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 | 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 | 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 | ctmr->head = head; |
81 | 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 | if (cpu_timer_queued(ctmr)) { |
92 | timerqueue_del(ctmr->head, &ctmr->node); |
93 | 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 | return ctmr->node.expires; |
102 | } |
103 | |
104 | static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp) |
105 | { |
106 | 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 | memset(pct, 0, sizeof(*pct)); |
148 | pct->bases[0].nextevt = U64_MAX; |
149 | pct->bases[1].nextevt = U64_MAX; |
150 | 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 | 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 |
259 | |