arch/mips/include/asm/system.h

   1 /*
   2  * Copyright (C) 1994 - 1999 by Ralf Baechle
   3  * Copyright (C) 1996 by Paul M. Antoine
   4  * Copyright (C) 1994 - 1999 by Ralf Baechle
   5  *
   6  * Changed set_except_vector declaration to allow return of previous
   7  * vector address value - necessary for "borrowing" vectors.
   8  *
   9  * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com
  10  * Copyright (C) 2000 MIPS Technologies, Inc.
  11  *
  12  * SPDX-License-Identifier:     GPL-2.0
  13  */
  14 #ifndef _ASM_SYSTEM_H
  15 #define _ASM_SYSTEM_H
  16
  17 #include <asm/sgidefs.h>
  18 #include <asm/ptrace.h>
  19 #if 0
  20 #include <linux/kernel.h>
  21 #endif
  22
  23 static __inline__ void
  24 __sti(void)
  25 {
  26         __asm__ __volatile__(
  27                 ".set\tpush\n\t"
  28                 ".set\treorder\n\t"
  29                 ".set\tnoat\n\t"
  30                 "mfc0\t$1,$12\n\t"
  31                 "ori\t$1,0x1f\n\t"
  32                 "xori\t$1,0x1e\n\t"
  33                 "mtc0\t$1,$12\n\t"
  34                 ".set\tpop\n\t"
  35                 : /* no outputs */
  36                 : /* no inputs */
  37                 : "$1", "memory");
  38 }
  39
  40 /*
  41  * For cli() we have to insert nops to make shure that the new value
  42  * has actually arrived in the status register before the end of this
  43  * macro.
  44  * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
  45  * no nops at all.
  46  */
  47 static __inline__ void
  48 __cli(void)
  49 {
  50         __asm__ __volatile__(
  51                 ".set\tpush\n\t"
  52                 ".set\treorder\n\t"
  53                 ".set\tnoat\n\t"
  54                 "mfc0\t$1,$12\n\t"
  55                 "ori\t$1,1\n\t"
  56                 "xori\t$1,1\n\t"
  57                 ".set\tnoreorder\n\t"
  58                 "mtc0\t$1,$12\n\t"
  59                 "nop\n\t"
  60                 "nop\n\t"
  61                 "nop\n\t"
  62                 ".set\tpop\n\t"
  63                 : /* no outputs */
  64                 : /* no inputs */
  65                 : "$1", "memory");
  66 }
  67
  68 #define __save_flags(x)                                                 \
  69 __asm__ __volatile__(                                                   \
  70         ".set\tpush\n\t"                                                \
  71         ".set\treorder\n\t"                                             \
  72         "mfc0\t%0,$12\n\t"                                              \
  73         ".set\tpop\n\t"                                                 \
  74         : "=r" (x))
  75
  76 #define __save_and_cli(x)                                               \
  77 __asm__ __volatile__(                                                   \
  78         ".set\tpush\n\t"                                                \
  79         ".set\treorder\n\t"                                             \
  80         ".set\tnoat\n\t"                                                \
  81         "mfc0\t%0,$12\n\t"                                              \
  82         "ori\t$1,%0,1\n\t"                                              \
  83         "xori\t$1,1\n\t"                                                \
  84         ".set\tnoreorder\n\t"                                           \
  85         "mtc0\t$1,$12\n\t"                                              \
  86         "nop\n\t"                                                       \
  87         "nop\n\t"                                                       \
  88         "nop\n\t"                                                       \
  89         ".set\tpop\n\t"                                                 \
  90         : "=r" (x)                                                      \
  91         : /* no inputs */                                               \
  92         : "$1", "memory")
  93
  94 #define __restore_flags(flags)                                          \
  95 do {                                                                    \
  96         unsigned long __tmp1;                                           \
  97                                                                         \
  98         __asm__ __volatile__(                                           \
  99                 ".set\tnoreorder\t\t\t# __restore_flags\n\t"            \
 100                 ".set\tnoat\n\t"                                        \
 101                 "mfc0\t$1, $12\n\t"                                     \
 102                 "andi\t%0, 1\n\t"                                       \
 103                 "ori\t$1, 1\n\t"                                        \
 104                 "xori\t$1, 1\n\t"                                       \
 105                 "or\t%0, $1\n\t"                                        \
 106                 "mtc0\t%0, $12\n\t"                                     \
 107                 "nop\n\t"                                               \
 108                 "nop\n\t"                                               \
 109                 "nop\n\t"                                               \
 110                 ".set\tat\n\t"                                          \
 111                 ".set\treorder"                                         \
 112                 : "=r" (__tmp1)                                         \
 113                 : "0" (flags)                                           \
 114                 : "$1", "memory");                                      \
 115 } while(0)
 116
 117 #ifdef CONFIG_SMP
 118
 119 extern void __global_sti(void);
 120 extern void __global_cli(void);
 121 extern unsigned long __global_save_flags(void);
 122 extern void __global_restore_flags(unsigned long);
 123 #  define sti() __global_sti()
 124 #  define cli() __global_cli()
 125 #  define save_flags(x) do { x = __global_save_flags(); } while (0)
 126 #  define restore_flags(x) __global_restore_flags(x)
 127 #  define save_and_cli(x) do { save_flags(x); cli(); } while(0)
 128
 129 #else /* Single processor */
 130
 131 #  define sti() __sti()
 132 #  define cli() __cli()
 133 #  define save_flags(x) __save_flags(x)
 134 #  define save_and_cli(x) __save_and_cli(x)
 135 #  define restore_flags(x) __restore_flags(x)
 136
 137 #endif /* SMP */
 138
 139 /* For spinlocks etc */
 140 #define local_irq_save(x)       __save_and_cli(x);
 141 #define local_irq_restore(x)    __restore_flags(x);
 142 #define local_irq_disable()     __cli();
 143 #define local_irq_enable()      __sti();
 144
 145 /*
 146  * These are probably defined overly paranoid ...
