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: 9205013 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 0B4406089F for ; Wed, 29 Jun 2016 12:23:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EDE2D28653 for ; Wed, 29 Jun 2016 12:23:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E280E2865B; Wed, 29 Jun 2016 12:23:14 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C12A628658 for ; Wed, 29 Jun 2016 12:23:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751962AbcF2MXL (ORCPT ); Wed, 29 Jun 2016 08:23:11 -0400 Received: from a.mx.sdesigns.eu ([78.31.43.6]:28584 "EHLO a.mx.sdesigns.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751674AbcF2MVo (ORCPT ); Wed, 29 Jun 2016 08:21:44 -0400 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 Cc: Linux ARM , linux-pm , Mark Rutland , Robin Murphy , Sebastian Frias , Thibaud Cornic , Mason 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> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.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)