diff options
| -rw-r--r-- | include/linux/timekeeper_internal.h | 10 | ||||
| -rw-r--r-- | include/uapi/linux/time.h | 11 | ||||
| -rw-r--r-- | kernel/time/Kconfig | 15 |
3 files changed, 32 insertions, 4 deletions
diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index bfcecad0e279..4201ae818f57 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -13,11 +13,17 @@ /** * timekeeper_ids - IDs for various time keepers in the kernel - * @TIMEKEEPER_CORE: The central core timekeeper managing system time - * @TIMEKEEPERS_MAX: The maximum number of timekeepers managed + * @TIMEKEEPER_CORE: The central core timekeeper managing system time + * @TIMEKEEPER_AUX_FIRST: The first AUX timekeeper + * @TIMEKEEPER_AUX_LAST: The last AUX timekeeper + * @TIMEKEEPERS_MAX: The maximum number of timekeepers managed */ enum timekeeper_ids { TIMEKEEPER_CORE, +#ifdef CONFIG_POSIX_AUX_CLOCKS + TIMEKEEPER_AUX_FIRST, + TIMEKEEPER_AUX_LAST = TIMEKEEPER_AUX_FIRST + MAX_AUX_CLOCKS - 1, +#endif TIMEKEEPERS_MAX, }; diff --git a/include/uapi/linux/time.h b/include/uapi/linux/time.h index 4f4b6e48e01c..16ca1ac206fd 100644 --- a/include/uapi/linux/time.h +++ b/include/uapi/linux/time.h @@ -64,6 +64,17 @@ struct timezone { #define CLOCK_TAI 11 #define MAX_CLOCKS 16 + +/* + * AUX clock support. AUXiliary clocks are dynamically configured by + * enabling a clock ID. These clock can be steered independently of the + * core timekeeper. The kernel can support up to 8 auxiliary clocks, but + * the actual limit depends on eventual architecture constraints vs. VDSO. + */ +#define CLOCK_AUX MAX_CLOCKS +#define MAX_AUX_CLOCKS 8 +#define CLOCK_AUX_LAST (CLOCK_AUX + MAX_AUX_CLOCKS - 1) + #define CLOCKS_MASK (CLOCK_REALTIME | CLOCK_MONOTONIC) #define CLOCKS_MONO CLOCK_MONOTONIC diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index b0b97a60aaa6..7c6a52f7836c 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -82,9 +82,9 @@ config CONTEXT_TRACKING_IDLE help Tracks idle state on behalf of RCU. -if GENERIC_CLOCKEVENTS menu "Timers subsystem" +if GENERIC_CLOCKEVENTS # Core internal switch. Selected by NO_HZ_COMMON / HIGH_RES_TIMERS. This is # only related to the tick functionality. Oneshot clockevent devices # are supported independent of this. @@ -208,6 +208,17 @@ config CLOCKSOURCE_WATCHDOG_MAX_SKEW_US interval and NTP's maximum frequency drift of 500 parts per million. If the clocksource is good enough for NTP, it is good enough for the clocksource watchdog! +endif + +config POSIX_AUX_CLOCKS + bool "Enable auxiliary POSIX clocks" + depends on POSIX_TIMERS + help + Auxiliary POSIX clocks are clocks which can be steered + independently of the core timekeeper, which controls the + MONOTONIC, REALTIME, BOOTTIME and TAI clocks. They are useful to + provide e.g. lockless time accessors to independent PTP clocks + and other clock domains, which are not correlated to the TAI/NTP + notion of time. endmenu -endif |