mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 19:16:40 +07:00
ef35a4e6d9
If the timer interrupt has been de-init or is just now being initialized, the default value of -1 should be preset as interrupt line. Check for that and if something is odd WARN us. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
533 lines
13 KiB
C
533 lines
13 KiB
C
/*
|
|
* Xen time implementation.
|
|
*
|
|
* This is implemented in terms of a clocksource driver which uses
|
|
* the hypervisor clock as a nanosecond timebase, and a clockevent
|
|
* driver which uses the hypervisor's timer mechanism.
|
|
*
|
|
* Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/clocksource.h>
|
|
#include <linux/clockchips.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <linux/math64.h>
|
|
#include <linux/gfp.h>
|
|
|
|
#include <asm/pvclock.h>
|
|
#include <asm/xen/hypervisor.h>
|
|
#include <asm/xen/hypercall.h>
|
|
|
|
#include <xen/events.h>
|
|
#include <xen/features.h>
|
|
#include <xen/interface/xen.h>
|
|
#include <xen/interface/vcpu.h>
|
|
|
|
#include "xen-ops.h"
|
|
|
|
/* Xen may fire a timer up to this many ns early */
|
|
#define TIMER_SLOP 100000
|
|
#define NS_PER_TICK (1000000000LL / HZ)
|
|
|
|
/* runstate info updated by Xen */
|
|
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 */
|
|
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)
|
|
{
|
|
u64 ret;
|
|
|
|
if (BITS_PER_LONG < 64) {
|
|
u32 *p32 = (u32 *)p;
|
|
u32 h, l;
|
|
|
|
/*
|
|
* Read high then low, and then make sure high is
|
|
* still the same; this will only loop if low wraps
|
|
* and carries into high.
|
|
* XXX some clean way to make this endian-proof?
|
|
*/
|
|
do {
|
|
h = p32[1];
|
|
barrier();
|
|
l = p32[0];
|
|
barrier();
|
|
} while (p32[1] != h);
|
|
|
|
ret = (((u64)h) << 32) | l;
|
|
} else
|
|
ret = *p;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Runstate accounting
|
|
*/
|
|
static void get_runstate_snapshot(struct vcpu_runstate_info *res)
|
|
{
|
|
u64 state_time;
|
|
struct vcpu_runstate_info *state;
|
|
|
|
BUG_ON(preemptible());
|
|
|
|
state = &__get_cpu_var(xen_runstate);
|
|
|
|
/*
|
|
* The runstate info is always updated by the hypervisor on
|
|
* the current CPU, so there's no need to use anything
|
|
* stronger than a compiler barrier when fetching it.
|
|
*/
|
|
do {
|
|
state_time = get64(&state->state_entry_time);
|
|
barrier();
|
|
*res = *state;
|
|
barrier();
|
|
} while (get64(&state->state_entry_time) != state_time);
|
|
}
|
|
|
|
/* return true when a vcpu could run but has no real cpu to run on */
|
|
bool xen_vcpu_stolen(int vcpu)
|
|
{
|
|
return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable;
|
|
}
|
|
|
|
void xen_setup_runstate_info(int cpu)
|
|
{
|
|
struct vcpu_register_runstate_memory_area area;
|
|
|
|
area.addr.v = &per_cpu(xen_runstate, cpu);
|
|
|
|
if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area,
|
|
cpu, &area))
|
|
BUG();
|
|
}
|
|
|
|
static void do_stolen_accounting(void)
|
|
{
|
|
struct vcpu_runstate_info state;
