LXR linux/arch/x86/include/asm/desc

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/* Written 2000 by Andi Kleen */
   3#ifndef _ASM_X86_DESC_DEFS_H
   4#define _ASM_X86_DESC_DEFS_H
   5
   6/*
   7 * Segment descriptor structure definitions, usable from both x86_64 and i386
   8 * archs.
   9 */
  10
  11#ifndef __ASSEMBLY__
  12
  13#include <linux/types.h>
  14
  15/* 8 byte segment descriptor */
  16struct desc_struct {
  17        u16     limit0;
  18        u16     base0;
  19        u16     base1: 8, type: 4, s: 1, dpl: 2, p: 1;
  20        u16     limit1: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
  21} __attribute__((packed));
  22
  23#define GDT_ENTRY_INIT(flags, base, limit)                      \
  24        {                                                       \
  25                .limit0         = (u16) (limit),                \
  26                .limit1         = ((limit) >> 16) & 0x0F,       \
  27                .base0          = (u16) (base),                 \
  28                .base1          = ((base) >> 16) & 0xFF,        \
  29                .base2          = ((base) >> 24) & 0xFF,        \
  30                .type           = (flags & 0x0f),               \
  31                .s              = (flags >> 4) & 0x01,          \
  32                .dpl            = (flags >> 5) & 0x03,          \
  33                .p              = (flags >> 7) & 0x01,          \
  34                .avl            = (flags >> 12) & 0x01,         \
  35                .l              = (flags >> 13) & 0x01,         \
  36                .d              = (flags >> 14) & 0x01,         \
  37                .g              = (flags >> 15) & 0x01,         \
  38        }
  39
  40enum {
  41        GATE_INTERRUPT = 0xE,
  42        GATE_TRAP = 0xF,
  43        GATE_CALL = 0xC,
  44        GATE_TASK = 0x5,
  45};
  46
  47enum {
  48        DESC_TSS = 0x9,
  49        DESC_LDT = 0x2,
  50        DESCTYPE_S = 0x10,      /* !system */
  51};
  52
  53/* LDT or TSS descriptor in the GDT. */
  54struct ldttss_desc {
  55        u16     limit0;
  56        u16     base0;
  57
  58        u16     base1 : 8, type : 5, dpl : 2, p : 1;
  59        u16     limit1 : 4, zero0 : 3, g : 1, base2 : 8;
  60#ifdef CONFIG_X86_64
  61        u32     base3;
  62        u32     zero1;
  63#endif
  64} __attribute__((packed));
  65
  66typedef struct ldttss_desc ldt_desc;
  67typedef struct ldttss_desc tss_desc;
  68
  69struct idt_bits {
  70        u16             ist     : 3,
  71                        zero    : 5,
  72                        type    : 5,
  73                        dpl     : 2,
  74                        p       : 1;
  75} __attribute__((packed));
  76
  77struct idt_data {
  78        unsigned int    vector;
  79        unsigned int    segment;
  80        struct idt_bits bits;
  81        const void      *addr;
  82};
  83
  84struct gate_struct {
  85        u16             offset_low;
  86        u16             segment;
  87        struct idt_bits bits;
  88        u16             offset_middle;
  89#ifdef CONFIG_X86_64
  90        u32             offset_high;
  91        u32             reserved;
  92#endif
  93} __attribute__((packed));
  94
  95typedef struct gate_struct gate_desc;
  96
  97static inline unsigned long gate_offset(const gate_desc *g)
  98{
  99#ifdef CONFIG_X86_64
 100        return g->offset_low | ((unsigned long)g->offset_middle << 16) |
 101                ((unsigned long) g->offset_high << 32);
 102#else
 103        return g->offset_low | ((unsigned long)g->offset_middle << 16);
 104#endif
 105}
 106
 107static inline unsigned long gate_segment(const gate_desc *g)
 108{
 109        return g->segment;
 110}
 111
 112struct desc_ptr {
 113        unsigned short size;
 114        unsigned long address;
 115} __attribute__((packed)) ;
 116
 117#endif /* !__ASSEMBLY__ */
 118
 119/* Boot IDT definitions */
 120#define BOOT_IDT_ENTRIES        32
 121
 122/* Access rights as returned by LAR */
 123#define AR_TYPE_RODATA          (0 * (1 << 9))
 124#define AR_TYPE_RWDATA          (1 * (1 << 9))
 125#define AR_TYPE_RODATA_EXPDOWN  (2 * (1 << 9))
 126#define AR_TYPE_RWDATA_EXPDOWN  (3 * (1 << 9))
 127#define AR_TYPE_XOCODE          (4 * (1 << 9))
 128#define AR_TYPE_XRCODE          (5 * (1 << 9))
 129#define AR_TYPE_XOCODE_CONF     (6 * (1 << 9))
 130#define AR_TYPE_XRCODE_CONF     (7 * (1 << 9))
 131#define AR_TYPE_MASK            (7 * (1 << 9))
 132
 133#define AR_DPL0                 (0 * (1 << 13))
 134#define AR_DPL3                 (3 * (1 << 13))
 135#define AR_DPL_MASK             (3 * (1 << 13))
 136
 137#define AR_A                    (1 << 8)   /* "Accessed" */
 138#define AR_S                    (1 << 12)  /* If clear, "System" segment */
 139#define AR_P                    (1 << 15)  /* "Present" */
 140#define AR_AVL                  (1 << 20)  /* "AVaiLable" (no HW effect) */
 141#define AR_L                    (1 << 21)  /* "Long mode" for code segments */
 142#define AR_DB                   (1 << 22)  /* D/B, effect depends on type */
 143#define AR_G                    (1 << 23)  /* "Granularity" (limit in pages) */
 144
 145#endif /* _ASM_X86_DESC_DEFS_H */
 146