[PATCH v1 1/2] nouveau/svm: fix missing folio unlock + put after make_device_exclusive_range()

[David Hildenbrand]

In case we have to retry the loop, we are missing to unlock+put the
folio. In that case, we will keep failing make_device_exclusive_range()
because we cannot grab the folio lock, and even return from the function
with the folio locked and referenced, effectively never succeeding the
make_device_exclusive_range().

While at it, convert the other unlock+put to use a folio as well.

This was found by code inspection.

Fixes: 8f187163eb89 ("nouveau/svm: implement atomic SVM access")
Signed-off-by: David Hildenbrand <da...@redhat.com>
---
 drivers/gpu/drm/nouveau/nouveau_svm.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c 
b/drivers/gpu/drm/nouveau/nouveau_svm.c
index b4da82ddbb6b2..8ea98f06d39af 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -590,6 +590,7 @@ static int nouveau_atomic_range_fault(struct nouveau_svmm 
*svmm,
        unsigned long timeout =
                jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
        struct mm_struct *mm = svmm->notifier.mm;
+       struct folio *folio;
        struct page *page;
        unsigned long start = args->p.addr;
        unsigned long notifier_seq;
@@ -616,12 +617,16 @@ static int nouveau_atomic_range_fault(struct nouveau_svmm 
*svmm,
                        ret = -EINVAL;
                        goto out;
                }
+               folio = page_folio(page);
 
                mutex_lock(&svmm->mutex);
                if (!mmu_interval_read_retry(&notifier->notifier,
                                             notifier_seq))
                        break;
                mutex_unlock(&svmm->mutex);
+
+               folio_unlock(folio);
+               folio_put(folio);
        }
 
        /* Map the page on the GPU. */
@@ -637,8 +642,8 @@ static int nouveau_atomic_range_fault(struct nouveau_svmm 
*svmm,
        ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, size, NULL);
        mutex_unlock(&svmm->mutex);
 
-       unlock_page(page);
-       put_page(page);
+       folio_unlock(folio);
+       folio_put(folio);
 
 out:
        mmu_interval_notifier_remove(&notifier->notifier);
-- 
2.47.1