[Intel-xe] [PATCH V11 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
hardware engine.

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.

V6:
  - Rebase to use s/xe_engine/xe_hw_engine/ - Matt
V5:
  - Remove timeout validation, not relevant - Niranjana
V4:
  - Rebase to replace hw engine with eclass interface
V3:
  - Rebase to per class engine props interface
V2:
  - Rebase
  - Update commit message to add tile

Reviewed-by: Matthew Brost <matthew.brost at intel.com>
Signed-off-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
---
 drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c | 29 +++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c b/drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c
index 8545f70be013..238275675297 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c
+++ b/drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c
@@ -120,6 +120,34 @@ 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_class_intf *eclass = kobj_to_eclass(kobj);
+	u32 timeout;
+	int err;
+
+	err = kstrtou32(buf, 0, &timeout);
+	if (err)
+		return err;
+
+	WRITE_ONCE(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_class_intf *eclass = kobj_to_eclass(kobj);
+
+	return sprintf(buf, "%u\n", 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)
@@ -142,6 +170,7 @@ 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