mm/huge_memory.c: update tlb entry if pmd is changed

When set_pmd_at is called in function do_huge_pmd_anonymous_page, new tlb
entry can be added by software on MIPS platform.

Here add update_mmu_cache_pmd when pmd entry is set, and
update_mmu_cache_pmd is defined as empty excepts arc/mips platform.  This
patch has no negative effect on other platforms except arc/mips system.

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]>

mm/huge_memory.c

@@ -636,6 +636,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
 		lru_cache_add_inactive_or_unevictable(page, vma);
 		pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable);
 		set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry);
+		update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
 		add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
 		mm_inc_nr_ptes(vma->vm_mm);
 		spin_unlock(vmf->ptl);
@@ -749,6 +750,7 @@ vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf)
 			} else {
 				set_huge_zero_page(pgtable, vma->vm_mm, vma,
 						   haddr, vmf->pmd, zero_page);
+				update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
 				spin_unlock(vmf->ptl);
 			}
 		} else {