drm/msm: dynamically allocate the drm-msm_gem shrinker

In preparation for implementing lockless slab shrink, use new APIs to
dynamically allocate the drm-msm_gem shrinker, so that it can be freed
asynchronously via RCU. Then it doesn't need to wait for RCU read-side
critical section when releasing the struct msm_drm_private.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Qi Zheng <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Acked-by: Daniel Vetter <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: Abhinav Kumar <[email protected]>
Cc: Dmitry Baryshkov <[email protected]>
Cc: Sean Paul <[email protected]>
Cc: Marijn Suijten <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Alasdair Kergon <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alyssa Rosenzweig <[email protected]>
Cc: Andreas Dilger <[email protected]>
Cc: Andreas Gruenbacher <[email protected]>
Cc: Anna Schumaker <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Bob Peterson <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Carlos Llamas <[email protected]>
Cc: Chandan Babu R <[email protected]>
Cc: Chao Yu <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Christian Koenig <[email protected]>
Cc: Chuck Lever <[email protected]>
Cc: Coly Li <[email protected]>
Cc: Dai Ngo <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: "Darrick J. Wong" <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Gao Xiang <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Huang Rui <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jaegeuk Kim <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jeffle Xu <[email protected]>
Cc: Joel Fernandes (Google) <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Mike Snitzer <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Neil Brown <[email protected]>
Cc: Oleksandr Tyshchenko <[email protected]>
Cc: Olga Kornievskaia <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Steven Price <[email protected]>
Cc: "Theodore Ts'o" <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tomeu Vizoso <[email protected]>
Cc: Tom Talpey <[email protected]>
Cc: Trond Myklebust <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Xuan Zhuo <[email protected]>
Cc: Yue Hu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

3 files changed, 25 insertions, 16 deletions

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 4bd028fa7500..7f20249d6071 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -462,7 +462,9 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
 	if (ret)
 		goto err_msm_uninit;
 
-	msm_gem_shrinker_init(ddev);
+	ret = msm_gem_shrinker_init(ddev);
+	if (ret)
+		goto err_msm_uninit;
 
 	if (priv->kms_init) {
 		ret = priv->kms_init(ddev);
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 02fd6c7d0bb7..e2fc56f161b5 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -221,7 +221,7 @@ struct msm_drm_private {
 	} vram;
 
 	struct notifier_block vmap_notifier;
-	struct shrinker shrinker;
+	struct shrinker *shrinker;
 
 	struct drm_atomic_state *pm_state;
 
@@ -283,7 +283,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 unsigned long msm_gem_shrinker_shrink(struct drm_device *dev, unsigned long nr_to_scan);
 #endif
 
-void msm_gem_shrinker_init(struct drm_device *dev);
+int msm_gem_shrinker_init(struct drm_device *dev);
 void msm_gem_shrinker_cleanup(struct drm_device *dev);
 
 struct sg_table *msm_gem_prime_get_sg_table(struct drm_gem_object *obj);
diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
index f38296ad8743..5a7d48c02c4b 100644
--- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
+++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
@@ -34,8 +34,7 @@ static bool can_block(struct shrink_control *sc)
 static unsigned long
 msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
 {
-	struct msm_drm_private *priv =
-		container_of(shrinker, struct msm_drm_private, shrinker);
+	struct msm_drm_private *priv = shrinker->private_data;
 	unsigned count = priv->lru.dontneed.count;
 
 	if (can_swap())
@@ -100,8 +99,7 @@ active_evict(struct drm_gem_object *obj)
 static unsigned long
 msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
 {
-	struct msm_drm_private *priv =
-		container_of(shrinker, struct msm_drm_private, shrinker);
+	struct msm_drm_private *priv = shrinker->private_data;
 	struct {
 		struct drm_gem_lru *lru;
 		bool (*shrink)(struct drm_gem_object *obj);
@@ -148,10 +146,11 @@ msm_gem_shrinker_shrink(struct drm_device *dev, unsigned long nr_to_scan)
 	struct shrink_control sc = {
 		.nr_to_scan = nr_to_scan,
 	};
-	int ret;
+	unsigned long ret = SHRINK_STOP;
 
 	fs_reclaim_acquire(GFP_KERNEL);
-	ret = msm_gem_shrinker_scan(&priv->shrinker, &sc);
+	if (priv->shrinker)
+		ret = msm_gem_shrinker_scan(priv->shrinker, &sc);
 	fs_reclaim_release(GFP_KERNEL);
 
 	return ret;
@@ -210,16 +209,24 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
  *
  * This function registers and sets up the msm shrinker.
  */
-void msm_gem_shrinker_init(struct drm_device *dev)
+int msm_gem_shrinker_init(struct drm_device *dev)
 {
 	struct msm_drm_private *priv = dev->dev_private;
-	priv->shrinker.count_objects = msm_gem_shrinker_count;
-	priv->shrinker.scan_objects = msm_gem_shrinker_scan;
-	priv->shrinker.seeks = DEFAULT_SEEKS;
-	WARN_ON(register_shrinker(&priv->shrinker, "drm-msm_gem"));
+
+	priv->shrinker = shrinker_alloc(0, "drm-msm_gem");
+	if (!priv->shrinker)
+		return -ENOMEM;
+
+	priv->shrinker->count_objects = msm_gem_shrinker_count;
+	priv->shrinker->scan_objects = msm_gem_shrinker_scan;
+	priv->shrinker->private_data = priv;
+
+	shrinker_register(priv->shrinker);
 
 	priv->vmap_notifier.notifier_call = msm_gem_shrinker_vmap;
 	WARN_ON(register_vmap_purge_notifier(&priv->vmap_notifier));
+
+	return 0;
 }
 
 /**
@@ -232,8 +239,8 @@ void msm_gem_shrinker_cleanup(struct drm_device *dev)
 {
 	struct msm_drm_private *priv = dev->dev_private;
 
-	if (priv->shrinker.nr_deferred) {
+	if (priv->shrinker) {
 		WARN_ON(unregister_vmap_purge_notifier(&priv->vmap_notifier));
-		unregister_shrinker(&priv->shrinker);
+		shrinker_free(priv->shrinker);
 	}
 }