int idled(void)
{
int do_power_save = 0;
/* Check if CPU can powersave (get rid of that soon!) */
if (cur_cpu_spec[smp_processor_id()]->cpu_features &
(CPU_FTR_CAN_DOZE | CPU_FTR_CAN_NAP))
do_power_save = 1;
/* endless loop with no priority at all */
for (;;) {
#ifdef CONFIG_SMP
if (!do_power_save) {
/*
* Deal with another CPU just having chosen a thread to
* run here:
*/
int oldval = xchg(¤t->need_resched, -1);
if (!oldval) {
while(current->need_resched == -1)
; /* Do Nothing */
}
}
#endif
#ifdef CONFIG_6xx
if (do_power_save && !current->need_resched)
power_save_6xx();
#endif /* CONFIG_6xx */
schedule();
check_pgt_cache();
}
return 0;
}
void cpu_idle(void)
{
int cpu = smp_processor_id();
boot_init_stack_canary();
current_thread_info()->status |= TS_POLLING;
while (1) {
tick_nohz_stop_sched_tick(1);
while (!need_resched()) {
check_pgt_cache();
rmb();
if (cpu_is_offline(cpu))
play_dead();
local_irq_disable();
stop_critical_timings();
pm_idle();
start_critical_timings();
}
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle(void)
{
int cpu = smp_processor_id();
current_thread_info()->status |= TS_POLLING;
/* endless idle loop with no priority at all */
while (1) {
tick_nohz_stop_sched_tick();
while (!need_resched()) {
check_pgt_cache();
rmb();
if (rcu_pending(cpu))
rcu_check_callbacks(cpu, 0);
if (cpu_is_offline(cpu))
play_dead();
local_irq_disable();
__get_cpu_var(irq_stat).idle_timestamp = jiffies;
/* Don't trace irqs off for idle */
stop_critical_timings();
pm_idle();
start_critical_timings();
}
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
/*
* The idle loop on a uniprocessor i386..
*/
static int cpu_idle(void *unused)
{
int work = 1;
unsigned long start_idle = 0;
/* endless idle loop with no priority at all */
current->priority = 0;
current->counter = -100;
for (;;) {
if (work)
start_idle = jiffies;
if (jiffies - start_idle > HARD_IDLE_TIMEOUT)
hard_idle();
else {
if (boot_cpu_data.hlt_works_ok && !hlt_counter && !current->need_resched)
__asm__("hlt");
}
work = current->need_resched;
schedule();
check_pgt_cache();
}
}
void cpu_idle(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
while (1) {
tick_nohz_idle_enter();
rcu_idle_enter();
while (!need_resched()) {
check_pgt_cache();
rmb();
clear_thread_flag(TIF_POLLING_NRFLAG);
local_irq_disable();
/* Don't trace irqs off for idle */
stop_critical_timings();
if (!need_resched() && powersave != NULL)
powersave();
start_critical_timings();
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
}
rcu_idle_exit();
tick_nohz_idle_exit();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
asmlinkage int sys_idle(void)
{
unsigned long start_idle = 0;
if (current->pid != 0)
return -EPERM;
/* endless idle loop with no priority at all */
current->priority = 0;
current->counter = 0;
for (;;) {
/*
* R4[36]00 have wait, R4[04]00 don't.
* FIXME: We should save power by reducing the clock where
* possible. Thiss will cut down the power consuption
* of R4200 systems to about 1/16th of normal, the
* same for logic clocked with the processor generated
* clocks.
*/
if (!start_idle) {
check_pgt_cache();
start_idle = jiffies;
}
if (wait_available && !current->need_resched)
__asm__(".set\tmips3\n\t"
"wait\n\t"
".set\tmips0");
run_task_queue(&tq_scheduler);
if (current->need_resched)
start_idle = 0;
schedule();
}
return 0;
}
/*
* Generic idle loop implementation
*
* Called with polling cleared.
*/
static void do_idle(void)
{
/*
* If the arch has a polling bit, we maintain an invariant:
*
* Our polling bit is clear if we're not scheduled (i.e. if rq->curr !=
* rq->idle). This means that, if rq->idle has the polling bit set,
* then setting need_resched is guaranteed to cause the CPU to
* reschedule.
