Return to timetc.h CVS log

Up to [local] / sys / sys

Annotation of sys/sys/timetc.h, Revision 1.1

1.1     ! nbrk        1: /*-
        !             2:  * ----------------------------------------------------------------------------
        !             3:  * "THE BEER-WARE LICENSE" (Revision 42):
        !             4:  * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
        !             5:  * can do whatever you want with this stuff. If we meet some day, and you think
        !             6:  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
        !             7:  * ----------------------------------------------------------------------------
        !             8:  *
        !             9:  * $OpenBSD: timetc.h,v 1.2 2006/10/30 20:19:33 otto Exp $
        !            10:  * $FreeBSD: src/sys/sys/timetc.h,v 1.57 2003/04/10 23:07:24 des Exp $
        !            11:  */
        !            12:
        !            13: #ifndef _SYS_TIMETC_H_
        !            14: #define        _SYS_TIMETC_H_
        !            15:
        !            16: #ifndef _KERNEL
        !            17: #error "no user-serviceable parts inside"
        !            18: #endif
        !            19:
        !            20: /*-
        !            21:  * `struct timecounter' is the interface between the hardware which implements
        !            22:  * a timecounter and the MI code which uses this to keep track of time.
        !            23:  *
        !            24:  * A timecounter is a binary counter which has two properties:
        !            25:  *    * it runs at a fixed, known frequency.
        !            26:  *    * it has sufficient bits to not roll over in less than approximately
        !            27:  *      max(2 msec, 2/HZ seconds).  (The value 2 here is really 1 + delta,
        !            28:  *      for some indeterminate value of delta.)
        !            29:  */
        !            30:
        !            31: struct timecounter;
        !            32: typedef u_int timecounter_get_t(struct timecounter *);
        !            33: typedef void timecounter_pps_t(struct timecounter *);
        !            34:
        !            35: struct timecounter {
        !            36:        timecounter_get_t       *tc_get_timecount;
        !            37:                /*
        !            38:                 * This function reads the counter.  It is not required to
        !            39:                 * mask any unimplemented bits out, as long as they are
        !            40:                 * constant.
        !            41:                 */
        !            42:        timecounter_pps_t       *tc_poll_pps;
        !            43:                /*
        !            44:                 * This function is optional.  It will be called whenever the
        !            45:                 * timecounter is rewound, and is intended to check for PPS
        !            46:                 * events.  Normal hardware does not need it but timecounters
        !            47:                 * which latch PPS in hardware (like sys/pci/xrpu.c) do.
        !            48:                 */
        !            49:        u_int                   tc_counter_mask;
        !            50:                /* This mask should mask off any unimplemented bits. */
        !            51:        u_int64_t               tc_frequency;
        !            52:                /* Frequency of the counter in Hz. */
        !            53:        char                    *tc_name;
        !            54:                /* Name of the timecounter. */
        !            55:        int                     tc_quality;
        !            56:                /*
        !            57:                 * Used to determine if this timecounter is better than
        !            58:                 * another timecounter higher means better.  Negative
        !            59:                 * means "only use at explicit request".
        !            60:                 */
        !            61:        void                    *tc_priv;
        !            62:                /* Pointer to the timecounter's private parts. */
        !            63:        struct timecounter      *tc_next;
        !            64:                /* Pointer to the next timecounter. */
        !            65:        int64_t                 tc_freq_adj;
        !            66:                /* Current frequency adjustment. */
        !            67: };
        !            68:
        !            69: extern struct timecounter *timecounter;
        !            70:
        !            71: u_int64_t tc_getfrequency(void);
        !            72: void   tc_init(struct timecounter *tc);
        !            73: void   tc_setclock(struct timespec *ts);
        !            74: void   tc_ticktock(void);
        !            75: void   inittimecounter(void);
        !            76: int    sysctl_tc(int *, u_int, void *, size_t *, void *, size_t);
        !            77: int    tc_adjfreq(int64_t *, int64_t *);
        !            78:
        !            79: #endif /* !_SYS_TIMETC_H_ */