summaryrefslogtreecommitdiffstats
path: root/include/linux/posix-timers.h
blob: 9cf126c3b27fb63d69b78f791c99025186434590 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _linux_POSIX_TIMERS_H
#define _linux_POSIX_TIMERS_H

#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/alarmtimer.h>
#include <linux/timerqueue.h>
#include <linux/task_work.h>

struct kernel_siginfo;
struct task_struct;

/*
 * Bit fields within a clockid:
 *
 * The most significant 29 bits hold either a pid or a file descriptor.
 *
 * Bit 2 indicates whether a cpu clock refers to a thread or a process.
 *
 * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
 *
 * A clockid is invalid if bits 2, 1, and 0 are all set.
 */
#define CPUCLOCK_PID(clock)		((pid_t) ~((clock) >> 3))
#define CPUCLOCK_PERTHREAD(clock) \
	(((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)

#define CPUCLOCK_PERTHREAD_MASK	4
#define CPUCLOCK_WHICH(clock)	((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
#define CPUCLOCK_CLOCK_MASK	3
#define CPUCLOCK_PROF		0
#define CPUCLOCK_VIRT		1
#define CPUCLOCK_SCHED		2
#define CPUCLOCK_MAX		3
#define CLOCKFD			CPUCLOCK_MAX
#define CLOCKFD_MASK		(CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)

static inline clockid_t make_process_cpuclock(const unsigned int pid,
		const clockid_t clock)
{
	return ((~pid) << 3) | clock;
}
static inline clockid_t make_thread_cpuclock(const unsigned int tid,
		const clockid_t clock)
{
	return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK);
}

static inline clockid_t fd_to_clockid(const int fd)
{
	return make_process_cpuclock((unsigned int) fd, CLOCKFD);
}

static inline int clockid_to_fd(const clockid_t clk)
{
	return ~(clk >> 3);
}

#ifdef CONFIG_POSIX_TIMERS

/**
 * cpu_timer - Posix CPU timer representation for k_itimer
 * @node:	timerqueue node to queue in the task/sig
 * @head:	timerqueue head on which this timer is queued
 * @task:	Pointer to target task
 * @elist:	List head for the expiry list
 * @firing:	Timer is currently firing
 */
struct cpu_timer {
	struct timerqueue_node	node;
	struct timerqueue_head	*head;
	struct pid		*pid;
	struct list_head	elist;
	int			firing;
};

static inline bool cpu_timer_enqueue(struct timerqueue_head *head,
				     struct cpu_timer *ctmr)
{
	ctmr->head = head;
	return timerqueue_add(head, &ctmr->node);
}

static inline bool cpu_timer_queued(struct cpu_timer *ctmr)
{
	return !!ctmr->head;
}

static inline bool cpu_timer_dequeue(struct cpu_timer *ctmr)
{
	if (cpu_timer_queued(ctmr)) {
		timerqueue_del(ctmr->head, &ctmr->node);
		ctmr->head = NULL;
		return true;
	}
	return false;
}

static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr)
{
	return ctmr->node.expires;
}

static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp)
{
	ctmr->node.expires = exp;
}

/**
 * posix_cputimer_base - Container per posix CPU clock
 * @nextevt:		Earliest-expiration cache
 * @tqhead:		timerqueue head for cpu_timers
 */
struct posix_cputimer_base {
	u64			nextevt;
	struct timerqueue_head	tqhead;
};

/**
 * posix_cputimers - Container for posix CPU timer related data
 * @bases:		Base container for posix CPU clocks
 * @timers_active:	Timers are queued.
 * @expiry_active:	Timer expiry is active. Used for
 *			process wide timers to avoid multiple
 *			task trying to handle expiry concurrently
 *
 * Used in task_struct and signal_struct
 */
struct posix_cputimers {
	struct posix_cputimer_base	bases[CPUCLOCK_MAX];
	unsigned int			timers_active;
	unsigned int			expiry_active;
};

