From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S943541AbdEZInv (ORCPT ); Fri, 26 May 2017 04:43:51 -0400 Received: from terminus.zytor.com ([65.50.211.136]:47269 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934529AbdEZInr (ORCPT ); Fri, 26 May 2017 04:43:47 -0400 Date: Fri, 26 May 2017 01:38:56 -0700 From: tip-bot for Sebastian Andrzej Siewior Message-ID: Cc: bigeasy@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org, paulmck@linux.vnet.ibm.com, tglx@linutronix.de, linux@armlinux.org.uk, rostedt@goodmis.org, mark.rutland@arm.com, hpa@zytor.com, will.deacon@arm.com Reply-To: paulmck@linux.vnet.ibm.com, tglx@linutronix.de, peterz@infradead.org, linux-kernel@vger.kernel.org, bigeasy@linutronix.de, mingo@kernel.org, will.deacon@arm.com, mark.rutland@arm.com, rostedt@goodmis.org, hpa@zytor.com, linux@armlinux.org.uk In-Reply-To: <20170524081548.170940729@linutronix.de> References: <20170524081548.170940729@linutronix.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:smp/hotplug] ARM/hw_breakpoint: Use cpuhp_setup_state_cpuslocked() Git-Commit-ID: fe2a5cd8aa038e2b02fda983afc2083e94c04b4f 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: fe2a5cd8aa038e2b02fda983afc2083e94c04b4f Gitweb: http://git.kernel.org/tip/fe2a5cd8aa038e2b02fda983afc2083e94c04b4f Author: Sebastian Andrzej Siewior AuthorDate: Wed, 24 May 2017 10:15:25 +0200 Committer: Thomas Gleixner CommitDate: Fri, 26 May 2017 10:10:40 +0200 ARM/hw_breakpoint: Use cpuhp_setup_state_cpuslocked() arch_hw_breakpoint_init() holds get_online_cpus() while registerring the hotplug callbacks. cpuhp_setup_state() invokes get_online_cpus() as well. This is correct, but prevents the conversion of the hotplug locking to a percpu rwsem. Use cpuhp_setup_state_cpuslocked() to avoid the nested call. Convert *_online_cpus() to the new interfaces while at it. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: Ingo Molnar Acked-by: Mark Rutland Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Will Deacon Cc: Steven Rostedt Cc: Russell King Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170524081548.170940729@linutronix.de --- arch/arm/kernel/hw_breakpoint.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index be3b3fb..63cb4c7 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -1090,7 +1090,7 @@ static int __init arch_hw_breakpoint_init(void) * driven low on this core and there isn't an architected way to * determine that. */ - get_online_cpus(); + cpus_read_lock(); register_undef_hook(&debug_reg_hook); /* @@ -1098,15 +1098,16 @@ static int __init arch_hw_breakpoint_init(void) * assume that a halting debugger will leave the world in a nice state * for us. */ - ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm/hw_breakpoint:online", - dbg_reset_online, NULL); + ret = cpuhp_setup_state_cpuslocked(CPUHP_AP_ONLINE_DYN, + "arm/hw_breakpoint:online", + dbg_reset_online, NULL); unregister_undef_hook(&debug_reg_hook); if (WARN_ON(ret < 0) || !cpumask_empty(&debug_err_mask)) { core_num_brps = 0; core_num_wrps = 0; if (ret > 0) cpuhp_remove_state_nocalls(ret); - put_online_cpus(); + cpus_read_unlock(); return 0; } @@ -1124,7 +1125,7 @@ static int __init arch_hw_breakpoint_init(void) TRAP_HWBKPT, "watchpoint debug exception"); hook_ifault_code(FAULT_CODE_DEBUG, hw_breakpoint_pending, SIGTRAP, TRAP_HWBKPT, "breakpoint debug exception"); - put_online_cpus(); + cpus_read_unlock(); /* Register PM notifiers. */ pm_init();