From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vJjTD1407zDqGh for ; Thu, 9 Feb 2017 13:58:55 +1100 (AEDT) Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v192wfCn053757 for ; Wed, 8 Feb 2017 21:58:54 -0500 Received: from e18.ny.us.ibm.com (e18.ny.us.ibm.com [129.33.205.208]) by mx0a-001b2d01.pphosted.com with ESMTP id 28gcn7ev2s-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 08 Feb 2017 21:58:53 -0500 Received: from localhost by e18.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 8 Feb 2017 21:58:52 -0500 From: "Aneesh Kumar K.V" To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au Cc: linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" Subject: [PATCH 2/3] powerpc/mm/radix: Use ptep_get_and_clear_full when clearing pte for full mm Date: Thu, 9 Feb 2017 08:28:20 +0530 In-Reply-To: <1486609101-5231-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1486609101-5231-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Message-Id: <1486609101-5231-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This helps us to do some optimization for application exit case, where we can skip the DD1 style pte update sequence. Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/include/asm/book3s/64/pgtable.h | 17 +++++++++++++++++ arch/powerpc/include/asm/book3s/64/radix.h | 23 ++++++++++++++++++++++- 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 6f15bde94da2..e91ada786d48 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -373,6 +373,23 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, return __pte(old); } +#define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL +static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, + unsigned long addr, + pte_t *ptep, int full) +{ + if (full && radix_enabled()) { + /* + * Let's skip the DD1 style pte update here. We know that + * this is a full mm pte clear and hence can be sure there is + * no parallel set_pte. + */ + return radix__ptep_get_and_clear_full(mm, addr, ptep, full); + } + return ptep_get_and_clear(mm, addr, ptep); +} + + static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t * ptep) { diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h index 70a3cdcdbe47..fcf822d6c204 100644 --- a/arch/powerpc/include/asm/book3s/64/radix.h +++ b/arch/powerpc/include/asm/book3s/64/radix.h @@ -139,7 +139,7 @@ static inline unsigned long radix__pte_update(struct mm_struct *mm, unsigned long new_pte; - old_pte = __radix_pte_update(ptep, ~0, 0); + old_pte = __radix_pte_update(ptep, ~0ul, 0); /* * new value of pte */ @@ -157,6 +157,27 @@ static inline unsigned long radix__pte_update(struct mm_struct *mm, return old_pte; } +static inline pte_t radix__ptep_get_and_clear_full(struct mm_struct *mm, + unsigned long addr, + pte_t *ptep, int full) +{ + unsigned long old_pte; + + if (full) { + /* + * If we are trying to clear the pte, we can skip + * the DD1 pte update sequence and batch the tlb flush. The + * tlb flush batching is done by mmu gather code. We + * still keep the cmp_xchg update to make sure we get + * correct R/C bit which might be updated via Nest MMU. + */ + old_pte = __radix_pte_update(ptep, ~0ul, 0); + } else + old_pte = radix__pte_update(mm, addr, ptep, ~0ul, 0, 0); + + return __pte(old_pte); +} + /* * Set the dirty and/or accessed bits atomically in a linux PTE, this * function doesn't need to invalidate tlb. -- 2.7.4