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-generic/int-ll64.h>
  42#include <asm/page.h>
  43
  44#include <xen/xen.h>
  45
  46#define build_mmio_read(name, size, type, reg, barrier) \
  47static inline type name(const volatile void __iomem *addr) \
  48{ type ret; asm volatile("mov" size " %1,%0":reg (ret) \
  49:"m" (*(volatile type __force *)addr) barrier); return ret; }
  50
  51#define build_mmio_write(name, size, type, reg, barrier) \
  52static inline void name(type val, volatile void __iomem *addr) \
  53{ asm volatile("mov" size " %0,%1": :reg (val), \
  54"m" (*(volatile type __force *)addr) barrier); }
  55
  56build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
  57build_mmio_read(readw, "w", unsigned short, "=r", :"memory")
  58build_mmio_read(readl, "l", unsigned int, "=r", :"memory")
  59
  60build_mmio_read(__readb, "b", unsigned char, "=q", )
  61build_mmio_read(__readw, "w", unsigned short, "=r", )
  62build_mmio_read(__readl, "l", unsigned int, "=r", )
  63
  64build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
  65build_mmio_write(writew, "w", unsigned short, "r", :"memory")
  66build_mmio_write(writel, "l", unsigned int, "r", :"memory")
  67
  68build_mmio_write(__writeb, "b", unsigned char, "q", )
  69build_mmio_write(__writew, "w", unsigned short, "r", )
  70build_mmio_write(__writel, "l", unsigned int, "r", )
  71
  72#define readb_relaxed(a) __readb(a)
  73#define readw_relaxed(a) __readw(a)
  74#define readl_relaxed(a) __readl(a)
  75#define __raw_readb __readb
  76#define __raw_readw __readw
  77#define __raw_readl __readl
  78
  79#define __raw_writeb __writeb
  80#define __raw_writew __writew
  81#define __raw_writel __writel
  82
  83#define mmiowb() barrier()
  84
  85#ifdef CONFIG_X86_64
  86
  87build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
  88build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
  89
  90#else
  91
  92static inline __u64 readq(const volatile void __iomem *addr)
  93{
  94        const volatile u32 __iomem *p = addr;
  95        u32 low, high;
  96
  97        low = readl(p);
  98        high = readl(p + 1);
  99
 100        return low + ((u64)high << 32);
 101}
 102
 103static inline void writeq(__u64 val, volatile void __iomem *addr)
 104{
 105        writel(val, addr);
 106        writel(val >> 32, addr+4);
 107}
 108
 109#endif
 110
 111#define readq_relaxed(a)        readq(a)
 112
 113#define __raw_readq(a)          readq(a)
 114#define __raw_writeq(val, addr) writeq(val, addr)
 115
 116/* Let people know that we have them */
 117#define readq                   readq
 118#define writeq                  writeq
 119
 120/**
 121 *      virt_to_phys    -       map virtual addresses to physical
 122 *      @address: address to remap
 123 *
 124 *      The returned physical address is the physical (CPU) mapping for
 125 *      the memory address given. It is only valid to use this function on
 126 *      addresses directly mapped or allocated via kmalloc.
 127 *
 128 *      This function does not give bus mappings for DMA transfers. In
 129 *      almost all conceivable cases a device driver should not be using
 130 *      this function
 131 */
 132
 133static inline phys_addr_t virt_to_phys(volatile void *address)
 134{
 135        return __pa(address);
 136}
 137
 138/**
 139 *      phys_to_virt    -       map physical address to virtual
 140 *      @address: address to remap
 141 *
 142 *      The returned virtual address is a current CPU mapping for
 143 *      the memory address given. It is only valid to use this function on
 144 *      addresses that have a kernel mapping
 145 *
 146 *      This function does not handle bus mappings for DMA transfers. In
 147 *      almost all conceivable cases a device driver should not be using
 148 *      this function
 149 */
 150
 151static inline void *phys_to_virt(phys_addr_t address)
 152{
 153        return __va(address);
 154}
 155
 156/*
 157 * Change "struct page" to physical address.
 158 */
 159#define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
 160
 161/*
 162 * ISA I/O bus memory addresses are 1:1 with the physical address.
 163 * However, we truncate the address to unsigned int to avoid undesirable
 164 * promitions in legacy drivers.
 165 */
 166static inline unsigned int isa_virt_to_bus(volatile void *address)
 167{
 168        return (unsigned int)virt_to_phys(address);
 169}
 170#define isa_page_to_bus(page)   ((unsigned int)page_to_phys(page))
 171#define isa_bus_to_virt         phys_to_virt
 172
 173/*
 174 * However PCI ones are not necessarily 1:1 and therefore these interfaces
 175 * are forbidden in portable PCI drivers.
 176 *
 177 * Allow them on x86 for legacy drivers, though.
 178 */
 179#define virt_to_bus virt_to_phys
 180#define bus_to_virt phys_to_virt
 181
 182/**
 183 * ioremap     -   map bus memory into CPU space
 184 * @offset:    bus address of the memory
 185 * @size:      size of the resource to map
 186 *
 187 * ioremap performs a platform specific sequence of operations to
 188 * make bus memory CPU accessible via the readb/readw/readl/writeb/
 189 * writew/writel functions and the other mmio helpers. The returned
 190 * address is not guaranteed to be usable directly as a virtual
 191 * address.
 192 *
 193 * If the area you are trying to map is a PCI BAR you should have a
 194 * look at pci_iomap().
