linux/arch/mips/include/asm/io.h
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   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 1994, 1995 Waldorf GmbH
   7 * Copyright (C) 1994 - 2000, 06 Ralf Baechle
   8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   9 * Copyright (C) 2004, 2005  MIPS Technologies, Inc.  All rights reserved.
  10 *      Author: Maciej W. Rozycki <macro@mips.com>
  11 */
  12#ifndef _ASM_IO_H
  13#define _ASM_IO_H
  14
  15#include <linux/compiler.h>
  16#include <linux/kernel.h>
  17#include <linux/types.h>
  18#include <linux/irqflags.h>
  19
  20#include <asm/addrspace.h>
  21#include <asm/bug.h>
  22#include <asm/byteorder.h>
  23#include <asm/cpu.h>
  24#include <asm/cpu-features.h>
  25#include <asm-generic/iomap.h>
  26#include <asm/page.h>
  27#include <asm/pgtable-bits.h>
  28#include <asm/processor.h>
  29#include <asm/string.h>
  30
  31#include <ioremap.h>
  32#include <mangle-port.h>
  33
  34/*
  35 * Slowdown I/O port space accesses for antique hardware.
  36 */
  37#undef CONF_SLOWDOWN_IO
  38
  39/*
  40 * Raw operations are never swapped in software.  OTOH values that raw
  41 * operations are working on may or may not have been swapped by the bus
  42 * hardware.  An example use would be for flash memory that's used for
  43 * execute in place.
  44 */
  45# define __raw_ioswabb(a, x)    (x)
  46# define __raw_ioswabw(a, x)    (x)
  47# define __raw_ioswabl(a, x)    (x)
  48# define __raw_ioswabq(a, x)    (x)
  49# define ____raw_ioswabq(a, x)  (x)
  50
  51/* ioswab[bwlq], __mem_ioswab[bwlq] are defined in mangle-port.h */
  52
  53#define IO_SPACE_LIMIT 0xffff
  54
  55/*
  56 * On MIPS I/O ports are memory mapped, so we access them using normal
  57 * load/store instructions. mips_io_port_base is the virtual address to
  58 * which all ports are being mapped.  For sake of efficiency some code
  59 * assumes that this is an address that can be loaded with a single lui
  60 * instruction, so the lower 16 bits must be zero.  Should be true on
  61 * on any sane architecture; generic code does not use this assumption.
  62 */
  63extern const unsigned long mips_io_port_base;
  64
  65/*
  66 * Gcc will generate code to load the value of mips_io_port_base after each
  67 * function call which may be fairly wasteful in some cases.  So we don't
  68 * play quite by the book.  We tell gcc mips_io_port_base is a long variable
  69 * which solves the code generation issue.  Now we need to violate the
  70 * aliasing rules a little to make initialization possible and finally we
  71 * will need the barrier() to fight side effects of the aliasing chat.
  72 * This trickery will eventually collapse under gcc's optimizer.  Oh well.
  73 */
  74static inline void set_io_port_base(unsigned long base)
  75{
  76        * (unsigned long *) &mips_io_port_base = base;
  77        barrier();
  78}
  79
  80/*
  81 * Thanks to James van Artsdalen for a better timing-fix than
  82 * the two short jumps: using outb's to a nonexistent port seems
  83 * to guarantee better timings even on fast machines.
  84 *
  85 * On the other hand, I'd like to be sure of a non-existent port:
  86 * I feel a bit unsafe about using 0x80 (should be safe, though)
  87 *
  88 *              Linus
  89 *
  90 */
  91
  92#define __SLOW_DOWN_IO \
  93        __asm__ __volatile__( \
  94                "sb\t$0,0x80(%0)" \
  95                : : "r" (mips_io_port_base));
  96
  97#ifdef CONF_SLOWDOWN_IO
  98#ifdef REALLY_SLOW_IO
  99#define SLOW_DOWN_IO { __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; }
 100#else
 101#define SLOW_DOWN_IO __SLOW_DOWN_IO
 102#endif
 103#else
 104#define SLOW_DOWN_IO
 105#endif
 106
 107/*
 108 *     virt_to_phys    -       map virtual addresses to physical
 109 *     @address: address to remap
 110 *
 111 *     The returned physical address is the physical (CPU) mapping for
 112 *     the memory address given. It is only valid to use this function on
 113 *     addresses directly mapped or allocated via kmalloc.
