xref: /linux/arch/arm/include/asm/io.h (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
1 /*
2  *  arch/arm/include/asm/io.h
3  *
4  *  Copyright (C) 1996-2000 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * Modifications:
11  *  16-Sep-1996	RMK	Inlined the inx/outx functions & optimised for both
12  *			constant addresses and variable addresses.
13  *  04-Dec-1997	RMK	Moved a lot of this stuff to the new architecture
14  *			specific IO header files.
15  *  27-Mar-1999	PJB	Second parameter of memcpy_toio is const..
16  *  04-Apr-1999	PJB	Added check_signature.
17  *  12-Dec-1999	RMK	More cleanups
18  *  18-Jun-2000 RMK	Removed virt_to_* and friends definitions
19  *  05-Oct-2004 BJD     Moved memory string functions to use void __iomem
20  */
21 #ifndef __ASM_ARM_IO_H
22 #define __ASM_ARM_IO_H
23 
24 #ifdef __KERNEL__
25 
26 #include <linux/string.h>
27 #include <linux/types.h>
28 #include <asm/byteorder.h>
29 #include <asm/memory.h>
30 #include <asm-generic/pci_iomap.h>
31 #include <xen/xen.h>
32 
33 /*
34  * ISA I/O bus memory addresses are 1:1 with the physical address.
35  */
36 #define isa_virt_to_bus virt_to_phys
37 #define isa_page_to_bus page_to_phys
38 #define isa_bus_to_virt phys_to_virt
39 
40 /*
41  * Atomic MMIO-wide IO modify
42  */
43 extern void atomic_io_modify(void __iomem *reg, u32 mask, u32 set);
44 extern void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set);
45 
46 /*
47  * Generic IO read/write.  These perform native-endian accesses.  Note
48  * that some architectures will want to re-define __raw_{read,write}w.
49  */
50 void __raw_writesb(volatile void __iomem *addr, const void *data, int bytelen);
51 void __raw_writesw(volatile void __iomem *addr, const void *data, int wordlen);
52 void __raw_writesl(volatile void __iomem *addr, const void *data, int longlen);
53 
54 void __raw_readsb(const volatile void __iomem *addr, void *data, int bytelen);
55 void __raw_readsw(const volatile void __iomem *addr, void *data, int wordlen);
56 void __raw_readsl(const volatile void __iomem *addr, void *data, int longlen);
57 
58 #if __LINUX_ARM_ARCH__ < 6
59 /*
60  * Half-word accesses are problematic with RiscPC due to limitations of
61  * the bus. Rather than special-case the machine, just let the compiler
62  * generate the access for CPUs prior to ARMv6.
63  */
64 #define __raw_readw(a)         (__chk_io_ptr(a), *(volatile unsigned short __force *)(a))
65 #define __raw_writew(v,a)      ((void)(__chk_io_ptr(a), *(volatile unsigned short __force *)(a) = (v)))
66 #else
67 /*
68  * When running under a hypervisor, we want to avoid I/O accesses with
69  * writeback addressing modes as these incur a significant performance
70  * overhead (the address generation must be emulated in software).
71  */
72 #define __raw_writew __raw_writew
73 static inline void __raw_writew(u16 val, volatile void __iomem *addr)
74 {
75 	asm volatile("strh %1, %0"
76 		     : : "Q" (*(volatile u16 __force *)addr), "r" (val));
77 }
78 
79 #define __raw_readw __raw_readw
80 static inline u16 __raw_readw(const volatile void __iomem *addr)
81 {
82 	u16 val;
83 	asm volatile("ldrh %0, %1"
84 		     : "=r" (val)
85 		     : "Q" (*(volatile u16 __force *)addr));
86 	return val;
87 }
88 #endif
89 
90 #define __raw_writeb __raw_writeb
91 static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
92 {
93 	asm volatile("strb %1, %0"
94 		     : : "Qo" (*(volatile u8 __force *)addr), "r" (val));
95 }
96 
97 #define __raw_writel __raw_writel
98 static inline void __raw_writel(u32 val, volatile void __iomem *addr)
99 {
100 	asm volatile("str %1, %0"
101 		     : : "Qo" (*(volatile u32 __force *)addr), "r" (val));
102 }
103 
104 #define __raw_readb __raw_readb
105 static inline u8 __raw_readb(const volatile void __iomem *addr)
106 {
107 	u8 val;
108 	asm volatile("ldrb %0, %1"
109 		     : "=r" (val)
110 		     : "Qo" (*(volatile u8 __force *)addr));
111 	return val;
112 }
113 
114 #define __raw_readl __raw_readl
115 static inline u32 __raw_readl(const volatile void __iomem *addr)
116 {
117 	u32 val;
118 	asm volatile("ldr %0, %1"
119 		     : "=r" (val)
120 		     : "Qo" (*(volatile u32 __force *)addr));
121 	return val;
122 }
123 
124 /*
125  * Architecture ioremap implementation.
