Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <asm/page.h> |
Kevin Cernekee | 565b60d | 2010-09-07 12:59:15 -0700 | [diff] [blame] | 17 | #include <spaces.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 { |
Ralf Baechle | f8829ca | 2006-10-21 23:17:35 +0100 | [diff] [blame] | 49 | #define FIX_N_COLOURS 8 |
| 50 | FIX_CMAP_BEGIN, |
Kevin Cernekee | 0f334a3 | 2009-09-07 11:11:31 -0700 | [diff] [blame] | 51 | FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * 2), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | #ifdef CONFIG_HIGHMEM |
Ralf Baechle | f8829ca | 2006-10-21 23:17:35 +0100 | [diff] [blame] | 53 | /* reserved pte's for temporary kernel mappings */ |
| 54 | FIX_KMAP_BEGIN = FIX_CMAP_END + 1, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, |
| 56 | #endif |
| 57 | __end_of_fixed_addresses |
| 58 | }; |
| 59 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) |
| 68 | #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) |
| 69 | |
Mark Salter | 19fd962 | 2014-01-23 15:53:54 -0800 | [diff] [blame] | 70 | #include <asm-generic/fixmap.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
Ralf Baechle | bb86bf2 | 2009-04-25 11:25:34 +0200 | [diff] [blame] | 72 | #define kmap_get_fixmap_pte(vaddr) \ |
| 73 | pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr)) |
| 74 | |
Ralf Baechle | 84fd089 | 2005-02-07 16:13:07 +0000 | [diff] [blame] | 75 | /* |
| 76 | * Called from pgtable_init() |
| 77 | */ |
| 78 | extern void fixrange_init(unsigned long start, unsigned long end, |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 79 | pgd_t *pgd_base); |
Ralf Baechle | 84fd089 | 2005-02-07 16:13:07 +0000 | [diff] [blame] | 80 | |
| 81 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | #endif |