xref: /linux/arch/mips/include/asm/io.h (revision 9ca953a3d6a649f4d5d2a4f1d5d51db10de46e5b)
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/bug.h>
24 #include <asm/byteorder.h>
25 #include <asm/cpu.h>
26 #include <asm/cpu-features.h>
27 #include <asm-generic/iomap.h>
28 #include <asm/page.h>
29 #include <asm/pgtable-bits.h>
30 #include <asm/processor.h>
31 #include <asm/string.h>
32 
33 #include <ioremap.h>
34 #include <mangle-port.h>
35 
36 /*
37  * Raw operations are never swapped in software.  OTOH values that raw
38  * operations are working on may or may not have been swapped by the bus
39  * hardware.  An example use would be for flash memory that's used for
40  * execute in place.
41  */
42 # define __raw_ioswabb(a, x)	(x)
43 # define __raw_ioswabw(a, x)	(x)
44 # define __raw_ioswabl(a, x)	(x)
45 # define __raw_ioswabq(a, x)	(x)
46 # define ____raw_ioswabq(a, x)	(x)
47 
48 /* ioswab[bwlq], __mem_ioswab[bwlq] are defined in mangle-port.h */
49 
50 #define IO_SPACE_LIMIT 0xffff
51 
52 /*
53  * On MIPS I/O ports are memory mapped, so we access them using normal
54  * load/store instructions. mips_io_port_base is the virtual address to
55  * which all ports are being mapped.  For sake of efficiency some code
56  * assumes that this is an address that can be loaded with a single lui
57  * instruction, so the lower 16 bits must be zero.  Should be true on
58  * on any sane architecture; generic code does not use this assumption.
59  */
60 extern const unsigned long mips_io_port_base;
61 
62 /*
63  * Gcc will generate code to load the value of mips_io_port_base after each
64  * function call which may be fairly wasteful in some cases.  So we don't
65  * play quite by the book.  We tell gcc mips_io_port_base is a long variable
66  * which solves the code generation issue.  Now we need to violate the
67  * aliasing rules a little to make initialization possible and finally we
68  * will need the barrier() to fight side effects of the aliasing chat.
69  * This trickery will eventually collapse under gcc's optimizer.  Oh well.
70  */
71 static inline void set_io_port_base(unsigned long base)
72 {
73 	* (unsigned long *) &mips_io_port_base = base;
74 	barrier();
75 }
76 
77 /*
78  * Provide the necessary definitions for generic iomap. We make use of
79  * mips_io_port_base for iomap(), but we don't reserve any low addresses for
80  * use with I/O ports.
81  */
82 #define HAVE_ARCH_PIO_SIZE
83 #define PIO_OFFSET	mips_io_port_base
84 #define PIO_MASK	IO_SPACE_LIMIT
85 #define PIO_RESERVED	0x0UL
86 
87 /*
88  *     virt_to_phys    -       map virtual addresses to physical
89  *     @address: address to remap
90  *
91  *     The returned physical address is the physical (CPU) mapping for
92  *     the memory address given. It is only valid to use this function on
93  *     addresses directly mapped or allocated via kmalloc.
94  *
95  *     This function does not give bus mappings for DMA transfers. In
96  *     almost all conceivable cases a device driver should not be using
97  *     this function
98  */
99 static inline unsigned long virt_to_phys(volatile const void *address)
100 {
101 	return __pa(address);
102 }
103 
104 /*
105  *     phys_to_virt    -       map physical address to virtual
106  *     @address: address to remap
107  *
108  *     The returned virtual address is a current CPU mapping for
109  *     the memory address given. It is only valid to use this function on
110  *     addresses that have a kernel mapping
111  *
112  *     This function does not handle bus mappings for DMA transfers. In
113  *     almost all conceivable cases a device driver should not be using
114  *     this function
115  */
116 static inline void * phys_to_virt(unsigned long address)
117 {
118 	return (void *)(address + PAGE_OFFSET - PHYS_OFFSET);
119 }
120 
121 /*
122  * ISA I/O bus memory addresses are 1:1 with the physical address.
123  */
124 static inline unsigned long isa_virt_to_bus(volatile void *address)
125 {
126 	return virt_to_phys(address);
127 }
128 
129 static inline void *isa_bus_to_virt(unsigned long address)
130 {
131 	return phys_to_virt(address);
132 }
133 
134 #define isa_page_to_bus page_to_phys
135 
136 /*
137  * However PCI ones are not necessarily 1:1 and therefore these interfaces
138  * are forbidden in portable PCI drivers.
