Commit graph

96,010 commits

Author SHA1 Message Date
Tom Herbert
ff3c44e675 rcu: Add list_next_or_null_rcu
This is a convenience function that returns the next entry in an RCU
list or NULL if at the end of the list.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09 16:36:13 -05:00
Toshi Kani
ff3cc952d3 resource: Add remove_resource interface
insert_resource() and insert_resource_conflict() are called
by resource producers to insert a new resource.  When there
is any conflict, they move conflicting resources down to the
children of the new resource.  There is no destructor of these
interfaces, however.

Add remove_resource(), which removes a resource previously
inserted by insert_resource() or insert_resource_conflict(),
and moves the children up to where they were before.

__release_resource() is changed to have @release_child, so
that this function can be used for remove_resource() as well.

Also add comments to clarify that these functions are intended
for producers of resources to avoid any confusion with
request/release_resource() for consumers.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-03-09 11:07:20 -08:00
Laxman Dewangan
e498b4984d thermal: of-thermal: Add devm version of thermal_zone_of_sensor_register
Add resource managed version of thermal_zone_of_sensor_register() and
thermal_zone_of_sensor_unregister().

This helps in reducing the code size in error path, remove of
driver remove callbacks and making proper sequence for deallocations.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2016-03-09 10:31:20 -08:00
Steven Rostedt (Red Hat)
dc17147de3 tracing: Fix check for cpu online when event is disabled
Commit f37755490f ("tracepoints: Do not trace when cpu is offline") added
a check to make sure that tracepoints only get called when the cpu is
online, as it uses rcu_read_lock_sched() for protection.

Commit 3a630178fd ("tracing: generate RCU warnings even when tracepoints
are disabled") added lockdep checks (including rcu checks) for events that
are not enabled to catch possible RCU issues that would only be triggered if
a trace event was enabled. Commit f37755490f only stopped the warnings
when the trace event was enabled but did not prevent warnings if the trace
event was called when disabled.

To fix this, the cpu online check is moved to where the condition is added
to the trace event. This will place the cpu online check in all places that
it may be used now and in the future.

Cc: stable@vger.kernel.org # v3.18+
Fixes: f37755490f ("tracepoints: Do not trace when cpu is offline")
Fixes: 3a630178fd ("tracing: generate RCU warnings even when tracepoints are disabled")
Reported-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-09 11:58:41 -05:00
Saurabh Sengar
713df30bd9 qe: Make cpm_muram_alloc_common static
as cpm_muram_alloc_common is used only in this file,
making it static

Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
Signed-off-by: Scott Wood <oss@buserror.net>
2016-03-09 10:44:12 -06:00
Linus Walleij
70aba44b6c Revert "gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free"
This reverts commit 3fab91ea28.
2016-03-09 22:00:27 +07:00
Luis R. Rodriguez
f6e45661f9 dma, mm/pat: Rename dma_*_writecombine() to dma_*_wc()
Rename dma_*_writecombine() to dma_*_wc(), so that the naming
is coherent across the various write-combining APIs. Keep the
old names for compatibility for a while, these can be removed
at a later time. A guard is left to enable backporting of the
rename, and later remove of the old mapping defines seemlessly.

Build tested successfully with allmodconfig.

The following Coccinelle SmPL patch was used for this simple
transformation:

@ rename_dma_alloc_writecombine @
expression dev, size, dma_addr, gfp;
@@

-dma_alloc_writecombine(dev, size, dma_addr, gfp)
+dma_alloc_wc(dev, size, dma_addr, gfp)

@ rename_dma_free_writecombine @
expression dev, size, cpu_addr, dma_addr;
@@

-dma_free_writecombine(dev, size, cpu_addr, dma_addr)
+dma_free_wc(dev, size, cpu_addr, dma_addr)

@ rename_dma_mmap_writecombine @
expression dev, vma, cpu_addr, dma_addr, size;
@@

-dma_mmap_writecombine(dev, vma, cpu_addr, dma_addr, size)
+dma_mmap_wc(dev, vma, cpu_addr, dma_addr, size)

We also keep the old names as compatibility helpers, and
guard against their definition to make backporting easier.

Generated-by: Coccinelle SmPL
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bhelgaas@google.com
Cc: bp@suse.de
Cc: dan.j.williams@intel.com
Cc: daniel.vetter@ffwll.ch
Cc: dhowells@redhat.com
Cc: julia.lawall@lip6.fr
Cc: konrad.wilk@oracle.com
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: luto@amacapital.net
Cc: mst@redhat.com
Cc: tomi.valkeinen@ti.com
Cc: toshi.kani@hp.com
Cc: vinod.koul@intel.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1453516462-4844-1-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-09 14:57:51 +01:00
Viresh Kumar
242aa883a6 cpufreq: Remove 'policy->governor_enabled'
The entire sequence of events (like INIT/START or STOP/EXIT) for which
cpufreq_governor() is called, is guaranteed to be protected by
policy->rwsem now.

The additional checks that were added earlier (as we were forced to drop
policy->rwsem before calling cpufreq_governor() for EXIT event), aren't
required anymore.

Over that, they weren't sufficient really. They just take care of
START/STOP events, but not INIT/EXIT and the state machine was never
maintained properly by them.

