arch/x86/include/asm/io_32.h

   1 #ifndef _ASM_X86_IO_32_H
   2 #define _ASM_X86_IO_32_H
   3
   4 #include <linux/string.h>
   5 #include <linux/compiler.h>
   6
   7 /*
   8  * This file contains the definitions for the x86 IO instructions
   9  * inb/inw/inl/outb/outw/outl and the "string versions" of the same
  10  * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
  11  * versions of the single-IO instructions (inb_p/inw_p/..).
  12  *
  13  * This file is not meant to be obfuscating: it's just complicated
  14  * to (a) handle it all in a way that makes gcc able to optimize it
  15  * as well as possible and (b) trying to avoid writing the same thing
  16  * over and over again with slight variations and possibly making a
  17  * mistake somewhere.
  18  */
  19
  20 /*
  21  * Thanks to James van Artsdalen for a better timing-fix than
  22  * the two short jumps: using outb's to a nonexistent port seems
  23  * to guarantee better timings even on fast machines.
  24  *
  25  * On the other hand, I'd like to be sure of a non-existent port:
  26  * I feel a bit unsafe about using 0x80 (should be safe, though)
  27  *
  28  *              Linus
  29  */
  30
  31  /*
  32   *  Bit simplified and optimized by Jan Hubicka
  33   *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999.
  34   *
  35   *  isa_memset_io, isa_memcpy_fromio, isa_memcpy_toio added,
  36   *  isa_read[wl] and isa_write[wl] fixed
  37   *  - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  38   */
  39
  40 #ifdef __KERNEL__
  41
  42 #include <asm-generic/iomap.h>
  43
  44 #include <linux/vmalloc.h>
  45
  46 /*
  47  * Convert a virtual cached pointer to an uncached pointer
  48  */
  49 #define xlate_dev_kmem_ptr(p)   p
  50
  51 static inline void
  52 memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
  53 {
  54         memset((void __force *)addr, val, count);
  55 }
  56
  57 static inline void
  58 memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
  59 {
  60         memcpy(dst, (const void __force *)src, count);
  61 }
  62
  63 static inline void
  64 memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
  65 {
  66         memcpy((void __force *)dst, src, count);
  67 }
  68
  69 /*
  70  * ISA space is 'always mapped' on a typical x86 system, no need to
  71  * explicitly ioremap() it. The fact that the ISA IO space is mapped
  72  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
  73  * are physical addresses. The following constant pointer can be
  74  * used as the IO-area pointer (it can be iounmapped as well, so the
  75  * analogy with PCI is quite large):
  76  */
  77 #define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
  78
  79 /*
  80  *      Cache management
  81  *
  82  *      This needed for two cases
  83  *      1. Out of order aware processors
  84  *      2. Accidentally out of order processors (PPro errata #51)
  85  */
  86
  87 #if defined(CONFIG_X86_OOSTORE) || defined(CONFIG_X86_PPRO_FENCE)
  88
  89 static inline void flush_write_buffers(void)
  90 {
  91         asm volatile("lock; addl $0,0(%%esp)": : :"memory");
  92 }
  93
  94 #else
  95
  96 #define flush_write_buffers() do { } while (0)
  97
  98 #endif
  99
 100 #endif /* __KERNEL__ */
 101
 102 extern void native_io_delay(void);
 103
 104 extern int io_delay_type;
 105 extern void io_delay_init(void);
 106
 107 #if defined(CONFIG_PARAVIRT)
 108 #include <asm/paravirt.h>
 109 #else
 110
 111 static inline void slow_down_io(void)
 112 {
 113         native_io_delay();
 114 #ifdef REALLY_SLOW_IO
 115         native_io_delay();
 116         native_io_delay();
 117         native_io_delay();
 118 #endif
 119 }
 120
 121 #endif
 122
 123 #define BUILDIO(bwl, bw, type)                                          \
 124 static inline void out##bwl(unsigned type value, int port)              \
 125 {                                                                       \
 126         asm volatile("out" #bwl " %" #bw "0, %w1"                       \
 127                      : : "a"(value), "Nd"(port));                       \
 128 }                                                                       \
 129                                                                         \
 130 static inline unsigned type in##bwl(int port)                           \
 131 {                                                                       \
 132         unsigned type value;                                            \
 133         asm volatile("in" #bwl " %w1, %" #bw "0"                        \
 134                      : "=a"(value) : "Nd"(port));                       \
 135         return value;                                                   \
 136 }                                                                       \
 137                                                                         \
 138 static inline void out##bwl##_p(unsigned type value, int port)          \
 139 {                                                                       \
 140         out##bwl(value, port);                                          \
 141         slow_down_io();                                                 \
 142 }                                                                       \
 143                                                                         \
 144 static inline unsigned type in##bwl##_p(int port)                       \
 145 {                                                                       \
 146         unsigned type value = in##bwl(port);                            \
 147         slow_down_io();                                                 \
 148         return value;                                                   \
 149 }                                                                       \
 150                                                                         \
 151 static inline void outs##bwl(int port, const void *addr, unsigned long count) \
 152 {                                                                       \
 153         asm volatile("rep; outs" #bwl                                   \
 154                      : "+S"(addr), "+c"(count) : "d"(port));            \
 155 }                                                                       \
 156                                                                         \
 157 static inline void ins##bwl(int port, void *addr, unsigned long count)  \
 158 {                                                                       \
 159         asm volatile("rep; ins" #bwl                                    \
 160                      : "+D"(addr), "+c"(count) : "d"(port));            \
 161 }
 162
 163 BUILDIO(b, b, char)
 164 BUILDIO(w, w, short)
 165 BUILDIO(l, , int)
 166
 167 #endif /* _ASM_X86_IO_32_H */