[PATCH v6 07/11] drm/amdgpu: validate userq's last fence prior to destroying

[Prike Liang]

The userq requires validating queue status before destroying
it, if user tries to destroy a busy userq by IOCTL then the
driver should report an error for this illegal usage.

Signed-off-by: Prike Liang <Prike.Liang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
index 81fbb00b6d91..bcbe8d3f66ed 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
@@ -281,7 +281,7 @@ amdgpu_userq_map_helper(struct amdgpu_userq_mgr *uq_mgr,
 	return r;
 }
 
-static void
+static int
 amdgpu_userq_wait_for_last_fence(struct amdgpu_userq_mgr *uq_mgr,
 				 struct amdgpu_usermode_queue *queue)
 {
@@ -290,10 +290,14 @@ amdgpu_userq_wait_for_last_fence(struct amdgpu_userq_mgr *uq_mgr,
 
 	if (f && !dma_fence_is_signaled(f)) {
 		ret = dma_fence_wait_timeout(f, true, msecs_to_jiffies(100));
-		if (ret <= 0)
+		if (ret <= 0) {
 			drm_file_err(uq_mgr->file, "Timed out waiting for fence=%llu:%llu\n",
 				     f->context, f->seqno);
+			return -ETIMEDOUT;
+		}
 	}
+
+	return 0;
 }
 
 static void
@@ -509,7 +513,12 @@ amdgpu_userq_destroy(struct drm_file *filp, int queue_id)
 		mutex_unlock(&uq_mgr->userq_mutex);
 		return -EINVAL;
 	}
-	amdgpu_userq_wait_for_last_fence(uq_mgr, queue);
+
+	if (amdgpu_userq_wait_for_last_fence(uq_mgr, queue)) {
+		drm_warn(adev_to_drm(uq_mgr->adev), "Don't destroy a busy userq\n");
+		/* For the fence signal timeout case, it requires resetting the busy queue.*/
+		r = -ETIMEDOUT;
+	}
 
 	/*
 	 * At this point the userq obj va should be mapped,
-- 
2.34.1