Hi

Am 18.08.25 um 14:40 schrieb Christian König:
[...]
+static int amdgpu_dma_buf_vmap(struct dma_buf *dma_buf, struct iosys_map *map)
+{
+       struct drm_gem_object *obj = dma_buf->priv;
+       struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
+       int ret;
+
+       /*
+        * Pin to keep buffer in place while it's vmap'ed. The actual
+        * location is not important as long as it's mapable.
Yeah, exactly that won't work here. Most of the locations are not CPU 
accessible.

You could use AMDGPU_GEM_DOMAIN_GTT, that should most likely work in all cases 
but isn't necessarily the most optimal solution.

No problem about that, but why not a bit more flexibility? When udl copies from the buffer, it is likely pinned to VRAM.

A bit mask of _CPU, _GTT, and _VRAM should work fine. The other domains are probably irrelevant for our use case.

Best regards
Thomas


Regards,
Christian.

+        *
+        * This code is required for exporting to GEM-SHMEM without S/G table.
+        * Once GEM-SHMEM supports dynamic imports, it should be dropped.
+        */
+       ret = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_MASK);
+       if (ret)
+               return ret;
+       ret = drm_gem_dmabuf_vmap(dma_buf, map);
+       if (ret)
+               amdgpu_bo_unpin(bo);
+
+       return ret;
+}
+
+static void amdgpu_dma_buf_vunmap(struct dma_buf *dma_buf, struct iosys_map 
*map)
+{
+       struct drm_gem_object *obj = dma_buf->priv;
+       struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
+
+       drm_gem_dmabuf_vunmap(dma_buf, map);
+       amdgpu_bo_unpin(bo);
+}
+
  const struct dma_buf_ops amdgpu_dmabuf_ops = {
        .attach = amdgpu_dma_buf_attach,
        .pin = amdgpu_dma_buf_pin,
@@ -294,8 +326,8 @@ const struct dma_buf_ops amdgpu_dmabuf_ops = {
        .release = drm_gem_dmabuf_release,
        .begin_cpu_access = amdgpu_dma_buf_begin_cpu_access,
        .mmap = drm_gem_dmabuf_mmap,
-       .vmap = drm_gem_dmabuf_vmap,
-       .vunmap = drm_gem_dmabuf_vunmap,
+       .vmap = amdgpu_dma_buf_vmap,
+       .vunmap = amdgpu_dma_buf_vunmap,
  };
/**

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)


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