diff options
Diffstat (limited to 'include/linux/clocksource.h')
| -rw-r--r-- | include/linux/clocksource.h | 72 |
1 files changed, 42 insertions, 30 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 65b7c41471c3..283d7297aa79 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -25,14 +25,28 @@ struct clocksource_base; struct clocksource; struct module; -#if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \ - defined(CONFIG_GENERIC_GETTIMEOFDAY) +#if defined(CONFIG_GENERIC_GETTIMEOFDAY) #include <asm/clocksource.h> #endif #include <vdso/clocksource.h> /** + * struct clocksource_hw_snapshot - Snapshot for the underlying hardware counter of derived + * clocksources like kvmclock or Hyper-V scaled TSC + * @hw_cycles: The hardware counter value + * @hw_csid: Clocksource ID of the hardware counter + * + * Such clocksources must implement the read_snapshot() callback and fill in the + * hardware counter value, the clocksource ID of the hardware counter and derive + * the actual clocksource cycles from @hw_cycles to provide an atomic snapshot + */ +struct clocksource_hw_snapshot { + u64 hw_cycles; + enum clocksource_ids hw_csid; +}; + +/** * struct clocksource - hardware abstraction for a free running counter * Provides mostly state-free accessors to the underlying hardware. * This is the structure used for system time. @@ -44,8 +58,6 @@ struct module; * @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%) - * @uncertainty_margin: Maximum uncertainty in nanoseconds per half second. - * Zero says to use default WATCHDOG_THRESHOLD. * @archdata: Optional arch-specific data * @max_cycles: Maximum safe cycle value which won't overflow on * multiplication @@ -75,6 +87,14 @@ struct module; * @flags: Flags describing special properties * @base: Hardware abstraction for clock on which a clocksource * is based + * @read_snapshot: Extended @read() function for clocksources such as + * kvmclock or the Hyper-V scaled TSC where the actual + * clocksource value for timekeeping is calculated from an + * underlying hardware counter. Returns the timekeeping + * relevant cycle value and stores the raw value of the + * underlying counter from which it was calculated + * including the clocksource ID of that counter in the + * clocksource hardware snapshot. * @enable: Optional function to enable the clocksource * @disable: Optional function to disable the clocksource * @suspend: Optional suspend function for the clocksource @@ -105,10 +125,6 @@ struct clocksource { u32 shift; u64 max_idle_ns; u32 maxadj; - u32 uncertainty_margin; -#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA - struct arch_clocksource_data archdata; -#endif u64 max_cycles; u64 max_raw_delta; const char *name; @@ -120,6 +136,7 @@ struct clocksource { unsigned long flags; struct clocksource_base *base; + u64 (*read_snapshot)(struct clocksource *cs, struct clocksource_hw_snapshot *chs); int (*enable)(struct clocksource *cs); void (*disable)(struct clocksource *cs); void (*suspend)(struct clocksource *cs); @@ -133,6 +150,7 @@ struct clocksource { struct list_head wd_list; u64 cs_last; u64 wd_last; + unsigned int wd_cpu; #endif struct module *owner; }; @@ -142,13 +160,19 @@ struct clocksource { */ #define CLOCK_SOURCE_IS_CONTINUOUS 0x01 #define CLOCK_SOURCE_MUST_VERIFY 0x02 +#define CLOCK_SOURCE_CALIBRATED 0x04 #define CLOCK_SOURCE_WATCHDOG 0x10 #define CLOCK_SOURCE_VALID_FOR_HRES 0x20 #define CLOCK_SOURCE_UNSTABLE 0x40 #define CLOCK_SOURCE_SUSPEND_NONSTOP 0x80 #define CLOCK_SOURCE_RESELECT 0x100 -#define CLOCK_SOURCE_VERIFY_PERCPU 0x200 +#define CLOCK_SOURCE_CAN_INLINE_READ 0x200 +#define CLOCK_SOURCE_HAS_COUPLED_CLOCK_EVENT 0x400 + +#define CLOCK_SOURCE_WDTEST 0x800 +#define CLOCK_SOURCE_WDTEST_PERCPU 0x1000 + /* simplify initialization of mask field */ #define CLOCKSOURCE_MASK(bits) GENMASK_ULL((bits) - 1, 0) @@ -236,8 +260,9 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec); */ extern int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq); -extern void -__clocksource_update_freq_scale(struct clocksource *cs, u32 scale, u32 freq); +extern int +__devm_clocksource_register_scale(struct device *dev, struct clocksource *cs, + u32 scale, u32 freq); /* * Don't call this unless you are a default clocksource @@ -258,14 +283,16 @@ static inline int clocksource_register_khz(struct clocksource *cs, u32 khz) return __clocksource_register_scale(cs, 1000, khz); } -static inline void __clocksource_update_freq_hz(struct clocksource *cs, u32 hz) +static inline int devm_clocksource_register_hz(struct device *dev, + struct clocksource *cs, u32 hz) { - __clocksource_update_freq_scale(cs, 1, hz); + return __devm_clocksource_register_scale(dev, cs, 1, hz); } -static inline void __clocksource_update_freq_khz(struct clocksource *cs, u32 khz) +static inline int devm_clocksource_register_khz(struct device *dev, + struct clocksource *cs, u32 khz) { - __clocksource_update_freq_scale(cs, 1000, khz); + return __devm_clocksource_register_scale(dev, cs, 1000, khz); } #ifdef CONFIG_ARCH_CLOCKSOURCE_INIT @@ -298,21 +325,6 @@ static inline void timer_probe(void) {} #define TIMER_ACPI_DECLARE(name, table_id, fn) \ ACPI_DECLARE_PROBE_ENTRY(timer, name, table_id, 0, NULL, 0, fn) -static inline unsigned int clocksource_get_max_watchdog_retry(void) -{ - /* - * When system is in the boot phase or under heavy workload, there - * can be random big latencies during the clocksource/watchdog - * read, so allow retries to filter the noise latency. As the - * latency's frequency and maximum value goes up with the number of - * CPUs, scale the number of retries with the number of online - * CPUs. - */ - return (ilog2(num_online_cpus()) / 2) + 1; -} - -void clocksource_verify_percpu(struct clocksource *cs); - /** * struct clocksource_base - hardware abstraction for clock on which a clocksource * is based |