linux/include/asm-i386/io.h
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   1#ifndef _ASM_IO_H
   2#define _ASM_IO_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#define IO_SPACE_LIMIT 0xffff
  41
  42#define XQUAD_PORTIO_BASE 0xfe400000
  43#define XQUAD_PORTIO_QUAD 0x40000  /* 256k per quad. */
  44
  45#ifdef __KERNEL__
  46
  47#include <asm-generic/iomap.h>
  48
  49#include <linux/vmalloc.h>
  50
  51/*
  52 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
  53 * access
  54 */
  55#define xlate_dev_mem_ptr(p)    __va(p)
  56
  57/*
  58 * Convert a virtual cached pointer to an uncached pointer
  59 */
  60#define xlate_dev_kmem_ptr(p)   p
  61
  62/**
  63 *      virt_to_phys    -       map virtual addresses to physical
  64 *      @address: address to remap
  65 *
  66 *      The returned physical address is the physical (CPU) mapping for
  67 *      the memory address given. It is only valid to use this function on
  68 *      addresses directly mapped or allocated via kmalloc. 
  69 *
  70 *      This function does not give bus mappings for DMA transfers. In
  71 *      almost all conceivable cases a device driver should not be using
  72 *      this function
  73 */
  74 
  75static inline unsigned long virt_to_phys(volatile void * address)
  76{
  77        return __pa(address);
  78}
  79
  80/**
  81 *      phys_to_virt    -       map physical address to virtual
  82 *      @address: address to remap
  83 *
  84 *      The returned virtual address is a current CPU mapping for
  85 *      the memory address given. It is only valid to use this function on
  86 *      addresses that have a kernel mapping
  87 *
  88 *      This function does not handle bus mappings for DMA transfers. In
  89 *      almost all conceivable cases a device driver should not be using
  90 *      this function
  91 */
  92
  93static inline void * phys_to_virt(unsigned long address)
  94{
  95        return __va(address);
  96}
  97
  98/*
  99 * Change "struct page" to physical address.
 100 */
 101#define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
 102
 103extern void __iomem * __ioremap(unsigned long offset, unsigned long size, unsigned long flags);
 104
 105/**
 106 * ioremap     -   map bus memory into CPU space
 107 * @offset:    bus address of the memory
 108 * @size:      size of the resource to map
 109 *
 110 * ioremap performs a platform specific sequence of operations to
 111 * make bus memory CPU accessible via the readb/readw/readl/writeb/
 112 * writew/writel functions and the other mmio helpers. The returned
 113 * address is not guaranteed to be usable directly as a virtual
 114 * address. 
 115 */
 116
 117static inline void __iomem * ioremap(unsigned long offset, unsigned long size)
 118{
 119        return __ioremap(offset, size, 0);
 120}
 121
 122extern void __iomem * ioremap_nocache(unsigned long offset, unsigned long size);
 123extern void iounmap(volatile void __iomem *addr);
 124
 125/*
 126 * bt_ioremap() and bt_iounmap() are for temporary early boot-time
 127 * mappings, before the real ioremap() is functional.
 128 * A boot-time mapping is currently limited to at most 16 pages.
 129 */
 130extern void *bt_ioremap(unsigned long offset, unsigned long size);
 131extern void bt_iounmap(void *addr, unsigned long size);
 132
 133/* Use early IO mappings for DMI because it's initialized early */
 134#define dmi_ioremap bt_ioremap
 135#define dmi_iounmap bt_iounmap
 136#define dmi_alloc alloc_bootmem
 137
 138/*
 139 * ISA I/O bus memory addresses are 1:1 with the physical address.
 140 */
 141#define isa_virt_to_bus virt_to_phys
 142#define isa_page_to_bus page_to_phys
 143#define isa_bus_to_virt phys_to_virt
 144
 145/*
 146 * However PCI ones are not necessarily 1:1 and therefore these interfaces
 147 * are forbidden in portable PCI drivers.
 148 *
 149 * Allow them on x86 for legacy drivers, though.
 150 */
 151#define virt_to_bus virt_to_phys
 152#define bus_to_virt phys_to_virt
 153
 154/*
 155 * readX/writeX() are used to access memory mapped devices. On some
 156 * architectures the memory mapped IO stuff needs to be accessed
 157 * differently. On the x86 architecture, we just read/write the
 158 * memory location directly.
