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authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-04 11:14:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-04 11:14:36 -0700
commitf46e9913faeebcb6bd29edf795f12b60acbff171 (patch)
tree1ed8871d0ebd638094d27317de1d8a53712ae15a /kernel
parent8d91530c5fd7f0b1e8c4ddfea2905e55a178569b (diff)
parent8d4b9d1bfef117862a2889dec4dac227068544c9 (diff)
downloadvexpress-lsk-f46e9913faeebcb6bd29edf795f12b60acbff171.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: PM / Runtime: Add runtime PM statistics (v3) PM / Runtime: Make runtime_status attribute not debug-only (v. 2) PM: Do not use dynamically allocated objects in pm_wakeup_event() PM / Suspend: Fix ordering of calls in suspend error paths PM / Hibernate: Fix snapshot error code path PM / Hibernate: Fix hibernation_platform_enter() pm_qos: Get rid of the allocation in pm_qos_add_request() pm_qos: Reimplement using plists plist: Add plist_last PM: Make it possible to avoid races between wakeup and system sleep PNPACPI: Add support for remote wakeup PM: describe kernel policy regarding wakeup defaults (v. 2) PM / Hibernate: Fix typos in comments in kernel/power/swap.c
Diffstat (limited to 'kernel')
-rw-r--r--kernel/pm_qos_params.c215
-rw-r--r--kernel/power/hibernate.c24
-rw-r--r--kernel/power/main.c55
-rw-r--r--kernel/power/suspend.c13
-rw-r--r--kernel/power/swap.c4
5 files changed, 194 insertions, 117 deletions
diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index f42d3f737a3..996a4dec5f9 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -48,59 +48,49 @@
* or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock
* held, taken with _irqsave. One lock to rule them all
*/
-struct pm_qos_request_list {
- struct list_head list;
- union {
- s32 value;
- s32 usec;
- s32 kbps;
- };
- int pm_qos_class;
+enum pm_qos_type {
+ PM_QOS_MAX, /* return the largest value */
+ PM_QOS_MIN /* return the smallest value */
};
-static s32 max_compare(s32 v1, s32 v2);
-static s32 min_compare(s32 v1, s32 v2);
-
struct pm_qos_object {
- struct pm_qos_request_list requests;
+ struct plist_head requests;
struct blocking_notifier_head *notifiers;
struct miscdevice pm_qos_power_miscdev;
char *name;
s32 default_value;
- atomic_t target_value;
- s32 (*comparitor)(s32, s32);
+ enum pm_qos_type type;
};
+static DEFINE_SPINLOCK(pm_qos_lock);
+
static struct pm_qos_object null_pm_qos;
static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier);
static struct pm_qos_object cpu_dma_pm_qos = {
- .requests = {LIST_HEAD_INIT(cpu_dma_pm_qos.requests.list)},
+ .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests, pm_qos_lock),
.notifiers = &cpu_dma_lat_notifier,
.name = "cpu_dma_latency",
.default_value = 2000 * USEC_PER_SEC,
- .target_value = ATOMIC_INIT(2000 * USEC_PER_SEC),
- .comparitor = min_compare
+ .type = PM_QOS_MIN,
};
static BLOCKING_NOTIFIER_HEAD(network_lat_notifier);
static struct pm_qos_object network_lat_pm_qos = {
- .requests = {LIST_HEAD_INIT(network_lat_pm_qos.requests.list)},
+ .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests, pm_qos_lock),
.notifiers = &network_lat_notifier,
.name = "network_latency",
.default_value = 2000 * USEC_PER_SEC,
- .target_value = ATOMIC_INIT(2000 * USEC_PER_SEC),
- .comparitor = min_compare
+ .type = PM_QOS_MIN
};
static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier);
static struct pm_qos_object network_throughput_pm_qos = {
- .requests = {LIST_HEAD_INIT(network_throughput_pm_qos.requests.list)},
+ .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests, pm_qos_lock),
.notifiers = &network_throughput_notifier,
