panthor: use drm_gem_object.gpuva.lock instead of gpuva_list_lock

Now that drm_gem_object has a dedicated mutex for the gpuva list that is
intended to be used in cases that must be fence signalling safe, use it
in Panthor.

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250827-gpuva-mutex-in-gem-v3-2-bd89f5a82c0d@google.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

3 files changed, 9 insertions, 23 deletions

diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/panthor/panthor_gem.c
index a123bc740ba1..c654a3377903 100644
--- a/drivers/gpu/drm/panthor/panthor_gem.c
+++ b/drivers/gpu/drm/panthor/panthor_gem.c
@@ -74,7 +74,6 @@ static void panthor_gem_free_object(struct drm_gem_object *obj)
 	mutex_destroy(&bo->label.lock);
 
 	drm_gem_free_mmap_offset(&bo->base.base);
-	mutex_destroy(&bo->gpuva_list_lock);
 	drm_gem_shmem_free(&bo->base);
 	drm_gem_object_put(vm_root_gem);
 }
@@ -246,8 +245,7 @@ struct drm_gem_object *panthor_gem_create_object(struct drm_device *ddev, size_t
 
 	obj->base.base.funcs = &panthor_gem_funcs;
 	obj->base.map_wc = !ptdev->coherent;
-	mutex_init(&obj->gpuva_list_lock);
-	drm_gem_gpuva_set_lock(&obj->base.base, &obj->gpuva_list_lock);
+	drm_gem_gpuva_set_lock(&obj->base.base, &obj->base.base.gpuva.lock);
 	mutex_init(&obj->label.lock);
 
 	panthor_gem_debugfs_bo_init(obj);
diff --git a/drivers/gpu/drm/panthor/panthor_gem.h b/drivers/gpu/drm/panthor/panthor_gem.h
index 8fc7215e9b90..80c6e24112d0 100644
--- a/drivers/gpu/drm/panthor/panthor_gem.h
+++ b/drivers/gpu/drm/panthor/panthor_gem.h
@@ -79,18 +79,6 @@ struct panthor_gem_object {
 	 */
 	struct drm_gem_object *exclusive_vm_root_gem;
 
-	/**
-	 * @gpuva_list_lock: Custom GPUVA lock.
-	 *
-	 * Used to protect insertion of drm_gpuva elements to the
-	 * drm_gem_object.gpuva.list list.
-	 *
-	 * We can't use the GEM resv for that, because drm_gpuva_link() is
-	 * called in a dma-signaling path, where we're not allowed to take
-	 * resv locks.
-	 */
-	struct mutex gpuva_list_lock;
-
 	/** @flags: Combination of drm_panthor_bo_flags flags. */
 	u32 flags;
 
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index 2003b91a8409..2881942ab511 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -1107,9 +1107,9 @@ static void panthor_vm_bo_put(struct drm_gpuvm_bo *vm_bo)
 	 * GEM vm_bo list.
 	 */
 	dma_resv_lock(drm_gpuvm_resv(vm), NULL);
-	mutex_lock(&bo->gpuva_list_lock);
+	mutex_lock(&bo->base.base.gpuva.lock);
 	unpin = drm_gpuvm_bo_put(vm_bo);
-	mutex_unlock(&bo->gpuva_list_lock);
+	mutex_unlock(&bo->base.base.gpuva.lock);
 	dma_resv_unlock(drm_gpuvm_resv(vm));
 
 	/* If the vm_bo object was destroyed, release the pin reference that
@@ -1282,9 +1282,9 @@ static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
 	 * calling this function.
 	 */
 	dma_resv_lock(panthor_vm_resv(vm), NULL);
-	mutex_lock(&bo->gpuva_list_lock);
+	mutex_lock(&bo->base.base.gpuva.lock);
 	op_ctx->map.vm_bo = drm_gpuvm_bo_obtain_prealloc(preallocated_vm_bo);
-	mutex_unlock(&bo->gpuva_list_lock);
+	mutex_unlock(&bo->base.base.gpuva.lock);
 	dma_resv_unlock(panthor_vm_resv(vm));
 
 	/* If the a vm_bo for this <VM,BO> combination exists, it already
@@ -2036,10 +2036,10 @@ static void panthor_vma_link(struct panthor_vm *vm,
 {
 	struct panthor_gem_object *bo = to_panthor_bo(vma->base.gem.obj);
 
-	mutex_lock(&bo->gpuva_list_lock);
+	mutex_lock(&bo->base.base.gpuva.lock);
 	drm_gpuva_link(&vma->base, vm_bo);
 	drm_WARN_ON(&vm->ptdev->base, drm_gpuvm_bo_put(vm_bo));
-	mutex_unlock(&bo->gpuva_list_lock);
+	mutex_unlock(&bo->base.base.gpuva.lock);
 }
 
 static void panthor_vma_unlink(struct panthor_vm *vm,
@@ -2048,9 +2048,9 @@ static void panthor_vma_unlink(struct panthor_vm *vm,
 	struct panthor_gem_object *bo = to_panthor_bo(vma->base.gem.obj);
 	struct drm_gpuvm_bo *vm_bo = drm_gpuvm_bo_get(vma->base.vm_bo);
 
-	mutex_lock(&bo->gpuva_list_lock);
+	mutex_lock(&bo->base.base.gpuva.lock);
 	drm_gpuva_unlink(&vma->base);
-	mutex_unlock(&bo->gpuva_list_lock);
+	mutex_unlock(&bo->base.base.gpuva.lock);
 
 	/* drm_gpuva_unlink() release the vm_bo, but we manually retained it
 	 * when entering this function, so we can implement deferred VMA