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 29 /* declarations for highmem.c */ 30 extern unsigned long highstart_pfn, highend_pfn; 31 32 extern pte_t *kmap_pte; 33 extern pgprot_t kmap_prot; 34 extern pte_t *pkmap_page_table; 35 36 /* 37 * Right now we initialize only a single pte table. It can be extended 38 * easily, subsequent pte tables have to be allocated in one physical 39 * chunk of RAM. 40 */ 41 /* 42 * Ordering is: 43 * 44 * FIXADDR_TOP 45 * fixed_addresses 46 * FIXADDR_START 47 * temp fixed addresses 48 * FIXADDR_BOOT_START 49 * Persistent kmap area 50 * PKMAP_BASE 51 * VMALLOC_END 52 * Vmalloc area 53 * VMALLOC_START 54 * high_memory 55 */ 56 #define LAST_PKMAP_MASK (LAST_PKMAP-1) 57 #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) 58 #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) 59 60 extern void *kmap_high(struct page *page); 61 extern void kunmap_high(struct page *page); 62 63 void *kmap(struct page *page); 64 void kunmap(struct page *page); 65 void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot); 66 void *kmap_atomic(struct page *page, enum km_type type); 67 void kunmap_atomic(void *kvaddr, enum km_type type); 68 void *kmap_atomic_pfn(unsigned long pfn, enum km_type type); 69 struct page *kmap_atomic_to_page(void *ptr); 70 71 #ifndef CONFIG_PARAVIRT 72 #define kmap_atomic_pte(page, type) kmap_atomic(page, type) 73 #endif 74 75 #define flush_cache_kmaps() do { } while (0) 76 77 extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn, 78 unsigned long end_pfn); 79 80 #endif /* __KERNEL__ */ 81 82 #endif /* _ASM_X86_HIGHMEM_H */ 83