.name = "network_throughput",
.default_value = 0,
- .target_value = ATOMIC_INIT(0),
- .comparitor = max_compare
+ .type = PM_QOS_MAX,
};
@@ -111,8 +101,6 @@ static struct pm_qos_object *pm_qos_array[] = {
&network_throughput_pm_qos
};
-static DEFINE_SPINLOCK(pm_qos_lock);
-
static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
size_t count, loff_t *f_pos);
static int pm_qos_power_open(struct inode *inode, struct file *filp);
@@ -124,46 +112,55 @@ static const struct file_operations pm_qos_power_fops = {
.release = pm_qos_power_release,
};
-/* static helper functions */
-static s32 max_compare(s32 v1, s32 v2)
+/* unlocked internal variant */
+static inline int pm_qos_get_value(struct pm_qos_object *o)
{
- return max(v1, v2);
-}
+ if (plist_head_empty(&o->requests))
+ return o->default_value;
-static s32 min_compare(s32 v1, s32 v2)
-{
- return min(v1, v2);
-}
+ switch (o->type) {
+ case PM_QOS_MIN:
+ return plist_last(&o->requests)->prio;
+ case PM_QOS_MAX:
+ return plist_first(&o->requests)->prio;
-static void update_target(int pm_qos_class)
+ default:
+ /* runtime check for not using enum */
+ BUG();
+ }
+}
+
+static void update_target(struct pm_qos_object *o, struct plist_node *node,
+ int del, int value)
{
- s32 extreme_value;
- struct pm_qos_request_list *node;
unsigned long flags;
- int call_notifier = 0;
+ int prev_value, curr_value;
spin_lock_irqsave(&pm_qos_lock, flags);
- extreme_value = pm_qos_array[pm_qos_class]->default_value;
- list_for_each_entry(node,
- &pm_qos_array[pm_qos_class]->requests.list, list) {
- extreme_value = pm_qos_array[pm_qos_class]->comparitor(
- extreme_value, node->value);
- }
- if (atomic_read(&pm_qos_array[pm_qos_class]->target_value) !=
- extreme_value) {
- call_notifier = 1;
- atomic_set(&pm_qos_array[pm_qos_class]->target_value,
- extreme_value);
- pr_debug(KERN_ERR "new target for qos %d is %d\n", pm_qos_class,
- atomic_read(&pm_qos_array[pm_qos_class]->target_value));
+ prev_value = pm_qos_get_value(o);
+ /* PM_QOS_DEFAULT_VALUE is a signal that the value is unchanged */
+ if (value != PM_QOS_DEFAULT_VALUE) {
+ /*
+ * to change the list, we atomically remove, reinit
+ * with new value and add, then see if the extremal
+ * changed
+ */
+ plist_del(node, &o->requests);
+ plist_node_init(node, value);
+ plist_add(node, &o->requests);
+ } else if (del) {
+ plist_del(node, &o->requests);
+ } else {
+ plist_add(node, &o->requests);
}
+ curr_value = pm_qos_get_value(o);
spin_unlock_irqrestore(&pm_qos_lock, flags);
- if (call_notifier)
- blocking_notifier_call_chain(
- pm_qos_array[pm_qos_class]->notifiers,
- (unsigned long) extreme_value, NULL);
+ if (prev_value != curr_value)
+ blocking_notifier_call_chain(o->notifiers,
+ (unsigned long)curr_value,
+ NULL);
}
static int register_pm_qos_misc(struct pm_qos_object *qos)
@@ -196,10 +193,23 @@ static int find_pm_qos_object_by_minor(int minor)
*/
int pm_qos_request(int pm_qos_class)
{
- return atomic_read(&pm_qos_array[pm_qos_class]->target_value);
+ unsigned long flags;
+ int value;
+
+ spin_lock_irqsave(&pm_qos_lock, flags);
+ value = pm_qos_get_value(pm_qos_array[pm_qos_class]);
+ spin_unlock_irqrestore(&pm_qos_lock, flags);
+
+ return value;
}
EXPORT_SYMBOL_GPL(pm_qos_request);
+int pm_qos_request_active(struct pm_qos_request_list *req)
+{
+ return req->pm_qos_class != 0;
+}
+EXPORT_SYMBOL_GPL(pm_qos_request_active);
+
/**
* pm_qos_add_request - inserts new qos request into the list
* @pm_qos_class: identifies which list of qos request to us
@@ -211,27 +221,23 @@ EXPORT_SYMBOL_GPL(pm_qos_request);
* element as a handle for use in updating and removal. Call needs to save
* this handle for later use.
