xref: /openbmc/linux/arch/mips/include/asm/io.h (revision 1eb4c977)
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 
19 #include <asm/addrspace.h>
20 #include <asm/byteorder.h>
21 #include <asm/cpu.h>
22 #include <asm/cpu-features.h>
23 #include <asm-generic/iomap.h>
24 #include <asm/page.h>
25 #include <asm/pgtable-bits.h>
26 #include <asm/processor.h>
27 #include <asm/string.h>
28 
29 #include <ioremap.h>
30 #include <mangle-port.h>
31 
32 /*
33  * Slowdown I/O port space accesses for antique hardware.
34  */
35 #undef CONF_SLOWDOWN_IO
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 /* ioswab[bwlq], __mem_ioswab[bwlq] are defined in mangle-port.h */
50 
51 #define IO_SPACE_LIMIT 0xffff
52 
53 /*
54  * On MIPS I/O ports are memory mapped, so we access them using normal
55  * load/store instructions. mips_io_port_base is the virtual address to
56  * which all ports are being mapped.  For sake of efficiency some code
57  * assumes that this is an address that can be loaded with a single lui
58  * instruction, so the lower 16 bits must be zero.  Should be true on
59  * on any sane architecture; generic code does not use this assumption.
60  */
61 extern const unsigned long mips_io_port_base;
62 
63 /*
64  * Gcc will generate code to load the value of mips_io_port_base after each
65  * function call which may be fairly wasteful in some cases.  So we don't
66  * play quite by the book.  We tell gcc mips_io_port_base is a long variable
67  * which solves the code generation issue.  Now we need to violate the
68  * aliasing rules a little to make initialization possible and finally we
69  * will need the barrier() to fight side effects of the aliasing chat.
70  * This trickery will eventually collapse under gcc's optimizer.  Oh well.
71  */
72 static inline void set_io_port_base(unsigned long base)
73 {
74 	* (unsigned long *) &mips_io_port_base = base;
75 	barrier();
76 }
77 
78 /*
79  * Thanks to James van Artsdalen for a better timing-fix than
80  * the two short jumps: using outb's to a nonexistent port seems
81  * to guarantee better timings even on fast machines.
82  *
83  * On the other hand, I'd like to be sure of a non-existent port:
84  * I feel a bit unsafe about using 0x80 (should be safe, though)
85  *
86  *		Linus
87  *
88  */
89 
90 #define __SLOW_DOWN_IO \
91 	__asm__ __volatile__( \
92 		"sb\t$0,0x80(%0)" \
93 		: : "r" (mips_io_port_base));
94 
95 #ifdef CONF_SLOWDOWN_IO
96 #ifdef REALLY_SLOW_IO
97 #define SLOW_DOWN_IO { __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; }
98 #else
99 #define SLOW_DOWN_IO __SLOW_DOWN_IO
100 #endif
101 #else
102 #define SLOW_DOWN_IO
103 #endif
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 (unsigned long)address - PAGE_OFFSET + PHYS_OFFSET;
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 (unsigned long)address - PAGE_OFFSET;
145 }
146 
147 static inline void * isa_bus_to_virt(unsigned long address)
148 {
149 	return (void *)(address + PAGE_OFFSET);
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_t offset, phys_t size, unsigned long flags);
169 extern void __iounmap(const volatile void __iomem *addr);
170 
171 static inline void __iomem * __ioremap_mode(phys_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_t)(addr) & (phys_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_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     -   map bus memory into CPU space
219  * @offset:    bus address of the memory
220  * @size:      size of the resource to map
221  *
222  * ioremap performs a platform specific sequence of operations to
223  * make bus memory CPU accessible via the readb/readw/readl/writeb/
224  * writew/writel functions and the other mmio helpers. The returned
225  * address is not guaranteed to be usable directly as a virtual
226  * address.
227  */
228 #define ioremap(offset, size)						\
229 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
230 
231 /*
232  * ioremap_nocache     -   map bus memory into CPU space
233  * @offset:    bus address of the memory
234  * @size:      size of the resource to map
235  *
236  * ioremap_nocache performs a platform specific sequence of operations to
237  * make bus memory CPU accessible via the readb/readw/readl/writeb/
238  * writew/writel functions and the other mmio helpers. The returned
239  * address is not guaranteed to be usable directly as a virtual
240  * address.
