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bbc17704 JH |
1 | /* |
2 | * fixmap.h: compile-time virtual memory allocation | |
3 | * | |
4 | * This file is subject to the terms and conditions of the GNU General Public | |
5 | * License. See the file "COPYING" in the main directory of this archive | |
6 | * for more details. | |
7 | * | |
8 | * Copyright (C) 1998 Ingo Molnar | |
9 | * | |
10 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 | |
11 | */ | |
12 | ||
13 | #ifndef _ASM_FIXMAP_H | |
14 | #define _ASM_FIXMAP_H | |
15 | ||
16 | #include <asm/pgtable.h> | |
17 | #ifdef CONFIG_HIGHMEM | |
18 | #include <linux/threads.h> | |
19 | #include <asm/kmap_types.h> | |
20 | #endif | |
21 | ||
22 | /* | |
23 | * Here we define all the compile-time 'special' virtual | |
24 | * addresses. The point is to have a constant address at | |
25 | * compile time, but to set the physical address only | |
26 | * in the boot process. We allocate these special addresses | |
27 | * from the end of the consistent memory region backwards. | |
28 | * Also this lets us do fail-safe vmalloc(), we | |
29 | * can guarantee that these special addresses and | |
30 | * vmalloc()-ed addresses never overlap. | |
31 | * | |
32 | * these 'compile-time allocated' memory buffers are | |
33 | * fixed-size 4k pages. (or larger if used with an increment | |
34 | * higher than 1) use fixmap_set(idx,phys) to associate | |
35 | * physical memory with fixmap indices. | |
36 | * | |
37 | * TLB entries of such buffers will not be flushed across | |
38 | * task switches. | |
39 | */ | |
40 | enum fixed_addresses { | |
41 | #define FIX_N_COLOURS 8 | |
42 | #ifdef CONFIG_HIGHMEM | |
43 | /* reserved pte's for temporary kernel mappings */ | |
44 | FIX_KMAP_BEGIN, | |
45 | FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, | |
46 | #endif | |
47 | __end_of_fixed_addresses | |
48 | }; | |
49 | ||
50 | #define FIXADDR_TOP (CONSISTENT_START - PAGE_SIZE) | |
51 | #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) | |
52 | #define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK) | |
53 | ||
1c5c8043 | 54 | #include <asm-generic/fixmap.h> |
bbc17704 JH |
55 | |
56 | #define kmap_get_fixmap_pte(vaddr) \ | |
57 | pte_offset_kernel( \ | |
58 | pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), \ | |
59 | (vaddr) \ | |
60 | ) | |
61 | ||
62 | /* | |
63 | * Called from pgtable_init() | |
64 | */ | |
65 | extern void fixrange_init(unsigned long start, unsigned long end, | |
66 | pgd_t *pgd_base); | |
67 | ||
68 | ||
69 | #endif |