Perf: keep events across hotplug

Keep event list alive across a CPU hotplug so that perf
can resume when the CPU comes back online. Bring a CPU
online when exiting a perf session so it can be cleaned
up properly.

Change-Id: Ie0e4a43f751beb77afdc84e9d52b21780f279d80
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>

Conflicts:
	kernel/events/core.c
Perf: bring CPU online if needed when disabling irq

When disabling an irq, check that the CPU is online
before trying to run on that CPU. Bring the CPU
online if necessary.

This fixes a problem where a CPU that was not online
when disabling the irq caused the disable and the
free to fail. A subsequent attempt to request the irq
also failed because it had not been freed.

Change-Id: Ib873b5ded83ab843ea4e609f196a31ef0083a213
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
Perf: Support sw events across hotplug

When CPUs are hotplugged off and on, let the various
sw events continue after the hotplug.

Change-Id: Id1aaf30c459c9cf7c9c38967f9ccad56d4062fd3
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
msm: perf: initialise krait perf L2 counter enables

Clear the L2 counter enables at initialisation.
They are undefined out of reset.

Change-Id: I957106012625ae09efec47d4f657381963d87a5a
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
msm: perf: clean up duplicate constraint events

Events with a duplicate constraint are set to state=OFF when detected,
so that their duplicate counts are not read. However, they were not being
cleaned up because the core code only cleaned up ACTIVE events.
This resulted in counters not being freed and eventually running out
of resources.

Clean up the events with state==OFF that were marked that way because of
constraint duplication.
Ensure counts are not updated for OFF events.

Change-Id: If532801c79e6ad6809869eb0a3063774f00c92c3
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>

Conflicts:
	kernel/events/core.c
Perf: Make per-process counters cumulative

In order to get overall value for performance counters, remove reset during
context switches. Add mechanism to calculate deltas for output to the trace
buffer.

Change-Id: I03d894a1b3bd400d8c256c3068f917ed001fbfd9
Signed-off-by: Sheetal Sahasrabudhe <sheetals@codeaurora.org>
Perf: Fix PID for tracepoints

Make previous value of PID a per_cpu variable.
This is required to get the correct value for previous_pid.

Change-Id: I63baf8164ae9226189c745339b122d806901789d
Signed-off-by: Sheetal Sahasrabudhe <sheetals@codeaurora.org>
Perf: preserve registers across hotplug

Preserve the registers with userspace bits in them
across hotplug and power collapse. This allows
userspace applications to use the performance counters.

Change-Id: I391563ab770df9aabb5d717b6bc4725750ad0283
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
msm: perf: fix formatting of trace entry

Remove extraneous comma which breaks processing of
the trace data.

Change-Id: I5fda44cde6a39b16be06c72bc968afc19636b32f
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
msm: perf: Fix cpu id logic in tracectr notifier

The code in tracecounter context switch notifier was using
smp_processor_id() in order to get cpu number. This was resulting
into following dmesg error: "BUG: using smp_processor_id() in
preemptible [00000000] code".
Use thread_info struct to get the cpu #.

Change-Id: Ic7c995d2c2bc25c4389248854dec91fb84ce3128
Signed-off-by: Sheetal Sahasrabudhe <sheetals@codeaurora.org>
msm: perf: tracectr: Initialize cnts after hotplug

Due to the mismatch between counter values saved across CPU hotplug
by perf and tracecounter logic, incorrect values are calculated for
first entry in trace buffer.
Ignore the first entry when CPU comes out of hotplug and set previous
counter values in this scenario.

Change-Id: Ieeeaa301d713f338f11f6e84aeb984a3708e45fc
Signed-off-by: Sheetal Sahasrabudhe <sheetals@codeaurora.org>
Perf: Reset pmu after hotplug

The counter enable bits were staying in undefined state after CPU
came out of hotplug when perf was not enabled.
This was resulting into non-zero values for counters in ftrace buffer
which were not enabled by perf.
Clear the pmu when CPU comes out of hotplug and perf is not enabled.

Change-Id: I31e17565ad914650a12102a5c359b363f8f2ca2a
Signed-off-by: Sheetal Sahasrabudhe <sheetals@codeaurora.org>
msm: perf: set filter bits for cycle counter on krait

When programming the cycle counter on krait, the filter
register needs to be programmed in order to set the
usermode/kernelmode filter options.

Change-Id: Ifd5b032c9a5df4821706438d4359f84d8f614468
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>