From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934040AbeCGRr7 (ORCPT ); Wed, 7 Mar 2018 12:47:59 -0500 Received: from g2t2352.austin.hpe.com ([15.233.44.25]:54233 "EHLO g2t2352.austin.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932905AbeCGRri (ORCPT ); Wed, 7 Mar 2018 12:47:38 -0500 From: Toshi Kani To: mhocko@suse.com, akpm@linux-foundation.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, bp@suse.de, catalin.marinas@arm.com Cc: guohanjun@huawei.com, will.deacon@arm.com, wxf.wang@hisilicon.com, linux-mm@kvack.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Toshi Kani Subject: [PATCH 2/2] x86/mm: implement free pmd/pte page interfaces Date: Wed, 7 Mar 2018 11:32:27 -0700 Message-Id: <20180307183227.17983-3-toshi.kani@hpe.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180307183227.17983-1-toshi.kani@hpe.com> References: <20180307183227.17983-1-toshi.kani@hpe.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Implement pud_free_pmd_page() and pmd_free_pte_page() on x86, which clear a given pud/pmd entry and free up lower level page table(s). Address range associated with the pud/pmd entry must have been purged by INVLPG. Signed-off-by: Toshi Kani Cc: Michal Hocko Cc: Andrew Morton Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Borislav Petkov --- arch/x86/mm/pgtable.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 942f4fa341f1..121c0114439e 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -710,7 +710,22 @@ int pmd_clear_huge(pmd_t *pmd) */ int pud_free_pmd_page(pud_t *pud) { - return pud_none(*pud); + pmd_t *pmd; + int i; + + if (pud_none(*pud)) + return 1; + + pmd = (pmd_t *)pud_page_vaddr(*pud); + + for (i = 0; i < PTRS_PER_PMD; i++) + if (!pmd_free_pte_page(&pmd[i])) + return 0; + + pud_clear(pud); + free_page((unsigned long)pmd); + + return 1; } /** @@ -720,6 +735,15 @@ int pud_free_pmd_page(pud_t *pud) */ int pmd_free_pte_page(pmd_t *pmd) { - return pmd_none(*pmd); + pte_t *pte; + + if (pmd_none(*pmd)) + return 1; + + pte = (pte_t *)pmd_page_vaddr(*pmd); + pmd_clear(pmd); + free_page((unsigned long)pte); + + return 1; } #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */