xref: /linux/arch/arm/include/asm/io.h (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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/types.h>
27 #include <asm/byteorder.h>
28 #include <asm/memory.h>
29 #include <asm-generic/pci_iomap.h>
30 
31 /*
32  * ISA I/O bus memory addresses are 1:1 with the physical address.
33  */
34 #define isa_virt_to_bus virt_to_phys
35 #define isa_page_to_bus page_to_phys
36 #define isa_bus_to_virt phys_to_virt
37 
38 /*
39  * Generic IO read/write.  These perform native-endian accesses.  Note
40  * that some architectures will want to re-define __raw_{read,write}w.
41  */
42 extern void __raw_writesb(void __iomem *addr, const void *data, int bytelen);
43 extern void __raw_writesw(void __iomem *addr, const void *data, int wordlen);
44 extern void __raw_writesl(void __iomem *addr, const void *data, int longlen);
45 
46 extern void __raw_readsb(const void __iomem *addr, void *data, int bytelen);
47 extern void __raw_readsw(const void __iomem *addr, void *data, int wordlen);
48 extern void __raw_readsl(const void __iomem *addr, void *data, int longlen);
49 
50 #if __LINUX_ARM_ARCH__ < 6
51 /*
52  * Half-word accesses are problematic with RiscPC due to limitations of
53  * the bus. Rather than special-case the machine, just let the compiler
54  * generate the access for CPUs prior to ARMv6.
55  */
56 #define __raw_readw(a)         (__chk_io_ptr(a), *(volatile unsigned short __force *)(a))
57 #define __raw_writew(v,a)      ((void)(__chk_io_ptr(a), *(volatile unsigned short __force *)(a) = (v)))
58 #else
59 /*
60  * When running under a hypervisor, we want to avoid I/O accesses with
61  * writeback addressing modes as these incur a significant performance
62  * overhead (the address generation must be emulated in software).
63  */
64 static inline void __raw_writew(u16 val, volatile void __iomem *addr)
65 {
66 	asm volatile("strh %1, %0"
67 		     : "+Q" (*(volatile u16 __force *)addr)
68 		     : "r" (val));
69 }
70 
71 static inline u16 __raw_readw(const volatile void __iomem *addr)
72 {
73 	u16 val;
74 	asm volatile("ldrh %1, %0"
75 		     : "+Q" (*(volatile u16 __force *)addr),
76 		       "=r" (val));
77 	return val;
78 }
79 #endif
80 
81 static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
82 {
83 	asm volatile("strb %1, %0"
84 		     : "+Qo" (*(volatile u8 __force *)addr)
85 		     : "r" (val));
86 }
87 
88 static inline void __raw_writel(u32 val, volatile void __iomem *addr)
89 {
90 	asm volatile("str %1, %0"
91 		     : "+Qo" (*(volatile u32 __force *)addr)
92 		     : "r" (val));
93 }
94 
95 static inline u8 __raw_readb(const volatile void __iomem *addr)
96 {
97 	u8 val;
98 	asm volatile("ldrb %1, %0"
99 		     : "+Qo" (*(volatile u8 __force *)addr),
100 		       "=r" (val));
101 	return val;
102 }
103 
104 static inline u32 __raw_readl(const volatile void __iomem *addr)
105 {
106 	u32 val;
107 	asm volatile("ldr %1, %0"
108 		     : "+Qo" (*(volatile u32 __force *)addr),
109 		       "=r" (val));
110 	return val;
111 }
112 
113 /*
114  * Architecture ioremap implementation.
115  */
116 #define MT_DEVICE		0
117 #define MT_DEVICE_NONSHARED	1
118 #define MT_DEVICE_CACHED	2
119 #define MT_DEVICE_WC		3
120 /*
121  * types 4 onwards can be found in asm/mach/map.h and are undefined
122  * for ioremap
123  */
124 
125 /*
126  * __arm_ioremap takes CPU physical address.
127  * __arm_ioremap_pfn takes a Page Frame Number and an offset into that page
128  * The _caller variety takes a __builtin_return_address(0) value for
129  * /proc/vmalloc to use - and should only be used in non-inline functions.
