linux/arch/x86/include/asm/io.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_X86_IO_H
   3#define _ASM_X86_IO_H
   4
   5/*
   6 * This file contains the definitions for the x86 IO instructions
   7 * inb/inw/inl/outb/outw/outl and the "string versions" of the same
   8 * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
   9 * versions of the single-IO instructions (inb_p/inw_p/..).
  10 *
  11 * This file is not meant to be obfuscating: it's just complicated
  12 * to (a) handle it all in a way that makes gcc able to optimize it
  13 * as well as possible and (b) trying to avoid writing the same thing
  14 * over and over again with slight variations and possibly making a
  15 * mistake somewhere.
  16 */
  17
  18/*
  19 * Thanks to James van Artsdalen for a better timing-fix than
  20 * the two short jumps: using outb's to a nonexistent port seems
  21 * to guarantee better timings even on fast machines.
  22 *
  23 * On the other hand, I'd like to be sure of a non-existent port:
  24 * I feel a bit unsafe about using 0x80 (should be safe, though)
  25 *
  26 *              Linus
  27 */
  28
  29 /*
  30  *  Bit simplified and optimized by Jan Hubicka
  31  *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999.
  32  *
  33  *  isa_memset_io, isa_memcpy_fromio, isa_memcpy_toio added,
  34  *  isa_read[wl] and isa_write[wl] fixed
  35  *  - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  36  */
  37
  38#define ARCH_HAS_IOREMAP_WC
  39#define ARCH_HAS_IOREMAP_WT
  40
  41#include <linux/string.h>
  42#include <linux/compiler.h>
  43#include <asm/page.h>
  44#include <asm/early_ioremap.h>
  45#include <asm/pgtable_types.h>
  46
  47#define build_mmio_read(name, size, type, reg, barrier) \
  48static inline type name(const volatile void __iomem *addr) \
  49{ type ret; asm volatile("mov" size " %1,%0":reg (ret) \
  50:"m" (*(volatile type __force *)addr) barrier); return ret; }
  51
  52#define build_mmio_write(name, size, type, reg, barrier) \
  53static inline void name(type val, volatile void __iomem *addr) \
  54{ asm volatile("mov" size " %0,%1": :reg (val), \
  55"m" (*(volatile type __force *)addr) barrier); }
  56
  57build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
  58build_mmio_read(readw, "w", unsigned short, "=r", :"memory")
  59build_mmio_read(readl, "l", unsigned int, "=r", :"memory")
  60
  61build_mmio_read(__readb, "b", unsigned char, "=q", )
  62build_mmio_read(__readw, "w", unsigned short, "=r", )
  63build_mmio_read(__readl, "l", unsigned int, "=r", )
  64
  65build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
  66build_mmio_write(writew, "w", unsigned short, "r", :"memory")
  67build_mmio_write(writel, "l", unsigned int, "r", :"memory")
  68
  69build_mmio_write(__writeb, "b", unsigned char, "q", )
  70build_mmio_write(__writew, "w", unsigned short, "r", )
  71build_mmio_write(__writel, "l", unsigned int, "r", )
  72
  73#define readb readb
  74#define readw readw
  75#define readl readl
  76#define readb_relaxed(a) __readb(a)
  77#define readw_relaxed(a) __readw(a)
  78#define readl_relaxed(a) __readl(a)
  79#define __raw_readb __readb
  80#define __raw_readw __readw
  81#define __raw_readl __readl
  82
  83#define writeb writeb
  84#define writew writew
  85#define writel writel
  86#define writeb_relaxed(v, a) __writeb(v, a)
  87#define writew_relaxed(v, a) __writew(v, a)
  88#define writel_relaxed(v, a) __writel(v, a)
  89#define __raw_writeb __writeb
  90#define __raw_writew __writew
  91#define __raw_writel __writel
  92
  93#ifdef CONFIG_X86_64
  94
  95build_mmio_read(readq, "q", u64, "=r", :"memory")
  96build_mmio_read(__readq, "q", u64, "=r", )
  97build_mmio_write(writeq, "q", u64, "r", :"memory")
  98build_mmio_write(__writeq, "q", u64, "r", )
  99
 100#define readq_relaxed(a)        __readq(a)
 101#define writeq_relaxed(v, a)    __writeq(v, a)
 102
 103#define __raw_readq             __readq
 104#define __raw_writeq            __writeq
 105
 106/* Let people know that we have them */
 107#define readq                   readq
 108#define writeq                  writeq
 109
 110#endif
 111
 112#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 113extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
 114extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
 115
 116/**
 117 *      virt_to_phys    -       map virtual addresses to physical
 118 *      @address: address to remap
 119 *
 120 *      The returned physical address is the physical (CPU) mapping for
 121 *      the memory address given. It is only valid to use this function on
 122 *      addresses directly mapped or allocated via kmalloc.
