accel/ivpu: Stop job_done_thread on suspend

Stop job_done thread when going to suspend. Use kthread_park() instead
of kthread_stop() to avoid memory allocation and potential failure
on resume.

Use separate function as thread wake up condition. Use spin lock to assure
rx_msg_list is properly protected against concurrent access. This avoid
race condition when the rx_msg_list list is modified and read in
ivpu_ipc_recive() at the same time.

Reviewed-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231028155936.1183342-4-stanislaw.gruszka@linux.intel.com

Author: Stanislaw Gruszka

drivers/accel/ivpu/ivpu_drv.c

@@ -378,6 +378,7 @@ int ivpu_boot(struct ivpu_device *vdev)
 	enable_irq(vdev->irq);
 	ivpu_hw_irq_enable(vdev);
 	ivpu_ipc_enable(vdev);
+	ivpu_job_done_thread_enable(vdev);
 	return 0;
 }
 
@@ -389,6 +390,7 @@ int ivpu_shutdown(struct ivpu_device *vdev)
 	disable_irq(vdev->irq);
 	ivpu_ipc_disable(vdev);
 	ivpu_mmu_disable(vdev);
+	ivpu_job_done_thread_disable(vdev);
 
 	ret = ivpu_hw_power_down(vdev);
 	if (ret)

drivers/accel/ivpu/ivpu_ipc.c

@@ -202,6 +202,20 @@ ivpu_ipc_send(struct ivpu_device *vdev, struct ivpu_ipc_consumer *cons, struct v
 	return ret;
 }
 
+static int ivpu_ipc_rx_need_wakeup(struct ivpu_ipc_consumer *cons)
+{
+	int ret = 0;
+
+	if (IS_KTHREAD())
+		ret |= (kthread_should_stop() || kthread_should_park());
+
+	spin_lock_irq(&cons->rx_msg_lock);
+	ret |= !list_empty(&cons->rx_msg_list);
+	spin_unlock_irq(&cons->rx_msg_lock);
+
+	return ret;
+}
+
 int ivpu_ipc_receive(struct ivpu_device *vdev, struct ivpu_ipc_consumer *cons,
 		     struct ivpu_ipc_hdr *ipc_buf,
 		     struct vpu_jsm_msg *ipc_payload, unsigned long timeout_ms)
@@ -211,8 +225,7 @@ int ivpu_ipc_receive(struct ivpu_device *vdev, struct ivpu_ipc_consumer *cons,
 	int wait_ret, ret = 0;
 
 	wait_ret = wait_event_interruptible_timeout(cons->rx_msg_wq,
-						    (IS_KTHREAD() && kthread_should_stop()) ||
-						    !list_empty(&cons->rx_msg_list),
+						    ivpu_ipc_rx_need_wakeup(cons),
 						    msecs_to_jiffies(timeout_ms));
 
 	if (IS_KTHREAD() && kthread_should_stop())

drivers/accel/ivpu/ivpu_job.c

@@ -590,6 +590,11 @@ static int ivpu_job_done_thread(void *arg)
 				ivpu_pm_schedule_recovery(vdev);
 			}
 		}
+		if (kthread_should_park()) {
+			ivpu_dbg(vdev, JOB, "Parked %s\n", __func__);
+			kthread_parkme();
+			ivpu_dbg(vdev, JOB, "Unparked %s\n", __func__);
+		}
 	}
 
 	ivpu_ipc_consumer_del(vdev, &cons);
@@ -610,16 +615,23 @@ int ivpu_job_done_thread_init(struct ivpu_device *vdev)
 		return -EIO;
 	}
 
-	get_task_struct(thread);
-	wake_up_process(thread);
-
 	vdev->job_done_thread = thread;
 
 	return 0;
 }
 
 void ivpu_job_done_thread_fini(struct ivpu_device *vdev)
 {
+	kthread_unpark(vdev->job_done_thread);
 	kthread_stop(vdev->job_done_thread);
-	put_task_struct(vdev->job_done_thread);
+}
+
+void ivpu_job_done_thread_disable(struct ivpu_device *vdev)
+{
+	kthread_park(vdev->job_done_thread);
+}
+
+void ivpu_job_done_thread_enable(struct ivpu_device *vdev)
+{
+	kthread_unpark(vdev->job_done_thread);
 }

drivers/accel/ivpu/ivpu_job.h

@@ -61,6 +61,8 @@ void ivpu_cmdq_reset_all_contexts(struct ivpu_device *vdev);
 
 int ivpu_job_done_thread_init(struct ivpu_device *vdev);
 void ivpu_job_done_thread_fini(struct ivpu_device *vdev);
+void ivpu_job_done_thread_disable(struct ivpu_device *vdev);
+void ivpu_job_done_thread_enable(struct ivpu_device *vdev);
 
 void ivpu_jobs_abort_all(struct ivpu_device *vdev);