Lines Matching +full:segment +full:- +full:1 +full:a
1 /* SPDX-License-Identifier: GPL-2.0 */
10 * Constructor for a conventional segment GDT (or LDT) entry.
11 * This is a macro so it can be used in initializers.
14 ((((base) & _AC(0xff000000,ULL)) << (56-24)) | \
16 (((limit) & _AC(0x000f0000,ULL)) << (48-16)) | \
36 * When running on Xen PV, the actual privilege level of the kernel is 1,
37 * not 0. Testing the Requested Privilege Level in a segment selector to
52 /* LDT segment has TI set ... */
61 * The layout of the per-CPU GDT under Linux:
63 * 0 - null <=== cacheline #1
64 * 1 - reserved
65 * 2 - reserved
66 * 3 - reserved
68 * 4 - unused <=== cacheline #2
69 * 5 - unused
71 * ------- start of TLS (Thread-Local Storage) segments:
73 * 6 - TLS segment #1 [ glibc's TLS segment ]
74 * 7 - TLS segment #2 [ Wine's %fs Win32 segment ]
75 * 8 - TLS segment #3 <=== cacheline #3
76 * 9 - reserved
77 * 10 - reserved
78 * 11 - reserved
80 * ------- start of kernel segments:
82 * 12 - kernel code segment <=== cacheline #4
83 * 13 - kernel data segment
84 * 14 - default user CS
85 * 15 - default user DS
86 * 16 - TSS <=== cacheline #5
87 * 17 - LDT
88 * 18 - PNPBIOS support (16->32 gate)
89 * 19 - PNPBIOS support
90 * 20 - PNPBIOS support <=== cacheline #6
91 * 21 - PNPBIOS support
92 * 22 - PNPBIOS support
93 * 23 - APM BIOS support
94 * 24 - APM BIOS support <=== cacheline #7
95 * 25 - APM BIOS support
97 * 26 - ESPFIX small SS
98 * 27 - per-cpu [ offset to per-cpu data area ]
99 * 28 - VDSO getcpu
100 * 29 - unused
101 * 30 - unused
102 * 31 - TSS for double fault handler
105 #define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
132 * Segment selector values corresponding to the above entries:
142 /* segment for calling fn: */
144 /* code segment for BIOS: */
150 /* data segment for BIOS: */
152 /* transfer data segment: */
154 /* another data segment: */
165 #else /* 64-bit: */
169 #define GDT_ENTRY_KERNEL32_CS 1
174 * We cannot use the same code segment descriptor for user and kernel mode,
177 * GDT layout to get 64-bit SYSCALL/SYSRET support right. SYSRET hardcodes
180 * if returning to 32-bit userspace: cs = STAR.SYSRET_CS,
181 * if returning to 64-bit userspace: cs = STAR.SYSRET_CS+16,
185 * thus USER_DS should be between 32-bit and 64-bit code selectors:
207 * Segment selector values corresponding to the above entries:
209 * Note, selectors also need to have a correct RPL,
210 * expressed with the +3 value for user-space selectors:
274 * early IDT. For simplicity, it's a real array with one entry point
276 * vector has no error code (two bytes), a 'push $vector_number' (two
277 * bytes), and a jump to the common entry code (up to five bytes).
283 * early_idt_handler_array it contains a prequel in the form of
299 * Load a segment. Fall back on loading the zero segment if something goes
300 * wrong. This variant assumes that loading zero fully clears the segment.
301 * This is always the case on Intel CPUs and, even on 64-bit AMD CPUs, any
310 "1: movl %k0,%%" #seg " \n" \
311 _ASM_EXTABLE_TYPE_REG(1b, 1b, EX_TYPE_ZERO_REG, %k0)\
322 * On 32-bit systems, the hidden parts of FS and GS are unobservable if
333 "1: movw %0, %%fs \n" in __loadsegment_fs()
336 _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_CLEAR_FS) in __loadsegment_fs()
348 * Save a segment register away: