xref: /openbmc/linux/arch/mips/include/asm/io.h (revision e52a6321)
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 /*
153  * However PCI ones are not necessarily 1:1 and therefore these interfaces
154  * are forbidden in portable PCI drivers.
155  *
156  * Allow them for x86 for legacy drivers, though.
157  */
158 #define virt_to_bus virt_to_phys
159 #define bus_to_virt phys_to_virt
160 
161 /*
162  * Change "struct page" to physical address.
163  */
164 #define page_to_phys(page)	((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
165 
166 extern void __iomem * __ioremap(phys_addr_t offset, phys_addr_t size, unsigned long flags);
167 extern void __iounmap(const volatile void __iomem *addr);
168 
169 static inline void __iomem * __ioremap_mode(phys_addr_t offset, unsigned long size,
170 	unsigned long flags)
171 {
172 	void __iomem *addr = plat_ioremap(offset, size, flags);
173 
174 	if (addr)
175 		return addr;
176 
177 #define __IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
178 
179 	if (cpu_has_64bit_addresses) {
180 		u64 base = UNCAC_BASE;
181 
182 		/*
183 		 * R10000 supports a 2 bit uncached attribute therefore
184 		 * UNCAC_BASE may not equal IO_BASE.
185 		 */
186 		if (flags == _CACHE_UNCACHED)
187 			base = (u64) IO_BASE;
188 		return (void __iomem *) (unsigned long) (base + offset);
189 	} else if (__builtin_constant_p(offset) &&
190 		   __builtin_constant_p(size) && __builtin_constant_p(flags)) {
191 		phys_addr_t phys_addr, last_addr;
192 
193 		phys_addr = fixup_bigphys_addr(offset, size);
194 
195 		/* Don't allow wraparound or zero size. */
196 		last_addr = phys_addr + size - 1;
197 		if (!size || last_addr < phys_addr)
198 			return NULL;
199 
200 		/*
201 		 * Map uncached objects in the low 512MB of address
202 		 * space using KSEG1.
203 		 */
204 		if (__IS_LOW512(phys_addr) && __IS_LOW512(last_addr) &&
205 		    flags == _CACHE_UNCACHED)
206 			return (void __iomem *)
207 				(unsigned long)CKSEG1ADDR(phys_addr);
208 	}
209 
210 	return __ioremap(offset, size, flags);
211 
212 #undef __IS_LOW512
213 }
214 
215 /*
216  * ioremap_prot     -   map bus memory into CPU space
217  * @offset:    bus address of the memory
218  * @size:      size of the resource to map
219 
220  * ioremap_prot gives the caller control over cache coherency attributes (CCA)
221  */
222 static inline void __iomem *ioremap_prot(phys_addr_t offset,
223 		unsigned long size, unsigned long prot_val) {
224 	return __ioremap_mode(offset, size, prot_val & _CACHE_MASK);
225 }
226 
227 /*
228  * ioremap     -   map bus memory into CPU space
229  * @offset:    bus address of the memory
230  * @size:      size of the resource to map
231  *
232  * ioremap performs a platform specific sequence of operations to
233  * make bus memory CPU accessible via the readb/readw/readl/writeb/
234  * writew/writel functions and the other mmio helpers. The returned
235  * address is not guaranteed to be usable directly as a virtual
236  * address.
237  */
238 #define ioremap(offset, size)						\
239 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
240 
241 /*
242  * ioremap_nocache     -   map bus memory into CPU space
243  * @offset:    bus address of the memory
244  * @size:      size of the resource to map
245  *
246  * ioremap_nocache performs a platform specific sequence of operations to
247  * make bus memory CPU accessible via the readb/readw/readl/writeb/
248  * writew/writel functions and the other mmio helpers. The returned
249  * address is not guaranteed to be usable directly as a virtual
250  * address.
251  *
252  * This version of ioremap ensures that the memory is marked uncachable
253  * on the CPU as well as honouring existing caching rules from things like
254  * the PCI bus. Note that there are other caches and buffers on many
255  * busses. In particular driver authors should read up on PCI writes
256  *
257  * It's useful if some control registers are in such an area and
258  * write combining or read caching is not desirable:
259  */
260 #define ioremap_nocache(offset, size)					\
261 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
262 #define ioremap_uc ioremap_nocache
263 
264 /*
265  * ioremap_cachable -	map bus memory into CPU space
266  * @offset:	    bus address of the memory
267  * @size:	    size of the resource to map
268  *
269  * ioremap_nocache performs a platform specific sequence of operations to
270  * make bus memory CPU accessible via the readb/readw/readl/writeb/
271  * writew/writel functions and the other mmio helpers. The returned
272  * address is not guaranteed to be usable directly as a virtual
273  * address.
