arch/x86/include/asm/io.h

   1 #ifndef _ASM_IO_H
   2 #define _ASM_IO_H
   3
   4 #include <compiler.h>
   5
   6 /*
   7  * This file contains the definitions for the x86 IO instructions
   8  * inb/inw/inl/outb/outw/outl and the "string versions" of the same
   9  * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
  10  * versions of the single-IO instructions (inb_p/inw_p/..).
  11  *
  12  * This file is not meant to be obfuscating: it's just complicated
  13  * to (a) handle it all in a way that makes gcc able to optimize it
  14  * as well as possible and (b) trying to avoid writing the same thing
  15  * over and over again with slight variations and possibly making a
  16  * mistake somewhere.
  17  */
  18
  19 /*
  20  * Thanks to James van Artsdalen for a better timing-fix than
  21  * the two short jumps: using outb's to a nonexistent port seems
  22  * to guarantee better timings even on fast machines.
  23  *
  24  * On the other hand, I'd like to be sure of a non-existent port:
  25  * I feel a bit unsafe about using 0x80 (should be safe, though)
  26  *
  27  *              Linus
  28  */
  29
  30  /*
  31   *  Bit simplified and optimized by Jan Hubicka
  32   *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999.
  33   *
  34   *  isa_memset_io, isa_memcpy_fromio, isa_memcpy_toio added,
  35   *  isa_read[wl] and isa_write[wl] fixed
  36   *  - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  37   */
  38
  39 #define IO_SPACE_LIMIT 0xffff
  40
  41 #include <asm/types.h>
  42
  43
  44 #ifdef __KERNEL__
  45
  46
  47 /*
  48  * readX/writeX() are used to access memory mapped devices. On some
  49  * architectures the memory mapped IO stuff needs to be accessed
  50  * differently. On the x86 architecture, we just read/write the
  51  * memory location directly.
  52  */
  53
  54 #define readb(addr) (*(volatile unsigned char *) (addr))
  55 #define readw(addr) (*(volatile unsigned short *) (addr))
  56 #define readl(addr) (*(volatile unsigned int *) (addr))
  57 #define __raw_readb readb
  58 #define __raw_readw readw
  59 #define __raw_readl readl
  60
  61 #define writeb(b,addr) (*(volatile unsigned char *) (addr) = (b))
  62 #define writew(b,addr) (*(volatile unsigned short *) (addr) = (b))
  63 #define writel(b,addr) (*(volatile unsigned int *) (addr) = (b))
  64 #define __raw_writeb writeb
  65 #define __raw_writew writew
  66 #define __raw_writel writel
  67
  68 #define memset_io(a,b,c)        memset((a),(b),(c))
  69 #define memcpy_fromio(a,b,c)    memcpy((a),(b),(c))
  70 #define memcpy_toio(a,b,c)      memcpy((a),(b),(c))
  71
  72 /*
  73  * ISA space is 'always mapped' on a typical x86 system, no need to
  74  * explicitly ioremap() it. The fact that the ISA IO space is mapped
  75  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
  76  * are physical addresses. The following constant pointer can be
  77  * used as the IO-area pointer (it can be iounmapped as well, so the
  78  * analogy with PCI is quite large):
  79  */
  80 #define isa_readb(a) readb((a))
  81 #define isa_readw(a) readw((a))
  82 #define isa_readl(a) readl((a))
  83 #define isa_writeb(b,a) writeb(b,(a))
  84 #define isa_writew(w,a) writew(w,(a))
  85 #define isa_writel(l,a) writel(l,(a))
  86 #define isa_memset_io(a,b,c)            memset_io((a),(b),(c))
  87 #define isa_memcpy_fromio(a,b,c)        memcpy_fromio((a),(b),(c))
  88 #define isa_memcpy_toio(a,b,c)          memcpy_toio((a),(b),(c))
  89
  90
  91 static inline int check_signature(unsigned long io_addr,
  92         const unsigned char *signature, int length)
  93 {
  94         int retval = 0;
  95         do {
  96                 if (readb(io_addr) != *signature)
  97                         goto out;
  98                 io_addr++;
  99                 signature++;
 100                 length--;
 101         } while (length);
 102         retval = 1;
 103 out:
 104         return retval;
 105 }
 106
 107 /**
 108  *      isa_check_signature             -       find BIOS signatures
 109  *      @io_addr: mmio address to check
 110  *      @signature:  signature block
 111  *      @length: length of signature
 112  *
 113  *      Perform a signature comparison with the ISA mmio address io_addr.
 114  *      Returns 1 on a match.
 115  *
 116  *      This function is deprecated. New drivers should use ioremap and
 117  *      check_signature.
