thp: introduce pmdp_invalidate()

On s390, a valid page table entry must not be changed while it is attached to any CPU. So instead of pmd_mknotpresent() and set_pmd_at(), an IDTE operation would be necessary there. This patch introduces the pmdp_invalidate() function, to allow architecture-specific implementations. Signed-off-by: Gerald Schaefer <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Hillf Danton <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Heiko Carstens <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
farmergreg · Oct 9, 2012 · 46dcde7 · 46dcde7
1 parent e3ebcf6
commit 46dcde7
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Showing 3 changed files with 17 additions and 2 deletions.
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
@@ -170,6 +170,11 @@ extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable);
 extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm);
 #endif
 
+#ifndef __HAVE_ARCH_PMDP_INVALIDATE
+extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+			    pmd_t *pmdp);
+#endif
+
 #ifndef __HAVE_ARCH_PTE_SAME
 static inline int pte_same(pte_t pte_a, pte_t pte_b)
 {

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
@@ -1361,8 +1361,7 @@ static int __split_huge_page_map(struct page *page,
 		 * SMP TLB and finally we write the non-huge version
 		 * of the pmd entry with pmd_populate.
 		 */
-		set_pmd_at(mm, address, pmd, pmd_mknotpresent(*pmd));
-		flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+		pmdp_invalidate(vma, address, pmd);
 		pmd_populate(mm, pmd, pgtable);
 		ret = 1;
 	}

diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
@@ -159,3 +159,14 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 #endif
+
+#ifndef __HAVE_ARCH_PMDP_INVALIDATE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+		     pmd_t *pmdp)
+{
+	set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(*pmdp));
+	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif