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_PHYSADDR_BITS 2^n: max size of physical address space 14 * MAX_PHYSMEM_BITS 2^n: how much memory we can have in that space 15 * 16 */ 17 18#ifdef CONFIG_X86_32 19# ifdef CONFIG_X86_PAE 20# define SECTION_SIZE_BITS 29 21# define MAX_PHYSADDR_BITS 36 22# define MAX_PHYSMEM_BITS 36 23# else 24# define SECTION_SIZE_BITS 26 25# define MAX_PHYSADDR_BITS 32 26# define MAX_PHYSMEM_BITS 32 27# endif 28#else /* CONFIG_X86_32 */ 29# define SECTION_SIZE_BITS 27 /* matt - 128 is convenient right now */ 30# ifdef CONFIG_X86_5LEVEL 31# define MAX_PHYSADDR_BITS 52 32# define MAX_PHYSMEM_BITS 52 33# else 34# define MAX_PHYSADDR_BITS 44 35# define MAX_PHYSMEM_BITS 46 36# endif 37#endif 38 39#endif /* CONFIG_SPARSEMEM */ 40#endif /* _ASM_X86_SPARSEMEM_H */ 41