xref: /openbmc/linux/arch/mips/include/asm/io.h (revision dea54fba)
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()		do { } while (0)
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 	return pfx##ioswab##bwlq(__mem, __val);				\
381 }
382 
383 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, p, slow)			\
384 									\
385 static inline void pfx##out##bwlq##p(type val, unsigned long port)	\
386 {									\
387 	volatile type *__addr;						\
388 	type __val;							\
389 									\
390 	war_io_reorder_wmb();					\
391 									\
392 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
393 									\
394 	__val = pfx##ioswab##bwlq(__addr, val);				\
395 									\
396 	/* Really, we want this to be atomic */				\
397 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
398 									\
399 	*__addr = __val;						\
400 	slow;								\
401 }									\
402 									\
403 static inline type pfx##in##bwlq##p(unsigned long port)			\
404 {									\
405 	volatile type *__addr;						\
406 	type __val;							\
407 									\
408 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
409 									\
410 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
411 									\
412 	__val = *__addr;						\
413 	slow;								\
414 									\
415 	return pfx##ioswab##bwlq(__addr, __val);			\
416 }
417 
418 #define __BUILD_MEMORY_PFX(bus, bwlq, type)				\
419 									\
420 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1)
421 
422 #define BUILDIO_MEM(bwlq, type)						\
423 									\
424 __BUILD_MEMORY_PFX(__raw_, bwlq, type)					\
425 __BUILD_MEMORY_PFX(, bwlq, type)					\
426 __BUILD_MEMORY_PFX(__mem_, bwlq, type)					\
427 
428 BUILDIO_MEM(b, u8)
429 BUILDIO_MEM(w, u16)
430 BUILDIO_MEM(l, u32)
431 BUILDIO_MEM(q, u64)
432 
433 #define __BUILD_IOPORT_PFX(bus, bwlq, type)				\
434 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, ,)			\
435 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, _p, SLOW_DOWN_IO)
436 
437 #define BUILDIO_IOPORT(bwlq, type)					\
438 	__BUILD_IOPORT_PFX(, bwlq, type)				\
439 	__BUILD_IOPORT_PFX(__mem_, bwlq, type)
440 
441 BUILDIO_IOPORT(b, u8)
442 BUILDIO_IOPORT(w, u16)
443 BUILDIO_IOPORT(l, u32)
444 #ifdef CONFIG_64BIT
445 BUILDIO_IOPORT(q, u64)
446 #endif
447 
448 #define __BUILDIO(bwlq, type)						\
449 									\
450 __BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 0)
451 
452 __BUILDIO(q, u64)
453 
454 #define readb_relaxed			readb
455 #define readw_relaxed			readw
456 #define readl_relaxed			readl
457 #define readq_relaxed			readq
458 
459 #define writeb_relaxed			writeb
460 #define writew_relaxed			writew
461 #define writel_relaxed			writel
462 #define writeq_relaxed			writeq
463 
464 #define readb_be(addr)							\
465 	__raw_readb((__force unsigned *)(addr))
466 #define readw_be(addr)							\
467 	be16_to_cpu(__raw_readw((__force unsigned *)(addr)))
468 #define readl_be(addr)							\
469 	be32_to_cpu(__raw_readl((__force unsigned *)(addr)))
470 #define readq_be(addr)							\
471 	be64_to_cpu(__raw_readq((__force unsigned *)(addr)))
472 
473 #define writeb_be(val, addr)						\
474 	__raw_writeb((val), (__force unsigned *)(addr))
475 #define writew_be(val, addr)						\
476 	__raw_writew(cpu_to_be16((val)), (__force unsigned *)(addr))
477 #define writel_be(val, addr)						\
478 	__raw_writel(cpu_to_be32((val)), (__force unsigned *)(addr))
479 #define writeq_be(val, addr)						\
480 	__raw_writeq(cpu_to_be64((val)), (__force unsigned *)(addr))
481 
482 /*
483  * Some code tests for these symbols
484  */
485 #define readq				readq
486 #define writeq				writeq
487 
488 #define __BUILD_MEMORY_STRING(bwlq, type)				\
489 									\
490 static inline void writes##bwlq(volatile void __iomem *mem,		\
491 				const void *addr, unsigned int count)	\
492 {									\
493 	const volatile type *__addr = addr;				\
494 									\
495 	while (count--) {						\
496 		__mem_write##bwlq(*__addr, mem);			\
497 		__addr++;						\
498 	}								\
499 }									\
500 									\
501 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,	\
502 			       unsigned int count)			\
503 {									\
504 	volatile type *__addr = addr;					\
505 									\
506 	while (count--) {						\
507 		*__addr = __mem_read##bwlq(mem);			\
508 		__addr++;						\
509 	}								\
510 }
511 
