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

5 files changed, 194 insertions, 117 deletions

diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index f42d3f737a33..996a4dec5f96 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 aa9e916da4d5..d26f04e92743 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 b58800b21fc0..62b0bc6e4983 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 f37cb7dd4402..7335952ee473 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 b0bb21778391..7c3ae83e41d7 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.
  */