From patchwork Sun Feb 23 19:29:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qais Yousef X-Patchwork-Id: 11399017 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B0A6814E3 for ; Sun, 23 Feb 2020 19:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8FFA920836 for ; Sun, 23 Feb 2020 19:29:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726534AbgBWT3y (ORCPT ); Sun, 23 Feb 2020 14:29:54 -0500 Received: from foss.arm.com ([217.140.110.172]:51252 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726208AbgBWT3y (ORCPT ); Sun, 23 Feb 2020 14:29:54 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3D692101E; Sun, 23 Feb 2020 11:29:54 -0800 (PST) Received: from e107158-lin.cambridge.arm.com (e107158-lin.cambridge.arm.com [10.1.195.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 437293F6CF; Sun, 23 Feb 2020 11:29:52 -0800 (PST) From: Qais Yousef To: Thomas Gleixner Cc: "Paul E . McKenney" , Qais Yousef , Helge Deller , Michael Ellerman , "David S. Miller" , Juergen Gross , Mark Rutland , Lorenzo Pieralisi , xen-devel@lists.xenproject.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 01/15] cpu: Add new {add,remove}_cpu() functions Date: Sun, 23 Feb 2020 19:29:28 +0000 Message-Id: <20200223192942.18420-2-qais.yousef@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200223192942.18420-1-qais.yousef@arm.com> References: <20200223192942.18420-1-qais.yousef@arm.com> Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org The new functions use device_{online,offline}() which are userspace safe. This is in preparation to move cpu_{up, down} kernel users to use a safer interface that is not racy with userspace. Suggested-by: "Paul E. McKenney" Signed-off-by: Qais Yousef CC: Thomas Gleixner CC: "Paul E. McKenney" CC: Helge Deller CC: Michael Ellerman CC: "David S. Miller" CC: Juergen Gross CC: Mark Rutland CC: Lorenzo Pieralisi CC: xen-devel@lists.xenproject.org CC: linux-parisc@vger.kernel.org CC: sparclinux@vger.kernel.org CC: linuxppc-dev@lists.ozlabs.org CC: linux-arm-kernel@lists.infradead.org CC: x86@kernel.org CC: linux-kernel@vger.kernel.org --- include/linux/cpu.h | 2 ++ kernel/cpu.c | 24 ++++++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 1ca2baf817ed..cf8cf38dca43 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -89,6 +89,7 @@ extern ssize_t arch_cpu_release(const char *, size_t); #ifdef CONFIG_SMP extern bool cpuhp_tasks_frozen; int cpu_up(unsigned int cpu); +int add_cpu(unsigned int cpu); void notify_cpu_starting(unsigned int cpu); extern void cpu_maps_update_begin(void); extern void cpu_maps_update_done(void); @@ -118,6 +119,7 @@ extern void cpu_hotplug_disable(void); extern void cpu_hotplug_enable(void); void clear_tasks_mm_cpumask(int cpu); int cpu_down(unsigned int cpu); +int remove_cpu(unsigned int cpu); #else /* CONFIG_HOTPLUG_CPU */ diff --git a/kernel/cpu.c b/kernel/cpu.c index 9c706af713fb..069802f7010f 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1057,6 +1057,18 @@ int cpu_down(unsigned int cpu) } EXPORT_SYMBOL(cpu_down); +int remove_cpu(unsigned int cpu) +{ + int ret; + + lock_device_hotplug(); + ret = device_offline(get_cpu_device(cpu)); + unlock_device_hotplug(); + + return ret; +} +EXPORT_SYMBOL_GPL(remove_cpu); + #else #define takedown_cpu NULL #endif /*CONFIG_HOTPLUG_CPU*/ @@ -1209,6 +1221,18 @@ int cpu_up(unsigned int cpu) } EXPORT_SYMBOL_GPL(cpu_up); +int add_cpu(unsigned int cpu) +{ + int ret; + + lock_device_hotplug(); + ret = device_online(get_cpu_device(cpu)); + unlock_device_hotplug(); + + return ret; +} +EXPORT_SYMBOL_GPL(add_cpu); + #ifdef CONFIG_PM_SLEEP_SMP static cpumask_var_t frozen_cpus; From patchwork Sun Feb 23 19:29:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qais Yousef X-Patchwork-Id: 11399021 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 349C314BC for ; Sun, 23 Feb 2020 19:30:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E5312187F for ; Sun, 23 Feb 2020 19:30:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727278AbgBWTaK (ORCPT ); Sun, 23 Feb 2020 14:30:10 -0500 Received: from foss.arm.com ([217.140.110.172]:51440 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727229AbgBWTaJ (ORCPT ); Sun, 23 Feb 2020 14:30:09 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5239611FB; Sun, 23 Feb 2020 11:30:09 -0800 (PST) Received: from e107158-lin.cambridge.arm.com (e107158-lin.cambridge.arm.com [10.1.195.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F37B13F6CF; Sun, 23 Feb 2020 11:30:07 -0800 (PST) From: Qais Yousef To: Thomas Gleixner Cc: "Paul E . McKenney" , Qais Yousef , "James E.J. Bottomley" , Helge Deller , Richard Fontana , Armijn Hemel , Greg Kroah-Hartman , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 10/15] parisc: Replace cpu_up/down with add/remove_cpu Date: Sun, 23 Feb 2020 19:29:37 +0000 Message-Id: <20200223192942.18420-11-qais.yousef@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200223192942.18420-1-qais.yousef@arm.com> References: <20200223192942.18420-1-qais.yousef@arm.com> Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org The core device API performs extra housekeeping bits that are missing from directly calling cpu_up/down. See commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") for an example description of what might go wrong. This also prepares to make cpu_up/down a private interface for anything but the cpu subsystem. Acked-by: Helge Deller Signed-off-by: Qais Yousef CC: "James E.J. Bottomley" CC: Helge Deller CC: Richard Fontana CC: Armijn Hemel CC: Greg Kroah-Hartman CC: Thomas Gleixner CC: linux-parisc@vger.kernel.org CC: linux-kernel@vger.kernel.org --- Helge, this now uses add_cpu() which you should be CCed on. I wasn't sure if I can keep your Ack or remove it in this case. Please let me know if you need more clarification. arch/parisc/kernel/processor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c index 13f771f74ee3..7f2d0c0ecc80 100644 --- a/arch/parisc/kernel/processor.c +++ b/arch/parisc/kernel/processor.c @@ -212,7 +212,7 @@ static int __init processor_probe(struct parisc_device *dev) #ifdef CONFIG_SMP if (cpuid) { set_cpu_present(cpuid, true); - cpu_up(cpuid); + add_cpu(cpuid); } #endif