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-rw-r--r--kernel/time/timekeeping.c78
1 files changed, 37 insertions, 41 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index dcf7f20..49cbcee 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -138,12 +138,7 @@ static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm)
static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
{
- /* Update both bases so mono and raw stay coupled. */
- tk->tkr_mono.base += delta;
- tk->tkr_raw.base += delta;
-
- /* Accumulate time spent in suspend */
- tk->time_suspended += delta;
+ tk->offs_boot = ktime_add(tk->offs_boot, delta);
}
/*
@@ -473,6 +468,36 @@ u64 ktime_get_raw_fast_ns(void)
}
EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns);
+/**
+ * ktime_get_boot_fast_ns - NMI safe and fast access to boot clock.
+ *
+ * To keep it NMI safe since we're accessing from tracing, we're not using a
+ * separate timekeeper with updates to monotonic clock and boot offset
+ * protected with seqlocks. This has the following minor side effects:
+ *
+ * (1) Its possible that a timestamp be taken after the boot offset is updated
+ * but before the timekeeper is updated. If this happens, the new boot offset
+ * is added to the old timekeeping making the clock appear to update slightly
+ * earlier:
+ * CPU 0 CPU 1
+ * timekeeping_inject_sleeptime64()
+ * __timekeeping_inject_sleeptime(tk, delta);
+ * timestamp();
+ * timekeeping_update(tk, TK_CLEAR_NTP...);
+ *
+ * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be
+ * partially updated. Since the tk->offs_boot update is a rare event, this
+ * should be a rare occurrence which postprocessing should be able to handle.
+ */
+u64 notrace ktime_get_boot_fast_ns(void)
+{
+ struct timekeeper *tk = &tk_core.timekeeper;
+
+ return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot));
+}
+EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns);
+
+
/*
* See comment for __ktime_get_fast_ns() vs. timestamp ordering
*/
@@ -764,6 +789,7 @@ EXPORT_SYMBOL_GPL(ktime_get_resolution_ns);
static ktime_t *offsets[TK_OFFS_MAX] = {
[TK_OFFS_REAL] = &tk_core.timekeeper.offs_real,
+ [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot,
[TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai,
};
@@ -861,39 +887,6 @@ void ktime_get_ts64(struct timespec64 *ts)
EXPORT_SYMBOL_GPL(ktime_get_ts64);
/**
- * ktime_get_active_ts64 - Get the active non-suspended monotonic clock
- * @ts: pointer to timespec variable
- *
- * The function calculates the monotonic clock from the realtime clock and
- * the wall_to_monotonic offset, subtracts the accumulated suspend time and
- * stores the result in normalized timespec64 format in the variable
- * pointed to by @ts.
- */
-void ktime_get_active_ts64(struct timespec64 *ts)
-{
- struct timekeeper *tk = &tk_core.timekeeper;
- struct timespec64 tomono, tsusp;
- u64 nsec, nssusp;
- unsigned int seq;
-
- WARN_ON(timekeeping_suspended);
-
- do {
- seq = read_seqcount_begin(&tk_core.seq);
- ts->tv_sec = tk->xtime_sec;
- nsec = timekeeping_get_ns(&tk->tkr_mono);
- tomono = tk->wall_to_monotonic;
- nssusp = tk->time_suspended;
- } while (read_seqcount_retry(&tk_core.seq, seq));
-
- ts->tv_sec += tomono.tv_sec;
- ts->tv_nsec = 0;
- timespec64_add_ns(ts, nsec + tomono.tv_nsec);
- tsusp = ns_to_timespec64(nssusp);
- *ts = timespec64_sub(*ts, tsusp);
-}
-
-/**
* ktime_get_seconds - Get the seconds portion of CLOCK_MONOTONIC
*
* Returns the seconds portion of CLOCK_MONOTONIC with a single non
@@ -1593,6 +1586,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
return;
}
tk_xtime_add(tk, delta);
+ tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta));
tk_update_sleep_time(tk, timespec64_to_ktime(*delta));
tk_debug_account_sleep_time(delta);
}
@@ -2125,7 +2119,7 @@ out:
void getboottime64(struct timespec64 *ts)
{
struct timekeeper *tk = &tk_core.timekeeper;
- ktime_t t = ktime_sub(tk->offs_real, tk->time_suspended);
+ ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot);
*ts = ktime_to_timespec64(t);
}
@@ -2188,6 +2182,7 @@ void do_timer(unsigned long ticks)
* ktime_get_update_offsets_now - hrtimer helper
* @cwsseq: pointer to check and store the clock was set sequence number
* @offs_real: pointer to storage for monotonic -> realtime offset
+ * @offs_boot: pointer to storage for monotonic -> boottime offset
* @offs_tai: pointer to storage for monotonic -> clock tai offset
*
* Returns current monotonic time and updates the offsets if the
@@ -2197,7 +2192,7 @@ void do_timer(unsigned long ticks)
* Called from hrtimer_interrupt() or retrigger_next_event()
*/
ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
- ktime_t *offs_tai)
+ ktime_t *offs_boot, ktime_t *offs_tai)
{
struct timekeeper *tk = &tk_core.timekeeper;
unsigned int seq;
@@ -2214,6 +2209,7 @@ ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
if (*cwsseq != tk->clock_was_set_seq) {
*cwsseq = tk->clock_was_set_seq;
*offs_real = tk->offs_real;
+ *offs_boot = tk->offs_boot;
*offs_tai = tk->offs_tai;
}
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