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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 | /* * 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 Terrabyte 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/init.h> #include <linux/interrupt.h> #include <asm/vaddrs.h> #include <asm/kmap_types.h> #include <asm/pgtable.h> /* undef for production */ #define HIGHMEM_DEBUG 1 /* 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; extern void kmap_init(void) __init; /* * 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. */ #define LAST_PKMAP 1024 #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 *kmap_high(struct page *page); extern void kunmap_high(struct page *page); static inline void *kmap(struct page *page) { if (in_interrupt()) BUG(); if (page < highmem_start_page) return page_address(page); return kmap_high(page); } static inline void kunmap(struct page *page) { if (in_interrupt()) BUG(); if (page < highmem_start_page) return; kunmap_high(page); } /* * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap * gives a more generic (and caching) interface. But kmap_atomic can * be used in IRQ contexts, so in some (very limited) cases we need * it. */ static inline void *kmap_atomic(struct page *page, enum km_type type) { unsigned long idx; unsigned long vaddr; if (page < highmem_start_page) return page_address(page); idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = FIX_KMAP_BEGIN + idx * PAGE_SIZE; /* XXX Fix - Anton */ #if 0 __flush_cache_one(vaddr); #else flush_cache_all(); #endif #if HIGHMEM_DEBUG if (!pte_none(*(kmap_pte+idx))) BUG(); #endif set_pte(kmap_pte+idx, mk_pte(page, kmap_prot)); /* XXX Fix - Anton */ #if 0 __flush_tlb_one(vaddr); #else flush_tlb_all(); #endif return (void*) vaddr; } static inline void kunmap_atomic(void *kvaddr, enum km_type type) { unsigned long vaddr = (unsigned long) kvaddr; unsigned long idx = type + KM_TYPE_NR*smp_processor_id(); if (vaddr < FIX_KMAP_BEGIN) // FIXME return; if (vaddr != FIX_KMAP_BEGIN + idx * PAGE_SIZE) BUG(); /* XXX Fix - Anton */ #if 0 __flush_cache_one(vaddr); #else flush_cache_all(); #endif #ifdef HIGHMEM_DEBUG /* * force other mappings to Oops if they'll try to access * this pte without first remap it */ pte_clear(kmap_pte+idx); /* XXX Fix - Anton */ #if 0 __flush_tlb_one(vaddr); #else flush_tlb_all(); #endif #endif } #endif /* __KERNEL__ */ #endif /* _ASM_HIGHMEM_H */ |