1 files changed, 86 insertions, 18 deletions

diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
index 07ca4ddfe4e3..1039e3c0a47b 100644
--- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
+++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
@@ -44,7 +44,76 @@ msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
 }
 
 static bool
-purge(struct drm_gem_object *obj)
+with_vm_locks(struct ww_acquire_ctx *ticket,
+	      void (*fn)(struct drm_gem_object *obj),
+	      struct drm_gem_object *obj)
+{
+	/*
+	 * Track last locked entry for for unwinding locks in error and
+	 * success paths
+	 */
+	struct drm_gpuvm_bo *vm_bo, *last_locked = NULL;
+	int ret = 0;
+
+	drm_gem_for_each_gpuvm_bo (vm_bo, obj) {
+		struct dma_resv *resv = drm_gpuvm_resv(vm_bo->vm);
+
+		if (resv == obj->resv)
+			continue;
+
+		ret = dma_resv_lock(resv, ticket);
+
+		/*
+		 * Since we already skip the case when the VM and obj
+		 * share a resv (ie. _NO_SHARE objs), we don't expect
+		 * to hit a double-locking scenario... which the lock
+		 * unwinding cannot really cope with.
+		 */
+		WARN_ON(ret == -EALREADY);
+
+		/*
+		 * Don't bother with slow-lock / backoff / retry sequence,
+		 * if we can't get the lock just give up and move on to
+		 * the next object.
+		 */
+		if (ret)
+			goto out_unlock;
+
+		/*
+		 * Hold a ref to prevent the vm_bo from being freed
+		 * and removed from the obj's gpuva list, as that would
+		 * would result in missing the unlock below
+		 */
+		drm_gpuvm_bo_get(vm_bo);
+
+		last_locked = vm_bo;
+	}
+
+	fn(obj);
+
+out_unlock:
+	if (last_locked) {
+		drm_gem_for_each_gpuvm_bo (vm_bo, obj) {
+			struct dma_resv *resv = drm_gpuvm_resv(vm_bo->vm);
+
+			if (resv == obj->resv)
+				continue;
+
+			dma_resv_unlock(resv);
+
+			/* Drop the ref taken while locking: */
+			drm_gpuvm_bo_put(vm_bo);
+
+			if (last_locked == vm_bo)
+				break;
+		}
+	}
+
+	return ret == 0;
+}
+
+static bool
+purge(struct drm_gem_object *obj, struct ww_acquire_ctx *ticket)
 {
 	if (!is_purgeable(to_msm_bo(obj)))
 		return false;
@@ -52,13 +121,11 @@ purge(struct drm_gem_object *obj)
 	if (msm_gem_active(obj))
 		return false;
 
-	msm_gem_purge(obj);
-
-	return true;
+	return with_vm_locks(ticket, msm_gem_purge, obj);
 }
 
 static bool
-evict(struct drm_gem_object *obj)
+evict(struct drm_gem_object *obj, struct ww_acquire_ctx *ticket)
 {
 	if (is_unevictable(to_msm_bo(obj)))
 		return false;
@@ -66,43 +133,42 @@ evict(struct drm_gem_object *obj)
 	if (msm_gem_active(obj))
 		return false;
 
-	msm_gem_evict(obj);
-
-	return true;
+	return with_vm_locks(ticket, msm_gem_evict, obj);
 }
 
 static bool
 wait_for_idle(struct drm_gem_object *obj)
 {
-	enum dma_resv_usage usage = dma_resv_usage_rw(true);
+	enum dma_resv_usage usage = DMA_RESV_USAGE_BOOKKEEP;
 	return dma_resv_wait_timeout(obj->resv, usage, false, 10) > 0;
 }
 
 static bool
-active_purge(struct drm_gem_object *obj)
+active_purge(struct drm_gem_object *obj, struct ww_acquire_ctx *ticket)
 {
 	if (!wait_for_idle(obj))
 		return false;
 
-	return purge(obj);
+	return purge(obj, ticket);
 }
 
 static bool
-active_evict(struct drm_gem_object *obj)
+active_evict(struct drm_gem_object *obj, struct ww_acquire_ctx *ticket)
 {
 	if (!wait_for_idle(obj))
 		return false;
 
-	return evict(obj);
+	return evict(obj, ticket);
 }
 
 static unsigned long
 msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
 {
 	struct msm_drm_private *priv = shrinker->private_data;
+	struct ww_acquire_ctx ticket;
 	struct {
 		struct drm_gem_lru *lru;
-		bool (*shrink)(struct drm_gem_object *obj);
+		bool (*shrink)(struct drm_gem_object *obj, struct ww_acquire_ctx *ticket);
 		bool cond;
 		unsigned long freed;
 		unsigned long remaining;
@@ -122,8 +188,9 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
 			continue;
 		stages[i].freed =
 			drm_gem_lru_scan(stages[i].lru, nr,
-					&stages[i].remaining,
-					 stages[i].shrink);
+					 &stages[i].remaining,
+					 stages[i].shrink,
+					 &ticket);
 		nr -= stages[i].freed;
 		freed += stages[i].freed;
 		remaining += stages[i].remaining;
@@ -164,7 +231,7 @@ msm_gem_shrinker_shrink(struct drm_device *dev, unsigned long nr_to_scan)
 static const int vmap_shrink_limit = 15;
 
 static bool
-vmap_shrink(struct drm_gem_object *obj)
+vmap_shrink(struct drm_gem_object *obj, struct ww_acquire_ctx *ticket)
 {
 	if (!is_vunmapable(to_msm_bo(obj)))
 		return false;
@@ -192,7 +259,8 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
 		unmapped += drm_gem_lru_scan(lrus[idx],
 					     vmap_shrink_limit - unmapped,
 					     &remaining,
-					     vmap_shrink);
+					     vmap_shrink,
+					     NULL);
 	}
 
 	*(unsigned long *)ptr += unmapped;