xref: /openbmc/linux/arch/mips/include/asm/io.h (revision 8b030a57)
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 /* Some callers use this older API instead.  */
106 #define mmiowb() iobarrier_w()
107 
108 /*
109  *     virt_to_phys    -       map virtual addresses to physical
110  *     @address: address to remap
111  *
112  *     The returned physical address is the physical (CPU) mapping for
113  *     the memory address given. It is only valid to use this function on
114  *     addresses directly mapped or allocated via kmalloc.
115  *
116  *     This function does not give bus mappings for DMA transfers. In
117  *     almost all conceivable cases a device driver should not be using
118  *     this function
119  */
120 static inline unsigned long virt_to_phys(volatile const void *address)
121 {
122 	return __pa(address);
123 }
124 
125 /*
126  *     phys_to_virt    -       map physical address to virtual
127  *     @address: address to remap
128  *
129  *     The returned virtual address is a current CPU mapping for
130  *     the memory address given. It is only valid to use this function on
131  *     addresses that have a kernel mapping
132  *
133  *     This function does not handle bus mappings for DMA transfers. In
134  *     almost all conceivable cases a device driver should not be using
135  *     this function
136  */
137 static inline void * phys_to_virt(unsigned long address)
138 {
139 	return (void *)(address + PAGE_OFFSET - PHYS_OFFSET);
140 }
141 
142 /*
143  * ISA I/O bus memory addresses are 1:1 with the physical address.
144  */
145 static inline unsigned long isa_virt_to_bus(volatile void *address)
146 {
147 	return virt_to_phys(address);
148 }
149 
150 static inline void *isa_bus_to_virt(unsigned long address)
151 {
152 	return phys_to_virt(address);
153 }
154 
155 #define isa_page_to_bus page_to_phys
156 
157 /*
158  * However PCI ones are not necessarily 1:1 and therefore these interfaces
159  * are forbidden in portable PCI drivers.
160  *
161  * Allow them for x86 for legacy drivers, though.
162  */
163 #define virt_to_bus virt_to_phys
164 #define bus_to_virt phys_to_virt
165 
166 /*
167  * Change "struct page" to physical address.
168  */
169 #define page_to_phys(page)	((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
170 
171 extern void __iomem * __ioremap(phys_addr_t offset, phys_addr_t size, unsigned long flags);
172 extern void __iounmap(const volatile void __iomem *addr);
173 
174 static inline void __iomem * __ioremap_mode(phys_addr_t offset, unsigned long size,
175 	unsigned long flags)
176 {
177 	void __iomem *addr = plat_ioremap(offset, size, flags);
178 
179 	if (addr)
180 		return addr;
181 
182 #define __IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
183 
184 	if (cpu_has_64bit_addresses) {
185 		u64 base = UNCAC_BASE;
186 
187 		/*
188 		 * R10000 supports a 2 bit uncached attribute therefore
189 		 * UNCAC_BASE may not equal IO_BASE.
190 		 */
191 		if (flags == _CACHE_UNCACHED)
192 			base = (u64) IO_BASE;
193 		return (void __iomem *) (unsigned long) (base + offset);
194 	} else if (__builtin_constant_p(offset) &&
195 		   __builtin_constant_p(size) && __builtin_constant_p(flags)) {
196 		phys_addr_t phys_addr, last_addr;
197 
198 		phys_addr = fixup_bigphys_addr(offset, size);
199 
200 		/* Don't allow wraparound or zero size. */
201 		last_addr = phys_addr + size - 1;
202 		if (!size || last_addr < phys_addr)
203 			return NULL;
204 
205 		/*
206 		 * Map uncached objects in the low 512MB of address
207 		 * space using KSEG1.
