1 #ifndef __ASM_SH_SYSTEM_H 2 #define __ASM_SH_SYSTEM_H 3 4 /* 5 * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima 6 * Copyright (C) 2002 Paul Mundt 7 * 8 * from linux kernel code. 9 */ 10 11 #include <linux/irqflags.h> 12 #include <asm/types.h> 13 14 /* 15 * switch_to() should switch tasks to task nr n, first 16 */ 17 18 #define switch_to(prev, next, last) do { \ 19 struct task_struct *__last; \ 20 register unsigned long *__ts1 __asm__ ("r1") = &prev->thread.sp; \ 21 register unsigned long *__ts2 __asm__ ("r2") = &prev->thread.pc; \ 22 register unsigned long *__ts4 __asm__ ("r4") = (unsigned long *)prev; \ 23 register unsigned long *__ts5 __asm__ ("r5") = (unsigned long *)next; \ 24 register unsigned long *__ts6 __asm__ ("r6") = &next->thread.sp; \ 25 register unsigned long __ts7 __asm__ ("r7") = next->thread.pc; \ 26 __asm__ __volatile__ (".balign 4\n\t" \ 27 "stc.l gbr, @-r15\n\t" \ 28 "sts.l pr, @-r15\n\t" \ 29 "mov.l r8, @-r15\n\t" \ 30 "mov.l r9, @-r15\n\t" \ 31 "mov.l r10, @-r15\n\t" \ 32 "mov.l r11, @-r15\n\t" \ 33 "mov.l r12, @-r15\n\t" \ 34 "mov.l r13, @-r15\n\t" \ 35 "mov.l r14, @-r15\n\t" \ 36 "mov.l r15, @r1 ! save SP\n\t" \ 37 "mov.l @r6, r15 ! change to new stack\n\t" \ 38 "mova 1f, %0\n\t" \ 39 "mov.l %0, @r2 ! save PC\n\t" \ 40 "mov.l 2f, %0\n\t" \ 41 "jmp @%0 ! call __switch_to\n\t" \ 42 " lds r7, pr ! with return to new PC\n\t" \ 43 ".balign 4\n" \ 44 "2:\n\t" \ 45 ".long __switch_to\n" \ 46 "1:\n\t" \ 47 "mov.l @r15+, r14\n\t" \ 48 "mov.l @r15+, r13\n\t" \ 49 "mov.l @r15+, r12\n\t" \ 50 "mov.l @r15+, r11\n\t" \ 51 "mov.l @r15+, r10\n\t" \ 52 "mov.l @r15+, r9\n\t" \ 53 "mov.l @r15+, r8\n\t" \ 54 "lds.l @r15+, pr\n\t" \ 55 "ldc.l @r15+, gbr\n\t" \ 56 : "=z" (__last) \ 57 : "r" (__ts1), "r" (__ts2), "r" (__ts4), \ 58 "r" (__ts5), "r" (__ts6), "r" (__ts7) \ 59 : "r3", "t"); \ 60 last = __last; \ 61 } while (0) 62 63 /* 64 * On SMP systems, when the scheduler does migration-cost autodetection, 65 * it needs a way to flush as much of the CPU's caches as possible. 66 * 67 * TODO: fill this in! 68 */ 69 static inline void sched_cacheflush(void) 70 { 71 } 72 73 #ifdef CONFIG_CPU_SH4A 74 #define __icbi() \ 75 { \ 76 unsigned long __addr; \ 77 __addr = 0xa8000000; \ 78 __asm__ __volatile__( \ 79 "icbi %0\n\t" \ 80 : /* no output */ \ 81 : "m" (__m(__addr))); \ 82 } 83 #endif 84 85 static inline unsigned long tas(volatile int *m) 86 { 87 unsigned long retval; 88 89 __asm__ __volatile__ ("tas.b @%1\n\t" 90 "movt %0" 91 : "=r" (retval): "r" (m): "t", "memory"); 92 return retval; 93 } 94 95 /* 96 * A brief note on ctrl_barrier(), the control register write barrier. 97 * 98 * Legacy SH cores typically require a sequence of 8 nops after 99 * modification of a control register in order for the changes to take 100 * effect. On newer cores (like the sh4a and sh5) this is accomplished 101 * with icbi. 102 * 103 * Also note that on sh4a in the icbi case we can forego a synco for the 104 * write barrier, as it's not necessary for control registers. 105 * 106 * Historically we have only done this type of barrier for the MMUCR, but 107 * it's also necessary for the CCR, so we make it generic here instead. 