![Rafael J. Wysocki](/assets/img/avatar_default.png)
The ACPI SCI (System Control Interrupt) is set up as a wakeup IRQ during suspend-to-idle transitions and, consequently, any events signaled through it wake up the system from that state. However, on some systems some of the events signaled via the ACPI SCI while suspended to idle should not cause the system to wake up. In fact, quite often they should just be discarded. Arguably, systems should not resume entirely on such events, but in order to decide which events really should cause the system to resume and which are spurious, it is necessary to resume up to the point when ACPI SCIs are actually handled and processed, which is after executing dpm_resume_noirq() in the system resume path. For this reasons, add a loop around freeze_enter() in which the platforms can process events signaled via multiplexed IRQ lines like the ACPI SCI and add suspend-to-idle hooks that can be used for this purpose to struct platform_freeze_ops. In the ACPI case, the ->wake hook is used for checking if the SCI has triggered while suspended and deferring the interrupt-induced system wakeup until the events signaled through it are actually processed sufficiently to decide whether or not the system should resume. In turn, the ->sync hook allows all of the relevant event queues to be flushed so as to prevent events from being missed due to race conditions. In addition to that, some ACPI code processing wakeup events needs to be modified to use the "hard" version of wakeup triggers, so that it will cause a system resume to happen on device-induced wakeup events even if the "soft" mechanism to prevent the system from suspending is not enabled (that also helps to catch device-induced wakeup events occurring during suspend transitions in progress). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
590 lines
14 KiB
C
590 lines
14 KiB
C
/*
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* kernel/power/suspend.c - Suspend to RAM and standby functionality.
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*
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* Copyright (c) 2003 Patrick Mochel
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* Copyright (c) 2003 Open Source Development Lab
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* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
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*
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* This file is released under the GPLv2.
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*/
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#include <linux/string.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/console.h>
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#include <linux/cpu.h>
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#include <linux/cpuidle.h>
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#include <linux/syscalls.h>
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#include <linux/gfp.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/export.h>
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#include <linux/suspend.h>
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#include <linux/syscore_ops.h>
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#include <linux/ftrace.h>
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#include <trace/events/power.h>
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#include <linux/compiler.h>
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#include <linux/moduleparam.h>
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#include "power.h"
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const char * const pm_labels[] = {
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[PM_SUSPEND_FREEZE] = "freeze",
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[PM_SUSPEND_STANDBY] = "standby",
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[PM_SUSPEND_MEM] = "mem",
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};
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const char *pm_states[PM_SUSPEND_MAX];
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static const char * const mem_sleep_labels[] = {
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[PM_SUSPEND_FREEZE] = "s2idle",
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[PM_SUSPEND_STANDBY] = "shallow",
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[PM_SUSPEND_MEM] = "deep",
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};
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const char *mem_sleep_states[PM_SUSPEND_MAX];
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suspend_state_t mem_sleep_current = PM_SUSPEND_FREEZE;
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static suspend_state_t mem_sleep_default = PM_SUSPEND_MEM;
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unsigned int pm_suspend_global_flags;
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EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
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static const struct platform_suspend_ops *suspend_ops;
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static const struct platform_freeze_ops *freeze_ops;
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static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
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enum freeze_state __read_mostly suspend_freeze_state;
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static DEFINE_SPINLOCK(suspend_freeze_lock);
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void freeze_set_ops(const struct platform_freeze_ops *ops)
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{
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lock_system_sleep();
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freeze_ops = ops;
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unlock_system_sleep();
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}
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static void freeze_begin(void)
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{
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suspend_freeze_state = FREEZE_STATE_NONE;
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}
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static void freeze_enter(void)
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{
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trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_FREEZE, true);
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spin_lock_irq(&suspend_freeze_lock);
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if (pm_wakeup_pending())
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goto out;
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suspend_freeze_state = FREEZE_STATE_ENTER;
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spin_unlock_irq(&suspend_freeze_lock);
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get_online_cpus();
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cpuidle_resume();
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/* Push all the CPUs into the idle loop. */
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wake_up_all_idle_cpus();
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pr_debug("PM: suspend-to-idle\n");
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/* Make the current CPU wait so it can enter the idle loop too. */
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wait_event(suspend_freeze_wait_head,
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suspend_freeze_state == FREEZE_STATE_WAKE);
