[PATCH v4 08/20] powerpc/mm: Enable 512k hugepage support with HW assistance on the 8xx

[Christophe Leroy]

For using 512k pages with hardware assistance, the PTEs have to be spread
every 128 bytes in the L2 table.

Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>
---
 arch/powerpc/include/asm/hugetlb.h |  4 +++-
 arch/powerpc/mm/hugetlbpage.c      | 13 +++++++++++++
 arch/powerpc/mm/tlb_nohash.c       |  3 +++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index e13843556414..b22f164216ad 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -75,7 +75,9 @@ static inline pte_t *hugepte_offset(hugepd_t hpd, unsigned long addr,
 	unsigned long idx = 0;
 
 	pte_t *dir = hugepd_page(hpd);
-#ifndef CONFIG_PPC_FSL_BOOK3E
+#ifdef CONFIG_PPC_8xx
+	idx = (addr & ((1UL << pdshift) - 1)) >> PAGE_SHIFT;
+#elif !defined(CONFIG_PPC_FSL_BOOK3E)
 	idx = (addr & ((1UL << pdshift) - 1)) >> hugepd_shift(hpd);
 #endif
 
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 16846649499b..527ea2451cc2 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -66,7 +66,11 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
 		cachep = PGT_CACHE(PTE_T_ORDER);
 		num_hugepd = 1 << (pshift - pdshift);
 	} else {
+#ifdef CONFIG_PPC_8xx
+		cachep = PGT_CACHE(PTE_SHIFT);
+#else
 		cachep = PGT_CACHE(pdshift - pshift);
+#endif
 		num_hugepd = 1;
 	}
 
@@ -330,8 +334,13 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif
 	if (shift >= pdshift)
 		hugepd_free(tlb, hugepte);
 	else
+#ifdef CONFIG_PPC_8xx
+		pgtable_free_tlb(tlb, hugepte,
+				 get_hugepd_cache_index(PTE_SHIFT));
+#else
 		pgtable_free_tlb(tlb, hugepte,
 				 get_hugepd_cache_index(pdshift - shift));
+#endif
 }
 
 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
@@ -699,7 +708,11 @@ static int __init hugetlbpage_init(void)
 		 * use pgt cache for hugepd.
 		 */
 		if (pdshift > shift)
+#ifdef CONFIG_PPC_8xx
+			pgtable_cache_add(PTE_SHIFT);
+#else
 			pgtable_cache_add(pdshift - shift);
+#endif
 #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
 		else
 			pgtable_cache_add(PTE_T_ORDER);
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index 49441963d285..15fe5f0c8665 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -97,6 +97,9 @@ struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
 		.shift	= 14,
 	},
 #endif
+	[MMU_PAGE_512K] = {
+		.shift	= 19,
+	},
 	[MMU_PAGE_8M] = {
 		.shift	= 23,
 	},
-- 
2.13.3