1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_PAGE_32_DEFS_H
3#define _ASM_X86_PAGE_32_DEFS_H
4
5#include <linux/const.h>
6
7/*
8 * This handles the memory map.
9 *
10 * A __PAGE_OFFSET of 0xC0000000 means that the kernel has
11 * a virtual address space of one gigabyte, which limits the
12 * amount of physical memory you can use to about 950MB.
13 *
14 * If you want more physical memory than this then see the CONFIG_HIGHMEM4G
15 * and CONFIG_HIGHMEM64G options in the kernel configuration.
16 */
17#define __PAGE_OFFSET_BASE _AC(CONFIG_PAGE_OFFSET, UL)
18#define __PAGE_OFFSET __PAGE_OFFSET_BASE
19
20#define __START_KERNEL_map __PAGE_OFFSET
21
22#define THREAD_SIZE_ORDER 1
23#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
24
25#define IRQ_STACK_SIZE THREAD_SIZE
26
27#define N_EXCEPTION_STACKS 1
28
29#ifdef CONFIG_X86_PAE
30/*
31 * This is beyond the 44 bit limit imposed by the 32bit long pfns,
32 * but we need the full mask to make sure inverted PROT_NONE
33 * entries have all the host bits set in a guest.
34 * The real limit is still 44 bits.
35 */
36#define __PHYSICAL_MASK_SHIFT 52
37#define __VIRTUAL_MASK_SHIFT 32
38
39#else /* !CONFIG_X86_PAE */
40#define __PHYSICAL_MASK_SHIFT 32
41#define __VIRTUAL_MASK_SHIFT 32
42#endif /* CONFIG_X86_PAE */
43
44/*
45 * User space process size: 3GB (default).
46 */
47#define IA32_PAGE_OFFSET __PAGE_OFFSET
48#define TASK_SIZE __PAGE_OFFSET
49#define TASK_SIZE_LOW TASK_SIZE
50#define TASK_SIZE_MAX TASK_SIZE
51#define DEFAULT_MAP_WINDOW TASK_SIZE
52#define STACK_TOP TASK_SIZE
53#define STACK_TOP_MAX STACK_TOP
54
55/*
56 * In spite of the name, KERNEL_IMAGE_SIZE is a limit on the maximum virtual
57 * address for the kernel image, rather than the limit on the size itself. On
58 * 32-bit, this is not a strict limit, but this value is used to limit the
59 * link-time virtual address range of the kernel, and by KASLR to limit the
60 * randomized address from which the kernel is executed. A relocatable kernel
61 * can be loaded somewhat higher than KERNEL_IMAGE_SIZE as long as enough space
62 * remains for the vmalloc area.
63 */
64#define KERNEL_IMAGE_SIZE (512 * 1024 * 1024)
65
66#ifndef __ASSEMBLY__
67
68/*
69 * This much address space is reserved for vmalloc() and iomap()
70 * as well as fixmap mappings.
71 */
72extern unsigned int __VMALLOC_RESERVE;
73extern int sysctl_legacy_va_layout;
74
75extern void find_low_pfn_range(void);
76extern void setup_bootmem_allocator(void);
77
78#endif /* !__ASSEMBLY__ */
79
80#endif /* _ASM_X86_PAGE_32_DEFS_H */
81

source code of linux/arch/x86/include/asm/page_32_types.h