xref: /linux/arch/mips/include/asm/io.h (revision 96ac6d435100450f0565708d9b885ea2a7400e0a)
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 #define ARCH_HAS_IOREMAP_WC
16 
17 #include <linux/compiler.h>
18 #include <linux/kernel.h>
19 #include <linux/types.h>
20 #include <linux/irqflags.h>
21 
22 #include <asm/addrspace.h>
23 #include <asm/barrier.h>
24 #include <asm/bug.h>
25 #include <asm/byteorder.h>
26 #include <asm/cpu.h>
27 #include <asm/cpu-features.h>
28 #include <asm-generic/iomap.h>
29 #include <asm/page.h>
30 #include <asm/pgtable-bits.h>
31 #include <asm/processor.h>
32 #include <asm/string.h>
33 
34 #include <ioremap.h>
35 #include <mangle-port.h>
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 # define __relaxed_ioswabb ioswabb
50 # define __relaxed_ioswabw ioswabw
51 # define __relaxed_ioswabl ioswabl
52 # define __relaxed_ioswabq ioswabq
53 
54 /* ioswab[bwlq], __mem_ioswab[bwlq] are defined in mangle-port.h */
55 
56 #define IO_SPACE_LIMIT 0xffff
57 
58 /*
59  * On MIPS I/O ports are memory mapped, so we access them using normal
60  * load/store instructions. mips_io_port_base is the virtual address to
61  * which all ports are being mapped.  For sake of efficiency some code
62  * assumes that this is an address that can be loaded with a single lui
63  * instruction, so the lower 16 bits must be zero.  Should be true on
64  * on any sane architecture; generic code does not use this assumption.
65  */
66 extern const unsigned long mips_io_port_base;
67 
68 /*
69  * Gcc will generate code to load the value of mips_io_port_base after each
70  * function call which may be fairly wasteful in some cases.  So we don't
71  * play quite by the book.  We tell gcc mips_io_port_base is a long variable
72  * which solves the code generation issue.  Now we need to violate the
73  * aliasing rules a little to make initialization possible and finally we
74  * will need the barrier() to fight side effects of the aliasing chat.
75  * This trickery will eventually collapse under gcc's optimizer.  Oh well.
76  */
77 static inline void set_io_port_base(unsigned long base)
78 {
79 	* (unsigned long *) &mips_io_port_base = base;
80 	barrier();
81 }
82 
83 /*
84  * Provide the necessary definitions for generic iomap. We make use of
85  * mips_io_port_base for iomap(), but we don't reserve any low addresses for
86  * use with I/O ports.
87  */
88 
89 #define HAVE_ARCH_PIO_SIZE
90 #define PIO_OFFSET	mips_io_port_base
91 #define PIO_MASK	IO_SPACE_LIMIT
92 #define PIO_RESERVED	0x0UL
93 
94 /*
95  * Enforce in-order execution of data I/O.  In the MIPS architecture
96  * these are equivalent to corresponding platform-specific memory
97  * barriers defined in <asm/barrier.h>.  API pinched from PowerPC,
98  * with sync additionally defined.
99  */
100 #define iobarrier_rw() mb()
101 #define iobarrier_r() rmb()
102 #define iobarrier_w() wmb()
103 #define iobarrier_sync() iob()
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 __pa(address);
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 virt_to_phys(address);
145 }
146 
147 static inline void *isa_bus_to_virt(unsigned long address)
148 {
149 	return phys_to_virt(address);
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_addr_t offset, phys_addr_t size, unsigned long flags);
169 extern void __iounmap(const volatile void __iomem *addr);
170 
171 static inline void __iomem * __ioremap_mode(phys_addr_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_addr_t)(addr) & (phys_addr_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_addr_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_prot     -   map bus memory into CPU space
219  * @offset:    bus address of the memory
220  * @size:      size of the resource to map
221 
222  * ioremap_prot gives the caller control over cache coherency attributes (CCA)
223  */
224 static inline void __iomem *ioremap_prot(phys_addr_t offset,
225 		unsigned long size, unsigned long prot_val) {
226 	return __ioremap_mode(offset, size, prot_val & _CACHE_MASK);
227 }
228 
229 /*
230  * ioremap     -   map bus memory into CPU space
231  * @offset:    bus address of the memory
232  * @size:      size of the resource to map
233  *
234  * ioremap performs a platform specific sequence of operations to
235  * make bus memory CPU accessible via the readb/readw/readl/writeb/
236  * writew/writel functions and the other mmio helpers. The returned
237  * address is not guaranteed to be usable directly as a virtual
238  * address.
