]>
Commit | Line | Data |
---|---|---|
b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
068fbad2 MD |
2 | #ifndef __ASM_GENERIC_CMPXCHG_LOCAL_H |
3 | #define __ASM_GENERIC_CMPXCHG_LOCAL_H | |
4 | ||
5 | #include <linux/types.h> | |
df9ee292 | 6 | #include <linux/irqflags.h> |
068fbad2 | 7 | |
aa93685a BW |
8 | extern unsigned long wrong_size_cmpxchg(volatile void *ptr) |
9 | __noreturn; | |
068fbad2 MD |
10 | |
11 | /* | |
12 | * Generic version of __cmpxchg_local (disables interrupts). Takes an unsigned | |
13 | * long parameter, supporting various types of architectures. | |
14 | */ | |
15 | static inline unsigned long __cmpxchg_local_generic(volatile void *ptr, | |
16 | unsigned long old, unsigned long new, int size) | |
17 | { | |
18 | unsigned long flags, prev; | |
19 | ||
20 | /* | |
21 | * Sanity checking, compile-time. | |
22 | */ | |
23 | if (size == 8 && sizeof(unsigned long) != 8) | |
24 | wrong_size_cmpxchg(ptr); | |
25 | ||
5042afe7 | 26 | raw_local_irq_save(flags); |
068fbad2 MD |
27 | switch (size) { |
28 | case 1: prev = *(u8 *)ptr; | |
29 | if (prev == old) | |
30 | *(u8 *)ptr = (u8)new; | |
31 | break; | |
32 | case 2: prev = *(u16 *)ptr; | |
33 | if (prev == old) | |
34 | *(u16 *)ptr = (u16)new; | |
35 | break; | |
36 | case 4: prev = *(u32 *)ptr; | |
37 | if (prev == old) | |
38 | *(u32 *)ptr = (u32)new; | |
39 | break; | |
40 | case 8: prev = *(u64 *)ptr; | |
41 | if (prev == old) | |
42 | *(u64 *)ptr = (u64)new; | |
43 | break; | |
44 | default: | |
45 | wrong_size_cmpxchg(ptr); | |
46 | } | |
5042afe7 | 47 | raw_local_irq_restore(flags); |
068fbad2 MD |
48 | return prev; |
49 | } | |
50 | ||
51 | /* | |
52 | * Generic version of __cmpxchg64_local. Takes an u64 parameter. | |
53 | */ | |
54 | static inline u64 __cmpxchg64_local_generic(volatile void *ptr, | |
55 | u64 old, u64 new) | |
56 | { | |
57 | u64 prev; | |
58 | unsigned long flags; | |
59 | ||
5042afe7 | 60 | raw_local_irq_save(flags); |
068fbad2 MD |
61 | prev = *(u64 *)ptr; |
62 | if (prev == old) | |
63 | *(u64 *)ptr = new; | |
5042afe7 | 64 | raw_local_irq_restore(flags); |
068fbad2 MD |
65 | return prev; |
66 | } | |
67 | ||
68 | #endif |