| Richard Kuo | a7e7984 | 2011-10-31 18:53:38 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Fixmap support for Hexagon - enough to support highmem features |
| 3 | * |
| 4 | * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 and |
| 8 | * only version 2 as published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 18 | * 02110-1301, USA. |
| 19 | */ |
| 20 | |
| 21 | #ifndef _ASM_FIXMAP_H |
| 22 | #define _ASM_FIXMAP_H |
| 23 | |
| 24 | /* |
| 25 | * A lot of the fixmap info is already in mem-layout.h |
| 26 | */ |
| 27 | #include <asm/mem-layout.h> |
| 28 | |
| 29 | /* |
| 30 | * Full fixmap support involves set_fixmap() functions, but |
| 31 | * these may not be needed if all we're after is an area for |
| 32 | * highmem kernel mappings. |
| 33 | */ |
| 34 | #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) |
| 35 | #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) |
| 36 | |
| 37 | extern void __this_fixmap_does_not_exist(void); |
| 38 | |
| 39 | /** |
| 40 | * fix_to_virt -- "index to address" translation. |
| 41 | * |
| 42 | * If anyone tries to use the idx directly without translation, |
| 43 | * we catch the bug with a NULL-deference kernel oops. Illegal |
| 44 | * ranges of incoming indices are caught too. |
| 45 | */ |
| 46 | static inline unsigned long fix_to_virt(const unsigned int idx) |
| 47 | { |
| 48 | /* |
| 49 | * This branch gets completely eliminated after inlining, |
| 50 | * except when someone tries to use fixaddr indices in an |
| 51 | * illegal way. (such as mixing up address types or using |
| 52 | * out-of-range indices). |
| 53 | * |
| 54 | * If it doesn't get removed, the linker will complain |
| 55 | * loudly with a reasonably clear error message.. |
| 56 | */ |
| 57 | if (idx >= __end_of_fixed_addresses) |
| 58 | __this_fixmap_does_not_exist(); |
| 59 | |
| 60 | return __fix_to_virt(idx); |
| 61 | } |
| 62 | |
| 63 | static inline unsigned long virt_to_fix(const unsigned long vaddr) |
| 64 | { |
| 65 | BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); |
| 66 | return __virt_to_fix(vaddr); |
| 67 | } |
| 68 | |
| 69 | #define kmap_get_fixmap_pte(vaddr) \ |
| 70 | pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), \ |
| 71 | (vaddr)), (vaddr)), (vaddr)) |
| 72 | |
| 73 | #endif |