arch/x86_64-pc/include/asm/io.h

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id: io.h 13216 2002-02-13 06:22:32Z iaint $
   4 */
   5
   6 #ifndef ASM_IO_H
   7 #define ASM_IO_H
   8
   9 /*
  10  * This file contains the definitions for the x86 IO instructions
  11  * inb/inw/inl/outb/outw/outl and the "string versions" of the same
  12  * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
  13  * versions of the single-IO instructions (inb_p/inw_p/..).
  14  *
  15  * This file is not meant to be obfuscating: it's just complicated
  16  * to (a) handle it all in a way that makes gcc able to optimize it
  17  * as well as possible and (b) trying to avoid writing the same thing
  18  * over and over again with slight variations and possibly making a
  19  * mistake somewhere.
  20  */
  21
  22 /*
  23  * Thanks to James van Artsdalen for a better timing-fix than
  24  * the two short jumps: using outb's to a nonexistent port seems
  25  * to guarantee better timings even on fast machines.
  26  *
  27  * On the other hand, I'd like to be sure of a non-existent port:
  28  * I feel a bit unsafe about using 0x80 (should be safe, though)
  29  *
  30  *              Linus
  31  */
  32
  33  /*
  34   *  Bit simplified and optimized by Jan Hubicka
  35   */
  36
  37 #ifdef SLOW_IO_BY_JUMPING
  38 #define __SLOW_DOWN_IO "\njmp 1f\n1:\tjmp 1f\n1:"
  39 #else
  40 #define __SLOW_DOWN_IO "\noutb %%al,$0x80"
  41 #endif
  42
  43 #ifdef REALLY_SLOW_IO
  44 #define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO
  45 #else
  46 #define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO
  47 #endif
  48
  49 /*
  50  * Talk about misusing macros..
  51  */
  52 #define __OUT1(s,x) \
  53 static inline void out##s(unsigned x value, unsigned short port) {
  54
  55 #define __OUT2(s,s1,s2) \
  56 __asm__ __volatile__ ("out" #s " %" s1 "0,%" s2 "1"
  57
  58 #define __OUT(s,s1,x) \
  59 __OUT1(s,x) __OUT2(s,s1,"w") : : "a" (value), "Nd" (port)); } \
  60 __OUT1(s##_p,x) __OUT2(s,s1,"w") __FULL_SLOW_DOWN_IO : : "a" (value), "Nd" (port));} \
  61
  62 #define __IN1(s) \
  63 static inline RETURN_TYPE in##s(unsigned short port) { RETURN_TYPE _v;
  64
  65 #define __IN2(s,s1,s2) \
  66 __asm__ __volatile__ ("in" #s " %" s2 "1,%" s1 "0"
  67
  68 #define __IN(s,s1,i...) \
  69 __IN1(s) __IN2(s,s1,"w") : "=a" (_v) : "Nd" (port) ,##i ); return _v; } \
  70 __IN1(s##_p) __IN2(s,s1,"w") __FULL_SLOW_DOWN_IO : "=a" (_v) : "Nd" (port) ,##i ); return _v; } \
  71
  72 #define __INS(s) \
  73 static inline void ins##s(unsigned short port, void * addr, unsigned long count) \
  74 { __asm__ __volatile__ ("cld ; rep ; ins" #s \
  75 : "=D" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
  76
  77 #define __OUTS(s) \
  78 static inline void outs##s(unsigned short port, const void * addr, unsigned long count) \
  79 { __asm__ __volatile__ ("cld ; rep ; outs" #s \
  80 : "=S" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
  81
  82 #define RETURN_TYPE unsigned char
  83 __IN(b,"")
  84 #undef RETURN_TYPE
  85 #define RETURN_TYPE unsigned short
  86 __IN(w,"")
  87 #undef RETURN_TYPE
  88 #define RETURN_TYPE unsigned int
  89 __IN(l,"")
  90 #undef RETURN_TYPE
  91
  92 __OUT(b,"b",char)
  93 __OUT(w,"w",short)
  94 __OUT(l,,int)
  95
  96 __INS(b)
  97 __INS(w)
  98 __INS(l)
  99
 100 __OUTS(b)
 101 __OUTS(w)
 102 __OUTS(l)
 103
 104 #endif