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

6 files changed, 101 insertions, 69 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.
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index dee341ae4ace..4b0b7cf2e019 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -642,9 +642,9 @@ int hibernation_platform_enter(void)
  */
 static void power_down(void)
 {
-#ifdef CONFIG_SUSPEND
 	int error;
 
+#ifdef CONFIG_SUSPEND
 	if (hibernation_mode == HIBERNATION_SUSPEND) {
 		error = suspend_devices_and_enter(mem_sleep_current);
 		if (error) {
@@ -667,7 +667,13 @@ static void power_down(void)
 		kernel_restart(NULL);
 		break;
 	case HIBERNATION_PLATFORM:
-		hibernation_platform_enter();
+		error = hibernation_platform_enter();
+		if (error == -EAGAIN || error == -EBUSY) {
+			swsusp_unmark();
+			events_check_enabled = false;
+			pr_info("Wakeup event detected during hibernation, rolling back.\n");
+			return;
+		}
 		fallthrough;
 	case HIBERNATION_SHUTDOWN:
 		if (kernel_can_power_off())
diff --git a/kernel/power/main.c b/kernel/power/main.c
index f6425ae3e8b0..b1ae9b677d03 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -60,22 +60,6 @@ EXPORT_SYMBOL_GPL(lock_system_sleep);
 
 void unlock_system_sleep(unsigned int flags)
 {
-	/*
-	 * Don't use freezer_count() because we don't want the call to
-	 * try_to_freeze() here.
-	 *
-	 * Reason:
-	 * Fundamentally, we just don't need it, because freezing condition
-	 * doesn't come into effect until we release the
-	 * system_transition_mutex lock, since the freezer always works with
-	 * system_transition_mutex held.
-	 *
-	 * More importantly, in the case of hibernation,
-	 * unlock_system_sleep() gets called in snapshot_read() and
-	 * snapshot_write() when the freezing condition is still in effect.
-	 * Which means, if we use try_to_freeze() here, it would make them
-	 * enter the refrigerator, thus causing hibernation to lockup.
-	 */
 	if (!(flags & PF_NOFREEZE))
 		current->flags &= ~PF_NOFREEZE;
 	mutex_unlock(&system_transition_mutex);
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 17fd9aaaf084..8499a39c62f4 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -175,6 +175,8 @@ extern int swsusp_write(unsigned int flags);
 void swsusp_close(void);
 #ifdef CONFIG_SUSPEND
 extern int swsusp_unmark(void);
+#else
+static inline int swsusp_unmark(void) { return 0; }
 #endif
 
 struct __kernel_old_timeval;
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 50a15408c3fc..5c96ff067c64 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1119,7 +1119,7 @@ static void mark_nosave_pages(struct memory_bitmap *bm)
 int create_basic_memory_bitmaps(void)
 {
 	struct memory_bitmap *bm1, *bm2;
-	int error = 0;
+	int error;
 
 	if (forbidden_pages_map && free_pages_map)
 		return 0;
@@ -1487,11 +1487,11 @@ static bool copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
 	s_page = pfn_to_page(src_pfn);
 	d_page = pfn_to_page(dst_pfn);
 	if (PageHighMem(s_page)) {
-		src = kmap_atomic(s_page);
-		dst = kmap_atomic(d_page);
+		src = kmap_local_page(s_page);
+		dst = kmap_local_page(d_page);
 		zeros_only = do_copy_page(dst, src);
-		kunmap_atomic(dst);
-		kunmap_atomic(src);
+		kunmap_local(dst);
+		kunmap_local(src);
 	} else {
 		if (PageHighMem(d_page)) {
 			/*
@@ -1499,9 +1499,9 @@ static bool copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
 			 * data modified by kmap_atomic()
 			 */
 			zeros_only = safe_copy_page(buffer, s_page);
-			dst = kmap_atomic(d_page);
+			dst = kmap_local_page(d_page);
 			copy_page(dst, buffer);
-			kunmap_atomic(dst);
+			kunmap_local(dst);
 		} else {
 			zeros_only = safe_copy_page(page_address(d_page), s_page);
 		}
@@ -2778,7 +2778,7 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
 int snapshot_write_next(struct snapshot_handle *handle)
 {
 	static struct chain_allocator ca;
-	int error = 0;
+	int error;
 
 next:
 	/* Check if we have already loaded the entire image */
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index a2cb0babb5ec..6053ddddaf65 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -451,7 +451,7 @@ err_close:
 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 		struct hib_bio_batch *hb)
 {
-	int error = 0;
+	int error;
 	sector_t offset;
 
 	if (!handle->cur)
@@ -606,11 +606,11 @@ static int crc32_threadfn(void *data)
 	unsigned i;
 
 	while (1) {
-		wait_event(d->go, atomic_read(&d->ready) ||
+		wait_event(d->go, atomic_read_acquire(&d->ready) ||
 		                  kthread_should_stop());
 		if (kthread_should_stop()) {
 			d->thr = NULL;
-			atomic_set(&d->stop, 1);
+			atomic_set_release(&d->stop, 1);
 			wake_up(&d->done);
 			break;
 		}
@@ -619,7 +619,7 @@ static int crc32_threadfn(void *data)
 		for (i = 0; i < d->run_threads; i++)
 			*d->crc32 = crc32_le(*d->crc32,
 			                     d->unc[i], *d->unc_len[i]);
-		atomic_set(&d->stop, 1);
+		atomic_set_release(&d->stop, 1);
 		wake_up(&d->done);
 	}
 	return 0;
@@ -649,12 +649,12 @@ static int lzo_compress_threadfn(void *data)
 	struct cmp_data *d = data;
 
