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-rw-r--r--arch/powerpc/include/asm/pgtable-ppc64.h4
-rw-r--r--arch/powerpc/mm/pgtable_64.c76
-rw-r--r--include/asm-generic/pgtable.h21
-rw-r--r--mm/huge_memory.c2
4 files changed, 67 insertions, 36 deletions
diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index f890f7ce1593..5f3a33784259 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -592,6 +592,10 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr,
extern void pmdp_splitting_flush(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp);
+extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp);
+#define pmdp_collapse_flush pmdp_collapse_flush
+
#define __HAVE_ARCH_PGTABLE_DEPOSIT
extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pgtable);
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 6bfadf1aa5cb..049d961802aa 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -560,41 +560,47 @@ pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t pmd;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
- if (pmd_trans_huge(*pmdp)) {
- pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
- } else {
- /*
- * khugepaged calls this for normal pmd
- */
- pmd = *pmdp;
- pmd_clear(pmdp);
- /*
- * Wait for all pending hash_page to finish. This is needed
- * in case of subpage collapse. When we collapse normal pages
- * to hugepage, we first clear the pmd, then invalidate all
- * the PTE entries. The assumption here is that any low level
- * page fault will see a none pmd and take the slow path that
- * will wait on mmap_sem. But we could very well be in a
- * hash_page with local ptep pointer value. Such a hash page
- * can result in adding new HPTE entries for normal subpages.
- * That means we could be modifying the page content as we
- * copy them to a huge page. So wait for parallel hash_page
- * to finish before invalidating HPTE entries. We can do this
- * by sending an IPI to all the cpus and executing a dummy
- * function there.
- */
- kick_all_cpus_sync();
- /*
- * Now invalidate the hpte entries in the range
- * covered by pmd. This make sure we take a
- * fault and will find the pmd as none, which will
- * result in a major fault which takes mmap_sem and
- * hence wait for collapse to complete. Without this
- * the __collapse_huge_page_copy can result in copying
- * the old content.
- */
- flush_tlb_pmd_range(vma->vm_mm, &pmd, address);
- }
+ VM_BUG_ON(!pmd_trans_huge(*pmdp));
+ pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
+ return pmd;
+}
+
+pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp)
+{
+ pmd_t pmd;
+
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+ VM_BUG_ON(pmd_trans_huge(*pmdp));
+
+ pmd = *pmdp;
+ pmd_clear(pmdp);
+ /*
+ * Wait for all pending hash_page to finish. This is needed
+ * in case of subpage collapse. When we collapse normal pages
+ * to hugepage, we first clear the pmd, then invalidate all
+ * the PTE entries. The assumption here is that any low level
+ * page fault will see a none pmd and take the slow path that
+ * will wait on mmap_sem. But we could very well be in a
+ * hash_page with local ptep pointer value. Such a hash page
+ * can result in adding new HPTE entries for normal subpages.
+ * That means we could be modifying the page content as we
+ * copy them to a huge page. So wait for parallel hash_page
+ * to finish before invalidating HPTE entries. We can do this
+ * by sending an IPI to all the cpus and executing a dummy
+ * function there.
+ */
+ kick_all_cpus_sync();
+ /*
+ * Now invalidate the hpte entries in the range
+ * covered by pmd. This make sure we take a
+ * fault and will find the pmd as none, which will
+ * result in a major fault which takes mmap_sem and
+ * hence wait for collapse to complete. Without this
+ * the __collapse_huge_page_copy can result in copying
+ * the old content.
+ */
+ flush_tlb_pmd_range(vma->vm_mm, &pmd, address);
return pmd;
}
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index bd910ceaccfa..d2c2171d1c32 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -189,6 +189,27 @@ extern void pmdp_splitting_flush(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp);
#endif
+#ifndef pmdp_collapse_flush
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
+ unsigned long address,
+ pmd_t *pmdp)
+{
+ return pmdp_clear_flush(vma, address, pmdp);
+}
+#define pmdp_collapse_flush pmdp_collapse_flush
+#else
+static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
+ unsigned long address,
+ pmd_t *pmdp)
+{
+ BUILD_BUG();
+ return *pmdp;
+}
+#define pmdp_collapse_flush pmdp_collapse_flush
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pgtable);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b3d8cd8d6968..65dd8d67287b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2499,7 +2499,7 @@ static void collapse_huge_page(struct mm_struct *mm,
* huge and small TLB entries for the same virtual address
* to avoid the risk of CPU bugs in that area.
*/
- _pmd = pmdp_clear_flush(vma, address, pmd);
+ _pmd = pmdp_collapse_flush(vma, address, pmd);
spin_unlock(pmd_ptl);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);