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;
struct timekeeper *tk = priv;
static bool settime64_supported = true;
int ret;
now.tv_sec = tk->xtime_sec;
now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
/*
* 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;
again:
if (settime64_supported) {
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 = xen_clocksource_read();
} else {
op.cmd = XENPF_settime32;
op.u.settime32.secs = now.tv_sec;
op.u.settime32.nsecs = now.tv_nsec;
op.u.settime32.system_time = xen_clocksource_read();
}
ret = HYPERVISOR_platform_op(&op);
if (ret == -ENOSYS && settime64_supported) {
settime64_supported = false;
goto again;
}
if (ret < 0)
return NOTIFY_BAD;
/*
* 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 int xen_pvclock_gtod_notify(struct notifier_block *nb,
unsigned long was_set, void *priv)
{
/* Protected by the calling core code serialization */
static struct timespec next_sync;
struct xen_platform_op op;
struct timespec now;
now = __current_kernel_time();
/*
* We only take the expensive HV call when the clock was set
* or when the 11 minutes RTC synchronization time elapsed.
*/
if (!was_set && timespec_compare(&now, &next_sync) < 0)
return NOTIFY_OK;
op.cmd = XENPF_settime;
op.u.settime.secs = now.tv_sec;
op.u.settime.nsecs = now.tv_nsec;
op.u.settime.system_time = xen_clocksource_read();
(void)HYPERVISOR_dom0_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 inline void spin_time_accum_blocked(u64 start)
{
u32 delta = xen_clocksource_read() - start;
__spin_time_accum(delta, spinlock_stats.histo_spin_blocked);
spinlock_stats.time_blocked += delta;
}
/*
* Xen sched_clock implementation. Returns the number of unstolen
* nanoseconds, which is nanoseconds the VCPU spent in RUNNING+BLOCKED
* states.
*/
unsigned long long xen_sched_clock(void)
{
struct vcpu_runstate_info state;
cycle_t now;
u64 ret;
s64 offset;
/*
* Ideally sched_clock should be called on a per-cpu basis
* anyway, so preempt should already be disabled, but that's
* not current practice at the moment.
*/
preempt_disable();
now = xen_clocksource_read();
get_runstate_snapshot(&state);
WARN_ON(state.state != RUNSTATE_running);
offset = now - state.state_entry_time;
if (offset < 0)
offset = 0;
ret = state.time[RUNSTATE_blocked] +
state.time[RUNSTATE_running] +
offset;
preempt_enable();
return ret;
}
static int xen_set_wallclock(unsigned long now)
{
struct xen_platform_op op;
int rc;
/* do nothing for domU */
if (!xen_initial_domain())
return -1;
op.cmd = XENPF_settime;
op.u.settime.secs = now;
op.u.settime.nsecs = 0;
op.u.settime.system_time = xen_clocksource_read();
rc = HYPERVISOR_dom0_op(&op);
WARN(rc != 0, "XENPF_settime failed: now=%ld\n", now);
return rc;
}
static u64 xen_clocksource_get_cycles(struct clocksource *cs)
{
return xen_clocksource_read();
}
/*
Get a hypervisor absolute time. In theory we could maintain an
offset between the kernel's time and the hypervisor's time, and
apply that to a kernel's absolute timeout. Unfortunately the
hypervisor and kernel times can drift even if the kernel is using
the Xen clocksource, because ntp can warp the kernel's clocksource.
*/
static s64 get_abs_timeout(unsigned long delta)
{
return xen_clocksource_read() + delta;
}
static u64 xen_sched_clock(void)
{
return xen_clocksource_read() - xen_sched_clock_offset;
}
static inline u64 spin_time_start(void)
{
return xen_clocksource_read();
}