/**
* suspend_prepare - Prepare for entering system sleep state.
*
* Common code run for every system sleep state that can be entered (except for
* hibernation). Run suspend notifiers, allocate the "suspend" console and
* freeze processes.
*/
static int suspend_prepare(suspend_state_t state)
{
int error;
if (!sleep_state_supported(state))
return -EPERM;
pm_prepare_console();
error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
if (error)
goto Finish;
trace_suspend_resume(TPS("freeze_processes"), 0, true);
error = suspend_freeze_processes();
trace_suspend_resume(TPS("freeze_processes"), 0, false);
if (!error)
return 0;
suspend_stats.failed_freeze++;
dpm_save_failed_step(SUSPEND_FREEZE);
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
return error;
}
static void s2idle_enter(void)
{
trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
raw_spin_lock_irq(&s2idle_lock);
if (pm_wakeup_pending())
goto out;
s2idle_state = S2IDLE_STATE_ENTER;
raw_spin_unlock_irq(&s2idle_lock);
get_online_cpus();
cpuidle_resume();
/* Push all the CPUs into the idle loop. */
wake_up_all_idle_cpus();
/* Make the current CPU wait so it can enter the idle loop too. */
swait_event_exclusive(s2idle_wait_head,
s2idle_state == S2IDLE_STATE_WAKE);
cpuidle_pause();
put_online_cpus();
raw_spin_lock_irq(&s2idle_lock);
out:
s2idle_state = S2IDLE_STATE_NONE;
raw_spin_unlock_irq(&s2idle_lock);
trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
}
/**
* enter_state - Do common work needed to enter system sleep state.
* @state: System sleep state to enter.
*
* Make sure that no one else is trying to put the system into a sleep state.
* Fail if that's not the case. Otherwise, prepare for system suspend, make the
* system enter the given sleep state and clean up after wakeup.
*/
static int enter_state(suspend_state_t state)
{
int error;
trace_suspend_resume(TPS("suspend_enter"), state, true);
if (state == PM_SUSPEND_TO_IDLE) {
#ifdef CONFIG_PM_DEBUG
if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
return -EAGAIN;
}
#endif
} else if (!valid_state(state)) {
return -EINVAL;
}
if (!mutex_trylock(&system_transition_mutex))
return -EBUSY;
if (state == PM_SUSPEND_TO_IDLE)
s2idle_begin();
#ifndef CONFIG_SUSPEND_SKIP_SYNC
trace_suspend_resume(TPS("sync_filesystems"), 0, true);
pr_info("Syncing filesystems ... ");
ksys_sync();
pr_cont("done.\n");
trace_suspend_resume(TPS("sync_filesystems"), 0, false);
#endif
pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
pm_suspend_clear_flags();
error = suspend_prepare(state);
if (error)
goto Unlock;
if (suspend_test(TEST_FREEZER))
goto Finish;
trace_suspend_resume(TPS("suspend_enter"), state, false);
pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
pm_restrict_gfp_mask();
error = suspend_devices_and_enter(state);
pm_restore_gfp_mask();
Finish:
events_check_enabled = false;
pm_pr_dbg("Finishing wakeup.\n");
suspend_finish();
Unlock:
mutex_unlock(&system_transition_mutex);
return error;
}
/**
* enter_state - Do common work needed to enter system sleep state.
* @state: System sleep state to enter.
*
* Make sure that no one else is trying to put the system into a sleep state.
* Fail if that's not the case. Otherwise, prepare for system suspend, make the
* system enter the given sleep state and clean up after wakeup.
