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fef74705 RB |
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 | #endif /* __ASM_CMPXCHG_H */ |