126  */
127 #define MT_DEVICE		0
128 #define MT_DEVICE_NONSHARED	1
129 #define MT_DEVICE_CACHED	2
130 #define MT_DEVICE_WC		3
131 /*
132  * types 4 onwards can be found in asm/mach/map.h and are undefined
133  * for ioremap
134  */
135 
136 /*
137  * __arm_ioremap takes CPU physical address.
138  * __arm_ioremap_pfn takes a Page Frame Number and an offset into that page
139  * The _caller variety takes a __builtin_return_address(0) value for
140  * /proc/vmalloc to use - and should only be used in non-inline functions.
141  */
142 extern void __iomem *__arm_ioremap_caller(phys_addr_t, size_t, unsigned int,
143 	void *);
144 extern void __iomem *__arm_ioremap_pfn(unsigned long, unsigned long, size_t, unsigned int);
145 extern void __iomem *__arm_ioremap_exec(phys_addr_t, size_t, bool cached);
146 extern void __iounmap(volatile void __iomem *addr);
147 
148 extern void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t,
149 	unsigned int, void *);
150 extern void (*arch_iounmap)(volatile void __iomem *);
151 
152 /*
153  * Bad read/write accesses...
154  */
155 extern void __readwrite_bug(const char *fn);
156 
157 /*
158  * A typesafe __io() helper
159  */
160 static inline void __iomem *__typesafe_io(unsigned long addr)
161 {
162 	return (void __iomem *)addr;
163 }
164 
165 #define IOMEM(x)	((void __force __iomem *)(x))
166 
167 /* IO barriers */
168 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
169 #include <asm/barrier.h>
170 #define __iormb()		rmb()
171 #define __iowmb()		wmb()
172 #else
173 #define __iormb()		do { } while (0)
174 #define __iowmb()		do { } while (0)
175 #endif
176 
177 /* PCI fixed i/o mapping */
178 #define PCI_IO_VIRT_BASE	0xfee00000
179 #define PCI_IOBASE		((void __iomem *)PCI_IO_VIRT_BASE)
180 
181 #if defined(CONFIG_PCI)
182 void pci_ioremap_set_mem_type(int mem_type);
183 #else
184 static inline void pci_ioremap_set_mem_type(int mem_type) {}
185 #endif
186 
187 extern int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr);
188 
189 /*
190  * Now, pick up the machine-defined IO definitions
191  */
192 #ifdef CONFIG_NEED_MACH_IO_H
193 #include <mach/io.h>
194 #elif defined(CONFIG_PCI)
195 #define IO_SPACE_LIMIT	((resource_size_t)0xfffff)
196 #define __io(a)		__typesafe_io(PCI_IO_VIRT_BASE + ((a) & IO_SPACE_LIMIT))
197 #else
198 #define __io(a)		__typesafe_io((a) & IO_SPACE_LIMIT)
199 #endif
200 
201 /*
202  * This is the limit of PC card/PCI/ISA IO space, which is by default
203  * 64K if we have PC card, PCI or ISA support.  Otherwise, default to
204  * zero to prevent ISA/PCI drivers claiming IO space (and potentially
205  * oopsing.)
