mirror of https://github.com/dzavalishin/oskit/
51 lines
1.7 KiB
C
Executable File
51 lines
1.7 KiB
C
Executable File
/*
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* Copyright (c) 1998, 1999 University of Utah and the Flux Group.
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* All rights reserved.
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*
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* This file is part of the Flux OSKit. The OSKit is free software, also known
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* as "open source;" you can redistribute it and/or modify it under the terms
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* of the GNU General Public License (GPL), version 2, as published by the Free
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* Software Foundation (FSF). To explore alternate licensing terms, contact
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* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
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*
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* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
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* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
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* received a copy of the GPL along with the OSKit; see the file COPYING. If
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* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
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*/
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#include <oskit/arm32/base_paging.h>
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void pdir_clean_range(oskit_addr_t pdir_pa, oskit_addr_t va, oskit_size_t size)
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{
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int i, j;
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pd_entry_t *pde;
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pt_entry_t *pte;
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oskit_addr_t ptab_pa;
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/* Loop over indicated PDEs looking for valid page table pages. */
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pde = pdir_find_pde(pdir_pa, va);
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for (i = round_page(size) >> PDESHIFT; i > 0; i--, pde++)
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{
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/* Skip invalid or superpage PDEs. */
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if (((*pde & ARM32_PDE_TYPE_MASK) == ARM32_PDE_TYPE_SECTION) ||
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((*pde & ARM32_PDE_TYPE_MASK) == ARM32_PDE_TYPE_INVALID))
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continue;
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/* Valid page table, determine if all entries are invalid. */
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ptab_pa = pde_to_pa(*pde);
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pte = ptab_find_pte(ptab_pa, 0);
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for (j = 0; j < 256; j++, pte++)
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if (*pte & ARM32_PTE_TYPE_MASK)
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break;
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/* If all are invalid, free up the page table page. */
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if (j == 256)
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{
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*pde = 0;
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ptab_free(ptab_pa);
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}
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}
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}
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