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C/C++ Source or Header  |  1995-01-13  |  4.6 KB  |  204 lines
  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 by Ralf Baechle
  9.  */
  10.  
  11. #ifndef __ASM_MIPS_SYSTEM_H
  12. #define __ASM_MIPS_SYSTEM_H
  13.  
  14. #include <linux/types.h>
  15. #include <asm/segment.h>
  16. #include <asm/mipsregs.h>
  17. #include <asm/mipsconfig.h>
  18.  
  19. /*
  20.  * (Currently empty to support debugging)
  21.  */
  22. #define move_to_user_mode()              \
  23. __asm__ __volatile__ (                   \
  24.     ".set\tnoreorder\n\t"            \
  25.     ".set\tnoat\n\t"                 \
  26.     "la\t$1,1f\n\t"                  \
  27.     "subu\t$1,$1,%0\n\t"             \
  28.     "jr\t$1\n\t"                     \
  29.     "mfc0\t$1,$12\n\t"               \
  30.     "1:ori\t$1,0x00\n\t"             \
  31.     "mtc0\t$1,$12\n\t"               \
  32.     "subu\t$29,%0\n\t"               \
  33.     ".set\tat\n\t"                   \
  34.     ".set\treorder"                  \
  35.     : /* no outputs */               \
  36.     : "r" (KERNELBASE));
  37.  
  38. #if defined (__R4000__)
  39. #define sti() \
  40. __asm__ __volatile__(                    \
  41.     ".set\tnoat\n\t"                 \
  42.     "mfc0\t$1,"STR(CP0_STATUS)"\n\t" \
  43.     "ori\t$1,$1,0x1f\n\t"            \
  44.     "xori\t$1,$1,0x1e\n\t"           \
  45.     "mtc0\t$1,"STR(CP0_STATUS)"\n\t" \
  46.     ".set\tat"                       \
  47.     : /* no outputs */               \
  48.     : /* no inputs */                \
  49.     : "$1")
  50.  
  51. #define cli() \
  52. __asm__ __volatile__(                    \
  53.     ".set\tnoat\n\t"                 \
  54.     "mfc0\t$1,"STR(CP0_STATUS)"\n\t" \
  55.     "ori\t$1,$1,1\n\t"               \
  56.     "xori\t$1,$1,1\n\t"              \
  57.     "mtc0\t$1,"STR(CP0_STATUS)"\n\t" \
  58.     ".set\tat"                       \
  59.     : /* no outputs */               \
  60.     : /* no inputs */                \
  61.     : "$1")
  62. #else /* !defined (__R4000__) */
  63. /*
  64.  * Cheese - I don't have a R3000 manual
  65.  */
  66. #error "Yikes - write cli()/sti() macros for  R3000!"
  67. #endif /* !defined (__R4000__) */
  68.  
  69. #define nop() __asm__ __volatile__ ("nop")
  70.  
  71. #define save_flags(x)                    \
  72. __asm__ __volatile__(                    \
  73.     "mfc0\t%0,$12"                   \
  74.     : "=r" (x))                      \
  75.  
  76. #define restore_flags(x)                 \
  77. __asm__ __volatile__(                    \
  78.     "mtc0\t%0,$12"                   \
  79.     : /* no output */                \
  80.     : "r" (x))                       \
  81.  
  82. extern inline unsigned long xchg_u8(char * m, unsigned long val)
  83. {
  84.     unsigned long flags, retval;
  85.  
  86.     save_flags(flags);
  87.     sti();
  88.     retval = *m;
  89.     *m = val;
  90.     restore_flags(flags);
  91.  
  92.     return retval;
  93. }
  94.  
  95. extern inline unsigned long xchg_u16(short * m, unsigned long val)
  96. {
  97.     unsigned long flags, retval;
  98.  
  99.     save_flags(flags);
  100.     sti();
  101.     retval = *m;
  102.     *m = val;
  103.     restore_flags(flags);
  104.  
  105.     return retval;
  106. }
  107.  
  108. /*
  109.  * For 32 and 64 bit operands we can take advantage of ll and sc.
  110.  * The later isn't currently being used.
  111.  */
  112. extern inline unsigned long xchg_u32(int * m, unsigned long val)
  113. {
  114.     unsigned long dummy;
  115.  
  116.     __asm__ __volatile__(
  117.         ".set\tnoreorder\n\t"
  118.         ".set\tnoat\n\t"
  119.         "ll\t%0,(%1)\n"
  120.         "1:\tmove\t$1,%2\n\t"
  121.         "sc\t$1,(%1)\n\t"
  122.         "beqzl\t%3,1b\n\t"
  123.         "ll\t%0,(%1)\n\t"
  124.         ".set\tat\n\t"
  125.         ".set\treorder"
  126.         : "=r" (val), "=r" (m), "=r" (dummy)
  127.         : "1" (*m), "2" (val));
  128.  
  129.     return val;
  130. }
  131.  
  132. extern inline unsigned long xchg_u64(long * m, unsigned long val)
  133. {
  134.     unsigned long dummy;
  135.  
  136.     __asm__ __volatile__(
  137.         ".set\tnoreorder\n\t"
  138.         ".set\tnoat\n\t"
  139.         "lld\t%0,(%1)\n"
  140.         "1:\tmove\t$1,%2\n\t"
  141.         "scd\t$1,(%1)\n\t"
  142.         "beqzl\t%3,1b\n\t"
  143.         "ll\t%0,(%1)\n\t"
  144.         ".set\tat\n\t"
  145.         ".set\treorder"
  146.         : "=r" (val), "=r" (m), "=r" (dummy)
  147.         : "1" (*m), "2" (val));
  148.  
  149.     return val;
  150. }
  151.  
  152. #if 0
  153. extern inline int tas(char * m)
  154. {
  155.     return xchg_u8(m,1);
  156. }
  157. #endif
  158.  
  159. extern inline void * xchg_ptr(void * m, void * val)
  160. {
  161.     return (void *) xchg_u32(m, (unsigned long) val);
  162. }
  163.  
  164. extern ulong IRQ_vectors[256];
  165. extern ulong exception_handlers[256];
  166.  
  167. #define set_intr_gate(n,addr) \
  168.     IRQ_vectors[n] = (ulong) (addr)
  169.  
  170. #define set_except_vector(n,addr) \
  171.     exception_handlers[n] = (ulong) (addr)
  172.  
  173. /*
  174.  * atomic exchange of one word
  175.  */
  176. #if defined (__R4000__)
  177. #define atomic_exchange(m,r)             \
  178.     __asm__ __volatile__(            \
  179.         ".set\tnoreorder\n\t"    \
  180.         "ll\t%0,(%2)\n"          \
  181.         "1:\tmove\t$8,%1\n\t"    \
  182.         "sc\t$8,(%2)\n\t"        \
  183.         "beql\t$0,$8,1b\n\t"     \
  184.         "ll\t%0,(%2)\n\t"        \
  185.         ".set\treorder"          \
  186.         : "=r" (r)               \
  187.         : "r" (r), "r" (&(m))    \
  188.         : "$8","memory")
  189. #else
  190. #define atomic_exchange(m,r)             \
  191.     {                                \
  192.         unsigned long flags;     \
  193.         unsigned long tmp;       \
  194.         save_flags(flags);       \    
  195.         cli();                   \
  196.         tmp = (m);               \
  197.         (m) = (r);               \
  198.         (r) = tmp;               \
  199.         restore_flags(flags);    \    
  200.     }
  201. #endif
  202.  
  203. #endif /* __ASM_MIPS_SYSTEM_H */
  204.