208 		 */
209 		if (__IS_LOW512(phys_addr) && __IS_LOW512(last_addr) &&
210 		    flags == _CACHE_UNCACHED)
211 			return (void __iomem *)
212 				(unsigned long)CKSEG1ADDR(phys_addr);
213 	}
214 
215 	return __ioremap(offset, size, flags);
216 
217 #undef __IS_LOW512
218 }
219 
220 /*
221  * ioremap_prot     -   map bus memory into CPU space
222  * @offset:    bus address of the memory
223  * @size:      size of the resource to map
224 
225  * ioremap_prot gives the caller control over cache coherency attributes (CCA)
226  */
227 static inline void __iomem *ioremap_prot(phys_addr_t offset,
228 		unsigned long size, unsigned long prot_val) {
229 	return __ioremap_mode(offset, size, prot_val & _CACHE_MASK);
230 }
231 
232 /*
233  * ioremap     -   map bus memory into CPU space
234  * @offset:    bus address of the memory
235  * @size:      size of the resource to map
236  *
237  * ioremap performs a platform specific sequence of operations to
238  * make bus memory CPU accessible via the readb/readw/readl/writeb/
239  * writew/writel functions and the other mmio helpers. The returned
240  * address is not guaranteed to be usable directly as a virtual
241  * address.
242  */
243 #define ioremap(offset, size)						\
244 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
245 
246 /*
247  * ioremap_nocache     -   map bus memory into CPU space
248  * @offset:    bus address of the memory
249  * @size:      size of the resource to map
250  *
251  * ioremap_nocache performs a platform specific sequence of operations to
252  * make bus memory CPU accessible via the readb/readw/readl/writeb/
253  * writew/writel functions and the other mmio helpers. The returned
254  * address is not guaranteed to be usable directly as a virtual
255  * address.
256  *
257  * This version of ioremap ensures that the memory is marked uncachable
258  * on the CPU as well as honouring existing caching rules from things like
259  * the PCI bus. Note that there are other caches and buffers on many
260  * busses. In particular driver authors should read up on PCI writes
261  *
262  * It's useful if some control registers are in such an area and
263  * write combining or read caching is not desirable:
264  */
265 #define ioremap_nocache(offset, size)					\
266 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
267 #define ioremap_uc ioremap_nocache
268 
269 /*
270  * ioremap_cachable -	map bus memory into CPU space
271  * @offset:	    bus address of the memory
272  * @size:	    size of the resource to map
273  *
274  * ioremap_nocache performs a platform specific sequence of operations to
275  * make bus memory CPU accessible via the readb/readw/readl/writeb/
276  * writew/writel functions and the other mmio helpers. The returned
277  * address is not guaranteed to be usable directly as a virtual
278  * address.
279  *
280  * This version of ioremap ensures that the memory is marked cachable by
281  * the CPU.  Also enables full write-combining.	 Useful for some
282  * memory-like regions on I/O busses.
283  */
284 #define ioremap_cachable(offset, size)					\
285 	__ioremap_mode((offset), (size), _page_cachable_default)
286 #define ioremap_cache ioremap_cachable
287 
288 /*
289  * ioremap_wc     -   map bus memory into CPU space
290  * @offset:    bus address of the memory
291  * @size:      size of the resource to map
292  *
293  * ioremap_wc performs a platform specific sequence of operations to
294  * make bus memory CPU accessible via the readb/readw/readl/writeb/
295  * writew/writel functions and the other mmio helpers. The returned
296  * address is not guaranteed to be usable directly as a virtual
297  * address.
298  *
299  * This version of ioremap ensures that the memory is marked uncachable
300  * but accelerated by means of write-combining feature. It is specifically
301  * useful for PCIe prefetchable windows, which may vastly improve a
302  * communications performance. If it was determined on boot stage, what
303  * CPU CCA doesn't support UCA, the method shall fall-back to the
304  * _CACHE_UNCACHED option (see cpu_probe() method).
