arch/x86/include/asm/io.h

   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 #include <asm/early_ioremap.h>
  43
  44 #define build_mmio_read(name, size, type, reg, barrier) \
  45 static inline type name(const volatile void __iomem *addr) \
  46 { type ret; asm volatile("mov" size " %1,%0":reg (ret) \
  47 :"m" (*(volatile type __force *)addr) barrier); return ret; }
  48
  49 #define build_mmio_write(name, size, type, reg, barrier) \
  50 static inline void name(type val, volatile void __iomem *addr) \
  51 { asm volatile("mov" size " %0,%1": :reg (val), \
  52 "m" (*(volatile type __force *)addr) barrier); }
  53
  54 build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
  55 build_mmio_read(__intentional_overflow(-1) readw, "w", unsigned short, "=r", :"memory")
  56 build_mmio_read(__intentional_overflow(-1) readl, "l", unsigned int, "=r", :"memory")
  57
  58 build_mmio_read(__readb, "b", unsigned char, "=q", )
  59 build_mmio_read(__intentional_overflow(-1) __readw, "w", unsigned short, "=r", )
  60 build_mmio_read(__intentional_overflow(-1) __readl, "l", unsigned int, "=r", )
  61
  62 build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
  63 build_mmio_write(writew, "w", unsigned short, "r", :"memory")
  64 build_mmio_write(writel, "l", unsigned int, "r", :"memory")
  65
  66 build_mmio_write(__writeb, "b", unsigned char, "q", )
  67 build_mmio_write(__writew, "w", unsigned short, "r", )
  68 build_mmio_write(__writel, "l", unsigned int, "r", )
  69
  70 #define readb_relaxed(a) __readb(a)
  71 #define readw_relaxed(a) __readw(a)
  72 #define readl_relaxed(a) __readl(a)
  73 #define __raw_readb __readb
  74 #define __raw_readw __readw
  75 #define __raw_readl __readl
  76
  77 #define writeb_relaxed(v, a) __writeb(v, a)
  78 #define writew_relaxed(v, a) __writew(v, a)
  79 #define writel_relaxed(v, a) __writel(v, a)
  80 #define __raw_writeb __writeb
  81 #define __raw_writew __writew
  82 #define __raw_writel __writel
  83
  84 #define mmiowb() barrier()
  85
  86 #ifdef CONFIG_X86_64
  87
  88 build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
  89 build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
  90
  91 #define readq_relaxed(a)        readq(a)
  92 #define writeq_relaxed(v, a)    writeq(v, a)
  93
  94 #define __raw_readq(a)          readq(a)
  95 #define __raw_writeq(val, addr) writeq(val, addr)
  96
  97 /* Let people know that we have them */
  98 #define readq                   readq
  99 #define writeq                  writeq
 100
 101 #endif
 102
 103 /**
 104  *      virt_to_phys    -       map virtual addresses to physical
 105  *      @address: address to remap
 106  *
 107  *      The returned physical address is the physical (CPU) mapping for
 108  *      the memory address given. It is only valid to use this function on
 109  *      addresses directly mapped or allocated via kmalloc.
 110  *
 111  *      This function does not give bus mappings for DMA transfers. In
 112  *      almost all conceivable cases a device driver should not be using
 113  *      this function
 114  */
 115
 116 static inline phys_addr_t __intentional_overflow(-1) virt_to_phys(volatile void *address)
 117 {
 118         return __pa(address);
 119 }
 120
 121 /**
 122  *      phys_to_virt    -       map physical address to virtual
 123  *      @address: address to remap
 124  *
 125  *      The returned virtual address is a current CPU mapping for
 126  *      the memory address given. It is only valid to use this function on
 127  *      addresses that have a kernel mapping
 128  *
 129  *      This function does not handle bus mappings for DMA transfers. In
 130  *      almost all conceivable cases a device driver should not be using
 131  *      this function
 132  */
 133
 134 static inline void *phys_to_virt(phys_addr_t address)
 135 {
 136         return __va(address);
 137 }
 138
 139 /*
 140  * Change "struct page" to physical address.
 141  */
 142 #define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
 143
 144 /*
 145  * ISA I/O bus memory addresses are 1:1 with the physical address.
 146  * However, we truncate the address to unsigned int to avoid undesirable
 147  * promitions in legacy drivers.
 148  */
 149 static inline unsigned int isa_virt_to_bus(volatile void *address)
 150 {
 151         return (unsigned int)virt_to_phys(address);
 152 }
 153 #define isa_page_to_bus(page)   ((unsigned int)page_to_phys(page))
 154 #define isa_bus_to_virt         phys_to_virt
 155
 156 /*
 157  * However PCI ones are not necessarily 1:1 and therefore these interfaces
 158  * are forbidden in portable PCI drivers.
 159  *
 160  * Allow them on x86 for legacy drivers, though.
 161  */
 162 #define virt_to_bus virt_to_phys
 163 #define bus_to_virt phys_to_virt
 164
 165 /**
 166  * ioremap     -   map bus memory into CPU space
 167  * @offset:    bus address of the memory
 168  * @size:      size of the resource to map
 169  *
 170  * ioremap performs a platform specific sequence of operations to
 171  * make bus memory CPU accessible via the readb/readw/readl/writeb/
 172  * writew/writel functions and the other mmio helpers. The returned
 173  * address is not guaranteed to be usable directly as a virtual
 174  * address.
 175  *
 176  * If the area you are trying to map is a PCI BAR you should have a
 177  * look at pci_iomap().