 159 */
 160
 161static inline unsigned char readb(const volatile void __iomem *addr)
 162{
 163        return *(volatile unsigned char __force *) addr;
 164}
 165static inline unsigned short readw(const volatile void __iomem *addr)
 166{
 167        return *(volatile unsigned short __force *) addr;
 168}
 169static inline unsigned int readl(const volatile void __iomem *addr)
 170{
 171        return *(volatile unsigned int __force *) addr;
 172}
 173#define readb_relaxed(addr) readb(addr)
 174#define readw_relaxed(addr) readw(addr)
 175#define readl_relaxed(addr) readl(addr)
 176#define __raw_readb readb
 177#define __raw_readw readw
 178#define __raw_readl readl
 179
 180static inline void writeb(unsigned char b, volatile void __iomem *addr)
 181{
 182        *(volatile unsigned char __force *) addr = b;
 183}
 184static inline void writew(unsigned short b, volatile void __iomem *addr)
 185{
 186        *(volatile unsigned short __force *) addr = b;
 187}
 188static inline void writel(unsigned int b, volatile void __iomem *addr)
 189{
 190        *(volatile unsigned int __force *) addr = b;
 191}
 192#define __raw_writeb writeb
 193#define __raw_writew writew
 194#define __raw_writel writel
 195
 196#define mmiowb()
 197
 198static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
 199{
 200        memset((void __force *) addr, val, count);
 201}
 202static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
 203{
 204        __memcpy(dst, (void __force *) src, count);
 205}
 206static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
 207{
 208        __memcpy((void __force *) dst, src, count);
 209}
 210
 211/*
 212 * ISA space is 'always mapped' on a typical x86 system, no need to
 213 * explicitly ioremap() it. The fact that the ISA IO space is mapped
 214 * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
 215 * are physical addresses. The following constant pointer can be
 216 * used as the IO-area pointer (it can be iounmapped as well, so the
 217 * analogy with PCI is quite large):
 218 */
 219#define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
 220
 221/*
 222 *      Cache management
 223 *
 224 *      This needed for two cases
 225 *      1. Out of order aware processors
 226 *      2. Accidentally out of order processors (PPro errata #51)
 227 */
 228 
 229#if defined(CONFIG_X86_OOSTORE) || defined(CONFIG_X86_PPRO_FENCE)
 230
 231static inline void flush_write_buffers(void)
 232{
 233        __asm__ __volatile__ ("lock; addl $0,0(%%esp)": : :"memory");
 234}
 235
 236#define dma_cache_inv(_start,_size)             flush_write_buffers()
 237#define dma_cache_wback(_start,_size)           flush_write_buffers()
 238#define dma_cache_wback_inv(_start,_size)       flush_write_buffers()
 239
 240#else
 241
 242/* Nothing to do */
 243
 244#define dma_cache_inv(_start,_size)             do { } while (0)
 245#define dma_cache_wback(_start,_size)           do { } while (0)
 246#define dma_cache_wback_inv(_start,_size)       do { } while (0)
 247#define flush_write_buffers()
 248
 249#endif
 250
 251#endif /* __KERNEL__ */
 252
 253static inline void native_io_delay(void)
 254{
 255        asm volatile("outb %%al,$0x80" : : : "memory");
 256}
 257
 258#if defined(CONFIG_PARAVIRT)
 259#include <asm/paravirt.h>
 260#else
 261
 262static inline void slow_down_io(void) {
 263        native_io_delay();
 264#ifdef REALLY_SLOW_IO
 265        native_io_delay();
 266        native_io_delay();
 267        native_io_delay();
 268#endif
 269}
 270
 271#endif
 272
 273#ifdef CONFIG_X86_NUMAQ
 274extern void *xquad_portio;    /* Where the IO area was mapped */
 275#define XQUAD_PORT_ADDR(port, quad) (xquad_portio + (XQUAD_PORTIO_QUAD*quad) + port)
 276#define __BUILDIO(bwl,bw,type) \
 277static inline void out##bwl##_quad(unsigned type value, int port, int quad) { \
 278        if (xquad_portio) \
 279                write##bwl(value, XQUAD_PORT_ADDR(port, quad)); \
 280        else \
 281                out##bwl##_local(value, port); \
 282} \
 283static inline void out##bwl(unsigned type value, int port) { \
 284        out##bwl##_quad(value, port, 0); \
 285} \
 286static inline unsigned type in##bwl##_quad(int port, int quad) { \
 287        if (xquad_portio) \
 288                return read##bwl(XQUAD_PORT_ADDR(port, quad)); \
 289        else \
 290                return in##bwl##_local(port); \
 291} \
 292static inline unsigned type in##bwl(int port) { \
 293        return in##bwl##_quad(port, 0); \
 294}
 295#else
 296#define __BUILDIO(bwl,bw,type) \
 297static inline void out##bwl(unsigned type value, int port) { \
 298        out##bwl##_local(value, port); \
 299} \
 300static inline unsigned type in##bwl(int port) { \
 301        return in##bwl##_local(port); \
 302}
 303#endif
 304
 305
 306#define BUILDIO(bwl,bw,type) \
 307static inline void out##bwl##_local(unsigned type value, int port) { \
 308        __asm__ __volatile__("out" #bwl " %" #bw "0, %w1" : : "a"(value), "Nd"(port)); \
 309} \
 310static inline unsigned type in##bwl##_local(int port) { \
 311        unsigned type value; \
 312        __asm__ __volatile__("in" #bwl " %w1, %" #bw "0" : "=a"(value) : "Nd"(port)); \
 313        return value; \
 314} \
 315static inline void out##bwl##_local_p(unsigned type value, int port) { \
 316        out##bwl##_local(value, port); \
 317        slow_down_io(); \
 318} \
 319static inline unsigned type in##bwl##_local_p(int port) { \
 320        unsigned type value = in##bwl##_local(port); \
 321        slow_down_io(); \
 322        return value; \
 323} \
 324__BUILDIO(bwl,bw,type) \
 325static inline void out##bwl##_p(unsigned type value, int port) { \
 326        out##bwl(value, port); \
 327        slow_down_io(); \
 328} \
 329static inline unsigned type in##bwl##_p(int port) { \
 330        unsigned type value = in##bwl(port); \
 331        slow_down_io(); \
 332        return value; \
 333} \
 334static inline void outs##bwl(int port, const void *addr, unsigned long count) { \
 335        __asm__ __volatile__("rep; outs" #bwl : "+S"(addr), "+c"(count) : "d"(port)); \
 336} \
 337static inline void ins##bwl(int port, void *addr, unsigned long count) { \
 338        __asm__ __volatile__("rep; ins" #bwl : "+D"(addr), "+c"(count) : "d"(port)); \
 339}
 340
 341BUILDIO(b,b,char)
 342BUILDIO(w,w,short)
 343BUILDIO(l,,int)
 344
 345#endif
 346
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