241  *
242  * This version of ioremap ensures that the memory is marked uncachable
243  * on the CPU as well as honouring existing caching rules from things like
244  * the PCI bus. Note that there are other caches and buffers on many
245  * busses. In particular driver authors should read up on PCI writes
246  *
247  * It's useful if some control registers are in such an area and
248  * write combining or read caching is not desirable:
249  */
250 #define ioremap_nocache(offset, size)					\
251 	__ioremap_mode((offset), (size), _CACHE_UNCACHED)
252 
253 /*
254  * ioremap_cachable -   map bus memory into CPU space
255  * @offset:         bus address of the memory
256  * @size:           size of the resource to map
257  *
258  * ioremap_nocache performs a platform specific sequence of operations to
259  * make bus memory CPU accessible via the readb/readw/readl/writeb/
260  * writew/writel functions and the other mmio helpers. The returned
261  * address is not guaranteed to be usable directly as a virtual
262  * address.
263  *
264  * This version of ioremap ensures that the memory is marked cachable by
265  * the CPU.  Also enables full write-combining.  Useful for some
266  * memory-like regions on I/O busses.
267  */
268 #define ioremap_cachable(offset, size)					\
269 	__ioremap_mode((offset), (size), _page_cachable_default)
270 
271 /*
272  * These two are MIPS specific ioremap variant.  ioremap_cacheable_cow
273  * requests a cachable mapping, ioremap_uncached_accelerated requests a
274  * mapping using the uncached accelerated mode which isn't supported on
275  * all processors.
276  */
277 #define ioremap_cacheable_cow(offset, size)				\
278 	__ioremap_mode((offset), (size), _CACHE_CACHABLE_COW)
279 #define ioremap_uncached_accelerated(offset, size)			\
280 	__ioremap_mode((offset), (size), _CACHE_UNCACHED_ACCELERATED)
281 
282 static inline void iounmap(const volatile void __iomem *addr)
283 {
284 	if (plat_iounmap(addr))
285 		return;
286 
287 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
288 
289 	if (cpu_has_64bit_addresses ||
290 	    (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
291 		return;
292 
293 	__iounmap(addr);
294 
295 #undef __IS_KSEG1
296 }
297 
298 #ifdef CONFIG_CPU_CAVIUM_OCTEON
299 #define war_octeon_io_reorder_wmb()  		wmb()
300 #else
301 #define war_octeon_io_reorder_wmb()		do { } while (0)
302 #endif
303 
304 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq)			\
305 									\
306 static inline void pfx##write##bwlq(type val,				\
307 				    volatile void __iomem *mem)		\
308 {									\
309 	volatile type *__mem;						\
310 	type __val;							\
311 									\
312 	war_octeon_io_reorder_wmb();					\
313 									\
314 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
315 									\
316 	__val = pfx##ioswab##bwlq(__mem, val);				\
317 									\
318 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long))	\
319 		*__mem = __val;						\
320 	else if (cpu_has_64bits) {					\
321 		unsigned long __flags;					\
322 		type __tmp;						\
323 									\
324 		if (irq)						\
325 			local_irq_save(__flags);			\
326 		__asm__ __volatile__(					\
327 			".set	mips3"		"\t\t# __writeq""\n\t"	\
328 			"dsll32	%L0, %L0, 0"			"\n\t"	\
329 			"dsrl32	%L0, %L0, 0"			"\n\t"	\
330 			"dsll32	%M0, %M0, 0"			"\n\t"	\
331 			"or	%L0, %L0, %M0"			"\n\t"	\
332 			"sd	%L0, %2"			"\n\t"	\
333 			".set	mips0"				"\n"	\
334 			: "=r" (__tmp)					\
335 			: "0" (__val), "m" (*__mem));			\
336 		if (irq)						\
337 			local_irq_restore(__flags);			\
338 	} else								\
339 		BUG();							\
340 }									\
341 									\
342 static inline type pfx##read##bwlq(const volatile void __iomem *mem)	\
343 {									\
344 	volatile type *__mem;						\
345 	type __val;							\
346 									\
347 	__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));	\
348 									\
349 	if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long))	\
350 		__val = *__mem;						\
351 	else if (cpu_has_64bits) {					\
352 		unsigned long __flags;					\
353 									\
354 		if (irq)						\
355 			local_irq_save(__flags);			\
356 		__asm__ __volatile__(					\
357 			".set	mips3"		"\t\t# __readq"	"\n\t"	\
358 			"ld	%L0, %1"			"\n\t"	\