512 #define __BUILD_IOPORT_STRING(bwlq, type)				\
513 									\
514 static inline void outs##bwlq(unsigned long port, const void *addr,	\
515 			      unsigned int count)			\
516 {									\
517 	const volatile type *__addr = addr;				\
518 									\
519 	while (count--) {						\
520 		__mem_out##bwlq(*__addr, port);				\
521 		__addr++;						\
522 	}								\
523 }									\
524 									\
525 static inline void ins##bwlq(unsigned long port, void *addr,		\
526 			     unsigned int count)			\
527 {									\
528 	volatile type *__addr = addr;					\
529 									\
530 	while (count--) {						\
531 		*__addr = __mem_in##bwlq(port);				\
532 		__addr++;						\
533 	}								\
534 }
535 
536 #define BUILDSTRING(bwlq, type)						\
537 									\
538 __BUILD_MEMORY_STRING(bwlq, type)					\
539 __BUILD_IOPORT_STRING(bwlq, type)
540 
541 BUILDSTRING(b, u8)
542 BUILDSTRING(w, u16)
543 BUILDSTRING(l, u32)
544 #ifdef CONFIG_64BIT
545 BUILDSTRING(q, u64)
546 #endif
547 
548 
549 #ifdef CONFIG_CPU_CAVIUM_OCTEON
550 #define mmiowb() wmb()
551 #else
552 /* Depends on MIPS II instruction set */
553 #define mmiowb() asm volatile ("sync" ::: "memory")
554 #endif
555 
556 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
557 {
558 	memset((void __force *) addr, val, count);
559 }
560 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
561 {
562 	memcpy(dst, (void __force *) src, count);
563 }
564 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
565 {
566 	memcpy((void __force *) dst, src, count);
567 }
568 
569 /*
570  * The caches on some architectures aren't dma-coherent and have need to
571  * handle this in software.  There are three types of operations that
572  * can be applied to dma buffers.
573  *
574  *  - dma_cache_wback_inv(start, size) makes caches and coherent by
575  *    writing the content of the caches back to memory, if necessary.
576  *    The function also invalidates the affected part of the caches as
577  *    necessary before DMA transfers from outside to memory.
578  *  - dma_cache_wback(start, size) makes caches and coherent by
579  *    writing the content of the caches back to memory, if necessary.
580  *    The function also invalidates the affected part of the caches as
581  *    necessary before DMA transfers from outside to memory.
582  *  - dma_cache_inv(start, size) invalidates the affected parts of the
583  *    caches.  Dirty lines of the caches may be written back or simply
584  *    be discarded.  This operation is necessary before dma operations
585  *    to the memory.
586  *
587  * This API used to be exported; it now is for arch code internal use only.
588  */
589 #if defined(CONFIG_DMA_NONCOHERENT) || defined(CONFIG_DMA_MAYBE_COHERENT)
590 
591 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
592 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
593 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
594 
595 #define dma_cache_wback_inv(start, size)	_dma_cache_wback_inv(start, size)
596 #define dma_cache_wback(start, size)		_dma_cache_wback(start, size)
597 #define dma_cache_inv(start, size)		_dma_cache_inv(start, size)
598 
599 #else /* Sane hardware */
600 
601 #define dma_cache_wback_inv(start,size) \
602 	do { (void) (start); (void) (size); } while (0)
603 #define dma_cache_wback(start,size)	\
604 	do { (void) (start); (void) (size); } while (0)
605 #define dma_cache_inv(start,size)	\
606 	do { (void) (start); (void) (size); } while (0)
607 
608 #endif /* CONFIG_DMA_NONCOHERENT || CONFIG_DMA_MAYBE_COHERENT */
609 
610 /*
611  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
612  * Avoid interrupt mucking, just adjust the address for 4-byte access.
613  * Assume the addresses are 8-byte aligned.
614  */
615 #ifdef __MIPSEB__
616 #define __CSR_32_ADJUST 4
617 #else
618 #define __CSR_32_ADJUST 0
619 #endif
620 
621 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
622 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
623 
624 /*
625  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
626  * access
627  */
628 #define xlate_dev_mem_ptr(p)	__va(p)
629 
630 /*
631  * Convert a virtual cached pointer to an uncached pointer
632  */
633 #define xlate_dev_kmem_ptr(p)	p
634 
635 void __ioread64_copy(void *to, const void __iomem *from, size_t count);
636 
637 #endif /* _ASM_IO_H */
638