xref: /linux/arch/x86/include/asm/sparsemem.h (revision bcefe12eff5dca6fdfa94ed85e5bee66380d5cd9)
1 #ifndef _ASM_X86_SPARSEMEM_H
2 #define _ASM_X86_SPARSEMEM_H
3 
4 #ifdef CONFIG_SPARSEMEM
5 /*
6  * generic non-linear memory support:
7  *
8  * 1) we will not split memory into more chunks than will fit into the flags
9  *    field of the struct page
10  *
11  * SECTION_SIZE_BITS		2^n: size of each section
12  * MAX_PHYSADDR_BITS		2^n: max size of physical address space
13  * MAX_PHYSMEM_BITS		2^n: how much memory we can have in that space
14  *
15  */
16 
17 #ifdef CONFIG_X86_32
18 # ifdef CONFIG_X86_PAE
19 #  define SECTION_SIZE_BITS	29
20 #  define MAX_PHYSADDR_BITS	36
21 #  define MAX_PHYSMEM_BITS	36
22 # else
23 #  define SECTION_SIZE_BITS	26
24 #  define MAX_PHYSADDR_BITS	32
25 #  define MAX_PHYSMEM_BITS	32
26 # endif
27 #else /* CONFIG_X86_32 */
28 # define SECTION_SIZE_BITS	27 /* matt - 128 is convenient right now */
29 # define MAX_PHYSADDR_BITS	44
30 # define MAX_PHYSMEM_BITS	46
31 #endif
32 
33 #endif /* CONFIG_SPARSEMEM */
34 #endif /* _ASM_X86_SPARSEMEM_H */
35