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 */ 179