Merge branch 'pm-sleep'

Merge system-wide power management updates for 6.8-rc1:

 - Fix possible deadlocks in the core system-wide PM code that occur if
   device-handling functions cannot be executed asynchronously during
   resune from system-wide suspend (Rafael J. Wysocki).

 - Clean up unnecessary local variable initializations in multiple
   places in the hibernation code (Wang chaodong, Li zeming).

 - Adjust core hibernation code to avoid missing wakeup events that
   occur after saving an image to persistent storage (Chris Feng).

 - Update hibernation code to enforce correct ordering during image
   compression and decompression (Hongchen Zhang).

 - Use kmap_local_page() instead of kmap_atomic() in copy_data_page()
   during hibernation and restore (Chen Haonan).

 - Adjust documentation and code comments to reflect recent task freezer
   changes (Kevin Hao).

 - Repair excess function parameter description warning in the
   hibernation image-saving code (Randy Dunlap).

* pm-sleep:
  PM: sleep: Fix possible deadlocks in core system-wide PM code
  async: Introduce async_schedule_dev_nocall()
  async: Split async_schedule_node_domain()
  PM: hibernate: Repair excess function parameter description warning
  PM: sleep: Remove obsolete comment from unlock_system_sleep()
  Documentation: PM: Adjust freezing-of-tasks.rst to the freezer changes
  PM: hibernate: Use kmap_local_page() in copy_data_page()
  PM: hibernate: Enforce ordering during image compression/decompression
  PM: hibernate: Avoid missing wakeup events during hibernation
  PM: hibernate: Do not initialize error in snapshot_write_next()
  PM: hibernate: Do not initialize error in swap_write_page()
  PM: hibernate: Drop unnecessary local variable initialization

1 files changed, 63 insertions, 22 deletions

diff --git a/kernel/async.c b/kernel/async.c
index b2c4ba5686ee..673bba6bdf3a 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -145,6 +145,39 @@ static void async_run_entry_fn(struct work_struct *work)
 	wake_up(&async_done);
 }
 
+static async_cookie_t __async_schedule_node_domain(async_func_t func,
+						   void *data, int node,
+						   struct async_domain *domain,
+						   struct async_entry *entry)
+{
+	async_cookie_t newcookie;
+	unsigned long flags;
+
+	INIT_LIST_HEAD(&entry->domain_list);
+	INIT_LIST_HEAD(&entry->global_list);
+	INIT_WORK(&entry->work, async_run_entry_fn);
+	entry->func = func;
+	entry->data = data;
+	entry->domain = domain;
+
+	spin_lock_irqsave(&async_lock, flags);
+
+	/* allocate cookie and queue */
+	newcookie = entry->cookie = next_cookie++;
+
+	list_add_tail(&entry->domain_list, &domain->pending);
+	if (domain->registered)
+		list_add_tail(&entry->global_list, &async_global_pending);
+
+	atomic_inc(&entry_count);
+	spin_unlock_irqrestore(&async_lock, flags);
+
+	/* schedule for execution */
+	queue_work_node(node, system_unbound_wq, &entry->work);
+
+	return newcookie;
+}
+
 /**
  * async_schedule_node_domain - NUMA specific version of async_schedule_domain
  * @func: function to execute asynchronously
@@ -186,29 +219,8 @@ async_cookie_t async_schedule_node_domain(async_func_t func, void *data,
 		func(data, newcookie);
 		return newcookie;
 	}
-	INIT_LIST_HEAD(&entry->domain_list);
-	INIT_LIST_HEAD(&entry->global_list);
-	INIT_WORK(&entry->work, async_run_entry_fn);
-	entry->func = func;
-	entry->data = data;
-	entry->domain = domain;
-
-	spin_lock_irqsave(&async_lock, flags);
-
-	/* allocate cookie and queue */
-	newcookie = entry->cookie = next_cookie++;
-
-	list_add_tail(&entry->domain_list, &domain->pending);
-	if (domain->registered)
-		list_add_tail(&entry->global_list, &async_global_pending);
-
-	atomic_inc(&entry_count);
-	spin_unlock_irqrestore(&async_lock, flags);
-
-	/* schedule for execution */
-	queue_work_node(node, system_unbound_wq, &entry->work);
 
-	return newcookie;
+	return __async_schedule_node_domain(func, data, node, domain, entry);
 }
 EXPORT_SYMBOL_GPL(async_schedule_node_domain);
 
@@ -232,6 +244,35 @@ async_cookie_t async_schedule_node(async_func_t func, void *data, int node)
 EXPORT_SYMBOL_GPL(async_schedule_node);
 
 /**
+ * async_schedule_dev_nocall - A simplified variant of async_schedule_dev()
+ * @func: function to execute asynchronously
+ * @dev: device argument to be passed to function
+ *
+ * @dev is used as both the argument for the function and to provide NUMA
+ * context for where to run the function.
+ *
+ * If the asynchronous execution of @func is scheduled successfully, return
+ * true. Otherwise, do nothing and return false, unlike async_schedule_dev()
+ * that will run the function synchronously then.
+ */
+bool async_schedule_dev_nocall(async_func_t func, struct device *dev)
+{
+	struct async_entry *entry;
+
+	entry = kzalloc(sizeof(struct async_entry), GFP_KERNEL);
+
+	/* Give up if there is no memory or too much work. */
+	if (!entry || atomic_read(&entry_count) > MAX_WORK) {
+		kfree(entry);
+		return false;
+	}
+
+	__async_schedule_node_domain(func, dev, dev_to_node(dev),
+				     &async_dfl_domain, entry);
+	return true;
+}
+
+/**
  * async_synchronize_full - synchronize all asynchronous function calls
  *
  * This function waits until all asynchronous function calls have been done.