projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
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 | ||
| 1da177e4 | 16 | #include <asm/page.h> |
| 565b60de | 17 | #include <spaces.h> |
| 1da177e4 LT |
18 | #ifdef CONFIG_HIGHMEM |
| 19 | #include <linux/threads.h> | |
| 20 | #include <asm/kmap_types.h> | |
| 21 | #endif | |
| 22 | ||
| 23 | /* | |
| 24 | * Here we define all the compile-time 'special' virtual | |
| 25 | * addresses. The point is to have a constant address at | |
| 26 | * compile time, but to set the physical address only | |
| 27 | * in the boot process. We allocate these special addresses | |
| 28 | * from the end of virtual memory (0xfffff000) backwards. | |
| 29 | * Also this lets us do fail-safe vmalloc(), we | |
| 30 | * can guarantee that these special addresses and | |
| 31 | * vmalloc()-ed addresses never overlap. | |
| 32 | * | |
| 33 | * these 'compile-time allocated' memory buffers are | |
| 34 | * fixed-size 4k pages. (or larger if used with an increment | |
| 35 | * highger than 1) use fixmap_set(idx,phys) to associate | |
| 36 | * physical memory with fixmap indices. | |
| 37 | * | |
| 38 | * TLB entries of such buffers will not be flushed across | |
| 39 | * task switches. | |
| 40 | */ | |
| 41 | ||
| 42 | /* | |
| 43 | * on UP currently we will have no trace of the fixmap mechanizm, | |
| 44 | * no page table allocations, etc. This might change in the | |
| 45 | * future, say framebuffers for the console driver(s) could be | |
| 46 | * fix-mapped? | |
| 47 | */ | |
| 48 | enum fixed_addresses { | |
| f8829cae RB |
49 | #define FIX_N_COLOURS 8 |
| 50 | FIX_CMAP_BEGIN, | |
| 0f334a3e | 51 | FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * 2), |
| 1da177e4 | 52 | #ifdef CONFIG_HIGHMEM |
| f8829cae RB |
53 | /* reserved pte's for temporary kernel mappings */ |
| 54 | FIX_KMAP_BEGIN = FIX_CMAP_END + 1, | |
| 1da177e4 LT |
55 | FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, |
| 56 | #endif | |
| 57 | __end_of_fixed_addresses | |
| 58 | }; | |
| 59 | ||
| 1da177e4 LT |
60 | /* |
| 61 | * used by vmalloc.c. | |
| 62 | * | |
| 63 | * Leave one empty page between vmalloc'ed areas and | |
| 64 | * the start of the fixmap, and leave one page empty | |
| 65 | * at the top of mem.. | |
| 66 | */ | |
| 1da177e4 LT |
67 | #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) |
| 68 | #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) | |
| 69 | ||
| 19fd9629 | 70 | #include <asm-generic/fixmap.h> |
| 1da177e4 | 71 | |
| bb86bf28 RB |
72 | #define kmap_get_fixmap_pte(vaddr) \ |
| 73 | pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr)) | |
| 74 | ||
| 84fd089a RB |
75 | /* |
| 76 | * Called from pgtable_init() | |
| 77 | */ | |
| 78 | extern void fixrange_init(unsigned long start, unsigned long end, | |
| 70342287 | 79 | pgd_t *pgd_base); |
| 84fd089a RB |
80 | |
| 81 | ||
| 1da177e4 | 82 | #endif |