1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2019 Justin Hibbits 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 #include <sys/param.h> 30 #include <sys/kernel.h> 31 #include <sys/lock.h> 32 #include <sys/mutex.h> 33 #include <sys/smp.h> 34 #include <sys/systm.h> 35 36 #include <machine/atomic.h> 37 #include <machine/param.h> 38 39 #include <vm/vm.h> 40 #include <vm/pmap.h> 41 42 enum { 43 ATOMIC64_ADD, 44 ATOMIC64_CLEAR, 45 ATOMIC64_CMPSET, 46 ATOMIC64_FCMPSET, 47 ATOMIC64_FETCHADD, 48 ATOMIC64_LOAD, 49 ATOMIC64_SET, 50 ATOMIC64_SUBTRACT, 51 ATOMIC64_STORE, 52 ATOMIC64_SWAP 53 }; 54 55 #ifdef _KERNEL 56 #ifdef SMP 57 58 #define A64_POOL_SIZE MAXCPU 59 /* Estimated size of a cacheline */ 60 #define CACHE_ALIGN CACHE_LINE_SIZE 61 static struct mtx a64_mtx_pool[A64_POOL_SIZE]; 62 63 #define GET_MUTEX(p) \ 64 (&a64_mtx_pool[(pmap_kextract((vm_offset_t)p) / CACHE_ALIGN) % (A64_POOL_SIZE)]) 65 66 #define LOCK_A64() \ 67 struct mtx *_amtx = GET_MUTEX(p); \ 68 if (smp_started) mtx_lock(_amtx) 69 70 #define UNLOCK_A64() if (smp_started) mtx_unlock(_amtx) 71 72 #else /* !SMP */ 73 74 #define LOCK_A64() { register_t s = intr_disable() 75 #define UNLOCK_A64() intr_restore(s); } 76 77 #endif /* SMP */ 78 79 #define ATOMIC64_EMU_UN(op, rt, block, ret) \ 80 rt \ 81 atomic_##op##_64(volatile uint64_t *p) { \ 82 uint64_t tmp __unused; \ 83 LOCK_A64(); \ 84 block; \ 85 UNLOCK_A64(); \ 86 ret; } struct hack 87 88 #define ATOMIC64_EMU_BIN(op, rt, block, ret) \ 89 rt \ 90 atomic_##op##_64(volatile uint64_t *p, uint64_t v) { \ 91 uint64_t tmp __unused; \ 92 LOCK_A64(); \ 93 block; \ 94 UNLOCK_A64(); \ 95 ret; } struct hack 96 97 ATOMIC64_EMU_BIN(add, void, (*p = *p + v), return); 98 ATOMIC64_EMU_BIN(clear, void, *p &= ~v, return); 99 ATOMIC64_EMU_BIN(fetchadd, uint64_t, (*p = *p + v, v = *p - v), return (v)); 100 ATOMIC64_EMU_UN(load, uint64_t, (tmp = *p), return (tmp)); 101 ATOMIC64_EMU_BIN(set, void, *p |= v, return); 102 ATOMIC64_EMU_BIN(subtract, void, (*p = *p - v), return); 103 ATOMIC64_EMU_BIN(store, void, *p = v, return); 104 ATOMIC64_EMU_BIN(swap, uint64_t, tmp = *p; *p = v; v = tmp, return(v)); 105 106 int atomic_cmpset_64(volatile uint64_t *p, uint64_t old, uint64_t new) 107 { 108 uint64_t tmp; 109 110 LOCK_A64(); 111 tmp = *p; 112 if (tmp == old) 113 *p = new; 114 UNLOCK_A64(); 115 116 return (tmp == old); 117 } 118 119 int atomic_fcmpset_64(volatile uint64_t *p, uint64_t *old, uint64_t new) 120 { 121 uint64_t tmp, tmp_old; 122 123 LOCK_A64(); 124 tmp = *p; 125 tmp_old = *old; 126 if (tmp == tmp_old) 127 *p = new; 128 else 129 *old = tmp; 130 UNLOCK_A64(); 131 132 return (tmp == tmp_old); 133 } 134 135 #ifdef SMP 136 static void 137 atomic64_mtxinit(void *x __unused) 138 { 139 int i; 140 141 for (i = 0; i < A64_POOL_SIZE; i++) 142 mtx_init(&a64_mtx_pool[i], "atomic64 mutex", NULL, MTX_DEF); 143 } 144 145 SYSINIT(atomic64_mtxinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, atomic64_mtxinit, NULL); 146 #endif /* SMP */ 147 148 #endif /* _KERNEL */ 149