linux/arch/arm64/mm/pgd.c
Catalin Marinas 1d18c47c73 arm64: MMU fault handling and page table management
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>
2012-09-17 13:41:57 +01:00

55 lines
1.3 KiB
C

/*
* PGD allocation/freeing
*
* Copyright (C) 2012 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/mm.h>
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <asm/pgalloc.h>
#include <asm/page.h>
#include <asm/tlbflush.h>
#include "mm.h"
#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *new_pgd;
if (PGD_SIZE == PAGE_SIZE)
new_pgd = (pgd_t *)get_zeroed_page(GFP_KERNEL);
else
new_pgd = kzalloc(PGD_SIZE, GFP_KERNEL);
if (!new_pgd)
return NULL;
return new_pgd;
}
void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
if (PGD_SIZE == PAGE_SIZE)
free_page((unsigned long)pgd);
else
kfree(pgd);
}