xref: /titanic_41/usr/src/grub/grub-0.97/netboot/io.h (revision b9175c69691c8949bec97fb8f689b7d1efdb05bb)
1 #ifndef	IO_H
2 #define IO_H
3 
4 
5 /* Amount of relocation etherboot is experiencing */
6 extern unsigned long virt_offset;
7 
8 /* Don't require identity mapped physical memory,
9  * osloader.c is the only valid user at the moment.
10  */
11 unsigned long virt_to_phys(volatile const void *virt_addr);
12 void *phys_to_virt(unsigned long phys_addr);
13 
14 /* virt_to_bus converts an addresss inside of etherboot [_start, _end]
15  * into a memory access cards can use.
16  */
17 #define virt_to_bus virt_to_phys
18 
19 
20 /* bus_to_virt reverses virt_to_bus, the address must be output
21  * from virt_to_bus to be valid.  This function does not work on
22  * all bus addresses.
23  */
24 #define bus_to_virt phys_to_virt
25 
26 /* ioremap converts a random 32bit bus address into something
27  * etherboot can access.
28  */
29 static inline void *ioremap(unsigned long bus_addr, unsigned long length __unused)
30 {
31 	return bus_to_virt(bus_addr);
32 }
33 
34 /* iounmap cleans up anything ioremap had to setup */
35 static inline void iounmap(void *virt_addr __unused)
36 {
37 	return;
38 }
39 
40 /*
41  * This file contains the definitions for the x86 IO instructions
42  * inb/inw/inl/outb/outw/outl and the "string versions" of the same
43  * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
44  * versions of the single-IO instructions (inb_p/inw_p/..).
45  *
46  * This file is not meant to be obfuscating: it's just complicated
47  * to (a) handle it all in a way that makes gcc able to optimize it
48  * as well as possible and (b) trying to avoid writing the same thing
49  * over and over again with slight variations and possibly making a
50  * mistake somewhere.
51  */
52 
53 /*
54  * Thanks to James van Artsdalen for a better timing-fix than
55  * the two short jumps: using outb's to a nonexistent port seems
56  * to guarantee better timings even on fast machines.
57  *
58  * On the other hand, I'd like to be sure of a non-existent port:
59  * I feel a bit unsafe about using 0x80 (should be safe, though)
60  *
61  *		Linus
62  */
63 
64 #ifdef	SLOW_IO_BY_JUMPING
65 #define __SLOW_DOWN_IO __asm__ __volatile__("jmp 1f\n1:\tjmp 1f\n1:")
66 #else
67 #define __SLOW_DOWN_IO __asm__ __volatile__("outb %al,$0x80")
68 #endif
69 
70 #ifdef	REALLY_SLOW_IO
71 #define SLOW_DOWN_IO { __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; }
72 #else
73 #define SLOW_DOWN_IO __SLOW_DOWN_IO
74 #endif
75 
76 /*
77  * readX/writeX() are used to access memory mapped devices. On some
78  * architectures the memory mapped IO stuff needs to be accessed
79  * differently. On the x86 architecture, we just read/write the
80  * memory location directly.
81  */
82 #define readb(addr) (*(volatile unsigned char *) (addr))
83 #define readw(addr) (*(volatile unsigned short *) (addr))
84 #define readl(addr) (*(volatile unsigned int *) (addr))
85 
86 #define writeb(b,addr) ((*(volatile unsigned char *) (addr)) = (b))
87 #define writew(b,addr) ((*(volatile unsigned short *) (addr)) = (b))
88 #define writel(b,addr) ((*(volatile unsigned int *) (addr)) = (b))
89 
90 #define memcpy_fromio(a,b,c)	memcpy((a),(void *)(b),(c))
91 #define memcpy_toio(a,b,c)	memcpy((void *)(a),(b),(c))
92 
93 /*
94  * Force strict CPU ordering.
95  * And yes, this is required on UP too when we're talking
96  * to devices.
97  *
98  * For now, "wmb()" doesn't actually do anything, as all
99  * Intel CPU's follow what Intel calls a *Processor Order*,
100  * in which all writes are seen in the program order even
101  * outside the CPU.
102  *
103  * I expect future Intel CPU's to have a weaker ordering,
104  * but I'd also expect them to finally get their act together
105  * and add some real memory barriers if so.
106  *
107  * Some non intel clones support out of order store. wmb() ceases to be a
108  * nop for these.
109  */
110 
111 #define mb() 	__asm__ __volatile__ ("lock; addl $0,0(%%esp)": : :"memory")
112 #define rmb()	mb()
113 #define wmb()	mb();
114 
115 
116 /*
117  * Talk about misusing macros..
