/**
* tick_is_oneshot_available - check for a oneshot capable event device
*/
int tick_is_oneshot_available(void)
{
struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT))
return 0;
if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
return 1;
return tick_broadcast_oneshot_available();
}
static void arch_perfmon_setup_counters(void)
{
union cpuid10_eax eax;
eax.full = cpuid_eax(0xa);
if (eax.split.version_id == 0 && __this_cpu_read(cpu_info.x86) == 6 &&
__this_cpu_read(cpu_info.x86_model) == 15) {
eax.split.version_id = 2;
eax.split.num_counters = 2;
eax.split.bit_width = 40;
}
num_counters = min((int)eax.split.num_counters, OP_MAX_COUNTER);
op_arch_perfmon_spec.num_counters = num_counters;
op_arch_perfmon_spec.num_controls = num_counters;
}
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);
}
void __tasklet_hi_schedule(struct tasklet_struct *t)
{
unsigned long flags;
local_irq_save(flags);
t->next = NULL;
*__this_cpu_read(tasklet_hi_vec.tail) = t;
__this_cpu_write(tasklet_hi_vec.tail, &(t->next));
raise_softirq_irqoff(HI_SOFTIRQ);
local_irq_restore(flags);
}
/**
* tick_check_oneshot_mode - check whether the system is in oneshot mode
*
* returns 1 when either nohz or highres are enabled. otherwise 0.
*/
int tick_oneshot_mode_active(void)
{
unsigned long flags;
int ret;
local_irq_save(flags);
ret = __this_cpu_read(tick_cpu_device.mode) == TICKDEV_MODE_ONESHOT;
local_irq_restore(flags);
return ret;
}
u64 xen_clocksource_read(void)
{
struct pvclock_vcpu_time_info *src;
u64 ret;
preempt_disable_notrace();
src = &__this_cpu_read(xen_vcpu)->time;
ret = pvclock_clocksource_read(src);
preempt_enable_notrace();
return ret;
}
static void tasklet_action(struct softirq_action *a)
{
struct tasklet_struct *list;
local_irq_disable();
list = __this_cpu_read(tasklet_vec.head);
__this_cpu_write(tasklet_vec.head, NULL);
__this_cpu_write(tasklet_vec.tail, &__get_cpu_var(tasklet_vec).head);
local_irq_enable();
while (list) {
struct tasklet_struct *t = list;
list = list->next;
if (tasklet_trylock(t)) {
if (!atomic_read(&t->count)) {
if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
BUG();
#ifdef CONFIG_SEC_DEBUG
sec_debug_irq_sched_log(-1, t->func, 3);
t->func(t->data);
sec_debug_irq_sched_log(-1, t->func, 4);
#else
t->func(t->data);
#endif
tasklet_unlock(t);
continue;
}
tasklet_unlock(t);
}
local_irq_disable();
t->next = NULL;
*__this_cpu_read(tasklet_vec.tail) = t;
__this_cpu_write(tasklet_vec.tail, &(t->next));
__raise_softirq_irqoff(TASKLET_SOFTIRQ);
local_irq_enable();
}
}
/**
* cpuidle_idle_call - the main idle loop
*
* NOTE: no locks or semaphores should be used here
* return non-zero on failure
*/
int cpuidle_idle_call(void)
{
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
struct cpuidle_driver *drv;
int next_state, entered_state;
if (off)
return -ENODEV;
if (!initialized)
return -ENODEV;
/* check if the device is ready */
if (!dev || !dev->enabled)
return -EBUSY;
drv = cpuidle_get_cpu_driver(dev);
/* ask the governor for the next state */
next_state = cpuidle_curr_governor->select(drv, dev);
if (need_resched()) {
dev->last_residency = 0;
/* give the governor an opportunity to reflect on the outcome */
if (cpuidle_curr_governor->reflect)
cpuidle_curr_governor->reflect(dev, next_state);
local_irq_enable();
return 0;
}
trace_cpu_idle_rcuidle(next_state, dev->cpu);
if (drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP)
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
&dev->cpu);
if (cpuidle_state_is_coupled(dev, drv, next_state))
entered_state = cpuidle_enter_state_coupled(dev, drv,
next_state);
else
entered_state = cpuidle_enter_state(dev, drv, next_state);
if (drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP)
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
&dev->cpu);
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
/* give the governor an opportunity to reflect on the outcome */
if (cpuidle_curr_governor->reflect)
cpuidle_curr_governor->reflect(dev, entered_state);
return 0;
}
/*S:010
* We approach the Switcher.