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pr_debug("PM: resume from suspend-to-idle\n");
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cpuidle_pause();
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put_online_cpus();
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spin_lock_irq(&suspend_freeze_lock);
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out:
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suspend_freeze_state = FREEZE_STATE_NONE;
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spin_unlock_irq(&suspend_freeze_lock);
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trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_FREEZE, false);
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}
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static void s2idle_loop(void)
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{
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do {
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freeze_enter();
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if (freeze_ops && freeze_ops->wake)
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freeze_ops->wake();
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dpm_resume_noirq(PMSG_RESUME);
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if (freeze_ops && freeze_ops->sync)
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freeze_ops->sync();
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if (pm_wakeup_pending())
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break;
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pm_wakeup_clear(false);
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} while (!dpm_suspend_noirq(PMSG_SUSPEND));
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}
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void freeze_wake(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&suspend_freeze_lock, flags);
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if (suspend_freeze_state > FREEZE_STATE_NONE) {
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suspend_freeze_state = FREEZE_STATE_WAKE;
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wake_up(&suspend_freeze_wait_head);
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}
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spin_unlock_irqrestore(&suspend_freeze_lock, flags);
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}
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EXPORT_SYMBOL_GPL(freeze_wake);
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static bool valid_state(suspend_state_t state)
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{
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/*
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* PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
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* support and need to be valid to the low level
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* implementation, no valid callback implies that none are valid.
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*/
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return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
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}
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void __init pm_states_init(void)
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{
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/* "mem" and "freeze" are always present in /sys/power/state. */
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pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
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pm_states[PM_SUSPEND_FREEZE] = pm_labels[PM_SUSPEND_FREEZE];
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/*
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* Suspend-to-idle should be supported even without any suspend_ops,
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* initialize mem_sleep_states[] accordingly here.
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*/
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mem_sleep_states[PM_SUSPEND_FREEZE] = mem_sleep_labels[PM_SUSPEND_FREEZE];
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}
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static int __init mem_sleep_default_setup(char *str)
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{
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suspend_state_t state;
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for (state = PM_SUSPEND_FREEZE; state <= PM_SUSPEND_MEM; state++)
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if (mem_sleep_labels[state] &&
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!strcmp(str, mem_sleep_labels[state])) {
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mem_sleep_default = state;
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break;
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}
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return 1;
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}
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__setup("mem_sleep_default=", mem_sleep_default_setup);
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/**
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* suspend_set_ops - Set the global suspend method table.
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* @ops: Suspend operations to use.
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*/
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void suspend_set_ops(const struct platform_suspend_ops *ops)
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{
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lock_system_sleep();
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suspend_ops = ops;
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if (valid_state(PM_SUSPEND_STANDBY)) {
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mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
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pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
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if (mem_sleep_default == PM_SUSPEND_STANDBY)
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mem_sleep_current = PM_SUSPEND_STANDBY;
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}
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if (valid_state(PM_SUSPEND_MEM)) {
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mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
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if (mem_sleep_default == PM_SUSPEND_MEM)
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mem_sleep_current = PM_SUSPEND_MEM;
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}
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unlock_system_sleep();
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}
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EXPORT_SYMBOL_GPL(suspend_set_ops);
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/**
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* suspend_valid_only_mem - Generic memory-only valid callback.
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*
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* Platform drivers that implement mem suspend only and only need to check for
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* that in their .valid() callback can use this instead of rolling their own
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* .valid() callback.
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*/
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int suspend_valid_only_mem(suspend_state_t state)
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{
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return state == PM_SUSPEND_MEM;
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}
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EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
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static bool sleep_state_supported(suspend_state_t state)
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{
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return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
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}
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static int platform_suspend_prepare(suspend_state_t state)
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{
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return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
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suspend_ops->prepare() : 0;
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}
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static int platform_suspend_prepare_late(suspend_state_t state)
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{
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return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
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freeze_ops->prepare() : 0;
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}
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static int platform_suspend_prepare_noirq(suspend_state_t state)
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{
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return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
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suspend_ops->prepare_late() : 0;
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}
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static void platform_resume_noirq(suspend_state_t state)
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{
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if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
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suspend_ops->wake();
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}
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static void platform_resume_early(suspend_state_t state)
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{
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if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
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freeze_ops->restore();
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}
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static void platform_resume_finish(suspend_state_t state)
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{
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if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
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suspend_ops->finish();
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}
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static int platform_suspend_begin(suspend_state_t state)
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{
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if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
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return freeze_ops->begin();
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else if (suspend_ops && suspend_ops->begin)
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return suspend_ops->begin(state);
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else
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return 0;
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}
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static void platform_resume_end(suspend_state_t state)
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{
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if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
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freeze_ops->end();
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else if (suspend_ops && suspend_ops->end)
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suspend_ops->end();
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}
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static void platform_recover(suspend_state_t state)
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{
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if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
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suspend_ops->recover();
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}
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static bool platform_suspend_again(suspend_state_t state)
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{
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return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
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suspend_ops->suspend_again() : false;
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}
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#ifdef CONFIG_PM_DEBUG
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static unsigned int pm_test_delay = 5;
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module_param(pm_test_delay, uint, 0644);
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MODULE_PARM_DESC(pm_test_delay,
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"Number of seconds to wait before resuming from suspend test");
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#endif
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static int suspend_test(int level)
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{
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#ifdef CONFIG_PM_DEBUG
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if (pm_test_level == level) {
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pr_info("suspend debug: Waiting for %d second(s).\n",
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pm_test_delay);
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mdelay(pm_test_delay * 1000);
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return 1;
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}
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#endif /* !CONFIG_PM_DEBUG */
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return 0;
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}
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/**
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* suspend_prepare - Prepare for entering system sleep state.
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*
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* Common code run for every system sleep state that can be entered (except for
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* hibernation). Run suspend notifiers, allocate the "suspend" console and
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* freeze processes.
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*/
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static int suspend_prepare(suspend_state_t state)
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{
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int error, nr_calls = 0;
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if (!sleep_state_supported(state))
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return -EPERM;
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pm_prepare_console();
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error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
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if (error) {
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nr_calls--;
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goto Finish;
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}
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trace_suspend_resume(TPS("freeze_processes"), 0, true);
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error = suspend_freeze_processes();
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trace_suspend_resume(TPS("freeze_processes"), 0, false);
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if (!error)
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return 0;
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suspend_stats.failed_freeze++;
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dpm_save_failed_step(SUSPEND_FREEZE);
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Finish:
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__pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
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pm_restore_console();
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return error;
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}
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/* default implementation */
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void __weak arch_suspend_disable_irqs(void)
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{
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local_irq_disable();
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}
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/* default implementation */
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void __weak arch_suspend_enable_irqs(void)
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{
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local_irq_enable();
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}
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/**
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* suspend_enter - Make the system enter the given sleep state.
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* @state: System sleep state to enter.
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* @wakeup: Returns information that the sleep state should not be re-entered.
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*
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* This function should be called after devices have been suspended.
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*/
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static int suspend_enter(suspend_state_t state, bool *wakeup)
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{
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int error;
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error = platform_suspend_prepare(state);
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if (error)
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goto Platform_finish;
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error = dpm_suspend_late(PMSG_SUSPEND);
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if (error) {
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pr_err("PM: late suspend of devices failed\n");
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goto Platform_finish;
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}
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error = platform_suspend_prepare_late(state);
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if (error)
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goto Devices_early_resume;
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error = dpm_suspend_noirq(PMSG_SUSPEND);
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if (error) {
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pr_err("PM: noirq suspend of devices failed\n");
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goto Platform_early_resume;
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}
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error = platform_suspend_prepare_noirq(state);
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if (error)
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goto Platform_wake;
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if (suspend_test(TEST_PLATFORM))
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goto Platform_wake;
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/*
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* PM_SUSPEND_FREEZE equals
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* frozen processes + suspended devices + idle processors.
