/*
|
* 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>
|
|
static struct kmem_cache *pgd_cache __ro_after_init;
|
|
pgd_t *pgd_alloc(struct mm_struct *mm)
|
{
|
if (PGD_SIZE == PAGE_SIZE)
|
return (pgd_t *)__get_free_page(PGALLOC_GFP);
|
else
|
return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
|
}
|
|
void pgd_free(struct mm_struct *mm, pgd_t *pgd)
|
{
|
if (PGD_SIZE == PAGE_SIZE)
|
free_page((unsigned long)pgd);
|
else
|
kmem_cache_free(pgd_cache, pgd);
|
}
|
|
void __init pgd_cache_init(void)
|
{
|
if (PGD_SIZE == PAGE_SIZE)
|
return;
|
|
#ifdef CONFIG_ARM64_PA_BITS_52
|
/*
|
* With 52-bit physical addresses, the architecture requires the
|
* top-level table to be aligned to at least 64 bytes.
|
*/
|
BUILD_BUG_ON(PGD_SIZE < 64);
|
#endif
|
|
/*
|
* Naturally aligned pgds required by the architecture.
|
*/
|
pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_SIZE,
|
SLAB_PANIC, NULL);
|
}
|