 114 *
 115 *     This function does not give bus mappings for DMA transfers. In
 116 *     almost all conceivable cases a device driver should not be using
 117 *     this function
 118 */
 119static inline unsigned long virt_to_phys(volatile const void *address)
 120{
 121        return __pa(address);
 122}
 123
 124/*
 125 *     phys_to_virt    -       map physical address to virtual
 126 *     @address: address to remap
 127 *
 128 *     The returned virtual address is a current CPU mapping for
 129 *     the memory address given. It is only valid to use this function on
 130 *     addresses that have a kernel mapping
 131 *
 132 *     This function does not handle bus mappings for DMA transfers. In
 133 *     almost all conceivable cases a device driver should not be using
 134 *     this function
 135 */
 136static inline void * phys_to_virt(unsigned long address)
 137{
 138        return (void *)(address + PAGE_OFFSET - PHYS_OFFSET);
 139}
 140
 141/*
 142 * ISA I/O bus memory addresses are 1:1 with the physical address.
 143 */
 144static inline unsigned long isa_virt_to_bus(volatile void * address)
 145{
 146        return (unsigned long)address - PAGE_OFFSET;
 147}
 148
 149static inline void * isa_bus_to_virt(unsigned long address)
 150{
 151        return (void *)(address + PAGE_OFFSET);
 152}
 153
 154#define isa_page_to_bus page_to_phys
 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 for 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 * Change "struct page" to physical address.
 167 */
 168#define page_to_phys(page)      ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
 169
 170extern void __iomem * __ioremap(phys_addr_t offset, phys_addr_t size, unsigned long flags);
 171extern void __iounmap(const volatile void __iomem *addr);
 172
 173#ifndef CONFIG_PCI
 174struct pci_dev;
 175static inline void pci_iounmap(struct pci_dev *dev, void __iomem *addr) {}
 176#endif
 177
 178static inline void __iomem * __ioremap_mode(phys_addr_t offset, unsigned long size,
 179        unsigned long flags)
 180{
 181        void __iomem *addr = plat_ioremap(offset, size, flags);
 182
 183        if (addr)
 184                return addr;
 185
 186#define __IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
 187
 188        if (cpu_has_64bit_addresses) {
 189                u64 base = UNCAC_BASE;
 190
 191                /*
 192                 * R10000 supports a 2 bit uncached attribute therefore
 193                 * UNCAC_BASE may not equal IO_BASE.
 194                 */
 195                if (flags == _CACHE_UNCACHED)
 196                        base = (u64) IO_BASE;
 197                return (void __iomem *) (unsigned long) (base + offset);
 198        } else if (__builtin_constant_p(offset) &&
 199                   __builtin_constant_p(size) && __builtin_constant_p(flags)) {
 200                phys_addr_t phys_addr, last_addr;
 201
 202                phys_addr = fixup_bigphys_addr(offset, size);
 203
 204                /* Don't allow wraparound or zero size. */
 205                last_addr = phys_addr + size - 1;
 206                if (!size || last_addr < phys_addr)
 207                        return NULL;
 208
 209                /*
 210                 * Map uncached objects in the low 512MB of address
 211                 * space using KSEG1.
 212                 */
 213                if (__IS_LOW512(phys_addr) && __IS_LOW512(last_addr) &&
 214                    flags == _CACHE_UNCACHED)
 215                        return (void __iomem *)
 216                                (unsigned long)CKSEG1ADDR(phys_addr);
 217        }
 218
 219        return __ioremap(offset, size, flags);
 220
 221#undef __IS_LOW512
 222}
 223
 224/*
 225 * ioremap     -   map bus memory into CPU space
 226 * @offset:    bus address of the memory
 227 * @size:      size of the resource to map
 228 *
 229 * ioremap performs a platform specific sequence of operations to
 230 * make bus memory CPU accessible via the readb/readw/readl/writeb/
 231 * writew/writel functions and the other mmio helpers. The returned
 232 * address is not guaranteed to be usable directly as a virtual
 233 * address.
