| 1 | /* |
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| 2 | * highmem.h: virtual kernel memory mappings for high memory |
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| 3 | * |
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| 4 | * Used in CONFIG_HIGHMEM systems for memory pages which |
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| 5 | * are not addressable by direct kernel virtual addresses. |
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| 6 | * |
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| 7 | * Copyright (C) 1999 Gerhard Wichert, Siemens AG |
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| 8 | * Gerhard.Wichert@pdb.siemens.de |
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| 9 | * |
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| 10 | * |
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| 11 | * Redesigned the x86 32-bit VM architecture to deal with |
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| 12 | * up to 16 Terabyte physical memory. With current x86 CPUs |
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| 13 | * we now support up to 64 Gigabytes physical RAM. |
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| 14 | * |
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| 15 | * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> |
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| 16 | */ |
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| 17 | |
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| 18 | #ifndef _ASM_HIGHMEM_H |
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| 19 | #define _ASM_HIGHMEM_H |
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| 20 | |
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| 21 | #ifdef __KERNEL__ |
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| 22 | |
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| 23 | #include <linux/interrupt.h> |
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| 24 | #include <linux/threads.h> |
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| 25 | #include <asm/kmap_types.h> |
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| 26 | #include <asm/tlbflush.h> |
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| 27 | |
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| 28 | /* declarations for highmem.c */ |
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| 29 | extern unsigned long highstart_pfn, highend_pfn; |
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| 30 | |
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| 31 | extern pte_t *kmap_pte; |
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| 32 | extern pgprot_t kmap_prot; |
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| 33 | extern pte_t *pkmap_page_table; |
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| 34 | |
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| 35 | /* |
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| 36 | * Right now we initialize only a single pte table. It can be extended |
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| 37 | * easily, subsequent pte tables have to be allocated in one physical |
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| 38 | * chunk of RAM. |
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| 39 | */ |
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| 40 | #ifdef CONFIG_X86_PAE |
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| 41 | #define LAST_PKMAP 512 |
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| 42 | #else |
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| 43 | #define LAST_PKMAP 1024 |
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| 44 | #endif |
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| 45 | /* |
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| 46 | * Ordering is: |
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| 47 | * |
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| 48 | * FIXADDR_TOP |
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| 49 | * fixed_addresses |
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| 50 | * FIXADDR_START |
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| 51 | * temp fixed addresses |
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| 52 | * FIXADDR_BOOT_START |
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| 53 | * Persistent kmap area |
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| 54 | * PKMAP_BASE |
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| 55 | * VMALLOC_END |
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| 56 | * Vmalloc area |
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| 57 | * VMALLOC_START |
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| 58 | * high_memory |
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| 59 | */ |
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| 60 | #define PKMAP_BASE ( (FIXADDR_BOOT_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK ) |
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| 61 | #define LAST_PKMAP_MASK (LAST_PKMAP-1) |
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| 62 | #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) |
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| 63 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) |
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| 64 | |
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| 65 | extern void * FASTCALL(kmap_high(struct page *page)); |
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| 66 | extern void FASTCALL(kunmap_high(struct page *page)); |
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| 67 | |
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| 68 | void *kmap(struct page *page); |
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| 69 | void kunmap(struct page *page); |
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| 70 | void *kmap_atomic(struct page *page, enum km_type type); |
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| 71 | void *kmap_atomic_pte(struct page *page, enum km_type type); |
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| 72 | void kunmap_atomic(void *kvaddr, enum km_type type); |
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| 73 | void *kmap_atomic_pfn(unsigned long pfn, enum km_type type); |
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| 74 | struct page *kmap_atomic_to_page(void *ptr); |
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| 75 | |
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| 76 | #define flush_cache_kmaps() do { } while (0) |
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| 77 | |
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| 78 | #endif /* __KERNEL__ */ |
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| 79 | |
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| 80 | #endif /* _ASM_HIGHMEM_H */ |
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