1 files changed, 115 insertions, 65 deletions

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 1f5b3dd31fcf..89da052f4f68 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -121,11 +121,14 @@ struct virtio_balloon {
 	struct page_reporting_dev_info pr_dev_info;
 
 	/* State for keeping the wakeup_source active while adjusting the balloon */
-	spinlock_t adjustment_lock;
-	bool adjustment_signal_pending;
-	bool adjustment_in_progress;
+	spinlock_t wakeup_lock;
+	bool processing_wakeup_event;
+	u32 wakeup_signal_mask;
 };
 
+#define VIRTIO_BALLOON_WAKEUP_SIGNAL_ADJUST (1 << 0)
+#define VIRTIO_BALLOON_WAKEUP_SIGNAL_STATS (1 << 1)
+
 static const struct virtio_device_id id_table[] = {
 	{ VIRTIO_ID_BALLOON, VIRTIO_DEV_ANY_ID },
 	{ 0 },
@@ -140,6 +143,36 @@ static u32 page_to_balloon_pfn(struct page *page)
 	return pfn * VIRTIO_BALLOON_PAGES_PER_PAGE;
 }
 
+static void start_wakeup_event(struct virtio_balloon *vb, u32 mask)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&vb->wakeup_lock, flags);
+	vb->wakeup_signal_mask |= mask;
+	if (!vb->processing_wakeup_event) {
+		vb->processing_wakeup_event = true;
+		pm_stay_awake(&vb->vdev->dev);
+	}
+	spin_unlock_irqrestore(&vb->wakeup_lock, flags);
+}
+
+static void process_wakeup_event(struct virtio_balloon *vb, u32 mask)
+{
+	spin_lock_irq(&vb->wakeup_lock);
+	vb->wakeup_signal_mask &= ~mask;
+	spin_unlock_irq(&vb->wakeup_lock);
+}
+
+static void finish_wakeup_event(struct virtio_balloon *vb)
+{
+	spin_lock_irq(&vb->wakeup_lock);
+	if (!vb->wakeup_signal_mask && vb->processing_wakeup_event) {
+		vb->processing_wakeup_event = false;
+		pm_relax(&vb->vdev->dev);
+	}
+	spin_unlock_irq(&vb->wakeup_lock);
+}
+
 static void balloon_ack(struct virtqueue *vq)
 {
 	struct virtio_balloon *vb = vq->vdev->priv;
@@ -218,7 +251,7 @@ static unsigned int fill_balloon(struct virtio_balloon *vb, size_t num)
 
 	for (num_pfns = 0; num_pfns < num;
 	     num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) {
-		struct page *page = balloon_page_alloc();
+		page = balloon_page_alloc();
 
 		if (!page) {
 			dev_info_ratelimited(&vb->vdev->dev,
@@ -316,34 +349,67 @@ static inline void update_stat(struct virtio_balloon *vb, int idx,
 
 #define pages_to_bytes(x) ((u64)(x) << PAGE_SHIFT)
 
-static unsigned int update_balloon_stats(struct virtio_balloon *vb)
+#ifdef CONFIG_VM_EVENT_COUNTERS
+/* Return the number of entries filled by vm events */
+static inline unsigned int update_balloon_vm_stats(struct virtio_balloon *vb)
 {
 	unsigned long events[NR_VM_EVENT_ITEMS];
-	struct sysinfo i;
 	unsigned int idx = 0;
-	long available;
-	unsigned long caches;
+	unsigned int zid;
+	unsigned long stall = 0;
 
