From 0902a9044fa5b7a0456ea4daacec2c2b3189ba8c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 3 May 2013 00:25:49 +0200 Subject: Driver core: Use generic offline/online for CPU offline/online Rework the CPU hotplug code in drivers/base/cpu.c to use the generic offline/online support introduced previously instead of its own CPU-specific code. For this purpose, modify cpu_subsys to provide offline and online callbacks for CONFIG_HOTPLUG_CPU set and remove the code handling the CPU-specific 'online' sysfs attribute. This modification is not supposed to change the user-observable behavior of the kernel (i.e. the 'online' attribute will be present in exactly the same place in sysfs and should trigger exactly the same actions as before). Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Reviewed-by: Toshi Kani --- drivers/base/cpu.c | 89 ++++++++++++++++++++---------------------------------- 1 file changed, 32 insertions(+), 57 deletions(-) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 3d48fc887ef4..25c8768172e9 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -16,12 +16,6 @@ #include "base.h" -struct bus_type cpu_subsys = { - .name = "cpu", - .dev_name = "cpu", -}; -EXPORT_SYMBOL_GPL(cpu_subsys); - static DEFINE_PER_CPU(struct device *, cpu_sys_devices); #ifdef CONFIG_HOTPLUG_CPU @@ -34,69 +28,45 @@ static void change_cpu_under_node(struct cpu *cpu, cpu->node_id = to_nid; } -static ssize_t show_online(struct device *dev, - struct device_attribute *attr, - char *buf) +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; + + cpu_hotplug_driver_lock(); + + from_nid = cpu_to_node(cpuid); + ret = cpu_up(cpuid); + /* + * When hot adding memory to memoryless node and enabling a cpu + * on the node, node number of the cpu may internally change. + */ + to_nid = cpu_to_node(cpuid); + if (from_nid != to_nid) + change_cpu_under_node(cpu, from_nid, to_nid); - return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id)); + cpu_hotplug_driver_unlock(); + return ret; } -static ssize_t __ref store_online(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) +static int cpu_subsys_offline(struct device *dev) { - struct cpu *cpu = container_of(dev, struct cpu, dev); - int cpuid = cpu->dev.id; - int from_nid, to_nid; - ssize_t ret; + int ret; cpu_hotplug_driver_lock(); - switch (buf[0]) { - case '0': - ret = cpu_down(cpuid); - if (!ret) - kobject_uevent(&dev->kobj, KOBJ_OFFLINE); - break; - case '1': - from_nid = cpu_to_node(cpuid); - ret = cpu_up(cpuid); - - /* - * When hot adding memory to memoryless node and enabling a cpu - * on the node, node number of the cpu may internally change. - */ - to_nid = cpu_to_node(cpuid); - if (from_nid != to_nid) - change_cpu_under_node(cpu, from_nid, to_nid); - - if (!ret) - kobject_uevent(&dev->kobj, KOBJ_ONLINE); - break; - default: - ret = -EINVAL; - } + ret = cpu_down(dev->id); cpu_hotplug_driver_unlock(); - - if (ret >= 0) - ret = count; return ret; } -static DEVICE_ATTR(online, 0644, show_online, store_online); -static void __cpuinit register_cpu_control(struct cpu *cpu) -{ - device_create_file(&cpu->dev, &dev_attr_online); -} void unregister_cpu(struct cpu *cpu) { int logical_cpu = cpu->dev.id; unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); - device_remove_file(&cpu->dev, &dev_attr_online); - device_unregister(&cpu->dev); per_cpu(cpu_sys_devices, logical_cpu) = NULL; return; @@ -123,12 +93,18 @@ 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 */ -static inline void register_cpu_control(struct cpu *cpu) -{ -} #endif /* CONFIG_HOTPLUG_CPU */ +struct bus_type cpu_subsys = { + .name = "cpu", + .dev_name = "cpu", +#ifdef CONFIG_HOTPLUG_CPU + .online = cpu_subsys_online, + .offline = cpu_subsys_offline, +#endif +}; +EXPORT_SYMBOL_GPL(cpu_subsys); + #ifdef CONFIG_KEXEC #include @@ -277,12 +253,11 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) cpu->dev.id = num; cpu->dev.bus = &cpu_subsys; cpu->dev.release = cpu_device_release; + cpu->dev.offline_disabled = !cpu->hotpluggable; #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE cpu->dev.bus->uevent = arch_cpu_uevent; #endif error = device_register(&cpu->dev); - if (!error && cpu->hotpluggable) - register_cpu_control(cpu); if (!error) per_cpu(cpu_sys_devices, num) = &cpu->dev; if (!error) -- cgit v1.2.3 From ac212b6980d8d5eda705864fc5a8ecddc6d6eacc Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 3 May 2013 00:26:22 +0200 Subject: ACPI / processor: Use common hotplug infrastructure Split the ACPI processor driver into two parts, one that is non-modular, resides in the ACPI core and handles the enumeration and hotplug of processors and one that implements the rest of the existing processor driver functionality. The non-modular part uses an ACPI scan handler object to enumerate processors on the basis of information provided by the ACPI namespace and to hook up with the common ACPI hotplug infrastructure. It also populates the ACPI handle of each processor device having a corresponding object in the ACPI namespace, which allows the driver proper