mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 19:00:25 +00:00
![John Stultz](/assets/img/avatar_default.png)
This patch exposes alarm-timers to userland via the posix clock and timers interface, using two new clockids: CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM. Both clockids behave identically to CLOCK_REALTIME and CLOCK_BOOTTIME, respectively, but timers set against the _ALARM suffixed clockids will wake the system if it is suspended. Some background can be found here: https://lwn.net/Articles/429925/ The concept for Alarm-timers was inspired by the Android Alarm driver (by Arve Hjønnevåg) found in the Android kernel tree. See: http://android.git.kernel.org/?p=kernel/common.git;a=blob;f=drivers/rtc/alarm.c;h=1250edfbdf3302f5e4ea6194847c6ef4bb7beb1c;hb=android-2.6.36 While the in-kernel interface is pretty similar between alarm-timers and Android alarm driver, the user-space interface for the Android alarm driver is via ioctls to a new char device. As mentioned above, I've instead chosen to export this functionality via the posix interface, as it seemed a little simpler and avoids creating duplicate interfaces to things like CLOCK_REALTIME and CLOCK_MONOTONIC under alternate names (ie:ANDROID_ALARM_RTC and ANDROID_ALARM_SYSTEMTIME). The semantics of the Android alarm driver are different from what this posix interface provides. For instance, threads other then the thread waiting on the Android alarm driver are able to modify the alarm being waited on. Also this interface does not allow the same wakelock semantics that the Android driver provides (ie: kernel takes a wakelock on RTC alarm-interupt, and holds it through process wakeup, and while the process runs, until the process either closes the char device or calls back in to wait on a new alarm). One potential way to implement similar semantics may be via the timerfd infrastructure, but this needs more research. There may also need to be some sort of sysfs system level policy hooks that allow alarm timers to be disabled to keep them from firing at inappropriate times (ie: laptop in a well insulated bag, mid-flight). CC: Arve Hjønnevåg <arve@android.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
314 lines
9.1 KiB
C
314 lines
9.1 KiB
C
#ifndef _LINUX_TIME_H
|
|
#define _LINUX_TIME_H
|
|
|
|
#include <linux/types.h>
|
|
|
|
#ifdef __KERNEL__
|
|
# include <linux/cache.h>
|
|
# include <linux/seqlock.h>
|
|
# include <linux/math64.h>
|
|
#endif
|
|
|
|
#ifndef _STRUCT_TIMESPEC
|
|
#define _STRUCT_TIMESPEC
|
|
struct timespec {
|
|
__kernel_time_t tv_sec; /* seconds */
|
|
long tv_nsec; /* nanoseconds */
|
|
};
|
|
#endif
|
|
|
|
struct timeval {
|
|
__kernel_time_t tv_sec; /* seconds */
|
|
__kernel_suseconds_t tv_usec; /* microseconds */
|
|
};
|
|
|
|
struct timezone {
|
|
int tz_minuteswest; /* minutes west of Greenwich */
|
|
int tz_dsttime; /* type of dst correction */
|
|
};
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
extern struct timezone sys_tz;
|
|
|
|
/* Parameters used to convert the timespec values: */
|
|
#define MSEC_PER_SEC 1000L
|
|
#define USEC_PER_MSEC 1000L
|
|
#define NSEC_PER_USEC 1000L
|
|
#define NSEC_PER_MSEC 1000000L
|
|
#define USEC_PER_SEC 1000000L
|
|
#define NSEC_PER_SEC 1000000000L
|
|
#define FSEC_PER_SEC 1000000000000000LL
|
|
|
|
#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
|
|
|
|
static inline int timespec_equal(const struct timespec *a,
|
|
const struct timespec *b)
|
|
{
|
|
return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
|
|
}
|
|
|
|
/*
|
|
* lhs < rhs: return <0
|
|
* lhs == rhs: return 0
|
|
* lhs > rhs: return >0
|
|
*/
|
|
static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
|
|
{
|
|
if (lhs->tv_sec < rhs->tv_sec)
|
|
return -1;
|
|
if (lhs->tv_sec > rhs->tv_sec)
|
|
return 1;
|
|
return lhs->tv_nsec - rhs->tv_nsec;
|
|
}
|
|
|
|
static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
|
|
{
|
|
if (lhs->tv_sec < rhs->tv_sec)
|
|
return -1;
|
|
if (lhs->tv_sec > rhs->tv_sec)
|
|
return 1;
|
|
return lhs->tv_usec - rhs->tv_usec;
|
|
}
|
|
|
|
extern unsigned long mktime(const unsigned int year, const unsigned int mon,
|
|
const unsigned int day, const unsigned int hour,
|
|
const unsigned int min, const unsigned int sec);
|
|
|
|
extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
|
|
|
|
/*
|
|
* timespec_add_safe assumes both values are positive and checks
|
|
* for overflow. It will return TIME_T_MAX if the reutrn would be
|
|
* smaller then either of the arguments.
