Commit 44c20087 authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm: Use idr_preload() 



Avoid allocation under idr_lock, to prevent deadlock against the
job_free() path (which runs on same thread as job_run(), which makes
it also part of the fence-signaling path.

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/527847/
Link: https://lore.kernel.org/r/20230320144356.803762-12-robdclark@gmail.com
parent e4f020c6

drivers/gpu/drm/msm/msm_gem_submit.c

+6 −2
Original line number Diff line number Diff line
@@ -882,6 +882,8 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, 


	submit->nr_cmds = i;



	idr_preload(GFP_KERNEL);



	spin_lock(&queue->idr_lock);



	/*
@@ -893,6 +895,7 @@ 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)) {

		spin_unlock(&queue->idr_lock);

		idr_preload_end();

		ret = -EINVAL;

		goto out;

	}
@@ -910,7 +913,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, 
		submit->fence_id = args->fence;

		ret = idr_alloc_u32(&queue->fence_idr, submit->user_fence,

				    &submit->fence_id, submit->fence_id,

				    GFP_KERNEL);

				    GFP_NOWAIT);

		/*

		 * We've already validated that the fence_id slot is valid,

		 * so if idr_alloc_u32 failed, it is a kernel bug
@@ -923,10 +926,11 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, 
		 */

		submit->fence_id = idr_alloc_cyclic(&queue->fence_idr,

						    submit->user_fence, 1,

						    INT_MAX, GFP_KERNEL);

						    INT_MAX, GFP_NOWAIT);

	}



	spin_unlock(&queue->idr_lock);

	idr_preload_end();



	if (submit->fence_id < 0) {

		ret = submit->fence_id;