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 */
52 struct cpu_context;
53 struct task_struct;
54 extern 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
74 extern void __xchg_called_with_bad_pointer(void);
75
xchg_u32(u32 val,volatile u32 * m)76 static 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
__xchg(unsigned long x,volatile void * ptr,int size)87 static 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
__cmpxchg_u32(volatile int * m,unsigned long old,unsigned long new)100 static 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
119 extern 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(). */
125 extern void __cmpxchg_called_with_bad_pointer(void);
126
127 #define __HAVE_ARCH_CMPXCHG 1
128
__cmpxchg(volatile void * ptr,unsigned long old,unsigned long new,int size)129 static 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
__cmpxchg_local(volatile void * ptr,unsigned long old,unsigned long new,int size)150 static 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
171 struct pt_regs;
172 void NORET_TYPE die(const char *str, struct pt_regs *regs, long err);
173 void _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 */
179