*/
__current_set_polling();
tick_nohz_idle_enter();
while (!need_resched()) {
check_pgt_cache();
rmb();
if (cpu_is_offline(smp_processor_id())) {
cpuhp_report_idle_dead();
arch_cpu_idle_dead();
}
local_irq_disable();
arch_cpu_idle_enter();
/*
* In poll mode we reenable interrupts and spin. Also if we
* detected in the wakeup from idle path that the tick
* broadcast device expired for us, we don't want to go deep
* idle as we know that the IPI is going to arrive right away.
*/
if (cpu_idle_force_poll || tick_check_broadcast_expired())
cpu_idle_poll();
else
cpuidle_idle_call();
arch_cpu_idle_exit();
}
/*
* Since we fell out of the loop above, we know TIF_NEED_RESCHED must
* be set, propagate it into PREEMPT_NEED_RESCHED.
*
* This is required because for polling idle loops we will not have had
* an IPI to fold the state for us.
*/
preempt_set_need_resched();
tick_nohz_idle_exit();
__current_clr_polling();
/*
* We promise to call sched_ttwu_pending() and reschedule if
* need_resched() is set while polling is set. That means that clearing
* polling needs to be visible before doing these things.
*/
smp_mb__after_atomic();
sched_ttwu_pending();
schedule_preempt_disabled();
}
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle(void)
{
int cpu = smp_processor_id();
current_thread_info()->status |= TS_POLLING;
/* endless idle loop with no priority at all */
while (1) {
tick_nohz_stop_sched_tick();
while (!need_resched()) {
void (*idle)(void);
if (__get_cpu_var(cpu_idle_state))
__get_cpu_var(cpu_idle_state) = 0;
check_pgt_cache();
rmb();
idle = pm_idle;
if (!idle)
idle = default_idle;
if (cpu_is_offline(cpu))
play_dead();
__get_cpu_var(irq_stat).idle_timestamp = jiffies;
idle();
}
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
/*
* Generic idle loop implementation
*/
static void cpu_idle_loop(void)
{
while (1) {
tick_nohz_idle_enter();
while (!need_resched()) {
check_pgt_cache();
rmb();
if (cpu_is_offline(smp_processor_id()))
arch_cpu_idle_dead();
local_irq_disable();
arch_cpu_idle_enter();
/*
* In poll mode we reenable interrupts and spin.
*
* Also if we detected in the wakeup from idle
* path that the tick broadcast device expired
* for us, we don't want to go deep idle as we
* know that the IPI is going to arrive right
* away
*/
if (cpu_idle_force_poll || tick_check_broadcast_expired()) {
cpu_idle_poll();
} else {
if (!current_clr_polling_and_test()) {
stop_critical_timings();
rcu_idle_enter();
arch_cpu_idle();
WARN_ON_ONCE(irqs_disabled());
rcu_idle_exit();
start_critical_timings();
} else {
local_irq_enable();
}
__current_set_polling();
}
arch_cpu_idle_exit();
}
/*
* Since we fell out of the loop above, we know
* TIF_NEED_RESCHED must be set, propagate it into
* PREEMPT_NEED_RESCHED.
*
* This is required because for polling idle loops we will
* not have had an IPI to fold the state for us.
*/
preempt_set_need_resched();
tick_nohz_idle_exit();
schedule_preempt_disabled();
}
}
/*
* Generic idle loop implementation
*
* Called with polling cleared.
*/
static void cpu_idle_loop(void)
{
while (1) {
/*
* If the arch has a polling bit, we maintain an invariant:
*
* Our polling bit is clear if we're not scheduled (i.e. if
* rq->curr != rq->idle). This means that, if rq->idle has
* the polling bit set, then setting need_resched is
* guaranteed to cause the cpu to reschedule.
*/
__current_set_polling();
tick_nohz_idle_enter();
while (!need_resched()) {
check_pgt_cache();
rmb();
local_irq_disable();
arch_cpu_idle_enter();
/*
* In poll mode we reenable interrupts and spin.
*
* Also if we detected in the wakeup from idle
* path that the tick broadcast device expired
* for us, we don't want to go deep idle as we
* know that the IPI is going to arrive right
* away
*/
if (cpu_idle_force_poll ||
tick_check_broadcast_expired() ||
__get_cpu_var(idle_force_poll))
cpu_idle_poll();
else
cpuidle_idle_call();
arch_cpu_idle_exit();
}
tick_nohz_idle_exit();
__current_clr_polling();
/*
* We promise to reschedule if need_resched is set while
* polling is set. That means that clearing polling
* needs to be visible before rescheduling.
