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Diffstat (limited to 'cpukit/include/sys/timetc.h')
| -rw-r--r-- | cpukit/include/sys/timetc.h | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/cpukit/include/sys/timetc.h b/cpukit/include/sys/timetc.h new file mode 100644 index 0000000000..347a140ed9 --- /dev/null +++ b/cpukit/include/sys/timetc.h @@ -0,0 +1,105 @@ +/*- + * ---------------------------------------------------------------------------- + * "THE BEER-WARE LICENSE" (Revision 42): + * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you + * can do whatever you want with this stuff. If we meet some day, and you think + * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp + * ---------------------------------------------------------------------------- + * + * $FreeBSD: head/sys/sys/timetc.h 304285 2016-08-17 09:52:09Z kib $ + */ + +#ifndef _SYS_TIMETC_H_ +#define _SYS_TIMETC_H_ + +#ifndef __rtems__ +#ifndef _KERNEL +#error "no user-serviceable parts inside" +#endif +#endif /* __rtems__ */ + +/*- + * `struct timecounter' is the interface between the hardware which implements + * a timecounter and the MI code which uses this to keep track of time. + * + * A timecounter is a binary counter which has two properties: + * * it runs at a fixed, known frequency. + * * it has sufficient bits to not roll over in less than approximately + * max(2 msec, 2/HZ seconds). (The value 2 here is really 1 + delta, + * for some indeterminate value of delta.) + */ + +struct timecounter; +struct vdso_timehands; +struct vdso_timehands32; +#ifndef __rtems__ +typedef u_int timecounter_get_t(struct timecounter *); +#else /* __rtems__ */ +typedef uint32_t timecounter_get_t(struct timecounter *); +#endif /* __rtems__ */ +typedef void timecounter_pps_t(struct timecounter *); +typedef uint32_t timecounter_fill_vdso_timehands_t(struct vdso_timehands *, + struct timecounter *); +typedef uint32_t timecounter_fill_vdso_timehands32_t(struct vdso_timehands32 *, + struct timecounter *); + +struct timecounter { + timecounter_get_t *tc_get_timecount; + /* + * This function reads the counter. It is not required to + * mask any unimplemented bits out, as long as they are + * constant. + */ + timecounter_pps_t *tc_poll_pps; + /* + * This function is optional. It will be called whenever the + * timecounter is rewound, and is intended to check for PPS + * events. Normal hardware does not need it but timecounters + * which latch PPS in hardware (like sys/pci/xrpu.c) do. + */ + uint32_t tc_counter_mask; + /* This mask should mask off any unimplemented bits. */ + uint64_t tc_frequency; + /* Frequency of the counter in Hz. */ + const char *tc_name; + /* Name of the timecounter. */ + int tc_quality; + /* + * Used to determine if this timecounter is better than + * another timecounter higher means better. Negative + * means "only use at explicit request". + */ + u_int tc_flags; +#define TC_FLAGS_C2STOP 1 /* Timer dies in C2+. */ +#define TC_FLAGS_SUSPEND_SAFE 2 /* + * Timer functional across + * suspend/resume. + */ + + void *tc_priv; + /* Pointer to the timecounter's private parts. */ + struct timecounter *tc_next; + /* Pointer to the next timecounter. */ +#ifndef __rtems__ + timecounter_fill_vdso_timehands_t *tc_fill_vdso_timehands; + timecounter_fill_vdso_timehands32_t *tc_fill_vdso_timehands32; +#endif /* __rtems__ */ +}; + +extern struct timecounter *timecounter; +extern int tc_min_ticktock_freq; /* + * Minimal tc_ticktock() call frequency, + * required to handle counter wraps. + */ + +u_int64_t tc_getfrequency(void); +void tc_init(struct timecounter *tc); +void tc_setclock(struct timespec *ts); +void tc_ticktock(int cnt); +void cpu_tick_calibration(void); + +#ifdef SYSCTL_DECL +SYSCTL_DECL(_kern_timecounter); +#endif + +#endif /* !_SYS_TIMETC_H_ */ |