to bind to those devices, and makes the driver bind to them if it is readily available (i.e. loaded) when the scan handler's .attach() routine is running. There are a few reasons to make this change. First, switching the ACPI processor driver to using the common ACPI hotplug infrastructure reduces code duplication and size considerably, even though a new file is created along with a header comment etc. Second, since the common hotplug code attempts to offline devices before starting the (non-reversible) removal procedure, it will abort (and possibly roll back) hot-remove operations involving processors if cpu_down() returns an error code for one of them instead of continuing them blindly (if /sys/firmware/acpi/hotplug/force_remove is unset). That is a more desirable behavior than what the current code does. Finally, the separation of the scan/hotplug part from the driver proper makes it possible to simplify the driver's .remove() routine, because it doesn't need to worry about the possible cleanup related to processor removal any more (the scan/hotplug part is responsible for that now) and can handle device removal and driver removal symmetricaly (i.e. as appropriate). Some user-visible changes in sysfs are made (for example, the 'sysdev' link from the ACPI device node to the processor device's directory is gone and a 'physical_node' link is present instead and a corresponding 'firmware_node' is present in the processor device's directory, the processor driver is now visible under /sys/bus/cpu/drivers/ and bound to the processor device), but that shouldn't affect the functionality that users care about (frequency scaling, C-states and thermal management). Tested on my venerable Toshiba Portege R500. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Reviewed-by: Toshi Kani --- drivers/base/cpu.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 25c8768172e9..7431ba6fc2d4 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -13,11 +13,21 @@ #include #include #include +#include #include "base.h" static DEFINE_PER_CPU(struct device *, cpu_sys_devices); +static int cpu_subsys_match(struct device *dev, struct device_driver *drv) +{ + /* ACPI style match is the only one that may succeed. */ + if (acpi_driver_match_device(dev, drv)) + return 1; + + return 0; +} + #ifdef CONFIG_HOTPLUG_CPU static void change_cpu_under_node(struct cpu *cpu, unsigned int from_nid, unsigned int to_nid) @@ -98,6 +108,7 @@ static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store); struct bus_type cpu_subsys = { .name = "cpu", .dev_name = "cpu", + .match = cpu_subsys_match, #ifdef CONFIG_HOTPLUG_CPU .online = cpu_subsys_online, .offline = cpu_subsys_offline, -- cgit v1.2.3 From c055da9fbad4b63bb3169f2b1a8b7ad429270bd0 Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Tue, 14 May 2013 16:46:06 +0200 Subject: cpu: fix "crash_notes" and "crash_notes_size" leaks in register_cpu() "crash_notes" and "crash_notes_size" are dynamically created with device_create_file() but aren't deleted anywhere. Define "crash_notes" and "crash_notes_size" statically via attribute groups so that device_register would create them automatically and files would be destroyed when CPU is destroyed. Signed-off-by: Igor Mammedov Tested-by: Konrad Rzeszutek Wilk Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman --- drivers/base/cpu.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 3d48fc887ef4..8f9e264220d2 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -164,7 +164,24 @@ static ssize_t show_crash_notes_size(struct device *dev, return rc; } static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL); + +static struct attribute *crash_note_cpu_attrs[] = { + &dev_attr_crash_notes.attr, + &dev_attr_crash_notes_size.attr, + NULL +}; + +static struct attribute_group crash_note_cpu_attr_group = { + .attrs = crash_note_cpu_attrs, +}; +#endif + +static const struct attribute_group *common_cpu_attr_groups[] = { +#ifdef CONFIG_KEXEC + &crash_note_cpu_attr_group, #endif + NULL +}; /* * Print cpu online, possible, present, and system maps @@ -280,6 +297,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE cpu->dev.bus->uevent = arch_cpu_uevent; #endif + cpu->dev.groups = common_cpu_attr_groups; error = device_register(&cpu->dev); if (!error && cpu->hotpluggable) register_cpu_control(cpu); @@ -288,13 +306,6 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) if (!error) register_cpu_under_node(num, cpu_to_node(num)); -#ifdef CONFIG_KEXEC - if (!error) - error = device_create_file(&cpu->dev, &dev_attr_crash_notes); - if (!error) - error = device_create_file(&cpu->dev, - &dev_attr_crash_notes_size); -#endif return error; } -- cgit v1.2.3 From 1c4e2d70afb132058bfe979f6854c1d0a732b556 Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Tue, 14 May 2013 16:46:07 +0200 Subject: cpu: make sure that cpu/online file created before KOBJ_ADD is emitted It fixes race between udev and hotplugged CPU registration by defining "online" attribute statically, so that device_add() would create it before notifying