Guan Xuetao | 8978bfd | 2012-03-28 18:30:03 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Atomics xchg/cmpxchg for PKUnity SoC and UniCore ISA |
| 3 | * |
| 4 | * Copyright (C) 2001-2012 GUAN Xue-tao |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | #ifndef __UNICORE_CMPXCHG_H__ |
| 11 | #define __UNICORE_CMPXCHG_H__ |
| 12 | |
| 13 | /* |
| 14 | * Generate a link failure on undefined symbol if the pointer points to a value |
| 15 | * of unsupported size. |
| 16 | */ |
| 17 | extern void __xchg_bad_pointer(void); |
| 18 | |
| 19 | static inline unsigned long __xchg(unsigned long x, volatile void *ptr, |
| 20 | int size) |
| 21 | { |
| 22 | unsigned long ret; |
| 23 | |
| 24 | switch (size) { |
| 25 | case 1: |
| 26 | asm volatile("swapb %0, %1, [%2]" |
| 27 | : "=&r" (ret) |
| 28 | : "r" (x), "r" (ptr) |
| 29 | : "memory", "cc"); |
| 30 | break; |
| 31 | case 4: |
| 32 | asm volatile("swapw %0, %1, [%2]" |
| 33 | : "=&r" (ret) |
| 34 | : "r" (x), "r" (ptr) |
| 35 | : "memory", "cc"); |
| 36 | break; |
| 37 | default: |
Guan Xuetao | 195d457 | 2012-06-14 15:39:48 +0800 | [diff] [blame] | 38 | __xchg_bad_pointer(); |
Guan Xuetao | 8978bfd | 2012-03-28 18:30:03 +0100 | [diff] [blame] | 39 | } |
| 40 | |
| 41 | return ret; |
| 42 | } |
| 43 | |
| 44 | #define xchg(ptr, x) \ |
| 45 | ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))) |
| 46 | |
| 47 | #include <asm-generic/cmpxchg-local.h> |
| 48 | |
| 49 | /* |
| 50 | * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make |
| 51 | * them available. |
| 52 | */ |
| 53 | #define cmpxchg_local(ptr, o, n) \ |
| 54 | ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), \ |
| 55 | (unsigned long)(o), (unsigned long)(n), sizeof(*(ptr)))) |
| 56 | #define cmpxchg64_local(ptr, o, n) \ |
| 57 | __cmpxchg64_local_generic((ptr), (o), (n)) |
| 58 | |
| 59 | #include <asm-generic/cmpxchg.h> |
| 60 | |
| 61 | #endif /* __UNICORE_CMPXCHG_H__ */ |