arch/mips/include/asm/io.h

   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  */
  63 extern 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  */
  74 static 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  */
 119 static 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  */
 136 static 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  */
 144 static inline unsigned long isa_virt_to_bus(volatile void * address)
 145 {
 146         return (unsigned long)address - PAGE_OFFSET;
 147 }
 148
 149 static 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
 170 extern void __iomem * __ioremap(phys_addr_t offset, phys_addr_t size, unsigned long flags);
 171 extern void __iounmap(const volatile void __iomem *addr);
 172
 173 #ifndef CONFIG_PCI
 174 struct pci_dev;
 175 static inline void pci_iounmap(struct pci_dev *dev, void __iomem *addr) {}
 176 #endif
 177
 178 static 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 #define ioremap_uc ioremap_nocache
 260
 261 /*
 262  * ioremap_cachable -   map bus memory into CPU space
 263  * @offset:         bus address of the memory
 264  * @size:           size of the resource to map
 265  *
 266  * ioremap_nocache performs a platform specific sequence of operations to
 267  * make bus memory CPU accessible via the readb/readw/readl/writeb/
 268  * writew/writel functions and the other mmio helpers. The returned
 269  * address is not guaranteed to be usable directly as a virtual
 270  * address.
 271  *
 272  * This version of ioremap ensures that the memory is marked cachable by
 273  * the CPU.  Also enables full write-combining.  Useful for some
 274  * memory-like regions on I/O busses.
 275  */
 276 #define ioremap_cachable(offset, size)                                  \
 277         __ioremap_mode((offset), (size), _page_cachable_default)
 278 #define ioremap_cache ioremap_cachable
 279
 280 /*
 281  * These two are MIPS specific ioremap variant.  ioremap_cacheable_cow
 282  * requests a cachable mapping, ioremap_uncached_accelerated requests a
 283  * mapping using the uncached accelerated mode which isn't supported on
 284  * all processors.
 285  */
 286 #define ioremap_cacheable_cow(offset, size)                             \
 287         __ioremap_mode((offset), (size), _CACHE_CACHABLE_COW)
 288 #define ioremap_uncached_accelerated(offset, size)                      \
 289         __ioremap_mode((offset), (size), _CACHE_UNCACHED_ACCELERATED)
 290
 291 static inline void iounmap(const volatile void __iomem *addr)
 292 {
 293         if (plat_iounmap(addr))
 294                 return;
 295
 296 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
 297
 298         if (cpu_has_64bit_addresses ||
 299             (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
 300                 return;
 301
 302         __iounmap(addr);
 303
 304 #undef __IS_KSEG1
 305 }
 306
 307 #if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_LOONGSON3_ENHANCEMENT)
 308 #define war_io_reorder_wmb()            wmb()
 309 #else
 310 #define war_io_reorder_wmb()            barrier()
 311 #endif
 312
 313 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq)                     \
 314                                                                         \
 315 static inline void pfx##write##bwlq(type val,                           \
 316                                     volatile void __iomem *mem)         \
 317 {                                                                       \
 318         volatile type *__mem;                                           \
 319         type __val;                                                     \
 320                                                                         \
 321         war_io_reorder_wmb();                                   \
 322                                                                         \
 323         __mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));    \
 324                                                                         \
 325         __val = pfx##ioswab##bwlq(__mem, val);                          \
 326                                                                         \
 327         if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
 328                 *__mem = __val;                                         \
 329         else if (cpu_has_64bits) {                                      \
 330                 unsigned long __flags;                                  \
 331                 type __tmp;                                             \
 332                                                                         \
 333                 if (irq)                                                \
 334                         local_irq_save(__flags);                        \
 335                 __asm__ __volatile__(                                   \
 336                         ".set   arch=r4000"     "\t\t# __writeq""\n\t"  \
 337                         "dsll32 %L0, %L0, 0"                    "\n\t"  \
 338                         "dsrl32 %L0, %L0, 0"                    "\n\t"  \
 339                         "dsll32 %M0, %M0, 0"                    "\n\t"  \
 340                         "or     %L0, %L0, %M0"                  "\n\t"  \
 341                         "sd     %L0, %2"                        "\n\t"  \
 342                         ".set   mips0"                          "\n"    \
