linux/arch/arm/include/asm/io.h
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   1/*
   2 *  arch/arm/include/asm/io.h
   3 *
   4 *  Copyright (C) 1996-2000 Russell King
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 *
  10 * Modifications:
  11 *  16-Sep-1996 RMK     Inlined the inx/outx functions & optimised for both
  12 *                      constant addresses and variable addresses.
  13 *  04-Dec-1997 RMK     Moved a lot of this stuff to the new architecture
  14 *                      specific IO header files.
  15 *  27-Mar-1999 PJB     Second parameter of memcpy_toio is const..
  16 *  04-Apr-1999 PJB     Added check_signature.
  17 *  12-Dec-1999 RMK     More cleanups
  18 *  18-Jun-2000 RMK     Removed virt_to_* and friends definitions
  19 *  05-Oct-2004 BJD     Moved memory string functions to use void __iomem
  20 */
  21#ifndef __ASM_ARM_IO_H
  22#define __ASM_ARM_IO_H
  23
  24#ifdef __KERNEL__
  25
  26#include <linux/string.h>
  27#include <linux/types.h>
  28#include <asm/byteorder.h>
  29#include <asm/memory.h>
  30#include <asm-generic/pci_iomap.h>
  31#include <xen/xen.h>
  32
  33/*
  34 * ISA I/O bus memory addresses are 1:1 with the physical address.
  35 */
  36#define isa_virt_to_bus virt_to_phys
  37#define isa_page_to_bus page_to_phys
  38#define isa_bus_to_virt phys_to_virt
  39
  40/*
  41 * Atomic MMIO-wide IO modify
  42 */
  43extern void atomic_io_modify(void __iomem *reg, u32 mask, u32 set);
  44extern void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set);
  45
  46/*
  47 * Generic IO read/write.  These perform native-endian accesses.  Note
  48 * that some architectures will want to re-define __raw_{read,write}w.
  49 */
  50void __raw_writesb(volatile void __iomem *addr, const void *data, int bytelen);
  51void __raw_writesw(volatile void __iomem *addr, const void *data, int wordlen);
  52void __raw_writesl(volatile void __iomem *addr, const void *data, int longlen);
  53
  54void __raw_readsb(const volatile void __iomem *addr, void *data, int bytelen);
  55void __raw_readsw(const volatile void __iomem *addr, void *data, int wordlen);
  56void __raw_readsl(const volatile void __iomem *addr, void *data, int longlen);
  57
  58#if __LINUX_ARM_ARCH__ < 6
  59/*
  60 * Half-word accesses are problematic with RiscPC due to limitations of
  61 * the bus. Rather than special-case the machine, just let the compiler
  62 * generate the access for CPUs prior to ARMv6.
  63 */
  64#define __raw_readw(a)         (__chk_io_ptr(a), *(volatile unsigned short __force *)(a))
  65#define __raw_writew(v,a)      ((void)(__chk_io_ptr(a), *(volatile unsigned short __force *)(a) = (v)))
  66#else
  67/*
  68 * When running under a hypervisor, we want to avoid I/O accesses with
  69 * writeback addressing modes as these incur a significant performance
  70 * overhead (the address generation must be emulated in software).
  71 */
  72#define __raw_writew __raw_writew
  73static inline void __raw_writew(u16 val, volatile void __iomem *addr)
  74{
  75        asm volatile("strh %1, %0"
  76                     : : "Q" (*(volatile u16 __force *)addr), "r" (val));
  77}
  78
  79#define __raw_readw __raw_readw
  80static inline u16 __raw_readw(const volatile void __iomem *addr)
  81{
  82        u16 val;
  83        asm volatile("ldrh %0, %1"
  84                     : "=r" (val)
  85                     : "Q" (*(volatile u16 __force *)addr));
  86        return val;
  87}
  88#endif
  89
  90#define __raw_writeb __raw_writeb
  91static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
  92{
  93        asm volatile("strb %1, %0"
  94                     : : "Qo" (*(volatile u8 __force *)addr), "r" (val));
  95}
  96
  97#define __raw_writel __raw_writel
  98static inline void __raw_writel(u32 val, volatile void __iomem *addr)
  99{
 100        asm volatile("str %1, %0"
 101                     : : "Qo" (*(volatile u32 __force *)addr), "r" (val));
 102}
 103
 104#define __raw_readb __raw_readb
 105static inline u8 __raw_readb(const volatile void __iomem *addr)
 106{
 107        u8 val;
 108        asm volatile("ldrb %0, %1"
 109                     : "=r" (val)
 110                     : "Qo" (*(volatile u8 __force *)addr));
 111        return val;
 112}
 113
 114#define __raw_readl __raw_readl
 115static inline u32 __raw_readl(const volatile void __iomem *addr)
 116{
 117        u32 val;
 118        asm volatile("ldr %0, %1"
 119                     : "=r" (val)
 120                     : "Qo" (*(volatile u32 __force *)addr));
 121        return val;
 122}
 123
 124/*
 125 * Architecture ioremap implementation.
 126 */
 127#define MT_DEVICE               0
 128#define MT_DEVICE_NONSHARED     1
 129#define MT_DEVICE_CACHED        2
 130#define MT_DEVICE_WC            3
 131/*
 132 * types 4 onwards can be found in asm/mach/map.h and are undefined
 133 * for ioremap
 134 */
 135
 136/*
 137 * __arm_ioremap takes CPU physical address.
 138 * __arm_ioremap_pfn takes a Page Frame Number and an offset into that page
 139 * The _caller variety takes a __builtin_return_address(0) value for
 140 * /proc/vmalloc to use - and should only be used in non-inline functions.
 141 */
 142extern void __iomem *__arm_ioremap_caller(phys_addr_t, size_t, unsigned int,
 143        void *);
 144extern void __iomem *__arm_ioremap_pfn(unsigned long, unsigned long, size_t, unsigned int);
 145extern void __iomem *__arm_ioremap_exec(phys_addr_t, size_t, bool cached);
 146extern void __iounmap(volatile void __iomem *addr);
 147
 148extern void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t,
 149        unsigned int, void *);
 150extern void (*arch_iounmap)(volatile void __iomem *);
 151
 152/*
 153 * Bad read/write accesses...
 154 */
 155extern void __readwrite_bug(const char *fn);
 156
 157/*
 158 * A typesafe __io() helper
 159 */
 160static inline void __iomem *__typesafe_io(unsigned long addr)
 161{
 162        return (void __iomem *)addr;
 163}
 164
 165#define IOMEM(x)        ((void __force __iomem *)(x))
 166
 167/* IO barriers */
 168#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
 169#include <asm/barrier.h>
 170#define __iormb()               rmb()
 171#define __iowmb()               wmb()
 172#else
 173#define __iormb()               do { } while (0)
 174#define __iowmb()               do { } while (0)
 175#endif
 176
 177/* PCI fixed i/o mapping */
 178#define PCI_IO_VIRT_BASE        0xfee00000
 179#define PCI_IOBASE              ((void __iomem *)PCI_IO_VIRT_BASE)
 180
 181#if defined(CONFIG_PCI)
 182void pci_ioremap_set_mem_type(int mem_type);
 183#else
 184static inline void pci_ioremap_set_mem_type(int mem_type) {}
 185#endif
 186
 187extern int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr);
 188
 189/*
 190 * PCI configuration space mapping function.
 191 *
 192 * The PCI specification does not allow configuration write
 193 * transactions to be posted. Add an arch specific
 194 * pci_remap_cfgspace() definition that is implemented
 195 * through strongly ordered memory mappings.
 196 */
 197#define pci_remap_cfgspace pci_remap_cfgspace
 198void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size);
 199/*
 200 * Now, pick up the machine-defined IO definitions
 201 */
 202#ifdef CONFIG_NEED_MACH_IO_H
 203#include <mach/io.h>
 204#elif defined(CONFIG_PCI)
 205#define IO_SPACE_LIMIT  ((resource_size_t)0xfffff)
 206#define __io(a)         __typesafe_io(PCI_IO_VIRT_BASE + ((a) & IO_SPACE_LIMIT))
 207#else
 208#define __io(a)         __typesafe_io((a) & IO_SPACE_LIMIT)
 209#endif
 210
 211/*
 212 * This is the limit of PC card/PCI/ISA IO space, which is by default
 213 * 64K if we have PC card, PCI or ISA support.  Otherwise, default to
 214 * zero to prevent ISA/PCI drivers claiming IO space (and potentially
 215 * oopsing.)
