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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_SPARSEMEM_H
3#define _ASM_X86_SPARSEMEM_H
4
5#ifdef CONFIG_SPARSEMEM
6/*
7 * generic non-linear memory support:
8 *
9 * 1) we will not split memory into more chunks than will fit into the flags
10 * field of the struct page
11 *
12 * SECTION_SIZE_BITS 2^n: size of each section
13 * MAX_PHYSMEM_BITS 2^n: max size of physical address space
14 *
15 */
16
17#ifdef CONFIG_X86_32
18# ifdef CONFIG_X86_PAE
19# define SECTION_SIZE_BITS 29
20# define MAX_PHYSMEM_BITS 36
21# else
22# define SECTION_SIZE_BITS 26
23# define MAX_PHYSMEM_BITS 32
24# endif
25#else /* CONFIG_X86_32 */
26# define SECTION_SIZE_BITS 27 /* matt - 128 is convenient right now */
27# define MAX_PHYSMEM_BITS (pgtable_l5_enabled() ? 52 : 46)
28#endif
29
30#endif /* CONFIG_SPARSEMEM */
31#endif /* _ASM_X86_SPARSEMEM_H */