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33d71d26 KG |
1 | /* |
2 | * highmem.h: virtual kernel memory mappings for high memory | |
3 | * | |
4 | * PowerPC version, stolen from the i386 version. | |
5 | * | |
6 | * Used in CONFIG_HIGHMEM systems for memory pages which | |
7 | * are not addressable by direct kernel virtual addresses. | |
8 | * | |
9 | * Copyright (C) 1999 Gerhard Wichert, Siemens AG | |
10 | * Gerhard.Wichert@pdb.siemens.de | |
11 | * | |
12 | * | |
13 | * Redesigned the x86 32-bit VM architecture to deal with | |
14 | * up to 16 Terrabyte physical memory. With current x86 CPUs | |
15 | * we now support up to 64 Gigabytes physical RAM. | |
16 | * | |
17 | * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> | |
18 | */ | |
19 | ||
20 | #ifndef _ASM_HIGHMEM_H | |
21 | #define _ASM_HIGHMEM_H | |
22 | ||
23 | #ifdef __KERNEL__ | |
24 | ||
33d71d26 KG |
25 | #include <linux/interrupt.h> |
26 | #include <asm/kmap_types.h> | |
27 | #include <asm/tlbflush.h> | |
28 | #include <asm/page.h> | |
2c419bde | 29 | #include <asm/fixmap.h> |
33d71d26 KG |
30 | |
31 | extern pte_t *kmap_pte; | |
32 | extern pgprot_t kmap_prot; | |
33 | extern pte_t *pkmap_page_table; | |
34 | ||
35 | /* | |
36 | * Right now we initialize only a single pte table. It can be extended | |
37 | * easily, subsequent pte tables have to be allocated in one physical | |
38 | * chunk of RAM. | |
39 | */ | |
ca9153a3 | 40 | /* |
e1240122 YT |
41 | * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte |
42 | * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP | |
43 | * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP | |
44 | * in case of 16K/64K/256K page sizes. | |
ca9153a3 IY |
45 | */ |
46 | #ifdef CONFIG_PPC_4K_PAGES | |
47 | #define PKMAP_ORDER PTE_SHIFT | |
48 | #else | |
e1240122 | 49 | #define PKMAP_ORDER 9 |
ca9153a3 IY |
50 | #endif |
51 | #define LAST_PKMAP (1 << PKMAP_ORDER) | |
52 | #ifndef CONFIG_PPC_4K_PAGES | |
53 | #define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) | |
54 | #else | |
2c419bde | 55 | #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK) |
ca9153a3 IY |
56 | #endif |
57 | #define LAST_PKMAP_MASK (LAST_PKMAP-1) | |
33d71d26 KG |
58 | #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) |
59 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) | |
60 | ||
33d71d26 KG |
61 | extern void *kmap_high(struct page *page); |
62 | extern void kunmap_high(struct page *page); | |
850f6ac3 BH |
63 | extern void *kmap_atomic_prot(struct page *page, enum km_type type, |
64 | pgprot_t prot); | |
597781f3 | 65 | extern void kunmap_atomic_notypecheck(void *kvaddr, enum km_type type); |
33d71d26 KG |
66 | |
67 | static inline void *kmap(struct page *page) | |
68 | { | |
69 | might_sleep(); | |
70 | if (!PageHighMem(page)) | |
71 | return page_address(page); | |
72 | return kmap_high(page); | |
73 | } | |
74 | ||
75 | static inline void kunmap(struct page *page) | |
76 | { | |
77 | BUG_ON(in_interrupt()); | |
78 | if (!PageHighMem(page)) | |
79 | return; | |
80 | kunmap_high(page); | |
81 | } | |
82 | ||
2c419bde KG |
83 | static inline void *kmap_atomic(struct page *page, enum km_type type) |
84 | { | |
85 | return kmap_atomic_prot(page, type, kmap_prot); | |
86 | } | |
87 | ||
33d71d26 KG |
88 | static inline struct page *kmap_atomic_to_page(void *ptr) |
89 | { | |
90 | unsigned long idx, vaddr = (unsigned long) ptr; | |
2c419bde | 91 | pte_t *pte; |
33d71d26 | 92 | |
2c419bde | 93 | if (vaddr < FIXADDR_START) |
33d71d26 KG |
94 | return virt_to_page(ptr); |
95 | ||
2c419bde KG |
96 | idx = virt_to_fix(vaddr); |
97 | pte = kmap_pte - (idx - FIX_KMAP_BEGIN); | |
98 | return pte_page(*pte); | |
33d71d26 KG |
99 | } |
100 | ||
850f6ac3 | 101 | |
33d71d26 KG |
102 | #define flush_cache_kmaps() flush_cache_all() |
103 | ||
104 | #endif /* __KERNEL__ */ | |
105 | ||
106 | #endif /* _ASM_HIGHMEM_H */ |