+ nouveau-svm-refactor-nouveau_range_fault.patch added to -mm tree

[akpm@xxxxxxxxxxxxxxxxxxxx]

The patch titled
     Subject: nouveau/svm: refactor nouveau_range_fault
has been added to the -mm tree.  Its filename is
     nouveau-svm-refactor-nouveau_range_fault.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/nouveau-svm-refactor-nouveau_range_fault.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/nouveau-svm-refactor-nouveau_range_fault.patch

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------------------------------------------------------
From: Alistair Popple <apopple@xxxxxxxxxx>
Subject: nouveau/svm: refactor nouveau_range_fault

Call mmu_interval_notifier_insert() as part of nouveau_range_fault(). 
This doesn't introduce any functional change but makes it easier for a
subsequent patch to alter the behaviour of nouveau_range_fault() to
support GPU atomic operations.

Link: https://lkml.kernel.org/r/20210524132725.12697-10-apopple@xxxxxxxxxx
Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
Reviewed-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
Cc: Balbir Singh <bsingharora@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 drivers/gpu/drm/nouveau/nouveau_svm.c |   34 ++++++++++++++----------
 1 file changed, 20 insertions(+), 14 deletions(-)

--- a/drivers/gpu/drm/nouveau/nouveau_svm.c~nouveau-svm-refactor-nouveau_range_fault
+++ a/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -567,18 +567,27 @@ static int nouveau_range_fault(struct no
 	unsigned long hmm_pfns[1];
 	struct hmm_range range = {
 		.notifier = &notifier->notifier,
-		.start = notifier->notifier.interval_tree.start,
-		.end = notifier->notifier.interval_tree.last + 1,
 		.default_flags = hmm_flags,
 		.hmm_pfns = hmm_pfns,
 		.dev_private_owner = drm->dev,
 	};
-	struct mm_struct *mm = notifier->notifier.mm;
+	struct mm_struct *mm = svmm->notifier.mm;
 	int ret;
 
+	ret = mmu_interval_notifier_insert(&notifier->notifier, mm,
+					args->p.addr, args->p.size,
+					&nouveau_svm_mni_ops);
+	if (ret)
+		return ret;
+
+	range.start = notifier->notifier.interval_tree.start;
+	range.end = notifier->notifier.interval_tree.last + 1;
+
 	while (true) {
-		if (time_after(jiffies, timeout))
-			return -EBUSY;
+		if (time_after(jiffies, timeout)) {
+			ret = -EBUSY;
+			goto out;
+		}
 
 		range.notifier_seq = mmu_interval_read_begin(range.notifier);
 		mmap_read_lock(mm);
@@ -587,7 +596,7 @@ static int nouveau_range_fault(struct no
 		if (ret) {
 			if (ret == -EBUSY)
 				continue;
-			return ret;
+			goto out;
 		}
 
 		mutex_lock(&svmm->mutex);
@@ -606,6 +615,9 @@ static int nouveau_range_fault(struct no
 	svmm->vmm->vmm.object.client->super = false;
 	mutex_unlock(&svmm->mutex);
 
+out:
+	mmu_interval_notifier_remove(&notifier->notifier);
+
 	return ret;
 }
 
@@ -727,14 +739,8 @@ nouveau_svm_fault(struct nvif_notify *no
 		}
 
 		notifier.svmm = svmm;
-		ret = mmu_interval_notifier_insert(&notifier.notifier, mm,
-						   args.i.p.addr, args.i.p.size,
-						   &nouveau_svm_mni_ops);
-		if (!ret) {
-			ret = nouveau_range_fault(svmm, svm->drm, &args.i,
-				sizeof(args), hmm_flags, &notifier);
-			mmu_interval_notifier_remove(&notifier.notifier);
-		}
+		ret = nouveau_range_fault(svmm, svm->drm, &args.i,
+					sizeof(args), hmm_flags, &notifier);
 		mmput(mm);
 
 		limit = args.i.p.addr + args.i.p.size;
_

Patches currently in -mm which might be from apopple@xxxxxxxxxx are

mm-remove-special-swap-entry-functions.patch
mm-swapops-rework-swap-entry-manipulation-code.patch
mm-rmap-split-try_to_munlock-from-try_to_unmap.patch
mm-rmap-split-migration-into-its-own-function.patch
mm-rename-migrate_pgmap_owner.patch
mm-memoryc-allow-different-return-codes-for-copy_nonpresent_pte.patch
mm-device-exclusive-memory-access.patch
mm-selftests-for-exclusive-device-memory.patch
nouveau-svm-refactor-nouveau_range_fault.patch
nouveau-svm-implement-atomic-svm-access.patch