From 2987557f52b97f679f0c324d8f51b8d66e1f2084 Mon Sep 17 00:00:00 2001 From: Josh Triplett Date: Sat, 3 Dec 2011 13:06:50 -0800 Subject: driver-core/cpu: Expose hotpluggability to the rest of the kernel When architectures register CPUs, they indicate whether the CPU allows hotplugging; notably, x86 and ARM don't allow hotplugging CPU 0. Userspace can easily query the hotpluggability of a CPU via sysfs; however, the kernel has no convenient way of accessing that property in an architecture-independent way. While the kernel can simply try it and see, some code needs to distinguish between "hotplug failed" and "hotplug has no hope of working on this CPU"; for example, rcutorture's CPU hotplug tests want to avoid drowning out real hotplug failures with expected failures. Expose this property via a new cpu_is_hotpluggable function, so that the rest of the kernel can access it in an architecture-independent way. Signed-off-by: Josh Triplett Signed-off-by: Paul E. McKenney --- drivers/base/cpu.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 251acea3d359..3991502b21e5 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -247,6 +247,13 @@ struct sys_device *get_cpu_sysdev(unsigned cpu) } EXPORT_SYMBOL_GPL(get_cpu_sysdev); +bool cpu_is_hotpluggable(unsigned cpu) +{ + struct sys_device *dev = get_cpu_sysdev(cpu); + return dev && container_of(dev, struct cpu, sysdev)->hotpluggable; +} +EXPORT_SYMBOL_GPL(cpu_is_hotpluggable); + int __init cpu_dev_init(void) { int err; -- cgit v1.2.3 From 8a25a2fd126c621f44f3aeaef80d51f00fc11639 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Wed, 21 Dec 2011 14:29:42 -0800 Subject: cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystem This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem and converts the devices to regular devices. The sysdev drivers are implemented as subsystem interfaces now. After all sysdev classes are ported to regular driver core entities, the sysdev implementation will be entirely removed from the kernel. Userspace relies on events and generic sysfs subsystem infrastructure from sysdev devices, which are made available with this conversion. Cc: Haavard Skinnemoen Cc: Hans-Christian Egtvedt Cc: Tony Luck Cc: Fenghua Yu Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Paul Mundt Cc: "David S. Miller" Cc: Chris Metcalf Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Borislav Petkov Cc: Tigran Aivazian Cc: Len Brown Cc: Zhang Rui Cc: Dave Jones Cc: Peter Zijlstra Cc: Russell King Cc: Andrew Morton Cc: Arjan van de Ven Cc: "Rafael J. Wysocki" Cc: "Srivatsa S. Bhat" Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- drivers/base/cpu.c | 146 ++++++++++++++++++++++++++++------------------------- 1 file changed, 77 insertions(+), 69 deletions(-) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 251acea3d359..5bb0298fbcc0 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -1,8 +1,7 @@ /* - * drivers/base/cpu.c - basic CPU class support + * CPU subsystem support */ -#include #include #include #include @@ -14,40 +13,40 @@ #include "base.h" -static struct sysdev_class_attribute *cpu_sysdev_class_attrs[]; - -struct sysdev_class cpu_sysdev_class = { +struct bus_type cpu_subsys = { .name = "cpu", - .attrs = cpu_sysdev_class_attrs, + .dev_name = "cpu", }; -EXPORT_SYMBOL(cpu_sysdev_class); +EXPORT_SYMBOL_GPL(cpu_subsys); -static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices); +static DEFINE_PER_CPU(struct device *, cpu_sys_devices); #ifdef CONFIG_HOTPLUG_CPU -static ssize_t show_online(struct sys_device *dev, struct sysdev_attribute *attr, +static ssize_t show_online(struct device *dev, + struct device_attribute *attr, char *buf) { - struct cpu *cpu = container_of(dev, struct cpu, sysdev); + struct cpu *cpu = container_of(dev, struct cpu, dev); - return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id)); + return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id)); } -static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribute *attr, - const char *buf, size_t count) +static ssize_t __ref store_online(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) { - struct cpu *cpu = container_of(dev, struct cpu, sysdev); + struct cpu *cpu = container_of(dev, struct cpu, dev); ssize_t ret; cpu_hotplug_driver_lock(); switch (buf[0]) { case '0': - ret = cpu_down(cpu->sysdev.id); + ret = cpu_down(cpu->dev.id); if (!ret) kobject_uevent(&dev->kobj, KOBJ_OFFLINE); break; case '1': - ret = cpu_up(cpu->sysdev.id); + ret = cpu_up(cpu->dev.id); if (!ret) kobject_uevent(&dev->kobj, KOBJ_ONLINE); break; @@ -60,44 +59,44 @@ static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribut ret = count; return ret; } -static SYSDEV_ATTR(online, 0644, show_online, store_online); +static DEVICE_ATTR(online, 0644, show_online, store_online); static void __cpuinit register_cpu_control(struct cpu *cpu) { - sysdev_create_file(&cpu->sysdev, &attr_online); + device_create_file(&cpu->dev, &dev_attr_online); } void unregister_cpu(struct cpu *cpu) { - int logical_cpu = cpu->sysdev.id; + int logical_cpu = cpu->dev.id; unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); - sysdev_remove_file(&cpu->sysdev, &attr_online); + device_remove_file(&cpu->dev, &dev_attr_online); - sysdev_unregister(&cpu->sysdev); + device_unregister(&cpu->dev); per_cpu(cpu_sys_devices, logical_cpu) = NULL; return; } #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE -static ssize_t cpu_probe_store(struct sysdev_class *class, - struct sysdev_class_attribute *attr, +static ssize_t cpu_probe_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) { return arch_cpu_probe(buf, count); } -static ssize_t cpu_release_store(struct sysdev_class *class, - struct sysdev_class_attribute *attr, +static ssize_t cpu_release_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) { return arch_cpu_release(buf, count); } -static SYSDEV_CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store); -static SYSDEV_CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store); +static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store); +static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store); #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ #else /* ... !CONFIG_HOTPLUG_CPU */ @@ -109,15 +108,15 @@ static inline void register_cpu_control(struct cpu *cpu) #ifdef CONFIG_KEXEC #include -static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute *attr, +static ssize_t show_crash_notes(struct device *dev, struct device_attribute *attr, char *buf) { - struct cpu *cpu = container_of(dev, struct cpu, sysdev); + struct cpu *cpu = container_of(dev, struct cpu, dev); ssize_t rc; unsigned long long addr; int cpunum; - cpunum = cpu->sysdev.id; + cpunum = cpu->dev.id; /* * Might be reading other cpu's data based on which cpu read thread @@ -129,7 +128,7 @@ static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute rc = sprintf(buf, "%Lx\n", addr); return rc; } -static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL); +static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL); #endif /* @@ -137,12 +136,12 @@ static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL); */ struct cpu_attr { - struct sysdev_class_attribute attr; + struct device_attribute attr; const struct cpumask *const * const map; }; -static ssize_t show_cpus_attr(struct sysdev_class *class, - struct sysdev_class_attribute *attr, +static ssize_t show_cpus_attr(struct device *dev, + struct device_attribute *attr, char *buf) { struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr); @@ -153,10 +152,10 @@ static ssize_t show_cpus_attr(struct sysdev_class *class, return n; } -#define _CPU_ATTR(name, map) \ - { _SYSDEV_CLASS_ATTR(name, 0444, show_cpus_attr, NULL), map } +#define _CPU_ATTR(name, map) \ + { __ATTR(name, 0444, show_cpus_attr, NULL), map } -/* Keep in sync with cpu_sysdev_class_attrs */ +/* Keep in sync with cpu_subsys_attrs */ static struct cpu_attr cpu_attrs[] = { _CPU_ATTR(online, &cpu_online_mask), _CPU_ATTR(possible, &cpu_possible_mask), @@ -166,19 +165,19 @@ static struct cpu_attr cpu_attrs[] = { /* * Print values for NR_CPUS and offlined cpus */ -static ssize_t print_cpus_kernel_max(struct sysdev_class *class, - struct sysdev_class_attribute *attr, char *buf) +static ssize_t print_cpus_kernel_max(struct device *dev, + struct device_attribute *attr, char *buf) { int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1); return n; } -static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL); +static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL); /* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */ unsigned int total_cpus; -static ssize_t print_cpus_offline(struct sysdev_class *class, - struct sysdev_class_attribute *attr, char *buf) +static ssize_t print_cpus_offline(struct device *dev, + struct