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 <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 NTHALAPI
  56 VOID
  57 DDKAPI
  58 READ_PORT_BUFFER_UCHAR (PUCHAR Port,
  59                         PUCHAR Buffer,
  60                         ULONG Count)
  61 {
  62    __asm__ __volatile__ ("cld ; rep ; insb\n\t"
  63                          : "=D" (Buffer), "=c" (Count)
  64                          : "d" (Port),"0" (Buffer),"1" (Count));
  65 }
  66
  67 #undef READ_PORT_BUFFER_USHORT
  68 NTHALAPI
  69 VOID
  70 DDKAPI
  71 READ_PORT_BUFFER_USHORT (USHORT* Port,
  72                          USHORT* Buffer,
  73                          ULONG Count)
  74 {
  75    __asm__ __volatile__ ("cld ; rep ; insw"
  76                          : "=D" (Buffer), "=c" (Count)
  77                          : "d" (Port),"0" (Buffer),"1" (Count));
  78 }
  79
  80 #undef READ_PORT_BUFFER_ULONG
  81 NTHALAPI
  82 VOID
  83 DDKAPI
  84 READ_PORT_BUFFER_ULONG (ULONG* Port,
  85                         ULONG* Buffer,
  86                         ULONG Count)
  87 {
  88    __asm__ __volatile__ ("cld ; rep ; insl"
  89                          : "=D" (Buffer), "=c" (Count)
  90                          : "d" (Port),"0" (Buffer),"1" (Count));
  91 }
  92
  93 #undef READ_PORT_UCHAR
  94 NTHALAPI
  95 UCHAR
  96 DDKAPI
  97 READ_PORT_UCHAR (PUCHAR Port)
  98 {
  99    UCHAR Value;
 100
 101    __asm__("inb %w1, %0\n\t"
 102            : "=a" (Value)
 103            : "d" (Port));
 104    SLOW_DOWN_IO;
 105    return(Value);
 106 }
 107
 108 #undef READ_PORT_USHORT
 109 NTHALAPI
 110 USHORT
 111 DDKAPI
 112 READ_PORT_USHORT (USHORT* Port)
 113 {
 114    USHORT Value;
 115
 116    __asm__("inw %w1, %0\n\t"
 117            : "=a" (Value)
 118            : "d" (Port));
 119    SLOW_DOWN_IO;
 120    return(Value);
 121 }
 122
 123 #undef READ_PORT_ULONG
 124 NTHALAPI
 125 ULONG
 126 DDKAPI
 127 READ_PORT_ULONG (ULONG* Port)
 128 {
 129    ULONG Value;
 130
 131    __asm__("inl %w1, %0\n\t"
 132            : "=a" (Value)
 133            : "d" (Port));
 134    SLOW_DOWN_IO;
 135    return(Value);
 136 }
 137
 138 #undef WRITE_PORT_BUFFER_UCHAR
 139 NTHALAPI
 140 VOID
 141 DDKAPI
 142 WRITE_PORT_BUFFER_UCHAR (PUCHAR Port,
 143                          PUCHAR Buffer,
 144                          ULONG Count)
 145 {
 146    __asm__ __volatile__ ("cld ; rep ; outsb"
 147                          : "=S" (Buffer), "=c" (Count)
 148                          : "d" (Port),"0" (Buffer),"1" (Count));
 149 }
 150
 151 #undef WRITE_PORT_BUFFER_USHORT
 152 NTHALAPI
 153 VOID
 154 DDKAPI
 155 WRITE_PORT_BUFFER_USHORT (USHORT* Port,
 156                           USHORT* Buffer,
 157                           ULONG Count)
 158 {
 159    __asm__ __volatile__ ("cld ; rep ; outsw"
 160                          : "=S" (Buffer), "=c" (Count)
 161                          : "d" (Port),"0" (Buffer),"1" (Count));
 162 }
 163
 164 #undef WRITE_PORT_BUFFER_ULONG
 165 NTHALAPI
 166 VOID
 167 DDKAPI
 168 WRITE_PORT_BUFFER_ULONG (ULONG* Port,
 169                          ULONG* Buffer,
 170                          ULONG Count)
 171 {
 172    __asm__ __volatile__ ("cld ; rep ; outsl"
 173                          : "=S" (Buffer), "=c" (Count)
 174                          : "d" (Port),"0" (Buffer),"1" (Count));
 175 }
 176
 177 #undef WRITE_PORT_UCHAR
 178 NTHALAPI
 179 VOID
 180 DDKAPI
 181 WRITE_PORT_UCHAR (PUCHAR Port,
 182                   UCHAR Value)
 183 {
 184    __asm__("outb %0, %w1\n\t"
 185            :
 186            : "a" (Value),
 187              "d" (Port));
 188    SLOW_DOWN_IO;
 189 }
 190
 191 #undef WRITE_PORT_USHORT
 192 NTHALAPI
 193 VOID
 194 DDKAPI
 195 WRITE_PORT_USHORT (USHORT* Port,
 196                    USHORT Value)
 197 {
 198    __asm__("outw %0, %w1\n\t"
 199            :
 200            : "a" (Value),
 201              "d" (Port));
 202    SLOW_DOWN_IO;
 203 }
 204
 205 #undef WRITE_PORT_ULONG
 206 NTHALAPI
 207 VOID
 208 DDKAPI
 209 WRITE_PORT_ULONG (ULONG* Port,
 210                   ULONG Value)
 211 {
 212    __asm__("outl %0, %w1\n\t"
 213            :
 214            : "a" (Value),
 215              "d" (Port));
 216    SLOW_DOWN_IO;
 217 }
 218
 219 /* EOF */