xref: /openbmc/linux/arch/x86/include/asm/io.h (revision 95e9fd10)
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 
43 #define build_mmio_read(name, size, type, reg, barrier) \
44 static inline type name(const volatile void __iomem *addr) \
45 { type ret; asm volatile("mov" size " %1,%0":reg (ret) \
46 :"m" (*(volatile type __force *)addr) barrier); return ret; }
47 
48 #define build_mmio_write(name, size, type, reg, barrier) \
49 static inline void name(type val, volatile void __iomem *addr) \
50 { asm volatile("mov" size " %0,%1": :reg (val), \
51 "m" (*(volatile type __force *)addr) barrier); }
52 
53 build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
54 build_mmio_read(readw, "w", unsigned short, "=r", :"memory")
55 build_mmio_read(readl, "l", unsigned int, "=r", :"memory")
56 
57 build_mmio_read(__readb, "b", unsigned char, "=q", )
58 build_mmio_read(__readw, "w", unsigned short, "=r", )
59 build_mmio_read(__readl, "l", unsigned int, "=r", )
60 
61 build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
62 build_mmio_write(writew, "w", unsigned short, "r", :"memory")
63 build_mmio_write(writel, "l", unsigned int, "r", :"memory")
64 
65 build_mmio_write(__writeb, "b", unsigned char, "q", )
66 build_mmio_write(__writew, "w", unsigned short, "r", )
67 build_mmio_write(__writel, "l", unsigned int, "r", )
68 
69 #define readb_relaxed(a) __readb(a)
70 #define readw_relaxed(a) __readw(a)
71 #define readl_relaxed(a) __readl(a)
72 #define __raw_readb __readb
73 #define __raw_readw __readw
74 #define __raw_readl __readl
75 
76 #define __raw_writeb __writeb
77 #define __raw_writew __writew
78 #define __raw_writel __writel
79 
80 #define mmiowb() barrier()
81 
82 #ifdef CONFIG_X86_64
83 
84 build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
85 build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
86 
87 #define readq_relaxed(a)	readq(a)
88 
89 #define __raw_readq(a)		readq(a)
90 #define __raw_writeq(val, addr)	writeq(val, addr)
91 
92 /* Let people know that we have them */
93 #define readq			readq
94 #define writeq			writeq
95 
96 #endif
97 
98 /**
99  *	virt_to_phys	-	map virtual addresses to physical
100  *	@address: address to remap
101  *
102  *	The returned physical address is the physical (CPU) mapping for
103  *	the memory address given. It is only valid to use this function on
104  *	addresses directly mapped or allocated via kmalloc.
105  *
106  *	This function does not give bus mappings for DMA transfers. In
107  *	almost all conceivable cases a device driver should not be using
108  *	this function
109  */
110 
111 static inline phys_addr_t virt_to_phys(volatile void *address)
112 {
113 	return __pa(address);
114 }
115 
116 /**
117  *	phys_to_virt	-	map physical address to virtual
118  *	@address: address to remap
119  *
120  *	The returned virtual address is a current CPU mapping for
121  *	the memory address given. It is only valid to use this function on
122  *	addresses that have a kernel mapping
123  *
124  *	This function does not handle bus mappings for DMA transfers. In
125  *	almost all conceivable cases a device driver should not be using
126  *	this function
127  */
128 
129 static inline void *phys_to_virt(phys_addr_t address)
130 {
131 	return __va(address);
132 }
133 
134 /*
135  * Change "struct page" to physical address.
136  */
137 #define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
138 
139 /*
140  * ISA I/O bus memory addresses are 1:1 with the physical address.
141  * However, we truncate the address to unsigned int to avoid undesirable
142  * promitions in legacy drivers.
143  */
144 static inline unsigned int isa_virt_to_bus(volatile void *address)
145 {
146 	return (unsigned int)virt_to_phys(address);
147 }
148 #define isa_page_to_bus(page)	((unsigned int)page_to_phys(page))
149 #define isa_bus_to_virt		phys_to_virt
150 
151 /*
152  * However PCI ones are not necessarily 1:1 and therefore these interfaces
153  * are forbidden in portable PCI drivers.
154  *
155  * Allow them on x86 for legacy drivers, though.
156  */
157 #define virt_to_bus virt_to_phys
158 #define bus_to_virt phys_to_virt
159 
160 /**
161  * ioremap     -   map bus memory into CPU space
162  * @offset:    bus address of the memory
163  * @size:      size of the resource to map
164  *
165  * ioremap performs a platform specific sequence of operations to
166  * make bus memory CPU accessible via the readb/readw/readl/writeb/
167  * writew/writel functions and the other mmio helpers. The returned
168  * address is not guaranteed to be usable directly as a virtual
169  * address.
170  *
171  * If the area you are trying to map is a PCI BAR you should have a
172  * look at pci_iomap().
