20 files changed, 118 insertions, 94 deletions

diff --git a/arch/arm/plat-omap/common.c b/arch/arm/plat-omap/common.c
index ebcf006406f9..95587b6c0259 100644
--- a/arch/arm/plat-omap/common.c
+++ b/arch/arm/plat-omap/common.c
@@ -253,11 +253,8 @@ static struct clocksource clocksource_32k = {
  */
 unsigned long long sched_clock(void)
 {
-        unsigned long long ret;
-
-        ret = (unsigned long long)clocksource_32k.read(&clocksource_32k);
-        ret = (ret * clocksource_32k.mult_orig) >> clocksource_32k.shift;
-        return ret;
+        return clocksource_cyc2ns(clocksource_32k.read(&clocksource_32k),
+                                  clocksource_32k.mult, clocksource_32k.shift);
 }
 
 static int __init omap_init_clocksource_32k(void)
diff --git a/arch/m68knommu/kernel/time.c b/arch/m68knommu/kernel/time.c
index c2aa717de08a..a90acf5b0cde 100644
--- a/arch/m68knommu/kernel/time.c
+++ b/arch/m68knommu/kernel/time.c
@@ -72,9 +72,10 @@ static unsigned long read_rtc_mmss(void)
         return  mktime(year, mon, day, hour, min, sec);
 }
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
-        return read_rtc_mmss();
+        ts->tv_sec = read_rtc_mmss();
+        ts->tv_nsec = 0;
 }
 
 int update_persistent_clock(struct timespec now)
diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c
index 463136e6685a..02f505f23c32 100644
--- a/arch/mips/dec/time.c
+++ b/arch/mips/dec/time.c
@@ -18,7 +18,7 @@
 #include <asm/dec/ioasic.h>
 #include <asm/dec/machtype.h>
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
         unsigned int year, mon, day, hour, min, sec, real_year;
         unsigned long flags;
@@ -53,7 +53,8 @@ unsigned long read_persistent_clock(void)
 
         year += real_year - 72 + 2000;
 
-        return mktime(year, mon, day, hour, min, sec);
+        ts->tv_sec = mktime(year, mon, day, hour, min, sec);
+        ts->tv_nsec = 0;
 }
 
 /*
diff --git a/arch/mips/lasat/ds1603.c b/arch/mips/lasat/ds1603.c
index 52cb1436a12a..c6fd96ff118d 100644
--- a/arch/mips/lasat/ds1603.c
+++ b/arch/mips/lasat/ds1603.c
@@ -135,7 +135,7 @@ static void rtc_end_op(void)
         lasat_ndelay(1000);
 }
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
         unsigned long word;
         unsigned long flags;
@@ -147,7 +147,8 @@ unsigned long read_persistent_clock(void)
         rtc_end_op();
         spin_unlock_irqrestore(&rtc_lock, flags);
 
-        return word;
+        ts->tv_sec = word;
+        ts->tv_nsec = 0;
 }
 
 int rtc_mips_set_mmss(unsigned long time)
diff --git a/arch/mips/lasat/sysctl.c b/arch/mips/lasat/sysctl.c
index 8f88886feb12..3f04d4c406b7 100644
--- a/arch/mips/lasat/sysctl.c
+++ b/arch/mips/lasat/sysctl.c
@@ -92,10 +92,12 @@ static int rtctmp;
 int proc_dolasatrtc(ctl_table *table, int write, struct file *filp,
                        void *buffer, size_t *lenp, loff_t *ppos)
 {
+        struct timespec ts;
         int r;
 
         if (!write) {
-                rtctmp = read_persistent_clock();
+                read_persistent_clock(&ts);
+                rtctmp = ts.tv_sec;
                 /* check for time < 0 and set to 0 */
                 if (rtctmp < 0)
                         rtctmp = 0;
@@ -134,9 +136,11 @@ int sysctl_lasat_rtc(ctl_table *table,
                     void *oldval, size_t *oldlenp,
                     void *newval, size_t newlen)
 {
+        struct timespec ts;
         int r;
 
-        rtctmp = read_persistent_clock();
+        read_persistent_clock(&ts);
+        rtctmp = ts.tv_sec;
         if (rtctmp < 0)
                 rtctmp = 0;
         r = sysctl_intvec(table, oldval, oldlenp, newval, newlen);
diff --git a/arch/mips/loongson/common/time.c b/arch/mips/loongson/common/time.c
index b13d17174654..0edbef32b862 100644
--- a/arch/mips/loongson/common/time.c
+++ b/arch/mips/loongson/common/time.c
@@ -21,7 +21,8 @@ void __init plat_time_init(void)
         mips_hpt_frequency = cpu_clock_freq / 2;
 }
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
-        return mc146818_get_cmos_time();
+        ts->tv_sec = return mc146818_get_cmos_time();
+        ts->tv_nsec = 0;
 }
diff --git a/arch/mips/mti-malta/malta-time.c b/arch/mips/mti-malta/malta-time.c
index 0b97d47691fc..3c6f190aa61c 100644
--- a/arch/mips/mti-malta/malta-time.c
+++ b/arch/mips/mti-malta/malta-time.c
@@ -100,9 +100,10 @@ static unsigned int __init estimate_cpu_frequency(void)
         return count;
 }
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
-        return mc146818_get_cmos_time();
+        ts->tv_sec = mc146818_get_cmos_time();
+        ts->tv_nsec = 0;
 }
 
 static void __init plat_perf_setup(void)
diff --git a/arch/mips/pmc-sierra/yosemite/setup.c b/arch/mips/pmc-sierra/yosemite/setup.c
index 2d3c0dca275d..3498ac9c35af 100644
--- a/arch/mips/pmc-sierra/yosemite/setup.c
+++ b/arch/mips/pmc-sierra/yosemite/setup.c
@@ -70,7 +70,7 @@ void __init bus_error_init(void)
 }
 
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
         unsigned int year, month, day, hour, min, sec;
         unsigned long flags;
@@ -92,7 +92,8 @@ unsigned long read_persistent_clock(void)
         m48t37_base->control = 0x00;
         spin_unlock_irqrestore(&rtc_lock, flags);
 
-        return mktime(year, month, day, hour, min, sec);
+        ts->tv_sec = mktime(year, month, day, hour, min, sec);
+        ts->tv_nsec = 0;
 }
 
 int rtc_mips_set_time(unsigned long tim)
diff --git a/arch/mips/sibyte/swarm/setup.c b/arch/mips/sibyte/swarm/setup.c
index 672e45d495a9..623ffc933c4c 100644
--- a/arch/mips/sibyte/swarm/setup.c
+++ b/arch/mips/sibyte/swarm/setup.c
@@ -87,19 +87,26 @@ enum swarm_rtc_type {
 
 enum swarm_rtc_type swarm_rtc_type;
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
+        unsigned long sec;
+
         switch (swarm_rtc_type) {
         case RTC_XICOR:
-                return xicor_get_time();
+                sec = xicor_get_time();
+                break;
 
         case RTC_M4LT81:
-                return m41t81_get_time();
+                sec = m41t81_get_time();
+                break;
 
         case RTC_NONE:
         default:
-                return mktime(2000, 1, 1, 0, 0, 0);
+                sec = mktime(2000, 1, 1, 0, 0, 0);
+                break;
         }
+        ts->tv_sec = sec;
+        tv->tv_nsec = 0;
 }
 
 int rtc_mips_set_time(unsigned long sec)
diff --git a/arch/mips/sni/time.c b/arch/mips/sni/time.c
index 0d9ec1a5c24a..62df6a598e0a 100644
--- a/arch/mips/sni/time.c
+++ b/arch/mips/sni/time.c
@@ -182,7 +182,8 @@ void __init plat_time_init(void)
         setup_pit_timer();
 }
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
-        return -1;
+        ts->tv_sec = -1;
+        ts->tv_nsec = 0;
 }
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index a180b4f9a4f6..465e498bcb33 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -774,11 +774,12 @@ int update_persistent_clock(struct timespec now)
         return ppc_md.set_rtc_time(&tm);
 }
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
         struct rtc_time tm;
         static int first = 1;
 
+        ts->tv_nsec = 0;
         /* XXX this is a litle fragile but will work okay in the short term */
         if (first) {
                 first = 0;
@@ -786,14 +787,18 @@ unsigned long read_persistent_clock(void)
                         timezone_offset = ppc_md.time_init();
 
                 /* get_boot_time() isn't guaranteed to be safe to call late */
-                if (ppc_md.get_boot_time)
-                        return ppc_md.get_boot_time() -timezone_offset;
+                if (ppc_md.get_boot_time) {
+                        ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;
+                        return;
+                }
+        }
+        if (!ppc_md.get_rtc_time) {
+                ts->tv_sec = 0;
+                return;
         }
-        if (!ppc_md.get_rtc_time)
-                return 0;
         ppc_md.get_rtc_time(&tm);
-        return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
-                      tm.tm_hour, tm.tm_min, tm.tm_sec);
+        ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
+                            tm.tm_hour, tm.tm_min, tm.tm_sec);
 }
 
 /* clocksource code */
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index e3dc28b8075d..34162a0b2caa 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -184,12 +184,14 @@ static void timing_alert_interrupt(__u16 code)
 static void etr_reset(void);
 static void stp_reset(void);
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
-        struct timespec ts;
+        tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, ts);
+}
 
