diff options
Diffstat (limited to 'arch/arm/include')
-rw-r--r-- | arch/arm/include/asm/sync_bitops.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/arm/include/asm/sync_bitops.h b/arch/arm/include/asm/sync_bitops.h new file mode 100644 index 000000000000..63479eecbf76 --- /dev/null +++ b/arch/arm/include/asm/sync_bitops.h | |||
@@ -0,0 +1,27 @@ | |||
1 | #ifndef __ASM_SYNC_BITOPS_H__ | ||
2 | #define __ASM_SYNC_BITOPS_H__ | ||
3 | |||
4 | #include <asm/bitops.h> | ||
5 | #include <asm/system.h> | ||
6 | |||
7 | /* sync_bitops functions are equivalent to the SMP implementation of the | ||
8 | * original functions, independently from CONFIG_SMP being defined. | ||
9 | * | ||
10 | * We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But | ||
11 | * under Xen you might be communicating with a completely external entity | ||
12 | * who might be on another CPU (e.g. two uniprocessor guests communicating | ||
13 | * via event channels and grant tables). So we need a variant of the bit | ||
14 | * ops which are SMP safe even on a UP kernel. | ||
15 | */ | ||
16 | |||
17 | #define sync_set_bit(nr, p) _set_bit(nr, p) | ||
18 | #define sync_clear_bit(nr, p) _clear_bit(nr, p) | ||
19 | #define sync_change_bit(nr, p) _change_bit(nr, p) | ||
20 | #define sync_test_and_set_bit(nr, p) _test_and_set_bit(nr, p) | ||
21 | #define sync_test_and_clear_bit(nr, p) _test_and_clear_bit(nr, p) | ||
22 | #define sync_test_and_change_bit(nr, p) _test_and_change_bit(nr, p) | ||
23 | #define sync_test_bit(nr, addr) test_bit(nr, addr) | ||
24 | #define sync_cmpxchg cmpxchg | ||
25 | |||
26 | |||
27 | #endif | ||