305  */
306 #define ioremap_wc(offset, size)					\
307 	__ioremap_mode((offset), (size), boot_cpu_data.writecombine)
308 
309 static inline void iounmap(const volatile void __iomem *addr)
310 {
311 	if (plat_iounmap(addr))
312 		return;
313 
314 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
315 
316 	if (cpu_has_64bit_addresses ||
317 	    (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
318 		return;
319 
320 	__iounmap(addr);
321 
322 #undef __IS_KSEG1
323 }
324 
325 #if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_CPU_LOONGSON3)
326 #define war_io_reorder_wmb()		wmb()
327 #else
328 #define war_io_reorder_wmb()		barrier()
329 #endif
330 
331 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, barrier, relax, irq)	\
332 									\
333 static inline void pfx##write##bwlq(type val,				\
334 				    volatile void __iomem *mem)		\
335 {									\
336 	volatile type *__mem;						\
337 	type __val;							\
338 									\
339 	if (barrier)							\
340 		iobarrier_rw();						\
341 	else								\
342 		war_io_reorder_wmb();					\
343 									\
344 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
345 									\
346 	__val = pfx##ioswab##bwlq(__mem, val);				\
347 									\
348 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
349 		*__mem = __val;						\
350 	else if (cpu_has_64bits) {					\
351 		unsigned long __flags;					\
352 		type __tmp;						\
353 									\
354 		if (irq)						\
355 			local_irq_save(__flags);			\
356 		__asm__ __volatile__(					\
357 			".set	push"		"\t\t# __writeq""\n\t"	\
358 			".set	arch=r4000"			"\n\t"	\
359 			"dsll32 %L0, %L0, 0"			"\n\t"	\
360 			"dsrl32 %L0, %L0, 0"			"\n\t"	\
361 			"dsll32 %M0, %M0, 0"			"\n\t"	\
362 			"or	%L0, %L0, %M0"			"\n\t"	\
363 			"sd	%L0, %2"			"\n\t"	\
364 			".set	pop"				"\n"	\
365 			: "=r" (__tmp)					\
366 			: "0" (__val), "m" (*__mem));			\
367 		if (irq)						\
368 			local_irq_restore(__flags);			\
369 	} else								\
370 		BUG();							\
371 }									\
372 									\
373 static inline type pfx##read##bwlq(const volatile void __iomem *mem)	\
374 {									\
375 	volatile type *__mem;						\
376 	type __val;							\
377 									\
378 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
379 									\
380 	if (barrier)							\
381 		iobarrier_rw();						\
382 									\
383 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
384 		__val = *__mem;						\
385 	else if (cpu_has_64bits) {					\
386 		unsigned long __flags;					\
387 									\
388 		if (irq)						\
389 			local_irq_save(__flags);			\
390 		__asm__ __volatile__(					\
391 			".set	push"		"\t\t# __readq" "\n\t"	\
392 			".set	arch=r4000"			"\n\t"	\
393 			"ld	%L0, %1"			"\n\t"	\
394 			"dsra32 %M0, %L0, 0"			"\n\t"	\
395 			"sll	%L0, %L0, 0"			"\n\t"	\
396 			".set	pop"				"\n"	\
397 			: "=r" (__val)					\
398 			: "m" (*__mem));				\
399 		if (irq)						\
400 			local_irq_restore(__flags);			\
401 	} else {							\
402 		__val = 0;						\
403 		BUG();							\
404 	}								\
405 									\
406 	/* prevent prefetching of coherent DMA data prematurely */	\
407 	if (!relax)							\
408 		rmb();							\
409 	return pfx##ioswab##bwlq(__mem, __val);				\
410 }
411 
412 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, barrier, relax, p)	\
413 									\
414 static inline void pfx##out##bwlq##p(type val, unsigned long port)	\
415 {									\
416 	volatile type *__addr;						\
417 	type __val;							\
418 									\
419 	if (barrier)							\
420 		iobarrier_rw();						\
421 	else								\
422 		war_io_reorder_wmb();					\
423 									\
424 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
425 									\
426 	__val = pfx##ioswab##bwlq(__addr, val);				\
427 									\
428 	/* Really, we want this to be atomic */				\
429 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
430 									\
431 	*__addr = __val;						\
432 }									\
433 									\
