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/mutex.h> |
8 | #include <linux/alarmtimer.h> |
9 | #include <linux/timerqueue.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(pid: tid, clock: clock | CPUCLOCK_PERTHREAD_MASK); |
48 | } |
49 | |
50 | static inline clockid_t fd_to_clockid(const int fd) |
51 | { |
52 | return make_process_cpuclock(pid: (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 | * @pid: Pointer to target task PID |
67 | * @elist: List head for the expiry list |
68 | * @firing: Timer is currently firing |
69 | * @handling: Pointer to the task which handles expiry |
70 | */ |
71 | struct cpu_timer { |
72 | struct timerqueue_node node; |
73 | struct timerqueue_head *head; |
74 | struct pid *pid; |
75 | struct list_head elist; |
76 | int firing; |
77 | struct task_struct __rcu *handling; |
78 | }; |
79 | |
80 | static inline bool cpu_timer_enqueue(struct timerqueue_head *head, |
81 | struct cpu_timer *ctmr) |
82 | { |
83 | ctmr->head = head; |
84 | return timerqueue_add(head, node: &ctmr->node); |
85 | } |
86 | |
87 | static inline bool cpu_timer_queued(struct cpu_timer *ctmr) |
88 | { |
89 | return !!ctmr->head; |
90 | } |
91 | |
92 | static inline bool cpu_timer_dequeue(struct cpu_timer *ctmr) |
93 | { |
94 | if (cpu_timer_queued(ctmr)) { |
95 | timerqueue_del(head: ctmr->head, node: &ctmr->node); |
96 | ctmr->head = NULL; |
97 | return true; |
98 | } |
99 | return false; |
100 | } |
101 | |
102 | static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr) |
103 | { |
104 | return ctmr->node.expires; |
105 | } |
106 | |
107 | static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp) |
108 | { |
109 | ctmr->node.expires = exp; |
110 | } |
111 | |
112 | /** |
113 | * posix_cputimer_base - Container per posix CPU clock |
114 | * @nextevt: Earliest-expiration cache |
115 | * @tqhead: timerqueue head for cpu_timers |
116 | */ |
117 | struct posix_cputimer_base { |
118 | u64 nextevt; |
119 | struct timerqueue_head tqhead; |
120 | }; |
121 | |
122 | /** |
123 | * posix_cputimers - Container for posix CPU timer related data |
124 | * @bases: Base container for posix CPU clocks |
125 | * @timers_active: Timers are queued. |
126 | * @expiry_active: Timer expiry is active. Used for |
127 | * process wide timers to avoid multiple |
128 | * task trying to handle expiry concurrently |
129 | * |
130 | * Used in task_struct and signal_struct |
131 | */ |
132 | struct posix_cputimers { |
133 | struct posix_cputimer_base bases[CPUCLOCK_MAX]; |
134 | unsigned int timers_active; |
135 | unsigned int expiry_active; |
136 | }; |
137 | |
138 | /** |
139 | * posix_cputimers_work - Container for task work based posix CPU timer expiry |
140 | * @work: The task work to be scheduled |
141 | * @mutex: Mutex held around expiry in context of this task work |
142 | * @scheduled: @work has been scheduled already, no further processing |
143 | */ |
144 | struct posix_cputimers_work { |
145 | struct callback_head work; |
146 | struct mutex mutex; |
147 | unsigned int scheduled; |
148 | }; |
149 | |
150 | static inline void posix_cputimers_init(struct posix_cputimers *pct) |
151 | { |
152 | memset(pct, 0, sizeof(*pct)); |
153 | pct->bases[0].nextevt = U64_MAX; |
154 | pct->bases[1].nextevt = U64_MAX; |
155 | pct->bases[2].nextevt = U64_MAX; |
156 | } |
157 | |
158 | void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit); |
159 | |
160 | static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct, |
161 | u64 runtime) |
162 | { |
163 | pct->bases[CPUCLOCK_SCHED].nextevt = runtime; |
164 | } |
165 | |
166 | /* Init task static initializer */ |
