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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
  19 #include <asm/addrspace.h>
  20 #include <asm/byteorder.h>
  21 #include <asm/cpu.h>
  22 #include <asm/cpu-features.h>
  23 #include <asm-generic/iomap.h>
  24 #include <asm/page.h>
  25 #include <asm/pgtable-bits.h>
  26 #include <asm/processor.h>
  27 #include <asm/string.h>
  28
  29 #include <ioremap.h>
  30 #include <mangle-port.h>
  31
  32 /*
  33  * Slowdown I/O port space accesses for antique hardware.
  34  */
  35 #undef CONF_SLOWDOWN_IO
  36
  37 /*
  38  * Raw operations are never swapped in software.  OTOH values that raw
  39  * operations are working on may or may not have been swapped by the bus
  40  * hardware.  An example use would be for flash memory that's used for
  41  * execute in place.
  42  */
  43 # define __raw_ioswabb(a, x)    (x)
  44 # define __raw_ioswabw(a, x)    (x)
  45 # define __raw_ioswabl(a, x)    (x)
  46 # define __raw_ioswabq(a, x)    (x)
  47 # define ____raw_ioswabq(a, x)  (x)
  48
  49 /* ioswab[bwlq], __mem_ioswab[bwlq] are defined in mangle-port.h */
  50
  51 #define IO_SPACE_LIMIT 0xffff
  52
  53 /*
  54  * On MIPS I/O ports are memory mapped, so we access them using normal
  55  * load/store instructions. mips_io_port_base is the virtual address to
  56  * which all ports are being mapped.  For sake of efficiency some code
  57  * assumes that this is an address that can be loaded with a single lui
  58  * instruction, so the lower 16 bits must be zero.  Should be true on
  59  * on any sane architecture; generic code does not use this assumption.
  60  */
  61 extern const unsigned long mips_io_port_base;
  62
  63 /*
  64  * Gcc will generate code to load the value of mips_io_port_base after each
  65  * function call which may be fairly wasteful in some cases.  So we don't
  66  * play quite by the book.  We tell gcc mips_io_port_base is a long variable
  67  * which solves the code generation issue.  Now we need to violate the
  68  * aliasing rules a little to make initialization possible and finally we
  69  * will need the barrier() to fight side effects of the aliasing chat.
  70  * This trickery will eventually collapse under gcc's optimizer.  Oh well.
  71  */
  72 static inline void set_io_port_base(unsigned long base)
  73 {
  74         * (unsigned long *) &mips_io_port_base = base;
  75         barrier();
  76 }
  77
  78 /*
  79  * Thanks to James van Artsdalen for a better timing-fix than
  80  * the two short jumps: using outb's to a nonexistent port seems
  81  * to guarantee better timings even on fast machines.
  82  *
  83  * On the other hand, I'd like to be sure of a non-existent port:
  84  * I feel a bit unsafe about using 0x80 (should be safe, though)
  85  *
  86  *              Linus
  87  *
  88  */
  89
  90 #define __SLOW_DOWN_IO \
  91         __asm__ __volatile__( \
  92                 "sb\t$0,0x80(%0)" \
  93                 : : "r" (mips_io_port_base));
  94
  95 #ifdef CONF_SLOWDOWN_IO
  96 #ifdef REALLY_SLOW_IO
  97 #define SLOW_DOWN_IO { __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; }
  98 #else
  99 #define SLOW_DOWN_IO __SLOW_DOWN_IO
 100 #endif
 101 #else
 102 #define SLOW_DOWN_IO
 103 #endif
 104
 105 /*
 106  *     virt_to_phys    -       map virtual addresses to physical
 107  *     @address: address to remap
 108  *
 109  *     The returned physical address is the physical (CPU) mapping for
 110  *     the memory address given. It is only valid to use this function on
 111  *     addresses directly mapped or allocated via kmalloc.
 112  *
 113  *     This function does not give bus mappings for DMA transfers. In
 114  *     almost all conceivable cases a device driver should not be using
 115  *     this function
 116  */
 117 static inline unsigned long virt_to_phys(volatile const void *address)
 118 {
 119         return (unsigned long)address - PAGE_OFFSET + PHYS_OFFSET;
 120 }
 121
 122 /*
 123  *     phys_to_virt    -       map physical address to virtual
 124  *     @address: address to remap
 125  *
 126  *     The returned virtual address is a current CPU mapping for
 127  *     the memory address given. It is only valid to use this function on
 128  *     addresses that have a kernel mapping
 129  *
 130  *     This function does not handle bus mappings for DMA transfers. In
 131  *     almost all conceivable cases a device driver should not be using
 132  *     this function
 133  */
 134 static inline void * phys_to_virt(unsigned long address)
 135 {
 136         return (void *)(address + PAGE_OFFSET - PHYS_OFFSET);
 137 }
 138
 139 /*
 140  * ISA I/O bus memory addresses are 1:1 with the physical address.
