include/asm-mips/system.h

/* */
This source file includes following definitions.
xchg_u8
xchg_u16
xchg_u32
xchg_u64
__xchg
   1 /*
   2  * include/asm-mips/system.h
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 1994, 1995 by Ralf Baechle
   9  */
  10 #ifndef __ASM_MIPS_SYSTEM_H
  11 #define __ASM_MIPS_SYSTEM_H
  12 
  13 #include <linux/kernel.h>
  14 
  15 #if defined (__R4000__)
  16 #define sti()                            \
  17 __asm__ __volatile__(                    \
  18         ".set\tnoreorder\n\t"            \
  19         ".set\tnoat\n\t"                 \
  20         "mfc0\t$1,$12\n\t"               \
  21         "ori\t$1,0x1f\n\t"               \
  22         "xori\t$1,0x1e\n\t"              \
  23         "mtc0\t$1,$12\n\t"               \
  24         ".set\tat\n\t"                   \
  25         ".set\treorder"                  \
  26         : /* no outputs */               \
  27         : /* no inputs */                \
  28         : "$1")
  29 
  30 #define cli()                            \
  31 __asm__ __volatile__(                    \
  32         ".set\tnoreorder\n\t"            \
  33         ".set\tnoat\n\t"                 \
  34         "mfc0\t$1,$12\n\t"               \
  35         "ori\t$1,1\n\t"                  \
  36         "xori\t$1,1\n\t"                 \
  37         "mtc0\t$1,$12\n\t"               \
  38         "nop\n\t"                        \
  39         "nop\n\t"                        \
  40         "nop\n\t"                        \
  41         ".set\tat\n\t"                   \
  42         ".set\treorder"                  \
  43         : /* no outputs */               \
  44         : /* no inputs */                \
  45         : "$1")
  46 
  47 #else /* !defined (__R4000__) */
  48 /*
  49  * Untested goodies for the R3000 based DECstation et al.
  50  */
  51 #define sti()                            \
  52 __asm__ __volatile__(                    \
  53         ".set\tnoreorder\n\t"            \
  54         ".set\tnoat\n\t"                 \
  55         "mfc0\t$1,$12\n\t"               \
  56         "ori\t$1,0x01\n\t"               \
  57         "mtc0\t$1,$12\n\t"               \
  58         ".set\tat\n\t"                   \
  59         ".set\treorder"                  \
  60         : /* no outputs */               \
  61         : /* no inputs */                \
  62         : "$1")
  63 
  64 #define cli()                            \
  65 __asm__ __volatile__(                    \
  66         ".set\tnoreorder\n\t"            \
  67         ".set\tnoat\n\t"                 \
  68         "mfc0\t$1,$12\n\t"               \
  69         "ori\t$1,1\n\t"                  \
  70         "xori\t$1,1\n\t"                 \
  71         "mtc0\t$1,$12\n\t"               \
  72         ".set\tat\n\t"                   \
  73         ".set\treorder"                  \
  74         : /* no outputs */               \
  75         : /* no inputs */                \
  76         : "$1")
  77 #endif /* !defined (__R4000__) */
  78 
  79 #define nop() __asm__ __volatile__ ("nop")
  80 
  81 #define save_flags(x)                    \
  82 __asm__ __volatile__(                    \
  83         ".set\tnoreorder\n\t"            \
  84         "mfc0\t%0,$12\n\t"               \
  85         ".set\treorder"                  \
  86         : "=r" (x))                      \
  87 
  88 #define restore_flags(x)                 \
  89 __asm__ __volatile__(                    \
  90         ".set\tnoreorder\n\t"            \
  91         "mtc0\t%0,$12\n\t"               \
  92         "nop\n\t"                        \
  93         "nop\n\t"                        \
  94         "nop\n\t"                        \
  95         ".set\treorder"                  \
  96         : /* no output */                \
  97         : "r" (x))                       \
  98 
  99 #define sync_mem()                       \
