From 44c200876a45429473ff683bd491ccf3a73eb915 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Mon, 20 Mar 2023 07:43:33 -0700 Subject: [PATCH] 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: Rob Clark Patchwork: https://patchwork.freedesktop.org/patch/527847/ Link: https://lore.kernel.org/r/20230320144356.803762-12-robdclark@gmail.com --- drivers/gpu/drm/msm/msm_gem_submit.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index 513c5d5..89375c2 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -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; -- 2.7.4