1 #ifndef _ASM_X86_PAGE_32_DEFS_H
2 #define _ASM_X86_PAGE_32_DEFS_H
4 #include <linux/const.h>
7 * This handles the memory map.
9 * A __PAGE_OFFSET of 0xC0000000 means that the kernel has
10 * a virtual address space of one gigabyte, which limits the
11 * amount of physical memory you can use to about 950MB.
13 * If you want more physical memory than this then see the CONFIG_HIGHMEM4G
14 * and CONFIG_HIGHMEM64G options in the kernel configuration.
16 #define __PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
18 #define __START_KERNEL_map __PAGE_OFFSET
20 #define THREAD_SIZE_ORDER 1
21 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
23 #define DOUBLEFAULT_STACK 1
27 #define N_EXCEPTION_STACKS 1
30 /* 44=32+12, the limit we can fit into an unsigned long pfn */
31 #define __PHYSICAL_MASK_SHIFT 44
32 #define __VIRTUAL_MASK_SHIFT 32
34 #else /* !CONFIG_X86_PAE */
35 #define __PHYSICAL_MASK_SHIFT 32
36 #define __VIRTUAL_MASK_SHIFT 32
37 #endif /* CONFIG_X86_PAE */
40 * Kernel image size is limited to 512 MB (see in arch/x86/kernel/head_32.S)
42 #define KERNEL_IMAGE_SIZE (512 * 1024 * 1024)
47 * This much address space is reserved for vmalloc() and iomap()
48 * as well as fixmap mappings.
50 extern unsigned int __VMALLOC_RESERVE;
51 extern int sysctl_legacy_va_layout;
53 extern void find_low_pfn_range(void);
54 extern void setup_bootmem_allocator(void);
56 #endif /* !__ASSEMBLY__ */
58 #endif /* _ASM_X86_PAGE_32_DEFS_H */