xref: /openbmc/linux/arch/x86/include/asm/io.h (revision 33ac9dba)
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 __raw_writeb __writeb
78 #define __raw_writew __writew
79 #define __raw_writel __writel
80 
81 #define mmiowb() barrier()
82 
83 #ifdef CONFIG_X86_64
84 
85 build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
86 build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
87 
88 #define readq_relaxed(a)	readq(a)
89 
90 #define __raw_readq(a)		readq(a)
91 #define __raw_writeq(val, addr)	writeq(val, addr)
92 
93 /* Let people know that we have them */
94 #define readq			readq
95 #define writeq			writeq
96 
97 #endif
98 
99 /**
100  *	virt_to_phys	-	map virtual addresses to physical
101  *	@address: address to remap
102  *
103  *	The returned physical address is the physical (CPU) mapping for
104  *	the memory address given. It is only valid to use this function on
105  *	addresses directly mapped or allocated via kmalloc.
106  *
107  *	This function does not give bus mappings for DMA transfers. In
108  *	almost all conceivable cases a device driver should not be using
109  *	this function
110  */
111 
112 static inline phys_addr_t virt_to_phys(volatile void *address)
113 {
114 	return __pa(address);
115 }
116 
117 /**
118  *	phys_to_virt	-	map physical address to virtual
119  *	@address: address to remap
120  *
121  *	The returned virtual address is a current CPU mapping for
122  *	the memory address given. It is only valid to use this function on
123  *	addresses that have a kernel mapping
124  *
125  *	This function does not handle bus mappings for DMA transfers. In
126  *	almost all conceivable cases a device driver should not be using
127  *	this function
128  */
129 
130 static inline void *phys_to_virt(phys_addr_t address)
131 {
132 	return __va(address);
133 }
134 
135 /*
136  * Change "struct page" to physical address.
137  */
138 #define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
139 
140 /*
141  * ISA I/O bus memory addresses are 1:1 with the physical address.
142  * However, we truncate the address to unsigned int to avoid undesirable
143  * promitions in legacy drivers.
144  */
145 static inline unsigned int isa_virt_to_bus(volatile void *address)
146 {
147 	return (unsigned int)virt_to_phys(address);
148 }
149 #define isa_page_to_bus(page)	((unsigned int)page_to_phys(page))
150 #define isa_bus_to_virt		phys_to_virt
151 
152 /*
153  * However PCI ones are not necessarily 1:1 and therefore these interfaces
154  * are forbidden in portable PCI drivers.
155  *
156  * Allow them on x86 for legacy drivers, though.
157  */
158 #define virt_to_bus virt_to_phys
159 #define bus_to_virt phys_to_virt
160 
161 /**
162  * ioremap     -   map bus memory into CPU space
163  * @offset:    bus address of the memory
164  * @size:      size of the resource to map
165  *
166  * ioremap performs a platform specific sequence of operations to
167  * make bus memory CPU accessible via the readb/readw/readl/writeb/
168  * writew/writel functions and the other mmio helpers. The returned
169  * address is not guaranteed to be usable directly as a virtual
170  * address.
171  *
172  * If the area you are trying to map is a PCI BAR you should have a
173  * look at pci_iomap().
