On Tue, Apr 22, 2025 at 10:04:11AM -0700, Matthew Brost wrote:
> From: Himal Prasad Ghimiray <himal.prasad.ghimi...@intel.com>
>
> This commit adds a new flag, devmem_only, to the drm_gpusvm structure. The
> purpose of this flag is to ensure that the get_pages function allocates
> memory exclusively from the device's memory. If the allocation from
> device memory fails, the function will return an -EFAULT error.
>
> v3:
> - s/vram_only/devmem_only/
>
> Signed-off-by: Matthew Brost <matthew.br...@intel.com>
Reviewed-by: Matthew Brost <matthew.br...@intel.com>
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimi...@intel.com>
> ---
> drivers/gpu/drm/drm_gpusvm.c | 5 +++++
> include/drm/drm_gpusvm.h | 2 ++
> 2 files changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_gpusvm.c b/drivers/gpu/drm/drm_gpusvm.c
> index 38431e8360e7..edf107809d20 100644
> --- a/drivers/gpu/drm/drm_gpusvm.c
> +++ b/drivers/gpu/drm/drm_gpusvm.c
> @@ -1454,6 +1454,11 @@ int drm_gpusvm_range_get_pages(struct drm_gpusvm
> *gpusvm,
> goto err_unmap;
> }
>
> + if (ctx->devmem_only) {
> + err = -EFAULT;
> + goto err_unmap;
> + }
> +
> addr = dma_map_page(gpusvm->drm->dev,
> page, 0,
> PAGE_SIZE << order,
> diff --git a/include/drm/drm_gpusvm.h b/include/drm/drm_gpusvm.h
> index df120b4d1f83..9fd25fc880a4 100644
> --- a/include/drm/drm_gpusvm.h
> +++ b/include/drm/drm_gpusvm.h
> @@ -286,6 +286,7 @@ struct drm_gpusvm {
> * @in_notifier: entering from a MMU notifier
> * @read_only: operating on read-only memory
> * @devmem_possible: possible to use device memory
> + * @devmem_only: use only device memory
> *
> * Context that is DRM GPUSVM is operating in (i.e. user arguments).
> */
> @@ -294,6 +295,7 @@ struct drm_gpusvm_ctx {
> unsigned int in_notifier :1;
> unsigned int read_only :1;
> unsigned int devmem_possible :1;
> + unsigned int devmem_only :1;
> };
>
> int drm_gpusvm_init(struct drm_gpusvm *gpusvm,
> --
> 2.34.1
>
