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068fbad2 MD |
1 | #ifndef __ASM_GENERIC_CMPXCHG_LOCAL_H |
2 | #define __ASM_GENERIC_CMPXCHG_LOCAL_H | |
3 | ||
4 | #include <linux/types.h> | |
df9ee292 | 5 | #include <linux/irqflags.h> |
068fbad2 MD |
6 | |
7 | extern unsigned long wrong_size_cmpxchg(volatile void *ptr); | |
8 | ||
9 | /* | |
10 | * Generic version of __cmpxchg_local (disables interrupts). Takes an unsigned | |
11 | * long parameter, supporting various types of architectures. | |
12 | */ | |
13 | static inline unsigned long __cmpxchg_local_generic(volatile void *ptr, | |
14 | unsigned long old, unsigned long new, int size) | |
15 | { | |
16 | unsigned long flags, prev; | |
17 | ||
18 | /* | |
19 | * Sanity checking, compile-time. | |
20 | */ | |
21 | if (size == 8 && sizeof(unsigned long) != 8) | |
22 | wrong_size_cmpxchg(ptr); | |
23 | ||
24 | local_irq_save(flags); | |
25 | switch (size) { | |
26 | case 1: prev = *(u8 *)ptr; | |
27 | if (prev == old) | |
28 | *(u8 *)ptr = (u8)new; | |
29 | break; | |
30 | case 2: prev = *(u16 *)ptr; | |
31 | if (prev == old) | |
32 | *(u16 *)ptr = (u16)new; | |
33 | break; | |
34 | case 4: prev = *(u32 *)ptr; | |
35 | if (prev == old) | |
36 | *(u32 *)ptr = (u32)new; | |
37 | break; | |
38 | case 8: prev = *(u64 *)ptr; | |
39 | if (prev == old) | |
40 | *(u64 *)ptr = (u64)new; | |
41 | break; | |
42 | default: | |
43 | wrong_size_cmpxchg(ptr); | |
44 | } | |
45 | local_irq_restore(flags); | |
46 | return prev; | |
47 | } | |
48 | ||
49 | /* | |
50 | * Generic version of __cmpxchg64_local. Takes an u64 parameter. | |
51 | */ | |
52 | static inline u64 __cmpxchg64_local_generic(volatile void *ptr, | |
53 | u64 old, u64 new) | |
54 | { | |
55 | u64 prev; | |
56 | unsigned long flags; | |
57 | ||
58 | local_irq_save(flags); | |
59 | prev = *(u64 *)ptr; | |
60 | if (prev == old) | |
61 | *(u64 *)ptr = new; | |
62 | local_irq_restore(flags); | |
63 | return prev; | |
64 | } | |
65 | ||
66 | #endif |