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_ */