*/
static int enter_state(suspend_state_t state)
{
int error;
trace_suspend_resume(TPS("suspend_enter"), state, true);
if (state == PM_SUSPEND_FREEZE) {
#ifdef CONFIG_PM_DEBUG
if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
pr_warning("PM: Unsupported test mode for freeze state,"
"please choose none/freezer/devices/platform.\n");
return -EAGAIN;
}
#endif
} else if (!valid_state(state)) {
return -EINVAL;
}
if (!mutex_trylock(&pm_mutex))
return -EBUSY;
if (state == PM_SUSPEND_FREEZE)
freeze_begin();
trace_suspend_resume(TPS("sync_filesystems"), 0, true);
printk(KERN_INFO "PM: Syncing filesystems ... ");
sys_sync();
printk("done.\n");
trace_suspend_resume(TPS("sync_filesystems"), 0, false);
pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
error = suspend_prepare(state);
if (error)
goto Unlock;
if (suspend_test(TEST_FREEZER))
goto Finish;
trace_suspend_resume(TPS("suspend_enter"), state, false);
pr_debug("PM: Entering %s sleep\n", pm_states[state]);
pm_restrict_gfp_mask();
error = suspend_devices_and_enter(state);
pm_restore_gfp_mask();
Finish:
pr_debug("PM: Finishing wakeup.\n");
suspend_finish();
Unlock:
mutex_unlock(&pm_mutex);
return error;
}
/**
* suspend_devices_and_enter - Suspend devices and enter system sleep state.
* @state: System sleep state to enter.
*/
int suspend_devices_and_enter(suspend_state_t state)
{
int error;
bool wakeup = false;
if (!sleep_state_supported(state))
return -ENOSYS;
pm_suspend_target_state = state;
error = platform_suspend_begin(state);
if (error)
goto Close;
suspend_console();
suspend_test_start();
error = dpm_suspend_start(PMSG_SUSPEND);
if (error) {
pr_err("Some devices failed to suspend, or early wake event detected\n");
goto Recover_platform;
}
suspend_test_finish("suspend devices");
if (suspend_test(TEST_DEVICES))
goto Recover_platform;
do {
error = suspend_enter(state, &wakeup);
} while (!error && !wakeup && platform_suspend_again(state));
Resume_devices:
suspend_test_start();
dpm_resume_end(PMSG_RESUME);
suspend_test_finish("resume devices");
trace_suspend_resume(TPS("resume_console"), state, true);
resume_console();
trace_suspend_resume(TPS("resume_console"), state, false);
Close:
platform_resume_end(state);
pm_suspend_target_state = PM_SUSPEND_ON;
return error;
Recover_platform:
platform_recover(state);
goto Resume_devices;
}
/**
* syscore_resume - Execute all the registered system core resume callbacks.
*
* This function is executed with one CPU on-line and disabled interrupts.
*/
void syscore_resume(void)
{
struct syscore_ops *ops;
trace_suspend_resume(TPS("syscore_resume"), 0, true);
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled before system core resume.\n");
list_for_each_entry(ops, &syscore_ops_list, node)
if (ops->resume) {
if (initcall_debug)
pr_info("PM: Calling %pF\n", ops->resume);
ops->resume();
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n", ops->resume);
}
trace_suspend_resume(TPS("syscore_resume"), 0, false);
}
int disable_nonboot_cpus(void)
{
int cpu, first_cpu, error = 0;
cpu_maps_update_begin();
first_cpu = cpumask_first(cpu_online_mask);
/*
* We take down all of the non-boot CPUs in one shot to avoid races
* with the userspace trying to use the CPU hotplug at the same time
*/
cpumask_clear(frozen_cpus);
pr_info("Disabling non-boot CPUs ...\n");
for_each_online_cpu(cpu) {
if (cpu == first_cpu)
continue;
trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
error = _cpu_down(cpu, 1);
trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
if (!error)
cpumask_set_cpu(cpu, frozen_cpus);
else {
pr_err("Error taking CPU%d down: %d\n", cpu, error);
break;
}
}
if (!error)
BUG_ON(num_online_cpus() > 1);
else
pr_err("Non-boot CPUs are not disabled\n");
/*
* Make sure the CPUs won't be enabled by someone else. We need to do
* this even in case of failure as all disable_nonboot_cpus() users are
* supposed to do enable_nonboot_cpus() on the failure path.
*/
cpu_hotplug_disabled++;
cpu_maps_update_done();
return error;
}
/**
* syscore_suspend - Execute all the registered system core suspend callbacks.
