include/asm/desc_defs.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /* Written 2000 by Andi Kleen */
0003 #ifndef _ASM_X86_DESC_DEFS_H
0004 #define _ASM_X86_DESC_DEFS_H
0005
0006 /*
0007  * Segment descriptor structure definitions, usable from both x86_64 and i386
0008  * archs.
0009  */
0010
0011 #ifndef __ASSEMBLY__
0012
0013 #include <linux/types.h>
0014
0015 /* 8 byte segment descriptor */
0016 struct desc_struct {
0017     u16 limit0;
0018     u16 base0;
0019     u16 base1: 8, type: 4, s: 1, dpl: 2, p: 1;
0020     u16 limit1: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
0021 } __attribute__((packed));
0022
0023 #define GDT_ENTRY_INIT(flags, base, limit)          \
0024     {                           \
0025         .limit0     = (u16) (limit),        \
0026         .limit1     = ((limit) >> 16) & 0x0F,   \
0027         .base0      = (u16) (base),         \
0028         .base1      = ((base) >> 16) & 0xFF,    \
0029         .base2      = ((base) >> 24) & 0xFF,    \
0030         .type       = (flags & 0x0f),       \
0031         .s      = (flags >> 4) & 0x01,      \
0032         .dpl        = (flags >> 5) & 0x03,      \
0033         .p      = (flags >> 7) & 0x01,      \
0034         .avl        = (flags >> 12) & 0x01,     \
0035         .l      = (flags >> 13) & 0x01,     \
0036         .d      = (flags >> 14) & 0x01,     \
0037         .g      = (flags >> 15) & 0x01,     \
0038     }
0039
0040 enum {
0041     GATE_INTERRUPT = 0xE,
0042     GATE_TRAP = 0xF,
0043     GATE_CALL = 0xC,
0044     GATE_TASK = 0x5,
0045 };
0046
0047 enum {
0048     DESC_TSS = 0x9,
0049     DESC_LDT = 0x2,
0050     DESCTYPE_S = 0x10,  /* !system */
0051 };
0052
0053 /* LDT or TSS descriptor in the GDT. */
0054 struct ldttss_desc {
0055     u16 limit0;
0056     u16 base0;
0057
0058     u16 base1 : 8, type : 5, dpl : 2, p : 1;
0059     u16 limit1 : 4, zero0 : 3, g : 1, base2 : 8;
0060 #ifdef CONFIG_X86_64
0061     u32 base3;
0062     u32 zero1;
0063 #endif
0064 } __attribute__((packed));
0065
0066 typedef struct ldttss_desc ldt_desc;
0067 typedef struct ldttss_desc tss_desc;
0068
0069 struct idt_bits {
0070     u16     ist : 3,
0071             zero    : 5,
0072             type    : 5,
0073             dpl : 2,
0074             p   : 1;
0075 } __attribute__((packed));
0076
0077 struct idt_data {
0078     unsigned int    vector;
0079     unsigned int    segment;
0080     struct idt_bits bits;
0081     const void  *addr;
0082 };
0083
0084 struct gate_struct {
0085     u16     offset_low;
0086     u16     segment;
0087     struct idt_bits bits;
0088     u16     offset_middle;
0089 #ifdef CONFIG_X86_64
0090     u32     offset_high;
0091     u32     reserved;
0092 #endif
0093 } __attribute__((packed));
0094
0095 typedef struct gate_struct gate_desc;
0096
0097 static inline unsigned long gate_offset(const gate_desc *g)
0098 {
0099 #ifdef CONFIG_X86_64
0100     return g->offset_low | ((unsigned long)g->offset_middle << 16) |
0101         ((unsigned long) g->offset_high << 32);
0102 #else
0103     return g->offset_low | ((unsigned long)g->offset_middle << 16);
0104 #endif
0105 }
0106
0107 static inline unsigned long gate_segment(const gate_desc *g)
0108 {
0109     return g->segment;
0110 }
0111
0112 struct desc_ptr {
0113     unsigned short size;
0114     unsigned long address;
0115 } __attribute__((packed)) ;
0116
0117 #endif /* !__ASSEMBLY__ */
0118
0119 /* Boot IDT definitions */
0120 #define BOOT_IDT_ENTRIES    32
0121
0122 /* Access rights as returned by LAR */
0123 #define AR_TYPE_RODATA      (0 * (1 << 9))
0124 #define AR_TYPE_RWDATA      (1 * (1 << 9))
0125 #define AR_TYPE_RODATA_EXPDOWN  (2 * (1 << 9))
0126 #define AR_TYPE_RWDATA_EXPDOWN  (3 * (1 << 9))
0127 #define AR_TYPE_XOCODE      (4 * (1 << 9))
0128 #define AR_TYPE_XRCODE      (5 * (1 << 9))
0129 #define AR_TYPE_XOCODE_CONF (6 * (1 << 9))
0130 #define AR_TYPE_XRCODE_CONF (7 * (1 << 9))
0131 #define AR_TYPE_MASK        (7 * (1 << 9))
0132
0133 #define AR_DPL0         (0 * (1 << 13))
0134 #define AR_DPL3         (3 * (1 << 13))
0135 #define AR_DPL_MASK     (3 * (1 << 13))
0136
0137 #define AR_A            (1 << 8)   /* "Accessed" */
0138 #define AR_S            (1 << 12)  /* If clear, "System" segment */
0139 #define AR_P            (1 << 15)  /* "Present" */
0140 #define AR_AVL          (1 << 20)  /* "AVaiLable" (no HW effect) */
0141 #define AR_L            (1 << 21)  /* "Long mode" for code segments */
0142 #define AR_DB           (1 << 22)  /* D/B, effect depends on type */
0143 #define AR_G            (1 << 23)  /* "Granularity" (limit in pages) */
0144
0145 #endif /* _ASM_X86_DESC_DEFS_H */