device_attribute *attr, char *buf) { int n = 0, len = PAGE_SIZE-2; cpumask_var_t offline; @@ -205,7 +204,7 @@ static ssize_t print_cpus_offline(struct sysdev_class *class, n += snprintf(&buf[n], len - n, "\n"); return n; } -static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL); +static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL); /* * register_cpu - Setup a sysfs device for a CPU. @@ -218,57 +217,66 @@ static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL); int __cpuinit register_cpu(struct cpu *cpu, int num) { int error; - cpu->node_id = cpu_to_node(num); - cpu->sysdev.id = num; - cpu->sysdev.cls = &cpu_sysdev_class; - - error = sysdev_register(&cpu->sysdev); + cpu->node_id = cpu_to_node(num); + cpu->dev.id = num; + cpu->dev.bus = &cpu_subsys; + error = device_register(&cpu->dev); if (!error && cpu->hotpluggable) register_cpu_control(cpu); if (!error) - per_cpu(cpu_sys_devices, num) = &cpu->sysdev; + per_cpu(cpu_sys_devices, num) = &cpu->dev; if (!error) register_cpu_under_node(num, cpu_to_node(num)); #ifdef CONFIG_KEXEC if (!error) - error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes); + error = device_create_file(&cpu->dev, &dev_attr_crash_notes); #endif return error; } -struct sys_device *get_cpu_sysdev(unsigned cpu) +struct device *get_cpu_device(unsigned cpu) { if (cpu < nr_cpu_ids && cpu_possible(cpu)) return per_cpu(cpu_sys_devices, cpu); else return NULL; } -EXPORT_SYMBOL_GPL(get_cpu_sysdev); +EXPORT_SYMBOL_GPL(get_cpu_device); + +static struct attribute *cpu_root_attrs[] = { +#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE + &dev_attr_probe.attr, + &dev_attr_release.attr, +#endif + &cpu_attrs[0].attr.attr, + &cpu_attrs[1].attr.attr, + &cpu_attrs[2].attr.attr, + &dev_attr_kernel_max.attr, + &dev_attr_offline.attr, + NULL +}; + +static struct attribute_group cpu_root_attr_group = { + .attrs = cpu_root_attrs, +}; + +static const struct attribute_group *cpu_root_attr_groups[] = { + &cpu_root_attr_group, + NULL, +}; int __init cpu_dev_init(void) { int err; - err = sysdev_class_register(&cpu_sysdev_class); + err = subsys_system_register(&cpu_subsys, cpu_root_attr_groups); + if (err) + return err; + #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) - if (!err) - err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class); + err = sched_create_sysfs_power_savings_entries(cpu_subsys.dev_root); #endif - return err; } - -static struct sysdev_class_attribute *cpu_sysdev_class_attrs[] = { -#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE - &attr_probe, - &attr_release, -#endif - &cpu_attrs[0].attr, - &cpu_attrs[1].attr, - &cpu_attrs[2].attr, - &attr_kernel_max, - &attr_offline, - NULL -}; -- cgit v1.2.3 From 024f78462c3da710642a54939888a92e28704653 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Tue, 10 Jan 2012 02:59:49 +0000 Subject: cpu: Do not return errors from cpu_dev_init() which will be ignored cpu_dev_init() is only called from driver_init(), which does not check its return value. Therefore make cpu_dev_init() return void. We must register the CPU subsystem, so panic if this fails. If sched_create_sysfs_power_savings_entries() fails, the damage is contained, so ignore this (as before). Signed-off-by: Ben Hutchings Signed-off-by: Linus Torvalds --- drivers/base/cpu.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 9a5578efbc93..bba70d08be6a 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -2,6 +2,7 @@ * CPU subsystem support */ +#include #include #include #include @@ -274,16 +275,12 @@ bool cpu_is_hotpluggable(unsigned cpu) } EXPORT_SYMBOL_GPL(cpu_is_hotpluggable); -int __init cpu_dev_init(void) +void __init cpu_dev_init(void) { - int err; - - err = subsys_system_register(&cpu_subsys, cpu_root_attr_groups); - if (err) - return err; + if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups)) + panic("Failed to register CPU subsystem"); #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) - err = sched_create_sysfs_power_savings_entries(cpu_subsys.dev_root); + sched_create_sysfs_power_savings_entries(cpu_subsys.dev_root); #endif - return err; } -- cgit v1.2.3 From 9f13a1fd452f11c18004ba2422a6384b424ec8a9 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Tue, 10 Jan 2012 03:04:32 +0000 Subject: cpu: Register a generic CPU device on architectures that currently do not frv, h8300, m68k, microblaze, openrisc, score, um and xtensa currently do not register a CPU device. Add the config option GENERIC_CPU_DEVICES which causes a generic CPU device to be registered for each present CPU, and make all these architectures select it. Richard Weinberger covered UML and suggested using per_cpu. Signed-off-by: Ben Hutchings Signed-off-by: Linus Torvalds --- drivers/base/cpu.