From d083268bd9ec08fd35fd2cce8faffa4dcdb06d24 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 30 Mar 2018 17:34:08 +0530 Subject: [PATCH] powerpc/mm/hugetlb: initialize the pagetable cache correctly for hugetlb commit 6fa504835d6969144b2bd3699684dd447c789ba2 upstream. With 64k page size, we have hugetlb pte entries at the pmd and pud level for book3s64. We don't need to create a separate page table cache for that. With 4k we need to make sure hugepd page table cache for 16M is placed at PUD level and 16G at the PGD level. Simplify all these by not using HUGEPD_PD_SHIFT which is confusing for book3s64. Without this patch, with 64k page size we create pagetable caches with shift value 10 and 7 which are not used at all. Fixes: 419df06eea5b ("powerpc: Reduce the PTE_INDEX_SIZE") Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman [bwh: Backported to 3.16: Don't use an #ifdef because this implementation of hugetlbpage_init() is only used if CONFIG_PPC_BOOK3S_64 is enabled.] Signed-off-by: Ben Hutchings --- arch/powerpc/mm/hugetlbpage.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 7e70ae968e5f..e95f95996a5b 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -175,9 +175,6 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, #ifdef CONFIG_PPC_FSL_BOOK3E #define HUGEPD_PGD_SHIFT PGDIR_SHIFT #define HUGEPD_PUD_SHIFT PUD_SHIFT -#else -#define HUGEPD_PGD_SHIFT PUD_SHIFT -#define HUGEPD_PUD_SHIFT PMD_SHIFT #endif #ifdef CONFIG_PPC_BOOK3S_64 @@ -871,15 +868,17 @@ static int __init hugetlbpage_init(void) shift = mmu_psize_to_shift(psize); - if (add_huge_page_size(1ULL << shift) < 0) + if (shift > PGDIR_SHIFT) continue; - - if (shift < PMD_SHIFT) - pdshift = PMD_SHIFT; - else if (shift < PUD_SHIFT) + else if (shift > PUD_SHIFT) + pdshift = PGDIR_SHIFT; + else if (shift > PMD_SHIFT) pdshift = PUD_SHIFT; else - pdshift = PGDIR_SHIFT; + pdshift = PMD_SHIFT; + + if (add_huge_page_size(1ULL << shift) < 0) + continue; /* * if we have pdshift and shift value same, we don't * use pgt cache for hugepd.