Drop the TASK_RUNNING test on user tasks for callchains as
this check doesn't seem to make any sense.

Also remove the tests for !current that is not supposed to
happen and current->pid as this should be handled at the
generic level, with exclude_idle attribute.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Tested-by: NWill Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Borislav Petkov <bp@amd64.org>

Hardware performance counters on ARM are 32-bits wide but atomic64_t
variables are used to represent counter data in the hw_perf_event structure.

The armpmu_event_update function right-shifts a signed 64-bit delta variable
and adds the result to the event count. This can lead to shifting in sign-bits
if the MSB of the 32-bit counter value is set. This results in perf output
such as:

 Performance counter stats for 'sleep 20':

 18446744073460670464  cycles             <-- 0xFFFFFFFFF12A6000
        7783773  instructions             #      0.000 IPC
            465  context-switches
            161  page-faults
        1172393  branches

   20.154242147  seconds time elapsed

This patch ensures that the delta value is treated as unsigned so that the
right shift sets the upper bits to zero.

Cc: <stable@kernel.org>
Acked-by: NJamie Iles <jamie.iles@picochip.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Since now all modification to event->count (and ->prev_count
and ->period_left) are local to a cpu, change then to local64_t so we
avoid the LOCK'ed ops.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For OProfile to initialise oprofilefs correctly, it needs to know
the number of counters it can represent.

This patch adds a function to the ARM perf-events backend to return
the number of hardware counters available for the current PMU.

Cc: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The perf-events framework for ARM only supports v6 and v7 cores.

This patch adds support for xscale v1 and v2 PMUs to perf, based on the
OProfile drivers in arch/arm/oprofile/op_model_xscale.c
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The ARM perf-events framework provides support for a number of different
PMUs using struct arm_pmu. The char *name field of this struct can be
used to identify the PMU, but this is cumbersome if used outside of perf.

This patch replaces the name string for a PMU with an enum, which holds
a unique ID for the PMU being represented. This ID can be used to index
an array of names within perf, so no functionality is lost. The presence
of the ID field, allows other kernel subsystems [currently oprofile] to
use their own mappings for the PMU name.

Cc: Jean Pihet <jpihet@mvista.com>
Acked-by: NJamie Iles <jamie.iles@picochip.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The current PMU infrastructure for ARM requires that the IRQs for the PMU
device are fixed at compile time and are selected based on the ARCH_ or MACH_ flags. This has the disadvantage of tying the Kernel down to a
particular board as far as profiling is concerned.

This patch replaces the compile-time IRQ registration with a runtime mechanism which allows the IRQs to be registered with the framework as
a platform_device.

A further advantage of this change is that there is scope for registering
different types of performance counters in the future by changing the id
of the platform_device and attaching different resources to it.
Acked-by: NJamie Iles <jamie.iles@picochip.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The event selection mask for ARMv7 cores [ARMV7_EVTSEL_MASK]
is incorrectly set to 0x7f. This means that the top bit of an
event ID is ignored, so counting branch misses (id=0x10) and
ISBs (id=0x90) give the same results.

This patch sets the event selection mask to the correct value
of 0xff.
Signed-off-by: NJean Pihet <jpihet@mvista.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

If IRQ balancing is used on a multicore ARM system, PMU interrupt
lines may be relocated onto CPUs other than the one causing the
counter overflow. This can result in misattribution of events to
the wrong core and, in the case that the CPU handling the interrupt
has not experience counter overflow, the interrupt can be disabled
because the handler returns IRQ_NONE.

This patch adds the IRQF_NOBALANCING flag to the request_irq call
in perf_events.c.
Acked-by: NJamie Iles <jamie.iles@picochip.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This makes it easier to extend perf_sample_data and fixes a bug on arm
and sparc, which failed to set ->raw to NULL, which can cause crashes
when combined with PERF_SAMPLE_RAW.

It also optimizes PowerPC and tracepoint, because the struct
initialization is forced to zero out the whole structure.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NJean Pihet <jpihet@mvista.com>
Reviewed-by: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Cc: Jamie Iles <jamie.iles@picochip.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: stable@kernel.org
LKML-Reference: <20100304140100.315416040@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Adds the Performance Events support for ARMv7 processor, using
the PMNC unit in HW.

Supports the following:
- Cortex-A8 and Cortex-A9 processors,
- dynamic detection of the number of available counters,
   based on the PMCR value,
- runtime detection of the CPU arch (v6 or v7)
   and model (Cortex-A8 or Cortex-A9)

Tested on OMAP3 (Cortex-A8) only.
Signed-off-by: NJean Pihet <jpihet@mvista.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch implements support for ARMv6 performance counters in the
Linux performance events subsystem. ARMv6 architectures that have the
performance counters should enable HW_PERF_EVENTS to get hardware
performance events support in addition to the software events.

Note: only ARM Ltd ARM cores are supported.

This implementation also provides an ARM PMU abstraction layer to allow
ARMv7 and others to be supported in the future by adding new a
'struct arm_pmu'.

Cc: Jean Pihet <jpihet@mvista.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NJamie Iles <jamie.iles@picochip.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>