udev about new CPU. Original issue report is at https://lkml.org/lkml/2012/4/30/198 " > On Mon, Apr 30, 2012 at 11:36:23AM -0400, Konrad Rzeszutek Wilk wrote: > > Hey Greg, > > > > Hoping you can help with some guidance on how to fix this. > > > > The issue is with CPU hotplug is that when a CPU goes up > > it calls 'arch_register_cpu' which eventually calls > > register_cpu. That function does these two things: > > > > 251 error = device_register(&cpu->dev); > > 252 if (!error && cpu->hotpluggable) > > 253 register_cpu_control(cpu); > > > > and the device_register creates a nice little SysFS directory: > > > > /sys/devices/system/cpu/cpu2/ which at line 251 has the 'add' attribute > > but no 'online' attribute. udev then tries to echo 1 to the 'online' > > and it we get: > > udevd-work[2421]: error opening ATTR{/sys/devices/system/cpu/cpu2/online} for writing: No such file or directory > > > > Line 253 creates said 'online' and at that time udev [or the system admin] > > can write 1 to 'online' and the CPU goes up. > > > > So .. any thoughts? Is there some way to inhibit from uevent being sent > > until line 253 has run? " Signed-off-by: Igor Mammedov Tested-by: Konrad Rzeszutek Wilk Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman --- drivers/base/cpu.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 8f9e264220d2..c377673320ed 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -85,18 +85,21 @@ static ssize_t __ref store_online(struct device *dev, } static DEVICE_ATTR(online, 0644, show_online, store_online); -static void __cpuinit register_cpu_control(struct cpu *cpu) -{ - device_create_file(&cpu->dev, &dev_attr_online); -} +static struct attribute *hotplug_cpu_attrs[] = { + &dev_attr_online.attr, + NULL +}; + +static struct attribute_group hotplug_cpu_attr_group = { + .attrs = hotplug_cpu_attrs, +}; + void unregister_cpu(struct cpu *cpu) { int logical_cpu = cpu->dev.id; unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); - device_remove_file(&cpu->dev, &dev_attr_online); - device_unregister(&cpu->dev); per_cpu(cpu_sys_devices, logical_cpu) = NULL; return; @@ -122,11 +125,6 @@ static ssize_t cpu_release_store(struct device *dev, 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 */ -static inline void register_cpu_control(struct cpu *cpu) -{ -} #endif /* CONFIG_HOTPLUG_CPU */ #ifdef CONFIG_KEXEC @@ -183,6 +181,16 @@ static const struct attribute_group *common_cpu_attr_groups[] = { NULL }; +static const struct attribute_group *hotplugable_cpu_attr_groups[] = { +#ifdef CONFIG_KEXEC + &crash_note_cpu_attr_group, +#endif +#ifdef CONFIG_HOTPLUG_CPU + &hotplug_cpu_attr_group, +#endif + NULL +}; + /* * Print cpu online, possible, present, and system maps */ @@ -298,9 +306,9 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) cpu->dev.bus->uevent = arch_cpu_uevent; #endif cpu->dev.groups = common_cpu_attr_groups; + if (cpu->hotpluggable) + cpu->dev.groups = hotplugable_cpu_attr_groups; error = device_register(&cpu->dev); - if (!error && cpu->hotpluggable) - register_cpu_control(cpu); if (!error) per_cpu(cpu_sys_devices, num) = &cpu->dev; if (!error) -- cgit v1.2.3 From 1001b4d4a8ee6b2e7a6078a02ccdf68f91b192bd Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 30 May 2013 00:30:05 +0200 Subject: CPU: Fix sysfs cpu/online of offlined CPUs As reported by Dave Hansen, sysfs cpu/online shows 1 for offlined CPUs at boot. Fix this problem by initializing dev.offline with cpu_online() when registering a CPU. References: https://lkml.org/lkml/2013/5/29/403 Reported-and-tested-by: Dave Hansen Signed-off-by: Toshi Kani Signed-off-by: Rafael J. Wysocki --- 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 7431ba6fc2d4..1d110dc6f0c1 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -265,6 +265,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) cpu->dev.bus = &cpu_subsys; cpu->dev.release = cpu_device_release; cpu->dev.offline_disabled = !cpu->hotpluggable; + cpu->dev.offline = !cpu_online(num); #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE cpu->dev.bus->uevent = arch_cpu_uevent; #endif -- cgit v1.2.3 From a83048ebd449a441fdbd3fa854e6b1a71552cc99 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Wed, 19 Jun 2013 15:22:41 -0400 Subject: drivers: delete __cpuinit usage from all remaining drivers files The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the remaining one-off uses of the __cpuinit macros from all C files in the drivers/* directory. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Greg Kroah-Hartman Acked-by: Greg Kroah-Hartman Signed-off-by: Paul Gortmaker --- drivers/base/cpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base/cpu.c') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index a16d20e389f0..4c358bc44c72 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -278,7 +278,7 @@ static void cpu_device_release(struct device *dev) * * Initialize and register the CPU device. */ -int __cpuinit register_cpu(struct cpu *cpu, int num) +int register_cpu(struct cpu *cpu, int num) { int error; -- cgit v1.2.3