include/asm-mips/system.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994 - 1999 by Ralf Baechle
   7  * Copyright (C) 1996 by Paul M. Antoine
   8  * Copyright (C) 1994 - 1999 by Ralf Baechle
   9  *
  10  * Changed set_except_vector declaration to allow return of previous
  11  * vector address value - necessary for "borrowing" vectors.
  12  *
  13  * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com
  14  * Copyright (C) 2000 MIPS Technologies, Inc.
  15  */
  16 #ifndef _ASM_SYSTEM_H
  17 #define _ASM_SYSTEM_H
  18
  19 #include <linux/config.h>
  20 #include <asm/sgidefs.h>
  21
  22 #include <linux/kernel.h>
  23
  24 #include <asm/addrspace.h>
  25 #include <asm/ptrace.h>
  26
  27 __asm__ (
  28         ".macro\t__sti\n\t"
  29         ".set\tpush\n\t"
  30         ".set\treorder\n\t"
  31         ".set\tnoat\n\t"
  32         "mfc0\t$1,$12\n\t"
  33         "ori\t$1,0x1f\n\t"
  34         "xori\t$1,0x1e\n\t"
  35         "mtc0\t$1,$12\n\t"
  36         ".set\tpop\n\t"
  37         ".endm");
  38
  39 extern __inline__ void
  40 __sti(void)
  41 {
  42         __asm__ __volatile__(
  43                 "__sti"
  44                 : /* no outputs */
  45                 : /* no inputs */
  46                 : "memory");
  47 }
  48
  49 /*
  50  * For cli() we have to insert nops to make sure that the new value
  51  * has actually arrived in the status register before the end of this
  52  * macro.
  53  * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
  54  * no nops at all.
  55  */
  56 __asm__ (
  57         ".macro\t__cli\n\t"
  58         ".set\tpush\n\t"
  59         ".set\tnoat\n\t"
  60         "mfc0\t$1,$12\n\t"
  61         "ori\t$1,1\n\t"
  62         "xori\t$1,1\n\t"
  63         ".set\tnoreorder\n\t"
  64         "mtc0\t$1,$12\n\t"
  65         "sll\t$0, $0, 1\t\t\t# nop\n\t"
  66         "sll\t$0, $0, 1\t\t\t# nop\n\t"
  67         "sll\t$0, $0, 1\t\t\t# nop\n\t"
  68         ".set\tpop\n\t"
  69         ".endm");
  70
  71 extern __inline__ void
  72 __cli(void)
  73 {
  74         __asm__ __volatile__(
  75                 "__cli"
  76                 : /* no outputs */
  77                 : /* no inputs */
  78                 : "memory");
  79 }
  80
  81 __asm__ (
  82         ".macro\t__save_flags flags\n\t"
  83         ".set\tpush\n\t"
  84         ".set\treorder\n\t"
  85         "mfc0\t\\flags, $12\n\t"
  86         ".set\tpop\n\t"
  87         ".endm");
  88
  89 #define __save_flags(x)                                                 \
  90 __asm__ __volatile__(                                                   \
  91         "__save_flags %0"                                               \
  92         : "=r" (x))
  93
  94 __asm__ (
  95         ".macro\t__save_and_cli result\n\t"
  96         ".set\tpush\n\t"
  97         ".set\treorder\n\t"
  98         ".set\tnoat\n\t"
  99         "mfc0\t\\result, $12\n\t"
 100         "ori\t$1, \\result, 1\n\t"
 101         "xori\t$1, 1\n\t"
 102         ".set\tnoreorder\n\t"
 103         "mtc0\t$1, $12\n\t"
 104         "sll\t$0, $0, 1\t\t\t# nop\n\t"
 105         "sll\t$0, $0, 1\t\t\t# nop\n\t"
 106         "sll\t$0, $0, 1\t\t\t# nop\n\t"
 107         ".set\tpop\n\t"
 108         ".endm");
 109
 110 #define __save_and_cli(x)                                               \
 111 __asm__ __volatile__(                                                   \
 112         "__save_and_cli\t%0"                                            \
 113         : "=r" (x)                                                      \
 114         : /* no inputs */                                               \
 115         : "memory")
 116
 117 #define __save_and_sti(x)       do { __save_flags(x); __sti(); } while(0);
 118
 119 __asm__(".macro\t__restore_flags flags\n\t"
 120         ".set\tnoreorder\n\t"
 121         ".set\tnoat\n\t"
 122         "mfc0\t$1, $12\n\t"
 123         "andi\t\\flags, 1\n\t"
 124         "ori\t$1, 1\n\t"
 125         "xori\t$1, 1\n\t"
 126         "or\t\\flags, $1\n\t"
 127         "mtc0\t\\flags, $12\n\t"
 128         "sll\t$0, $0, 1\t\t\t# nop\n\t"
 129         "sll\t$0, $0, 1\t\t\t# nop\n\t"
 130         "sll\t$0, $0, 1\t\t\t# nop\n\t"
 131         ".set\tat\n\t"
 132         ".set\treorder\n\t"
 133         ".endm");
 134
 135 #define __restore_flags(flags)                                          \