274  *
275  * This version of ioremap ensures that the memory is marked cachable by
276  * the CPU.  Also enables full write-combining.	 Useful for some
277  * memory-like regions on I/O busses.
278  */
279 #define ioremap_cachable(offset, size)					\
280 	__ioremap_mode((offset), (size), _page_cachable_default)
281 #define ioremap_cache ioremap_cachable
282 
283 /*
284  * ioremap_wc     -   map bus memory into CPU space
285  * @offset:    bus address of the memory
286  * @size:      size of the resource to map
287  *
288  * ioremap_wc performs a platform specific sequence of operations to
289  * make bus memory CPU accessible via the readb/readw/readl/writeb/
290  * writew/writel functions and the other mmio helpers. The returned
291  * address is not guaranteed to be usable directly as a virtual
292  * address.
293  *
294  * This version of ioremap ensures that the memory is marked uncachable
295  * but accelerated by means of write-combining feature. It is specifically
296  * useful for PCIe prefetchable windows, which may vastly improve a
297  * communications performance. If it was determined on boot stage, what
298  * CPU CCA doesn't support UCA, the method shall fall-back to the
299  * _CACHE_UNCACHED option (see cpu_probe() method).
300  */
301 #define ioremap_wc(offset, size)					\
302 	__ioremap_mode((offset), (size), boot_cpu_data.writecombine)
303 
304 static inline void iounmap(const volatile void __iomem *addr)
305 {
306 	if (plat_iounmap(addr))
307 		return;
308 
309 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
310 
311 	if (cpu_has_64bit_addresses ||
312 	    (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
313 		return;
314 
315 	__iounmap(addr);
316 
317 #undef __IS_KSEG1
318 }
319 
320 #if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_CPU_LOONGSON3)
321 #define war_io_reorder_wmb()		wmb()
322 #else
323 #define war_io_reorder_wmb()		barrier()
324 #endif
325 
326 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, barrier, relax, irq)	\
327 									\
328 static inline void pfx##write##bwlq(type val,				\
329 				    volatile void __iomem *mem)		\
330 {									\
331 	volatile type *__mem;						\
332 	type __val;							\
333 									\
334 	if (barrier)							\
335 		iobarrier_rw();						\
336 	else								\
337 		war_io_reorder_wmb();					\
338 									\
339 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
340 									\
341 	__val = pfx##ioswab##bwlq(__mem, val);				\
342 									\
343 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
344 		*__mem = __val;						\
345 	else if (cpu_has_64bits) {					\
346 		unsigned long __flags;					\
347 		type __tmp;						\
348 									\
349 		if (irq)						\
350 			local_irq_save(__flags);			\
351 		__asm__ __volatile__(					\
352 			".set	push"		"\t\t# __writeq""\n\t"	\
353 			".set	arch=r4000"			"\n\t"	\
354 			"dsll32 %L0, %L0, 0"			"\n\t"	\
355 			"dsrl32 %L0, %L0, 0"			"\n\t"	\
356 			"dsll32 %M0, %M0, 0"			"\n\t"	\
357 			"or	%L0, %L0, %M0"			"\n\t"	\
358 			"sd	%L0, %2"			"\n\t"	\
359 			".set	pop"				"\n"	\
360 			: "=r" (__tmp)					\
361 			: "0" (__val), "m" (*__mem));			\
362 		if (irq)						\
363 			local_irq_restore(__flags);			\
364 	} else								\
365 		BUG();							\
366 }									\
367 									\
368 static inline type pfx##read##bwlq(const volatile void __iomem *mem)	\
369 {									\
370 	volatile type *__mem;						\
371 	type __val;							\
372 									\
373 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
374 									\
375 	if (barrier)							\
376 		iobarrier_rw();						\
377 									\
378 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
379 		__val = *__mem;						\
380 	else if (cpu_has_64bits) {					\
381 		unsigned long __flags;					\
382 									\
383 		if (irq)						\
384 			local_irq_save(__flags);			\
385 		__asm__ __volatile__(					\
386 			".set	push"		"\t\t# __readq" "\n\t"	\
387 			".set	arch=r4000"			"\n\t"	\
388 			"ld	%L0, %1"			"\n\t"	\
389 			"dsra32 %M0, %L0, 0"			"\n\t"	\
390 			"sll	%L0, %L0, 0"			"\n\t"	\
391 			".set	pop"				"\n"	\
392 			: "=r" (__val)					\
393 			: "m" (*__mem));				\
394 		if (irq)						\