|
|
*/
|
|
extern struct timespec timespec_add_safe(const struct timespec lhs,
|
|
const struct timespec rhs);
|
|
|
|
|
|
static inline struct timespec timespec_add(struct timespec lhs,
|
|
struct timespec rhs)
|
|
{
|
|
struct timespec ts_delta;
|
|
set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
|
|
lhs.tv_nsec + rhs.tv_nsec);
|
|
return ts_delta;
|
|
}
|
|
|
|
/*
|
|
* sub = lhs - rhs, in normalized form
|
|
*/
|
|
static inline struct timespec timespec_sub(struct timespec lhs,
|
|
struct timespec rhs)
|
|
{
|
|
struct timespec ts_delta;
|
|
set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
|
|
lhs.tv_nsec - rhs.tv_nsec);
|
|
return ts_delta;
|
|
}
|
|
|
|
/*
|
|
* Returns true if the timespec is norm, false if denorm:
|
|
*/
|
|
#define timespec_valid(ts) \
|
|
(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
|
|
|
|
extern void read_persistent_clock(struct timespec *ts);
|
|
extern void read_boot_clock(struct timespec *ts);
|
|
extern int update_persistent_clock(struct timespec now);
|
|
extern int no_sync_cmos_clock __read_mostly;
|
|
void timekeeping_init(void);
|
|
extern int timekeeping_suspended;
|
|
|
|
unsigned long get_seconds(void);
|
|
struct timespec current_kernel_time(void);
|
|
struct timespec __current_kernel_time(void); /* does not take xtime_lock */
|
|
struct timespec get_monotonic_coarse(void);
|
|
void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
|
|
struct timespec *wtom, struct timespec *sleep);
|
|
void timekeeping_inject_sleeptime(struct timespec *delta);
|
|
|
|
#define CURRENT_TIME (current_kernel_time())
|
|
#define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 })
|
|
|
|
/* Some architectures do not supply their own clocksource.
|
|
* This is mainly the case in architectures that get their
|
|
* inter-tick times by reading the counter on their interval
|
|
* timer. Since these timers wrap every tick, they're not really
|
|
* useful as clocksources. Wrapping them to act like one is possible
|
|
* but not very efficient. So we provide a callout these arches
|
|
* can implement for use with the jiffies clocksource to provide
|
|
* finer then tick granular time.
|
|
*/
|
|
#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
|
|
extern u32 arch_gettimeoffset(void);
|
|
#else
|
|
static inline u32 arch_gettimeoffset(void) { return 0; }
|
|
#endif
|
|
|
|
extern void do_gettimeofday(struct timeval *tv);
|
|
extern int do_settimeofday(const struct timespec *tv);
|
|
extern int do_sys_settimeofday(const struct timespec *tv,
|
|
const struct timezone *tz);
|
|
#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
|
|
extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
|
|
struct itimerval;
|
|
extern int do_setitimer(int which, struct itimerval *value,
|
|
struct itimerval *ovalue);
|
|
extern unsigned int alarm_setitimer(unsigned int seconds);
|
|
extern int do_getitimer(int which, struct itimerval *value);
|
|
extern void getnstimeofday(struct timespec *tv);
|
|
extern void getrawmonotonic(struct timespec *ts);
|
|
extern void getnstime_raw_and_real(struct timespec *ts_raw,
|
|
struct timespec *ts_real);
|
|
extern void getboottime(struct timespec *ts);
|
|
extern void monotonic_to_bootbased(struct timespec *ts);
|
|
extern void get_monotonic_boottime(struct timespec *ts);
|
|
|
|
extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
|
|
extern int timekeeping_valid_for_hres(void);
|
|
extern u64 timekeeping_max_deferment(void);
|
|
extern void timekeeping_leap_insert(int leapsecond);
|
|
extern int timekeeping_inject_offset(struct timespec *ts);
|
|
|
|
struct tms;
|
|
extern void do_sys_times(struct tms *);
|
|
|
|
/*
|
|
* Similar to the struct tm in userspace <time.h>, but it needs to be here so
|
|
* that the kernel source is self contained.
|
|
*/
|
|
struct tm {
|
|
/*
|
|
* the number of seconds after the minute, normally in the range
|
|
* 0 to 59, but can be up to 60 to allow for leap seconds
|
|
*/
|
|
int tm_sec;
|
|
/* the number of minutes after the hour, in the range 0 to 59*/
|
|
int tm_min;
|
|
/* the number of hours past midnight, in the range 0 to 23 */
|
|
int tm_hour;
|
|
/* the day of the month, in the range 1 to 31 */
|
|
int tm_mday;
|
|
/* the number of months since January, in the range 0 to 11 */
|
|
int tm_mon;
|
|
/* the number of years since 1900 */
|
|
long tm_year;
|
|
/* the number of days since Sunday, in the range 0 to 6 */
|
|
int tm_wday;
|
|
/* the number of days since January 1, in the range 0 to 365 */
|
|
int tm_yday;
|
|
};
|
|
|
|
void time_to_tm(time_t totalsecs, int offset, struct tm *result);
|
|
|
|
/**
|
|
* timespec_to_ns - Convert timespec to nanoseconds
|
|
* @ts: pointer to the timespec variable to be converted
|
|
*
|
|
* Returns the scalar nanosecond representation of the timespec
|
|
* parameter.