 234 */
 235#define ioremap(offset, size)                                           \
 236        __ioremap_mode((offset), (size), _CACHE_UNCACHED)
 237
 238/*
 239 * ioremap_nocache     -   map bus memory into CPU space
 240 * @offset:    bus address of the memory
 241 * @size:      size of the resource to map
 242 *
 243 * ioremap_nocache performs a platform specific sequence of operations to
 244 * make bus memory CPU accessible via the readb/readw/readl/writeb/
 245 * writew/writel functions and the other mmio helpers. The returned
 246 * address is not guaranteed to be usable directly as a virtual
 247 * address.
 248 *
 249 * This version of ioremap ensures that the memory is marked uncachable
 250 * on the CPU as well as honouring existing caching rules from things like
 251 * the PCI bus. Note that there are other caches and buffers on many
 252 * busses. In particular driver authors should read up on PCI writes
 253 *
 254 * It's useful if some control registers are in such an area and
 255 * write combining or read caching is not desirable:
 256 */
 257#define ioremap_nocache(offset, size)                                   \
 258        __ioremap_mode((offset), (size), _CACHE_UNCACHED)
 259
 260/*
 261 * ioremap_cachable -   map bus memory into CPU space
 262 * @offset:         bus address of the memory
 263 * @size:           size of the resource to map
 264 *
 265 * ioremap_nocache performs a platform specific sequence of operations to
 266 * make bus memory CPU accessible via the readb/readw/readl/writeb/
 267 * writew/writel functions and the other mmio helpers. The returned
 268 * address is not guaranteed to be usable directly as a virtual
 269 * address.
 270 *
 271 * This version of ioremap ensures that the memory is marked cachable by
 272 * the CPU.  Also enables full write-combining.  Useful for some
 273 * memory-like regions on I/O busses.
 274 */
 275#define ioremap_cachable(offset, size)                                  \
 276        __ioremap_mode((offset), (size), _page_cachable_default)
 277
 278/*
 279 * These two are MIPS specific ioremap variant.  ioremap_cacheable_cow
 280 * requests a cachable mapping, ioremap_uncached_accelerated requests a
 281 * mapping using the uncached accelerated mode which isn't supported on
 282 * all processors.
 283 */
 284#define ioremap_cacheable_cow(offset, size)                             \
 285        __ioremap_mode((offset), (size), _CACHE_CACHABLE_COW)
 286#define ioremap_uncached_accelerated(offset, size)                      \
 287        __ioremap_mode((offset), (size), _CACHE_UNCACHED_ACCELERATED)
 288
 289static inline void iounmap(const volatile void __iomem *addr)
 290{
 291        if (plat_iounmap(addr))
 292                return;
 293
 294#define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
 295
 296        if (cpu_has_64bit_addresses ||
 297            (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
 298                return;
 299
 300        __iounmap(addr);
 301
 302#undef __IS_KSEG1
 303}
 304
 305#ifdef CONFIG_CPU_CAVIUM_OCTEON
 306#define war_octeon_io_reorder_wmb()             wmb()
 307#else
 308#define war_octeon_io_reorder_wmb()             do { } while (0)
 309#endif
 310
 311#define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq)                     \
 312                                                                        \
 313static inline void pfx##write##bwlq(type val,                           \
 314                                    volatile void __iomem *mem)         \
 315{                                                                       \
 316        volatile type *__mem;                                           \
 317        type __val;                                                     \
 318                                                                        \
 319        war_octeon_io_reorder_wmb();                                    \
 320                                                                        \
 321        __mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));    \
 322                                                                        \
 323        __val = pfx##ioswab##bwlq(__mem, val);                          \
 324                                                                        \
 325        if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
 326                *__mem = __val;                                         \
 327        else if (cpu_has_64bits) {                                      \
 328                unsigned long __flags;                                  \
 329                type __tmp;                                             \
 330                                                                        \
 331                if (irq)                                                \
 332                        local_irq_save(__flags);                        \
 333                __asm__ __volatile__(                                   \
 334                        ".set   arch=r4000"     "\t\t# __writeq""\n\t"  \
 335                        "dsll32 %L0, %L0, 0"                    "\n\t"  \
 336                        "dsrl32 %L0, %L0, 0"                    "\n\t"  \
 337                        "dsll32 %M0, %M0, 0"                    "\n\t"  \
 338                        "or     %L0, %L0, %M0"                  "\n\t"  \