395 			local_irq_restore(__flags);			\
396 	} else {							\
397 		__val = 0;						\
398 		BUG();							\
399 	}								\
400 									\
401 	/* prevent prefetching of coherent DMA data prematurely */	\
402 	if (!relax)							\
403 		rmb();							\
404 	return pfx##ioswab##bwlq(__mem, __val);				\
405 }
406 
407 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, barrier, relax, p)	\
408 									\
409 static inline void pfx##out##bwlq##p(type val, unsigned long port)	\
410 {									\
411 	volatile type *__addr;						\
412 	type __val;							\
413 									\
414 	if (barrier)							\
415 		iobarrier_rw();						\
416 	else								\
417 		war_io_reorder_wmb();					\
418 									\
419 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
420 									\
421 	__val = pfx##ioswab##bwlq(__addr, val);				\
422 									\
423 	/* Really, we want this to be atomic */				\
424 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
425 									\
426 	*__addr = __val;						\
427 }									\
428 									\
429 static inline type pfx##in##bwlq##p(unsigned long port)			\
430 {									\
431 	volatile type *__addr;						\
432 	type __val;							\
433 									\
434 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
435 									\
436 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
437 									\
438 	if (barrier)							\
439 		iobarrier_rw();						\
440 									\
441 	__val = *__addr;						\
442 									\
443 	/* prevent prefetching of coherent DMA data prematurely */	\
444 	if (!relax)							\
445 		rmb();							\
446 	return pfx##ioswab##bwlq(__addr, __val);			\
447 }
448 
449 #define __BUILD_MEMORY_PFX(bus, bwlq, type, relax)			\
450 									\
451 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1, relax, 1)
452 
453 #define BUILDIO_MEM(bwlq, type)						\
454 									\
455 __BUILD_MEMORY_PFX(__raw_, bwlq, type, 0)				\
456 __BUILD_MEMORY_PFX(__relaxed_, bwlq, type, 1)				\
457 __BUILD_MEMORY_PFX(__mem_, bwlq, type, 0)				\
458 __BUILD_MEMORY_PFX(, bwlq, type, 0)
459 
460 BUILDIO_MEM(b, u8)
461 BUILDIO_MEM(w, u16)
462 BUILDIO_MEM(l, u32)
463 #ifdef CONFIG_64BIT
464 BUILDIO_MEM(q, u64)
465 #else
466 __BUILD_MEMORY_PFX(__raw_, q, u64, 0)
467 __BUILD_MEMORY_PFX(__mem_, q, u64, 0)
468 #endif
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 #ifdef CONFIG_64BIT
495 #define readq_relaxed			__relaxed_readq
496 #endif
497 
498 #define writeb_relaxed			__relaxed_writeb
499 #define writew_relaxed			__relaxed_writew
500 #define writel_relaxed			__relaxed_writel
501 #ifdef CONFIG_64BIT
502 #define writeq_relaxed			__relaxed_writeq
503 #endif
504 
505 #define readb_be(addr)							\
506 	__raw_readb((__force unsigned *)(addr))
507 #define readw_be(addr)							\
508 	be16_to_cpu(__raw_readw((__force unsigned *)(addr)))
509 #define readl_be(addr)							\
510 	be32_to_cpu(__raw_readl((__force unsigned *)(addr)))
511 #define readq_be(addr)							\
512 	be64_to_cpu(__raw_readq((__force unsigned *)(addr)))
513 
514 #define writeb_be(val, addr)						\
515 	__raw_writeb((val), (__force unsigned *)(addr))
516 #define writew_be(val, addr)						\
517 	__raw_writew(cpu_to_be16((val)), (__force unsigned *)(addr))
518 #define writel_be(val, addr)						\
519 	__raw_writel(cpu_to_be32((val)), (__force unsigned *)(addr))
520 #define writeq_be(val, addr)						\
521 	__raw_writeq(cpu_to_be64((val)), (__force unsigned *)(addr))
522 
523 /*
524  * Some code tests for these symbols
525  */
526 #ifdef CONFIG_64BIT
527 #define readq				readq
528 #define writeq				writeq
529 #endif
530 
531 #define __BUILD_MEMORY_STRING(bwlq, type)				\
532 									\
533 static inline void writes##bwlq(volatile void __iomem *mem,		\
534 				const void *addr, unsigned int count)	\
535 {									\
536 	const volatile type *__addr = addr;				\
537 									\
538 	while (count--) {						\
539 		__mem_write##bwlq(*__addr, mem);			\
540 		__addr++;						\
541 	}								\
542 }									\
543 									\
544 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,	\
545 			       unsigned int count)			\
546 {									\
547 	volatile type *__addr = addr;					\
548 									\
549 	while (count--) {						\
