xref: /linux/arch/x86/include/asm/page_64_types.h (revision ab93e0dd72c37d378dd936f031ffb83ff2bd87ce)
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 __ASSEMBLER__
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 #define __PAGE_OFFSET           page_offset_base
45 
46 #define __START_KERNEL_map	_AC(0xffffffff80000000, UL)
47 
48 /* See Documentation/arch/x86/x86_64/mm.rst for a description of the memory map. */
49 
50 #define __PHYSICAL_MASK_SHIFT	52
51 #define __VIRTUAL_MASK_SHIFT	(pgtable_l5_enabled() ? 56 : 47)
52 
53 #define TASK_SIZE_MAX		task_size_max()
54 #define DEFAULT_MAP_WINDOW	((1UL << 47) - PAGE_SIZE)
55 
56 /* This decides where the kernel will search for a free chunk of vm
57  * space during mmap's.
58  */
59 #define IA32_PAGE_OFFSET	((current->personality & ADDR_LIMIT_3GB) ? \
60 					0xc0000000 : 0xFFFFe000)
61 
62 #define TASK_SIZE_LOW		(test_thread_flag(TIF_ADDR32) ? \
63 					IA32_PAGE_OFFSET : DEFAULT_MAP_WINDOW)
64 #define TASK_SIZE		(test_thread_flag(TIF_ADDR32) ? \
65 					IA32_PAGE_OFFSET : TASK_SIZE_MAX)
66 #define TASK_SIZE_OF(child)	((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
67 					IA32_PAGE_OFFSET : TASK_SIZE_MAX)
68 
69 #define STACK_TOP		TASK_SIZE_LOW
70 #define STACK_TOP_MAX		TASK_SIZE_MAX
71 
72 /*
73  * In spite of the name, KERNEL_IMAGE_SIZE is a limit on the maximum virtual
74  * address for the kernel image, rather than the limit on the size itself.
75  * This can be at most 1 GiB, due to the fixmap living in the next 1 GiB (see
76  * level2_kernel_pgt in arch/x86/kernel/head_64.S).
77  *
78  * On KASLR use 1 GiB by default, leaving 1 GiB for modules once the
79  * page tables are fully set up.
80  *
81  * If KASLR is disabled we can shrink it to 0.5 GiB and increase the size
82  * of the modules area to 1.5 GiB.
83  */
84 #ifdef CONFIG_RANDOMIZE_BASE
85 #define KERNEL_IMAGE_SIZE	(1024 * 1024 * 1024)
86 #else
87 #define KERNEL_IMAGE_SIZE	(512 * 1024 * 1024)
88 #endif
89 
90 #endif /* _ASM_X86_PAGE_64_DEFS_H */
91