pci_bus_distribute_available_resources() and
pci_bridge_distribute_available_resources() retain bridge window resources
and related data needed for distributing the available window in
independent variables for io, memory, and prefetchable memory windows. The
code is essentially the same for all of them and therefore repeated three
times with different variable names.
Refactor pci_bus_distribute_available_resources() to take an array. This
is complicated slightly by the function taking advantage of passing the
struct as value, which cannot be done for arrays in C. Therefore, copy the
data into a local array in the stack in the first loop.
Variable names are (hopefully) improved slightly as well.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-21-ilpo.jarvinen@linux.intel.com
__pci_bus_size_bridges() goes to great lengths of helping pbus_size_mem()
in which types it should put into a particular bridge window, requiring
passing up to three resource type into pbus_size_mem().
Instead of having complex logic in __pci_bus_size_bridges() and a
non-straightforward interface between those functions, use
pbus_select_window_for_type() and pbus_select_window() to find the correct
bridge window and compare if the resources belong to that window.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-20-ilpo.jarvinen@linux.intel.com
pbus_upstream_space_available() figures out the upstream bridge window
resources on its own. Migrate it to use pbus_select_window().
Note: pbus_select_window() -> pbus_select_window_for_type() calls
find_bus_resource_of_type() for root bus, which does not do parent check
similar to what pbus_upstream_space_available() did earlier, but the
difference does not matter because pbus_upstream_space_available() itself
stops when it encounters the root bus.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-19-ilpo.jarvinen@linux.intel.com
Resource is going to be passed in as argument aften an upcoming change.
Rename the struct resource variable from "r" to "res" to avoid using one
letter variable name in a function argument.
This rename is made separately to reduce churn in the upcoming change.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-18-ilpo.jarvinen@linux.intel.com
Prior to a BAR resize, __resource_resize_store() loops through the normal
resources of the PCI device and releases those that match to the flags of
the BAR to be resized. This is necessary to allow resizing also the
upstream bridge window as only childless bridge windows can be resized.
While the flags check (mostly) works (if corner cases are ignored), the
more straightforward way is to check if the resources share the bridge
window. Change __resource_resize_store() to do the check using
pbus_select_window().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-16-ilpo.jarvinen@linux.intel.com
BAR resizing calls to pci_reassign_bridge_resources(), which attempts to
release any upstream bridge window to allow them to accommodate the new BAR
size. The release can only be performed if there are no other child
resources for the bridge window. Previously the code continued silently
when other child resources were detected.
Add pci_warn() to inform user that a bridge window could not be released
because of child resources. As a small bridge window is often the reason
why BAR resize fails, this warning will help to pinpoint to the cause.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-15-ilpo.jarvinen@linux.intel.com
pci_reassign_bridge_resources() walks upwards in the PCI bus hierarchy,
locates the relevant bridge window on each level using flags check, and
attempts to release the bridge window. The flags-based check is fragile due
to various fallbacks in the bridge window selection logic. As such, the
algorithm might not locate the correct bridge window.
Refactor pci_reassign_bridge_resources() to determine the correct bridge
window using pbus_select_window(), which contains logic to handle all
fallback cases correctly. Change function prefix to pbus as it now inputs
struct bus and resource for which to locate the bridge window.
The main purpose is to make bridge window selection logic consistent across
the entire PCI core (one step at a time). While this technically also fixes
the commit 8bb705e3e7 ("PCI: Add pci_resize_resource() for resizing
BARs") making the bridge window walk algorithm more robust, the normal
setup having a 64-bit resizable BAR underneath bridge(s) with 64-bit
prefetchable windows does not need to use any fallbacks. As such, the
practical impact is low (requiring BAR resize use case and a non-typical
bridge device).
The way to detect if unrelated resource failed again is left to use the
type based approximation which should not behave worse than before.
Fixes: 8bb705e3e7 ("PCI: Add pci_resize_resource() for resizing BARs")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-14-ilpo.jarvinen@linux.intel.com
Various places in the PCI core code independently decide into which bridge
window a child resource should be placed. It is hard to see whether these
decisions always end up in agreement, especially in the corner cases, and
in some places it requires complex logic to pass multiple resource types
and/or bridge windows around.
