diff options
| -rw-r--r-- | include/linux/timekeeping.h | 3 | ||||
| -rw-r--r-- | kernel/time/timekeeping.c | 59 |
2 files changed, 32 insertions, 30 deletions
diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 86bc2026efce..686bc27acef0 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -243,7 +243,8 @@ extern void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot); extern int persistent_clock_is_local; extern void read_persistent_clock64(struct timespec64 *ts); -extern void read_boot_clock64(struct timespec64 *ts); +void read_persistent_clock_and_boot_offset(struct timespec64 *wall_clock, + struct timespec64 *boot_offset); extern int update_persistent_clock64(struct timespec64 now); /* diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 4786df904c22..cb738f825c12 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -17,6 +17,7 @@ #include <linux/nmi.h> #include <linux/sched.h> #include <linux/sched/loadavg.h> +#include <linux/sched/clock.h> #include <linux/syscore_ops.h> #include <linux/clocksource.h> #include <linux/jiffies.h> @@ -1496,18 +1497,20 @@ void __weak read_persistent_clock64(struct timespec64 *ts64) } /** - * read_boot_clock64 - Return time of the system start. + * read_persistent_wall_and_boot_offset - Read persistent clock, and also offset + * from the boot. * * Weak dummy function for arches that do not yet support it. - * Function to read the exact time the system has been started. - * Returns a timespec64 with tv_sec=0 and tv_nsec=0 if unsupported. - * - * XXX - Do be sure to remove it once all arches implement it. + * wall_time - current time as returned by persistent clock + * boot_offset - offset that is defined as wall_time - boot_time + * default to 0. */ -void __weak read_boot_clock64(struct timespec64 *ts) +void __weak __init +read_persistent_wall_and_boot_offset(struct timespec64 *wall_time, + struct timespec64 *boot_offset) { - ts->tv_sec = 0; - ts->tv_nsec = 0; + read_persistent_clock64(wall_time); + *boot_offset = (struct timespec64){0}; } /* Flag for if timekeeping_resume() has injected sleeptime */ @@ -1521,28 +1524,29 @@ static bool persistent_clock_exists; */ void __init timekeeping_init(void) { + struct timespec64 wall_time, boot_offset, wall_to_mono; struct timekeeper *tk = &tk_core.timekeeper; struct clocksource *clock; unsigned long flags; - struct timespec64 now, boot, tmp; - - read_persistent_clock64(&now); - if (!timespec64_valid_strict(&now)) { - pr_warn("WARNING: Persistent clock returned invalid value!\n" - " Check your CMOS/BIOS settings.\n"); - now.tv_sec = 0; - now.tv_nsec = 0; - } else if (now.tv_sec || now.tv_nsec) - persistent_clock_exists = true; - read_boot_clock64(&boot); - if (!timespec64_valid_strict(&boot)) { - pr_warn("WARNING: Boot clock returned invalid value!\n" - " Check your CMOS/BIOS settings.\n"); - boot.tv_sec = 0; - boot.tv_nsec = 0; + read_persistent_wall_and_boot_offset(&wall_time, &boot_offset); + if (timespec64_valid_strict(&wall_time) && + timespec64_to_ns(&wall_time) > 0) { + persistent_clock_exists = true; + } else { + pr_warn("Persistent clock returned invalid value"); + wall_time = (struct timespec64){0}; } + if (timespec64_compare(&wall_time, &boot_offset) < 0) + boot_offset = (struct timespec64){0}; + + /* + * We want set wall_to_mono, so the following is true: + * wall time + wall_to_mono = boot time + */ + wall_to_mono = timespec64_sub(boot_offset, wall_time); + raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.seq); ntp_init(); @@ -1552,13 +1556,10 @@ void __init timekeeping_init(void) clock->enable(clock); tk_setup_internals(tk, clock); - tk_set_xtime(tk, &now); + tk_set_xtime(tk, &wall_time); tk->raw_sec = 0; - if (boot.tv_sec == 0 && boot.tv_nsec == 0) - boot = tk_xtime(tk); - set_normalized_timespec64(&tmp, -boot.tv_sec, -boot.tv_nsec); - tk_set_wall_to_mono(tk, tmp); + tk_set_wall_to_mono(tk, wall_to_mono); timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |