1 /*
2  * Copyright (c) 2006 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/platform/vkernel/platform/kqueue.c,v 1.6 2007/07/02 03:44:12 dillon Exp $
35  */
36 
37 #include <sys/types.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/systimer.h>
41 #include <sys/sysctl.h>
42 #include <sys/signal.h>
43 #include <sys/interrupt.h>
44 #include <sys/bus.h>
45 #include <sys/time.h>
46 #include <sys/event.h>
47 #include <sys/time.h>
48 #include <machine/cpu.h>
49 #include <machine/globaldata.h>
50 #include <machine/md_var.h>
51 
52 #include <sys/thread2.h>
53 
54 #include <unistd.h>
55 #include <signal.h>
56 #include <stdlib.h>
57 #include <fcntl.h>
58 
59 struct kqueue_info {
60 	void (*func)(void *, struct intrframe *);
61 	void *data;
62 	int fd;
63 };
64 
65 static void kqueuesig(int signo);
66 static void kqueue_intr(void *arg __unused, void *frame __unused);
67 
68 static int KQueueFd = -1;
69 static void *VIntr1;
70 
71 /*
72  * Initialize kqueue based I/O
73  *
74  * Use SIGIO to get an immediate event when the kqueue has something waiting
75  * for us.  Setup the SIGIO signal as a mailbox signal for efficiency.
76  *
77  * Currently only read events are supported.
78  */
79 void
80 init_kqueue(void)
81 {
82 	struct sigaction sa;
83 
84 	bzero(&sa, sizeof(sa));
85 	/*sa.sa_mailbox = &mdcpu->gd_mailbox;*/
86 	sa.sa_flags = SA_NODEFER;
87 	sa.sa_handler = kqueuesig;
88 	sigemptyset(&sa.sa_mask);
89 	sigaction(SIGIO, &sa, NULL);
90 	KQueueFd = kqueue();
91 	if (fcntl(KQueueFd, F_SETOWN, getpid()) < 0)
92 		panic("Cannot configure kqueue for SIGIO, update your kernel");
93 	if (fcntl(KQueueFd, F_SETFL, O_ASYNC) < 0)
94 		panic("Cannot configure kqueue for SIGIO, update your kernel");
95 }
96 
97 /*
98  * Signal handler dispatches interrupt thread.  Use interrupt #1
99  */
100 static void
101 kqueuesig(int signo)
102 {
103 	signalintr(1);
104 }
105 
106 /*
107  * Generic I/O event support
108  */
109 struct kqueue_info *
110 kqueue_add(int fd, void (*func)(void *, struct intrframe *), void *data)
111 {
112 	struct timespec ts = { 0, 0 };
113 	struct kqueue_info *info;
114 	struct kevent kev;
115 
116 	if (VIntr1 == NULL)
117 		VIntr1 = register_int(1, kqueue_intr, NULL, "kqueue", NULL, 0);
118 
119 	info = kmalloc(sizeof(*info), M_DEVBUF, M_ZERO|M_INTWAIT);
120 	info->func = func;
121 	info->data = data;
122 	info->fd = fd;
123 	EV_SET(&kev, fd, EVFILT_READ, EV_ADD|EV_ENABLE|EV_CLEAR, 0, 0, info);
124 	if (kevent(KQueueFd, &kev, 1, NULL, 0, &ts) < 0)
125 		panic("kqueue: kevent() call could not add descriptor");
126 	return(info);
127 }
128 
129 /*
130  * Medium resolution timer support
131  */
132 struct kqueue_info *
133 kqueue_add_timer(void (*func)(void *, struct intrframe *), void *data)
134 {
135 	struct kqueue_info *info;
136 
137 	if (VIntr1 == NULL)
138 		VIntr1 = register_int(1, kqueue_intr, NULL, "kqueue", NULL, 0);
139 
140 	info = kmalloc(sizeof(*info), M_DEVBUF, M_ZERO|M_INTWAIT);
141 	info->func = func;
142 	info->data = data;
143 	info->fd = (uintptr_t)info;
144 	return(info);
145 }
146 
147 void
148 kqueue_reload_timer(struct kqueue_info *info, int ms)
149 {
150 	struct timespec ts = { 0, 0 };
151 	struct kevent kev;
152 
153 	KKASSERT(ms > 0);
154 
155 	EV_SET(&kev, info->fd, EVFILT_TIMER,
156 		EV_ADD|EV_ENABLE|EV_ONESHOT|EV_CLEAR, 0, (uintptr_t)ms, info);
157 	if (kevent(KQueueFd, &kev, 1, NULL, 0, &ts) < 0)
158 		panic("kqueue_reload_timer: Failed");
159 }
160 
161 /*
162  * Destroy a previously added kqueue event
163  */
164 void
165 kqueue_del(struct kqueue_info *info)
166 {
167 	struct timespec ts = { 0, 0 };
168 	struct kevent kev;
169 
170 	KKASSERT(info->fd >= 0);
171 	EV_SET(&kev, info->fd, EVFILT_READ, EV_DELETE, 0, 0, NULL);
172 	if (kevent(KQueueFd, &kev, 1, NULL, 0, &ts) < 0)
173 		panic("kevent: failed to delete descriptor %d", info->fd);
174 	info->fd = -1;
175 	kfree(info, M_DEVBUF);
176 }
177 
178 /*
179  * Safely called via DragonFly's normal interrupt handling mechanism.
180  *
181  * Calleld with the MP lock held.  Note that this is still an interrupt
182  * thread context.
183  */
184 static
185 void
186 kqueue_intr(void *arg __unused, void *frame __unused)
187 {
188 	struct timespec ts;
189 	struct kevent kevary[8];
190 	int n;
191 	int i;
192 
193 	ts.tv_sec = 0;
194 	ts.tv_nsec = 0;
195 	do {
196 		n = kevent(KQueueFd, NULL, 0, kevary, 8, &ts);
197 		for (i = 0; i < n; ++i) {
198 			struct kevent *kev = &kevary[i];
199 			struct kqueue_info *info = (void *)kev->udata;
200 
201 			info->func(info->data, frame);
202 		}
203 	} while (n == 8);
204 }
205