Kevin Brodsky 49eea433b3 arm64: Add support for CLOCK_MONOTONIC_RAW in clock_gettime() vDSO ... So far the arm64 clock_gettime() vDSO implementation only supported the following clocks, falling back to the syscall for the others: - CLOCK_REALTIME{,_COARSE} - CLOCK_MONOTONIC{,_COARSE} This patch adds support for the CLOCK_MONOTONIC_RAW clock, taking advantage of the recent refactoring of the vDSO time functions. Like the non-_COARSE clocks, this only works when the "arch_sys_counter" clocksource is in use (allowing us to read the current time from the virtual counter register), otherwise we also have to fall back to the syscall. Most of the data is shared with CLOCK_MONOTONIC, and the algorithm is similar. The reference implementation in kernel/time/timekeeping.c shows that: - CLOCK_MONOTONIC = tk->wall_to_monotonic + tk->xtime_sec + timekeeping_get_ns(&tk->tkr_mono) - CLOCK_MONOTONIC_RAW = tk->raw_time + timekeeping_get_ns(&tk->tkr_raw) - tkr_mono and tkr_raw are identical (in particular, same clocksource), except these members: * mult (only mono's multiplier is NTP-adjusted) * xtime_nsec (always 0 for raw) Therefore, tk->raw_time and tkr_raw->mult are now also stored in the vDSO data page. Cc: Ali Saidi <ali.saidi@arm.com> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Reviewed-by: Dave Martin <dave.martin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>		2016-07-12 16:06:32 +01:00
..
asm	arm64: Add support for CLOCK_MONOTONIC_RAW in clock_gettime() vDSO	2016-07-12 16:06:32 +01:00
uapi/asm	asm-generic: Drop renameat syscall from default list	2016-05-05 00:42:21 +02:00