xref: /openbmc/linux/arch/x86/include/asm/io.h (revision 81d67439)
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 #include <xen/xen.h>
44 
45 #define build_mmio_read(name, size, type, reg, barrier) \
46 static inline type name(const volatile void __iomem *addr) \
47 { type ret; asm volatile("mov" size " %1,%0":reg (ret) \
48 :"m" (*(volatile type __force *)addr) barrier); return ret; }
49 
50 #define build_mmio_write(name, size, type, reg, barrier) \
51 static inline void name(type val, volatile void __iomem *addr) \
52 { asm volatile("mov" size " %0,%1": :reg (val), \
53 "m" (*(volatile type __force *)addr) barrier); }
54 
55 build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
56 build_mmio_read(readw, "w", unsigned short, "=r", :"memory")
57 build_mmio_read(readl, "l", unsigned int, "=r", :"memory")
58 
59 build_mmio_read(__readb, "b", unsigned char, "=q", )
60 build_mmio_read(__readw, "w", unsigned short, "=r", )
61 build_mmio_read(__readl, "l", unsigned int, "=r", )
62 
63 build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
64 build_mmio_write(writew, "w", unsigned short, "r", :"memory")
65 build_mmio_write(writel, "l", unsigned int, "r", :"memory")
66 
67 build_mmio_write(__writeb, "b", unsigned char, "q", )
68 build_mmio_write(__writew, "w", unsigned short, "r", )
69 build_mmio_write(__writel, "l", unsigned int, "r", )
70 
71 #define readb_relaxed(a) __readb(a)
72 #define readw_relaxed(a) __readw(a)
73 #define readl_relaxed(a) __readl(a)
74 #define __raw_readb __readb
75 #define __raw_readw __readw
76 #define __raw_readl __readl
77 
78 #define __raw_writeb __writeb
79 #define __raw_writew __writew
80 #define __raw_writel __writel
81 
82 #define mmiowb() barrier()
83 
84 #ifdef CONFIG_X86_64
85 
86 build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
87 build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
88 
89 #define readq_relaxed(a)	readq(a)
90 
91 #define __raw_readq(a)		readq(a)
92 #define __raw_writeq(val, addr)	writeq(val, addr)
93 
94 /* Let people know that we have them */
95 #define readq			readq
96 #define writeq			writeq
97 
98 #endif
99 
100 /**
101  *	virt_to_phys	-	map virtual addresses to physical
102  *	@address: address to remap
103  *
104  *	The returned physical address is the physical (CPU) mapping for
105  *	the memory address given. It is only valid to use this function on
106  *	addresses directly mapped or allocated via kmalloc.
107  *
108  *	This function does not give bus mappings for DMA transfers. In
109  *	almost all conceivable cases a device driver should not be using
110  *	this function
111  */
112 
113 static inline phys_addr_t virt_to_phys(volatile void *address)
114 {
115 	return __pa(address);
116 }
117 
118 /**
119  *	phys_to_virt	-	map physical address to virtual
120  *	@address: address to remap
121  *
122  *	The returned virtual address is a current CPU mapping for
123  *	the memory address given. It is only valid to use this function on
124  *	addresses that have a kernel mapping
125  *
126  *	This function does not handle bus mappings for DMA transfers. In
127  *	almost all conceivable cases a device driver should not be using
128  *	this function
129  */
130 
131 static inline void *phys_to_virt(phys_addr_t address)
132 {
133 	return __va(address);
134 }
135 
136 /*
137  * Change "struct page" to physical address.
138  */
139 #define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
140 
141 /*
142  * ISA I/O bus memory addresses are 1:1 with the physical address.
143  * However, we truncate the address to unsigned int to avoid undesirable
144  * promitions in legacy drivers.
145  */
146 static inline unsigned int isa_virt_to_bus(volatile void *address)
147 {
148 	return (unsigned int)virt_to_phys(address);
149 }
150 #define isa_page_to_bus(page)	((unsigned int)page_to_phys(page))
151 #define isa_bus_to_virt		phys_to_virt
152 
153 /*
154  * However PCI ones are not necessarily 1:1 and therefore these interfaces
155  * are forbidden in portable PCI drivers.
156  *
157  * Allow them on x86 for legacy drivers, though.
158  */
159 #define virt_to_bus virt_to_phys
160 #define bus_to_virt phys_to_virt
161 
162 /**
163  * ioremap     -   map bus memory into CPU space
164  * @offset:    bus address of the memory
165  * @size:      size of the resource to map
166  *
167  * ioremap performs a platform specific sequence of operations to
168  * make bus memory CPU accessible via the readb/readw/readl/writeb/
169  * writew/writel functions and the other mmio helpers. The returned
170  * address is not guaranteed to be usable directly as a virtual
171  * address.
172  *
173  * If the area you are trying to map is a PCI BAR you should have a
174  * look at pci_iomap().
