1 // Code to access multiple segments within gcc.
3 // Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
5 // This file may be distributed under the terms of the GNU LGPLv3 license.
9 #include "ioport.h" // insb
11 // Dummy definitions used to make sure gcc understands dependencies
12 // between SET_SEG and GET/READ/WRITE_SEG macros.
13 extern u16 __segment_ES, __segment_CS, __segment_DS, __segment_SS;
14 extern u16 __segment_FS, __segment_GS;
16 // Low level macros for reading/writing memory via a segment selector.
17 #define READ8_SEG(SEG, value, var) \
18 __asm__("movb %%" #SEG ":%1, %b0" : "=Qi"(value) \
19 : "m"(var), "m"(__segment_ ## SEG))
20 #define READ16_SEG(SEG, value, var) \
21 __asm__("movw %%" #SEG ":%1, %w0" : "=ri"(value) \
22 : "m"(var), "m"(__segment_ ## SEG))
23 #define READ32_SEG(SEG, value, var) \
24 __asm__("movl %%" #SEG ":%1, %0" : "=ri"(value) \
25 : "m"(var), "m"(__segment_ ## SEG))
26 #define READ64_SEG(SEG, value, var) do { \
27 union u64_u32_u __value; \
28 union u64_u32_u *__r64_ptr = (union u64_u32_u *)&(var); \
29 READ32_SEG(SEG, __value.hi, __r64_ptr->hi); \
30 READ32_SEG(SEG, __value.lo, __r64_ptr->lo); \
31 (value) = __value.val; \
33 #define WRITE8_SEG(SEG, var, value) \
34 __asm__("movb %b1, %%" #SEG ":%0" : "=m"(var) \
35 : "Q"(value), "m"(__segment_ ## SEG))
36 #define WRITE16_SEG(SEG, var, value) \
37 __asm__("movw %w1, %%" #SEG ":%0" : "=m"(var) \
38 : "r"(value), "m"(__segment_ ## SEG))
39 #define WRITE32_SEG(SEG, var, value) \
40 __asm__("movl %1, %%" #SEG ":%0" : "=m"(var) \
41 : "r"(value), "m"(__segment_ ## SEG))
42 #define WRITE64_SEG(SEG, var, value) do { \
43 union u64_u32_u __value; \
44 union u64_u32_u *__w64_ptr = (union u64_u32_u *)&(var); \
45 __value.val = (value); \
46 WRITE32_SEG(SEG, __w64_ptr->hi, __value.hi); \
47 WRITE32_SEG(SEG, __w64_ptr->lo, __value.lo); \
50 // Low level macros for getting/setting a segment register.
51 #define __SET_SEG(SEG, value) \
52 __asm__("movw %w1, %%" #SEG : "=m"(__segment_ ## SEG) \
54 #define __GET_SEG(SEG) ({ \
56 __asm__("movw %%" #SEG ", %w0" : "=rm"(__seg) \
57 : "m"(__segment_ ## SEG)); \
60 // Macros for automatically choosing the appropriate memory size
62 extern void __force_link_error__unknown_type();
64 #define __GET_VAR(seg, var) ({ \
66 if (sizeof(__val) == 1) \
67 READ8_SEG(seg, __val, var); \
68 else if (sizeof(__val) == 2) \
69 READ16_SEG(seg, __val, var); \
70 else if (sizeof(__val) == 4) \
71 READ32_SEG(seg, __val, var); \
72 else if (sizeof(__val) == 8) \
73 READ64_SEG(seg, __val, var); \
75 __force_link_error__unknown_type(); \
78 #define __SET_VAR(seg, var, val) do { \
79 if (sizeof(var) == 1) \
80 WRITE8_SEG(seg, var, (val)); \
81 else if (sizeof(var) == 2) \
82 WRITE16_SEG(seg, var, (val)); \
83 else if (sizeof(var) == 4) \
84 WRITE32_SEG(seg, var, (val)); \
85 else if (sizeof(var) == 8) \
86 WRITE64_SEG(seg, var, (val)); \
88 __force_link_error__unknown_type(); \
91 // Macros for accessing a variable in another segment. (They
92 // automatically update the %es segment and then make the appropriate
94 #define __GET_FARVAR(seg, var) ({ \
96 GET_VAR(ES, (var)); })
97 #define __SET_FARVAR(seg, var, val) do { \
98 typeof(var) __sfv_val = (val); \
100 SET_VAR(ES, (var), __sfv_val); \
103 // Macros for accesssing a 32bit flat mode pointer from 16bit real
104 // mode. (They automatically update the %es segment, break the
105 // pointer into segment/offset, and then make the access.)