*/
smp_mb__after_atomic();
schedule_preempt_disabled();
if (cpu_is_offline(smp_processor_id()))
arch_cpu_idle_dead();
}
}
/* This is being executed in task 0 'user space'. */
int cpu_idle(void)
{
/* endless idle loop with no priority at all */
while(1) {
if(current->need_resched) {
schedule();
check_pgt_cache();
}
barrier(); /* or else gcc optimizes... */
}
}
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
init_idle();
while (1) {
while (!current->need_resched) {
}
schedule();
check_pgt_cache();
}
}
/*
* This function clears all user-level page tables of a process - this
* is needed by execve(), so that old pages aren't in the way.
*/
void clear_page_tables(struct mm_struct *mm, unsigned long first, int nr)
{
pgd_t * page_dir = mm->pgd;
page_dir += first;
do {
free_one_pgd(page_dir);
page_dir++;
} while (--nr);
/* keep the page table cache within bounds */
check_pgt_cache();
}
ATTRIB_NORET void cpu_idle(void)
{
/* endless idle loop with no priority at all */
init_idle();
while (1) {
while (!current->need_resched)
if (cpu_wait)
(*cpu_wait)();
schedule();
check_pgt_cache();
}
}
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched())
barrier();
preempt_enable_no_resched();
schedule();
preempt_disable();
check_pgt_cache();
}
}
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
current->nice = 20;
current->counter = -100;
init_idle();
while (1) {
while (!current->need_resched)
if (cpu_wait)
(*cpu_wait)();
schedule();
check_pgt_cache();
}
}
/*
* Generic idle loop implementation
*/
static void cpu_idle_loop(void)
{
while (1) {
tick_nohz_idle_enter();
while (!need_resched()) {
check_pgt_cache();
rmb();
local_irq_disable();
arch_cpu_idle_enter();
/*
* In poll mode we reenable interrupts and spin.
*
* Also if we detected in the wakeup from idle
* path that the tick broadcast device expired
* for us, we don't want to go deep idle as we
* know that the IPI is going to arrive right
* away
*/
if (cpu_idle_force_poll ||
tick_check_broadcast_expired() ||
__get_cpu_var(idle_force_poll)) {
cpu_idle_poll();
} else {
if (!current_clr_polling_and_test()) {
stop_critical_timings();
rcu_idle_enter();
arch_cpu_idle();
WARN_ON_ONCE(irqs_disabled());
rcu_idle_exit();
start_critical_timings();
} else {
local_irq_enable();
}
__current_set_polling();
}
arch_cpu_idle_exit();
}
tick_nohz_idle_exit();
schedule_preempt_disabled();
if (cpu_is_offline(smp_processor_id()))
arch_cpu_idle_dead();
}
}
/*
* the idle loop on a Sparc... ;)
*/
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
for (;;) {
if (ARCH_SUN4C) {
static int count = HZ;
static unsigned long last_jiffies;
static unsigned long last_faults;
static unsigned long fps;
unsigned long now;
unsigned long faults;
extern unsigned long sun4c_kernel_faults;
extern void sun4c_grow_kernel_ring(void);
local_irq_disable();
now = jiffies;
count -= (now - last_jiffies);
last_jiffies = now;
if (count < 0) {
count += HZ;
faults = sun4c_kernel_faults;
fps = (fps + (faults - last_faults)) >> 1;
last_faults = faults;
#if 0
printk("kernel faults / second = %ld\n", fps);
#endif
if (fps >= SUN4C_FAULT_HIGH) {
sun4c_grow_kernel_ring();
}
}
local_irq_enable();
}
if (pm_idle) {
while (!need_resched())
(*pm_idle)();
} else {
while (!need_resched())
cpu_relax();
}
preempt_enable_no_resched();
schedule();
preempt_disable();
check_pgt_cache();
}
/*
* the idle loop on a Sparc... ;)
*/
int cpu_idle(void)
{
int ret = -EPERM;
if (current->pid != 0)
goto out;
/* endless idle loop with no priority at all */
current->nice = 20;
current->counter = -100;
init_idle();
for (;;) {
if (ARCH_SUN4C_SUN4) {
static int count = HZ;
static unsigned long last_jiffies = 0;
static unsigned long last_faults = 0;
