diff options
Diffstat (limited to 'arch/arm/xen')
| -rw-r--r-- | arch/arm/xen/enlighten.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 6370222b8053..75cd7345c654 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -26,7 +26,10 @@ #include <linux/cpufreq.h> #include <linux/cpu.h> #include <linux/console.h> +#include <linux/pvclock_gtod.h> +#include <linux/time64.h> #include <linux/timekeeping.h> +#include <linux/timekeeper_internal.h> #include <linux/mm.h> @@ -115,6 +118,49 @@ static void xen_read_wallclock(struct timespec64 *ts) *ts = timespec64_add(now, ts_monotonic); } +static int xen_pvclock_gtod_notify(struct notifier_block *nb, + unsigned long was_set, void *priv) +{ + /* Protected by the calling core code serialization */ + static struct timespec64 next_sync; + + struct xen_platform_op op; + struct timespec64 now, system_time; + struct timekeeper *tk = priv; + + now.tv_sec = tk->xtime_sec; + now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); + system_time = timespec64_add(now, tk->wall_to_monotonic); + + /* + * We only take the expensive HV call when the clock was set + * or when the 11 minutes RTC synchronization time elapsed. + */ + if (!was_set && timespec64_compare(&now, &next_sync) < 0) + return NOTIFY_OK; + + op.cmd = XENPF_settime64; + op.u.settime64.mbz = 0; + op.u.settime64.secs = now.tv_sec; + op.u.settime64.nsecs = now.tv_nsec; + op.u.settime64.system_time = timespec64_to_ns(&system_time); + (void)HYPERVISOR_platform_op(&op); + + /* + * Move the next drift compensation time 11 minutes + * ahead. That's emulating the sync_cmos_clock() update for + * the hardware RTC. + */ + next_sync = now; + next_sync.tv_sec += 11 * 60; + + return NOTIFY_OK; +} + +static struct notifier_block xen_pvclock_gtod_notifier = { + .notifier_call = xen_pvclock_gtod_notify, +}; + static void xen_percpu_init(void) { struct vcpu_register_vcpu_info info; @@ -311,6 +357,8 @@ static int __init xen_guest_init(void) pv_time_ops.steal_clock = xen_stolen_accounting; static_key_slow_inc(¶virt_steal_enabled); + if (xen_initial_domain()) + pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); return 0; } |