Kill the unnecessary checks and policy->governor_enabled field.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09 14:41:12 +01:00
Viresh Kumar
68e80dae09 Revert "cpufreq: Drop rwsem lock around CPUFREQ_GOV_POLICY_EXIT"
Earlier, when the struct freq-attr was used to represent governor
attributes, the standard cpufreq show/store sysfs attribute callbacks
were applied to the governor tunable attributes and they always acquire
the policy->rwsem lock before carrying out the operation.  That could
have resulted in an ABBA deadlock if governor tunable attributes are
removed under policy->rwsem while one of them is being accessed
concurrently (if sysfs attributes removal wins the race, it will wait
for the access to complete with policy->rwsem held while the attribute
callback will block on policy->rwsem indefinitely).

We attempted to address this issue by dropping policy->rwsem around
governor tunable attributes removal (that is, around invocations of the
->governor callback with the event arg equal to CPUFREQ_GOV_POLICY_EXIT)
in cpufreq_set_policy(), but that opened up race conditions that had not
been possible with policy->rwsem held all the time.

The previous commit, "cpufreq: governor: New sysfs show/store callbacks
for governor tunables", fixed the original ABBA deadlock by adding new
governor specific show/store callbacks.

We don't have to drop rwsem around invocations of governor event
CPUFREQ_GOV_POLICY_EXIT anymore, and original fix can be reverted now.

Fixes: 955ef48335 (cpufreq: Drop rwsem lock around CPUFREQ_GOV_POLICY_EXIT)
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reported-by: Juri Lelli <juri.lelli@arm.com>
Tested-by: Juri Lelli <juri.lelli@arm.com>
Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09 14:40:59 +01:00
Rafael J. Wysocki
34e2c555f3 cpufreq: Add mechanism for registering utilization update callbacks
Introduce a mechanism by which parts of the cpufreq subsystem
("setpolicy" drivers or the core) can register callbacks to be
executed from cpufreq_update_util() which is invoked by the
scheduler's update_load_avg() on CPU utilization changes.

This allows the "setpolicy" drivers to dispense with their timers
and do all of the computations they need and frequency/voltage
adjustments in the update_load_avg() code path, among other things.

The update_load_avg() changes were suggested by Peter Zijlstra.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
2016-03-09 14:39:19 +01:00
Frederic Barrat
0d3a13fbf1 cxl: Remove cxl_get_phys_dev() kernel API
The cxl_get_phys_dev() API returns a struct device pointer which could
belong to either a struct pci_dev (bare-metal) or platform_device
(powerVM). To avoid potential problems in drivers, remove that API. It
was introduced to allow drivers to read the VPD of the adapter, but
the cxl driver now provides the cxl_pci_read_adapter_vpd() API for
that purpose.

Co-authored-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09 23:40:02 +11:00
Frederic Barrat
d601ea918b cxl: Support the cxl kernel API from a guest
Like on bare-metal, the cxl driver creates a virtual PHB and a pci
device for the AFU. The configuration space of the device is mapped to
the configuration record of the AFU.

Reuse the code defined in afu_cr_read8|16|32() when reading the
configuration space of the AFU device.

Even though the (virtual) AFU device is a pci device, the adapter is
not. So a driver using the cxl kernel API cannot read the VPD of the
adapter through the usual PCI interface. Therefore, we add a call to
the cxl kernel API:
ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count);

Co-authored-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09 23:40:00 +11:00
Christophe Lombard
594ff7d067 cxl: Support to flash a new image on the adapter from a guest
The new flash.c file contains the logic to flash a new image on the
adapter, through a hcall. It is an iterative process, with chunks of
data of 1M at a time. There are also 2 phases: write and verify. The
flash operation itself is driven from a user-land tool.
Once flashing is successful, an rtas call is made to update the device
tree with the new properties values for the adapter and the AFU(s)

Add a new char device for the adapter, so that the flash tool can
access the card, even if there is no valid AFU on it.

Co-authored-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09 23:39:56 +11:00
Paolo Bonzini
ab92f30875 KVM/ARM updates for 4.6
- VHE support so that we can run the kernel at EL2 on ARMv8.1 systems
 - PMU support for guests
 - 32bit world switch rewritten in C
 - Various optimizations to the vgic save/restore code
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Merge tag 'kvm-arm-for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/ARM updates for 4.6

- VHE support so that we can run the kernel at EL2 on ARMv8.1 systems
- PMU support for guests
- 32bit world switch rewritten in C
- Various optimizations to the vgic save/restore code

Conflicts:
	include/uapi/linux/kvm.h
2016-03-09 11:50:42 +01:00
Linus Walleij
0bae2f1732 Merge branch 'ib-mfd-regulator-gpio-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd into devel 2016-03-09 17:40:37 +07:00
Lee Jones
bab070620e Merge branches 'ib-mfd-clk-4.6', 'ib-mfd-input-iio-4.6', 'ib-mfd-regulator-4.6' and 'ib-mfd-regulator-gpio-4.6' into ibs-for-mfd-merged 2016-03-09 12:56:47 +07:00
Robin H. Johnson
caf02abf9b PCI: Add QEMU top-level IDs for (sub)vendor & device
Introduce PCI_VENDOR/PCI_SUBVENDOR/PCI_SUBDEVICE defines to replace the
constants scattered in the kernel already used to detect QEMU.

They are defined in the QEMU codebase per docs/specs/pci-ids.txt.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-03-08 22:31:21 -06:00
Marc Zyngier
1b8e83c04e arm64: KVM: vgic-v3: Avoid accessing ICH registers
Just like on GICv2, we're a bit hammer-happy with GICv3, and access
them more often than we should.

