xref: /openbsd/sys/kern/subr_evcount.c (revision 8529ddd3)
1 /*	$OpenBSD: subr_evcount.c,v 1.12 2015/03/14 03:38:50 jsg 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/timeout.h>
31 #include <sys/systm.h>
32 #include <sys/sysctl.h>
33 
34 static TAILQ_HEAD(,evcount) evcount_list = TAILQ_HEAD_INITIALIZER(evcount_list);
35 
36 void
37 evcount_attach(struct evcount *ec, const char *name, void *data)
38 {
39 	static int nextid = 0;
40 
41 	memset(ec, 0, sizeof(*ec));
42 	ec->ec_name = name;
43 	ec->ec_id = ++nextid;
44 	ec->ec_data = data;
45 	TAILQ_INSERT_TAIL(&evcount_list, ec, next);
46 }
47 
48 void
49 evcount_detach(struct evcount *ec)
50 {
51 	TAILQ_REMOVE(&evcount_list, ec, next);
52 }
53 
54 #ifndef	SMALL_KERNEL
55 
56 int
57 evcount_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
58     void *newp, size_t newlen)
59 {
60 	int error = 0, s, nintr, i;
61 	struct evcount *ec;
62 	u_int64_t count;
63 
64 	if (newp != NULL)
65 		return (EPERM);
66 
67 	if (name[0] != KERN_INTRCNT_NUM) {
68 		if (namelen != 2)
69 			return (ENOTDIR);
70 		if (name[1] < 0)
71 			return (EINVAL);
72 		i = name[1];
73 	} else
74 		i = -1;
75 
76 	nintr = 0;
77 	TAILQ_FOREACH(ec, &evcount_list, next) {
78 		if (nintr++ == i)
79 			break;
80 	}
81 
82 	switch (name[0]) {
83 	case KERN_INTRCNT_NUM:
84 		error = sysctl_rdint(oldp, oldlenp, NULL, nintr);
85 		break;
86 	case KERN_INTRCNT_CNT:
87 		if (ec == NULL)
88 			return (ENOENT);
89 		s = splhigh();
90 		count = ec->ec_count;
91 		splx(s);
92 		error = sysctl_rdquad(oldp, oldlenp, NULL, count);
93 		break;
94 	case KERN_INTRCNT_NAME:
95 		if (ec == NULL)
96 			return (ENOENT);
97 		error = sysctl_rdstring(oldp, oldlenp, NULL, ec->ec_name);
98 		break;
99 	case KERN_INTRCNT_VECTOR:
100 		if (ec == NULL || ec->ec_data == NULL)
101 			return (ENOENT);
102 		error = sysctl_rdint(oldp, oldlenp, NULL,
103 		    *((int *)ec->ec_data));
104 		break;
105 	default:
106 		error = EOPNOTSUPP;
107 		break;
108 	}
109 
110 	return (error);
111 }
112 #endif	/* SMALL_KERNEL */
113