 100 __asm__ __volatile__(                    \
 101         ".set\tnoreorder\n\t"            \
 102         "sync\n\t"                       \
 103         ".set\treorder")                 \
 104 
 105 /*
 106  * The 8 and 16 bit variants have to disable interrupts temporarily.
 107  * Both are currently unused.
 108  */
 109 extern inline unsigned long xchg_u8(volatile char * m, unsigned long val)
     /*  */
 110 {
 111         unsigned long flags, retval;
 112 
 113         save_flags(flags);
 114         sti();
 115         retval = *m;
 116         *m = val;
 117         restore_flags(flags);
 118 
 119         return retval;
 120 }
 121 
 122 extern inline unsigned long xchg_u16(volatile short * m, unsigned long val)
     /*  */
 123 {
 124         unsigned long flags, retval;
 125 
 126         save_flags(flags);
 127         sti();
 128         retval = *m;
 129         *m = val;
 130         restore_flags(flags);
 131 
 132         return retval;
 133 }
 134 
 135 /*
 136  * For 32 and 64 bit operands we can take advantage of ll and sc.
 137  * FIXME: This doesn't work for R3000 machines.
 138  */
 139 extern inline unsigned long xchg_u32(volatile int * m, unsigned long val)
     /*  */
 140 {
 141         unsigned long dummy;
 142 
 143         __asm__ __volatile__(
 144                 ".set\tnoreorder\n\t"
 145                 ".set\tnoat\n\t"
 146                 "ll\t%0,(%1)\n"
 147                 "1:\tmove\t$1,%2\n\t"
 148                 "sc\t$1,(%1)\n\t"
 149                 "beqzl\t$1,1b\n\t"
 150                 "ll\t%0,(%1)\n\t"
 151                 ".set\tat\n\t"
 152                 ".set\treorder"
 153                 : "=r" (val), "=r" (m), "=r" (dummy)
 154                 : "1" (m), "2" (val));
 155 
 156         return val;
 157 }
 158 
 159 /*
 160  * Only used for 64 bit kernel.
 161  */
 162 extern inline unsigned long xchg_u64(volatile long * m, unsigned long val)
     /*  */
 163 {
 164         unsigned long dummy;
 165 
 166         __asm__ __volatile__(
 167                 ".set\tnoreorder\n\t"
 168                 ".set\tnoat\n\t"
 169                 "lld\t%0,(%1)\n"
 170                 "1:\tmove\t$1,%2\n\t"
 171                 "scd\t$1,(%1)\n\t"
 172                 "beqzl\t$1,1b\n\t"
 173                 "ll\t%0,(%1)\n\t"
 174                 ".set\tat\n\t"
 175                 ".set\treorder"
 176                 : "=r" (val), "=r" (m), "=r" (dummy)
 177                 : "1" (m), "2" (val));
 178 
 179         return val;
 180 }
 181 
 182 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 183 #define tas(ptr) (xchg((ptr),1))
 184 
 185 /*
 186  * This function doesn't exist, so you'll get a linker error
 187  * if something tries to do an invalid xchg().
 188  *
 189  * This only works if the compiler isn't horribly bad at optimizing.
 190  * gcc-2.5.8 reportedly can't handle this, but I define that one to
 191  * be dead anyway.
 192  */
 193 extern void __xchg_called_with_bad_pointer(void);
 194 
 195 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
     /*  */
 196 {
 197         switch (size) {
 198                 case 1:
 199                         return xchg_u8(ptr, x);
 200                 case 2:
 201                         return xchg_u16(ptr, x);
 202                 case 4:
 203                         return xchg_u32(ptr, x);
 204                 case 8:
 205                         return xchg_u64(ptr, x);
 206         }
 207         __xchg_called_with_bad_pointer();
 208         return x;
 209 }
 210 
 211 extern unsigned long IRQ_vectors[16];
 212 extern unsigned long exception_handlers[32];
 213 
 214 #define set_int_vector(n,addr) \
 215         IRQ_vectors[n] = (unsigned long) (addr)
 216 
 217 #define set_except_vector(n,addr) \
 218         exception_handlers[n] = (unsigned long) (addr)
 219 
 220 #endif /* __ASM_MIPS_SYSTEM_H */
/* */
root/include/asm-mips/system.h

INCLUDED FROM

DEFINITIONS
