000P Chipset Memory Controller Hub +-02.0-[0000:03-08]--+-00.0-[0000:04-07]--+-00.0-[0000:05-06]----00.0-[0000:06]----00.0 Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC2, 2.4 kernel name eth1, 2.6 kernel name eth0) +-1c.0-[0000:01-02]----00.0-[0000:02]----00.0 Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC1, 2.4 kernel name eth0, 2.6 kernel name eth1) Other factors, such as device driver load order and the presence of PCI slots at various points in the bus hierarchy further complicate this problem; I'm not trying to solve those here, just restore the device order, and thus basic behavior, that 2.4 kernels had. Solution: The solution can come in multiple steps. Suggested fix #1: kernel Patch below optionally sorts the two device lists into breadth-first ordering to maintain compatibility with 2.4 kernels. It adds two new command line options: pci=bfsort pci=nobfsort to force the sort order, or not, as you wish. It also adds DMI checks for the specific Dell systems which exhibit "backwards" ordering, to make them "right". Suggested fix #2: udev rules from userland Many people also have the expectation that embedded NICs are always discovered before add-in NICs (which this patch does not try to do). Using the PCI IRQ Routing Table provided by system BIOS, it's easy to determine which PCI devices are embedded, or if add-in, which PCI slot they're in. I'm working on a tool that would allow udev to name ethernet devices in ascending embedded, slot 1 .. slot N order, subsort by PCI bus/dev/fn breadth-first. It'll be possible to use it independent of udev as well for those distributions that don't use udev in their installers. Suggested fix #3: system board routing rules One can constrain the system board layout to put NIC1 ahead of NIC2 regardless of breadth-first or depth-first discovery order. This adds a significant level of complexity to board routing, and may not be possible in all instances (witness the above systems from several major manufacturers). I don't want to encourage this particular train of thought too far, at the expense of not doing #1 or #2 above. Feedback appreciated. Patch tested on a Dell PowerEdge 1955 blade with 2.6.18. You'll also note I took some liberty and temporarily break the klist abstraction to simplify and speed up the sort algorithm. I think that's both safe and appropriate in this instance. Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-29 15:23:23 -05:00
PCI: optionally sort device lists breadth-first Problem: New Dell PowerEdge servers have 2 embedded ethernet ports, which are labeled NIC1 and NIC2 on the chassis, in the BIOS setup screens, and in the printed documentation. Assuming no other add-in ethernet ports in the system, Linux 2.4 kernels name these eth0 and eth1 respectively. Many people have come to expect this naming. Linux 2.6 kernels name these eth1 and eth0 respectively (backwards from expectations). I also have reports that various Sun and HP servers have similar behavior. Root cause: Linux 2.4 kernels walk the pci_devices list, which happens to be sorted in breadth-first order (or pcbios_find_device order on i386, which most often is breadth-first also). 2.6 kernels have both the pci_devices list and the pci_bus_type.klist_devices list, the latter is what is walked at driver load time to match the pci_id tables; this klist happens to be in depth-first order. On systems where, for physical routing reasons, NIC1 appears on a lower bus number than NIC2, but NIC2's bridge is discovered first in the depth-first ordering, NIC2 will be discovered before NIC1. If the list were sorted breadth-first, NIC1 would be discovered before NIC2. A PowerEdge 1955 system has the following topology which easily exhibits the difference between depth-first and breadth-first device lists. -[0000:00]-+-00.0 Intel Corporation 5000P Chipset Memory Controller Hub +-02.0-[0000:03-08]--+-00.0-[0000:04-07]--+-00.0-[0000:05-06]----00.0-[0000:06]----00.0 Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC2, 2.4 kernel name eth1, 2.6 kernel name eth0) +-1c.0-[0000:01-02]----00.0-[0000:02]----00.0 Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC1, 2.4 kernel name eth0, 2.6 kernel name eth1) Other factors, such as device driver load order and the presence of PCI slots at various points in the bus hierarchy further complicate this problem; I'm not trying to solve those here, just restore the device order, and thus basic behavior, that 2.4 kernels had. Solution: The solution can come in multiple steps. Suggested fix #1: kernel Patch below optionally sorts the two device lists into breadth-first ordering to maintain compatibility