175  */
176 extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
177 extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
178 extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
179 				unsigned long prot_val);
180 
181 /*
182  * The default ioremap() behavior is non-cached:
183  */
184 static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
185 {
186 	return ioremap_nocache(offset, size);
187 }
188 
189 extern void iounmap(volatile void __iomem *addr);
190 
191 extern void set_iounmap_nonlazy(void);
192 
193 #ifdef __KERNEL__
194 
195 #include <asm-generic/iomap.h>
196 
197 #include <linux/vmalloc.h>
198 
199 /*
200  * Convert a virtual cached pointer to an uncached pointer
201  */
202 #define xlate_dev_kmem_ptr(p)	p
203 
204 static inline void
205 memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
206 {
207 	memset((void __force *)addr, val, count);
208 }
209 
210 static inline void
211 memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
212 {
213 	memcpy(dst, (const void __force *)src, count);
214 }
215 
216 static inline void
217 memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
218 {
219 	memcpy((void __force *)dst, src, count);
220 }
221 
222 /*
223  * ISA space is 'always mapped' on a typical x86 system, no need to
224  * explicitly ioremap() it. The fact that the ISA IO space is mapped
225  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
226  * are physical addresses. The following constant pointer can be
227  * used as the IO-area pointer (it can be iounmapped as well, so the
228  * analogy with PCI is quite large):
229  */
230 #define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
231 
232 /*
233  *	Cache management
234  *
235  *	This needed for two cases
236  *	1. Out of order aware processors
237  *	2. Accidentally out of order processors (PPro errata #51)
238  */
239 
240 static inline void flush_write_buffers(void)
241 {
242 #if defined(CONFIG_X86_OOSTORE) || defined(CONFIG_X86_PPRO_FENCE)
243 	asm volatile("lock; addl $0,0(%%esp)": : :"memory");
244 #endif
245 }
246 
247 #endif /* __KERNEL__ */
248 
249 extern void native_io_delay(void);
250 
251 extern int io_delay_type;
252 extern void io_delay_init(void);
253 
254 #if defined(CONFIG_PARAVIRT)
255 #include <asm/paravirt.h>
256 #else
257 
258 static inline void slow_down_io(void)
259 {
260 	native_io_delay();
261 #ifdef REALLY_SLOW_IO
262 	native_io_delay();
263 	native_io_delay();
264 	native_io_delay();
265 #endif
266 }
267 
268 #endif
269 
270 #define BUILDIO(bwl, bw, type)						\
271 static inline void out##bwl(unsigned type value, int port)		\
272 {									\
273 	asm volatile("out" #bwl " %" #bw "0, %w1"			\
274 		     : : "a"(value), "Nd"(port));			\
275 }									\
276 									\
277 static inline unsigned type in##bwl(int port)				\
278 {									\
279 	unsigned type value;						\
280 	asm volatile("in" #bwl " %w1, %" #bw "0"			\
281 		     : "=a"(value) : "Nd"(port));			\
282 	return value;							\
283 }									\
284 									\
285 static inline void out##bwl##_p(unsigned type value, int port)		\
286 {									\
287 	out##bwl(value, port);						\
288 	slow_down_io();							\
289 }									\
290 									\
291 static inline unsigned type in##bwl##_p(int port)			\
292 {									\
293 	unsigned type value = in##bwl(port);				\
294 	slow_down_io();							\
295 	return value;							\
296 }									\
297 									\
298 static inline void outs##bwl(int port, const void *addr, unsigned long count) \
299 {									\
300 	asm volatile("rep; outs" #bwl					\
301 		     : "+S"(addr), "+c"(count) : "d"(port));		\
302 }									\
303 									\
304 static inline void ins##bwl(int port, void *addr, unsigned long count)	\
305 {									\
306 	asm volatile("rep; ins" #bwl					\
307 		     : "+D"(addr), "+c"(count) : "d"(port));		\
308 }
309 
310 BUILDIO(b, b, char)
311 BUILDIO(w, w, short)
312 BUILDIO(l, , int)
313 
314 extern void *xlate_dev_mem_ptr(unsigned long phys);
315 extern void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
316 
317 extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
318 				unsigned long prot_val);
319 extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
320 
321 /*
322  * early_ioremap() and early_iounmap() are for temporary early boot-time
323  * mappings, before the real ioremap() is functional.
324  * A boot-time mapping is currently limited to at most 16 pages.
325  */
326 extern void early_ioremap_init(void);
327 extern void early_ioremap_reset(void);
328 extern void __iomem *early_ioremap(resource_size_t phys_addr,
329 				   unsigned long size);
330 extern void __iomem *early_memremap(resource_size_t phys_addr,
331 				    unsigned long size);
332 extern void early_iounmap(void __iomem *addr, unsigned long size);
333 extern void fixup_early_ioremap(void);
334 extern bool is_early_ioremap_ptep(pte_t *ptep);
335 
336 #ifdef CONFIG_XEN
337 struct bio_vec;
338 
339 extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
340 				      const struct bio_vec *vec2);
341 
342 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\
343 	(__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&				\
344 	 (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
345 #endif	/* CONFIG_XEN */
346 
347 #define IO_SPACE_LIMIT 0xffff
348 
349 #endif /* _ASM_X86_IO_H */
350