239  */
240 #define ioremap(offset, size)						\
241 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
242 
243 /*
244  * ioremap_nocache     -   map bus memory into CPU space
245  * @offset:    bus address of the memory
246  * @size:      size of the resource to map
247  *
248  * ioremap_nocache performs a platform specific sequence of operations to
249  * make bus memory CPU accessible via the readb/readw/readl/writeb/
250  * writew/writel functions and the other mmio helpers. The returned
251  * address is not guaranteed to be usable directly as a virtual
252  * address.
253  *
254  * This version of ioremap ensures that the memory is marked uncachable
255  * on the CPU as well as honouring existing caching rules from things like
256  * the PCI bus. Note that there are other caches and buffers on many
257  * busses. In particular driver authors should read up on PCI writes
258  *
259  * It's useful if some control registers are in such an area and
260  * write combining or read caching is not desirable:
261  */
262 #define ioremap_nocache(offset, size)					\
263 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
264 #define ioremap_uc ioremap_nocache
265 
266 /*
267  * ioremap_cachable -	map bus memory into CPU space
268  * @offset:	    bus address of the memory
269  * @size:	    size of the resource to map
270  *
271  * ioremap_nocache performs a platform specific sequence of operations to
272  * make bus memory CPU accessible via the readb/readw/readl/writeb/
273  * writew/writel functions and the other mmio helpers. The returned
274  * address is not guaranteed to be usable directly as a virtual
275  * address.
276  *
277  * This version of ioremap ensures that the memory is marked cachable by
278  * the CPU.  Also enables full write-combining.	 Useful for some
279  * memory-like regions on I/O busses.
280  */
281 #define ioremap_cachable(offset, size)					\
282 	__ioremap_mode((offset), (size), _page_cachable_default)
283 #define ioremap_cache ioremap_cachable
284 
285 /*
286  * ioremap_wc     -   map bus memory into CPU space
287  * @offset:    bus address of the memory
288  * @size:      size of the resource to map
289  *
290  * ioremap_wc performs a platform specific sequence of operations to
291  * make bus memory CPU accessible via the readb/readw/readl/writeb/
292  * writew/writel functions and the other mmio helpers. The returned
293  * address is not guaranteed to be usable directly as a virtual
294  * address.
295  *
296  * This version of ioremap ensures that the memory is marked uncachable
297  * but accelerated by means of write-combining feature. It is specifically
298  * useful for PCIe prefetchable windows, which may vastly improve a
299  * communications performance. If it was determined on boot stage, what
300  * CPU CCA doesn't support UCA, the method shall fall-back to the
301  * _CACHE_UNCACHED option (see cpu_probe() method).
