mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 18:11:56 +00:00
1355e2a6eb
This patch adds support for hugetlbfs based on the x86 implementation. It allows mapping of 2MB sections (see Documentation/vm/hugetlbpage.txt for usage). The 64K pages configuration is not supported (section size is 512MB in this case). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [steve.capper@linaro.org: symbolic constants replace numbers in places. Split up into multiple files, to simplify future non-LPAE support, removed huge_pmd_share code, as this is very rarely executed, Added PROT_NONE support]. Signed-off-by: Steve Capper <steve.capper@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com>
102 lines
2.3 KiB
C
102 lines
2.3 KiB
C
/*
|
|
* arch/arm/mm/hugetlbpage.c
|
|
*
|
|
* Copyright (C) 2012 ARM Ltd.
|
|
*
|
|
* Based on arch/x86/include/asm/hugetlb.h and Bill Carson's patches
|
|
*
|
|
* 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, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/hugetlb.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/err.h>
|
|
#include <linux/sysctl.h>
|
|
#include <asm/mman.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/pgalloc.h>
|
|
|
|
/*
|
|
* On ARM, huge pages are backed by pmd's rather than pte's, so we do a lot
|
|
* of type casting from pmd_t * to pte_t *.
|
|
*/
|
|
|
|
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
|
|
{
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pmd_t *pmd = NULL;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
if (pgd_present(*pgd)) {
|
|
pud = pud_offset(pgd, addr);
|
|
if (pud_present(*pud))
|
|
pmd = pmd_offset(pud, addr);
|
|
}
|
|
|
|
return (pte_t *)pmd;
|
|
}
|
|
|
|
struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
|
|
int write)
|
|
{
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
int pud_huge(pud_t pud)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
pte_t *huge_pte_alloc(struct mm_struct *mm,
|
|
unsigned long addr, unsigned long sz)
|
|
{
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pte_t *pte = NULL;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
pud = pud_alloc(mm, pgd, addr);
|
|
if (pud)
|
|
pte = (pte_t *)pmd_alloc(mm, pud, addr);
|
|
|
|
return pte;
|
|
}
|
|
|
|
struct page *
|
|
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
|
|
pmd_t *pmd, int write)
|
|
{
|
|
struct page *page;
|
|
|
|
page = pte_page(*(pte_t *)pmd);
|
|
if (page)
|
|
page += ((address & ~PMD_MASK) >> PAGE_SHIFT);
|
|
return page;
|
|
}
|
|
|
|
int pmd_huge(pmd_t pmd)
|
|
{
|
|
return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
|
|
}
|