 	while (1) {
-		wait_event(d->go, atomic_read(&d->ready) ||
+		wait_event(d->go, atomic_read_acquire(&d->ready) ||
 		                  kthread_should_stop());
 		if (kthread_should_stop()) {
 			d->thr = NULL;
 			d->ret = -1;
-			atomic_set(&d->stop, 1);
+			atomic_set_release(&d->stop, 1);
 			wake_up(&d->done);
 			break;
 		}
@@ -663,7 +663,7 @@ static int lzo_compress_threadfn(void *data)
 		d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 		                          d->cmp + LZO_HEADER, &d->cmp_len,
 		                          d->wrk);
-		atomic_set(&d->stop, 1);
+		atomic_set_release(&d->stop, 1);
 		wake_up(&d->done);
 	}
 	return 0;
@@ -798,7 +798,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
 
 			data[thr].unc_len = off;
 
-			atomic_set(&data[thr].ready, 1);
+			atomic_set_release(&data[thr].ready, 1);
 			wake_up(&data[thr].go);
 		}
 
@@ -806,12 +806,12 @@ static int save_image_lzo(struct swap_map_handle *handle,
 			break;
 
 		crc->run_threads = thr;
-		atomic_set(&crc->ready, 1);
+		atomic_set_release(&crc->ready, 1);
 		wake_up(&crc->go);
 
 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 			wait_event(data[thr].done,
-			           atomic_read(&data[thr].stop));
+				atomic_read_acquire(&data[thr].stop));
 			atomic_set(&data[thr].stop, 0);
 
 			ret = data[thr].ret;
@@ -850,7 +850,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
 			}
 		}
 
-		wait_event(crc->done, atomic_read(&crc->stop));
+		wait_event(crc->done, atomic_read_acquire(&crc->stop));
 		atomic_set(&crc->stop, 0);
 	}
 
@@ -1132,12 +1132,12 @@ static int lzo_decompress_threadfn(void *data)
 	struct dec_data *d = data;
 
 	while (1) {
-		wait_event(d->go, atomic_read(&d->ready) ||
+		wait_event(d->go, atomic_read_acquire(&d->ready) ||
 		                  kthread_should_stop());
 		if (kthread_should_stop()) {
 			d->thr = NULL;
 			d->ret = -1;
-			atomic_set(&d->stop, 1);
+			atomic_set_release(&d->stop, 1);
 			wake_up(&d->done);
 			break;
 		}
@@ -1150,7 +1150,7 @@ static int lzo_decompress_threadfn(void *data)
 			flush_icache_range((unsigned long)d->unc,
 					   (unsigned long)d->unc + d->unc_len);
 
-		atomic_set(&d->stop, 1);
+		atomic_set_release(&d->stop, 1);
 		wake_up(&d->done);
 	}
 	return 0;
@@ -1335,7 +1335,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
 		}
 
 		if (crc->run_threads) {
-			wait_event(crc->done, atomic_read(&crc->stop));
+			wait_event(crc->done, atomic_read_acquire(&crc->stop));
 			atomic_set(&crc->stop, 0);
 			crc->run_threads = 0;
 		}
@@ -1371,7 +1371,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
 					pg = 0;
 			}
 
-			atomic_set(&data[thr].ready, 1);
+			atomic_set_release(&data[thr].ready, 1);
 			wake_up(&data[thr].go);
 		}
 
@@ -1390,7 +1390,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
 
 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 			wait_event(data[thr].done,
-			           atomic_read(&data[thr].stop));
+				atomic_read_acquire(&data[thr].stop));
 			atomic_set(&data[thr].stop, 0);
 
 			ret = data[thr].ret;
@@ -1421,7 +1421,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
 				ret = snapshot_write_next(snapshot);
 				if (ret <= 0) {
 					crc->run_threads = thr + 1;
-					atomic_set(&crc->ready, 1);
+					atomic_set_release(&crc->ready, 1);
 					wake_up(&crc->go);
 					goto out_finish;
 				}
@@ -1429,13 +1429,13 @@ static int load_image_lzo(struct swap_map_handle *handle,
 		}
 
 		crc->run_threads = thr;
-		atomic_set(&crc->ready, 1);
+		atomic_set_release(&crc->ready, 1);
 		wake_up(&crc->go);
 	}
 
 out_finish:
 	if (crc->run_threads) {
-		wait_event(crc->done, atomic_read(&crc->stop));
+		wait_event(crc->done, atomic_read_acquire(&crc->stop));
 		atomic_set(&crc->stop, 0);
 	}
 	stop = ktime_get();
@@ -1566,7 +1566,6 @@ put:
 
 /**
  * swsusp_close - close resume device.
- * @exclusive: Close the resume device which is exclusively opened.
  */
 
 void swsusp_close(void)