|
|
struct vcpu_runstate_info *snap;
|
|
s64 blocked, runnable, offline, stolen;
|
|
cputime_t ticks;
|
|
|
|
get_runstate_snapshot(&state);
|
|
|
|
WARN_ON(state.state != RUNSTATE_running);
|
|
|
|
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];
|
|
|
|
*snap = state;
|
|
|
|
/* Add the appropriate number of ticks of stolen time,
|
|
including any left-overs from last time. */
|
|
stolen = runnable + offline + __this_cpu_read(xen_residual_stolen);
|
|
|
|
if (stolen < 0)
|
|
stolen = 0;
|
|
|
|
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 */
|
|
static unsigned long xen_tsc_khz(void)
|
|
{
|
|
struct pvclock_vcpu_time_info *info =
|
|
&HYPERVISOR_shared_info->vcpu_info[0].time;
|
|
|
|
return pvclock_tsc_khz(info);
|
|
}
|
|
|
|
cycle_t xen_clocksource_read(void)
|
|
{
|
|
struct pvclock_vcpu_time_info *src;
|
|
cycle_t ret;
|
|
|
|
preempt_disable_notrace();
|
|
src = &__get_cpu_var(xen_vcpu)->time;
|
|
ret = pvclock_clocksource_read(src);
|
|
preempt_enable_notrace();
|
|
return ret;
|
|
}
|
|
|
|
static cycle_t xen_clocksource_get_cycles(struct clocksource *cs)
|
|
{
|
|
return xen_clocksource_read();
|
|
}
|
|
|
|
static void xen_read_wallclock(struct timespec *ts)
|
|
{
|
|
struct shared_info *s = HYPERVISOR_shared_info;
|
|
struct pvclock_wall_clock *wall_clock = &(s->wc);
|
|
struct pvclock_vcpu_time_info *vcpu_time;
|
|
|
|
vcpu_time = &get_cpu_var(xen_vcpu)->time;
|
|
pvclock_read_wallclock(wall_clock, vcpu_time, ts);
|
|
put_cpu_var(xen_vcpu);
|
|
}
|
|
|
|
static unsigned long xen_get_wallclock(void)
|
|
{
|
|
struct timespec ts;
|
|
|
|
xen_read_wallclock(&ts);
|
|
return ts.tv_sec;
|
|
}
|
|
|
|
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 struct clocksource xen_clocksource __read_mostly = {
|
|
.name = "xen",
|
|
.rating = 400,
|
|
.read = xen_clocksource_get_cycles,
|
|
.mask = ~0,
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
};
|
|
|
|
/*
|
|
Xen clockevent implementation
|
|
|
|
Xen has two clockevent implementations:
|
|
|
|
The old timer_op one works with all released versions of Xen prior
|
|
to version 3.0.4. This version of the hypervisor provides a
|
|
single-shot timer with nanosecond resolution. However, sharing the
|
|
same event channel is a 100Hz tick which is delivered while the
|
|
vcpu is running. We don't care about or use this tick, but it will
|
|
cause the core time code to think the timer fired too soon, and
|
|
will end up resetting it each time. It could be filtered, but
|
|
doing so has complications when the ktime clocksource is not yet
|
|
the xen clocksource (ie, at boot time).
|
|
|
|
The new vcpu_op-based timer interface allows the tick timer period
|
|
to be changed or turned off. The tick timer is not useful as a
|
|
periodic timer because events are only delivered to running vcpus.
|
|
The one-shot timer can report when a timeout is in the past, so
|
|
set_next_event is capable of returning -ETIME when appropriate.
|
|
This interface is used when available.
