From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 928A6C433E2 for ; Wed, 1 Jul 2020 16:46:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DD0620747 for ; Wed, 1 Jul 2020 16:46:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593621969; bh=75Bvp9rTjJq7/rqKLR8yq70YXGcG1LBRpMCeEA7JJ58=; h=Subject:To:From:Date:List-ID:From; b=z4Nz5TJ3cShiudIKYEggpmq7Rdb5Ct2Tu8mie9hH+DCi4MCZsBXYMGLfuK3n6z611 UdTVF9VGGfoLmHvA5lfN9VfPXeGuMrWZKAXBE3cwk8gOPchgPxqTuIClFgzsHTYUoz ZFbn+C2Y6f868AUzSsyBy8I26YxUSsUowADdjtpo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732449AbgGAQqI (ORCPT ); Wed, 1 Jul 2020 12:46:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:54918 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732161AbgGAQqI (ORCPT ); Wed, 1 Jul 2020 12:46:08 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 02DE820747; Wed, 1 Jul 2020 16:46:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593621967; bh=75Bvp9rTjJq7/rqKLR8yq70YXGcG1LBRpMCeEA7JJ58=; h=Subject:To:From:Date:From; b=csZjnICjv8QrlvP3n0qbmg5bKG5A0UWusRaIxHb23eE6l2GCes4rDgK7fC0POvOzh smB02yESoCDSdiz68jTtCGi0JflF6AHlKuvCnNIuviPcuFJd/bxCZT/EDW8yhYFYWz 9NUlIKAKLErr8lK5wZrXD1oLqmdeLU+sPKW9mIuU= Subject: patch "coresight: etmv4: Fix CPU power management setup in probe() function" added to char-misc-linus To: mike.leach@linaro.org, gregkh@linuxfoundation.org, mathieu.poirier@linaro.org, stable@vger.kernel.org From: Date: Wed, 01 Jul 2020 18:45:45 +0200 Message-ID: <1593621945134218@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled coresight: etmv4: Fix CPU power management setup in probe() function to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 9b6a3f3633a5cc928b78627764793b60cb62e0f6 Mon Sep 17 00:00:00 2001 From: Mike Leach Date: Wed, 1 Jul 2020 10:08:52 -0600 Subject: coresight: etmv4: Fix CPU power management setup in probe() function The current probe() function calls a pair of cpuhp_xxx API functions to setup CPU hotplug handling. The hotplug lock is held for the duration of the two calls and other CPU related code using cpus_read_lock() / cpus_read_unlock() calls. The problem is that on error states, goto: statements bypass the cpus_read_unlock() call. This code has increased in complexity as the driver has developed. This patch introduces a pair of helper functions etm4_pm_setup_cpuslocked() and etm4_pm_clear() which correct the issues above and group the PM code a little better. The two functions etm4_cpu_pm_register() and etm4_cpu_pm_unregister() are dropped as these call cpu_pm_register_notifier() / ..unregister_notifier() dependent on CONFIG_CPU_PM - but this define is used to nop these functions out in the pm headers - so the wrapper functions are superfluous. Fixes: f188b5e76aae ("coresight: etm4x: Save/restore state across CPU low power states") Fixes: e9f5d63f84fe ("hwtracing/coresight-etm4x: Use cpuhp_setup_state_nocalls_cpuslocked()") Fixes: 58eb457be028 ("hwtracing/coresight-etm4x: Convert to hotplug state machine") Signed-off-by: Mike Leach Cc: stable Reviewed-by: Mathieu Poirier Link: https://lore.kernel.org/r/20200701160852.2782823-3-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-etm4x.c | 82 ++++++++++++------- 1 file changed, 53 insertions(+), 29 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 747afc875f91..0c35cd5e0d1d 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -1388,18 +1388,57 @@ static struct notifier_block etm4_cpu_pm_nb = { .notifier_call = etm4_cpu_pm_notify, }; -static int etm4_cpu_pm_register(void) +/* Setup PM. Called with cpus locked. Deals with error conditions and counts */ +static int etm4_pm_setup_cpuslocked(void) { - if (IS_ENABLED(CONFIG_CPU_PM)) - return cpu_pm_register_notifier(&etm4_cpu_pm_nb); + int ret; - return 0; + if (etm4_count++) + return 0; + + ret = cpu_pm_register_notifier(&etm4_cpu_pm_nb); + if (ret) + goto reduce_count; + + ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING, + "arm/coresight4:starting", + etm4_starting_cpu, etm4_dying_cpu); + + if (ret) + goto unregister_notifier; + + ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, + "arm/coresight4:online", + etm4_online_cpu, NULL); + + /* HP dyn state ID returned in ret on success */ + if (ret > 0) { + hp_online = ret; + return 0; + } + + /* failed dyn state - remove others */ + cpuhp_remove_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING); + +unregister_notifier: + cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); + +reduce_count: + --etm4_count; + return ret; } -static void etm4_cpu_pm_unregister(void) +static void etm4_pm_clear(void) { - if (IS_ENABLED(CONFIG_CPU_PM)) - cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); + if (--etm4_count != 0) + return; + + cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); + cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); + if (hp_online) { + cpuhp_remove_state_nocalls(hp_online); + hp_online = 0; + } } static int etm4_probe(struct amba_device *adev, const struct amba_id *id) @@ -1453,24 +1492,15 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) etm4_init_arch_data, drvdata, 1)) dev_err(dev, "ETM arch init failed\n"); - if (!etm4_count++) { - cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING, - "arm/coresight4:starting", - etm4_starting_cpu, etm4_dying_cpu); - ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, - "arm/coresight4:online", - etm4_online_cpu, NULL); - if (ret < 0) - goto err_arch_supported; - hp_online = ret; + ret = etm4_pm_setup_cpuslocked(); + cpus_read_unlock(); - ret = etm4_cpu_pm_register(); - if (ret) - goto err_arch_supported; + /* etm4_pm_setup_cpuslocked() does its own cleanup - exit on error */ + if (ret) { + etmdrvdata[drvdata->cpu] = NULL; + return ret; } - cpus_read_unlock(); - if (etm4_arch_supported(drvdata->arch) == false) { ret = -EINVAL; goto err_arch_supported; @@ -1517,13 +1547,7 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) err_arch_supported: etmdrvdata[drvdata->cpu] = NULL; - if (--etm4_count == 0) { - etm4_cpu_pm_unregister(); - - cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); - if (hp_online) - cpuhp_remove_state_nocalls(hp_online); - } + etm4_pm_clear(); return ret; } -- 2.27.0