 339                        "sd     %L0, %2"                        "\n\t"  \
 340                        ".set   mips0"                          "\n"    \
 341                        : "=r" (__tmp)                                  \
 342                        : "0" (__val), "m" (*__mem));                   \
 343                if (irq)                                                \
 344                        local_irq_restore(__flags);                     \
 345        } else                                                          \
 346                BUG();                                                  \
 347}                                                                       \
 348                                                                        \
 349static inline type pfx##read##bwlq(const volatile void __iomem *mem)    \
 350{                                                                       \
 351        volatile type *__mem;                                           \
 352        type __val;                                                     \
 353                                                                        \
 354        __mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));    \
 355                                                                        \
 356        if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
 357                __val = *__mem;                                         \
 358        else if (cpu_has_64bits) {                                      \
 359                unsigned long __flags;                                  \
 360                                                                        \
 361                if (irq)                                                \
 362                        local_irq_save(__flags);                        \
 363                __asm__ __volatile__(                                   \
 364                        ".set   arch=r4000"     "\t\t# __readq" "\n\t"  \
 365                        "ld     %L0, %1"                        "\n\t"  \
 366                        "dsra32 %M0, %L0, 0"                    "\n\t"  \
 367                        "sll    %L0, %L0, 0"                    "\n\t"  \
 368                        ".set   mips0"                          "\n"    \
 369                        : "=r" (__val)                                  \
 370                        : "m" (*__mem));                                \
 371                if (irq)                                                \
 372                        local_irq_restore(__flags);                     \
 373        } else {                                                        \
 374                __val = 0;                                              \
 375                BUG();                                                  \
 376        }                                                               \
 377                                                                        \
 378        return pfx##ioswab##bwlq(__mem, __val);                         \
 379}
 380
 381#define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, p, slow)                 \
 382                                                                        \
 383static inline void pfx##out##bwlq##p(type val, unsigned long port)      \
 384{                                                                       \
 385        volatile type *__addr;                                          \
 386        type __val;                                                     \
 387                                                                        \
 388        war_octeon_io_reorder_wmb();                                    \
 389                                                                        \
 390        __addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
 391                                                                        \
 392        __val = pfx##ioswab##bwlq(__addr, val);                         \
 393                                                                        \
 394        /* Really, we want this to be atomic */                         \
 395        BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));             \
 396                                                                        \
 397        *__addr = __val;                                                \
 398        slow;                                                           \
 399}                                                                       \
 400                                                                        \
 401static inline type pfx##in##bwlq##p(unsigned long port)                 \
 402{                                                                       \
 403        volatile type *__addr;                                          \
 404        type __val;                                                     \
 405                                                                        \
 406        __addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
 407                                                                        \
 408        BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));             \
 409                                                                        \
