[Intel-xe] [PATCH V3 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/gtN/engines/ccs/preempt_timeout_us

and can be disabled by setting it to 0.

Signed-off-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
---
 drivers/gpu/drm/xe/xe_gt_sysfs.c | 44 +++++++++++++++++++++++++++++---
 1 file changed, 40 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_sysfs.c b/drivers/gpu/drm/xe/xe_gt_sysfs.c
index 6ca77c5917cc..4c8f589870ba 100644
--- a/drivers/gpu/drm/xe/xe_gt_sysfs.c
+++ b/drivers/gpu/drm/xe/xe_gt_sysfs.c
@@ -34,6 +34,37 @@ static const struct kobj_type kobj_xe_engine_type = {
 	.sysfs_ops = &kobj_sysfs_ops
 };
 
+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->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->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 timeslice_duration_store(struct kobject *kobj,
 					struct kobj_attribute *attr,
 					const char *buf, size_t count)
@@ -100,6 +131,7 @@ __ATTR(job_timeout_ms, 0644, job_timeout_show, job_timeout_store);
 static const struct attribute *files[] = {
 	&job_timeout_attr.attr,
 	&timeslice_duration_attr.attr,
+	&preempt_timeout_attr.attr,
 	NULL
 };
 
@@ -261,10 +293,14 @@ int xe_gt_sysfs_engines(struct xe_gt *gt)
 		}
 
 		err = sysfs_create_files(&khwe->base, files);
-		if (err) {
-			kobject_put(kobj);
-			return err;
-		}
+		if (err)
+			goto err_object;
+	}
+
+	if (0) {
+err_object:
+		kobject_put(kobj);
+		return err;
 	}
 
 	return err;
-- 
2.25.1