From patchwork Thu Aug 28 14:45:06 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Capper X-Patchwork-Id: 4805191 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 04C559F2A9 for ; Thu, 28 Aug 2014 14:51:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 61C94200E0 for ; Thu, 28 Aug 2014 14:51:16 +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 97FAB200FE for ; Thu, 28 Aug 2014 14:51:14 +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 1XN0yG-0004K2-V1; Thu, 28 Aug 2014 14:46:40 +0000 Received: from casper.infradead.org ([2001:770:15f::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XN0xb-0003kr-4V for linux-arm-kernel@bombadil.infradead.org; Thu, 28 Aug 2014 14:45:59 +0000 Received: from mail-we0-f170.google.com ([74.125.82.170]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XN0xY-000561-05 for linux-arm-kernel@lists.infradead.org; Thu, 28 Aug 2014 14:45:57 +0000 Received: by mail-we0-f170.google.com with SMTP id p10so885531wes.15 for ; Thu, 28 Aug 2014 07:45:31 -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=TnqM4ZmU51V7gbfzkQfTRwAxEiGqKkHbGitbfUF2yCg=; b=YYyXk8MFN0TvYoFSUqXRNUFbtcWckS9T1cw6S9a31AsrUi48kWJ7SbsqoWvwFZBwOq /AmjlYbnyz94/rRLz3U1IL9hVkD9ancoMLAmZPe5PbEM/BGS7qBOivQg/tOjK+sLQBfW thqAKex7F2aHvsOTqd7uAEJSSCJ9Pg/Qt+XgPNV2KiwrvP0vbS6YURwTqaKKfRhpV5+s HTqRM+VFuy1K7WGiB6ZFZbbebOCT1huGvjPqw9jk0LbAVkpK9MinNVpyk2yjJp378uNT eVaREGtbAL2h3w48tCO9VTQP2AEt4wssuHegd6iXWEpuzuhVureAgQlT7T8vBKOxUTa7 61ZQ== X-Gm-Message-State: ALoCoQk0OXoxf/gGPnBkc8fqA8no/c6XPk48r2i5Vfry7DgJQdWPtU8WH20pgHCzuY5yN8PkPa8n X-Received: by 10.194.57.237 with SMTP id l13mr5962415wjq.102.1409237130207; Thu, 28 Aug 2014 07:45:30 -0700 (PDT) Received: from marmot.wormnet.eu (marmot.wormnet.eu. [188.246.204.87]) by mx.google.com with ESMTPSA id js2sm10538153wjc.9.2014.08.28.07.45.28 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 28 Aug 2014 07:45:29 -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, akpm@linux-foundation.org Subject: [PATCH V3 5/6] arm64: mm: Enable HAVE_RCU_TABLE_FREE logic Date: Thu, 28 Aug 2014 15:45:06 +0100 Message-Id: <1409237107-24228-6-git-send-email-steve.capper@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1409237107-24228-1-git-send-email-steve.capper@linaro.org> References: <1409237107-24228-1-git-send-email-steve.capper@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140828_154556_059806_D262EDFF X-CRM114-Status: GOOD ( 13.03 ) X-Spam-Score: -2.6 (--) 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 , 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, RCVD_IN_DNSWL_NONE, 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 Tested-by: Dann Frazier Acked-by: Catalin Marinas --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/tlb.h | 20 +++++++++++++++++--- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index fd4e81a..ce9062b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -54,6 +54,7 @@ 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 62731ef..a82c0c5 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); } #if CONFIG_ARM64_PGTABLE_LEVELS > 2 @@ -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 @@ -105,7 +119,7 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp, unsigned long addr) { tlb_add_flush(tlb, addr); - tlb_remove_page(tlb, virt_to_page(pudp)); + tlb_remove_entry(tlb, virt_to_page(pudp)); } #endif