Re: [PATCH v8 04/11] drm/xe/hw_engine_group: Add helper to suspend faulting LR jobs

[Matthew Brost <matthew.brost@intel.com>]

On Thu, Aug 08, 2024 at 08:40:22PM +0200, Francois Dugast wrote:
> This is a required feature for dma fence jobs to preempt faulting long
> running jobs in order to ensure mutual exclusion on a given hw engine
> group.
> 
> v2: Pipeline calls to suspend(q) and suspend_wait(q) to improve
>     efficiency, switch to lockdep_assert_held_write (Matt Brost)
> 
> v3: Return error on suspend_wait failure to propagate on the call stack
>     up to IOCTL (Matt Brost)
> 
> Signed-off-by: Francois Dugast <francois.dugast@intel.com>

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> ---
>  drivers/gpu/drm/xe/xe_hw_engine_group.c | 36 +++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_hw_engine_group.c b/drivers/gpu/drm/xe/xe_hw_engine_group.c
> index b362af7ffab5..8659332012dd 100644
> --- a/drivers/gpu/drm/xe/xe_hw_engine_group.c
> +++ b/drivers/gpu/drm/xe/xe_hw_engine_group.c
> @@ -166,3 +166,39 @@ void xe_hw_engine_group_del_exec_queue(struct xe_hw_engine_group *group, struct
>  
>  	up_write(&group->mode_sem);
>  }
> +
> +/**
> + * xe_hw_engine_group_suspend_faulting_lr_jobs() - Suspend the faulting LR jobs of this group
> + * @group: The hw engine group
> + *
> + * Return: 0 on success, negative error code on error.
> + */
> +static int xe_hw_engine_group_suspend_faulting_lr_jobs(struct xe_hw_engine_group *group)
> +{
> +	int err;
> +	struct xe_exec_queue *q;
> +
> +	lockdep_assert_held_write(&group->mode_sem);
> +
> +	list_for_each_entry(q, &group->exec_queue_list, hw_engine_group_link) {
> +		if (!xe_vm_in_fault_mode(q->vm))
> +			continue;
> +
> +		q->ops->suspend(q);
> +	}
> +
> +	list_for_each_entry(q, &group->exec_queue_list, hw_engine_group_link) {
> +		if (!xe_vm_in_fault_mode(q->vm))
> +			continue;
> +
> +		err = q->ops->suspend_wait(q);
> +		if (err)
> +			goto err_suspend;
> +	}
> +
> +	return 0;
> +
> +err_suspend:
> +	up_write(&group->mode_sem);
> +	return err;
> +}
> -- 
> 2.43.0
>