From: Ralph Campbell <rcampbell@nvidia.com>
Date: Wed, 4 Mar 2020 00:13:37 +0000 (-0800)
Subject: drm/nouveau/svm: check for SVM initialized before migrating
X-Git-Tag: v5.4.35~49
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f3955f1e58bec57ee2176aa81e6521461e977454;p=platform%2Fkernel%2Flinux-rpi.git

drm/nouveau/svm: check for SVM initialized before migrating

[ 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>
---

diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index 668d4bd..25b7055 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -173,6 +173,11 @@ 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;