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
  43 #define build_mmio_read(name, size, type, reg, barrier) \
  44 static 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) \
  49 static 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
  53 build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
  54 build_mmio_read(readw, "w", unsigned short, "=r", :"memory")
  55 build_mmio_read(readl, "l", unsigned int, "=r", :"memory")
  56
  57 build_mmio_read(__readb, "b", unsigned char, "=q", )
  58 build_mmio_read(__readw, "w", unsigned short, "=r", )
  59 build_mmio_read(__readl, "l", unsigned int, "=r", )
  60
  61 build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
  62 build_mmio_write(writew, "w", unsigned short, "r", :"memory")
  63 build_mmio_write(writel, "l", unsigned int, "r", :"memory")
  64
  65 build_mmio_write(__writeb, "b", unsigned char, "q", )
  66 build_mmio_write(__writew, "w", unsigned short, "r", )
  67 build_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
  84 build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
  85 build_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
 111 static 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
 129 static 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  */
 144 static 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  */
 174 extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
 175 extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
 176 extern 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  */
 182 static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
 183 {
 184         return ioremap_nocache(offset, size);
 185 }
 186
 187 extern void iounmap(volatile void __iomem *addr);
 188
 189 extern 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
 202 static inline void
 203 memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
 204 {
 205         memset((void __force *)addr, val, count);
 206 }
 207
 208 static inline void
 209 memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
 210 {
 211         memcpy(dst, (const void __force *)src, count);
 212 }
 213
 214 static inline void
 215 memcpy_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
 238 static 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
 247 extern void native_io_delay(void);
 248
 249 extern int io_delay_type;
 250 extern void io_delay_init(void);
 251
 252 #if defined(CONFIG_PARAVIRT)
 253 #include <asm/paravirt.h>
 254 #else
 255
 256 static 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)                                          \
 269 static 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                                                                         \
 275 static 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                                                                         \
 283 static inline void out##bwl##_p(unsigned type value, int port)          \
 284 {                                                                       \
 285         out##bwl(value, port);                                          \
 286         slow_down_io();                                                 \
 287 }                                                                       \
 288                                                                         \
 289 static 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                                                                         \
 296 static 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                                                                         \
 302 static 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
 308 BUILDIO(b, b, char)
 309 BUILDIO(w, w, short)
 310 BUILDIO(l, , int)
 311
 312 extern void *xlate_dev_mem_ptr(unsigned long phys);
 313 extern void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
 314
 315 extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 316                                 unsigned long prot_val);
 317 extern 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  */
 324 extern void early_ioremap_init(void);
 325 extern void early_ioremap_reset(void);
 326 extern void __iomem *early_ioremap(resource_size_t phys_addr,
 327                                    unsigned long size);
 328 extern void __iomem *early_memremap(resource_size_t phys_addr,
 329                                     unsigned long size);
 330 extern void early_iounmap(void __iomem *addr, unsigned long size);
 331 extern void fixup_early_ioremap(void);
 332 extern bool is_early_ioremap_ptep(pte_t *ptep);
 333
 334 #ifdef CONFIG_XEN
 335 #include <xen/xen.h>
 336 struct bio_vec;
 337
 338 extern 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
 349 extern int __must_check arch_phys_wc_add(unsigned long base,
 350                                          unsigned long size);
 351 extern 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 */