 141  */
 142 static inline unsigned long isa_virt_to_bus(volatile void * address)
 143 {
 144         return (unsigned long)address - PAGE_OFFSET;
 145 }
 146
 147 static inline void * isa_bus_to_virt(unsigned long address)
 148 {
 149         return (void *)(address + PAGE_OFFSET);
 150 }
 151
 152 #define isa_page_to_bus page_to_phys
 153
 154 /*
 155  * However PCI ones are not necessarily 1:1 and therefore these interfaces
 156  * are forbidden in portable PCI drivers.
 157  *
 158  * Allow them for x86 for legacy drivers, though.
 159  */
 160 #define virt_to_bus virt_to_phys
 161 #define bus_to_virt phys_to_virt
 162
 163 /*
 164  * Change "struct page" to physical address.
 165  */
 166 #define page_to_phys(page)      ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
 167
 168 extern void __iomem * __ioremap(phys_t offset, phys_t size, unsigned long flags);
 169 extern void __iounmap(const volatile void __iomem *addr);
 170
 171 static inline void __iomem * __ioremap_mode(phys_t offset, unsigned long size,
 172         unsigned long flags)
 173 {
 174         void __iomem *addr = plat_ioremap(offset, size, flags);
 175
 176         if (addr)
 177                 return addr;
 178
 179 #define __IS_LOW512(addr) (!((phys_t)(addr) & (phys_t) ~0x1fffffffULL))
 180
 181         if (cpu_has_64bit_addresses) {
 182                 u64 base = UNCAC_BASE;
 183
 184                 /*
 185                  * R10000 supports a 2 bit uncached attribute therefore
 186                  * UNCAC_BASE may not equal IO_BASE.
 187                  */
 188                 if (flags == _CACHE_UNCACHED)
 189                         base = (u64) IO_BASE;
 190                 return (void __iomem *) (unsigned long) (base + offset);
 191         } else if (__builtin_constant_p(offset) &&
 192                    __builtin_constant_p(size) && __builtin_constant_p(flags)) {
 193                 phys_t phys_addr, last_addr;
 194
 195                 phys_addr = fixup_bigphys_addr(offset, size);
 196
 197                 /* Don't allow wraparound or zero size. */
 198                 last_addr = phys_addr + size - 1;
 199                 if (!size || last_addr < phys_addr)
 200                         return NULL;
 201
 202                 /*
 203                  * Map uncached objects in the low 512MB of address
 204                  * space using KSEG1.
 205                  */
 206                 if (__IS_LOW512(phys_addr) && __IS_LOW512(last_addr) &&
 207                     flags == _CACHE_UNCACHED)
 208                         return (void __iomem *)
 209                                 (unsigned long)CKSEG1ADDR(phys_addr);
 210         }
 211
 212         return __ioremap(offset, size, flags);
 213
 214 #undef __IS_LOW512
 215 }
 216
 217 /*
 218  * ioremap     -   map bus memory into CPU space
 219  * @offset:    bus address of the memory
 220  * @size:      size of the resource to map
 221  *
 222  * ioremap performs a platform specific sequence of operations to
 223  * make bus memory CPU accessible via the readb/readw/readl/writeb/
 224  * writew/writel functions and the other mmio helpers. The returned
 225  * address is not guaranteed to be usable directly as a virtual
 226  * address.
 227  */
 228 #define ioremap(offset, size)                                           \
 229         __ioremap_mode((offset), (size), _CACHE_UNCACHED)
 230
 231 /*
 232  * ioremap_nocache     -   map bus memory into CPU space
 233  * @offset:    bus address of the memory
 234  * @size:      size of the resource to map
 235  *
 236  * ioremap_nocache performs a platform specific sequence of operations to
 237  * make bus memory CPU accessible via the readb/readw/readl/writeb/
 238  * writew/writel functions and the other mmio helpers. The returned
 239  * address is not guaranteed to be usable directly as a virtual
 240  * address.
