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/[email protected]
Signed-off-by: Bibo Mao <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Daniel Silsby <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Paul Burton <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

2 files changed, 0 insertions, 2 deletions

diff --git a/arch/mips/mm/pgtable-32.c b/arch/mips/mm/pgtable-32.c
index bd4b0656add3..61891af25019 100644
--- a/arch/mips/mm/pgtable-32.c
+++ b/arch/mips/mm/pgtable-32.c
@@ -45,7 +45,6 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 		pmd_t *pmdp, pmd_t pmd)
 {
 	*pmdp = pmd;
-	flush_tlb_all();
 }
 #endif /* defined(CONFIG_TRANSPARENT_HUGEPAGE) */
 
diff --git a/arch/mips/mm/pgtable-64.c b/arch/mips/mm/pgtable-64.c
index 183ff9f9c026..7536f7804c44 100644
--- a/arch/mips/mm/pgtable-64.c
+++ b/arch/mips/mm/pgtable-64.c
@@ -100,7 +100,6 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 		pmd_t *pmdp, pmd_t pmd)
 {
 	*pmdp = pmd;
-	flush_tlb_all();
 }
 
 void __init pagetable_init(void)