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
make_process_cpuclock(const unsigned int pid,const clockid_t clock)39 static inline clockid_t make_process_cpuclock(const unsigned int pid,
40 const clockid_t clock)
41 {
42 return ((~pid) << 3) | clock;
43 }
make_thread_cpuclock(const unsigned int tid,const clockid_t clock)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
fd_to_clockid(const int fd)50 static inline clockid_t fd_to_clockid(const int fd)
51 {
52 return make_process_cpuclock((unsigned int) fd, CLOCKFD);
53 }
54
clockid_to_fd(const clockid_t clk)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
cpu_timer_enqueue(struct timerqueue_head * head,struct cpu_timer * ctmr)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
cpu_timer_dequeue(struct cpu_timer * ctmr)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
cpu_timer_getexpires(struct cpu_timer * ctmr)93 static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr)
94 {
95 return ctmr->node.expires;
96 }
97
cpu_timer_setexpires(struct cpu_timer * ctmr,u64 exp)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
posix_cputimers_init(struct posix_cputimers * pct)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
posix_cputimers_rt_watchdog(struct posix_cputimers * pct,u64 runtime)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)
posix_cputimers_init(struct posix_cputimers * pct)174 static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
posix_cputimers_group_init(struct posix_cputimers * pct,u64 cpu_limit)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
posix_cputimers_init_work(void)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