Adopt a policy similar to what we do for GICv2, only save/restoring
the minimal set of registers. As we don't access the registers
linearly anymore (we may skip some), the convoluted accessors become
slightly simpler, and we can drop the ugly indexing macro that
tended to confuse the reviewers.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:04 +00:00
Marc Zyngier
59f00ff9af KVM: arm/arm64: vgic-v2: Avoid accessing GICH registers
GICv2 registers are *slow*. As in "terrifyingly slow". Which is bad.
But we're equaly bad, as we make a point in accessing them even if
we don't have any interrupt in flight.

A good solution is to first find out if we have anything useful to
write into the GIC, and if we don't, to simply not do it. This
involves tracking which LRs actually have something valid there.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:22:20 +00:00
Daniel Borkmann
e28e87ed47 ip_tunnel, bpf: ip_tunnel_info_opts_{get, set} depends on CONFIG_INET
Helpers like ip_tunnel_info_opts_{get,set}() are only available if
CONFIG_INET is set, thus add an empty definition into the header for
the !CONFIG_INET case, where already other empty inline helpers are
defined.

This avoids ifdef kludge inside filter.c, but also vxlan and geneve
themself where this facility can only be used with, depend on INET
being set. For the !INET case TUNNEL_OPTIONS_PRESENT would never be
set in flags.

Fixes: 14ca0751c9 ("bpf: support for access to tunnel options")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 23:20:53 -05:00
Axel Lin
3fab91ea28 gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free
The implementation of lp3943_gpio_request/lp3943_gpio_free test pin_used
for tracing the pin usage. However, gpiolib already checks FLAG_REQUESTED
flag for the same purpose. So remove the redundant implementation.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-03-09 09:17:55 +07:00
Chen Fan
e237a55184 x86/ACPI/PCI: Recognize that Interrupt Line 255 means "not connected"
Per the x86-specific footnote to PCI spec r3.0, sec 6.2.4, the value 255 in
the Interrupt Line register means "unknown" or "no connection."
Previously, when we couldn't derive an IRQ from the _PRT, we fell back to
using the value from Interrupt Line as an IRQ.  It's questionable whether
we should do that at all, but the spec clearly suggests we shouldn't do it
for the value 255 on x86.

Calling request_irq() with IRQ 255 may succeed, but the driver won't
receive any interrupts.  Or, if IRQ 255 is shared with another device, it
may succeed, and the driver's ISR will be called at random times when the
*other* device interrupts.  Or it may fail if another device is using IRQ
255 with incompatible flags.  What we *want* is for request_irq() to fail
predictably so the driver can fall back to polling.

On x86, assume 255 in the Interrupt Line means the INTx line is not
connected.  In that case, set dev->irq to IRQ_NOTCONNECTED so request_irq()
will fail gracefully with -ENOTCONN.

We found this problem on a system where Secure Boot firmware assigned
Interrupt Line 255 to an i801_smbus device and another device was already
using MSI-X IRQ 255.  This was in v3.10, where i801_probe() fails if
request_irq() fails:

  i801_smbus 0000:00:1f.3: enabling device (0140 -> 0143)
  i801_smbus 0000:00:1f.3: can't derive routing for PCI INT C
  i801_smbus 0000:00:1f.3: PCI INT C: no GSI
  genirq: Flags mismatch irq 255. 00000080 (i801_smbus) vs. 00000000 (megasa)
  CPU: 0 PID: 2487 Comm: kworker/0:1 Not tainted 3.10.0-229.el7.x86_64 #1
  Hardware name: FUJITSU PRIMEQUEST 2800E2/D3736, BIOS PRIMEQUEST 2000 Serie5
  Call Trace:
    dump_stack+0x19/0x1b
    __setup_irq+0x54a/0x570
    request_threaded_irq+0xcc/0x170
    i801_probe+0x32f/0x508 [i2c_i801]
    local_pci_probe+0x45/0xa0
  i801_smbus 0000:00:1f.3: Failed to allocate irq 255: -16
  i801_smbus: probe of 0000:00:1f.3 failed with error -16

After aeb8a3d16a ("i2c: i801: Check if interrupts are disabled"),
i801_probe() will fall back to polling if request_irq() fails.  But we
still need this patch because request_irq() may succeed or fail depending
on other devices in the system.  If request_irq() fails, i801_smbus will
work by falling back to polling, but if it succeeds, i801_smbus won't work
because it expects interrupts that it may not receive.

Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09 01:23:35 +01:00
Wei Yang
7b77061f8d PCI: Add pcibios_bus_add_device() weak function
This adds weak function pcibios_bus_add_device() for arch dependent
code could do proper setup. For example, powerpc could setup EEH
related resources for SRIOV VFs.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09 09:58:14 +11:00
Wei Yang
c194f7ea7f PCI/IOV: Rename and export virtfn_{add, remove}
During EEH recovery, hotplug is applied to the devices which don't
have drivers or their drivers don't support EEH. However, the hotplug,
which was implemented based on PCI bus, can't be applied to VF directly.
Instead, we unplug and plug individual PCI devices (VFs).