|
|
*/
|
|
|
|
|
|
/*
|
|
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 void xen_timerop_set_mode(enum clock_event_mode mode,
|
|
struct clock_event_device *evt)
|
|
{
|
|
switch (mode) {
|
|
case CLOCK_EVT_MODE_PERIODIC:
|
|
/* unsupported */
|
|
WARN_ON(1);
|
|
break;
|
|
|
|
case CLOCK_EVT_MODE_ONESHOT:
|
|
case CLOCK_EVT_MODE_RESUME:
|
|
break;
|
|
|
|
case CLOCK_EVT_MODE_UNUSED:
|
|
case CLOCK_EVT_MODE_SHUTDOWN:
|
|
HYPERVISOR_set_timer_op(0); /* cancel timeout */
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int xen_timerop_set_next_event(unsigned long delta,
|
|
struct clock_event_device *evt)
|
|
{
|
|
WARN_ON(evt->mode != CLOCK_EVT_MODE_ONESHOT);
|
|
|
|
if (HYPERVISOR_set_timer_op(get_abs_timeout(delta)) < 0)
|
|
BUG();
|
|
|
|
/* We may have missed the deadline, but there's no real way of
|
|
knowing for sure. If the event was in the past, then we'll
|
|
get an immediate interrupt. */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct clock_event_device xen_timerop_clockevent = {
|
|
.name = "xen",
|
|
.features = CLOCK_EVT_FEAT_ONESHOT,
|
|
|
|
.max_delta_ns = 0xffffffff,
|
|
.min_delta_ns = TIMER_SLOP,
|
|
|
|
.mult = 1,
|
|
.shift = 0,
|
|
.rating = 500,
|
|
|
|
.set_mode = xen_timerop_set_mode,
|
|
.set_next_event = xen_timerop_set_next_event,
|
|
};
|
|
|
|
|
|
|
|
static void xen_vcpuop_set_mode(enum clock_event_mode mode,
|
|
struct clock_event_device *evt)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
|
|
switch (mode) {
|
|
case CLOCK_EVT_MODE_PERIODIC:
|
|
WARN_ON(1); /* unsupported */
|
|
break;
|
|
|
|
case CLOCK_EVT_MODE_ONESHOT:
|
|
if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL))
|
|
BUG();
|
|
break;
|
|
|
|
case CLOCK_EVT_MODE_UNUSED:
|
|
case CLOCK_EVT_MODE_SHUTDOWN:
|
|
if (HYPERVISOR_vcpu_op(VCPUOP_stop_singleshot_timer, cpu, NULL) ||
|
|
HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL))
|
|
BUG();
|
|
break;
|
|
case CLOCK_EVT_MODE_RESUME:
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int xen_vcpuop_set_next_event(unsigned long delta,
|
|
struct clock_event_device *evt)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
struct vcpu_set_singleshot_timer single;
|
|
int ret;
|
|
|
|
WARN_ON(evt->mode != CLOCK_EVT_MODE_ONESHOT);
|
|
|
|
single.timeout_abs_ns = get_abs_timeout(delta);
|
|
single.flags = VCPU_SSHOTTMR_future;
|
|
|
|
ret = HYPERVISOR_vcpu_op(VCPUOP_set_singleshot_timer, cpu, &single);
|
|
|
|
BUG_ON(ret != 0 && ret != -ETIME);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct clock_event_device xen_vcpuop_clockevent = {
|
|
.name = "xen",
|
|
.features = CLOCK_EVT_FEAT_ONESHOT,
|
|
|
|
.max_delta_ns = 0xffffffff,
|
|
.min_delta_ns = TIMER_SLOP,
|
|
|
|
.mult = 1,
|
|
.shift = 0,
|
|
.rating = 500,
|
|
|
|
.set_mode = xen_vcpuop_set_mode,
|
|
.set_next_event = xen_vcpuop_set_next_event,
|
|
};
|
|
|
|
static const struct clock_event_device *xen_clockevent =
|
|
&xen_timerop_clockevent;
|
|
static DEFINE_PER_CPU(struct clock_event_device, xen_clock_events) = { .irq = -1 };
|
|
|
|
static irqreturn_t xen_timer_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct clock_event_device *evt = &__get_cpu_var(xen_clock_events);
|
|
irqreturn_t ret;
|
|
|
|
ret = IRQ_NONE;
|
|
if (evt->event_handler) {
|
|
evt->event_handler(evt);
|
|
ret = IRQ_HANDLED;
|
|
}
|
|
|
|
do_stolen_accounting();
|
|
|
|
return ret;
|
|
}
|
|
|
|
void xen_setup_timer(int cpu)
|
|
{
|
|
const char *name;
