root/include/asm-i386/io.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. virt_to_phys
  2. phys_to_virt

   1 #ifndef _ASM_IO_H
   2 #define _ASM_IO_H
   3 
   4 /*
   5  * This file contains the definitions for the x86 IO instructions
   6  * inb/inw/inl/outb/outw/outl and the "string versions" of the same
   7  * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
   8  * versions of the single-IO instructions (inb_p/inw_p/..).
   9  *
  10  * This file is not meant to be obfuscating: it's just complicated
  11  * to (a) handle it all in a way that makes gcc able to optimize it
  12  * as well as possible and (b) trying to avoid writing the same thing
  13  * over and over again with slight variations and possibly making a
  14  * mistake somewhere.
  15  */
  16 
  17 /*
  18  * Thanks to James van Artsdalen for a better timing-fix than
  19  * the two short jumps: using outb's to a nonexistent port seems
  20  * to guarantee better timings even on fast machines.
  21  *
  22  * On the other hand, I'd like to be sure of a non-existent port:
  23  * I feel a bit unsafe about using 0x80 (should be safe, though)
  24  *
  25  *              Linus
  26  */
  27 
  28 #ifdef SLOW_IO_BY_JUMPING
  29 #define __SLOW_DOWN_IO __asm__ __volatile__("jmp 1f\n1:\tjmp 1f\n1:")
  30 #else
  31 #define __SLOW_DOWN_IO __asm__ __volatile__("outb %al,$0x80")
  32 #endif
  33 
  34 #ifdef REALLY_SLOW_IO
  35 #define SLOW_DOWN_IO { __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; }
  36 #else
  37 #define SLOW_DOWN_IO __SLOW_DOWN_IO
  38 #endif
  39 
  40 /*
  41  * Change virtual addresses to physical addresses and vv.
  42  * These are trivial on the 1:1 Linux/i386 mapping (but if we ever
  43  * make the kernel segment mapped at 0, we need to do translation
  44  * on the i386 as well)
  45  */
  46 extern inline unsigned long virt_to_phys(void * address)
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  47 {
  48         return (unsigned long) address;
  49 }
  50 
  51 extern inline void * phys_to_virt(unsigned long address)
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  52 {
  53         return (void *) address;
  54 }
  55 
  56 /*
  57  * IO bus memory addresses are also 1:1 with the physical address
  58  */
  59 #define virt_to_bus virt_to_phys
  60 #define bus_to_virt phys_to_virt
  61 
  62 /*
  63  * Talk about misusing macros..
  64  */
  65 
  66 #define __OUT1(s,x) \
  67 extern inline void __out##s(unsigned x value, unsigned short port) {
  68 
  69 #define __OUT2(s,s1,s2) \
  70 __asm__ __volatile__ ("out" #s " %" s1 "0,%" s2 "1"
  71 
  72 #define __OUT(s,s1,x) \
  73 __OUT1(s,x) __OUT2(s,s1,"w") : : "a" (value), "d" (port)); } \
  74 __OUT1(s##c,x) __OUT2(s,s1,"") : : "a" (value), "i" (port)); } \
  75 __OUT1(s##_p,x) __OUT2(s,s1,"w") : : "a" (value), "d" (port)); SLOW_DOWN_IO; } \
  76 __OUT1(s##c_p,x) __OUT2(s,s1,"") : : "a" (value), "i" (port)); SLOW_DOWN_IO; }
  77 
  78 #define __IN1(s) \
  79 extern inline unsigned int __in##s(unsigned short port) { unsigned int _v;
  80 
  81 #define __IN2(s,s1,s2) \
  82 __asm__ __volatile__ ("in" #s " %" s2 "1,%" s1 "0"
  83 
  84 #define __IN(s,s1,i...) \
  85 __IN1(s) __IN2(s,s1,"w") : "=a" (_v) : "d" (port) ,##i ); return _v; } \
