perf: Generalize some arch callchain code

- Most archs use one callchain buffer per cpu, except x86 that needs
  to deal with NMIs. Provide a default perf_callchain_buffer()
  implementation that x86 overrides.

- Centralize all the kernel/user regs handling and invoke new arch
  handlers from there: perf_callchain_user() / perf_callchain_kernel()
  That avoid all the user_mode(), current->mm checks and so...

- Invert some parameters in perf_callchain_*() helpers: entry to the
  left, regs to the right, following the traditional (dst, src).

Signed-off-by: Frederic Weisbecker <[email protected]>
Acked-by: Paul Mackerras <[email protected]>
Tested-by: Will Deacon <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: David Miller <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Borislav Petkov <[email protected]>

0 files changed, 0 insertions, 0 deletions