|
|
struct clock_event_device *evt;
|
|
int irq;
|
|
|
|
evt = &per_cpu(xen_clock_events, cpu);
|
|
WARN(evt->irq >= 0, "IRQ%d for CPU%d is already allocated\n", evt->irq, cpu);
|
|
|
|
printk(KERN_INFO "installing Xen timer for CPU %d\n", cpu);
|
|
|
|
name = kasprintf(GFP_KERNEL, "timer%d", cpu);
|
|
if (!name)
|
|
name = "<timer kasprintf failed>";
|
|
|
|
irq = bind_virq_to_irqhandler(VIRQ_TIMER, cpu, xen_timer_interrupt,
|
|
IRQF_DISABLED|IRQF_PERCPU|
|
|
IRQF_NOBALANCING|IRQF_TIMER|
|
|
IRQF_FORCE_RESUME,
|
|
name, NULL);
|
|
|
|
memcpy(evt, xen_clockevent, sizeof(*evt));
|
|
|
|
evt->cpumask = cpumask_of(cpu);
|
|
evt->irq = irq;
|
|
}
|
|
|
|
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));
|
|
}
|
|
|
|
void xen_timer_resume(void)
|
|
{
|
|
int cpu;
|
|
|
|
pvclock_resume();
|
|
|
|
if (xen_clockevent != &xen_vcpuop_clockevent)
|
|
return;
|
|
|
|
for_each_online_cpu(cpu) {
|
|
if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL))
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
static const struct pv_time_ops xen_time_ops __initconst = {
|
|
.sched_clock = xen_clocksource_read,
|
|
};
|
|
|
|
static void __init xen_time_init(void)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
struct timespec tp;
|
|
|
|
clocksource_register_hz(&xen_clocksource, NSEC_PER_SEC);
|
|
|
|
if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL) == 0) {
|
|
/* Successfully turned off 100Hz tick, so we have the
|
|
vcpuop-based timer interface */
|
|
printk(KERN_DEBUG "Xen: using vcpuop timer interface\n");
|
|
xen_clockevent = &xen_vcpuop_clockevent;
|
|
}
|
|
|
|
/* Set initial system time with full resolution */
|
|
xen_read_wallclock(&tp);
|
|
do_settimeofday(&tp);
|
|
|
|
setup_force_cpu_cap(X86_FEATURE_TSC);
|
|
|
|
xen_setup_runstate_info(cpu);
|
|
xen_setup_timer(cpu);
|
|
xen_setup_cpu_clockevents();
|
|
}
|
|
|
|
void __init xen_init_time_ops(void)
|
|
{
|
|
pv_time_ops = xen_time_ops;
|
|
|
|
x86_init.timers.timer_init = xen_time_init;
|
|
x86_init.timers.setup_percpu_clockev = x86_init_noop;
|
|
x86_cpuinit.setup_percpu_clockev = x86_init_noop;
|
|
|
|
x86_platform.calibrate_tsc = xen_tsc_khz;
|
|
x86_platform.get_wallclock = xen_get_wallclock;
|
|
x86_platform.set_wallclock = xen_set_wallclock;
|
|
}
|
|
|
|
#ifdef CONFIG_XEN_PVHVM
|
|
static void xen_hvm_setup_cpu_clockevents(void)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
xen_setup_runstate_info(cpu);
|
|
/*
|
|
* xen_setup_timer(cpu) - snprintf is bad in atomic context. Hence
|
|
* doing it xen_hvm_cpu_notify (which gets called by smp_init during
|
|
* early bootup and also during CPU hotplug events).
|
|
*/
|
|
xen_setup_cpu_clockevents();
|
|
}
|
|
|
|
void __init xen_hvm_init_time_ops(void)
|
|
{
|
|
/* vector callback is needed otherwise we cannot receive interrupts
|
|
* on cpu > 0 and at this point we don't know how many cpus are
|
|
* available */
|
|
if (!xen_have_vector_callback)
|
|
return;
|
|
if (!xen_feature(XENFEAT_hvm_safe_pvclock)) {
|
|
printk(KERN_INFO "Xen doesn't support pvclock on HVM,"
|
|
"disable pv timer\n");
|
|
return;
|
|
}
|
|
|
|
pv_time_ops = xen_time_ops;
|
|
x86_init.timers.setup_percpu_clockev = xen_time_init;
|
|
x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents;
|
|
|
|
x86_platform.calibrate_tsc = xen_tsc_khz;
|
|
x86_platform.get_wallclock = xen_get_wallclock;
|
|
x86_platform.set_wallclock = xen_set_wallclock;
|
|
}
|
|
#endif
|