3 files changed, 24 insertions, 5 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 86d143db6523..1290d0dce840 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -17,6 +17,7 @@
 #include <linux/timer.h>
 #include <linux/init.h>
 #include <linux/of.h>
+#include <linux/clocksource_ids.h>
 #include <asm/div64.h>
 #include <asm/io.h>
 
@@ -62,6 +63,10 @@ struct module;
  *			400-499: Perfect
  *				The ideal clocksource. A must-use where
  *				available.
+ * @id:			Defaults to CSID_GENERIC. The id value is captured
+ *			in certain snapshot functions to allow callers to
+ *			validate the clocksource from which the snapshot was
+ *			taken.
  * @flags:		Flags describing special properties
  * @enable:		Optional function to enable the clocksource
  * @disable:		Optional function to disable the clocksource
@@ -100,6 +105,7 @@ struct clocksource {
 	const char		*name;
 	struct list_head	list;
 	int			rating;
+	enum clocksource_ids	id;
 	enum vdso_clock_mode	vdso_clock_mode;
 	unsigned long		flags;
 
diff --git a/include/linux/clocksource_ids.h b/include/linux/clocksource_ids.h
new file mode 100644
index 000000000000..4d8e19e05328
--- /dev/null
+++ b/include/linux/clocksource_ids.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_CLOCKSOURCE_IDS_H
+#define _LINUX_CLOCKSOURCE_IDS_H
+
+/* Enum to give clocksources a unique identifier */
+enum clocksource_ids {
+	CSID_GENERIC		= 0,
+	CSID_MAX,
+};
+
+#endif
diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index c6792cf01bc7..78a98bdff76d 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -3,6 +3,7 @@
 #define _LINUX_TIMEKEEPING_H
 
 #include <linux/errno.h>
+#include <linux/clocksource_ids.h>
 
 /* Included from linux/ktime.h */
 
@@ -243,11 +244,12 @@ struct ktime_timestamps {
  * @cs_was_changed_seq:	The sequence number of clocksource change events
  */
 struct system_time_snapshot {
-	u64		cycles;
-	ktime_t		real;
-	ktime_t		raw;
-	unsigned int	clock_was_set_seq;
-	u8		cs_was_changed_seq;
+	u64			cycles;
+	ktime_t			real;
+	ktime_t			raw;
+	enum clocksource_ids	cs_id;
+	unsigned int		clock_was_set_seq;
+	u8			cs_was_changed_seq;
 };
 
 /**