*
* This function is executed with one CPU on-line and disabled interrupts.
*/
int syscore_suspend(void)
{
struct syscore_ops *ops;
int ret = 0;
trace_suspend_resume(TPS("syscore_suspend"), 0, true);
pr_debug("Checking wakeup interrupts\n");
/* Return error code if there are any wakeup interrupts pending. */
if (pm_wakeup_pending())
return -EBUSY;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled before system core suspend.\n");
list_for_each_entry_reverse(ops, &syscore_ops_list, node)
if (ops->suspend) {
if (initcall_debug)
pr_info("PM: Calling %pF\n", ops->suspend);
ret = ops->suspend();
if (ret)
goto err_out;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n", ops->suspend);
}
trace_suspend_resume(TPS("syscore_suspend"), 0, false);
return 0;
err_out:
pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend);
list_for_each_entry_continue(ops, &syscore_ops_list, node)
if (ops->resume)
ops->resume();
return ret;
}
void __ref enable_nonboot_cpus(void)
{
int cpu, error;
/* Allow everyone to use the CPU hotplug again */
cpu_maps_update_begin();
cpu_hotplug_disabled = 0;
if (cpumask_empty(frozen_cpus))
goto out;
pr_info("Enabling non-boot CPUs ...\n");
arch_enable_nonboot_cpus_begin();
for_each_cpu(cpu, frozen_cpus) {
trace_suspend_resume(TPS("CPU_ON"), cpu, true);
error = _cpu_up(cpu, 1);
trace_suspend_resume(TPS("CPU_ON"), cpu, false);
if (!error) {
pr_info("CPU%d is up\n", cpu);
continue;
}
pr_warn("Error taking CPU%d up: %d\n", cpu, error);
}
/**
* tick_freeze - Suspend the local tick and (possibly) timekeeping.
*
* Check if this is the last online CPU executing the function and if so,
* suspend timekeeping. Otherwise suspend the local tick.
*
* Call with interrupts disabled. Must be balanced with %tick_unfreeze().
* Interrupts must not be enabled before the subsequent %tick_unfreeze().
*/
void tick_freeze(void)
{
raw_spin_lock(&tick_freeze_lock);
tick_freeze_depth++;
if (tick_freeze_depth == num_online_cpus()) {
trace_suspend_resume(TPS("timekeeping_freeze"),
smp_processor_id(), true);
timekeeping_suspend();
} else {
tick_suspend_local();
}
raw_spin_unlock(&tick_freeze_lock);
}
/**
* tick_unfreeze - Resume the local tick and (possibly) timekeeping.
*
* Check if this is the first CPU executing the function and if so, resume
* timekeeping. Otherwise resume the local tick.
*
* Call with interrupts disabled. Must be balanced with %tick_freeze().
* Interrupts must not be enabled after the preceding %tick_freeze().
*/
void tick_unfreeze(void)
{
raw_spin_lock(&tick_freeze_lock);
if (tick_freeze_depth == num_online_cpus()) {
timekeeping_resume();
trace_suspend_resume(TPS("timekeeping_freeze"),
smp_processor_id(), false);
} else {
tick_resume_local();
}
tick_freeze_depth--;
raw_spin_unlock(&tick_freeze_lock);
}
/**
* create_image - Create a hibernation image.
* @platform_mode: Whether or not to use the platform driver.
*
* Execute device drivers' "late" and "noirq" freeze callbacks, create a
* hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
*
* Control reappears in this routine after the subsequent restore.
