linux/kernel/time/posix-timers.h
Andrei Vagin 9c71a2e8a7 posix-clocks: Introduce clock_get_ktime() callback
The callsite in common_timer_get() has already a comment:
    /*
     * The timespec64 based conversion is suboptimal, but it's not
     * worth to implement yet another callback.
     */
    kc->clock_get(timr->it_clock, &ts64);
    now = timespec64_to_ktime(ts64);

The upcoming support for time namespaces requires to have access to:

 - The time in a task's time namespace for sys_clock_gettime()
 - The time in the root name space for common_timer_get()

That adds a valid reason to finally implement a separate callback which
returns the time in ktime_t format.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-10-dima@arista.com
2020-01-14 12:20:51 +01:00

46 lines
1.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#define TIMER_RETRY 1
struct k_clock {
int (*clock_getres)(const clockid_t which_clock,
struct timespec64 *tp);
int (*clock_set)(const clockid_t which_clock,
const struct timespec64 *tp);
/* Returns the clock value in the current time namespace. */
int (*clock_get_timespec)(const clockid_t which_clock,
struct timespec64 *tp);
/* Returns the clock value in the root time namespace. */
ktime_t (*clock_get_ktime)(const clockid_t which_clock);
int (*clock_adj)(const clockid_t which_clock, struct __kernel_timex *tx);
int (*timer_create)(struct k_itimer *timer);
int (*nsleep)(const clockid_t which_clock, int flags,
const struct timespec64 *);
int (*timer_set)(struct k_itimer *timr, int flags,
struct itimerspec64 *new_setting,
struct itimerspec64 *old_setting);
int (*timer_del)(struct k_itimer *timr);
void (*timer_get)(struct k_itimer *timr,
struct itimerspec64 *cur_setting);
void (*timer_rearm)(struct k_itimer *timr);
s64 (*timer_forward)(struct k_itimer *timr, ktime_t now);
ktime_t (*timer_remaining)(struct k_itimer *timr, ktime_t now);
int (*timer_try_to_cancel)(struct k_itimer *timr);
void (*timer_arm)(struct k_itimer *timr, ktime_t expires,
bool absolute, bool sigev_none);
void (*timer_wait_running)(struct k_itimer *timr);
};
extern const struct k_clock clock_posix_cpu;
extern const struct k_clock clock_posix_dynamic;
extern const struct k_clock clock_process;
extern const struct k_clock clock_thread;
extern const struct k_clock alarm_clock;
int posix_timer_event(struct k_itimer *timr, int si_private);
void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting);
int common_timer_set(struct k_itimer *timr, int flags,
struct itimerspec64 *new_setting,
struct itimerspec64 *old_setting);
int common_timer_del(struct k_itimer *timer);