From patchwork Wed Jun 25 15:40:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Capper X-Patchwork-Id: 4421491 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6BD80BEEAA for ; Wed, 25 Jun 2014 15:43:26 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 97D622038D for ; Wed, 25 Jun 2014 15:43:25 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AFCB62038C for ; Wed, 25 Jun 2014 15:43:24 +0000 (UTC) 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 1WzpJz-0002J2-Qo; Wed, 25 Jun 2014 15:41:15 +0000 Received: from mail-wg0-f46.google.com ([74.125.82.46]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WzpJm-00026G-Fd for linux-arm-kernel@lists.infradead.org; Wed, 25 Jun 2014 15:41:05 +0000 Received: by mail-wg0-f46.google.com with SMTP id y10so2255740wgg.17 for ; Wed, 25 Jun 2014 08:40:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=8lGkkvQgLrkI28BkH4CkBlZR2rKj4O5UvxC1WiFoNvY=; b=TJnmi46GPbEjYSfD8C5cU9Sfym1UIsjHG16nM8gZi92lY8cNt6RTs1EuqwvrMaGR5Y mR8MKuVUb0dFXCpRyi78XCk9FnGSMC9Kemvo/Ffip9G9fMI0b/wKgwDNbSeT2mrroEIM zZI2KGWVoMfn8Fc+lv8aTcUlvlu+1vcNK1sF1fuMIKcB4SrvQJv8BfPzKT6+CloW35SU Y+UCShuskisah8aZh3+4pTxT37/r5kskhzq3srBpzgHn6dWpThYzv56bIS3Gw415d1UP 7pqim57Je8XJH93bqbBn70F1YMCNrSjNwFiAedNeml+LgJFf0FO9KT83Upbx8nPtR6K5 DafQ== X-Gm-Message-State: ALoCoQmsf6KeTMniygLYmCKFenAvVldJuVpJ/0cwNQAwfga+aRbh3BU9OhUiexUuth7lYRe60nUp X-Received: by 10.194.89.40 with SMTP id bl8mr10573861wjb.90.1403710843608; Wed, 25 Jun 2014 08:40:43 -0700 (PDT) Received: from marmot.wormnet.eu (marmot.wormnet.eu. [188.246.204.87]) by mx.google.com with ESMTPSA id i3sm54967269wiz.13.2014.06.25.08.40.42 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Jun 2014 08:40:42 -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: [PATCH 5/6] arm64: mm: Enable HAVE_RCU_TABLE_FREE logic Date: Wed, 25 Jun 2014 16:40:23 +0100 Message-Id: <1403710824-24340-6-git-send-email-steve.capper@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1403710824-24340-1-git-send-email-steve.capper@linaro.org> References: <1403710824-24340-1-git-send-email-steve.capper@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140625_084102_680159_59EEA8E8 X-CRM114-Status: GOOD ( 11.94 ) X-Spam-Score: -0.7 (/) Cc: anders.roxell@linaro.org, peterz@infradead.org, gary.robertson@linaro.org, will.deacon@arm.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+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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/arm64/Kconfig | 1 + arch/arm64/include/asm/tlb.h | 18 ++++++++++++++++-- 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a474de34..e1d2eef 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -49,6 +49,7 @@ config ARM64 select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_RCU_TABLE_FREE select HAVE_SYSCALL_TRACEPOINTS select IRQ_DOMAIN select MODULES_USE_ELF_RELA diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h index 80e2c08..8e4dde5 100644 --- a/arch/arm64/include/asm/tlb.h +++ b/arch/arm64/include/asm/tlb.h @@ -23,6 +23,20 @@ #include +#include +#include + +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + +#define tlb_remove_entry(tlb, entry) tlb_remove_table(tlb, entry) +static inline void __tlb_remove_table(void *_table) +{ + free_page_and_swap_cache((struct page *)_table); +} +#else +#define tlb_remove_entry(tlb, entry) tlb_remove_page(tlb, entry) +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ + /* * There's three ways the TLB shootdown code is used: * 1. Unmapping a range of vmas. See zap_page_range(), unmap_region(). @@ -88,7 +102,7 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, { pgtable_page_dtor(pte); tlb_add_flush(tlb, addr); - tlb_remove_page(tlb, pte); + tlb_remove_entry(tlb, pte); } #ifndef CONFIG_ARM64_64K_PAGES @@ -96,7 +110,7 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr) { tlb_add_flush(tlb, addr); - tlb_remove_page(tlb, virt_to_page(pmdp)); + tlb_remove_entry(tlb, virt_to_page(pmdp)); } #endif