 147  */
 148 #ifdef CONFIG_CPU_HAS_WB
 149
 150 #include <asm/wbflush.h>
 151 #define rmb()   do { } while(0)
 152 #define wmb()   wbflush()
 153 #define mb()    wbflush()
 154
 155 #else /* CONFIG_CPU_HAS_WB  */
 156
 157 #define mb()                                            \
 158 __asm__ __volatile__(                                   \
 159         "# prevent instructions being moved around\n\t" \
 160         ".set\tnoreorder\n\t"                           \
 161         "# 8 nops to fool the R4400 pipeline\n\t"       \
 162         "nop;nop;nop;nop;nop;nop;nop;nop\n\t"           \
 163         ".set\treorder"                                 \
 164         : /* no output */                               \
 165         : /* no input */                                \
 166         : "memory")
 167 #define rmb() mb()
 168 #define wmb() mb()
 169
 170 #endif /* CONFIG_CPU_HAS_WB  */
 171
 172 #ifdef CONFIG_SMP
 173 #define smp_mb()        mb()
 174 #define smp_rmb()       rmb()
 175 #define smp_wmb()       wmb()
 176 #else
 177 #define smp_mb()        barrier()
 178 #define smp_rmb()       barrier()
 179 #define smp_wmb()       barrier()
 180 #endif
 181
 182 #define set_mb(var, value) \
 183 do { var = value; mb(); } while (0)
 184
 185 #define set_wmb(var, value) \
 186 do { var = value; wmb(); } while (0)
 187
 188 #if !defined (_LANGUAGE_ASSEMBLY)
 189 /*
 190  * switch_to(n) should switch tasks to task nr n, first
 191  * checking that n isn't the current task, in which case it does nothing.
 192  */
 193 #if 0
 194 extern asmlinkage void *resume(void *last, void *next);
 195 #endif
 196 #endif /* !defined (_LANGUAGE_ASSEMBLY) */
 197
 198 #define prepare_to_switch()     do { } while(0)
 199 #define switch_to(prev,next,last) \
 200 do { \
 201         (last) = resume(prev, next); \
 202 } while(0)
 203
 204 /*
 205  * For 32 and 64 bit operands we can take advantage of ll and sc.
 206  * FIXME: This doesn't work for R3000 machines.
 207  */
 208 static __inline__ unsigned long xchg_u32(volatile int * m, unsigned long val)
 209 {
 210 #ifdef CONFIG_CPU_HAS_LLSC
 211         unsigned long dummy;
 212
 213         __asm__ __volatile__(
 214                 ".set\tnoreorder\t\t\t# xchg_u32\n\t"
 215                 ".set\tnoat\n\t"
 216                 "ll\t%0, %3\n"
 217                 "1:\tmove\t$1, %2\n\t"
 218                 "sc\t$1, %1\n\t"
 219                 "beqzl\t$1, 1b\n\t"
 220                 " ll\t%0, %3\n\t"
 221                 ".set\tat\n\t"
 222                 ".set\treorder"
 223                 : "=r" (val), "=o" (*m), "=r" (dummy)
 224                 : "o" (*m), "2" (val)
 225                 : "memory");
 226
 227         return val;
 228 #else
 229         unsigned long flags, retval;
 230
 231         save_flags(flags);
 232         cli();
 233         retval = *m;
 234         *m = val;
 235         restore_flags(flags);
 236         return retval;
 237 #endif /* Processor-dependent optimization */
 238 }
 239
 240 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 241 #define tas(ptr) (xchg((ptr),1))
 242
 243 static __inline__ unsigned long
 244 __xchg(unsigned long x, volatile void * ptr, int size)
 245 {
 246         switch (size) {
 247                 case 4:
 248                         return xchg_u32(ptr, x);
 249         }
 250         return x;
 251 }
 252
 253 extern void *set_except_vector(int n, void *addr);
 254
 255 extern void __die(const char *, struct pt_regs *, const char *where,
 256         unsigned long line) __attribute__((noreturn));
 257 extern void __die_if_kernel(const char *, struct pt_regs *, const char *where,
 258         unsigned long line);
 259
 260 #define die(msg, regs)                                                  \
 261         __die(msg, regs, __FILE__ ":"__FUNCTION__, __LINE__)
 262 #define die_if_kernel(msg, regs)                                        \
 263         __die_if_kernel(msg, regs, __FILE__ ":"__FUNCTION__, __LINE__)
 264
 265 #endif /* _ASM_SYSTEM_H */