mirror of https://gitee.com/openkylin/linux.git
74 lines
2.3 KiB
C
74 lines
2.3 KiB
C
/*
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* Fixmap support for Hexagon - enough to support highmem features
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*
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* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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#ifndef _ASM_FIXMAP_H
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#define _ASM_FIXMAP_H
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/*
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* A lot of the fixmap info is already in mem-layout.h
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*/
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#include <asm/mem-layout.h>
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/*
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* Full fixmap support involves set_fixmap() functions, but
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* these may not be needed if all we're after is an area for
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* highmem kernel mappings.
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*/
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#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
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#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
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extern void __this_fixmap_does_not_exist(void);
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/**
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* fix_to_virt -- "index to address" translation.
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*
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* If anyone tries to use the idx directly without translation,
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* we catch the bug with a NULL-deference kernel oops. Illegal
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* ranges of incoming indices are caught too.
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*/
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static inline unsigned long fix_to_virt(const unsigned int idx)
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{
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/*
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* This branch gets completely eliminated after inlining,
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* except when someone tries to use fixaddr indices in an
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* illegal way. (such as mixing up address types or using
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* out-of-range indices).
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*
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* If it doesn't get removed, the linker will complain
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* loudly with a reasonably clear error message..
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*/
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if (idx >= __end_of_fixed_addresses)
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__this_fixmap_does_not_exist();
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return __fix_to_virt(idx);
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}
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static inline unsigned long virt_to_fix(const unsigned long vaddr)
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{
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BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
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return __virt_to_fix(vaddr);
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}
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#define kmap_get_fixmap_pte(vaddr) \
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pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), \
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(vaddr)), (vaddr)), (vaddr))
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#endif
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