*/
-struct pm_qos_request_list *pm_qos_add_request(int pm_qos_class, s32 value)
+void pm_qos_add_request(struct pm_qos_request_list *dep,
+ int pm_qos_class, s32 value)
{
- struct pm_qos_request_list *dep;
- unsigned long flags;
+ struct pm_qos_object *o = pm_qos_array[pm_qos_class];
+ int new_value;
- dep = kzalloc(sizeof(struct pm_qos_request_list), GFP_KERNEL);
- if (dep) {
- if (value == PM_QOS_DEFAULT_VALUE)
- dep->value = pm_qos_array[pm_qos_class]->default_value;
- else
- dep->value = value;
- dep->pm_qos_class = pm_qos_class;
-
- spin_lock_irqsave(&pm_qos_lock, flags);
- list_add(&dep->list,
- &pm_qos_array[pm_qos_class]->requests.list);
- spin_unlock_irqrestore(&pm_qos_lock, flags);
- update_target(pm_qos_class);
+ if (pm_qos_request_active(dep)) {
+ WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n");
+ return;
}
-
- return dep;
+ if (value == PM_QOS_DEFAULT_VALUE)
+ new_value = o->default_value;
+ else
+ new_value = value;
+ plist_node_init(&dep->list, new_value);
+ dep->pm_qos_class = pm_qos_class;
+ update_target(o, &dep->list, 0, PM_QOS_DEFAULT_VALUE);
}
EXPORT_SYMBOL_GPL(pm_qos_add_request);
@@ -246,27 +252,28 @@ EXPORT_SYMBOL_GPL(pm_qos_add_request);
* Attempts are made to make this code callable on hot code paths.
*/
void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req,
- s32 new_value)
+ s32 new_value)
{
- unsigned long flags;
- int pending_update = 0;
s32 temp;
+ struct pm_qos_object *o;
+
+ if (!pm_qos_req) /*guard against callers passing in null */
+ return;
- if (pm_qos_req) { /*guard against callers passing in null */
- spin_lock_irqsave(&pm_qos_lock, flags);
- if (new_value == PM_QOS_DEFAULT_VALUE)
- temp = pm_qos_array[pm_qos_req->pm_qos_class]->default_value;
- else
- temp = new_value;
-
- if (temp != pm_qos_req->value) {
- pending_update = 1;
- pm_qos_req->value = temp;
- }
- spin_unlock_irqrestore(&pm_qos_lock, flags);
- if (pending_update)
- update_target(pm_qos_req->pm_qos_class);
+ if (!pm_qos_request_active(pm_qos_req)) {
+ WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n");
+ return;
}
+
+ o = pm_qos_array[pm_qos_req->pm_qos_class];
+
+ if (new_value == PM_QOS_DEFAULT_VALUE)
+ temp = o->default_value;
+ else
+ temp = new_value;
+
+ if (temp != pm_qos_req->list.prio)
+ update_target(o, &pm_qos_req->list, 0, temp);
}
EXPORT_SYMBOL_GPL(pm_qos_update_request);
@@ -280,19 +287,20 @@ EXPORT_SYMBOL_GPL(pm_qos_update_request);
*/
void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req)
{
- unsigned long flags;
- int qos_class;
+ struct pm_qos_object *o;
if (pm_qos_req == NULL)
return;
/* silent return to keep pcm code cleaner */
- qos_class = pm_qos_req->pm_qos_class;
- spin_lock_irqsave(&pm_qos_lock, flags);
- list_del(&pm_qos_req->list);
- kfree(pm_qos_req);
- spin_unlock_irqrestore(&pm_qos_lock, flags);
- update_target(qos_class);
+ if (!pm_qos_request_active(pm_qos_req)) {
+ WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n");
+ return;
+ }
+
+ o = pm_qos_array[pm_qos_req->pm_qos_class];
+ update_target(o, &pm_qos_req->list, 1, PM_QOS_DEFAULT_VALUE);
+ memset(pm_qos_req, 0, sizeof(*pm_qos_req));
}
EXPORT_SYMBOL_GPL(pm_qos_remove_request);
@@ -340,8 +348,12 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp)
pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
if (pm_qos_class >= 0) {
- filp->private_data = (void *) pm_qos_add_request(pm_qos_class,
- PM_QOS_DEFAULT_VALUE);
+ struct pm_qos_request_list *req = kzalloc(GFP_KERNEL, sizeof(*req));
+ if (!req)
+ return -ENOMEM;
+
+ pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE);
+ filp->private_data = req;
if (filp->private_data)
return 0;
@@ -353,8 +365,9 @@ static int pm_qos_power_release(struct inode *inode, struct file *filp)
{
struct pm_qos_request_list *req;
- req = (struct pm_qos_request_list *)filp->private_data;
+ req = filp->private_data;
pm_qos_remove_request(req);
+ kfree(req);
return 0;
}
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index aa9e916da4d..d26f04e9274 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -277,7 +277,7 @@ static int create_image(int platform_mode)
goto Enable_irqs;
}
- if (hibernation_test(TEST_CORE))
+ if (hibernation_test(TEST_CORE) || !pm_check_wakeup_events())
goto Power_up;
in_suspend = 1;
@@ -288,8 +288,10 @@ static int create_image(int platform_mode)
error);
/* Restore control flow magically appears here */
restore_processor_state();
- if (!in_suspend)
+ if (!in_suspend) {
+ events_check_enabled = false;
platform_leave(platform_mode);
+ }
Power_up:
sysdev_resume();
@@ -328,7 +330,7 @@ int hibernation_snapshot(int platform_mode)
error = platform_begin(platform_mode);
if (error)
- return error;
+ goto Close;
/* Preallocate image memory before shutting down devices. */
error = hibernate_preallocate_memory();
@@ -511,18 +513,24 @@ int hibernation_platform_enter(void)
local_irq_disable();
sysdev_suspend(PMSG_HIBERNATE);
+ if (!pm_check_wakeup_events()) {
+ error = -EAGAIN;
+ goto Power_up;
+ }
+
hibernation_ops->enter();
/* We should never get here */
while (1);
- /*
- * We don't need to reenable the nonboot CPUs or resume consoles, since
- * the system is going to be halted anyway.
- */
+ Power_up:
+ sysdev_resume();
+ local_irq_enable();
+ enable_nonboot_cpus();
+
Platform_finish:
hibernation_ops->finish();
- dpm_suspend_noirq(PMSG_RESTORE);
+ dpm_resume_noirq(PMSG_RESTORE);
Resume_devices:
entering_platform_hibernation = false;
diff --git a/kernel/power/main.c b/kernel/power/main.c
index b58800b21fc..62b0bc6e498 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -204,6 +204,60 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
power_attr(state);
+#ifdef CONFIG_PM_SLEEP
+/*
+ * The 'wakeup_count' attribute, along with the functions defined in
+ * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
+ * handled in a non-racy way.
