include/asm/segment.h

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 1 #ifndef _ASM_SEGMENT_H
 2 #define _ASM_SEGMENT_H
 3
 4 staticinlineunsigned charget_user_byte(const char* addr)
 5 {
 6 registerunsigned char _v;
 7
 8 __asm__("movb %%fs:%1,%0":"=q"(_v):"m"(*addr));
 9 return _v;
 10 }
 11
 12 #define get_fs_byte(addr) get_user_byte((char *)(addr))
 13
 14 staticinlineunsigned shortget_user_word(const short*addr)
 15 {
 16 unsigned short _v;
 17
 18 __asm__("movw %%fs:%1,%0":"=r"(_v):"m"(*addr));
 19 return _v;
 20 }
 21
 22 #define get_fs_word(addr) get_user_word((short *)(addr))
 23
 24 staticinlineunsigned longget_user_long(const int*addr)
 25 {
 26 unsigned long _v;
 27
 28 __asm__("movl %%fs:%1,%0":"=r"(_v):"m"(*addr)); \
 29 return _v;
 30 }
 31
 32 #define get_fs_long(addr) get_user_long((int *)(addr))
 33
 34 staticinlinevoidput_user_byte(char val,char*addr)
 35 {
 36 __asm__("movb %0,%%fs:%1":/* no outputs */:"iq"(val),"m"(*addr));
 37 }
 38
 39 #define put_fs_byte(x,addr) put_user_byte((x),(char *)(addr))
 40
 41 staticinlinevoidput_user_word(short val,short* addr)
 42 {
 43 __asm__("movw %0,%%fs:%1":/* no outputs */:"ir"(val),"m"(*addr));
 44 }
 45
 46 #define put_fs_word(x,addr) put_user_word((x),(short *)(addr))
 47
 48 staticinlinevoidput_user_long(unsigned long val,int* addr)
 49 {
 50 __asm__("movl %0,%%fs:%1":/* no outputs */:"ir"(val),"m"(*addr));
 51 }
 52
 53 #define put_fs_long(x,addr) put_user_long((x),(int *)(addr))
 54
 55 staticinlinevoid__generic_memcpy_tofs(void* to,const void* from,unsigned long n)
 56 {
 57 __asm__("cld\n\t"
 58 "push %%es\n\t"
 59 "push %%fs\n\t"
 60 "pop %%es\n\t"
 61 "testb $1,%%cl\n\t"
 62 "je 1f\n\t"
 63 "movsb\n"
 64 "1:\ttestb $2,%%cl\n\t"
 65 "je 2f\n\t"
 66 "movsw\n"
 67 "2:\tshrl $2,%%ecx\n\t"
 68 "rep ; movsl\n\t"
 69 "pop %%es"
 70 :/* no outputs */
 71 :"c"(n),"D"((long) to),"S"((long) from)
 72 :"cx","di","si");
 73 }
 74
 75 staticinlinevoid__constant_memcpy_tofs(void* to,const void* from,unsigned long n)
 76 {
 77 switch(n) {
 78 case0:
 79 return;
 80 case1:
 81 put_user_byte(*(const char*) from, (char*) to);
 82 return;
 83 case2:
 84 put_user_word(*(const short*) from, (short*) to);
 85 return;
 86 case3:
 87 put_user_word(*(const short*) from, (short*) to);
 88 put_user_byte(*(2+(const char*) from),2+(char*) to);
 89 return;
 90 case4:
 91 put_user_long(*(const int*) from, (int*) to);
 92 return;
 93 }
 94 #define COMMON(x) \
 95 __asm__("cld\n\t" \
 96 "push %%es\n\t" \
 97 "push %%fs\n\t" \
 98 "pop %%es\n\t" \
 99 "rep ; movsl\n\t" \
 100  x \
 101 "pop %%es" \
 102  :/* no outputs */ \
 103  :"c" (n/4),"D" ((long) to),"S" ((long) from) \
 104  :"cx","di","si")
 105
 106 switch(n %4) {
 107 case0:
 108 COMMON("");
 109 return;
 110 case1:
 111 COMMON("movsb\n\t");
 112 return;
 113 case2:
 114 COMMON("movsw\n\t");
 115 return;
 116 case3:
 117 COMMON("movsw\n\tmovsb\n\t");
 118 return;
 119 }
 120 #undef COMMON
 121 }
 122
 123 staticinlinevoid__generic_memcpy_fromfs(void* to,const void* from,unsigned long n)
 124 {
 125 __asm__("cld\n\t"
 126 "testb $1,%%cl\n\t"
 127 "je 1f\n\t"
 128 "fs ; movsb\n"
 129 "1:\ttestb $2,%%cl\n\t"
 130 "je 2f\n\t"
 131 "fs ; movsw\n"
 132 "2:\tshrl $2,%%ecx\n\t"
 133 "rep ; fs ; movsl"
 134 :/* no outputs */
 135 :"c"(n),"D"((long) to),"S"((long) from)
 136 :"cx","di","si","memory");
 137 }
 138
 139 staticinlinevoid__constant_memcpy_fromfs(void* to,const void* from,unsigned long n)
 140 {
 141 switch(n) {
 142 case0:
 143 return;
 144 case1:
 145 *(char*)to =get_user_byte((const char*) from);
 146 return;
 147 case2:
 148 *(short*)to =get_user_word((const short*) from);
 149 return;
 150 case3:
 151 *(short*) to =get_user_word((const short*) from);
 152 *(char*) to =get_user_byte(2+(const char*) from);
 153 return;
 154 case4:
 155 *(int*) to =get_user_long((const int*) from);
 156 return;
 157 }
 158 #define COMMON(x) \
 159 __asm__("cld\n\t" \
 160 "rep ; fs ; movsl\n\t" \
 161  x \
 162  :/* no outputs */ \
 163  :"c" (n/4),"D" ((long) to),"S" ((long) from) \
 164  :"cx","di","si","memory")
 165
 166 switch(n %4) {
 167 case0:
 168 COMMON("");
 169 return;
 170 case1:
 171 COMMON("fs ; movsb");
 172 return;
 173 case2:
 174 COMMON("fs ; movsw");
 175 return;
 176 case3:
 177 COMMON("fs ; movsw\n\tfs ; movsb");
 178 return;
 179 }
 180 #undef COMMON
 181 }
 182
 183 #define memcpy_fromfs(to, from, n) \
 184 (__builtin_constant_p(n) ? \
 185  __constant_memcpy_fromfs((to),(from),(n)) : \
 186  __generic_memcpy_fromfs((to),(from),(n)))
 187
 188 #define memcpy_tofs(to, from, n) \
 189 (__builtin_constant_p(n) ? \
 190  __constant_memcpy_tofs((to),(from),(n)) : \
 191  __generic_memcpy_tofs((to),(from),(n)))
 192
 193 /*
 194  * Someone who knows GNU asm better than I should double check the following.
 195  * It seems to work, but I don't know if I'm doing something subtly wrong.
 196  * --- TYT, 11/24/91
 197  * [ nothing wrong here, Linus: I just changed the ax to be any reg ]
 198  */
 199
 200 staticinlineunsigned longget_fs(void)
 201 {
 202 unsigned long _v;
 203 __asm__("mov %%fs,%w0":"=r"(_v):"0"(0));
 204 return _v;
 205 }
 206
 207 staticinlineunsigned longget_ds(void)
 208 {
 209 unsigned long _v;
 210 __asm__("mov %%ds,%w0":"=r"(_v):"0"(0));
 211 return _v;
 212 }
 213
 214 staticinlinevoidset_fs(unsigned long val)
 215 {
 216  __asm__ __volatile__("mov %w0,%%fs":/* no output */:"r"(val));
 217 }
 218
 219 #endif/* _ASM_SEGMENT_H */