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/asm.h>
  18 #include <asm/sgidefs.h>
  19 #include <asm/ptrace.h>
  20 #include <linux/stringify.h>
  21 #if 0
  22 #include <linux/kernel.h>
  23 #endif
  24
  25 static __inline__ void
  26 __sti(void)
  27 {
  28         __asm__ __volatile__(
  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                 : /* no outputs */
  38                 : /* no inputs */
  39                 : "$1", "memory");
  40 }
  41
  42 /*
  43  * For cli() we have to insert nops to make shure that the new value
  44  * has actually arrived in the status register before the end of this
  45  * macro.
  46  * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
  47  * no nops at all.
  48  */
  49 static __inline__ void
  50 __cli(void)
  51 {
  52         __asm__ __volatile__(
  53                 ".set\tpush\n\t"
  54                 ".set\treorder\n\t"
  55                 ".set\tnoat\n\t"
  56                 "mfc0\t$1,$12\n\t"
  57                 "ori\t$1,1\n\t"
  58                 "xori\t$1,1\n\t"
  59                 ".set\tnoreorder\n\t"
  60                 "mtc0\t$1,$12\n\t"
  61                 "nop\n\t"
  62                 "nop\n\t"
  63                 "nop\n\t"
  64                 ".set\tpop\n\t"
  65                 : /* no outputs */
  66                 : /* no inputs */
  67                 : "$1", "memory");
  68 }
  69
  70 #define __save_flags(x)                                                 \
  71 __asm__ __volatile__(                                                   \
  72         ".set\tpush\n\t"                                                \
  73         ".set\treorder\n\t"                                             \
  74         "mfc0\t%0,$12\n\t"                                              \
  75         ".set\tpop\n\t"                                                 \
  76         : "=r" (x))
  77
  78 #define __save_and_cli(x)                                               \
  79 __asm__ __volatile__(                                                   \
  80         ".set\tpush\n\t"                                                \
  81         ".set\treorder\n\t"                                             \
  82         ".set\tnoat\n\t"                                                \
  83         "mfc0\t%0,$12\n\t"                                              \
  84         "ori\t$1,%0,1\n\t"                                              \
  85         "xori\t$1,1\n\t"                                                \
  86         ".set\tnoreorder\n\t"                                           \
  87         "mtc0\t$1,$12\n\t"                                              \
  88         "nop\n\t"                                                       \
  89         "nop\n\t"                                                       \
  90         "nop\n\t"                                                       \
  91         ".set\tpop\n\t"                                                 \
  92         : "=r" (x)                                                      \
  93         : /* no inputs */                                               \
  94         : "$1", "memory")
  95
  96 #define __restore_flags(flags)                                          \
  97 do {                                                                    \
  98         unsigned long __tmp1;                                           \
  99                                                                         \
 100         __asm__ __volatile__(                                           \
 101                 ".set\tnoreorder\t\t\t# __restore_flags\n\t"            \
 102                 ".set\tnoat\n\t"                                        \
 103                 "mfc0\t$1, $12\n\t"                                     \
 104                 "andi\t%0, 1\n\t"                                       \
 105                 "ori\t$1, 1\n\t"                                        \
 106                 "xori\t$1, 1\n\t"                                       \
 107                 "or\t%0, $1\n\t"                                        \
 108                 "mtc0\t%0, $12\n\t"                                     \
 109                 "nop\n\t"                                               \
 110                 "nop\n\t"                                               \
 111                 "nop\n\t"                                               \
 112                 ".set\tat\n\t"                                          \
 113                 ".set\treorder"                                         \
 114                 : "=r" (__tmp1)                                         \
 115                 : "0" (flags)                                           \
 116                 : "$1", "memory");                                      \
 117 } while(0)
 118
 119 #ifdef CONFIG_SMP
 120
 121 extern void __global_sti(void);
 122 extern void __global_cli(void);
 123 extern unsigned long __global_save_flags(void);
 124 extern void __global_restore_flags(unsigned long);
 125 #  define sti() __global_sti()
 126 #  define cli() __global_cli()
 127 #  define save_flags(x) do { x = __global_save_flags(); } while (0)
 128 #  define restore_flags(x) __global_restore_flags(x)
 129 #  define save_and_cli(x) do { save_flags(x); cli(); } while(0)
 130
 131 #else /* Single processor */
 132
 133 #  define sti() __sti()
 134 #  define cli() __cli()
 135 #  define save_flags(x) __save_flags(x)
 136 #  define save_and_cli(x) __save_and_cli(x)
 137 #  define restore_flags(x) __restore_flags(x)
 138
 139 #endif /* SMP */
 140
 141 /* For spinlocks etc */
 142 #define local_irq_save(x)       __save_and_cli(x);
 143 #define local_irq_restore(x)    __restore_flags(x);
 144 #define local_irq_disable()     __cli();
 145 #define local_irq_enable()      __sti();
 146
 147 /*
 148  * These are probably defined overly paranoid ...
 149  */
 150 #ifdef CONFIG_CPU_HAS_WB
 151
 152 #include <asm/wbflush.h>
 153 #define rmb()   do { } while(0)
 154 #define wmb()   wbflush()
 155 #define mb()    wbflush()
 156
 157 #else /* CONFIG_CPU_HAS_WB  */
 158
 159 #define mb()                                            \
 160 __asm__ __volatile__(                                   \
 161         "# prevent instructions being moved around\n\t" \
 162         ".set\tnoreorder\n\t"                           \
 163         "# 8 nops to fool the R4400 pipeline\n\t"       \
 164         "nop;nop;nop;nop;nop;nop;nop;nop\n\t"           \
 165         ".set\treorder"                                 \
 166         : /* no output */                               \
 167         : /* no input */                                \
 168         : "memory")
 169 #define rmb() mb()
 170 #define wmb() mb()
 171
 172 #endif /* CONFIG_CPU_HAS_WB  */
 173
 174 #ifdef CONFIG_SMP
 175 #define smp_mb()        mb()
 176 #define smp_rmb()       rmb()
 177 #define smp_wmb()       wmb()
 178 #else
 179 #define smp_mb()        barrier()
 180 #define smp_rmb()       barrier()
 181 #define smp_wmb()       barrier()
 182 #endif
 183
 184 #define set_mb(var, value) \
 185 do { var = value; mb(); } while (0)
 186
 187 #define set_wmb(var, value) \
 188 do { var = value; wmb(); } while (0)
 189
 190 #if !defined (_LANGUAGE_ASSEMBLY)
 191 /*
 192  * switch_to(n) should switch tasks to task nr n, first
 193  * checking that n isn't the current task, in which case it does nothing.
 194  */
 195 #if 0
 196 extern asmlinkage void *resume(void *last, void *next);
 197 #endif
 198 #endif /* !defined (_LANGUAGE_ASSEMBLY) */
 199
 200 #define prepare_to_switch()     do { } while(0)
 201 #define switch_to(prev,next,last) \
 202 do { \
 203         (last) = resume(prev, next); \
 204 } while(0)
 205
 206 /*
 207  * For 32 and 64 bit operands we can take advantage of ll and sc.
 208  * FIXME: This doesn't work for R3000 machines.
 209  */
 210 static __inline__ unsigned long xchg_u32(volatile int * m, unsigned long val)
 211 {
 212 #ifdef CONFIG_CPU_HAS_LLSC
 213         unsigned long dummy;
 214
 215         __asm__ __volatile__(
 216                 ".set\tnoreorder\t\t\t# xchg_u32\n\t"
 217                 ".set\tnoat\n\t"
 218                 "ll\t%0, %3\n"
 219                 "1:\tmove\t$1, %2\n\t"
 220                 "sc\t$1, %1\n\t"
 221                 "beqzl\t$1, 1b\n\t"
 222                 " ll\t%0, %3\n\t"
 223                 ".set\tat\n\t"
 224                 ".set\treorder"
 225                 : "=r" (val), "=o" (*m), "=r" (dummy)
 226                 : "o" (*m), "2" (val)
 227                 : "memory");
 228
 229         return val;
 230 #else
 231         unsigned long flags, retval;
 232
 233         save_flags(flags);
 234         cli();
 235         retval = *m;
 236         *m = val;
 237         restore_flags(flags);
 238         return retval;
 239 #endif /* Processor-dependent optimization */
 240 }
 241
 242 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 243 #define tas(ptr) (xchg((ptr),1))
 244
 245 static __inline__ unsigned long
 246 __xchg(unsigned long x, volatile void * ptr, int size)
 247 {
 248         switch (size) {
 249                 case 4:
 250                         return xchg_u32(ptr, x);
 251         }
 252         return x;
 253 }
 254
 255 extern void *set_except_vector(int n, void *addr);
 256
 257 extern void __die(const char *, struct pt_regs *, const char *where,
 258         unsigned long line) __attribute__((noreturn));
 259 extern void __die_if_kernel(const char *, struct pt_regs *, const char *where,
 260         unsigned long line);
 261
 262 #define die(msg, regs)                                                  \
 263         __die(msg, regs, __FILE__ ":"__FUNCTION__, __LINE__)
 264 #define die_if_kernel(msg, regs)                                        \
 265         __die_if_kernel(msg, regs, __FILE__ ":"__FUNCTION__, __LINE__)
 266
 267 static inline void execution_hazard_barrier(void)
 268 {
 269         __asm__ __volatile__(
 270                 ".set noreorder\n"
 271                 "ehb\n"
 272                 ".set reorder");
 273 }
 274
 275 static inline void instruction_hazard_barrier(void)
 276 {
 277         unsigned long tmp;
 278
 279         asm volatile(
 280         __stringify(PTR_LA) "\t%0, 1f\n"
 281         "       jr.hb   %0\n"
 282         "1:     .insn"
 283         : "=&r"(tmp));
 284 }
 285
 286 #endif /* _ASM_SYSTEM_H */