 343                         : "=r" (__tmp)                                  \
 344                         : "0" (__val), "m" (*__mem));                   \
 345                 if (irq)                                                \
 346                         local_irq_restore(__flags);                     \
 347         } else                                                          \
 348                 BUG();                                                  \
 349 }                                                                       \
 350                                                                         \
 351 static inline type pfx##read##bwlq(const volatile void __iomem *mem)    \
 352 {                                                                       \
 353         volatile type *__mem;                                           \
 354         type __val;                                                     \
 355                                                                         \
 356         __mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));    \
 357                                                                         \
 358         if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
 359                 __val = *__mem;                                         \
 360         else if (cpu_has_64bits) {                                      \
 361                 unsigned long __flags;                                  \
 362                                                                         \
 363                 if (irq)                                                \
 364                         local_irq_save(__flags);                        \
 365                 __asm__ __volatile__(                                   \
 366                         ".set   arch=r4000"     "\t\t# __readq" "\n\t"  \
 367                         "ld     %L0, %1"                        "\n\t"  \
 368                         "dsra32 %M0, %L0, 0"                    "\n\t"  \
 369                         "sll    %L0, %L0, 0"                    "\n\t"  \
 370                         ".set   mips0"                          "\n"    \
 371                         : "=r" (__val)                                  \
 372                         : "m" (*__mem));                                \
 373                 if (irq)                                                \
 374                         local_irq_restore(__flags);                     \
 375         } else {                                                        \
 376                 __val = 0;                                              \
 377                 BUG();                                                  \
 378         }                                                               \
 379                                                                         \
 380         /* prevent prefetching of coherent DMA data prematurely */      \
 381         rmb();                                                          \
 382         return pfx##ioswab##bwlq(__mem, __val);                         \
 383 }
 384
 385 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, p, slow)                 \
 386                                                                         \
 387 static inline void pfx##out##bwlq##p(type val, unsigned long port)      \
 388 {                                                                       \
 389         volatile type *__addr;                                          \
 390         type __val;                                                     \
 391                                                                         \
 392         war_io_reorder_wmb();                                   \
 393                                                                         \
 394         __addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
 395                                                                         \
 396         __val = pfx##ioswab##bwlq(__addr, val);                         \
 397                                                                         \
 398         /* Really, we want this to be atomic */                         \
 399         BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));             \
 400                                                                         \
 401         *__addr = __val;                                                \
 402         slow;                                                           \
 403 }                                                                       \
 404                                                                         \
 405 static inline type pfx##in##bwlq##p(unsigned long port)                 \
 406 {                                                                       \
 407         volatile type *__addr;                                          \
 408         type __val;                                                     \
 409                                                                         \
 410         __addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
 411                                                                         \
 412         BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));             \
 413                                                                         \
