From patchwork Mon Jun 17 20:35:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aaro Koskinen X-Patchwork-Id: 11000453 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 40F1B6C5 for ; Mon, 17 Jun 2019 20:35:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 31E06288E6 for ; Mon, 17 Jun 2019 20:35:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 259F6289F2; Mon, 17 Jun 2019 20:35:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 028EF288DA for ; Mon, 17 Jun 2019 20:35:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=/IaCbkdbN90D8dyqPpYCv77MtRh26XREuUO1I8xfG0M=; b=YIZ qxgvsaQ+yeKsAhthtWeRvD+7dIBL8fw5pguVGIHg/xbCKrGSwea/GN2GXSYau9K9L5KeaVPWd21QQ UyS+/Rpks/UPaF2kduAl5aHWwVKWpRwqV0ZqPpE6iuUe7kCqu9K+zDzQGhMwSPvsMwH5USZdqfHuo /fostvgFnqSVw8YjR+P6nshS0jIAJaLoJmfjFwgtvV7qqR1uH2sEBBC9l2RYRNs+Z8bIQ5YSGK+ku cIRnqF0a7gpnjmh48z46cesoKVpoqnelpKFE5pxQI+mNaXrtSYSzyVCp/HhR2Yx4g8t7aI8Z6zZek C3CWSd4ObII+ngGDXrvx1JR/S4L4mJQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hcyLk-0002mu-5R; Mon, 17 Jun 2019 20:35:32 +0000 Received: from emh01.mail.saunalahti.fi ([62.142.5.107]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hcyLe-0002lW-Tt for linux-arm-kernel@lists.infradead.org; Mon, 17 Jun 2019 20:35:29 +0000 Received: from localhost.localdomain (85-76-83-177-nat.elisa-mobile.fi [85.76.83.177]) by emh01.mail.saunalahti.fi (Postfix) with ESMTP id 180A72004A; Mon, 17 Jun 2019 23:35:19 +0300 (EEST) From: Aaro Koskinen To: Catalin Marinas , Will Deacon , James Morse , Jayachandran Chandrasekharan Nair Subject: [PATCH v2 1/2] arm64: Improve parking of stopped CPUs Date: Mon, 17 Jun 2019 23:35:18 +0300 Message-Id: <20190617203519.328-1-aaro.koskinen@iki.fi> X-Mailer: git-send-email 2.17.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190617_133527_135112_AB8F98E5 X-CRM114-Status: UNSURE ( 7.93 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Aaro Koskinen , linux-arm-kernel@lists.infradead.org, Aaro Koskinen MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jayachandran C The current code puts the stopped cpus in an 'yield' instruction loop. Using a busy loop here is unnecessary, we can use the cpu_park_loop() function here to do a wfi/wfe. Signed-off-by: Jayachandran C Signed-off-by: Aaro Koskinen Acked-by: Will Deacon --- v2: Add Acked-by v1: https://patchwork.kernel.org/patch/10988099/ arch/arm64/kernel/smp.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index bb4b3f07761a..1a1b96a50245 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -854,9 +854,7 @@ static void ipi_cpu_stop(unsigned int cpu) local_daif_mask(); sdei_mask_local_cpu(); - - while (1) - cpu_relax(); + cpu_park_loop(); } #ifdef CONFIG_KEXEC_CORE From patchwork Mon Jun 17 20:35:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aaro Koskinen X-Patchwork-Id: 11000455 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F02296C5 for ; Mon, 17 Jun 2019 20:35:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E1D642875C for ; Mon, 17 Jun 2019 20:35:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D3F882267B; Mon, 17 Jun 2019 20:35:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6319F288DA for ; Mon, 17 Jun 2019 20:35:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=AJV8M/nXjyPQqv7kjrnYfdlGMzePkE+VKKEHH8lyksQ=; b=RmMO1r9jPWO92Y2ahXeDpCrbuS