 216 *
 217 * Only set this larger if you really need inb() et.al. to operate over
 218 * a larger address space.  Note that SOC_COMMON ioremaps each sockets
 219 * IO space area, and so inb() et.al. must be defined to operate as per
 220 * readb() et.al. on such platforms.
 221 */
 222#ifndef IO_SPACE_LIMIT
 223#if defined(CONFIG_PCMCIA_SOC_COMMON) || defined(CONFIG_PCMCIA_SOC_COMMON_MODULE)
 224#define IO_SPACE_LIMIT ((resource_size_t)0xffffffff)
 225#elif defined(CONFIG_PCI) || defined(CONFIG_ISA) || defined(CONFIG_PCCARD)
 226#define IO_SPACE_LIMIT ((resource_size_t)0xffff)
 227#else
 228#define IO_SPACE_LIMIT ((resource_size_t)0)
 229#endif
 230#endif
 231
 232/*
 233 *  IO port access primitives
 234 *  -------------------------
 235 *
 236 * The ARM doesn't have special IO access instructions; all IO is memory
 237 * mapped.  Note that these are defined to perform little endian accesses
 238 * only.  Their primary purpose is to access PCI and ISA peripherals.
 239 *
 240 * Note that for a big endian machine, this implies that the following
 241 * big endian mode connectivity is in place, as described by numerous
 242 * ARM documents:
 243 *
 244 *    PCI:  D0-D7   D8-D15 D16-D23 D24-D31
 245 *    ARM: D24-D31 D16-D23  D8-D15  D0-D7
 246 *
 247 * The machine specific io.h include defines __io to translate an "IO"
 248 * address to a memory address.
 249 *
 250 * Note that we prevent GCC re-ordering or caching values in expressions
 251 * by introducing sequence points into the in*() definitions.  Note that
 252 * __raw_* do not guarantee this behaviour.
 253 *
 254 * The {in,out}[bwl] macros are for emulating x86-style PCI/ISA IO space.
 255 */
 256#ifdef __io
 257#define outb(v,p)       ({ __iowmb(); __raw_writeb(v,__io(p)); })
 258#define outw(v,p)       ({ __iowmb(); __raw_writew((__force __u16) \
 259                                        cpu_to_le16(v),__io(p)); })
 260#define outl(v,p)       ({ __iowmb(); __raw_writel((__force __u32) \
 261                                        cpu_to_le32(v),__io(p)); })
 262
 263#define inb(p)  ({ __u8 __v = __raw_readb(__io(p)); __iormb(); __v; })
 264#define inw(p)  ({ __u16 __v = le16_to_cpu((__force __le16) \
 265                        __raw_readw(__io(p))); __iormb(); __v; })
 266#define inl(p)  ({ __u32 __v = le32_to_cpu((__force __le32) \
 267                        __raw_readl(__io(p))); __iormb(); __v; })
 268
 269#define outsb(p,d,l)            __raw_writesb(__io(p),d,l)
 270#define outsw(p,d,l)            __raw_writesw(__io(p),d,l)
 271#define outsl(p,d,l)            __raw_writesl(__io(p),d,l)
 272
 273#define insb(p,d,l)             __raw_readsb(__io(p),d,l)
 274#define insw(p,d,l)             __raw_readsw(__io(p),d,l)
 275#define insl(p,d,l)             __raw_readsl(__io(p),d,l)
 276#endif
 277
 278/*
 279 * String version of IO memory access ops:
 280 */
 281extern void _memcpy_fromio(void *, const volatile void __iomem *, size_t);
 282extern void _memcpy_toio(volatile void __iomem *, const void *, size_t);
 283extern void _memset_io(volatile void __iomem *, int, size_t);
 284
 285#define mmiowb()
 286
 287/*
 288 *  Memory access primitives
 289 *  ------------------------
 290 *
 291 * These perform PCI memory accesses via an ioremap region.  They don't
 292 * take an address as such, but a cookie.
