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 bool cpu_timer_queued(struct cpu_timer *ctmr) 86 { 87 return !!ctmr->head; 88 } 89 90 static inline bool cpu_timer_dequeue(struct cpu_timer *ctmr) 91 { 92 if (cpu_timer_queued(ctmr)) { 93 timerqueue_del(ctmr->head, &ctmr->node); 94 ctmr->head = NULL; 95 return true; 96 } 97 return false; 98 } 99 100 static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr) 101 { 102 return ctmr->node.expires; 103 } 104 105 static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp) 106 { 107 ctmr->node.expires = exp; 108 } 109 110 /** 111 * posix_cputimer_base - Container per posix CPU clock 112 * @nextevt: Earliest-expiration cache 113 * @tqhead: timerqueue head for cpu_timers 114 */ 115 struct posix_cputimer_base { 116 u64 nextevt; 117 struct timerqueue_head tqhead; 118 }; 119 120 /** 121 * posix_cputimers - Container for posix CPU timer related data 122 * @bases: Base container for posix CPU clocks 123 * @timers_active: Timers are queued. 124 * @expiry_active: Timer expiry is active. Used for 125 * process wide timers to avoid multiple 126 * task trying to handle expiry concurrently 127 * 128 * Used in task_struct and signal_struct 129 */ 130 struct posix_cputimers { 131 struct posix_cputimer_base bases[CPUCLOCK_MAX]; 132 unsigned int timers_active; 133 unsigned int expiry_active; 134 }; 135 136 /** 137 * posix_cputimers_work - Container for task work based posix CPU timer expiry 138 * @work: The task work to be scheduled 139 * @scheduled: @work has been scheduled already, no further processing 140 */ 141 struct posix_cputimers_work { 142 struct callback_head work; 143 unsigned int scheduled; 144 }; 145 146 static inline void posix_cputimers_init(struct posix_cputimers *pct) 147 { 148 memset(pct, 0, sizeof(*pct)); 149 pct->bases[0].nextevt = U64_MAX; 150 pct->bases[1].nextevt = U64_MAX; 151 pct->bases[2].nextevt = U64_MAX; 152 } 153 154 void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit); 155 156 static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct, 157 u64 runtime) 158 { 159 pct->bases[CPUCLOCK_SCHED].nextevt = runtime; 160 } 161 162 /* Init task static initializer */ 163 #define INIT_CPU_TIMERBASE(b) { \ 164 .nextevt = U64_MAX, \ 165 } 166 167 #define INIT_CPU_TIMERBASES(b) { \ 168 INIT_CPU_TIMERBASE(b[0]), \ 169 INIT_CPU_TIMERBASE(b[1]), \ 170 INIT_CPU_TIMERBASE(b[2]), \ 171 } 172 173 #define INIT_CPU_TIMERS(s) \ 174 .posix_cputimers = { \ 175 .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \ 176 }, 177 #else 178 struct posix_cputimers { }; 179 struct cpu_timer { }; 180 #define INIT_CPU_TIMERS(s) 181 static inline void posix_cputimers_init(struct posix_cputimers *pct) { } 182 static inline void posix_cputimers_group_init(struct posix_cputimers *pct, 183 u64 cpu_limit) { } 184 #endif 185 186 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 187 void posix_cputimers_init_work(void); 188 #else 189 static inline void posix_cputimers_init_work(void) { } 190 #endif 191 192 #define REQUEUE_PENDING 1 193 194 /** 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 206 * signal delivery 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 214 * internals. 215 * @rcu: RCU head for freeing the timer. 216 */ 217 struct k_itimer { 218 struct list_head list; 219 struct hlist_node t_hash; 220 spinlock_t it_lock; 221 const struct k_clock *kclock; 222 clockid_t it_clock; 223 timer_t it_id; 224 int it_active; 225 s64 it_overrun; 226 s64 it_overrun_last; 227 int it_requeue_pending; 228 int it_sigev_notify; 229 ktime_t it_interval; 230 struct signal_struct *it_signal; 231 union { 232 struct pid *it_pid; 233 struct task_struct *it_process; 234 }; 235 struct sigqueue *sigq; 236 union { 237 struct { 238 struct hrtimer timer; 239 } real; 240 struct cpu_timer cpu; 241 struct { 242 struct alarm alarmtimer; 243 } alarm; 244 } it; 245 struct rcu_head rcu; 246 }; 247 248 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); 253 254 void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new); 255 256 void posixtimer_rearm(struct kernel_siginfo *info); 257 #endif 258