reactos/boot/freeldr/freeldr/arch/i386/portio.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/hal/x86/portio.c
   6  * PURPOSE:         Port I/O functions
   7  * PROGRAMMER:      Eric Kohl (ekohl@abo.rhein-zeitung.de)
   8  * UPDATE HISTORY:
   9  *                  Created 18/10/99
  10  */
  11
  12 //#include <ddk/ntddk.h>
  13 #include <freeldr.h>
  14
  15
  16 /* FUNCTIONS ****************************************************************/
  17
  18 /*
  19  * This file contains the definitions for the x86 IO instructions
  20  * inb/inw/inl/outb/outw/outl and the "string versions" of the same
  21  * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
  22  * versions of the single-IO instructions (inb_p/inw_p/..).
  23  *
  24  * This file is not meant to be obfuscating: it's just complicated
  25  * to (a) handle it all in a way that makes gcc able to optimize it
  26  * as well as possible and (b) trying to avoid writing the same thing
  27  * over and over again with slight variations and possibly making a
  28  * mistake somewhere.
  29  */
  30
  31 /*
  32  * Thanks to James van Artsdalen for a better timing-fix than
  33  * the two short jumps: using outb's to a nonexistent port seems
  34  * to guarantee better timings even on fast machines.
  35  *
  36  * On the other hand, I'd like to be sure of a non-existent port:
  37  * I feel a bit unsafe about using 0x80 (should be safe, though)
  38  *
  39  *              Linus
  40  */
  41
  42 #ifdef SLOW_IO_BY_JUMPING
  43 #define __SLOW_DOWN_IO __asm__ __volatile__("jmp 1f\n1:\tjmp 1f\n1:")
  44 #else
  45 #define __SLOW_DOWN_IO __asm__ __volatile__("outb %al,$0x80")
  46 #endif
  47
  48 #ifdef REALLY_SLOW_IO
  49 #define SLOW_DOWN_IO { __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; }
  50 #else
  51 #define SLOW_DOWN_IO __SLOW_DOWN_IO
  52 #endif
  53
  54 #undef READ_PORT_BUFFER_UCHAR
  55 VOID
  56 STDCALL
  57 READ_PORT_BUFFER_UCHAR (PUCHAR Port,
  58                         PUCHAR Buffer,
  59                         ULONG Count)
  60 {
  61    __asm__ __volatile__ ("cld ; rep ; insb\n\t"
  62                          : "=D" (Buffer), "=c" (Count)
  63                          : "d" (Port),"0" (Buffer),"1" (Count));
  64 }
  65
  66 #undef READ_PORT_BUFFER_USHORT
  67 VOID
  68 STDCALL
  69 READ_PORT_BUFFER_USHORT (USHORT* Port,
  70                          USHORT* Buffer,
  71                          ULONG Count)
  72 {
  73    __asm__ __volatile__ ("cld ; rep ; insw"
  74                          : "=D" (Buffer), "=c" (Count)
  75                          : "d" (Port),"0" (Buffer),"1" (Count));
  76 }
  77
  78 #undef READ_PORT_BUFFER_ULONG
  79 VOID
  80 STDCALL
  81 READ_PORT_BUFFER_ULONG (ULONG* Port,
  82                         ULONG* Buffer,
  83                         ULONG Count)
  84 {
  85    __asm__ __volatile__ ("cld ; rep ; insl"
  86                          : "=D" (Buffer), "=c" (Count)
  87                          : "d" (Port),"0" (Buffer),"1" (Count));
  88 }
  89
  90 #undef READ_PORT_UCHAR
  91 UCHAR
  92 STDCALL
  93 READ_PORT_UCHAR (PUCHAR Port)
  94 {
  95    UCHAR Value;
  96
  97    __asm__("inb %w1, %0\n\t"
  98            : "=a" (Value)
  99            : "d" (Port));
 100    SLOW_DOWN_IO;
 101    return(Value);
 102 }
 103
 104 #undef READ_PORT_USHORT
 105 USHORT
 106 STDCALL
 107 READ_PORT_USHORT (USHORT* Port)
 108 {
 109    USHORT Value;
 110
 111    __asm__("inw %w1, %0\n\t"
 112            : "=a" (Value)
 113            : "d" (Port));
 114    SLOW_DOWN_IO;
 115    return(Value);
 116 }
 117
 118 #undef READ_PORT_ULONG
 119 ULONG
 120 STDCALL
 121 READ_PORT_ULONG (ULONG* Port)
 122 {
 123    ULONG Value;
 124
 125    __asm__("inl %w1, %0\n\t"
 126            : "=a" (Value)
 127            : "d" (Port));
 128    SLOW_DOWN_IO;
 129    return(Value);
 130 }
 131
 132 #undef WRITE_PORT_BUFFER_UCHAR
 133 VOID
 134 STDCALL
 135 WRITE_PORT_BUFFER_UCHAR (PUCHAR Port,
 136                          PUCHAR Buffer,
 137                          ULONG Count)
 138 {
 139    __asm__ __volatile__ ("cld ; rep ; outsb"
 140                          : "=S" (Buffer), "=c" (Count)
 141                          : "d" (Port),"0" (Buffer),"1" (Count));
 142 }
 143
 144 #undef WRITE_PORT_BUFFER_USHORT
 145 VOID
 146 STDCALL
 147 WRITE_PORT_BUFFER_USHORT (USHORT* Port,
 148                           USHORT* Buffer,
 149                           ULONG Count)
 150 {
 151    __asm__ __volatile__ ("cld ; rep ; outsw"
 152                          : "=S" (Buffer), "=c" (Count)
 153                          : "d" (Port),"0" (Buffer),"1" (Count));
 154 }
 155
 156 #undef WRITE_PORT_BUFFER_ULONG
 157 VOID
 158 STDCALL
 159 WRITE_PORT_BUFFER_ULONG (ULONG* Port,
 160                          ULONG* Buffer,
 161                          ULONG Count)
 162 {
 163    __asm__ __volatile__ ("cld ; rep ; outsl"
 164                          : "=S" (Buffer), "=c" (Count)
 165                          : "d" (Port),"0" (Buffer),"1" (Count));
 166 }
 167
 168 #undef WRITE_PORT_UCHAR
 169 VOID
 170 STDCALL
 171 WRITE_PORT_UCHAR (PUCHAR Port,
 172                   UCHAR Value)
 173 {
 174    __asm__("outb %0, %w1\n\t"
 175            :
 176            : "a" (Value),
 177              "d" (Port));
 178    SLOW_DOWN_IO;
 179 }
 180
 181 #undef WRITE_PORT_USHORT
 182 VOID
 183 STDCALL
 184 WRITE_PORT_USHORT (USHORT* Port,
 185                    USHORT Value)
 186 {
 187    __asm__("outw %0, %w1\n\t"
 188            :
 189            : "a" (Value),
 190              "d" (Port));
 191    SLOW_DOWN_IO;
 192 }
 193
 194 #undef WRITE_PORT_ULONG
 195 VOID
 196 STDCALL
 197 WRITE_PORT_ULONG (ULONG* Port,
 198                   ULONG Value)
 199 {
 200    __asm__("outl %0, %w1\n\t"
 201            :
 202            : "a" (Value),
 203              "d" (Port));
 204    SLOW_DOWN_IO;
 205 }
 206
 207 /* EOF */