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index bba70d08be6a..db87e78d7459 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "base.h" @@ -275,11 +276,29 @@ bool cpu_is_hotpluggable(unsigned cpu) } EXPORT_SYMBOL_GPL(cpu_is_hotpluggable); +#ifdef CONFIG_GENERIC_CPU_DEVICES +static DEFINE_PER_CPU(struct cpu, cpu_devices); +#endif + +static void __init cpu_dev_register_generic(void) +{ +#ifdef CONFIG_GENERIC_CPU_DEVICES + int i; + + for_each_possible_cpu(i) { + if (register_cpu(&per_cpu(cpu_devices, i), i)) + panic("Failed to register CPU device"); + } +#endif +} + void __init cpu_dev_init(void) { if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups)) panic("Failed to register CPU subsystem"); + cpu_dev_register_generic(); + #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) sched_create_sysfs_power_savings_entries(cpu_subsys.dev_root); #endif -- cgit v1.2.3 From 2885e25c422fb68208f677f944a45fce8eda2a3c Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 2 Feb 2012 10:36:33 -0800 Subject: driver core: cpu: remove kernel warning when removing a cpu With the movement of the cpu sysdev code to be real stuct devices, now when we remove a cpu from the system, the driver core rightfully complains that there is not a release method for this device. For now, paper over this issue by quieting the driver core, but comment this in detail. This will be resolved in future kernels to be solved properly. Reported-by: Konrad Rzeszutek Wilk Tested-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman --- drivers/base/cpu.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index db87e78d7459..23f2c4cd48d1 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -208,6 +208,25 @@ static ssize_t print_cpus_offline(struct device *dev, } static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL); +static void cpu_device_release(struct device *dev) +{ + /* + * This is an empty function to prevent the driver core from spitting a + * warning at us. Yes, I know this is directly opposite of what the + * documentation for the driver core and kobjects say, and the author + * of this code has already been publically ridiculed for doing + * something as foolish as this. However, at this point in time, it is + * the only way to handle the issue of statically allocated cpu + * devices. The different architectures will have their cpu device + * code reworked to properly handle this in the near future, so this + * function will then be changed to correctly free up the memory held + * by the cpu device. + * + * Never copy this way of doing things, or you too will be made fun of + * on the linux-kerenl list, you have been warned. + */ +} + /* * register_cpu - Setup a sysfs device for a CPU. * @cpu - cpu->hotpluggable field set to 1 will generate a control file in @@ -223,6 +242,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) cpu->node_id = cpu_to_node(num); cpu->dev.id = num; cpu->dev.bus = &cpu_subsys; + cpu->dev.release = cpu_device_release; error = device_register(&cpu->dev); if (!error && cpu->hotpluggable) register_cpu_control(cpu); -- cgit v1.2.3 From 29bb5d4fd3140a7d5d02d858118c74a45f15c296 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 8 Feb 2012 15:11:17 -0800 Subject: driver-core: cpu: fix kobject warning when hotplugging a cpu Due to the sysdev conversion to struct device, the cpu objects get reused when adding a cpu after offlining it, which causes a big warning that the kobject portion is not properly initialized. So clear out the object before we register it again, so all is quiet. Reported-by: Konrad Rzeszutek Wilk Tested-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman --- drivers/base/cpu.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 23f2c4cd48d1..4dabf5077c48 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -240,6 +240,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) int error; cpu->node_id = cpu_to_node(num); + memset(&cpu->dev, 0x00, sizeof(struct device)); cpu->dev.id = num; cpu->dev.bus = &cpu_subsys; cpu->dev.release = cpu_device_release; -- cgit v1.2.3