1 /* $OpenBSD: softintr.c,v 1.11 2021/03/25 04:12:00 jsg Exp $ */
2 /* $NetBSD: softintr.c,v 1.2 2003/07/15 00:24:39 lukem Exp $ */
3
4 /*
5 * Copyright (c) 2001 Wasabi Systems, Inc.
6 * All rights reserved.
7 *
8 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed for the NetBSD Project by
21 * Wasabi Systems, Inc.
22 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
23 * or promote products derived from this software without specific prior
24 * written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/malloc.h>
42
43 #include <uvm/uvm_extern.h>
44
45 #include <machine/intr.h>
46
47 struct soft_intrq soft_intrq[SI_NQUEUES];
48
49 /*
50 * softintr_init:
51 *
52 * Initialize the software interrupt system.
53 */
54 void
softintr_init(void)55 softintr_init(void)
56 {
57 struct soft_intrq *siq;
58 int i;
59
60 for (i = 0; i < SI_NQUEUES; i++) {
61 siq = &soft_intrq[i];
62 TAILQ_INIT(&siq->siq_list);
63 mtx_init(&siq->siq_mtx, IPL_HIGH);
64 siq->siq_si = i;
65 }
66 }
67
68 /*
69 * softintr_dispatch:
70 *
71 * Process pending software interrupts on the specified queue.
72 *
73 * NOTE: We must already be at the correct interrupt priority level.
74 */
75 void
softintr_dispatch(int si)76 softintr_dispatch(int si)
77 {
78 struct soft_intrq *siq = &soft_intrq[si];
79 struct soft_intrhand *sih;
80
81 for (;;) {
82 mtx_enter(&siq->siq_mtx);
83 sih = TAILQ_FIRST(&siq->siq_list);
84 if (sih == NULL) {
85 mtx_leave(&siq->siq_mtx);
86 break;
87 }
88
89 TAILQ_REMOVE(&siq->siq_list, sih, sih_list);
90 sih->sih_pending = 0;
91
92 uvmexp.softs++;
93 mtx_leave(&siq->siq_mtx);
94
95 KERNEL_LOCK();
96 (*sih->sih_func)(sih->sih_arg);
97 KERNEL_UNLOCK();
98 }
99 }
100
101 /*
102 * softintr_establish: [interface]
103 *
104 * Register a software interrupt handler.
105 */
106 void *
softintr_establish(int ipl,void (* func)(void *),void * arg)107 softintr_establish(int ipl, void (*func)(void *), void *arg)
108 {
109 struct soft_intrhand *sih;
110 int si;
111
112 switch (ipl) {
113 case IPL_SOFT:
114 si = SI_SOFT;
115 break;
116
117 case IPL_SOFTCLOCK:
118 si = SI_SOFTCLOCK;
119 break;
120
121 case IPL_SOFTNET:
122 si = SI_SOFTNET;
123 break;
124
125 case IPL_TTY:
126 case IPL_SOFTTTY:
127 si = SI_SOFTTTY;
128 break;
129
130 default:
131 panic("softintr_establish: unknown soft IPL %d", ipl);
132 }
133
134 sih = malloc(sizeof(*sih), M_DEVBUF, M_NOWAIT);
135 if (__predict_true(sih != NULL)) {
136 sih->sih_func = func;
137 sih->sih_arg = arg;
138 sih->sih_siq = &soft_intrq[si];
139 sih->sih_pending = 0;
140 }
141 return (sih);
142 }
143
144 /*
145 * softintr_disestablish: [interface]
146 *
147 * Unregister a software interrupt handler.
148 */
149 void
softintr_disestablish(void * arg)150 softintr_disestablish(void *arg)
151 {
152 struct soft_intrhand *sih = arg;
153 struct soft_intrq *siq = sih->sih_siq;
154
155 mtx_enter(&siq->siq_mtx);
156 if (sih->sih_pending) {
157 TAILQ_REMOVE(&siq->siq_list, sih, sih_list);
158 sih->sih_pending = 0;
159 }
160 mtx_leave(&siq->siq_mtx);
161
162 free(sih, M_DEVBUF, 0);
163 }
164