 293 *
 294 * Again, these are defined to perform little endian accesses.  See the
 295 * IO port primitives for more information.
 296 */
 297#ifndef readl
 298#define readb_relaxed(c) ({ u8  __r = __raw_readb(c); __r; })
 299#define readw_relaxed(c) ({ u16 __r = le16_to_cpu((__force __le16) \
 300                                        __raw_readw(c)); __r; })
 301#define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32) \
 302                                        __raw_readl(c)); __r; })
 303
 304#define writeb_relaxed(v,c)     __raw_writeb(v,c)
 305#define writew_relaxed(v,c)     __raw_writew((__force u16) cpu_to_le16(v),c)
 306#define writel_relaxed(v,c)     __raw_writel((__force u32) cpu_to_le32(v),c)
 307
 308#define readb(c)                ({ u8  __v = readb_relaxed(c); __iormb(); __v; })
 309#define readw(c)                ({ u16 __v = readw_relaxed(c); __iormb(); __v; })
 310#define readl(c)                ({ u32 __v = readl_relaxed(c); __iormb(); __v; })
 311
 312#define writeb(v,c)             ({ __iowmb(); writeb_relaxed(v,c); })
 313#define writew(v,c)             ({ __iowmb(); writew_relaxed(v,c); })
 314#define writel(v,c)             ({ __iowmb(); writel_relaxed(v,c); })
 315
 316#define readsb(p,d,l)           __raw_readsb(p,d,l)
 317#define readsw(p,d,l)           __raw_readsw(p,d,l)
 318#define readsl(p,d,l)           __raw_readsl(p,d,l)
 319
 320#define writesb(p,d,l)          __raw_writesb(p,d,l)
 321#define writesw(p,d,l)          __raw_writesw(p,d,l)
 322#define writesl(p,d,l)          __raw_writesl(p,d,l)
 323
 324#ifndef __ARMBE__
 325static inline void memset_io(volatile void __iomem *dst, unsigned c,
 326        size_t count)
 327{
 328        extern void mmioset(void *, unsigned int, size_t);
 329        mmioset((void __force *)dst, c, count);
 330}
 331#define memset_io(dst,c,count) memset_io(dst,c,count)
 332
 333static inline void memcpy_fromio(void *to, const volatile void __iomem *from,
 334        size_t count)
 335{
 336        extern void mmiocpy(void *, const void *, size_t);
 337        mmiocpy(to, (const void __force *)from, count);
 338}
 339#define memcpy_fromio(to,from,count) memcpy_fromio(to,from,count)
 340
 341static inline void memcpy_toio(volatile void __iomem *to, const void *from,
 342        size_t count)
 343{
 344        extern void mmiocpy(void *, const void *, size_t);
 345        mmiocpy((void __force *)to, from, count);
 346}
 347#define memcpy_toio(to,from,count) memcpy_toio(to,from,count)
 348
 349#else
 350#define memset_io(c,v,l)        _memset_io(c,(v),(l))
 351#define memcpy_fromio(a,c,l)    _memcpy_fromio((a),c,(l))
 352#define memcpy_toio(c,a,l)      _memcpy_toio(c,(a),(l))
 353#endif
 354
 355#endif  /* readl */
 356
 357/*
 358 * ioremap() and friends.
 359 *
 360 * ioremap() takes a resource address, and size.  Due to the ARM memory
 361 * types, it is important to use the correct ioremap() function as each
 362 * mapping has specific properties.
 363 *
 364 * Function             Memory type     Cacheability    Cache hint
 365 * ioremap()            Device          n/a             n/a
 366 * ioremap_nocache()    Device          n/a             n/a
 367 * ioremap_cache()      Normal          Writeback       Read allocate
 368 * ioremap_wc()         Normal          Non-cacheable   n/a
 369 * ioremap_wt()         Normal          Non-cacheable   n/a
 370 *
 371 * All device mappings have the following properties:
 372 * - no access speculation
 373 * - no repetition (eg, on return from an exception)
 374 * - number, order and size of accesses are maintained
 375 * - unaligned accesses are "unpredictable"
 376 * - writes may be delayed before they hit the endpoint device
 377 *
 378 * ioremap_nocache() is the same as ioremap() as there are too many device
 379 * drivers using this for device registers, and documentation which tells
 380 * people to use it for such for this to be any different.  This is not a
 381 * safe fallback for memory-like mappings, or memory regions where the
 382 * compiler may generate unaligned accesses - eg, via inlining its own
 383 * memcpy.
