1/* 2 * highmem.h: virtual kernel memory mappings for high memory 3 * 4 * Used in CONFIG_HIGHMEM systems for memory pages which 5 * are not addressable by direct kernel virtual addresses. 6 * 7 * Copyright (C) 1999 Gerhard Wichert, Siemens AG 8 * Gerhard.Wichert@pdb.siemens.de 9 * 10 * 11 * Redesigned the x86 32-bit VM architecture to deal with 12 * up to 16 Terabyte physical memory. With current x86 CPUs 13 * we now support up to 64 Gigabytes physical RAM. 14 * 15 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> 16 */ 17#ifndef _ASM_HIGHMEM_H 18#define _ASM_HIGHMEM_H 19 20#ifdef __KERNEL__ 21 22#include <linux/init.h> 23#include <linux/interrupt.h> 24#include <linux/uaccess.h> 25#include <asm/kmap_types.h> 26 27/* undef for production */ 28#define HIGHMEM_DEBUG 1 29 30/* declarations for highmem.c */ 31extern unsigned long highstart_pfn, highend_pfn; 32 33extern pte_t *kmap_pte; 34extern pgprot_t kmap_prot; 35extern pte_t *pkmap_page_table; 36 37/* 38 * Right now we initialize only a single pte table. It can be extended 39 * easily, subsequent pte tables have to be allocated in one physical 40 * chunk of RAM. 41 */ 42#define PKMAP_BASE (0xfe000000UL) 43#define LAST_PKMAP 1024 44#define LAST_PKMAP_MASK (LAST_PKMAP-1) 45#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) 46#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) 47 48extern void * kmap_high(struct page *page); 49extern void kunmap_high(struct page *page); 50 51extern void *__kmap(struct page *page); 52extern void __kunmap(struct page *page); 53extern void *__kmap_atomic(struct page *page, enum km_type type); 54extern void __kunmap_atomic(void *kvaddr, enum km_type type); 55extern void *kmap_atomic_pfn(unsigned long pfn, enum km_type type); 56extern void *kmap_atomic_pfn_prot(unsigned long pfn, enum km_type type, pgprot_t prot); 57extern struct page *__kmap_atomic_to_page(void *ptr); 58 59#define kmap __kmap 60#define kunmap __kunmap 61#define kmap_atomic __kmap_atomic 62#define kunmap_atomic __kunmap_atomic 63#define kmap_atomic_to_page __kmap_atomic_to_page 64 65#define flush_cache_kmaps() flush_cache_all() 66 67#endif /* __KERNEL__ */ 68 69#endif /* _ASM_HIGHMEM_H */ 70