 123 *
 124 *      This function does not give 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 phys_addr_t virt_to_phys(volatile void *address)
 130{
 131        return __pa(address);
 132}
 133#define virt_to_phys virt_to_phys
 134
 135/**
 136 *      phys_to_virt    -       map physical address to virtual
 137 *      @address: address to remap
 138 *
 139 *      The returned virtual address is a current CPU mapping for
 140 *      the memory address given. It is only valid to use this function on
 141 *      addresses that have a kernel mapping
 142 *
 143 *      This function does not handle bus mappings for DMA transfers. In
 144 *      almost all conceivable cases a device driver should not be using
 145 *      this function
 146 */
 147
 148static inline void *phys_to_virt(phys_addr_t address)
 149{
 150        return __va(address);
 151}
 152#define phys_to_virt phys_to_virt
 153
 154/*
 155 * Change "struct page" to physical address.
 156 */
 157#define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
 158
 159/*
 160 * ISA I/O bus memory addresses are 1:1 with the physical address.
 161 * However, we truncate the address to unsigned int to avoid undesirable
 162 * promotions in legacy drivers.
 163 */
 164static inline unsigned int isa_virt_to_bus(volatile void *address)
 165{
 166        return (unsigned int)virt_to_phys(address);
 167}
 168#define isa_bus_to_virt         phys_to_virt
 169
 170/*
 171 * However PCI ones are not necessarily 1:1 and therefore these interfaces
 172 * are forbidden in portable PCI drivers.
 173 *
 174 * Allow them on x86 for legacy drivers, though.
 175 */
 176#define virt_to_bus virt_to_phys
 177#define bus_to_virt phys_to_virt
 178
 179/*
 180 * The default ioremap() behavior is non-cached; if you need something
 181 * else, you probably want one of the following.
 182 */
 183extern void __iomem *ioremap_uc(resource_size_t offset, unsigned long size);
 184#define ioremap_uc ioremap_uc
 185extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
 186#define ioremap_cache ioremap_cache
 187extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size, unsigned long prot_val);
 188#define ioremap_prot ioremap_prot
 189extern void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned long size);
 190#define ioremap_encrypted ioremap_encrypted
 191
 192/**
 193 * ioremap     -   map bus memory into CPU space
 194 * @offset:    bus address of the memory
 195 * @size:      size of the resource to map
 196 *
 197 * ioremap performs a platform specific sequence of operations to
 198 * make bus memory CPU accessible via the readb/readw/readl/writeb/
 199 * writew/writel functions and the other mmio helpers. The returned
 200 * address is not guaranteed to be usable directly as a virtual
 201 * address.
 202 *
 203 * If the area you are trying to map is a PCI BAR you should have a
 204 * look at pci_iomap().
