drm: GEM CMA: Split object creation into object alloc and DMA memory alloc
This allows creating a GEM CMA object without an associated DMA memory
buffer, and will be used to implement DRM PRIME support.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index 0a7e011..8cce330 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -32,11 +32,44 @@
return (unsigned int)obj->map_list.hash.key << PAGE_SHIFT;
}
-static void drm_gem_cma_buf_destroy(struct drm_device *drm,
- struct drm_gem_cma_object *cma_obj)
+/*
+ * __drm_gem_cma_create - Create a GEM CMA object without allocating memory
+ * @drm: The drm device
+ * @size: The GEM object size
+ *
+ * This function creates and initializes a GEM CMA object of the given size, but
+ * doesn't allocate any memory to back the object.
+ *
+ * Return a struct drm_gem_cma_object* on success or ERR_PTR values on failure.
+ */
+static struct drm_gem_cma_object *
+__drm_gem_cma_create(struct drm_device *drm, unsigned int size)
{
- dma_free_writecombine(drm->dev, cma_obj->base.size, cma_obj->vaddr,
- cma_obj->paddr);
+ struct drm_gem_cma_object *cma_obj;
+ struct drm_gem_object *gem_obj;
+ int ret;
+
+ cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
+ if (!cma_obj)
+ return ERR_PTR(-ENOMEM);
+
+ gem_obj = &cma_obj->base;
+
+ ret = drm_gem_object_init(drm, gem_obj, size);
+ if (ret)
+ goto error;
+
+ ret = drm_gem_create_mmap_offset(gem_obj);
+ if (ret) {
+ drm_gem_object_release(gem_obj);
+ goto error;
+ }
+
+ return cma_obj;
+
+error:
+ kfree(cma_obj);
+ return ERR_PTR(ret);
}
/*
@@ -49,45 +82,23 @@
unsigned int size)
{
struct drm_gem_cma_object *cma_obj;
- struct drm_gem_object *gem_obj;
- int ret;
size = round_up(size, PAGE_SIZE);
- cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
- if (!cma_obj)
- return ERR_PTR(-ENOMEM);
+ cma_obj = __drm_gem_cma_create(drm, size);
+ if (IS_ERR(cma_obj))
+ return cma_obj;
cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size,
&cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN);
if (!cma_obj->vaddr) {
- dev_err(drm->dev, "failed to allocate buffer with size %d\n", size);
- ret = -ENOMEM;
- goto err_dma_alloc;
+ dev_err(drm->dev, "failed to allocate buffer with size %d\n",
+ size);
+ drm_gem_cma_free_object(&cma_obj->base);
+ return ERR_PTR(-ENOMEM);
}
- gem_obj = &cma_obj->base;
-
- ret = drm_gem_object_init(drm, gem_obj, size);
- if (ret)
- goto err_obj_init;
-
- ret = drm_gem_create_mmap_offset(gem_obj);
- if (ret)
- goto err_create_mmap_offset;
-
return cma_obj;
-
-err_create_mmap_offset:
- drm_gem_object_release(gem_obj);
-
-err_obj_init:
- drm_gem_cma_buf_destroy(drm, cma_obj);
-
-err_dma_alloc:
- kfree(cma_obj);
-
- return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(drm_gem_cma_create);
@@ -143,11 +154,13 @@
if (gem_obj->map_list.map)
drm_gem_free_mmap_offset(gem_obj);
- drm_gem_object_release(gem_obj);
-
cma_obj = to_drm_gem_cma_obj(gem_obj);
- drm_gem_cma_buf_destroy(gem_obj->dev, cma_obj);
+ if (cma_obj->vaddr)
+ dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size,
+ cma_obj->vaddr, cma_obj->paddr);
+
+ drm_gem_object_release(gem_obj);
kfree(cma_obj);
}