This renames virtn_{add,remove}() and exports them so they can be used
in PCI hotplug during EEH recovery.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09 09:58:13 +11:00
Bob Moore
1e059e20ac ACPICA: Utilities: Update trace mechinism for acquire_object
ACPICA commit 0824ab90e03c2e4239e890615f447e7962b1daa2

Was not using the correct macro. Updated a comment in
acoutput.h

Link: 0824ab90
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-08 22:56:21 +01:00
Thierry Reding
057bd2e052 PCI: Add pci_ops.{add,remove}_bus() callbacks
Add pci_ops.{add,remove}_bus() callbacks, which will be called on every
newly created bus and when a bus is being removed, respectively.  This can
be used by drivers to implement driver-specific initialization and teardown
of the bus, in addition to the architecture-specifics implemented by the
pcibios_add_bus() and the pcibios_remove_bus() functions.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-03-08 15:40:37 -06:00
Alexei Starovoitov
557c0c6e7d bpf: convert stackmap to pre-allocation
It was observed that calling bpf_get_stackid() from a kprobe inside
slub or from spin_unlock causes similar deadlock as with hashmap,
therefore convert stackmap to use pre-allocated memory.

The call_rcu is no longer feasible mechanism, since delayed freeing
causes bpf_get_stackid() to fail unpredictably when number of actual
stacks is significantly less than user requested max_entries.
Since elements are no longer freed into slub, we can push elements into
freelist immediately and let them be recycled.
However the very unlikley race between user space map_lookup() and
program-side recycling is possible:
     cpu0                          cpu1
     ----                          ----
user does lookup(stackidX)
starts copying ips into buffer
                                   delete(stackidX)
                                   calls bpf_get_stackid()
				   which recyles the element and
                                   overwrites with new stack trace

To avoid user space seeing a partial stack trace consisting of two
merged stack traces, do bucket = xchg(, NULL); copy; xchg(,bucket);
to preserve consistent stack trace delivery to user space.
Now we can move memset(,0) of left-over element value from critical
path of bpf_get_stackid() into slow-path of user space lookup.
Also disallow lookup() from bpf program, since it's useless and
program shouldn't be messing with collected stack trace.

Note that similar race between user space lookup and kernel side updates
is also present in hashmap, but it's not a new race. bpf programs were
always allowed to modify hash and array map elements while user space
is copying them.

Fixes: d5a3b1f691 ("bpf: introduce BPF_MAP_TYPE_STACK_TRACE")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:28:31 -05:00
Alexei Starovoitov
6c90598174 bpf: pre-allocate hash map elements
If kprobe is placed on spin_unlock then calling kmalloc/kfree from
bpf programs is not safe, since the following dead lock is possible:
kfree->spin_lock(kmem_cache_node->lock)...spin_unlock->kprobe->
bpf_prog->map_update->kmalloc->spin_lock(of the same kmem_cache_node->lock)
and deadlocks.

The following solutions were considered and some implemented, but
eventually discarded
- kmem_cache_create for every map
- add recursion check to slow-path of slub
- use reserved memory in bpf_map_update for in_irq or in preempt_disabled
- kmalloc via irq_work

At the end pre-allocation of all map elements turned out to be the simplest
solution and since the user is charged upfront for all the memory, such
pre-allocation doesn't affect the user space visible behavior.

Since it's impossible to tell whether kprobe is triggered in a safe
location from kmalloc point of view, use pre-allocation by default
and introduce new BPF_F_NO_PREALLOC flag.

While testing of per-cpu hash maps it was discovered
that alloc_percpu(GFP_ATOMIC) has odd corner cases and often
fails to allocate memory even when 90% of it is free.
The pre-allocation of per-cpu hash elements solves this problem as well.

Turned out that bpf_map_update() quickly followed by
bpf_map_lookup()+bpf_map_delete() is very common pattern used
in many of iovisor/bcc/tools, so there is additional benefit of
pre-allocation, since such use cases are must faster.

Since all hash map elements are now pre-allocated we can remove
atomic increment of htab->count and save few more cycles.

Also add bpf_map_precharge_memlock() to check rlimit_memlock early to avoid
large malloc/free done by users who don't have sufficient limits.

Pre-allocation is done with vmalloc and alloc/free is done
via percpu_freelist. Here are performance numbers for different
pre-allocation algorithms that were implemented, but discarded
in favor of percpu_freelist:

1 cpu:
pcpu_ida	2.1M
pcpu_ida nolock	2.3M
bt		2.4M
kmalloc		1.8M
hlist+spinlock	2.3M
pcpu_freelist	2.6M

4 cpu:
pcpu_ida	1.5M
pcpu_ida nolock	1.8M
bt w/smp_align	1.7M
bt no/smp_align	1.1M
kmalloc		0.7M
hlist+spinlock	0.2M
pcpu_freelist	2.0M

8 cpu:
pcpu_ida	0.7M
bt w/smp_align	0.8M
kmalloc		0.4M
pcpu_freelist	1.5M

32 cpu:
kmalloc		0.13M
pcpu_freelist	0.49M

pcpu_ida nolock is a modified percpu_ida algorithm without
percpu_ida_cpu locks and without cross-cpu tag stealing.
It's faster than existing percpu_ida, but not as fast as pcpu_freelist.

bt is a variant of block/blk-mq-tag.c simlified and customized
for bpf use case. bt w/smp_align is using cache line for every 'long'
(similar to blk-mq-tag). bt no/smp_align allocates 'long'
bitmasks continuously to save memory. It's comparable to percpu_ida
and in some cases faster, but slower than percpu_freelist

hlist+spinlock is the simplest free list with single spinlock.
As expeceted it has very bad scaling in SMP.

kmalloc is existing implementation which is still available via
BPF_F_NO_PREALLOC flag. It's significantly slower in single cpu and
in 8 cpu setup it's 3 times slower than pre-allocation with pcpu_freelist,
but saves memory, so in cases where map->max_entries can be large
and number of map update/delete per second is low, it may make
sense to use it.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:28:31 -05:00
Alexei Starovoitov
b121d1e74d bpf: prevent kprobe+bpf deadlocks
if kprobe is placed within update or delete hash map helpers
that hold bucket spin lock and triggered bpf program is trying to
grab the spinlock for the same bucket on the same cpu, it will
deadlock.
Fix it by extending existing recursion prevention mechanism.

