xref: /openbmc/linux/arch/x86/include/asm/desc_defs.h (revision 711aab1d)
1 /* Written 2000 by Andi Kleen */
2 #ifndef _ASM_X86_DESC_DEFS_H
3 #define _ASM_X86_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 	u16	base1: 8, type: 4, s: 1, dpl: 2, p: 1;
19 	u16	limit1: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
20 } __attribute__((packed));
21 
22 #define GDT_ENTRY_INIT(flags, base, limit)			\
23 	{							\
24 		.limit0		= (u16) (limit),		\
25 		.limit1		= ((limit) >> 16) & 0x0F,	\
26 		.base0		= (u16) (base),			\
27 		.base1		= ((base) >> 16) & 0xFF,	\
28 		.base2		= ((base) >> 24) & 0xFF,	\
29 		.type		= (flags & 0x0f),		\
30 		.s		= (flags >> 4) & 0x01,		\
31 		.dpl		= (flags >> 5) & 0x03,		\
32 		.p		= (flags >> 7) & 0x01,		\
33 		.avl		= (flags >> 12) & 0x01,		\
34 		.l		= (flags >> 13) & 0x01,		\
35 		.d		= (flags >> 14) & 0x01,		\
36 		.g		= (flags >> 15) & 0x01,		\
37 	}
38 
39 enum {
40 	GATE_INTERRUPT = 0xE,
41 	GATE_TRAP = 0xF,
42 	GATE_CALL = 0xC,
43 	GATE_TASK = 0x5,
44 };
45 
46 enum {
47 	DESC_TSS = 0x9,
48 	DESC_LDT = 0x2,
49 	DESCTYPE_S = 0x10,	/* !system */
50 };
51 
52 /* LDT or TSS descriptor in the GDT. */
53 struct ldttss_desc {
54 	u16	limit0;
55 	u16	base0;
56 
57 	u16	base1 : 8, type : 5, dpl : 2, p : 1;
58 	u16	limit1 : 4, zero0 : 3, g : 1, base2 : 8;
59 #ifdef CONFIG_X86_64
60 	u32	base3;
61 	u32	zero1;
62 #endif
63 } __attribute__((packed));
64 
65 typedef struct ldttss_desc ldt_desc;
66 typedef struct ldttss_desc tss_desc;
67 
68 struct idt_bits {
69 	u16		ist	: 3,
70 			zero	: 5,
71 			type	: 5,
72 			dpl	: 2,
73 			p	: 1;
74 } __attribute__((packed));
75 
76 struct gate_struct {
77 	u16		offset_low;
78 	u16		segment;
79 	struct idt_bits	bits;
80 	u16		offset_middle;
81 #ifdef CONFIG_X86_64
82 	u32		offset_high;
83 	u32		reserved;
84 #endif
85 } __attribute__((packed));
86 
87 typedef struct gate_struct gate_desc;
88 
89 static inline unsigned long gate_offset(const gate_desc *g)
90 {
91 #ifdef CONFIG_X86_64
92 	return g->offset_low | ((unsigned long)g->offset_middle << 16) |
93 		((unsigned long) g->offset_high << 32);
94 #else
95 	return g->offset_low | ((unsigned long)g->offset_middle << 16);
96 #endif
97 }
98 
99 static inline unsigned long gate_segment(const gate_desc *g)
100 {
101 	return g->segment;
102 }
103 
104 struct desc_ptr {
105 	unsigned short size;
106 	unsigned long address;
107 } __attribute__((packed)) ;
108 
109 #endif /* !__ASSEMBLY__ */
110 
111 /* Access rights as returned by LAR */
112 #define AR_TYPE_RODATA		(0 * (1 << 9))
113 #define AR_TYPE_RWDATA		(1 * (1 << 9))
114 #define AR_TYPE_RODATA_EXPDOWN	(2 * (1 << 9))
115 #define AR_TYPE_RWDATA_EXPDOWN	(3 * (1 << 9))
116 #define AR_TYPE_XOCODE		(4 * (1 << 9))
117 #define AR_TYPE_XRCODE		(5 * (1 << 9))
118 #define AR_TYPE_XOCODE_CONF	(6 * (1 << 9))
119 #define AR_TYPE_XRCODE_CONF	(7 * (1 << 9))
120 #define AR_TYPE_MASK		(7 * (1 << 9))
121 
122 #define AR_DPL0			(0 * (1 << 13))
123 #define AR_DPL3			(3 * (1 << 13))
124 #define AR_DPL_MASK		(3 * (1 << 13))
125 
126 #define AR_A			(1 << 8)   /* "Accessed" */
127 #define AR_S			(1 << 12)  /* If clear, "System" segment */
128 #define AR_P			(1 << 15)  /* "Present" */
129 #define AR_AVL			(1 << 20)  /* "AVaiLable" (no HW effect) */
130 #define AR_L			(1 << 21)  /* "Long mode" for code segments */
131 #define AR_DB			(1 << 22)  /* D/B, effect depends on type */
132 #define AR_G			(1 << 23)  /* "Granularity" (limit in pages) */
133 
134 #endif /* _ASM_X86_DESC_DEFS_H */
135