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authorThomas Gleixner <tglx@linutronix.de>2020-02-07 13:38:53 +0100
committerThomas Gleixner <tglx@linutronix.de>2020-02-17 14:40:22 +0100
commit3bd142a46b561a12408e8db78cc6d62eb1c6b84e (patch)
tree66002999edf36c0315a065e9a245acadeb13a5b9
parent25a2a6567829119f5e3e11eb0ce3d8ae985b6019 (diff)
downloadlinux-3bd142a46b561a12408e8db78cc6d62eb1c6b84e.tar.bz2
clocksource: Cleanup struct clocksource and documentation
Reformat the struct definition, add missing member documentation. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124402.825471920@linutronix.de
-rw-r--r--include/linux/clocksource.h87
1 files changed, 47 insertions, 40 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index b21db536fd52..2c4574b517d2 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -32,9 +32,19 @@ struct module;
* Provides mostly state-free accessors to the underlying hardware.
* This is the structure used for system time.
*
- * @name: ptr to clocksource name
- * @list: list head for registration
- * @rating: rating value for selection (higher is better)
+ * @read: Returns a cycle value, passes clocksource as argument
+ * @mask: Bitmask for two's complement
+ * subtraction of non 64 bit counters
+ * @mult: Cycle to nanosecond multiplier
+ * @shift: Cycle to nanosecond divisor (power of two)
+ * @max_idle_ns: Maximum idle time permitted by the clocksource (nsecs)
+ * @maxadj: Maximum adjustment value to mult (~11%)
+ * @archdata: Optional arch-specific data
+ * @max_cycles: Maximum safe cycle value which won't overflow on
+ * multiplication
+ * @name: Pointer to clocksource name
+ * @list: List head for registration (internal)
+ * @rating: Rating value for selection (higher is better)
* To avoid rating inflation the following
* list should give you a guide as to how
* to assign your clocksource a rating
@@ -49,27 +59,23 @@ struct module;
* 400-499: Perfect
* The ideal clocksource. A must-use where
* available.
- * @read: returns a cycle value, passes clocksource as argument
- * @enable: optional function to enable the clocksource
- * @disable: optional function to disable the clocksource
- * @mask: bitmask for two's complement
- * subtraction of non 64 bit counters
- * @mult: cycle to nanosecond multiplier
- * @shift: cycle to nanosecond divisor (power of two)
- * @max_idle_ns: max idle time permitted by the clocksource (nsecs)
- * @maxadj: maximum adjustment value to mult (~11%)
- * @max_cycles: maximum safe cycle value which won't overflow on multiplication
- * @flags: flags describing special properties
- * @archdata: arch-specific data
- * @suspend: suspend function for the clocksource, if necessary
- * @resume: resume function for the clocksource, if necessary
+ * @flags: Flags describing special properties
+ * @enable: Optional function to enable the clocksource
+ * @disable: Optional function to disable the clocksource
+ * @suspend: Optional suspend function for the clocksource
+ * @resume: Optional resume function for the clocksource
* @mark_unstable: Optional function to inform the clocksource driver that
* the watchdog marked the clocksource unstable
- * @owner: module reference, must be set by clocksource in modules
+ * @tick_stable: Optional function called periodically from the watchdog
+ * code to provide stable syncrhonization points
+ * @wd_list: List head to enqueue into the watchdog list (internal)
+ * @cs_last: Last clocksource value for clocksource watchdog
+ * @wd_last: Last watchdog value corresponding to @cs_last
+ * @owner: Module reference, must be set by clocksource in modules
*
* Note: This struct is not used in hotpathes of the timekeeping code
* because the timekeeper caches the hot path fields in its own data
- * structure, so no line cache alignment is required,
+ * structure, so no cache line alignment is required,
*
* The pointer to the clocksource itself is handed to the read
* callback. If you need extra information there you can wrap struct
@@ -78,35 +84,36 @@ struct module;
* structure.
*/
struct clocksource {
- u64 (*read)(struct clocksource *cs);
- u64 mask;
- u32 mult;
- u32 shift;
- u64 max_idle_ns;
- u32 maxadj;
+ u64 (*read)(struct clocksource *cs);
+ u64 mask;
+ u32 mult;
+ u32 shift;
+ u64 max_idle_ns;
+ u32 maxadj;
#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
struct arch_clocksource_data archdata;
#endif
- u64 max_cycles;
- const char *name;
- struct list_head list;
- int rating;
- int (*enable)(struct clocksource *cs);
- void (*disable)(struct clocksource *cs);
- unsigned long flags;
- void (*suspend)(struct clocksource *cs);
- void (*resume)(struct clocksource *cs);
- void (*mark_unstable)(struct clocksource *cs);
- void (*tick_stable)(struct clocksource *cs);
+ u64 max_cycles;
+ const char *name;
+ struct list_head list;
+ int rating;
+ unsigned long flags;
+
+ int (*enable)(struct clocksource *cs);
+ void (*disable)(struct clocksource *cs);
+ void (*suspend)(struct clocksource *cs);
+ void (*resume)(struct clocksource *cs);
+ void (*mark_unstable)(struct clocksource *cs);
+ void (*tick_stable)(struct clocksource *cs);
/* private: */
#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
/* Watchdog related data, used by the framework */
- struct list_head wd_list;
- u64 cs_last;
- u64 wd_last;
+ struct list_head wd_list;
+ u64 cs_last;
+ u64 wd_last;
#endif
- struct module *owner;
+ struct module *owner;
};
/*