[PATCH V2 4/4] powerpc/mm/hash64: memset the pagetable pages on allocation.

[Aneesh Kumar K.V]

Now that we are using second half of the table to store slot details and we
don't clear them in the huge_pte_get_and_clear, we need to make sure we zero
out the range on allocation.

Simplify this by calling the object initialization after kmem_cache_alloc and
update the constructor do nothing.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/book3s/32/pgalloc.h | 16 +++++++++++++
 arch/powerpc/include/asm/book3s/64/pgalloc.h | 34 +++++++++++++++++++++++-----
 arch/powerpc/include/asm/nohash/pgalloc.h    | 16 +++++++++++++
 arch/powerpc/mm/init-common.c                | 15 ------------
 4 files changed, 60 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index 5073cc75f1c8..9f5c411bce1b 100644
--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h
@@ -139,4 +139,20 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
 	pgtable_page_dtor(table);
 	pgtable_free_tlb(tlb, page_address(table), 0);
 }
+
+static inline void pgd_ctor(void *addr)
+{
+	memset(addr, 0, PGD_TABLE_SIZE);
+}
+
+static inline void pud_ctor(void *addr)
+{
+	memset(addr, 0, PUD_TABLE_SIZE);
+}
+
+static inline void pmd_ctor(void *addr)
+{
+	memset(addr, 0, PMD_TABLE_SIZE);
+}
+
 #endif /* _ASM_POWERPC_BOOK3S_32_PGALLOC_H */
diff --git a/arch/powerpc/include/asm/book3s/64/pgalloc.h b/arch/powerpc/include/asm/book3s/64/pgalloc.h
index 53df86d3cfce..d6ee7563b09d 100644
--- a/arch/powerpc/include/asm/book3s/64/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h
@@ -73,10 +73,13 @@ static inline void radix__pgd_free(struct mm_struct *mm, pgd_t *pgd)
 
 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 {
+	pgd_t *pgd;
 	if (radix_enabled())
 		return radix__pgd_alloc(mm);
-	return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
-		pgtable_gfp_flags(mm, GFP_KERNEL));
+	pgd = kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
+			       pgtable_gfp_flags(mm, GFP_KERNEL));
+	memset(pgd, 0, PGD_TABLE_SIZE);
+	return pgd;
 }
 
 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
@@ -93,8 +96,11 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
 
 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	return kmem_cache_alloc(PGT_CACHE(PUD_CACHE_INDEX),
-		pgtable_gfp_flags(mm, GFP_KERNEL));
+	pud_t *pud;
+	pud = kmem_cache_alloc(PGT_CACHE(PUD_CACHE_INDEX),
+			       pgtable_gfp_flags(mm, GFP_KERNEL));
+	memset(pud, 0, PUD_TABLE_SIZE);
+	return pud;
 }
 
 static inline void pud_free(struct mm_struct *mm, pud_t *pud)
@@ -120,8 +126,12 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
 
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	return kmem_cache_alloc(PGT_CACHE(PMD_CACHE_INDEX),
-		pgtable_gfp_flags(mm, GFP_KERNEL));
+	pmd_t *pmd;
+	pmd = kmem_cache_alloc(PGT_CACHE(PMD_CACHE_INDEX),
+			       pgtable_gfp_flags(mm, GFP_KERNEL));
+	memset(pmd, 0, PMD_TABLE_SIZE);
+	return pmd;
+
 }
 
 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
@@ -218,4 +228,16 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
 
 #define check_pgt_cache()	do { } while (0)
 
+static inline void pgd_ctor(void *addr)
+{
+}
+
+static inline void pud_ctor(void *addr)
+{
+}
+
+static inline void pmd_ctor(void *addr)
+{
+}
+
 #endif /* _ASM_POWERPC_BOOK3S_64_PGALLOC_H */
diff --git a/arch/powerpc/include/asm/nohash/pgalloc.h b/arch/powerpc/include/asm/nohash/pgalloc.h
index 0634f2949438..df3be548ff97 100644
--- a/arch/powerpc/include/asm/nohash/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/pgalloc.h
@@ -21,4 +21,20 @@ static inline void tlb_flush_pgtable(struct mmu_gather *tlb,
 #else
 #include <asm/nohash/32/pgalloc.h>
 #endif
+
+static inline void pgd_ctor(void *addr)
+{
+	memset(addr, 0, PGD_TABLE_SIZE);
+}
+
+static inline void pud_ctor(void *addr)
+{
+	memset(addr, 0, PUD_TABLE_SIZE);
+}
+
+static inline void pmd_ctor(void *addr)
+{
+	memset(addr, 0, PMD_TABLE_SIZE);
+}
+
 #endif /* _ASM_POWERPC_NOHASH_PGALLOC_H */
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index 2b656e67f2ea..f92dd8cee3c5 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -25,21 +25,6 @@
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 
-static void pgd_ctor(void *addr)
-{
-	memset(addr, 0, PGD_TABLE_SIZE);
-}
-
-static void pud_ctor(void *addr)
-{
-	memset(addr, 0, PUD_TABLE_SIZE);
-}
-
-static void pmd_ctor(void *addr)
-{
-	memset(addr, 0, PMD_TABLE_SIZE);
-}
-
 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];
 EXPORT_SYMBOL_GPL(pgtable_cache);	/* used by kvm_hv module */
 
-- 
2.14.3