[PATCH v4 1/2] drm/xe: Add clear_stats GT debugfs

[Matthew Brost <matthew.brost@intel.com>]

It helpful to clear GT stats, run a test cases which is being profiled,
and look at the results of the stats from the individual test case. Add
clear_stats GT debugfs entry whih allows the clearing of GT stats.

v4:
 - Make clear_stats write only permissions (Himal)

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/xe/xe_gt_debugfs.c | 22 ++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_gt_stats.c   | 14 ++++++++++++++
 drivers/gpu/drm/xe/xe_gt_stats.h   |  1 +
 3 files changed, 37 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_gt_debugfs.c b/drivers/gpu/drm/xe/xe_gt_debugfs.c
index bf3a67b5951c..2cd14b36c75a 100644
--- a/drivers/gpu/drm/xe/xe_gt_debugfs.c
+++ b/drivers/gpu/drm/xe/xe_gt_debugfs.c
@@ -363,6 +363,27 @@ static ssize_t write_to_gt_call(const char __user *userbuf, size_t count, loff_t
 	return count;
 }
 
+static void clear_stats(struct xe_gt *gt)
+{
+	xe_gt_stats_clear(gt);
+}
+
+static ssize_t clear_stats_write(struct file *file,
+				 const char __user *userbuf,
+				 size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct xe_gt *gt = s->private;
+
+	return write_to_gt_call(userbuf, count, ppos, clear_stats, gt);
+}
+
+static int clear_stats_show(struct seq_file *s, void *unused)
+{
+	return 0;
+}
+DEFINE_SHOW_STORE_ATTRIBUTE(clear_stats);
+
 static void force_reset(struct xe_gt *gt)
 {
 	struct xe_device *xe = gt_to_xe(gt);
@@ -448,6 +469,7 @@ void xe_gt_debugfs_register(struct xe_gt *gt)
 	root->d_inode->i_private = gt;
 
 	/* VF safe */
+	debugfs_create_file("clear_stats", 0200, root, gt, &clear_stats_fops);
 	debugfs_create_file("force_reset", 0600, root, gt, &force_reset_fops);
 	debugfs_create_file("force_reset_sync", 0600, root, gt, &force_reset_sync_fops);
 
diff --git a/drivers/gpu/drm/xe/xe_gt_stats.c b/drivers/gpu/drm/xe/xe_gt_stats.c
index 30f942671c2b..7e12fc3759e2 100644
--- a/drivers/gpu/drm/xe/xe_gt_stats.c
+++ b/drivers/gpu/drm/xe/xe_gt_stats.c
@@ -50,3 +50,17 @@ int xe_gt_stats_print_info(struct xe_gt *gt, struct drm_printer *p)
 
 	return 0;
 }
+
+/**
+ * xe_gt_stats_clear - Clear the GT stats
+ * @gt: GT structure
+ *
+ * This clear (zeros) all the available GT stats.
+ */
+void xe_gt_stats_clear(struct xe_gt *gt)
+{
+	enum xe_gt_stats_id id;
+
+	for (id = 0; id < __XE_GT_STATS_NUM_IDS; ++id)
+		atomic64_set(&gt->stats.counters[id], 0);
+}
diff --git a/drivers/gpu/drm/xe/xe_gt_stats.h b/drivers/gpu/drm/xe/xe_gt_stats.h
index 38325ef53617..e8aea32bc971 100644
--- a/drivers/gpu/drm/xe/xe_gt_stats.h
+++ b/drivers/gpu/drm/xe/xe_gt_stats.h
@@ -13,6 +13,7 @@ struct drm_printer;
 
 #ifdef CONFIG_DEBUG_FS
 int xe_gt_stats_print_info(struct xe_gt *gt, struct drm_printer *p);
+void xe_gt_stats_clear(struct xe_gt *gt);
 void xe_gt_stats_incr(struct xe_gt *gt, const enum xe_gt_stats_id id, int incr);
 #else
 static inline void
-- 
2.34.1