From 8a6d48c0542876eb3acfc0970c0ab7872db08d5f Mon Sep 17 00:00:00 2001 From: Zheng Da Date: Sun, 6 Dec 2009 05:26:23 +0100 Subject: check in the original version of dde linux26. --- libdde_linux26/contrib/include/linux/clocksource.h | 245 +++++++++++++++++++++ 1 file changed, 245 insertions(+) create mode 100644 libdde_linux26/contrib/include/linux/clocksource.h (limited to 'libdde_linux26/contrib/include/linux/clocksource.h') diff --git a/libdde_linux26/contrib/include/linux/clocksource.h b/libdde_linux26/contrib/include/linux/clocksource.h new file mode 100644 index 00000000..f88d32f8 --- /dev/null +++ b/libdde_linux26/contrib/include/linux/clocksource.h @@ -0,0 +1,245 @@ +/* linux/include/linux/clocksource.h + * + * This file contains the structure definitions for clocksources. + * + * If you are not a clocksource, or timekeeping code, you should + * not be including this file! + */ +#ifndef _LINUX_CLOCKSOURCE_H +#define _LINUX_CLOCKSOURCE_H + +#include +#include +#include +#include +#include +#include +#include +#include + +/* clocksource cycle base type */ +typedef u64 cycle_t; +struct clocksource; + +/** + * struct clocksource - hardware abstraction for a free running counter + * Provides mostly state-free accessors to the underlying hardware. + * + * @name: ptr to clocksource name + * @list: list head for registration + * @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 + * 1-99: Unfit for real use + * Only available for bootup and testing purposes. + * 100-199: Base level usability. + * Functional for real use, but not desired. + * 200-299: Good. + * A correct and usable clocksource. + * 300-399: Desired. + * A reasonably fast and accurate clocksource. + * 400-499: Perfect + * The ideal clocksource. A must-use where + * available. + * @read: returns a cycle value + * @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) + * @shift: cycle to nanosecond divisor (power of two) + * @flags: flags describing special properties + * @vread: vsyscall based read + * @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 { + /* + * First part of structure is read mostly + */ + char *name; + struct list_head list; + int rating; + cycle_t (*read)(void); + cycle_t mask; + u32 mult; + u32 mult_orig; + u32 shift; + unsigned long flags; + cycle_t (*vread)(void); + void (*resume)(void); +#ifdef CONFIG_IA64 + void *fsys_mmio; /* used by fsyscall asm code */ +#define CLKSRC_FSYS_MMIO_SET(mmio, addr) ((mmio) = (addr)) +#else +#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 */ + struct list_head wd_list; + cycle_t wd_last; +#endif +}; + +extern struct clocksource *clock; /* current clocksource */ + +/* + * Clock source flags bits:: + */ +#define CLOCK_SOURCE_IS_CONTINUOUS 0x01 +#define CLOCK_SOURCE_MUST_VERIFY 0x02 + +#define CLOCK_SOURCE_WATCHDOG 0x10 +#define CLOCK_SOURCE_VALID_FOR_HRES 0x20 + +/* simplify initialization of mask field */ +#define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1) + +/** + * clocksource_khz2mult - calculates mult from khz and shift + * @khz: Clocksource frequency in KHz + * @shift_constant: Clocksource shift factor + * + * Helper functions that converts a khz counter frequency to a timsource + * multiplier, given the clocksource shift value + */ +static inline u32 clocksource_khz2mult(u32 khz, u32 shift_constant) +{ + /* khz = cyc/(Million ns) + * mult/2^shift = ns/cyc + * mult = ns/cyc * 2^shift + * mult = 1Million/khz * 2^shift + * mult = 1000000 * 2^shift / khz + * mult = (1000000<read(); +} + +/** + * 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) +{ + u64 ret = (u64)cycles; + ret = (ret * cs->mult) >> cs->shift; + return ret; +} + +/** + * 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) +{ + 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; +} + + +/* 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); + +#ifdef CONFIG_GENERIC_TIME_VSYSCALL +extern void update_vsyscall(struct timespec *ts, struct clocksource *c); +extern void update_vsyscall_tz(void); +#else +static inline void update_vsyscall(struct timespec *ts, struct clocksource *c) +{ +} + +static inline void update_vsyscall_tz(void) +{ +} +#endif + +#endif /* _LINUX_CLOCKSOURCE_H */ -- cgit v1.2.3