7 files changed, 71 insertions, 103 deletions

diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index 7a11b905ef49..361aca8b3ec3 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -18,6 +18,10 @@ config GENERIC_TIME
         bool
         default y
 
+config GENERIC_CMOS_UPDATE
+        bool
+        default y
+
 config CLOCKSOURCE_WATCHDOG
         bool
         default y
diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c
index a665df61f08c..19a6c678d02e 100644
--- a/arch/i386/kernel/time.c
+++ b/arch/i386/kernel/time.c
@@ -207,55 +207,9 @@ unsigned long read_persistent_clock(void)
         return retval;
 }
 
-static void sync_cmos_clock(unsigned long dummy);
-
-static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0);
-int no_sync_cmos_clock;
-
-static void sync_cmos_clock(unsigned long dummy)
-{
-        struct timeval now, next;
-        int fail = 1;
-
-        /*
-         * If we have an externally synchronized Linux clock, then update
-         * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
-         * called as close as possible to 500 ms before the new second starts.
-         * This code is run on a timer.  If the clock is set, that timer
-         * may not expire at the correct time.  Thus, we adjust...
-         */
-        if (!ntp_synced())
-                /*
-                 * Not synced, exit, do not restart a timer (if one is
-                 * running, let it run out).
-                 */
-                return;
-
-        do_gettimeofday(&now);
-        if (now.tv_usec >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 &&
-            now.tv_usec <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2)
-                fail = set_rtc_mmss(now.tv_sec);
-
-        next.tv_usec = USEC_AFTER - now.tv_usec;
-        if (next.tv_usec <= 0)
-                next.tv_usec += USEC_PER_SEC;
-
-        if (!fail)
-                next.tv_sec = 659;
-        else
-                next.tv_sec = 0;
-
-        if (next.tv_usec >= USEC_PER_SEC) {
-                next.tv_sec++;
-                next.tv_usec -= USEC_PER_SEC;
-        }
-        mod_timer(&sync_cmos_timer, jiffies + timeval_to_jiffies(&next));
-}
-
-void notify_arch_cmos_timer(void)
+int update_persistent_clock(struct timespec now)
 {
-        if (!no_sync_cmos_clock)
-                mod_timer(&sync_cmos_timer, jiffies + 1);
+        return set_rtc_mmss(now.tv_sec);
 }
 
 extern void (*late_time_init)(void);
diff --git a/arch/sparc64/Kconfig b/arch/sparc64/Kconfig
index f1cc55677ff2..33dabf588bdd 100644
--- a/arch/sparc64/Kconfig
+++ b/arch/sparc64/Kconfig
@@ -23,6 +23,10 @@ config GENERIC_TIME
         bool
         default y
 
+config GENERIC_CMOS_UPDATE
+        bool
+        default y
+
 config GENERIC_CLOCKEVENTS
         bool
         default y
diff --git a/arch/sparc64/kernel/time.c b/arch/sparc64/kernel/time.c
index 87c10a7544da..49063ca2efcd 100644
--- a/arch/sparc64/kernel/time.c
+++ b/arch/sparc64/kernel/time.c
@@ -403,58 +403,9 @@ static struct sparc64_tick_ops hbtick_operations __read_mostly = {
 
 static unsigned long timer_ticks_per_nsec_quotient __read_mostly;
 
-#define TICK_SIZE (tick_nsec / 1000)
-
-#define USEC_AFTER      500000
-#define USEC_BEFORE     500000
-
-static void sync_cmos_clock(unsigned long dummy);
-
-static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0);
-
-static void sync_cmos_clock(unsigned long dummy)
-{
-        struct timeval now, next;
-        int fail = 1;
-
-        /*
-         * If we have an externally synchronized Linux clock, then update
-         * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
-         * called as close as possible to 500 ms before the new second starts.
-         * This code is run on a timer.  If the clock is set, that timer
-         * may not expire at the correct time.  Thus, we adjust...
-         */
-        if (!ntp_synced())
-                /*
-                 * Not synced, exit, do not restart a timer (if one is
-                 * running, let it run out).
-                 */
-                return;
-
-        do_gettimeofday(&now);
-        if (now.tv_usec >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 &&
-            now.tv_usec <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2)
-                fail = set_rtc_mmss(now.tv_sec);
-
-        next.tv_usec = USEC_AFTER - now.tv_usec;
-        if (next.tv_usec <= 0)
-                next.tv_usec += USEC_PER_SEC;
-
-        if (!fail)
-                next.tv_sec = 659;
-        else
-                next.tv_sec = 0;
-
-        if (next.tv_usec >= USEC_PER_SEC) {
-                next.tv_sec++;
-                next.tv_usec -= USEC_PER_SEC;
-        }
-        mod_timer(&sync_cmos_timer, jiffies + timeval_to_jiffies(&next));
-}
-
-void notify_arch_cmos_timer(void)
+int update_persistent_clock(struct timespec now)
 {
-        mod_timer(&sync_cmos_timer, jiffies + 1);
+        return set_rtc_mmss(now.tv_sec);
 }
 