130  */
131 extern void __iomem *__arm_ioremap_pfn_caller(unsigned long, unsigned long,
132 	size_t, unsigned int, void *);
133 extern void __iomem *__arm_ioremap_caller(unsigned long, size_t, unsigned int,
134 	void *);
135 
136 extern void __iomem *__arm_ioremap_pfn(unsigned long, unsigned long, size_t, unsigned int);
137 extern void __iomem *__arm_ioremap(unsigned long, size_t, unsigned int);
138 extern void __iomem *__arm_ioremap_exec(unsigned long, size_t, bool cached);
139 extern void __iounmap(volatile void __iomem *addr);
140 extern void __arm_iounmap(volatile void __iomem *addr);
141 
142 extern void __iomem * (*arch_ioremap_caller)(unsigned long, size_t,
143 	unsigned int, void *);
144 extern void (*arch_iounmap)(volatile void __iomem *);
145 
146 /*
147  * Bad read/write accesses...
148  */
149 extern void __readwrite_bug(const char *fn);
150 
151 /*
152  * A typesafe __io() helper
153  */
154 static inline void __iomem *__typesafe_io(unsigned long addr)
155 {
156 	return (void __iomem *)addr;
157 }
158 
159 #define IOMEM(x)	((void __force __iomem *)(x))
160 
161 /* IO barriers */
162 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
163 #include <asm/barrier.h>
164 #define __iormb()		rmb()
165 #define __iowmb()		wmb()
166 #else
167 #define __iormb()		do { } while (0)
168 #define __iowmb()		do { } while (0)
169 #endif
170 
171 /* PCI fixed i/o mapping */
172 #define PCI_IO_VIRT_BASE	0xfee00000
173 
174 extern int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr);
175 
176 /*
177  * Now, pick up the machine-defined IO definitions
178  */
179 #ifdef CONFIG_NEED_MACH_IO_H
180 #include <mach/io.h>
181 #elif defined(CONFIG_PCI)
182 #define IO_SPACE_LIMIT	((resource_size_t)0xfffff)
183 #define __io(a)		__typesafe_io(PCI_IO_VIRT_BASE + ((a) & IO_SPACE_LIMIT))
184 #else
185 #define __io(a)		__typesafe_io((a) & IO_SPACE_LIMIT)
186 #endif
187 
188 /*
189  * This is the limit of PC card/PCI/ISA IO space, which is by default
190  * 64K if we have PC card, PCI or ISA support.  Otherwise, default to
191  * zero to prevent ISA/PCI drivers claiming IO space (and potentially
192  * oopsing.)
193  *
194  * Only set this larger if you really need inb() et.al. to operate over
195  * a larger address space.  Note that SOC_COMMON ioremaps each sockets
196  * IO space area, and so inb() et.al. must be defined to operate as per
197  * readb() et.al. on such platforms.
198  */
199 #ifndef IO_SPACE_LIMIT
200 #if defined(CONFIG_PCMCIA_SOC_COMMON) || defined(CONFIG_PCMCIA_SOC_COMMON_MODULE)
201 #define IO_SPACE_LIMIT ((resource_size_t)0xffffffff)
202 #elif defined(CONFIG_PCI) || defined(CONFIG_ISA) || defined(CONFIG_PCCARD)
203 #define IO_SPACE_LIMIT ((resource_size_t)0xffff)
204 #else
205 #define IO_SPACE_LIMIT ((resource_size_t)0)
206 #endif
207 #endif
208 
209 /*
210  *  IO port access primitives
211  *  -------------------------
212  *
213  * The ARM doesn't have special IO access instructions; all IO is memory
214  * mapped.  Note that these are defined to perform little endian accesses
215  * only.  Their primary purpose is to access PCI and ISA peripherals.
216  *
217  * Note that for a big endian machine, this implies that the following
218  * big endian mode connectivity is in place, as described by numerous
219  * ARM documents:
220  *
221  *    PCI:  D0-D7   D8-D15 D16-D23 D24-D31
222  *    ARM: D24-D31 D16-D23  D8-D15  D0-D7
223  *
224  * The machine specific io.h include defines __io to translate an "IO"
225  * address to a memory address.
226  *
227  * Note that we prevent GCC re-ordering or caching values in expressions
228  * by introducing sequence points into the in*() definitions.  Note that
229  * __raw_* do not guarantee this behaviour.
230  *
231  * The {in,out}[bwl] macros are for emulating x86-style PCI/ISA IO space.