Add pbus_select_window() and pbus_select_window_for_type() for cases where
the former cannot be used so that eventually the same helper can be used to
select the bridge window everywhere. Using the same function ensures the
selected bridge window remains always the same and it can be easily
recalculated in-situ allowing simplifying the interfaces between internal
functions in upcoming changes.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-13-ilpo.jarvinen@linux.intel.com
include/linux/pci.h provides PCI_BRIDGE_{IO,MEM,PREF_MEM}_WINDOW defines,
however, they're based on the resource array indexing in the pci_dev
struct. The struct pci_bus also has pointers to those same resources but
they start from zeroth index.
Add PCI_BUS_BRIDGE_{IO,MEM,PREF_MEM}_WINDOW defines to get rid of literal
indexing.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-12-ilpo.jarvinen@linux.intel.com
When a bridge window is found unused or fails to assign, the flags of the
associated resource are cleared. Clearing flags is problematic as it also
removes the type information of the resource which is needed later.
Thus, always preserve the bridge window type flags and use IORESOURCE_UNSET
and IORESOURCE_DISABLED to indicate the status of the bridge window. Also,
when initializing resources, make sure all valid bridge windows do get
their type flags set.
Change various places that relied on resource flags being cleared to check
for IORESOURCE_UNSET and IORESOURCE_DISABLED to allow bridge window
resource to retain their type flags. Add pdev_resource_assignable() and
pdev_resource_should_fit() helpers to filter out disabled bridge windows
during resource fitting; the latter combines more common checks into the
helper.
When reading the bridge windows from the registers, instead of leaving the
resource flags cleared for bridge windows that are not enabled, always
set up the flags and set IORESOURCE_UNSET | IORESOURCE_DISABLED as needed.
When resource fitting or assignment fails for a bridge window resource, or
the bridge window is not needed, mark the resource with IORESOURCE_UNSET or
IORESOURCE_DISABLED, respectively.
Use dummy zero resource in resource_show() for backwards compatibility as
lspci will otherwise misrepresent disabled bridge windows.
This change fixes an issue which highlights the importance of keeping the
resource type flags intact:
At the end of __assign_resources_sorted(), reset_resource() is called,
previously clearing the flags. Later, pci_prepare_next_assign_round()
attempted to release bridge resources using
pci_bus_release_bridge_resources() that calls into
pci_bridge_release_resources() that assumes type flags are still present.
As type flags were cleared, IORESOURCE_MEM_64 was not set leading to
resources under an incorrect bridge window to be released (idx = 1
instead of idx = 2). While the assignments performed later covered this
problem so that the wrongly released resources got assigned in the end,
it was still causing extra release+assign pairs.
There are other reasons why the resource flags should be retained in
upcoming changes too.
Removing the flag reset for non-bridge window resource is left as future
work, in part because it has a much higher regression potential due to
pci_enable_resources() that will start to work also for those resources
then and due to what endpoint drivers might assume about resources.
Despite the Fixes tag, backporting this (at least any time soon) is highly
discouraged. The issue fixed is borderline cosmetic as the later
assignments normally cover the problem entirely. Also there might be
non-obvious dependencies.
Fixes: 5b28541552 ("PCI: Restrict 64-bit prefetchable bridge windows to 64-bit resources")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-11-ilpo.jarvinen@linux.intel.com
A normal PCI bridge has multiple bridge windows and not all of them are
always required by devices underneath the bridge. If a Root Port or bridge
does not have a device underneath, no bridge windows get assigned. Yet,
pci_enable_resources() is set to fail indiscriminantly on any resource
assignment failure if the resource is not known to be optional.
In practice, the code in pci_enable_resources() is currently largely
dormant. The kernel sets resource flags to zero for any unused bridge
window and resets flags to zero in case of an resource assignment failure,
which short-circuits pci_enable_resources() because of this check:
if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
continue;
However, an upcoming change to resource flags will alter how bridge window
resource flags behave activating these long dormants checks in
pci_enable_resources().