+ *
+ * If a wakeup event occurs when the system is in a sleep state, it simply is
+ * woken up. In turn, if an event that would wake the system up from a sleep
+ * state occurs when it is undergoing a transition to that sleep state, the
+ * transition should be aborted. Moreover, if such an event occurs when the
+ * system is in the working state, an attempt to start a transition to the
+ * given sleep state should fail during certain period after the detection of
+ * the event. Using the 'state' attribute alone is not sufficient to satisfy
+ * these requirements, because a wakeup event may occur exactly when 'state'
+ * is being written to and may be delivered to user space right before it is
+ * frozen, so the event will remain only partially processed until the system is
+ * woken up by another event. In particular, it won't cause the transition to
+ * a sleep state to be aborted.
+ *
+ * This difficulty may be overcome if user space uses 'wakeup_count' before
+ * writing to 'state'. It first should read from 'wakeup_count' and store
+ * the read value. Then, after carrying out its own preparations for the system
+ * transition to a sleep state, it should write the stored value to
+ * 'wakeup_count'. If that fails, at least one wakeup event has occured since
+ * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
+ * is allowed to write to 'state', but the transition will be aborted if there
+ * are any wakeup events detected after 'wakeup_count' was written to.
+ */
+
+static ssize_t wakeup_count_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ unsigned long val;
+
+ return pm_get_wakeup_count(&val) ? sprintf(buf, "%lu\n", val) : -EINTR;
+}
+
+static ssize_t wakeup_count_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t n)
+{
+ unsigned long val;
+
+ if (sscanf(buf, "%lu", &val) == 1) {
+ if (pm_save_wakeup_count(val))
+ return n;
+ }
+ return -EINVAL;
+}
+
+power_attr(wakeup_count);
+#endif /* CONFIG_PM_SLEEP */
+
#ifdef CONFIG_PM_TRACE
int pm_trace_enabled;
@@ -236,6 +290,7 @@ static struct attribute * g[] = {
#endif
#ifdef CONFIG_PM_SLEEP
&pm_async_attr.attr,
+ &wakeup_count_attr.attr,
#ifdef CONFIG_PM_DEBUG
&pm_test_attr.attr,
#endif
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index f37cb7dd440..7335952ee47 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -136,19 +136,19 @@ static int suspend_enter(suspend_state_t state)
if (suspend_ops->prepare) {
error = suspend_ops->prepare();
if (error)
- return error;
+ goto Platform_finish;
}
error = dpm_suspend_noirq(PMSG_SUSPEND);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down\n");
- goto Platfrom_finish;
+ goto Platform_finish;
}
if (suspend_ops->prepare_late) {
error = suspend_ops->prepare_late();
if (error)
- goto Power_up_devices;
+ goto Platform_wake;
}
if (suspend_test(TEST_PLATFORM))
@@ -163,8 +163,10 @@ static int suspend_enter(suspend_state_t state)
error = sysdev_suspend(PMSG_SUSPEND);
if (!error) {
- if (!suspend_test(TEST_CORE))
+ if (!suspend_test(TEST_CORE) && pm_check_wakeup_events()) {
error = suspend_ops->enter(state);
+ events_check_enabled = false;
+ }
sysdev_resume();
}
@@ -178,10 +180,9 @@ static int suspend_enter(suspend_state_t state)
if (suspend_ops->wake)
suspend_ops->wake();
- Power_up_devices:
dpm_resume_noirq(PMSG_RESUME);
- Platfrom_finish:
+ Platform_finish:
if (suspend_ops->finish)
suspend_ops->finish();
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index b0bb2177839..7c3ae83e41d 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -32,7 +32,7 @@
/*
* The swap map is a data structure used for keeping track of each page
* written to a swap partition. It consists of many swap_map_page
- * structures that contain each an array of MAP_PAGE_SIZE swap entries.
+ * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
* These structures are stored on the swap and linked together with the
* help of the .next_swap member.
*
@@ -148,7 +148,7 @@ sector_t alloc_swapdev_block(int swap)
/**
* free_all_swap_pages - free swap pages allocated for saving image data.
- * It also frees the extents used to register which swap entres had been
+ * It also frees the extents used to register which swap entries had been
* allocated.
*/