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