Note, map_lookup and other tracing helpers don't have this problem,
since they don't hold any locks and don't modify global data.
bpf_trace_printk has its own recursive check and ok as well.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:28:30 -05:00
Michal Kubeček
3dc94f93be ipv6: per netns FIB garbage collection
One of our customers observed issues with FIB6 garbage collectors
running in different network namespaces blocking each other, resulting
in soft lockups (fib6_run_gc() initiated from timer runs always in
forced mode).

Now that FIB6 walkers are separated per namespace, there is no more need
for instances of fib6_run_gc() in different namespaces blocking each
other. There is still a call to icmp6_dst_gc() which operates on shared
data but this function is protected by its own shared lock.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:16:51 -05:00
Michal Kubeček
9a03cd8f38 ipv6: per netns fib6 walkers
The IPv6 FIB data structures are separated per network namespace but
there is still only one global walkers list and one global walker list
lock. This means changes in one namespace unnecessarily interfere with
walkers in other namespaces.

Replace the global list with per-netns lists (and give each its own
lock).

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:16:51 -05:00
Marcelo Ricardo Leitner
133800d1f0 sctp: fix copying more bytes than expected in sctp_add_bind_addr
Dmitry reported that sctp_add_bind_addr may read more bytes than
expected in case the parameter is a IPv4 addr supplied by the user
through calls such as sctp_bindx_add(), because it always copies
sizeof(union sctp_addr) while the buffer may be just a struct
sockaddr_in, which is smaller.

This patch then fixes it by limiting the memcpy to the min between the
union size and a (new parameter) provided addr size. Where possible this
parameter still is the size of that union, except for reading from
user-provided buffers, which then it accounts for protocol type.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:04:08 -05:00
David S. Miller
4c38cd61ae Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter updates for your net-next tree,
they are:

1) Remove useless debug message when deleting IPVS service, from
   Yannick Brosseau.

2) Get rid of compilation warning when CONFIG_PROC_FS is unset in
   several spots of the IPVS code, from Arnd Bergmann.

3) Add prandom_u32 support to nft_meta, from Florian Westphal.

4) Remove unused variable in xt_osf, from Sudip Mukherjee.

5) Don't calculate IP checksum twice from netfilter ipv4 defrag hook
   since fixing af_packet defragmentation issues, from Joe Stringer.

6) On-demand hook registration for iptables from netns. Instead of
   registering the hooks for every available netns whenever we need
   one of the support tables, we register this on the specific netns
   that needs it, patchset from Florian Westphal.

7) Add missing port range selection to nf_tables masquerading support.

BTW, just for the record, there is a typo in the description of
5f6c253ebe ("netfilter: bridge: register hooks only when bridge
interface is added") that refers to the cluster match as deprecated, but
it is actually the CLUSTERIP target (which registers hooks
inconditionally) the one that is scheduled for removal.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 14:25:20 -05:00
Daniel Borkmann
db3c6139e6 bpf, vxlan, geneve, gre: fix usage of dst_cache on xmit
The assumptions from commit 0c1d70af92 ("net: use dst_cache for vxlan
device"), 468dfffcd7 ("geneve: add dst caching support") and 3c1cb4d260
("net/ipv4: add dst cache support for gre lwtunnels") on dst_cache usage
when ip_tunnel_info is used is unfortunately not always valid as assumed.

While it seems correct for ip_tunnel_info front-ends such as OVS, eBPF
however can fill in ip_tunnel_info for consumers like vxlan, geneve or gre
with different remote dsts, tos, etc, therefore they cannot be assumed as
packet independent.

Right now vxlan, geneve, gre would cache the dst for eBPF and every packet
would reuse the same entry that was first created on the initial route
lookup. eBPF doesn't store/cache the ip_tunnel_info, so each skb may have
a different one.

Fix it by adding a flag that checks the ip_tunnel_info. Also the !tos test
in vxlan needs to be handeled differently in this context as it is currently
inferred from ip_tunnel_info as well if present. ip_tunnel_dst_cache_usable()
helper is added for the three tunnel cases, which checks if we can use dst
cache.

Fixes: 0c1d70af92 ("net: use dst_cache for vxlan device")
Fixes: 468dfffcd7 ("geneve: add dst caching support")
Fixes: 3c1cb4d260 ("net/ipv4: add dst cache support for gre lwtunnels")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 13:58:47 -05:00
Daniel Borkmann
14ca0751c9 bpf: support for access to tunnel options
After eBPF being able to programmatically access/manage tunnel key meta
data via commit d3aa45ce6b ("bpf: add helpers to access tunnel metadata")
and more recently also for IPv6 through c6c3345407 ("bpf: support ipv6
for bpf_skb_{set,get}_tunnel_key"), this work adds two complementary
helpers to generically access their auxiliary tunnel options.