static unsigned long fps = 0;
unsigned long now;
unsigned long faults;
unsigned long flags;
extern unsigned long sun4c_kernel_faults;
extern void sun4c_grow_kernel_ring(void);
save_and_cli(flags);
now = jiffies;
count -= (now - last_jiffies);
last_jiffies = now;
if (count < 0) {
count += HZ;
faults = sun4c_kernel_faults;
fps = (fps + (faults - last_faults)) >> 1;
last_faults = faults;
#if 0
printk("kernel faults / second = %d\n", fps);
#endif
if (fps >= SUN4C_FAULT_HIGH) {
sun4c_grow_kernel_ring();
}
}
restore_flags(flags);
}
check_pgt_cache();
schedule();
}
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle(void)
{
int cpu = smp_processor_id();
/*
* If we're the non-boot CPU, nothing set the stack canary up
* for us. CPU0 already has it initialized but no harm in
* doing it again. This is a good place for updating it, as
* we wont ever return from this function (so the invalid
* canaries already on the stack wont ever trigger).
*/
boot_init_stack_canary();
current_thread_info()->status |= TS_POLLING;
/* endless idle loop with no priority at all */
while (1) {
tick_nohz_stop_sched_tick(1);
while (!need_resched()) {
check_pgt_cache();
rmb();
if (cpu_is_offline(cpu))
play_dead();
local_irq_disable();
enter_idle();
/* Don't trace irqs off for idle */
stop_critical_timings();
pm_idle();
start_critical_timings();
/*
* In many cases the interrupt that ended idle
* has already called exit_idle. But some idle
* loops can be woken up without interrupt.
*/
__exit_idle();
}
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
void cpu_idle(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
while (1) {
void (*idle)(void) = pm_idle;
if (!idle)
idle = default_idle;
tick_nohz_stop_sched_tick(1);
while (!need_resched())
idle();
tick_nohz_restart_sched_tick();
schedule_preempt_disabled();
check_pgt_cache();
}
}
int cpu_idle(void *unused)
{
/* endless idle loop with no priority at all */
current->priority = 0;
current->counter = -100;
while(1) {
if (current_cpu_data.hlt_works_ok && !hlt_counter &&
!current->need_resched)
__asm__("hlt");
/*
* although we are an idle CPU, we do not want to
* get into the scheduler unnecessarily.
*/
if (current->need_resched) {
schedule();
check_pgt_cache();
}
}
}
/*
* The idle thread. There's no useful work to be done, so just try to conserve
* power and have a low exit latency (ie sit in a loop waiting for somebody to
* say that they'd like to reschedule)
*/
void cpu_idle(void)
{
unsigned int cpu = smp_processor_id();
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
while (1) {
tick_nohz_idle_enter();
rcu_idle_enter();
while (!need_resched()) {
check_pgt_cache();
rmb();
if (cpu_is_offline(cpu))
play_dead();
local_irq_disable();
/* Don't trace irqs off for idle */
stop_critical_timings();
if (cpuidle_idle_call())
sh_idle();
/*
* Sanity check to ensure that sh_idle() returns
* with IRQs enabled
*/
WARN_ON(irqs_disabled());
start_critical_timings();
}
rcu_idle_exit();
tick_nohz_idle_exit();
schedule_preempt_disabled();
}
}
/*
* Generic idle loop implementation
*
* Called with polling cleared.
*/
static void cpu_idle_loop(void)
{
while (1) {
/*
* If the arch has a polling bit, we maintain an invariant:
*
* Our polling bit is clear if we're not scheduled (i.e. if
* rq->curr != rq->idle). This means that, if rq->idle has
* the polling bit set, then setting need_resched is
* guaranteed to cause the cpu to reschedule.
*/
__current_set_polling();
tick_nohz_idle_enter();
while (!need_resched()) {
check_pgt_cache();
rmb();
if (cpu_is_offline(smp_processor_id()))
arch_cpu_idle_dead();
local_irq_disable();
arch_cpu_idle_enter();
/*
* In poll mode we reenable interrupts and spin.
