xref: /linux/arch/x86/include/asm/io.h (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 #ifndef _ASM_X86_IO_H
2 #define _ASM_X86_IO_H
3 
4 /*
5  * This file contains the definitions for the x86 IO instructions
6  * inb/inw/inl/outb/outw/outl and the "string versions" of the same
7  * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
8  * versions of the single-IO instructions (inb_p/inw_p/..).
9  *
10  * This file is not meant to be obfuscating: it's just complicated
11  * to (a) handle it all in a way that makes gcc able to optimize it
12  * as well as possible and (b) trying to avoid writing the same thing
13  * over and over again with slight variations and possibly making a
14  * mistake somewhere.
15  */
16 
17 /*
18  * Thanks to James van Artsdalen for a better timing-fix than
19  * the two short jumps: using outb's to a nonexistent port seems
20  * to guarantee better timings even on fast machines.
21  *
22  * On the other hand, I'd like to be sure of a non-existent port:
23  * I feel a bit unsafe about using 0x80 (should be safe, though)
24  *
25  *		Linus
26  */
27 
28  /*
29   *  Bit simplified and optimized by Jan Hubicka
30   *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999.
31   *
32   *  isa_memset_io, isa_memcpy_fromio, isa_memcpy_toio added,
33   *  isa_read[wl] and isa_write[wl] fixed
34   *  - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
35   */
36 
37 #define ARCH_HAS_IOREMAP_WC
38 
39 #include <linux/string.h>
40 #include <linux/compiler.h>
41 #include <asm/page.h>
42 #include <asm/early_ioremap.h>
43 
44 #define build_mmio_read(name, size, type, reg, barrier) \
45 static inline type name(const volatile void __iomem *addr) \
46 { type ret; asm volatile("mov" size " %1,%0":reg (ret) \
47 :"m" (*(volatile type __force *)addr) barrier); return ret; }
48 
49 #define build_mmio_write(name, size, type, reg, barrier) \
50 static inline void name(type val, volatile void __iomem *addr) \
51 { asm volatile("mov" size " %0,%1": :reg (val), \
52 "m" (*(volatile type __force *)addr) barrier); }
53 
54 build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
55 build_mmio_read(readw, "w", unsigned short, "=r", :"memory")
56 build_mmio_read(readl, "l", unsigned int, "=r", :"memory")
57 
58 build_mmio_read(__readb, "b", unsigned char, "=q", )
59 build_mmio_read(__readw, "w", unsigned short, "=r", )
60 build_mmio_read(__readl, "l", unsigned int, "=r", )
61 
62 build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
63 build_mmio_write(writew, "w", unsigned short, "r", :"memory")
64 build_mmio_write(writel, "l", unsigned int, "r", :"memory")
65 
66 build_mmio_write(__writeb, "b", unsigned char, "q", )
67 build_mmio_write(__writew, "w", unsigned short, "r", )
68 build_mmio_write(__writel, "l", unsigned int, "r", )
69 
70 #define readb_relaxed(a) __readb(a)
71 #define readw_relaxed(a) __readw(a)
72 #define readl_relaxed(a) __readl(a)
73 #define __raw_readb __readb
74 #define __raw_readw __readw
75 #define __raw_readl __readl
76 
77 #define writeb_relaxed(v, a) __writeb(v, a)
78 #define writew_relaxed(v, a) __writew(v, a)
79 #define writel_relaxed(v, a) __writel(v, a)
80 #define __raw_writeb __writeb
81 #define __raw_writew __writew
82 #define __raw_writel __writel
83 
84 #define mmiowb() barrier()
85 
86 #ifdef CONFIG_X86_64
87 
88 build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
89 build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
90 
91 #define readq_relaxed(a)	readq(a)
92 #define writeq_relaxed(v, a)	writeq(v, a)
93 
94 #define __raw_readq(a)		readq(a)
95 #define __raw_writeq(val, addr)	writeq(val, addr)
96 
97 /* Let people know that we have them */
98 #define readq			readq
99 #define writeq			writeq
100 
101 #endif
102 
103 /**
104  *	virt_to_phys	-	map virtual addresses to physical
105  *	@address: address to remap
106  *
107  *	The returned physical address is the physical (CPU) mapping for
108  *	the memory address given. It is only valid to use this function on
109  *	addresses directly mapped or allocated via kmalloc.
110  *
111  *	This function does not give bus mappings for DMA transfers. In
112  *	almost all conceivable cases a device driver should not be using
113  *	this function
114  */
115 
116 static inline phys_addr_t virt_to_phys(volatile void *address)
117 {
118 	return __pa(address);
119 }
120 
121 /**
122  *	phys_to_virt	-	map physical address to virtual
123  *	@address: address to remap
124  *
125  *	The returned virtual address is a current CPU mapping for
126  *	the memory address given. It is only valid to use this function on
127  *	addresses that have a kernel mapping
128  *
129  *	This function does not handle bus mappings for DMA transfers. In
130  *	almost all conceivable cases a device driver should not be using
131  *	this function
132  */
133 
134 static inline void *phys_to_virt(phys_addr_t address)
135 {
136 	return __va(address);
137 }
138 
139 /*
140  * Change "struct page" to physical address.
141  */
142 #define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
143 
144 /*
145  * ISA I/O bus memory addresses are 1:1 with the physical address.
146  * However, we truncate the address to unsigned int to avoid undesirable
147  * promitions in legacy drivers.
148  */
149 static inline unsigned int isa_virt_to_bus(volatile void *address)
150 {
151 	return (unsigned int)virt_to_phys(address);
152 }
153 #define isa_page_to_bus(page)	((unsigned int)page_to_phys(page))
154 #define isa_bus_to_virt		phys_to_virt
155 
156 /*
157  * However PCI ones are not necessarily 1:1 and therefore these interfaces
158  * are forbidden in portable PCI drivers.
