From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754880AbcKUPsW (ORCPT ); Mon, 21 Nov 2016 10:48:22 -0500 Received: from terminus.zytor.com ([198.137.202.10]:40148 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753934AbcKUPsU (ORCPT ); Mon, 21 Nov 2016 10:48:20 -0500 Date: Mon, 21 Nov 2016 07:48:13 -0800 From: tip-bot for Sebastian Andrzej Siewior Message-ID: Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, bigeasy@linutronix.de, hpa@zytor.com, tglx@linutronix.de Reply-To: bigeasy@linutronix.de, mingo@kernel.org, tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org In-Reply-To: <20161117183541.8588-4-bigeasy@linutronix.de> References: <20161117183541.8588-4-bigeasy@linutronix.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:smp/hotplug] x86/msr: Convert to hotplug state machine Git-Commit-ID: 216a5d1b866538a021af00bfb7c5dcd1da8ff884 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 216a5d1b866538a021af00bfb7c5dcd1da8ff884 Gitweb: http://git.kernel.org/tip/216a5d1b866538a021af00bfb7c5dcd1da8ff884 Author: Sebastian Andrzej Siewior AuthorDate: Thu, 17 Nov 2016 19:35:24 +0100 Committer: Thomas Gleixner CommitDate: Mon, 21 Nov 2016 16:37:05 +0100 x86/msr: Convert to hotplug state machine Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Move the callbacks to online/offline as there is no point in having the files around before the cpu is online and until its completely gone. [ tglx: Move the callbacks to online/offline ] Signed-off-by: Sebastian Andrzej Siewior Cc: rt@linuxtronix.de Link: http://lkml.kernel.org/r/20161117183541.8588-4-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- arch/x86/kernel/msr.c | 66 +++++++++++---------------------------------------- 1 file changed, 14 insertions(+), 52 deletions(-) diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index 7f3550a..7935815 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -44,6 +44,7 @@ #include static struct class *msr_class; +static enum cpuhp_state cpuhp_msr_state; static ssize_t msr_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -180,7 +181,7 @@ static const struct file_operations msr_fops = { .compat_ioctl = msr_ioctl, }; -static int msr_device_create(int cpu) +static int msr_device_create(unsigned int cpu) { struct device *dev; @@ -189,34 +190,12 @@ static int msr_device_create(int cpu) return PTR_ERR_OR_ZERO(dev); } -static void msr_device_destroy(int cpu) +static int msr_device_destroy(unsigned int cpu) { device_destroy(msr_class, MKDEV(MSR_MAJOR, cpu)); + return 0; } -static int msr_class_cpu_callback(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - unsigned int cpu = (unsigned long)hcpu; - int err = 0; - - switch (action) { - case CPU_UP_PREPARE: - err = msr_device_create(cpu); - break; - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - case CPU_DEAD: - msr_device_destroy(cpu); - break; - } - return notifier_from_errno(err); -} - -static struct notifier_block __refdata msr_class_cpu_notifier = { - .notifier_call = msr_class_cpu_callback, -}; - static char *msr_devnode(struct device *dev, umode_t *mode) { return kasprintf(GFP_KERNEL, "cpu/%u/msr", MINOR(dev->devt)); @@ -224,8 +203,7 @@ static char *msr_devnode(struct device *dev, umode_t *mode) static int __init msr_init(void) { - int i, err = 0; - i = 0; + int err; if (__register_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr", &msr_fops)) { pr_err("unable to get major %d for msr\n", MSR_MAJOR); @@ -239,44 +217,28 @@ static int __init msr_init(void) } msr_class->devnode = msr_devnode; - cpu_notifier_register_begin(); - for_each_online_cpu(i) { - err = msr_device_create(i); - if (err != 0) - goto out_class; - } - __register_hotcpu_notifier(&msr_class_cpu_notifier); - cpu_notifier_register_done(); - - err = 0; - goto out; + err = cpuhp_setup_state(CPUHP_X86_MSR_PREPARE, "x86/msr:online", + msr_device_create, msr_device_destroy); + if (err < 0) + goto out_class; + cpuhp_msr_state = err; + return 0; out_class: - i = 0; - for_each_online_cpu(i) - msr_device_destroy(i); - cpu_notifier_register_done(); + cpuhp_remove_state(cpuhp_msr_state); class_destroy(msr_class); out_chrdev: __unregister_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr"); -out: return err; } +module_init(msr_init); static void __exit msr_exit(void) { - int cpu = 0; - - cpu_notifier_register_begin(); - for_each_online_cpu(cpu) - msr_device_destroy(cpu); + cpuhp_remove_state(cpuhp_msr_state); class_destroy(msr_class); __unregister_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr"); - __unregister_hotcpu_notifier(&msr_class_cpu_notifier); - cpu_notifier_register_done(); } - -module_init(msr_init); module_exit(msr_exit) MODULE_AUTHOR("H. Peter Anvin ");