1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.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 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #ifndef __MACHINE_COUNTER_H__ 32 #define __MACHINE_COUNTER_H__ 33 34 #include <sys/pcpu.h> 35 #ifdef INVARIANTS 36 #include <sys/proc.h> 37 #endif 38 #include <machine/md_var.h> 39 #include <machine/specialreg.h> 40 41 #define EARLY_COUNTER &__pcpu[0].pc_early_dummy_counter 42 43 #define counter_enter() do { \ 44 if ((cpu_feature & CPUID_CX8) == 0) \ 45 critical_enter(); \ 46 } while (0) 47 48 #define counter_exit() do { \ 49 if ((cpu_feature & CPUID_CX8) == 0) \ 50 critical_exit(); \ 51 } while (0) 52 53 static inline void 54 counter_64_inc_8b(uint64_t *p, int64_t inc) 55 { 56 57 __asm __volatile( 58 "movl %%fs:(%%esi),%%eax\n\t" 59 "movl %%fs:4(%%esi),%%edx\n" 60 "1:\n\t" 61 "movl %%eax,%%ebx\n\t" 62 "movl %%edx,%%ecx\n\t" 63 "addl (%%edi),%%ebx\n\t" 64 "adcl 4(%%edi),%%ecx\n\t" 65 "cmpxchg8b %%fs:(%%esi)\n\t" 66 "jnz 1b" 67 : 68 : "S" ((char *)p - (char *)&__pcpu[0]), "D" (&inc) 69 : "memory", "cc", "eax", "edx", "ebx", "ecx"); 70 } 71 72 #ifdef IN_SUBR_COUNTER_C 73 struct counter_u64_fetch_cx8_arg { 74 uint64_t res; 75 uint64_t *p; 76 }; 77 78 static uint64_t 79 counter_u64_read_one_8b(uint64_t *p) 80 { 81 uint32_t res_lo, res_high; 82 83 __asm __volatile( 84 "movl %%eax,%%ebx\n\t" 85 "movl %%edx,%%ecx\n\t" 86 "cmpxchg8b (%2)" 87 : "=a" (res_lo), "=d"(res_high) 88 : "SD" (p) 89 : "cc", "ebx", "ecx"); 90 return (res_lo + ((uint64_t)res_high << 32)); 91 } 92 93 static void 94 counter_u64_fetch_cx8_one(void *arg1) 95 { 96 struct counter_u64_fetch_cx8_arg *arg; 97 uint64_t val; 98 99 arg = arg1; 100 val = counter_u64_read_one_8b((uint64_t *)((char *)arg->p + 101 UMA_PCPU_ALLOC_SIZE * PCPU_GET(cpuid))); 102 atomic_add_64(&arg->res, val); 103 } 104 105 static inline uint64_t 106 counter_u64_fetch_inline(uint64_t *p) 107 { 108 struct counter_u64_fetch_cx8_arg arg; 109 uint64_t res; 110 int i; 111 112 res = 0; 113 if ((cpu_feature & CPUID_CX8) == 0) { 114 /* 115 * The machines without cmpxchg8b are not SMP. 116 * Disabling the preemption provides atomicity of the 117 * counter reading, since update is done in the 118 * critical section as well. 119 */ 120 critical_enter(); 121 CPU_FOREACH(i) { 122 res += *(uint64_t *)((char *)p + 123 UMA_PCPU_ALLOC_SIZE * i); 124 } 125 critical_exit(); 126 } else { 127 arg.p = p; 128 arg.res = 0; 129 smp_rendezvous(NULL, counter_u64_fetch_cx8_one, NULL, &arg); 130 res = arg.res; 131 } 132 return (res); 133 } 134 135 static inline void 136 counter_u64_zero_one_8b(uint64_t *p) 137 { 138 139 __asm __volatile( 140 "movl (%0),%%eax\n\t" 141 "movl 4(%0),%%edx\n" 142 "xorl %%ebx,%%ebx\n\t" 143 "xorl %%ecx,%%ecx\n\t" 144 "1:\n\t" 145 "cmpxchg8b (%0)\n\t" 146 "jnz 1b" 147 : 148 : "SD" (p) 149 : "memory", "cc", "eax", "edx", "ebx", "ecx"); 150 } 151 152 static void 153 counter_u64_zero_one_cpu(void *arg) 154 { 155 uint64_t *p; 156 157 p = (uint64_t *)((char *)arg + UMA_PCPU_ALLOC_SIZE * PCPU_GET(cpuid)); 158 counter_u64_zero_one_8b(p); 159 } 160 161 static inline void 162 counter_u64_zero_inline(counter_u64_t c) 163 { 164 int i; 165 166 if ((cpu_feature & CPUID_CX8) == 0) { 167 critical_enter(); 168 CPU_FOREACH(i) 169 *(uint64_t *)((char *)c + UMA_PCPU_ALLOC_SIZE * i) = 0; 170 critical_exit(); 171 } else { 172 smp_rendezvous(smp_no_rendezvous_barrier, 173 counter_u64_zero_one_cpu, smp_no_rendezvous_barrier, c); 174 } 175 } 176 #endif 177 178 #define counter_u64_add_protected(c, inc) do { \ 179 if ((cpu_feature & CPUID_CX8) == 0) { \ 180 CRITICAL_ASSERT(curthread); \ 181 *(uint64_t *)zpcpu_get(c) += (inc); \ 182 } else \ 183 counter_64_inc_8b((c), (inc)); \ 184 } while (0) 185 186 static inline void 187 counter_u64_add(counter_u64_t c, int64_t inc) 188 { 189 190 if ((cpu_feature & CPUID_CX8) == 0) { 191 critical_enter(); 192 *(uint64_t *)zpcpu_get(c) += inc; 193 critical_exit(); 194 } else { 195 counter_64_inc_8b(c, inc); 196 } 197 } 198 199 #endif /* ! __MACHINE_COUNTER_H__ */ 200