*
* Remember that each CPU has two pages which are visible to the Guest when it
* runs on that CPU. This has to contain the state for that Guest: we copy the
* state in just before we run the Guest.
*
* Each Guest has "changed" flags which indicate what has changed in the Guest
* since it last ran. We saw this set in interrupts_and_traps.c and
* segments.c.
*/
static void copy_in_guest_info(struct lg_cpu *cpu, struct lguest_pages *pages)
{
/*
* Copying all this data can be quite expensive. We usually run the
* same Guest we ran last time (and that Guest hasn't run anywhere else
* meanwhile). If that's not the case, we pretend everything in the
* Guest has changed.
*/
if (__this_cpu_read(lg_last_cpu) != cpu || cpu->last_pages != pages) {
__this_cpu_write(lg_last_cpu, cpu);
cpu->last_pages = pages;
cpu->changed = CHANGED_ALL;
}
/*
* These copies are pretty cheap, so we do them unconditionally: */
/* Save the current Host top-level page directory.
*/
#ifdef CONFIG_PAX_PER_CPU_PGD
pages->state.host_cr3 = read_cr3();
#else
pages->state.host_cr3 = __pa(current->mm->pgd);
#endif
/*
* Set up the Guest's page tables to see this CPU's pages (and no
* other CPU's pages).
*/
map_switcher_in_guest(cpu, pages);
/*
* Set up the two "TSS" members which tell the CPU what stack to use
* for traps which do directly into the Guest (ie. traps at privilege
* level 1).
*/
pages->state.guest_tss.sp1 = cpu->esp1;
pages->state.guest_tss.ss1 = cpu->ss1;
/* Copy direct-to-Guest trap entries. */
if (cpu->changed & CHANGED_IDT)
copy_traps(cpu, pages->state.guest_idt, default_idt_entries);
/* Copy all GDT entries which the Guest can change. */
if (cpu->changed & CHANGED_GDT)
copy_gdt(cpu, pages->state.guest_gdt);
/* If only the TLS entries have changed, copy them. */
else if (cpu->changed & CHANGED_GDT_TLS)
copy_gdt_tls(cpu, pages->state.guest_gdt);
/* Mark the Guest as unchanged for next time. */
cpu->changed = 0;
}
unsigned long cmci_intel_adjust_timer(unsigned long interval)
{
if ((this_cpu_read(cmci_backoff_cnt) > 0) &&
(__this_cpu_read(cmci_storm_state) == CMCI_STORM_ACTIVE)) {
mce_notify_irq();
return CMCI_STORM_INTERVAL;
}
switch (__this_cpu_read(cmci_storm_state)) {
case CMCI_STORM_ACTIVE:
/*
* We switch back to interrupt mode once the poll timer has
* silenced itself. That means no events recorded and the timer
* interval is back to our poll interval.
*/
__this_cpu_write(cmci_storm_state, CMCI_STORM_SUBSIDED);
if (!atomic_sub_return(1, &cmci_storm_on_cpus))
pr_notice("CMCI storm subsided: switching to interrupt mode\n");
/* FALLTHROUGH */
case CMCI_STORM_SUBSIDED:
/*
* We wait for all CPUs to go back to SUBSIDED state. When that
* happens we switch back to interrupt mode.
*/
if (!atomic_read(&cmci_storm_on_cpus)) {
__this_cpu_write(cmci_storm_state, CMCI_STORM_NONE);
cmci_reenable();
cmci_recheck();
}
return CMCI_POLL_INTERVAL;
default:
/* We have shiny weather. Let the poll do whatever it thinks. */
return interval;
}
}
/* Callback function for perf event subsystem */
static void watchdog_overflow_callback(struct perf_event *event,
struct perf_sample_data *data,
struct pt_regs *regs)
{
/* Ensure the watchdog never gets throttled */
event->hw.interrupts = 0;
if (__this_cpu_read(watchdog_nmi_touch) == true) {
__this_cpu_write(watchdog_nmi_touch, false);
return;
}
/* check for a hardlockup
* This is done by making sure our timer interrupt
* is incrementing. The timer interrupt should have
* fired multiple times before we overflow'd. If it hasn't
* then this is a good indication the cpu is stuck
*/
if (is_hardlockup()) {
int this_cpu = smp_processor_id();
/* only print hardlockups once */
if (__this_cpu_read(hard_watchdog_warn) == true)
return;
if (hardlockup_panic) {
trigger_all_cpu_backtrace();
panic("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
}
else
WARN(1, "Watchdog detected hard LOCKUP on cpu %d", this_cpu);
__this_cpu_write(hard_watchdog_warn, true);
return;
}
__this_cpu_write(hard_watchdog_warn, false);
return;
}
asmlinkage __visible void xen_maybe_preempt_hcall(void)
{
if (unlikely(__this_cpu_read(xen_in_preemptible_hcall)
&& need_resched())) {
/*
* Clear flag as we may be rescheduled on a different
* cpu.