While complex logic could be built to selectively enable a bridge only
under some conditions, a few versions of such logic were tried during
development of this change and none of them worked satisfactorily. Thus, I
just gave up and decided to enable any bridge regardless of the bridge
windows as there seems to be no clear benefit from not enabling it, but a
major downside as pcieport will not be probed for the bridge if it's not
enabled.
Therefore, change pci_enable_resources() to not check if bridge window
resources remain unassigned. Resource assignment failures are pretty noisy
already so there is no need to log that for bridge windows in
pci_enable_resources().
Ignoring bridge window failures hopefully prevents an obvious source of
regressions when the upcoming change that no longer clears resource flags
for bridge windows is enacted. I've hit this problem even during my own
testing on multiple occasions so I expect it to be a quite common problem.
This can always be revisited later if somebody thinks the enable check for
bridges is not strict enough, but expect a mind-boggling number of
regressions from such a change.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-10-ilpo.jarvinen@linux.intel.com
A few places in setup-bus.c call release_resource() directly and end up
duplicating functionality from pci_release_resource() such as parent check,
logging, and clearing the resource. Worse yet, the way the resource is
cleared is inconsistent between different sites.
Convert release_resource() calls into pci_release_resource() to remove code
duplication. This will also make the resource start, end, and flags
behavior consistent, i.e., start address is cleared, and only
IORESOURCE_UNSET is asserted for the resource.
While at it, eliminate the unnecessary initialization of idx variable in
pci_bridge_release_resources().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-9-ilpo.jarvinen@linux.intel.com
If clipping or claiming the bridge window fails, the bridge window is left
in a state that does not match the kernel's view on what the bridge window
is.
Disable the bridge window by writing the magic disable value into the Base
and Limit Registers if clipping or claiming failed. To detect if claiming
the resource was successful, add res->parent checks into the bridge setup
functions.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-8-ilpo.jarvinen@linux.intel.com
When the claim of a resource fails for the full range in
pci_claim_bridge_resource(), clipping the resource to a smaller size is
attempted. If clipping is successful, the new bridge window is programmed
and only as the last step the code attempts to claim the resource again.
The order of the last two steps is slightly illogical and inconsistent with
the assignment call chains.
If claiming the bridge window after clipping fails, the bridge window that
was set up is left in place.
Rework the logic such that the bridge window is claimed before calling the
relevant bridge setup function. This make the behavior consistent with
resource fitting call chains that always assign the bridge window before
programming it.
If claiming the bridge window fails, the clipped bridge window is no longer
set up but pci_claim_bridge_resource() returns without writing the bridge
window at all.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-7-ilpo.jarvinen@linux.intel.com
pci-legacy.c under MIPS has a copy of pci_enable_resources() named as
pcibios_enable_resources(). Having own copy of same functionality could
lead to inconsistencies in behavior, especially now as
pci_enable_resources() and the bridge window resource flags behavior are
going to be altered by upcoming changes.
The check for !r->start && r->end is already covered by the more generic
checks done in pci_enable_resources().
Call pci_enable_resources() from MIPS's pcibios_enable_device() and remove
pcibios_enable_resources().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: https://patch.msgid.link/20250829131113.36754-4-ilpo.jarvinen@linux.intel.com
Under arch/sparc/ there are multiple copies of pcibios_enable_device() but
none of those seem to do anything extra beyond what pci_enable_resources()
is supposed to do. These functions could lead to inconsistencies in
behavior, especially now as pci_enable_resources() and the bridge window
resource flags behavior are going to be altered by upcoming changes.
Remove all pcibios_enable_device() from arch/sparc/ so that PCI core can
simply call into pci_enable_resources() instead using its __weak version
of pcibios_enable_device().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-3-ilpo.jarvinen@linux.intel.com
m68k has a resource enable (check) loop in its pcibios_enable_device()
which for some reason differs from pci_enable_resources(). This could lead
to inconsistencies in behavior, especially now as pci_enable_resources()
and the bridge window resource flags behavior are going to be altered by
upcoming changes.
