From f6913f990273a1fbfc0ec501d4998faa4f1ebae6 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 29 Aug 2013 18:22:06 -0600 Subject: hotplug / x86: Fix online state in cpu0 debug interface _debug_hotplug_cpu() is a debug interface that puts cpu0 offline during boot-up when CONFIG_DEBUG_HOTPLUG_CPU0 is set. After cpu0 is put offline in this interface, however, /sys/devices/system/cpu/cpu0/online still shows 1 (online). This patch fixes _debug_hotplug_cpu() to update dev->offline when CPU online/offline operation succeeded. Signed-off-by: Toshi Kani Acked-by: Yasuaki Ishimatsu Signed-off-by: Rafael J. Wysocki --- arch/x86/kernel/topology.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c index 6e60b5fe224..5823bbd668f 100644 --- a/arch/x86/kernel/topology.c +++ b/arch/x86/kernel/topology.c @@ -72,16 +72,19 @@ int __ref _debug_hotplug_cpu(int cpu, int action) ret = cpu_down(cpu); if (!ret) { pr_info("CPU %u is now offline\n", cpu); + dev->offline = true; kobject_uevent(&dev->kobj, KOBJ_OFFLINE); } else pr_debug("Can't offline CPU%d.\n", cpu); break; case 1: ret = cpu_up(cpu); - if (!ret) + if (!ret) { + dev->offline = false; kobject_uevent(&dev->kobj, KOBJ_ONLINE); - else + } else { pr_debug("Can't online CPU%d.\n", cpu); + } break; default: ret = -EINVAL; -- cgit v1.2.3-18-g5258 From 574b851e99923c884fee4e0d7cf7e7c3dc023ffa Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 29 Aug 2013 18:22:07 -0600 Subject: hotplug / x86: Add hotplug lock to missing places lock_device_hotplug[_sysfs]() serializes CPU & Memory online/offline and hotplug operations. However, this lock is not held in the debug interfaces below that initiate CPU online/offline operations. - _debug_hotplug_cpu(), cpu0 hotplug test interface enabled by CONFIG_DEBUG_HOTPLUG_CPU0. - cpu_probe_store() and cpu_release_store(), cpu hotplug test interface enabled by CONFIG_ARCH_CPU_PROBE_RELEASE. This patch changes the above interfaces to hold lock_device_hotplug(). Signed-off-by: Toshi Kani Acked-by: Greg Kroah-Hartman Acked-by: Yasuaki Ishimatsu Signed-off-by: Rafael J. Wysocki --- arch/x86/kernel/topology.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c index 5823bbd668f..a3f35ebb3b5 100644 --- a/arch/x86/kernel/topology.c +++ b/arch/x86/kernel/topology.c @@ -65,6 +65,7 @@ int __ref _debug_hotplug_cpu(int cpu, int action) if (!cpu_is_hotpluggable(cpu)) return -EINVAL; + lock_device_hotplug(); cpu_hotplug_driver_lock(); switch (action) { @@ -91,6 +92,7 @@ int __ref _debug_hotplug_cpu(int cpu, int action) } cpu_hotplug_driver_unlock(); + unlock_device_hotplug(); return ret; } -- cgit v1.2.3-18-g5258 From 1cad5e9a3978d182aa9b0e909fb0379da5ba45af Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 29 Aug 2013 18:22:08 -0600 Subject: hotplug / x86: Disable ARCH_CPU_PROBE_RELEASE on x86 Commit d7c53c9e enabled ARCH_CPU_PROBE_RELEASE on x86 in order to serialize CPU online/offline operations. Although it is the config option to enable CPU hotplug test interfaces, probe & release, it is also the option to enable cpu_hotplug_driver_lock() as well. Therefore, this option had to be enabled on x86 with dummy arch_cpu_probe() and arch_cpu_release(). Since then, lock_device_hotplug() was introduced to serialize CPU online/offline & hotplug operations. Therefore, this config option is no longer required for the serialization. This patch disables this config option on x86 and revert the changes made by commit d7c53c9e. Signed-off-by: Toshi Kani Acked-by: Yasuaki Ishimatsu Signed-off-by: Rafael J. Wysocki --- arch/x86/Kconfig | 4 ---- arch/x86/kernel/smpboot.c | 21 --------------------- 2 files changed, 25 deletions(-) (limited to 'arch') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ee2fb9d3774..dcdb5130cf8 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -254,10 +254,6 @@ config ARCH_HWEIGHT_CFLAGS default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 -config ARCH_CPU_PROBE_RELEASE - def_bool y - depends on HOTPLUG_CPU - config ARCH_SUPPORTS_UPROBES def_bool y diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 6cacab671f9..e73b3f53310 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -82,27 +82,6 @@ /* State of each CPU */ DEFINE_PER_CPU(int, cpu_state) = { 0 }; -#ifdef CONFIG_HOTPLUG_CPU -/* - * We need this for trampoline_base protection from concurrent accesses when - * off- and onlining cores wildly. - */ -static DEFINE_MUTEX(x86_cpu_hotplug_driver_mutex); - -void cpu_hotplug_driver_lock(void) -{ - mutex_lock(&x86_cpu_hotplug_driver_mutex); -} - -void cpu_hotplug_driver_unlock(void) -{ - mutex_unlock(&x86_cpu_hotplug_driver_mutex); -} - -ssize_t arch_cpu_probe(const char *buf, size_t count) { return -1; } -ssize_t arch_cpu_release(const char *buf, size_t count) { return -1; } -#endif - /* Number of siblings per CPU package */ int smp_num_siblings = 1; EXPORT_SYMBOL(smp_num_siblings); -- cgit v1.2.3-18-g5258 From 6dedcca610c6d6189b4a54d32118d1654adb73d2 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Wed, 25 Sep 2013 15:08:27 -0600 Subject: hotplug, powerpc, x86: Remove cpu_hotplug_driver_lock() 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 Reviewed-by: Nathan Fontenot Signed-off-by: Rafael J. Wysocki --- arch/powerpc/kernel/smp.c | 12 ---------- arch/powerpc/platforms/pseries/dlpar.c | 43 +++++++++++++--------------------- arch/x86/kernel/topology.c | 2 -- 3 files changed, 16 insertions(+), 41 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 8e59abc237d..930cd8af350 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 7cfdaae1721..a8fe5aa3d34 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 a3f35ebb3b5..649b010da00 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; -- cgit v1.2.3-18-g5258