108 */ 109 #ifdef CONFIG_CPU_SH4A 110 #define mb() __asm__ __volatile__ ("synco": : :"memory") 111 #define rmb() mb() 112 #define wmb() __asm__ __volatile__ ("synco": : :"memory") 113 #define ctrl_barrier() __icbi() 114 #define read_barrier_depends() do { } while(0) 115 #else 116 #define mb() __asm__ __volatile__ ("": : :"memory") 117 #define rmb() mb() 118 #define wmb() __asm__ __volatile__ ("": : :"memory") 119 #define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop") 120 #define read_barrier_depends() do { } while(0) 121 #endif 122 123 #ifdef CONFIG_SMP 124 #define smp_mb() mb() 125 #define smp_rmb() rmb() 126 #define smp_wmb() wmb() 127 #define smp_read_barrier_depends() read_barrier_depends() 128 #else 129 #define smp_mb() barrier() 130 #define smp_rmb() barrier() 131 #define smp_wmb() barrier() 132 #define smp_read_barrier_depends() do { } while(0) 133 #endif 134 135 #define set_mb(var, value) do { xchg(&var, value); } while (0) 136 137 /* 138 * Jump to P2 area. 139 * When handling TLB or caches, we need to do it from P2 area. 140 */ 141 #define jump_to_P2() \ 142 do { \ 143 unsigned long __dummy; \ 144 __asm__ __volatile__( \ 145 "mov.l 1f, %0\n\t" \ 146 "or %1, %0\n\t" \ 147 "jmp @%0\n\t" \ 148 " nop\n\t" \ 149 ".balign 4\n" \ 150 "1: .long 2f\n" \ 151 "2:" \ 152 : "=&r" (__dummy) \ 153 : "r" (0x20000000)); \ 154 } while (0) 155 156 /* 157 * Back to P1 area. 158 */ 159 #define back_to_P1() \ 160 do { \ 161 unsigned long __dummy; \ 162 ctrl_barrier(); \ 163 __asm__ __volatile__( \ 164 "mov.l 1f, %0\n\t" \ 165 "jmp @%0\n\t" \ 166 " nop\n\t" \ 167 ".balign 4\n" \ 168 "1: .long 2f\n" \ 169 "2:" \ 170 : "=&r" (__dummy)); \ 171 } while (0) 172 173 static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val) 174 { 175 unsigned long flags, retval; 176 177 local_irq_save(flags); 178 retval = *m; 179 *m = val; 180 local_irq_restore(flags); 181 return retval; 182 } 183 184 static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val) 185 { 186 unsigned long flags, retval; 187 188 local_irq_save(flags); 189 retval = *m; 190 *m = val & 0xff; 191 local_irq_restore(flags); 192 return retval; 193 } 194 195 extern void __xchg_called_with_bad_pointer(void); 196 197 #define __xchg(ptr, x, size) \ 198 ({ \ 199 unsigned long __xchg__res; \ 200 volatile void *__xchg_ptr = (ptr); \ 201 switch (size) { \ 202 case 4: \ 203 __xchg__res = xchg_u32(__xchg_ptr, x); \ 204 break; \ 205 case 1: \ 206 __xchg__res = xchg_u8(__xchg_ptr, x); \ 207 break; \ 208 default: \ 209 __xchg_called_with_bad_pointer(); \ 210 __xchg__res = x; \ 211 break; \ 212 } \ 213 \ 214 __xchg__res; \ 215 }) 216 217 #define xchg(ptr,x) \ 218 ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr)))) 219 220 static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old, 221 unsigned long new) 222 { 223 __u32 retval; 224 unsigned long flags; 225 226 local_irq_save(flags); 227 retval = *m; 228 if (retval == old) 229 *m = new; 230 local_irq_restore(flags); /* implies memory barrier */ 231 return retval; 232 } 233 234 /* This function doesn't exist, so you'll get a linker error 235 * if something tries to do an invalid cmpxchg(). */ 236 extern void __cmpxchg_called_with_bad_pointer(void); 237 238 #define __HAVE_ARCH_CMPXCHG 1 239 240 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old, 241 unsigned long new, int size) 242 { 243 switch (size) { 244 case 4: 245 return __cmpxchg_u32(ptr, old, new); 246 } 247 __cmpxchg_called_with_bad_pointer(); 248 return old; 249 } 250 251 #define cmpxchg(ptr,o,n) \ 252 ({ \ 253 __typeof__(*(ptr)) _o_ = (o); \ 254 __typeof__(*(ptr)) _n_ = (n); \ 255 (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ 256 (unsigned long)_n_, sizeof(*(ptr))); \ 257 }) 258 259 extern void *set_exception_table_vec(unsigned int vec, void *handler); 260 261 static inline void *set_exception_table_evt(unsigned int evt, void *handler) 262 { 263 return set_exception_table_vec(evt >> 5, handler); 264 } 265 266 /* XXX 267 * disable hlt during certain critical i/o operations 268 */ 269 #define HAVE_DISABLE_HLT 270 void disable_hlt(void); 271 void enable_hlt(void); 272 273 #define arch_align_stack(x) (x) 274 275 #endif 276