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 DOUBLEFAULT_STACK 1
26#define NMI_STACK 0
27#define DEBUG_STACK 0
28#define MCE_STACK 0
29#define N_EXCEPTION_STACKS 1
30
31#ifdef CONFIG_X86_PAE
32/*
33 * This is beyond the 44 bit limit imposed by the 32bit long pfns,
34 * but we need the full mask to make sure inverted PROT_NONE
35 * entries have all the host bits set in a guest.
36 * The real limit is still 44 bits.
37 */
38#define __PHYSICAL_MASK_SHIFT 52
39#define __VIRTUAL_MASK_SHIFT 32
40
41#else /* !CONFIG_X86_PAE */
42#define __PHYSICAL_MASK_SHIFT 32
43#define __VIRTUAL_MASK_SHIFT 32
44#endif /* CONFIG_X86_PAE */
45
46/*
47 * Kernel image size is limited to 512 MB (see in arch/x86/kernel/head_32.S)
48 */
49#define KERNEL_IMAGE_SIZE (512 * 1024 * 1024)
50
51#ifndef __ASSEMBLY__
52
53/*
54 * This much address space is reserved for vmalloc() and iomap()
55 * as well as fixmap mappings.
56 */
57extern unsigned int __VMALLOC_RESERVE;
58extern int sysctl_legacy_va_layout;
59
60extern void find_low_pfn_range(void);
61extern void setup_bootmem_allocator(void);
62
63#endif /* !__ASSEMBLY__ */
64
65#endif /* _ASM_X86_PAGE_32_DEFS_H */
66