5 files changed, 553 insertions, 180 deletions

diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 905b0b50792..0b0a6366c9d 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -1,4 +1,4 @@
-obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o
+obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o
 
 obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD)         += clockevents.o
 obj-$(CONFIG_GENERIC_CLOCKEVENTS)               += tick-common.o
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index ea2f48af83c..d13be216a79 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -68,6 +68,17 @@ void clockevents_set_mode(struct clock_event_device *dev,
         if (dev->mode != mode) {
                 dev->set_mode(mode, dev);
                 dev->mode = mode;
+
+                /*
+                 * A nsec2cyc multiplicator of 0 is invalid and we'd crash
+                 * on it, so fix it up and emit a warning:
+                 */
+                if (mode == CLOCK_EVT_MODE_ONESHOT) {
+                        if (unlikely(!dev->mult)) {
+                                dev->mult = 1;
+                                WARN_ON(1);
+                        }
+                }
         }
 }
 
@@ -168,15 +179,6 @@ void clockevents_register_device(struct clock_event_device *dev)
         BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
         BUG_ON(!dev->cpumask);
 
-        /*
-         * A nsec2cyc multiplicator of 0 is invalid and we'd crash
-         * on it, so fix it up and emit a warning:
-         */
-        if (unlikely(!dev->mult)) {
-                dev->mult = 1;
-                WARN_ON(1);
-        }
-
         spin_lock(&clockevents_lock);
 
         list_add(&dev->list, &clockevent_devices);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index ca89e1593f0..c46c931a7fe 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -31,6 +31,82 @@
 #include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */
 #include <linux/tick.h>
 
+void timecounter_init(struct timecounter *tc,
+                      const struct cyclecounter *cc,
+                      u64 start_tstamp)
+{
+        tc->cc = cc;
+        tc->cycle_last = cc->read(cc);
+        tc->nsec = start_tstamp;
+}
+EXPORT_SYMBOL(timecounter_init);
+
+/**
+ * timecounter_read_delta - get nanoseconds since last call of this function
+ * @tc:         Pointer to time counter
+ *
+ * When the underlying cycle counter runs over, this will be handled
+ * correctly as long as it does not run over more than once between
+ * calls.
+ *
+ * The first call to this function for a new time counter initializes
+ * the time tracking and returns an undefined result.
+ */
+static u64 timecounter_read_delta(struct timecounter *tc)
+{
+        cycle_t cycle_now, cycle_delta;
+        u64 ns_offset;
+
+        /* read cycle counter: */
+        cycle_now = tc->cc->read(tc->cc);
+
+        /* calculate the delta since the last timecounter_read_delta(): */
+        cycle_delta = (cycle_now - tc->cycle_last) & tc->cc->mask;
+
+        /* convert to nanoseconds: */
+        ns_offset = cyclecounter_cyc2ns(tc->cc, cycle_delta);
+
+        /* update time stamp of timecounter_read_delta() call: */
+        tc->cycle_last = cycle_now;
+
+        return ns_offset;
+}
+
+u64 timecounter_read(struct timecounter *tc)
+{
+        u64 nsec;
+
+        /* increment time by nanoseconds since last call */
+        nsec = timecounter_read_delta(tc);
+        nsec += tc->nsec;
+        tc->nsec = nsec;
+
+        return nsec;
+}
+EXPORT_SYMBOL(timecounter_read);
+
+u64 timecounter_cyc2time(struct timecounter *tc,
+                         cycle_t cycle_tstamp)
+{
+        u64 cycle_delta = (cycle_tstamp - tc->cycle_last) & tc->cc->mask;
+        u64 nsec;
+
+        /*
+         * Instead of always treating cycle_tstamp as more recent
+         * than tc->cycle_last, detect when it is too far in the
+         * future and treat it as old time stamp instead.
+         */
+        if (cycle_delta > tc->cc->mask / 2) {
+                cycle_delta = (tc->cycle_last - cycle_tstamp) & tc->cc->mask;
+                nsec = tc->nsec - cyclecounter_cyc2ns(tc->cc, cycle_delta);
+        } else {
+                nsec = cyclecounter_cyc2ns(tc->cc, cycle_delta) + tc->nsec;
+        }
+
+        return nsec;
+}
+EXPORT_SYMBOL(timecounter_cyc2time);
+
 /* XXX - Would like a better way for initializing curr_clocksource */
 extern struct clocksource clocksource_jiffies;
 
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index f5f793d9241..7fc64375ff4 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -1,71 +1,129 @@
 /*
- * linux/kernel/time/ntp.c
- *
  * NTP state machine interfaces and logic.
  *
  * This code was mainly moved from kernel/timer.c and kernel/time.c
  * Please see those files for relevant copyright info and historical
  * changelogs.
  */
-
-#include <linux/mm.h>
-#include <linux/time.h>
-#include <linux/timex.h>
-#include <linux/jiffies.h>
-#include <linux/hrtimer.h>
 #include <linux/capability.h>
-#include <linux/math64.h>
 #include <linux/clocksource.h>
 #include <linux/workqueue.h>
-#include <asm/timex.h>
+#include <linux/hrtimer.h>
+#include <linux/jiffies.h>
+#include <linux/math64.h>
+#include <linux/timex.h>
+#include <linux/time.h>
+#include <linux/mm.h>
 
 /*
- * Timekeeping variables
+ * NTP timekeeping variables:
  */
-unsigned long tick_usec = TICK_USEC;            /* USER_HZ period (usec) */
-unsigned long tick_nsec;                        /* ACTHZ period (nsec) */
-u64 tick_length;
-static u64 tick_length_base;
 
-static struct hrtimer leap_timer;
+/* USER_HZ period (usecs): */
+unsigned long                   tick_usec = TICK_USEC;
 
-#define MAX_TICKADJ             500             /* microsecs */
-#define MAX_TICKADJ_SCALED      (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
-                                  NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
+/* ACTHZ period (nsecs): */
+unsigned long                   tick_nsec;
+
+u64                             tick_length;
+static u64                      tick_length_base;
+
+static struct hrtimer           leap_timer;
+
+#define MAX_TICKADJ             500LL           /* usecs */
+#define MAX_TICKADJ_SCALED \
+        (((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
 
 /*
  * phase-lock loop variables
  */
-/* TIME_ERROR prevents overwriting the CMOS clock */
-static int time_state = TIME_OK;        /* clock synchronization status */
-int time_status = STA_UNSYNC;           /* clock status bits            */
-static long time_tai;                   /* TAI offset (s)               */
-static s64 time_offset;                 /* time adjustment (ns)         */
-static long time_constant = 2;          /* pll time constant            */