arch/x86/include/asm/page_32_types.h

   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 /* 44=32+12, the limit we can fit into an unsigned long pfn */
  33 #define __PHYSICAL_MASK_SHIFT   44
  34 #define __VIRTUAL_MASK_SHIFT    32
  35
  36 #else  /* !CONFIG_X86_PAE */
  37 #define __PHYSICAL_MASK_SHIFT   32
  38 #define __VIRTUAL_MASK_SHIFT    32
  39 #endif  /* CONFIG_X86_PAE */
  40
  41 /*
  42  * Kernel image size is limited to 512 MB (see in arch/x86/kernel/head_32.S)
  43  */
  44 #define KERNEL_IMAGE_SIZE       (512 * 1024 * 1024)
  45
  46 #ifndef __ASSEMBLY__
  47
  48 /*
  49  * This much address space is reserved for vmalloc() and iomap()
  50  * as well as fixmap mappings.
  51  */
  52 extern unsigned int __VMALLOC_RESERVE;
  53 extern int sysctl_legacy_va_layout;
  54
  55 extern void find_low_pfn_range(void);
  56 extern void setup_bootmem_allocator(void);
  57
  58 #endif  /* !__ASSEMBLY__ */
  59
  60 #endif /* _ASM_X86_PAGE_32_DEFS_H */