powerpc/mm: Use page fragments for allocation page table at PMD level

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/book3s/64/hash.h

@@ -23,16 +23,6 @@
 				 H_PUD_INDEX_SIZE + H_PGD_INDEX_SIZE + PAGE_SHIFT)
 #define H_PGTABLE_RANGE		(ASM_CONST(1) << H_PGTABLE_EADDR_SIZE)
 
-#if (defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE)) && \
-	defined(CONFIG_PPC_64K_PAGES)
-/*
- * only with hash 64k we need to use the second half of pmd page table
- * to store pointer to deposited pgtable_t
- */
-#define H_PMD_CACHE_INDEX	(H_PMD_INDEX_SIZE + 1)
-#else
-#define H_PMD_CACHE_INDEX	H_PMD_INDEX_SIZE
-#endif
 /*
  * We store the slot details in the second half of page table.
  * Increase the pud level table so that hugetlb ptes can be stored

arch/powerpc/include/asm/book3s/64/pgalloc.h

@@ -90,8 +90,7 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 	 * need to do this for 4k.
 	 */
 #if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_PPC_64K_PAGES) && \
-	((H_PGD_INDEX_SIZE == H_PUD_CACHE_INDEX) ||		     \
-	 (H_PGD_INDEX_SIZE == H_PMD_CACHE_INDEX))
+	(H_PGD_INDEX_SIZE == H_PUD_CACHE_INDEX)
 	memset(pgd, 0, PGD_TABLE_SIZE);
 #endif
 	return pgd;
@@ -138,13 +137,12 @@ 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));
+	return pmd_fragment_alloc(mm, addr);
 }
 
 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 {
-	kmem_cache_free(PGT_CACHE(PMD_CACHE_INDEX), pmd);
+	pmd_fragment_free((unsigned long *)pmd);
 }
 
 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,

arch/powerpc/include/asm/book3s/64/pgtable.h

@@ -212,13 +212,13 @@ extern unsigned long __pte_index_size;
 extern unsigned long __pmd_index_size;
 extern unsigned long __pud_index_size;
 extern unsigned long __pgd_index_size;
-extern unsigned long __pmd_cache_index;
 extern unsigned long __pud_cache_index;
 #define PTE_INDEX_SIZE  __pte_index_size
 #define PMD_INDEX_SIZE  __pmd_index_size
 #define PUD_INDEX_SIZE  __pud_index_size
 #define PGD_INDEX_SIZE  __pgd_index_size
-#define PMD_CACHE_INDEX __pmd_cache_index
+/* pmd table use page table fragments */
+#define PMD_CACHE_INDEX  0
 #define PUD_CACHE_INDEX __pud_cache_index
 /*
  * Because of use of pte fragments and THP, size of page table

arch/powerpc/mm/hash_utils_64.c

@@ -1020,7 +1020,6 @@ void __init hash__early_init_mmu(void)
 	__pud_index_size = H_PUD_INDEX_SIZE;
 	__pgd_index_size = H_PGD_INDEX_SIZE;
 	__pud_cache_index = H_PUD_CACHE_INDEX;
-	__pmd_cache_index = H_PMD_CACHE_INDEX;
 	__pte_table_size = H_PTE_TABLE_SIZE;
 	__pmd_table_size = H_PMD_TABLE_SIZE;
 	__pud_table_size = H_PUD_TABLE_SIZE;

arch/powerpc/mm/pgtable-book3s64.c

@@ -400,7 +400,7 @@ static inline void pgtable_free(void *table, int index)
 		pte_fragment_free(table, 0);
 		break;
 	case PMD_INDEX:
-		kmem_cache_free(PGT_CACHE(PMD_CACHE_INDEX), table);
+		pmd_fragment_free(table);
 		break;
 	case PUD_INDEX:
 		kmem_cache_free(PGT_CACHE(PUD_CACHE_INDEX), table);
@@ -431,7 +431,6 @@ void __tlb_remove_table(void *_table)
 #else
 void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index)
 {
-
 	return pgtable_free(table, index);
 }
 #endif

arch/powerpc/mm/pgtable-radix.c

@@ -617,7 +617,6 @@ void __init radix__early_init_mmu(void)
 	__pud_index_size = RADIX_PUD_INDEX_SIZE;
 	__pgd_index_size = RADIX_PGD_INDEX_SIZE;
 	__pud_cache_index = RADIX_PUD_INDEX_SIZE;
-	__pmd_cache_index = RADIX_PMD_INDEX_SIZE;
 	__pte_table_size = RADIX_PTE_TABLE_SIZE;
 	__pmd_table_size = RADIX_PMD_TABLE_SIZE;
 	__pud_table_size = RADIX_PUD_TABLE_SIZE;

arch/powerpc/mm/pgtable_64.c

@@ -72,8 +72,6 @@ unsigned long __pud_index_size;
 EXPORT_SYMBOL(__pud_index_size);
 unsigned long __pgd_index_size;
 EXPORT_SYMBOL(__pgd_index_size);
-unsigned long __pmd_cache_index;
-EXPORT_SYMBOL(__pmd_cache_index);
 unsigned long __pud_cache_index;
 EXPORT_SYMBOL(__pud_cache_index);
 unsigned long __pte_table_size;