 241  *
 242  * This version of ioremap ensures that the memory is marked uncachable
 243  * on the CPU as well as honouring existing caching rules from things like
 244  * the PCI bus. Note that there are other caches and buffers on many
 245  * busses. In paticular driver authors should read up on PCI writes
 246  *
 247  * It's useful if some control registers are in such an area and
 248  * write combining or read caching is not desirable:
 249  */
 250 #define ioremap_nocache(offset, size)                                   \
 251         __ioremap_mode((offset), (size), _CACHE_UNCACHED)
 252
 253 /*
 254  * ioremap_cachable -   map bus memory into CPU space
 255  * @offset:         bus address of the memory
 256  * @size:           size of the resource to map
 257  *
 258  * ioremap_nocache performs a platform specific sequence of operations to
 259  * make bus memory CPU accessible via the readb/readw/readl/writeb/
 260  * writew/writel functions and the other mmio helpers. The returned
 261  * address is not guaranteed to be usable directly as a virtual
 262  * address.
 263  *
 264  * This version of ioremap ensures that the memory is marked cachable by
 265  * the CPU.  Also enables full write-combining.  Useful for some
 266  * memory-like regions on I/O busses.
 267  */
 268 #define ioremap_cachable(offset, size)                                  \
 269         __ioremap_mode((offset), (size), _page_cachable_default)
 270
 271 /*
 272  * These two are MIPS specific ioremap variant.  ioremap_cacheable_cow
 273  * requests a cachable mapping, ioremap_uncached_accelerated requests a
 274  * mapping using the uncached accelerated mode which isn't supported on
 275  * all processors.
 276  */
 277 #define ioremap_cacheable_cow(offset, size)                             \
 278         __ioremap_mode((offset), (size), _CACHE_CACHABLE_COW)
 279 #define ioremap_uncached_accelerated(offset, size)                      \
 280         __ioremap_mode((offset), (size), _CACHE_UNCACHED_ACCELERATED)
 281
 282 static inline void iounmap(const volatile void __iomem *addr)
 283 {
 284         if (plat_iounmap(addr))
 285                 return;
 286
 287 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
 288
 289         if (cpu_has_64bit_addresses ||
 290             (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
 291                 return;
 292
 293         __iounmap(addr);
 294
 295 #undef __IS_KSEG1
 296 }
 297
 298 #ifdef CONFIG_CPU_CAVIUM_OCTEON
 299 #define war_octeon_io_reorder_wmb()             wmb()
 300 #else
 301 #define war_octeon_io_reorder_wmb()             do { } while (0)
 302 #endif
 303
 304 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq)                     \
 305                                                                         \
 306 static inline void pfx##write##bwlq(type val,                           \
 307                                     volatile void __iomem *mem)         \
 308 {                                                                       \
 309         volatile type *__mem;                                           \
 310         type __val;                                                     \
 311                                                                         \
 312         war_octeon_io_reorder_wmb();                                    \
 313                                                                         \
 314         __mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));    \
 315                                                                         \
 316         __val = pfx##ioswab##bwlq(__mem, val);                          \
 317                                                                         \
 318         if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
 319                 *__mem = __val;                                         \
 320         else if (cpu_has_64bits) {                                      \
 321                 unsigned long __flags;                                  \
 322                 type __tmp;                                             \
 323                                                                         \
 324                 if (irq)                                                \
 325                         local_irq_save(__flags);                        \
 326                 __asm__ __volatile__(                                   \
 327                         ".set   mips3"          "\t\t# __writeq""\n\t"  \
 328                         "dsll32 %L0, %L0, 0"                    "\n\t"  \
 329                         "dsrl32 %L0, %L0, 0"                    "\n\t"  \
 330                         "dsll32 %M0, %M0, 0"                    "\n\t"  \
 331                         "or     %L0, %L0, %M0"                  "\n\t"  \
 332                         "sd     %L0, %2"                        "\n\t"  \
 333                         ".set   mips0"                          "\n"    \
 334                         : "=r" (__tmp)                                  \
 335                         : "0" (__val), "m" (*__mem));                   \
 336                 if (irq)                                                \
 337                         local_irq_restore(__flags);                     \
 338         } else                                                          \
 339                 BUG();                                                  \
 340 }                                                                       \
 341                                                                         \
 342 static inline type pfx##read##bwlq(const volatile void __iomem *mem)    \
 343 {                                                                       \
 344         volatile type *__mem;                                           \
 345         type __val;                                                     \
 346                                                                         \
 347         __mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));    \
 348                                                                         \
 349         if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
 350                 __val = *__mem;                                         \
 351         else if (cpu_has_64bits) {                                      \
 352                 unsigned long __flags;                                  \
 353                                                                         \
