[PATCH AUTOSEL 5.6 077/129] drm/nouveau/svm: check for SVM initialized before migrating

Sasha Levin
2020-04-15T13:05:40Z

From: Ralph Campbell <rcampbell@nvidia.com>

[ Upstream commit 822cab6150d3002952407a8297ff5a0d32bb7b54 ]

When migrating system memory to GPU memory, check that SVM has been
enabled. Even though most errors can be ignored since migration is
a performance optimization, return an error because this is a violation
of the API.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/nouveau/nouveau_svm.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index df9bf1fd1bc0b..3ec5da025bea7 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -171,6 +171,11 @@ nouveau_svmm_bind(struct drm_device *dev, void *data,
mm = get_task_mm(current);
down_read(&mm->mmap_sem);

+ if (!cli->svm.svmm) {
+ up_read(&mm->mmap_sem);
+ return -EINVAL;
+ }
+
for (addr = args->va_start, end = args->va_start + size; addr < end;) {
struct vm_area_struct *vma;
unsigned long next;
--
2.20.1