diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-12-09 09:09:27 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-04-07 18:33:20 +0300 |
| commit | b2c67cbe9f447312f5cdd7c6641b463f2349aec0 (patch) | |
| tree | 3df86da966a25b85da7c84cb893edb2705ccd720 /include/linux/clocksource.h | |
| parent | a8cf291bdac5d415eadb55e79df1fca8c3f0dfef (diff) | |
| download | linux-b2c67cbe9f447312f5cdd7c6641b463f2349aec0.tar.xz | |
time: Add mechanism to recognize clocksource in time_get_snapshot
System time snapshots are not conveying information about the current
clocksource which was used, but callers like the PTP KVM guest
implementation have the requirement to evaluate the clocksource type to
select the appropriate mechanism.
Introduce a clocksource id field in struct clocksource which is by default
set to CSID_GENERIC (0). Clocksource implementations can set that field to
a value which allows to identify the clocksource.
Store the clocksource id of the current clocksource in the
system_time_snapshot so callers can evaluate which clocksource was used to
take the snapshot and act accordingly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201209060932.212364-5-jianyong.wu@arm.com
Diffstat (limited to 'include/linux/clocksource.h')
| -rw-r--r-- | include/linux/clocksource.h | 6 |
1 files changed, 6 insertions, 0 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; |