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 #include <linux/task_work.h> 10 11 struct kernel_siginfo; 12 struct task_struct; 13 14 /* 15 * Bit fields within a clockid: 16 * 17 * The most significant 29 bits hold either a pid or a file descriptor. 18 * 19 * Bit 2 indicates whether a cpu clock refers to a thread or a process. 20 * 21 * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3. 22 * 23 * A clockid is invalid if bits 2, 1, and 0 are all set. 24 */ 25 #define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3)) 26 #define CPUCLOCK_PERTHREAD(clock) \ 27 (((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0) 28 29 #define CPUCLOCK_PERTHREAD_MASK 4 30 #define CPUCLOCK_WHICH(clock) ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK) 31 #define CPUCLOCK_CLOCK_MASK 3 32 #define CPUCLOCK_PROF 0 33 #define CPUCLOCK_VIRT 1 34 #define CPUCLOCK_SCHED 2 35 #define CPUCLOCK_MAX 3 36 #define CLOCKFD CPUCLOCK_MAX 37 #define CLOCKFD_MASK (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK) 38 39 static inline clockid_t make_process_cpuclock(const unsigned int pid, 40 const clockid_t clock) 41 { 42 return ((~pid) << 3) | clock; 43 } 44 static inline clockid_t make_thread_cpuclock(const unsigned int tid, 45 const clockid_t clock) 46 { 47 return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK); 48 } 49 50 static inline clockid_t fd_to_clockid(const int fd) 51 { 52 return make_process_cpuclock((unsigned int) fd, CLOCKFD); 53 } 54 55 static inline int clockid_to_fd(const clockid_t clk) 56 { 57 return ~(clk >> 3); 58 } 59 60 #ifdef CONFIG_POSIX_TIMERS 61 62 /** 63 * cpu_timer - Posix CPU timer representation for k_itimer 64 * @node: timerqueue node to queue in the task/sig 65 * @head: timerqueue head on which this timer is queued 66 * @task: Pointer to target task 67 * @elist: List head for the expiry list 68 * @firing: Timer is currently firing 69 */ 70 struct cpu_timer { 71 struct timerqueue_node node; 72 struct timerqueue_head *head; 73 struct pid *pid; 74 struct list_head elist; 75 int firing; 76 }; 77 78 static inline bool cpu_timer_enqueue(struct timerqueue_head *head, 79 struct cpu_timer *ctmr) 80 { 81 ctmr->head = head; 82 return timerqueue_add(head, &ctmr->node); 83 } 84 85 static inline void cpu_timer_dequeue(struct cpu_timer *ctmr) 86 { 87 if (ctmr->head) { 88 timerqueue_del(ctmr->head, &ctmr->node); 89 ctmr->head = NULL; 90 } 91 } 92 93 static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr) 94 { 95 return ctmr->node.expires; 96 } 97 98 static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp) 99 { 100 ctmr->node.expires = exp; 101 } 102 103 /** 104 * posix_cputimer_base - Container per posix CPU clock 105 * @nextevt: Earliest-expiration cache 106 * @tqhead: timerqueue head for cpu_timers 107 */ 108 struct posix_cputimer_base { 109 u64 nextevt; 110 struct timerqueue_head tqhead; 111 }; 112 113 /** 114 * posix_cputimers - Container for posix CPU timer related data 115 * @bases: Base container for posix CPU clocks 116 * @timers_active: Timers are queued. 117 * @expiry_active: Timer expiry is active. Used for 118 * process wide timers to avoid multiple 119 * task trying to handle expiry concurrently 120 * 121 * Used in task_struct and signal_struct 122 */ 123 struct posix_cputimers { 124 struct posix_cputimer_base bases[CPUCLOCK_MAX]; 125 unsigned int timers_active; 126 unsigned int expiry_active; 127 }; 128 129 /** 130 * posix_cputimers_work - Container for task work based posix CPU timer expiry 131 * @work: The task work to be scheduled 132 * @scheduled: @work has been scheduled already, no further processing 133 */ 134 struct posix_cputimers_work { 135 struct callback_head work; 136 unsigned int scheduled; 137 }; 138 139 static inline void posix_cputimers_init(struct posix_cputimers *pct) 140 { 141 memset(pct, 0, sizeof(*pct)); 142 pct->bases[0].nextevt = U64_MAX; 143 pct->bases[1].nextevt = U64_MAX; 144 pct->bases[2].nextevt = U64_MAX; 145 } 146 147 void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit); 148 149 static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct, 150 u64 runtime) 151 { 152 pct->bases[CPUCLOCK_SCHED].nextevt = runtime; 153 } 154 155 /* Init task static initializer */ 156 #define INIT_CPU_TIMERBASE(b) { \ 157 .nextevt = U64_MAX, \ 158 } 159 160 #define INIT_CPU_TIMERBASES(b) { \ 161 INIT_CPU_TIMERBASE(b[0]), \ 162 INIT_CPU_TIMERBASE(b[1]), \ 163 INIT_CPU_TIMERBASE(b[2]), \ 164 } 165 166 #define INIT_CPU_TIMERS(s) \ 167 .posix_cputimers = { \ 168 .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \ 169 }, 170 #else 171 struct posix_cputimers { }; 172 struct cpu_timer { }; 173 #define INIT_CPU_TIMERS(s) 174 static inline void posix_cputimers_init(struct posix_cputimers *pct) { } 175 static inline void posix_cputimers_group_init(struct posix_cputimers *pct, 176 u64 cpu_limit) { } 177 #endif 178 179 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 180 void posix_cputimers_init_work(void); 181 #else 182 static inline void posix_cputimers_init_work(void) { } 183 #endif 184 185 #define REQUEUE_PENDING 1 186 187 /** 188 * struct k_itimer - POSIX.1b interval timer structure. 189 * @list: List head for binding the timer to signals->posix_timers 190 * @t_hash: Entry in the posix timer hash table 191 * @it_lock: Lock protecting the timer 192 * @kclock: Pointer to the k_clock struct handling this timer 193 * @it_clock: The posix timer clock id 194 * @it_id: The posix timer id for identifying the timer 195 * @it_active: Marker that timer is active 196 * @it_overrun: The overrun counter for pending signals 197 * @it_overrun_last: The overrun at the time of the last delivered signal 198 * @it_requeue_pending: Indicator that timer waits for being requeued on 199 * signal delivery 200 * @it_sigev_notify: The notify word of sigevent struct for signal delivery 201 * @it_interval: The interval for periodic timers 202 * @it_signal: Pointer to the creators signal struct 203 * @it_pid: The pid of the process/task targeted by the signal 204 * @it_process: The task to wakeup on clock_nanosleep (CPU timers) 205 * @sigq: Pointer to preallocated sigqueue 206 * @it: Union representing the various posix timer type 207 * internals. 208 * @rcu: RCU head for freeing the timer. 209 */ 210 struct k_itimer { 211 struct list_head list; 212 struct hlist_node t_hash; 213 spinlock_t it_lock; 214 const struct k_clock *kclock; 215 clockid_t it_clock; 216 timer_t it_id; 217 int it_active; 218 s64 it_overrun; 219 s64 it_overrun_last; 220 int it_requeue_pending; 221 int it_sigev_notify; 222 ktime_t it_interval; 223 struct signal_struct *it_signal; 224 union { 225 struct pid *it_pid; 226 struct task_struct *it_process; 227 }; 228 struct sigqueue *sigq; 229 union { 230 struct { 231 struct hrtimer timer; 232 } real; 233 struct cpu_timer cpu; 234 struct { 235 struct alarm alarmtimer; 236 } alarm; 237 } it; 238 struct rcu_head rcu; 239 }; 240 241 void run_posix_cpu_timers(void); 242 void posix_cpu_timers_exit(struct task_struct *task); 243 void posix_cpu_timers_exit_group(struct task_struct *task); 244 void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx, 245 u64 *newval, u64 *oldval); 246 247 void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new); 248 249 void posixtimer_rearm(struct kernel_siginfo *info); 250 #endif 251