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