linux/arch/x86/include/asm/io.h
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   1#ifndef _ASM_X86_IO_H
   2#define _ASM_X86_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 ARCH_HAS_IOREMAP_WC
  38
  39#include <linux/string.h>
  40#include <linux/compiler.h>
  41#include <asm/page.h>
  42
  43#define build_mmio_read(name, size, type, reg, barrier) \
  44static inline type name(const volatile void __iomem *addr) \
  45{ type ret; asm volatile("mov" size " %1,%0":reg (ret) \
  46:"m" (*(volatile type __force *)addr) barrier); return ret; }
  47
  48#define build_mmio_write(name, size, type, reg, barrier) \
  49static inline void name(type val, volatile void __iomem *addr) \
  50{ asm volatile("mov" size " %0,%1": :reg (val), \
  51"m" (*(volatile type __force *)addr) barrier); }
  52
  53build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
  54build_mmio_read(readw, "w", unsigned short, "=r", :"memory")
  55build_mmio_read(readl, "l", unsigned int, "=r", :"memory")
  56
  57build_mmio_read(__readb, "b", unsigned char, "=q", )
  58build_mmio_read(__readw, "w", unsigned short, "=r", )
  59build_mmio_read(__readl, "l", unsigned int, "=r", )
  60
  61build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
  62build_mmio_write(writew, "w", unsigned short, "r", :"memory")
  63build_mmio_write(writel, "l", unsigned int, "r", :"memory")
  64
  65build_mmio_write(__writeb, "b", unsigned char, "q", )
  66build_mmio_write(__writew, "w", unsigned short, "r", )
  67build_mmio_write(__writel, "l", unsigned int, "r", )
  68
  69#define readb_relaxed(a) __readb(a)
  70#define readw_relaxed(a) __readw(a)
  71#define readl_relaxed(a) __readl(a)
  72#define __raw_readb __readb
  73#define __raw_readw __readw
  74#define __raw_readl __readl
  75
  76#define __raw_writeb __writeb
  77#define __raw_writew __writew
  78#define __raw_writel __writel
  79
  80#define mmiowb() barrier()
  81
  82#ifdef CONFIG_X86_64
  83
  84build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
  85build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
  86
  87#define readq_relaxed(a)        readq(a)
  88
  89#define __raw_readq(a)          readq(a)
  90#define __raw_writeq(val, addr) writeq(val, addr)
  91
  92/* Let people know that we have them */
  93#define readq                   readq
  94#define writeq                  writeq
  95
  96#endif
  97
  98/**
  99 *      virt_to_phys    -       map virtual addresses to physical
 100 *      @address: address to remap
 101 *
 102 *      The returned physical address is the physical (CPU) mapping for
 103 *      the memory address given. It is only valid to use this function on
 104 *      addresses directly mapped or allocated via kmalloc.
 105 *
 106 *      This function does not give bus mappings for DMA transfers. In
 107 *      almost all conceivable cases a device driver should not be using
 108 *      this function
 109 */
 110
 111static inline phys_addr_t virt_to_phys(volatile void *address)
 112{
 113        return __pa(address);
 114}
 115
 116/**
 117 *      phys_to_virt    -       map physical address to virtual
 118 *      @address: address to remap
 119 *
 120 *      The returned virtual address is a current CPU mapping for
 121 *      the memory address given. It is only valid to use this function on
 122 *      addresses that have a kernel mapping
 123 *
 124 *      This function does not handle bus mappings for DMA transfers. In
 125 *      almost all conceivable cases a device driver should not be using
 126 *      this function
 127 */
 128
 129static inline void *phys_to_virt(phys_addr_t address)
 130{
 131        return __va(address);
 132}
 133
 134/*
 135 * Change "struct page" to physical address.
 136 */
 137#define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
 138
 139/*
 140 * ISA I/O bus memory addresses are 1:1 with the physical address.
 141 * However, we truncate the address to unsigned int to avoid undesirable
 142 * promitions in legacy drivers.
 143 */
 144static inline unsigned int isa_virt_to_bus(volatile void *address)
 145{
 146        return (unsigned int)virt_to_phys(address);
 147}
 148#define isa_page_to_bus(page)   ((unsigned int)page_to_phys(page))
 149#define isa_bus_to_virt         phys_to_virt
 150
 151/*
 152 * However PCI ones are not necessarily 1:1 and therefore these interfaces
 153 * are forbidden in portable PCI drivers.
 154 *
 155 * Allow them on x86 for legacy drivers, though.
 156 */
 157#define virt_to_bus virt_to_phys
 158#define bus_to_virt phys_to_virt
 159
 160/**
 161 * ioremap     -   map bus memory into CPU space
 162 * @offset:    bus address of the memory
 163 * @size:      size of the resource to map
 164 *
 165 * ioremap performs a platform specific sequence of operations to
 166 * make bus memory CPU accessible via the readb/readw/readl/writeb/
 167 * writew/writel functions and the other mmio helpers. The returned
 168 * address is not guaranteed to be usable directly as a virtual
 169 * address.
 170 *
 171 * If the area you are trying to map is a PCI BAR you should have a
 172 * look at pci_iomap().