174  */
175 extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
176 extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
177 extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
178 				unsigned long prot_val);
179 
180 /*
181  * The default ioremap() behavior is non-cached:
182  */
183 static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
184 {
185 	return ioremap_nocache(offset, size);
186 }
187 
188 extern void iounmap(volatile void __iomem *addr);
189 
190 extern void set_iounmap_nonlazy(void);
191 
192 #ifdef __KERNEL__
193 
194 #include <asm-generic/iomap.h>
195 
196 #include <linux/vmalloc.h>
197 
198 /*
199  * Convert a virtual cached pointer to an uncached pointer
200  */
201 #define xlate_dev_kmem_ptr(p)	p
202 
203 static inline void
204 memset_io(volatile void __iomem *addr, unsigned char val, size_t count)
205 {
206 	memset((void __force *)addr, val, count);
207 }
208 
209 static inline void
210 memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count)
211 {
212 	memcpy(dst, (const void __force *)src, count);
213 }
214 
215 static inline void
216 memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
217 {
218 	memcpy((void __force *)dst, src, count);
219 }
220 
221 /*
222  * ISA space is 'always mapped' on a typical x86 system, no need to
223  * explicitly ioremap() it. The fact that the ISA IO space is mapped
224  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
225  * are physical addresses. The following constant pointer can be
226  * used as the IO-area pointer (it can be iounmapped as well, so the
227  * analogy with PCI is quite large):
228  */
229 #define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
230 
231 /*
232  *	Cache management
233  *
234  *	This needed for two cases
235  *	1. Out of order aware processors
236  *	2. Accidentally out of order processors (PPro errata #51)
237  */
238 
239 static inline void flush_write_buffers(void)
240 {
241 #if defined(CONFIG_X86_PPRO_FENCE)
242 	asm volatile("lock; addl $0,0(%%esp)": : :"memory");
243 #endif
244 }
245 
246 #endif /* __KERNEL__ */
247 
248 extern void native_io_delay(void);
249 
250 extern int io_delay_type;
251 extern void io_delay_init(void);
252 
253 #if defined(CONFIG_PARAVIRT)
254 #include <asm/paravirt.h>
255 #else
256 
257 static inline void slow_down_io(void)
258 {
259 	native_io_delay();
260 #ifdef REALLY_SLOW_IO
261 	native_io_delay();
262 	native_io_delay();
263 	native_io_delay();
264 #endif
265 }
266 
267 #endif
268 
269 #define BUILDIO(bwl, bw, type)						\
270 static inline void out##bwl(unsigned type value, int port)		\
271 {									\
272 	asm volatile("out" #bwl " %" #bw "0, %w1"			\
273 		     : : "a"(value), "Nd"(port));			\
274 }									\
275 									\
276 static inline unsigned type in##bwl(int port)				\
277 {									\
278 	unsigned type value;						\
279 	asm volatile("in" #bwl " %w1, %" #bw "0"			\
280 		     : "=a"(value) : "Nd"(port));			\
281 	return value;							\
282 }									\
283 									\
284 static inline void out##bwl##_p(unsigned type value, int port)		\
285 {									\
286 	out##bwl(value, port);						\
287 	slow_down_io();							\
288 }									\
289 									\
290 static inline unsigned type in##bwl##_p(int port)			\
291 {									\
292 	unsigned type value = in##bwl(port);				\
293 	slow_down_io();							\
294 	return value;							\
295 }									\
296 									\
297 static inline void outs##bwl(int port, const void *addr, unsigned long count) \
298 {									\
299 	asm volatile("rep; outs" #bwl					\
300 		     : "+S"(addr), "+c"(count) : "d"(port));		\
301 }									\
302 									\
303 static inline void ins##bwl(int port, void *addr, unsigned long count)	\
304 {									\
305 	asm volatile("rep; ins" #bwl					\
306 		     : "+D"(addr), "+c"(count) : "d"(port));		\
307 }
308 
309 BUILDIO(b, b, char)
310 BUILDIO(w, w, short)
311 BUILDIO(l, , int)
312 
313 extern void *xlate_dev_mem_ptr(unsigned long phys);
314 extern void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
315 
316 extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
317 				unsigned long prot_val);
318 extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
319 
320 extern bool is_early_ioremap_ptep(pte_t *ptep);
321 
322 #ifdef CONFIG_XEN
323 #include <xen/xen.h>
324 struct bio_vec;
325 
326 extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
327 				      const struct bio_vec *vec2);
328 
329 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\
330 	(__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&				\
331 	 (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
332 #endif	/* CONFIG_XEN */
333 
334 #define IO_SPACE_LIMIT 0xffff
335 
336 #ifdef CONFIG_MTRR
337 extern int __must_check arch_phys_wc_add(unsigned long base,
338 					 unsigned long size);
339 extern void arch_phys_wc_del(int handle);
340 #define arch_phys_wc_add arch_phys_wc_add
341 #endif
342 
343 #endif /* _ASM_X86_IO_H */
344