*/
static int create_image(int platform_mode)
{
int error;
error = dpm_suspend_end(PMSG_FREEZE);
if (error) {
pr_err("Some devices failed to power down, aborting hibernation\n");
return error;
}
error = platform_pre_snapshot(platform_mode);
if (error || hibernation_test(TEST_PLATFORM))
goto Platform_finish;
error = disable_nonboot_cpus();
if (error || hibernation_test(TEST_CPUS))
goto Enable_cpus;
local_irq_disable();
error = syscore_suspend();
if (error) {
pr_err("Some system devices failed to power down, aborting hibernation\n");
goto Enable_irqs;
}
if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
goto Power_up;
in_suspend = 1;
save_processor_state();
trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
error = swsusp_arch_suspend();
/* Restore control flow magically appears here */
restore_processor_state();
trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
if (error)
pr_err("Error %d creating hibernation image\n", error);
if (!in_suspend) {
events_check_enabled = false;
clear_free_pages();
}
platform_leave(platform_mode);
Power_up:
syscore_resume();
Enable_irqs:
local_irq_enable();
Enable_cpus:
enable_nonboot_cpus();
Platform_finish:
platform_finish(platform_mode);
dpm_resume_start(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
return error;
}
/**
* suspend_enter - Make the system enter the given sleep state.
* @state: System sleep state to enter.
* @wakeup: Returns information that the sleep state should not be re-entered.
*
* This function should be called after devices have been suspended.
*/
static int suspend_enter(suspend_state_t state, bool *wakeup)
{
int error;
error = platform_suspend_prepare(state);
if (error)
goto Platform_finish;
error = dpm_suspend_late(PMSG_SUSPEND);
if (error) {
printk(KERN_ERR "PM: late suspend of devices failed\n");
goto Platform_finish;
}
error = platform_suspend_prepare_late(state);
if (error)
goto Devices_early_resume;
error = dpm_suspend_noirq(PMSG_SUSPEND);
if (error) {
printk(KERN_ERR "PM: noirq suspend of devices failed\n");
goto Platform_early_resume;
}
error = platform_suspend_prepare_noirq(state);
if (error)
goto Platform_wake;
if (suspend_test(TEST_PLATFORM))
goto Platform_wake;
/*
* PM_SUSPEND_FREEZE equals
* frozen processes + suspended devices + idle processors.
* Thus we should invoke freeze_enter() soon after
* all the devices are suspended.
*/
if (state == PM_SUSPEND_FREEZE) {
trace_suspend_resume(TPS("machine_suspend"), state, true);
freeze_enter();
trace_suspend_resume(TPS("machine_suspend"), state, false);
goto Platform_wake;
}
error = disable_nonboot_cpus();
if (error || suspend_test(TEST_CPUS))
goto Enable_cpus;
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
error = syscore_suspend();
if (!error) {
*wakeup = pm_wakeup_pending();
if (!(suspend_test(TEST_CORE) || *wakeup)) {
trace_suspend_resume(TPS("machine_suspend"),
state, true);
error = suspend_ops->enter(state);
trace_suspend_resume(TPS("machine_suspend"),
state, false);
events_check_enabled = false;
}
syscore_resume();
}
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
Enable_cpus:
enable_nonboot_cpus();
Platform_wake:
platform_resume_noirq(state);
dpm_resume_noirq(PMSG_RESUME);
Platform_early_resume:
platform_resume_early(state);
Devices_early_resume:
dpm_resume_early(PMSG_RESUME);
Platform_finish:
platform_resume_finish(state);
return error;
}
/**
* suspend_enter - Make the system enter the given sleep state.
* @state: System sleep state to enter.
* @wakeup: Returns information that the sleep state should not be re-entered.
*
* This function should be called after devices have been suspended.
