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 writeb_relaxed(v, a) __writeb(v, a)
  77#define writew_relaxed(v, a) __writew(v, a)
  78#define writel_relaxed(v, a) __writel(v, a)
  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#define readq_relaxed(a)        readq(a)
  91#define writeq_relaxed(v, a)    writeq(v, a)
  92
  93#define __raw_readq(a)          readq(a)
  94#define __raw_writeq(val, addr) writeq(val, addr)
  95
  96/* Let people know that we have them */
  97#define readq                   readq
  98#define writeq                  writeq
  99
 100#endif
 101
 102/**
 103 *      virt_to_phys    -       map virtual addresses to physical
 104 *      @address: address to remap
 105 *
 106 *      The returned physical address is the physical (CPU) mapping for
 107 *      the memory address given. It is only valid to use this function on
 108 *      addresses directly mapped or allocated via kmalloc.
 109 *
 110 *      This function does not give bus mappings for DMA transfers. In
 111 *      almost all conceivable cases a device driver should not be using
 112 *      this function
 113 */
 114
 115static inline phys_addr_t virt_to_phys(volatile void *address)
 116{
 117        return __pa(address);
 118}
 119
 120/**
 121 *      phys_to_virt    -       map physical address to virtual
 122 *      @address: address to remap
 123 *
 124 *      The returned virtual address is a current CPU mapping for
 125 *      the memory address given. It is only valid to use this function on
 126 *      addresses that have a kernel mapping
 127 *
 128 *      This function does not handle 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 void *phys_to_virt(phys_addr_t address)
 134{
 135        return __va(address);
 136}
 137
 138/*
 139 * Change "struct page" to physical address.
 140 */
 141#define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
 142
 143/*
 144 * ISA I/O bus memory addresses are 1:1 with the physical address.
 145 * However, we truncate the address to unsigned int to avoid undesirable
 146 * promitions in legacy drivers.
 147 */
 148static inline unsigned int isa_virt_to_bus(volatile void *address)
 149{
 150        return (unsigned int)virt_to_phys(address);
 151}
 152#define isa_page_to_bus(page)   ((unsigned int)page_to_phys(page))
 153#define isa_bus_to_virt         phys_to_virt
 154
 155/*
 156 * However PCI ones are not necessarily 1:1 and therefore these interfaces
 157 * are forbidden in portable PCI drivers.
 158 *
 159 * Allow them on x86 for legacy drivers, though.
 160 */
 161#define virt_to_bus virt_to_phys
 162#define bus_to_virt phys_to_virt
 163
 164/**
 165 * ioremap     -   map bus memory into CPU space
 166 * @offset:    bus address of the memory
 167 * @size:      size of the resource to map
 168 *
 169 * ioremap performs a platform specific sequence of operations to
 170 * make bus memory CPU accessible via the readb/readw/readl/writeb/
 171 * writew/writel functions and the other mmio helpers. The returned
 172 * address is not guaranteed to be usable directly as a virtual
 173 * address.
 174 *
 175 * If the area you are trying to map is a PCI BAR you should have a
 176 * look at pci_iomap().
 177 */
 178extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
 179extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
 180extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
 181                                unsigned long prot_val);
 182extern void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned long size);
 183
 184/*
 185 * The default ioremap() behavior is non-cached:
 186 */
 187static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
 188{
 189        return ioremap_nocache(offset, size);
 190}
 191
 192extern void iounmap(volatile void __iomem *addr);
 193
 194extern void set_iounmap_nonlazy(void);
 195
 196#ifdef __KERNEL__
 197
 198#include <asm-generic/iomap.h>
 199
 200#include <linux/vmalloc.h>
 201
 202/*
 203 * Convert a virtual cached pointer to an uncached pointer
 204 */
 205#define xlate_dev_kmem_ptr(p)   p
 206
 207static inline void
 208memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
 209{
 210        memset((void __force *)addr, val, count);
 211}
 212
 213static inline void
 214memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
 215{
 216        memcpy(dst, (const void __force *)src, count);
 217}
 218
 219static inline void
 220memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
 221{
 222        memcpy((void __force *)dst, src, count);
 223}
 224
 225/*
 226 * ISA space is 'always mapped' on a typical x86 system, no need to
 227 * explicitly ioremap() it. The fact that the ISA IO space is mapped
 228 * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
 229 * are physical addresses. The following constant pointer can be
 230 * used as the IO-area pointer (it can be iounmapped as well, so the
 231 * analogy with PCI is quite large):
 232 */
 233#define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
 234
 235/*
 236 *      Cache management
 237 *
 238 *      This needed for two cases
 239 *      1. Out of order aware processors
 240 *      2. Accidentally out of order processors (PPro errata #51)
 241 */
 242
 243static inline void flush_write_buffers(void)
 244{
 245#if defined(CONFIG_X86_PPRO_FENCE)
 246        asm volatile("lock; addl $0,0(%%esp)": : :"memory");
 247#endif
 248}
 249
 250#endif /* __KERNEL__ */
 251
 252extern void native_io_delay(void);
 253
 254extern int io_delay_type;
 255extern void io_delay_init(void);
 256
 257#if defined(CONFIG_PARAVIRT)
 258#include <asm/paravirt.h>
 259#else
 260
 261static inline void slow_down_io(void)
 262{
 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_AMD_MEM_ENCRYPT
 274#include <linux/jump_label.h>
 275
 276extern struct static_key sev_enable_key;
 277
 278static inline bool sev_key_active(void)
 279{
 280        return static_key_false(&sev_enable_key);
 281}
 282
 283#else /* !CONFIG_AMD_MEM_ENCRYPT */
 284
 285static inline bool sev_key_active(void) { return false; }
 286
 287#endif /* CONFIG_AMD_MEM_ENCRYPT */
 288
 289#define BUILDIO(bwl, bw, type)                                          \
 290static inline void out##bwl(unsigned type value, int port)              \
 291{                                                                       \
 292        asm volatile("out" #bwl " %" #bw "0, %w1"                       \
 293                     : : "a"(value), "Nd"(port));                       \
 294}                                                                       \
 295                                                                        \