106 #define __GET_FLATPTR(ptr) ({ \
107 typeof(&(ptr)) __ptr = &(ptr); \
108 GET_FARVAR(FLATPTR_TO_SEG(__ptr) \
109 , *(typeof(__ptr))FLATPTR_TO_OFFSET(__ptr)); })
110 #define __SET_FLATPTR(ptr, val) do { \
111 typeof (&(ptr)) __ptr = &(ptr); \
112 SET_FARVAR(FLATPTR_TO_SEG(__ptr) \
113 , *(typeof(__ptr))FLATPTR_TO_OFFSET(__ptr) \
117 // Macros for converting to/from 32bit flat mode pointers to their
118 // equivalent 16bit segment/offset values.
119 #define FLATPTR_TO_SEG(p) (((u32)(p)) >> 4)
120 #define FLATPTR_TO_OFFSET(p) (((u32)(p)) & 0xf)
121 #define MAKE_FLATPTR(seg,off) ((void*)(((u32)(seg)<<4)+(u32)(off)))
126 // Definitions when in 16 bit mode.
127 #define GET_FARVAR(seg, var) __GET_FARVAR((seg), (var))
128 #define SET_FARVAR(seg, var, val) __SET_FARVAR((seg), (var), (val))
129 #define GET_VAR(seg, var) __GET_VAR(seg, (var))
130 #define SET_VAR(seg, var, val) __SET_VAR(seg, (var), (val))
131 #define SET_SEG(SEG, value) __SET_SEG(SEG, (value))
132 #define GET_SEG(SEG) __GET_SEG(SEG)
133 #define GET_FLATPTR(ptr) __GET_FLATPTR(ptr)
134 #define SET_FLATPTR(ptr, val) __SET_FLATPTR((ptr), (val))
136 static inline void insb_fl(u16 port, void *ptr_fl, u16 count) {
137 SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl));
138 insb(port, (u8*)FLATPTR_TO_OFFSET(ptr_fl), count);
140 static inline void insw_fl(u16 port, void *ptr_fl, u16 count) {
141 SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl));
142 insw(port, (u16*)FLATPTR_TO_OFFSET(ptr_fl), count);
144 static inline void insl_fl(u16 port, void *ptr_fl, u16 count) {
145 SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl));
146 insl(port, (u32*)FLATPTR_TO_OFFSET(ptr_fl), count);
148 static inline void outsb_fl(u16 port, void *ptr_fl, u16 count) {
149 SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl));
150 outsb(port, (u8*)FLATPTR_TO_OFFSET(ptr_fl), count);
152 static inline void outsw_fl(u16 port, void *ptr_fl, u16 count) {
153 SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl));
154 outsw(port, (u16*)FLATPTR_TO_OFFSET(ptr_fl), count);
156 static inline void outsl_fl(u16 port, void *ptr_fl, u16 count) {
157 SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl));
158 outsl(port, (u32*)FLATPTR_TO_OFFSET(ptr_fl), count);
161 extern void __force_link_error__only_in_32bit() __attribute__ ((noreturn));
162 #define ASSERT16() do { } while (0)
163 #define ASSERT32() __force_link_error__only_in_32bit()
167 // In 32-bit mode there is no need to mess with the segments.
168 #define GET_FARVAR(seg, var) \
169 (*((typeof(&(var)))MAKE_FLATPTR((seg), &(var))))
170 #define SET_FARVAR(seg, var, val) \
171 do { GET_FARVAR((seg), (var)) = (val); } while (0)
172 #define GET_VAR(seg, var) (var)
173 #define SET_VAR(seg, var, val) do { (var) = (val); } while (0)
174 #define SET_SEG(SEG, value) ((void)(value))
175 #define GET_SEG(SEG) 0
176 #define GET_FLATPTR(ptr) (ptr)
177 #define SET_FLATPTR(ptr, val) do { (ptr) = (val); } while (0)
179 #define insb_fl(port, ptr_fl, count) insb(port, ptr_fl, count)
180 #define insw_fl(port, ptr_fl, count) insw(port, ptr_fl, count)
181 #define insl_fl(port, ptr_fl, count) insl(port, ptr_fl, count)
182 #define outsb_fl(port, ptr_fl, count) outsb(port, ptr_fl, count)
183 #define outsw_fl(port, ptr_fl, count) outsw(port, ptr_fl, count)
184 #define outsl_fl(port, ptr_fl, count) outsl(port, ptr_fl, count)
186 extern void __force_link_error__only_in_16bit() __attribute__ ((noreturn));
187 #define ASSERT16() __force_link_error__only_in_16bit()
188 #define ASSERT32() do { } while (0)