302  */
303 #define ioremap_wc(offset, size)					\
304 	__ioremap_mode((offset), (size), boot_cpu_data.writecombine)
305 
306 static inline void iounmap(const volatile void __iomem *addr)
307 {
308 	if (plat_iounmap(addr))
309 		return;
310 
311 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
312 
313 	if (cpu_has_64bit_addresses ||
314 	    (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
315 		return;
316 
317 	__iounmap(addr);
318 
319 #undef __IS_KSEG1
320 }
321 
322 #if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_CPU_LOONGSON3)
323 #define war_io_reorder_wmb()		wmb()
324 #else
325 #define war_io_reorder_wmb()		barrier()
326 #endif
327 
328 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, barrier, relax, irq)	\
329 									\
330 static inline void pfx##write##bwlq(type val,				\
331 				    volatile void __iomem *mem)		\
332 {									\
333 	volatile type *__mem;						\
334 	type __val;							\
335 									\
336 	if (barrier)							\
337 		iobarrier_rw();						\
338 	else								\
339 		war_io_reorder_wmb();					\
340 									\
341 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
342 									\
343 	__val = pfx##ioswab##bwlq(__mem, val);				\
344 									\
345 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
346 		*__mem = __val;						\
347 	else if (cpu_has_64bits) {					\
348 		unsigned long __flags;					\
349 		type __tmp;						\
350 									\
351 		if (irq)						\
352 			local_irq_save(__flags);			\
353 		__asm__ __volatile__(					\
354 			".set	push"		"\t\t# __writeq""\n\t"	\
355 			".set	arch=r4000"			"\n\t"	\
356 			"dsll32 %L0, %L0, 0"			"\n\t"	\
357 			"dsrl32 %L0, %L0, 0"			"\n\t"	\
358 			"dsll32 %M0, %M0, 0"			"\n\t"	\
359 			"or	%L0, %L0, %M0"			"\n\t"	\
360 			"sd	%L0, %2"			"\n\t"	\
361 			".set	pop"				"\n"	\
362 			: "=r" (__tmp)					\
363 			: "0" (__val), "m" (*__mem));			\
364 		if (irq)						\
365 			local_irq_restore(__flags);			\
366 	} else								\
367 		BUG();							\
368 }									\
369 									\
370 static inline type pfx##read##bwlq(const volatile void __iomem *mem)	\
371 {									\
372 	volatile type *__mem;						\
373 	type __val;							\
374 									\
375 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
376 									\
377 	if (barrier)							\
378 		iobarrier_rw();						\
379 									\
380 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
381 		__val = *__mem;						\
382 	else if (cpu_has_64bits) {					\
383 		unsigned long __flags;					\
384 									\
385 		if (irq)						\
386 			local_irq_save(__flags);			\
387 		__asm__ __volatile__(					\
388 			".set	push"		"\t\t# __readq" "\n\t"	\
389 			".set	arch=r4000"			"\n\t"	\
390 			"ld	%L0, %1"			"\n\t"	\
391 			"dsra32 %M0, %L0, 0"			"\n\t"	\
392 			"sll	%L0, %L0, 0"			"\n\t"	\
393 			".set	pop"				"\n"	\
394 			: "=r" (__val)					\
395 			: "m" (*__mem));				\
396 		if (irq)						\
397 			local_irq_restore(__flags);			\
398 	} else {							\
399 		__val = 0;						\
400 		BUG();							\
401 	}								\
402 									\
403 	/* prevent prefetching of coherent DMA data prematurely */	\
404 	if (!relax)							\
405 		rmb();							\
406 	return pfx##ioswab##bwlq(__mem, __val);				\
407 }
408 
409 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, barrier, relax, p)	\
410 									\
411 static inline void pfx##out##bwlq##p(type val, unsigned long port)	\
412 {									\
413 	volatile type *__addr;						\
414 	type __val;							\
415 									\
416 	if (barrier)							\
417 		iobarrier_rw();						\
418 	else								\
419 		war_io_reorder_wmb();					\
420 									\
421 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
422 									\
423 	__val = pfx##ioswab##bwlq(__addr, val);				\
424 									\
425 	/* Really, we want this to be atomic */				\
426 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
427 									\
428 	*__addr = __val;						\
429 }									\
430 									\
