[PATCH 06/10] drm/msm: wire up vmap shrinker

[Rob Clark]

Signed-off-by: Rob Clark <robdclark at gmail.com>
---
 drivers/gpu/drm/msm/msm_drv.h          |  2 ++
 drivers/gpu/drm/msm/msm_gem.c          | 25 ++++++++++++++++-----
 drivers/gpu/drm/msm/msm_gem.h          | 10 +++++++++
 drivers/gpu/drm/msm/msm_gem_shrinker.c | 40 ++++++++++++++++++++++++++++++++++
 4 files changed, 72 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 2c16385..3ab10a1 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -149,6 +149,7 @@ struct msm_drm_private {
 		struct drm_mm mm;
 	} vram;
 
+	struct notifier_block vmap_notifier;
 	struct shrinker shrinker;
 
 	struct msm_vblank_ctrl vblank_ctrl;
@@ -202,6 +203,7 @@ void msm_gem_put_vaddr_locked(struct drm_gem_object *obj);
 void msm_gem_put_vaddr(struct drm_gem_object *obj);
 int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv);
 void msm_gem_purge(struct drm_gem_object *obj);
+void msm_gem_vunmap(struct drm_gem_object *obj);
 int msm_gem_sync_object(struct drm_gem_object *obj,
 		struct msm_fence_context *fctx, bool exclusive);
 void msm_gem_move_to_active(struct drm_gem_object *obj,
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index c05fc1d..886cfe0 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -421,6 +421,7 @@ void *msm_gem_get_vaddr_locked(struct drm_gem_object *obj)
 		if (msm_obj->vaddr == NULL)
 			return ERR_PTR(-ENOMEM);
 	}
+	msm_obj->vmap_count++;
 	return msm_obj->vaddr;
 }
 
@@ -435,13 +436,17 @@ void *msm_gem_get_vaddr(struct drm_gem_object *obj)
 
 void msm_gem_put_vaddr_locked(struct drm_gem_object *obj)
 {
+	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
-	/* no-op for now */
+	WARN_ON(msm_obj->vmap_count < 1);
+	msm_obj->vmap_count--;
 }
 
 void msm_gem_put_vaddr(struct drm_gem_object *obj)
 {
-	/* no-op for now */
+	mutex_lock(&obj->dev->struct_mutex);
+	msm_gem_put_vaddr_locked(obj);
+	mutex_unlock(&obj->dev->struct_mutex);
 }
 
 /* Update madvise status, returns true if not purged, else
@@ -470,8 +475,7 @@ void msm_gem_purge(struct drm_gem_object *obj)
 
 	put_iova(obj);
 
-	vunmap(msm_obj->vaddr);
-	msm_obj->vaddr = NULL;
+	msm_gem_vunmap(obj);
 
 	put_pages(obj);
 
@@ -491,6 +495,17 @@ void msm_gem_purge(struct drm_gem_object *obj)
 			0, (loff_t)-1);
 }
 
+void msm_gem_vunmap(struct drm_gem_object *obj)
+{
+	struct msm_gem_object *msm_obj = to_msm_bo(obj);
+
+	if (!msm_obj->vaddr || WARN_ON(!is_vunmapable(msm_obj)))
+		return;
+
+	vunmap(msm_obj->vaddr);
+	msm_obj->vaddr = NULL;
+}
+
 /* must be called before _move_to_active().. */
 int msm_gem_sync_object(struct drm_gem_object *obj,
 		struct msm_fence_context *fctx, bool exclusive)
@@ -694,7 +709,7 @@ void msm_gem_free_object(struct drm_gem_object *obj)
 
 		drm_prime_gem_destroy(obj, msm_obj->sgt);
 	} else {
-		vunmap(msm_obj->vaddr);
+		msm_gem_vunmap(obj);
 		put_pages(obj);
 	}
 
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index 631dab5..7a4da81 100644
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -34,6 +34,11 @@ struct msm_gem_object {
 	 */
 	uint8_t madv;
 
+	/**
+	 * count of active vmap'ing
+	 */
+	uint8_t vmap_count;
+
 	/* And object is either:
 	 *  inactive - on priv->inactive_list
 	 *  active   - on one one of the gpu's active_list..  well, at
@@ -83,6 +88,11 @@ static inline bool is_purgeable(struct msm_gem_object *msm_obj)
 			!msm_obj->base.dma_buf && !msm_obj->base.import_attach;
 }
 
+static inline bool is_vunmapable(struct msm_gem_object *msm_obj)
+{
+	return (msm_obj->vmap_count == 0) && msm_obj->vaddr;
+}
+
 #define MAX_CMDS 4
 
 /* Created per submit-ioctl, to track bo's and cmdstream bufs, etc,
diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
index 2bbd6d0..8d13b9e 100644
--- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
+++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
@@ -100,6 +100,42 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
 	return freed;
 }
 
+static int
+msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
+{
+	struct msm_drm_private *priv =
+		container_of(nb, struct msm_drm_private, vmap_notifier);
+	struct drm_device *dev = priv->dev;
+	struct msm_gem_object *msm_obj;
+	unsigned unmapped = 0;
+	bool unlock;
+
+	if (!msm_gem_shrinker_lock(dev, &unlock))
+		return NOTIFY_DONE;
+
+	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
+		if (is_vunmapable(msm_obj)) {
+			msm_gem_vunmap(&msm_obj->base);
+			/* since we don't know any better, lets bail after a few
+			 * and if necessary the shrinker will be invoked again.
+			 * Seems better than unmapping *everything*
+			 */
+			if (++unmapped >= 5)
+				break;
+		}
+	}
+
+	if (unlock)
+		mutex_unlock(&dev->struct_mutex);
+
+	*(unsigned long *)ptr += unmapped;
+
+	if (unmapped > 0)
+		pr_info("Purging %u vmaps\n", unmapped);
+
+	return NOTIFY_DONE;
+}
+
 /**
  * msm_gem_shrinker_init - Initialize msm shrinker
  * @dev_priv: msm device
@@ -113,6 +149,9 @@ void msm_gem_shrinker_init(struct drm_device *dev)
 	priv->shrinker.scan_objects = msm_gem_shrinker_scan;
 	priv->shrinker.seeks = DEFAULT_SEEKS;
 	WARN_ON(register_shrinker(&priv->shrinker));
+
+	priv->vmap_notifier.notifier_call = msm_gem_shrinker_vmap;
+	WARN_ON(register_vmap_purge_notifier(&priv->vmap_notifier));
 }
 
 /**
@@ -124,5 +163,6 @@ void msm_gem_shrinker_init(struct drm_device *dev)
 void msm_gem_shrinker_cleanup(struct drm_device *dev)
 {
 	struct msm_drm_private *priv = dev->dev_private;
+	WARN_ON(unregister_vmap_purge_notifier(&priv->vmap_notifier));
 	unregister_shrinker(&priv->shrinker);
 }
-- 
2.5.5