232  */
233 #ifdef __io
234 #define outb(v,p)	({ __iowmb(); __raw_writeb(v,__io(p)); })
235 #define outw(v,p)	({ __iowmb(); __raw_writew((__force __u16) \
236 					cpu_to_le16(v),__io(p)); })
237 #define outl(v,p)	({ __iowmb(); __raw_writel((__force __u32) \
238 					cpu_to_le32(v),__io(p)); })
239 
240 #define inb(p)	({ __u8 __v = __raw_readb(__io(p)); __iormb(); __v; })
241 #define inw(p)	({ __u16 __v = le16_to_cpu((__force __le16) \
242 			__raw_readw(__io(p))); __iormb(); __v; })
243 #define inl(p)	({ __u32 __v = le32_to_cpu((__force __le32) \
244 			__raw_readl(__io(p))); __iormb(); __v; })
245 
246 #define outsb(p,d,l)		__raw_writesb(__io(p),d,l)
247 #define outsw(p,d,l)		__raw_writesw(__io(p),d,l)
248 #define outsl(p,d,l)		__raw_writesl(__io(p),d,l)
249 
250 #define insb(p,d,l)		__raw_readsb(__io(p),d,l)
251 #define insw(p,d,l)		__raw_readsw(__io(p),d,l)
252 #define insl(p,d,l)		__raw_readsl(__io(p),d,l)
253 #endif
254 
255 #define outb_p(val,port)	outb((val),(port))
256 #define outw_p(val,port)	outw((val),(port))
257 #define outl_p(val,port)	outl((val),(port))
258 #define inb_p(port)		inb((port))
259 #define inw_p(port)		inw((port))
260 #define inl_p(port)		inl((port))
261 
262 #define outsb_p(port,from,len)	outsb(port,from,len)
263 #define outsw_p(port,from,len)	outsw(port,from,len)
264 #define outsl_p(port,from,len)	outsl(port,from,len)
265 #define insb_p(port,to,len)	insb(port,to,len)
266 #define insw_p(port,to,len)	insw(port,to,len)
267 #define insl_p(port,to,len)	insl(port,to,len)
268 
269 /*
270  * String version of IO memory access ops:
271  */
272 extern void _memcpy_fromio(void *, const volatile void __iomem *, size_t);
273 extern void _memcpy_toio(volatile void __iomem *, const void *, size_t);
274 extern void _memset_io(volatile void __iomem *, int, size_t);
275 
276 #define mmiowb()
277 
278 /*
279  *  Memory access primitives
280  *  ------------------------
281  *
282  * These perform PCI memory accesses via an ioremap region.  They don't
283  * take an address as such, but a cookie.
284  *
285  * Again, this are defined to perform little endian accesses.  See the
286  * IO port primitives for more information.
287  */
288 #ifndef readl
289 #define readb_relaxed(c) ({ u8  __r = __raw_readb(c); __r; })
290 #define readw_relaxed(c) ({ u16 __r = le16_to_cpu((__force __le16) \
291 					__raw_readw(c)); __r; })
292 #define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32) \
293 					__raw_readl(c)); __r; })
294 
295 #define writeb_relaxed(v,c)	__raw_writeb(v,c)
296 #define writew_relaxed(v,c)	__raw_writew((__force u16) cpu_to_le16(v),c)
297 #define writel_relaxed(v,c)	__raw_writel((__force u32) cpu_to_le32(v),c)
298 
299 #define readb(c)		({ u8  __v = readb_relaxed(c); __iormb(); __v; })
300 #define readw(c)		({ u16 __v = readw_relaxed(c); __iormb(); __v; })
301 #define readl(c)		({ u32 __v = readl_relaxed(c); __iormb(); __v; })
302 
303 #define writeb(v,c)		({ __iowmb(); writeb_relaxed(v,c); })
304 #define writew(v,c)		({ __iowmb(); writew_relaxed(v,c); })
305 #define writel(v,c)		({ __iowmb(); writel_relaxed(v,c); })
306 
307 #define readsb(p,d,l)		__raw_readsb(p,d,l)
308 #define readsw(p,d,l)		__raw_readsw(p,d,l)
309 #define readsl(p,d,l)		__raw_readsl(p,d,l)
310 
311 #define writesb(p,d,l)		__raw_writesb(p,d,l)
312 #define writesw(p,d,l)		__raw_writesw(p,d,l)
313 #define writesl(p,d,l)		__raw_writesl(p,d,l)
314 
315 #define memset_io(c,v,l)	_memset_io(c,(v),(l))
316 #define memcpy_fromio(a,c,l)	_memcpy_fromio((a),c,(l))
317 #define memcpy_toio(c,a,l)	_memcpy_toio(c,(a),(l))
318 
319 #endif	/* readl */
320 
321 /*
322  * ioremap and friends.
