mm/hmm: remove hmm_range vma

Since hmm_range_fault() doesn't use the struct hmm_range vma field, remove
it.

Link: https://lore.kernel.org/r/20190726005650.2566-8-rcampbell@nvidia.comSuggested-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/gpu/drm/nouveau/nouveau_svm.c

@@ -496,12 +496,12 @@ nouveau_range_fault(struct hmm_mirror *mirror, struct hmm_range *range)
 				 range->start, range->end,
 				 PAGE_SHIFT);
 	if (ret) {
-		up_read(&range->vma->vm_mm->mmap_sem);
+		up_read(&range->hmm->mm->mmap_sem);
 		return (int)ret;
 	}
 
 	if (!hmm_range_wait_until_valid(range, HMM_RANGE_DEFAULT_TIMEOUT)) {
-		up_read(&range->vma->vm_mm->mmap_sem);
+		up_read(&range->hmm->mm->mmap_sem);
 		return -EBUSY;
 	}
 
@@ -509,7 +509,7 @@ nouveau_range_fault(struct hmm_mirror *mirror, struct hmm_range *range)
 	if (ret <= 0) {
 		if (ret == 0)
 			ret = -EBUSY;
-		up_read(&range->vma->vm_mm->mmap_sem);
+		up_read(&range->hmm->mm->mmap_sem);
 		hmm_range_unregister(range);
 		return ret;
 	}
@@ -682,7 +682,6 @@ nouveau_svm_fault(struct nvif_notify *notify)
 			 args.i.p.addr + args.i.p.size, fn - fi);
 
 		/* Have HMM fault pages within the fault window to the GPU. */
-		range.vma = vma;
 		range.start = args.i.p.addr;
 		range.end = args.i.p.addr + args.i.p.size;
 		range.pfns = args.phys;

include/linux/hmm.h

@@ -164,7 +164,6 @@ enum hmm_pfn_value_e {
  */
 struct hmm_range {
 	struct hmm		*hmm;
-	struct vm_area_struct	*vma;
 	struct list_head	list;
 	unsigned long		start;
 	unsigned long		end;

mm/hmm.c

@@ -1002,7 +1002,6 @@ long hmm_range_fault(struct hmm_range *range, unsigned int flags)
 			return -EPERM;
 		}
 
-		range->vma = vma;
 		hmm_vma_walk.pgmap = NULL;
 		hmm_vma_walk.last = start;
 		hmm_vma_walk.flags = flags;