LXR linux/arch/x86/include/asm/highmem.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * highmem.h: virtual kernel memory mappings for high memory
   4 *
   5 * Used in CONFIG_HIGHMEM systems for memory pages which
   6 * are not addressable by direct kernel virtual addresses.
   7 *
   8 * Copyright (C) 1999 Gerhard Wichert, Siemens AG
   9 *                    Gerhard.Wichert@pdb.siemens.de
  10 *
  11 *
  12 * Redesigned the x86 32-bit VM architecture to deal with
  13 * up to 16 Terabyte physical memory. With current x86 CPUs
  14 * we now support up to 64 Gigabytes physical RAM.
  15 *
  16 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
  17 */
  18
  19#ifndef _ASM_X86_HIGHMEM_H
  20#define _ASM_X86_HIGHMEM_H
  21
  22#ifdef __KERNEL__
  23
  24#include <linux/interrupt.h>
  25#include <linux/threads.h>
  26#include <asm/tlbflush.h>
  27#include <asm/paravirt.h>
  28#include <asm/fixmap.h>
  29
  30/* declarations for highmem.c */
  31extern unsigned long highstart_pfn, highend_pfn;
  32
  33/*
  34 * Right now we initialize only a single pte table. It can be extended
  35 * easily, subsequent pte tables have to be allocated in one physical
  36 * chunk of RAM.
  37 */
  38/*
  39 * Ordering is:
  40 *
  41 * high memory on:                                    high_memory off:
  42 *    FIXADDR_TOP                                        FIXADDR_TOP
  43 *        fixed addresses                                    fixed addresses
  44 *    FIXADDR_START                                      FIXADDR_START
  45 *        temp fixed addresses/persistent kmap area      VMALLOC_END
  46 *    PKMAP_BASE                                             temp fixed addresses/vmalloc area
  47 *    VMALLOC_END                                        VMALLOC_START
  48 *        vmalloc area                                   high_memory
  49 *    VMALLOC_START
  50 *    high_memory
  51 *
  52 * The temp fixed area is only used during boot for early_ioremap(), and
  53 * it is unused when the ioremap() is functional. vmalloc/pkmap area become
  54 * available after early boot so the temp fixed area is available for re-use.
  55 */
  56#define LAST_PKMAP_MASK (LAST_PKMAP-1)
  57#define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
  58#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  59
  60#define flush_cache_kmaps()     do { } while (0)
  61
  62#define arch_kmap_local_post_map(vaddr, pteval)         \
  63        arch_flush_lazy_mmu_mode()
  64
  65#define arch_kmap_local_post_unmap(vaddr)               \
  66        do {                                            \
  67                flush_tlb_one_kernel((vaddr));          \
  68                arch_flush_lazy_mmu_mode();             \
  69        } while (0)
  70
  71extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
  72                                        unsigned long end_pfn);
  73
  74#endif /* __KERNEL__ */
  75
  76#endif /* _ASM_X86_HIGHMEM_H */
  77