 410        __val = *__addr;                                                \
 411        slow;                                                           \
 412                                                                        \
 413        return pfx##ioswab##bwlq(__addr, __val);                        \
 414}
 415
 416#define __BUILD_MEMORY_PFX(bus, bwlq, type)                             \
 417                                                                        \
 418__BUILD_MEMORY_SINGLE(bus, bwlq, type, 1)
 419
 420#define BUILDIO_MEM(bwlq, type)                                         \
 421                                                                        \
 422__BUILD_MEMORY_PFX(__raw_, bwlq, type)                                  \
 423__BUILD_MEMORY_PFX(, bwlq, type)                                        \
 424__BUILD_MEMORY_PFX(__mem_, bwlq, type)                                  \
 425
 426BUILDIO_MEM(b, u8)
 427BUILDIO_MEM(w, u16)
 428BUILDIO_MEM(l, u32)
 429BUILDIO_MEM(q, u64)
 430
 431#define __BUILD_IOPORT_PFX(bus, bwlq, type)                             \
 432        __BUILD_IOPORT_SINGLE(bus, bwlq, type, ,)                       \
 433        __BUILD_IOPORT_SINGLE(bus, bwlq, type, _p, SLOW_DOWN_IO)
 434
 435#define BUILDIO_IOPORT(bwlq, type)                                      \
 436        __BUILD_IOPORT_PFX(, bwlq, type)                                \
 437        __BUILD_IOPORT_PFX(__mem_, bwlq, type)
 438
 439BUILDIO_IOPORT(b, u8)
 440BUILDIO_IOPORT(w, u16)
 441BUILDIO_IOPORT(l, u32)
 442#ifdef CONFIG_64BIT
 443BUILDIO_IOPORT(q, u64)
 444#endif
 445
 446#define __BUILDIO(bwlq, type)                                           \
 447                                                                        \
 448__BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 0)
 449
 450__BUILDIO(q, u64)
 451
 452#define readb_relaxed                   readb
 453#define readw_relaxed                   readw
 454#define readl_relaxed                   readl
 455#define readq_relaxed                   readq
 456
 457#define writeb_relaxed                  writeb
 458#define writew_relaxed                  writew
 459#define writel_relaxed                  writel
 460#define writeq_relaxed                  writeq
 461
 462#define readb_be(addr)                                                  \
 463        __raw_readb((__force unsigned *)(addr))
 464#define readw_be(addr)                                                  \
 465        be16_to_cpu(__raw_readw((__force unsigned *)(addr)))
 466#define readl_be(addr)                                                  \
 467        be32_to_cpu(__raw_readl((__force unsigned *)(addr)))
 468#define readq_be(addr)                                                  \
 469        be64_to_cpu(__raw_readq((__force unsigned *)(addr)))
 470
 471#define writeb_be(val, addr)                                            \
 472        __raw_writeb((val), (__force unsigned *)(addr))
 473#define writew_be(val, addr)                                            \
 474        __raw_writew(cpu_to_be16((val)), (__force unsigned *)(addr))
 475#define writel_be(val, addr)                                            \
 476        __raw_writel(cpu_to_be32((val)), (__force unsigned *)(addr))
 477#define writeq_be(val, addr)                                            \
 478        __raw_writeq(cpu_to_be64((val)), (__force unsigned *)(addr))
 479
 480/*
 481 * Some code tests for these symbols
 482 */
 483#define readq                           readq
 484#define writeq                          writeq
 485
 486#define __BUILD_MEMORY_STRING(bwlq, type)                               \
 487                                                                        \
 488static inline void writes##bwlq(volatile void __iomem *mem,             \
 489                                const void *addr, unsigned int count)   \
 490{                                                                       \
 491        const volatile type *__addr = addr;                             \
 492                                                                        \
 493        while (count--) {                                               \
 494                __mem_write##bwlq(*__addr, mem);                        \
 495                __addr++;                                               \
 496        }                                                               \
 497}                                                                       \
 498                                                                        \
 499static inline void reads##bwlq(volatile void __iomem *mem, void *addr,  \
 500                               unsigned int count)                      \
 501{                                                                       \
 502        volatile type *__addr = addr;                                   \
 503                                                                        \
 504        while (count--) {                                               \
 505                *__addr = __mem_read##bwlq(mem);                        \
 506                __addr++;                                               \
 507        }                                                               \
 508}
 509
 510#define __BUILD_IOPORT_STRING(bwlq, type)                               \
 511                                                                        \