431 static inline type pfx##in##bwlq##p(unsigned long port)			\
432 {									\
433 	volatile type *__addr;						\
434 	type __val;							\
435 									\
436 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
437 									\
438 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
439 									\
440 	if (barrier)							\
441 		iobarrier_rw();						\
442 									\
443 	__val = *__addr;						\
444 									\
445 	/* prevent prefetching of coherent DMA data prematurely */	\
446 	if (!relax)							\
447 		rmb();							\
448 	return pfx##ioswab##bwlq(__addr, __val);			\
449 }
450 
451 #define __BUILD_MEMORY_PFX(bus, bwlq, type, relax)			\
452 									\
453 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1, relax, 1)
454 
455 #define BUILDIO_MEM(bwlq, type)						\
456 									\
457 __BUILD_MEMORY_PFX(__raw_, bwlq, type, 0)				\
458 __BUILD_MEMORY_PFX(__relaxed_, bwlq, type, 1)				\
459 __BUILD_MEMORY_PFX(__mem_, bwlq, type, 0)				\
460 __BUILD_MEMORY_PFX(, bwlq, type, 0)
461 
462 BUILDIO_MEM(b, u8)
463 BUILDIO_MEM(w, u16)
464 BUILDIO_MEM(l, u32)
465 BUILDIO_MEM(q, u64)
466 
467 #define __BUILD_IOPORT_PFX(bus, bwlq, type)				\
468 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, 1, 0,)			\
469 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, 1, 0, _p)
470 
471 #define BUILDIO_IOPORT(bwlq, type)					\
472 	__BUILD_IOPORT_PFX(, bwlq, type)				\
473 	__BUILD_IOPORT_PFX(__mem_, bwlq, type)
474 
475 BUILDIO_IOPORT(b, u8)
476 BUILDIO_IOPORT(w, u16)
477 BUILDIO_IOPORT(l, u32)
478 #ifdef CONFIG_64BIT
479 BUILDIO_IOPORT(q, u64)
480 #endif
481 
482 #define __BUILDIO(bwlq, type)						\
483 									\
484 __BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 1, 0, 0)
485 
486 __BUILDIO(q, u64)
487 
488 #define readb_relaxed			__relaxed_readb
489 #define readw_relaxed			__relaxed_readw
490 #define readl_relaxed			__relaxed_readl
491 #define readq_relaxed			__relaxed_readq
492 
493 #define writeb_relaxed			__relaxed_writeb
494 #define writew_relaxed			__relaxed_writew
495 #define writel_relaxed			__relaxed_writel
496 #define writeq_relaxed			__relaxed_writeq
497 
498 #define readb_be(addr)							\
499 	__raw_readb((__force unsigned *)(addr))
500 #define readw_be(addr)							\
501 	be16_to_cpu(__raw_readw((__force unsigned *)(addr)))
502 #define readl_be(addr)							\
503 	be32_to_cpu(__raw_readl((__force unsigned *)(addr)))
504 #define readq_be(addr)							\
505 	be64_to_cpu(__raw_readq((__force unsigned *)(addr)))
506 
507 #define writeb_be(val, addr)						\
508 	__raw_writeb((val), (__force unsigned *)(addr))
509 #define writew_be(val, addr)						\
510 	__raw_writew(cpu_to_be16((val)), (__force unsigned *)(addr))
511 #define writel_be(val, addr)						\
512 	__raw_writel(cpu_to_be32((val)), (__force unsigned *)(addr))
513 #define writeq_be(val, addr)						\
514 	__raw_writeq(cpu_to_be64((val)), (__force unsigned *)(addr))
515 
516 /*
517  * Some code tests for these symbols
518  */
519 #define readq				readq
520 #define writeq				writeq
521 
522 #define __BUILD_MEMORY_STRING(bwlq, type)				\
523 									\
524 static inline void writes##bwlq(volatile void __iomem *mem,		\
525 				const void *addr, unsigned int count)	\
526 {									\
527 	const volatile type *__addr = addr;				\
528 									\
529 	while (count--) {						\
530 		__mem_write##bwlq(*__addr, mem);			\
531 		__addr++;						\
532 	}								\
533 }									\
534 									\
535 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,	\
536 			       unsigned int count)			\
537 {									\
538 	volatile type *__addr = addr;					\
539 									\
540 	while (count--) {						\
541 		*__addr = __mem_read##bwlq(mem);			\
542 		__addr++;						\
543 	}								\
544 }
545 
546 #define __BUILD_IOPORT_STRING(bwlq, type)				\
547 									\
548 static inline void outs##bwlq(unsigned long port, const void *addr,	\
549 			      unsigned int count)			\
