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| author | Thomas Gleixner <tglx@linutronix.de> | 2016-11-16 14:19:34 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-11-16 14:19:34 +0100 |
| commit | 7ce7f35b33eb42b6aa4cf176fa34372b21b8472b (patch) | |
| tree | 12f3027003f1d7cce30f838265e4fab2d52c6cef /arch/arc/kernel/time.c | |
| parent | x86/intel_rdt: Update percpu closid immeditately on CPUs affected by changee (diff) | |
| parent | x86/cpuid: Provide get_scattered_cpuid_leaf() (diff) | |
| download | linux-7ce7f35b33eb42b6aa4cf176fa34372b21b8472b.tar.xz linux-7ce7f35b33eb42b6aa4cf176fa34372b21b8472b.zip | |
Merge branch 'x86/cpufeature' into x86/cache
Resolve the cpu/scattered conflict.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/arc/kernel/time.c')
| -rw-r--r-- | arch/arc/kernel/time.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c index f927b8dc6edd..c10390d1ddb6 100644 --- a/arch/arc/kernel/time.c +++ b/arch/arc/kernel/time.c @@ -152,14 +152,17 @@ static cycle_t arc_read_rtc(struct clocksource *cs) cycle_t full; } stamp; - - __asm__ __volatile( - "1: \n" - " lr %0, [AUX_RTC_LOW] \n" - " lr %1, [AUX_RTC_HIGH] \n" - " lr %2, [AUX_RTC_CTRL] \n" - " bbit0.nt %2, 31, 1b \n" - : "=r" (stamp.low), "=r" (stamp.high), "=r" (status)); + /* + * hardware has an internal state machine which tracks readout of + * low/high and updates the CTRL.status if + * - interrupt/exception taken between the two reads + * - high increments after low has been read + */ + do { + stamp.low = read_aux_reg(AUX_RTC_LOW); + stamp.high = read_aux_reg(AUX_RTC_HIGH); + status = read_aux_reg(AUX_RTC_CTRL); + } while (!(status & _BITUL(31))); return stamp.full; } |