Always allow backtraces when using oprofile on ARM, even if a PMU
isn't present. Restores functionality originally introduced in commit
1b7b5698 ("oprofile: Always allow
backtraces on ARM") by Richard Purdie.

It is not that obvious, but there is now only one oprofile_arch_init()
function. So the .backtrace callback is available also in timer mode.

Implemented by removing code and using stubs for oprofile_perf_{init,
exit} provided by <linux/oprofile.h>. This allows cleaning of other
architecture specific implementations too.

Cc: stable@kernel.org # 37.x
Signed-off-by: NAri Kauppi <kauppi@papupata.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Move the perf-events backend from arch/arm/oprofile into
drivers/oprofile so that the code can be shared between architectures.

This allows each architecture to maintain only a single copy of the PMU
accessor functions instead of one for both perf and OProfile. It also
becomes possible for other architectures to delete much of their
OProfile code in favour of the common code now available in
drivers/oprofile/oprofile_perf.c.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Tested-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

In preparation for moving the majority of this oprofile code into an
architecture-neutral place separate the architecture-independent code
into oprofile_perf_init() and oprofile_perf_exit().
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Tested-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

In preparation for moving the generic functions out of this file, give
the functions more general names (e.g. remove "arm" from the names).
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Tested-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Make op_name_from_perf_id() global so that we have a way for each
architecture to construct an oprofile name for op->cpu_type. We need to
remove the argument from the function prototype so that we can hide all
implementation details inside the function.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The number of counters for the registered pmu is needed in a few places
so provide a helper function that returns this number.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Tested-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch removes some unnecessary goto statements.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch simplifies op_create_counter(). Removing if/else if paths
and return code variable by direct returning from function.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

There is duplicate cleanup code in the init and exit functions. Now,
oprofile_arch_exit() is also used if oprofile_arch_init() fails.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch fixes a resource leak on failure, where the
oprofilefs and some counters may not released properly.
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: <stable@kernel.org> # .35.x
LKML-Reference: <20100929145225.GJ13563@erda.amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The kernel perf event creation path shouldn't use find_task_by_vpid()
because a vpid exists in a specific namespace. find_task_by_vpid() uses
current's pid namespace which isn't always the correct namespace to use
for the vpid in all the places perf_event_create_kernel_counter() (and
thus find_get_context()) is called.

The goal is to clean up pid namespace handling and prevent bugs like:

	https://bugzilla.kernel.org/show_bug.cgi?id=17281

Instead of using pids switch find_get_context() to use task struct
pointers directly. The syscall is responsible for resolving the pid to
a task struct. This moves the pid namespace resolution into the syscall
much like every other syscall that takes pid parameters.
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robin Green <greenrd@greenrd.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
LKML-Reference: <a134e5e392ab0204961fd1a62c84a222bf5874a9.1284407763.git.matthltc@us.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The pointers must be NULL'ed to avoid double-freeing the pointers in
rare cases during reinitialization.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Now that oprofile_arch_exit is only called when the OProfile module
is unloaded, it can assume that init completed successfully and not
have to worry about double frees or releasing NULL perf events.

This patch ensures that oprofile_arch_init fails gracefully on ARM
and simplifies the exit code based on the above.

Cc: Robert Richter <robert.richter@amd.com>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This is a reworking of an original patch posted by Aaro Koskinen:

oprofile does not work with PM, because sysdev_suspend() is done with
interrupts disabled and oprofile needs a mutex. Implementing oprofile
as a platform device solves this problem.

Cc: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NAaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There are currently two hardware performance monitoring subsystems in
the kernel for ARM: OProfile and perf-events. This creates the
following problems:

1.) Duplicate PMU accessor code. Inevitable code drift may lead to
bugs in one framework that are fixed in the other.

2.) Locking issues. OProfile doesn't reprogram hardware counters
between profiling runs if the events to be monitored have not been
changed. This means that other profiling frameworks cannot use the
counters if OProfile is in use.

3.) Due to differences in the two frameworks, it may not be possible to
compare the results obtained by OProfile with those obtained by perf.

This patch removes the OProfile PMU driver code and replaces it with
calls to perf, therefore solving the issues mentioned above.

The only userspace-visible change is the lack of SCU counter support
for 11MPCore. This is currently unsupported by OProfile userspace tools anyway and therefore shouldn't cause any problems.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Jamie Iles <jamie.iles@picochip.com>
Cc: Jean Pihet <jpihet@mvista.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add Oprofile kernel support for ARMv7.
Tested on OMAP3430 and OMAP3530 chipsets (Cortex-A8).
Signed-off-by: NJean Pihet <jpihet@mvista.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

All kobjects require a dynamically allocated name now. We no longer
need to keep track if the name is statically assigned, we can just
unconditionally free() all kobject names on cleanup.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Always allow backtrace when using oprofile on ARM, even if a PMU
isn't present.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add the glue for ARM11 SMP oprofile support, which also supports the
performance monitor in the coherency unit.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add oprofile glue for ARM11 (ARMv6) oprofile support.  This
connects the ARM11 core profiling support to the oprofile code
for uniprocessor configurations.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We need this to be zero initialised.  Since this is an array, use kcalloc
rather than kzalloc or kmalloc.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

op_arm_sem is being used as a mutex, so convert it to use
real mutexes.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Russ Dill

The oprofile init code was broken in commit c6b9da. The new logic will
always return -ENODEV. This fixes oprofile_arch_init to return 0 on
success, and return the return value of spec->init() if applicable.
Signed-off-by: NRuss Dill <Russ.Dill@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There is nothing special about having the init code separate from
the common code, so combine the two.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The common oprofile code assumes the name "PMU" (from Intel's
performance management unit).  This is misleading when we
start adding oprofile support for other machine types which
don't use the same terminology.  Call it op_arm_* instead of
pmu_*.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The oprofile suspend/resume was missing locking.  If we failed
to start oprofile on resume, we still reported that it was
enabled.  Instead, disable oprofile on error.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!