From patchwork Fri Sep 5 11:22:19 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 4851521 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 ECF4D9F2EC for ; Fri, 5 Sep 2014 11:27:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DE3A32021A for ; Fri, 5 Sep 2014 11:27:06 +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 20229201D3 for ; Fri, 5 Sep 2014 11:27:02 +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 1XPrcL-0004G1-At; Fri, 05 Sep 2014 11:23:49 +0000 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XPrcH-00043O-QL for linux-arm-kernel@lists.infradead.org; Fri, 05 Sep 2014 11:23:46 +0000 Received: from leverpostej.cambridge.arm.com (leverpostej.cambridge.arm.com [10.1.205.151]) by cam-admin0.cambridge.arm.com (8.12.6/8.12.6) with ESMTP id s85BMPwq016013; Fri, 5 Sep 2014 12:22:28 +0100 (BST) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/2] arm: psci: don't call CPU_OFF blindly Date: Fri, 5 Sep 2014 12:22:19 +0100 Message-Id: <1409916139-20127-3-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1409916139-20127-1-git-send-email-mark.rutland@arm.com> References: <1409916139-20127-1-git-send-email-mark.rutland@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140905_042346_230412_A3A5BD2E X-CRM114-Status: GOOD ( 16.73 ) X-Spam-Score: -6.7 (------) Cc: Mark Rutland , robh@kernel.org, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, catalin.marinas@arm.com, will.deacon@arm.com, ashwin.chaugule@linaro.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=-3.6 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 The generic PSCI operations for arm check the presence of a CPU_OFF ID far too late, and in the absence of an ID will panic(), rather than producing a warning. This patch adds a psci_cpu_disable callback which tests the presence of a CPU_OFF id. As this is called earlier than psci_cpu_die, the failure can be handled gracefully without brining down the system. Additionally a check is added for a UP trusted OS in the presence of PSCI 0.2+. Full support will require the use of MIGRATE, but for now rejecting hotplug will prevent psci_cpu_die from brining down the system. The now redundant check for scpi_ops.cpu_off is removed from psci_cpu_die. At the same time, the whitespace is corrected from seven spaces to tabs. Signed-off-by: Mark Rutland Cc: Ashwin Chaugule Cc: Rob Herring Cc: Stefano Stabellini Cc: Ian Campbell Cc: Christoffer Dall Cc: Will Deacon Cc: Catalin Marinas --- arch/arm/kernel/psci_smp.c | 36 +++++++++++++++++++++++++++++------- 1 file changed, 29 insertions(+), 7 deletions(-) Stefano, I've followed your lead with the __ref annotation here, but I couldn't figure out why they exist on cpu_die and cpu_kill; it feels rather dodgy. Do you know why they were added, or if they are superfluous? There are some other cleanups that should happen here (static, CPU_METHOD_OF_DECLARE), but those will come as a later cleanups series. diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c index 28a1db4..2b00d3c 100644 --- a/arch/arm/kernel/psci_smp.c +++ b/arch/arm/kernel/psci_smp.c @@ -56,17 +56,38 @@ static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle) } #ifdef CONFIG_HOTPLUG_CPU +int __ref psci_cpu_disable(unsigned int cpu) +{ + /* Fail early if we don't have CPU_OFF support */ + if (!psci_ops.cpu_off) + return -EOPNOTSUPP; + + /* + * In the presence of a UP trusted OS, it might not be possible to + * hotplug certain CPUs, and CPU_OFF may return (which would be bad). + * Supporting a UP trusted OS requires careful use of + * MIGRATE_INFO_UP_CPU and MIGRATE, so for now fail in the presence of + * a UP Trusted OS. + */ + if (psci_ops.migrate_info_type && + psci_ops.migrate_info_type() != PSCI_0_2_TOS_MP) { + pr_warn("Unable to handle UP trusted OS\n"); + return -EPERM; + } + + return 0; +} + void __ref psci_cpu_die(unsigned int cpu) { - const struct psci_power_state ps = { - .type = PSCI_POWER_STATE_TYPE_POWER_DOWN, - }; + const struct psci_power_state ps = { + .type = PSCI_POWER_STATE_TYPE_POWER_DOWN, + }; - if (psci_ops.cpu_off) - psci_ops.cpu_off(ps); + psci_ops.cpu_off(ps); - /* We should never return */ - panic("psci: cpu %d failed to shutdown\n", cpu); + /* We should never return */ + panic("psci: cpu %d failed to shutdown\n", cpu); } int __ref psci_cpu_kill(unsigned int cpu) @@ -109,6 +130,7 @@ bool __init psci_smp_available(void) struct smp_operations __initdata psci_smp_ops = { .smp_boot_secondary = psci_boot_secondary, #ifdef CONFIG_HOTPLUG_CPU + .cpu_disable = psci_cpu_disable, .cpu_die = psci_cpu_die, .cpu_kill = psci_cpu_kill, #endif