|
|
*/
|
|
static inline s64 timespec_to_ns(const struct timespec *ts)
|
|
{
|
|
return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
|
|
}
|
|
|
|
/**
|
|
* timeval_to_ns - Convert timeval to nanoseconds
|
|
* @ts: pointer to the timeval variable to be converted
|
|
*
|
|
* Returns the scalar nanosecond representation of the timeval
|
|
* parameter.
|
|
*/
|
|
static inline s64 timeval_to_ns(const struct timeval *tv)
|
|
{
|
|
return ((s64) tv->tv_sec * NSEC_PER_SEC) +
|
|
tv->tv_usec * NSEC_PER_USEC;
|
|
}
|
|
|
|
/**
|
|
* ns_to_timespec - Convert nanoseconds to timespec
|
|
* @nsec: the nanoseconds value to be converted
|
|
*
|
|
* Returns the timespec representation of the nsec parameter.
|
|
*/
|
|
extern struct timespec ns_to_timespec(const s64 nsec);
|
|
|
|
/**
|
|
* ns_to_timeval - Convert nanoseconds to timeval
|
|
* @nsec: the nanoseconds value to be converted
|
|
*
|
|
* Returns the timeval representation of the nsec parameter.
|
|
*/
|
|
extern struct timeval ns_to_timeval(const s64 nsec);
|
|
|
|
/**
|
|
* timespec_add_ns - Adds nanoseconds to a timespec
|
|
* @a: pointer to timespec to be incremented
|
|
* @ns: unsigned nanoseconds value to be added
|
|
*
|
|
* This must always be inlined because its used from the x86-64 vdso,
|
|
* which cannot call other kernel functions.
|
|
*/
|
|
static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
|
|
{
|
|
a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
|
|
a->tv_nsec = ns;
|
|
}
|
|
#endif /* __KERNEL__ */
|
|
|
|
#define NFDBITS __NFDBITS
|
|
|
|
#define FD_SETSIZE __FD_SETSIZE
|
|
#define FD_SET(fd,fdsetp) __FD_SET(fd,fdsetp)
|
|
#define FD_CLR(fd,fdsetp) __FD_CLR(fd,fdsetp)
|
|
#define FD_ISSET(fd,fdsetp) __FD_ISSET(fd,fdsetp)
|
|
#define FD_ZERO(fdsetp) __FD_ZERO(fdsetp)
|
|
|
|
/*
|
|
* Names of the interval timers, and structure
|
|
* defining a timer setting:
|
|
*/
|
|
#define ITIMER_REAL 0
|
|
#define ITIMER_VIRTUAL 1
|
|
#define ITIMER_PROF 2
|
|
|
|
struct itimerspec {
|
|
struct timespec it_interval; /* timer period */
|
|
struct timespec it_value; /* timer expiration */
|
|
};
|
|
|
|
struct itimerval {
|
|
struct timeval it_interval; /* timer interval */
|
|
struct timeval it_value; /* current value */
|
|
};
|
|
|
|
/*
|
|
* The IDs of the various system clocks (for POSIX.1b interval timers):
|
|
*/
|
|
#define CLOCK_REALTIME 0
|
|
#define CLOCK_MONOTONIC 1
|
|
#define CLOCK_PROCESS_CPUTIME_ID 2
|
|
#define CLOCK_THREAD_CPUTIME_ID 3
|
|
#define CLOCK_MONOTONIC_RAW 4
|
|
#define CLOCK_REALTIME_COARSE 5
|
|
#define CLOCK_MONOTONIC_COARSE 6
|
|
#define CLOCK_BOOTTIME 7
|
|
#define CLOCK_REALTIME_ALARM 8
|
|
#define CLOCK_BOOTTIME_ALARM 9
|
|
|
|
/*
|
|
* The IDs of various hardware clocks:
|
|
*/
|
|
#define CLOCK_SGI_CYCLE 10
|
|
#define MAX_CLOCKS 16
|
|
#define CLOCKS_MASK (CLOCK_REALTIME | CLOCK_MONOTONIC)
|
|
#define CLOCKS_MONO CLOCK_MONOTONIC
|
|
|
|
/*
|
|
* The various flags for setting POSIX.1b interval timers:
|
|
*/
|
|
#define TIMER_ABSTIME 0x01
|
|
|
|
#endif
|