1d18c47c73
This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
/*
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* PGD allocation/freeing
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*
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* Copyright (C) 2012 ARM Ltd.
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* Author: Catalin Marinas <catalin.marinas@arm.com>
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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 as
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* 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, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/mm.h>
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#include <linux/gfp.h>
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#include <linux/highmem.h>
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#include <linux/slab.h>
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#include <asm/pgalloc.h>
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#include <asm/page.h>
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#include <asm/tlbflush.h>
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#include "mm.h"
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#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
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pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *new_pgd;
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if (PGD_SIZE == PAGE_SIZE)
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new_pgd = (pgd_t *)get_zeroed_page(GFP_KERNEL);
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else
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new_pgd = kzalloc(PGD_SIZE, GFP_KERNEL);
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if (!new_pgd)
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return NULL;
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return new_pgd;
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}
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void pgd_free(struct mm_struct *mm, pgd_t *pgd)
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{
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if (PGD_SIZE == PAGE_SIZE)
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free_page((unsigned long)pgd);
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else
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kfree(pgd);
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}
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