ARM, clocksource/drivers: Provide read_boot_clock64() and read_persistent_clock64() and use them

As part of addressing "y2038 problem" for in-kernel uses, this
patch converts read_boot_clock() to read_boot_clock64() and
read_persistent_clock() to read_persistent_clock64() using
timespec64 by converting clock_access_fn to use timespec64.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Thierry Reding <treding@nvidia.com> (for tegra part)
Cc: Russell King <rmk@dyn-67.arm.linux.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-7-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/arm/include/asm/mach/time.h

@@ -12,8 +12,7 @@
 
 extern void timer_tick(void);
 
-struct timespec;
-typedef void (*clock_access_fn)(struct timespec *);
+typedef void (*clock_access_fn)(struct timespec64 *);
 extern int register_persistent_clock(clock_access_fn read_boot,
 				     clock_access_fn read_persistent);
 

arch/arm/kernel/time.c

@@ -76,7 +76,7 @@ void timer_tick(void)
 }
 #endif
 
-static void dummy_clock_access(struct timespec *ts)
+static void dummy_clock_access(struct timespec64 *ts)
 {
 	ts->tv_sec = 0;
 	ts->tv_nsec = 0;
@@ -85,12 +85,12 @@ static void dummy_clock_access(struct timespec *ts)
 static clock_access_fn __read_persistent_clock = dummy_clock_access;
 static clock_access_fn __read_boot_clock = dummy_clock_access;;
 
-void read_persistent_clock(struct timespec *ts)
+void read_persistent_clock64(struct timespec64 *ts)
 {
 	__read_persistent_clock(ts);
 }
 
-void read_boot_clock(struct timespec *ts)
+void read_boot_clock64(struct timespec64 *ts)
 {
 	__read_boot_clock(ts);
 }

arch/arm/plat-omap/counter_32k.c

@@ -70,14 +70,6 @@ static void omap_read_persistent_clock64(struct timespec64 *ts)
 	*ts = persistent_ts;
 }
 
-static void omap_read_persistent_clock(struct timespec *ts)
-{
-	struct timespec64 ts64;
-
-	omap_read_persistent_clock64(&ts64);
-	*ts = timespec64_to_timespec(ts64);
-}
-
 /**
  * omap_init_clocksource_32k - setup and register counter 32k as a
  * kernel clocksource
@@ -118,7 +110,7 @@ int __init omap_init_clocksource_32k(void __iomem *vbase)
 	}
 
 	sched_clock_register(omap_32k_read_sched_clock, 32, 32768);
-	register_persistent_clock(NULL, omap_read_persistent_clock);
+	register_persistent_clock(NULL, omap_read_persistent_clock64);
 	pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");
 
 	return 0;

drivers/clocksource/tegra20_timer.c

@@ -141,14 +141,6 @@ static void tegra_read_persistent_clock64(struct timespec64 *ts)
 	*ts = persistent_ts;
 }
 
-static void tegra_read_persistent_clock(struct timespec *ts)
-{
-	struct timespec ts64;
-
-	tegra_read_persistent_clock64(&ts64);
-	*ts = timespec64_to_timespec(ts64);
-}
-
 static unsigned long tegra_delay_timer_read_counter_long(void)
 {
 	return readl(timer_reg_base + TIMERUS_CNTR_1US);
@@ -259,7 +251,7 @@ static void __init tegra20_init_rtc(struct device_node *np)
 	else
 		clk_prepare_enable(clk);
 
-	register_persistent_clock(NULL, tegra_read_persistent_clock);
+	register_persistent_clock(NULL, tegra_read_persistent_clock64);
 }
 CLOCKSOURCE_OF_DECLARE(tegra20_rtc, "nvidia,tegra20-rtc", tegra20_init_rtc);