Commit Graph

29 Commits

Author SHA1 Message Date
Linus Torvalds 597f03f9d1 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull CPU hotplug updates from Thomas Gleixner:
 "Yet another batch of cpu hotplug core updates and conversions:

   - Provide core infrastructure for multi instance drivers so the
     drivers do not have to keep custom lists.

   - Convert custom lists to the new infrastructure. The block-mq custom
     list conversion comes through the block tree and makes the diffstat
     tip over to more lines removed than added.

   - Handle unbalanced hotplug enable/disable calls more gracefully.

   - Remove the obsolete CPU_STARTING/DYING notifier support.

   - Convert another batch of notifier users.

   The relayfs changes which conflicted with the conversion have been
   shipped to me by Andrew.

   The remaining lot is targeted for 4.10 so that we finally can remove
   the rest of the notifiers"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  cpufreq: Fix up conversion to hotplug state machine
  blk/mq: Reserve hotplug states for block multiqueue
  x86/apic/uv: Convert to hotplug state machine
  s390/mm/pfault: Convert to hotplug state machine
  mips/loongson/smp: Convert to hotplug state machine
  mips/octeon/smp: Convert to hotplug state machine
  fault-injection/cpu: Convert to hotplug state machine
  padata: Convert to hotplug state machine
  cpufreq: Convert to hotplug state machine
  ACPI/processor: Convert to hotplug state machine
  virtio scsi: Convert to hotplug state machine
  oprofile/timer: Convert to hotplug state machine
  block/softirq: Convert to hotplug state machine
  lib/irq_poll: Convert to hotplug state machine
  x86/microcode: Convert to hotplug state machine
  sh/SH-X3 SMP: Convert to hotplug state machine
  ia64/mca: Convert to hotplug state machine
  ARM/OMAP/wakeupgen: Convert to hotplug state machine
  ARM/shmobile: Convert to hotplug state machine
  arm64/FP/SIMD: Convert to hotplug state machine
  ...
2016-10-03 19:43:08 -07:00
Linus Torvalds 7af8a0f808 arm64 updates for 4.9:
- Support for execute-only page permissions
 - Support for hibernate and DEBUG_PAGEALLOC
 - Support for heterogeneous systems with mismatches cache line sizes
 - Errata workarounds (A53 843419 update and QorIQ A-008585 timer bug)
 - arm64 PMU perf updates, including cpumasks for heterogeneous systems
 - Set UTS_MACHINE for building rpm packages
 - Yet another head.S tidy-up
 - Some cleanups and refactoring, particularly in the NUMA code
 - Lots of random, non-critical fixes across the board
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABCgAGBQJX7k31AAoJELescNyEwWM0XX0H/iOaWCfKlWOhvBsStGUCsLrK
 XryTzQT2KjdnLKf3jwP+1ateCuBR5ROurYxoDCX5/7mD63c5KiI338Vbv61a1lE1
 AAwjt1stmQVUg/j+kqnuQwB/0DYg+2C8se3D3q5Iyn7zc19cDZJEGcBHNrvLMufc
 XgHrgHgl/rzBDDlHJXleknDFge/MfhU5/Q1vJMRRb4JYrpAtmIokzCO75CYMRcCT
 ND2QbmppKtsyuFPGUTVbAFzJlP6dGKb3eruYta7/ct5d0pJQxav3u98D2yWGfjdM
 YaYq1EmX5Pol7rWumqLtk0+mA9yCFcKLLc+PrJu20Vx0UkvOq8G8Xt70sHNvZU8=
 =gdPM
 -----END PGP SIGNATURE-----

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "It's a bit all over the place this time with no "killer feature" to
  speak of.  Support for mismatched cache line sizes should help people
  seeing whacky JIT failures on some SoCs, and the big.LITTLE perf
  updates have been a long time coming, but a lot of the changes here
  are cleanups.

  We stray outside arch/arm64 in a few areas: the arch/arm/ arch_timer
  workaround is acked by Russell, the DT/OF bits are acked by Rob, the
  arch_timer clocksource changes acked by Marc, CPU hotplug by tglx and
  jump_label by Peter (all CC'd).

  Summary:

   - Support for execute-only page permissions
   - Support for hibernate and DEBUG_PAGEALLOC
   - Support for heterogeneous systems with mismatches cache line sizes
   - Errata workarounds (A53 843419 update and QorIQ A-008585 timer bug)
   - arm64 PMU perf updates, including cpumasks for heterogeneous systems
   - Set UTS_MACHINE for building rpm packages
   - Yet another head.S tidy-up
   - Some cleanups and refactoring, particularly in the NUMA code
   - Lots of random, non-critical fixes across the board"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (100 commits)
  arm64: tlbflush.h: add __tlbi() macro
  arm64: Kconfig: remove SMP dependence for NUMA
  arm64: Kconfig: select OF/ACPI_NUMA under NUMA config
  arm64: fix dump_backtrace/unwind_frame with NULL tsk
  arm/arm64: arch_timer: Use archdata to indicate vdso suitability
  arm64: arch_timer: Work around QorIQ Erratum A-008585
  arm64: arch_timer: Add device tree binding for A-008585 erratum
  arm64: Correctly bounds check virt_addr_valid
  arm64: migrate exception table users off module.h and onto extable.h
  arm64: pmu: Hoist pmu platform device name
  arm64: pmu: Probe default hw/cache counters
  arm64: pmu: add fallback probe table
  MAINTAINERS: Update ARM PMU PROFILING AND DEBUGGING entry
  arm64: Improve kprobes test for atomic sequence
  arm64/kvm: use alternative auto-nop
  arm64: use alternative auto-nop
  arm64: alternative: add auto-nop infrastructure
  arm64: lse: convert lse alternatives NOP padding to use __nops
  arm64: barriers: introduce nops and __nops macros for NOP sequences
  arm64: sysreg: replace open-coded mrs_s/msr_s with {read,write}_sysreg_s
  ...
2016-10-03 08:58:35 -07:00
Mark Salter dbee3a74ef arm64: pmu: add fallback probe table
In preparation for ACPI support, add a pmu_probe_info table to
the arm_pmu_device_probe() call. This table gets used when
probing in the absence of a devicetree node for PMU.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-16 17:11:33 +01:00
Mark Rutland 48538b5863 drivers/perf: arm_pmu: expose a cpumask in sysfs
In systems with heterogeneous CPUs, there are multiple logical CPU PMUs,
each of which covers a subset of CPUs in the system. In some cases
userspace needs to know which CPUs a given logical PMU covers, so we'd
like to expose a cpumask under sysfs, similar to what is done for uncore
PMUs.

Unfortunately, prior to commit 00e727bb38 ("perf stat: Balance
opening and reading events"), perf stat only correctly handled a cpumask
holding a single CPU, and only when profiling in system-wide mode. In
other cases, the presence of a cpumask file could cause perf stat to
behave erratically.

Thus, exposing a cpumask file would break older perf binaries in cases
where they would otherwise work.

To avoid this issue while still providing userspace with the information
it needs, this patch exposes a differently-named file (cpus) under
sysfs. New tools can look for this and operate correctly, while older
tools will not be adversely affected by its presence.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09 14:51:51 +01:00
Mark Rutland 1589680da6 drivers/perf: arm_pmu: only use common attr_groups
Now that the 32-bit and 64-bit perf backends use the common groups
directly, remove the fallback and no longer allow the groups array to be
overridden.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09 14:51:51 +01:00
Mark Rutland 86cdd72af9 drivers/perf: arm_pmu: add common attr group fields
In preparation for adding common attribute groups, add an array of
attribute group pointers to arm_pmu, which will be used if the
backend hasn't already set pmu::attr_groups.

Subsequent patches will move backends over to using these, before adding
common fields.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09 14:51:51 +01:00
Marc Zyngier 282b879635 drivers/perf: arm_pmu: Always consider IRQ0 as an error
As declared by the chief penguin, and enforced by the NO_IRQ brigade,
IRQ0 doesn't exist, and is considered as an error (no irq).

Unfortunately, the arm_pmu driver still considers it as valid in
a large number of cases. Let's fix this.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-06 18:26:33 +01:00
Sebastian Andrzej Siewior 6e103c0cfe arm/perf: Use multi instance instead of custom list
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160817171420.sdwk2qivxunzryz4@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-02 20:05:06 +02:00
Stefan Wahren 63fb0a9516 drivers/perf: arm_pmu: Fix NULL pointer dereference during probe
Patch 7f1d642fbb ("drivers/perf: arm-pmu: Fix handling of SPI lacking
interrupt-affinity property") unintended also fixes perf_event support
for bcm2835 which doesn't have PMU interrupts. Unfortunately this change
introduce a NULL pointer dereference on bcm2835, because irq_is_percpu
always expected to be called with a valid IRQ. So fix this regression
by validating the IRQ before.

Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Fixes: 7f1d642fbb ("drivers/perf: arm-pmu: Fix handling of SPI lacking "interrupt-affinity" property")
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-09-02 17:17:52 +01:00
Stefan Wahren 753246840d drivers/perf: arm_pmu: Fix leak in error path
In case of a IRQ type mismatch in of_pmu_irq_cfg() the
device node for interrupt affinity isn't freed. So fix this
issue by calling of_node_put().

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Fixes: fa8ad7889d ("arm: perf: factor arm_pmu core out to drivers")
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-09-02 17:17:52 +01:00
Marc Zyngier 7f1d642fbb drivers/perf: arm-pmu: Fix handling of SPI lacking "interrupt-affinity" property
Patch 19a469a587 ("drivers/perf: arm-pmu: Handle per-interrupt
affinity mask") added support for partitionned PPI setups, but
inadvertently broke setups using SPIs without the "interrupt-affinity"
property (which is the case for UP platforms).

This patch restore the broken functionnality by testing whether the
interrupt is percpu or not instead of relying on the using_spi flag
that really means "SPI *and* interrupt-affinity property".

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 19a469a587 ("drivers/perf: arm-pmu: Handle per-interrupt affinity mask")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-09 17:57:39 +01:00
Sudeep Holla a026bb12cc drivers/perf: arm-pmu: convert arm_pmu_mutex to spinlock
arm_pmu_mutex is never held long and we don't want to sleep while the
lock is being held as it's executed in the context of hotplug notifiers.
So it can be converted to a simple spinlock instead.

Without this patch we get the following warning:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/2
no locks held by swapper/2/0.
irq event stamp: 381314
hardirqs last  enabled at (381313): _raw_spin_unlock_irqrestore+0x7c/0x88
hardirqs last disabled at (381314): cpu_die+0x28/0x48
softirqs last  enabled at (381294): _local_bh_enable+0x28/0x50
softirqs last disabled at (381293): irq_enter+0x58/0x78
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.7.0 #12
Call trace:
 dump_backtrace+0x0/0x220
 show_stack+0x24/0x30
 dump_stack+0xb4/0xf0
 ___might_sleep+0x1d8/0x1f0
 __might_sleep+0x5c/0x98
 mutex_lock_nested+0x54/0x400
 arm_perf_starting_cpu+0x34/0xb0
 cpuhp_invoke_callback+0x88/0x3d8
 notify_cpu_starting+0x78/0x98
 secondary_start_kernel+0x108/0x1a8

This patch converts the mutex to spinlock to eliminate the above
warnings. This constraints pmu->reset to be non-blocking call which is
the case with all the ARM PMU backends.

Cc: Stephen Boyd <sboyd@codeaurora.org>
Fixes: 37b502f121 ("arm/perf: Fix hotplug state machine conversion")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-09 17:33:38 +01:00
Linus Torvalds a6408f6cb6 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp hotplug updates from Thomas Gleixner:
 "This is the next part of the hotplug rework.

   - Convert all notifiers with a priority assigned

   - Convert all CPU_STARTING/DYING notifiers

     The final removal of the STARTING/DYING infrastructure will happen
     when the merge window closes.