 205 */
 206void __iomem *ioremap(resource_size_t offset, unsigned long size);
 207#define ioremap ioremap
 208
 209extern void iounmap(volatile void __iomem *addr);
 210#define iounmap iounmap
 211
 212extern void set_iounmap_nonlazy(void);
 213
 214#ifdef __KERNEL__
 215
 216void memcpy_fromio(void *, const volatile void __iomem *, size_t);
 217void memcpy_toio(volatile void __iomem *, const void *, size_t);
 218void memset_io(volatile void __iomem *, int, size_t);
 219
 220#define memcpy_fromio memcpy_fromio
 221#define memcpy_toio memcpy_toio
 222#define memset_io memset_io
 223
 224#include <asm-generic/iomap.h>
 225
 226/*
 227 * ISA space is 'always mapped' on a typical x86 system, no need to
 228 * explicitly ioremap() it. The fact that the ISA IO space is mapped
 229 * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
 230 * are physical addresses. The following constant pointer can be
 231 * used as the IO-area pointer (it can be iounmapped as well, so the
 232 * analogy with PCI is quite large):
 233 */
 234#define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
 235
 236#endif /* __KERNEL__ */
 237
 238extern void native_io_delay(void);
 239
 240extern int io_delay_type;
 241extern void io_delay_init(void);
 242
 243#if defined(CONFIG_PARAVIRT)
 244#include <asm/paravirt.h>
 245#else
 246
 247static inline void slow_down_io(void)
 248{
 249        native_io_delay();
 250#ifdef REALLY_SLOW_IO
 251        native_io_delay();
 252        native_io_delay();
 253        native_io_delay();
 254#endif
 255}
 256
 257#endif
 258
 259#ifdef CONFIG_AMD_MEM_ENCRYPT
 260#include <linux/jump_label.h>
 261
 262extern struct static_key_false sev_enable_key;
 263static inline bool sev_key_active(void)
 264{
 265        return static_branch_unlikely(&sev_enable_key);
 266}
 267
 268#else /* !CONFIG_AMD_MEM_ENCRYPT */
 269
 270static inline bool sev_key_active(void) { return false; }
 271
 272#endif /* CONFIG_AMD_MEM_ENCRYPT */
 273
 274#define BUILDIO(bwl, bw, type)                                          \
 275static inline void out##bwl(unsigned type value, int port)              \
 276{                                                                       \
 277        asm volatile("out" #bwl " %" #bw "0, %w1"                       \
 278                     : : "a"(value), "Nd"(port));                       \
 279}                                                                       \
 280                                                                        \
 281static inline unsigned type in##bwl(int port)                           \
 282{                                                                       \
 283        unsigned type value;                                            \
 284        asm volatile("in" #bwl " %w1, %" #bw "0"                        \
 285                     : "=a"(value) : "Nd"(port));                       \
 286        return value;                                                   \
 287}                                                                       \
 288                                                                        \
 289static inline void out##bwl##_p(unsigned type value, int port)          \
 290{                                                                       \
 291        out##bwl(value, port);                                          \
 292        slow_down_io();                                                 \
 293}                                                                       \
 294                                                                        \
 295static inline unsigned type in##bwl##_p(int port)                       \
 296{                                                                       \
 297        unsigned type value = in##bwl(port);                            \
 298        slow_down_io();                                                 \
 299        return value;                                                   \
 300}                                                                       \
 301                                                                        \
 302static inline void outs##bwl(int port, const void *addr, unsigned long count) \
 303{                                                                       \
 304        if (sev_key_active()) {                                         \
 305                unsigned type *value = (unsigned type *)addr;           \
 306                while (count) {                                         \
 307                        out##bwl(*value, port);                         \
 308                        value++;                                        \
 309                        count--;                                        \
 310                }                                                       \