 	all_vm_events(events);
-	si_meminfo(&i);
-
-	available = si_mem_available();
-	caches = global_node_page_state(NR_FILE_PAGES);
-
-#ifdef CONFIG_VM_EVENT_COUNTERS
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_IN,
-				pages_to_bytes(events[PSWPIN]));
+		    pages_to_bytes(events[PSWPIN]));
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_OUT,
-				pages_to_bytes(events[PSWPOUT]));
+		    pages_to_bytes(events[PSWPOUT]));
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_MAJFLT, events[PGMAJFAULT]);
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_MINFLT, events[PGFAULT]);
+	update_stat(vb, idx++, VIRTIO_BALLOON_S_OOM_KILL, events[OOM_KILL]);
+
+	/* sum all the stall events */
+	for (zid = 0; zid < MAX_NR_ZONES; zid++)
+		stall += events[ALLOCSTALL_NORMAL - ZONE_NORMAL + zid];
+
+	update_stat(vb, idx++, VIRTIO_BALLOON_S_ALLOC_STALL, stall);
+
+	update_stat(vb, idx++, VIRTIO_BALLOON_S_ASYNC_SCAN,
+		    pages_to_bytes(events[PGSCAN_KSWAPD]));
+	update_stat(vb, idx++, VIRTIO_BALLOON_S_DIRECT_SCAN,
+		    pages_to_bytes(events[PGSCAN_DIRECT]));
+	update_stat(vb, idx++, VIRTIO_BALLOON_S_ASYNC_RECLAIM,
+		    pages_to_bytes(events[PGSTEAL_KSWAPD]));
+	update_stat(vb, idx++, VIRTIO_BALLOON_S_DIRECT_RECLAIM,
+		    pages_to_bytes(events[PGSTEAL_DIRECT]));
+
 #ifdef CONFIG_HUGETLB_PAGE
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGALLOC,
 		    events[HTLB_BUDDY_PGALLOC]);
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGFAIL,
 		    events[HTLB_BUDDY_PGALLOC_FAIL]);
-#endif
-#endif
+#endif /* CONFIG_HUGETLB_PAGE */
+
+	return idx;
+}
+#else /* CONFIG_VM_EVENT_COUNTERS */
+static inline unsigned int update_balloon_vm_stats(struct virtio_balloon *vb)
+{
+	return 0;
+}
+#endif /* CONFIG_VM_EVENT_COUNTERS */
+
+static unsigned int update_balloon_stats(struct virtio_balloon *vb)
+{
+	struct sysinfo i;
+	unsigned int idx;
+	long available;
+	unsigned long caches;
+
+	idx = update_balloon_vm_stats(vb);
+
+	si_meminfo(&i);
+	available = si_mem_available();
+	caches = global_node_page_state(NR_FILE_PAGES);
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMFREE,
 				pages_to_bytes(i.freeram));
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMTOT,
@@ -370,8 +436,10 @@ static void stats_request(struct virtqueue *vq)
 	struct virtio_balloon *vb = vq->vdev->priv;
 
 	spin_lock(&vb->stop_update_lock);
-	if (!vb->stop_update)
+	if (!vb->stop_update) {
+		start_wakeup_event(vb, VIRTIO_BALLOON_WAKEUP_SIGNAL_STATS);
 		queue_work(system_freezable_wq, &vb->update_balloon_stats_work);
+	}
 	spin_unlock(&vb->stop_update_lock);
 }
 
@@ -444,29 +512,10 @@ static void virtio_balloon_queue_free_page_work(struct virtio_balloon *vb)
 
 static void start_update_balloon_size(struct virtio_balloon *vb)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&vb->adjustment_lock, flags);
-	vb->adjustment_signal_pending = true;
-	if (!vb->adjustment_in_progress) {
-		vb->adjustment_in_progress = true;
-		pm_stay_awake(vb->vdev->dev.parent);
-	}
-	spin_unlock_irqrestore(&vb->adjustment_lock, flags);
-
+	start_wakeup_event(vb, VIRTIO_BALLOON_WAKEUP_SIGNAL_ADJUST);
 	queue_work(system_freezable_wq, &vb->update_balloon_size_work);
 }
 
-static void end_update_balloon_size(struct virtio_balloon *vb)
-{
-	spin_lock_irq(&vb->adjustment_lock);
-	if (!vb->adjustment_signal_pending && vb->adjustment_in_progress) {
-		vb->adjustment_in_progress = false;
-		pm_relax(vb->vdev->dev.parent);
-	}
-	spin_unlock_irq(&vb->adjustment_lock);
-}
-
 static void virtballoon_changed(struct virtio_device *vdev)
 {
 	struct virtio_balloon *vb = vdev->priv;
@@ -495,7 +544,10 @@ static void update_balloon_stats_func(struct work_struct *work)
 
 	vb = container_of(work, struct virtio_balloon,
 			  update_balloon_stats_work);
+
+	process_wakeup_event(vb, VIRTIO_BALLOON_WAKEUP_SIGNAL_STATS);
 	stats_handle_request(vb);
+	finish_wakeup_event(vb);
 }
 
 static void update_balloon_size_func(struct work_struct *work)
@@ -506,9 +558,7 @@ static void update_balloon_size_func(struct work_struct *work)
 	vb = container_of(work, struct virtio_balloon,
 			  update_balloon_size_work);
 
-	spin_lock_irq(&vb->adjustment_lock);
-	vb->adjustment_signal_pending = false;
-	spin_unlock_irq(&vb->adjustment_lock);
+	process_wakeup_event(vb, VIRTIO_BALLOON_WAKEUP_SIGNAL_ADJUST);
 
 	diff = towards_target(vb);
 
