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aafe4dbe AB |
1 | /* Generic system definitions, based on MN10300 definitions. |
2 | * | |
3 | * It should be possible to use these on really simple architectures, | |
4 | * but it serves more as a starting point for new ports. | |
5 | * | |
6 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
7 | * Written by David Howells (dhowells@redhat.com) | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public Licence | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the Licence, or (at your option) any later version. | |
13 | */ | |
14 | #ifndef __ASM_GENERIC_SYSTEM_H | |
15 | #define __ASM_GENERIC_SYSTEM_H | |
16 | ||
aafe4dbe AB |
17 | #ifndef __ASSEMBLY__ |
18 | ||
19 | #include <linux/types.h> | |
20 | #include <linux/irqflags.h> | |
21 | ||
22 | #include <asm/cmpxchg-local.h> | |
c6691126 | 23 | #include <asm/cmpxchg.h> |
aafe4dbe AB |
24 | |
25 | struct task_struct; | |
26 | ||
27 | /* context switching is now performed out-of-line in switch_to.S */ | |
28 | extern struct task_struct *__switch_to(struct task_struct *, | |
29 | struct task_struct *); | |
30 | #define switch_to(prev, next, last) \ | |
31 | do { \ | |
32 | ((last) = __switch_to((prev), (next))); \ | |
33 | } while (0) | |
34 | ||
35 | #define arch_align_stack(x) (x) | |
36 | ||
37 | #define nop() asm volatile ("nop") | |
38 | ||
39 | #endif /* !__ASSEMBLY__ */ | |
40 | ||
41 | /* | |
42 | * Force strict CPU ordering. | |
43 | * And yes, this is required on UP too when we're talking | |
44 | * to devices. | |
45 | * | |
46 | * This implementation only contains a compiler barrier. | |
47 | */ | |
48 | ||
49 | #define mb() asm volatile ("": : :"memory") | |
50 | #define rmb() mb() | |
51 | #define wmb() asm volatile ("": : :"memory") | |
52 | ||
53 | #ifdef CONFIG_SMP | |
54 | #define smp_mb() mb() | |
55 | #define smp_rmb() rmb() | |
56 | #define smp_wmb() wmb() | |
57 | #else | |
58 | #define smp_mb() barrier() | |
59 | #define smp_rmb() barrier() | |
60 | #define smp_wmb() barrier() | |
61 | #endif | |
62 | ||
63 | #define set_mb(var, value) do { var = value; mb(); } while (0) | |
64 | #define set_wmb(var, value) do { var = value; wmb(); } while (0) | |
65 | ||
66 | #define read_barrier_depends() do {} while (0) | |
67 | #define smp_read_barrier_depends() do {} while (0) | |
68 | ||
69 | /* | |
70 | * we make sure local_irq_enable() doesn't cause priority inversion | |
71 | */ | |
72 | #ifndef __ASSEMBLY__ | |
73 | ||
74 | /* This function doesn't exist, so you'll get a linker error | |
75 | * if something tries to do an invalid xchg(). */ | |
76 | extern void __xchg_called_with_bad_pointer(void); | |
77 | ||
78 | static inline | |
79 | unsigned long __xchg(unsigned long x, volatile void *ptr, int size) | |
80 | { | |
81 | unsigned long ret, flags; | |
82 | ||
83 | switch (size) { | |
84 | case 1: | |
85 | #ifdef __xchg_u8 | |
86 | return __xchg_u8(x, ptr); | |
87 | #else | |
88 | local_irq_save(flags); | |
89 | ret = *(volatile u8 *)ptr; | |
90 | *(volatile u8 *)ptr = x; | |
91 | local_irq_restore(flags); | |
92 | return ret; | |
93 | #endif /* __xchg_u8 */ | |
94 | ||
95 | case 2: | |
96 | #ifdef __xchg_u16 | |
97 | return __xchg_u16(x, ptr); | |
98 | #else | |
99 | local_irq_save(flags); | |
100 | ret = *(volatile u16 *)ptr; | |
101 | *(volatile u16 *)ptr = x; | |
102 | local_irq_restore(flags); | |
103 | return ret; | |
104 | #endif /* __xchg_u16 */ | |
105 | ||
106 | case 4: | |
107 | #ifdef __xchg_u32 | |
108 | return __xchg_u32(x, ptr); | |
109 | #else | |
110 | local_irq_save(flags); | |
111 | ret = *(volatile u32 *)ptr; | |
112 | *(volatile u32 *)ptr = x; | |
113 | local_irq_restore(flags); | |
114 | return ret; | |
115 | #endif /* __xchg_u32 */ | |
116 | ||
117 | #ifdef CONFIG_64BIT | |
118 | case 8: | |
119 | #ifdef __xchg_u64 | |
120 | return __xchg_u64(x, ptr); | |
121 | #else | |
122 | local_irq_save(flags); | |
123 | ret = *(volatile u64 *)ptr; | |
124 | *(volatile u64 *)ptr = x; | |
125 | local_irq_restore(flags); | |
126 | return ret; | |
127 | #endif /* __xchg_u64 */ | |
128 | #endif /* CONFIG_64BIT */ | |
129 | ||
130 | default: | |
131 | __xchg_called_with_bad_pointer(); | |
132 | return x; | |
133 | } | |
134 | } | |
135 | ||
136 | #define xchg(ptr, x) \ | |
137 | ((__typeof__(*(ptr))) __xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))) | |
138 | ||
aafe4dbe AB |
139 | #endif /* !__ASSEMBLY__ */ |
140 | ||
aafe4dbe | 141 | #endif /* __ASM_GENERIC_SYSTEM_H */ |