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 */ 32