arch/x86/include/asm/pgtable_32_types.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_PGTABLE_32_DEFS_H
   3 #define _ASM_X86_PGTABLE_32_DEFS_H
   4
   5 /*
   6  * The Linux x86 paging architecture is 'compile-time dual-mode', it
   7  * implements both the traditional 2-level x86 page tables and the
   8  * newer 3-level PAE-mode page tables.
   9  */
  10 #ifdef CONFIG_X86_PAE
  11 # include <asm/pgtable-3level_types.h>
  12 # define PMD_SIZE       (1UL << PMD_SHIFT)
  13 # define PMD_MASK       (~(PMD_SIZE - 1))
  14 #else
  15 # include <asm/pgtable-2level_types.h>
  16 #endif
  17
  18 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  19 #define PGDIR_MASK      (~(PGDIR_SIZE - 1))
  20
  21 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  22  * current 8MB value just means that there will be a 8MB "hole" after the
  23  * physical memory until the kernel virtual memory starts.  That means that
  24  * any out-of-bounds memory accesses will hopefully be caught.
  25  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  26  * area for the same reason. ;)
  27  */
  28 #define VMALLOC_OFFSET  (8 * 1024 * 1024)
  29
  30 #ifndef __ASSEMBLY__
  31 extern bool __vmalloc_start_set; /* set once high_memory is set */
  32 #endif
  33
  34 #define VMALLOC_START   ((unsigned long)high_memory + VMALLOC_OFFSET)
  35 #ifdef CONFIG_X86_PAE
  36 #define LAST_PKMAP 512
  37 #else
  38 #define LAST_PKMAP 1024
  39 #endif
  40
  41 #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE * (LAST_PKMAP + 1))      \
  42                     & PMD_MASK)
  43
  44 #ifdef CONFIG_HIGHMEM
  45 # define VMALLOC_END    (PKMAP_BASE - 2 * PAGE_SIZE)
  46 #else
  47 # define VMALLOC_END    (FIXADDR_START - 2 * PAGE_SIZE)
  48 #endif
  49
  50 #define MODULES_VADDR   VMALLOC_START
  51 #define MODULES_END     VMALLOC_END
  52 #define MODULES_LEN     (MODULES_VADDR - MODULES_END)
  53
  54 #define MAXMEM  (VMALLOC_END - PAGE_OFFSET - __VMALLOC_RESERVE)
  55
  56 #endif /* _ASM_X86_PGTABLE_32_DEFS_H */