linux/arch/mips/mm/pgtable-32.c
Bibo Mao aba677f94b MIPS: do not call flush_tlb_all when setting pmd entry
Function set_pmd_at is to set pmd entry, if tlb entry need to be flushed,
there exists pmdp_huge_clear_flush alike function before set_pmd_at is
called.  So it is not necessary to call flush_tlb_all in this function.

In these scenarios, tlb for the pmd range needs to be flushed:

 - privilege degrade such as wrprotect is set on the pmd entry

 - pmd entry is cleared

 - there is exception if set_pmd_at is issued by dup_mmap, since
   flush_tlb_mm is called for parent process, it is not necessary to
   flush tlb in function copy_huge_pmd.

Link: http://lkml.kernel.org/r/1592990792-1923-3-git-send-email-maobibo@loongson.cn
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Daniel Silsby <dansilsby@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00

91 lines
2.1 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2003 by Ralf Baechle
*/
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/highmem.h>
#include <asm/fixmap.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
void pgd_init(unsigned long page)
{
unsigned long *p = (unsigned long *) page;
int i;
for (i = 0; i < USER_PTRS_PER_PGD; i+=8) {
p[i + 0] = (unsigned long) invalid_pte_table;
p[i + 1] = (unsigned long) invalid_pte_table;
p[i + 2] = (unsigned long) invalid_pte_table;
p[i + 3] = (unsigned long) invalid_pte_table;
p[i + 4] = (unsigned long) invalid_pte_table;
p[i + 5] = (unsigned long) invalid_pte_table;
p[i + 6] = (unsigned long) invalid_pte_table;
p[i + 7] = (unsigned long) invalid_pte_table;
}
}
#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
pmd_t mk_pmd(struct page *page, pgprot_t prot)
{
pmd_t pmd;
pmd_val(pmd) = (page_to_pfn(page) << _PFN_SHIFT) | pgprot_val(prot);
return pmd;
}
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
*pmdp = pmd;
}
#endif /* defined(CONFIG_TRANSPARENT_HUGEPAGE) */
void __init pagetable_init(void)
{
unsigned long vaddr;
pgd_t *pgd_base;
#ifdef CONFIG_HIGHMEM
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
#endif
/* Initialize the entire pgd. */
pgd_init((unsigned long)swapper_pg_dir);
pgd_init((unsigned long)swapper_pg_dir
+ sizeof(pgd_t) * USER_PTRS_PER_PGD);
pgd_base = swapper_pg_dir;
/*
* Fixed mappings:
*/
vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
fixrange_init(vaddr & PMD_MASK, vaddr + FIXADDR_SIZE, pgd_base);
#ifdef CONFIG_HIGHMEM
/*
* Permanent kmaps:
*/
vaddr = PKMAP_BASE;
fixrange_init(vaddr & PMD_MASK, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
pgd = swapper_pg_dir + pgd_index(vaddr);
p4d = p4d_offset(pgd, vaddr);
pud = pud_offset(p4d, vaddr);
pmd = pmd_offset(pud, vaddr);
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
#endif
}