139  *
140  * Allow them for x86 for legacy drivers, though.
141  */
142 #define virt_to_bus virt_to_phys
143 #define bus_to_virt phys_to_virt
144 
145 /*
146  * Change "struct page" to physical address.
147  */
148 #define page_to_phys(page)	((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
149 
150 extern void __iomem * __ioremap(phys_addr_t offset, phys_addr_t size, unsigned long flags);
151 extern void __iounmap(const volatile void __iomem *addr);
152 
153 static inline void __iomem * __ioremap_mode(phys_addr_t offset, unsigned long size,
154 	unsigned long flags)
155 {
156 	void __iomem *addr = plat_ioremap(offset, size, flags);
157 
158 	if (addr)
159 		return addr;
160 
161 #define __IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
162 
163 	if (cpu_has_64bit_addresses) {
164 		u64 base = UNCAC_BASE;
165 
166 		/*
167 		 * R10000 supports a 2 bit uncached attribute therefore
168 		 * UNCAC_BASE may not equal IO_BASE.
169 		 */
170 		if (flags == _CACHE_UNCACHED)
171 			base = (u64) IO_BASE;
172 		return (void __iomem *) (unsigned long) (base + offset);
173 	} else if (__builtin_constant_p(offset) &&
174 		   __builtin_constant_p(size) && __builtin_constant_p(flags)) {
175 		phys_addr_t phys_addr, last_addr;
176 
177 		phys_addr = fixup_bigphys_addr(offset, size);
178 
179 		/* Don't allow wraparound or zero size. */
180 		last_addr = phys_addr + size - 1;
181 		if (!size || last_addr < phys_addr)
182 			return NULL;
183 
184 		/*
185 		 * Map uncached objects in the low 512MB of address
186 		 * space using KSEG1.
187 		 */
188 		if (__IS_LOW512(phys_addr) && __IS_LOW512(last_addr) &&
189 		    flags == _CACHE_UNCACHED)
190 			return (void __iomem *)
191 				(unsigned long)CKSEG1ADDR(phys_addr);
192 	}
193 
194 	return __ioremap(offset, size, flags);
195 
196 #undef __IS_LOW512
197 }
198 
199 /*
200  * ioremap     -   map bus memory into CPU space
201  * @offset:    bus address of the memory
202  * @size:      size of the resource to map
203  *
204  * ioremap performs a platform specific sequence of operations to
205  * make bus memory CPU accessible via the readb/readw/readl/writeb/
206  * writew/writel functions and the other mmio helpers. The returned
207  * address is not guaranteed to be usable directly as a virtual
208  * address.
209  */
210 #define ioremap(offset, size)						\
211 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
212 
213 /*
214  * ioremap_nocache     -   map bus memory into CPU space
215  * @offset:    bus address of the memory
216  * @size:      size of the resource to map
217  *
218  * ioremap_nocache performs a platform specific sequence of operations to
219  * make bus memory CPU accessible via the readb/readw/readl/writeb/
220  * writew/writel functions and the other mmio helpers. The returned
221  * address is not guaranteed to be usable directly as a virtual
222  * address.
223  *
224  * This version of ioremap ensures that the memory is marked uncachable
225  * on the CPU as well as honouring existing caching rules from things like
226  * the PCI bus. Note that there are other caches and buffers on many
227  * busses. In particular driver authors should read up on PCI writes
228  *
229  * It's useful if some control registers are in such an area and
230  * write combining or read caching is not desirable:
231  */
232 #define ioremap_nocache(offset, size)					\
233 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
234 #define ioremap_uc ioremap_nocache
235 
236 /*
237  * ioremap_cachable -	map bus memory into CPU space
238  * @offset:	    bus address of the memory
239  * @size:	    size of the resource to map
240  *
241  * ioremap_nocache performs a platform specific sequence of operations to
242  * make bus memory CPU accessible via the readb/readw/readl/writeb/
243  * writew/writel functions and the other mmio helpers. The returned
244  * address is not guaranteed to be usable directly as a virtual
245  * address.
246  *
247  * This version of ioremap ensures that the memory is marked cachable by
248  * the CPU.  Also enables full write-combining.	 Useful for some
249  * memory-like regions on I/O busses.
250  */
251 #define ioremap_cachable(offset, size)					\
252 	__ioremap_mode((offset), (size), _page_cachable_default)
253 #define ioremap_cache ioremap_cachable
254 
255 /*
256  * ioremap_wc     -   map bus memory into CPU space
257  * @offset:    bus address of the memory
258  * @size:      size of the resource to map
259  *
260  * ioremap_wc performs a platform specific sequence of operations to
261  * make bus memory CPU accessible via the readb/readw/readl/writeb/
262  * writew/writel functions and the other mmio helpers. The returned
263  * address is not guaranteed to be usable directly as a virtual
264  * address.
265  *
266  * This version of ioremap ensures that the memory is marked uncachable
267  * but accelerated by means of write-combining feature. It is specifically
268  * useful for PCIe prefetchable windows, which may vastly improve a
269  * communications performance. If it was determined on boot stage, what
270  * CPU CCA doesn't support UCA, the method shall fall-back to the
271  * _CACHE_UNCACHED option (see cpu_probe() method).
272  */
273 #define ioremap_wc(offset, size)					\
274 	__ioremap_mode((offset), (size), boot_cpu_data.writecombine)
275 
276 static inline void iounmap(const volatile void __iomem *addr)
277 {
278 	if (plat_iounmap(addr))
279 		return;
280 
281 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
282 
283 	if (cpu_has_64bit_addresses ||
284 	    (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
285 		return;
286 
287 	__iounmap(addr);
288 
289 #undef __IS_KSEG1
290 }
291 
292 #if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_LOONGSON3_ENHANCEMENT)
293 #define war_io_reorder_wmb()		wmb()
294 #else
295 #define war_io_reorder_wmb()		barrier()
296 #endif
297 
298 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq)			\
299 									\
300 static inline void pfx##write##bwlq(type val,				\
301 				    volatile void __iomem *mem)		\
302 {									\
303 	volatile type *__mem;						\
304 	type __val;							\
305 									\
306 	war_io_reorder_wmb();					\
307 									\
308 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
309 									\
310 	__val = pfx##ioswab##bwlq(__mem, val);				\
311 									\
312 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
313 		*__mem = __val;						\
314 	else if (cpu_has_64bits) {					\
315 		unsigned long __flags;					\
316 		type __tmp;						\
317 									\
318 		if (irq)						\
319 			local_irq_save(__flags);			\
320 		__asm__ __volatile__(					\
321 			".set	arch=r4000"	"\t\t# __writeq""\n\t"	\
322 			"dsll32 %L0, %L0, 0"			"\n\t"	\
323 			"dsrl32 %L0, %L0, 0"			"\n\t"	\
324 			"dsll32 %M0, %M0, 0"			"\n\t"	\
325 			"or	%L0, %L0, %M0"			"\n\t"	\
326 			"sd	%L0, %2"			"\n\t"	\
327 			".set	mips0"				"\n"	\
328 			: "=r" (__tmp)					\
329 			: "0" (__val), "m" (*__mem));			\
330 		if (irq)						\
331 			local_irq_restore(__flags);			\
332 	} else								\
333 		BUG();							\
334 }									\
335 									\
336 static inline type pfx##read##bwlq(const volatile void __iomem *mem)	\
337 {									\
338 	volatile type *__mem;						\
339 	type __val;							\
340 									\
341 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
342 									\
343 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
344 		__val = *__mem;						\
345 	else if (cpu_has_64bits) {					\
346 		unsigned long __flags;					\
347 									\
348 		if (irq)						\
349 			local_irq_save(__flags);			\
350 		__asm__ __volatile__(					\
351 			".set	arch=r4000"	"\t\t# __readq" "\n\t"	\
352 			"ld	%L0, %1"			"\n\t"	\
353 			"dsra32 %M0, %L0, 0"			"\n\t"	\
354 			"sll	%L0, %L0, 0"			"\n\t"	\
355 			".set	mips0"				"\n"	\
356 			: "=r" (__val)					\
357 			: "m" (*__mem));				\
358 		if (irq)						\
359 			local_irq_restore(__flags);			\
360 	} else {							\
361 		__val = 0;						\
362 		BUG();							\
363 	}								\
364 									\
365 	/* prevent prefetching of coherent DMA data prematurely */	\
366 	rmb();								\
367 	return pfx##ioswab##bwlq(__mem, __val);				\
368 }
369 
370 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, p)			\
371 									\