359 			"dsra32	%M0, %L0, 0"			"\n\t"	\
360 			"sll	%L0, %L0, 0"			"\n\t"	\
361 			".set	mips0"				"\n"	\
362 			: "=r" (__val)					\
363 			: "m" (*__mem));				\
364 		if (irq)						\
365 			local_irq_restore(__flags);			\
366 	} else {							\
367 		__val = 0;						\
368 		BUG();							\
369 	}								\
370 									\
371 	return pfx##ioswab##bwlq(__mem, __val);				\
372 }
373 
374 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, p, slow)			\
375 									\
376 static inline void pfx##out##bwlq##p(type val, unsigned long port)	\
377 {									\
378 	volatile type *__addr;						\
379 	type __val;							\
380 									\
381 	war_octeon_io_reorder_wmb();					\
382 									\
383 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
384 									\
385 	__val = pfx##ioswab##bwlq(__addr, val);				\
386 									\
387 	/* Really, we want this to be atomic */				\
388 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
389 									\
390 	*__addr = __val;						\
391 	slow;								\
392 }									\
393 									\
394 static inline type pfx##in##bwlq##p(unsigned long port)			\
395 {									\
396 	volatile type *__addr;						\
397 	type __val;							\
398 									\
399 	__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
400 									\
401 	BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));		\
402 									\
403 	__val = *__addr;						\
404 	slow;								\
405 									\
406 	return pfx##ioswab##bwlq(__addr, __val);			\
407 }
408 
409 #define __BUILD_MEMORY_PFX(bus, bwlq, type)				\
410 									\
411 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1)
412 
413 #define BUILDIO_MEM(bwlq, type)						\
414 									\
415 __BUILD_MEMORY_PFX(__raw_, bwlq, type)					\
416 __BUILD_MEMORY_PFX(, bwlq, type)					\
417 __BUILD_MEMORY_PFX(__mem_, bwlq, type)					\
418 
419 BUILDIO_MEM(b, u8)
420 BUILDIO_MEM(w, u16)
421 BUILDIO_MEM(l, u32)
422 BUILDIO_MEM(q, u64)
423 
424 #define __BUILD_IOPORT_PFX(bus, bwlq, type)				\
425 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, ,)			\
426 	__BUILD_IOPORT_SINGLE(bus, bwlq, type, _p, SLOW_DOWN_IO)
427 
428 #define BUILDIO_IOPORT(bwlq, type)					\
429 	__BUILD_IOPORT_PFX(, bwlq, type)				\
430 	__BUILD_IOPORT_PFX(__mem_, bwlq, type)
431 
432 BUILDIO_IOPORT(b, u8)
433 BUILDIO_IOPORT(w, u16)
434 BUILDIO_IOPORT(l, u32)
435 #ifdef CONFIG_64BIT
436 BUILDIO_IOPORT(q, u64)
437 #endif
438 
439 #define __BUILDIO(bwlq, type)						\
440 									\
441 __BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 0)
442 
443 __BUILDIO(q, u64)
444 
445 #define readb_relaxed			readb
446 #define readw_relaxed			readw
447 #define readl_relaxed			readl
448 #define readq_relaxed			readq
449 
450 #define readb_be(addr)							\
451 	__raw_readb((__force unsigned *)(addr))
452 #define readw_be(addr)							\
453 	be16_to_cpu(__raw_readw((__force unsigned *)(addr)))
454 #define readl_be(addr)							\
455 	be32_to_cpu(__raw_readl((__force unsigned *)(addr)))
456 #define readq_be(addr)							\
457 	be64_to_cpu(__raw_readq((__force unsigned *)(addr)))
458 
459 #define writeb_be(val, addr)						\
460 	__raw_writeb((val), (__force unsigned *)(addr))
461 #define writew_be(val, addr)						\
462 	__raw_writew(cpu_to_be16((val)), (__force unsigned *)(addr))
463 #define writel_be(val, addr)						\
464 	__raw_writel(cpu_to_be32((val)), (__force unsigned *)(addr))
465 #define writeq_be(val, addr)						\
466 	__raw_writeq(cpu_to_be64((val)), (__force unsigned *)(addr))
467 
468 /*
469  * Some code tests for these symbols
470  */
471 #define readq				readq
472 #define writeq				writeq
473 
474 #define __BUILD_MEMORY_STRING(bwlq, type)				\
475 									\
476 static inline void writes##bwlq(volatile void __iomem *mem,		\
477 				const void *addr, unsigned int count)	\
478 {									\
479 	const volatile type *__addr = addr;				\
480 									\
481 	while (count--) {						\
482 		__mem_write##bwlq(*__addr, mem);			\
483 		__addr++;						\
484 	}								\
485 }									\
486 									\
487 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,	\
488 			       unsigned int count)			\
489 {									\
490 	volatile type *__addr = addr;					\
491 									\
492 	while (count--) {						\
493 		*__addr = __mem_read##bwlq(mem);			\
494 		__addr++;						\
495 	}								\
496 }
497 
498 #define __BUILD_IOPORT_STRING(bwlq, type)				\
499 									\
500 static inline void outs##bwlq(unsigned long port, const void *addr,	\
501 			      unsigned int count)			\
502 {									\
503 	const volatile type *__addr = addr;				\
504 									\
505 	while (count--) {						\
506 		__mem_out##bwlq(*__addr, port);				\
507 		__addr++;						\
508 	}								\
509 }									\
510 									\
511 static inline void ins##bwlq(unsigned long port, void *addr,		\
512 			     unsigned int count)			\
513 {									\
514 	volatile type *__addr = addr;					\
515 									\
516 	while (count--) {						\
517 		*__addr = __mem_in##bwlq(port);				\
518 		__addr++;						\
519 	}								\
520 }
521 
522 #define BUILDSTRING(bwlq, type)						\
523 									\
524 __BUILD_MEMORY_STRING(bwlq, type)					\
525 __BUILD_IOPORT_STRING(bwlq, type)
526 
527 BUILDSTRING(b, u8)
528 BUILDSTRING(w, u16)
529 BUILDSTRING(l, u32)
530 #ifdef CONFIG_64BIT
531 BUILDSTRING(q, u64)
532 #endif
533 
534 
535 #ifdef CONFIG_CPU_CAVIUM_OCTEON
536 #define mmiowb() wmb()
537 #else
538 /* Depends on MIPS II instruction set */
539 #define mmiowb() asm volatile ("sync" ::: "memory")
540 #endif
541 
542 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
543 {
544 	memset((void __force *) addr, val, count);
545 }
546 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
547 {
548 	memcpy(dst, (void __force *) src, count);
549 }
550 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
551 {
552 	memcpy((void __force *) dst, src, count);
553 }
554 
555 /*
556  * The caches on some architectures aren't dma-coherent and have need to
557  * handle this in software.  There are three types of operations that
558  * can be applied to dma buffers.
559  *
560  *  - dma_cache_wback_inv(start, size) makes caches and coherent by
561  *    writing the content of the caches back to memory, if necessary.
562  *    The function also invalidates the affected part of the caches as
563  *    necessary before DMA transfers from outside to memory.
564  *  - dma_cache_wback(start, size) makes caches and coherent by
565  *    writing the content of the caches back to memory, if necessary.
566  *    The function also invalidates the affected part of the caches as
567  *    necessary before DMA transfers from outside to memory.
568  *  - dma_cache_inv(start, size) invalidates the affected parts of the
569  *    caches.  Dirty lines of the caches may be written back or simply
570  *    be discarded.  This operation is necessary before dma operations
571  *    to the memory.
572  *
573  * This API used to be exported; it now is for arch code internal use only.
574  */
575 #ifdef CONFIG_DMA_NONCOHERENT
576 
577 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
578 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
579 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
580 
581 #define dma_cache_wback_inv(start, size)	_dma_cache_wback_inv(start, size)
582 #define dma_cache_wback(start, size)		_dma_cache_wback(start, size)
583 #define dma_cache_inv(start, size)		_dma_cache_inv(start, size)
584 
585 #else /* Sane hardware */
586 
587 #define dma_cache_wback_inv(start,size)	\
588 	do { (void) (start); (void) (size); } while (0)
589 #define dma_cache_wback(start,size)	\
590 	do { (void) (start); (void) (size); } while (0)
591 #define dma_cache_inv(start,size)	\
592 	do { (void) (start); (void) (size); } while (0)
593 
594 #endif /* CONFIG_DMA_NONCOHERENT */
595 
596 /*
597  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
598  * Avoid interrupt mucking, just adjust the address for 4-byte access.
599  * Assume the addresses are 8-byte aligned.
600  */
601 #ifdef __MIPSEB__
602 #define __CSR_32_ADJUST 4
603 #else
604 #define __CSR_32_ADJUST 0
605 #endif
606 
607 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
608 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
609 
610 /*
611  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
612  * access
613  */
614 #define xlate_dev_mem_ptr(p)	__va(p)
615 
616 /*
617  * Convert a virtual cached pointer to an uncached pointer
618  */
619 #define xlate_dev_kmem_ptr(p)	p
620 
621 #endif /* _ASM_IO_H */
622