From a451570c008b9e19592e29f15cfd295bdf818c7a Mon Sep 17 00:00:00 2001 From: Xunlei Pang Date: Wed, 1 Apr 2015 20:34:24 -0700 Subject: [PATCH] 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 Signed-off-by: John Stultz Acked-by: Tony Lindgren Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1427945681-29972-5-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar --- arch/arm/plat-omap/counter_32k.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c index 43cf74561cfd..b7b7b0793228 100644 --- a/arch/arm/plat-omap/counter_32k.c +++ b/arch/arm/plat-omap/counter_32k.c @@ -44,24 +44,20 @@ static u64 notrace omap_32k_read_sched_clock(void) } /** - * omap_read_persistent_clock - Return time from a persistent clock. + * omap_read_persistent_clock64 - Return time from a persistent clock. * * Reads the time from a source which isn't disabled during PM, the * 32k sync timer. Convert the cycles elapsed since last read into - * nsecs and adds to a monotonically increasing timespec. + * nsecs and adds to a monotonically increasing timespec64. */ -static struct timespec persistent_ts; +static struct timespec64 persistent_ts; static cycles_t cycles; static unsigned int persistent_mult, persistent_shift; -static DEFINE_SPINLOCK(read_persistent_clock_lock); -static void omap_read_persistent_clock(struct timespec *ts) +static void omap_read_persistent_clock64(struct timespec64 *ts) { unsigned long long nsecs; cycles_t last_cycles; - unsigned long flags; - - spin_lock_irqsave(&read_persistent_clock_lock, flags); last_cycles = cycles; cycles = sync32k_cnt_reg ? readl_relaxed(sync32k_cnt_reg) : 0; @@ -69,11 +65,17 @@ static void omap_read_persistent_clock(struct timespec *ts) nsecs = clocksource_cyc2ns(cycles - last_cycles, persistent_mult, persistent_shift); - timespec_add_ns(&persistent_ts, nsecs); + timespec64_add_ns(&persistent_ts, nsecs); *ts = persistent_ts; +} + +static void omap_read_persistent_clock(struct timespec *ts) +{ + struct timespec64 ts64; - spin_unlock_irqrestore(&read_persistent_clock_lock, flags); + omap_read_persistent_clock64(&ts64); + *ts = timespec64_to_timespec(ts64); } /** -- 2.20.1