|  | #ifndef _ASM_SEGMENT_H | 
|  | #define _ASM_SEGMENT_H | 
|  |  | 
|  | /* | 
|  | * The layout of the per-CPU GDT under Linux: | 
|  | * | 
|  | *   0 - null | 
|  | *   1 - reserved | 
|  | *   2 - reserved | 
|  | *   3 - reserved | 
|  | * | 
|  | *   4 - unused			<==== new cacheline | 
|  | *   5 - unused | 
|  | * | 
|  | *  ------- start of TLS (Thread-Local Storage) segments: | 
|  | * | 
|  | *   6 - TLS segment #1			[ glibc's TLS segment ] | 
|  | *   7 - TLS segment #2			[ Wine's %fs Win32 segment ] | 
|  | *   8 - TLS segment #3 | 
|  | *   9 - reserved | 
|  | *  10 - reserved | 
|  | *  11 - reserved | 
|  | * | 
|  | *  ------- start of kernel segments: | 
|  | * | 
|  | *  12 - kernel code segment		<==== new cacheline | 
|  | *  13 - kernel data segment | 
|  | *  14 - default user CS | 
|  | *  15 - default user DS | 
|  | *  16 - TSS | 
|  | *  17 - LDT | 
|  | *  18 - PNPBIOS support (16->32 gate) | 
|  | *  19 - PNPBIOS support | 
|  | *  20 - PNPBIOS support | 
|  | *  21 - PNPBIOS support | 
|  | *  22 - PNPBIOS support | 
|  | *  23 - APM BIOS support | 
|  | *  24 - APM BIOS support | 
|  | *  25 - APM BIOS support | 
|  | * | 
|  | *  26 - ESPFIX small SS | 
|  | *  27 - per-cpu			[ offset to per-cpu data area ] | 
|  | *  28 - unused | 
|  | *  29 - unused | 
|  | *  30 - unused | 
|  | *  31 - TSS for double fault handler | 
|  | */ | 
|  | #define GDT_ENTRY_TLS_ENTRIES	3 | 
|  | #define GDT_ENTRY_TLS_MIN	6 | 
|  | #define GDT_ENTRY_TLS_MAX 	(GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1) | 
|  |  | 
|  | #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8) | 
|  |  | 
|  | #define GDT_ENTRY_DEFAULT_USER_CS	14 | 
|  | #define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS * 8 + 3) | 
|  |  | 
|  | #define GDT_ENTRY_DEFAULT_USER_DS	15 | 
|  | #define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS * 8 + 3) | 
|  |  | 
|  | #define GDT_ENTRY_KERNEL_BASE	12 | 
|  |  | 
|  | #define GDT_ENTRY_KERNEL_CS		(GDT_ENTRY_KERNEL_BASE + 0) | 
|  | #define __KERNEL_CS (GDT_ENTRY_KERNEL_CS * 8) | 
|  |  | 
|  | #define GDT_ENTRY_KERNEL_DS		(GDT_ENTRY_KERNEL_BASE + 1) | 
|  | #define __KERNEL_DS (GDT_ENTRY_KERNEL_DS * 8) | 
|  |  | 
|  | #define GDT_ENTRY_TSS			(GDT_ENTRY_KERNEL_BASE + 4) | 
|  | #define GDT_ENTRY_LDT			(GDT_ENTRY_KERNEL_BASE + 5) | 
|  |  | 
|  | #define GDT_ENTRY_PNPBIOS_BASE		(GDT_ENTRY_KERNEL_BASE + 6) | 
|  | #define GDT_ENTRY_APMBIOS_BASE		(GDT_ENTRY_KERNEL_BASE + 11) | 
|  |  | 
|  | #define GDT_ENTRY_ESPFIX_SS		(GDT_ENTRY_KERNEL_BASE + 14) | 
|  | #define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8) | 
|  |  | 
|  | #define GDT_ENTRY_PERCPU			(GDT_ENTRY_KERNEL_BASE + 15) | 
|  | #ifdef CONFIG_SMP | 
|  | #define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8) | 