550 {									\
551 	const volatile type *__addr = addr;				\
552 									\
553 	while (count--) {						\
554 		__mem_out##bwlq(*__addr, port);				\
555 		__addr++;						\
556 	}								\
557 }									\
558 									\
559 static inline void ins##bwlq(unsigned long port, void *addr,		\
560 			     unsigned int count)			\
561 {									\
562 	volatile type *__addr = addr;					\
563 									\
564 	while (count--) {						\
565 		*__addr = __mem_in##bwlq(port);				\
566 		__addr++;						\
567 	}								\
568 }
569 
570 #define BUILDSTRING(bwlq, type)						\
571 									\
572 __BUILD_MEMORY_STRING(bwlq, type)					\
573 __BUILD_IOPORT_STRING(bwlq, type)
574 
575 BUILDSTRING(b, u8)
576 BUILDSTRING(w, u16)
577 BUILDSTRING(l, u32)
578 #ifdef CONFIG_64BIT
579 BUILDSTRING(q, u64)
580 #endif
581 
582 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
583 {
584 	memset((void __force *) addr, val, count);
585 }
586 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
587 {
588 	memcpy(dst, (void __force *) src, count);
589 }
590 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
591 {
592 	memcpy((void __force *) dst, src, count);
593 }
594 
595 /*
596  * The caches on some architectures aren't dma-coherent and have need to
597  * handle this in software.  There are three types of operations that
598  * can be applied to dma buffers.
599  *
600  *  - dma_cache_wback_inv(start, size) makes caches and coherent by
601  *    writing the content of the caches back to memory, if necessary.
602  *    The function also invalidates the affected part of the caches as
603  *    necessary before DMA transfers from outside to memory.
604  *  - dma_cache_wback(start, size) makes caches and coherent by
605  *    writing the content of the caches back to memory, if necessary.
606  *    The function also invalidates the affected part of the caches as
607  *    necessary before DMA transfers from outside to memory.
608  *  - dma_cache_inv(start, size) invalidates the affected parts of the
609  *    caches.  Dirty lines of the caches may be written back or simply
610  *    be discarded.  This operation is necessary before dma operations
611  *    to the memory.
612  *
613  * This API used to be exported; it now is for arch code internal use only.
614  */
615 #ifdef CONFIG_DMA_NONCOHERENT
616 
617 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
618 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
619 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
620 
621 #define dma_cache_wback_inv(start, size)	_dma_cache_wback_inv(start, size)
622 #define dma_cache_wback(start, size)		_dma_cache_wback(start, size)
623 #define dma_cache_inv(start, size)		_dma_cache_inv(start, size)
624 
625 #else /* Sane hardware */
626 
627 #define dma_cache_wback_inv(start,size) \
628 	do { (void) (start); (void) (size); } while (0)
629 #define dma_cache_wback(start,size)	\
630 	do { (void) (start); (void) (size); } while (0)
631 #define dma_cache_inv(start,size)	\
632 	do { (void) (start); (void) (size); } while (0)
633 
634 #endif /* CONFIG_DMA_NONCOHERENT */
635 
636 /*
637  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
638  * Avoid interrupt mucking, just adjust the address for 4-byte access.
639  * Assume the addresses are 8-byte aligned.
640  */
641 #ifdef __MIPSEB__
642 #define __CSR_32_ADJUST 4
643 #else
644 #define __CSR_32_ADJUST 0
645 #endif
646 
647 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
648 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
649 
650 /*
651  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
652  * access
653  */
654 #define xlate_dev_mem_ptr(p)	__va(p)
655 
656 /*
657  * Convert a virtual cached pointer to an uncached pointer
658  */
659 #define xlate_dev_kmem_ptr(p)	p
660 
661 void __ioread64_copy(void *to, const void __iomem *from, size_t count);
662 
663 #endif /* _ASM_IO_H */
664