*/
__this_cpu_write(xen_in_preemptible_hcall, false);
_cond_resched();
__this_cpu_write(xen_in_preemptible_hcall, true);
}
}
static unsigned int
tee_tg4(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_tee_tginfo *info = par->targinfo;
struct iphdr *iph;
if (__this_cpu_read(tee_active))
return XT_CONTINUE;
/*
* Copy the skb, and route the copy. Will later return %XT_CONTINUE for
* the original skb, which should continue on its way as if nothing has
* happened. The copy should be independently delivered to the TEE
* --gateway.
*/
skb = pskb_copy(skb, GFP_ATOMIC);
if (skb == NULL)
return XT_CONTINUE;
#ifdef WITH_CONNTRACK
/* Avoid counting cloned packets towards the original connection. */
nf_conntrack_put(skb->nfct);
skb->nfct = &nf_ct_untracked_get()->ct_general;
skb->nfctinfo = IP_CT_NEW;
nf_conntrack_get(skb->nfct);
#endif
/*
* If we are in PREROUTING/INPUT, the checksum must be recalculated
* since the length could have changed as a result of defragmentation.
*
* We also decrease the TTL to mitigate potential TEE loops
* between two hosts.
*
* Set %IP_DF so that the original source is notified of a potentially
* decreased MTU on the clone route. IPv6 does this too.
*/
iph = ip_hdr(skb);
iph->frag_off |= htons(IP_DF);
if (par->hooknum == NF_INET_PRE_ROUTING ||
par->hooknum == NF_INET_LOCAL_IN)
--iph->ttl;
ip_send_check(iph);
if (tee_tg_route4(skb, info)) {
__this_cpu_write(tee_active, true);
ip_local_out(skb);
__this_cpu_write(tee_active, false);
} else {
kfree_skb(skb);
}
return XT_CONTINUE;
}
int cpuidle_idle_call(void)
{
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
struct cpuidle_driver *drv = cpuidle_get_driver();
int next_state, entered_state;
if (off)
return -ENODEV;
if (!initialized)
return -ENODEV;
if (!dev || !dev->enabled)
return -EBUSY;
#if 0
hrtimer_peek_ahead_timers();
#endif
next_state = cpuidle_curr_governor->select(drv, dev);
if (need_resched()) {
local_irq_enable();
return 0;
}
trace_power_start_rcuidle(POWER_CSTATE, next_state, dev->cpu);
trace_cpu_idle_rcuidle(next_state, dev->cpu);
entered_state = cpuidle_enter_ops(dev, drv, next_state);
trace_power_end_rcuidle(dev->cpu);
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
if (entered_state >= 0) {
dev->states_usage[entered_state].time +=
(unsigned long long)dev->last_residency;
dev->states_usage[entered_state].usage++;
} else {
dev->last_residency = 0;
}
if (cpuidle_curr_governor->reflect)
cpuidle_curr_governor->reflect(dev, entered_state);
return 0;
}
/**
* cpuidle_idle_call - the main idle loop
*
* NOTE: no locks or semaphores should be used here
* return non-zero on failure
*/
int cpuidle_idle_call(void)
{
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
struct cpuidle_driver *drv = cpuidle_get_driver();
int next_state, entered_state;
if (off)
return -ENODEV;
if (!initialized)
return -ENODEV;
/* check if the device is ready */
if (!dev || !dev->enabled)
return -EBUSY;
/* ask the governor for the next state */
next_state = cpuidle_curr_governor->select(drv, dev);
if (need_resched()) {
dev->last_residency = 0;
/* give the governor an opportunity to reflect on the outcome */
if (cpuidle_curr_governor->reflect)
cpuidle_curr_governor->reflect(dev, next_state);
local_irq_enable();
return 0;
}
trace_cpu_idle_rcuidle(next_state, dev->cpu);
if (need_resched()) {
dev->last_residency = 0;
local_irq_enable();
entered_state = next_state;
goto exit;
}
if (cpuidle_state_is_coupled(dev, drv, next_state))
