From: Xunlei Pang <pang.xunlei@xxxxxxxxxx>
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@xxxxxxxxxx>
---
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 61b4d70..d422e36 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);
}
/**
--
1.9.1
--
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