550 		*__addr = __mem_read##bwlq(mem);			\
551 		__addr++;						\
552 	}								\
553 }
554 
555 #define __BUILD_IOPORT_STRING(bwlq, type)				\
556 									\
557 static inline void outs##bwlq(unsigned long port, const void *addr,	\
558 			      unsigned int count)			\
559 {									\
560 	const volatile type *__addr = addr;				\
561 									\
562 	while (count--) {						\
563 		__mem_out##bwlq(*__addr, port);				\
564 		__addr++;						\
565 	}								\
566 }									\
567 									\
568 static inline void ins##bwlq(unsigned long port, void *addr,		\
569 			     unsigned int count)			\
570 {									\
571 	volatile type *__addr = addr;					\
572 									\
573 	while (count--) {						\
574 		*__addr = __mem_in##bwlq(port);				\
575 		__addr++;						\
576 	}								\
577 }
578 
579 #define BUILDSTRING(bwlq, type)						\
580 									\
581 __BUILD_MEMORY_STRING(bwlq, type)					\
582 __BUILD_IOPORT_STRING(bwlq, type)
583 
584 BUILDSTRING(b, u8)
585 BUILDSTRING(w, u16)
586 BUILDSTRING(l, u32)
587 #ifdef CONFIG_64BIT
588 BUILDSTRING(q, u64)
589 #endif
590 
591 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
592 {
593 	memset((void __force *) addr, val, count);
594 }
595 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
596 {
597 	memcpy(dst, (void __force *) src, count);
598 }
599 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
600 {
601 	memcpy((void __force *) dst, src, count);
602 }
603 
604 /*
605  * The caches on some architectures aren't dma-coherent and have need to
606  * handle this in software.  There are three types of operations that
607  * can be applied to dma buffers.
608  *
609  *  - dma_cache_wback_inv(start, size) makes caches and coherent by
610  *    writing the content of the caches back to memory, if necessary.
611  *    The function also invalidates the affected part of the caches as
612  *    necessary before DMA transfers from outside to memory.
613  *  - dma_cache_wback(start, size) makes caches and coherent by
614  *    writing the content of the caches back to memory, if necessary.
615  *    The function also invalidates the affected part of the caches as
616  *    necessary before DMA transfers from outside to memory.
617  *  - dma_cache_inv(start, size) invalidates the affected parts of the
618  *    caches.  Dirty lines of the caches may be written back or simply
619  *    be discarded.  This operation is necessary before dma operations
620  *    to the memory.
621  *
622  * This API used to be exported; it now is for arch code internal use only.
623  */
624 #ifdef CONFIG_DMA_NONCOHERENT
625 
626 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
627 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
628 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
629 
630 #define dma_cache_wback_inv(start, size)	_dma_cache_wback_inv(start, size)
631 #define dma_cache_wback(start, size)		_dma_cache_wback(start, size)
632 #define dma_cache_inv(start, size)		_dma_cache_inv(start, size)
633 
634 #else /* Sane hardware */
635 
636 #define dma_cache_wback_inv(start,size) \
637 	do { (void) (start); (void) (size); } while (0)
638 #define dma_cache_wback(start,size)	\
639 	do { (void) (start); (void) (size); } while (0)
640 #define dma_cache_inv(start,size)	\
641 	do { (void) (start); (void) (size); } while (0)
642 
643 #endif /* CONFIG_DMA_NONCOHERENT */
644 
645 /*
646  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
647  * Avoid interrupt mucking, just adjust the address for 4-byte access.
648  * Assume the addresses are 8-byte aligned.
649  */
650 #ifdef __MIPSEB__
651 #define __CSR_32_ADJUST 4
652 #else
653 #define __CSR_32_ADJUST 0
654 #endif
655 
656 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
657 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
658 
659 /*
660  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
661  * access
662  */
663 #define xlate_dev_mem_ptr(p)	__va(p)
664 
665 /*
666  * Convert a virtual cached pointer to an uncached pointer
667  */
668 #define xlate_dev_kmem_ptr(p)	p
669 
670 void __ioread64_copy(void *to, const void __iomem *from, size_t count);
671 
672 #endif /* _ASM_IO_H */
673