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Diffstat (limited to '')
| -rw-r--r-- | include/linux/posix-timers.h | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h new file mode 100644 index 000000000..8e284161b --- /dev/null +++ b/include/linux/posix-timers.h @@ -0,0 +1,257 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _linux_POSIX_TIMERS_H +#define _linux_POSIX_TIMERS_H + +#include <linux/spinlock.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/alarmtimer.h> +#include <linux/timerqueue.h> +#include <linux/task_work.h> + +struct kernel_siginfo; +struct task_struct; + +/* + * 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) + +static inline clockid_t make_process_cpuclock(const unsigned int pid, + const clockid_t clock) +{ + return ((~pid) << 3) | clock; +} +static inline clockid_t make_thread_cpuclock(const unsigned int tid, + const clockid_t clock) +{ + return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK); +} + +static inline clockid_t fd_to_clockid(const int fd) +{ + return make_process_cpuclock((unsigned int) fd, CLOCKFD); +} + +static inline int clockid_to_fd(const clockid_t clk) +{ + return ~(clk >> 3); +} + +#ifdef CONFIG_POSIX_TIMERS + +/** + * cpu_timer - Posix CPU timer representation for k_itimer + * @node: timerqueue node to queue in the task/sig + * @head: timerqueue head on which this timer is queued + * @pid: Pointer to target task PID + * @elist: List head for the expiry list + * @firing: Timer is currently firing + * @handling: Pointer to the task which handles expiry + */ +struct cpu_timer { + struct timerqueue_node node; + struct timerqueue_head *head; + struct pid *pid; + struct list_head elist; + int firing; + struct task_struct __rcu *handling; +}; + +static inline bool cpu_timer_enqueue(struct timerqueue_head *head, + struct cpu_timer *ctmr) +{ + ctmr->head = head; + return timerqueue_add(head, &ctmr->node); +} + +static inline void cpu_timer_dequeue(struct cpu_timer *ctmr) +{ + if (ctmr->head) { + timerqueue_del(ctmr->head, &ctmr->node); + ctmr->head = NULL; + } +} + +static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr) +{ + return ctmr->node.expires; +} + +static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp) +{ + ctmr->node.expires = exp; +} + +/** + * posix_cputimer_base - Container per posix CPU clock + * @nextevt: Earliest-expiration cache + * @tqhead: timerqueue head for cpu_timers + */ +struct posix_cputimer_base { + u64 nextevt; + struct timerqueue_head tqhead; +}; + +/** + * posix_cputimers - Container for posix CPU timer related data + * @bases: Base container for posix CPU clocks + * @timers_active: Timers are queued. + * @expiry_active: Timer expiry is active. Used for + * process wide timers to avoid multiple + * task trying to handle expiry concurrently + * + * Used in task_struct and signal_struct + */ +struct posix_cputimers { + struct posix_cputimer_base bases[CPUCLOCK_MAX]; + unsigned int timers_active; + unsigned int expiry_active; +}; + +/** + * posix_cputimers_work - Container for task work based posix CPU timer expiry + * @work: The task work to be scheduled + * @mutex: Mutex held around expiry in context of this task work + * @scheduled: @work has been scheduled already, no further processing + */ +struct posix_cputimers_work { + struct callback_head work; + struct mutex mutex; + unsigned int scheduled; +}; + +static inline void posix_cputimers_init(struct posix_cputimers *pct) +{ + memset(pct, 0, sizeof(*pct)); + pct->bases[0].nextevt = U64_MAX; + pct->bases[1].nextevt = U64_MAX; + pct->bases[2].nextevt = U64_MAX; +} + +void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit); + +static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct, + u64 runtime) +{ + pct->bases[CPUCLOCK_SCHED].nextevt = runtime; +} + +/* Init task static initializer */ +#define INIT_CPU_TIMERBASE(b) { \ + .nextevt = U64_MAX, \ +} + +#define INIT_CPU_TIMERBASES(b) { \ + INIT_CPU_TIMERBASE(b[0]), \ + INIT_CPU_TIMERBASE(b[1]), \ + INIT_CPU_TIMERBASE(b[2]), \ +} + +#define INIT_CPU_TIMERS(s) \ + .posix_cputimers = { \ + .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \ + }, +#else +struct posix_cputimers { }; +struct cpu_timer { }; +#define INIT_CPU_TIMERS(s) +static inline void posix_cputimers_init(struct posix_cputimers *pct) { } +static inline void posix_cputimers_group_init(struct posix_cputimers *pct, + u64 cpu_limit) { } +#endif + +#ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK +void clear_posix_cputimers_work(struct task_struct *p); +void posix_cputimers_init_work(void); +#else +static inline void clear_posix_cputimers_work(struct task_struct *p) { } +static inline void posix_cputimers_init_work(void) { } +#endif + +#define REQUEUE_PENDING 1 + +/** + * struct k_itimer - POSIX.1b interval timer structure. + * @list: List head for binding the timer to signals->posix_timers + * @t_hash: Entry in the posix timer hash table + * @it_lock: Lock protecting the timer + * @kclock: Pointer to the k_clock struct handling this timer + * @it_clock: The posix timer clock id + * @it_id: The posix timer id for identifying the timer + * @it_active: Marker that timer is active + * @it_overrun: The overrun counter for pending signals + * @it_overrun_last: The overrun at the time of the last delivered signal + * @it_requeue_pending: Indicator that timer waits for being requeued on + * signal delivery + * @it_sigev_notify: The notify word of sigevent struct for signal delivery + * @it_interval: The interval for periodic timers + * @it_signal: Pointer to the creators signal struct + * @it_pid: The pid of the process/task targeted by the signal + * @it_process: The task to wakeup on clock_nanosleep (CPU timers) + * @sigq: Pointer to preallocated sigqueue + * @it: Union representing the various posix timer type + * internals. + * @rcu: RCU head for freeing the timer. + */ +struct k_itimer { + struct list_head list; + struct hlist_node t_hash; + spinlock_t it_lock; + const struct k_clock *kclock; + clockid_t it_clock; + timer_t it_id; + int it_active; + s64 it_overrun; + s64 it_overrun_last; + int it_requeue_pending; + int it_sigev_notify; + ktime_t it_interval; + struct signal_struct *it_signal; + union { + struct pid *it_pid; + struct task_struct *it_process; + }; + struct sigqueue *sigq; + union { + struct { + struct hrtimer timer; + } real; + struct cpu_timer cpu; + struct { + struct alarm alarmtimer; + } alarm; + } it; + struct rcu_head rcu; +}; + +void run_posix_cpu_timers(void); +void posix_cpu_timers_exit(struct task_struct *task); +void posix_cpu_timers_exit_group(struct task_struct *task); +void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx, + u64 *newval, u64 *oldval); + +void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new); + +void posixtimer_rearm(struct kernel_siginfo *info); +#endif |