entered_state = cpuidle_enter_state_coupled(dev, drv,
next_state);
else
entered_state = cpuidle_enter_state(dev, drv, next_state);
exit:
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
/* give the governor an opportunity to reflect on the outcome */
if (cpuidle_curr_governor->reflect)
cpuidle_curr_governor->reflect(dev, entered_state);
return 0;
}
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);
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;
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);
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);
}
static void tasklet_hi_action(struct softirq_action *a)
{
struct tasklet_struct *list;
local_irq_disable();
list = __this_cpu_read(tasklet_hi_vec.head);
__this_cpu_write(tasklet_hi_vec.head, NULL);
__this_cpu_write(tasklet_hi_vec.tail, &__get_cpu_var(tasklet_hi_vec).head);
local_irq_enable();
while (list) {
struct tasklet_struct *t = list;
list = list->next;
if (tasklet_trylock(t)) {
if (!atomic_read(&t->count)) {
if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
BUG();
exynos_ss_softirq(ESS_FLAG_SOFTIRQ_HI_TASKLET,
t->func, irqs_disabled(), ESS_FLAG_IN);
t->func(t->data);
exynos_ss_softirq(ESS_FLAG_SOFTIRQ_HI_TASKLET,
t->func, irqs_disabled(), ESS_FLAG_OUT);
tasklet_unlock(t);
continue;
}
tasklet_unlock(t);
}
local_irq_disable();
t->next = NULL;
*__this_cpu_read(tasklet_hi_vec.tail) = t;
__this_cpu_write(tasklet_hi_vec.tail, &(t->next));
__raise_softirq_irqoff(HI_SOFTIRQ);
local_irq_enable();
}
}
/*
* Optimized increment and decrement functions.
*
* These are only for a single page and therefore can take a struct page *
* argument instead of struct zone *. This allows the inclusion of the code
* generated for page_zone(page) into the optimized functions.
*
* No overflow check is necessary and therefore the differential can be
* incremented or decremented in place which may allow the compilers to
* generate better code.
* The increment or decrement is known and therefore one boundary check can
* be omitted.
*
* NOTE: These functions are very performance sensitive. Change only
* with care.
*
* Some processors have inc/dec instructions that are atomic vs an interrupt.
* However, the code must first determine the differential location in a zone
* based on the processor number and then inc/dec the counter. There is no
* guarantee without disabling preemption that the processor will not change
* in between and therefore the atomicity vs. interrupt cannot be exploited
* in a useful way here.
*/
void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
struct per_cpu_pageset __percpu *pcp = zone->pageset;
s8 __percpu *p = pcp->vm_stat_diff + item;
s8 v, t;
v = __this_cpu_inc_return(*p);
t = __this_cpu_read(pcp->stat_threshold);
if (unlikely(v > t)) {
s8 overstep = t >> 1;
zone_page_state_add(v + overstep, zone, item);
__this_cpu_write(*p, -overstep);
}
/**
* cpuidle_idle_call - the main idle loop
*
* NOTE: no locks or semaphores should be used here
* return non-zero on failure
*/
int cpuidle_idle_call(void)
{
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
struct cpuidle_driver *drv = cpuidle_get_driver();
int next_state, entered_state;
if (off)
return -ENODEV;
if (!initialized)
return -ENODEV;
/* check if the device is ready */
if (!dev || !dev->enabled)
return -EBUSY;
#if 0
/* shows regressions, re-enable for 2.6.29 */
/*
* run any timers that can be run now, at this point
* before calculating the idle duration etc.
