blob: 3c118c0446330f4b43a93811da79828edf6e2288 [file] [log] [blame]
/*
* kernel/power/wakeup_reason.c
*
* Logs the reasons which caused the kernel to resume from
* the suspend mode.
*
* Copyright (C) 2020 Google, Inc.
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/wakeup_reason.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <linux/suspend.h>
#include <linux/slab.h>
/*
* struct wakeup_irq_node - stores data and relationships for IRQs logged as
* either base or nested wakeup reasons during suspend/resume flow.
* @siblings - for membership on leaf or parent IRQ lists
* @irq - the IRQ number
* @irq_name - the name associated with the IRQ, or a default if none
*/
struct wakeup_irq_node {
struct list_head siblings;
int irq;
const char *irq_name;
};
static DEFINE_SPINLOCK(wakeup_reason_lock);
static LIST_HEAD(leaf_irqs); /* kept in ascending IRQ sorted order */
static LIST_HEAD(parent_irqs); /* unordered */
static struct kmem_cache *wakeup_irq_nodes_cache;
static const char *default_irq_name = "(unnamed)";
static struct kobject *kobj;
static bool capture_reasons;
static bool suspend_abort;
static bool abnormal_wake;
static char non_irq_wake_reason[MAX_SUSPEND_ABORT_LEN];
static ktime_t last_monotime; /* monotonic time before last suspend */
static ktime_t curr_monotime; /* monotonic time after last suspend */
static ktime_t last_stime; /* monotonic boottime offset before last suspend */
static ktime_t curr_stime; /* monotonic boottime offset after last suspend */
static void init_node(struct wakeup_irq_node *p, int irq)
{
struct irq_desc *desc;
INIT_LIST_HEAD(&p->siblings);
p->irq = irq;
desc = irq_to_desc(irq);
if (desc && desc->action && desc->action->name)
p->irq_name = desc->action->name;
else
p->irq_name = default_irq_name;
}
static struct wakeup_irq_node *create_node(int irq)
{
struct wakeup_irq_node *result;
result = kmem_cache_alloc(wakeup_irq_nodes_cache, GFP_ATOMIC);
if (unlikely(!result))
pr_warn("Failed to log wakeup IRQ %d\n", irq);
else
init_node(result, irq);
return result;
}
static void delete_list(struct list_head *head)
{
struct wakeup_irq_node *n;
while (!list_empty(head)) {
n = list_first_entry(head, struct wakeup_irq_node, siblings);
list_del(&n->siblings);
kmem_cache_free(wakeup_irq_nodes_cache, n);
}
}
static bool add_sibling_node_sorted(struct list_head *head, int irq)
{
struct wakeup_irq_node *n = NULL;
struct list_head *predecessor = head;
if (unlikely(WARN_ON(!head)))
return NULL;
if (!list_empty(head))
list_for_each_entry(n, head, siblings) {
if (n->irq < irq)
predecessor = &n->siblings;
else if (n->irq == irq)
return true;
else
break;
}
n = create_node(irq);
if (n) {
list_add(&n->siblings, predecessor);
return true;
}
return false;
}
static struct wakeup_irq_node *find_node_in_list(struct list_head *head,
int irq)
{
struct wakeup_irq_node *n;
if (unlikely(WARN_ON(!head)))
return NULL;
list_for_each_entry(n, head, siblings)
if (n->irq == irq)
return n;
return NULL;
}
void log_irq_wakeup_reason(int irq)
{
unsigned long flags;
spin_lock_irqsave(&wakeup_reason_lock, flags);
if (!capture_reasons) {
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
return;
}
if (find_node_in_list(&parent_irqs, irq) == NULL)
add_sibling_node_sorted(&leaf_irqs, irq);
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
}
void log_threaded_irq_wakeup_reason(int irq, int parent_irq)
{
struct wakeup_irq_node *parent;
unsigned long flags;
/*
* Intentionally unsynchronized. Calls that come in after we have
* resumed should have a fast exit path since there's no work to be
* done, any any coherence issue that could cause a wrong value here is
* both highly improbable - given the set/clear timing - and very low
* impact (parent IRQ gets logged instead of the specific child).
*/
if (!capture_reasons)
return;
spin_lock_irqsave(&wakeup_reason_lock, flags);
if (!capture_reasons || (find_node_in_list(&leaf_irqs, irq) != NULL)) {
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
return;
}
parent = find_node_in_list(&parent_irqs, parent_irq);
if (parent != NULL)
add_sibling_node_sorted(&leaf_irqs, irq);
else {
parent = find_node_in_list(&leaf_irqs, parent_irq);
if (parent != NULL) {
list_del_init(&parent->siblings);
list_add_tail(&parent->siblings, &parent_irqs);
add_sibling_node_sorted(&leaf_irqs, irq);
}
}
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
}
static void __log_abort_or_abnormal_wake(bool abort, const char *fmt,
va_list args)
{
unsigned long flags;
spin_lock_irqsave(&wakeup_reason_lock, flags);
/* Suspend abort or abnormal wake reason has already been logged. */
if (suspend_abort || abnormal_wake) {
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
return;
}
suspend_abort = abort;
abnormal_wake = !abort;
vsnprintf(non_irq_wake_reason, MAX_SUSPEND_ABORT_LEN, fmt, args);
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
}
void log_suspend_abort_reason(const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
__log_abort_or_abnormal_wake(true, fmt, args);
va_end(args);
}
void log_abnormal_wakeup_reason(const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
__log_abort_or_abnormal_wake(false, fmt, args);
va_end(args);
}
void clear_wakeup_reasons(void)
{
unsigned long flags;
spin_lock_irqsave(&wakeup_reason_lock, flags);
delete_list(&leaf_irqs);
delete_list(&parent_irqs);
suspend_abort = false;
abnormal_wake = false;
capture_reasons = true;
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
}
static void print_wakeup_sources(void)
{
struct wakeup_irq_node *n;
unsigned long flags;
spin_lock_irqsave(&wakeup_reason_lock, flags);
capture_reasons = false;
if (suspend_abort) {
pr_info("Abort: %s\n", non_irq_wake_reason);
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
return;
}
if (!list_empty(&leaf_irqs))
list_for_each_entry(n, &leaf_irqs, siblings)
pr_info("Resume caused by IRQ %d, %s\n", n->irq,
n->irq_name);
else if (abnormal_wake)
pr_info("Resume caused by %s\n", non_irq_wake_reason);
else
pr_info("Resume cause unknown\n");
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
}
static ssize_t last_resume_reason_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
ssize_t buf_offset = 0;
struct wakeup_irq_node *n;
unsigned long flags;
spin_lock_irqsave(&wakeup_reason_lock, flags);
if (suspend_abort) {
buf_offset = scnprintf(buf, PAGE_SIZE, "Abort: %s",
non_irq_wake_reason);
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
return buf_offset;
}
if (!list_empty(&leaf_irqs))
list_for_each_entry(n, &leaf_irqs, siblings)
buf_offset += scnprintf(buf + buf_offset,
PAGE_SIZE - buf_offset,
"%d %s\n", n->irq, n->irq_name);
else if (abnormal_wake)
buf_offset = scnprintf(buf, PAGE_SIZE, "-1 %s",
non_irq_wake_reason);
spin_unlock_irqrestore(&wakeup_reason_lock, flags);
return buf_offset;
}
static ssize_t last_suspend_time_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct timespec64 sleep_time;
struct timespec64 total_time;
struct timespec64 suspend_resume_time;
/*
* total_time is calculated from monotonic bootoffsets because
* unlike CLOCK_MONOTONIC it include the time spent in suspend state.
*/
total_time = ktime_to_timespec64(ktime_sub(curr_stime, last_stime));
/*
* suspend_resume_time is calculated as monotonic (CLOCK_MONOTONIC)
* time interval before entering suspend and post suspend.
*/
suspend_resume_time =
ktime_to_timespec64(ktime_sub(curr_monotime, last_monotime));
/* sleep_time = total_time - suspend_resume_time */
sleep_time = timespec64_sub(total_time, suspend_resume_time);
/* Export suspend_resume_time and sleep_time in pair here. */
return sprintf(buf, "%llu.%09lu %llu.%09lu\n",
(unsigned long long)suspend_resume_time.tv_sec,
suspend_resume_time.tv_nsec,
(unsigned long long)sleep_time.tv_sec,
sleep_time.tv_nsec);
}
static struct kobj_attribute resume_reason = __ATTR_RO(last_resume_reason);
static struct kobj_attribute suspend_time = __ATTR_RO(last_suspend_time);
static struct attribute *attrs[] = {
&resume_reason.attr,
&suspend_time.attr,
NULL,
};
static struct attribute_group attr_group = {
.attrs = attrs,
};
/* Detects a suspend and clears all the previous wake up reasons*/
static int wakeup_reason_pm_event(struct notifier_block *notifier,
unsigned long pm_event, void *unused)
{
switch (pm_event) {
case PM_SUSPEND_PREPARE:
/* monotonic time since boot */
last_monotime = ktime_get();
/* monotonic time since boot including the time spent in suspend */
last_stime = ktime_get_boottime();
clear_wakeup_reasons();
break;
case PM_POST_SUSPEND:
/* monotonic time since boot */
curr_monotime = ktime_get();
/* monotonic time since boot including the time spent in suspend */
curr_stime = ktime_get_boottime();
print_wakeup_sources();
break;
default:
break;
}
return NOTIFY_DONE;
}
static struct notifier_block wakeup_reason_pm_notifier_block = {
.notifier_call = wakeup_reason_pm_event,
};
static int __init wakeup_reason_init(void)
{
if (register_pm_notifier(&wakeup_reason_pm_notifier_block)) {
pr_warn("[%s] failed to register PM notifier\n", __func__);
goto fail;
}
kobj = kobject_create_and_add("wakeup_reasons", kernel_kobj);
if (!kobj) {
pr_warn("[%s] failed to create a sysfs kobject\n", __func__);
goto fail_unregister_pm_notifier;
}
if (sysfs_create_group(kobj, &attr_group)) {
pr_warn("[%s] failed to create a sysfs group\n", __func__);
goto fail_kobject_put;
}
wakeup_irq_nodes_cache =
kmem_cache_create("wakeup_irq_node_cache",
sizeof(struct wakeup_irq_node), 0, 0, NULL);
if (!wakeup_irq_nodes_cache)
goto fail_remove_group;
return 0;
fail_remove_group:
sysfs_remove_group(kobj, &attr_group);
fail_kobject_put:
kobject_put(kobj);
fail_unregister_pm_notifier:
unregister_pm_notifier(&wakeup_reason_pm_notifier_block);
fail:
return 1;
}
late_initcall(wakeup_reason_init);