root/include/linux/posix-timers.h

INCLUDED FROM

DEFINITIONS

1. cputime_to_expires
2. expires_to_cputime

#ifndef _linux_POSIX_TIMERS_H
#define _linux_POSIX_TIMERS_H

#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/timex.h>
#include <linux/alarmtimer.h>


static inline unsigned long long cputime_to_expires(cputime_t expires)
{
        return (__force unsigned long long)expires;
}

static inline cputime_t expires_to_cputime(unsigned long long expires)
{
        return (__force cputime_t)expires;
}

struct cpu_timer_list {
        struct list_head entry;
        unsigned long long expires, incr;
        struct task_struct *task;
        int firing;
};

/*
 * Bit fields within a clockid:
 *
 * The most significant 29 bits hold either a pid or a file descriptor.
 *
 * Bit 2 indicates whether a cpu clock refers to a thread or a process.
 *
 * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
 *
 * A clockid is invalid if bits 2, 1, and 0 are all set.
 */
#define CPUCLOCK_PID(clock)             ((pid_t) ~((clock) >> 3))
#define CPUCLOCK_PERTHREAD(clock) \
        (((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)

#define CPUCLOCK_PERTHREAD_MASK 4
#define CPUCLOCK_WHICH(clock)   ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
#define CPUCLOCK_CLOCK_MASK     3
#define CPUCLOCK_PROF           0
#define CPUCLOCK_VIRT           1
#define CPUCLOCK_SCHED          2
#define CPUCLOCK_MAX            3
#define CLOCKFD                 CPUCLOCK_MAX
#define CLOCKFD_MASK            (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)

#define MAKE_PROCESS_CPUCLOCK(pid, clock) \
        ((~(clockid_t) (pid) << 3) | (clockid_t) (clock))
#define MAKE_THREAD_CPUCLOCK(tid, clock) \
        MAKE_PROCESS_CPUCLOCK((tid), (clock) | CPUCLOCK_PERTHREAD_MASK)

#define FD_TO_CLOCKID(fd)       ((~(clockid_t) (fd) << 3) | CLOCKFD)
#define CLOCKID_TO_FD(clk)      ((unsigned int) ~((clk) >> 3))

/* POSIX.1b interval timer structure. */
struct k_itimer {
        struct list_head list;          /* free/ allocate list */
        struct hlist_node t_hash;
        spinlock_t it_lock;
        clockid_t it_clock;             /* which timer type */
        timer_t it_id;                  /* timer id */
        int it_overrun;                 /* overrun on pending signal  */
        int it_overrun_last;            /* overrun on last delivered signal */
        int it_requeue_pending;         /* waiting to requeue this timer */
#define REQUEUE_PENDING 1
        int it_sigev_notify;            /* notify word of sigevent struct */
        struct signal_struct *it_signal;
        union {
                struct pid *it_pid;     /* pid of process to send signal to */
                struct task_struct *it_process; /* for clock_nanosleep */
        };
        struct sigqueue *sigq;          /* signal queue entry. */
        union {
                struct {
                        struct hrtimer timer;
                        ktime_t interval;
                } real;
                struct cpu_timer_list cpu;
                struct {
                        unsigned int clock;
                        unsigned int node;
                        unsigned long incr;
                        unsigned long expires;
                } mmtimer;
                struct {
                        struct alarm alarmtimer;
                        ktime_t interval;
                } alarm;
                struct rcu_head rcu;
        } it;
};

struct k_clock {
        int (*clock_getres) (const clockid_t which_clock, struct timespec *tp);
        int (*clock_set) (const clockid_t which_clock,
                          const struct timespec *tp);
        int (*clock_get) (const clockid_t which_clock, struct timespec * tp);
        int (*clock_adj) (const clockid_t which_clock, struct timex *tx);
        int (*timer_create) (struct k_itimer *timer);
        int (*nsleep) (const clockid_t which_clock, int flags,
                       struct timespec *, struct timespec __user *);
        long (*nsleep_restart) (struct restart_block *restart_block);
        int (*timer_set) (struct k_itimer * timr, int flags,
                          struct itimerspec * new_setting,
                          struct itimerspec * old_setting);
        int (*timer_del) (struct k_itimer * timr);
#define TIMER_RETRY 1
        void (*timer_get) (struct k_itimer * timr,
                           struct itimerspec * cur_setting);
};

extern struct k_clock clock_posix_cpu;
extern struct k_clock clock_posix_dynamic;

void posix_timers_register_clock(const clockid_t clock_id, struct k_clock *new_clock);

/* function to call to trigger timer event */
int posix_timer_event(struct k_itimer *timr, int si_private);

void posix_cpu_timer_schedule(struct k_itimer *timer);

void run_posix_cpu_timers(struct task_struct *task);
void posix_cpu_timers_exit(struct task_struct *task);
void posix_cpu_timers_exit_group(struct task_struct *task);

bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk);

void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
                           cputime_t *newval, cputime_t *oldval);

long clock_nanosleep_restart(struct restart_block *restart_block);

void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);

#endif