 136 do {                                                                    \
 137         unsigned long __tmp1;                                           \
 138                                                                         \
 139         __asm__ __volatile__(                                           \
 140                 "__restore_flags\t%0"                                   \
 141                 : "=r" (__tmp1)                                         \
 142                 : "0" (flags)                                           \
 143                 : "memory");                                            \
 144 } while(0)
 145
 146 #ifdef CONFIG_SMP
 147
 148 extern void __global_sti(void);
 149 extern void __global_cli(void);
 150 extern unsigned long __global_save_flags(void);
 151 extern void __global_restore_flags(unsigned long);
 152 #  define sti() __global_sti()
 153 #  define cli() __global_cli()
 154 #  define save_flags(x) do { x = __global_save_flags(); } while (0)
 155 #  define restore_flags(x) __global_restore_flags(x)
 156 #  define save_and_cli(x) do { save_flags(x); cli(); } while(0)
 157 #  define save_and_sti(x) do { save_flags(x); sti(); } while(0)
 158
 159 #else /* Single processor */
 160
 161 #  define sti() __sti()
 162 #  define cli() __cli()
 163 #  define save_flags(x) __save_flags(x)
 164 #  define save_and_cli(x) __save_and_cli(x)
 165 #  define restore_flags(x) __restore_flags(x)
 166 #  define save_and_sti(x) __save_and_sti(x)
 167
 168 #endif /* SMP */
 169
 170 /* For spinlocks etc */
 171 #define local_irq_save(x)       __save_and_cli(x)
 172 #define local_irq_set(x)        __save_and_sti(x)
 173 #define local_irq_restore(x)    __restore_flags(x)
 174 #define local_irq_disable()     __cli()
 175 #define local_irq_enable()      __sti()
 176
 177 #ifdef CONFIG_CPU_HAS_SYNC
 178 #define __sync()                                \
 179         __asm__ __volatile__(                   \
 180                 ".set   push\n\t"               \
 181                 ".set   noreorder\n\t"          \
 182                 ".set   mips2\n\t"              \
 183                 "sync\n\t"                      \
 184                 ".set   pop"                    \
 185                 : /* no output */               \
 186                 : /* no input */                \
 187                 : "memory")
 188 #else
 189 #define __sync()        do { } while(0)
 190 #endif
 191
 192 #define __fast_iob()                            \
 193         __asm__ __volatile__(                   \
 194                 ".set   push\n\t"               \
 195                 ".set   noreorder\n\t"          \
 196                 "lw     $0,%0\n\t"              \
 197                 "nop\n\t"                       \
 198                 ".set   pop"                    \
 199                 : /* no output */               \
 200                 : "m" (*(int *)KSEG1)           \
 201                 : "memory")
 202
 203 #define fast_wmb()      __sync()
 204 #define fast_rmb()      __sync()
 205 #define fast_mb()       __sync()
 206 #define fast_iob()                              \
 207         do {                                    \
 208                 __sync();                       \
 209                 __fast_iob();                   \
 210         } while (0)
 211
 212 #ifdef CONFIG_CPU_HAS_WB
 213
 214 #include <asm/wbflush.h>
 215
 216 #define wmb()           fast_wmb()
 217 #define rmb()           fast_rmb()
 218 #define mb()            wbflush();
 219 #define iob()           wbflush();
 220
 221 #else /* !CONFIG_CPU_HAS_WB */
 222
 223 #define wmb()           fast_wmb()
 224 #define rmb()           fast_rmb()
 225 #define mb()            fast_mb()
 226 #define iob()           fast_iob()
 227
 228 #endif /* !CONFIG_CPU_HAS_WB */
 229
 230 #ifdef CONFIG_SMP
 231 #define smp_mb()        mb()
 232 #define smp_rmb()       rmb()
 233 #define smp_wmb()       wmb()
 234 #else
 235 #define smp_mb()        barrier()
 236 #define smp_rmb()       barrier()
 237 #define smp_wmb()       barrier()
 238 #endif
 239
 240 #define set_mb(var, value) \
 241 do { var = value; mb(); } while (0)
 242
 243 #define set_wmb(var, value) \
 244 do { var = value; wmb(); } while (0)
 245
 246 #ifndef __ASSEMBLY__
 247 /*
 248  * switch_to(n) should switch tasks to task nr n, first
 249  * checking that n isn't the current task, in which case it does nothing.
