[Intel-xe] [PATCH V5 4/6] drm/xe: Add timeslice duration engine property to sysfs

[Matthew Brost]

On Thu, Jul 20, 2023 at 07:55:08PM +0530, Tejas Upadhyay wrote:
> Timeslices between multiple context is supported via
> guc scheduling. Add sysfs entry to provide user defined
> timeslice duration to guc scheduling.
> 
> The timeslice duration can be adjusted per-engine class using,
> 
> /sys/class/drm/cardX/device/tileN/gtN/engines/ccs/timeslice_duration_us
> 
> V3:
>   - Rebase
>   - Update commit messge to add tile
> V2:
>   - Rebase
> 
> Signed-off-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_engine_class_sysfs.c | 33 ++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_engine_class_sysfs.c b/drivers/gpu/drm/xe/xe_engine_class_sysfs.c
> index 7f4ecef4ef81..7d2688bb5cee 100644
> --- a/drivers/gpu/drm/xe/xe_engine_class_sysfs.c
> +++ b/drivers/gpu/drm/xe/xe_engine_class_sysfs.c
> @@ -81,6 +81,38 @@ static ssize_t job_timeout_default(struct kobject *kobj,
>  static struct kobj_attribute job_timeout_def =
>  __ATTR(job_timeout_ms, 0444, job_timeout_default, NULL);
>  
> +static ssize_t timeslice_duration_store(struct kobject *kobj,
> +					struct kobj_attribute *attr,
> +					const char *buf, size_t count)
> +{
> +	struct xe_hw_engine *hwe = kobj_to_hwe(kobj);
> +	u32 duration;
> +	int err;
> +
> +	err = kstrtou32(buf, 0, &duration);
> +	if (err)
> +		return err;
> +
> +	if (duration > jiffies_to_usecs(MAX_SCHEDULE_TIMEOUT))

MAX_SCHEDULE_TIMEOUT doesn't seem correct here as this a kernel value
and max value for timeslice_us is a GuC interface value. I don't know
what to max is off the top of my head but we need to check with the GuC
team to figure this out.

Matt 

> +		return -EINVAL;
> +
> +	WRITE_ONCE(hwe->sched_props.timeslice_us, duration);
> +
> +	return count;
> +}
> +
> +static ssize_t timeslice_duration_show(struct kobject *kobj,
> +		struct kobj_attribute *attr, char *buf)
> +{
> +	struct xe_hw_engine *hwe = kobj_to_hwe(kobj);
> +
> +	return sprintf(buf, "%u\n", hwe->sched_props.timeslice_us);
> +}
> +
> +static struct kobj_attribute timeslice_duration_attr =
> +	__ATTR(timeslice_duration_us, 0644, timeslice_duration_show, 
> +	       timeslice_duration_store);
> +
>  static ssize_t timeslice_default(struct kobject *kobj,
>  				 struct kobj_attribute *attr, char *buf)
>  {
> @@ -113,6 +145,7 @@ static const struct attribute *defaults[] = {
>  
>  static const struct attribute *files[] = {
>  	&job_timeout_attr.attr,
> +	&timeslice_duration_attr.attr,
>  	NULL
>  };
>  
> -- 
> 2.25.1
>