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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 | ||
17 | #ifdef __KERNEL__ | |
18 | #ifndef __ASSEMBLY__ | |
19 | ||
20 | #include <linux/types.h> | |
21 | #include <linux/irqflags.h> | |
22 | ||
23 | #include <asm/cmpxchg-local.h> | |
c6691126 | 24 | #include <asm/cmpxchg.h> |
aafe4dbe AB |
25 | |
26 | struct task_struct; | |
27 | ||
28 | /* context switching is now performed out-of-line in switch_to.S */ | |
29 | extern struct task_struct *__switch_to(struct task_struct *, | |
30 | struct task_struct *); | |
31 | #define switch_to(prev, next, last) \ | |
32 | do { \ | |
33 | ((last) = __switch_to((prev), (next))); \ | |
34 | } while (0) | |
35 | ||
36 | #define arch_align_stack(x) (x) | |
37 | ||
38 | #define nop() asm volatile ("nop") | |
39 | ||
40 | #endif /* !__ASSEMBLY__ */ | |
41 | ||
42 | /* | |
43 | * Force strict CPU ordering. | |
44 | * And yes, this is required on UP too when we're talking | |
45 | * to devices. | |
46 | * | |
47 | * This implementation only contains a compiler barrier. | |
48 | */ | |
49 | ||
50 | #define mb() asm volatile ("": : :"memory") | |
51 | #define rmb() mb() | |
52 | #define wmb() asm volatile ("": : :"memory") | |
53 | ||
54 | #ifdef CONFIG_SMP | |
55 | #define smp_mb() mb() | |
56 | #define smp_rmb() rmb() | |
57 | #define smp_wmb() wmb() | |
58 | #else | |
59 | #define smp_mb() barrier() | |
60 | #define smp_rmb() barrier() | |
61 | #define smp_wmb() barrier() | |
62 | #endif | |
63 | ||
64 | #define set_mb(var, value) do { var = value; mb(); } while (0) | |
65 | #define set_wmb(var, value) do { var = value; wmb(); } while (0) | |
66 | ||
67 | #define read_barrier_depends() do {} while (0) | |
68 | #define smp_read_barrier_depends() do {} while (0) | |
69 | ||
70 | /* | |
71 | * we make sure local_irq_enable() doesn't cause priority inversion | |
72 | */ | |
73 | #ifndef __ASSEMBLY__ | |
74 | ||
75 | /* This function doesn't exist, so you'll get a linker error | |
76 | * if something tries to do an invalid xchg(). */ | |
77 | extern void __xchg_called_with_bad_pointer(void); | |
78 | ||
79 | static inline | |
80 | unsigned long __xchg(unsigned long x, volatile void *ptr, int size) | |
81 | { | |
82 | unsigned long ret, flags; | |
83 | ||
84 | switch (size) { | |
85 | case 1: | |
86 | #ifdef __xchg_u8 | |
87 | return __xchg_u8(x, ptr); | |
88 | #else | |
89 | local_irq_save(flags); | |
90 | ret = *(volatile u8 *)ptr; | |
91 | *(volatile u8 *)ptr = x; | |
92 | local_irq_restore(flags); | |
93 | return ret; | |
94 | #endif /* __xchg_u8 */ | |
95 | ||
96 | case 2: | |
97 | #ifdef __xchg_u16 | |
98 | return __xchg_u16(x, ptr); | |
99 | #else | |
100 | local_irq_save(flags); | |
101 | ret = *(volatile u16 *)ptr; | |
102 | *(volatile u16 *)ptr = x; | |
103 | local_irq_restore(flags); | |
104 | return ret; | |
105 | #endif /* __xchg_u16 */ | |
106 | ||
107 | case 4: | |
108 | #ifdef __xchg_u32 | |
109 | return __xchg_u32(x, ptr); | |
110 | #else | |
111 | local_irq_save(flags); | |
112 | ret = *(volatile u32 *)ptr; | |
113 | *(volatile u32 *)ptr = x; | |
114 | local_irq_restore(flags); | |
115 | return ret; | |
116 | #endif /* __xchg_u32 */ | |
117 | ||
118 | #ifdef CONFIG_64BIT | |
119 | case 8: | |
120 | #ifdef __xchg_u64 | |
121 | return __xchg_u64(x, ptr); | |
122 | #else | |
123 | local_irq_save(flags); | |
124 | ret = *(volatile u64 *)ptr; | |
125 | *(volatile u64 *)ptr = x; | |
126 | local_irq_restore(flags); | |
127 | return ret; | |
128 | #endif /* __xchg_u64 */ | |
129 | #endif /* CONFIG_64BIT */ | |
130 | ||
131 | default: | |
132 | __xchg_called_with_bad_pointer(); | |
133 | return x; | |
134 | } | |
135 | } | |
136 | ||
137 | #define xchg(ptr, x) \ | |
138 | ((__typeof__(*(ptr))) __xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))) | |
139 | ||
aafe4dbe AB |
140 | #endif /* !__ASSEMBLY__ */ |
141 | ||
142 | #endif /* __KERNEL__ */ | |
143 | #endif /* __ASM_GENERIC_SYSTEM_H */ |