1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_PAGE_32_DEFS_H 3 #define _ASM_X86_PAGE_32_DEFS_H 4 5 #include <linux/const.h> 6 7 /* 8 * This handles the memory map. 9 * 10 * A __PAGE_OFFSET of 0xC0000000 means that the kernel has 11 * a virtual address space of one gigabyte, which limits the 12 * amount of physical memory you can use to about 950MB. 13 * 14 * If you want more physical memory than this then see the CONFIG_HIGHMEM4G 15 * and CONFIG_HIGHMEM64G options in the kernel configuration. 16 */ 17 #define __PAGE_OFFSET_BASE _AC(CONFIG_PAGE_OFFSET, UL) 18 #define __PAGE_OFFSET __PAGE_OFFSET_BASE 19 20 #define __START_KERNEL_map __PAGE_OFFSET 21 22 #define THREAD_SIZE_ORDER 1 23 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) 24 25 #define DOUBLEFAULT_STACK 1 26 #define NMI_STACK 0 27 #define DEBUG_STACK 0 28 #define MCE_STACK 0 29 #define N_EXCEPTION_STACKS 1 30 31 #ifdef CONFIG_X86_PAE 32 /* 33 * This is beyond the 44 bit limit imposed by the 32bit long pfns, 34 * but we need the full mask to make sure inverted PROT_NONE 35 * entries have all the host bits set in a guest. 36 * The real limit is still 44 bits. 37 */ 38 #define __PHYSICAL_MASK_SHIFT 52 39 #define __VIRTUAL_MASK_SHIFT 32 40 41 #else /* !CONFIG_X86_PAE */ 42 #define __PHYSICAL_MASK_SHIFT 32 43 #define __VIRTUAL_MASK_SHIFT 32 44 #endif /* CONFIG_X86_PAE */ 45 46 /* 47 * Kernel image size is limited to 512 MB (see in arch/x86/kernel/head_32.S) 48 */ 49 #define KERNEL_IMAGE_SIZE (512 * 1024 * 1024) 50 51 #ifndef __ASSEMBLY__ 52 53 /* 54 * This much address space is reserved for vmalloc() and iomap() 55 * as well as fixmap mappings. 56 */ 57 extern unsigned int __VMALLOC_RESERVE; 58 extern int sysctl_legacy_va_layout; 59 60 extern void find_low_pfn_range(void); 61 extern void setup_bootmem_allocator(void); 62 63 #endif /* !__ASSEMBLY__ */ 64 65 #endif /* _ASM_X86_PAGE_32_DEFS_H */ 66
