From 8fa29272172b5ef42486e4e9c70abd1d619f2605 Mon Sep 17 00:00:00 2001
From: Felix Kuehling <Felix.Kuehling@amd.com>
Date: Tue, 24 Jan 2017 20:44:07 -0500
Subject: [PATCH 1577/4131] drm/amdkfd: Avoid calling resume_mm during process
 termination

When unmap_memory_from_gpu is called during process termination,
don't call resume_mm. It would fail because current->mm is NULL in
a work queue.

Change-Id: I720e4dbb4c3928d894f1e131de626d1c3a9b1ffb
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 097d336..c440419 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1534,10 +1534,13 @@ int amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu(
 unreserve_out:
 	unreserve_bo_and_vms(&ctx, false);
 
-	while (num_to_resume--) {
-		/* Now resume GPU's queues while bo and VMs are unreserved.
-		 * resume_mm() is reference counted, and that is why we can
-		 * call it multiple times.
+	while (current->mm && num_to_resume--) {
+		/* Now resume GPU's queues while bo and VMs are
+		 * unreserved. This function runs in a work queue
+		 * during process termination. Only resume queues if
+		 * we're running in process context. resume_mm() is
+		 * reference counted, and that is why we can call it
+		 * multiple times.
 		 */
 		ret = kgd2kfd->resume_mm(adev->kfd, current->mm);
 		if (ret != 0) {
-- 
2.7.4