xref: /openbmc/u-boot/arch/x86/include/asm/io.h (revision 63495ad7)
1 #ifndef _ASM_IO_H
2 #define _ASM_IO_H
3 
4 #include <compiler.h>
5 
6 /*
7  * This file contains the definitions for the x86 IO instructions
8  * inb/inw/inl/outb/outw/outl and the "string versions" of the same
9  * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
10  * versions of the single-IO instructions (inb_p/inw_p/..).
11  *
12  * This file is not meant to be obfuscating: it's just complicated
13  * to (a) handle it all in a way that makes gcc able to optimize it
14  * as well as possible and (b) trying to avoid writing the same thing
15  * over and over again with slight variations and possibly making a
16  * mistake somewhere.
17  */
18 
19 /*
20  * Thanks to James van Artsdalen for a better timing-fix than
21  * the two short jumps: using outb's to a nonexistent port seems
22  * to guarantee better timings even on fast machines.
23  *
24  * On the other hand, I'd like to be sure of a non-existent port:
25  * I feel a bit unsafe about using 0x80 (should be safe, though)
26  *
27  *		Linus
28  */
29 
30  /*
31   *  Bit simplified and optimized by Jan Hubicka
32   *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999.
33   *
34   *  isa_memset_io, isa_memcpy_fromio, isa_memcpy_toio added,
35   *  isa_read[wl] and isa_write[wl] fixed
36   *  - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
37   */
38 
39 #define IO_SPACE_LIMIT 0xffff
40 
41 #include <asm/types.h>
42 
43 
44 #ifdef __KERNEL__
45 
46 
47 /*
48  * readX/writeX() are used to access memory mapped devices. On some
49  * architectures the memory mapped IO stuff needs to be accessed
50  * differently. On the x86 architecture, we just read/write the
51  * memory location directly.
52  */
53 
54 #define readb(addr) (*(volatile unsigned char *) (addr))
55 #define readw(addr) (*(volatile unsigned short *) (addr))
56 #define readl(addr) (*(volatile unsigned int *) (addr))
57 #define __raw_readb readb
58 #define __raw_readw readw
59 #define __raw_readl readl
60 
61 #define writeb(b,addr) (*(volatile unsigned char *) (addr) = (b))
62 #define writew(b,addr) (*(volatile unsigned short *) (addr) = (b))
63 #define writel(b,addr) (*(volatile unsigned int *) (addr) = (b))
64 #define __raw_writeb writeb
65 #define __raw_writew writew
66 #define __raw_writel writel
67 
68 #define memset_io(a,b,c)	memset((a),(b),(c))
69 #define memcpy_fromio(a,b,c)	memcpy((a),(b),(c))
70 #define memcpy_toio(a,b,c)	memcpy((a),(b),(c))
71 
72 /*
73  * ISA space is 'always mapped' on a typical x86 system, no need to
74  * explicitly ioremap() it. The fact that the ISA IO space is mapped
75  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
76  * are physical addresses. The following constant pointer can be
77  * used as the IO-area pointer (it can be iounmapped as well, so the
78  * analogy with PCI is quite large):
79  */
80 #define isa_readb(a) readb((a))
81 #define isa_readw(a) readw((a))
82 #define isa_readl(a) readl((a))
83 #define isa_writeb(b,a) writeb(b,(a))
84 #define isa_writew(w,a) writew(w,(a))
85 #define isa_writel(l,a) writel(l,(a))
86 #define isa_memset_io(a,b,c)		memset_io((a),(b),(c))
87 #define isa_memcpy_fromio(a,b,c)	memcpy_fromio((a),(b),(c))
88 #define isa_memcpy_toio(a,b,c)		memcpy_toio((a),(b),(c))
89 
90 
91 static inline int check_signature(unsigned long io_addr,
92 	const unsigned char *signature, int length)
93 {
94 	int retval = 0;
95 	do {
96 		if (readb(io_addr) != *signature)
97 			goto out;
98 		io_addr++;
99 		signature++;
100 		length--;
101 	} while (length);
102 	retval = 1;
103 out:
104 	return retval;
105 }
106 
107 /**
108  *	isa_check_signature		-	find BIOS signatures
109  *	@io_addr: mmio address to check
110  *	@signature:  signature block
111  *	@length: length of signature
112  *
113  *	Perform a signature comparison with the ISA mmio address io_addr.
114  *	Returns 1 on a match.
115  *
116  *	This function is deprecated. New drivers should use ioremap and
117  *	check_signature.
