1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
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
28#ifndef _SYS_EPOCH_H_
29#define _SYS_EPOCH_H_
30
31#include <sys/cdefs.h>
32
33struct epoch_context {
34 void *data[2];
35} __aligned(sizeof(void *));
36
37typedef struct epoch_context *epoch_context_t;
38typedef void epoch_callback_t(epoch_context_t);
39
40#ifdef _KERNEL
41#include <sys/lock.h>
42#include <sys/pcpu.h>
43#include <ck_epoch.h>
44
45struct epoch;
46typedef struct epoch *epoch_t;
47
48#define EPOCH_PREEMPT 0x1
49#define EPOCH_LOCKED 0x2
50
51extern epoch_t global_epoch;
52extern epoch_t global_epoch_preempt;
53
54struct epoch_tracker {
55 TAILQ_ENTRY(epoch_tracker) et_link;
56 struct thread *et_td;
57 ck_epoch_section_t et_section;
58 uint8_t et_old_priority;
59#ifdef EPOCH_TRACE
60 struct epoch *et_epoch;
61 SLIST_ENTRY(epoch_tracker) et_tlink;
62 const char *et_file;
63 int et_line;
64 int et_flags;
65#define ET_REPORT_EXIT 0x1
66#endif
67} __aligned(sizeof(void *));
68typedef struct epoch_tracker *epoch_tracker_t;
69
70epoch_t epoch_alloc(const char *name, int flags);
71void epoch_free(epoch_t epoch);
72void epoch_wait(epoch_t epoch);
73void epoch_wait_preempt(epoch_t epoch);
74void epoch_drain_callbacks(epoch_t epoch);
75void epoch_call(epoch_t epoch, epoch_callback_t cb, epoch_context_t ctx);
76int in_epoch(epoch_t epoch);
77int in_epoch_verbose(epoch_t epoch, int dump_onfail);
78DPCPU_DECLARE(int, epoch_cb_count);
79DPCPU_DECLARE(struct grouptask, epoch_cb_task);
80
81#ifdef EPOCH_TRACE
82#define EPOCH_FILE_LINE , const char *file, int line
83#else
84#define EPOCH_FILE_LINE
85#endif
86
87void _epoch_enter_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE);
88void _epoch_exit_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE);
89#ifdef EPOCH_TRACE
90void epoch_trace_list(struct thread *);
91void epoch_where_report(epoch_t);
92#define epoch_enter_preempt(epoch, et) _epoch_enter_preempt(epoch, et, __FILE__, __LINE__)
93#define epoch_exit_preempt(epoch, et) _epoch_exit_preempt(epoch, et, __FILE__, __LINE__)
94#else
95#define epoch_enter_preempt(epoch, et) _epoch_enter_preempt(epoch, et)
96#define epoch_exit_preempt(epoch, et) _epoch_exit_preempt(epoch, et)
97#endif
98void epoch_enter(epoch_t epoch);
99void epoch_exit(epoch_t epoch);
100
101/*
102 * Globally recognized epochs in the FreeBSD kernel.
103 */
104/* Network preemptible epoch, declared in sys/net/if.c. */
105extern epoch_t net_epoch_preempt;
106#define NET_EPOCH_ENTER(et) epoch_enter_preempt(net_epoch_preempt, &(et))
107#define NET_EPOCH_EXIT(et) epoch_exit_preempt(net_epoch_preempt, &(et))
108#define NET_EPOCH_WAIT() epoch_wait_preempt(net_epoch_preempt)
109#define NET_EPOCH_CALL(f, c) epoch_call(net_epoch_preempt, (f), (c))
110#define NET_EPOCH_DRAIN_CALLBACKS() epoch_drain_callbacks(net_epoch_preempt)
111#define NET_EPOCH_ASSERT() MPASS(in_epoch(net_epoch_preempt))
112#define NET_TASK_INIT(t, p, f, c) TASK_INIT_FLAGS(t, p, f, c, TASK_NETWORK)
113#define NET_GROUPTASK_INIT(gtask, prio, func, ctx) \
114 GTASK_INIT(&(gtask)->gt_task, TASK_NETWORK, (prio), (func), (ctx))
115
116#endif /* _KERNEL */
117#endif /* _SYS_EPOCH_H_ */