nouveau/svm: fix missing folio unlock + put after make_device_exclusive_range()

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 <david@redhat.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250124181524.3584236-2-david@redhat.com

diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index b4da82ddbb6b2f180b80bbe258e933b76965a3ec..8ea98f06d39afcb9376e02123dd7f051b96fc229 100644 (file)
--- 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);