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
41enum {
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
60static 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
96ATOMIC64_EMU_BIN(add, void, (*p = *p + v), return);
97ATOMIC64_EMU_BIN(clear, void, *p &= ~v, return);
98ATOMIC64_EMU_BIN(fetchadd, uint64_t, (*p = *p + v, v = *p - v), return (v));
99ATOMIC64_EMU_UN(load, uint64_t, (tmp = *p), return (tmp));
100ATOMIC64_EMU_BIN(set, void, *p |= v, return);
101ATOMIC64_EMU_BIN(subtract, void, (*p = *p - v), return);
102ATOMIC64_EMU_BIN(store, void, *p = v, return);
103ATOMIC64_EMU_BIN(swap, uint64_t, tmp = *p; *p = v; v = tmp, return(v));
104
105int 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
118int 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
135static void
136atomic64_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
144SYSINIT(atomic64_mtxinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, atomic64_mtxinit, NULL);
145#endif	/* SMP */
146
147#endif	/* _KERNEL */
148