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