@@ -523,14 +573,13 @@ static void update_balloon_size_func(struct work_struct *work)
 	if (diff)
 		queue_work(system_freezable_wq, work);
 	else
-		end_update_balloon_size(vb);
+		finish_wakeup_event(vb);
 }
 
 static int init_vqs(struct virtio_balloon *vb)
 {
+	struct virtqueue_info vqs_info[VIRTIO_BALLOON_VQ_MAX] = {};
 	struct virtqueue *vqs[VIRTIO_BALLOON_VQ_MAX];
-	vq_callback_t *callbacks[VIRTIO_BALLOON_VQ_MAX];
-	const char *names[VIRTIO_BALLOON_VQ_MAX];
 	int err;
 
 	/*
@@ -538,33 +587,26 @@ static int init_vqs(struct virtio_balloon *vb)
 	 * will be NULL if the related feature is not enabled, which will
 	 * cause no allocation for the corresponding virtqueue in find_vqs.
 	 */
-	callbacks[VIRTIO_BALLOON_VQ_INFLATE] = balloon_ack;
-	names[VIRTIO_BALLOON_VQ_INFLATE] = "inflate";
-	callbacks[VIRTIO_BALLOON_VQ_DEFLATE] = balloon_ack;
-	names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate";
-	callbacks[VIRTIO_BALLOON_VQ_STATS] = NULL;
-	names[VIRTIO_BALLOON_VQ_STATS] = NULL;
-	callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
-	names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
-	names[VIRTIO_BALLOON_VQ_REPORTING] = NULL;
+	vqs_info[VIRTIO_BALLOON_VQ_INFLATE].callback = balloon_ack;
+	vqs_info[VIRTIO_BALLOON_VQ_INFLATE].name = "inflate";
+	vqs_info[VIRTIO_BALLOON_VQ_DEFLATE].callback = balloon_ack;
+	vqs_info[VIRTIO_BALLOON_VQ_DEFLATE].name = "deflate";
 
 	if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
-		names[VIRTIO_BALLOON_VQ_STATS] = "stats";
-		callbacks[VIRTIO_BALLOON_VQ_STATS] = stats_request;
+		vqs_info[VIRTIO_BALLOON_VQ_STATS].name = "stats";
+		vqs_info[VIRTIO_BALLOON_VQ_STATS].callback = stats_request;
 	}
 
-	if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
-		names[VIRTIO_BALLOON_VQ_FREE_PAGE] = "free_page_vq";
-		callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
-	}
+	if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
+		vqs_info[VIRTIO_BALLOON_VQ_FREE_PAGE].name = "free_page_vq";
 
 	if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) {
-		names[VIRTIO_BALLOON_VQ_REPORTING] = "reporting_vq";
-		callbacks[VIRTIO_BALLOON_VQ_REPORTING] = balloon_ack;
+		vqs_info[VIRTIO_BALLOON_VQ_REPORTING].name = "reporting_vq";
+		vqs_info[VIRTIO_BALLOON_VQ_REPORTING].callback = balloon_ack;
 	}
 
 	err = virtio_find_vqs(vb->vdev, VIRTIO_BALLOON_VQ_MAX, vqs,
-			      callbacks, names, NULL);
+			      vqs_info, NULL);
 	if (err)
 		return err;
 
@@ -1027,7 +1069,16 @@ static int virtballoon_probe(struct virtio_device *vdev)
 			goto out_unregister_oom;
 	}
 
-	spin_lock_init(&vb->adjustment_lock);
+	spin_lock_init(&vb->wakeup_lock);
+
+	/*
+	 * The virtio balloon itself can't wake up the device, but it is
+	 * responsible for processing wakeup events passed up from the transport
+	 * layer. Wakeup sources don't support nesting/chaining calls, so we use
+	 * our own wakeup source to ensure wakeup events are properly handled
+	 * without trampling on the transport layer's wakeup source.
+	 */
+	device_set_wakeup_capable(&vb->vdev->dev, true);
 
 	virtio_device_ready(vdev);
 
@@ -1155,7 +1206,6 @@ static struct virtio_driver virtio_balloon_driver = {
 	.feature_table = features,
 	.feature_table_size = ARRAY_SIZE(features),
 	.driver.name =	KBUILD_MODNAME,
-	.driver.owner =	THIS_MODULE,
 	.id_table =	id_table,
 	.validate =	virtballoon_validate,
 	.probe =	virtballoon_probe,