1 files changed, 55 insertions, 0 deletions
diff --git a/kernel/time/timekeeping_debug.c b/kernel/time/timekeeping_debug.c
new file mode 100644
index 000000000..b73e8850e
--- /dev/null
+++ b/kernel/time/timekeeping_debug.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * debugfs file to track time spent in suspend
+ *
+ * Copyright (c) 2011, Google, Inc.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/seq_file.h>
+#include <linux/suspend.h>
+#include <linux/time.h>
+
+#include "timekeeping_internal.h"
+
+#define NUM_BINS 32
+
+static unsigned int sleep_time_bin[NUM_BINS] = {0};
+
+static int tk_debug_sleep_time_show(struct seq_file *s, void *data)
+{
+	unsigned int bin;
+	seq_puts(s, "      time (secs)        count\n");
+	seq_puts(s, "------------------------------\n");
+	for (bin = 0; bin < 32; bin++) {
+		if (sleep_time_bin[bin] == 0)
+			continue;
+		seq_printf(s, "%10u - %-10u %4u\n",
+			bin ? 1 << (bin - 1) : 0, 1 << bin,
+				sleep_time_bin[bin]);
+	}
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(tk_debug_sleep_time);
+
+static int __init tk_debug_sleep_time_init(void)
+{
+	debugfs_create_file("sleep_time", 0444, NULL, NULL,
+			    &tk_debug_sleep_time_fops);
+	return 0;
+}
+late_initcall(tk_debug_sleep_time_init);
+
+void tk_debug_account_sleep_time(const struct timespec64 *t)
+{
+	/* Cap bin index so we don't overflow the array */
+	int bin = min(fls(t->tv_sec), NUM_BINS-1);
+
+	sleep_time_bin[bin]++;
+	pm_deferred_pr_dbg("Timekeeping suspended for %lld.%03lu seconds\n",
+			   (s64)t->tv_sec, t->tv_nsec / NSEC_PER_MSEC);
+}
+