 /* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
diff --git a/include/asm-i386/timer.h b/include/asm-i386/timer.h
index 51a713e33a9e..b371667cfdeb 100644
--- a/include/asm-i386/timer.h
+++ b/include/asm-i386/timer.h
@@ -11,7 +11,6 @@ unsigned long native_calculate_cpu_khz(void);
 
 extern int timer_ack;
 extern int no_timer_check;
-extern int no_sync_cmos_clock;
 extern int recalibrate_cpu_khz(void);
 
 #ifndef CONFIG_PARAVIRT
diff --git a/include/linux/time.h b/include/linux/time.h
index ec3b0ced0afe..e6aea5146e5d 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -4,6 +4,7 @@
 #include <linux/types.h>
 
 #ifdef __KERNEL__
+# include <linux/cache.h>
 # include <linux/seqlock.h>
 #endif
 
@@ -94,6 +95,8 @@ extern struct timespec wall_to_monotonic;
 extern seqlock_t xtime_lock __attribute__((weak));
 
 extern unsigned long read_persistent_clock(void);
+extern int update_persistent_clock(struct timespec now);
+extern int no_sync_cmos_clock __read_mostly;
 void timekeeping_init(void);
 
 static inline unsigned long get_seconds(void)
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index b5e352597cbb..cd91237dbfe3 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -10,6 +10,7 @@
 
 #include <linux/mm.h>
 #include <linux/time.h>
+#include <linux/timer.h>
 #include <linux/timex.h>
 #include <linux/jiffies.h>
 #include <linux/hrtimer.h>
@@ -175,12 +176,64 @@ u64 current_tick_length(void)
         return tick_length;
 }
 
+#ifdef CONFIG_GENERIC_CMOS_UPDATE
 
-void __attribute__ ((weak)) notify_arch_cmos_timer(void)
+/* Disable the cmos update - used by virtualization and embedded */
+int no_sync_cmos_clock  __read_mostly;
+
+static void sync_cmos_clock(unsigned long dummy);
+
+static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0);
+
+static void sync_cmos_clock(unsigned long dummy)
+{
+        struct timespec now, next;
+        int fail = 1;
+
+        /*
+         * If we have an externally synchronized Linux clock, then update
+         * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
+         * called as close as possible to 500 ms before the new second starts.
+         * This code is run on a timer.  If the clock is set, that timer
+         * may not expire at the correct time.  Thus, we adjust...
+         */
+        if (!ntp_synced())
+                /*
+                 * Not synced, exit, do not restart a timer (if one is
+                 * running, let it run out).
+                 */
+                return;
+
+        getnstimeofday(&now);
+        if (abs(xtime.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
+                fail = update_persistent_clock(now);
+
+        next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec;
+        if (next.tv_nsec <= 0)
+                next.tv_nsec += NSEC_PER_SEC;
+
+        if (!fail)
+                next.tv_sec = 659;
+        else
+                next.tv_sec = 0;
+
+        if (next.tv_nsec >= NSEC_PER_SEC) {
+                next.tv_sec++;
+                next.tv_nsec -= NSEC_PER_SEC;
+        }
+        mod_timer(&sync_cmos_timer, jiffies + timespec_to_jiffies(&next));
+}
+
+static void notify_cmos_timer(void)
 {
-        return;
+        if (no_sync_cmos_clock)
+                mod_timer(&sync_cmos_timer, jiffies + 1);
 }
 
+#else
+static inline void notify_cmos_timer(void) { }
+#endif
+
 /* adjtimex mainly allows reading (and writing, if superuser) of
  * kernel time-keeping variables. used by xntpd.
  */
@@ -345,6 +398,6 @@ leave:	if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0)
         txc->stbcnt        = 0;
         write_sequnlock_irq(&xtime_lock);
         do_gettimeofday(&txc->time);
-        notify_arch_cmos_timer();
+        notify_cmos_timer();
         return(result);
 }