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author | Richard Kuo <rkuo@codeaurora.org> | 2011-10-31 23:53:38 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-11-01 14:34:20 (GMT) |
commit | a7e79840991eac8da36f437c653ee4b8cfbdafdc (patch) | |
tree | a673266d06a67c7f4f32b0e048848e752b6bb441 /arch/hexagon/include/asm/fixmap.h | |
parent | b7f3785fbb3df3307290d4c236ffaa7ad172b6ed (diff) | |
download | linux-a7e79840991eac8da36f437c653ee4b8cfbdafdc.tar.xz |
Hexagon: Add page table header files & etc.
Signed-off-by: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Linas Vepstas <linas@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/hexagon/include/asm/fixmap.h')
-rw-r--r-- | arch/hexagon/include/asm/fixmap.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/hexagon/include/asm/fixmap.h b/arch/hexagon/include/asm/fixmap.h new file mode 100644 index 0000000..b27f494 --- /dev/null +++ b/arch/hexagon/include/asm/fixmap.h @@ -0,0 +1,73 @@ +/* + * Fixmap support for Hexagon - enough to support highmem features + * + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#ifndef _ASM_FIXMAP_H +#define _ASM_FIXMAP_H + +/* + * A lot of the fixmap info is already in mem-layout.h + */ +#include <asm/mem-layout.h> + +/* + * Full fixmap support involves set_fixmap() functions, but + * these may not be needed if all we're after is an area for + * highmem kernel mappings. + */ +#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) +#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) + +extern void __this_fixmap_does_not_exist(void); + +/** + * fix_to_virt -- "index to address" translation. + * + * If anyone tries to use the idx directly without translation, + * we catch the bug with a NULL-deference kernel oops. Illegal + * ranges of incoming indices are caught too. + */ +static inline unsigned long fix_to_virt(const unsigned int idx) +{ + /* + * This branch gets completely eliminated after inlining, + * except when someone tries to use fixaddr indices in an + * illegal way. (such as mixing up address types or using + * out-of-range indices). + * + * If it doesn't get removed, the linker will complain + * loudly with a reasonably clear error message.. + */ + if (idx >= __end_of_fixed_addresses) + __this_fixmap_does_not_exist(); + + return __fix_to_virt(idx); +} + +static inline unsigned long virt_to_fix(const unsigned long vaddr) +{ + BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); + return __virt_to_fix(vaddr); +} + +#define kmap_get_fixmap_pte(vaddr) \ + pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), \ + (vaddr)), (vaddr)), (vaddr)) + +#endif |