Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * Copyright (C) 2004-2006 Atmel Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8#ifndef __ASM_AVR32_SYSTEM_H
9#define __ASM_AVR32_SYSTEM_H
10
11#include <linux/compiler.h>
12#include <linux/linkage.h>
13#include <linux/types.h>
14
15#include <asm/ptrace.h>
16#include <asm/sysreg.h>
17
18#define xchg(ptr,x) \
19 ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
20
21#define nop() asm volatile("nop")
22
23#define mb() asm volatile("" : : : "memory")
24#define rmb() mb()
25#define wmb() asm volatile("sync 0" : : : "memory")
26#define read_barrier_depends() do { } while(0)
27#define set_mb(var, value) do { var = value; mb(); } while(0)
28
29/*
30 * Help PathFinder and other Nexus-compliant debuggers keep track of
31 * the current PID by emitting an Ownership Trace Message each time we
32 * switch task.
33 */
34#ifdef CONFIG_OWNERSHIP_TRACE
35#include <asm/ocd.h>
36#define finish_arch_switch(prev) \
37 do { \
38 ocd_write(PID, prev->pid); \
39 ocd_write(PID, current->pid); \
40 } while(0)
41#endif
42
43/*
44 * switch_to(prev, next, last) should switch from task `prev' to task
45 * `next'. `prev' will never be the same as `next'.
46 *
47 * We just delegate everything to the __switch_to assembly function,
48 * which is implemented in arch/avr32/kernel/switch_to.S
49 *
50 * mb() tells GCC not to cache `current' across this call.
51 */
52struct cpu_context;
53struct task_struct;
54extern struct task_struct *__switch_to(struct task_struct *,
55 struct cpu_context *,
56 struct cpu_context *);
57#define switch_to(prev, next, last) \
58 do { \
59 last = __switch_to(prev, &prev->thread.cpu_context + 1, \
60 &next->thread.cpu_context); \
61 } while (0)
62
63#ifdef CONFIG_SMP
64# error "The AVR32 port does not support SMP"
65#else
66# define smp_mb() barrier()
67# define smp_rmb() barrier()
68# define smp_wmb() barrier()
69# define smp_read_barrier_depends() do { } while(0)
70#endif
71
72#include <linux/irqflags.h>
73
74extern void __xchg_called_with_bad_pointer(void);
75
76static inline unsigned long xchg_u32(u32 val, volatile u32 *m)
77{
78 u32 ret;
79
80 asm volatile("xchg %[ret], %[m], %[val]"
81 : [ret] "=&r"(ret), "=m"(*m)
82 : "m"(*m), [m] "r"(m), [val] "r"(val)
83 : "memory");
84 return ret;
85}
86
87static inline unsigned long __xchg(unsigned long x,
88 volatile void *ptr,
89 int size)
90{
91 switch(size) {
92 case 4:
93 return xchg_u32(x, ptr);
94 default:
95 __xchg_called_with_bad_pointer();
96 return x;
97 }
98}
99
100static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
101 unsigned long new)
102{
103 __u32 ret;
104
105 asm volatile(
106 "1: ssrf 5\n"
107 " ld.w %[ret], %[m]\n"
108 " cp.w %[ret], %[old]\n"
109 " brne 2f\n"
110 " stcond %[m], %[new]\n"
111 " brne 1b\n"
112 "2:\n"
113 : [ret] "=&r"(ret), [m] "=m"(*m)
114 : "m"(m), [old] "ir"(old), [new] "r"(new)
115 : "memory", "cc");
116 return ret;
117}
118
119extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
120 volatile int * m, unsigned long old, unsigned long new);
121#define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
122
123/* This function doesn't exist, so you'll get a linker error
124 if something tries to do an invalid cmpxchg(). */
125extern void __cmpxchg_called_with_bad_pointer(void);
126
127#define __HAVE_ARCH_CMPXCHG 1
128
129static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
130 unsigned long new, int size)
131{
132 switch (size) {
133 case 4:
134 return __cmpxchg_u32(ptr, old, new);
135 case 8:
136 return __cmpxchg_u64(ptr, old, new);
137 }
138
139 __cmpxchg_called_with_bad_pointer();
140 return old;
141}
142
143#define cmpxchg(ptr, old, new) \
144 ((typeof(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), \
145 (unsigned long)(new), \
146 sizeof(*(ptr))))
147
148#include <asm-generic/cmpxchg-local.h>
149
150static inline unsigned long __cmpxchg_local(volatile void *ptr,
151 unsigned long old,
152 unsigned long new, int size)
153{
154 switch (size) {
155 case 4:
156 return __cmpxchg_u32(ptr, old, new);
157 default:
158 return __cmpxchg_local_generic(ptr, old, new, size);
159 }
160
161 return old;
162}
163
164#define cmpxchg_local(ptr, old, new) \
165 ((typeof(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(old), \
166 (unsigned long)(new), \
167 sizeof(*(ptr))))
168
169#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
170
171struct pt_regs;
172void NORET_TYPE die(const char *str, struct pt_regs *regs, long err);
173void _exception(long signr, struct pt_regs *regs, int code,
174 unsigned long addr);
175
176#define arch_align_stack(x) (x)
177
178#endif /* __ASM_AVR32_SYSTEM_H */