ia64/xen-unstable

view linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/segment.h @ 8976:4f4625f80528

Rename XENFEAT_ring0_kernel to slightly more generic XENFEAT_supervisor_mode_kernel.
Add comments in public header version.h to explain what all the different
feature flags mean. Add a new flag XENFEAT_pae_pgdir_above_4gb to inform the guest
that its PAE page directories do not need to conform to the usual hardware
restriction.

Signed-off-by: Keir Fraser <keir@xensource.com>
author kaf24@firebug.cl.cam.ac.uk
date Thu Feb 23 11:59:27 2006 +0100 (2006-02-23)
parents 697fac283c9e
children b883ef5fad48
line source
1 #ifndef _ASM_SEGMENT_H
2 #define _ASM_SEGMENT_H
4 /*
5 * The layout of the per-CPU GDT under Linux:
6 *
7 * 0 - null
8 * 1 - reserved
9 * 2 - reserved
10 * 3 - reserved
11 *
12 * 4 - unused <==== new cacheline
13 * 5 - unused
14 *
15 * ------- start of TLS (Thread-Local Storage) segments:
16 *
17 * 6 - TLS segment #1 [ glibc's TLS segment ]
18 * 7 - TLS segment #2 [ Wine's %fs Win32 segment ]
19 * 8 - TLS segment #3
20 * 9 - reserved
21 * 10 - reserved
22 * 11 - reserved
23 *
24 * ------- start of kernel segments:
25 *
26 * 12 - kernel code segment <==== new cacheline
27 * 13 - kernel data segment
28 * 14 - default user CS
29 * 15 - default user DS
30 * 16 - TSS
31 * 17 - LDT
32 * 18 - PNPBIOS support (16->32 gate)
33 * 19 - PNPBIOS support
34 * 20 - PNPBIOS support
35 * 21 - PNPBIOS support
36 * 22 - PNPBIOS support
37 * 23 - APM BIOS support
38 * 24 - APM BIOS support
39 * 25 - APM BIOS support
40 *
41 * 26 - ESPFIX small SS
42 * 27 - unused
43 * 28 - unused
44 * 29 - unused
45 * 30 - unused
46 * 31 - TSS for double fault handler
47 */
48 #define GDT_ENTRY_TLS_ENTRIES 3
49 #define GDT_ENTRY_TLS_MIN 6
50 #define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
52 #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)
54 #define GDT_ENTRY_DEFAULT_USER_CS 14
55 #define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS * 8 + 3)
57 #define GDT_ENTRY_DEFAULT_USER_DS 15
58 #define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS * 8 + 3)
60 #define GDT_ENTRY_KERNEL_BASE 12
62 #define GDT_ENTRY_KERNEL_CS (GDT_ENTRY_KERNEL_BASE + 0)
63 #define __KERNEL_CS (GDT_ENTRY_KERNEL_CS * 8)
64 #define GET_KERNEL_CS() (__KERNEL_CS | (xen_feature(XENFEAT_supervisor_mode_kernel)?0:1) )
66 #define GDT_ENTRY_KERNEL_DS (GDT_ENTRY_KERNEL_BASE + 1)
67 #define __KERNEL_DS (GDT_ENTRY_KERNEL_DS * 8)
68 #define GET_KERNEL_DS() (__KERNEL_DS | (xen_feature(XENFEAT_supervisor_mode_kernel)?0:1) )
70 #define GDT_ENTRY_TSS (GDT_ENTRY_KERNEL_BASE + 4)
71 #define GDT_ENTRY_LDT (GDT_ENTRY_KERNEL_BASE + 5)
73 #define GDT_ENTRY_PNPBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 6)
74 #define GDT_ENTRY_APMBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 11)
76 #define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE + 14)
77 #define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8)
79 #define GDT_ENTRY_DOUBLEFAULT_TSS 31
81 /*
82 * The GDT has 32 entries
83 */
84 #define GDT_ENTRIES 32
86 #define GDT_SIZE (GDT_ENTRIES * 8)
88 /* Simple and small GDT entries for booting only */
90 #define __BOOT_CS FLAT_KERNEL_CS
92 #define __BOOT_DS FLAT_KERNEL_DS
94 /* The PnP BIOS entries in the GDT */
95 #define GDT_ENTRY_PNPBIOS_CS32 (GDT_ENTRY_PNPBIOS_BASE + 0)
96 #define GDT_ENTRY_PNPBIOS_CS16 (GDT_ENTRY_PNPBIOS_BASE + 1)
97 #define GDT_ENTRY_PNPBIOS_DS (GDT_ENTRY_PNPBIOS_BASE + 2)
98 #define GDT_ENTRY_PNPBIOS_TS1 (GDT_ENTRY_PNPBIOS_BASE + 3)
99 #define GDT_ENTRY_PNPBIOS_TS2 (GDT_ENTRY_PNPBIOS_BASE + 4)
101 /* The PnP BIOS selectors */
102 #define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32 * 8) /* segment for calling fn */
103 #define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16 * 8) /* code segment for BIOS */
104 #define PNP_DS (GDT_ENTRY_PNPBIOS_DS * 8) /* data segment for BIOS */
105 #define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1 * 8) /* transfer data segment */
106 #define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2 * 8) /* another data segment */
108 /*
109 * The interrupt descriptor table has room for 256 idt's,
110 * the global descriptor table is dependent on the number
111 * of tasks we can have..
112 */
113 #define IDT_ENTRIES 256
115 #endif