206  *
207  * Only set this larger if you really need inb() et.al. to operate over
208  * a larger address space.  Note that SOC_COMMON ioremaps each sockets
209  * IO space area, and so inb() et.al. must be defined to operate as per
210  * readb() et.al. on such platforms.
211  */
212 #ifndef IO_SPACE_LIMIT
213 #if defined(CONFIG_PCMCIA_SOC_COMMON) || defined(CONFIG_PCMCIA_SOC_COMMON_MODULE)
214 #define IO_SPACE_LIMIT ((resource_size_t)0xffffffff)
215 #elif defined(CONFIG_PCI) || defined(CONFIG_ISA) || defined(CONFIG_PCCARD)
216 #define IO_SPACE_LIMIT ((resource_size_t)0xffff)
217 #else
218 #define IO_SPACE_LIMIT ((resource_size_t)0)
219 #endif
220 #endif
221 
222 /*
223  *  IO port access primitives
224  *  -------------------------
225  *
226  * The ARM doesn't have special IO access instructions; all IO is memory
227  * mapped.  Note that these are defined to perform little endian accesses
228  * only.  Their primary purpose is to access PCI and ISA peripherals.
229  *
230  * Note that for a big endian machine, this implies that the following
231  * big endian mode connectivity is in place, as described by numerous
232  * ARM documents:
233  *
234  *    PCI:  D0-D7   D8-D15 D16-D23 D24-D31
235  *    ARM: D24-D31 D16-D23  D8-D15  D0-D7
236  *
237  * The machine specific io.h include defines __io to translate an "IO"
238  * address to a memory address.
239  *
240  * Note that we prevent GCC re-ordering or caching values in expressions
241  * by introducing sequence points into the in*() definitions.  Note that
242  * __raw_* do not guarantee this behaviour.
243  *
244  * The {in,out}[bwl] macros are for emulating x86-style PCI/ISA IO space.
245  */
246 #ifdef __io
247 #define outb(v,p)	({ __iowmb(); __raw_writeb(v,__io(p)); })
248 #define outw(v,p)	({ __iowmb(); __raw_writew((__force __u16) \
249 					cpu_to_le16(v),__io(p)); })
250 #define outl(v,p)	({ __iowmb(); __raw_writel((__force __u32) \
251 					cpu_to_le32(v),__io(p)); })
252 
253 #define inb(p)	({ __u8 __v = __raw_readb(__io(p)); __iormb(); __v; })
254 #define inw(p)	({ __u16 __v = le16_to_cpu((__force __le16) \
255 			__raw_readw(__io(p))); __iormb(); __v; })
256 #define inl(p)	({ __u32 __v = le32_to_cpu((__force __le32) \
257 			__raw_readl(__io(p))); __iormb(); __v; })
258 
259 #define outsb(p,d,l)		__raw_writesb(__io(p),d,l)
260 #define outsw(p,d,l)		__raw_writesw(__io(p),d,l)
261 #define outsl(p,d,l)		__raw_writesl(__io(p),d,l)
262 
263 #define insb(p,d,l)		__raw_readsb(__io(p),d,l)
264 #define insw(p,d,l)		__raw_readsw(__io(p),d,l)
265 #define insl(p,d,l)		__raw_readsl(__io(p),d,l)
266 #endif
267 
268 /*
269  * String version of IO memory access ops:
270  */
271 extern void _memcpy_fromio(void *, const volatile void __iomem *, size_t);
272 extern void _memcpy_toio(volatile void __iomem *, const void *, size_t);
273 extern void _memset_io(volatile void __iomem *, int, size_t);
274 
275 #define mmiowb()
276 
277 /*
278  *  Memory access primitives
279  *  ------------------------
280  *
281  * These perform PCI memory accesses via an ioremap region.  They don't
282  * take an address as such, but a cookie.
283  *
284  * Again, these are defined to perform little endian accesses.  See the
285  * IO port primitives for more information.