*/
static int suspend_enter(suspend_state_t state, bool *wakeup)
{
int error;
error = platform_suspend_prepare(state);
if (error)
goto Platform_finish;
error = dpm_suspend_late(PMSG_SUSPEND);
if (error) {
pr_err("late suspend of devices failed\n");
goto Platform_finish;
}
error = platform_suspend_prepare_late(state);
if (error)
goto Devices_early_resume;
if (state == PM_SUSPEND_TO_IDLE && pm_test_level != TEST_PLATFORM) {
s2idle_loop();
goto Platform_early_resume;
}
error = dpm_suspend_noirq(PMSG_SUSPEND);
if (error) {
pr_err("noirq suspend of devices failed\n");
goto Platform_early_resume;
}
error = platform_suspend_prepare_noirq(state);
if (error)
goto Platform_wake;
if (suspend_test(TEST_PLATFORM))
goto Platform_wake;
error = disable_nonboot_cpus();
if (error || suspend_test(TEST_CPUS))
goto Enable_cpus;
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
system_state = SYSTEM_SUSPEND;
error = syscore_suspend();
if (!error) {
*wakeup = pm_wakeup_pending();
if (!(suspend_test(TEST_CORE) || *wakeup)) {
trace_suspend_resume(TPS("machine_suspend"),
state, true);
error = suspend_ops->enter(state);
trace_suspend_resume(TPS("machine_suspend"),
state, false);
} else if (*wakeup) {
error = -EBUSY;
}
syscore_resume();
}
system_state = SYSTEM_RUNNING;
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
Enable_cpus:
enable_nonboot_cpus();
Platform_wake:
platform_resume_noirq(state);
dpm_resume_noirq(PMSG_RESUME);
Platform_early_resume:
platform_resume_early(state);
Devices_early_resume:
dpm_resume_early(PMSG_RESUME);
Platform_finish:
platform_resume_finish(state);
return error;
}
/**
* suspend_enter - Make the system enter the given sleep state.
* @state: System sleep state to enter.
* @wakeup: Returns information that the sleep state should not be re-entered.
*
* This function should be called after devices have been suspended.
*/
static int suspend_enter(suspend_state_t state, bool *wakeup)
{
char suspend_abort[MAX_SUSPEND_ABORT_LEN];
int error, last_dev;
error = platform_suspend_prepare(state);
if (error)
goto Platform_finish;
error = dpm_suspend_late(PMSG_SUSPEND);
if (error) {
last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
last_dev %= REC_FAILED_NUM;
printk(KERN_ERR "PM: late suspend of devices failed\n");
log_suspend_abort_reason("%s device failed to power down",
suspend_stats.failed_devs[last_dev]);
goto Platform_finish;
}
error = platform_suspend_prepare_late(state);
if (error)
goto Devices_early_resume;
error = dpm_suspend_noirq(PMSG_SUSPEND);
if (error) {
last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
last_dev %= REC_FAILED_NUM;
printk(KERN_ERR "PM: noirq suspend of devices failed\n");
log_suspend_abort_reason("noirq suspend of %s device failed",
suspend_stats.failed_devs[last_dev]);
goto Platform_early_resume;
}
error = platform_suspend_prepare_noirq(state);
if (error)
goto Platform_wake;
if (suspend_test(TEST_PLATFORM))
goto Platform_wake;
/*
* PM_SUSPEND_FREEZE equals
* frozen processes + suspended devices + idle processors.
* Thus we should invoke freeze_enter() soon after
* all the devices are suspended.
*/
if (state == PM_SUSPEND_FREEZE) {
trace_suspend_resume(TPS("machine_suspend"), state, true);
freeze_enter();
trace_suspend_resume(TPS("machine_suspend"), state, false);
goto Platform_wake;
}
error = disable_nonboot_cpus();
if (error || suspend_test(TEST_CPUS)) {
log_suspend_abort_reason("Disabling non-boot cpus failed");
goto Enable_cpus;
}
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
error = syscore_suspend();
if (!error) {
*wakeup = pm_wakeup_pending();
if (!(suspend_test(TEST_CORE) || *wakeup)) {
trace_suspend_resume(TPS("machine_suspend"),
state, true);
error = suspend_ops->enter(state);
trace_suspend_resume(TPS("machine_suspend"),
state, false);
events_check_enabled = false;
} else if (*wakeup) {
pm_get_active_wakeup_sources(suspend_abort,
MAX_SUSPEND_ABORT_LEN);
log_suspend_abort_reason(suspend_abort);
error = -EBUSY;
}
syscore_resume();
}
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
Enable_cpus:
enable_nonboot_cpus();
Platform_wake:
platform_resume_noirq(state);
dpm_resume_noirq(PMSG_RESUME);
Platform_early_resume:
platform_resume_early(state);
Devices_early_resume:
dpm_resume_early(PMSG_RESUME);
Platform_finish:
platform_resume_finish(state);
return error;
}