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// SPDX-License-Identifier: GPL-2.0-only/* * kernel/power/suspend.c - Suspend to RAM and standby functionality. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Open Source Development Lab * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. */ #define pr_fmt(fmt) "PM: " fmt #include <linux/string.h>#include <linux/delay.h>#include <linux/errno.h>#include <linux/init.h>#include <linux/console.h>#include <linux/cpu.h>#include <linux/cpuidle.h>#include <linux/gfp.h>#include <linux/io.h>#include <linux/kernel.h>#include <linux/list.h>#include <linux/mm.h>#include <linux/slab.h>#include <linux/export.h>#include <linux/suspend.h>#include <linux/syscore_ops.h>#include <linux/swait.h>#include <linux/ftrace.h>#include <trace/events/power.h>#include <linux/compiler.h>#include <linux/moduleparam.h>#include <linux/fs.h> #include "power.h" const char * const pm_labels[] = {	[PM_SUSPEND_TO_IDLE] = "freeze",	[PM_SUSPEND_STANDBY] = "standby",	[PM_SUSPEND_MEM] = "mem",};const char *pm_states[PM_SUSPEND_MAX];static const char * const mem_sleep_labels[] = {	[PM_SUSPEND_TO_IDLE] = "s2idle",	[PM_SUSPEND_STANDBY] = "shallow",	[PM_SUSPEND_MEM] = "deep",};const char *mem_sleep_states[PM_SUSPEND_MAX]; suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;suspend_state_t pm_suspend_target_state;EXPORT_SYMBOL_GPL(pm_suspend_target_state); unsigned int pm_suspend_global_flags;EXPORT_SYMBOL_GPL(pm_suspend_global_flags); static const struct platform_suspend_ops *suspend_ops;static const struct platform_s2idle_ops *s2idle_ops;static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head); enum s2idle_states __read_mostly s2idle_state;static DEFINE_RAW_SPINLOCK(s2idle_lock); /** * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend. * * Return 'true' if suspend-to-idle has been selected as the default system * suspend method. */bool pm_suspend_default_s2idle(void){	return mem_sleep_current == PM_SUSPEND_TO_IDLE;}EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle); void s2idle_set_ops(const struct platform_s2idle_ops *ops){	unsigned int sleep_flags; 	sleep_flags = lock_system_sleep();	s2idle_ops = ops;	unlock_system_sleep(sleep_flags);} static void s2idle_begin(void){	s2idle_state = S2IDLE_STATE_NONE;} static void s2idle_enter(void){	trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true); 	/*	 * The correctness of the code below depends on the number of online	 * CPUs being stable, but CPUs cannot be taken offline or put online	 * while it is running.	 *	 * The s2idle_lock must be acquired before the pending wakeup check to	 * prevent pm_system_wakeup() from running as a whole between that check	 * and the subsequent s2idle_state update in which case a wakeup event	 * would get lost.	 */	raw_spin_lock_irq(&s2idle_lock);	if (pm_wakeup_pending())		goto out; 	s2idle_state = S2IDLE_STATE_ENTER;	raw_spin_unlock_irq(&s2idle_lock); 	/* 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); 	/*	 * Kick all CPUs to ensure that they resume their timers and restore	 * consistent system state.	 */	wake_up_all_idle_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);} static void s2idle_loop(void){	pm_pr_dbg("suspend-to-idle\n"); 	/*	 * Suspend-to-idle equals:	 * frozen processes + suspended devices + idle processors.	 * Thus s2idle_enter() should be called right after all devices have	 * been suspended.	 *	 * Wakeups during the noirq suspend of devices may be spurious, so try	 * to avoid them upfront.	 */	for (;;) {		if (s2idle_ops && s2idle_ops->wake) {			if (s2idle_ops->wake())				break;		} else if (pm_wakeup_pending()) {			break;		} 		if (s2idle_ops && s2idle_ops->check)			s2idle_ops->check(); 		s2idle_enter();	} 	pm_pr_dbg("resume from suspend-to-idle\n");} void s2idle_wake(void){	unsigned long flags; 	raw_spin_lock_irqsave(&s2idle_lock, flags);	if (s2idle_state > S2IDLE_STATE_NONE) {		s2idle_state = S2IDLE_STATE_WAKE;		swake_up_one(&s2idle_wait_head);	}	raw_spin_unlock_irqrestore(&s2idle_lock, flags);}EXPORT_SYMBOL_GPL(s2idle_wake); static bool valid_state(suspend_state_t state){	/*	 * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level	 * support and need to be valid to the low-level implementation.	 *	 * No ->valid() or ->enter() callback implies that none are valid.	 */	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) &&		suspend_ops->enter;} void __init pm_states_init(void){	/* "mem" and "freeze" are always present in /sys/power/state. */	pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];	pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];	/*	 * Suspend-to-idle should be supported even without any suspend_ops,	 * initialize mem_sleep_states[] accordingly here.	 */	mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];} static int __init mem_sleep_default_setup(char *str){	suspend_state_t state; 	for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)		if (mem_sleep_labels[state] &&		    !strcmp(str, mem_sleep_labels[state])) {			mem_sleep_default = state;			mem_sleep_current = state;			break;		} 	return 1;}__setup("mem_sleep_default=", mem_sleep_default_setup); /** * suspend_set_ops - Set the global suspend method table. * @ops: Suspend operations to use. */void suspend_set_ops(const struct platform_suspend_ops *ops){	unsigned int sleep_flags; 	sleep_flags = lock_system_sleep(); 	suspend_ops = ops; 	if (valid_state(PM_SUSPEND_STANDBY)) {		mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];		pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];		if (mem_sleep_default == PM_SUSPEND_STANDBY)			mem_sleep_current = PM_SUSPEND_STANDBY;	}	if (valid_state(PM_SUSPEND_MEM)) {		mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];		if (mem_sleep_default >= PM_SUSPEND_MEM)			mem_sleep_current = PM_SUSPEND_MEM;	} 	unlock_system_sleep(sleep_flags);}EXPORT_SYMBOL_GPL(suspend_set_ops); /** * suspend_valid_only_mem - Generic memory-only valid callback. * @state: Target system sleep state. * * Platform drivers that implement mem suspend only and only need to check for * that in their .valid() callback can use this instead of rolling their own * .valid() callback. */int suspend_valid_only_mem(suspend_state_t state){	return state == PM_SUSPEND_MEM;}EXPORT_SYMBOL_GPL(suspend_valid_only_mem); static bool sleep_state_supported(suspend_state_t state){	return state == PM_SUSPEND_TO_IDLE ||	       (valid_state(state) && !cxl_mem_active());} static int platform_suspend_prepare(suspend_state_t state){	return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?		suspend_ops->prepare() : 0;} static int platform_suspend_prepare_late(suspend_state_t state){	return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?		s2idle_ops->prepare() : 0;} static int platform_suspend_prepare_noirq(suspend_state_t state){	if (state == PM_SUSPEND_TO_IDLE)		return s2idle_ops && s2idle_ops->prepare_late ?			s2idle_ops->prepare_late() : 0; 	return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;} static void platform_resume_noirq(suspend_state_t state){	if (state == PM_SUSPEND_TO_IDLE) {		if (s2idle_ops && s2idle_ops->restore_early)			s2idle_ops->restore_early();	} else if (suspend_ops->wake) {		suspend_ops->wake();	}} static void platform_resume_early(suspend_state_t state){	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)		s2idle_ops->restore();} static void platform_resume_finish(suspend_state_t state){	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)		suspend_ops->finish();} static int platform_suspend_begin(suspend_state_t state){	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)		return s2idle_ops->begin();	else if (suspend_ops && suspend_ops->begin)		return suspend_ops->begin(state);	else		return 0;} static void platform_resume_end(suspend_state_t state){	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)		s2idle_ops->end();	else if (suspend_ops && suspend_ops->end)		suspend_ops->end();} static void platform_recover(suspend_state_t state){	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)		suspend_ops->recover();} static bool platform_suspend_again(suspend_state_t state){	return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?		suspend_ops->suspend_again() : false;} #ifdef CONFIG_PM_DEBUGstatic unsigned int pm_test_delay = 5;module_param(pm_test_delay, uint, 0644);MODULE_PARM_DESC(pm_test_delay,		 "Number of seconds to wait before resuming from suspend test");#endif static int suspend_test(int level){#ifdef CONFIG_PM_DEBUG	int i; 	if (pm_test_level == level) {		pr_info("suspend debug: Waiting for %d second(s).\n",				pm_test_delay);		for (i = 0; i < pm_test_delay && !pm_wakeup_pending(); i++) {			if (level > TEST_CORE)				msleep(1000);			else				mdelay(1000);		}		return 1;	}#endif /* !CONFIG_PM_DEBUG */	return 0;} /** * suspend_prepare - Prepare for entering system sleep state. * @state: Target 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_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);	if (error)		goto Restore; 	filesystems_freeze(filesystem_freeze_enabled);	trace_suspend_resume(TPS("freeze_processes"), 0, true);	error = suspend_freeze_processes();	trace_suspend_resume(TPS("freeze_processes"), 0, false);	if (!error)		return 0; 	dpm_save_failed_step(SUSPEND_FREEZE);	filesystems_thaw();	pm_notifier_call_chain(PM_POST_SUSPEND); Restore:	pm_restore_console();	return error;} /* default implementation */void __weak arch_suspend_disable_irqs(void){	local_irq_disable();} /* default implementation */void __weak arch_suspend_enable_irqs(void){	local_irq_enable();} /** * 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; 	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; 	if (state == PM_SUSPEND_TO_IDLE) {		s2idle_loop();		goto Platform_wake;	} 	error = pm_sleep_disable_secondary_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:	pm_sleep_enable_secondary_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;} /**

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