 354                 if (irq)                                                \
 355                         local_irq_save(__flags);                        \
 356                 __asm__ __volatile__(                                   \
 357                         ".set   mips3"          "\t\t# __readq" "\n\t"  \
 358                         "ld     %L0, %1"                        "\n\t"  \
 359                         "dsra32 %M0, %L0, 0"                    "\n\t"  \
 360                         "sll    %L0, %L0, 0"                    "\n\t"  \
 361                         ".set   mips0"                          "\n"    \
 362                         : "=r" (__val)                                  \
 363                         : "m" (*__mem));                                \
 364                 if (irq)                                                \
 365                         local_irq_restore(__flags);                     \
 366         } else {                                                        \
 367                 __val = 0;                                              \
 368                 BUG();                                                  \
 369         }                                                               \
 370                                                                         \
 371         return pfx##ioswab##bwlq(__mem, __val);                         \
 372 }
 373
 374 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, p, slow)                 \
 375                                                                         \
 376 static inline void pfx##out##bwlq##p(type val, unsigned long port)      \
 377 {                                                                       \
 378         volatile type *__addr;                                          \
 379         type __val;                                                     \
 380                                                                         \
 381         war_octeon_io_reorder_wmb();                                    \
 382                                                                         \
 383         __addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
 384                                                                         \
 385         __val = pfx##ioswab##bwlq(__addr, val);                         \
 386                                                                         \
 387         /* Really, we want this to be atomic */                         \
 388         BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));             \
 389                                                                         \
 390         *__addr = __val;                                                \
 391         slow;                                                           \
 392 }                                                                       \
 393                                                                         \
 394 static inline type pfx##in##bwlq##p(unsigned long port)                 \
 395 {                                                                       \
 396         volatile type *__addr;                                          \
 397         type __val;                                                     \
 398                                                                         \
 399         __addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
 400                                                                         \
 401         BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));             \
 402                                                                         \
 403         __val = *__addr;                                                \
 404         slow;                                                           \
 405                                                                         \
 406         return pfx##ioswab##bwlq(__addr, __val);                        \
 407 }
 408
 409 #define __BUILD_MEMORY_PFX(bus, bwlq, type)                             \
 410                                                                         \
 411 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1)
 412
 413 #define BUILDIO_MEM(bwlq, type)                                         \
 414                                                                         \
 415 __BUILD_MEMORY_PFX(__raw_, bwlq, type)                                  \
 416 __BUILD_MEMORY_PFX(, bwlq, type)                                        \
 417 __BUILD_MEMORY_PFX(__mem_, bwlq, type)                                  \
 418
 419 BUILDIO_MEM(b, u8)
 420 BUILDIO_MEM(w, u16)
 421 BUILDIO_MEM(l, u32)
 422 BUILDIO_MEM(q, u64)
 423
 424 #define __BUILD_IOPORT_PFX(bus, bwlq, type)                             \
 425         __BUILD_IOPORT_SINGLE(bus, bwlq, type, ,)                       \
 426         __BUILD_IOPORT_SINGLE(bus, bwlq, type, _p, SLOW_DOWN_IO)
 427
 428 #define BUILDIO_IOPORT(bwlq, type)                                      \
 429         __BUILD_IOPORT_PFX(, bwlq, type)                                \
 430         __BUILD_IOPORT_PFX(__mem_, bwlq, type)
 431
 432 BUILDIO_IOPORT(b, u8)
 433 BUILDIO_IOPORT(w, u16)
 434 BUILDIO_IOPORT(l, u32)
 435 #ifdef CONFIG_64BIT
 436 BUILDIO_IOPORT(q, u64)
 437 #endif
 438
 439 #define __BUILDIO(bwlq, type)                                           \
 440                                                                         \
 441 __BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 0)
 442
 443 __BUILDIO(q, u64)
 444
 445 #define readb_relaxed                   readb
 446 #define readw_relaxed                   readw
 447 #define readl_relaxed                   readl
 448 #define readq_relaxed                   readq
 449
 450 /*
 451  * Some code tests for these symbols
 452  */
 453 #define readq                           readq
 454 #define writeq                          writeq
 455
 456 #define __BUILD_MEMORY_STRING(bwlq, type)                               \
 457                                                                         \
 458 static inline void writes##bwlq(volatile void __iomem *mem,             \
 459                                 const void *addr, unsigned int count)   \
 460 {                                                                       \
 461         const volatile type *__addr = addr;                             \
 462                                                                         \
 463         while (count--) {                                               \
