1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 * $FreeBSD$
28 */
29
30#include <sys/cdefs.h>
31#include <sys/param.h>
32#include <sys/kernel.h>
33#include <sys/lock.h>
34#include <sys/mutex.h>
35#include <sys/smp.h>
36#include <sys/systm.h>
37
38#include <machine/atomic.h>
39#include <machine/param.h>
40
41#include <vm/vm.h>
42#include <vm/pmap.h>
43
44enum {
45    ATOMIC64_ADD,
46    ATOMIC64_CLEAR,
47    ATOMIC64_CMPSET,
48    ATOMIC64_FCMPSET,
49    ATOMIC64_FETCHADD,
50    ATOMIC64_LOAD,
51    ATOMIC64_SET,
52    ATOMIC64_SUBTRACT,
53    ATOMIC64_STORE,
54    ATOMIC64_SWAP
55};
56
57#ifdef _KERNEL
58#ifdef SMP
59
60#define	A64_POOL_SIZE	MAXCPU
61/* Estimated size of a cacheline */
62#define	CACHE_ALIGN	CACHE_LINE_SIZE
63static struct mtx a64_mtx_pool[A64_POOL_SIZE];
64
65#define GET_MUTEX(p) \
66    (&a64_mtx_pool[(pmap_kextract((vm_offset_t)p) / CACHE_ALIGN) % (A64_POOL_SIZE)])
67
68#define LOCK_A64()			\
69    struct mtx *_amtx = GET_MUTEX(p);	\
70    if (smp_started) mtx_lock(_amtx)
71
72#define UNLOCK_A64()	if (smp_started) mtx_unlock(_amtx)
73
74#else	/* !SMP */
75
76#define	LOCK_A64()	{ register_t s = intr_disable()
77#define	UNLOCK_A64()	intr_restore(s); }
78
79#endif	/* SMP */
80
81#define ATOMIC64_EMU_UN(op, rt, block, ret) \
82    rt \
83    atomic_##op##_64(volatile u_int64_t *p) {			\
84	u_int64_t tmp __unused;					\
85	LOCK_A64();						\
86	block;							\
87	UNLOCK_A64();						\
88	ret; } struct hack
89
90#define	ATOMIC64_EMU_BIN(op, rt, block, ret) \
91    rt \
92    atomic_##op##_64(volatile u_int64_t *p, u_int64_t v) {	\
93	u_int64_t tmp __unused;					\
94	LOCK_A64();						\
95	block;							\
96	UNLOCK_A64();						\
97	ret; } struct hack
98
99ATOMIC64_EMU_BIN(add, void, (*p = *p + v), return);
100ATOMIC64_EMU_BIN(clear, void, *p &= ~v, return);
101ATOMIC64_EMU_BIN(fetchadd, u_int64_t, (*p = *p + v, v = *p - v), return (v));
102ATOMIC64_EMU_UN(load, u_int64_t, (tmp = *p), return (tmp));
103ATOMIC64_EMU_BIN(set, void, *p |= v, return);
104ATOMIC64_EMU_BIN(subtract, void, (*p = *p - v), return);
105ATOMIC64_EMU_BIN(store, void, *p = v, return);
106ATOMIC64_EMU_BIN(swap, u_int64_t, tmp = *p; *p = v; v = tmp, return(v));
107
108int atomic_cmpset_64(volatile u_int64_t *p, u_int64_t old, u_int64_t new)
109{
110	u_int64_t tmp;
111
112	LOCK_A64();
113	tmp = *p;
114	if (tmp == old)
115		*p = new;
116	UNLOCK_A64();
117
118	return (tmp == old);
119}
120
121int atomic_fcmpset_64(volatile u_int64_t *p, u_int64_t *old, u_int64_t new)
122{
123	u_int64_t tmp, tmp_old;
124
125	LOCK_A64();
126	tmp = *p;
127	tmp_old = *old;
128	if (tmp == tmp_old)
129		*p = new;
130	else
131		*old = tmp;
132	UNLOCK_A64();
133
134	return (tmp == tmp_old);
135}
136
137#ifdef SMP
138static void
139atomic64_mtxinit(void *x __unused)
140{
141	int i;
142
143	for (i = 0; i < A64_POOL_SIZE; i++)
144		mtx_init(&a64_mtx_pool[i], "atomic64 mutex", NULL, MTX_DEF);
145}
146
147SYSINIT(atomic64_mtxinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, atomic64_mtxinit, NULL);
148#endif	/* SMP */
149
150#endif	/* _KERNEL */
151