Commit 51ab7ba2 authored by Dave Airlie's avatar Dave Airlie
Browse files

drm/prime: introduce sg->pages/addr arrays helper 



the ttm drivers need this currently, in order to get fault handling
working and efficient.

It also allows addrs to be NULL for devices like udl.

Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 4d93914a

drivers/gpu/drm/drm_prime.c

+36 −0
Original line number Diff line number Diff line
@@ -227,6 +227,42 @@ struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages) 
}

EXPORT_SYMBOL(drm_prime_pages_to_sg);



/* export an sg table into an array of pages and addresses

   this is currently required by the TTM driver in order to do correct fault

   handling */

int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,

				     dma_addr_t *addrs, int max_pages)

{

	unsigned count;

	struct scatterlist *sg;

	struct page *page;

	u32 len, offset;

	int pg_index;

	dma_addr_t addr;



	pg_index = 0;

	for_each_sg(sgt->sgl, sg, sgt->nents, count) {

		len = sg->length;

		offset = sg->offset;

		page = sg_page(sg);

		addr = sg_dma_address(sg);



		while (len > 0) {

			if (WARN_ON(pg_index >= max_pages))

				return -1;

			pages[pg_index] = page;

			if (addrs)

				addrs[pg_index] = addr;



			page++;

			addr += PAGE_SIZE;

			len -= PAGE_SIZE;

			pg_index++;

		}

	}

	return 0;

}

EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);

/* helper function to cleanup a GEM/prime object */

void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg)

{

include/drm/drmP.h

+2 −0
Original line number Diff line number Diff line
@@ -1558,6 +1558,8 @@ extern int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, 
extern int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,

					struct drm_file *file_priv);



extern int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,

					    dma_addr_t *addrs, int max_pages);

extern struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages);

extern void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg);