diff options
Diffstat (limited to 'include/linux/clocksource.h')
| -rw-r--r-- | include/linux/clocksource.h | 155 |
1 files changed, 57 insertions, 98 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index c56457c8334e..c37b21ad5a3b 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -14,6 +14,7 @@ #include <linux/list.h> #include <linux/cache.h> #include <linux/timer.h> +#include <linux/init.h> #include <asm/div64.h> #include <asm/io.h> @@ -148,14 +149,13 @@ extern u64 timecounter_cyc2time(struct timecounter *tc, * @disable: optional function to disable the clocksource * @mask: bitmask for two's complement * subtraction of non 64 bit counters - * @mult: cycle to nanosecond multiplier (adjusted by NTP) - * @mult_orig: cycle to nanosecond multiplier (unadjusted by NTP) + * @mult: cycle to nanosecond multiplier * @shift: cycle to nanosecond divisor (power of two) + * @max_idle_ns: max idle time permitted by the clocksource (nsecs) * @flags: flags describing special properties * @vread: vsyscall based read + * @suspend: suspend function for the clocksource, if necessary * @resume: resume function for the clocksource, if necessary - * @cycle_interval: Used internally by timekeeping core, please ignore. - * @xtime_interval: Used internally by timekeeping core, please ignore. */ struct clocksource { /* @@ -169,11 +169,12 @@ struct clocksource { void (*disable)(struct clocksource *cs); cycle_t mask; u32 mult; - u32 mult_orig; u32 shift; + u64 max_idle_ns; unsigned long flags; cycle_t (*vread)(void); - void (*resume)(void); + void (*suspend)(struct clocksource *cs); + void (*resume)(struct clocksource *cs); #ifdef CONFIG_IA64 void *fsys_mmio; /* used by fsyscall asm code */ #define CLKSRC_FSYS_MMIO_SET(mmio, addr) ((mmio) = (addr)) @@ -181,19 +182,12 @@ struct clocksource { #define CLKSRC_FSYS_MMIO_SET(mmio, addr) do { } while (0) #endif - /* timekeeping specific data, ignore */ - cycle_t cycle_interval; - u64 xtime_interval; - u32 raw_interval; /* * Second part is written at each timer interrupt * Keep it in a different cache line to dirty no * more than one cache line. */ cycle_t cycle_last ____cacheline_aligned_in_smp; - u64 xtime_nsec; - s64 error; - struct timespec raw_time; #ifdef CONFIG_CLOCKSOURCE_WATCHDOG /* Watchdog related data, used by the framework */ @@ -202,8 +196,6 @@ struct clocksource { #endif }; -extern struct clocksource *clock; /* current clocksource */ - /* * Clock source flags bits:: */ @@ -212,6 +204,7 @@ extern struct clocksource *clock; /* current clocksource */ #define CLOCK_SOURCE_WATCHDOG 0x10 #define CLOCK_SOURCE_VALID_FOR_HRES 0x20 +#define CLOCK_SOURCE_UNSTABLE 0x40 /* simplify initialization of mask field */ #define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1) @@ -268,112 +261,76 @@ static inline u32 clocksource_hz2mult(u32 hz, u32 shift_constant) } /** - * clocksource_read: - Access the clocksource's current cycle value - * @cs: pointer to clocksource being read + * clocksource_cyc2ns - converts clocksource cycles to nanoseconds * - * Uses the clocksource to return the current cycle_t value - */ -static inline cycle_t clocksource_read(struct clocksource *cs) -{ - return cs->read(cs); -} - -/** - * clocksource_enable: - enable clocksource - * @cs: pointer to clocksource + * Converts cycles to nanoseconds, using the given mult and shift. * - * Enables the specified clocksource. The clocksource callback - * function should start up the hardware and setup mult and field - * members of struct clocksource to reflect hardware capabilities. + * XXX - This could use some mult_lxl_ll() asm optimization */ -static inline int clocksource_enable(struct clocksource *cs) +static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift) { - int ret = 0; + return ((u64) cycles * mult) >> shift; +} - if (cs->enable) - ret = cs->enable(cs); - /* save mult_orig on enable */ - cs->mult_orig = cs->mult; +extern int clocksource_register(struct clocksource*); +extern void clocksource_unregister(struct clocksource*); +extern void clocksource_touch_watchdog(void); +extern struct clocksource* clocksource_get_next(void); +extern void clocksource_change_rating(struct clocksource *cs, int rating); +extern void clocksource_suspend(void); +extern void clocksource_resume(void); +extern struct clocksource * __init __weak clocksource_default_clock(void); +extern void clocksource_mark_unstable(struct clocksource *cs); - return ret; -} +extern void +clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec); -/** - * clocksource_disable: - disable clocksource - * @cs: pointer to clocksource - * - * Disables the specified clocksource. The clocksource callback - * function should power down the now unused hardware block to - * save power. +/* + * Don't call __clocksource_register_scale directly, use + * clocksource_register_hz/khz */ -static inline void clocksource_disable(struct clocksource *cs) +extern int +__clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq); +extern void +__clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq); + +static inline int clocksource_register_hz(struct clocksource *cs, u32 hz) { - if (cs->disable) - cs->disable(cs); + return __clocksource_register_scale(cs, 1, hz); } -/** - * cyc2ns - converts clocksource cycles to nanoseconds - * @cs: Pointer to clocksource - * @cycles: Cycles - * - * Uses the clocksource and ntp ajdustment to convert cycle_ts to nanoseconds. - * - * XXX - This could use some mult_lxl_ll() asm optimization - */ -static inline s64 cyc2ns(struct clocksource *cs, cycle_t cycles) +static inline int clocksource_register_khz(struct clocksource *cs, u32 khz) { - u64 ret = (u64)cycles; - ret = (ret * cs->mult) >> cs->shift; - return ret; + return __clocksource_register_scale(cs, 1000, khz); } -/** - * clocksource_calculate_interval - Calculates a clocksource interval struct - * - * @c: Pointer to clocksource. - * @length_nsec: Desired interval length in nanoseconds. - * - * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment - * pair and interval request. - * - * Unless you're the timekeeping code, you should not be using this! - */ -static inline void clocksource_calculate_interval(struct clocksource *c, - unsigned long length_nsec) +static inline void __clocksource_updatefreq_hz(struct clocksource *cs, u32 hz) { - u64 tmp; - - /* Do the ns -> cycle conversion first, using original mult */ - tmp = length_nsec; - tmp <<= c->shift; - tmp += c->mult_orig/2; - do_div(tmp, c->mult_orig); - - c->cycle_interval = (cycle_t)tmp; - if (c->cycle_interval == 0) - c->cycle_interval = 1; - - /* Go back from cycles -> shifted ns, this time use ntp adjused mult */ - c->xtime_interval = (u64)c->cycle_interval * c->mult; - c->raw_interval = ((u64)c->cycle_interval * c->mult_orig) >> c->shift; + __clocksource_updatefreq_scale(cs, 1, hz); } +static inline void __clocksource_updatefreq_khz(struct clocksource *cs, u32 khz) +{ + __clocksource_updatefreq_scale(cs, 1000, khz); +} -/* used to install a new clocksource */ -extern int clocksource_register(struct clocksource*); -extern void clocksource_unregister(struct clocksource*); -extern void clocksource_touch_watchdog(void); -extern struct clocksource* clocksource_get_next(void); -extern void clocksource_change_rating(struct clocksource *cs, int rating); -extern void clocksource_resume(void); +static inline void +clocksource_calc_mult_shift(struct clocksource *cs, u32 freq, u32 minsec) +{ + return clocks_calc_mult_shift(&cs->mult, &cs->shift, freq, + NSEC_PER_SEC, minsec); +} #ifdef CONFIG_GENERIC_TIME_VSYSCALL -extern void update_vsyscall(struct timespec *ts, struct clocksource *c); +extern void +update_vsyscall(struct timespec *ts, struct timespec *wtm, + struct clocksource *c, u32 mult); extern void update_vsyscall_tz(void); #else -static inline void update_vsyscall(struct timespec *ts, struct clocksource *c) +static inline void +update_vsyscall(struct timespec *ts, struct timespec *wtm, + struct clocksource *c, u32 mult) { } @@ -382,4 +339,6 @@ static inline void update_vsyscall_tz(void) } #endif +extern void timekeeping_notify(struct clocksource *clock); + #endif /* _LINUX_CLOCKSOURCE_H */ |