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("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/counter.h> 33 #include <sys/kernel.h> 34 #include <sys/smp.h> 35 #include <sys/sysctl.h> 36 #include <vm/uma.h> 37 38 static uma_zone_t uint64_pcpu_zone; 39 40 void 41 counter_u64_zero(counter_u64_t c) 42 { 43 int i; 44 45 for (i = 0; i < mp_ncpus; i++) 46 *(uint64_t *)((char *)c + sizeof(struct pcpu) * i) = 0; 47 } 48 49 uint64_t 50 counter_u64_fetch(counter_u64_t c) 51 { 52 uint64_t r; 53 int i; 54 55 r = 0; 56 for (i = 0; i < mp_ncpus; i++) 57 r += *(uint64_t *)((char *)c + sizeof(struct pcpu) * i); 58 59 return (r); 60 } 61 62 counter_u64_t 63 counter_u64_alloc(int flags) 64 { 65 counter_u64_t r; 66 67 r = uma_zalloc(uint64_pcpu_zone, flags); 68 if (r != NULL) 69 counter_u64_zero(r); 70 71 return (r); 72 } 73 74 void 75 counter_u64_free(counter_u64_t c) 76 { 77 78 uma_zfree(uint64_pcpu_zone, c); 79 } 80 81 int 82 sysctl_handle_counter_u64(SYSCTL_HANDLER_ARGS) 83 { 84 uint64_t out; 85 int error; 86 87 out = counter_u64_fetch(*(counter_u64_t *)arg1); 88 89 error = SYSCTL_OUT(req, &out, sizeof(uint64_t)); 90 91 if (error || !req->newptr) 92 return (error); 93 94 /* 95 * Any write attempt to a counter zeroes it. 96 */ 97 counter_u64_zero(*(counter_u64_t *)arg1); 98 99 return (0); 100 } 101 102 static void 103 counter_startup(void) 104 { 105 106 uint64_pcpu_zone = uma_zcreate("uint64 pcpu", sizeof(uint64_t), 107 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_PCPU); 108 } 109 SYSINIT(counter, SI_SUB_CPU, SI_ORDER_FOURTH, counter_startup, NULL); 110