with 2.4 kernels. It adds two new command line options: pci=bfsort pci=nobfsort to force the sort order, or not, as you wish. It also adds DMI checks for the specific Dell systems which exhibit "backwards" ordering, to make them "right". Suggested fix #2: udev rules from userland Many people also have the expectation that embedded NICs are always discovered before add-in NICs (which this patch does not try to do). Using the PCI IRQ Routing Table provided by system BIOS, it's easy to determine which PCI devices are embedded, or if add-in, which PCI slot they're in. I'm working on a tool that would allow udev to name ethernet devices in ascending embedded, slot 1 .. slot N order, subsort by PCI bus/dev/fn breadth-first. It'll be possible to use it independent of udev as well for those distributions that don't use udev in their installers. Suggested fix #3: system board routing rules One can constrain the system board layout to put NIC1 ahead of NIC2 regardless of breadth-first or depth-first discovery order. This adds a significant level of complexity to board routing, and may not be possible in all instances (witness the above systems from several major manufacturers). I don't want to encourage this particular train of thought too far, at the expense of not doing #1 or #2 above. Feedback appreciated. Patch tested on a Dell PowerEdge 1955 blade with 2.6.18. You'll also note I took some liberty and temporarily break the klist abstraction to simplify and speed up the sort algorithm. I think that's both safe and appropriate in this instance. Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-29 15:23:23 -05:00
PCI: optionally sort device lists breadth-first Problem: New Dell PowerEdge servers have 2 embedded ethernet ports, which are labeled NIC1 and NIC2 on the chassis, in the BIOS setup screens, and in the printed documentation. Assuming no other add-in ethernet ports in the system, Linux 2.4 kernels name these eth0 and eth1 respectively. Many people have come to expect this naming. Linux 2.6 kernels name these eth1 and eth0 respectively (backwards from expectations). I also have reports that various Sun and HP servers have similar behavior. Root cause: Linux 2.4 kernels walk the pci_devices list, which happens to be sorted in breadth-first order (or pcbios_find_device order on i386, which most often is breadth-first also). 2.6 kernels have both the pci_devices list and the pci_bus_type.klist_devices list, the latter is what is walked at driver load time to match the pci_id tables; this klist happens to be in depth-first order. On systems where, for physical routing reasons, NIC1 appears on a lower bus number than NIC2, but NIC2's bridge is discovered first in the depth-first ordering, NIC2 will be discovered before NIC1. If the list were sorted breadth-first, NIC1 would be discovered before NIC2. A PowerEdge 1955 system has the following topology which easily exhibits the difference between depth-first and breadth-first device lists. -[0000:00]-+-00.0 Intel Corporation 5000P Chipset Memory Controller Hub +-02.0-[0000:03-08]--+-00.0-[0000:04-07]--+-00.0-[0000:05-06]----00.0-[0000:06]----00.0 Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC2, 2.4 kernel name eth1, 2.6 kernel name eth0) +-1c.0-[0000:01-02]----00.0-[0000:02]----00.0 Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC1, 2.4 kernel name eth0, 2.6 kernel name eth1) Other factors, such as device driver load order and the presence of PCI slots at various points in the bus hierarchy further complicate this problem; I'm not trying to solve those here, just restore the device order, and thus basic behavior, that 2.4 kernels had. Solution: The solution can come in multiple steps. Suggested fix #1: kernel Patch below optionally sorts the two device lists into breadth-first ordering to maintain compatibility with 2.4 kernels. It adds two new command line options: pci=bfsort pci=nobfsort to force the sort order, or not, as you wish. It also adds DMI checks for the specific Dell systems which exhibit "backwards" ordering, to make them "right". Suggested fix #2: udev rules from userland Many people also have the expectation that embedded NICs are always discovered before add-in NICs (which this patch does not try to do). Using the PCI IRQ Routing Table provided by system BIOS, it's easy to determine which PCI devices are embedded, or if add-in, which PCI slot they're in. I'm working on a tool that would allow udev to name ethernet devices in ascending embedded, slot 1 .. slot N order, subsort by PCI bus/dev/fn breadth-first. It'll be possible to use it independent of udev as well for those distributions that don't