 178  */
 179 extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
 180 extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
 181 extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
 182                                 unsigned long prot_val);
 183
 184 /*
 185  * The default ioremap() behavior is non-cached:
 186  */
 187 static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
 188 {
 189         return ioremap_nocache(offset, size);
 190 }
 191
 192 extern void iounmap(const volatile void __iomem *addr);
 193
 194 extern void set_iounmap_nonlazy(void);
 195
 196 #ifdef __KERNEL__
 197
 198 #include <asm-generic/iomap.h>
 199
 200 #include <linux/vmalloc.h>
 201
 202 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 203 static inline int valid_phys_addr_range(unsigned long addr, size_t count)
 204 {
 205         return ((addr + count + PAGE_SIZE - 1) >> PAGE_SHIFT) < (1ULL << (boot_cpu_data.x86_phys_bits - PAGE_SHIFT)) ? 1 : 0;
 206 }
 207
 208 static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t count)
 209 {
 210         return (pfn + (count >> PAGE_SHIFT)) < (1ULL << (boot_cpu_data.x86_phys_bits - PAGE_SHIFT)) ? 1 : 0;
 211 }
 212
 213 /*
 214  * Convert a virtual cached pointer to an uncached pointer
 215  */
 216 #define xlate_dev_kmem_ptr(p)   p
 217
 218 static inline void
 219 memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
 220 {
 221         memset((void __force *)addr, val, count);
 222 }
 223
 224 static inline void
 225 memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
 226 {
 227         memcpy(dst, (const void __force *)src, count);
 228 }
 229
 230 static inline void
 231 memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
 232 {
 233         memcpy((void __force *)dst, src, count);
 234 }
 235
 236 /*
 237  * ISA space is 'always mapped' on a typical x86 system, no need to
 238  * explicitly ioremap() it. The fact that the ISA IO space is mapped
 239  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
 240  * are physical addresses. The following constant pointer can be
 241  * used as the IO-area pointer (it can be iounmapped as well, so the
 242  * analogy with PCI is quite large):
 243  */
 244 #define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
 245
 246 /*
 247  *      Cache management
 248  *
 249  *      This needed for two cases
 250  *      1. Out of order aware processors
 251  *      2. Accidentally out of order processors (PPro errata #51)
 252  */
 253
 254 static inline void flush_write_buffers(void)
 255 {
 256 #if defined(CONFIG_X86_PPRO_FENCE)
 257         asm volatile("lock; addl $0,0(%%esp)": : :"memory");
 258 #endif
 259 }
 260
 261 #endif /* __KERNEL__ */
 262
 263 extern void native_io_delay(void);
 264
 265 extern int io_delay_type;
 266 extern void io_delay_init(void);
 267
 268 #if defined(CONFIG_PARAVIRT)
 269 #include <asm/paravirt.h>
 270 #else
 271
 272 static inline void slow_down_io(void)
 273 {
 274         native_io_delay();
 275 #ifdef REALLY_SLOW_IO
 276         native_io_delay();
 277         native_io_delay();
 278         native_io_delay();
 279 #endif
 280 }
 281
 282 #endif
 283
 284 #define BUILDIO(bwl, bw, type)                                          \
 285 static inline void out##bwl(unsigned type value, int port)              \
 286 {                                                                       \
 287         asm volatile("out" #bwl " %" #bw "0, %w1"                       \
 288                      : : "a"(value), "Nd"(port));                       \
 289 }                                                                       \
 290                                                                         \
 291 static inline unsigned type in##bwl(int port)                           \
 292 {                                                                       \
 293         unsigned type value;                                            \
 294         asm volatile("in" #bwl " %w1, %" #bw "0"                        \
 295                      : "=a"(value) : "Nd"(port));                       \
 296         return value;                                                   \
 297 }                                                                       \
 298                                                                         \
 299 static inline void out##bwl##_p(unsigned type value, int port)          \
 300 {                                                                       \
 301         out##bwl(value, port);                                          \
 302         slow_down_io();                                                 \
 303 }                                                                       \
 304                                                                         \
 305 static inline unsigned type in##bwl##_p(int port)                       \
 306 {                                                                       \
 307         unsigned type value = in##bwl(port);                            \
 308         slow_down_io();                                                 \
 309         return value;                                                   \
 310 }                                                                       \
 311                                                                         \
 312 static inline void outs##bwl(int port, const void *addr, unsigned long count) \
 313 {                                                                       \
 314         asm volatile("rep; outs" #bwl                                   \
 315                      : "+S"(addr), "+c"(count) : "d"(port));            \
 316 }                                                                       \
 317                                                                         \
 318 static inline void ins##bwl(int port, void *addr, unsigned long count)  \
 319 {                                                                       \
 320         asm volatile("rep; ins" #bwl                                    \
 321                      : "+D"(addr), "+c"(count) : "d"(port));            \
 322 }
 323
 324 BUILDIO(b, b, char)
 325 BUILDIO(w, w, short)
 326 BUILDIO(l, , int)
 327
 328 extern void *xlate_dev_mem_ptr(phys_addr_t phys);
 329 extern void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr);
 330
 331 extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 332                                 enum page_cache_mode pcm);
 333 extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
 334
 335 extern bool is_early_ioremap_ptep(pte_t *ptep);
 336
 337 #ifdef CONFIG_XEN
 338 #include <xen/xen.h>
 339 struct bio_vec;
 340
 341 extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 342                                       const struct bio_vec *vec2);
 343
 344 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)                               \
 345         (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&                         \
 346          (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
 347 #endif  /* CONFIG_XEN */
 348
 349 #define IO_SPACE_LIMIT 0xffff
 350
 351 #ifdef CONFIG_MTRR
 352 extern int __must_check arch_phys_wc_add(unsigned long base,
 353                                          unsigned long size);
 354 extern void arch_phys_wc_del(int handle);
 355 #define arch_phys_wc_add arch_phys_wc_add
 356 #endif
 357
 358 #endif /* _ASM_X86_IO_H */