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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2019-11-20 11:56:07 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2019-11-21 11:03:31 +0100 |
| commit | 92ec07677107974c31b32030a4f897398e452ca9 (patch) | |
| tree | c820e36349d08240f22e3afa6ecf67f761a0c1aa | |
| parent | fedf7a441fe89d17907218f6cd53975a9a929837 (diff) | |
| download | linux-92ec07677107974c31b32030a4f897398e452ca9.tar.bz2 | |
drm/msm: Don't init ww_mutec acquire ctx before needed
For locking semantics it really doesn't matter when we grab the
ticket. But for lockdep validation it does: the acquire ctx is a fake
lockdep. Since other drivers might want to do a full multi-lock dance
in their fault-handler, not just lock a single dma_resv. Therefore we
must init the acquire_ctx only after we've done all the copy_*_user or
anything else that might trigger a pagefault. For msm this means we
need to move it past submit_lookup_objects.
Aside: Why is msm still using struct_mutex, it seems to be using
dma_resv_lock for general buffer state protection?
v2:
- Add comment to explain why the ww ticket setup is separate (Rob)
- Fix up error handling, we need to make sure we don't call
ww_acquire_fini without _init.
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-and-tested-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20191120105607.3023-1-daniel.vetter@ffwll.ch
| -rw-r--r-- | drivers/gpu/drm/msm/msm_gem_submit.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index be5327af16fa..7d04c47d0023 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -54,7 +54,6 @@ static struct msm_gem_submit *submit_create(struct drm_device *dev, INIT_LIST_HEAD(&submit->node); INIT_LIST_HEAD(&submit->bo_list); - ww_acquire_init(&submit->ticket, &reservation_ww_class); return submit; } @@ -390,8 +389,6 @@ static void submit_cleanup(struct msm_gem_submit *submit) list_del_init(&msm_obj->submit_entry); drm_gem_object_put(&msm_obj->base); } - - ww_acquire_fini(&submit->ticket); } int msm_ioctl_gem_submit(struct drm_device *dev, void *data, @@ -408,6 +405,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, struct msm_ringbuffer *ring; int out_fence_fd = -1; struct pid *pid = get_pid(task_pid(current)); + bool has_ww_ticket = false; unsigned i; int ret, submitid; if (!gpu) @@ -489,6 +487,9 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, if (ret) goto out; + /* copy_*_user while holding a ww ticket upsets lockdep */ + ww_acquire_init(&submit->ticket, &reservation_ww_class); + has_ww_ticket = true; ret = submit_lock_objects(submit); if (ret) goto out; @@ -588,6 +589,8 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, out: submit_cleanup(submit); + if (has_ww_ticket) + ww_acquire_fini(&submit->ticket); if (ret) msm_gem_submit_free(submit); out_unlock: |