 311        } else {                                                        \
 312                asm volatile("rep; outs" #bwl                           \
 313                             : "+S"(addr), "+c"(count)                  \
 314                             : "d"(port) : "memory");                   \
 315        }                                                               \
 316}                                                                       \
 317                                                                        \
 318static inline void ins##bwl(int port, void *addr, unsigned long count)  \
 319{                                                                       \
 320        if (sev_key_active()) {                                         \
 321                unsigned type *value = (unsigned type *)addr;           \
 322                while (count) {                                         \
 323                        *value = in##bwl(port);                         \
 324                        value++;                                        \
 325                        count--;                                        \
 326                }                                                       \
 327        } else {                                                        \
 328                asm volatile("rep; ins" #bwl                            \
 329                             : "+D"(addr), "+c"(count)                  \
 330                             : "d"(port) : "memory");                   \
 331        }                                                               \
 332}
 333
 334BUILDIO(b, b, char)
 335BUILDIO(w, w, short)
 336BUILDIO(l, , int)
 337
 338#define inb inb
 339#define inw inw
 340#define inl inl
 341#define inb_p inb_p
 342#define inw_p inw_p
 343#define inl_p inl_p
 344#define insb insb
 345#define insw insw
 346#define insl insl
 347
 348#define outb outb
 349#define outw outw
 350#define outl outl
 351#define outb_p outb_p
 352#define outw_p outw_p
 353#define outl_p outl_p
 354#define outsb outsb
 355#define outsw outsw
 356#define outsl outsl
 357
 358extern void *xlate_dev_mem_ptr(phys_addr_t phys);
 359extern void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr);
 360
 361#define xlate_dev_mem_ptr xlate_dev_mem_ptr
 362#define unxlate_dev_mem_ptr unxlate_dev_mem_ptr
 363
 364extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 365                                enum page_cache_mode pcm);
 366extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
 367#define ioremap_wc ioremap_wc
 368extern void __iomem *ioremap_wt(resource_size_t offset, unsigned long size);
 369#define ioremap_wt ioremap_wt
 370
 371extern bool is_early_ioremap_ptep(pte_t *ptep);
 372
 373#define IO_SPACE_LIMIT 0xffff
 374
 375#include <asm-generic/io.h>
 376#undef PCI_IOBASE
 377
 378#ifdef CONFIG_MTRR
 379extern int __must_check arch_phys_wc_index(int handle);
 380#define arch_phys_wc_index arch_phys_wc_index
 381
 382extern int __must_check arch_phys_wc_add(unsigned long base,
 383                                         unsigned long size);
 384extern void arch_phys_wc_del(int handle);
 385#define arch_phys_wc_add arch_phys_wc_add
 386#endif
 387
 388#ifdef CONFIG_X86_PAT
 389extern int arch_io_reserve_memtype_wc(resource_size_t start, resource_size_t size);
 390extern void arch_io_free_memtype_wc(resource_size_t start, resource_size_t size);
 391#define arch_io_reserve_memtype_wc arch_io_reserve_memtype_wc
 392#endif
 393
 394extern bool arch_memremap_can_ram_remap(resource_size_t offset,
 395                                        unsigned long size,
 396                                        unsigned long flags);
 397#define arch_memremap_can_ram_remap arch_memremap_can_ram_remap
 398
 399extern bool phys_mem_access_encrypted(unsigned long phys_addr,
 400                                      unsigned long size);
 401
 402/**
 403 * iosubmit_cmds512 - copy data to single MMIO location, in 512-bit units
 404 * @dst: destination, in MMIO space (must be 512-bit aligned)
 405 * @src: source
 406 * @count: number of 512 bits quantities to submit
 407 *
 408 * Submit data from kernel space to MMIO space, in units of 512 bits at a
 409 * time.  Order of access is not guaranteed, nor is a memory barrier
 410 * performed afterwards.
 411 *
 412 * Warning: Do not use this helper unless your driver has checked that the CPU
 413 * instruction is supported on the platform.
 414 */
 415static inline void iosubmit_cmds512(void __iomem *dst, const void *src,
 416                                    size_t count)
 417{
 418        const u8 *from = src;
 419        const u8 *end = from + count * 64;
 420
 421        while (from < end) {
 422                movdir64b(dst, from);
 423                from += 64;
 424        }
 425}
 426
 427#endif /* _ASM_X86_IO_H */
 428