434 static inline type pfx##in##bwlq##p(unsigned long port)			\
435 {									\
436 	volatile type *__addr;						\
437 	type __val;							\
438 									\
439 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
440 									\
441 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
442 									\
443 	if (barrier)							\
444 		iobarrier_rw();						\
445 									\
446 	__val = *__addr;						\
447 									\
448 	/* prevent prefetching of coherent DMA data prematurely */	\
449 	if (!relax)							\
450 		rmb();							\
451 	return pfx##ioswab##bwlq(__addr, __val);			\
452 }
453 
454 #define __BUILD_MEMORY_PFX(bus, bwlq, type, relax)			\
455 									\
456 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1, relax, 1)
457 
458 #define BUILDIO_MEM(bwlq, type)						\
459 									\
460 __BUILD_MEMORY_PFX(__raw_, bwlq, type, 0)				\
461 __BUILD_MEMORY_PFX(__relaxed_, bwlq, type, 1)				\
462 __BUILD_MEMORY_PFX(__mem_, bwlq, type, 0)				\
463 __BUILD_MEMORY_PFX(, bwlq, type, 0)
464 
465 BUILDIO_MEM(b, u8)
466 BUILDIO_MEM(w, u16)
467 BUILDIO_MEM(l, u32)
468 BUILDIO_MEM(q, u64)
469 
470 #define __BUILD_IOPORT_PFX(bus, bwlq, type)				\
471 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, 1, 0,)			\
472 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, 1, 0, _p)
473 
474 #define BUILDIO_IOPORT(bwlq, type)					\
475 	__BUILD_IOPORT_PFX(, bwlq, type)				\
476 	__BUILD_IOPORT_PFX(__mem_, bwlq, type)
477 
478 BUILDIO_IOPORT(b, u8)
479 BUILDIO_IOPORT(w, u16)
480 BUILDIO_IOPORT(l, u32)
481 #ifdef CONFIG_64BIT
482 BUILDIO_IOPORT(q, u64)
483 #endif
484 
485 #define __BUILDIO(bwlq, type)						\
486 									\
487 __BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 1, 0, 0)
488 
489 __BUILDIO(q, u64)
490 
491 #define readb_relaxed			__relaxed_readb
492 #define readw_relaxed			__relaxed_readw
493 #define readl_relaxed			__relaxed_readl
494 #define readq_relaxed			__relaxed_readq
495 
496 #define writeb_relaxed			__relaxed_writeb
497 #define writew_relaxed			__relaxed_writew
498 #define writel_relaxed			__relaxed_writel
499 #define writeq_relaxed			__relaxed_writeq
500 
501 #define readb_be(addr)							\
502 	__raw_readb((__force unsigned *)(addr))
503 #define readw_be(addr)							\
504 	be16_to_cpu(__raw_readw((__force unsigned *)(addr)))
505 #define readl_be(addr)							\
506 	be32_to_cpu(__raw_readl((__force unsigned *)(addr)))
507 #define readq_be(addr)							\
508 	be64_to_cpu(__raw_readq((__force unsigned *)(addr)))
509 
510 #define writeb_be(val, addr)						\
511 	__raw_writeb((val), (__force unsigned *)(addr))
512 #define writew_be(val, addr)						\
513 	__raw_writew(cpu_to_be16((val)), (__force unsigned *)(addr))
514 #define writel_be(val, addr)						\
515 	__raw_writel(cpu_to_be32((val)), (__force unsigned *)(addr))
516 #define writeq_be(val, addr)						\
517 	__raw_writeq(cpu_to_be64((val)), (__force unsigned *)(addr))
518 
519 /*
520  * Some code tests for these symbols
521  */
522 #define readq				readq
523 #define writeq				writeq
524 
525 #define __BUILD_MEMORY_STRING(bwlq, type)				\
526 									\
527 static inline void writes##bwlq(volatile void __iomem *mem,		\
528 				const void *addr, unsigned int count)	\
529 {									\
530 	const volatile type *__addr = addr;				\
531 									\
532 	while (count--) {						\
533 		__mem_write##bwlq(*__addr, mem);			\
534 		__addr++;						\
535 	}								\
536 }									\
537 									\
538 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,	\
539 			       unsigned int count)			\
540 {									\
541 	volatile type *__addr = addr;					\
542 									\
543 	while (count--) {						\
544 		*__addr = __mem_read##bwlq(mem);			\
545 		__addr++;						\
546 	}								\
547 }
548 
549 #define __BUILD_IOPORT_STRING(bwlq, type)				\
550 									\
551 static inline void outs##bwlq(unsigned long port, const void *addr,	\
552 			      unsigned int count)			\
