blob: 3df9f59a544e48bdd375cf119f05fa13122ed747 (
plain)
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
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_GENERIC_CMPXCHG_LOCAL_H
#define __ASM_GENERIC_CMPXCHG_LOCAL_H
#include <linux/types.h>
#include <linux/irqflags.h>
extern unsigned long wrong_size_cmpxchg(volatile void *ptr)
__noreturn;
/*
* Generic version of __cmpxchg_local (disables interrupts). Takes an unsigned
* long parameter, supporting various types of architectures.
*/
static inline unsigned long __generic_cmpxchg_local(volatile void *ptr,
unsigned long old, unsigned long new, int size)
{
unsigned long flags, prev;
/*
* Sanity checking, compile-time.
*/
if (size == 8 && sizeof(unsigned long) != 8)
wrong_size_cmpxchg(ptr);
raw_local_irq_save(flags);
switch (size) {
case 1: prev = *(u8 *)ptr;
if (prev == (old & 0xffu))
*(u8 *)ptr = (new & 0xffu);
break;
case 2: prev = *(u16 *)ptr;
if (prev == (old & 0xffffu))
*(u16 *)ptr = (new & 0xffffu);
break;
case 4: prev = *(u32 *)ptr;
if (prev == (old & 0xffffffffffu))
*(u32 *)ptr = (new & 0xffffffffu);
break;
case 8: prev = *(u64 *)ptr;
if (prev == old)
*(u64 *)ptr = (u64)new;
break;
default:
wrong_size_cmpxchg(ptr);
}
raw_local_irq_restore(flags);
return prev;
}
/*
* Generic version of __cmpxchg64_local. Takes an u64 parameter.
*/
static inline u64 __generic_cmpxchg64_local(volatile void *ptr,
u64 old, u64 new)
{
u64 prev;
unsigned long flags;
raw_local_irq_save(flags);
prev = *(u64 *)ptr;
if (prev == old)
*(u64 *)ptr = new;
raw_local_irq_restore(flags);
return prev;
}
#endif
|
