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 18#ifndef _ASM_X86_HIGHMEM_H 19#define _ASM_X86_HIGHMEM_H 20 21#ifdef __KERNEL__ 22 23#include <linux/interrupt.h> 24#include <linux/threads.h> 25#include <asm/kmap_types.h> 26#include <asm/tlbflush.h> 27#include <asm/paravirt.h> 28#include <asm/fixmap.h> 29 30/* declarations for highmem.c */ 31extern unsigned long highstart_pfn, highend_pfn; 32 33/* 34 * Right now we initialize only a single pte table. It can be extended 35 * easily, subsequent pte tables have to be allocated in one physical 36 * chunk of RAM. 37 */ 38/* 39 * Ordering is: 40 * 41 * FIXADDR_TOP 42 * fixed_addresses 43 * FIXADDR_START 44 * temp fixed addresses 45 * FIXADDR_BOOT_START 46 * Persistent kmap area 47 * PKMAP_BASE 48 * VMALLOC_END 49 * Vmalloc area 50 * VMALLOC_START 51 * high_memory 52 */ 53#define LAST_PKMAP_MASK (LAST_PKMAP-1) 54#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) 55#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) 56 57extern void *kmap_high(struct page *page); 58extern void kunmap_high(struct page *page); 59 60void *kmap(struct page *page); 61void kunmap(struct page *page); 62 63void *kmap_atomic_prot(struct page *page, pgprot_t prot); 64void *kmap_atomic(struct page *page); 65void __kunmap_atomic(void *kvaddr); 66void *kmap_atomic_pfn(unsigned long pfn); 67void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot); 68struct page *kmap_atomic_to_page(void *ptr); 69 70#define flush_cache_kmaps() do { } while (0) 71 72extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn, 73 unsigned long end_pfn); 74 75#endif /* __KERNEL__ */ 76 77#endif /* _ASM_X86_HIGHMEM_H */ 78