1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _linux_POSIX_TIMERS_H
3 #define _linux_POSIX_TIMERS_H
5 #include <linux/spinlock.h>
6 #include <linux/list.h>
7 #include <linux/mutex.h>
8 #include <linux/alarmtimer.h>
9 #include <linux/timerqueue.h>
10 #include <linux/task_work.h>
12 struct kernel_siginfo;
16 * Bit fields within a clockid:
18 * The most significant 29 bits hold either a pid or a file descriptor.
20 * Bit 2 indicates whether a cpu clock refers to a thread or a process.
22 * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
24 * A clockid is invalid if bits 2, 1, and 0 are all set.
26 #define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3))
27 #define CPUCLOCK_PERTHREAD(clock) \
28 (((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
30 #define CPUCLOCK_PERTHREAD_MASK 4
31 #define CPUCLOCK_WHICH(clock) ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
32 #define CPUCLOCK_CLOCK_MASK 3
33 #define CPUCLOCK_PROF 0
34 #define CPUCLOCK_VIRT 1
35 #define CPUCLOCK_SCHED 2
36 #define CPUCLOCK_MAX 3
37 #define CLOCKFD CPUCLOCK_MAX
38 #define CLOCKFD_MASK (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
40 static inline clockid_t make_process_cpuclock(const unsigned int pid,
41 const clockid_t clock)
43 return ((~pid) << 3) | clock;
45 static inline clockid_t make_thread_cpuclock(const unsigned int tid,
46 const clockid_t clock)
48 return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK);
51 static inline clockid_t fd_to_clockid(const int fd)
53 return make_process_cpuclock((unsigned int) fd, CLOCKFD);
56 static inline int clockid_to_fd(const clockid_t clk)
61 #ifdef CONFIG_POSIX_TIMERS
64 * cpu_timer - Posix CPU timer representation for k_itimer
65 * @node: timerqueue node to queue in the task/sig
66 * @head: timerqueue head on which this timer is queued
67 * @pid: Pointer to target task PID
68 * @elist: List head for the expiry list
69 * @firing: Timer is currently firing
70 * @handling: Pointer to the task which handles expiry
73 struct timerqueue_node node;
74 struct timerqueue_head *head;
76 struct list_head elist;
78 struct task_struct __rcu *handling;
81 static inline bool cpu_timer_enqueue(struct timerqueue_head *head,
82 struct cpu_timer *ctmr)
85 return timerqueue_add(head, &ctmr->node);
88 static inline void cpu_timer_dequeue(struct cpu_timer *ctmr)
91 timerqueue_del(ctmr->head, &ctmr->node);
96 static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr)
98 return ctmr->node.expires;
101 static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp)
103 ctmr->node.expires = exp;
107 * posix_cputimer_base - Container per posix CPU clock
108 * @nextevt: Earliest-expiration cache
109 * @tqhead: timerqueue head for cpu_timers
111 struct posix_cputimer_base {
113 struct timerqueue_head tqhead;
117 * posix_cputimers - Container for posix CPU timer related data
118 * @bases: Base container for posix CPU clocks
119 * @timers_active: Timers are queued.
120 * @expiry_active: Timer expiry is active. Used for
121 * process wide timers to avoid multiple
122 * task trying to handle expiry concurrently
124 * Used in task_struct and signal_struct
126 struct posix_cputimers {
127 struct posix_cputimer_base bases[CPUCLOCK_MAX];
128 unsigned int timers_active;
129 unsigned int expiry_active;
133 * posix_cputimers_work - Container for task work based posix CPU timer expiry
134 * @work: The task work to be scheduled
135 * @mutex: Mutex held around expiry in context of this task work
136 * @scheduled: @work has been scheduled already, no further processing
138 struct posix_cputimers_work {
139 struct callback_head work;
141 unsigned int scheduled;
144 static inline void posix_cputimers_init(struct posix_cputimers *pct)
146 memset(pct, 0, sizeof(*pct));
147 pct->bases[0].nextevt = U64_MAX;
148 pct->bases[1].nextevt = U64_MAX;
149 pct->bases[2].nextevt = U64_MAX;
152 void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit);
154 static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
157 pct->bases[CPUCLOCK_SCHED].nextevt = runtime;
160 /* Init task static initializer */
161 #define INIT_CPU_TIMERBASE(b) { \
162 .nextevt = U64_MAX, \
165 #define INIT_CPU_TIMERBASES(b) { \
166 INIT_CPU_TIMERBASE(b[0]), \
167 INIT_CPU_TIMERBASE(b[1]), \
168 INIT_CPU_TIMERBASE(b[2]), \
171 #define INIT_CPU_TIMERS(s) \
172 .posix_cputimers = { \
173 .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \
176 struct posix_cputimers { };
177 struct cpu_timer { };
178 #define INIT_CPU_TIMERS(s)
179 static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
180 static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
184 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
185 void clear_posix_cputimers_work(struct task_struct *p);
186 void posix_cputimers_init_work(void);
188 static inline void clear_posix_cputimers_work(struct task_struct *p) { }
189 static inline void posix_cputimers_init_work(void) { }
192 #define REQUEUE_PENDING 1
195 * struct k_itimer - POSIX.1b interval timer structure.
196 * @list: List head for binding the timer to signals->posix_timers
197 * @t_hash: Entry in the posix timer hash table
198 * @it_lock: Lock protecting the timer
199 * @kclock: Pointer to the k_clock struct handling this timer
200 * @it_clock: The posix timer clock id
201 * @it_id: The posix timer id for identifying the timer
202 * @it_active: Marker that timer is active
203 * @it_overrun: The overrun counter for pending signals
204 * @it_overrun_last: The overrun at the time of the last delivered signal
205 * @it_requeue_pending: Indicator that timer waits for being requeued on
207 * @it_sigev_notify: The notify word of sigevent struct for signal delivery
208 * @it_interval: The interval for periodic timers
209 * @it_signal: Pointer to the creators signal struct
210 * @it_pid: The pid of the process/task targeted by the signal
211 * @it_process: The task to wakeup on clock_nanosleep (CPU timers)
212 * @sigq: Pointer to preallocated sigqueue
213 * @it: Union representing the various posix timer type
215 * @rcu: RCU head for freeing the timer.
218 struct list_head list;
219 struct hlist_node t_hash;
221 const struct k_clock *kclock;
227 int it_requeue_pending;
230 struct signal_struct *it_signal;
233 struct task_struct *it_process;
235 struct sigqueue *sigq;
238 struct hrtimer timer;
240 struct cpu_timer cpu;
242 struct alarm alarmtimer;
248 void run_posix_cpu_timers(void);
249 void posix_cpu_timers_exit(struct task_struct *task);
250 void posix_cpu_timers_exit_group(struct task_struct *task);
251 void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
252 u64 *newval, u64 *oldval);
254 void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
256 void posixtimer_rearm(struct kernel_siginfo *info);