From 5fe774eaaef84666dd77a88a6a5c3a7c4c65d676 Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark@chromium.org>
Date: Tue, 27 Jul 2021 18:06:16 -0700
Subject: drm/msm: Drop struct_mutex in submit path
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Git-commit: e3e24ee51ed2c4a5f46b1032b4be1a0a5da90c06
Patch-mainline: v5.15-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

It is sufficient to serialize on the submit queue now.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20210728010632.2633470-12-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/msm/msm_gem_submit.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 9aa6b66c7e65..5040b09edf24 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -707,7 +707,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	struct msm_drm_private *priv = dev->dev_private;
 	struct drm_msm_gem_submit *args = data;
 	struct msm_file_private *ctx = file->driver_priv;
-	struct msm_gem_submit *submit;
+	struct msm_gem_submit *submit = NULL;
 	struct msm_gpu *gpu = priv->gpu;
 	struct msm_gpu_submitqueue *queue;
 	struct msm_ringbuffer *ring;
@@ -751,7 +751,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	trace_msm_gpu_submit(pid_nr(pid), ring->id, submitid,
 		args->nr_bos, args->nr_cmds);
 
-	ret = mutex_lock_interruptible(&dev->struct_mutex);
+	ret = mutex_lock_interruptible(&queue->lock);
 	if (ret)
 		goto out_post_unlock;
 
@@ -872,10 +872,8 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	 * Allocate an id which can be used by WAIT_FENCE ioctl to map back
 	 * to the underlying fence.
 	 */
-	mutex_lock(&queue->lock);
 	submit->fence_id = idr_alloc_cyclic(&queue->fence_idr,
 			submit->user_fence, 0, INT_MAX, GFP_KERNEL);
-	mutex_unlock(&queue->lock);
 	if (submit->fence_id < 0) {
 		ret = submit->fence_id = 0;
 		submit->fence_id = 0;
@@ -910,12 +908,12 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	submit_cleanup(submit, !!ret);
 	if (has_ww_ticket)
 		ww_acquire_fini(&submit->ticket);
-	msm_gem_submit_put(submit);
 out_unlock:
 	if (ret && (out_fence_fd >= 0))
 		put_unused_fd(out_fence_fd);
-	mutex_unlock(&dev->struct_mutex);
-
+	mutex_unlock(&queue->lock);
+	if (submit)
+		msm_gem_submit_put(submit);
 out_post_unlock:
 	if (!IS_ERR_OR_NULL(post_deps)) {
 		for (i = 0; i < args->nr_out_syncobjs; ++i) {
-- 
2.38.1