perf tsc: Add rdtsc() for Arm64

The system register CNTVCT_EL0 can be used to retrieve the counter from
user space.  Add rdtsc() for Arm64.

Signed-off-by: Leo Yan <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Gustavo A. R. Silva <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kemeng Shi <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Nick Gasson <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Remi Bernon <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Steve Maclean <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Zou Wei <[email protected]>
Cc: [email protected]
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions