1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _linux_POSIX_TIMERS_H 3 #define _linux_POSIX_TIMERS_H 4 5 #include <linux/spinlock.h> 6 #include <linux/list.h> 7 #include <linux/alarmtimer.h> 8 #include <linux/timerqueue.h> 9 10 struct kernel_siginfo; 11 struct task_struct; 12 13 /* 14 * Bit fields within a clockid: 15 * 16 * The most significant 29 bits hold either a pid or a file descriptor. 17 * 18 * Bit 2 indicates whether a cpu clock refers to a thread or a process. 19 * 20 * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3. 21 * 22 * A clockid is invalid if bits 2, 1, and 0 are all set. 23 */ 24 #define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3)) 25 #define CPUCLOCK_PERTHREAD(clock) \ 26 (((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0) 27 28 #define CPUCLOCK_PERTHREAD_MASK 4 29 #define CPUCLOCK_WHICH(clock) ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK) 30 #define CPUCLOCK_CLOCK_MASK 3 31 #define CPUCLOCK_PROF 0 32 #define CPUCLOCK_VIRT 1 33 #define CPUCLOCK_SCHED 2 34 #define CPUCLOCK_MAX 3 35 #define CLOCKFD CPUCLOCK_MAX 36 #define CLOCKFD_MASK (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK) 37 38 static inline clockid_t make_process_cpuclock(const unsigned int pid, 39 const clockid_t clock) 40 { 41 return ((~pid) << 3) | clock; 42 } 43 static inline clockid_t make_thread_cpuclock(const unsigned int tid, 44 const clockid_t clock) 45 { 46 return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK); 47 } 48 49 static inline clockid_t fd_to_clockid(const int fd) 50 { 51 return make_process_cpuclock((unsigned int) fd, CLOCKFD); 52 } 53 54 static inline int clockid_to_fd(const clockid_t clk) 55 { 56 return ~(clk >> 3); 57 } 58 59 #ifdef CONFIG_POSIX_TIMERS 60 61 /** 62 * cpu_timer - Posix CPU timer representation for k_itimer 63 * @node: timerqueue node to queue in the task/sig 64 * @head: timerqueue head on which this timer is queued 65 * @task: Pointer to target task 66 * @elist: List head for the expiry list 67 * @firing: Timer is currently firing 68 */ 69 struct cpu_timer { 70 struct timerqueue_node node; 71 struct timerqueue_head *head; 72 struct pid *pid; 73 struct list_head elist; 74 int firing; 75 }; 76 77 static inline bool cpu_timer_enqueue(struct timerqueue_head *head, 78 struct cpu_timer *ctmr) 79 { 80 ctmr->head = head; 81 return timerqueue_add(head, &ctmr->node); 82 } 83 84 static inline void cpu_timer_dequeue(struct cpu_timer *ctmr) 85 { 86 if (ctmr->head) { 87 timerqueue_del(ctmr->head, &ctmr->node); 88 ctmr->head = NULL; 89 } 90 } 91 92 static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr) 93 { 94 return ctmr->node.expires; 95 } 96 97 static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp) 98 { 99 ctmr->node.expires = exp; 100 } 101 102 /** 103 * posix_cputimer_base - Container per posix CPU clock 104 * @nextevt: Earliest-expiration cache 105 * @tqhead: timerqueue head for cpu_timers 106 */ 107 struct posix_cputimer_base { 108 u64 nextevt; 109 struct timerqueue_head tqhead; 110 }; 111 112 /** 113 * posix_cputimers - Container for posix CPU timer related data 114 * @bases: Base container for posix CPU clocks 115 * @timers_active: Timers are queued. 116 * @expiry_active: Timer expiry is active. Used for 117 * process wide timers to avoid multiple 118 * task trying to handle expiry concurrently 119 * 120 * Used in task_struct and signal_struct 121 */ 122 struct posix_cputimers { 123 struct posix_cputimer_base bases[CPUCLOCK_MAX]; 124 unsigned int timers_active; 125 unsigned int expiry_active; 126 }; 127 128 static inline void posix_cputimers_init(struct posix_cputimers *pct) 129 { 130 memset(pct, 0, sizeof(*pct)); 131 pct->bases[0].nextevt = U64_MAX; 132 pct->bases[1].nextevt = U64_MAX; 133 pct->bases[2].nextevt = U64_MAX; 134 } 135 136 void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit); 137 138 static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct, 139 u64 runtime) 140 { 141 pct->bases[CPUCLOCK_SCHED].nextevt = runtime; 142 } 143 144 /* Init task static initializer */ 145 #define INIT_CPU_TIMERBASE(b) { \ 146 .nextevt = U64_MAX, \ 147 } 148 149 #define INIT_CPU_TIMERBASES(b) { \ 150 INIT_CPU_TIMERBASE(b[0]), \ 151 INIT_CPU_TIMERBASE(b[1]), \ 152 INIT_CPU_TIMERBASE(b[2]), \ 153 } 154 155 #define INIT_CPU_TIMERS(s) \ 156 .posix_cputimers = { \ 157 .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \ 158 }, 159 #else 160 struct posix_cputimers { }; 161 struct cpu_timer { }; 162 #define INIT_CPU_TIMERS(s) 163 static inline void posix_cputimers_init(struct posix_cputimers *pct) { } 164 static inline void posix_cputimers_group_init(struct posix_cputimers *pct, 165 u64 cpu_limit) { } 166 #endif 167 168 #define REQUEUE_PENDING 1 169 170 /** 171 * struct k_itimer - POSIX.1b interval timer structure. 172 * @list: List head for binding the timer to signals->posix_timers 173 * @t_hash: Entry in the posix timer hash table 174 * @it_lock: Lock protecting the timer 175 * @kclock: Pointer to the k_clock struct handling this timer 176 * @it_clock: The posix timer clock id 177 * @it_id: The posix timer id for identifying the timer 178 * @it_active: Marker that timer is active 179 * @it_overrun: The overrun counter for pending signals 180 * @it_overrun_last: The overrun at the time of the last delivered signal 181 * @it_requeue_pending: Indicator that timer waits for being requeued on 182 * signal delivery 183 * @it_sigev_notify: The notify word of sigevent struct for signal delivery 184 * @it_interval: The interval for periodic timers 185 * @it_signal: Pointer to the creators signal struct 186 * @it_pid: The pid of the process/task targeted by the signal 187 * @it_process: The task to wakeup on clock_nanosleep (CPU timers) 188 * @sigq: Pointer to preallocated sigqueue 189 * @it: Union representing the various posix timer type 190 * internals. 191 * @rcu: RCU head for freeing the timer. 192 */ 193 struct k_itimer { 194 struct list_head list; 195 struct hlist_node t_hash; 196 spinlock_t it_lock; 197 const struct k_clock *kclock; 198 clockid_t it_clock; 199 timer_t it_id; 200 int it_active; 201 s64 it_overrun; 202 s64 it_overrun_last; 203 int it_requeue_pending; 204 int it_sigev_notify; 205 ktime_t it_interval; 206 struct signal_struct *it_signal; 207 union { 208 struct pid *it_pid; 209 struct task_struct *it_process; 210 }; 211 struct sigqueue *sigq; 212 union { 213 struct { 214 struct hrtimer timer; 215 } real; 216 struct cpu_timer cpu; 217 struct { 218 struct alarm alarmtimer; 219 } alarm; 220 } it; 221 struct rcu_head rcu; 222 }; 223 224 void run_posix_cpu_timers(void); 225 void posix_cpu_timers_exit(struct task_struct *task); 226 void posix_cpu_timers_exit_group(struct task_struct *task); 227 void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx, 228 u64 *newval, u64 *oldval); 229 230 void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new); 231 232 void posixtimer_rearm(struct kernel_siginfo *info); 233 #endif 234