 250  */
 251 extern asmlinkage void *resume(void *last, void *next);
 252 #endif /* !__ASSEMBLY__ */
 253
 254 #define prepare_to_switch()     do { } while(0)
 255
 256 struct task_struct;
 257
 258 extern asmlinkage void lazy_fpu_switch(void *);
 259 extern asmlinkage void init_fpu(void);
 260 extern asmlinkage void save_fp(struct task_struct *);
 261 extern asmlinkage void restore_fp(struct task_struct *);
 262
 263 #define switch_to(prev,next,last) \
 264 do { \
 265         (last) = resume(prev, next); \
 266 } while(0)
 267
 268 /*
 269  * For 32 and 64 bit operands we can take advantage of ll and sc.
 270  * FIXME: This doesn't work for R3000 machines.
 271  */
 272 extern __inline__ unsigned long xchg_u32(volatile int * m, unsigned long val)
 273 {
 274 #ifdef CONFIG_CPU_HAS_LLSC
 275         unsigned long dummy;
 276
 277         __asm__ __volatile__(
 278                 ".set\tpush\t\t\t\t# xchg_u32\n\t"
 279                 ".set\tnoreorder\n\t"
 280                 ".set\tnomacro\n\t"
 281                 "ll\t%0, %3\n"
 282                 "1:\tmove\t%2, %z4\n\t"
 283                 "sc\t%2, %1\n\t"
 284                 "beqzl\t%2, 1b\n\t"
 285                 " ll\t%0, %3\n\t"
 286                 "sync\n\t"
 287                 ".set\tpop"
 288                 : "=&r" (val), "=m" (*m), "=&r" (dummy)
 289                 : "R" (*m), "Jr" (val)
 290                 : "memory");
 291
 292         return val;
 293 #else
 294         unsigned long flags, retval;
 295
 296         save_flags(flags);
 297         cli();
 298         retval = *m;
 299         *m = val;
 300         restore_flags(flags);   /* implies memory barrier  */
 301         return retval;
 302 #endif /* Processor-dependent optimization */
 303 }
 304
 305 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 306 #define tas(ptr) (xchg((ptr),1))
 307
 308 static __inline__ unsigned long
 309 __xchg(unsigned long x, volatile void * ptr, int size)
 310 {
 311         switch (size) {
 312                 case 4:
 313                         return xchg_u32(ptr, x);
 314         }
 315         return x;
 316 }
 317
 318 extern void *set_except_vector(int n, void *addr);
 319
 320 extern void __die(const char *, struct pt_regs *, const char *file,
 321         const char *func, unsigned long line) __attribute__((noreturn));
 322 extern void __die_if_kernel(const char *, struct pt_regs *, const char *file,
 323         const char *func, unsigned long line);
 324
 325 #define die(msg, regs)                                                  \
 326         __die(msg, regs, __FILE__ ":", __FUNCTION__, __LINE__)
 327 #define die_if_kernel(msg, regs)                                        \
 328         __die_if_kernel(msg, regs, __FILE__ ":", __FUNCTION__, __LINE__)
 329
 330 #endif /* _ASM_SYSTEM_H */