use udev in their installers. Suggested fix #3: system board routing rules One can constrain the system board layout to put NIC1 ahead of NIC2 regardless of breadth-first or depth-first discovery order. This adds a significant level of complexity to board routing, and may not be possible in all instances (witness the above systems from several major manufacturers). I don't want to encourage this particular train of thought too far, at the expense of not doing #1 or #2 above. Feedback appreciated. Patch tested on a Dell PowerEdge 1955 blade with 2.6.18. You'll also note I took some liberty and temporarily break the klist abstraction to simplify and speed up the sort algorithm. I think that's both safe and appropriate in this instance. Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-29 15:23:23 -05:00
PCI: optionally sort device lists breadth-first Problem: New Dell PowerEdge servers have 2 embedded ethernet ports, which are labeled NIC1 and NIC2 on the chassis, in the BIOS setup screens, and in the printed documentation. Assuming no other add-in ethernet ports in the system, Linux 2.4 kernels name these eth0 and eth1 respectively. Many people have come to expect this naming. Linux 2.6 kernels name these eth1 and eth0 respectively (backwards from expectations). I also have reports that various Sun and HP servers have similar behavior. Root cause: Linux 2.4 kernels walk the pci_devices list, which happens to be sorted in breadth-first order (or pcbios_find_device order on i386, which most often is breadth-first also). 2.6 kernels have both the pci_devices list and the pci_bus_type.klist_devices list, the latter is what is walked at driver load time to match the pci_id tables; this klist happens to be in depth-first order. On systems where, for physical routing reasons, NIC1 appears on a lower bus number than NIC2, but NIC2's bridge is discovered first in the depth-first ordering, NIC2 will be discovered before NIC1. If the list were sorted breadth-first, NIC1 would be discovered before NIC2. A PowerEdge 1955 system has the following topology which easily exhibits the difference between depth-first and breadth-first device lists. -[0000:00]-+-00.0 Intel Corporation 5000P Chipset Memory Controller Hub +-02.0-[0000:03-08]--+-00.0-[0000:04-07]--+-00.0-[0000:05-06]----00.0-[0000:06]----00.0 Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC2, 2.4 kernel name eth1, 2.6 kernel name eth0) +-1c.0-[0000:01-02]----00.0-[0000:02]----00.0 Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC1, 2.4 kernel name eth0, 2.6 kernel name eth1) Other factors, such as device driver load order and the presence of PCI slots at various points in the bus hierarchy further complicate this problem; I'm not trying to solve those here, just restore the device order, and thus basic behavior, that 2.4 kernels had. Solution: The solution can come in multiple steps. Suggested fix #1: kernel Patch below optionally sorts the two device lists into breadth-first ordering to maintain compatibility with 2.4 kernels. It adds two new command line options: pci=bfsort pci=nobfsort to force the sort order, or not, as you wish. It also adds DMI checks for the specific Dell systems which exhibit "backwards" ordering, to make them "right". Suggested fix #2: udev rules from userland Many people also have the expectation that embedded NICs are always discovered before add-in NICs (which this patch does not try to do). Using the PCI IRQ Routing Table provided by system BIOS, it's easy to determine which PCI devices are embedded, or if add-in, which PCI slot they're in. I'm working on a tool that would allow udev to name ethernet devices in ascending embedded, slot 1 .. slot N order, subsort by PCI bus/dev/fn breadth-first. It'll be possible to use it independent of udev as well for those distributions that don't use udev in their installers. Suggested fix #3: system board routing rules One can constrain the system board layout to put NIC1 ahead of NIC2 regardless of breadth-first or depth-first discovery order. This adds a significant level of complexity to board routing, and may not be possible in all instances (witness the above systems from several major manufacturers). I don't want to encourage this particular train of thought too far, at the expense of not doing #1 or #2 above. Feedback appreciated. Patch tested on a Dell PowerEdge 1955 blade with 2.6.18. You'll also note I took some liberty and temporarily break the klist abstraction to simplify and speed up the sort algorithm. I think that's both safe and appropriate in this instance. Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-29 15:23:23 -05:00