drm/amdgpu: use a rw_semaphore for MMU notifiers

Allow at least some parallel processing.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index df85a1314799b81979052c53599c17f6c81c973e..6d216abd0e1d7572377880ca4218c2b6a0e06a21 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -50,7 +50,7 @@ struct amdgpu_mn {
        struct hlist_node       node;
 
        /* objects protected by lock */
-       struct mutex            lock;
+       struct rw_semaphore     lock;
        struct rb_root          objects;
 };
 
@@ -74,7 +74,7 @@ static void amdgpu_mn_destroy(struct work_struct *work)
        struct amdgpu_bo *bo, *next_bo;
 
        mutex_lock(&adev->mn_lock);
-       mutex_lock(&rmn->lock);
+       down_write(&rmn->lock);
        hash_del(&rmn->node);
        rbtree_postorder_for_each_entry_safe(node, next_node, &rmn->objects,
                                             it.rb) {
@@ -84,7 +84,7 @@ static void amdgpu_mn_destroy(struct work_struct *work)
                }
                kfree(node);
        }
-       mutex_unlock(&rmn->lock);
+       up_write(&rmn->lock);
        mutex_unlock(&adev->mn_lock);
        mmu_notifier_unregister_no_release(&rmn->mn, rmn->mm);
        kfree(rmn);
@@ -160,7 +160,7 @@ static void amdgpu_mn_invalidate_page(struct mmu_notifier *mn,
        struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
        struct interval_tree_node *it;
 
-       mutex_lock(&rmn->lock);
+       down_read(&rmn->lock);
 
        it = interval_tree_iter_first(&rmn->objects, address, address);
        if (it) {
@@ -170,7 +170,7 @@ static void amdgpu_mn_invalidate_page(struct mmu_notifier *mn,
                amdgpu_mn_invalidate_node(node, address, address);
        }
 
-       mutex_unlock(&rmn->lock);
+       up_read(&rmn->lock);
 }
 
 /**
@@ -195,7 +195,7 @@ static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
        /* notification is exclusive, but interval is inclusive */
        end -= 1;
 
-       mutex_lock(&rmn->lock);
+       down_read(&rmn->lock);
 
        it = interval_tree_iter_first(&rmn->objects, start, end);
        while (it) {
@@ -207,7 +207,7 @@ static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
                amdgpu_mn_invalidate_node(node, start, end);
        }
 
-       mutex_unlock(&rmn->lock);
+       up_read(&rmn->lock);
 }
 
 static const struct mmu_notifier_ops amdgpu_mn_ops = {
@@ -248,7 +248,7 @@ static struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev)
        rmn->adev = adev;
        rmn->mm = mm;
        rmn->mn.ops = &amdgpu_mn_ops;
-       mutex_init(&rmn->lock);
+       init_rwsem(&rmn->lock);
        rmn->objects = RB_ROOT;
 
        r = __mmu_notifier_register(&rmn->mn, mm);
@@ -295,7 +295,7 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
 
        INIT_LIST_HEAD(&bos);
 
-       mutex_lock(&rmn->lock);
+       down_write(&rmn->lock);
 
        while ((it = interval_tree_iter_first(&rmn->objects, addr, end))) {
                kfree(node);
@@ -309,7 +309,7 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
        if (!node) {
                node = kmalloc(sizeof(struct amdgpu_mn_node), GFP_KERNEL);
                if (!node) {
-                       mutex_unlock(&rmn->lock);
+                       up_write(&rmn->lock);
                        return -ENOMEM;
                }
        }
@@ -324,7 +324,7 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
 
        interval_tree_insert(&node->it, &rmn->objects);
 
-       mutex_unlock(&rmn->lock);
+       up_write(&rmn->lock);
 
        return 0;
 }
@@ -350,7 +350,7 @@ void amdgpu_mn_unregister(struct amdgpu_bo *bo)
                return;
        }
 
-       mutex_lock(&rmn->lock);
+       down_write(&rmn->lock);
 
        /* save the next list entry for later */
        head = bo->mn_list.next;
@@ -365,6 +365,6 @@ void amdgpu_mn_unregister(struct amdgpu_bo *bo)
                kfree(node);
        }
 
-       mutex_unlock(&rmn->lock);
+       up_write(&rmn->lock);
        mutex_unlock(&adev->mn_lock);
 }