/* Written 2000 by Andi Kleen */ #ifndef _ASM_X86_DESC_DEFS_H #define _ASM_X86_DESC_DEFS_H /* * Segment descriptor structure definitions, usable from both x86_64 and i386 * archs. */ #ifndef __ASSEMBLY__ #include <linux/types.h> /* * FIXME: Acessing the desc_struct through its fields is more elegant, * and should be the one valid thing to do. However, a lot of open code * still touches the a and b acessors, and doing this allow us to do it * incrementally. We keep the signature as a struct, rather than an union, * so we can get rid of it transparently in the future -- glommer */ /* 8 byte segment descriptor */ struct desc_struct { union { struct { unsigned int a; unsigned int b; }; struct { u16 limit0; u16 base0; unsigned base1: 8, type: 4, s: 1, dpl: 2, p: 1; unsigned limit: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8; }; }; } __attribute__((packed)); enum { GATE_INTERRUPT = 0xE, GATE_TRAP = 0xF, GATE_CALL = 0xC, GATE_TASK = 0x5, }; /* 16byte gate */ struct gate_struct64 { u16 offset_low; u16 segment; unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1; u16 offset_middle; u32 offset_high; u32 zero1; } __attribute__((packed)); #define PTR_LOW(x) ((unsigned long long)(x) & 0xFFFF) #define PTR_MIDDLE(x) (((unsigned long long)(x) >> 16) & 0xFFFF) #define PTR_HIGH(x) ((unsigned long long)(x) >> 32) enum { DESC_TSS = 0x9, DESC_LDT = 0x2, DESCTYPE_S = 0x10, /* !system */ }; /* LDT or TSS descriptor in the GDT. 16 bytes. */ struct ldttss_desc64 { u16 limit0; u16 base0; unsigned base1 : 8, type : 5, dpl : 2, p : 1; unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8; u32 base3; u32 zero1; } __attribute__((packed)); #ifdef CONFIG_X86_64 typedef struct gate_struct64 gate_desc; typedef struct ldttss_desc64 ldt_desc; typedef struct ldttss_desc64 tss_desc; #define gate_offset(g) ((g).offset_low | ((unsigned long)(g).offset_middle << 16) | ((unsigned long)(g).offset_high << 32)) #define gate_segment(g) ((g).segment) #else typedef struct desc_struct gate_desc; typedef struct desc_struct ldt_desc; typedef struct desc_struct tss_desc; #define gate_offset(g) (((g).b & 0xffff0000) | ((g).a & 0x0000ffff)) #define gate_segment(g) ((g).a >> 16) #endif struct desc_ptr { unsigned short size; unsigned long address; } __attribute__((packed)) ; #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_DESC_DEFS_H */