linux/arch/x86/include/asm/page_64_types.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_X86_PAGE_64_DEFS_H
   3#define _ASM_X86_PAGE_64_DEFS_H
   4
   5#ifndef __ASSEMBLY__
   6#include <asm/kaslr.h>
   7#endif
   8
   9#ifdef CONFIG_KASAN
  10#define KASAN_STACK_ORDER 1
  11#else
  12#define KASAN_STACK_ORDER 0
  13#endif
  14
  15#define THREAD_SIZE_ORDER       (2 + KASAN_STACK_ORDER)
  16#define THREAD_SIZE  (PAGE_SIZE << THREAD_SIZE_ORDER)
  17
  18#define EXCEPTION_STACK_ORDER (0 + KASAN_STACK_ORDER)
  19#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
  20
  21#define IRQ_STACK_ORDER (2 + KASAN_STACK_ORDER)
  22#define IRQ_STACK_SIZE (PAGE_SIZE << IRQ_STACK_ORDER)
  23
  24/*
  25 * The index for the tss.ist[] array. The hardware limit is 7 entries.
  26 */
  27#define IST_INDEX_DF            0
  28#define IST_INDEX_NMI           1
  29#define IST_INDEX_DB            2
  30#define IST_INDEX_MCE           3
  31#define IST_INDEX_VC            4
  32
  33/*
  34 * Set __PAGE_OFFSET to the most negative possible address +
  35 * PGDIR_SIZE*17 (pgd slot 273).
  36 *
  37 * The gap is to allow a space for LDT remap for PTI (1 pgd slot) and space for
  38 * a hypervisor (16 slots). Choosing 16 slots for a hypervisor is arbitrary,
  39 * but it's what Xen requires.
  40 */
  41#define __PAGE_OFFSET_BASE_L5   _AC(0xff11000000000000, UL)
  42#define __PAGE_OFFSET_BASE_L4   _AC(0xffff888000000000, UL)
  43
  44#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
  45#define __PAGE_OFFSET           page_offset_base
  46#else
  47#define __PAGE_OFFSET           __PAGE_OFFSET_BASE_L4
  48#endif /* CONFIG_DYNAMIC_MEMORY_LAYOUT */
  49
  50#define __START_KERNEL_map      _AC(0xffffffff80000000, UL)
  51
  52/* See Documentation/x86/x86_64/mm.rst for a description of the memory map. */
  53
  54#define __PHYSICAL_MASK_SHIFT   52
  55
  56#ifdef CONFIG_X86_5LEVEL
  57#define __VIRTUAL_MASK_SHIFT    (pgtable_l5_enabled() ? 56 : 47)
  58/* See task_size_max() in <asm/page_64.h> */
  59#else
  60#define __VIRTUAL_MASK_SHIFT    47
  61#define task_size_max()         ((_AC(1,UL) << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE)
  62#endif
  63
  64#define TASK_SIZE_MAX           task_size_max()
  65#define DEFAULT_MAP_WINDOW      ((1UL << 47) - PAGE_SIZE)
  66
  67/* This decides where the kernel will search for a free chunk of vm
  68 * space during mmap's.
  69 */
  70#define IA32_PAGE_OFFSET        ((current->personality & ADDR_LIMIT_3GB) ? \
  71                                        0xc0000000 : 0xFFFFe000)
  72
  73#define TASK_SIZE_LOW           (test_thread_flag(TIF_ADDR32) ? \
  74                                        IA32_PAGE_OFFSET : DEFAULT_MAP_WINDOW)
  75#define TASK_SIZE               (test_thread_flag(TIF_ADDR32) ? \
  76                                        IA32_PAGE_OFFSET : TASK_SIZE_MAX)
  77#define TASK_SIZE_OF(child)     ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
  78                                        IA32_PAGE_OFFSET : TASK_SIZE_MAX)
  79
  80#define STACK_TOP               TASK_SIZE_LOW
  81#define STACK_TOP_MAX           TASK_SIZE_MAX
  82
  83/*
  84 * In spite of the name, KERNEL_IMAGE_SIZE is a limit on the maximum virtual
  85 * address for the kernel image, rather than the limit on the size itself.
  86 * This can be at most 1 GiB, due to the fixmap living in the next 1 GiB (see
  87 * level2_kernel_pgt in arch/x86/kernel/head_64.S).
  88 *
  89 * On KASLR use 1 GiB by default, leaving 1 GiB for modules once the
  90 * page tables are fully set up.
  91 *
  92 * If KASLR is disabled we can shrink it to 0.5 GiB and increase the size
  93 * of the modules area to 1.5 GiB.
  94 */
  95#ifdef CONFIG_RANDOMIZE_BASE
  96#define KERNEL_IMAGE_SIZE       (1024 * 1024 * 1024)
  97#else
  98#define KERNEL_IMAGE_SIZE       (512 * 1024 * 1024)
  99#endif
 100
 101#endif /* _ASM_X86_PAGE_64_DEFS_H */
 102