include/asm-x86/desc_defs.h

   1 /* Written 2000 by Andi Kleen */
   2 #ifndef __ARCH_DESC_DEFS_H
   3 #define __ARCH_DESC_DEFS_H
   4
   5 /*
   6  * Segment descriptor structure definitions, usable from both x86_64 and i386
   7  * archs.
   8  */
   9
  10 #ifndef __ASSEMBLY__
  11
  12 #include <linux/types.h>
  13
  14 // 8 byte segment descriptor
  15 struct desc_struct {
  16         u16 limit0;
  17         u16 base0;
  18         unsigned base1 : 8, type : 4, s : 1, dpl : 2, p : 1;
  19         unsigned limit : 4, avl : 1, l : 1, d : 1, g : 1, base2 : 8;
  20 } __attribute__((packed));
  21
  22 struct n_desc_struct {
  23         unsigned int a,b;
  24 };
  25
  26 enum {
  27         GATE_INTERRUPT = 0xE,
  28         GATE_TRAP = 0xF,
  29         GATE_CALL = 0xC,
  30 };
  31
  32 // 16byte gate
  33 struct gate_struct {
  34         u16 offset_low;
  35         u16 segment;
  36         unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
  37         u16 offset_middle;
  38         u32 offset_high;
  39         u32 zero1;
  40 } __attribute__((packed));
  41
  42 #define PTR_LOW(x) ((unsigned long)(x) & 0xFFFF)
  43 #define PTR_MIDDLE(x) (((unsigned long)(x) >> 16) & 0xFFFF)
  44 #define PTR_HIGH(x) ((unsigned long)(x) >> 32)
  45
  46 enum {
  47         DESC_TSS = 0x9,
  48         DESC_LDT = 0x2,
  49 };
  50
  51 // LDT or TSS descriptor in the GDT. 16 bytes.
  52 struct ldttss_desc {
  53         u16 limit0;
  54         u16 base0;
  55         unsigned base1 : 8, type : 5, dpl : 2, p : 1;
  56         unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
  57         u32 base3;
  58         u32 zero1;
  59 } __attribute__((packed));
  60
  61 struct desc_ptr {
  62         unsigned short size;
  63         unsigned long address;
  64 } __attribute__((packed)) ;
  65
  66
  67 #endif /* !__ASSEMBLY__ */
  68
  69 #endif