perf_counter: powerpc: use u64 for event codes internally

perf_counter: powerpc: use u64 for event codes internally

Although the perf_counter API allows 63-bit raw event codes,
internally in the powerpc back-end we had been using 32-bit
event codes.  This expands them to 64 bits so that we can add
bits for specifying threshold start/stop events and instruction
sampling modes later.

This also corrects the return value of can_go_on_limited_pmc;
we were returning an event code rather than just a 0/1 value in
some circumstances. That didn't particularly matter while event
codes were 32-bit, but now that event codes are 64-bit it
might, so this fixes it.

[ Impact: extend PowerPC perfcounter interfaces from u32 to u64 ]

Signed-off-by: Paul Mackerras <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Corey Ashford <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>