*/
hrtimer_peek_ahead_timers();
#endif
/* ask the governor for the next state */
next_state = cpuidle_curr_governor->select(drv, dev);
if (need_resched()) {
local_irq_enable();
return 0;
}
trace_power_start_rcuidle(POWER_CSTATE, next_state, dev->cpu);
trace_cpu_idle_rcuidle(next_state, dev->cpu);
if (cpuidle_state_is_coupled(dev, drv, next_state))
entered_state = cpuidle_enter_state_coupled(dev, drv,
next_state);
else
entered_state = cpuidle_enter_state(dev, drv, next_state);
trace_power_end_rcuidle(dev->cpu);
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
/* give the governor an opportunity to reflect on the outcome */
if (cpuidle_curr_governor->reflect)
cpuidle_curr_governor->reflect(dev, entered_state);
return 0;
}
static void xtensa_mx_irq_unmask(struct irq_data *d)
{
unsigned int mask = 1u << d->hwirq;
if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
HW_IRQ_MX_BASE), MIENGSET);
} else {
mask |= __this_cpu_read(cached_irq_mask);
__this_cpu_write(cached_irq_mask, mask);
set_sr(mask, intenable);
}
}
/**
* acpi_idle_enter_simple - enters an ACPI state without BM handling
* @dev: the target CPU
* @drv: cpuidle driver with cpuidle state information
* @index: the index of suggested state
*/
static int acpi_idle_enter_simple(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
struct acpi_processor *pr;
struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
pr = __this_cpu_read(processors);
if (unlikely(!pr))
return -EINVAL;
if (cx->entry_method != ACPI_CSTATE_FFH) {
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we test
* NEED_RESCHED:
*/
smp_mb();
if (unlikely(need_resched())) {
current_thread_info()->status |= TS_POLLING;
return -EINVAL;
}
}
/*
* Must be done before busmaster disable as we might need to
* access HPET !
*/
lapic_timer_state_broadcast(pr, cx, 1);
if (cx->type == ACPI_STATE_C3)
ACPI_FLUSH_CPU_CACHE();
/* Tell the scheduler that we are going deep-idle: */
sched_clock_idle_sleep_event();
acpi_idle_do_entry(cx);
sched_clock_idle_wakeup_event(0);
if (cx->entry_method != ACPI_CSTATE_FFH)
current_thread_info()->status |= TS_POLLING;
cx->usage++;
lapic_timer_state_broadcast(pr, cx, 0);
return index;
}
static void takeover_tasklets(unsigned int cpu)
{
/* CPU is dead, so no lock needed. */
local_irq_disable();
/* Find end, append list for that CPU. */
if (&per_cpu(tasklet_vec, cpu).head != per_cpu(tasklet_vec, cpu).tail) {
*__this_cpu_read(tasklet_vec.tail) = per_cpu(tasklet_vec, cpu).head;
this_cpu_write(tasklet_vec.tail, per_cpu(tasklet_vec, cpu).tail);
per_cpu(tasklet_vec, cpu).head = NULL;
per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head;
}
raise_softirq_irqoff(TASKLET_SOFTIRQ);
if (&per_cpu(tasklet_hi_vec, cpu).head != per_cpu(tasklet_hi_vec, cpu).tail) {
*__this_cpu_read(tasklet_hi_vec.tail) = per_cpu(tasklet_hi_vec, cpu).head;
__this_cpu_write(tasklet_hi_vec.tail, per_cpu(tasklet_hi_vec, cpu).tail);
per_cpu(tasklet_hi_vec, cpu).head = NULL;
per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head;
}
raise_softirq_irqoff(HI_SOFTIRQ);
local_irq_enable();
}
/**
* cpuidle_idle_call - the main idle loop
*
* NOTE: no locks or semaphores should be used here
* return non-zero on failure
*/
int cpuidle_idle_call(void)
{
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
struct cpuidle_state *target_state;
int next_state;
if (off)
return -ENODEV;
if (!initialized)
return -ENODEV;
/* check if the device is ready */
if (!dev || !dev->enabled)
return -EBUSY;
#if 0
/* shows regressions, re-enable for 2.6.29 */
/*
* run any timers that can be run now, at this point
* before calculating the idle duration etc.
*/
hrtimer_peek_ahead_timers();
#endif
/* ask the governor for the next state */
next_state = cpuidle_curr_governor->select(dev);
if (need_resched()) {
local_irq_enable();
return 0;
}
target_state = &dev->states[next_state];
/* enter the state and update stats */
dev->last_state = target_state;
RCU_NONIDLE(
trace_power_start(POWER_CSTATE, next_state, dev->cpu);
trace_cpu_idle(next_state, dev->cpu)
);
dev->last_residency = target_state->enter(dev, target_state);
RCU_NONIDLE(
trace_power_end(dev->cpu);
trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
);
/**
* cpuidle_play_dead - cpu off-lining
*
* Returns in case of an error or no driver
*/
int cpuidle_play_dead(void)
{
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
int i;
if (!drv)
return -ENODEV;
/* Find lowest-power state that supports long-term idle */
for (i = drv->state_count - 1; i >= CPUIDLE_DRIVER_STATE_START; i--)
if (drv->states[i].enter_dead)
return drv->states[i].enter_dead(dev, i);
return -ENODEV;
}
bool mce_intel_cmci_poll(void)
{
if (__this_cpu_read(cmci_storm_state) == CMCI_STORM_NONE)
return false;
/*
* Reset the counter if we've logged an error in the last poll
* during the storm.
