accel/ivpu: Fix locking order in ivpu_job_submit

Fix deadlock in job submission and abort handling.
When a thread aborts currently executing jobs due to a fault,
it first locks the global lock protecting submitted_jobs (#1).

After the last job is destroyed, it proceeds to release the related context
and locks file_priv (#2). Meanwhile, in the job submission thread,
the file_priv lock (#2) is taken first, and then the submitted_jobs
lock (#1) is obtained when a job is added to the submitted jobs list.

       CPU0                            CPU1
       ----                    	       ----
  (for example due to a fault)         (jobs submissions keep coming)

  lock(&vdev->submitted_jobs_lock) #1
  ivpu_jobs_abort_all()
  job_destroy()
                                      lock(&file_priv->lock)           #2
                                      lock(&vdev->submitted_jobs_lock) #1
  file_priv_release()
  lock(&vdev->context_list_lock)
  lock(&file_priv->lock)           #2

This order of locking causes a deadlock. To resolve this issue,
change the order of locking in ivpu_job_submit().

Signed-off-by: Karol Wachowski <karol.wachowski@intel.com>
Signed-off-by: Maciej Falkowski <maciej.falkowski@linux.intel.com>
Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250107173238.381120-12-maciej.falkowski@linux.intel.com

diff --git a/drivers/accel/ivpu/ivpu_job.c b/drivers/accel/ivpu/ivpu_job.c
index c694822..c93ea37 100644 (file)
--- a/drivers/accel/ivpu/ivpu_job.c
+++ b/drivers/accel/ivpu/ivpu_job.c
@@ -597,6 +597,7 @@ static int ivpu_job_submit(struct ivpu_job *job, u8 priority, u32 cmdq_id)
        if (ret < 0)
                return ret;
 
+       mutex_lock(&vdev->submitted_jobs_lock);
        mutex_lock(&file_priv->lock);
 
        if (cmdq_id == 0)
@@ -606,19 +607,17 @@ static int ivpu_job_submit(struct ivpu_job *job, u8 priority, u32 cmdq_id)
        if (!cmdq) {
                ivpu_warn_ratelimited(vdev, "Failed to get job queue, ctx %d\n", file_priv->ctx.id);
                ret = -EINVAL;
-               goto err_unlock_file_priv;
+               goto err_unlock;
        }
 
        ret = ivpu_cmdq_register(file_priv, cmdq);
        if (ret) {
                ivpu_err(vdev, "Failed to register command queue: %d\n", ret);
-               goto err_unlock_file_priv;
+               goto err_unlock;
        }
 
        job->cmdq_id = cmdq->id;
 
-       mutex_lock(&vdev->submitted_jobs_lock);
-
        is_first_job = xa_empty(&vdev->submitted_jobs_xa);
        ret = xa_alloc_cyclic(&vdev->submitted_jobs_xa, &job->job_id, job, file_priv->job_limit,
                              &file_priv->job_id_next, GFP_KERNEL);
@@ -626,7 +625,7 @@ static int ivpu_job_submit(struct ivpu_job *job, u8 priority, u32 cmdq_id)
                ivpu_dbg(vdev, JOB, "Too many active jobs in ctx %d\n",
                         file_priv->ctx.id);
                ret = -EBUSY;
-               goto err_unlock_submitted_jobs;
+               goto err_unlock;
        }
 
        ret = ivpu_cmdq_push_job(cmdq, job);
@@ -649,22 +648,20 @@ static int ivpu_job_submit(struct ivpu_job *job, u8 priority, u32 cmdq_id)
                 job->job_id, file_priv->ctx.id, job->engine_idx, cmdq->priority,
                 job->cmd_buf_vpu_addr, cmdq->jobq->header.tail);
 
-       mutex_unlock(&vdev->submitted_jobs_lock);
        mutex_unlock(&file_priv->lock);
 
        if (unlikely(ivpu_test_mode & IVPU_TEST_MODE_NULL_HW)) {
-               mutex_lock(&vdev->submitted_jobs_lock);
                ivpu_job_signal_and_destroy(vdev, job->job_id, VPU_JSM_STATUS_SUCCESS);
-               mutex_unlock(&vdev->submitted_jobs_lock);
        }
 
+       mutex_unlock(&vdev->submitted_jobs_lock);
+
        return 0;
 
 err_erase_xa:
        xa_erase(&vdev->submitted_jobs_xa, job->job_id);
-err_unlock_submitted_jobs:
+err_unlock:
        mutex_unlock(&vdev->submitted_jobs_lock);
-err_unlock_file_priv:
        mutex_unlock(&file_priv->lock);
        ivpu_rpm_put(vdev);
        return ret;