include/asm-i386/system.h

/* */
This source file includes following definitions.
_get_base
get_limit
xchg_u8
xchg_u16
xchg_u32
tas
xchg_ptr
   1 #ifndef __ASM_SYSTEM_H
   2 #define __ASM_SYSTEM_H
   3 
   4 #include <asm/segment.h>
   5 
   6 /*
   7  * Entry into gdt where to find first TSS. GDT layout:
   8  *   0 - nul
   9  *   1 - kernel code segment
  10  *   2 - kernel data segment
  11  *   3 - user code segment
  12  *   4 - user data segment
  13  * ...
  14  *   8 - TSS #0
  15  *   9 - LDT #0
  16  *  10 - TSS #1
  17  *  11 - LDT #1
  18  */
  19 #define FIRST_TSS_ENTRY 8
  20 #define FIRST_LDT_ENTRY (FIRST_TSS_ENTRY+1)
  21 #define _TSS(n) ((((unsigned long) n)<<4)+(FIRST_TSS_ENTRY<<3))
  22 #define _LDT(n) ((((unsigned long) n)<<4)+(FIRST_LDT_ENTRY<<3))
  23 #define load_TR(n) __asm__("ltr %%ax": /* no output */ :"a" (_TSS(n)))
  24 #define load_ldt(n) __asm__("lldt %%ax": /* no output */ :"a" (_LDT(n)))
  25 #define store_TR(n) \
  26 __asm__("str %%ax\n\t" \
  27         "subl %2,%%eax\n\t" \
  28         "shrl $4,%%eax" \
  29         :"=a" (n) \
  30         :"0" (0),"i" (FIRST_TSS_ENTRY<<3))
  31 
  32 /* This special macro can be used to load a debugging register */
  33 
  34 #define loaddebug(register) \
  35                 __asm__("movl %0,%%edx\n\t" \
  36                         "movl %%edx,%%db" #register "\n\t" \
  37                         : /* no output */ \
  38                         :"m" (current->debugreg[register]) \
  39                         :"dx");
  40 
  41 
  42 /*
  43  *      switch_to(n) should switch tasks to task nr n, first
  44  * checking that n isn't the current task, in which case it does nothing.
  45  * This also clears the TS-flag if the task we switched to has used
  46  * the math co-processor latest.
  47  *
  48  * It also reloads the debug regs if necessary..
  49  */
  50 #define switch_to(tsk) do { \
  51 __asm__("cli\n\t" \
  52         "xchgl %%ecx,"SYMBOL_NAME_STR(current)"\n\t" \
  53         "ljmp %0\n\t" \
  54         "sti\n\t" \
  55         "cmpl %%ecx,"SYMBOL_NAME_STR(last_task_used_math)"\n\t" \
  56         "jne 1f\n\t" \
  57         "clts\n" \
  58         "1:" \
  59         : /* no output */ \
  60         :"m" (*(((char *)&tsk->tss.tr)-4)), \
  61          "c" (tsk) \
  62         :"cx"); \
  63         /* Now maybe reload the debug registers */ \
  64         if(current->debugreg[7]){ \
  65                 loaddebug(0); \
  66                 loaddebug(1); \
  67                 loaddebug(2); \
  68                 loaddebug(3); \
  69                 loaddebug(6); \
  70         } \
  71 } while (0)
  72 
  73 #define _set_base(addr,base) \
  74 __asm__("movw %%dx,%0\n\t" \
  75         "rorl $16,%%edx\n\t" \
  76         "movb %%dl,%1\n\t" \
  77         "movb %%dh,%2" \
  78         : /* no output */ \
  79         :"m" (*((addr)+2)), \
  80          "m" (*((addr)+4)), \
  81          "m" (*((addr)+7)), \
  82          "d" (base) \
  83         :"dx")
  84 
  85 #define _set_limit(addr,limit) \
  86 __asm__("movw %%dx,%0\n\t" \
  87         "rorl $16,%%edx\n\t" \
  88         "movb %1,%%dh\n\t" \
  89         "andb $0xf0,%%dh\n\t" \
  90         "orb %%dh,%%dl\n\t" \
  91         "movb %%dl,%1" \
  92         : /* no output */ \
  93         :"m" (*(addr)), \
  94          "m" (*((addr)+6)), \
  95          "d" (limit) \
  96         :"dx")
  97 
  98 #define set_base(ldt,base) _set_base( ((char *)&(ldt)) , base )
  99 #define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , (limit-1)>>12 )
 100 
 101 static inline unsigned long _get_base(char * addr)
     /*  */
 102 {
 103         unsigned long __base;
 104         __asm__("movb %3,%%dh\n\t"
 105                 "movb %2,%%dl\n\t"
 106                 "shll $16,%%edx\n\t"
 107                 "movw %1,%%dx"
 108                 :"=&d" (__base)
 109                 :"m" (*((addr)+2)),
 110                  "m" (*((addr)+4)),
 111                  "m" (*((addr)+7)));
 112         return __base;
 113 }
 114 
 115 #define get_base(ldt) _get_base( ((char *)&(ldt)) )
 116 
 117 static inline unsigned long get_limit(unsigned long segment)
     /*  */
 118 {
 119         unsigned long __limit;
 120         __asm__("lsll %1,%0"