553 {									\
554 	const volatile type *__addr = addr;				\
555 									\
556 	while (count--) {						\
557 		__mem_out##bwlq(*__addr, port);				\
558 		__addr++;						\
559 	}								\
560 }									\
561 									\
562 static inline void ins##bwlq(unsigned long port, void *addr,		\
563 			     unsigned int count)			\
564 {									\
565 	volatile type *__addr = addr;					\
566 									\
567 	while (count--) {						\
568 		*__addr = __mem_in##bwlq(port);				\
569 		__addr++;						\
570 	}								\
571 }
572 
573 #define BUILDSTRING(bwlq, type)						\
574 									\
575 __BUILD_MEMORY_STRING(bwlq, type)					\
576 __BUILD_IOPORT_STRING(bwlq, type)
577 
578 BUILDSTRING(b, u8)
579 BUILDSTRING(w, u16)
580 BUILDSTRING(l, u32)
581 #ifdef CONFIG_64BIT
582 BUILDSTRING(q, u64)
583 #endif
584 
585 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
586 {
587 	memset((void __force *) addr, val, count);
588 }
589 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
590 {
591 	memcpy(dst, (void __force *) src, count);
592 }
593 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
594 {
595 	memcpy((void __force *) dst, src, count);
596 }
597 
598 /*
599  * The caches on some architectures aren't dma-coherent and have need to
600  * handle this in software.  There are three types of operations that
601  * can be applied to dma buffers.
602  *
603  *  - dma_cache_wback_inv(start, size) makes caches and coherent by
604  *    writing the content of the caches back to memory, if necessary.
605  *    The function also invalidates the affected part of the caches as
606  *    necessary before DMA transfers from outside to memory.
607  *  - dma_cache_wback(start, size) makes caches and coherent by
608  *    writing the content of the caches back to memory, if necessary.
609  *    The function also invalidates the affected part of the caches as
610  *    necessary before DMA transfers from outside to memory.
611  *  - dma_cache_inv(start, size) invalidates the affected parts of the
612  *    caches.  Dirty lines of the caches may be written back or simply
613  *    be discarded.  This operation is necessary before dma operations
614  *    to the memory.
615  *
616  * This API used to be exported; it now is for arch code internal use only.
617  */
618 #ifdef CONFIG_DMA_NONCOHERENT
619 
620 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
621 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
622 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
623 
624 #define dma_cache_wback_inv(start, size)	_dma_cache_wback_inv(start, size)
625 #define dma_cache_wback(start, size)		_dma_cache_wback(start, size)
626 #define dma_cache_inv(start, size)		_dma_cache_inv(start, size)
627 
628 #else /* Sane hardware */
629 
630 #define dma_cache_wback_inv(start,size) \
631 	do { (void) (start); (void) (size); } while (0)
632 #define dma_cache_wback(start,size)	\
633 	do { (void) (start); (void) (size); } while (0)
634 #define dma_cache_inv(start,size)	\
635 	do { (void) (start); (void) (size); } while (0)
636 
637 #endif /* CONFIG_DMA_NONCOHERENT */
638 
639 /*
640  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
641  * Avoid interrupt mucking, just adjust the address for 4-byte access.
642  * Assume the addresses are 8-byte aligned.
643  */
644 #ifdef __MIPSEB__
645 #define __CSR_32_ADJUST 4
646 #else
647 #define __CSR_32_ADJUST 0
648 #endif
649 
650 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
651 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
652 
653 /*
654  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
655  * access
656  */
657 #define xlate_dev_mem_ptr(p)	__va(p)
658 
659 /*
660  * Convert a virtual cached pointer to an uncached pointer
661  */
662 #define xlate_dev_kmem_ptr(p)	p
663 
664 void __ioread64_copy(void *to, const void __iomem *from, size_t count);
665 
666 #endif /* _ASM_IO_H */
667