*
* Also if we detected in the wakeup from idle
* path that the tick broadcast device expired
* for us, we don't want to go deep idle as we
* know that the IPI is going to arrive right
* away
*/
if (cpu_idle_force_poll || tick_check_broadcast_expired())
cpu_idle_poll();
else
cpuidle_idle_call();
arch_cpu_idle_exit();
/*
* We need to test and propagate the TIF_NEED_RESCHED
* bit here because we might not have send the
* reschedule IPI to idle tasks.
*/
if (tif_need_resched())
set_preempt_need_resched();
}
tick_nohz_idle_exit();
__current_clr_polling();
/*
* We promise to call sched_ttwu_pending and reschedule
* if need_resched is set while polling is set. That
* means that clearing polling needs to be visible
* before doing these things.
*/
smp_mb();
sched_ttwu_pending();
schedule_preempt_disabled();
}
}
pgd_t *get_pgd_slow(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
new_pgd = alloc_pgd_table(GFP_KERNEL);
if (!new_pgd)
goto no_pgd;
/*
* This lock is here just to satisfy pmd_alloc and pte_lock
*/
spin_lock(&mm->page_table_lock);
/*
* On ARM, first page must always be allocated since it contains
* the machine vectors.
*/
new_pmd = pmd_alloc(mm, new_pgd, 0);
if (!new_pmd)
goto no_pmd;
new_pte = pte_alloc(mm, new_pmd, 0);
if (!new_pte)
goto no_pte;
init_pgd = pgd_offset_k(0);
init_pmd = pmd_offset(init_pgd, 0);
init_pte = pte_offset(init_pmd, 0);
set_pte(new_pte, *init_pte);
/*
* most of the page table entries are zeroed
* wne the table is created.
*/
memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
spin_unlock(&mm->page_table_lock);
/* update MEMC tables */
cpu_memc_update_all(new_pgd);
return new_pgd;
no_pte:
spin_unlock(&mm->page_table_lock);
pmd_free(new_pmd);
check_pgt_cache();
free_pgd_slow(new_pgd);
return NULL;
no_pmd:
spin_unlock(&mm->page_table_lock);
free_pgd_slow(new_pgd);
return NULL;
no_pgd:
return NULL;
}
/*
* Generic idle loop implementation
*
* Called with polling cleared.
*/
static void cpu_idle_loop(void)
{
while (1) {
/*
* If the arch has a polling bit, we maintain an invariant:
*
* Our polling bit is clear if we're not scheduled (i.e. if
* rq->curr != rq->idle). This means that, if rq->idle has
* the polling bit set, then setting need_resched is
* guaranteed to cause the cpu to reschedule.
*/
__current_set_polling();
quiet_vmstat();
tick_nohz_idle_enter();
while (!need_resched()) {
check_pgt_cache();
rmb();
if (cpu_is_offline(smp_processor_id())) {
rcu_cpu_notify(NULL, CPU_DYING_IDLE,
(void *)(long)smp_processor_id());
smp_mb(); /* all activity before dead. */
this_cpu_write(cpu_dead_idle, true);
arch_cpu_idle_dead();
}
local_irq_disable();
arch_cpu_idle_enter();
/*
* In poll mode we reenable interrupts and spin.
*
* Also if we detected in the wakeup from idle
* path that the tick broadcast device expired
* for us, we don't want to go deep idle as we
* know that the IPI is going to arrive right
* away
*/
if (cpu_idle_force_poll || tick_check_broadcast_expired())
cpu_idle_poll();
else
cpuidle_idle_call();
arch_cpu_idle_exit();
}
/*
* Since we fell out of the loop above, we know
* TIF_NEED_RESCHED must be set, propagate it into
* PREEMPT_NEED_RESCHED.
*
* This is required because for polling idle loops we will
* not have had an IPI to fold the state for us.
*/
preempt_set_need_resched();
tick_nohz_idle_exit();
__current_clr_polling();
/*
* We promise to call sched_ttwu_pending and reschedule
* if need_resched is set while polling is set. That
* means that clearing polling needs to be visible
* before doing these things.
*/
smp_mb__after_atomic();
sched_ttwu_pending();
schedule_preempt_disabled();
}
}
