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 */
  31 extern 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
  57 extern void *kmap_high(struct page *page);
  58 extern void kunmap_high(struct page *page);
  59
  60 void *kmap(struct page *page);
  61 void kunmap(struct page *page);
  62
  63 void *kmap_atomic_prot(struct page *page, pgprot_t prot);
  64 void *__kmap_atomic(struct page *page);
  65 void __kunmap_atomic(void *kvaddr);
  66 void *kmap_atomic_pfn(unsigned long pfn);
  67 void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
  68 struct page *kmap_atomic_to_page(void *ptr);
  69
  70 #define flush_cache_kmaps()     do { } while (0)
  71
  72 extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
  73                                         unsigned long end_pfn);
  74
  75 #endif /* __KERNEL__ */
  76
  77 #endif /* _ASM_X86_HIGHMEM_H */