  Another 700 hundred line of unpenetrable maze gone :)"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  timers/core: Correct callback order during CPU hot plug
  leds/trigger/cpu: Move from CPU_STARTING to ONLINE level
  powerpc/numa: Convert to hotplug state machine
  arm/perf: Fix hotplug state machine conversion
  irqchip/armada: Avoid unused function warnings
  ARC/time: Convert to hotplug state machine
  clocksource/atlas7: Convert to hotplug state machine
  clocksource/armada-370-xp: Convert to hotplug state machine
  clocksource/exynos_mct: Convert to hotplug state machine
  clocksource/arm_global_timer: Convert to hotplug state machine
  rcu: Convert rcutree to hotplug state machine
  KVM/arm/arm64/vgic-new: Convert to hotplug state machine
  smp/cfd: Convert core to hotplug state machine
  x86/x2apic: Convert to CPU hotplug state machine
  profile: Convert to hotplug state machine
  timers/core: Convert to hotplug state machine
  hrtimer: Convert to hotplug state machine
  x86/tboot: Convert to hotplug state machine
  arm64/armv8 deprecated: Convert to hotplug state machine
  hwtracing/coresight-etm4x: Convert to hotplug state machine
  ...
2016-07-29 13:55:30 -07:00
Sebastian Andrzej Siewior 37b502f121 arm/perf: Fix hotplug state machine conversion
Mark Rutland pointed out that this commit is incomplete:

  7d88eb695a ("arm/perf: Convert to hotplug state machine")

The problem is that:

 > We may have multiple PMUs (e.g. two in big.LITTLE systems), and
 > __oprofile_cpu_pmu only contains one of these. So this conversion is not
 > correct.
 >
 > We were relying on the notifier list implicitly containing a list of
 > those PMUs. It seems like we need an explicit list here.
 >
 > We keep __oprofile_cpu_pmu around for legacy 32-bit users of OProfile
 > (on non-hetereogeneous systems), and that's all that the variable should
 > be used for.

Introduce arm_pmu_list to correctly handle multiple PMUs in the system.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-tip-commits@vger.kernel.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160719111733.GA22911@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-20 09:57:34 +02:00
Thomas Gleixner 7d88eb695a arm/perf: Convert to hotplug state machine
Straight forward conversion w/o bells and whistles.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153335.794097159@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-15 10:40:23 +02:00
Marc Zyngier 19a469a587 drivers/perf: arm-pmu: Handle per-interrupt affinity mask
On a big-little system, PMUs can be wired to CPUs using per CPU
interrups (PPI). In this case, it is important to make sure that
the enable/disable do happen on the right set of CPUs.

So instead of relying on the interrupt-affinity property, we can
use the actual percpu affinity that DT exposes as part of the
interrupt specifier. The DT binding is also updated to reflect
the fact that the interrupt-affinity property shouldn't be used
in that case.

Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-08 17:39:55 +01:00
Mark Salter f7a6c1492a arm: pmu: Fix non-devicetree probing
There is a problem in the non-devicetree PMU probing where some
probe functions may get the number of supported events through
smp_call_function_any() using the arm_pmu supported_cpus mask.
But at the time the probe function is called, the supported_cpus
mask is empty so the call fails. This patch makes sure the mask
is set before calling the init function rather than after.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-06-15 09:51:35 +01:00
Julien Grall 5988a363ed drivers/perf: arm_pmu: Avoid leaking pmu->irq_affinity on error
pmu->irq_affinity will not be freed if an error occurred within
arm_pmu_device_probe after of_pmu_irq_cfg has been called.

Note that in the case of_pmu_irq_cfg is returning an error,
pmu->irq_affinity will not be set, but it should be NULL as pmu was
kzalloc'd. Therefore the result kfree(NULL) is benign.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-06-03 10:16:21 +01:00
Julien Grall 0f254c7671 drivers/perf: arm_pmu: Defer the setting of __oprofile_cpu_pmu
The global variable __oprofile_cpu_pmu is set before the PMU is fully
initialized. If an error occurs before the end of the initialization,
the PMU will be freed and the variable will contain an invalid pointer.

This will result in a kernel crash when perf will be used.

Fix it by moving the setting of __oprofile_cpu_pmu when the PMU is fully
initialized (i.e when it is no longer possible to fail).

Cc: <stable@vger.kernel.org>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-06-03 10:16:21 +01:00
Julien Grall 121323ae66 drivers/perf: arm_pmu: Fix reference count of a device_node in of_pmu_irq_cfg
The only function called by of_pmu_irq_cfg that will increment the
reference count on dn is of_parse_phandle.

Each time we successfully parse a possible CPU from an
interrupt-affinity property, we increment the refcount of that CPU node
once via of_parse_handle. After validating the CPU is possible, we
decrement the refcount once. Subsequently, we decrement the refcount
again, either as part of an early break if we don't have a matching SPI,
or as part of the end of the loop body.

This will lead to decrementing twice the refcounnt.
Remove the second pairs of call to of_node_put as nobody is using dn
between the first and second call to of_node_put.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-06-03 10:16:20 +01:00
Mark Rutland 5101ef20f0 perf/arm: Special-case hetereogeneous CPUs
Commit:

  2665784850 ("perf/core: Verify we have a single perf_hw_context PMU")

forcefully prevents multiple PMUs from sharing perf_hw_context, as this
generally doesn't make sense. It is a common bug for uncore PMUs to
use perf_hw_context rather than perf_invalid_context, which this detects.

However, systems exist with heterogeneous CPUs (and hence heterogeneous
HW PMUs), for which sharing perf_hw_context is necessary, and possible
in some limited cases.

To make this work we have to perform some gymnastics, as we did in these
commits:

  66eb579e66 ("perf: allow for PMU-specific event filtering")
  c904e32a69 ("arm: perf: filter unschedulable events")

To allow those systems to work, we must allow PMUs for heterogeneous
CPUs to share perf_hw_context, though we must still disallow sharing
otherwise to detect the common misuse of perf_hw_context.

This patch adds a new PERF_PMU_CAP_HETEROGENEOUS_CPUS for this, updates
the core logic to account for this, and makes use of it in the arm_pmu
code that is used for systems with heterogeneous CPUs. Comments are
added to make the rationale clear and hopefully avoid accidental abuse.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20160426103346.GA20836@leverpostej
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-05 10:13:59 +02:00
Lorenzo Pieralisi cbcc72e037 drivers/perf: arm-pmu: fix RCU usage on pmu resume from low-power
Commit da4e4f18af ("drivers/perf: arm_pmu: implement CPU_PM notifier")
added code in the arm perf infrastructure that allows the kernel to
save/restore perf counters whenever the CPU enters a low-power
state. The kernel saves/restores the counters for each active event
through the armpmu_{stop/start} ARM pmu API, so that the low-power state
enter/exit cycle is emulated through pmu start/stop operations for each
event in use.

However, calling armpmu_start() for each active event on power up
executes code that requires RCU locking (perf_event_update_userpage())
to be functional, so, given that the core may call the CPU_PM notifiers
while running the idle thread in an quiescent RCU state this is not
allowed as detected through the following splat when kernel is run with
CONFIG_PROVE_LOCKING enabled:

[   49.293286]
[   49.294761] ===============================
[   49.298895] [ INFO: suspicious RCU usage. ]
[   49.303031] 4.6.0-rc3+ #421 Not tainted
[   49.306821] -------------------------------
[   49.310956] include/linux/rcupdate.h:872 rcu_read_lock() used
illegally while idle!
[   49.318530]
[   49.318530] other info that might help us debug this:
[   49.318530]
[   49.326451]
[   49.326451] RCU used illegally from idle CPU!
[   49.326451] rcu_scheduler_active = 1, debug_locks = 0
[   49.337209] RCU used illegally from extended quiescent state!
[   49.342892] 2 locks held by swapper/2/0:
[   49.346768]  #0:  (cpu_pm_notifier_lock){......}, at:
[<ffffff8008163c28>] cpu_pm_exit+0x18/0x80
[   49.355492]  #1:  (rcu_read_lock){......}, at: [<ffffff800816dc38>]
perf_event_update_userpage+0x0/0x260

This patch wraps the armpmu_start() call (that indirectly calls
perf_event_update_userpage()) on CPU_PM notifier power state exit (or
failed entry) within the RCU_NONIDLE() macro so that the RCU subsystem
is made aware the calling cpu is not idle from an RCU perspective for
the armpmu_start() call duration, therefore fixing the issue.

Fixes: da4e4f18af ("drivers/perf: arm_pmu: implement CPU_PM notifier")
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reported-by: James Morse <james.morse@arm.com>
Suggested-by: Kevin Hilman <khilman@baylibre.com>
Cc: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-04-21 15:03:06 +01:00
Will Deacon 357b565d5d drivers/perf: arm_pmu: avoid NULL dereference when not using devicetree
Commit c6b90653f1 ("drivers/perf: arm_pmu: make info messages more
verbose") breaks booting on systems where the PMU is probed without
devicetree (e.g by inspecting the MIDR of the current CPU). In this case,
pdev->dev.of_node is NULL and we shouldn't try to access its ->fullname
field when printing probe error messages.

