projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 65559100 MF |
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 | |
| 22def768 MF |
26 | * in the boot process. We allocate these special addresses |
| 27 | * from the start of the consistent memory region upwards. | |
| 65559100 MF |
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 | enum fixed_addresses { | |
| 38 | #ifdef CONFIG_HIGHMEM | |
| 39 | /* reserved pte's for temporary kernel mappings */ | |
| 40 | FIX_KMAP_BEGIN, | |
| 32544d9c MF |
41 | FIX_KMAP_END = FIX_KMAP_BEGIN + |
| 42 | (KM_TYPE_NR * NR_CPUS * DCACHE_N_COLORS) - 1, | |
| 65559100 MF |
43 | #endif |
| 44 | __end_of_fixed_addresses | |
| 45 | }; | |
| 46 | ||
| 47 | #define FIXADDR_TOP (VMALLOC_START - PAGE_SIZE) | |
| 48 | #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) | |
| 49 | #define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK) | |
| 50 | ||
| 22def768 MF |
51 | #define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT)) |
| 52 | #define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT) | |
| 53 | ||
| 54 | #ifndef __ASSEMBLY__ | |
| 55 | /* | |
| 56 | * 'index to address' translation. If anyone tries to use the idx | |
| 57 | * directly without translation, we catch the bug with a NULL-deference | |
| 58 | * kernel oops. Illegal ranges of incoming indices are caught too. | |
| 59 | */ | |
| 60 | static __always_inline unsigned long fix_to_virt(const unsigned int idx) | |
| 61 | { | |
| d39af902 MF |
62 | /* Check if this memory layout is broken because fixmap overlaps page |
| 63 | * table. | |
| 64 | */ | |
| 65 | BUILD_BUG_ON(FIXADDR_START < | |
| 66 | XCHAL_PAGE_TABLE_VADDR + XCHAL_PAGE_TABLE_SIZE); | |
| 22def768 MF |
67 | BUILD_BUG_ON(idx >= __end_of_fixed_addresses); |
| 68 | return __fix_to_virt(idx); | |
| 69 | } | |
| 70 | ||
| 71 | static inline unsigned long virt_to_fix(const unsigned long vaddr) | |
| 72 | { | |
| 73 | BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); | |
| 74 | return __virt_to_fix(vaddr); | |
| 75 | } | |
| 76 | ||
| 77 | #endif | |
| 65559100 MF |
78 | |
| 79 | #define kmap_get_fixmap_pte(vaddr) \ | |
| 80 | pte_offset_kernel( \ | |
| 81 | pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), \ | |
| 82 | (vaddr) \ | |
| 83 | ) | |
| 84 | ||
| 85 | #endif |