From patchwork Wed Sep 25 21:08:27 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Toshi Kani X-Patchwork-Id: 278017 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id C56602C035B for ; Thu, 26 Sep 2013 07:11:03 +1000 (EST) Received: from g4t0015.houston.hp.com (g4t0015.houston.hp.com [15.201.24.18]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "smtp.hp.com", Issuer "VeriSign Class 3 Secure Server CA - G3" (not verified)) by ozlabs.org (Postfix) with ESMTPS id C3E102C007B for ; Thu, 26 Sep 2013 07:10:33 +1000 (EST) Received: from g4t0018.houston.hp.com (g4t0018.houston.hp.com [16.234.32.27]) by g4t0015.houston.hp.com (Postfix) with ESMTP id EBAD78587; Wed, 25 Sep 2013 21:10:29 +0000 (UTC) Received: from misato.fc.hp.com (misato.fc.hp.com [16.71.12.41]) by g4t0018.houston.hp.com (Postfix) with ESMTP id A54C410245; Wed, 25 Sep 2013 21:10:28 +0000 (UTC) From: Toshi Kani To: rjw@sisk.pl Subject: [PATCH RESEND 4/4] hotplug, powerpc, x86: Remove cpu_hotplug_driver_lock() Date: Wed, 25 Sep 2013 15:08:27 -0600 Message-Id: <1380143307-25462-1-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.8.1.4 Cc: fenghua.yu@intel.com, bp@suse.de, Toshi Kani , gregkh@linuxfoundation.org, x86@kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, isimatu.yasuaki@jp.fujitsu.com, mingo@redhat.com, srivatsa.bhat@linux.vnet.ibm.com, nfont@linux.vnet.ibm.com, tglx@linutronix.de, hpa@linux.intel.com, linuxppc-dev@lists.ozlabs.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.16rc2 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" cpu_hotplug_driver_lock() serializes CPU online/offline operations when ARCH_CPU_PROBE_RELEASE is set. This lock interface is no longer necessary with the following reason: - lock_device_hotplug() now protects CPU online/offline operations, including the probe & release interfaces enabled by ARCH_CPU_PROBE_RELEASE. The use of cpu_hotplug_driver_lock() is redundant. - cpu_hotplug_driver_lock() is only valid when ARCH_CPU_PROBE_RELEASE is defined, which is misleading and is only enabled on powerpc. This patch removes the cpu_hotplug_driver_lock() interface. As a result, ARCH_CPU_PROBE_RELEASE only enables / disables the cpu probe & release interface as intended. There is no functional change in this patch. Signed-off-by: Toshi Kani Acked-by: Rafael J. Wysocki Reviewed-by: Nathan Fontenot --- Performed build test only on powerpc. Resend: Rebased to linux-next of the PM tree (3.12-rc2). --- arch/powerpc/kernel/smp.c | 12 --------- arch/powerpc/platforms/pseries/dlpar.c | 43 ++++++++++++-------------------- arch/x86/kernel/topology.c | 2 - drivers/base/cpu.c | 15 ++--------- include/linux/cpu.h | 13 ---------- 5 files changed, 19 insertions(+), 66 deletions(-) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 8e59abc..930cd8a 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -844,18 +844,6 @@ void __cpu_die(unsigned int cpu) smp_ops->cpu_die(cpu); } -static DEFINE_MUTEX(powerpc_cpu_hotplug_driver_mutex); - -void cpu_hotplug_driver_lock() -{ - mutex_lock(&powerpc_cpu_hotplug_driver_mutex); -} - -void cpu_hotplug_driver_unlock() -{ - mutex_unlock(&powerpc_cpu_hotplug_driver_mutex); -} - void cpu_die(void) { if (ppc_md.cpu_die) diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c index 7cfdaae..a8fe5aa 100644 --- a/arch/powerpc/platforms/pseries/dlpar.c +++ b/arch/powerpc/platforms/pseries/dlpar.c @@ -404,46 +404,38 