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/*
* highmem.h: virtual kernel memory mappings for high memory
*
* Used in CONFIG_HIGHMEM systems for memory pages which
* are not addressable by direct kernel virtual addresses.
*
* Copyright (C) 1999 Gerhard Wichert, Siemens AG
* Gerhard.Wichert@pdb.siemens.de
*
*
* Redesigned the x86 32-bit VM architecture to deal with
* up to 16 Terabyte physical memory. With current x86 CPUs
* we now support up to 64 Gigabytes physical RAM.
*
* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
*/
#ifndef _ASM_HIGHMEM_H
#define _ASM_HIGHMEM_H
#ifdef __KERNEL__
#include <linux/interrupt.h>
#include <linux/threads.h>
#include <asm/kmap_types.h>
#include <asm/tlbflush.h>
/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;
extern pte_t *kmap_pte;
extern pgprot_t kmap_prot;
extern pte_t *pkmap_page_table;
/*
* Right now we initialize only a single pte table. It can be extended
* easily, subsequent pte tables have to be allocated in one physical
* chunk of RAM.
*/
#ifdef CONFIG_X86_PAE
#define LAST_PKMAP 512
#else
#define LAST_PKMAP 1024
#endif
/*
* Ordering is:
*
* FIXADDR_TOP
* fixed_addresses
* FIXADDR_START
* temp fixed addresses
* FIXADDR_BOOT_START
* Persistent kmap area
* PKMAP_BASE
* VMALLOC_END
* Vmalloc area
* VMALLOC_START
* high_memory
*/
#define PKMAP_BASE ( (FIXADDR_BOOT_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK )
#define LAST_PKMAP_MASK (LAST_PKMAP-1)
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
extern void * FASTCALL(kmap_high(struct page *page));
extern void FASTCALL(kunmap_high(struct page *page));
void *kmap(struct page *page);
void kunmap(struct page *page);
void *kmap_atomic(struct page *page, enum km_type type);
void kunmap_atomic(void *kvaddr, enum km_type type);
void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
struct page *kmap_atomic_to_page(void *ptr);
#define flush_cache_kmaps() do { } while (0)
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
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