arch/arm64/mm/pgd.c

   1 /*
   2  * PGD allocation/freeing
   3  *
   4  * Copyright (C) 2012 ARM Ltd.
   5  * Author: Catalin Marinas <catalin.marinas@arm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/mm.h>
  21 #include <linux/gfp.h>
  22 #include <linux/highmem.h>
  23 #include <linux/slab.h>
  24
  25 #include <asm/pgalloc.h>
  26 #include <asm/page.h>
  27 #include <asm/tlbflush.h>
  28
  29 static struct kmem_cache *pgd_cache;
  30
  31 pgd_t *pgd_alloc(struct mm_struct *mm)
  32 {
  33         if (PGD_SIZE == PAGE_SIZE)
  34                 return (pgd_t *)__get_free_page(PGALLOC_GFP);
  35         else
  36                 return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
  37 }
  38
  39 void pgd_free(struct mm_struct *mm, pgd_t *pgd)
  40 {
  41         if (PGD_SIZE == PAGE_SIZE)
  42                 free_page((unsigned long)pgd);
  43         else
  44                 kmem_cache_free(pgd_cache, pgd);
  45 }
  46
  47 void __init pgd_cache_init(void)
  48 {
  49         if (PGD_SIZE == PAGE_SIZE)
  50                 return;
  51
  52         /*
  53          * Naturally aligned pgds required by the architecture.
  54          */
  55         pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_SIZE,
  56                                       SLAB_PANIC, NULL);
  57 }