286  */
287 #ifndef readl
288 #define readb_relaxed(c) ({ u8  __r = __raw_readb(c); __r; })
289 #define readw_relaxed(c) ({ u16 __r = le16_to_cpu((__force __le16) \
290 					__raw_readw(c)); __r; })
291 #define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32) \
292 					__raw_readl(c)); __r; })
293 
294 #define writeb_relaxed(v,c)	__raw_writeb(v,c)
295 #define writew_relaxed(v,c)	__raw_writew((__force u16) cpu_to_le16(v),c)
296 #define writel_relaxed(v,c)	__raw_writel((__force u32) cpu_to_le32(v),c)
297 
298 #define readb(c)		({ u8  __v = readb_relaxed(c); __iormb(); __v; })
299 #define readw(c)		({ u16 __v = readw_relaxed(c); __iormb(); __v; })
300 #define readl(c)		({ u32 __v = readl_relaxed(c); __iormb(); __v; })
301 
302 #define writeb(v,c)		({ __iowmb(); writeb_relaxed(v,c); })
303 #define writew(v,c)		({ __iowmb(); writew_relaxed(v,c); })
304 #define writel(v,c)		({ __iowmb(); writel_relaxed(v,c); })
305 
306 #define readsb(p,d,l)		__raw_readsb(p,d,l)
307 #define readsw(p,d,l)		__raw_readsw(p,d,l)
308 #define readsl(p,d,l)		__raw_readsl(p,d,l)
309 
310 #define writesb(p,d,l)		__raw_writesb(p,d,l)
311 #define writesw(p,d,l)		__raw_writesw(p,d,l)
312 #define writesl(p,d,l)		__raw_writesl(p,d,l)
313 
314 #ifndef __ARMBE__
315 static inline void memset_io(volatile void __iomem *dst, unsigned c,
316 	size_t count)
317 {
318 	extern void mmioset(void *, unsigned int, size_t);
319 	mmioset((void __force *)dst, c, count);
320 }
321 #define memset_io(dst,c,count) memset_io(dst,c,count)
322 
323 static inline void memcpy_fromio(void *to, const volatile void __iomem *from,
324 	size_t count)
325 {
326 	extern void mmiocpy(void *, const void *, size_t);
327 	mmiocpy(to, (const void __force *)from, count);
328 }
329 #define memcpy_fromio(to,from,count) memcpy_fromio(to,from,count)
330 
331 static inline void memcpy_toio(volatile void __iomem *to, const void *from,
332 	size_t count)
333 {
334 	extern void mmiocpy(void *, const void *, size_t);
335 	mmiocpy((void __force *)to, from, count);
336 }
337 #define memcpy_toio(to,from,count) memcpy_toio(to,from,count)
338 
339 #else
340 #define memset_io(c,v,l)	_memset_io(c,(v),(l))
341 #define memcpy_fromio(a,c,l)	_memcpy_fromio((a),c,(l))
342 #define memcpy_toio(c,a,l)	_memcpy_toio(c,(a),(l))
343 #endif
344 
345 #endif	/* readl */
346 
347 /*
348  * ioremap() and friends.
349  *
350  * ioremap() takes a resource address, and size.  Due to the ARM memory
351  * types, it is important to use the correct ioremap() function as each
352  * mapping has specific properties.
353  *
354  * Function		Memory type	Cacheability	Cache hint
355  * ioremap()		Device		n/a		n/a
356  * ioremap_nocache()	Device		n/a		n/a
357  * ioremap_cache()	Normal		Writeback	Read allocate
358  * ioremap_wc()		Normal		Non-cacheable	n/a
359  * ioremap_wt()		Normal		Non-cacheable	n/a
360  *
361  * All device mappings have the following properties:
362  * - no access speculation
363  * - no repetition (eg, on return from an exception)
364  * - number, order and size of accesses are maintained
365  * - unaligned accesses are "unpredictable"
366  * - writes may be delayed before they hit the endpoint device
367  *
368  * ioremap_nocache() is the same as ioremap() as there are too many device
369  * drivers using this for device registers, and documentation which tells
370  * people to use it for such for this to be any different.  This is not a
371  * safe fallback for memory-like mappings, or memory regions where the
372  * compiler may generate unaligned accesses - eg, via inlining its own
373  * memcpy.
