1 /*-
2 * Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/10.0/sys/kern/subr_counter.c 253565 2013-07-23 11:16:40Z glebius $");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/lock.h>
34 #include <sys/mutex.h>
35 #include <sys/proc.h>
36 #include <sys/sched.h>
37 #include <sys/smp.h>
38 #include <sys/sysctl.h>
39 #include <vm/uma.h>
40
41 #define IN_SUBR_COUNTER_C
42 #include <sys/counter.h>
43
44 static uma_zone_t uint64_pcpu_zone;
45
46 void
47 counter_u64_zero(counter_u64_t c)
48 {
49
50 counter_u64_zero_inline(c);
51 }
52
53 uint64_t
54 counter_u64_fetch(counter_u64_t c)
55 {
56
57 return (counter_u64_fetch_inline(c));
58 }
59
60 counter_u64_t
61 counter_u64_alloc(int flags)
62 {
63 counter_u64_t r;
64
65 r = uma_zalloc(uint64_pcpu_zone, flags);
66 if (r != NULL)
67 counter_u64_zero(r);
68
69 return (r);
70 }
71
72 void
73 counter_u64_free(counter_u64_t c)
74 {
75
76 uma_zfree(uint64_pcpu_zone, c);
77 }
78
79 int
80 sysctl_handle_counter_u64(SYSCTL_HANDLER_ARGS)
81 {
82 uint64_t out;
83 int error;
84
85 out = counter_u64_fetch(*(counter_u64_t *)arg1);
86
87 error = SYSCTL_OUT(req, &out, sizeof(uint64_t));
88
89 if (error || !req->newptr)
90 return (error);
91
92 /*
93 * Any write attempt to a counter zeroes it.
94 */
95 counter_u64_zero(*(counter_u64_t *)arg1);
96
97 return (0);
98 }
99
100 static void
101 counter_startup(void)
102 {
103
104 uint64_pcpu_zone = uma_zcreate("uint64 pcpu", sizeof(uint64_t),
105 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_PCPU);
106 }
107 SYSINIT(counter, SI_SUB_KMEM, SI_ORDER_ANY, counter_startup, NULL);
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