Geneve and vxlan support this facility. For geneve, TLVs can be pushed,
and for the vxlan case its GBP extension. I.e. setting tunnel key for geneve
case only makes sense, if we can also read/write TLVs into it. In the GBP
case, it provides the flexibility to easily map the group policy ID in
combination with other helpers or maps.

I chose to model this as two separate helpers, bpf_skb_{set,get}_tunnel_opt(),
for a couple of reasons. bpf_skb_{set,get}_tunnel_key() is already rather
complex by itself, and there may be cases for tunnel key backends where
tunnel options are not always needed. If we would have integrated this
into bpf_skb_{set,get}_tunnel_key() nevertheless, we are very limited with
remaining helper arguments, so keeping compatibility on structs in case of
passing in a flat buffer gets more cumbersome. Separating both also allows
for more flexibility and future extensibility, f.e. options could be fed
directly from a map, etc.

Moreover, change geneve's xmit path to test only for info->options_len
instead of TUNNEL_GENEVE_OPT flag. This makes it more consistent with vxlan's
xmit path and allows for avoiding to specify a protocol flag in the API on
xmit, so it can be protocol agnostic. Having info->options_len is enough
information that is needed. Tested with vxlan and geneve.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 13:58:46 -05:00
Daniel Borkmann
2208087061 bpf: allow to propagate df in bpf_skb_set_tunnel_key
Added by 9a628224a6 ("ip_tunnel: Add dont fragment flag."), allow to
feed df flag into tunneling facilities (currently supported on TX by
vxlan, geneve and gre) as a hint from eBPF's bpf_skb_set_tunnel_key()
helper.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 13:58:46 -05:00
Daniel Borkmann
8afd54c87a bpf: add flags to bpf_skb_store_bytes for clearing hash
When overwriting parts of the packet with bpf_skb_store_bytes() that
were fed previously into skb->hash calculation, we should clear the
current hash with skb_clear_hash(), so that a next skb_get_hash() call
can determine the correct hash related to this skb.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 13:55:15 -05:00
Daniel Borkmann
8050c0f027 bpf: allow bpf_csum_diff to feed bpf_l3_csum_replace as well
Commit 7d672345ed ("bpf: add generic bpf_csum_diff helper") added a
generic checksum diff helper that can feed bpf_l4_csum_replace() with
a target __wsum diff that is to be applied to the L4 checksum. This
facility is very flexible, can be cascaded, allows for adding, removing,
or diffing data, or for calculating the pseudo header checksum from
scratch, but it can also be reused for working with the IPv4 header
checksum.

Thus, analogous to bpf_l4_csum_replace(), add a case for header field
value of 0 to change the checksum at a given offset through a new helper
csum_replace_by_diff(). Also, in addition to that, this provides an
easy to use interface for feeding precalculated diffs f.e. coming from
a map. It nicely complements bpf_l3_csum_replace() that currently allows
only for csum updates of 2 and 4 byte diffs.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 13:55:15 -05:00
Stefan Agner
4774f40093 Input: ad7879 - move header to platform_data directory
The header file is used by the SPI and I2C variant of the driver.
Therefore, move it to a more generic place under platform_data.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2016-03-08 10:51:10 -08:00
Bjorn Helgaas
0c0e0736ac PCI: Set ROM shadow location in arch code, not in PCI core
IORESOURCE_ROM_SHADOW means there is a copy of a device's option ROM in
RAM.  The existence of such a copy and its location are arch-specific.
Previously the IORESOURCE_ROM_SHADOW flag was set in arch code, but the
0xC0000-0xDFFFF location was hard-coded into the PCI core.

If we're using a shadow copy in RAM, disable the ROM BAR and release the
address space it was consuming.  Move the location information from the PCI
core to the arch code that sets IORESOURCE_ROM_SHADOW.  Save the location
of the RAM copy in the struct resource for PCI_ROM_RESOURCE.

After this change, pci_map_rom() will call pci_assign_resource() and
pci_enable_rom() for these IORESOURCE_ROM_SHADOW resources, which we did
not do before.  This is safe because:

  - pci_assign_resource() will do nothing because the resource is marked
    IORESOURCE_PCI_FIXED, which means we can't move it, and

  - pci_enable_rom() will not turn on the ROM BAR's enable bit because the
    resource is marked IORESOURCE_ROM_SHADOW, which means it is in RAM
    rather than in PCI memory space.

Storing the location in the struct resource means "lspci" will show the
shadow location, not the value from the ROM BAR.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-03-08 12:14:31 -06:00
Linus Torvalds
7f02bf6b5f sound fixes for 4.5
It's always an ambivalent feeling to send a large pull request at the
 late stage like this, especially when most of patches came from me.
 In anyway, this is a collection of lots of small fixes that slipped
 from the previous pull request.
 
 All fixes are about ASoC, and the majority of changes are corrections
 of the wrong access types in ALSA ctl enum items.  They are mostly
 harmless on 32bit architectures, but actually buggy on 64bit.  So we
 addressed all these now in a shot.  The rest are various small ASoC
 driver fixes.
 
 Among them, only two changes have been done to ASoC core, and both of
 them are trivial.  The rest are all device-specific.  So overall, they
 should be safe to apply.
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Merge tag 'sound-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound fixes from Takashi Iwai:
 "It's always an ambivalent feeling to send a large pull request at the
  late stage like this, especially when most of patches came from me.
  Anyway, this is a collection of lots of small fixes that slipped from
  the previous pull request.