 464                 __mem_write##bwlq(*__addr, mem);                        \
 465                 __addr++;                                               \
 466         }                                                               \
 467 }                                                                       \
 468                                                                         \
 469 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,  \
 470                                unsigned int count)                      \
 471 {                                                                       \
 472         volatile type *__addr = addr;                                   \
 473                                                                         \
 474         while (count--) {                                               \
 475                 *__addr = __mem_read##bwlq(mem);                        \
 476                 __addr++;                                               \
 477         }                                                               \
 478 }
 479
 480 #define __BUILD_IOPORT_STRING(bwlq, type)                               \
 481                                                                         \
 482 static inline void outs##bwlq(unsigned long port, const void *addr,     \
 483                               unsigned int count)                       \
 484 {                                                                       \
 485         const volatile type *__addr = addr;                             \
 486                                                                         \
 487         while (count--) {                                               \
 488                 __mem_out##bwlq(*__addr, port);                         \
 489                 __addr++;                                               \
 490         }                                                               \
 491 }                                                                       \
 492                                                                         \
 493 static inline void ins##bwlq(unsigned long port, void *addr,            \
 494                              unsigned int count)                        \
 495 {                                                                       \
 496         volatile type *__addr = addr;                                   \
 497                                                                         \
 498         while (count--) {                                               \
 499                 *__addr = __mem_in##bwlq(port);                         \
 500                 __addr++;                                               \
 501         }                                                               \
 502 }
 503
 504 #define BUILDSTRING(bwlq, type)                                         \
 505                                                                         \
 506 __BUILD_MEMORY_STRING(bwlq, type)                                       \
 507 __BUILD_IOPORT_STRING(bwlq, type)
 508
 509 BUILDSTRING(b, u8)
 510 BUILDSTRING(w, u16)
 511 BUILDSTRING(l, u32)
 512 #ifdef CONFIG_64BIT
 513 BUILDSTRING(q, u64)
 514 #endif
 515
 516
 517 #ifdef CONFIG_CPU_CAVIUM_OCTEON
 518 #define mmiowb() wmb()
 519 #else
 520 /* Depends on MIPS II instruction set */
 521 #define mmiowb() asm volatile ("sync" ::: "memory")
 522 #endif
 523
 524 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
 525 {
 526         memset((void __force *) addr, val, count);
 527 }
 528 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
 529 {
 530         memcpy(dst, (void __force *) src, count);
 531 }
 532 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
 533 {
 534         memcpy((void __force *) dst, src, count);
 535 }
 536
 537 /*
 538  * The caches on some architectures aren't dma-coherent and have need to
 539  * handle this in software.  There are three types of operations that
 540  * can be applied to dma buffers.
 541  *
 542  *  - dma_cache_wback_inv(start, size) makes caches and coherent by
 543  *    writing the content of the caches back to memory, if necessary.
 544  *    The function also invalidates the affected part of the caches as
 545  *    necessary before DMA transfers from outside to memory.
 546  *  - dma_cache_wback(start, size) makes caches and coherent by
 547  *    writing the content of the caches back to memory, if necessary.
 548  *    The function also invalidates the affected part of the caches as
 549  *    necessary before DMA transfers from outside to memory.
 550  *  - dma_cache_inv(start, size) invalidates the affected parts of the
 551  *    caches.  Dirty lines of the caches may be written back or simply
 552  *    be discarded.  This operation is necessary before dma operations
 553  *    to the memory.
 554  *
 555  * This API used to be exported; it now is for arch code internal use only.
 556  */
 557 #ifdef CONFIG_DMA_NONCOHERENT
 558
 559 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
 560 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
 561 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
 562
 563 #define dma_cache_wback_inv(start, size)        _dma_cache_wback_inv(start, size)
 564 #define dma_cache_wback(start, size)            _dma_cache_wback(start, size)
 565 #define dma_cache_inv(start, size)              _dma_cache_inv(start, size)
 566
 567 #else /* Sane hardware */
 568
 569 #define dma_cache_wback_inv(start,size) \
 570         do { (void) (start); (void) (size); } while (0)
 571 #define dma_cache_wback(start,size)     \
 572         do { (void) (start); (void) (size); } while (0)
 573 #define dma_cache_inv(start,size)       \
 574         do { (void) (start); (void) (size); } while (0)
 575
 576 #endif /* CONFIG_DMA_NONCOHERENT */
 577
 578 /*
 579  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
 580  * Avoid interrupt mucking, just adjust the address for 4-byte access.
 581  * Assume the addresses are 8-byte aligned.
 582  */
 583 #ifdef __MIPSEB__
 584 #define __CSR_32_ADJUST 4
 585 #else
 586 #define __CSR_32_ADJUST 0
 587 #endif
 588
 589 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
 590 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
 591
 592 /*
 593  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
 594  * access
 595  */
 596 #define xlate_dev_mem_ptr(p)    __va(p)
 597
 598 /*
 599  * Convert a virtual cached pointer to an uncached pointer
 600  */
 601 #define xlate_dev_kmem_ptr(p)   p
 602
 603 #endif /* _ASM_IO_H */