372 static inline void pfx##out##bwlq##p(type val, unsigned long port)	\
373 {									\
374 	volatile type *__addr;						\
375 	type __val;							\
376 									\
377 	war_io_reorder_wmb();					\
378 									\
379 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
380 									\
381 	__val = pfx##ioswab##bwlq(__addr, val);				\
382 									\
383 	/* Really, we want this to be atomic */				\
384 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
385 									\
386 	*__addr = __val;						\
387 }									\
388 									\
389 static inline type pfx##in##bwlq##p(unsigned long port)			\
390 {									\
391 	volatile type *__addr;						\
392 	type __val;							\
393 									\
394 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
395 									\
396 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
397 									\
398 	__val = *__addr;						\
399 									\
400 	/* prevent prefetching of coherent DMA data prematurely */	\
401 	rmb();								\
402 	return pfx##ioswab##bwlq(__addr, __val);			\
403 }
404 
405 #define __BUILD_MEMORY_PFX(bus, bwlq, type)				\
406 									\
407 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1)
408 
409 #define BUILDIO_MEM(bwlq, type)						\
410 									\
411 __BUILD_MEMORY_PFX(__raw_, bwlq, type)					\
412 __BUILD_MEMORY_PFX(, bwlq, type)					\
413 __BUILD_MEMORY_PFX(__mem_, bwlq, type)					\
414 
415 BUILDIO_MEM(b, u8)
416 BUILDIO_MEM(w, u16)
417 BUILDIO_MEM(l, u32)
418 BUILDIO_MEM(q, u64)
419 
420 #define __BUILD_IOPORT_PFX(bus, bwlq, type)				\
421 	__BUILD_IOPORT_SINGLE(bus, bwlq, type,)				\
422 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, _p)
423 
424 #define BUILDIO_IOPORT(bwlq, type)					\
425 	__BUILD_IOPORT_PFX(, bwlq, type)				\
426 	__BUILD_IOPORT_PFX(__mem_, bwlq, type)
427 
428 BUILDIO_IOPORT(b, u8)
429 BUILDIO_IOPORT(w, u16)
430 BUILDIO_IOPORT(l, u32)
431 #ifdef CONFIG_64BIT
432 BUILDIO_IOPORT(q, u64)
433 #endif
434 
435 #define __BUILDIO(bwlq, type)						\
436 									\
437 __BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 0)
438 
439 __BUILDIO(q, u64)
440 
441 #define readb_relaxed			readb
442 #define readw_relaxed			readw
443 #define readl_relaxed			readl
444 #define readq_relaxed			readq
445 
446 #define writeb_relaxed			writeb
447 #define writew_relaxed			writew
448 #define writel_relaxed			writel
449 #define writeq_relaxed			writeq
450 
451 #define readb_be(addr)							\
452 	__raw_readb((__force unsigned *)(addr))
453 #define readw_be(addr)							\
454 	be16_to_cpu(__raw_readw((__force unsigned *)(addr)))
455 #define readl_be(addr)							\
456 	be32_to_cpu(__raw_readl((__force unsigned *)(addr)))
457 #define readq_be(addr)							\
458 	be64_to_cpu(__raw_readq((__force unsigned *)(addr)))
459 
460 #define writeb_be(val, addr)						\
461 	__raw_writeb((val), (__force unsigned *)(addr))
462 #define writew_be(val, addr)						\
463 	__raw_writew(cpu_to_be16((val)), (__force unsigned *)(addr))
464 #define writel_be(val, addr)						\
465 	__raw_writel(cpu_to_be32((val)), (__force unsigned *)(addr))
466 #define writeq_be(val, addr)						\
467 	__raw_writeq(cpu_to_be64((val)), (__force unsigned *)(addr))
468 
469 /*
470  * Some code tests for these symbols
471  */
472 #define readq				readq
473 #define writeq				writeq
474 
475 #define __BUILD_MEMORY_STRING(bwlq, type)				\
476 									\
477 static inline void writes##bwlq(volatile void __iomem *mem,		\
478 				const void *addr, unsigned int count)	\
479 {									\
480 	const volatile type *__addr = addr;				\
481 									\
482 	while (count--) {						\
483 		__mem_write##bwlq(*__addr, mem);			\
484 		__addr++;						\
485 	}								\
486 }									\
487 									\
488 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,	\
489 			       unsigned int count)			\
490 {									\
491 	volatile type *__addr = addr;					\
492 									\
493 	while (count--) {						\
494 		*__addr = __mem_read##bwlq(mem);			\
495 		__addr++;						\
496 	}								\
497 }
498 
499 #define __BUILD_IOPORT_STRING(bwlq, type)				\
500 									\
501 static inline void outs##bwlq(unsigned long port, const void *addr,	\
