[Intel-xe] [PATCH V3 4/6] drm/xe: Add timeslice duration engine property to sysfs

[Tejas Upadhyay]

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/gtN/engines/ccs/timeslice_duration_us

V2:
  - Rebase

Signed-off-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
---
 drivers/gpu/drm/xe/xe_gt_sysfs.c | 33 ++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_gt_sysfs.c b/drivers/gpu/drm/xe/xe_gt_sysfs.c
index 4b2ff4f796b4..6ca77c5917cc 100644
--- a/drivers/gpu/drm/xe/xe_gt_sysfs.c
+++ b/drivers/gpu/drm/xe/xe_gt_sysfs.c
@@ -34,6 +34,38 @@ static const struct kobj_type kobj_xe_engine_type = {
 	.sysfs_ops = &kobj_sysfs_ops
 };
 
+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))
+		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 job_timeout_store(struct kobject *kobj,
 				 struct kobj_attribute *attr,
 				 const char *buf, size_t count)
@@ -67,6 +99,7 @@ __ATTR(job_timeout_ms, 0644, job_timeout_show, job_timeout_store);
 
 static const struct attribute *files[] = {
 	&job_timeout_attr.attr,
+	&timeslice_duration_attr.attr,
 	NULL
 };
 
-- 
2.25.1