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 */ 31 extern 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 * high memory on: high_memory off: 42 * FIXADDR_TOP FIXADDR_TOP 43 * fixed addresses fixed addresses 44 * FIXADDR_START FIXADDR_START 45 * temp fixed addresses/persistent kmap area VMALLOC_END 46 * PKMAP_BASE temp fixed addresses/vmalloc area 47 * VMALLOC_END VMALLOC_START 48 * vmalloc area high_memory 49 * VMALLOC_START 50 * high_memory 51 * 52 * The temp fixed area is only used during boot for early_ioremap(), and 53 * it is unused when the ioremap() is functional. vmalloc/pkmap area become 54 * available after early boot so the temp fixed area is available for re-use. 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 66 void *kmap_atomic_prot(struct page *page, pgprot_t prot); 67 void *kmap_atomic(struct page *page); 68 void __kunmap_atomic(void *kvaddr); 69 void *kmap_atomic_pfn(unsigned long pfn); 70 void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot); 71 struct page *kmap_atomic_to_page(void *ptr); 72 73 #define flush_cache_kmaps() do { } while (0) 74 75 extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn, 76 unsigned long end_pfn); 77 78 #endif /* __KERNEL__ */ 79 80 #endif /* _ASM_X86_HIGHMEM_H */ 81