167 | #define INIT_CPU_TIMERBASE(b) { \ |
168 | .nextevt = U64_MAX, \ |
169 | } |
170 | |
171 | #define INIT_CPU_TIMERBASES(b) { \ |
172 | INIT_CPU_TIMERBASE(b[0]), \ |
173 | INIT_CPU_TIMERBASE(b[1]), \ |
174 | INIT_CPU_TIMERBASE(b[2]), \ |
175 | } |
176 | |
177 | #define INIT_CPU_TIMERS(s) \ |
178 | .posix_cputimers = { \ |
179 | .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \ |
180 | }, |
181 | #else |
182 | struct posix_cputimers { }; |
183 | struct cpu_timer { }; |
184 | #define INIT_CPU_TIMERS(s) |
185 | static inline void posix_cputimers_init(struct posix_cputimers *pct) { } |
186 | static inline void posix_cputimers_group_init(struct posix_cputimers *pct, |
187 | u64 cpu_limit) { } |
188 | #endif |
189 | |
190 | #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK |
191 | void clear_posix_cputimers_work(struct task_struct *p); |
192 | void posix_cputimers_init_work(void); |
193 | #else |
194 | static inline void clear_posix_cputimers_work(struct task_struct *p) { } |
195 | static inline void posix_cputimers_init_work(void) { } |
196 | #endif |
197 | |
198 | #define REQUEUE_PENDING 1 |
199 | |
200 | /** |
201 | * struct k_itimer - POSIX.1b interval timer structure. |
202 | * @list: List head for binding the timer to signals->posix_timers |
203 | * @t_hash: Entry in the posix timer hash table |
204 | * @it_lock: Lock protecting the timer |
205 | * @kclock: Pointer to the k_clock struct handling this timer |
206 | * @it_clock: The posix timer clock id |
207 | * @it_id: The posix timer id for identifying the timer |
208 | * @it_active: Marker that timer is active |
209 | * @it_overrun: The overrun counter for pending signals |
210 | * @it_overrun_last: The overrun at the time of the last delivered signal |
211 | * @it_requeue_pending: Indicator that timer waits for being requeued on |
212 | * signal delivery |
213 | * @it_sigev_notify: The notify word of sigevent struct for signal delivery |
214 | * @it_interval: The interval for periodic timers |
215 | * @it_signal: Pointer to the creators signal struct |
216 | * @it_pid: The pid of the process/task targeted by the signal |
217 | * @it_process: The task to wakeup on clock_nanosleep (CPU timers) |
218 | * @sigq: Pointer to preallocated sigqueue |
219 | * @it: Union representing the various posix timer type |
220 | * internals. |
221 | * @rcu: RCU head for freeing the timer. |
222 | */ |
223 | struct k_itimer { |
224 | struct list_head list; |
225 | struct hlist_node t_hash; |
226 | spinlock_t it_lock; |
227 | const struct k_clock *kclock; |
228 | clockid_t it_clock; |
229 | timer_t it_id; |
230 | int it_active; |
231 | s64 it_overrun; |
232 | s64 it_overrun_last; |
233 | int it_requeue_pending; |
234 | int it_sigev_notify; |
235 | ktime_t it_interval; |
236 | struct signal_struct *it_signal; |
237 | union { |
238 | struct pid *it_pid; |
239 | struct task_struct *it_process; |
240 | }; |
241 | struct sigqueue *sigq; |
242 | union { |
243 | struct { |
244 | struct hrtimer timer; |
245 | } real; |
246 | struct cpu_timer cpu; |
247 | struct { |
248 | struct alarm alarmtimer; |
249 | } alarm; |
250 | } it; |
251 | struct rcu_head rcu; |
252 | }; |
253 | |
254 | void run_posix_cpu_timers(void); |
255 | void posix_cpu_timers_exit(struct task_struct *task); |
256 | void posix_cpu_timers_exit_group(struct task_struct *task); |
257 | void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx, |
258 | u64 *newval, u64 *oldval); |
259 | |
260 | int update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new); |
261 | |
262 | void posixtimer_rearm(struct kernel_siginfo *info); |
263 | #endif |
264 | |