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count) unsigned long drc_index; int rc; - cpu_hotplug_driver_lock(); rc = strict_strtoul(buf, 0, &drc_index); - if (rc) { - rc = -EINVAL; - goto out; - } + if (rc) + return -EINVAL; parent = of_find_node_by_path("/cpus"); - if (!parent) { - rc = -ENODEV; - goto out; - } + if (!parent) + return -ENODEV; dn = dlpar_configure_connector(drc_index, parent); - if (!dn) { - rc = -EINVAL; - goto out; - } + if (!dn) + return -EINVAL; of_node_put(parent); rc = dlpar_acquire_drc(drc_index); if (rc) { dlpar_free_cc_nodes(dn); - rc = -EINVAL; - goto out; + return -EINVAL; } rc = dlpar_attach_node(dn); if (rc) { dlpar_release_drc(drc_index); dlpar_free_cc_nodes(dn); - goto out; + return rc; } rc = dlpar_online_cpu(dn); -out: - cpu_hotplug_driver_unlock(); + if (rc) + return rc; - return rc ? rc : count; + return count; } static int dlpar_offline_cpu(struct device_node *dn) @@ -516,30 +508,27 @@ static ssize_t dlpar_cpu_release(const char *buf, size_t count) return -EINVAL; } - cpu_hotplug_driver_lock(); rc = dlpar_offline_cpu(dn); if (rc) { of_node_put(dn); - rc = -EINVAL; - goto out; + return -EINVAL; } rc = dlpar_release_drc(*drc_index); if (rc) { of_node_put(dn); - goto out; + return rc; } rc = dlpar_detach_node(dn); if (rc) { dlpar_acquire_drc(*drc_index); - goto out; + return rc; } of_node_put(dn); -out: - cpu_hotplug_driver_unlock(); - return rc ? rc : count; + + return count; } static int __init pseries_dlpar_init(void) diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c index a3f35eb..649b010 100644 --- a/arch/x86/kernel/topology.c +++ b/arch/x86/kernel/topology.c @@ -66,7 +66,6 @@ int __ref _debug_hotplug_cpu(int cpu, int action) return -EINVAL; lock_device_hotplug(); - cpu_hotplug_driver_lock(); switch (action) { case 0: @@ -91,7 +90,6 @@ int __ref _debug_hotplug_cpu(int cpu, int action) ret = -EINVAL; } - cpu_hotplug_driver_unlock(); unlock_device_hotplug(); return ret; diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 51f5d7f..f48370d 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -44,13 +44,11 @@ static int __ref cpu_subsys_online(struct device *dev) struct cpu *cpu = container_of(dev, struct cpu, dev); int cpuid = dev->id; int from_nid, to_nid; - int ret = -ENODEV; - - cpu_hotplug_driver_lock(); + int ret; from_nid = cpu_to_node(cpuid); if (from_nid == NUMA_NO_NODE) - goto out; + return -ENODEV; ret = cpu_up(cpuid); /* @@ -61,19 +59,12 @@ static int __ref cpu_subsys_online(struct device *dev) if (from_nid != to_nid) change_cpu_under_node(cpu, from_nid, to_nid); - out: - cpu_hotplug_driver_unlock(); return ret; } static int cpu_subsys_offline(struct device *dev) { - int ret; - - cpu_hotplug_driver_lock(); - ret = cpu_down(dev->id); - cpu_hotplug_driver_unlock(); - return ret; + return cpu_down(dev->id); } void unregister_cpu(struct cpu *cpu) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 801ff9e..3434ef7 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -185,19 +185,6 @@ extern void cpu_hotplug_enable(void); void clear_tasks_mm_cpumask(int cpu); int cpu_down(unsigned int cpu); -#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE -extern void cpu_hotplug_driver_lock(void); -extern void cpu_hotplug_driver_unlock(void); -#else -static inline void cpu_hotplug_driver_lock(void) -{ -} - -static inline void cpu_hotplug_driver_unlock(void) -{ -} -#endif - #else /* CONFIG_HOTPLUG_CPU */ static inline void cpu_hotplug_begin(void) {}