From patchwork Wed Dec 19 15:11:07 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 1895971 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 23A5CDF230 for ; Wed, 19 Dec 2012 15:16:56 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TlLKv-0004o2-Lv; Wed, 19 Dec 2012 15:13:33 +0000 Received: from service87.mimecast.com ([91.220.42.44]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TlLJz-0004J6-K6 for linux-arm-kernel@lists.infradead.org; Wed, 19 Dec 2012 15:12:37 +0000 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Wed, 19 Dec 2012 15:12:33 +0000 Received: from localhost.localdomain ([10.1.255.212]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.0); Wed, 19 Dec 2012 15:12:31 +0000 From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Subject: [PATCHv2 08/11] arm: arch_timer: add arch_counter_set_user_access Date: Wed, 19 Dec 2012 15:11:07 +0000 Message-Id: <1355929870-30252-9-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1355929870-30252-1-git-send-email-mark.rutland@arm.com> References: <1355929870-30252-1-git-send-email-mark.rutland@arm.com> X-OriginalArrivalTime: 19 Dec 2012 15:12:31.0233 (UTC) FILETIME=[44146710:01CDDDFB] X-MC-Unique: 112121915123302801 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20121219_101236_288966_21AE2272 X-CRM114-Status: GOOD ( 11.04 ) 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: marc.zyngier@arm.com, catalin.marinas@arm.com, Mark Rutland , will.deacon@arm.com, sboyd@codeaurora.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Several bits in CNTKCTL reset to 0, including PL0VTEN. For platforms using the generic timer which wish to have a fast gettimeofday vDSO implementation, these bits must be set to 1 by the kernel. On other platforms, the bootloader might enable userspace access when we don't want it. This patch adds arch_counter_set_user_access, which sets the PL0 access permissions to that required by the platform. For arm, this currently means disabling all userspace access. Signed-off-by: Mark Rutland --- arch/arm/include/asm/arch_timer.h | 11 +++++++++++ arch/arm/kernel/arch_timer.c | 2 ++ 2 files changed, 13 insertions(+), 0 deletions(-) diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h index 701f2b7..05e3593 100644 --- a/arch/arm/include/asm/arch_timer.h +++ b/arch/arm/include/asm/arch_timer.h @@ -108,6 +108,17 @@ static inline u64 arch_counter_get_cntvct(void) return cval; } +static inline void __cpuinit arch_counter_set_user_access(void) +{ + u32 cntkctl; + + asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl)); + + /* disable user access to everything */ + cntkctl &= ~((3 << 8) | (7 << 0)); + + asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl)); +} #else static inline int arch_timer_of_register(void) diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index 834d347..4f39e68 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -155,6 +155,8 @@ static int __cpuinit arch_timer_setup(struct clock_event_device *clk) enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0); } + arch_counter_set_user_access(); + return 0; }