The check for !r->start && r->end is already covered by the more generic
checks done in pci_enable_resources().
The entire pcibios_enable_device() suspiciously looks copy-paste from some
other arch as also indicated by the preceding comment. However, it also
enables PCI_COMMAND_IO | PCI_COMMAND_MEMORY always for bridges. It is not
clear why that is being done as the commit e93a6bbeb5 ("m68k: common PCI
support definitions and code") introducing this code states "Nothing
specific to any PCI implementation in any m68k class CPU hardware yet".
Replace the resource enable loop with a call to pci_enable_resources() and
adjust the Command Register afterwards as it's unclear if that is necessary
or not so keep it for now.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-2-ilpo.jarvinen@linux.intel.com
Since 96336ec702 ("PCI: Perform reset_resource() and build fail list in
sync") the failed list is always built and returned to let the caller
decide what to do with the failures. The caller may want to retry resource
fitting and assignment and before that can happen, the resources should be
restored to their original state (a reset effectively clears the struct
resource), which requires returning them to the failed list so the original
state remains stored in the associated struct pci_dev_resource.
Resource resizing is different from the ordinary resource fitting and
assignment in that it only considers part of the resources. This means
failures for other resource types are not relevant at all and should be
ignored. As resize doesn't unassign such unrelated resources, those
resources ending up in the failed list implies assignment of that
resource must have failed before resize too. The check in
pci_reassign_bridge_resources() to decide if the whole assignment is
successful, however, is based on list emptiness which will cause false
negatives when the failed list has resources with an unrelated type.
If the failed list is not empty, call pci_required_resource_failed() and
extend it to be able to filter on specific resource types too (if
provided).
Calling pci_required_resource_failed() at this point is slightly
problematic because the resource itself is reset when the failed list
is constructed in __assign_resources_sorted(). As a result,
pci_resource_is_optional() does not have access to the original
resource flags. This could be worked around by restoring and
re-resetting the resource around the call to pci_resource_is_optional(),
however, it shouldn't cause issue as resource resizing is meant for
64-bit prefetchable resources according to Christian König (see the
Link which unfortunately doesn't point directly to Christian's reply
because lore didn't store that email at all).
Fixes: 96336ec702 ("PCI: Perform reset_resource() and build fail list in sync")
Link: https://lore.kernel.org/all/c5d1b5d8-8669-5572-75a7-0b480f581ac1@linux.intel.com/
Reported-by: D Scott Phillips <scott@os.amperecomputing.com>
Closes: https://lore.kernel.org/all/86plf0lgit.fsf@scott-ph-mail.amperecomputing.com/
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: D Scott Phillips <scott@os.amperecomputing.com>
Reviewed-by: D Scott Phillips <scott@os.amperecomputing.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org # v6.15+
Link: https://patch.msgid.link/20250822123359.16305-4-ilpo.jarvinen@linux.intel.com
pdev_sort_resources() uses pdev_resources_assignable() helper to decide if
device's resources cannot be assigned, so it ignores class 0
(PCI_CLASS_NOT_DEFINED) devices. pbus_size_mem(), on the other hand, does
not do the same check. This could lead into a situation where a resource
ends up on realloc_head list but is not on the head list, which in turn
prevents emptying the resource from the realloc_head list in
__assign_resources_sorted().
A non-empty realloc_head is unacceptable because it triggers an internal
sanity check as shown in this log with a device that has class 0
(PCI_CLASS_NOT_DEFINED):
pci 0001:01:00.0: [144d:a5a5] type 00 class 0x000000 PCIe Endpoint
pci 0001:01:00.0: BAR 0 [mem 0x00000000-0x000fffff 64bit]
pci 0001:01:00.0: ROM [mem 0x00000000-0x0000ffff pref]
pcieport 0001:00:00.0: bridge window [mem 0x00100000-0x001fffff] to [bus 01-ff] add_size 100000 add_align 100000
pcieport 0001:00:00.0: bridge window [mem 0x40000000-0x401fffff]: assigned
------------[ cut here ]------------
kernel BUG at drivers/pci/setup-bus.c:2532!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
...