-        tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, &ts);
-        return ts.tv_sec;
+void read_boot_clock(struct timespec *ts)
+{
+        tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, ts);
 }
 
 static cycle_t read_tod_clock(struct clocksource *cs)
@@ -207,6 +209,10 @@ static struct clocksource clocksource_tod = {
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
+struct clocksource * __init clocksource_default_clock(void)
+{
+        return &clocksource_tod;
+}
 
 void update_vsyscall(struct timespec *wall_time, struct clocksource *clock)
 {
@@ -244,10 +250,6 @@ void update_vsyscall_tz(void)
  */
 void __init time_init(void)
 {
-        struct timespec ts;
-        unsigned long flags;
-        cycle_t now;
-
         /* Reset time synchronization interfaces. */
         etr_reset();
         stp_reset();
@@ -263,26 +265,6 @@ void __init time_init(void)
         if (clocksource_register(&clocksource_tod) != 0)
                 panic("Could not register TOD clock source");
 
-        /*
-         * The TOD clock is an accurate clock. The xtime should be
-         * initialized in a way that the difference between TOD and
-         * xtime is reasonably small. Too bad that timekeeping_init
-         * sets xtime.tv_nsec to zero. In addition the clock source
-         * change from the jiffies clock source to the TOD clock
-         * source add another error of up to 1/HZ second. The same
-         * function sets wall_to_monotonic to a value that is too
-         * small for /proc/uptime to be accurate.
-         * Reset xtime and wall_to_monotonic to sane values.
-         */
-        write_seqlock_irqsave(&xtime_lock, flags);
-        now = get_clock();
-        tod_to_timeval(now - TOD_UNIX_EPOCH, &xtime);
-        clocksource_tod.cycle_last = now;
-        clocksource_tod.raw_time = xtime;
-        tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, &ts);
-        set_normalized_timespec(&wall_to_monotonic, -ts.tv_sec, -ts.tv_nsec);
-        write_sequnlock_irqrestore(&xtime_lock, flags);
-
         /* Enable TOD clock interrupts on the boot cpu. */
         init_cpu_timer();
 
diff --git a/arch/sh/kernel/time.c b/arch/sh/kernel/time.c
index 9b352a1e3fb4..0e0e8581cf7a 100644
--- a/arch/sh/kernel/time.c
+++ b/arch/sh/kernel/time.c
@@ -39,11 +39,9 @@ void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time;
 int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;
 
 #ifdef CONFIG_GENERIC_CMOS_UPDATE
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
-        struct timespec tv;
-        rtc_sh_get_time(&tv);
-        return tv.tv_sec;
+        rtc_sh_get_time(ts);
 }
 
 int update_persistent_clock(struct timespec now)
diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h
index dc27a69e5d2a..3d61e204826f 100644
--- a/arch/x86/include/asm/vgtod.h
+++ b/arch/x86/include/asm/vgtod.h
@@ -21,6 +21,7 @@ struct vsyscall_gtod_data {
                 u32     shift;
         } clock;
         struct timespec wall_to_monotonic;
+        struct timespec wall_time_coarse;
 };
 extern struct vsyscall_gtod_data __vsyscall_gtod_data
 __section_vsyscall_gtod_data;
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index 5cf36c053ac4..23c167925a5c 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c
@@ -19,12 +19,6 @@
 DEFINE_SPINLOCK(i8253_lock);
 EXPORT_SYMBOL(i8253_lock);
 
-#ifdef CONFIG_X86_32
-static void pit_disable_clocksource(void);
-#else
-static inline void pit_disable_clocksource(void) { }
-#endif
-
 /*
  * HPET replaces the PIT, when enabled. So we need to know, which of
  * the two timers is used
@@ -57,12 +51,10 @@ static void init_pit_timer(enum clock_event_mode mode,
                         outb_pit(0, PIT_CH0);
                         outb_pit(0, PIT_CH0);
                 }
-                pit_disable_clocksource();
                 break;
 
         case CLOCK_EVT_MODE_ONESHOT:
                 /* One shot setup */
-                pit_disable_clocksource();
                 outb_pit(0x38, PIT_MODE);
                 break;
 
@@ -200,17 +192,6 @@ static struct clocksource pit_cs = {
         .shift          = 20,
 };
 
-static void pit_disable_clocksource(void)
-{
-        /*
-         * Use mult to check whether it is registered or not
-         */
-        if (pit_cs.mult) {
-                clocksource_unregister(&pit_cs);
-                pit_cs.mult = 0;
-        }
-}
-
 static int __init init_pit_clocksource(void)
 {
          /*
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 5d465b207e72..bf67dcb4a44c 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -178,7 +178,7 @@ static int set_rtc_mmss(unsigned long nowtime)
 }
 
 /* not static: needed by APM */
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
         unsigned long retval, flags;
 
