drm/ttm: expose CPU address of DMA-allocated pages

Pages allocated using the DMA API have a coherent memory mapping. Make
this mapping visible to drivers so they can decide to use it instead of
creating their own redundant one.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This commit is contained in:
Alexandre Courbot 2014-08-04 18:28:54 +09:00 committed by Ben Skeggs
parent 7963e9db1b
commit 3d50d4dcb0
3 changed files with 12 additions and 5 deletions

View File

@ -848,6 +848,7 @@ static int ttm_dma_pool_get_pages(struct dma_pool *pool,
if (count) {
d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
ttm->pages[index] = d_page->p;
ttm_dma->cpu_address[index] = d_page->vaddr;
ttm_dma->dma_address[index] = d_page->dma;
list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
r = 0;
@ -979,6 +980,7 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
INIT_LIST_HEAD(&ttm_dma->pages_list);
for (i = 0; i < ttm->num_pages; i++) {
ttm->pages[i] = NULL;
ttm_dma->cpu_address[i] = 0;
ttm_dma->dma_address[i] = 0;
}

View File

@ -55,9 +55,12 @@ static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
static void ttm_dma_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
{
ttm->ttm.pages = drm_calloc_large(ttm->ttm.num_pages, sizeof(void*));
ttm->dma_address = drm_calloc_large(ttm->ttm.num_pages,
sizeof(*ttm->dma_address));
ttm->ttm.pages = drm_calloc_large(ttm->ttm.num_pages,
sizeof(*ttm->ttm.pages) +
sizeof(*ttm->dma_address) +
sizeof(*ttm->cpu_address));
ttm->cpu_address = (void *) (ttm->ttm.pages + ttm->ttm.num_pages);
ttm->dma_address = (void *) (ttm->cpu_address + ttm->ttm.num_pages);
}
#ifdef CONFIG_X86
@ -228,7 +231,7 @@ int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
INIT_LIST_HEAD(&ttm_dma->pages_list);
ttm_dma_tt_alloc_page_directory(ttm_dma);
if (!ttm->pages || !ttm_dma->dma_address) {
if (!ttm->pages) {
ttm_tt_destroy(ttm);
pr_err("Failed allocating page table\n");
return -ENOMEM;
@ -243,7 +246,7 @@ void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma)
drm_free_large(ttm->pages);
ttm->pages = NULL;
drm_free_large(ttm_dma->dma_address);
ttm_dma->cpu_address = NULL;
ttm_dma->dma_address = NULL;
}
EXPORT_SYMBOL(ttm_dma_tt_fini);

View File

@ -133,6 +133,7 @@ struct ttm_tt {
* struct ttm_dma_tt
*
* @ttm: Base ttm_tt struct.
* @cpu_address: The CPU address of the pages
* @dma_address: The DMA (bus) addresses of the pages
* @pages_list: used by some page allocation backend
*
@ -142,6 +143,7 @@ struct ttm_tt {
*/
struct ttm_dma_tt {
struct ttm_tt ttm;
void **cpu_address;
dma_addr_t *dma_address;
struct list_head pages_list;
};