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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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_HIGHMEM_H
19#define _ASM_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 */
30extern unsigned long highstart_pfn, highend_pfn;
31
32extern pte_t *kmap_pte;
33extern pgprot_t kmap_prot;
34extern 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
60extern void *kmap_high(struct page *page);
61extern void kunmap_high(struct page *page);
62
63void *kmap(struct page *page);
64void kunmap(struct page *page);
65void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot);
66void *kmap_atomic(struct page *page, enum km_type type);
67void kunmap_atomic(void *kvaddr, enum km_type type);
68void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
69struct 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#endif /* __KERNEL__ */
78
79#endif /* _ASM_HIGHMEM_H */