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
make_process_cpuclock(const unsigned int pid,const clockid_t clock)38 static inline clockid_t make_process_cpuclock(const unsigned int pid,
39 const clockid_t clock)
40 {
41 return ((~pid) << 3) | clock;
42 }
make_thread_cpuclock(const unsigned int tid,const clockid_t clock)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
fd_to_clockid(const int fd)49 static inline clockid_t fd_to_clockid(const int fd)
50 {
51 return make_process_cpuclock((unsigned int) fd, CLOCKFD);
52 }
53
clockid_to_fd(const clockid_t clk)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 task_struct *task;
73 struct list_head elist;
74 int firing;
75 };
76
cpu_timer_enqueue(struct timerqueue_head * head,struct cpu_timer * ctmr)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
cpu_timer_dequeue(struct cpu_timer * ctmr)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
cpu_timer_getexpires(struct cpu_timer * ctmr)92 static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr)
93 {
94 return ctmr->node.expires;
95 }
96
cpu_timer_setexpires(struct cpu_timer * ctmr,u64 exp)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
posix_cputimers_init(struct posix_cputimers * pct)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
posix_cputimers_rt_watchdog(struct posix_cputimers * pct,u64 runtime)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)
posix_cputimers_init(struct posix_cputimers * pct)163 static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
posix_cputimers_group_init(struct posix_cputimers * pct,u64 cpu_limit)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
