[PATCH] drm/nouveau/mmu: fix reuse of nvkm_umem

From: Karol Herbst
Date: Mon Feb 07 2022 - 11:17:19 EST


I am not entirely sure if this fixes anything, but the code standed out
while investigated problematic calls to vunmap.

nvkm_umem.io is only ever set for the NVKM_OBJECT_MAP_IO case in
nvkm_umem_map, but never for the NVKM_OBJECT_MAP_VA one, which could lead
to taking the wrong patch inside nvkm_umem_unmap.

I just don't know if this is a real issue or not, but the code doesn't
look correct this way.

Fixes: c83c4097eba8 ("drm/nouveau/mmu: define user interfaces to mmu memory allocation")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.15+
---
drivers/gpu/drm/nouveau/nvkm/subdev/mmu/umem.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/umem.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/umem.c
index e530bb8b3b17..2608e0796066 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/umem.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/umem.c
@@ -102,6 +102,7 @@ nvkm_umem_map(struct nvkm_object *object, void *argv, u32 argc,
*handle = (unsigned long)(void *)umem->map;
*length = nvkm_memory_size(umem->memory);
*type = NVKM_OBJECT_MAP_VA;
+ umem->io = false;
return 0;
} else
if ((umem->type & NVKM_MEM_VRAM) ||
@@ -112,12 +113,11 @@ nvkm_umem_map(struct nvkm_object *object, void *argv, u32 argc,
return ret;

*type = NVKM_OBJECT_MAP_IO;
- } else {
- return -EINVAL;
+ umem->io = true;
+ return 0;
}

- umem->io = (*type == NVKM_OBJECT_MAP_IO);
- return 0;
+ return -EINVAL;
}

static void *
--
2.34.1