 384 *
 385 * All normal memory mappings have the following properties:
 386 * - reads can be repeated with no side effects
 387 * - repeated reads return the last value written
 388 * - reads can fetch additional locations without side effects
 389 * - writes can be repeated (in certain cases) with no side effects
 390 * - writes can be merged before accessing the target
 391 * - unaligned accesses can be supported
 392 * - ordering is not guaranteed without explicit dependencies or barrier
 393 *   instructions
 394 * - writes may be delayed before they hit the endpoint memory
 395 *
 396 * The cache hint is only a performance hint: CPUs may alias these hints.
 397 * Eg, a CPU not implementing read allocate but implementing write allocate
 398 * will provide a write allocate mapping instead.
 399 */
 400void __iomem *ioremap(resource_size_t res_cookie, size_t size);
 401#define ioremap ioremap
 402#define ioremap_nocache ioremap
 403
 404/*
 405 * Do not use ioremap_cache for mapping memory. Use memremap instead.
 406 */
 407void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size);
 408#define ioremap_cache ioremap_cache
 409
 410/*
 411 * Do not use ioremap_cached in new code. Provided for the benefit of
 412 * the pxa2xx-flash MTD driver only.
 413 */
 414void __iomem *ioremap_cached(resource_size_t res_cookie, size_t size);
 415
 416void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size);
 417#define ioremap_wc ioremap_wc
 418#define ioremap_wt ioremap_wc
 419
 420void iounmap(volatile void __iomem *iomem_cookie);
 421#define iounmap iounmap
 422
 423void *arch_memremap_wb(phys_addr_t phys_addr, size_t size);
 424#define arch_memremap_wb arch_memremap_wb
 425
 426/*
 427 * io{read,write}{16,32}be() macros
 428 */
 429#define ioread16be(p)           ({ __u16 __v = be16_to_cpu((__force __be16)__raw_readw(p)); __iormb(); __v; })
 430#define ioread32be(p)           ({ __u32 __v = be32_to_cpu((__force __be32)__raw_readl(p)); __iormb(); __v; })
 431
 432#define iowrite16be(v,p)        ({ __iowmb(); __raw_writew((__force __u16)cpu_to_be16(v), p); })
 433#define iowrite32be(v,p)        ({ __iowmb(); __raw_writel((__force __u32)cpu_to_be32(v), p); })
 434
 435#ifndef ioport_map
 436#define ioport_map ioport_map
 437extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
 438#endif
 439#ifndef ioport_unmap
 440#define ioport_unmap ioport_unmap
 441extern void ioport_unmap(void __iomem *addr);
 442#endif
 443
 444struct pci_dev;
 445
 446#define pci_iounmap pci_iounmap
 447extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
 448
 449/*
 450 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
 451 * access
 452 */
 453#define xlate_dev_mem_ptr(p)    __va(p)
 454
 455/*
 456 * Convert a virtual cached pointer to an uncached pointer
 457 */
 458#define xlate_dev_kmem_ptr(p)   p
 459
 460#include <asm-generic/io.h>
 461
 462/*
 463 * can the hardware map this into one segment or not, given no other
 464 * constraints.
 465 */
 466#define BIOVEC_MERGEABLE(vec1, vec2)    \
 467        ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 468
 469struct bio_vec;
 470extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 471                                      const struct bio_vec *vec2);
 472#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)                               \
 473        (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&                         \
 474         (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
 475
 476#ifdef CONFIG_MMU
 477#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 478extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
 479extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
 480extern int devmem_is_allowed(unsigned long pfn);
 481#endif
 482
 483/*
 484 * Register ISA memory and port locations for glibc iopl/inb/outb
 485 * emulation.
 486 */
 487extern void register_isa_ports(unsigned int mmio, unsigned int io,
 488                               unsigned int io_shift);
 489
 490#endif  /* __KERNEL__ */
 491#endif  /* __ASM_ARM_IO_H */
 492