 414         __val = *__addr;                                                \
 415         slow;                                                           \
 416                                                                         \
 417         return pfx##ioswab##bwlq(__addr, __val);                        \
 418 }
 419
 420 #define __BUILD_MEMORY_PFX(bus, bwlq, type)                             \
 421                                                                         \
 422 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1)
 423
 424 #define BUILDIO_MEM(bwlq, type)                                         \
 425                                                                         \
 426 __BUILD_MEMORY_PFX(__raw_, bwlq, type)                                  \
 427 __BUILD_MEMORY_PFX(, bwlq, type)                                        \
 428 __BUILD_MEMORY_PFX(__mem_, bwlq, type)                                  \
 429
 430 BUILDIO_MEM(b, u8)
 431 BUILDIO_MEM(w, u16)
 432 BUILDIO_MEM(l, u32)
 433 BUILDIO_MEM(q, u64)
 434
 435 #define __BUILD_IOPORT_PFX(bus, bwlq, type)                             \
 436         __BUILD_IOPORT_SINGLE(bus, bwlq, type, ,)                       \
 437         __BUILD_IOPORT_SINGLE(bus, bwlq, type, _p, SLOW_DOWN_IO)
 438
 439 #define BUILDIO_IOPORT(bwlq, type)                                      \
 440         __BUILD_IOPORT_PFX(, bwlq, type)                                \
 441         __BUILD_IOPORT_PFX(__mem_, bwlq, type)
 442
 443 BUILDIO_IOPORT(b, u8)
 444 BUILDIO_IOPORT(w, u16)
 445 BUILDIO_IOPORT(l, u32)
 446 #ifdef CONFIG_64BIT
 447 BUILDIO_IOPORT(q, u64)
 448 #endif
 449
 450 #define __BUILDIO(bwlq, type)                                           \
 451                                                                         \
 452 __BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 0)
 453
 454 __BUILDIO(q, u64)
 455
 456 #define readb_relaxed                   readb
 457 #define readw_relaxed                   readw
 458 #define readl_relaxed                   readl
 459 #define readq_relaxed                   readq
 460
 461 #define writeb_relaxed                  writeb
 462 #define writew_relaxed                  writew
 463 #define writel_relaxed                  writel
 464 #define writeq_relaxed                  writeq
 465
 466 #define readb_be(addr)                                                  \
 467         __raw_readb((__force unsigned *)(addr))
 468 #define readw_be(addr)                                                  \
 469         be16_to_cpu(__raw_readw((__force unsigned *)(addr)))
 470 #define readl_be(addr)                                                  \
 471         be32_to_cpu(__raw_readl((__force unsigned *)(addr)))
 472 #define readq_be(addr)                                                  \
 473         be64_to_cpu(__raw_readq((__force unsigned *)(addr)))
 474
 475 #define writeb_be(val, addr)                                            \
 476         __raw_writeb((val), (__force unsigned *)(addr))
 477 #define writew_be(val, addr)                                            \
 478         __raw_writew(cpu_to_be16((val)), (__force unsigned *)(addr))
 479 #define writel_be(val, addr)                                            \
 480         __raw_writel(cpu_to_be32((val)), (__force unsigned *)(addr))
 481 #define writeq_be(val, addr)                                            \
 482         __raw_writeq(cpu_to_be64((val)), (__force unsigned *)(addr))
 483
 484 /*
 485  * Some code tests for these symbols
 486  */
 487 #define readq                           readq
 488 #define writeq                          writeq
 489
 490 #define __BUILD_MEMORY_STRING(bwlq, type)                               \
 491                                                                         \
 492 static inline void writes##bwlq(volatile void __iomem *mem,             \
 493                                 const void *addr, unsigned int count)   \
 494 {                                                                       \
 495         const volatile type *__addr = addr;                             \
 496                                                                         \
 497         while (count--) {                                               \
 498                 __mem_write##bwlq(*__addr, mem);                        \
 499                 __addr++;                                               \
 500         }                                                               \
 501 }                                                                       \
 502                                                                         \
 503 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,  \
 504                                unsigned int count)                      \
 505 {                                                                       \
 506         volatile type *__addr = addr;                                   \
 507                                                                         \
 508         while (count--) {                                               \
 509                 *__addr = __mem_read##bwlq(mem);                        \
 510                 __addr++;                                               \
 511         }                                                               \
 512 }
 513
