diff options
Diffstat (limited to 'arch/mips/include/asm/cmpxchg.h')
| -rw-r--r-- | arch/mips/include/asm/cmpxchg.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h new file mode 100644 index 000000000000..4a812c3ceb90 --- /dev/null +++ b/arch/mips/include/asm/cmpxchg.h | |||
| @@ -0,0 +1,124 @@ | |||
| 1 | /* | ||
| 2 | * This file is subject to the terms and conditions of the GNU General Public | ||
| 3 | * License. See the file "COPYING" in the main directory of this archive | ||
| 4 | * for more details. | ||
| 5 | * | ||
| 6 | * Copyright (C) 2003, 06, 07 by Ralf Baechle (ralf@linux-mips.org) | ||
| 7 | */ | ||
| 8 | #ifndef __ASM_CMPXCHG_H | ||
| 9 | #define __ASM_CMPXCHG_H | ||
| 10 | |||
| 11 | #include <linux/irqflags.h> | ||
| 12 | |||
| 13 | #define __HAVE_ARCH_CMPXCHG 1 | ||
| 14 | |||
| 15 | #define __cmpxchg_asm(ld, st, m, old, new) \ | ||
| 16 | ({ \ | ||
| 17 | __typeof(*(m)) __ret; \ | ||
| 18 | \ | ||
| 19 | if (cpu_has_llsc && R10000_LLSC_WAR) { \ | ||
| 20 | __asm__ __volatile__( \ | ||
| 21 | " .set push \n" \ | ||
| 22 | " .set noat \n" \ | ||
| 23 | " .set mips3 \n" \ | ||
| 24 | "1: " ld " %0, %2 # __cmpxchg_asm \n" \ | ||
| 25 | " bne %0, %z3, 2f \n" \ | ||
| 26 | " .set mips0 \n" \ | ||
| 27 | " move $1, %z4 \n" \ | ||
| 28 | " .set mips3 \n" \ | ||
| 29 | " " st " $1, %1 \n" \ | ||
| 30 | " beqzl $1, 1b \n" \ | ||
| 31 | "2: \n" \ | ||
| 32 | " .set pop \n" \ | ||
| 33 | : "=&r" (__ret), "=R" (*m) \ | ||
| 34 | : "R" (*m), "Jr" (old), "Jr" (new) \ | ||
| 35 | : "memory"); \ | ||
| 36 | } else if (cpu_has_llsc) { \ | ||
| 37 | __asm__ __volatile__( \ | ||
| 38 | " .set push \n" \ | ||
| 39 | " .set noat \n" \ | ||
| 40 | " .set mips3 \n" \ | ||
| 41 | "1: " ld " %0, %2 # __cmpxchg_asm \n" \ | ||
| 42 | " bne %0, %z3, 2f \n" \ | ||
| 43 | " .set mips0 \n" \ | ||
| 44 | " move $1, %z4 \n" \ | ||
| 45 | " .set mips3 \n" \ | ||
| 46 | " " st " $1, %1 \n" \ | ||
| 47 | " beqz $1, 3f \n" \ | ||
| 48 | "2: \n" \ | ||
| 49 | " .subsection 2 \n" \ | ||
| 50 | "3: b 1b \n" \ | ||
| 51 | " .previous \n" \ | ||
| 52 | " .set pop \n" \ | ||
| 53 | : "=&r" (__ret), "=R" (*m) \ | ||
| 54 | : "R" (*m), "Jr" (old), "Jr" (new) \ | ||
| 55 | : "memory"); \ | ||
| 56 | } else { \ | ||
| 57 | unsigned long __flags; \ | ||
| 58 | \ | ||
| 59 | raw_local_irq_save(__flags); \ | ||
| 60 | __ret = *m; \ | ||
| 61 | if (__ret == old) \ | ||
| 62 | *m = new; \ | ||
| 63 | raw_local_irq_restore(__flags); \ | ||
| 64 | } \ | ||
| 65 | \ | ||
| 66 | __ret; \ | ||
| 67 | }) | ||
| 68 | |||
| 69 | /* | ||
| 70 | * This function doesn't exist, so you'll get a linker error | ||
| 71 | * if something tries to do an invalid cmpxchg(). | ||
| 72 | */ | ||
| 73 | extern void __cmpxchg_called_with_bad_pointer(void); | ||
| 74 | |||
| 75 | #define __cmpxchg(ptr, old, new, barrier) \ | ||
| 76 | ({ \ | ||
| 77 | __typeof__(ptr) __ptr = (ptr); \ | ||
| 78 | __typeof__(*(ptr)) __old = (old); \ | ||
| 79 | __typeof__(*(ptr)) __new = (new); \ | ||
| 80 | __typeof__(*(ptr)) __res = 0; \ | ||
| 81 | \ | ||
| 82 | barrier; \ | ||
| 83 | \ | ||
| 84 | switch (sizeof(*(__ptr))) { \ | ||
| 85 | case 4: \ | ||
| 86 | __res = __cmpxchg_asm("ll", "sc", __ptr, __old, __new); \ | ||
| 87 | break; \ | ||
| 88 | case 8: \ | ||
| 89 | if (sizeof(long) == 8) { \ | ||
| 90 | __res = __cmpxchg_asm("lld", "scd", __ptr, \ | ||
| 91 | __old, __new); \ | ||
| 92 | break; \ | ||
| 93 | } \ | ||
| 94 | default: \ | ||
| 95 | __cmpxchg_called_with_bad_pointer(); \ | ||
| 96 | break; \ | ||
| 97 | } \ | ||
| 98 | \ | ||
| 99 | barrier; \ | ||
| 100 | \ | ||
| 101 | __res; \ | ||
| 102 | }) | ||
| 103 | |||
| 104 | #define cmpxchg(ptr, old, new) __cmpxchg(ptr, old, new, smp_llsc_mb()) | ||
| 105 | #define cmpxchg_local(ptr, old, new) __cmpxchg(ptr, old, new, ) | ||
| 106 | |||
| 107 | #define cmpxchg64(ptr, o, n) \ | ||
| 108 | ({ \ | ||
| 109 | BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ | ||
| 110 | cmpxchg((ptr), (o), (n)); \ | ||
| 111 | }) | ||
| 112 | |||
| 113 | #ifdef CONFIG_64BIT | ||
| 114 | #define cmpxchg64_local(ptr, o, n) \ | ||
| 115 | ({ \ | ||
| 116 | BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ | ||
| 117 | cmpxchg_local((ptr), (o), (n)); \ | ||
| 118 | }) | ||
| 119 | #else | ||
| 120 | #include <asm-generic/cmpxchg-local.h> | ||
| 121 | #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) | ||
| 122 | #endif | ||
| 123 | |||
| 124 | #endif /* __ASM_CMPXCHG_H */ | ||