From patchwork Thu Aug 21 15:43:29 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Capper X-Patchwork-Id: 35769 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-pd0-f198.google.com (mail-pd0-f198.google.com [209.85.192.198]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id AC75E20540 for ; Thu, 21 Aug 2014 15:45:38 +0000 (UTC) Received: by mail-pd0-f198.google.com with SMTP id fp1sf74324979pdb.1 for ; Thu, 21 Aug 2014 08:45:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:delivered-to:from:to:subject:date:message-id :in-reply-to:references:cc:precedence:list-id:list-unsubscribe :list-archive:list-post:list-help:list-subscribe:mime-version:sender :errors-to:x-original-sender:x-original-authentication-results :mailing-list:content-type:content-transfer-encoding; bh=2pRaHvpxdftnk4CKIaoHRYBIJ+G67gYlruB/l2n+zN8=; b=FCimZIbHKsO04NxDfBJptrTT2+e2CW8Ey2hwwH9vOKxPWyl2TlhZ+fo+Jdml1mDUXE EuwSQ3EdnF2/l+v0jh1bvQzZg7uz8jSrf1YL0RE8SgCVEOo+HXV0qugV7jwHH7P0Jxzo wVXcEgT9cVt0asGQxpGvPdQenUNpNyV5zGDksRoq01D1fnKDz46B0Vp6UXie63JVJ3+2 nceJbvMWJG5MbQYVwnJ1psm6xWydddg1hFQBBEvSguEHfmrDO3/O10U4KU36rb08Yu4y Vl3BuafoHYjmHp1we5gbA5a33MI2yj3IjIrLLB2YxhUlDd9TWUEKuduQZMLAwkMYaFg3 BFSg== X-Gm-Message-State: ALoCoQn6u1mhY0RGCZV/mEiQWc8TpYIaFNwLIKRy8+6FtmfPQub2+R6kDoJ/f7ZDY4Trmcw9OiLw X-Received: by 10.66.66.170 with SMTP id g10mr28129496pat.12.1408635938015; Thu, 21 Aug 2014 08:45:38 -0700 (PDT) X-BeenThere: patchwork-forward@linaro.org Received: by 10.140.89.5 with SMTP id u5ls758473qgd.72.gmail; Thu, 21 Aug 2014 08:45:37 -0700 (PDT) X-Received: by 10.52.119.229 with SMTP id kx5mr964615vdb.40.1408635937907; Thu, 21 Aug 2014 08:45:37 -0700 (PDT) Received: from mail-vc0-f181.google.com (mail-vc0-f181.google.com [209.85.220.181]) by mx.google.com with ESMTPS id yw7si12462108vdb.63.2014.08.21.08.45.37 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 21 Aug 2014 08:45:37 -0700 (PDT) Received-SPF: pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.220.181 as permitted sender) client-ip=209.85.220.181; Received: by mail-vc0-f181.google.com with SMTP id lf12so11052656vcb.12 for ; Thu, 21 Aug 2014 08:45:37 -0700 (PDT) X-Received: by 10.220.114.66 with SMTP id d2mr42440591vcq.27.1408635937844; Thu, 21 Aug 2014 08:45:37 -0700 (PDT) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patch@linaro.org Received: by 10.221.45.67 with SMTP id uj3csp146024vcb; Thu, 21 Aug 2014 08:45:37 -0700 (PDT) X-Received: by 10.68.242.202 with SMTP id ws10mr61915907pbc.32.1408635936942; Thu, 21 Aug 2014 08:45:36 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id yl3si37032555pac.53.2014.08.21.08.45.36 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Aug 2014 08:45:36 -0700 (PDT) Received-SPF: none (google.com: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org does not designate permitted sender hosts) client-ip=2001:1868:205::9; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XKUXY-0000vz-DL; Thu, 21 Aug 2014 15:44:40 +0000 Received: from mail-wi0-f171.google.com ([209.85.212.171]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XKUX2-0000Oy-W4 for linux-arm-kernel@lists.infradead.org; Thu, 21 Aug 2014 15:44:09 +0000 Received: by mail-wi0-f171.google.com with SMTP id hi2so8910385wib.4 for ; Thu, 21 Aug 2014 08:43:46 -0700 (PDT) X-Received: by 10.194.84.69 with SMTP id w5mr69939338wjy.0.1408635826733; Thu, 21 Aug 2014 08:43:46 -0700 (PDT) Received: from marmot.wormnet.eu (marmot.wormnet.eu. [188.246.204.87]) by mx.google.com with ESMTPSA id wi9sm67591585wjc.23.2014.08.21.08.43.45 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Aug 2014 08:43:45 -0700 (PDT) From: Steve Capper To: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, linux@arm.linux.org.uk, linux-arch@vger.kernel.org, linux-mm@kvack.org Subject: [PATH V2 3/6] arm: mm: Enable HAVE_RCU_TABLE_FREE logic Date: Thu, 21 Aug 2014 16:43:29 +0100 Message-Id: <1408635812-31584-4-git-send-email-steve.capper@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1408635812-31584-1-git-send-email-steve.capper@linaro.org> References: <1408635812-31584-1-git-send-email-steve.capper@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140821_084409_200671_98D90FDA X-CRM114-Status: GOOD ( 14.19 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.212.171 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 RCVD_IN_MSPIKE_H3 RBL: Good reputation (+3) [209.85.212.171 listed in wl.mailspike.net] -0.0 RCVD_IN_MSPIKE_WL Mailspike good senders Cc: mark.rutland@arm.com, anders.roxell@linaro.org, peterz@infradead.org, gary.robertson@linaro.org, will.deacon@arm.com, mgorman@suse.de, dann.frazier@canonical.com, Steve Capper , akpm@linux-foundation.org, christoffer.dall@linaro.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: , List-Help: , List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: steve.capper@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.220.181 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 In order to implement fast_get_user_pages we need to ensure that the page table walker is protected from page table pages being freed from under it. This patch enables HAVE_RCU_TABLE_FREE, any page table pages belonging to address spaces with multiple users will be call_rcu_sched freed. Meaning that disabling interrupts will block the free and protect the fast gup page walker. Signed-off-by: Steve Capper --- arch/arm/Kconfig | 1 + arch/arm/include/asm/tlb.h | 38 ++++++++++++++++++++++++++++++++++++-- 2 files changed, 37 insertions(+), 2 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c49a775..cc740d2 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -60,6 +60,7 @@ config ARM select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE) select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_SYSCALL_TRACEPOINTS select HAVE_UID16 diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h index f1a0dac..3cadb72 100644 --- a/arch/arm/include/asm/tlb.h +++ b/arch/arm/include/asm/tlb.h @@ -35,12 +35,39 @@ #define MMU_GATHER_BUNDLE 8 +#ifdef CONFIG_HAVE_RCU_TABLE_FREE +static inline void __tlb_remove_table(void *_table) +{ + free_page_and_swap_cache((struct page *)_table); +} + +struct mmu_table_batch { + struct rcu_head rcu; + unsigned int nr; + void *tables[0]; +}; + +#define MAX_TABLE_BATCH \ + ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *)) + +extern void tlb_table_flush(struct mmu_gather *tlb); +extern void tlb_remove_table(struct mmu_gather *tlb, void *table); + +#define tlb_remove_entry(tlb, entry) tlb_remove_table(tlb, entry) +#else +#define tlb_remove_entry(tlb, entry) tlb_remove_page(tlb, entry) +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ + /* * TLB handling. This allows us to remove pages from the page * tables, and efficiently handle the TLB issues. */ struct mmu_gather { struct mm_struct *mm; +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + struct mmu_table_batch *batch; + unsigned int need_flush; +#endif unsigned int fullmm; struct vm_area_struct *vma; unsigned long start, end; @@ -101,6 +128,9 @@ static inline void __tlb_alloc_page(struct mmu_gather *tlb) static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) { tlb_flush(tlb); +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + tlb_table_flush(tlb); +#endif } static inline void tlb_flush_mmu_free(struct mmu_gather *tlb) @@ -129,6 +159,10 @@ tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long start tlb->pages = tlb->local; tlb->nr = 0; __tlb_alloc_page(tlb); + +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + tlb->batch = NULL; +#endif } static inline void @@ -205,7 +239,7 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, tlb_add_flush(tlb, addr + SZ_1M); #endif - tlb_remove_page(tlb, pte); + tlb_remove_entry(tlb, pte); } static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, @@ -213,7 +247,7 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, { #ifdef CONFIG_ARM_LPAE tlb_add_flush(tlb, addr); - tlb_remove_page(tlb, virt_to_page(pmdp)); + tlb_remove_entry(tlb, virt_to_page(pmdp)); #endif }