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Diffstat (limited to 'include/asm-i386/highmem.h')
-rw-r--r-- | include/asm-i386/highmem.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/include/asm-i386/highmem.h b/include/asm-i386/highmem.h new file mode 100644 index 0000000..1df42bf --- /dev/null +++ b/include/asm-i386/highmem.h @@ -0,0 +1,79 @@ +/* + * 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/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); +struct page *kmap_atomic_to_page(void *ptr); + +#define flush_cache_kmaps() do { } while (0) + +#endif /* __KERNEL__ */ + +#endif /* _ASM_HIGHMEM_H */ |