118  */
119 
120 
121 static inline int isa_check_signature(unsigned long io_addr,
122 	const unsigned char *signature, int length)
123 {
124 	int retval = 0;
125 	do {
126 		if (isa_readb(io_addr) != *signature)
127 			goto out;
128 		io_addr++;
129 		signature++;
130 		length--;
131 	} while (length);
132 	retval = 1;
133 out:
134 	return retval;
135 }
136 
137 #endif /* __KERNEL__ */
138 
139 #ifdef SLOW_IO_BY_JUMPING
140 #define __SLOW_DOWN_IO "\njmp 1f\n1:\tjmp 1f\n1:"
141 #else
142 #define __SLOW_DOWN_IO "\noutb %%al,$0xed"
143 #endif
144 
145 #ifdef REALLY_SLOW_IO
146 #define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO __SLOW_DOWN_IO
147 #else
148 #define __FULL_SLOW_DOWN_IO __SLOW_DOWN_IO
149 #endif
150 
151 
152 /*
153  * Talk about misusing macros..
154  */
155 #define __OUT1(s,x) \
156 static inline void out##s(unsigned x value, unsigned short port) {
157 
158 #define __OUT2(s,s1,s2) \
159 __asm__ __volatile__ ("out" #s " %" s1 "0,%" s2 "1"
160 
161 
162 #define __OUT(s,s1,x) \
163 __OUT1(s,x) __OUT2(s,s1,"w") : : "a" (value), "Nd" (port)); } \
164 __OUT1(s##_p,x) __OUT2(s,s1,"w") __FULL_SLOW_DOWN_IO : : "a" (value), "Nd" (port));}
165 
166 #define __IN1(s) \
167 static inline RETURN_TYPE in##s(unsigned short port) { RETURN_TYPE _v;
168 
169 #define __IN2(s,s1,s2) \
170 __asm__ __volatile__ ("in" #s " %" s2 "1,%" s1 "0"
171 
172 #define __IN(s,s1,i...) \
173 __IN1(s) __IN2(s,s1,"w") : "=a" (_v) : "Nd" (port) ,##i ); return _v; } \
174 __IN1(s##_p) __IN2(s,s1,"w") __FULL_SLOW_DOWN_IO : "=a" (_v) : "Nd" (port) ,##i ); return _v; }
175 
176 #define __INS(s) \
177 static inline void ins##s(unsigned short port, void * addr, unsigned long count) \
178 { __asm__ __volatile__ ("rep ; ins" #s \
179 : "=D" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
180 
181 #define __OUTS(s) \
182 static inline void outs##s(unsigned short port, const void * addr, unsigned long count) \
183 { __asm__ __volatile__ ("rep ; outs" #s \
184 : "=S" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
185 
186 #define RETURN_TYPE unsigned char
187 __IN(b,"")
188 #undef RETURN_TYPE
189 #define RETURN_TYPE unsigned short
190 __IN(w,"")
191 #undef RETURN_TYPE
192 #define RETURN_TYPE unsigned int
193 __IN(l,"")
194 #undef RETURN_TYPE
195 
196 __OUT(b,"b",char)
197 __OUT(w,"w",short)
198 __OUT(l,,int)
199 
200 __INS(b)
201 __INS(w)
202 __INS(l)
203 
204 __OUTS(b)
205 __OUTS(w)
206 __OUTS(l)
207 
208 static inline void sync(void)
209 {
210 }
211 
212 /*
213  * Given a physical address and a length, return a virtual address
214  * that can be used to access the memory range with the caching
215  * properties specified by "flags".
216  */
217 #define MAP_NOCACHE	(0)
218 #define MAP_WRCOMBINE	(0)
219 #define MAP_WRBACK	(0)
220 #define MAP_WRTHROUGH	(0)
221 
222 static inline void *
223 map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags)
224 {
225 	return (void *)(uintptr_t)paddr;
226 }
227 
228 /*
229  * Take down a mapping set up by map_physmem().
230  */
231 static inline void unmap_physmem(void *vaddr, unsigned long flags)
232 {
233 
234 }
235 
236 static inline phys_addr_t virt_to_phys(void * vaddr)
237 {
238 	return (phys_addr_t)(uintptr_t)(vaddr);
239 }
240 
241 /*
242  * TODO: The kernel offers some more advanced versions of barriers, it might
243  * have some advantages to use them instead of the simple one here.
244  */
245 #define dmb()		__asm__ __volatile__ ("" : : : "memory")
246 #define __iormb()	dmb()
247 #define __iowmb()	dmb()
248 
249 #endif
250