git://bbs.cooldavid.org / net-next-2.6.git / blame
| Commit | Line | Data |
|---|---|---|
| 774400a3 TP |
1 | /* |
| 2 | * cmpxchg*() fallbacks for CPU not supporting these instructions | |
| 3 | */ | |
| 4 | ||
| 5 | #include <linux/kernel.h> | |
| 6 | #include <linux/smp.h> | |
| 7 | #include <linux/module.h> | |
| 8 | ||
| 9 | #ifndef CONFIG_X86_CMPXCHG | |
| 10 | unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new) | |
| 11 | { | |
| 12 | u8 prev; | |
| 13 | unsigned long flags; | |
| 14 | ||
| 15 | /* Poor man's cmpxchg for 386. Unsuitable for SMP */ | |
| 16 | local_irq_save(flags); | |
| 17 | prev = *(u8 *)ptr; | |
| 18 | if (prev == old) | |
| 19 | *(u8 *)ptr = new; | |
| 20 | local_irq_restore(flags); | |
| 21 | return prev; | |
| 22 | } | |
| 23 | EXPORT_SYMBOL(cmpxchg_386_u8); | |
| 24 | ||
| 25 | unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new) | |
| 26 | { | |
| 27 | u16 prev; | |
| 28 | unsigned long flags; | |
| 29 | ||
| 30 | /* Poor man's cmpxchg for 386. Unsuitable for SMP */ | |
| 31 | local_irq_save(flags); | |
| 32 | prev = *(u16 *)ptr; | |
| 33 | if (prev == old) | |
| 34 | *(u16 *)ptr = new; | |
| 35 | local_irq_restore(flags); | |
| 36 | return prev; | |
| 37 | } | |
| 38 | EXPORT_SYMBOL(cmpxchg_386_u16); | |
| 39 | ||
| 40 | unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new) | |
| 41 | { | |
| 42 | u32 prev; | |
| 43 | unsigned long flags; | |
| 44 | ||
| 45 | /* Poor man's cmpxchg for 386. Unsuitable for SMP */ | |
| 46 | local_irq_save(flags); | |
| 47 | prev = *(u32 *)ptr; | |
| 48 | if (prev == old) | |
| 49 | *(u32 *)ptr = new; | |
| 50 | local_irq_restore(flags); | |
| 51 | return prev; | |
| 52 | } | |
| 53 | EXPORT_SYMBOL(cmpxchg_386_u32); | |
| 54 | #endif | |
| 55 | ||
| 56 | #ifndef CONFIG_X86_CMPXCHG64 | |
| 57 | unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new) | |
| 58 | { | |
| 59 | u64 prev; | |
| 60 | unsigned long flags; | |
| 61 | ||
| 62 | /* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */ | |
| 63 | local_irq_save(flags); | |
| 64 | prev = *(u64 *)ptr; | |
| 65 | if (prev == old) | |
| 66 | *(u64 *)ptr = new; | |
| 67 | local_irq_restore(flags); | |
| 68 | return prev; | |
| 69 | } | |
| 70 | EXPORT_SYMBOL(cmpxchg_486_u64); | |
| 71 | #endif | |
| 72 |