[Intel-xe] [PATCH V6 5/6] drm/xe: Add sysfs for preempt reset timeout

[Tejas Upadhyay]

The preemption request and timeout is used for
higher priority context or kill hung context and reset
gpu.

The preempt timeout can be adjusted per-engine class using,

/sys/class/drm/cardX/device/tileN/gtN/engines/ccs/preempt_timeout_us

and can be disabled by setting it to 0.

V3:
  - Rebase to per class engine props interface
V2:
  - Rebase
  - Update commit message to add tile

Signed-off-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
---
 drivers/gpu/drm/xe/xe_engine_class_sysfs.c | 32 ++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_engine_class_sysfs.c b/drivers/gpu/drm/xe/xe_engine_class_sysfs.c
index c9f9b62cfacd..8e0021cdb10d 100644
--- a/drivers/gpu/drm/xe/xe_engine_class_sysfs.c
+++ b/drivers/gpu/drm/xe/xe_engine_class_sysfs.c
@@ -124,6 +124,37 @@ static ssize_t timeslice_default(struct kobject *kobj,
 static struct kobj_attribute timeslice_duration_def =
 __ATTR(timeslice_duration_us, 0444, timeslice_default, NULL);
 
+static ssize_t preempt_timeout_store(struct kobject *kobj,
+				     struct kobj_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct xe_hw_engine *hwe = kobj_to_hwe(kobj);
+	u32 timeout;
+	int err;
+
+	err = kstrtou32(buf, 0, &timeout);
+	if (err)
+		return err;
+
+	if (timeout > jiffies_to_usecs(MAX_SCHEDULE_TIMEOUT))
+		return -EINVAL;
+
+	WRITE_ONCE(hwe->eclass->sched_props.preempt_timeout_us, timeout);
+
+	return count;
+}
+
+static ssize_t preempt_timeout_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->eclass->sched_props.preempt_timeout_us);
+}
+
+static struct kobj_attribute preempt_timeout_attr =
+__ATTR(preempt_timeout_us, 0644, preempt_timeout_show, preempt_timeout_store);
+
 static ssize_t preempt_timeout_default(struct kobject *kobj,
 				       struct kobj_attribute *attr,
 				       char *buf)
@@ -146,6 +177,7 @@ static const struct attribute *defaults[] = {
 static const struct attribute *files[] = {
 	&job_timeout_attr.attr,
 	&timeslice_duration_attr.attr,
+	&preempt_timeout_attr.attr,
 	NULL
 };
 
-- 
2.25.1