 512static inline void outs##bwlq(unsigned long port, const void *addr,     \
 513                              unsigned int count)                       \
 514{                                                                       \
 515        const volatile type *__addr = addr;                             \
 516                                                                        \
 517        while (count--) {                                               \
 518                __mem_out##bwlq(*__addr, port);                         \
 519                __addr++;                                               \
 520        }                                                               \
 521}                                                                       \
 522                                                                        \
 523static inline void ins##bwlq(unsigned long port, void *addr,            \
 524                             unsigned int count)                        \
 525{                                                                       \
 526        volatile type *__addr = addr;                                   \
 527                                                                        \
 528        while (count--) {                                               \
 529                *__addr = __mem_in##bwlq(port);                         \
 530                __addr++;                                               \
 531        }                                                               \
 532}
 533
 534#define BUILDSTRING(bwlq, type)                                         \
 535                                                                        \
 536__BUILD_MEMORY_STRING(bwlq, type)                                       \
 537__BUILD_IOPORT_STRING(bwlq, type)
 538
 539BUILDSTRING(b, u8)
 540BUILDSTRING(w, u16)
 541BUILDSTRING(l, u32)
 542#ifdef CONFIG_64BIT
 543BUILDSTRING(q, u64)
 544#endif
 545
 546
 547#ifdef CONFIG_CPU_CAVIUM_OCTEON
 548#define mmiowb() wmb()
 549#else
 550/* Depends on MIPS II instruction set */
 551#define mmiowb() asm volatile ("sync" ::: "memory")
 552#endif
 553
 554static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
 555{
 556        memset((void __force *) addr, val, count);
 557}
 558static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
 559{
 560        memcpy(dst, (void __force *) src, count);
 561}
 562static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
 563{
 564        memcpy((void __force *) dst, src, count);
 565}
 566
 567/*
 568 * The caches on some architectures aren't dma-coherent and have need to
 569 * handle this in software.  There are three types of operations that
 570 * can be applied to dma buffers.
 571 *
 572 *  - dma_cache_wback_inv(start, size) makes caches and coherent by
 573 *    writing the content of the caches back to memory, if necessary.
 574 *    The function also invalidates the affected part of the caches as
 575 *    necessary before DMA transfers from outside to memory.
 576 *  - dma_cache_wback(start, size) makes caches and coherent by
 577 *    writing the content of the caches back to memory, if necessary.
 578 *    The function also invalidates the affected part of the caches as
 579 *    necessary before DMA transfers from outside to memory.
 580 *  - dma_cache_inv(start, size) invalidates the affected parts of the
 581 *    caches.  Dirty lines of the caches may be written back or simply
 582 *    be discarded.  This operation is necessary before dma operations
 583 *    to the memory.
 584 *
 585 * This API used to be exported; it now is for arch code internal use only.
 586 */
 587#if defined(CONFIG_DMA_NONCOHERENT) || defined(CONFIG_DMA_MAYBE_COHERENT)
 588
 589extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
 590extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
 591extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
 592
 593#define dma_cache_wback_inv(start, size)        _dma_cache_wback_inv(start, size)
 594#define dma_cache_wback(start, size)            _dma_cache_wback(start, size)
 595#define dma_cache_inv(start, size)              _dma_cache_inv(start, size)
 596
 597#else /* Sane hardware */
 598
 599#define dma_cache_wback_inv(start,size) \
 600        do { (void) (start); (void) (size); } while (0)
 601#define dma_cache_wback(start,size)     \
 602        do { (void) (start); (void) (size); } while (0)
 603#define dma_cache_inv(start,size)       \
 604        do { (void) (start); (void) (size); } while (0)
 605
 606#endif /* CONFIG_DMA_NONCOHERENT || CONFIG_DMA_MAYBE_COHERENT */
 607
 608/*
 609 * Read a 32-bit register that requires a 64-bit read cycle on the bus.
 610 * Avoid interrupt mucking, just adjust the address for 4-byte access.
 611 * Assume the addresses are 8-byte aligned.
 612 */
 613#ifdef __MIPSEB__
 614#define __CSR_32_ADJUST 4
 615#else
 616#define __CSR_32_ADJUST 0
 617#endif
 618
 619#define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
 620#define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
 621
 622/*
 623 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
 624 * access
 625 */
 626#define xlate_dev_mem_ptr(p)    __va(p)
 627
 628/*
 629 * Convert a virtual cached pointer to an uncached pointer
 630 */
 631#define xlate_dev_kmem_ptr(p)   p
 632
 633#endif /* _ASM_IO_H */
 634