include/asm-i386/io.h

   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  /*
  29   *  Bit simplified and optimized by Jan Hubicka
  30   *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999.
  31   *
  32   *  isa_memset_io, isa_memcpy_fromio, isa_memcpy_toio added,
  33   *  isa_read[wl] and isa_write[wl] fixed
  34   *  - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  35   */
  36
  37 #define IO_SPACE_LIMIT 0xffff
  38
  39
  40 #ifdef __KERNEL__
  41
  42
  43 /*
  44  * readX/writeX() are used to access memory mapped devices. On some
  45  * architectures the memory mapped IO stuff needs to be accessed
  46  * differently. On the x86 architecture, we just read/write the
  47  * memory location directly.
  48  */
  49
  50 #define readb(addr) (*(volatile unsigned char *) (addr))
  51 #define readw(addr) (*(volatile unsigned short *) (addr))
  52 #define readl(addr) (*(volatile unsigned int *) (addr))
  53 #define __raw_readb readb
  54 #define __raw_readw readw
  55 #define __raw_readl readl
  56
  57 #define writeb(b,addr) (*(volatile unsigned char *) (addr) = (b))
  58 #define writew(b,addr) (*(volatile unsigned short *) (addr) = (b))
  59 #define writel(b,addr) (*(volatile unsigned int *) (addr) = (b))
  60 #define __raw_writeb writeb
  61 #define __raw_writew writew
  62 #define __raw_writel writel
  63
  64 #define memset_io(a,b,c)        memset((a),(b),(c))
  65 #define memcpy_fromio(a,b,c)    memcpy((a),(b),(c))
  66 #define memcpy_toio(a,b,c)      memcpy((a),(b),(c))
  67
  68 /*
  69  * ISA space is 'always mapped' on a typical x86 system, no need to
  70  * explicitly ioremap() it. The fact that the ISA IO space is mapped
  71  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
  72  * are physical addresses. The following constant pointer can be
  73  * used as the IO-area pointer (it can be iounmapped as well, so the
  74  * analogy with PCI is quite large):
  75  */
  76 #define isa_readb(a) readb((a))
  77 #define isa_readw(a) readw((a))
  78 #define isa_readl(a) readl((a))
  79 #define isa_writeb(b,a) writeb(b,(a))
  80 #define isa_writew(w,a) writew(w,(a))
  81 #define isa_writel(l,a) writel(l,(a))
  82 #define isa_memset_io(a,b,c)            memset_io((a),(b),(c))
  83 #define isa_memcpy_fromio(a,b,c)        memcpy_fromio((a),(b),(c))
  84 #define isa_memcpy_toio(a,b,c)          memcpy_toio((a),(b),(c))
  85
  86
  87 static inline int check_signature(unsigned long io_addr,
  88         const unsigned char *signature, int length)
  89 {
  90         int retval = 0;
  91         do {
  92                 if (readb(io_addr) != *signature)
  93                         goto out;
  94                 io_addr++;
  95                 signature++;
  96                 length--;
  97         } while (length);
  98         retval = 1;
  99 out:
 100         return retval;
 101 }
 102
 103 /**
 104  *      isa_check_signature             -       find BIOS signatures
 105  *      @io_addr: mmio address to check
 106  *      @signature:  signature block
 107  *      @length: length of signature
 108  *
 109  *      Perform a signature comparison with the ISA mmio address io_addr.
 110  *      Returns 1 on a match.
 111  *
 112  *      This function is deprecated. New drivers should use ioremap and
 113  *      check_signature.
 114  */
 115
 116
 117 static inline int isa_check_signature(unsigned long io_addr,
 118         const unsigned char *signature, int length)
 119 {
 120         int retval = 0;
 121         do {
 122                 if (isa_readb(io_addr) != *signature)
 123                         goto out;
 124                 io_addr++;
 125                 signature++;
 126                 length--;
 127         } while (length);
 128         retval = 1;
 129 out:
 130         return retval;
 131 }
 132
 133 #endif /* __KERNEL__ */
 134
 135 #ifdef SLOW_IO_BY_JUMPING
 136 #define __SLOW_DOWN_IO "\njmp 1f\n1:\tjmp 1f\n1:"
 137 #else
 138 #define __SLOW_DOWN_IO "\noutb %%al,$0x80"
 139 #endif
 140
 141 #ifdef REALLY_SLOW_IO
 142 #define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO
 143 #else
 144 #define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO
 145 #endif
 146
 147
 148 /*
 149  * Talk about misusing macros..
 150  */
 151 #define __OUT1(s,x) \
 152 static inline void out##s(unsigned x value, unsigned short port) {
 153
 154 #define __OUT2(s,s1,s2) \
 155 __asm__ __volatile__ ("out" #s " %" s1 "0,%" s2 "1"
 156
 157
 158 #define __OUT(s,s1,x) \
 159 __OUT1(s,x) __OUT2(s,s1,"w") : : "a" (value), "Nd" (port)); } \
 160 __OUT1(s##_p,x) __OUT2(s,s1,"w") __FULL_SLOW_DOWN_IO : : "a" (value), "Nd" (port));}
 161
 162 #define __IN1(s) \
 163 static inline RETURN_TYPE in##s(unsigned short port) { RETURN_TYPE _v;
 164
 165 #define __IN2(s,s1,s2) \
 166 __asm__ __volatile__ ("in" #s " %" s2 "1,%" s1 "0"
 167
 168 #define __IN(s,s1,i...) \
 169 __IN1(s) __IN2(s,s1,"w") : "=a" (_v) : "Nd" (port) ,##i ); return _v; } \
 170 __IN1(s##_p) __IN2(s,s1,"w") __FULL_SLOW_DOWN_IO : "=a" (_v) : "Nd" (port) ,##i ); return _v; }
 171
 172 #define __INS(s) \
 173 static inline void ins##s(unsigned short port, void * addr, unsigned long count) \
 174 { __asm__ __volatile__ ("rep ; ins" #s \
 175 : "=D" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
 176
 177 #define __OUTS(s) \
 178 static inline void outs##s(unsigned short port, const void * addr, unsigned long count) \
 179 { __asm__ __volatile__ ("rep ; outs" #s \
 180 : "=S" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
 181
 182 #define RETURN_TYPE unsigned char
 183 __IN(b,"")
 184 #undef RETURN_TYPE
 185 #define RETURN_TYPE unsigned short
 186 __IN(w,"")
 187 #undef RETURN_TYPE
 188 #define RETURN_TYPE unsigned int
 189 __IN(l,"")
 190 #undef RETURN_TYPE
 191
 192 __OUT(b,"b",char)
 193 __OUT(w,"w",short)
 194 __OUT(l,,int)
 195
 196 __INS(b)
 197 __INS(w)
 198 __INS(l)
 199
 200 __OUTS(b)
 201 __OUTS(w)
 202 __OUTS(l)
 203
 204 #endif