|  | #else | 
|  | #define __KERNEL_PERCPU 0 | 
|  | #endif | 
|  |  | 
|  | #define GDT_ENTRY_DOUBLEFAULT_TSS	31 | 
|  |  | 
|  | /* | 
|  | * The GDT has 32 entries | 
|  | */ | 
|  | #define GDT_ENTRIES 32 | 
|  | #define GDT_SIZE (GDT_ENTRIES * 8) | 
|  |  | 
|  | /* Simple and small GDT entries for booting only */ | 
|  |  | 
|  | #define GDT_ENTRY_BOOT_CS		2 | 
|  | #define __BOOT_CS	(GDT_ENTRY_BOOT_CS * 8) | 
|  |  | 
|  | #define GDT_ENTRY_BOOT_DS		(GDT_ENTRY_BOOT_CS + 1) | 
|  | #define __BOOT_DS	(GDT_ENTRY_BOOT_DS * 8) | 
|  |  | 
|  | /* The PnP BIOS entries in the GDT */ | 
|  | #define GDT_ENTRY_PNPBIOS_CS32		(GDT_ENTRY_PNPBIOS_BASE + 0) | 
|  | #define GDT_ENTRY_PNPBIOS_CS16		(GDT_ENTRY_PNPBIOS_BASE + 1) | 
|  | #define GDT_ENTRY_PNPBIOS_DS		(GDT_ENTRY_PNPBIOS_BASE + 2) | 
|  | #define GDT_ENTRY_PNPBIOS_TS1		(GDT_ENTRY_PNPBIOS_BASE + 3) | 
|  | #define GDT_ENTRY_PNPBIOS_TS2		(GDT_ENTRY_PNPBIOS_BASE + 4) | 
|  |  | 
|  | /* The PnP BIOS selectors */ | 
|  | #define PNP_CS32   (GDT_ENTRY_PNPBIOS_CS32 * 8)	/* segment for calling fn */ | 
|  | #define PNP_CS16   (GDT_ENTRY_PNPBIOS_CS16 * 8)	/* code segment for BIOS */ | 
|  | #define PNP_DS     (GDT_ENTRY_PNPBIOS_DS * 8)	/* data segment for BIOS */ | 
|  | #define PNP_TS1    (GDT_ENTRY_PNPBIOS_TS1 * 8)	/* transfer data segment */ | 
|  | #define PNP_TS2    (GDT_ENTRY_PNPBIOS_TS2 * 8)	/* another data segment */ | 
|  |  | 
|  | /* | 
|  | * The interrupt descriptor table has room for 256 idt's, | 
|  | * the global descriptor table is dependent on the number | 
|  | * of tasks we can have.. | 
|  | */ | 
|  | #define IDT_ENTRIES 256 | 
|  |  | 
|  | /* Bottom two bits of selector give the ring privilege level */ | 
|  | #define SEGMENT_RPL_MASK	0x3 | 
|  | /* Bit 2 is table indicator (LDT/GDT) */ | 
|  | #define SEGMENT_TI_MASK		0x4 | 
|  |  | 
|  | /* User mode is privilege level 3 */ | 
|  | #define USER_RPL		0x3 | 
|  | /* LDT segment has TI set, GDT has it cleared */ | 
|  | #define SEGMENT_LDT		0x4 | 
|  | #define SEGMENT_GDT		0x0 | 
|  |  | 
|  | #ifndef CONFIG_PARAVIRT | 
|  | #define get_kernel_rpl()  0 | 
|  | #endif | 
|  | /* | 
|  | * Matching rules for certain types of segments. | 
|  | */ | 
|  |  | 
|  | /* Matches only __KERNEL_CS, ignoring PnP / USER / APM segments */ | 
|  | #define SEGMENT_IS_KERNEL_CODE(x) (((x) & 0xfc) == GDT_ENTRY_KERNEL_CS * 8) | 
|  |  | 
|  | /* Matches __KERNEL_CS and __USER_CS (they must be 2 entries apart) */ | 
|  | #define SEGMENT_IS_FLAT_CODE(x)  (((x) & 0xec) == GDT_ENTRY_KERNEL_CS * 8) | 
|  |  | 
|  | /* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */ | 
|  | #define SEGMENT_IS_PNP_CODE(x)   (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8) | 
|  |  | 
|  | #endif |