323  *
324  * ioremap takes a PCI memory address, as specified in
325  * Documentation/io-mapping.txt.
326  *
327  */
328 #define ioremap(cookie,size)		__arm_ioremap((cookie), (size), MT_DEVICE)
329 #define ioremap_nocache(cookie,size)	__arm_ioremap((cookie), (size), MT_DEVICE)
330 #define ioremap_cached(cookie,size)	__arm_ioremap((cookie), (size), MT_DEVICE_CACHED)
331 #define ioremap_wc(cookie,size)		__arm_ioremap((cookie), (size), MT_DEVICE_WC)
332 #define iounmap				__arm_iounmap
333 
334 /*
335  * io{read,write}{8,16,32} macros
336  */
337 #ifndef ioread8
338 #define ioread8(p)	({ unsigned int __v = __raw_readb(p); __iormb(); __v; })
339 #define ioread16(p)	({ unsigned int __v = le16_to_cpu((__force __le16)__raw_readw(p)); __iormb(); __v; })
340 #define ioread32(p)	({ unsigned int __v = le32_to_cpu((__force __le32)__raw_readl(p)); __iormb(); __v; })
341 
342 #define ioread16be(p)	({ unsigned int __v = be16_to_cpu((__force __be16)__raw_readw(p)); __iormb(); __v; })
343 #define ioread32be(p)	({ unsigned int __v = be32_to_cpu((__force __be32)__raw_readl(p)); __iormb(); __v; })
344 
345 #define iowrite8(v,p)	({ __iowmb(); __raw_writeb(v, p); })
346 #define iowrite16(v,p)	({ __iowmb(); __raw_writew((__force __u16)cpu_to_le16(v), p); })
347 #define iowrite32(v,p)	({ __iowmb(); __raw_writel((__force __u32)cpu_to_le32(v), p); })
348 
349 #define iowrite16be(v,p) ({ __iowmb(); __raw_writew((__force __u16)cpu_to_be16(v), p); })
350 #define iowrite32be(v,p) ({ __iowmb(); __raw_writel((__force __u32)cpu_to_be32(v), p); })
351 
352 #define ioread8_rep(p,d,c)	__raw_readsb(p,d,c)
353 #define ioread16_rep(p,d,c)	__raw_readsw(p,d,c)
354 #define ioread32_rep(p,d,c)	__raw_readsl(p,d,c)
355 
356 #define iowrite8_rep(p,s,c)	__raw_writesb(p,s,c)
357 #define iowrite16_rep(p,s,c)	__raw_writesw(p,s,c)
358 #define iowrite32_rep(p,s,c)	__raw_writesl(p,s,c)
359 
360 extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
361 extern void ioport_unmap(void __iomem *addr);
362 #endif
363 
364 struct pci_dev;
365 
366 extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
367 
368 /*
369  * can the hardware map this into one segment or not, given no other
370  * constraints.
371  */
372 #define BIOVEC_MERGEABLE(vec1, vec2)	\
373 	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
374 
375 #ifdef CONFIG_MMU
376 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
377 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
378 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
379 extern int devmem_is_allowed(unsigned long pfn);
380 #endif
381 
382 /*
383  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
384  * access
385  */
386 #define xlate_dev_mem_ptr(p)	__va(p)
387 
388 /*
389  * Convert a virtual cached pointer to an uncached pointer
390  */
391 #define xlate_dev_kmem_ptr(p)	p
392 
393 /*
394  * Register ISA memory and port locations for glibc iopl/inb/outb
395  * emulation.
396  */
397 extern void register_isa_ports(unsigned int mmio, unsigned int io,
398 			       unsigned int io_shift);
399 
400 #endif	/* __KERNEL__ */
401 #endif	/* __ASM_ARM_IO_H */
402