From patchwork Wed Jun 29 12:21:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Gonzalez X-Patchwork-Id: 9205015 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2319460757 for ; Wed, 29 Jun 2016 12:23:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1411228653 for ; Wed, 29 Jun 2016 12:23:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 08BD42865A; Wed, 29 Jun 2016 12:23:36 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 966C328653 for ; Wed, 29 Jun 2016 12:23:35 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bIEVN-0005Kl-AO; Wed, 29 Jun 2016 12:22:09 +0000 Received: from a.mx.sdesigns.eu ([78.31.43.6]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bIEVJ-0005A9-UU for linux-arm-kernel@lists.infradead.org; Wed, 29 Jun 2016 12:22:07 +0000 Received: from [172.27.0.114] (summerrain.france.sdesigns.com [172.27.0.114]) by hibou.france.sdesigns.com (Postfix) with ESMTP id 352371C0FFF; Wed, 29 Jun 2016 14:21:42 +0200 (CEST) Subject: [PATCH v4 1/2] ARM: tango: add HOTPLUG_CPU support To: arm-soc References: <57726597.8030501@sigmadesigns.com> <577266AD.8000006@sigmadesigns.com> From: Marc Gonzalez Message-ID: <5773BD56.5040104@sigmadesigns.com> Date: Wed, 29 Jun 2016 14:21:42 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:43.0) Gecko/20100101 Firefox/43.0 SeaMonkey/2.40 MIME-Version: 1.0 In-Reply-To: <577266AD.8000006@sigmadesigns.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160629_052206_185577_0B596198 X-CRM114-Status: GOOD ( 13.11 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Sebastian Frias , linux-pm , Thibaud Cornic , Mason , Robin Murphy , Linux ARM 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 cpu_die() and cpu_kill() are implemented in firmware. Signed-off-by: Marc Gonzalez --- New in v4: o panic() if tango_cpu_die() returns unexpectedly o timeout after 10 tries in tango_cpu_kill() --- arch/arm/mach-tango/platsmp.c | 36 ++++++++++++++++++++++++++++++++++++ arch/arm/mach-tango/smc.h | 4 +++- 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-tango/platsmp.c b/arch/arm/mach-tango/platsmp.c index a21f55e000d2..8380699d4fa3 100644 --- a/arch/arm/mach-tango/platsmp.c +++ b/arch/arm/mach-tango/platsmp.c @@ -1,3 +1,4 @@ +#include #include #include #include "smc.h" @@ -9,8 +10,43 @@ static int tango_boot_secondary(unsigned int cpu, struct task_struct *idle) return 0; } +#ifdef CONFIG_HOTPLUG_CPU +/* + * cpu_kill() and cpu_die() run concurrently on different cores. + * Firmware will only "kill" a core once it has properly "died". + * Try a few times to kill a core before giving up, and sleep + * between tries to give that core enough time to die. + */ +static int tango_cpu_kill(unsigned int cpu) +{ + int i, err; + + for (i = 0; i < 10; ++i) { + msleep(10); + err = tango_aux_core_kill(cpu); + if (!err) + return true; + } + + return false; +} + +static void tango_cpu_die(unsigned int cpu) +{ + while (tango_aux_core_die(cpu) < 0) + cpu_relax(); + + panic("cpu %d failed to die\n", cpu); +} +#else +#define tango_cpu_kill NULL +#define tango_cpu_die NULL +#endif + static const struct smp_operations tango_smp_ops __initconst = { .smp_boot_secondary = tango_boot_secondary, + .cpu_kill = tango_cpu_kill, + .cpu_die = tango_cpu_die, }; CPU_METHOD_OF_DECLARE(tango4_smp, "sigma,tango4-smp", &tango_smp_ops); diff --git a/arch/arm/mach-tango/smc.h b/arch/arm/mach-tango/smc.h index 7a4af35cc390..3d31f984f44c 100644 --- a/arch/arm/mach-tango/smc.h +++ b/arch/arm/mach-tango/smc.h @@ -2,4 +2,6 @@ extern int tango_smc(unsigned int val, unsigned int service); #define tango_set_l2_control(val) tango_smc(val, 0x102) #define tango_start_aux_core(val) tango_smc(val, 0x104) -#define tango_set_aux_boot_addr(val) tango_smc((unsigned int)val, 0x105) +#define tango_set_aux_boot_addr(val) tango_smc(val, 0x105) +#define tango_aux_core_die(val) tango_smc(val, 0x121) +#define tango_aux_core_kill(val) tango_smc(val, 0x122)