drm/ttm: add ttm_sg_tt_init

This allows drivers to only allocate dma addresses, but not a page
array.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Roger He <Hongbo.He@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 45 insertions, 9 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 8e0b525cda00..971133106ec2 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -108,6 +108,16 @@ static int ttm_dma_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
         return 0;
 }
 
+static int ttm_sg_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
+{
+        ttm->dma_address = kvmalloc_array(ttm->ttm.num_pages,
+                                          sizeof(*ttm->dma_address),
+                                          GFP_KERNEL | __GFP_ZERO);
+        if (!ttm->dma_address)
+                return -ENOMEM;
+        return 0;
+}
+
 #ifdef CONFIG_X86
 static inline int ttm_tt_set_page_caching(struct page *p,
                                           enum ttm_caching_state c_old,
@@ -227,8 +237,8 @@ void ttm_tt_destroy(struct ttm_tt *ttm)
         ttm->func->destroy(ttm);
 }
 
-int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
-                unsigned long size, uint32_t page_flags)
+void ttm_tt_init_fields(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
+                        unsigned long size, uint32_t page_flags)
 {
         ttm->bdev = bdev;
         ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
@@ -236,6 +246,12 @@ int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
         ttm->page_flags = page_flags;
         ttm->state = tt_unpopulated;
         ttm->swap_storage = NULL;
+}
+
+int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
+                unsigned long size, uint32_t page_flags)
+{
+        ttm_tt_init_fields(ttm, bdev, size, page_flags);
 
         if (ttm_tt_alloc_page_directory(ttm)) {
                 ttm_tt_destroy(ttm);
@@ -258,12 +274,7 @@ int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
 {
         struct ttm_tt *ttm = &ttm_dma->ttm;
 
-        ttm->bdev = bdev;
-        ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
-        ttm->caching_state = tt_cached;
-        ttm->page_flags = page_flags;
-        ttm->state = tt_unpopulated;
-        ttm->swap_storage = NULL;
+        ttm_tt_init_fields(ttm, bdev, size, page_flags);
 
         INIT_LIST_HEAD(&ttm_dma->pages_list);
         if (ttm_dma_tt_alloc_page_directory(ttm_dma)) {
@@ -275,11 +286,36 @@ int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
 }
 EXPORT_SYMBOL(ttm_dma_tt_init);
 
+int ttm_sg_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
+                   unsigned long size, uint32_t page_flags)
+{
+        struct ttm_tt *ttm = &ttm_dma->ttm;
+        int ret;
+
+        ttm_tt_init_fields(ttm, bdev, size, page_flags);
+
+        INIT_LIST_HEAD(&ttm_dma->pages_list);
+        if (page_flags & TTM_PAGE_FLAG_SG)
+                ret = ttm_sg_tt_alloc_page_directory(ttm_dma);
+        else
+                ret = ttm_dma_tt_alloc_page_directory(ttm_dma);
+        if (ret) {
+                ttm_tt_destroy(ttm);
+                pr_err("Failed allocating page table\n");
+                return -ENOMEM;
+        }
+        return 0;
+}
+EXPORT_SYMBOL(ttm_sg_tt_init);
+
 void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma)
 {
         struct ttm_tt *ttm = &ttm_dma->ttm;
 
-        kvfree(ttm->pages);
+        if (ttm->pages)
+                kvfree(ttm->pages);
+        else
+                kvfree(ttm_dma->dma_address);
         ttm->pages = NULL;
         ttm_dma->dma_address = NULL;
 }