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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
33d71d26 KG |
2 | /* |
3 | * highmem.h: virtual kernel memory mappings for high memory | |
4 | * | |
5 | * PowerPC version, stolen from the i386 version. | |
6 | * | |
7 | * Used in CONFIG_HIGHMEM systems for memory pages which | |
8 | * are not addressable by direct kernel virtual addresses. | |
9 | * | |
10 | * Copyright (C) 1999 Gerhard Wichert, Siemens AG | |
11 | * Gerhard.Wichert@pdb.siemens.de | |
12 | * | |
13 | * | |
14 | * Redesigned the x86 32-bit VM architecture to deal with | |
15 | * up to 16 Terrabyte physical memory. With current x86 CPUs | |
16 | * we now support up to 64 Gigabytes physical RAM. | |
17 | * | |
18 | * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> | |
19 | */ | |
20 | ||
21 | #ifndef _ASM_HIGHMEM_H | |
22 | #define _ASM_HIGHMEM_H | |
23 | ||
24 | #ifdef __KERNEL__ | |
25 | ||
33d71d26 KG |
26 | #include <linux/interrupt.h> |
27 | #include <asm/kmap_types.h> | |
45ef5992 | 28 | #include <asm/cacheflush.h> |
33d71d26 | 29 | #include <asm/page.h> |
2c419bde | 30 | #include <asm/fixmap.h> |
33d71d26 KG |
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 | */ | |
ca9153a3 | 41 | /* |
e1240122 YT |
42 | * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte |
43 | * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP | |
44 | * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP | |
45 | * in case of 16K/64K/256K page sizes. | |
ca9153a3 IY |
46 | */ |
47 | #ifdef CONFIG_PPC_4K_PAGES | |
48 | #define PKMAP_ORDER PTE_SHIFT | |
49 | #else | |
e1240122 | 50 | #define PKMAP_ORDER 9 |
ca9153a3 IY |
51 | #endif |
52 | #define LAST_PKMAP (1 << PKMAP_ORDER) | |
53 | #ifndef CONFIG_PPC_4K_PAGES | |
54 | #define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) | |
55 | #else | |
2c419bde | 56 | #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK) |
ca9153a3 IY |
57 | #endif |
58 | #define LAST_PKMAP_MASK (LAST_PKMAP-1) | |
33d71d26 KG |
59 | #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) |
60 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) | |
61 | ||
33d71d26 KG |
62 | extern void *kmap_high(struct page *page); |
63 | extern void kunmap_high(struct page *page); | |
3e4d3af5 PZ |
64 | extern void *kmap_atomic_prot(struct page *page, pgprot_t prot); |
65 | extern void __kunmap_atomic(void *kvaddr); | |
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 | ||
a24401bc | 83 | static inline void *kmap_atomic(struct page *page) |
2c419bde | 84 | { |
3e4d3af5 | 85 | return kmap_atomic_prot(page, kmap_prot); |
2c419bde KG |
86 | } |
87 | ||
850f6ac3 | 88 | |
33d71d26 KG |
89 | #define flush_cache_kmaps() flush_cache_all() |
90 | ||
91 | #endif /* __KERNEL__ */ | |
92 | ||
93 | #endif /* _ASM_HIGHMEM_H */ |