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* Thus we should invoke freeze_enter() soon after
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* all the devices are suspended.
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*/
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if (state == PM_SUSPEND_FREEZE) {
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s2idle_loop();
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goto Platform_early_resume;
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}
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error = disable_nonboot_cpus();
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if (error || suspend_test(TEST_CPUS))
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goto Enable_cpus;
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arch_suspend_disable_irqs();
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BUG_ON(!irqs_disabled());
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error = syscore_suspend();
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if (!error) {
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*wakeup = pm_wakeup_pending();
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if (!(suspend_test(TEST_CORE) || *wakeup)) {
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trace_suspend_resume(TPS("machine_suspend"),
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state, true);
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error = suspend_ops->enter(state);
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trace_suspend_resume(TPS("machine_suspend"),
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state, false);
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events_check_enabled = false;
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} else if (*wakeup) {
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error = -EBUSY;
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}
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syscore_resume();
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}
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arch_suspend_enable_irqs();
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BUG_ON(irqs_disabled());
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Enable_cpus:
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enable_nonboot_cpus();
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Platform_wake:
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platform_resume_noirq(state);
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dpm_resume_noirq(PMSG_RESUME);
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Platform_early_resume:
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platform_resume_early(state);
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Devices_early_resume:
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dpm_resume_early(PMSG_RESUME);
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Platform_finish:
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platform_resume_finish(state);
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return error;
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}
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/**
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* suspend_devices_and_enter - Suspend devices and enter system sleep state.
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* @state: System sleep state to enter.
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*/
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int suspend_devices_and_enter(suspend_state_t state)
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{
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int error;
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bool wakeup = false;
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if (!sleep_state_supported(state))
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return -ENOSYS;
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error = platform_suspend_begin(state);
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if (error)
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goto Close;
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suspend_console();
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suspend_test_start();
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error = dpm_suspend_start(PMSG_SUSPEND);
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if (error) {
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pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
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goto Recover_platform;
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}
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suspend_test_finish("suspend devices");
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if (suspend_test(TEST_DEVICES))
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goto Recover_platform;
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do {
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error = suspend_enter(state, &wakeup);
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} while (!error && !wakeup && platform_suspend_again(state));
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Resume_devices:
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suspend_test_start();
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dpm_resume_end(PMSG_RESUME);
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suspend_test_finish("resume devices");
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trace_suspend_resume(TPS("resume_console"), state, true);
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resume_console();
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trace_suspend_resume(TPS("resume_console"), state, false);
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Close:
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platform_resume_end(state);
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return error;
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Recover_platform:
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platform_recover(state);
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goto Resume_devices;
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}
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/**
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* suspend_finish - Clean up before finishing the suspend sequence.
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*
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* Call platform code to clean up, restart processes, and free the console that
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* we've allocated. This routine is not called for hibernation.
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*/
|
|
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_FREEZE) {
|
|
#ifdef CONFIG_PM_DEBUG
|
|
if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
|
|
pr_warn("PM: 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(&pm_mutex))
|
|
return -EBUSY;
|
|
|
|
if (state == PM_SUSPEND_FREEZE)
|
|
freeze_begin();
|
|
|
|
#ifndef CONFIG_SUSPEND_SKIP_SYNC
|
|
trace_suspend_resume(TPS("sync_filesystems"), 0, true);
|
|
pr_info("PM: Syncing filesystems ... ");
|
|
sys_sync();
|
|
pr_cont("done.\n");
|
|
trace_suspend_resume(TPS("sync_filesystems"), 0, false);
|
|
#endif
|
|
|
|
pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[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);
|
|
pr_debug("PM: Suspending system (%s)\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;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
|
|
error = enter_state(state);
|
|
if (error) {
|
|
suspend_stats.fail++;
|
|
dpm_save_failed_errno(error);
|
|
} else {
|
|
suspend_stats.success++;
|
|
}
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL(pm_suspend);
|