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 #include <asm/ptrace.h>
  22 #if 0
  23 #include <linux/kernel.h>
  24 #endif
  25
  26 extern __inline__ void
  27 __sti(void)
  28 {
  29         __asm__ __volatile__(
  30                 ".set\tpush\n\t"
  31                 ".set\treorder\n\t"
  32                 ".set\tnoat\n\t"
  33                 "mfc0\t$1,$12\n\t"
  34                 "ori\t$1,0x1f\n\t"
  35                 "xori\t$1,0x1e\n\t"
  36                 "mtc0\t$1,$12\n\t"
  37                 ".set\tpop\n\t"
  38                 : /* no outputs */
  39                 : /* no inputs */
  40                 : "$1", "memory");
  41 }
  42
  43 /*
  44  * For cli() we have to insert nops to make shure that the new value
  45  * has actually arrived in the status register before the end of this
  46  * macro.
  47  * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
  48  * no nops at all.
  49  */
  50 extern __inline__ void
  51 __cli(void)
  52 {
  53         __asm__ __volatile__(
  54                 ".set\tpush\n\t"
  55                 ".set\treorder\n\t"
  56                 ".set\tnoat\n\t"
  57                 "mfc0\t$1,$12\n\t"
  58                 "ori\t$1,1\n\t"
  59                 "xori\t$1,1\n\t"
  60                 ".set\tnoreorder\n\t"
  61                 "mtc0\t$1,$12\n\t"
  62                 "nop\n\t"
  63                 "nop\n\t"
  64                 "nop\n\t"
  65                 ".set\tpop\n\t"
  66                 : /* no outputs */
  67                 : /* no inputs */
  68                 : "$1", "memory");
  69 }
  70
  71 #define __save_flags(x)                                                 \
  72 __asm__ __volatile__(                                                   \
  73         ".set\tpush\n\t"                                                \
  74         ".set\treorder\n\t"                                             \
  75         "mfc0\t%0,$12\n\t"                                              \
  76         ".set\tpop\n\t"                                                 \
  77         : "=r" (x))
  78
  79 #define __save_and_cli(x)                                               \
  80 __asm__ __volatile__(                                                   \
  81         ".set\tpush\n\t"                                                \
  82         ".set\treorder\n\t"                                             \
  83         ".set\tnoat\n\t"                                                \
  84         "mfc0\t%0,$12\n\t"                                              \
  85         "ori\t$1,%0,1\n\t"                                              \
  86         "xori\t$1,1\n\t"                                                \
  87         ".set\tnoreorder\n\t"                                           \
  88         "mtc0\t$1,$12\n\t"                                              \
  89         "nop\n\t"                                                       \
  90         "nop\n\t"                                                       \
  91         "nop\n\t"                                                       \
  92         ".set\tpop\n\t"                                                 \
  93         : "=r" (x)                                                      \
  94         : /* no inputs */                                               \
  95         : "$1", "memory")
  96
  97 #define __restore_flags(flags)                                          \
  98 do {                                                                    \
  99         unsigned long __tmp1;                                           \
 100                                                                         \
 101         __asm__ __volatile__(                                           \
 102                 ".set\tnoreorder\t\t\t# __restore_flags\n\t"            \
 103                 ".set\tnoat\n\t"                                        \
 104                 "mfc0\t$1, $12\n\t"                                     \
 105                 "andi\t%0, 1\n\t"                                       \
 106                 "ori\t$1, 1\n\t"                                        \
 107                 "xori\t$1, 1\n\t"                                       \
 108                 "or\t%0, $1\n\t"                                        \
 109                 "mtc0\t%0, $12\n\t"                                     \
 110                 "nop\n\t"                                               \
 111                 "nop\n\t"                                               \
 112                 "nop\n\t"                                               \
 113                 ".set\tat\n\t"                                          \
 114                 ".set\treorder"                                         \
 115                 : "=r" (__tmp1)                                         \
 116                 : "0" (flags)                                           \
 117                 : "$1", "memory");                                      \
 118 } while(0)
 119
 120 #ifdef CONFIG_SMP
 121
 122 extern void __global_sti(void);
 123 extern void __global_cli(void);
 124 extern unsigned long __global_save_flags(void);
 125 extern void __global_restore_flags(unsigned long);
 126 #  define sti() __global_sti()
 127 #  define cli() __global_cli()
 128 #  define save_flags(x) do { x = __global_save_flags(); } while (0)
 129 #  define restore_flags(x) __global_restore_flags(x)
 130 #  define save_and_cli(x) do { save_flags(x); cli(); } while(0)
 131
 132 #else /* Single processor */
 133
 134 #  define sti() __sti()
 135 #  define cli() __cli()
 136 #  define save_flags(x) __save_flags(x)
 137 #  define save_and_cli(x) __save_and_cli(x)
 138 #  define restore_flags(x) __restore_flags(x)
 139
 140 #endif /* SMP */
 141
 142 /* For spinlocks etc */
 143 #define local_irq_save(x)       __save_and_cli(x);
 144 #define local_irq_restore(x)    __restore_flags(x);
 145 #define local_irq_disable()     __cli();
 146 #define local_irq_enable()      __sti();
 147
 148 /*
 149  * These are probably defined overly paranoid ...
