1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_SPARSEMEM_H
3 #define _ASM_X86_SPARSEMEM_H
5 #ifdef CONFIG_SPARSEMEM
7 * generic non-linear memory support:
9 * 1) we will not split memory into more chunks than will fit into the flags
10 * field of the struct page
12 * SECTION_SIZE_BITS 2^n: size of each section
13 * MAX_PHYSMEM_BITS 2^n: max size of physical address space
18 # ifdef CONFIG_X86_PAE
19 # define SECTION_SIZE_BITS 29
20 # define MAX_PHYSMEM_BITS 36
22 # define SECTION_SIZE_BITS 26
23 # define MAX_PHYSMEM_BITS 32
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)
30 #endif /* CONFIG_SPARSEMEM */
31 #endif /* _ASM_X86_SPARSEMEM_H */