Call trace:
pci_assign_unassigned_bus_resources+0x110/0x114 (P)
pci_rescan_bus+0x28/0x48
Use pdev_resources_assignable() also within pbus_size_mem() to skip
processing of non-assignable resources which removes the disparity in
between what resources pdev_sort_resources() and pbus_size_mem() consider.
As non-assignable resources are no longer processed, they are not added to
the realloc_head list, thus the sanity check no longer triggers.
This disparity problem is very old but only now became apparent after
2499f53484 ("PCI: Rework optional resource handling") that made the ROM
resources optional when calculating bridge window sizes which required
adding the resource to the realloc_head list. Previously, bridge windows
were just sized larger than necessary.
Fixes: 2499f53484 ("PCI: Rework optional resource handling")
Reported-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Closes: https://lore.kernel.org/all/5f103643-5e1c-43c6-b8fe-9617d3b5447c@linaro.org/
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v6.15+
Link: https://patch.msgid.link/20250822123359.16305-3-ilpo.jarvinen@linux.intel.com
When using relaxed tail alignment for the bridge window, pbus_size_mem()
also tries to minimize min_align, which can under certain scenarios end up
increasing min_align from that found by calculate_mem_align().
Ensure min_align is not increased by the relaxed tail alignment.
Eventually, it would be better to add calculate_relaxed_head_align()
similar to calculate_mem_align() which finds out what alignment can be used
for the head without introducing any gaps into the bridge window to give
flexibility on head address too. But that looks relatively complex so it
requires much more testing than fixing the immediate problem causing a
regression.
Fixes: 67f9085596 ("PCI: Allow relaxed bridge window tail sizing for optional resources")
Reported-by: Rio Liu <rio@r26.me>
Closes: https://lore.kernel.org/all/o2bL8MtD_40-lf8GlslTw-AZpUPzm8nmfCnJKvS8RQ3NOzOW1uq1dVCEfRpUjJ2i7G2WjfQhk2IWZ7oGp-7G-jXN4qOdtnyOcjRR0PZWK5I=@r26.me/
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Rio Liu <rio@r26.me>
Cc: stable@vger.kernel.org # v6.15+
Link: https://patch.msgid.link/20250822123359.16305-2-ilpo.jarvinen@linux.intel.com
The checks in plane_has_modifier() should check against display version
instead of graphics version.
Bspec: 67165, 70815
Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Link: https://lore.kernel.org/r/20250903170821.310143-1-matthew.s.atwood@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Currently, LKMM docs are not included in any of kernel documentation
books.
Commit e40573a43d ("docs: put atomic*.txt and memory-barriers.txt
into the core-api book") covered plain-text docs under Documentation/
by using the "include::" directive along with the ":literal:" option.
As LKMM docs are not under Documentation/, the same approach would not
work due to the directive's restriction.
As a matter of fact, kernel documentation has an extended directive
by the name of "kernel-include::", which loosens such restriction and
accepts any files under the kernel source tree.
Rather than moving LKMM docs around, use the latter and pull them into
the dev-tools book next to KCSAN.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <7ce84a93-5cbc-420e-894a-06a0372c52ab@gmail.com>
Include <linux/mod_devicetable.h> to declare struct of_device_id.
Avoids dependency on backlight header to include it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250715122643.137027-15-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
Include <linux/of.h> to declare struct device_node and include
<linux/mod_devicetable.h> to declare struct of_device_id. Avoids
dependency on backlight header to include it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250715122643.137027-14-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
Include <linux/of.h> to declare struct of_count_phandle_with_args().
Avoids dependency on backlight header to include it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250715122643.137027-13-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
Include <linux/mod_devicetable.h> to declare struct of_device_id.
Avoids dependency on backlight header to include it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Nick Chan <towinchenmi@gmail.com>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Acked-by: Duje Mihanović <duje.mihanovic@skole.hr>
Link: https://lore.kernel.org/r/20250715122643.137027-12-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
Include <linux/io.h> to declare IOMEM(). Avoids dependency on
backlight header to include it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250715122643.137027-11-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
Include <linux/mod_devicetable.h> to declare struct platform_device_id.
Avoids dependency on backlight header to include it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250715122643.137027-10-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
Include <linux/of.h> to declare various OF helpers. Avoids dependency
on backlight header to include it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250715122643.137027-9-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
Include <linux/mod_devicetable.h> to declare struct of_device_id.
Avoids dependency on backlight header to include it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Nick Chan <towinchenmi@gmail.com>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250715122643.137027-8-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
Include <linux/of.h> to avoid dependency on backlight header to
include it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250715122643.137027-7-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
There appears to be a cut-n-paste error with the incorrect field
ndr_desc->numa_node being reported for the target node. Fix this by
using ndr_desc->target_node instead.
Fixes: f060db9937 ("ACPI: NFIT: Use fallback node id when numa info in NFIT table is incorrect")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Use the string choice helper function str_plural() to simplify the code.
Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Commit 11502feab4 ("Documentation: PCI: Tidy AER documentation")
replaced the terms "PCI-E", "PCI-Express" and "PCI Express" with "PCIe"
in the AER documentation.
Do the same in the documentation on PCI error recovery. While at it,
add a missing period and a missing blank.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/db56b7ef12043f709a04ce67c1d1e102ab5f4e19.1757942121.git.lukas@wunner.de
Amend the documentation on PCI error recovery with specifics about
Downstream Port Containment and Advanced Error Reporting:
* Explain that with DPC, devices are inaccessible upon an error (similar
to EEH on powerpc) and do not become accessible until the link is
re-enabled.
* Explain that with AER, although devices may already be accessible in the
->error_detected() callback, accesses should be deferred to the
->mmio_enabled() callback for compatibility with EEH on powerpc and with
s390.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/61d8eeadb20ee71c3a852f44c863bfe0209c454d.1757942121.git.lukas@wunner.de
Amend the documentation on PCI error recovery to fix minor inaccuracies
vis-à-vis the actual code:
* The documentation claims that a missing ->resume() or ->mmio_enabled()
callback always leads to recovery through reset. But none of the
implementations do this (pcie_do_recovery(), eeh_handle_normal_event(),
zpci_event_do_error_state_clear()).
Drop the claim to align the documentation with the code.
* The documentation does not list PCI_ERS_RESULT_RECOVERED as a valid
return value from ->error_detected(). But none of the implementations
forbid this and some drivers are returning it, e.g.:
drivers/bus/mhi/host/pci_generic.c
drivers/infiniband/hw/hfi1/pcie.c
Further down in the documentation it is implied that the return value is
in fact allowed:
"The platform will call the resume() callback on all affected device
drivers if all drivers on the segment have returned
PCI_ERS_RESULT_RECOVERED from one of the 3 previous callbacks."
The "3 previous callbacks" being ->error_detected(), ->mmio_enabled()
and ->slot_reset().
Add it to the valid return values for consistency.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/ed3c3385499775fcc25f1ee66f395e212919f94a.1757942121.git.lukas@wunner.de
The PCIe Advanced Error Reporting driver has evolved over the years but
its documentation hasn't. Catch up with past code changes:
* The documentation claims that Correctable Errors are logged with
KERN_INFO severity, but the code uses KERN_WARN.
It had used KERN_WARN from the beginning with commit 6c2b374d74
("PCI-Express AER implemetation: AER core and aerdriver"). In 2013,
commit 2cced2d959 ("aerdrv: Cleanup log output for AER") switched to
KERN_ERR, until 2020 when it was reverted back to KERN_WARN by commit
e83e2ca3c3 ("PCI/AER: Log correctable errors as warning, not error").
* An example log message in the documentation uses the term "Uncorrected",
but the code uses "Uncorrectable" since commit 02a06f5f1a ("PCI/AER:
Use 'Correctable' and 'Uncorrectable' spec terms for errors").
