Commit 72fa8709 authored by Himal Prasad Ghimiray's avatar Himal Prasad Ghimiray
Browse files

drm/gpusvm: Introduce drm_gpusvm_find_vma_start() function 



The drm_gpusvm_find_vma_start() function is used to determine the starting
address of a CPU VMA within a specified user range. If the range does not
contain any VMA, the function returns ULONG_MAX.

v2
- Rename function as drm_gpusvm_find_vma_start() (Matthew Brost)
- mmget/mmput

v3
- s/mmget/mmget_not_zero/

Reviewed-by: default avatarMatthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250513040228.470682-13-himal.prasad.ghimiray@intel.com


Signed-off-by: default avatarHimal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
parent 6275362f

drivers/gpu/drm/drm_gpusvm.c

+34 −0
Original line number Diff line number Diff line
@@ -980,6 +980,40 @@ static void drm_gpusvm_driver_lock_held(struct drm_gpusvm *gpusvm) 
}

#endif



/**

 * drm_gpusvm_find_vma_start() - Find start address for first VMA in range

 * @gpusvm: Pointer to the GPU SVM structure

 * @start: The inclusive start user address.

 * @end: The exclusive end user address.

 *

 * Returns: The start address of first VMA within the provided range,

 * ULONG_MAX otherwise. Assumes start_addr < end_addr.

 */

unsigned long

drm_gpusvm_find_vma_start(struct drm_gpusvm *gpusvm,

			  unsigned long start,

			  unsigned long end)

{

	struct mm_struct *mm = gpusvm->mm;

	struct vm_area_struct *vma;

	unsigned long addr = ULONG_MAX;



	if (!mmget_not_zero(mm))

		return addr;



	mmap_read_lock(mm);



	vma = find_vma_intersection(mm, start, end);

	if (vma)

		addr =  vma->vm_start;



	mmap_read_unlock(mm);

	mmput(mm);



	return addr;

}

EXPORT_SYMBOL_GPL(drm_gpusvm_find_vma_start);



/**

 * drm_gpusvm_range_find_or_insert() - Find or insert GPU SVM range

 * @gpusvm: Pointer to the GPU SVM structure

include/drm/drm_gpusvm.h

+5 −0
Original line number Diff line number Diff line
@@ -327,6 +327,11 @@ void drm_gpusvm_fini(struct drm_gpusvm *gpusvm); 


void drm_gpusvm_free(struct drm_gpusvm *gpusvm);



unsigned long

drm_gpusvm_find_vma_start(struct drm_gpusvm *gpusvm,

			  unsigned long start,

			  unsigned long end);



struct drm_gpusvm_range *

drm_gpusvm_range_find_or_insert(struct drm_gpusvm *gpusvm,

				unsigned long fault_addr,