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-rw-r--r--arch/x86/xen/time.c116
1 files changed, 73 insertions, 43 deletions
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 3d88bfdf9e1..ee365895b06 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -14,6 +14,8 @@
#include <linux/kernel_stat.h>
#include <linux/math64.h>
#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/pvclock_gtod.h>
#include <asm/pvclock.h>
#include <asm/xen/hypervisor.h>
@@ -36,9 +38,8 @@ static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate);
/* snapshots of runstate info */
static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot);
-/* unused ns of stolen and blocked time */
+/* unused ns of stolen time */
static DEFINE_PER_CPU(u64, xen_residual_stolen);
-static DEFINE_PER_CPU(u64, xen_residual_blocked);
/* return an consistent snapshot of 64-bit time/counter value */
static u64 get64(const u64 *p)
@@ -115,7 +116,7 @@ static void do_stolen_accounting(void)
{
struct vcpu_runstate_info state;
struct vcpu_runstate_info *snap;
- s64 blocked, runnable, offline, stolen;
+ s64 runnable, offline, stolen;
cputime_t ticks;
get_runstate_snapshot(&state);
@@ -125,7 +126,6 @@ static void do_stolen_accounting(void)
snap = &__get_cpu_var(xen_runstate_snapshot);
/* work out how much time the VCPU has not been runn*ing* */
- blocked = state.time[RUNSTATE_blocked] - snap->time[RUNSTATE_blocked];
runnable = state.time[RUNSTATE_runnable] - snap->time[RUNSTATE_runnable];
offline = state.time[RUNSTATE_offline] - snap->time[RUNSTATE_offline];
@@ -141,17 +141,6 @@ static void do_stolen_accounting(void)
ticks = iter_div_u64_rem(stolen, NS_PER_TICK, &stolen);
__this_cpu_write(xen_residual_stolen, stolen);
account_steal_ticks(ticks);
-
- /* Add the appropriate number of ticks of blocked time,
- including any left-overs from last time. */
- blocked += __this_cpu_read(xen_residual_blocked);
-
- if (blocked < 0)
- blocked = 0;
-
- ticks = iter_div_u64_rem(blocked, NS_PER_TICK, &blocked);
- __this_cpu_write(xen_residual_blocked, blocked);
- account_idle_ticks(ticks);
}
/* Get the TSC speed from Xen */
@@ -191,34 +180,56 @@ static void xen_read_wallclock(struct timespec *ts)
put_cpu_var(xen_vcpu);
}
-static unsigned long xen_get_wallclock(void)
+static void xen_get_wallclock(struct timespec *now)
{
- struct timespec ts;
+ xen_read_wallclock(now);
+}
- xen_read_wallclock(&ts);
- return ts.tv_sec;
+static int xen_set_wallclock(const struct timespec *now)
+{
+ return -1;
}
-static int xen_set_wallclock(unsigned long now)
+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;
- int rc;
+ struct timespec now;
- /* do nothing for domU */
- if (!xen_initial_domain())
- return -1;
+ 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;
- op.u.settime.nsecs = 0;
+ op.u.settime.secs = now.tv_sec;
+ op.u.settime.nsecs = now.tv_nsec;
op.u.settime.system_time = xen_clocksource_read();
- rc = HYPERVISOR_dom0_op(&op);
- WARN(rc != 0, "XENPF_settime failed: now=%ld\n", now);
+ (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 rc;
+ return NOTIFY_OK;
}
+static struct notifier_block xen_pvclock_gtod_notifier = {
+ .notifier_call = xen_pvclock_gtod_notify,
+};
+
static struct clocksource xen_clocksource __read_mostly = {
.name = "xen",
.rating = 400,
@@ -377,11 +388,16 @@ static const struct clock_event_device xen_vcpuop_clockevent = {
static const struct clock_event_device *xen_clockevent =
&xen_timerop_clockevent;
-static DEFINE_PER_CPU(struct clock_event_device, xen_clock_events) = { .irq = -1 };
+
+struct xen_clock_event_device {
+ struct clock_event_device evt;
+ char *name;
+};
+static DEFINE_PER_CPU(struct xen_clock_event_device, xen_clock_events) = { .evt.irq = -1 };
static irqreturn_t xen_timer_interrupt(int irq, void *dev_id)
{
- struct clock_event_device *evt = &__get_cpu_var(xen_clock_events);
+ struct clock_event_device *evt = &__get_cpu_var(xen_clock_events).evt;
irqreturn_t ret;
ret = IRQ_NONE;
@@ -395,14 +411,30 @@ static irqreturn_t xen_timer_interrupt(int irq, void *dev_id)
return ret;
}
+void xen_teardown_timer(int cpu)
+{
+ struct clock_event_device *evt;
+ BUG_ON(cpu == 0);
+ evt = &per_cpu(xen_clock_events, cpu).evt;
+
+ if (evt->irq >= 0) {
+ unbind_from_irqhandler(evt->irq, NULL);
+ evt->irq = -1;
+ kfree(per_cpu(xen_clock_events, cpu).name);
+ per_cpu(xen_clock_events, cpu).name = NULL;
+ }
+}
+
void xen_setup_timer(int cpu)
{
- const char *name;
+ char *name;
struct clock_event_device *evt;
int irq;
- evt = &per_cpu(xen_clock_events, cpu);
+ evt = &per_cpu(xen_clock_events, cpu).evt;
WARN(evt->irq >= 0, "IRQ%d for CPU%d is already allocated\n", evt->irq, cpu);
+ if (evt->irq >= 0)
+ xen_teardown_timer(cpu);
printk(KERN_INFO "installing Xen timer for CPU %d\n", cpu);
@@ -420,22 +452,15 @@ void xen_setup_timer(int cpu)
evt->cpumask = cpumask_of(cpu);
evt->irq = irq;
+ per_cpu(xen_clock_events, cpu).name = name;
}
-void xen_teardown_timer(int cpu)
-{
- struct clock_event_device *evt;
- BUG_ON(cpu == 0);
- evt = &per_cpu(xen_clock_events, cpu);
- unbind_from_irqhandler(evt->irq, NULL);
- evt->irq = -1;
-}
void xen_setup_cpu_clockevents(void)
{
BUG_ON(preemptible());
- clockevents_register_device(&__get_cpu_var(xen_clock_events));
+ clockevents_register_device(&__get_cpu_var(xen_clock_events).evt);
}
void xen_timer_resume(void)
@@ -480,6 +505,9 @@ static void __init xen_time_init(void)
xen_setup_runstate_info(cpu);
xen_setup_timer(cpu);
xen_setup_cpu_clockevents();
+
+ if (xen_initial_domain())
+ pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
}
void __init xen_init_time_ops(void)
@@ -492,7 +520,9 @@ void __init xen_init_time_ops(void)
x86_platform.calibrate_tsc = xen_tsc_khz;
x86_platform.get_wallclock = xen_get_wallclock;
- x86_platform.set_wallclock = xen_set_wallclock;
+ /* Dom0 uses the native method to set the hardware RTC. */
+ if (!xen_initial_domain())
+ x86_platform.set_wallclock = xen_set_wallclock;
}
#ifdef CONFIG_XEN_PVHVM
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-30 17:21:19 +0000