159  *
160  * Allow them on x86 for legacy drivers, though.
161  */
162 #define virt_to_bus virt_to_phys
163 #define bus_to_virt phys_to_virt
164 
165 /**
166  * ioremap     -   map bus memory into CPU space
167  * @offset:    bus address of the memory
168  * @size:      size of the resource to map
169  *
170  * ioremap performs a platform specific sequence of operations to
171  * make bus memory CPU accessible via the readb/readw/readl/writeb/
172  * writew/writel functions and the other mmio helpers. The returned
173  * address is not guaranteed to be usable directly as a virtual
174  * address.
175  *
176  * If the area you are trying to map is a PCI BAR you should have a
177  * look at pci_iomap().
178  */
179 extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
180 extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
181 extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
182 				unsigned long prot_val);
183 
184 /*
185  * The default ioremap() behavior is non-cached:
186  */
187 static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
188 {
189 	return ioremap_nocache(offset, size);
190 }
191 
192 extern void iounmap(volatile void __iomem *addr);
193 
194 extern void set_iounmap_nonlazy(void);
195 
196 #ifdef __KERNEL__
197 
198 #include <asm-generic/iomap.h>
199 
200 #include <linux/vmalloc.h>
201 
202 /*
203  * Convert a virtual cached pointer to an uncached pointer
204  */
205 #define xlate_dev_kmem_ptr(p)	p
206 
207 static inline void
208 memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
209 {
210 	memset((void __force *)addr, val, count);
211 }
212 
213 static inline void
214 memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
215 {
216 	memcpy(dst, (const void __force *)src, count);
217 }
218 
219 static inline void
220 memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
221 {
222 	memcpy((void __force *)dst, src, count);
223 }
224 
225 /*
226  * ISA space is 'always mapped' on a typical x86 system, no need to
227  * explicitly ioremap() it. The fact that the ISA IO space is mapped
228  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
229  * are physical addresses. The following constant pointer can be
230  * used as the IO-area pointer (it can be iounmapped as well, so the
231  * analogy with PCI is quite large):
232  */
233 #define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
234 
235 /*
236  *	Cache management
237  *
238  *	This needed for two cases
239  *	1. Out of order aware processors
240  *	2. Accidentally out of order processors (PPro errata #51)
241  */
242 
243 static inline void flush_write_buffers(void)
244 {
245 #if defined(CONFIG_X86_PPRO_FENCE)
246 	asm volatile("lock; addl $0,0(%%esp)": : :"memory");
247 #endif
248 }
249 
250 #endif /* __KERNEL__ */
251 
252 extern void native_io_delay(void);
253 
254 extern int io_delay_type;
255 extern void io_delay_init(void);
256 
257 #if defined(CONFIG_PARAVIRT)
258 #include <asm/paravirt.h>
259 #else
260 
261 static inline void slow_down_io(void)
262 {
263 	native_io_delay();
264 #ifdef REALLY_SLOW_IO
265 	native_io_delay();
266 	native_io_delay();
267 	native_io_delay();
268 #endif
269 }
270 
271 #endif
272 
273 #define BUILDIO(bwl, bw, type)						\
274 static inline void out##bwl(unsigned type value, int port)		\
275 {									\
276 	asm volatile("out" #bwl " %" #bw "0, %w1"			\
277 		     : : "a"(value), "Nd"(port));			\
278 }									\
279 									\
280 static inline unsigned type in##bwl(int port)				\
281 {									\
282 	unsigned type value;						\
283 	asm volatile("in" #bwl " %w1, %" #bw "0"			\
284 		     : "=a"(value) : "Nd"(port));			\
285 	return value;							\
286 }									\
287 									\
288 static inline void out##bwl##_p(unsigned type value, int port)		\
289 {									\
290 	out##bwl(value, port);						\
291 	slow_down_io();							\
292 }									\
293 									\
294 static inline unsigned type in##bwl##_p(int port)			\
295 {									\
296 	unsigned type value = in##bwl(port);				\
297 	slow_down_io();							\
298 	return value;							\
299 }									\
300 									\
301 static inline void outs##bwl(int port, const void *addr, unsigned long count) \
302 {									\
303 	asm volatile("rep; outs" #bwl					\
304 		     : "+S"(addr), "+c"(count) : "d"(port));		\
305 }									\
306 									\
307 static inline void ins##bwl(int port, void *addr, unsigned long count)	\
308 {									\
309 	asm volatile("rep; ins" #bwl					\
310 		     : "+D"(addr), "+c"(count) : "d"(port));		\
311 }
312 
313 BUILDIO(b, b, char)
314 BUILDIO(w, w, short)
315 BUILDIO(l, , int)
316 
317 extern void *xlate_dev_mem_ptr(phys_addr_t phys);
318 extern void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr);
319 
320 extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
321 				enum page_cache_mode pcm);
322 extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
323 
324 extern bool is_early_ioremap_ptep(pte_t *ptep);
325 
326 #ifdef CONFIG_XEN
327 #include <xen/xen.h>
328 struct bio_vec;
329 
330 extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
331 				      const struct bio_vec *vec2);
332 
333 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\
334 	(__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&				\
335 	 (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
336 #endif	/* CONFIG_XEN */
337 
338 #define IO_SPACE_LIMIT 0xffff
339 
340 #ifdef CONFIG_MTRR
341 extern int __must_check arch_phys_wc_add(unsigned long base,
342 					 unsigned long size);
343 extern void arch_phys_wc_del(int handle);
344 #define arch_phys_wc_add arch_phys_wc_add
345 #endif
346 
347 #endif /* _ASM_X86_IO_H */
348