Linux kernel mirror (for testing)
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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 __mtdr(DBGREG_PID, prev->pid); \
39 __mtdr(DBGREG_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
76#ifdef __CHECKER__
77extern unsigned long __builtin_xchg(void *ptr, unsigned long x);
78#endif
79
80#define xchg_u32(val, m) __builtin_xchg((void *)m, val)
81
82static inline unsigned long __xchg(unsigned long x,
83 volatile void *ptr,
84 int size)
85{
86 switch(size) {
87 case 4:
88 return xchg_u32(x, ptr);
89 default:
90 __xchg_called_with_bad_pointer();
91 return x;
92 }
93}
94
95static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
96 unsigned long new)
97{
98 __u32 ret;
99
100 asm volatile(
101 "1: ssrf 5\n"
102 " ld.w %[ret], %[m]\n"
103 " cp.w %[ret], %[old]\n"
104 " brne 2f\n"
105 " stcond %[m], %[new]\n"
106 " brne 1b\n"
107 "2:\n"
108 : [ret] "=&r"(ret), [m] "=m"(*m)
109 : "m"(m), [old] "ir"(old), [new] "r"(new)
110 : "memory", "cc");
111 return ret;
112}
113
114extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
115 volatile int * m, unsigned long old, unsigned long new);
116#define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
117
118/* This function doesn't exist, so you'll get a linker error
119 if something tries to do an invalid cmpxchg(). */
120extern void __cmpxchg_called_with_bad_pointer(void);
121
122#define __HAVE_ARCH_CMPXCHG 1
123
124static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
125 unsigned long new, int size)
126{
127 switch (size) {
128 case 4:
129 return __cmpxchg_u32(ptr, old, new);
130 case 8:
131 return __cmpxchg_u64(ptr, old, new);
132 }
133
134 __cmpxchg_called_with_bad_pointer();
135 return old;
136}
137
138#define cmpxchg(ptr, old, new) \
139 ((typeof(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), \
140 (unsigned long)(new), \
141 sizeof(*(ptr))))
142
143struct pt_regs;
144void NORET_TYPE die(const char *str, struct pt_regs *regs, long err);
145void _exception(long signr, struct pt_regs *regs, int code,
146 unsigned long addr);
147
148#define arch_align_stack(x) (x)
149
150#endif /* __ASM_AVR32_SYSTEM_H */