v4.19.13 snapshot.
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
new file mode 100644
index 0000000..0bd595a
--- /dev/null
+++ b/kernel/power/suspend.c
@@ -0,0 +1,628 @@
+/*
+ * 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.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#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/syscalls.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 "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);
+
+bool pm_suspend_via_s2idle(void)
+{
+ return mem_sleep_current == PM_SUSPEND_TO_IDLE;
+}
+EXPORT_SYMBOL_GPL(pm_suspend_via_s2idle);
+
+void s2idle_set_ops(const struct platform_s2idle_ops *ops)
+{
+ lock_system_sleep();
+ s2idle_ops = ops;
+ unlock_system_sleep();
+}
+
+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);
+
+ 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);
+}
+
+static void s2idle_loop(void)
+{
+ pm_pr_dbg("suspend-to-idle\n");
+
+ for (;;) {
+ int error;
+
+ dpm_noirq_begin();
+
+ /*
+ * 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 prevent them from terminating the loop right away.
+ */
+ error = dpm_noirq_suspend_devices(PMSG_SUSPEND);
+ if (!error)
+ s2idle_enter();
+ else if (error == -EBUSY && pm_wakeup_pending())
+ error = 0;
+
+ if (!error && s2idle_ops && s2idle_ops->wake)
+ s2idle_ops->wake();
+
+ dpm_noirq_resume_devices(PMSG_RESUME);
+
+ dpm_noirq_end();
+
+ if (error)
+ break;
+
+ if (s2idle_ops && s2idle_ops->sync)
+ s2idle_ops->sync();
+
+ if (pm_wakeup_pending())
+ break;
+
+ pm_wakeup_clear(false);
+ }
+
+ 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)
+{
+ /*
+ * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
+ * support and need to be valid to the low level
+ * implementation, no valid callback implies that none are valid.
+ */
+ return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
+}
+
+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;
+ 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)
+{
+ 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();
+}
+EXPORT_SYMBOL_GPL(suspend_set_ops);
+
+/**
+ * suspend_valid_only_mem - Generic memory-only valid callback.
+ *
+ * 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 || (suspend_ops && suspend_ops->enter);
+}
+
+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)
+{
+ return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ?
+ suspend_ops->prepare_late() : 0;
+}
+
+static void platform_resume_noirq(suspend_state_t state)
+{
+ if (state != PM_SUSPEND_TO_IDLE && 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_DEBUG
+static 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
+ if (pm_test_level == level) {
+ pr_info("suspend debug: Waiting for %d second(s).\n",
+ pm_test_delay);
+ mdelay(pm_test_delay * 1000);
+ return 1;
+ }
+#endif /* !CONFIG_PM_DEBUG */
+ return 0;
+}
+
+/**
+ * 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, nr_calls = 0;
+
+ if (!sleep_state_supported(state))
+ return -EPERM;
+
+ pm_prepare_console();
+
+ error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
+ if (error) {
+ nr_calls--;
+ 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, nr_calls, NULL);
+ 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;
+
+ 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_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;
+}
+
+/**
+ * suspend_finish - Clean up before finishing the suspend sequence.
+ *
+ * Call platform code to clean up, restart processes, and free the console that
+ * we've allocated. This routine is not called for hibernation.
+ */
+static void suspend_finish(void)
+{
+ suspend_thaw_processes();
+ pm_notifier_call_chain(PM_POST_SUSPEND);
+ pm_restore_console();
+}
+
+/**
+ * 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;
+}
+
+/**
+ * pm_suspend - Externally visible function for suspending the system.
+ * @state: System sleep state to enter.
+ *
+ * Check if the value of @state represents one of the supported states,
+ * execute enter_state() and update system suspend statistics.
+ */
+int pm_suspend(suspend_state_t state)
+{
+ int error;
+
+ if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
+ return -EINVAL;
+
+ pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
+ error = enter_state(state);
+ if (error) {
+ suspend_stats.fail++;
+ dpm_save_failed_errno(error);
+ } else {
+ suspend_stats.success++;
+ }
+ pr_info("suspend exit\n");
+ return error;
+}
+EXPORT_SYMBOL(pm_suspend);