173  */
174 extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
175 extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
176 extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
177 				unsigned long prot_val);
178 
179 /*
180  * The default ioremap() behavior is non-cached:
181  */
182 static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
183 {
184 	return ioremap_nocache(offset, size);
185 }
186 
187 extern void iounmap(volatile void __iomem *addr);
188 
189 extern void set_iounmap_nonlazy(void);
190 
191 #ifdef __KERNEL__
192 
193 #include <asm-generic/iomap.h>
194 
195 #include <linux/vmalloc.h>
196 
197 /*
198  * Convert a virtual cached pointer to an uncached pointer
199  */
200 #define xlate_dev_kmem_ptr(p)	p
201 
202 static inline void
203 memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
204 {
205 	memset((void __force *)addr, val, count);
206 }
207 
208 static inline void
209 memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
210 {
211 	memcpy(dst, (const void __force *)src, count);
212 }
213 
214 static inline void
215 memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
216 {
217 	memcpy((void __force *)dst, src, count);
218 }
219 
220 /*
221  * ISA space is 'always mapped' on a typical x86 system, no need to
222  * explicitly ioremap() it. The fact that the ISA IO space is mapped
223  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
224  * are physical addresses. The following constant pointer can be
225  * used as the IO-area pointer (it can be iounmapped as well, so the
226  * analogy with PCI is quite large):
227  */
228 #define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
229 
230 /*
231  *	Cache management
232  *
233  *	This needed for two cases
234  *	1. Out of order aware processors
235  *	2. Accidentally out of order processors (PPro errata #51)
236  */
237 
238 static inline void flush_write_buffers(void)
239 {
240 #if defined(CONFIG_X86_OOSTORE) || defined(CONFIG_X86_PPRO_FENCE)
241 	asm volatile("lock; addl $0,0(%%esp)": : :"memory");
242 #endif
243 }
244 
245 #endif /* __KERNEL__ */
246 
247 extern void native_io_delay(void);
248 
249 extern int io_delay_type;
250 extern void io_delay_init(void);
251 
252 #if defined(CONFIG_PARAVIRT)
253 #include <asm/paravirt.h>
254 #else
255 
256 static inline void slow_down_io(void)
257 {
258 	native_io_delay();
259 #ifdef REALLY_SLOW_IO
260 	native_io_delay();
261 	native_io_delay();
262 	native_io_delay();
263 #endif
264 }
265 
266 #endif
267 
268 #define BUILDIO(bwl, bw, type)						\
269 static inline void out##bwl(unsigned type value, int port)		\
270 {									\
271 	asm volatile("out" #bwl " %" #bw "0, %w1"			\
272 		     : : "a"(value), "Nd"(port));			\
273 }									\
274 									\
275 static inline unsigned type in##bwl(int port)				\
276 {									\
277 	unsigned type value;						\
278 	asm volatile("in" #bwl " %w1, %" #bw "0"			\
279 		     : "=a"(value) : "Nd"(port));			\
280 	return value;							\
281 }									\
282 									\
283 static inline void out##bwl##_p(unsigned type value, int port)		\
284 {									\
285 	out##bwl(value, port);						\
286 	slow_down_io();							\
287 }									\
288 									\
289 static inline unsigned type in##bwl##_p(int port)			\
290 {									\
291 	unsigned type value = in##bwl(port);				\
292 	slow_down_io();							\
293 	return value;							\
294 }									\
295 									\
296 static inline void outs##bwl(int port, const void *addr, unsigned long count) \
297 {									\
298 	asm volatile("rep; outs" #bwl					\
299 		     : "+S"(addr), "+c"(count) : "d"(port));		\
300 }									\
301 									\
302 static inline void ins##bwl(int port, void *addr, unsigned long count)	\
303 {									\
304 	asm volatile("rep; ins" #bwl					\
305 		     : "+D"(addr), "+c"(count) : "d"(port));		\
306 }
307 
308 BUILDIO(b, b, char)
309 BUILDIO(w, w, short)
310 BUILDIO(l, , int)
311 
312 extern void *xlate_dev_mem_ptr(unsigned long phys);
313 extern void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
314 
315 extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
316 				unsigned long prot_val);
317 extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
318 
319 /*
320  * early_ioremap() and early_iounmap() are for temporary early boot-time
321  * mappings, before the real ioremap() is functional.
322  * A boot-time mapping is currently limited to at most 16 pages.
323  */
324 extern void early_ioremap_init(void);
325 extern void early_ioremap_reset(void);
326 extern void __iomem *early_ioremap(resource_size_t phys_addr,
327 				   unsigned long size);
328 extern void __iomem *early_memremap(resource_size_t phys_addr,
329 				    unsigned long size);
330 extern void early_iounmap(void __iomem *addr, unsigned long size);
331 extern void fixup_early_ioremap(void);
332 extern bool is_early_ioremap_ptep(pte_t *ptep);
333 
334 #ifdef CONFIG_XEN
335 #include <xen/xen.h>
336 struct bio_vec;
337 
338 extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
339 				      const struct bio_vec *vec2);
340 
341 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\
342 	(__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&				\
343 	 (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
344 #endif	/* CONFIG_XEN */
345 
346 #define IO_SPACE_LIMIT 0xffff
347 
348 #endif /* _ASM_X86_IO_H */
349