time: Clean up CLOCK_MONOTONIC_RAW time handling

Now that we fixed the sub-ns handling for CLOCK_MONOTONIC_RAW,
remove the duplicitive tk->raw_time.tv_nsec, which can be
stored in tk->tkr_raw.xtime_nsec (similarly to how its handled
for monotonic time).

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Daniel Mentz <danielmentz@google.com>
Tested-by: Daniel Mentz <danielmentz@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index d0cb007fa4823791be514b8a5ac65d8d408f099d..7492d90096108ad327a0000710b6560f01235aca 100644 (file)
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -220,10 +220,8 @@ void update_vsyscall(struct timekeeper *tk)
        if (!use_syscall) {
                /* tkr_mono.cycle_last == tkr_raw.cycle_last */
                vdso_data->cs_cycle_last        = tk->tkr_mono.cycle_last;
-               vdso_data->raw_time_sec         = tk->raw_time.tv_sec;
-               vdso_data->raw_time_nsec        = (tk->raw_time.tv_nsec <<
-                                                  tk->tkr_raw.shift) +
-                                                 tk->tkr_raw.xtime_nsec;
+               vdso_data->raw_time_sec         = tk->raw_sec;
+               vdso_data->raw_time_nsec        = tk->tkr_raw.xtime_nsec;
                vdso_data->xtime_clock_sec      = tk->xtime_sec;
                vdso_data->xtime_clock_nsec     = tk->tkr_mono.xtime_nsec;
                vdso_data->cs_mono_mult         = tk->tkr_mono.mult;

diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h
index f7043ccca81cc65f15c252158e745dc4c2948155..0a0a53daf2a2206c38d26d133b90a5f069f2c851 100644 (file)
--- a/include/linux/timekeeper_internal.h
+++ b/include/linux/timekeeper_internal.h
@@ -51,7 +51,7 @@ struct tk_read_base {
  * @clock_was_set_seq: The sequence number of clock was set events
  * @cs_was_changed_seq:        The sequence number of clocksource change events
  * @next_leap_ktime:   CLOCK_MONOTONIC time value of a pending leap-second
- * @raw_time:          Monotonic raw base time in timespec64 format
+ * @raw_sec:           CLOCK_MONOTONIC_RAW  time in seconds
  * @cycle_interval:    Number of clock cycles in one NTP interval
  * @xtime_interval:    Number of clock shifted nano seconds in one NTP
  *                     interval.
@@ -93,7 +93,7 @@ struct timekeeper {
        unsigned int            clock_was_set_seq;
        u8                      cs_was_changed_seq;
        ktime_t                 next_leap_ktime;
-       struct timespec64       raw_time;
+       u64                     raw_sec;
 
        /* The following members are for timekeeping internal use */
        u64                     cycle_interval;

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index b602c48cb84123890dbdc40b9a3da94439ba3a9d..0454bfa24353e75d19536c21ec95343eb7cf1555 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -72,6 +72,10 @@ static inline void tk_normalize_xtime(struct timekeeper *tk)
                tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift;
                tk->xtime_sec++;
        }
+       while (tk->tkr_raw.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_raw.shift)) {
+               tk->tkr_raw.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_raw.shift;
+               tk->raw_sec++;
+       }
 }
 
 static inline struct timespec64 tk_xtime(struct timekeeper *tk)
@@ -285,12 +289,14 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
         /* if changing clocks, convert xtime_nsec shift units */
        if (old_clock) {
                int shift_change = clock->shift - old_clock->shift;
-               if (shift_change < 0)
+               if (shift_change < 0) {
                        tk->tkr_mono.xtime_nsec >>= -shift_change;
-               else
+                       tk->tkr_raw.xtime_nsec >>= -shift_change;
+               } else {
                        tk->tkr_mono.xtime_nsec <<= shift_change;
+                       tk->tkr_raw.xtime_nsec <<= shift_change;
+               }
        }
-       tk->tkr_raw.xtime_nsec = 0;
 
        tk->tkr_mono.shift = clock->shift;
        tk->tkr_raw.shift = clock->shift;
@@ -619,9 +625,6 @@ static inline void tk_update_ktime_data(struct timekeeper *tk)
        nsec = (u32) tk->wall_to_monotonic.tv_nsec;
        tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
 