 150  */
 151 #ifdef CONFIG_CPU_HAS_WB
 152
 153 #include <asm/wbflush.h>
 154 #define rmb()   do { } while(0)
 155 #define wmb()   wbflush()
 156 #define mb()    wbflush()
 157
 158 #else /* CONFIG_CPU_HAS_WB  */
 159
 160 #define mb()                                            \
 161 __asm__ __volatile__(                                   \
 162         "# prevent instructions being moved around\n\t" \
 163         ".set\tnoreorder\n\t"                           \
 164         "# 8 nops to fool the R4400 pipeline\n\t"       \
 165         "nop;nop;nop;nop;nop;nop;nop;nop\n\t"           \
 166         ".set\treorder"                                 \
 167         : /* no output */                               \
 168         : /* no input */                                \
 169         : "memory")
 170 #define rmb() mb()
 171 #define wmb() mb()
 172
 173 #endif /* CONFIG_CPU_HAS_WB  */
 174
 175 #ifdef CONFIG_SMP
 176 #define smp_mb()        mb()
 177 #define smp_rmb()       rmb()
 178 #define smp_wmb()       wmb()
 179 #else
 180 #define smp_mb()        barrier()
 181 #define smp_rmb()       barrier()
 182 #define smp_wmb()       barrier()
 183 #endif
 184
 185 #define set_mb(var, value) \
 186 do { var = value; mb(); } while (0)
 187
 188 #define set_wmb(var, value) \
 189 do { var = value; wmb(); } while (0)
 190
 191 #if !defined (_LANGUAGE_ASSEMBLY)
 192 /*
 193  * switch_to(n) should switch tasks to task nr n, first
 194  * checking that n isn't the current task, in which case it does nothing.
 195  */
 196 #if 0
 197 extern asmlinkage void *resume(void *last, void *next);
 198 #endif
 199 #endif /* !defined (_LANGUAGE_ASSEMBLY) */
 200
 201 #define prepare_to_switch()     do { } while(0)
 202 #define switch_to(prev,next,last) \
 203 do { \
 204         (last) = resume(prev, next); \
 205 } while(0)
 206
 207 /*
 208  * For 32 and 64 bit operands we can take advantage of ll and sc.
 209  * FIXME: This doesn't work for R3000 machines.
 210  */
 211 extern __inline__ unsigned long xchg_u32(volatile int * m, unsigned long val)
 212 {
 213 #ifdef CONFIG_CPU_HAS_LLSC
 214         unsigned long dummy;
 215
 216         __asm__ __volatile__(
 217                 ".set\tnoreorder\t\t\t# xchg_u32\n\t"
 218                 ".set\tnoat\n\t"
 219                 "ll\t%0, %3\n"
 220                 "1:\tmove\t$1, %2\n\t"
 221                 "sc\t$1, %1\n\t"
 222                 "beqzl\t$1, 1b\n\t"
 223                 " ll\t%0, %3\n\t"
 224                 ".set\tat\n\t"
 225                 ".set\treorder"
 226                 : "=r" (val), "=o" (*m), "=r" (dummy)
 227                 : "o" (*m), "2" (val)
 228                 : "memory");
 229
 230         return val;
 231 #else
 232         unsigned long flags, retval;
 233
 234         save_flags(flags);
 235         cli();
 236         retval = *m;
 237         *m = val;
 238         restore_flags(flags);
 239         return retval;
 240 #endif /* Processor-dependent optimization */
 241 }
 242
 243 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 244 #define tas(ptr) (xchg((ptr),1))
 245
 246 static __inline__ unsigned long
 247 __xchg(unsigned long x, volatile void * ptr, int size)
 248 {
 249         switch (size) {
 250                 case 4:
 251                         return xchg_u32(ptr, x);
 252         }
 253         return x;
 254 }
 255
 256 extern void *set_except_vector(int n, void *addr);
 257
 258 extern void __die(const char *, struct pt_regs *, const char *where,
 259         unsigned long line) __attribute__((noreturn));
 260 extern void __die_if_kernel(const char *, struct pt_regs *, const char *where,
 261         unsigned long line);
 262
 263 #define die(msg, regs)                                                  \
 264         __die(msg, regs, __FILE__ ":"__FUNCTION__, __LINE__)
 265 #define die_if_kernel(msg, regs)                                        \
 266         __die_if_kernel(msg, regs, __FILE__ ":"__FUNCTION__, __LINE__)
 267
 268 #endif /* _ASM_SYSTEM_H */