From patchwork Wed Mar 27 17:11:52 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 2352161 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id 858B4400E6 for ; Wed, 27 Mar 2013 17:18:45 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UKtwP-0001q2-DP; Wed, 27 Mar 2013 17:15:13 +0000 Received: from service87.mimecast.com ([91.220.42.44]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UKtub-0000xL-6C for linux-arm-kernel@lists.infradead.org; Wed, 27 Mar 2013 17:13:22 +0000 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Wed, 27 Mar 2013 17:13:17 +0000 Received: from e106331-lin.cambridge.arm.com ([10.1.255.212]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.0); Wed, 27 Mar 2013 17:13:16 +0000 From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 5/5] ARM: arch_timer: stop virtual timer when booted in HYP mode Date: Wed, 27 Mar 2013 17:11:52 +0000 Message-Id: <1364404312-4427-6-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 1.8.1.1 In-Reply-To: <1364404312-4427-1-git-send-email-mark.rutland@arm.com> References: <1364404312-4427-1-git-send-email-mark.rutland@arm.com> X-OriginalArrivalTime: 27 Mar 2013 17:13:16.0811 (UTC) FILETIME=[5F435DB0:01CE2B0E] X-MC-Unique: 113032717131705801 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130327_131321_484425_CD5C6F12 X-CRM114-Status: UNSURE ( 8.81 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [91.220.42.44 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Mark Rutland , cdall@cs.columbia.edu, dave.martin@linaro.org, kgene.kim@samsung.com, swarren@wwwdotorg.org, Marc Zyngier , rob.herring@calxeda.com, santosh.shilimkar@ti.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 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 From: Marc Zyngier When booting the kernel, a bootloader could have left the virtual timer ticking away, potentially generating interrupts. This could be troublesome if the user of the virtual timer is not careful when enabling the interrupt. In order to avoid any surprise, stop the virtual timer from interrupting us when booted in HYP mode, as we'll use the physical timer in this case. Reported-by: Giridhar Maruthy Signed-off-by: Marc Zyngier Signed-off-by: Mark Rutland Cc: Dave Martin --- arch/arm/kernel/hyp-stub.S | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S index dbe2110..4910232 100644 --- a/arch/arm/kernel/hyp-stub.S +++ b/arch/arm/kernel/hyp-stub.S @@ -155,6 +155,11 @@ THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL mov r7, #0 mcrr p15, 4, r7, r7, c14 @ CNTVOFF + + @ Disable virtual timer in case it was counting + mrc p15, 0, r7, c14, c3, 1 @ CNTV_CTL + bic r7, #1 @ Clear ENABLE + mcr p15, 0, r7, c14, c3, 1 @ CNTV_CTL 1: #endif