502 			      unsigned int count)			\
503 {									\
504 	const volatile type *__addr = addr;				\
505 									\
506 	while (count--) {						\
507 		__mem_out##bwlq(*__addr, port);				\
508 		__addr++;						\
509 	}								\
510 }									\
511 									\
512 static inline void ins##bwlq(unsigned long port, void *addr,		\
513 			     unsigned int count)			\
514 {									\
515 	volatile type *__addr = addr;					\
516 									\
517 	while (count--) {						\
518 		*__addr = __mem_in##bwlq(port);				\
519 		__addr++;						\
520 	}								\
521 }
522 
523 #define BUILDSTRING(bwlq, type)						\
524 									\
525 __BUILD_MEMORY_STRING(bwlq, type)					\
526 __BUILD_IOPORT_STRING(bwlq, type)
527 
528 BUILDSTRING(b, u8)
529 BUILDSTRING(w, u16)
530 BUILDSTRING(l, u32)
531 #ifdef CONFIG_64BIT
532 BUILDSTRING(q, u64)
533 #endif
534 
535 
536 #ifdef CONFIG_CPU_CAVIUM_OCTEON
537 #define mmiowb() wmb()
538 #else
539 /* Depends on MIPS II instruction set */
540 #define mmiowb() asm volatile ("sync" ::: "memory")
541 #endif
542 
543 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
544 {
545 	memset((void __force *) addr, val, count);
546 }
547 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
548 {
549 	memcpy(dst, (void __force *) src, count);
550 }
551 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
552 {
553 	memcpy((void __force *) dst, src, count);
554 }
555 
556 /*
557  * The caches on some architectures aren't dma-coherent and have need to
558  * handle this in software.  There are three types of operations that
559  * can be applied to dma buffers.
560  *
561  *  - dma_cache_wback_inv(start, size) makes caches and coherent by
562  *    writing the content of the caches back to memory, if necessary.
563  *    The function also invalidates the affected part of the caches as
564  *    necessary before DMA transfers from outside to memory.
565  *  - dma_cache_wback(start, size) makes caches and coherent by
566  *    writing the content of the caches back to memory, if necessary.
567  *    The function also invalidates the affected part of the caches as
568  *    necessary before DMA transfers from outside to memory.
569  *  - dma_cache_inv(start, size) invalidates the affected parts of the
570  *    caches.  Dirty lines of the caches may be written back or simply
571  *    be discarded.  This operation is necessary before dma operations
572  *    to the memory.
573  *
574  * This API used to be exported; it now is for arch code internal use only.
575  */
576 #ifdef CONFIG_DMA_NONCOHERENT
577 
578 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
579 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
580 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
581 
582 #define dma_cache_wback_inv(start, size)	_dma_cache_wback_inv(start, size)
583 #define dma_cache_wback(start, size)		_dma_cache_wback(start, size)
584 #define dma_cache_inv(start, size)		_dma_cache_inv(start, size)
585 
586 #else /* Sane hardware */
587 
588 #define dma_cache_wback_inv(start,size) \
589 	do { (void) (start); (void) (size); } while (0)
590 #define dma_cache_wback(start,size)	\
591 	do { (void) (start); (void) (size); } while (0)
592 #define dma_cache_inv(start,size)	\
593 	do { (void) (start); (void) (size); } while (0)
594 
595 #endif /* CONFIG_DMA_NONCOHERENT */
596 
597 /*
598  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
599  * Avoid interrupt mucking, just adjust the address for 4-byte access.
600  * Assume the addresses are 8-byte aligned.
601  */
602 #ifdef __MIPSEB__
603 #define __CSR_32_ADJUST 4
604 #else
605 #define __CSR_32_ADJUST 0
606 #endif
607 
608 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
609 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
610 
611 /*
612  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
613  * access
614  */
615 #define xlate_dev_mem_ptr(p)	__va(p)
616 
617 /*
618  * Convert a virtual cached pointer to an uncached pointer
619  */
620 #define xlate_dev_kmem_ptr(p)	p
621 
622 void __ioread64_copy(void *to, const void __iomem *from, size_t count);
623 
624 #endif /* _ASM_IO_H */
625