1 /* $OpenBSD: subr_evcount.c,v 1.16 2023/09/16 09:33:27 mpi Exp $ */
2 /*
3 * Copyright (c) 2004 Artur Grabowski <art@openbsd.org>
4 * Copyright (c) 2004 Aaron Campbell <aaron@openbsd.org>
5 * All rights reserved.
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. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
17 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
18 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
19 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include <sys/param.h>
29 #include <sys/evcount.h>
30 #include <sys/systm.h>
31 #include <sys/sysctl.h>
32 #include <sys/percpu.h>
33
34 static TAILQ_HEAD(,evcount) evcount_list = TAILQ_HEAD_INITIALIZER(evcount_list);
35 static TAILQ_HEAD(,evcount) evcount_percpu_init_list =
36 TAILQ_HEAD_INITIALIZER(evcount_percpu_init_list);
37 static int evcount_percpu_done;
38
39 void
evcount_attach(struct evcount * ec,const char * name,void * data)40 evcount_attach(struct evcount *ec, const char *name, void *data)
41 {
42 static int nextid = 0;
43
44 memset(ec, 0, sizeof(*ec));
45 ec->ec_name = name;
46 ec->ec_id = ++nextid;
47 ec->ec_data = data;
48 TAILQ_INSERT_TAIL(&evcount_list, ec, next);
49 }
50
51 void
evcount_percpu(struct evcount * ec)52 evcount_percpu(struct evcount *ec)
53 {
54 if (evcount_percpu_done == 0) {
55 TAILQ_REMOVE(&evcount_list, ec, next);
56 TAILQ_INSERT_TAIL(&evcount_percpu_init_list, ec, next);
57 } else {
58 ec->ec_percpu = counters_alloc(1);
59 }
60 }
61
62 void
evcount_init_percpu(void)63 evcount_init_percpu(void)
64 {
65 struct evcount *ec;
66
67 KASSERT(evcount_percpu_done == 0);
68 TAILQ_FOREACH(ec, &evcount_percpu_init_list, next) {
69 ec->ec_percpu = counters_alloc(1);
70 counters_add(ec->ec_percpu, 0, ec->ec_count);
71 ec->ec_count = 0;
72 }
73 TAILQ_CONCAT(&evcount_list, &evcount_percpu_init_list, next);
74 evcount_percpu_done = 1;
75 }
76
77 void
evcount_detach(struct evcount * ec)78 evcount_detach(struct evcount *ec)
79 {
80 TAILQ_REMOVE(&evcount_list, ec, next);
81 if (ec->ec_percpu != NULL) {
82 counters_free(ec->ec_percpu, 1);
83 ec->ec_percpu = NULL;
84 }
85 }
86
87 void
evcount_inc(struct evcount * ec)88 evcount_inc(struct evcount *ec)
89 {
90 if (ec->ec_percpu != NULL)
91 counters_inc(ec->ec_percpu, 0);
92 else
93 ec->ec_count++;
94 }
95
96 #ifndef SMALL_KERNEL
97
98 int
evcount_sysctl(int * name,u_int namelen,void * oldp,size_t * oldlenp,void * newp,size_t newlen)99 evcount_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
100 void *newp, size_t newlen)
101 {
102 int error = 0, s, nintr, i;
103 struct evcount *ec;
104 uint64_t count, scratch;
105
106 if (newp != NULL)
107 return (EPERM);
108
109 if (name[0] != KERN_INTRCNT_NUM) {
110 if (namelen != 2)
111 return (ENOTDIR);
112 if (name[1] < 0)
113 return (EINVAL);
114 i = name[1];
115 } else
116 i = -1;
117
118 nintr = 0;
119 TAILQ_FOREACH(ec, &evcount_list, next) {
120 if (nintr++ == i)
121 break;
122 }
123
124 switch (name[0]) {
125 case KERN_INTRCNT_NUM:
126 error = sysctl_rdint(oldp, oldlenp, NULL, nintr);
127 break;
128 case KERN_INTRCNT_CNT:
129 if (ec == NULL)
130 return (ENOENT);
131 if (ec->ec_percpu != NULL) {
132 counters_read(ec->ec_percpu, &count, 1, &scratch);
133 } else {
134 s = splhigh();
135 count = ec->ec_count;
136 splx(s);
137 }
138 error = sysctl_rdquad(oldp, oldlenp, NULL, count);
139 break;
140 case KERN_INTRCNT_NAME:
141 if (ec == NULL)
142 return (ENOENT);
143 error = sysctl_rdstring(oldp, oldlenp, NULL, ec->ec_name);
144 break;
145 case KERN_INTRCNT_VECTOR:
146 if (ec == NULL || ec->ec_data == NULL)
147 return (ENOENT);
148 error = sysctl_rdint(oldp, oldlenp, NULL,
149 *((int *)ec->ec_data));
150 break;
151 default:
152 error = EOPNOTSUPP;
153 break;
154 }
155
156 return (error);
157 }
158 #endif /* SMALL_KERNEL */
159