374  *
375  * All normal memory mappings have the following properties:
376  * - reads can be repeated with no side effects
377  * - repeated reads return the last value written
378  * - reads can fetch additional locations without side effects
379  * - writes can be repeated (in certain cases) with no side effects
380  * - writes can be merged before accessing the target
381  * - unaligned accesses can be supported
382  * - ordering is not guaranteed without explicit dependencies or barrier
383  *   instructions
384  * - writes may be delayed before they hit the endpoint memory
385  *
386  * The cache hint is only a performance hint: CPUs may alias these hints.
387  * Eg, a CPU not implementing read allocate but implementing write allocate
388  * will provide a write allocate mapping instead.
389  */
390 void __iomem *ioremap(resource_size_t res_cookie, size_t size);
391 #define ioremap ioremap
392 #define ioremap_nocache ioremap
393 
394 /*
395  * Do not use ioremap_cache for mapping memory. Use memremap instead.
396  */
397 void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size);
398 #define ioremap_cache ioremap_cache
399 
400 /*
401  * Do not use ioremap_cached in new code. Provided for the benefit of
402  * the pxa2xx-flash MTD driver only.
403  */
404 void __iomem *ioremap_cached(resource_size_t res_cookie, size_t size);
405 
406 void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size);
407 #define ioremap_wc ioremap_wc
408 #define ioremap_wt ioremap_wc
409 
410 void iounmap(volatile void __iomem *iomem_cookie);
411 #define iounmap iounmap
412 
413 void *arch_memremap_wb(phys_addr_t phys_addr, size_t size);
414 #define arch_memremap_wb arch_memremap_wb
415 
416 /*
417  * io{read,write}{16,32}be() macros
418  */
419 #define ioread16be(p)		({ __u16 __v = be16_to_cpu((__force __be16)__raw_readw(p)); __iormb(); __v; })
420 #define ioread32be(p)		({ __u32 __v = be32_to_cpu((__force __be32)__raw_readl(p)); __iormb(); __v; })
421 
422 #define iowrite16be(v,p)	({ __iowmb(); __raw_writew((__force __u16)cpu_to_be16(v), p); })
423 #define iowrite32be(v,p)	({ __iowmb(); __raw_writel((__force __u32)cpu_to_be32(v), p); })
424 
425 #ifndef ioport_map
426 #define ioport_map ioport_map
427 extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
428 #endif
429 #ifndef ioport_unmap
430 #define ioport_unmap ioport_unmap
431 extern void ioport_unmap(void __iomem *addr);
432 #endif
433 
434 struct pci_dev;
435 
436 #define pci_iounmap pci_iounmap
437 extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
438 
439 /*
440  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
441  * access
442  */
443 #define xlate_dev_mem_ptr(p)	__va(p)
444 
445 /*
446  * Convert a virtual cached pointer to an uncached pointer
447  */
448 #define xlate_dev_kmem_ptr(p)	p
449 
450 #include <asm-generic/io.h>
451 
452 /*
453  * can the hardware map this into one segment or not, given no other
454  * constraints.
455  */
456 #define BIOVEC_MERGEABLE(vec1, vec2)	\
457 	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
458 
459 struct bio_vec;
460 extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
461 				      const struct bio_vec *vec2);
462 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\
463 	(__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&				\
464 	 (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
465 
466 #ifdef CONFIG_MMU
467 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
468 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
469 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
470 extern int devmem_is_allowed(unsigned long pfn);
471 #endif
472 
473 /*
474  * Register ISA memory and port locations for glibc iopl/inb/outb
475  * emulation.
476  */
477 extern void register_isa_ports(unsigned int mmio, unsigned int io,
478 			       unsigned int io_shift);
479 
480 #endif	/* __KERNEL__ */
481 #endif	/* __ASM_ARM_IO_H */
482