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/param.h>
29 #include <sys/kernel.h>
30 #include <sys/lock.h>
31 #include <sys/mutex.h>
32 #include <sys/smp.h>
33 #include <sys/systm.h>
34
35 #include <machine/atomic.h>
36 #include <machine/param.h>
37
38 #include <vm/vm.h>
39 #include <vm/pmap.h>
40
41 enum {
42 ATOMIC64_ADD,
43 ATOMIC64_CLEAR,
44 ATOMIC64_CMPSET,
45 ATOMIC64_FCMPSET,
46 ATOMIC64_FETCHADD,
47 ATOMIC64_LOAD,
48 ATOMIC64_SET,
49 ATOMIC64_SUBTRACT,
50 ATOMIC64_STORE,
51 ATOMIC64_SWAP
52 };
53
54 #ifdef _KERNEL
55 #ifdef SMP
56
57 #define A64_POOL_SIZE MAXCPU
58 /* Estimated size of a cacheline */
59 #define CACHE_ALIGN CACHE_LINE_SIZE
60 static struct mtx a64_mtx_pool[A64_POOL_SIZE];
61
62 #define GET_MUTEX(p) \
63 (&a64_mtx_pool[(pmap_kextract((vm_offset_t)p) / CACHE_ALIGN) % (A64_POOL_SIZE)])
64
65 #define LOCK_A64() \
66 struct mtx *_amtx = GET_MUTEX(p); \
67 if (smp_started) mtx_lock(_amtx)
68
69 #define UNLOCK_A64() if (smp_started) mtx_unlock(_amtx)
70
71 #else /* !SMP */
72
73 #define LOCK_A64() { register_t s = intr_disable()
74 #define UNLOCK_A64() intr_restore(s); }
75
76 #endif /* SMP */
77
78 #define ATOMIC64_EMU_UN(op, rt, block, ret) \
79 rt \
80 atomic_##op##_64(volatile uint64_t *p) { \
81 uint64_t tmp __unused; \
82 LOCK_A64(); \
83 block; \
84 UNLOCK_A64(); \
85 ret; } struct hack
86
87 #define ATOMIC64_EMU_BIN(op, rt, block, ret) \
88 rt \
89 atomic_##op##_64(volatile uint64_t *p, uint64_t v) { \
90 uint64_t tmp __unused; \
91 LOCK_A64(); \
92 block; \
93 UNLOCK_A64(); \
94 ret; } struct hack
95
96 ATOMIC64_EMU_BIN(add, void, (*p = *p + v), return);
97 ATOMIC64_EMU_BIN(clear, void, *p &= ~v, return);
98 ATOMIC64_EMU_BIN(fetchadd, uint64_t, (*p = *p + v, v = *p - v), return (v));
99 ATOMIC64_EMU_UN(load, uint64_t, (tmp = *p), return (tmp));
100 ATOMIC64_EMU_BIN(set, void, *p |= v, return);
101 ATOMIC64_EMU_BIN(subtract, void, (*p = *p - v), return);
102 ATOMIC64_EMU_BIN(store, void, *p = v, return);
103 ATOMIC64_EMU_BIN(swap, uint64_t, tmp = *p; *p = v; v = tmp, return(v));
104
atomic_cmpset_64(volatile uint64_t * p,uint64_t old,uint64_t new)105 int atomic_cmpset_64(volatile uint64_t *p, uint64_t old, uint64_t new)
106 {
107 uint64_t tmp;
108
109 LOCK_A64();
110 tmp = *p;
111 if (tmp == old)
112 *p = new;
113 UNLOCK_A64();
114
115 return (tmp == old);
116 }
117
atomic_fcmpset_64(volatile uint64_t * p,uint64_t * old,uint64_t new)118 int atomic_fcmpset_64(volatile uint64_t *p, uint64_t *old, uint64_t new)
119 {
120 uint64_t tmp, tmp_old;
121
122 LOCK_A64();
123 tmp = *p;
124 tmp_old = *old;
125 if (tmp == tmp_old)
126 *p = new;
127 else
128 *old = tmp;
129 UNLOCK_A64();
130
131 return (tmp == tmp_old);
132 }
133
134 #ifdef SMP
135 static void
atomic64_mtxinit(void * x __unused)136 atomic64_mtxinit(void *x __unused)
137 {
138 int i;
139
140 for (i = 0; i < A64_POOL_SIZE; i++)
141 mtx_init(&a64_mtx_pool[i], "atomic64 mutex", NULL, MTX_DEF);
142 }
143
144 SYSINIT(atomic64_mtxinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, atomic64_mtxinit, NULL);
145 #endif /* SMP */
146
147 #endif /* _KERNEL */
148