drm/amdgpu: Limit the maximum size of contiguous VRAM that can be encapsulated by...

[Why]
Enable 1:1 mapping between VRAM of a DRM node and a scatterlist node

[How]
Ensure construction of DRM node to not exceed specified limit

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Ramesh Errabolu <Ramesh.Errabolu@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 d2de2a7..c89b66b 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -473,6 +473,9 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
        for (i = 0; pages_left >= pages_per_node; ++i) {
                unsigned long pages = rounddown_pow_of_two(pages_left);
 
+               /* Limit maximum size to 2GB due to SG table limitations */
+               pages = min(pages, (2UL << (30 - PAGE_SHIFT)));
+
                r = drm_mm_insert_node_in_range(mm, &nodes[i], pages,
                                                pages_per_node, 0,
                                                place->fpfn, lpfn,