ZQ4JDDAdpgavFGZAKzujdJB7TBUfHvjrJXzuvz9GLO3Hy2jIjnP2O4yZdqNSB/z2df0ECwVucz8gF O8boHTbgUjyQQmifyRJa8PaKBd/uOq41HaUwirqI0eSsE0ZVxmLZSVVfXRT7s1bb4GJNU0i3t6KRJ I/jGonohkrmeZz1efhnXAAKRC6VLg4HW2f+D9c9nmlPTremFuuaICMd5u//VSq2IJIx6OBtRDJjyH m8Q/LfEFbDs4wWWTMCkwZuwP6qRgb8OyL+1cyjH70ZAx+fRAuVktoSimEX8nSlUPoJeEJblGxBUCV Jo9JlLyg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hcyLu-0002wP-AF; Mon, 17 Jun 2019 20:35:42 +0000 Received: from emh01.mail.saunalahti.fi ([62.142.5.107]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hcyLf-0002lY-NJ for linux-arm-kernel@lists.infradead.org; Mon, 17 Jun 2019 20:35:29 +0000 Received: from localhost.localdomain (85-76-83-177-nat.elisa-mobile.fi [85.76.83.177]) by emh01.mail.saunalahti.fi (Postfix) with ESMTP id BF33D20005; Mon, 17 Jun 2019 23:35:20 +0300 (EEST) From: Aaro Koskinen To: Catalin Marinas , Will Deacon , James Morse , Jayachandran Chandrasekharan Nair Subject: [PATCH v2 2/2] arm64: Implement panic_smp_self_stop() Date: Mon, 17 Jun 2019 23:35:19 +0300 Message-Id: <20190617203519.328-2-aaro.koskinen@iki.fi> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20190617203519.328-1-aaro.koskinen@iki.fi> References: <20190617203519.328-1-aaro.koskinen@iki.fi> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190617_133527_927556_91E7D1A3 X-CRM114-Status: UNSURE ( 8.92 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Aaro Koskinen , linux-arm-kernel@lists.infradead.org, Aaro Koskinen MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Aaro Koskinen Currently arm64 uses the default implementation of panic_smp_self_stop() where the CPU runs in a cpu_relax() loop unable to receive IPIs anymore. As a result, when two CPUs panic() simultaneously we get "SMP: failed to stop secondary CPUs" warnings and extra delays before a reset, because smp_send_stop() still tries to stop the other paniced CPU. Provide an implementation of panic_smp_self_stop() that is identical to the IPI CPU stop handler, so that the online status of stopped CPUs gets properly updated. Signed-off-by: Aaro Koskinen Acked-by: Will Deacon --- v2: Update the commit log Rename ipi_cpu_stop() to local_cpu_stop() and make it void func Add a comment for panic_smp_self_stop() v1: https://patchwork.kernel.org/patch/10988103/ arch/arm64/kernel/smp.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 1a1b96a50245..1ac4aa34ffb6 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -845,18 +845,25 @@ void arch_irq_work_raise(void) } #endif -/* - * ipi_cpu_stop - handle IPI from smp_send_stop() - */ -static void ipi_cpu_stop(unsigned int cpu) +static void local_cpu_stop(void) { - set_cpu_online(cpu, false); + set_cpu_online(smp_processor_id(), false); local_daif_mask(); sdei_mask_local_cpu(); cpu_park_loop(); } +/* + * We need to implement panic_smp_self_stop() for parallel panic() calls, so + * that cpu_online_mask gets correctly updated and smp_send_stop() can skip + * CPUs that have already stopped themselves. + */ +void panic_smp_self_stop(void) +{ + local_cpu_stop(); +} + #ifdef CONFIG_KEXEC_CORE static atomic_t waiting_for_crash_ipi = ATOMIC_INIT(0); #endif @@ -907,7 +914,7 @@ void handle_IPI(int ipinr, struct pt_regs *regs) case IPI_CPU_STOP: irq_enter(); - ipi_cpu_stop(cpu); + local_cpu_stop(); irq_exit(); break;