Commit 7d08df5d authored by Matthew Brost's avatar Matthew Brost
Browse files

drm/ttm: Add ttm_bo_access 



Non-contiguous VRAM cannot easily be mapped in TTM nor can non-visible
VRAM easily be accessed. Add ttm_bo_access, which is similar to
ttm_bo_vm_access, to access such memory.

v4:
 - Fix checkpatch warnings (CI)
v5:
 - Fix checkpatch warnings (CI)
v6:
 - Fix kernel doc (Auld)
v7:
 - Move ttm_bo_access to ttm_bo_vm.c (Christian)

Cc: Christian König <christian.koenig@amd.com>
Reported-by: default avatarChristoph Manszewski <christoph.manszewski@intel.com>
Suggested-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Tested-by: default avatarMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241126174615.2665852-3-matthew.brost@intel.com
parent f85dc3c5

drivers/gpu/drm/ttm/ttm_bo_vm.c

+32 −8
Original line number Diff line number Diff line
@@ -405,13 +405,25 @@ static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo, 
	return len;

}



int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,

/**

 * ttm_bo_access - Helper to access a buffer object

 *

 * @bo: ttm buffer object

 * @offset: access offset into buffer object

 * @buf: pointer to caller memory to read into or write from

 * @len: length of access

 * @write: write access

 *

 * Utility function to access a buffer object. Useful when buffer object cannot

 * be easily mapped (non-contiguous, non-visible, etc...). Should not directly

 * be exported to user space via a peak / poke interface.

 *

 * Returns:

 * @len if successful, negative error code on failure.

 */

int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset,

		  void *buf, int len, int write)

{

	struct ttm_buffer_object *bo = vma->vm_private_data;

	unsigned long offset = (addr) - vma->vm_start +

		((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))

		 << PAGE_SHIFT);

	int ret;



	if (len < 1 || (offset + len) > bo->base.size)
@@ -429,8 +441,8 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, 
		break;

	default:

		if (bo->bdev->funcs->access_memory)

			ret = bo->bdev->funcs->access_memory(

				bo, offset, buf, len, write);

			ret = bo->bdev->funcs->access_memory

				(bo, offset, buf, len, write);

		else

			ret = -EIO;

	}
@@ -439,6 +451,18 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, 


	return ret;

}

EXPORT_SYMBOL(ttm_bo_access);



int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,

		     void *buf, int len, int write)

{

	struct ttm_buffer_object *bo = vma->vm_private_data;

	unsigned long offset = (addr) - vma->vm_start +

		((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))

		 << PAGE_SHIFT);



	return ttm_bo_access(bo, offset, buf, len, write);

}

EXPORT_SYMBOL(ttm_bo_vm_access);



static const struct vm_operations_struct ttm_bo_vm_ops = {

include/drm/ttm/ttm_bo.h

+2 −0
Original line number Diff line number Diff line
@@ -421,6 +421,8 @@ void ttm_bo_unpin(struct ttm_buffer_object *bo); 
int ttm_bo_evict_first(struct ttm_device *bdev,

		       struct ttm_resource_manager *man,

		       struct ttm_operation_ctx *ctx);

int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset,

		  void *buf, int len, int write);

vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,

			     struct vm_fault *vmf);

vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,