1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_PAGE_64_DEFS_H
3#define _ASM_X86_PAGE_64_DEFS_H
4
5#ifndef __ASSEMBLY__
6#include <asm/kaslr.h>
7#endif
8
9#ifdef CONFIG_KASAN
10#define KASAN_STACK_ORDER 1
11#else
12#define KASAN_STACK_ORDER 0
13#endif
14
15#define THREAD_SIZE_ORDER (2 + KASAN_STACK_ORDER)
16#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
17
18#define EXCEPTION_STACK_ORDER (1 + KASAN_STACK_ORDER)
19#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
20
21#define IRQ_STACK_ORDER (2 + KASAN_STACK_ORDER)
22#define IRQ_STACK_SIZE (PAGE_SIZE << IRQ_STACK_ORDER)
23
24/*
25 * The index for the tss.ist[] array. The hardware limit is 7 entries.
26 */
27#define IST_INDEX_DF 0
28#define IST_INDEX_NMI 1
29#define IST_INDEX_DB 2
30#define IST_INDEX_MCE 3
31#define IST_INDEX_VC 4
32
33/*
34 * Set __PAGE_OFFSET to the most negative possible address +
35 * PGDIR_SIZE*17 (pgd slot 273).
36 *
37 * The gap is to allow a space for LDT remap for PTI (1 pgd slot) and space for
38 * a hypervisor (16 slots). Choosing 16 slots for a hypervisor is arbitrary,
39 * but it's what Xen requires.
40 */
41#define __PAGE_OFFSET_BASE_L5 _AC(0xff11000000000000, UL)
42#define __PAGE_OFFSET_BASE_L4 _AC(0xffff888000000000, UL)
43
44#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
45#define __PAGE_OFFSET page_offset_base
46#else
47#define __PAGE_OFFSET __PAGE_OFFSET_BASE_L4
48#endif /* CONFIG_DYNAMIC_MEMORY_LAYOUT */
49
50#define __START_KERNEL_map _AC(0xffffffff80000000, UL)
51
52/* See Documentation/arch/x86/x86_64/mm.rst for a description of the memory map. */
53
54#define __PHYSICAL_MASK_SHIFT 52
55
56#ifdef CONFIG_X86_5LEVEL
57#define __VIRTUAL_MASK_SHIFT (pgtable_l5_enabled() ? 56 : 47)
58/* See task_size_max() in <asm/page_64.h> */
59#else
60#define __VIRTUAL_MASK_SHIFT 47
61#define task_size_max() ((_AC(1,UL) << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE)
62#endif
63
64#define TASK_SIZE_MAX task_size_max()
65#define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE)
66
67/* This decides where the kernel will search for a free chunk of vm
68 * space during mmap's.
69 */
70#define IA32_PAGE_OFFSET ((current->personality & ADDR_LIMIT_3GB) ? \
71 0xc0000000 : 0xFFFFe000)
72
73#define TASK_SIZE_LOW (test_thread_flag(TIF_ADDR32) ? \
74 IA32_PAGE_OFFSET : DEFAULT_MAP_WINDOW)
75#define TASK_SIZE (test_thread_flag(TIF_ADDR32) ? \
76 IA32_PAGE_OFFSET : TASK_SIZE_MAX)
77#define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
78 IA32_PAGE_OFFSET : TASK_SIZE_MAX)
79
80#define STACK_TOP TASK_SIZE_LOW
81#define STACK_TOP_MAX TASK_SIZE_MAX
82
83/*
84 * In spite of the name, KERNEL_IMAGE_SIZE is a limit on the maximum virtual
85 * address for the kernel image, rather than the limit on the size itself.
86 * This can be at most 1 GiB, due to the fixmap living in the next 1 GiB (see
87 * level2_kernel_pgt in arch/x86/kernel/head_64.S).
88 *
89 * On KASLR use 1 GiB by default, leaving 1 GiB for modules once the
90 * page tables are fully set up.
91 *
92 * If KASLR is disabled we can shrink it to 0.5 GiB and increase the size
93 * of the modules area to 1.5 GiB.
94 */
95#ifdef CONFIG_RANDOMIZE_BASE
96#define KERNEL_IMAGE_SIZE (1024 * 1024 * 1024)
97#else
98#define KERNEL_IMAGE_SIZE (512 * 1024 * 1024)
99#endif
100
101#endif /* _ASM_X86_PAGE_64_DEFS_H */
102

source code of linux/arch/x86/include/asm/page_64_types.h