drm/ttm: fix pipelined gutting v2

We need to make sure to allocate the sys_mem resource before the point
of no return.

v2: add missing return value checking, also handle idle case

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210608081931.11339-1-christian.koenig@amd.com

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 9be6a10..2f57f82 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -582,9 +582,14 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
 {
        static const struct ttm_place sys_mem = { .mem_type = TTM_PL_SYSTEM };
        struct ttm_buffer_object *ghost;
+       struct ttm_resource *sys_res;
        struct ttm_tt *ttm;
        int ret;
 
+       ret = ttm_resource_alloc(bo, &sys_mem, &sys_res);
+       if (ret)
+               return ret;
+
        /* If already idle, no need for ghost object dance. */
        ret = ttm_bo_wait(bo, false, true);
        if (ret != -EBUSY) {
@@ -592,14 +597,15 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
                        /* See comment below about clearing. */
                        ret = ttm_tt_create(bo, true);
                        if (ret)
-                               return ret;
+                               goto error_free_sys_mem;
                } else {
                        ttm_tt_unpopulate(bo->bdev, bo->ttm);
                        if (bo->type == ttm_bo_type_device)
                                ttm_tt_mark_for_clear(bo->ttm);
                }
                ttm_resource_free(bo, &bo->resource);
-               return ttm_resource_alloc(bo, &sys_mem, &bo->resource);
+               ttm_bo_assign_mem(bo, sys_res);
+               return 0;
        }
 
        /*
@@ -615,13 +621,11 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
        ret = ttm_tt_create(bo, true);
        swap(bo->ttm, ttm);
        if (ret)
-               return ret;
+               goto error_free_sys_mem;
 
        ret = ttm_buffer_object_transfer(bo, &ghost);
-       if (ret) {
-               ttm_tt_destroy(bo->bdev, ttm);
-               return ret;
-       }
+       if (ret)
+               goto error_destroy_tt;
 
        ret = dma_resv_copy_fences(&ghost->base._resv, bo->base.resv);
        /* Last resort, wait for the BO to be idle when we are OOM */
@@ -631,6 +635,14 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
        dma_resv_unlock(&ghost->base._resv);
        ttm_bo_put(ghost);
        bo->ttm = ttm;
+       bo->resource = NULL;
+       ttm_bo_assign_mem(bo, sys_res);
+       return 0;
+
+error_destroy_tt:
+       ttm_tt_destroy(bo->bdev, ttm);
 
-       return ttm_resource_alloc(bo, &sys_mem, &bo->resource);
+error_free_sys_mem:
+       ttm_resource_free(bo, &sys_res);
+       return ret;
 }