 195 */
 196extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
 197extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
 198extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
 199                                unsigned long prot_val);
 200
 201/*
 202 * The default ioremap() behavior is non-cached:
 203 */
 204static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
 205{
 206        return ioremap_nocache(offset, size);
 207}
 208
 209extern void iounmap(volatile void __iomem *addr);
 210
 211extern void set_iounmap_nonlazy(void);
 212
 213#ifdef __KERNEL__
 214
 215#include <asm-generic/iomap.h>
 216
 217#include <linux/vmalloc.h>
 218
 219/*
 220 * Convert a virtual cached pointer to an uncached pointer
 221 */
 222#define xlate_dev_kmem_ptr(p)   p
 223
 224static inline void
 225memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
 226{
 227        memset((void __force *)addr, val, count);
 228}
 229
 230static inline void
 231memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
 232{
 233        memcpy(dst, (const void __force *)src, count);
 234}
 235
 236static inline void
 237memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
 238{
 239        memcpy((void __force *)dst, src, count);
 240}
 241
 242/*
 243 * ISA space is 'always mapped' on a typical x86 system, no need to
 244 * explicitly ioremap() it. The fact that the ISA IO space is mapped
 245 * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
 246 * are physical addresses. The following constant pointer can be
 247 * used as the IO-area pointer (it can be iounmapped as well, so the
 248 * analogy with PCI is quite large):
 249 */
 250#define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
 251
 252/*
 253 *      Cache management
 254 *
 255 *      This needed for two cases
 256 *      1. Out of order aware processors
 257 *      2. Accidentally out of order processors (PPro errata #51)
 258 */
 259
 260static inline void flush_write_buffers(void)
 261{
 262#if defined(CONFIG_X86_OOSTORE) || defined(CONFIG_X86_PPRO_FENCE)
 263        asm volatile("lock; addl $0,0(%%esp)": : :"memory");
 264#endif
 265}
 266
 267#endif /* __KERNEL__ */
 268
 269extern void native_io_delay(void);
 270
 271extern int io_delay_type;
 272extern void io_delay_init(void);
 273
 274#if defined(CONFIG_PARAVIRT)
 275#include <asm/paravirt.h>
 276#else
 277
 278static inline void slow_down_io(void)
 279{
 280        native_io_delay();
 281#ifdef REALLY_SLOW_IO
 282        native_io_delay();
 283        native_io_delay();
 284        native_io_delay();
 285#endif
 286}
 287
 288#endif
 289
 290#define BUILDIO(bwl, bw, type)                                          \
 291static inline void out##bwl(unsigned type value, int port)              \
 292{                                                                       \
 293        asm volatile("out" #bwl " %" #bw "0, %w1"                       \
 294                     : : "a"(value), "Nd"(port));                       \
 295}                                                                       \
 296                                                                        \
 297static inline unsigned type in##bwl(int port)                           \
 298{                                                                       \
 299        unsigned type value;                                            \
 300        asm volatile("in" #bwl " %w1, %" #bw "0"                        \
 301                     : "=a"(value) : "Nd"(port));                       \
 302        return value;                                                   \
 303}                                                                       \
 304                                                                        \
 305static inline void out##bwl##_p(unsigned type value, int port)          \
 306{                                                                       \
 307        out##bwl(value, port);                                          \
 308        slow_down_io();                                                 \
 309}                                                                       \
 310                                                                        \
 311static inline unsigned type in##bwl##_p(int port)                       \
 312{                                                                       \
 313        unsigned type value = in##bwl(port);                            \
 314        slow_down_io();                                                 \
 315        return value;                                                   \
 316}                                                                       \
 317                                                                        \
 318static inline void outs##bwl(int port, const void *addr, unsigned long count) \
 319{                                                                       \
 320        asm volatile("rep; outs" #bwl                                   \
 321                     : "+S"(addr), "+c"(count) : "d"(port));            \
 322}                                                                       \
 323                                                                        \
 324static inline void ins##bwl(int port, void *addr, unsigned long count)  \
 325{                                                                       \
 326        asm volatile("rep; ins" #bwl                                    \
 327                     : "+D"(addr), "+c"(count) : "d"(port));            \
 328}
 329
 330BUILDIO(b, b, char)
 331BUILDIO(w, w, short)
 332BUILDIO(l, , int)
 333
 334extern void *xlate_dev_mem_ptr(unsigned long phys);
 335extern void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
 336
 337extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 338                                unsigned long prot_val);
 339extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
 340
 341/*
 342 * early_ioremap() and early_iounmap() are for temporary early boot-time
 343 * mappings, before the real ioremap() is functional.
 344 * A boot-time mapping is currently limited to at most 16 pages.
 345 */
 346extern void early_ioremap_init(void);
 347extern void early_ioremap_reset(void);
 348extern void __iomem *early_ioremap(resource_size_t phys_addr,
 349                                   unsigned long size);
 350extern void __iomem *early_memremap(resource_size_t phys_addr,
 351                                    unsigned long size);
 352extern void early_iounmap(void __iomem *addr, unsigned long size);
 353extern void fixup_early_ioremap(void);
 354extern bool is_early_ioremap_ptep(pte_t *ptep);
 355
 356#ifdef CONFIG_XEN
 357struct bio_vec;
 358
 359extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 360                                      const struct bio_vec *vec2);
 361
 362#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)                               \
 363        (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&                         \
 364         (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
 365#endif  /* CONFIG_XEN */
 366
 367#define IO_SPACE_LIMIT 0xffff
 368
 369#endif /* _ASM_X86_IO_H */
 370