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b920de1b DH |
1 | /* MN10300 Virtual kernel memory mappings for high memory |
2 | * | |
3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * - Derived from include/asm-i386/highmem.h | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public Licence | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the Licence, or (at your option) any later version. | |
11 | */ | |
12 | #ifndef _ASM_HIGHMEM_H | |
13 | #define _ASM_HIGHMEM_H | |
14 | ||
15 | #ifdef __KERNEL__ | |
16 | ||
17 | #include <linux/init.h> | |
18 | #include <linux/interrupt.h> | |
19 | #include <asm/kmap_types.h> | |
20 | #include <asm/pgtable.h> | |
21 | ||
22 | /* undef for production */ | |
23 | #undef HIGHMEM_DEBUG | |
24 | ||
25 | /* declarations for highmem.c */ | |
26 | extern unsigned long highstart_pfn, highend_pfn; | |
27 | ||
28 | extern pte_t *kmap_pte; | |
29 | extern pgprot_t kmap_prot; | |
30 | extern pte_t *pkmap_page_table; | |
31 | ||
32 | extern void __init kmap_init(void); | |
33 | ||
34 | /* | |
35 | * Right now we initialize only a single pte table. It can be extended | |
36 | * easily, subsequent pte tables have to be allocated in one physical | |
37 | * chunk of RAM. | |
38 | */ | |
39 | #define PKMAP_BASE 0xfe000000UL | |
40 | #define LAST_PKMAP 1024 | |
41 | #define LAST_PKMAP_MASK (LAST_PKMAP - 1) | |
42 | #define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT) | |
43 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) | |
44 | ||
21534301 HH |
45 | extern unsigned long kmap_high(struct page *page); |
46 | extern void kunmap_high(struct page *page); | |
b920de1b DH |
47 | |
48 | static inline unsigned long kmap(struct page *page) | |
49 | { | |
50 | if (in_interrupt()) | |
51 | BUG(); | |
52 | if (page < highmem_start_page) | |
53 | return page_address(page); | |
54 | return kmap_high(page); | |
55 | } | |
56 | ||
57 | static inline void kunmap(struct page *page) | |
58 | { | |
59 | if (in_interrupt()) | |
60 | BUG(); | |
61 | if (page < highmem_start_page) | |
62 | return; | |
63 | kunmap_high(page); | |
64 | } | |
65 | ||
66 | /* | |
67 | * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap | |
68 | * gives a more generic (and caching) interface. But kmap_atomic can | |
69 | * be used in IRQ contexts, so in some (very limited) cases we need | |
70 | * it. | |
71 | */ | |
72 | static inline unsigned long kmap_atomic(struct page *page, enum km_type type) | |
73 | { | |
74 | enum fixed_addresses idx; | |
75 | unsigned long vaddr; | |
76 | ||
77 | if (page < highmem_start_page) | |
78 | return page_address(page); | |
79 | ||
80 | idx = type + KM_TYPE_NR * smp_processor_id(); | |
81 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); | |
82 | #if HIGHMEM_DEBUG | |
83 | if (!pte_none(*(kmap_pte - idx))) | |
84 | BUG(); | |
85 | #endif | |
86 | set_pte(kmap_pte - idx, mk_pte(page, kmap_prot)); | |
87 | __flush_tlb_one(vaddr); | |
88 | ||
89 | return vaddr; | |
90 | } | |
91 | ||
92 | static inline void kunmap_atomic(unsigned long vaddr, enum km_type type) | |
93 | { | |
94 | #if HIGHMEM_DEBUG | |
95 | enum fixed_addresses idx = type + KM_TYPE_NR * smp_processor_id(); | |
96 | ||
97 | if (vaddr < FIXADDR_START) /* FIXME */ | |
98 | return; | |
99 | ||
100 | if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)) | |
101 | BUG(); | |
102 | ||
103 | /* | |
104 | * force other mappings to Oops if they'll try to access | |
105 | * this pte without first remap it | |
106 | */ | |
107 | pte_clear(kmap_pte - idx); | |
108 | __flush_tlb_one(vaddr); | |
109 | #endif | |
110 | } | |
111 | ||
112 | #endif /* __KERNEL__ */ | |
113 | ||
114 | #endif /* _ASM_HIGHMEM_H */ |