  All fixes are about ASoC, and the majority of changes are corrections
  of the wrong access types in ALSA ctl enum items.  They are mostly
  harmless on 32bit architectures, but actually buggy on 64bit.  So we
  addressed all these now in a shot.  The rest are various small ASoC
  driver fixes.

  Among them, only two changes have been done to ASoC core, and both of
  them are trivial.  The rest are all device-specific.  So overall, they
  should be safe to apply"

* tag 'sound-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (33 commits)
  ASoC: wm_adsp: Fix enum ctl accesses in a wrong type
  ASoC: wm9081: Fix enum ctl accesses in a wrong type
  ASoC: wm8996: Fix enum ctl accesses in a wrong type
  ASoC: wm8994: Fix enum ctl accesses in a wrong type
  ASoC: wm8985: Fix enum ctl accesses in a wrong type
  ASoC: wm8983: Fix enum ctl accesses in a wrong type
  ASoC: wm8958: Fix enum ctl accesses in a wrong type
  ASoC: wm8904: Fix enum ctl accesses in a wrong type
  ASoC: wm8753: Fix enum ctl accesses in a wrong type
  ASoC: wl1273: Fix enum ctl accesses in a wrong type
  ASoC: tlv320dac33: Fix enum ctl accesses in a wrong type
  ASoC: max98095: Fix enum ctl accesses in a wrong type
  ASoC: max98088: Fix enum ctl accesses in a wrong type
  ASoC: ab8500: Fix enum ctl accesses in a wrong type
  ASoC: da732x: Fix enum ctl accesses in a wrong type
  ASoC: cs42l51: Fix enum ctl accesses in a wrong type
  ASoC: intel: mfld: Fix enum ctl accesses in a wrong type
  ASoC: omap: rx51: Fix enum ctl accesses in a wrong type
  ASoC: omap: n810: Fix enum ctl accesses in a wrong type
  ASoC: pxa: tosa: Fix enum ctl accesses in a wrong type
  ...
2016-03-08 09:41:20 -08:00
David S. Miller
810813c47a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Several cases of overlapping changes, as well as one instance
(vxlan) of a bug fix in 'net' overlapping with code movement
in 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 12:34:12 -05:00
Tejun Heo
f6d635ad34 cgroup: implement cgroup_subsys->implicit_on_dfl
Some controllers, perf_event for now and possibly freezer in the
future, don't really make sense to control explicitly through
"cgroup.subtree_control".  For example, the primary role of perf_event
is identifying the cgroups of tasks; however, because the controller
also keeps a small amount of state per cgroup, it can't be replaced
with simple cgroup membership tests.

This patch implements cgroup_subsys->implicit_on_dfl flag.  When set,
the controller is implicitly enabled on all cgroups on the v2
hierarchy so that utility type controllers such as perf_event can be
enabled and function transparently.

An implicit controller doesn't show up in "cgroup.controllers" or
"cgroup.subtree_control", is exempt from no internal process rule and
can be stolen from the default hierarchy even if there are non-root
csses.

v2: Reimplemented on top of the recent updates to css handling and
    subsystem rebinding.  Rebinding implicit subsystems is now a
    simple matter of exempting it from the busy subsystem check.

Signed-off-by: Tejun Heo <tj@kernel.org>
2016-03-08 11:51:26 -05:00
Tejun Heo
e4857982f4 cgroup: use css_set->mg_dst_cgrp for the migration target cgroup
Migration can be multi-target on the default hierarchy when a
controller is enabled - processes belonging to each child cgroup have
to be moved to the child cgroup itself to refresh css association.

This isn't a problem for cgroup_migrate_add_src() as each source
css_set still maps to single source and target cgroups; however,
cgroup_migrate_prepare_dst() is called once after all source css_sets
are added and thus might not have a single destination cgroup.  This
is currently worked around by specifying NULL for @dst_cgrp and using
the source's default cgroup as destination as the only multi-target
migration in use is self-targetting.  While this works, it's subtle
and clunky.

As all taget cgroups are already specified while preparing the source
css_sets, this clunkiness can easily be removed by recording the
target cgroup in each source css_set.  This patch adds
css_set->mg_dst_cgrp which is recorded on cgroup_migrate_src() and
used by cgroup_migrate_prepare_dst().  This also makes migration code
ready for arbitrary multi-target migration.

Signed-off-by: Tejun Heo <tj@kernel.org>
2016-03-08 11:51:26 -05:00
Yang Shi
a664edb374 tracing, writeback: Replace cgroup path to cgroup ino
commit 5634cc2aa9 ("writeback: update writeback
tracepoints to report cgroup") made writeback tracepoints print out cgroup
path when CGROUP_WRITEBACK is enabled, but it may trigger the below bug on -rt
kernel since kernfs_path and kernfs_path_len are called by tracepoints, which
acquire spin lock that is sleepable on -rt kernel.

BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:930
in_atomic(): 1, irqs_disabled(): 0, pid: 625, name: kworker/u16:3
INFO: lockdep is turned off.
Preemption disabled at:[<ffffffc000374a5c>] wb_writeback+0xec/0x830

CPU: 7 PID: 625 Comm: kworker/u16:3 Not tainted 4.4.1-rt5 #20
Hardware name: Freescale Layerscape 2085a RDB Board (DT)
Workqueue: writeback wb_workfn (flush-7:0)
Call trace:
[<ffffffc00008d708>] dump_backtrace+0x0/0x200
[<ffffffc00008d92c>] show_stack+0x24/0x30
[<ffffffc0007b0f40>] dump_stack+0x88/0xa8
[<ffffffc000127d74>] ___might_sleep+0x2ec/0x300
[<ffffffc000d5d550>] rt_spin_lock+0x38/0xb8
[<ffffffc0003e0548>] kernfs_path_len+0x30/0x90
[<ffffffc00036b360>] trace_event_raw_event_writeback_work_class+0xe8/0x2e8
[<ffffffc000374f90>] wb_writeback+0x620/0x830
[<ffffffc000376224>] wb_workfn+0x61c/0x950
[<ffffffc000110adc>] process_one_work+0x3ac/0xb30
[<ffffffc0001112fc>] worker_thread+0x9c/0x7a8
[<ffffffc00011a9e8>] kthread+0x190/0x1b0
[<ffffffc000086ca0>] ret_from_fork+0x10/0x30

With unlocked kernfs_* functions, synchronize_sched() has to be called in
kernfs_rename which could be called in syscall path, but it is problematic.
So, print out cgroup ino instead of path name, which could be converted to
path name by userland.

Withouth CGROUP_WRITEBACK enabled, it just prints out root dir. But, root
dir ino vary from different filesystems, so printing out -1U to indicate
an invalid cgroup ino.

Link: http://lkml.kernel.org/r/1456996137-8354-1-git-send-email-yang.shi@linaro.org

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:37 -05:00
Tom Zanussi
c4a5923055 tracing: Add event record param to trigger_ops.func()
Some triggers may need access to the trace event, so pass it in.  Also
fix up the existing trigger funcs and their callers.

Link: http://lkml.kernel.org/r/543e31e9fc445ef61077421ab219033401c39846.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:31 -05:00
Steven Rostedt (Red Hat)
633f6f58af tracing: Remove duplicate checks for online CPUs
Some trace events have conditions that check if the current CPU is online or
not before recording the tracepoint. That's because certain trace events are
in locations that can be called as the CPU is going offline and when RCU no
longer monitors it (like kfree and friends). The check was added because
trace events require RCU to be active.

This is a trace event infrastructure issue and not something that individual
trace events should worry about. The tracepoint.h code now has added a check
to see if the current CPU is considered online, and it only does the
tracepoint if it is. There's no more need for individual trace events to
also include this check. It is now redundant.

Cc: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:28 -05:00
Lionel Landwerlin
5488dc16fd drm: introduce pipe color correction properties
Patch based on a previous series by Shashank Sharma.

This introduces optional properties to enable color correction at the
pipe level. It relies on 3 transformations applied to every pixels
displayed. First a lookup into a degamma table, then a multiplication
of the rgb components by a 3x3 matrix and finally another lookup into
a gamma table.

The following properties can be added to a pipe :
  - DEGAMMA_LUT : blob containing degamma LUT
  - DEGAMMA_LUT_SIZE : number of elements in DEGAMMA_LUT
  - CTM : transformation matrix applied after the degamma LUT
  - GAMMA_LUT : blob containing gamma LUT
  - GAMMA_LUT_SIZE : number of elements in GAMMA_LUT

DEGAMMA_LUT_SIZE and GAMMA_LUT_SIZE are read only properties, set by
the driver to tell userspace applications what sizes should be the
lookup tables in DEGAMMA_LUT and GAMMA_LUT.

A helper is also provided so legacy gamma correction is redirected
through these new properties.

v2: Register LUT size properties as range

v3: Fix round in drm_color_lut_get_value() helper
    More docs on how degamma/gamma properties are used

v4: Update contributors

v5: Rename CTM_MATRIX property to CTM (Doh!)
    Add legacy gamma_set atomic helper
    Describe CTM/LUT acronyms in the kernel doc

v6: Fix missing blob unref in drm_atomic_helper_crtc_reset

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Kumar, Kiran S <kiran.s.kumar@intel.com>
Signed-off-by: Kausal Malladi <kausalmalladi@gmail.com>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Rob Bradford <robert.bradford@intel.com>
[danvet: CrOS maintainers are also happy with the userspacde side:
https://codereview.chromium.org/1182063002/ ]
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1456506302-640-4-git-send-email-lionel.g.landwerlin@intel.com
2016-03-08 13:57:32 +01:00
Ingo Molnar
1f25184656 Merge branch 'timers/core-v9' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz
Pull nohz enhancements from Frederic Weisbecker:

"Currently in nohz full configs, the tick dependency is checked
 asynchronously by nohz code from interrupt and context switch for each
 concerned subsystem with a set of function provided by these. Such
 functions are made of many conditions and details that can be heavyweight
 as they are called on fastpath: sched_can_stop_tick(),
 posix_cpu_timer_can_stop_tick(), perf_event_can_stop_tick()...

 Thomas suggested a few months ago to make that tick dependency check
 synchronous. Instead of checking subsystems details from each interrupt
 to guess if the tick can be stopped, every subsystem that may have a tick
 dependency should set itself a flag specifying the state of that
 dependency. This way we can verify if we can stop the tick with a single
 lightweight mask check on fast path.

 This conversion from a pull to a push model to implement tick dependency
 is the core feature of this patchset that is split into:

  * Nohz wide kick simplification
  * Improve nohz tracing
  * Introduce tick dependency mask
  * Migrate scheduler, posix timers, perf events and sched clock tick
    dependencies to the tick dependency mask."

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08 13:17:54 +01:00
Ingo Molnar
fe36d8912c Merge branch 'linus' into irq/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08 12:26:07 +01:00