Loading...
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 | /* * 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/config.h> #include <linux/init.h> #include <linux/interrupt.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 PKMAP_BASE (0xfe000000UL) #ifdef CONFIG_X86_PAE #define LAST_PKMAP 512 #else #define LAST_PKMAP 1024 #endif #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)); 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) { enum fixed_addresses idx; unsigned long vaddr; if (page < highmem_start_page) return page_address(page); idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); #if HIGHMEM_DEBUG if (!pte_none(*(kmap_pte-idx))) BUG(); #endif set_pte(kmap_pte-idx, mk_pte(page, kmap_prot)); __flush_tlb_one(vaddr); return (void*) vaddr; } static inline void kunmap_atomic(void *kvaddr, enum km_type type) { #if HIGHMEM_DEBUG unsigned long vaddr = (unsigned long) kvaddr; enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); if (vaddr < FIXADDR_START) // FIXME return; if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx)) BUG(); /* * force other mappings to Oops if they'll try to access * this pte without first remap it */ pte_clear(kmap_pte-idx); __flush_tlb_one(vaddr); #endif } #endif /* __KERNEL__ */ #endif /* _ASM_HIGHMEM_H */ |