When a BO gets pinned the placement may get changed. If the memory is mapped into user space and user space has already accessed the mapped range the page tables are set up but now point to the wrong memory. A call to ttm_bo_unmap_virtual() will invalidate all page tables of all mappings of this BO. When user space accesses this memory again we will receive a page fault and are able to set up the page tables to point to the correct physical memory.
Signed-off-by: Egbert Eich eich@suse.com --- drivers/gpu/drm/mgag200/mgag200_ttm.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/mgag200/mgag200_ttm.c b/drivers/gpu/drm/mgag200/mgag200_ttm.c index 3a2e5e2..8ceeb0c 100644 --- a/drivers/gpu/drm/mgag200/mgag200_ttm.c +++ b/drivers/gpu/drm/mgag200/mgag200_ttm.c @@ -321,6 +321,7 @@ int mgag200_bo_create(struct drm_device *dev, int size, int align,
mgabo->gem.driver_private = NULL; mgabo->bo.bdev = &mdev->ttm.bdev; + mgabo->bo.bdev->dev_mapping = dev->dev_mapping;
mgag200_ttm_placement(mgabo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);
@@ -359,6 +360,7 @@ int mgag200_bo_pin(struct mgag200_bo *bo, u32 pl_flag, u64 *gpu_addr) if (ret) return ret; } + ttm_bo_unmap_virtual(&bo->bo); bo->pin_count++; if (gpu_addr) *gpu_addr = mgag200_bo_gpu_offset(bo);