Commit 8a9b978e authored by Himal Prasad Ghimiray's avatar Himal Prasad Ghimiray Committed by Matthew Brost
Browse files

drm/gpusvm: Introduce devmem_only flag for allocation 



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.

Required for shared CPU and GPU atomics on certain devices.

v3:
 - s/vram_only/devmem_only/

Fixes: 99624bdf ("drm/gpusvm: Add support for GPU Shared Virtual Memory")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Signed-off-by: default avatarHimal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: default avatarMatthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250512135500.1405019-2-matthew.brost@intel.com
parent e5c13e2c

drivers/gpu/drm/drm_gpusvm.c

+5 −0
Original line number Diff line number Diff line
@@ -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,

include/drm/drm_gpusvm.h

+2 −0
Original line number Diff line number Diff line
@@ -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,