@@ -186,7 +186,8 @@ unsigned long read_persistent_clock(void)
         retval = get_wallclock();
         spin_unlock_irqrestore(&rtc_lock, flags);
 
-        return retval;
+        ts->tv_sec = retval;
+        ts->tv_nsec = 0;
 }
 
 int update_persistent_clock(struct timespec now)
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 71f4368b357e..fc3672a303d6 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -744,10 +744,16 @@ static cycle_t __vsyscall_fn vread_tsc(void)
 }
 #endif
 
+static void resume_tsc(void)
+{
+        clocksource_tsc.cycle_last = 0;
+}
+
 static struct clocksource clocksource_tsc = {
         .name                   = "tsc",
         .rating                 = 300,
         .read                   = read_tsc,
+        .resume                 = resume_tsc,
         .mask                   = CLOCKSOURCE_MASK(64),
         .shift                  = 22,
         .flags                  = CLOCK_SOURCE_IS_CONTINUOUS |
@@ -761,12 +767,14 @@ void mark_tsc_unstable(char *reason)
 {
         if (!tsc_unstable) {
                 tsc_unstable = 1;
-                printk("Marking TSC unstable due to %s\n", reason);
+                printk(KERN_INFO "Marking TSC unstable due to %s\n", reason);
                 /* Change only the rating, when not registered */
                 if (clocksource_tsc.mult)
-                        clocksource_change_rating(&clocksource_tsc, 0);
-                else
+                        clocksource_mark_unstable(&clocksource_tsc);
+                else {
+                        clocksource_tsc.flags |= CLOCK_SOURCE_UNSTABLE;
                         clocksource_tsc.rating = 0;
+                }
         }
 }
 
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 25ee06a80aad..cf53a78e2dcf 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -87,6 +87,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock)
         vsyscall_gtod_data.wall_time_sec = wall_time->tv_sec;
         vsyscall_gtod_data.wall_time_nsec = wall_time->tv_nsec;
         vsyscall_gtod_data.wall_to_monotonic = wall_to_monotonic;
+        vsyscall_gtod_data.wall_time_coarse = __current_kernel_time();
         write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
 }
 
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 6a40b78b46aa..ee55754cc3c5 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -86,14 +86,47 @@ notrace static noinline int do_monotonic(struct timespec *ts)
         return 0;
 }
 
+notrace static noinline int do_realtime_coarse(struct timespec *ts)
+{
+        unsigned long seq;
+        do {
+                seq = read_seqbegin(&gtod->lock);
+                ts->tv_sec = gtod->wall_time_coarse.tv_sec;
+                ts->tv_nsec = gtod->wall_time_coarse.tv_nsec;
+        } while (unlikely(read_seqretry(&gtod->lock, seq)));
+        return 0;
+}
+
+notrace static noinline int do_monotonic_coarse(struct timespec *ts)
+{
+        unsigned long seq, ns, secs;
+        do {
+                seq = read_seqbegin(&gtod->lock);
+                secs = gtod->wall_time_coarse.tv_sec;
+                ns = gtod->wall_time_coarse.tv_nsec;
+                secs += gtod->wall_to_monotonic.tv_sec;
+                ns += gtod->wall_to_monotonic.tv_nsec;
+        } while (unlikely(read_seqretry(&gtod->lock, seq)));
+        vset_normalized_timespec(ts, secs, ns);
+        return 0;
+}
+
 notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
 {
-        if (likely(gtod->sysctl_enabled && gtod->clock.vread))
+        if (likely(gtod->sysctl_enabled))
                 switch (clock) {
                 case CLOCK_REALTIME:
-                        return do_realtime(ts);
+                        if (likely(gtod->clock.vread))
+                                return do_realtime(ts);
+                        break;
                 case CLOCK_MONOTONIC:
-                        return do_monotonic(ts);
+                        if (likely(gtod->clock.vread))
+                                return do_monotonic(ts);
+                        break;
+                case CLOCK_REALTIME_COARSE:
+                        return do_realtime_coarse(ts);
+                case CLOCK_MONOTONIC_COARSE:
+                        return do_monotonic_coarse(ts);
                 }
         return vdso_fallback_gettime(clock, ts);
 }
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c
index 8848120d291b..19085ff0484a 100644
--- a/arch/xtensa/kernel/time.c
+++ b/arch/xtensa/kernel/time.c
@@ -59,9 +59,8 @@ static struct irqaction timer_irqaction = {
 
 void __init time_init(void)
 {
-        xtime.tv_nsec = 0;
-        xtime.tv_sec = read_persistent_clock();
-
+        /* FIXME: xtime&wall_to_monotonic are set in timekeeping_init. */
+        read_persistent_clock(&xtime);
         set_normalized_timespec(&wall_to_monotonic,
                 -xtime.tv_sec, -xtime.tv_nsec);