LXR linux/arch/x86/include/asm/page_32

   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 IRQ_STACK_SIZE          THREAD_SIZE
  26
  27#define N_EXCEPTION_STACKS      1
  28
  29#ifdef CONFIG_X86_PAE
  30/*
  31 * This is beyond the 44 bit limit imposed by the 32bit long pfns,
  32 * but we need the full mask to make sure inverted PROT_NONE
  33 * entries have all the host bits set in a guest.
  34 * The real limit is still 44 bits.
  35 */
  36#define __PHYSICAL_MASK_SHIFT   52
  37#define __VIRTUAL_MASK_SHIFT    32
  38
  39#else  /* !CONFIG_X86_PAE */
  40#define __PHYSICAL_MASK_SHIFT   32
  41#define __VIRTUAL_MASK_SHIFT    32
  42#endif  /* CONFIG_X86_PAE */
  43
  44/*
  45 * User space process size: 3GB (default).
  46 */
  47#define IA32_PAGE_OFFSET        __PAGE_OFFSET
  48#define TASK_SIZE               __PAGE_OFFSET
  49#define TASK_SIZE_LOW           TASK_SIZE
  50#define TASK_SIZE_MAX           TASK_SIZE
  51#define DEFAULT_MAP_WINDOW      TASK_SIZE
  52#define STACK_TOP               TASK_SIZE
  53#define STACK_TOP_MAX           STACK_TOP
  54
  55/*
  56 * In spite of the name, KERNEL_IMAGE_SIZE is a limit on the maximum virtual
  57 * address for the kernel image, rather than the limit on the size itself. On
  58 * 32-bit, this is not a strict limit, but this value is used to limit the
  59 * link-time virtual address range of the kernel, and by KASLR to limit the
  60 * randomized address from which the kernel is executed. A relocatable kernel
  61 * can be loaded somewhat higher than KERNEL_IMAGE_SIZE as long as enough space
  62 * remains for the vmalloc area.
  63 */
  64#define KERNEL_IMAGE_SIZE       (512 * 1024 * 1024)
  65
  66#ifndef __ASSEMBLY__
  67
  68/*
  69 * This much address space is reserved for vmalloc() and iomap()
  70 * as well as fixmap mappings.
  71 */
  72extern unsigned int __VMALLOC_RESERVE;
  73extern int sysctl_legacy_va_layout;
  74
  75extern void find_low_pfn_range(void);
  76extern void setup_bootmem_allocator(void);
  77
  78#endif  /* !__ASSEMBLY__ */
  79
  80#endif /* _ASM_X86_PAGE_32_DEFS_H */
  81