 514 #define __BUILD_IOPORT_STRING(bwlq, type)                               \
 515                                                                         \
 516 static inline void outs##bwlq(unsigned long port, const void *addr,     \
 517                               unsigned int count)                       \
 518 {                                                                       \
 519         const volatile type *__addr = addr;                             \
 520                                                                         \
 521         while (count--) {                                               \
 522                 __mem_out##bwlq(*__addr, port);                         \
 523                 __addr++;                                               \
 524         }                                                               \
 525 }                                                                       \
 526                                                                         \
 527 static inline void ins##bwlq(unsigned long port, void *addr,            \
 528                              unsigned int count)                        \
 529 {                                                                       \
 530         volatile type *__addr = addr;                                   \
 531                                                                         \
 532         while (count--) {                                               \
 533                 *__addr = __mem_in##bwlq(port);                         \
 534                 __addr++;                                               \
 535         }                                                               \
 536 }
 537
 538 #define BUILDSTRING(bwlq, type)                                         \
 539                                                                         \
 540 __BUILD_MEMORY_STRING(bwlq, type)                                       \
 541 __BUILD_IOPORT_STRING(bwlq, type)
 542
 543 BUILDSTRING(b, u8)
 544 BUILDSTRING(w, u16)
 545 BUILDSTRING(l, u32)
 546 #ifdef CONFIG_64BIT
 547 BUILDSTRING(q, u64)
 548 #endif
 549
 550
 551 #ifdef CONFIG_CPU_CAVIUM_OCTEON
 552 #define mmiowb() wmb()
 553 #else
 554 /* Depends on MIPS II instruction set */
 555 #define mmiowb() asm volatile ("sync" ::: "memory")
 556 #endif
 557
 558 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
 559 {
 560         memset((void __force *) addr, val, count);
 561 }
 562 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
 563 {
 564         memcpy(dst, (void __force *) src, count);
 565 }
 566 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
 567 {
 568         memcpy((void __force *) dst, src, count);
 569 }
 570
 571 /*
 572  * The caches on some architectures aren't dma-coherent and have need to
 573  * handle this in software.  There are three types of operations that
 574  * can be applied to dma buffers.
 575  *
 576  *  - dma_cache_wback_inv(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_wback(start, size) makes caches and coherent by
 581  *    writing the content of the caches back to memory, if necessary.
 582  *    The function also invalidates the affected part of the caches as
 583  *    necessary before DMA transfers from outside to memory.
 584  *  - dma_cache_inv(start, size) invalidates the affected parts of the
 585  *    caches.  Dirty lines of the caches may be written back or simply
 586  *    be discarded.  This operation is necessary before dma operations
 587  *    to the memory.
 588  *
 589  * This API used to be exported; it now is for arch code internal use only.
 590  */
 591 #if defined(CONFIG_DMA_NONCOHERENT) || defined(CONFIG_DMA_MAYBE_COHERENT)
 592
 593 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
 594 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
 595 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
 596
 597 #define dma_cache_wback_inv(start, size)        _dma_cache_wback_inv(start, size)
 598 #define dma_cache_wback(start, size)            _dma_cache_wback(start, size)
 599 #define dma_cache_inv(start, size)              _dma_cache_inv(start, size)
 600
 601 #else /* Sane hardware */
 602
 603 #define dma_cache_wback_inv(start,size) \
 604         do { (void) (start); (void) (size); } while (0)
 605 #define dma_cache_wback(start,size)     \
 606         do { (void) (start); (void) (size); } while (0)
 607 #define dma_cache_inv(start,size)       \
 608         do { (void) (start); (void) (size); } while (0)
 609
 610 #endif /* CONFIG_DMA_NONCOHERENT || CONFIG_DMA_MAYBE_COHERENT */
 611
 612 /*
 613  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
 614  * Avoid interrupt mucking, just adjust the address for 4-byte access.
 615  * Assume the addresses are 8-byte aligned.
 616  */
 617 #ifdef __MIPSEB__
 618 #define __CSR_32_ADJUST 4
 619 #else
 620 #define __CSR_32_ADJUST 0
 621 #endif
 622
 623 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
 624 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
 625
 626 /*
 627  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
 628  * access
 629  */
 630 #define xlate_dev_mem_ptr(p)    __va(p)
 631
 632 /*
 633  * Convert a virtual cached pointer to an uncached pointer
 634  */
 635 #define xlate_dev_kmem_ptr(p)   p
 636
 637 void __ioread64_copy(void *to, const void __iomem *from, size_t count);
 638
 639 #endif /* _ASM_IO_H */