118  */
119 
120 #define __OUT1(s,x) \
121 extern void __out##s(unsigned x value, unsigned short port); \
122 extern inline void __out##s(unsigned x value, unsigned short port) {
123 
124 #define __OUT2(s,s1,s2) \
125 __asm__ __volatile__ ("out" #s " %" s1 "0,%" s2 "1"
126 
127 #define __OUT(s,s1,x) \
128 __OUT1(s,x) __OUT2(s,s1,"w") : : "a" (value), "d" (port)); } \
129 __OUT1(s##c,x) __OUT2(s,s1,"") : : "a" (value), "id" (port)); } \
130 __OUT1(s##_p,x) __OUT2(s,s1,"w") : : "a" (value), "d" (port)); SLOW_DOWN_IO; } \
131 __OUT1(s##c_p,x) __OUT2(s,s1,"") : : "a" (value), "id" (port)); SLOW_DOWN_IO; }
132 
133 #define __IN1(s,x) \
134 extern unsigned x __in##s(unsigned short port); \
135 extern inline unsigned x __in##s(unsigned short port) { unsigned x _v;
136 
137 #define __IN2(s,s1,s2) \
138 __asm__ __volatile__ ("in" #s " %" s2 "1,%" s1 "0"
139 
140 #define __IN(s,s1,x,i...) \
141 __IN1(s,x) __IN2(s,s1,"w") : "=a" (_v) : "d" (port) ,##i ); return _v; } \
142 __IN1(s##c,x) __IN2(s,s1,"") : "=a" (_v) : "id" (port) ,##i ); return _v; } \
143 __IN1(s##_p,x) __IN2(s,s1,"w") : "=a" (_v) : "d" (port) ,##i ); SLOW_DOWN_IO; return _v; } \
144 __IN1(s##c_p,x) __IN2(s,s1,"") : "=a" (_v) : "id" (port) ,##i ); SLOW_DOWN_IO; return _v; }
145 
146 #define __INS(s) \
147 extern void ins##s(unsigned short port, void * addr, unsigned long count); \
148 extern inline void ins##s(unsigned short port, void * addr, unsigned long count) \
149 { __asm__ __volatile__ ("cld ; rep ; ins" #s \
150 : "=D" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
151 
152 #define __OUTS(s) \
153 extern void outs##s(unsigned short port, const void * addr, unsigned long  count); \
154 extern inline void outs##s(unsigned short port, const void * addr, unsigned long count) \
155 { __asm__ __volatile__ ("cld ; rep ; outs" #s \
156 : "=S" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }
157 
158 __IN(b,"", char)
159 __IN(w,"",short)
160 __IN(l,"", long)
161 
162 __OUT(b,"b",char)
163 __OUT(w,"w",short)
164 __OUT(l,,int)
165 
166 __INS(b)
167 __INS(w)
168 __INS(l)
169 
170 __OUTS(b)
171 __OUTS(w)
172 __OUTS(l)
173 
174 /*
175  * Note that due to the way __builtin_constant_p() works, you
176  *  - can't use it inside a inline function (it will never be true)
177  *  - you don't have to worry about side effects within the __builtin..
178  */
179 #define outb(val,port) \
180 ((__builtin_constant_p((port)) && (port) < 256) ? \
181 	__outbc((val),(port)) : \
182 	__outb((val),(port)))
183 
184 #define inb(port) \
185 ((__builtin_constant_p((port)) && (port) < 256) ? \
186 	__inbc(port) : \
187 	__inb(port))
188 
189 #define outb_p(val,port) \
190 ((__builtin_constant_p((port)) && (port) < 256) ? \
191 	__outbc_p((val),(port)) : \
192 	__outb_p((val),(port)))
193 
194 #define inb_p(port) \
195 ((__builtin_constant_p((port)) && (port) < 256) ? \
196 	__inbc_p(port) : \
197 	__inb_p(port))
198 
199 #define outw(val,port) \
200 ((__builtin_constant_p((port)) && (port) < 256) ? \
201 	__outwc((val),(port)) : \
202 	__outw((val),(port)))
203 
204 #define inw(port) \
205 ((__builtin_constant_p((port)) && (port) < 256) ? \
206 	__inwc(port) : \
207 	__inw(port))
208 
209 #define outw_p(val,port) \
210 ((__builtin_constant_p((port)) && (port) < 256) ? \
211 	__outwc_p((val),(port)) : \
212 	__outw_p((val),(port)))
213 
214 #define inw_p(port) \
215 ((__builtin_constant_p((port)) && (port) < 256) ? \
216 	__inwc_p(port) : \
217 	__inw_p(port))
218 
219 #define outl(val,port) \
220 ((__builtin_constant_p((port)) && (port) < 256) ? \
221 	__outlc((val),(port)) : \
222 	__outl((val),(port)))
223 
224 #define inl(port) \
225 ((__builtin_constant_p((port)) && (port) < 256) ? \
226 	__inlc(port) : \
227 	__inl(port))
228 
229 #define outl_p(val,port) \
230 ((__builtin_constant_p((port)) && (port) < 256) ? \
231 	__outlc_p((val),(port)) : \
232 	__outl_p((val),(port)))
233 
234 #define inl_p(port) \
235 ((__builtin_constant_p((port)) && (port) < 256) ? \
236 	__inlc_p(port) : \
237 	__inl_p(port))
238 
239 #endif /* ETHERBOOT_IO_H */
240