 296static inline unsigned type in##bwl(int port)                           \
 297{                                                                       \
 298        unsigned type value;                                            \
 299        asm volatile("in" #bwl " %w1, %" #bw "0"                        \
 300                     : "=a"(value) : "Nd"(port));                       \
 301        return value;                                                   \
 302}                                                                       \
 303                                                                        \
 304static inline void out##bwl##_p(unsigned type value, int port)          \
 305{                                                                       \
 306        out##bwl(value, port);                                          \
 307        slow_down_io();                                                 \
 308}                                                                       \
 309                                                                        \
 310static inline unsigned type in##bwl##_p(int port)                       \
 311{                                                                       \
 312        unsigned type value = in##bwl(port);                            \
 313        slow_down_io();                                                 \
 314        return value;                                                   \
 315}                                                                       \
 316                                                                        \
 317static inline void outs##bwl(int port, const void *addr, unsigned long count) \
 318{                                                                       \
 319        if (sev_key_active()) {                                         \
 320                unsigned type *value = (unsigned type *)addr;           \
 321                while (count) {                                         \
 322                        out##bwl(*value, port);                         \
 323                        value++;                                        \
 324                        count--;                                        \
 325                }                                                       \
 326        } else {                                                        \
 327                asm volatile("rep; outs" #bwl                           \
 328                             : "+S"(addr), "+c"(count)                  \
 329                             : "d"(port) : "memory");                   \
 330        }                                                               \
 331}                                                                       \
 332                                                                        \
 333static inline void ins##bwl(int port, void *addr, unsigned long count)  \
 334{                                                                       \
 335        if (sev_key_active()) {                                         \
 336                unsigned type *value = (unsigned type *)addr;           \
 337                while (count) {                                         \
 338                        *value = in##bwl(port);                         \
 339                        value++;                                        \
 340                        count--;                                        \
 341                }                                                       \
 342        } else {                                                        \
 343                asm volatile("rep; ins" #bwl                            \
 344                             : "+D"(addr), "+c"(count)                  \
 345                             : "d"(port) : "memory");                   \
 346        }                                                               \
 347}
 348
 349BUILDIO(b, b, char)
 350BUILDIO(w, w, short)
 351BUILDIO(l, , int)
 352
 353extern void *xlate_dev_mem_ptr(phys_addr_t phys);
 354extern void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr);
 355
 356extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 357                                enum page_cache_mode pcm);
 358extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
 359
 360/*
 361 * early_ioremap() and early_iounmap() are for temporary early boot-time
 362 * mappings, before the real ioremap() is functional.
 363 * A boot-time mapping is currently limited to at most 16 pages.
 364 */
 365extern void early_ioremap_init(void);
 366extern void early_ioremap_reset(void);
 367extern void __iomem *early_ioremap(resource_size_t phys_addr,
 368                                   unsigned long size);
 369extern void *early_memremap(resource_size_t phys_addr,
 370                                    unsigned long size);
 371extern void early_iounmap(void __iomem *addr, unsigned long size);
 372extern void early_memunmap(void *addr, unsigned long size);
 373extern void fixup_early_ioremap(void);
 374extern bool is_early_ioremap_ptep(pte_t *ptep);
 375
 376#ifdef CONFIG_XEN
 377#include <xen/xen.h>
 378struct bio_vec;
 379
 380extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 381                                      const struct bio_vec *vec2);
 382
 383#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)                               \
 384        (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&                         \
 385         (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
 386#endif  /* CONFIG_XEN */
 387
 388#define IO_SPACE_LIMIT 0xffff
 389
 390#ifdef CONFIG_MTRR
 391extern int __must_check arch_phys_wc_add(unsigned long base,
 392                                         unsigned long size);
 393extern void arch_phys_wc_del(int handle);
 394#define arch_phys_wc_add arch_phys_wc_add
 395#endif
 396
 397extern bool arch_memremap_can_ram_remap(resource_size_t offset,
 398                                        unsigned long size,
 399                                        unsigned long flags);
 400#define arch_memremap_can_ram_remap arch_memremap_can_ram_remap
 401
 402extern bool phys_mem_access_encrypted(unsigned long phys_addr,
 403                                      unsigned long size);
 404
 405#ifdef CONFIG_X86_PAT
 406extern int arch_io_reserve_memtype_wc(resource_size_t start, resource_size_t size);
 407extern void arch_io_free_memtype_wc(resource_size_t start, resource_size_t size);
 408#define arch_io_reserve_memtype_wc arch_io_reserve_memtype_wc
 409#endif
 410
 411#endif /* _ASM_X86_IO_H */
 412