xref: /freebsd/sys/sys/epoch.h (revision 271171e0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2018, Matthew Macy <mmacy@freebsd.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #ifndef _SYS_EPOCH_H_
31 #define _SYS_EPOCH_H_
32 
33 #include <sys/cdefs.h>
34 
35 struct epoch_context {
36 	void   *data[2];
37 } __aligned(sizeof(void *));
38 
39 typedef struct epoch_context *epoch_context_t;
40 typedef	void epoch_callback_t(epoch_context_t);
41 
42 #ifdef _KERNEL
43 #include <sys/lock.h>
44 #include <sys/pcpu.h>
45 #include <ck_epoch.h>
46 
47 struct epoch;
48 typedef struct epoch *epoch_t;
49 
50 #define EPOCH_PREEMPT 0x1
51 #define EPOCH_LOCKED 0x2
52 
53 extern epoch_t global_epoch;
54 extern epoch_t global_epoch_preempt;
55 
56 struct epoch_tracker {
57 	TAILQ_ENTRY(epoch_tracker) et_link;
58 	struct thread *et_td;
59 	ck_epoch_section_t et_section;
60 	uint8_t et_old_priority;
61 #ifdef EPOCH_TRACE
62 	struct epoch *et_epoch;
63 	SLIST_ENTRY(epoch_tracker) et_tlink;
64 	const char *et_file;
65 	int et_line;
66 	int et_flags;
67 #define	ET_REPORT_EXIT	0x1
68 #endif
69 }  __aligned(sizeof(void *));
70 typedef struct epoch_tracker *epoch_tracker_t;
71 
72 epoch_t	epoch_alloc(const char *name, int flags);
73 void	epoch_free(epoch_t epoch);
74 void	epoch_wait(epoch_t epoch);
75 void	epoch_wait_preempt(epoch_t epoch);
76 void	epoch_drain_callbacks(epoch_t epoch);
77 void	epoch_call(epoch_t epoch, epoch_callback_t cb, epoch_context_t ctx);
78 int	in_epoch(epoch_t epoch);
79 int in_epoch_verbose(epoch_t epoch, int dump_onfail);
80 DPCPU_DECLARE(int, epoch_cb_count);
81 DPCPU_DECLARE(struct grouptask, epoch_cb_task);
82 
83 #ifdef EPOCH_TRACE
84 #define	EPOCH_FILE_LINE	, const char *file, int line
85 #else
86 #define	EPOCH_FILE_LINE
87 #endif
88 
89 void _epoch_enter_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE);
90 void _epoch_exit_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE);
91 #ifdef EPOCH_TRACE
92 void epoch_trace_list(struct thread *);
93 void epoch_where_report(epoch_t);
94 #define	epoch_enter_preempt(epoch, et)	_epoch_enter_preempt(epoch, et, __FILE__, __LINE__)
95 #define	epoch_exit_preempt(epoch, et)	_epoch_exit_preempt(epoch, et, __FILE__, __LINE__)
96 #else
97 #define epoch_enter_preempt(epoch, et)	_epoch_enter_preempt(epoch, et)
98 #define	epoch_exit_preempt(epoch, et)	_epoch_exit_preempt(epoch, et)
99 #endif
100 void epoch_enter(epoch_t epoch);
101 void epoch_exit(epoch_t epoch);
102 
103 /*
104  * Globally recognized epochs in the FreeBSD kernel.
105  */
106 /* Network preemptible epoch, declared in sys/net/if.c. */
107 extern epoch_t net_epoch_preempt;
108 #define	NET_EPOCH_ENTER(et)	epoch_enter_preempt(net_epoch_preempt, &(et))
109 #define	NET_EPOCH_EXIT(et)	epoch_exit_preempt(net_epoch_preempt, &(et))
110 #define	NET_EPOCH_WAIT()	epoch_wait_preempt(net_epoch_preempt)
111 #define	NET_EPOCH_CALL(f, c)	epoch_call(net_epoch_preempt, (f), (c))
112 #define	NET_EPOCH_DRAIN_CALLBACKS() epoch_drain_callbacks(net_epoch_preempt)
113 #define	NET_EPOCH_ASSERT()	MPASS(in_epoch(net_epoch_preempt))
114 #define	NET_TASK_INIT(t, p, f, c) TASK_INIT_FLAGS(t, p, f, c, TASK_NETWORK)
115 #define	NET_GROUPTASK_INIT(gtask, prio, func, ctx)			\
116 	    GTASK_INIT(&(gtask)->gt_task, TASK_NETWORK, (prio), (func), (ctx))
117 
118 #endif	/* _KERNEL */
119 #endif	/* _SYS_EPOCH_H_ */
120