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

   1/*
   2 * highmem.h: virtual kernel memory mappings for high memory
   3 *
   4 * Used in CONFIG_HIGHMEM systems for memory pages which
   5 * are not addressable by direct kernel virtual addresses.
   6 *
   7 * Copyright (C) 1999 Gerhard Wichert, Siemens AG
   8 *                    Gerhard.Wichert@pdb.siemens.de
   9 *
  10 *
  11 * Redesigned the x86 32-bit VM architecture to deal with
  12 * up to 16 Terabyte physical memory. With current x86 CPUs
  13 * we now support up to 64 Gigabytes physical RAM.
  14 *
  15 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
  16 */
  17
  18#ifndef _ASM_X86_HIGHMEM_H
  19#define _ASM_X86_HIGHMEM_H
  20
  21#ifdef __KERNEL__
  22
  23#include <linux/interrupt.h>
  24#include <linux/threads.h>
  25#include <asm/kmap_types.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 * FIXADDR_TOP
  42 *                      fixed_addresses
  43 * FIXADDR_START
  44 *                      temp fixed addresses
  45 * FIXADDR_BOOT_START
  46 *                      Persistent kmap area
  47 * PKMAP_BASE
  48 * VMALLOC_END
  49 *                      Vmalloc area
  50 * VMALLOC_START
  51 * high_memory
  52 */
  53#define LAST_PKMAP_MASK (LAST_PKMAP-1)
  54#define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
  55#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  56
  57extern void *kmap_high(struct page *page);
  58extern void kunmap_high(struct page *page);
  59
  60void *kmap(struct page *page);
  61void kunmap(struct page *page);
  62void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot);
  63void *kmap_atomic(struct page *page, enum km_type type);
  64void kunmap_atomic(void *kvaddr, enum km_type type);
  65void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
  66struct page *kmap_atomic_to_page(void *ptr);
  67
  68#ifndef CONFIG_PARAVIRT
  69#define kmap_atomic_pte(page, type)     kmap_atomic(page, type)
  70#endif
  71
  72#define flush_cache_kmaps()     do { } while (0)
  73
  74extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
  75                                        unsigned long end_pfn);
  76
  77#endif /* __KERNEL__ */
  78
  79#endif /* _ASM_X86_HIGHMEM_H */
  80