powerpc/perf: e500 support
This implements perf_event support for the Freescale embedded performance monitor, based on the existing perf_event.c that supports server/classic chips. Some limitations: - Performance monitor interrupts are regular EE interrupts, and thus you can't profile places with interrupts disabled. We may want to implement soft IRQ-disabling, with perfmon interrupts exempted and treated as NMIs. - When trying to schedule multiple event groups at once, and using restricted events, situations could arise where scheduling fails even though it would be possible. Consider three groups, each with two events. One group has restricted events, the others don't. The two non-restricted groups are scheduled, then one is removed, which happens to occupy the two counters that can't do restricted events. The remaining non-restricted group will not be moved to the non-restricted-capable counters to make room if the restricted group tries to be scheduled. Signed-off-by: Scott Wood <scottwood@freescale.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
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