drm/amd/amdgpu: Bail out of BO node creation if not enough VRAM (v3)

(v2): Return 0 and set mem->mm_node to NULL.
(v3): Use atomic64_add_return instead.

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index 8aea2f2..c963ad8 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -276,7 +276,7 @@ static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
        struct drm_mm_node *nodes;
        enum drm_mm_insert_mode mode;
        unsigned long lpfn, num_nodes, pages_per_node, pages_left;
-       uint64_t usage = 0, vis_usage = 0;
+       uint64_t vis_usage = 0;
        unsigned i;
        int r;
 
@@ -284,6 +284,13 @@ static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
        if (!lpfn)
                lpfn = man->size;
 
+       /* bail out quickly if there's likely not enough VRAM for this BO */
+       if (atomic64_add_return(mem->num_pages << PAGE_SHIFT, &mgr->usage) > adev->gmc.mc_vram_size) {
+               atomic64_sub(mem->num_pages << PAGE_SHIFT, &mgr->usage);
+               mem->mm_node = NULL;
+               return 0;
+       }
+
        if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
                pages_per_node = ~0ul;
                num_nodes = 1;
@@ -300,8 +307,10 @@ static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
 
        nodes = kvmalloc_array((uint32_t)num_nodes, sizeof(*nodes),
                               GFP_KERNEL | __GFP_ZERO);
-       if (!nodes)
+       if (!nodes) {
+               atomic64_sub(mem->num_pages << PAGE_SHIFT, &mgr->usage);
                return -ENOMEM;
+       }
 
        mode = DRM_MM_INSERT_BEST;
        if (place->flags & TTM_PL_FLAG_TOPDOWN)
@@ -321,7 +330,6 @@ static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
                if (unlikely(r))
                        break;
 
-               usage += nodes[i].size << PAGE_SHIFT;
                vis_usage += amdgpu_vram_mgr_vis_size(adev, &nodes[i]);
                amdgpu_vram_mgr_virt_start(mem, &nodes[i]);
                pages_left -= pages;
@@ -341,14 +349,12 @@ static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
                if (unlikely(r))
                        goto error;
 
-               usage += nodes[i].size << PAGE_SHIFT;
                vis_usage += amdgpu_vram_mgr_vis_size(adev, &nodes[i]);
                amdgpu_vram_mgr_virt_start(mem, &nodes[i]);
                pages_left -= pages;
        }
        spin_unlock(&mgr->lock);
 
-       atomic64_add(usage, &mgr->usage);
        atomic64_add(vis_usage, &mgr->vis_usage);
 
        mem->mm_node = nodes;
@@ -359,6 +365,7 @@ error:
        while (i--)
                drm_mm_remove_node(&nodes[i]);
        spin_unlock(&mgr->lock);
+       atomic64_sub(mem->num_pages << PAGE_SHIFT, &mgr->usage);
 
        kvfree(nodes);
        return r == -ENOSPC ? 0 : r;