projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| d550bbd4 DH |
1 | /* 32-bit atomic xchg() and cmpxchg() definitions. |
| 2 | * | |
| 3 | * Copyright (C) 1996 David S. Miller (davem@davemloft.net) | |
| 4 | * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com.au) | |
| 5 | * Copyright (C) 2007 Kyle McMartin (kyle@parisc-linux.org) | |
| 6 | * | |
| 7 | * Additions by Keith M Wesolowski (wesolows@foobazco.org) based | |
| 8 | * on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>. | |
| 9 | */ | |
| 10 | ||
| 11 | #ifndef __ARCH_SPARC_CMPXCHG__ | |
| 12 | #define __ARCH_SPARC_CMPXCHG__ | |
| 13 | ||
| d550bbd4 DH |
14 | static inline unsigned long xchg_u32(__volatile__ unsigned long *m, unsigned long val) |
| 15 | { | |
| d550bbd4 DH |
16 | __asm__ __volatile__("swap [%2], %0" |
| 17 | : "=&r" (val) | |
| 18 | : "0" (val), "r" (m) | |
| 19 | : "memory"); | |
| 20 | return val; | |
| d550bbd4 DH |
21 | } |
| 22 | ||
| f05a6865 | 23 | void __xchg_called_with_bad_pointer(void); |
| d550bbd4 DH |
24 | |
| 25 | static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int size) | |
| 26 | { | |
| 27 | switch (size) { | |
| 28 | case 4: | |
| 29 | return xchg_u32(ptr, x); | |
| 30 | } | |
| 31 | __xchg_called_with_bad_pointer(); | |
| 32 | return x; | |
| 33 | } | |
| 34 | ||
| 35 | #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) | |
| 36 | ||
| 37 | /* Emulate cmpxchg() the same way we emulate atomics, | |
| 38 | * by hashing the object address and indexing into an array | |
| 39 | * of spinlocks to get a bit of performance... | |
| 40 | * | |
| 41 | * See arch/sparc/lib/atomic32.c for implementation. | |
| 42 | * | |
| 43 | * Cribbed from <asm-parisc/atomic.h> | |
| 44 | */ | |
| 45 | #define __HAVE_ARCH_CMPXCHG 1 | |
| 46 | ||
| 47 | /* bug catcher for when unsupported size is used - won't link */ | |
| f05a6865 | 48 | void __cmpxchg_called_with_bad_pointer(void); |
| d550bbd4 | 49 | /* we only need to support cmpxchg of a u32 on sparc */ |
| f05a6865 | 50 | unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_); |
| d550bbd4 DH |
51 | |
| 52 | /* don't worry...optimizer will get rid of most of this */ | |
| 53 | static inline unsigned long | |
| 54 | __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) | |
| 55 | { | |
| 56 | switch (size) { | |
| 57 | case 4: | |
| 58 | return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_); | |
| 59 | default: | |
| 60 | __cmpxchg_called_with_bad_pointer(); | |
| 61 | break; | |
| 62 | } | |
| 63 | return old; | |
| 64 | } | |
| 65 | ||
| 66 | #define cmpxchg(ptr, o, n) \ | |
| 67 | ({ \ | |
| 68 | __typeof__(*(ptr)) _o_ = (o); \ | |
| 69 | __typeof__(*(ptr)) _n_ = (n); \ | |
| 70 | (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ | |
| 71 | (unsigned long)_n_, sizeof(*(ptr))); \ | |
| 72 | }) | |
| 73 | ||
| 74 | #include <asm-generic/cmpxchg-local.h> | |
| 75 | ||
| 76 | /* | |
| 77 | * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make | |
| 78 | * them available. | |
| 79 | */ | |
| 80 | #define cmpxchg_local(ptr, o, n) \ | |
| 81 | ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ | |
| 82 | (unsigned long)(n), sizeof(*(ptr)))) | |
| 83 | #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) | |
| 84 | ||
| 85 | #endif /* __ARCH_SPARC_CMPXCHG__ */ |