 118  */
 119
 120
 121 static inline int isa_check_signature(unsigned long io_addr,
 122         const unsigned char *signature, int length)
 123 {
 124         int retval = 0;
 125         do {
 126                 if (isa_readb(io_addr) != *signature)
 127                         goto out;
 128                 io_addr++;
 129                 signature++;
 130                 length--;
 131         } while (length);
 132         retval = 1;
 133 out:
 134         return retval;
 135 }
 136
 137 #endif /* __KERNEL__ */
 138
 139 #ifdef SLOW_IO_BY_JUMPING
 140 #define __SLOW_DOWN_IO "\njmp 1f\n1:\tjmp 1f\n1:"
 141 #else
 142 #define __SLOW_DOWN_IO "\noutb %%al,$0xed"
 143 #endif
 144
 145 #ifdef REALLY_SLOW_IO
 146 #define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO
 147 #else
 148 #define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO
 149 #endif
 150
 151
 152 /*
 153  * Talk about misusing macros..
 154  */
 155 #define __OUT1(s,x) \
 156 static inline void out##s(unsigned x value, unsigned short port) {
 157
 158 #define __OUT2(s,s1,s2) \
 159 __asm__ __volatile__ ("out" #s " %" s1 "0,%" s2 "1"
 160
 161
 162 #define __OUT(s,s1,x) \
 163 __OUT1(s,x) __OUT2(s,s1,"w") : : "a" (value), "Nd" (port)); } \
 164 __OUT1(s##_p,x) __OUT2(s,s1,"w") __FULL_SLOW_DOWN_IO : : "a" (value), "Nd" (port));}
 165
 166 #define __IN1(s) \
 167 static inline RETURN_TYPE in##s(unsigned short port) { RETURN_TYPE _v;
 168
 169 #define __IN2(s,s1,s2) \
 170 __asm__ __volatile__ ("in" #s " %" s2 "1,%" s1 "0"
 171
 172 #define __IN(s,s1,i...) \
 173 __IN1(s) __IN2(s,s1,"w") : "=a" (_v) : "Nd" (port) ,##i ); return _v; } \
 174 __IN1(s##_p) __IN2(s,s1,"w") __FULL_SLOW_DOWN_IO : "=a" (_v) : "Nd" (port) ,##i ); return _v; }
 175
 176 #define __INS(s) \
 177 static inline void ins##s(unsigned short port, void * addr, unsigned long count) \
 178 { __asm__ __volatile__ ("rep ; ins" #s \
 179 : "=D" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
 180
 181 #define __OUTS(s) \
 182 static inline void outs##s(unsigned short port, const void * addr, unsigned long count) \
 183 { __asm__ __volatile__ ("rep ; outs" #s \
 184 : "=S" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
 185
 186 #define RETURN_TYPE unsigned char
 187 __IN(b,"")
 188 #undef RETURN_TYPE
 189 #define RETURN_TYPE unsigned short
 190 __IN(w,"")
 191 #undef RETURN_TYPE
 192 #define RETURN_TYPE unsigned int
 193 __IN(l,"")
 194 #undef RETURN_TYPE
 195
 196 __OUT(b,"b",char)
 197 __OUT(w,"w",short)
 198 __OUT(l,,int)
 199
 200 __INS(b)
 201 __INS(w)
 202 __INS(l)
 203
 204 __OUTS(b)
 205 __OUTS(w)
 206 __OUTS(l)
 207
 208 static inline void sync(void)
 209 {
 210 }
 211
 212 /*
 213  * Given a physical address and a length, return a virtual address
 214  * that can be used to access the memory range with the caching
 215  * properties specified by "flags".
 216  */
 217 #define MAP_NOCACHE     (0)
 218 #define MAP_WRCOMBINE   (0)
 219 #define MAP_WRBACK      (0)
 220 #define MAP_WRTHROUGH   (0)
 221
 222 static inline void *
 223 map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags)
 224 {
 225         return (void *)(uintptr_t)paddr;
 226 }
 227
 228 /*
 229  * Take down a mapping set up by map_physmem().
 230  */
 231 static inline void unmap_physmem(void *vaddr, unsigned long flags)
 232 {
 233
 234 }
 235
 236 static inline phys_addr_t virt_to_phys(void * vaddr)
 237 {
 238         return (phys_addr_t)(uintptr_t)(vaddr);
 239 }
 240
 241 /*
 242  * TODO: The kernel offers some more advanced versions of barriers, it might
 243  * have some advantages to use them instead of the simple one here.
 244  */
 245 #define dmb()           __asm__ __volatile__ ("" : : : "memory")
 246 #define __iormb()       dmb()
 247 #define __iowmb()       dmb()
 248
 249 #endif