From: Himal Prasad Ghimiray Date: Mon, 12 May 2025 13:54:55 +0000 (-0700) Subject: drm/gpusvm: Introduce devmem_only flag for allocation X-Git-Tag: v6.15-rc7~11^2^2~6 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7bd68ce21d39150d80806233965326359f517b78;p=thirdparty%2Flinux.git 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: 99624bdff867 ("drm/gpusvm: Add support for GPU Shared Virtual Memory") Cc: stable@vger.kernel.org Signed-off-by: Matthew Brost Signed-off-by: Himal Prasad Ghimiray Reviewed-by: Matthew Brost Link: https://lore.kernel.org/r/20250512135500.1405019-2-matthew.brost@intel.com (cherry picked from commit 8a9b978ebd47df9e0694c34748c2d6fa0c31eb4d) Signed-off-by: Lucas De Marchi --- diff --git a/drivers/gpu/drm/drm_gpusvm.c b/drivers/gpu/drm/drm_gpusvm.c index de424e670995c..a58d03e6cac27 100644 --- a/drivers/gpu/drm/drm_gpusvm.c +++ b/drivers/gpu/drm/drm_gpusvm.c @@ -1454,6 +1454,11 @@ map_pages: 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 df120b4d1f836..9fd25fc880a49 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,