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	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>
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					 3 changed files with 12 additions and 5 deletions
				
			
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			@ -848,6 +848,7 @@ static int ttm_dma_pool_get_pages(struct dma_pool *pool,
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	if (count) {
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		d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
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		ttm->pages[index] = d_page->p;
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		ttm_dma->cpu_address[index] = d_page->vaddr;
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		ttm_dma->dma_address[index] = d_page->dma;
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		list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
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		r = 0;
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			@ -979,6 +980,7 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
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	INIT_LIST_HEAD(&ttm_dma->pages_list);
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	for (i = 0; i < ttm->num_pages; i++) {
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		ttm->pages[i] = NULL;
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		ttm_dma->cpu_address[i] = 0;
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		ttm_dma->dma_address[i] = 0;
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	}
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			@ -55,9 +55,12 @@ static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
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static void ttm_dma_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
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{
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	ttm->ttm.pages = drm_calloc_large(ttm->ttm.num_pages, sizeof(void*));
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	ttm->dma_address = drm_calloc_large(ttm->ttm.num_pages,
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					    sizeof(*ttm->dma_address));
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	ttm->ttm.pages = drm_calloc_large(ttm->ttm.num_pages,
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					  sizeof(*ttm->ttm.pages) +
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					  sizeof(*ttm->dma_address) +
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					  sizeof(*ttm->cpu_address));
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	ttm->cpu_address = (void *) (ttm->ttm.pages + ttm->ttm.num_pages);
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	ttm->dma_address = (void *) (ttm->cpu_address + ttm->ttm.num_pages);
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}
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#ifdef CONFIG_X86
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			@ -228,7 +231,7 @@ int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
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	INIT_LIST_HEAD(&ttm_dma->pages_list);
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	ttm_dma_tt_alloc_page_directory(ttm_dma);
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	if (!ttm->pages || !ttm_dma->dma_address) {
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	if (!ttm->pages) {
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		ttm_tt_destroy(ttm);
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		pr_err("Failed allocating page table\n");
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		return -ENOMEM;
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			@ -243,7 +246,7 @@ void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma)
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	drm_free_large(ttm->pages);
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	ttm->pages = NULL;
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	drm_free_large(ttm_dma->dma_address);
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	ttm_dma->cpu_address = NULL;
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	ttm_dma->dma_address = NULL;
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}
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EXPORT_SYMBOL(ttm_dma_tt_fini);
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			@ -133,6 +133,7 @@ struct ttm_tt {
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 * struct ttm_dma_tt
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 *
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 * @ttm: Base ttm_tt struct.
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 * @cpu_address: The CPU address of the pages
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 * @dma_address: The DMA (bus) addresses of the pages
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 * @pages_list: used by some page allocation backend
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 *
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			@ -142,6 +143,7 @@ struct ttm_tt {
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 */
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struct ttm_dma_tt {
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	struct ttm_tt ttm;
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	void **cpu_address;
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	dma_addr_t *dma_address;
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	struct list_head pages_list;
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};
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