Commit 4f942aae authored by Oak Zeng's avatar Oak Zeng Committed by Alex Deucher
Browse files

drm/amdkfd: Fix a concurrency issue during kfd recovery 



start_cpsch and stop_cpsch can be called during kfd device
initialization or during gpu reset/recovery. So they can
run concurrently. Currently in start_cpsch and stop_cpsch,
pm_init and pm_uninit is not protected by the dpm lock.
Imagine such a case that user use packet manager's function
to submit a pm4 packet to hang hws (ie through command
cat /sys/class/kfd/kfd/topology/nodes/1/gpu_id | sudo tee
/sys/kernel/debug/kfd/hang_hws), while kfd device is under
device reset/recovery so packet manager can be not initialized.
There will be unpredictable protection fault in such case.

This patch moves pm_init/uninit inside the dpm lock and check
packet manager is initialized before using packet manager
function.

Signed-off-by: default avatarOak Zeng <Oak.Zeng@amd.com>
Acked-by: default avatarChristian Konig <christian.koenig@amd.com>
Reviewed-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 78ccea9f

drivers/gpu/drm/amd/amdkfd/kfd_device.c

+1 −7
Original line number Diff line number Diff line
@@ -1382,18 +1382,12 @@ void kgd2kfd_smi_event_throttle(struct kfd_dev *kfd, uint32_t throttle_bitmask) 
 */

int kfd_debugfs_hang_hws(struct kfd_dev *dev)

{

	int r = 0;



	if (dev->dqm->sched_policy != KFD_SCHED_POLICY_HWS) {

		pr_err("HWS is not enabled");

		return -EINVAL;

	}



	r = pm_debugfs_hang_hws(&dev->dqm->packet_mgr);

	if (!r)

		r = dqm_debugfs_execute_queues(dev->dqm);



	return r;

	return dqm_debugfs_hang_hws(dev->dqm);

}



#endif

drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c

+9 −3
Original line number Diff line number Diff line
@@ -1164,6 +1164,7 @@ static int start_cpsch(struct device_queue_manager *dqm) 


	retval = 0;



	dqm_lock(dqm);

	retval = pm_init(&dqm->packet_mgr, dqm);

	if (retval)

		goto fail_packet_manager_init;
@@ -1186,7 +1187,6 @@ static int start_cpsch(struct device_queue_manager *dqm) 


	init_interrupts(dqm);



	dqm_lock(dqm);

	/* clear hang status when driver try to start the hw scheduler */

	dqm->is_hws_hang = false;

	dqm->is_resetting = false;
@@ -1199,6 +1199,7 @@ static int start_cpsch(struct device_queue_manager *dqm) 
fail_set_sched_resources:

	pm_uninit(&dqm->packet_mgr, false);

fail_packet_manager_init:

	dqm_unlock(dqm);

	return retval;

}
@@ -1211,12 +1212,12 @@ static int stop_cpsch(struct device_queue_manager *dqm) 
		unmap_queues_cpsch(dqm, KFD_UNMAP_QUEUES_FILTER_ALL_QUEUES, 0);

	hanging = dqm->is_hws_hang || dqm->is_resetting;

	dqm->sched_running = false;

	dqm_unlock(dqm);



	pm_release_ib(&dqm->packet_mgr);



	kfd_gtt_sa_free(dqm->dev, dqm->fence_mem);

	pm_uninit(&dqm->packet_mgr, hanging);

	dqm_unlock(dqm);



	return 0;

}
@@ -2099,11 +2100,16 @@ int dqm_debugfs_hqds(struct seq_file *m, void *data) 
	return r;

}



int dqm_debugfs_execute_queues(struct device_queue_manager *dqm)

int dqm_debugfs_hang_hws(struct device_queue_manager *dqm)

{

	int r = 0;



	dqm_lock(dqm);

	r = pm_debugfs_hang_hws(&dqm->packet_mgr);

	if (r) {

		dqm_unlock(dqm);

		return r;

	}

	dqm->active_runlist = true;

	r = execute_queues_cpsch(dqm, KFD_UNMAP_QUEUES_FILTER_ALL_QUEUES, 0);

	dqm_unlock(dqm);

drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c

+3 −0
Original line number Diff line number Diff line
@@ -448,6 +448,9 @@ int pm_debugfs_hang_hws(struct packet_manager *pm) 
	uint32_t *buffer, size;

	int r = 0;



	if (!pm->priv_queue)

		return -EAGAIN;



	size = pm->pmf->query_status_size;

	mutex_lock(&pm->lock);

	kq_acquire_packet_buffer(pm->priv_queue,

drivers/gpu/drm/amd/amdkfd/kfd_priv.h

+1 −1
Original line number Diff line number Diff line
@@ -1194,7 +1194,7 @@ int pm_debugfs_runlist(struct seq_file *m, void *data); 


int kfd_debugfs_hang_hws(struct kfd_dev *dev);

int pm_debugfs_hang_hws(struct packet_manager *pm);

int dqm_debugfs_execute_queues(struct device_queue_manager *dqm);

int dqm_debugfs_hang_hws(struct device_queue_manager *dqm);



#else