linux/include/asm-x86/segment.h

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#ifndef ASM_X86__SEGMENT_H
#define ASM_X86__SEGMENT_H
/* Constructor for a conventional segment GDT (or LDT) entry */
/* This is a macro so it can be used in initializers */
#define GDT_ENTRY(flags, base, limit) \
((((base) & 0xff000000ULL) << (56-24)) | \
(((flags) & 0x0000f0ffULL) << 40) | \
(((limit) & 0x000f0000ULL) << (48-16)) | \
(((base) & 0x00ffffffULL) << 16) | \
(((limit) & 0x0000ffffULL)))
/* 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)
#define GDT_ENTRY_BOOT_TSS (GDT_ENTRY_BOOT_CS + 2)
#define __BOOT_TSS (GDT_ENTRY_BOOT_TSS * 8)
#ifdef CONFIG_X86_32
/*
* 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_MIN 6
#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
#define GDT_ENTRY_DEFAULT_USER_CS 14
#define GDT_ENTRY_DEFAULT_USER_DS 15
#define GDT_ENTRY_KERNEL_BASE 12
#define GDT_ENTRY_KERNEL_CS (GDT_ENTRY_KERNEL_BASE + 0)
#define GDT_ENTRY_KERNEL_DS (GDT_ENTRY_KERNEL_BASE + 1)
#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
/* 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 */
/* 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
/*
* Matching rules for certain types of segments.
*/
/* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */
#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8)
#else
#include <asm/cache.h>
#define GDT_ENTRY_KERNEL32_CS 1
#define GDT_ENTRY_KERNEL_CS 2
#define GDT_ENTRY_KERNEL_DS 3
#define __KERNEL32_CS (GDT_ENTRY_KERNEL32_CS * 8)
/*
* we cannot use the same code segment descriptor for user and kernel
* -- not even in the long flat mode, because of different DPL /kkeil
* The segment offset needs to contain a RPL. Grr. -AK
* GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)
*/
#define GDT_ENTRY_DEFAULT_USER32_CS 4
#define GDT_ENTRY_DEFAULT_USER_DS 5
#define GDT_ENTRY_DEFAULT_USER_CS 6
#define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS * 8 + 3)
#define __USER32_DS __USER_DS
#define GDT_ENTRY_TSS 8 /* needs two entries */
#define GDT_ENTRY_LDT 10 /* needs two entries */
#define GDT_ENTRY_TLS_MIN 12
#define GDT_ENTRY_TLS_MAX 14
#define GDT_ENTRY_PER_CPU 15 /* Abused to load per CPU data from limit */
#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU * 8 + 3)
/* TLS indexes for 64bit - hardcoded in arch_prctl */
#define FS_TLS 0
#define GS_TLS 1
#define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3)
#define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3)
#define GDT_ENTRIES 16
#endif
#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS * 8)
#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS * 8)
#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS* 8 + 3)
#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS* 8 + 3)
#ifndef CONFIG_PARAVIRT
#define get_kernel_rpl() 0
#endif
/* 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
/* 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
#define IDT_ENTRIES 256
#define NUM_EXCEPTION_VECTORS 32
#define GDT_SIZE (GDT_ENTRIES * 8)
#define GDT_ENTRY_TLS_ENTRIES 3
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10];
#endif
#endif
#endif /* ASM_X86__SEGMENT_H */