xref: /linux/include/linux/posix-timers_types.h (revision eee51b0a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _linux_POSIX_TIMERS_TYPES_H
3 #define _linux_POSIX_TIMERS_TYPES_H
4 
5 #include <linux/mutex_types.h>
6 #include <linux/timerqueue_types.h>
7 #include <linux/types.h>
8 
9 /*
10  * Bit fields within a clockid:
11  *
12  * The most significant 29 bits hold either a pid or a file descriptor.
13  *
14  * Bit 2 indicates whether a cpu clock refers to a thread or a process.
15  *
16  * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
17  *
18  * A clockid is invalid if bits 2, 1, and 0 are all set.
19  */
20 #define CPUCLOCK_PID(clock)		((pid_t) ~((clock) >> 3))
21 #define CPUCLOCK_PERTHREAD(clock) \
22 	(((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
23 
24 #define CPUCLOCK_PERTHREAD_MASK	4
25 #define CPUCLOCK_WHICH(clock)	((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
26 #define CPUCLOCK_CLOCK_MASK	3
27 #define CPUCLOCK_PROF		0
28 #define CPUCLOCK_VIRT		1
29 #define CPUCLOCK_SCHED		2
30 #define CPUCLOCK_MAX		3
31 #define CLOCKFD			CPUCLOCK_MAX
32 #define CLOCKFD_MASK		(CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
33 
34 #ifdef CONFIG_POSIX_TIMERS
35 
36 /**
37  * posix_cputimer_base - Container per posix CPU clock
38  * @nextevt:		Earliest-expiration cache
39  * @tqhead:		timerqueue head for cpu_timers
40  */
41 struct posix_cputimer_base {
42 	u64			nextevt;
43 	struct timerqueue_head	tqhead;
44 };
45 
46 /**
47  * posix_cputimers - Container for posix CPU timer related data
48  * @bases:		Base container for posix CPU clocks
49  * @timers_active:	Timers are queued.
50  * @expiry_active:	Timer expiry is active. Used for
51  *			process wide timers to avoid multiple
52  *			task trying to handle expiry concurrently
53  *
54  * Used in task_struct and signal_struct
55  */
56 struct posix_cputimers {
57 	struct posix_cputimer_base	bases[CPUCLOCK_MAX];
58 	unsigned int			timers_active;
59 	unsigned int			expiry_active;
60 };
61 
62 /**
63  * posix_cputimers_work - Container for task work based posix CPU timer expiry
64  * @work:	The task work to be scheduled
65  * @mutex:	Mutex held around expiry in context of this task work
66  * @scheduled:  @work has been scheduled already, no further processing
67  */
68 struct posix_cputimers_work {
69 	struct callback_head	work;
70 	struct mutex		mutex;
71 	unsigned int		scheduled;
72 };
73 
74 #else /* CONFIG_POSIX_TIMERS */
75 
76 struct posix_cputimers { };
77 
78 #endif /* CONFIG_POSIX_TIMERS */
79 
80 #endif /* _linux_POSIX_TIMERS_TYPES_H */
81