 173 */
 174extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
 175extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
 176extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
 177                                unsigned long prot_val);
 178
 179/*
 180 * The default ioremap() behavior is non-cached:
 181 */
 182static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
 183{
 184        return ioremap_nocache(offset, size);
 185}
 186
 187extern void iounmap(volatile void __iomem *addr);
 188
 189extern void set_iounmap_nonlazy(void);
 190
 191#ifdef __KERNEL__
 192
 193#include <asm-generic/iomap.h>
 194
 195#include <linux/vmalloc.h>
 196
 197/*
 198 * Convert a virtual cached pointer to an uncached pointer
 199 */
 200#define xlate_dev_kmem_ptr(p)   p
 201
 202static inline void
 203memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
 204{
 205        memset((void __force *)addr, val, count);
 206}
 207
 208static inline void
 209memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
 210{
 211        memcpy(dst, (const void __force *)src, count);
 212}
 213
 214static inline void
 215memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
 216{
 217        memcpy((void __force *)dst, src, count);
 218}
 219
 220/*
 221 * ISA space is 'always mapped' on a typical x86 system, no need to
 222 * explicitly ioremap() it. The fact that the ISA IO space is mapped
 223 * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
 224 * are physical addresses. The following constant pointer can be
 225 * used as the IO-area pointer (it can be iounmapped as well, so the
 226 * analogy with PCI is quite large):
 227 */
 228#define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
 229
 230/*
 231 *      Cache management
 232 *
 233 *      This needed for two cases
 234 *      1. Out of order aware processors
 235 *      2. Accidentally out of order processors (PPro errata #51)
 236 */
 237
 238static inline void flush_write_buffers(void)
 239{
 240#if defined(CONFIG_X86_OOSTORE) || defined(CONFIG_X86_PPRO_FENCE)
 241        asm volatile("lock; addl $0,0(%%esp)": : :"memory");
 242#endif
 243}
 244
 245#endif /* __KERNEL__ */
 246
 247extern void native_io_delay(void);
 248
 249extern int io_delay_type;
 250extern void io_delay_init(void);
 251
 252#if defined(CONFIG_PARAVIRT)
 253#include <asm/paravirt.h>
 254#else
 255
 256static inline void slow_down_io(void)
 257{
 258        native_io_delay();
 259#ifdef REALLY_SLOW_IO
 260        native_io_delay();
 261        native_io_delay();
 262        native_io_delay();
 263#endif
 264}
 265
 266#endif
 267
 268#define BUILDIO(bwl, bw, type)                                          \
 269static inline void out##bwl(unsigned type value, int port)              \
 270{                                                                       \
 271        asm volatile("out" #bwl " %" #bw "0, %w1"                       \
 272                     : : "a"(value), "Nd"(port));                       \
 273}                                                                       \
 274                                                                        \
 275static inline unsigned type in##bwl(int port)                           \
 276{                                                                       \
 277        unsigned type value;                                            \
 278        asm volatile("in" #bwl " %w1, %" #bw "0"                        \
 279                     : "=a"(value) : "Nd"(port));                       \
 280        return value;                                                   \
 281}                                                                       \
 282                                                                        \
 283static inline void out##bwl##_p(unsigned type value, int port)          \
 284{                                                                       \
 285        out##bwl(value, port);                                          \
 286        slow_down_io();                                                 \
 287}                                                                       \
 288                                                                        \
 289static inline unsigned type in##bwl##_p(int port)                       \
 290{                                                                       \
 291        unsigned type value = in##bwl(port);                            \
 292        slow_down_io();                                                 \
 293        return value;                                                   \
 294}                                                                       \
 295                                                                        \
 296static inline void outs##bwl(int port, const void *addr, unsigned long count) \
 297{                                                                       \
 298        asm volatile("rep; outs" #bwl                                   \
 299                     : "+S"(addr), "+c"(count) : "d"(port));            \
 300}                                                                       \
 301                                                                        \
 302static inline void ins##bwl(int port, void *addr, unsigned long count)  \
 303{                                                                       \
 304        asm volatile("rep; ins" #bwl                                    \
 305                     : "+D"(addr), "+c"(count) : "d"(port));            \
 306}
 307
 308BUILDIO(b, b, char)
 309BUILDIO(w, w, short)
 310BUILDIO(l, , int)
 311
 312extern void *xlate_dev_mem_ptr(unsigned long phys);
 313extern void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
 314
 315extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 316                                unsigned long prot_val);
 317extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
 318
 319/*
 320 * early_ioremap() and early_iounmap() are for temporary early boot-time
 321 * mappings, before the real ioremap() is functional.
 322 * A boot-time mapping is currently limited to at most 16 pages.
 323 */
 324extern void early_ioremap_init(void);
 325extern void early_ioremap_reset(void);
 326extern void __iomem *early_ioremap(resource_size_t phys_addr,
 327                                   unsigned long size);
 328extern void __iomem *early_memremap(resource_size_t phys_addr,
 329                                    unsigned long size);
 330extern void early_iounmap(void __iomem *addr, unsigned long size);
 331extern void fixup_early_ioremap(void);
 332extern bool is_early_ioremap_ptep(pte_t *ptep);
 333
 334#ifdef CONFIG_XEN
 335#include <xen/xen.h>
 336struct bio_vec;
 337
 338extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 339                                      const struct bio_vec *vec2);
 340
 341#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)                               \
 342        (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&                         \
 343         (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
 344#endif  /* CONFIG_XEN */
 345
 346#define IO_SPACE_LIMIT 0xffff
 347
 348#ifdef CONFIG_MTRR
 349extern int __must_check arch_phys_wc_add(unsigned long base,
 350                                         unsigned long size);
 351extern void arch_phys_wc_del(int handle);
 352#define arch_phys_wc_add arch_phys_wc_add
 353#endif
 354
 355#endif /* _ASM_X86_IO_H */
 356