*/
if (machine_check_poll(0, this_cpu_ptr(&mce_banks_owned)))
this_cpu_write(cmci_backoff_cnt, INITIAL_CHECK_INTERVAL);
else
this_cpu_dec(cmci_backoff_cnt);
return true;
}
int notrace __ipipe_check_percpu_access(void)
{
struct ipipe_percpu_domain_data *p;
struct ipipe_domain *this_domain;
unsigned long flags;
int ret = 0;
flags = hard_local_irq_save_notrace();
/*
* Don't use __ipipe_current_domain here, this would recurse
* indefinitely.
*/
this_domain = __this_cpu_read(ipipe_percpu.curr)->domain;
/*
* Only the root domain may implement preemptive CPU migration
* of tasks, so anything above in the pipeline should be fine.
*/
if (this_domain != ipipe_root_domain)
goto out;
if (raw_irqs_disabled_flags(flags))
goto out;
/*
* Last chance: hw interrupts were enabled on entry while
* running over the root domain, but the root stage might be
* currently stalled, in which case preemption would be
* disabled, and no migration could occur.
*/
if (this_domain == ipipe_root_domain) {
p = ipipe_this_cpu_root_context();
if (test_bit(IPIPE_STALL_FLAG, &p->status))
goto out;
}
/*
* Our caller may end up accessing the wrong per-cpu variable
* instance due to CPU migration; tell it to complain about
* this.
*/
ret = 1;
out:
hard_local_irq_restore_notrace(flags);
return ret;
}
/**
* acpi_idle_lpi_enter - enters an ACPI any LPI state
* @dev: the target CPU
* @drv: cpuidle driver containing cpuidle state info
* @index: index of target state
*
* Return: 0 for success or negative value for error
*/
static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
struct acpi_processor *pr;
struct acpi_lpi_state *lpi;
pr = __this_cpu_read(processors);
if (unlikely(!pr))
return -EINVAL;
lpi = &pr->power.lpi_states[index];
if (lpi->entry_method == ACPI_CSTATE_FFH)
return acpi_processor_ffh_lpi_enter(lpi);
return -EINVAL;
}
int psci_cpu_suspend_enter(unsigned long index)
{
int ret;
u32 *state = __this_cpu_read(psci_power_state);
/*
* idle state index 0 corresponds to wfi, should never be called
* from the cpu_suspend operations
*/
if (WARN_ON_ONCE(!index))
return -EINVAL;
if (!psci_power_state_loses_context(state[index - 1]))
ret = psci_ops.cpu_suspend(state[index - 1], 0);
else
ret = cpu_suspend(index, psci_suspend_finisher);
return ret;
}
/**
* This function is both preempt and irq safe. The former is due to explicit
* preemption disable. The latter is guaranteed by the fact that the slow path
* is explicitly protected by an irq-safe spinlock whereas the fast patch uses
* this_cpu_add which is irq-safe by definition. Hence there is no need muck
* with irq state before calling this one
*/
void percpu_counter_add_batch(struct percpu_counter *fbc, int64_t amount,
int32_t batch)
{
int64_t count;
preempt_disable();
count = __this_cpu_read(*fbc->counters) + amount;
if (count >= batch || count <= -batch) {
unsigned long flags;
spin_lock_irqsave(&fbc->lock);
fbc->count += count;
__this_cpu_sub(*fbc->counters, count - amount);
spin_unlock_irqsave(&fbc->lock);
} else {
this_cpu_add(*fbc->counters, amount);
}
preempt_enable();
}
/**
* acpi_idle_enter_c1 - enters an ACPI C1 state-type
* @dev: the target CPU
* @drv: cpuidle driver containing cpuidle state info
* @index: index of target state
*
* This is equivalent to the HALT instruction.
*/
static int acpi_idle_enter_c1(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
struct acpi_processor *pr;
struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
pr = __this_cpu_read(processors);
if (unlikely(!pr))
return -EINVAL;
lapic_timer_state_broadcast(pr, cx, 1);
acpi_idle_do_entry(cx);
lapic_timer_state_broadcast(pr, cx, 0);
return index;
}