 121                 :"=r" (__limit):"r" (segment));
 122         return __limit+1;
 123 }
 124 
 125 #define nop() __asm__ __volatile__ ("nop")
 126 
 127 /*
 128  * Clear and set 'TS' bit respectively
 129  */
 130 #define clts() __asm__ __volatile__ ("clts")
 131 #define stts() \
 132 __asm__ __volatile__ ( \
 133         "movl %%cr0,%%eax\n\t" \
 134         "orl $8,%%eax\n\t" \
 135         "movl %%eax,%%cr0" \
 136         : /* no outputs */ \
 137         : /* no inputs */ \
 138         :"ax")
 139 
 140 
 141 extern inline unsigned long xchg_u8(char * m, unsigned long val)
     /*  */
 142 {
 143         __asm__("xchgb %b0,%1":"=q" (val),"=m" (*m):"0" (val):"memory");
 144         return val;
 145 }
 146 
 147 extern inline unsigned long xchg_u16(short * m, unsigned long val)
     /*  */
 148 {
 149         __asm__("xchgw %w0,%1":"=r" (val),"=m" (*m):"0" (val):"memory");
 150         return val;
 151 }
 152 
 153 extern inline unsigned long xchg_u32(int * m, unsigned long val)
     /*  */
 154 {
 155         __asm__("xchgl %0,%1":"=r" (val),"=m" (*m):"0" (val):"memory");
 156         return val;
 157 }
 158 
 159 extern inline int tas(char * m)
     /*  */
 160 {
 161         return xchg_u8(m,1);
 162 }
 163 
 164 extern inline void * xchg_ptr(void * m, void * val)
     /*  */
 165 {
 166         return (void *) xchg_u32(m, (unsigned long) val);
 167 }
 168 
 169 #define mb()  __asm__ __volatile__ (""   : : :"memory")
 170 #define sti() __asm__ __volatile__ ("sti": : :"memory")
 171 #define cli() __asm__ __volatile__ ("cli": : :"memory")
 172 
 173 #define save_flags(x) \
 174 __asm__ __volatile__("pushfl ; popl %0":"=r" (x): /* no input */ :"memory")
 175 
 176 #define restore_flags(x) \
 177 __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"r" (x):"memory")
 178 
 179 #define iret() __asm__ __volatile__ ("iret": : :"memory")
 180 
 181 #define _set_gate(gate_addr,type,dpl,addr) \
 182 __asm__ __volatile__ ("movw %%dx,%%ax\n\t" \
 183         "movw %2,%%dx\n\t" \
 184         "movl %%eax,%0\n\t" \
 185         "movl %%edx,%1" \
 186         :"=m" (*((long *) (gate_addr))), \
 187          "=m" (*(1+(long *) (gate_addr))) \
 188         :"i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
 189          "d" ((char *) (addr)),"a" (KERNEL_CS << 16) \
 190         :"ax","dx")
 191 
 192 #define set_intr_gate(n,addr) \
 193         _set_gate(&idt[n],14,0,addr)
 194 
 195 #define set_trap_gate(n,addr) \
 196         _set_gate(&idt[n],15,0,addr)
 197 
 198 #define set_system_gate(n,addr) \
 199         _set_gate(&idt[n],15,3,addr)
 200 
 201 #define set_call_gate(a,addr) \
 202         _set_gate(a,12,3,addr)
 203 
 204 #define _set_seg_desc(gate_addr,type,dpl,base,limit) {\
 205         *((gate_addr)+1) = ((base) & 0xff000000) | \
 206                 (((base) & 0x00ff0000)>>16) | \
 207                 ((limit) & 0xf0000) | \
 208                 ((dpl)<<13) | \
 209                 (0x00408000) | \
 210                 ((type)<<8); \
 211         *(gate_addr) = (((base) & 0x0000ffff)<<16) | \
 212                 ((limit) & 0x0ffff); }
 213 
 214 #define _set_tssldt_desc(n,addr,limit,type) \
 215 __asm__ __volatile__ ("movw $" #limit ",%1\n\t" \
 216         "movw %%ax,%2\n\t" \
 217         "rorl $16,%%eax\n\t" \
 218         "movb %%al,%3\n\t" \
 219         "movb $" type ",%4\n\t" \
 220         "movb $0x00,%5\n\t" \
 221         "movb %%ah,%6\n\t" \
 222         "rorl $16,%%eax" \
 223         : /* no output */ \
 224         :"a" (addr+0xc0000000), "m" (*(n)), "m" (*(n+2)), "m" (*(n+4)), \
 225          "m" (*(n+5)), "m" (*(n+6)), "m" (*(n+7)) \
 226         )
 227 
 228 #define set_tss_desc(n,addr) _set_tssldt_desc(((char *) (n)),((int)(addr)),235,"0x89")
 229 #define set_ldt_desc(n,addr,size) \
 230         _set_tssldt_desc(((char *) (n)),((int)(addr)),((size << 3) - 1),"0x82")
 231 
 232 /*
 233  * This is the ldt that every process will get unless we need
 234  * something other than this.
 235  */
 236 extern struct desc_struct default_ldt;
 237 
 238 /*
 239  * disable hlt during certain critical i/o operations
 240  */
 241 #define HAVE_DISABLE_HLT
 242 void disable_hlt(void);
 243 void enable_hlt(void);
 244 
 245 #endif
/* */
root/include/asm-i386/system.h

INCLUDED FROM

DEFINITIONS
