4 files changed, 64 insertions, 0 deletions

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index f0a7fb984413..f88d32f8ff7c 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -79,6 +79,7 @@ struct clocksource {
         /* timekeeping specific data, ignore */
         cycle_t cycle_interval;
         u64     xtime_interval;
+        u32     raw_interval;
         /*
          * Second part is written at each timer interrupt
          * Keep it in a different cache line to dirty no
@@ -87,6 +88,7 @@ struct clocksource {
         cycle_t cycle_last ____cacheline_aligned_in_smp;
         u64 xtime_nsec;
         s64 error;
+        struct timespec raw_time;
 
 #ifdef CONFIG_CLOCKSOURCE_WATCHDOG
         /* Watchdog related data, used by the framework */
@@ -215,6 +217,7 @@ static inline void clocksource_calculate_interval(struct clocksource *c,
 
         /* Go back from cycles -> shifted ns, this time use ntp adjused mult */
         c->xtime_interval = (u64)c->cycle_interval * c->mult;
+        c->raw_interval = ((u64)c->cycle_interval * c->mult_orig) >> c->shift;
 }
 
 
diff --git a/include/linux/time.h b/include/linux/time.h
index e15206a7e82e..205f974b9ebf 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -117,6 +117,7 @@ extern int do_setitimer(int which, struct itimerval *value,
 extern unsigned int alarm_setitimer(unsigned int seconds);
 extern int do_getitimer(int which, struct itimerval *value);
 extern void getnstimeofday(struct timespec *tv);
+extern void getrawmonotonic(struct timespec *ts);
 extern void getboottime(struct timespec *ts);
 extern void monotonic_to_bootbased(struct timespec *ts);
 
@@ -214,6 +215,7 @@ struct itimerval {
 #define CLOCK_MONOTONIC                 1
 #define CLOCK_PROCESS_CPUTIME_ID        2
 #define CLOCK_THREAD_CPUTIME_ID         3
+#define CLOCK_MONOTONIC_RAW             4
 
 /*
  * The IDs of various hardware clocks:
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index e36d5798cbff..d3c66b53dff6 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -223,6 +223,15 @@ static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp)
 }
 
 /*
+ * Get monotonic time for posix timers
+ */
+static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
+{
+        getrawmonotonic(tp);
+        return 0;
+}
+
+/*
  * Initialize everything, well, just everything in Posix clocks/timers ;)
  */
 static __init int init_posix_timers(void)
@@ -235,9 +244,15 @@ static __init int init_posix_timers(void)
                 .clock_get = posix_ktime_get_ts,
                 .clock_set = do_posix_clock_nosettime,
         };
+        struct k_clock clock_monotonic_raw = {
+                .clock_getres = hrtimer_get_res,
+                .clock_get = posix_get_monotonic_raw,
+                .clock_set = do_posix_clock_nosettime,
+        };
 
         register_posix_clock(CLOCK_REALTIME, &clock_realtime);
         register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic);
+        register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
 
         posix_timers_cache = kmem_cache_create("posix_timers_cache",
                                         sizeof (struct k_itimer), 0, SLAB_PANIC,
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 83d3555a6998..5099c95b8aa2 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -75,6 +75,9 @@ static void clocksource_forward_now(void)
 
         nsec = cyc2ns(clock, cycle_delta);
         timespec_add_ns(&xtime, nsec);
+
+        nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
+        clock->raw_time.tv_nsec += nsec;
 }
 
 /**
@@ -183,6 +186,8 @@ static void change_clocksource(void)
 
         clocksource_forward_now();
 
+        new->raw_time = clock->raw_time;
+
         clock = new;
         clock->cycle_last = 0;
         clock->cycle_last = clocksource_read(new);
@@ -205,6 +210,39 @@ static inline void change_clocksource(void) { }
 #endif
 
 /**
+ * getrawmonotonic - Returns the raw monotonic time in a timespec
+ * @ts:         pointer to the timespec to be set
+ *
+ * Returns the raw monotonic time (completely un-modified by ntp)
+ */
+void getrawmonotonic(struct timespec *ts)
+{
+        unsigned long seq;
+        s64 nsecs;
+        cycle_t cycle_now, cycle_delta;
+
+        do {
+                seq = read_seqbegin(&xtime_lock);
+
+                /* read clocksource: */
+                cycle_now = clocksource_read(clock);
+
+                /* calculate the delta since the last update_wall_time: */
+                cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+
+                /* convert to nanoseconds: */
+                nsecs = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
+
+                *ts = clock->raw_time;
+
+        } while (read_seqretry(&xtime_lock, seq));
+
+        timespec_add_ns(ts, nsecs);
+}
+EXPORT_SYMBOL(getrawmonotonic);
+
+
+/**
  * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
  */
 int timekeeping_valid_for_hres(void)
@@ -466,6 +504,12 @@ void update_wall_time(void)
                         second_overflow();
                 }
 
+                clock->raw_time.tv_nsec += clock->raw_interval;
+                if (clock->raw_time.tv_nsec >= NSEC_PER_SEC) {
+                        clock->raw_time.tv_nsec -= NSEC_PER_SEC;
+                        clock->raw_time.tv_sec++;
+                }
+
                 /* accumulate error between NTP and clock interval */
                 clock->error += tick_length;
                 clock->error -= clock->xtime_interval << (NTP_SCALE_SHIFT - clock->shift);