Line data    Source code

       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           0 :         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           0 :         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           0 :         ctmr->head = head;
      81           0 :         return timerqueue_add(head, &ctmr->node);
      82             : }
      83             : 
      84             : static inline bool cpu_timer_queued(struct cpu_timer *ctmr)
      85             : {
      86             :         return !!ctmr->head;
      87             : }
      88             : 
      89             : static inline bool cpu_timer_dequeue(struct cpu_timer *ctmr)
      90             : {
      91           0 :         if (cpu_timer_queued(ctmr)) {
      92           0 :                 timerqueue_del(ctmr->head, &ctmr->node);
      93           0 :                 ctmr->head = NULL;
      94             :                 return true;
      95             :         }
      96             :         return false;
      97             : }
      98             : 
      99             : static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr)
     100             : {
     101           0 :         return ctmr->node.expires;
     102             : }
     103             : 
     104             : static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp)
     105             : {
     106           0 :         ctmr->node.expires = exp;
     107             : }
     108             : 
     109             : /**
     110             :  * posix_cputimer_base - Container per posix CPU clock
     111             :  * @nextevt:            Earliest-expiration cache
     112             :  * @tqhead:             timerqueue head for cpu_timers
     113             :  */
     114             : struct posix_cputimer_base {
     115             :         u64                     nextevt;
     116             :         struct timerqueue_head  tqhead;
     117             : };
     118             : 
     119             : /**
     120             :  * posix_cputimers - Container for posix CPU timer related data
     121             :  * @bases:              Base container for posix CPU clocks
     122             :  * @timers_active:      Timers are queued.
     123             :  * @expiry_active:      Timer expiry is active. Used for
     124             :  *                      process wide timers to avoid multiple
     125             :  *                      task trying to handle expiry concurrently
     126             :  *
     127             :  * Used in task_struct and signal_struct
     128             :  */
     129             : struct posix_cputimers {
     130             :         struct posix_cputimer_base      bases[CPUCLOCK_MAX];
     131             :         unsigned int                    timers_active;
     132             :         unsigned int                    expiry_active;
     133             : };
     134             : 
     135             : /**
     136             :  * posix_cputimers_work - Container for task work based posix CPU timer expiry
     137             :  * @work:       The task work to be scheduled
     138             :  * @scheduled:  @work has been scheduled already, no further processing
     139             :  */
     140             : struct posix_cputimers_work {
     141             :         struct callback_head    work;
     142             :         unsigned int            scheduled;
     143             : };
     144             : 
     145             : static inline void posix_cputimers_init(struct posix_cputimers *pct)
     146             : {
     147         696 :         memset(pct, 0, sizeof(*pct));
     148         696 :         pct->bases[0].nextevt = U64_MAX;
     149         696 :         pct->bases[1].nextevt = U64_MAX;
     150         696 :         pct->bases[2].nextevt = U64_MAX;
     151             : }
     152             : 
     153             : void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit);
     154             : 
     155             : static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
     156             :                                                u64 runtime)
     157             : {
     158           0 :         pct->bases[CPUCLOCK_SCHED].nextevt = runtime;
     159             : }
     160             : 
     161             : /* Init task static initializer */
     162             : #define INIT_CPU_TIMERBASE(b) {                                         \
     163             :         .nextevt        = U64_MAX,                                      \
     164             : }
     165             : 
     166             : #define INIT_CPU_TIMERBASES(b) {                                        \
     167             :         INIT_CPU_TIMERBASE(b[0]),                                       \
     168             :         INIT_CPU_TIMERBASE(b[1]),                                       \
     169             :         INIT_CPU_TIMERBASE(b[2]),                                       \
     170             : }
     171             : 
     172             : #define INIT_CPU_TIMERS(s)                                              \
     173             :         .posix_cputimers = {                                            \
     174             :                 .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases),  \
     175             :         },
     176             : #else
     177             : struct posix_cputimers { };
     178             : struct cpu_timer { };
     179             : #define INIT_CPU_TIMERS(s)
     180             : static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
     181             : static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
     182             :                                               u64 cpu_limit) { }
     183             : #endif
     184             : 
     185             : #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
     186             : void clear_posix_cputimers_work(struct task_struct *p);
     187             : void posix_cputimers_init_work(void);
     188             : #else
     189             : static inline void clear_posix_cputimers_work(struct task_struct *p) { }
     190             : static inline void posix_cputimers_init_work(void) { }
     191             : #endif
     192             : 
     193             : #define REQUEUE_PENDING 1
     194             : 
     195             : /**
     196             :  * struct k_itimer - POSIX.1b interval timer structure.
     197             :  * @list:               List head for binding the timer to signals->posix_timers
     198             :  * @t_hash:             Entry in the posix timer hash table
     199             :  * @it_lock:            Lock protecting the timer
     200             :  * @kclock:             Pointer to the k_clock struct handling this timer
     201             :  * @it_clock:           The posix timer clock id
     202             :  * @it_id:              The posix timer id for identifying the timer
     203             :  * @it_active:          Marker that timer is active
     204             :  * @it_overrun:         The overrun counter for pending signals
     205             :  * @it_overrun_last:    The overrun at the time of the last delivered signal
     206             :  * @it_requeue_pending: Indicator that timer waits for being requeued on
     207             :  *                      signal delivery
     208             :  * @it_sigev_notify:    The notify word of sigevent struct for signal delivery
     209             :  * @it_interval:        The interval for periodic timers
     210             :  * @it_signal:          Pointer to the creators signal struct
     211             :  * @it_pid:             The pid of the process/task targeted by the signal
     212             :  * @it_process:         The task to wakeup on clock_nanosleep (CPU timers)
     213             :  * @sigq:               Pointer to preallocated sigqueue
     214             :  * @it:                 Union representing the various posix timer type
     215             :  *                      internals.
     216             :  * @rcu:                RCU head for freeing the timer.
     217             :  */
     218             : struct k_itimer {
     219             :         struct list_head        list;
     220             :         struct hlist_node       t_hash;
     221             :         spinlock_t              it_lock;
     222             :         const struct k_clock    *kclock;
     223             :         clockid_t               it_clock;
     224             :         timer_t                 it_id;
     225             :         int                     it_active;
     226             :         s64                     it_overrun;
     227             :         s64                     it_overrun_last;
     228             :         int                     it_requeue_pending;
     229             :         int                     it_sigev_notify;
     230             :         ktime_t                 it_interval;
     231             :         struct signal_struct    *it_signal;
     232             :         union {
     233             :                 struct pid              *it_pid;
     234             :                 struct task_struct      *it_process;
     235             :         };
     236             :         struct sigqueue         *sigq;
     237             :         union {
     238             :                 struct {
     239             :                         struct hrtimer  timer;
     240             :                 } real;
     241             :                 struct cpu_timer        cpu;
     242             :                 struct {
     243             :                         struct alarm    alarmtimer;
     244             :                 } alarm;
     245             :         } it;
     246             :         struct rcu_head         rcu;
     247             : };
     248             : 
     249             : void run_posix_cpu_timers(void);
     250             : void posix_cpu_timers_exit(struct task_struct *task);
     251             : void posix_cpu_timers_exit_group(struct task_struct *task);
     252             : void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
     253             :                            u64 *newval, u64 *oldval);
     254             : 
     255             : int update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
     256             : 
     257             : void posixtimer_rearm(struct kernel_siginfo *info);
     258             : #endif