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From: John Stultz <john.stultz@linaro.org>
To: lkml <linux-kernel@vger.kernel.org>
Cc: Xunlei Pang <pang.xunlei@linaro.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>,
	John Stultz <john.stultz@linaro.org>
Subject: [PATCH 04/21] ARM: OMAP: 32k counter: Provide y2038-safe omap_read_persistent_clock() replacement
Date: Wed,  1 Apr 2015 20:34:24 -0700	[thread overview]
Message-ID: <1427945681-29972-5-git-send-email-john.stultz@linaro.org> (raw)
In-Reply-To: <1427945681-29972-1-git-send-email-john.stultz@linaro.org>

From: Xunlei Pang <pang.xunlei@linaro.org>

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.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 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 43cf745..b7b7b07 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


  parent reply	other threads:[~2015-04-02  3:39 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-02  3:34 [PATCH 00/21] 4.1 time and rtc changes for tip/timers/core John Stultz
2015-04-02  3:34 ` [PATCH 01/21] time: Add y2038 safe read_boot_clock64() John Stultz
2015-04-03  8:15   ` [tip:timers/core] " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 02/21] time: Add y2038 safe read_persistent_clock64() John Stultz
2015-04-03  8:15   ` [tip:timers/core] " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 03/21] time: Add y2038 safe update_persistent_clock64() John Stultz
2015-04-03  8:16   ` [tip:timers/core] time: Add y2038 safe update_persistent_clock64( ) tip-bot for Xunlei Pang
2015-04-02  3:34 ` John Stultz [this message]
2015-04-03  8:16   ` [tip:timers/core] ARM: OMAP: 32k counter: Provide y2038-safe omap_read_persistent_clock() replacement tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 05/21] ARM: tegra: clock: Provide y2038-safe tegra_read_persistent_clock() replacement John Stultz
2015-04-03  8:16   ` [tip:timers/core] clocksource/drivers/tegra: " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 06/21] ARM: time: Provide read_boot_clock64() and read_persistent_clock64() John Stultz
2015-04-03  8:17   ` [tip:timers/core] ARM, clocksource/drivers: Provide read_boot_clock64() and read_persistent_clock64() and use them tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 07/21] rtc: Provide y2038 safe rtc_class_ops.set_mmss() replacement John Stultz
2015-04-03  8:17   ` [tip:timers/core] drivers/rtc: " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 08/21] rtc/test: Update driver to address y2038/y2106 issues John Stultz
2015-04-03  8:17   ` [tip:timers/core] drivers/rtc/test: " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 09/21] rtc/ab3100: " John Stultz
2015-04-03  8:17   ` [tip:timers/core] drivers/rtc/ab3100: " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 10/21] rtc/mc13xxx: " John Stultz
2015-04-03  8:18   ` [tip:timers/core] drivers/rtc/mc13xxx: " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 11/21] rtc/mxc: Modify rtc_update_alarm() not to touch the alarm time John Stultz
2015-04-03  8:18   ` [tip:timers/core] drivers/rtc/mxc: " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 12/21] rtc/mxc: Convert get_alarm_or_time()/set_alarm_or_time() to use time64_t John Stultz
2015-04-03  8:18   ` [tip:timers/core] drivers/rtc/mxc: Convert get_alarm_or_time()/ set_alarm_or_time() " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 13/21] rtc/mxc: Update driver to address y2038/y2106 issues John Stultz
2015-04-03  8:19   ` [tip:timers/core] drivers/rtc/mxc: Update driver to address y2038 /y2106 issues tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 14/21] alpha: rtc: Change to use rtc_class_ops's set_mmss64() John Stultz
2015-04-03  8:19   ` [tip:timers/core] alpha, rtc: Change to use rtc_class_ops' s set_mmss64() tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 15/21] time: Don't build timekeeping_inject_sleeptime64() if no one uses it John Stultz
2015-04-03  8:19   ` [tip:timers/core] time: Don' t " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 16/21] rtc: Remove redundant rtc_valid_tm() from rtc_resume() John Stultz
2015-04-03  8:19   ` [tip:timers/core] drivers/rtc: " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 17/21] time: Fix a bug in timekeeping_suspend() with no persistent clock John Stultz
2015-04-03  6:16   ` Ingo Molnar
2015-04-03  8:20   ` [tip:timers/core] " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 18/21] time: rtc: Don't bother into rtc_resume() for the nonstop clocksource John Stultz
2015-04-03  8:20   ` [tip:timers/core] time, drivers/rtc: Don't bother with rtc_resume () " tip-bot for Xunlei Pang
2015-04-02  3:34 ` [PATCH 19/21] clocksource: Improve comment explaining clocks_calc_max_nsecs()'s 50% safety margin John Stultz
2015-04-02  8:50   ` Peter Zijlstra
2015-04-02 17:30     ` John Stultz
2015-04-02 18:34       ` Peter Zijlstra
2015-04-02 18:41         ` John Stultz
2015-04-02 18:43           ` Peter Zijlstra
2015-04-02 18:50             ` John Stultz
2015-04-02 19:04               ` Peter Zijlstra
2015-04-03  8:20   ` [tip:timers/core] " tip-bot for John Stultz
2015-04-02  3:34 ` [PATCH 20/21] timekeeping: Change timekeeping_check_update() to take a tk_read_base John Stultz
2015-04-02  3:34 ` [PATCH 21/21] time: Rework debugging variables so they aren't global John Stultz
2015-04-02  7:47   ` Peter Zijlstra
2015-04-02  7:51     ` Ingo Molnar
2015-04-02  8:36       ` Peter Zijlstra
2015-04-02  8:41         ` Peter Zijlstra
2015-04-02 17:32       ` John Stultz
2015-04-03  6:21         ` Ingo Molnar

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