  86 __IN1(s##c) __IN2(s,s1,"") : "=a" (_v) : "i" (port) ,##i ); return _v; } \
  87 __IN1(s##_p) __IN2(s,s1,"w") : "=a" (_v) : "d" (port) ,##i ); SLOW_DOWN_IO; return _v; } \
  88 __IN1(s##c_p) __IN2(s,s1,"") : "=a" (_v) : "i" (port) ,##i ); SLOW_DOWN_IO; return _v; }
  89 
  90 #define __INS(s) \
  91 extern inline void ins##s(unsigned short port, void * addr, unsigned long count) \
  92 { __asm__ __volatile__ ("cld ; rep ; ins" #s \
  93 : "=D" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
  94 
  95 #define __OUTS(s) \
  96 extern inline void outs##s(unsigned short port, const void * addr, unsigned long count) \
  97 { __asm__ __volatile__ ("cld ; rep ; outs" #s \
  98 : "=S" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
  99 
 100 __IN(b,"b","0" (0))
 101 __IN(w,"w","0" (0))
 102 __IN(l,"")
 103 
 104 __OUT(b,"b",char)
 105 __OUT(w,"w",short)
 106 __OUT(l,,int)
 107 
 108 __INS(b)
 109 __INS(w)
 110 __INS(l)
 111 
 112 __OUTS(b)
 113 __OUTS(w)
 114 __OUTS(l)
 115 
 116 /*
 117  * Note that due to the way __builtin_constant_p() works, you
 118  *  - can't use it inside a inline function (it will never be true)
 119  *  - you don't have to worry about side effects within the __builtin..
 120  */
 121 #define outb(val,port) \
 122 ((__builtin_constant_p((port)) && (port) < 256) ? \
 123         __outbc((val),(port)) : \
 124         __outb((val),(port)))
 125 
 126 #define inb(port) \
 127 ((__builtin_constant_p((port)) && (port) < 256) ? \
 128         __inbc(port) : \
 129         __inb(port))
 130 
 131 #define outb_p(val,port) \
 132 ((__builtin_constant_p((port)) && (port) < 256) ? \
 133         __outbc_p((val),(port)) : \
 134         __outb_p((val),(port)))
 135 
 136 #define inb_p(port) \
 137 ((__builtin_constant_p((port)) && (port) < 256) ? \
 138         __inbc_p(port) : \
 139         __inb_p(port))
 140 
 141 #define outw(val,port) \
 142 ((__builtin_constant_p((port)) && (port) < 256) ? \
 143         __outwc((val),(port)) : \
 144         __outw((val),(port)))
 145 
 146 #define inw(port) \
 147 ((__builtin_constant_p((port)) && (port) < 256) ? \
 148         __inwc(port) : \
 149         __inw(port))
 150 
 151 #define outw_p(val,port) \
 152 ((__builtin_constant_p((port)) && (port) < 256) ? \
 153         __outwc_p((val),(port)) : \
 154         __outw_p((val),(port)))
 155 
 156 #define inw_p(port) \
 157 ((__builtin_constant_p((port)) && (port) < 256) ? \
 158         __inwc_p(port) : \
 159         __inw_p(port))
 160 
 161 #define outl(val,port) \
 162 ((__builtin_constant_p((port)) && (port) < 256) ? \
 163         __outlc((val),(port)) : \
 164         __outl((val),(port)))
 165 
 166 #define inl(port) \
 167 ((__builtin_constant_p((port)) && (port) < 256) ? \
 168         __inlc(port) : \
 169         __inl(port))
 170 
 171 #define outl_p(val,port) \
 172 ((__builtin_constant_p((port)) && (port) < 256) ? \
 173         __outlc_p((val),(port)) : \
 174         __outl_p((val),(port)))
 175 
 176 #define inl_p(port) \
 177 ((__builtin_constant_p((port)) && (port) < 256) ? \
 178         __inlc_p(port) : \
 179         __inl_p(port))
 180 
 181 #endif

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