* The example contains the Requester ID "id=0500", which is omitted since
commit 010caed4cc ("PCI/AER: Decode Error Source Requester ID").
* The example contains the error name "Unsupported Request", which is
instead reported as "UnsupReq" since commit bd237801fe ("PCI/AER:
Adopt lspci names for AER error decoding").
* The example doesn't prepend "0x" to hex values from the TLP Header Log,
as introduced by commit f68ea779d9 ("PCI: Add pcie_print_tlp_log() to
print TLP Header and Prefix Log").
* The documentation refers to a reset_link callback which was removed by
commit b6cf1a42f9 ("PCI/ERR: Remove service dependency in
pcie_do_recovery()").
* Commit 5790862255 ("PCI/ERR: Recover from RCiEP AER errors") added
support to recover Root Complex Integrated Endpoints by applying a
Function Level Reset, alternatively to the Secondary Bus Reset which is
applied otherwise.
* On non-fatal errors, a reset was previously never performed. But the
AER driver has just been amended to allow drivers to opt in to a reset.
* The documentation claims that a warning message is logged if a driver
lacks pci_error_handlers. But the message has been informational
(logged with KERN_INFO severity) since its introduction with commit
01daacfb90 ("PCI/AER: Log which device prevents error recovery").
The documentation claims that the message is only logged for fatal
errors, which is incorrect. Moreover it refers to "section 3", even
though the documentation no longer contains section numbers since commit
4e37f055a9 ("Documentation: PCI: convert pcieaer-howto.txt to reST").
Section 3 is titled "Developer Guide". That's the same section where
the reference is located, so it is self-referential and can be dropped.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/7501bfc5b9920193a25998a3cbcf72c47674ec63.1757942121.git.lukas@wunner.de
According to LP8556 datasheet EPROM region starts at 0x98 so adjust value
in the driver accordingly.
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250909074304.92135-2-clamor95@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
Add 'name' argument to of_led_get() such that it can lookup LEDs in
devicetree by either name or index.
And use this modified function to add devicetree support to the generic
(non devicetree specific) [devm_]led_get() function.
This uses the standard devicetree pattern of adding a -names string array
to map names to the indexes for an array of resources.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Aleksandrs Vinarskis <alex@vinarskis.com>
Link: https://lore.kernel.org/r/20250910-leds-v5-3-bb90a0f897d5@vinarskis.com
Signed-off-by: Lee Jones <lee@kernel.org>
The xe_preempt_fence_create() function returns error pointers. It
never returns NULL. Update the error checking to match.
Fixes: dd08ebf6c3 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/aJTMBdX97cof_009@stanley.mountain
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit 75cc23ffe5)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Replace calls of devm_kzalloc() with devm_kcalloc() in led_bl_get_leds()
and led_bl_parse_levels() for safer memory allocation with built-in
overflow protection.
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250819035804.433615-1-rongqianfeng@vivo.com
Signed-off-by: Lee Jones <lee@kernel.org>
Add support for the RTC found in the SpacemiT P1 PMIC. Initially
only setting and reading the time are supported.
The PMIC is implemented as a multi-function device. This RTC is
probed based on this driver being named in a MFD cell in the simple
MFD I2C driver.
Signed-off-by: Alex Elder <elder@riscstar.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20250825172057.163883-5-elder@riscstar.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Add read_alarm and set_alarm ops from the rtc framework.
The support of an alarm is handled by a kernel thread waiting in OP-TEE
for an asynchronous notification that comes in the interrupt
handler of the alarm interruption on OP-TEE secure world.
Once the notification arrives, the kernel thread previously suspended
is rescheduled (this is handled by the OP-TEE kernel driver) and comes
back with the alarm information to the kernel.
A second session is therefore needed to enable/disable/cancel a waiting
alarm event as the kernel thread stopped in OP-TEE takes a form of mutex
on the session and so no one can use this session in parallel.
Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Link: https://lore.kernel.org/r/20250715-upstream-optee-rtc-v1-3-e0fdf8aae545@foss.st.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