This patch fixes the probing code to use of_node_full_name, which safely
handles NULL nodes and removes the "Error %i" part of the string, since
it's not terribly useful.

Reported-by: Guenter Roeck <private@roeck-us.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-03-21 11:36:17 +00:00
Lorenzo Pieralisi da4e4f18af drivers/perf: arm_pmu: implement CPU_PM notifier
When a CPU is suspended (either through suspend-to-RAM or CPUidle),
its PMU registers content can be lost, which means that counters
registers values that were initialized on power down entry have to be
reprogrammed on power-up to make sure the counters set-up is preserved
(ie on power-up registers take the reset values on Cold or Warm reset,
which can be architecturally UNKNOWN).

To guarantee seamless profiling conditions across a core power down
this patch adds a CPU PM notifier to ARM pmus, that upon CPU PM
entry/exit from low-power states saves/restores the pmu registers
set-up (by using the ARM perf API), so that the power-down/up cycle does
not affect the perf behaviour (apart from a black-out period between
power-up/down CPU PM notifications that is unavoidable).

Cc: Will Deacon <will.deacon@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-26 14:37:06 +00:00
Dirk Behme c6b90653f1 drivers/perf: arm_pmu: make info messages more verbose
On a big.LITTLE system e.g. with Cortex A57 and A53 in case not all cores
are online at PMU probe time we might get

hw perfevents: failed to probe PMU!
hw perfevents: failed to register PMU devices!

making it unclear which cores failed, here.

Add the device tree full name which failed and the error value resulting
in a more verbose and helpful message like

hw perfevents: /soc/pmu_a53: failed to probe PMU! Error -6
hw perfevents: /soc/pmu_a53: failed to register PMU devices! Error -6

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-09 11:18:39 +00:00
Martin Fuzzey 8d1a0ae724 ARM: perf: Set ARMv7 SDER SUNIDEN bit
ARMv7 counters other than the CPU cycle counter only work if the Secure
Debug Enable Register (SDER) SUNIDEN bit is set.

Since access to the SDER is only possible in secure state, it will
only be done if the device tree property "secure-reg-access" is set.

Without this:

 Performance counter stats for 'sleep 1':

          14606094 cycles                    #    0.000 GHz
                 0 instructions              #    0.00  insns per cycle

After applying:

 Performance counter stats for 'sleep 1':

           5843809 cycles
           2566484 instructions              #    0.44  insns per cycle

       1.020144000 seconds time elapsed

Some platforms (eg i.MX53) may also need additional platform specific
setup.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Pooya Keshavarzi <Pooya.Keshavarzi@de.bosch.com>
Signed-off-by: George G. Davis <george_davis@mentor.com>
[will: add warning if property is found on arm64]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-25 18:37:44 +00:00
Mark Rutland b916b785af drivers/perf: kill armpmu_register
Nothing outside of drivers/perf/arm_pmu.c should call armpmu_register
any more, so it no longer needs to be in include/linux/perf/arm_pmu.h.
Additionally, by folding it in to arm_pmu_device_probe we can allow
drivers to override struct pmu fields without getting blatted by the
armpmu code.

This patch folds armpmu_register into arm_pmu_device_probe. The logging
to the console is moved to after the PMU is successfully registered with
the core perf code.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Will Deacon <will.deacon@arm.com>
Cc: Drew Richardson <drew.richardson@arm.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-11-16 15:41:49 +00:00
Will Deacon fb659882cc drivers/perf: arm_pmu: avoid CPU device_node reference leak
of_cpu_device_node_get increments the reference count on the CPU
device_node, so we must take care to of_node_put once we've finished
with it.

This patch fixes the perf IRQ probing code to avoid the leak.

Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2015-10-15 17:11:23 +02:00
Mark Rutland fa8ad7889d arm: perf: factor arm_pmu core out to drivers
To enable sharing of the arm_pmu code with arm64, this patch factors it
out to drivers/perf/. A new drivers/perf directory is added for
performance monitor drivers to live under.

MAINTAINERS is updated accordingly. Files added previously without a
corresponsing MAINTAINERS update (perf_regs.c, perf_callchain.c, and
perf_event.h) are also added.

Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[will: augmented Kconfig help slightly]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-31 15:01:14 +01:00