mirror of https://gitee.com/openkylin/linux.git
ARM: OMAP: 32k counter: Provide y2038-safe omap_read_persistent_clock() replacement
As part of addressing "y2038 problem" for in-kernel uses, this patch adds the y2038-safe omap_read_persistent_clock64() using timespec64. Because we rely on some subsequent changes to convert arm multiarch support, omap_read_persistent_clock() will be removed then. Also remove the needless spinlock, because read_persistent_clock() doesn't run simultaneously. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Tony Lindgren <tony@atomide.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-5-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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@ -44,24 +44,20 @@ static u64 notrace omap_32k_read_sched_clock(void)
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/**
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/**
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* omap_read_persistent_clock - Return time from a persistent clock.
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* omap_read_persistent_clock64 - Return time from a persistent clock.
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*
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*
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* Reads the time from a source which isn't disabled during PM, the
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* Reads the time from a source which isn't disabled during PM, the
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* 32k sync timer. Convert the cycles elapsed since last read into
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* 32k sync timer. Convert the cycles elapsed since last read into
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* nsecs and adds to a monotonically increasing timespec.
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* nsecs and adds to a monotonically increasing timespec64.
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*/
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*/
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static struct timespec persistent_ts;
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static struct timespec64 persistent_ts;
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static cycles_t cycles;
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static cycles_t cycles;
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static unsigned int persistent_mult, persistent_shift;
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static unsigned int persistent_mult, persistent_shift;
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static DEFINE_SPINLOCK(read_persistent_clock_lock);
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static void omap_read_persistent_clock(struct timespec *ts)
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static void omap_read_persistent_clock64(struct timespec64 *ts)
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{
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{
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unsigned long long nsecs;
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unsigned long long nsecs;
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cycles_t last_cycles;
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cycles_t last_cycles;
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unsigned long flags;
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spin_lock_irqsave(&read_persistent_clock_lock, flags);
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last_cycles = cycles;
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last_cycles = cycles;
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cycles = sync32k_cnt_reg ? readl_relaxed(sync32k_cnt_reg) : 0;
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cycles = sync32k_cnt_reg ? readl_relaxed(sync32k_cnt_reg) : 0;
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@ -69,11 +65,17 @@ static void omap_read_persistent_clock(struct timespec *ts)
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nsecs = clocksource_cyc2ns(cycles - last_cycles,
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nsecs = clocksource_cyc2ns(cycles - last_cycles,
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persistent_mult, persistent_shift);
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persistent_mult, persistent_shift);
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timespec_add_ns(&persistent_ts, nsecs);
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timespec64_add_ns(&persistent_ts, nsecs);
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*ts = persistent_ts;
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*ts = persistent_ts;
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}
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spin_unlock_irqrestore(&read_persistent_clock_lock, flags);
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static void omap_read_persistent_clock(struct timespec *ts)
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{
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struct timespec64 ts64;
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omap_read_persistent_clock64(&ts64);
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*ts = timespec64_to_timespec(ts64);
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}
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}
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/**
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/**
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