/**
 * posix_cputimers_work - Container for task work based posix CPU timer expiry
 * @work:	The task work to be scheduled
 * @scheduled:  @work has been scheduled already, no further processing
 */
struct posix_cputimers_work {
	struct callback_head	work;
	unsigned int		scheduled;
};

static inline void posix_cputimers_init(struct posix_cputimers *pct)
{
	memset(pct, 0, sizeof(*pct));
	pct->bases[0].nextevt = U64_MAX;
	pct->bases[1].nextevt = U64_MAX;
	pct->bases[2].nextevt = U64_MAX;
}

void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit);

static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
					       u64 runtime)
{
	pct->bases[CPUCLOCK_SCHED].nextevt = runtime;
}

/* Init task static initializer */
#define INIT_CPU_TIMERBASE(b) {						\
	.nextevt	= U64_MAX,					\
}

#define INIT_CPU_TIMERBASES(b) {					\
	INIT_CPU_TIMERBASE(b[0]),					\
	INIT_CPU_TIMERBASE(b[1]),					\
	INIT_CPU_TIMERBASE(b[2]),					\
}

#define INIT_CPU_TIMERS(s)						\
	.posix_cputimers = {						\
		.bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases),	\
	},
#else
struct posix_cputimers { };
struct cpu_timer { };
#define INIT_CPU_TIMERS(s)
static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
					      u64 cpu_limit) { }
#endif

#ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
void clear_posix_cputimers_work(struct task_struct *p);
void posix_cputimers_init_work(void);
#else
static inline void clear_posix_cputimers_work(struct task_struct *p) { }
static inline void posix_cputimers_init_work(void) { }
#endif

#define REQUEUE_PENDING 1

/**
 * struct k_itimer - POSIX.1b interval timer structure.
 * @list:		List head for binding the timer to signals->posix_timers
 * @t_hash:		Entry in the posix timer hash table
 * @it_lock:		Lock protecting the timer
 * @kclock:		Pointer to the k_clock struct handling this timer
 * @it_clock:		The posix timer clock id
 * @it_id:		The posix timer id for identifying the timer
 * @it_active:		Marker that timer is active
 * @it_overrun:		The overrun counter for pending signals
 * @it_overrun_last:	The overrun at the time of the last delivered signal
 * @it_requeue_pending:	Indicator that timer waits for being requeued on
 *			signal delivery
 * @it_sigev_notify:	The notify word of sigevent struct for signal delivery
 * @it_interval:	The interval for periodic timers
 * @it_signal:		Pointer to the creators signal struct
 * @it_pid:		The pid of the process/task targeted by the signal
 * @it_process:		The task to wakeup on clock_nanosleep (CPU timers)
 * @sigq:		Pointer to preallocated sigqueue
 * @it:			Union representing the various posix timer type
 *			internals.
 * @rcu:		RCU head for freeing the timer.
 */
struct k_itimer {
	struct list_head	list;
	struct hlist_node	t_hash;
	spinlock_t		it_lock;
	const struct k_clock	*kclock;
	clockid_t		it_clock;
	timer_t			it_id;
	int			it_active;
	s64			it_overrun;
	s64			it_overrun_last;
	int			it_requeue_pending;
	int			it_sigev_notify;
	ktime_t			it_interval;
	struct signal_struct	*it_signal;
	union {
		struct pid		*it_pid;
		struct task_struct	*it_process;
	};
	struct sigqueue		*sigq;
	union {
		struct {
			struct hrtimer	timer;
		} real;
		struct cpu_timer	cpu;
		struct {
			struct alarm	alarmtimer;
		} alarm;
	} it;
	struct rcu_head		rcu;
};

void run_posix_cpu_timers(void);
void posix_cpu_timers_exit(struct task_struct *task);
void posix_cpu_timers_exit_group(struct task_struct *task);
void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
			   u64 *newval, u64 *oldval);

int update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);

void posixtimer_rearm(struct kernel_siginfo *info);
#endif