[PATCH 1/2] drm/nouveau/dmem: pin VRAM for the whole registered range

[Junrui Luo via B4 Relay]

From: Junrui Luo <moonafterrain@xxxxxxxxxxx>

Commit c32287471077 ("gpu/drm/nouveau: enable THP support for GPU memory
migration") grew the device-private region that
nouveau_dmem_chunk_alloc() registers from DMEM_CHUNK_SIZE to
DMEM_CHUNK_SIZE * NR_CHUNKS, but left the VRAM buffer object backing that
region at DMEM_CHUNK_SIZE.

nouveau_dmem_page_addr() returns chunk->bo->offset plus the page's offset
within the registered region, so every page past the first chunk resolves
to VRAM outside the buffer object.

Size the buffer object to the region it backs.

Fixes: c32287471077 ("gpu/drm/nouveau: enable THP support for GPU memory migration")
Reported-by: Yuhao Jiang <danisjiang@xxxxxxxxx>
Assisted-by: Claude:claude-opus-5
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Junrui Luo <moonafterrain@xxxxxxxxxxx>
---
 drivers/gpu/drm/nouveau/nouveau_dmem.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 9442ec6e1f6c..356ff8f3c1b8 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -325,8 +325,8 @@ nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, struct page **ppage,
 	chunk->pagemap.ops = &nouveau_dmem_pagemap_ops;
 	chunk->pagemap.owner = drm->dev;
 
-	ret = nouveau_bo_new_pin(&drm->client, NOUVEAU_GEM_DOMAIN_VRAM, DMEM_CHUNK_SIZE,
-				 &chunk->bo);
+	ret = nouveau_bo_new_pin(&drm->client, NOUVEAU_GEM_DOMAIN_VRAM,
+				 DMEM_CHUNK_SIZE * NR_CHUNKS, &chunk->bo);
 	if (ret)
 		goto out_release;
 

-- 
2.51.2