1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#include <linux/cache.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/atomic.h>
#include <arch/chip.h>
/* This page is remapped on startup to be hash-for-home. */
int atomic_locks[PAGE_SIZE / sizeof(int)] __page_aligned_bss;
int *__atomic_hashed_lock(volatile void *v)
{
/* NOTE: this code must match "sys_cmpxchg" in kernel/intvec_32.S */
/*
* Use bits [3, 3 + ATOMIC_HASH_SHIFT) as the lock index.
* Using mm works here because atomic_locks is page aligned.
*/
unsigned long ptr = __insn_mm((unsigned long)v >> 1,
(unsigned long)atomic_locks,
2, (ATOMIC_HASH_SHIFT + 2) - 1);
return (int *)ptr;
}
#ifdef CONFIG_SMP
/* Return whether the passed pointer is a valid atomic lock pointer. */
static int is_atomic_lock(int *p)
{
return p >= &atomic_locks[0] && p < &atomic_locks[ATOMIC_HASH_SIZE];
}
void __atomic_fault_unlock(int *irqlock_word)
{
BUG_ON(!is_atomic_lock(irqlock_word));
BUG_ON(*irqlock_word != 1);
*irqlock_word = 0;
}
#endif /* CONFIG_SMP */
static inline int *__atomic_setup(volatile void *v)
{
/* Issue a load to the target to bring it into cache. */
*(volatile int *)v;
return __atomic_hashed_lock(v);
}
int _atomic_xchg(atomic_t *v, int n)
{
return __atomic_xchg(&v->counter, __atomic_setup(v), n).val;
}
EXPORT_SYMBOL(_atomic_xchg);
int _atomic_xchg_add(atomic_t *v, int i)
{
return __atomic_xchg_add(&v->counter, __atomic_setup(v), i).val;
}
EXPORT_SYMBOL(_atomic_xchg_add);
int _atomic_xchg_add_unless(atomic_t *v, int a, int u)
{
/*
* Note: argument order is switched here since it is easier
* to use the first argument consistently as the "old value"
* in the assembly, as is done for _atomic_cmpxchg().
*/
return __atomic_xchg_add_unless(&v->counter, __atomic_setup(v), u, a)
.val;
}
EXPORT_SYMBOL(_atomic_xchg_add_unless);
int _atomic_cmpxchg(atomic_t *v, int o, int n)
{
return __atomic_cmpxchg(&v->counter, __atomic_setup(v), o, n).val;
}
EXPORT_SYMBOL(_atomic_cmpxchg);
unsigned long _atomic_or(volatile unsigned long *p, unsigned long mask)
{
return __atomic_or((int *)p, __atomic_setup(p), mask).val;
}
EXPORT_SYMBOL(_atomic_or);
unsigned long _atomic_andn(volatile unsigned long *p, unsigned long mask)
{
return __atomic_andn((int *)p, __atomic_setup(p), mask).val;
}
EXPORT_SYMBOL(_atomic_andn);
unsigned long _atomic_xor(volatile unsigned long *p, unsigned long mask)
{
return __atomic_xor((int *)p, __atomic_setup(p), mask).val;
}
EXPORT_SYMBOL(_atomic_xor);
u64 _atomic64_xchg(atomic64_t *v, u64 n)
{
return __atomic64_xchg(&v->counter, __atomic_setup(v), n);
}
EXPORT_SYMBOL(_atomic64_xchg);
u64 _atomic64_xchg_add(atomic64_t *v, u64 i)
{
return __atomic64_xchg_add(&v->counter, __atomic_setup(v), i);
}
EXPORT_SYMBOL(_atomic64_xchg_add);
u64 _atomic64_xchg_add_unless(atomic64_t *v, u64 a, u64 u)
{
/*
* Note: argument order is switched here since it is easier
* to use the first argument consistently as the "old value"
* in the assembly, as is done for _atomic_cmpxchg().
*/
return __atomic64_xchg_add_unless(&v->counter, __atomic_setup(v),
u, a);
}
EXPORT_SYMBOL(_atomic64_xchg_add_unless);
u64 _atomic64_cmpxchg(atomic64_t *v, u64 o, u64 n)
{
return __atomic64_cmpxchg(&v->counter, __atomic_setup(v), o, n);
}
EXPORT_SYMBOL(_atomic64_cmpxchg);
/*
* If any of the atomic or futex routines hit a bad address (not in
* the page tables at kernel PL) this routine is called. The futex
* routines are never used on kernel space, and the normal atomics and
* bitops are never used on user space. So a fault on kernel space
* must be fatal, but a fault on userspace is a futex fault and we
* need to return -EFAULT. Note that the context this routine is
* invoked in is the context of the "_atomic_xxx()" routines called
* by the functions in this file.
*/
struct __get_user __atomic_bad_address(int __user *addr)
{
if (unlikely(!access_ok(VERIFY_WRITE, addr, sizeof(int))))
panic("Bad address used for kernel atomic op: %p\n", addr);
return (struct __get_user) { .err = -EFAULT };
}
void __init __init_atomic_per_cpu(void)
{
/* Validate power-of-two and "bigger than cpus" assumption */
BUILD_BUG_ON(ATOMIC_HASH_SIZE & (ATOMIC_HASH_SIZE-1));
BUG_ON(ATOMIC_HASH_SIZE < nr_cpu_ids);
/*
* On TILEPro we prefer to use a single hash-for-home
* page, since this means atomic operations are less
* likely to encounter a TLB fault and thus should
* in general perform faster. You may wish to disable
* this in situations where few hash-for-home tiles
* are configured.
*/
BUG_ON((unsigned long)atomic_locks % PAGE_SIZE != 0);
/* The locks must all fit on one page. */
BUILD_BUG_ON(ATOMIC_HASH_SIZE * sizeof(int) > PAGE_SIZE);
/*
* We use the page offset of the atomic value's address as
* an index into atomic_locks, excluding the low 3 bits.
* That should not produce more indices than ATOMIC_HASH_SIZE.
*/
BUILD_BUG_ON((PAGE_SIZE >> 3) > ATOMIC_HASH_SIZE);
}
|
