[PATCH v2 10/23] drm/msm: Switch idr_lock to spinlock

[Rob Clark]

From: Rob Clark <robdclark at chromium.org>

Needed to idr_preload() which returns with preemption disabled.

Signed-off-by: Rob Clark <robdclark at chromium.org>
---
 drivers/gpu/drm/msm/msm_drv.c         |  6 ++----
 drivers/gpu/drm/msm/msm_gem_submit.c  | 10 +++++-----
 drivers/gpu/drm/msm/msm_gpu.h         |  2 +-
 drivers/gpu/drm/msm/msm_submitqueue.c |  2 +-
 4 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index aca48c868c14..ce1a77b607d1 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -918,13 +918,11 @@ static int wait_fence(struct msm_gpu_submitqueue *queue, uint32_t fence_id,
 	 * retired, so if the fence is not found it means there is nothing
 	 * to wait for
 	 */
-	ret = mutex_lock_interruptible(&queue->idr_lock);
-	if (ret)
-		return ret;
+	spin_lock(&queue->idr_lock);
 	fence = idr_find(&queue->fence_idr, fence_id);
 	if (fence)
 		fence = dma_fence_get_rcu(fence);
-	mutex_unlock(&queue->idr_lock);
+	spin_unlock(&queue->idr_lock);
 
 	if (!fence)
 		return 0;
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 1d8e7c2a8024..b9d81e5acb42 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -79,9 +79,9 @@ void __msm_gem_submit_destroy(struct kref *kref)
 	unsigned i;
 
 	if (submit->fence_id) {
-		mutex_lock(&submit->queue->idr_lock);
+		spin_lock(&submit->queue->idr_lock);
 		idr_remove(&submit->queue->fence_idr, submit->fence_id);
-		mutex_unlock(&submit->queue->idr_lock);
+		spin_unlock(&submit->queue->idr_lock);
 	}
 
 	dma_fence_put(submit->user_fence);
@@ -882,7 +882,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 
 	submit->nr_cmds = i;
 
-	mutex_lock(&queue->idr_lock);
+	spin_lock(&queue->idr_lock);
 
 	/*
 	 * If using userspace provided seqno fence, validate that the id
@@ -892,7 +892,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	 */
 	if ((args->flags & MSM_SUBMIT_FENCE_SN_IN) &&
 			idr_find(&queue->fence_idr, args->fence)) {
-		mutex_unlock(&queue->idr_lock);
+		spin_unlock(&queue->idr_lock);
 		ret = -EINVAL;
 		goto out;
 	}
@@ -926,7 +926,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 						    INT_MAX, GFP_KERNEL);
 	}
 
-	mutex_unlock(&queue->idr_lock);
+	spin_unlock(&queue->idr_lock);
 
 	if (submit->fence_id < 0) {
 		ret = submit->fence_id;
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index fc1c0d8611a8..5929ecaa1fcd 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -499,7 +499,7 @@ struct msm_gpu_submitqueue {
 	struct msm_file_private *ctx;
 	struct list_head node;
 	struct idr fence_idr;
-	struct mutex idr_lock;
+	struct spinlock idr_lock;
 	struct mutex lock;
 	struct kref ref;
 	struct drm_sched_entity *entity;
diff --git a/drivers/gpu/drm/msm/msm_submitqueue.c b/drivers/gpu/drm/msm/msm_submitqueue.c
index c6929e205b51..0e803125a325 100644
--- a/drivers/gpu/drm/msm/msm_submitqueue.c
+++ b/drivers/gpu/drm/msm/msm_submitqueue.c
@@ -200,7 +200,7 @@ int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
 		*id = queue->id;
 
 	idr_init(&queue->fence_idr);
-	mutex_init(&queue->idr_lock);
+	spin_lock_init(&queue->idr_lock);
 	mutex_init(&queue->lock);
 
 	list_add_tail(&queue->node, &ctx->submitqueues);
-- 
2.39.2