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:
	arch/arm/kernel/perf_event.c
	include/linux/perf_event.h
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>
lost debug inf