-       /* Update the monotonic raw base */
-       tk->tkr_raw.base = timespec64_to_ktime(tk->raw_time);
-
        /*
         * The sum of the nanoseconds portions of xtime and
         * wall_to_monotonic can be greater/equal one second. Take
@@ -631,6 +634,11 @@ static inline void tk_update_ktime_data(struct timekeeper *tk)
        if (nsec >= NSEC_PER_SEC)
                seconds++;
        tk->ktime_sec = seconds;
+
+       /* Update the monotonic raw base */
+       seconds = tk->raw_sec;
+       nsec = (u32)(tk->tkr_raw.xtime_nsec >> tk->tkr_raw.shift);
+       tk->tkr_raw.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
 }
 
 /* must hold timekeeper_lock */
@@ -672,7 +680,6 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
 static void timekeeping_forward_now(struct timekeeper *tk)
 {
        u64 cycle_now, delta;
-       u64 nsec;
 
        cycle_now = tk_clock_read(&tk->tkr_mono);
        delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
@@ -684,10 +691,13 @@ static void timekeeping_forward_now(struct timekeeper *tk)
        /* If arch requires, add in get_arch_timeoffset() */
        tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift;
 
-       tk_normalize_xtime(tk);
 
-       nsec = clocksource_cyc2ns(delta, tk->tkr_raw.mult, tk->tkr_raw.shift);
-       timespec64_add_ns(&tk->raw_time, nsec);
+       tk->tkr_raw.xtime_nsec += delta * tk->tkr_raw.mult;
+
+       /* If arch requires, add in get_arch_timeoffset() */
+       tk->tkr_raw.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_raw.shift;
+
+       tk_normalize_xtime(tk);
 }
 
 /**
@@ -1373,19 +1383,18 @@ int timekeeping_notify(struct clocksource *clock)
 void getrawmonotonic64(struct timespec64 *ts)
 {
        struct timekeeper *tk = &tk_core.timekeeper;
-       struct timespec64 ts64;
        unsigned long seq;
        u64 nsecs;
 
        do {
                seq = read_seqcount_begin(&tk_core.seq);
+               ts->tv_sec = tk->raw_sec;
                nsecs = timekeeping_get_ns(&tk->tkr_raw);
-               ts64 = tk->raw_time;
 
        } while (read_seqcount_retry(&tk_core.seq, seq));
 
-       timespec64_add_ns(&ts64, nsecs);
-       *ts = ts64;
+       ts->tv_nsec = 0;
+       timespec64_add_ns(ts, nsecs);
 }
 EXPORT_SYMBOL(getrawmonotonic64);
 
@@ -1509,8 +1518,7 @@ void __init timekeeping_init(void)
        tk_setup_internals(tk, clock);
 
        tk_set_xtime(tk, &now);
-       tk->raw_time.tv_sec = 0;
-       tk->raw_time.tv_nsec = 0;
+       tk->raw_sec = 0;
        if (boot.tv_sec == 0 && boot.tv_nsec == 0)
                boot = tk_xtime(tk);
 
@@ -2011,15 +2019,12 @@ static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset,
        *clock_set |= accumulate_nsecs_to_secs(tk);
 
        /* Accumulate raw time */
-       tk->tkr_raw.xtime_nsec += (u64)tk->raw_time.tv_nsec << tk->tkr_raw.shift;
        tk->tkr_raw.xtime_nsec += tk->raw_interval << shift;
        snsec_per_sec = (u64)NSEC_PER_SEC << tk->tkr_raw.shift;
        while (tk->tkr_raw.xtime_nsec >= snsec_per_sec) {
                tk->tkr_raw.xtime_nsec -= snsec_per_sec;
-               tk->raw_time.tv_sec++;
+               tk->raw_sec++;
        }
-       tk->raw_time.tv_nsec = tk->tkr_raw.xtime_nsec >> tk->tkr_raw.shift;
-       tk->tkr_raw.xtime_nsec -= (u64)tk->raw_time.tv_nsec << tk->tkr_raw.shift;
 
        /* Accumulate error between NTP and clock interval */
        tk->ntp_error += tk->ntp_tick << shift;