102 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			102 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Written 2000 by Andi Kleen */
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| #ifndef _ASM_X86_DESC_DEFS_H
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| #define _ASM_X86_DESC_DEFS_H
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| 
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| /*
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|  * Segment descriptor structure definitions, usable from both x86_64 and i386
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|  * archs.
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|  */
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| 
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| #ifndef __ASSEMBLY__
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| 
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| #include <linux/types.h>
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| 
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| /*
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|  * FIXME: Acessing the desc_struct through its fields is more elegant,
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|  * and should be the one valid thing to do. However, a lot of open code
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|  * still touches the a and b acessors, and doing this allow us to do it
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|  * incrementally. We keep the signature as a struct, rather than an union,
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|  * so we can get rid of it transparently in the future -- glommer
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|  */
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| /* 8 byte segment descriptor */
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| struct desc_struct {
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| 	union {
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| 		struct {
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| 			unsigned int a;
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| 			unsigned int b;
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| 		};
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| 		struct {
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| 			u16 limit0;
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| 			u16 base0;
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| 			unsigned base1: 8, type: 4, s: 1, dpl: 2, p: 1;
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| 			unsigned limit: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
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| 		};
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| 	};
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| } __attribute__((packed));
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| 
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| #define GDT_ENTRY_INIT(flags, base, limit) { { { \
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| 		.a = ((limit) & 0xffff) | (((base) & 0xffff) << 16), \
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| 		.b = (((base) & 0xff0000) >> 16) | (((flags) & 0xf0ff) << 8) | \
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| 			((limit) & 0xf0000) | ((base) & 0xff000000), \
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| 	} } }
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| 
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| enum {
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| 	GATE_INTERRUPT = 0xE,
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| 	GATE_TRAP = 0xF,
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| 	GATE_CALL = 0xC,
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| 	GATE_TASK = 0x5,
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| };
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| 
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| /* 16byte gate */
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| struct gate_struct64 {
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| 	u16 offset_low;
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| 	u16 segment;
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| 	unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
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| 	u16 offset_middle;
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| 	u32 offset_high;
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| 	u32 zero1;
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| } __attribute__((packed));
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| 
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| #define PTR_LOW(x) ((unsigned long long)(x) & 0xFFFF)
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| #define PTR_MIDDLE(x) (((unsigned long long)(x) >> 16) & 0xFFFF)
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| #define PTR_HIGH(x) ((unsigned long long)(x) >> 32)
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| 
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| enum {
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| 	DESC_TSS = 0x9,
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| 	DESC_LDT = 0x2,
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| 	DESCTYPE_S = 0x10,	/* !system */
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| };
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| 
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| /* LDT or TSS descriptor in the GDT. 16 bytes. */
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| struct ldttss_desc64 {
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| 	u16 limit0;
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| 	u16 base0;
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| 	unsigned base1 : 8, type : 5, dpl : 2, p : 1;
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| 	unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
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| 	u32 base3;
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| 	u32 zero1;
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| } __attribute__((packed));
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| 
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| #ifdef CONFIG_X86_64
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| typedef struct gate_struct64 gate_desc;
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| typedef struct ldttss_desc64 ldt_desc;
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| typedef struct ldttss_desc64 tss_desc;
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| #define gate_offset(g) ((g).offset_low | ((unsigned long)(g).offset_middle << 16) | ((unsigned long)(g).offset_high << 32))
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| #define gate_segment(g) ((g).segment)
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| #else
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| typedef struct desc_struct gate_desc;
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| typedef struct desc_struct ldt_desc;
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| typedef struct desc_struct tss_desc;
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| #define gate_offset(g)		(((g).b & 0xffff0000) | ((g).a & 0x0000ffff))
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| #define gate_segment(g)		((g).a >> 16)
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| #endif
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| 
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| struct desc_ptr {
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| 	unsigned short size;
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| 	unsigned long address;
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| } __attribute__((packed)) ;
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| 
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| #endif /* !__ASSEMBLY__ */
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| 
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| #endif /* _ASM_X86_DESC_DEFS_H */
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