[PATCH v10 09/10] nouveau/svm: Refactor nouveau_range_fault

From: Alistair Popple
Date: Mon Jun 07 2021 - 03:59:47 EST


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.

Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
Reviewed-by: Ben Skeggs <bskeggs@xxxxxxxxxx>

---

v9:

* Added Ben's Reviewed-By (thanks!)
---
drivers/gpu/drm/nouveau/nouveau_svm.c | 34 ++++++++++++++++-----------
1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index 94f841026c3b..a195e48c9aee 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -567,18 +567,27 @@ static int nouveau_range_fault(struct nouveau_svmm *svmm,
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 nouveau_svmm *svmm,
if (ret) {
if (ret == -EBUSY)
continue;
- return ret;
+ goto out;
}

mutex_lock(&svmm->mutex);
@@ -606,6 +615,9 @@ static int nouveau_range_fault(struct nouveau_svmm *svmm,
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 *notify)
}

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;
--
2.20.1