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path: root/drivers/acpi/acpi_processor.c
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2013-10-28Merge branch 'acpi-processor'Rafael J. Wysocki
* acpi-processor: ACPI / processor: fixed a brace coding style issue ACPI / processor: Remove outdated comments ACPI / processor: remove unnecessary if (!pr) check ACPI / processor: remove some dead code in acpi_processor_get_info() x86 / ACPI: simplify _acpi_map_lsapic() ACPI / processor: use apic_id and remove duplicated _MAT evaluation ACPI / processor: Introduce apic_id in struct processor to save parsed APIC id
2013-09-24ACPI / processor: Remove outdated commentsHanjun Guo
acpi_get_processor_id() can be find nowhere, and the acpi id is synchronized to APIC id when acpi_get_cpuid() is called, so the comments can be removed. Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-24ACPI / processor: remove unnecessary if (!pr) checkHanjun Guo
acpi_processor_errata() is only called in acpi_processor_get_info(), and the argument 'pr' passed to acpi_processor_errata() will never be NULL, so the if (!pr) check is unnecessary and can be removed. Since the 'pr' argument is not used by acpi_processor_errata() any more, so change the argument into void too. Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-24ACPI / processor: remove some dead code in acpi_processor_get_info()Jiang Liu
errata.smp is used by nowhere, so the variable assignment is meanless, remove it. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-24ACPI / processor: use apic_id and remove duplicated _MAT evaluationJiang Liu
Since APIC id is saved in processor struct, just use it and remove the duplicated _MAT evaluation. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-24ACPI / processor: Introduce apic_id in struct processor to save parsed APIC idJiang Liu
For cpu hot add, we evaluate _MAT or parse MADT twice to get APIC id, here is the code logic: acpi_processor_add() acpi_processor_get_info() acpi_get_cpuid() will evaluate _MAT or parse MADT; acpi_processor_hotadd_init() acpi_map_lsapic() will evaluate _MAT again; This can be done more effectively, this patch introduces apic_id in struct processor to save parsed APIC id, and then we can use it and remove the duplicated _MAT evaluation. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-24acpi_processor: convert acpi_evaluate_object() to acpi_evaluate_integer()Zhang Rui
acpi_evaluate_integer() is an ACPI API introduced to evaluate an ACPI control method that is known to have an integer return value. This API can simplify the code because the calling function does not need to use the specified acpi_buffer structure required by acpi_evaluate_object(); Convert acpi_evaluate_object() to acpi_evaluate_integer() in drivers/acpi/acpi_processor.c in this patch. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-13ACPI / processor: Acquire writer lock to update CPU mapsToshi Kani
CPU system maps are protected with reader/writer locks. The reader lock, get_online_cpus(), assures that the maps are not updated while holding the lock. The writer lock, cpu_hotplug_begin(), is used to udpate the cpu maps along with cpu_maps_update_begin(). However, the ACPI processor handler updates the cpu maps without holding the the writer lock. acpi_map_lsapic() is called from acpi_processor_hotadd_init() to update cpu_possible_mask and cpu_present_mask. acpi_unmap_lsapic() is called from acpi_processor_remove() to update cpu_possible_mask. Currently, they are either unprotected or protected with the reader lock, which is not correct. For example, the get_online_cpus() below is supposed to assure that cpu_possible_mask is not changed while the code is iterating with for_each_possible_cpu(). get_online_cpus(); for_each_possible_cpu(cpu) { : } put_online_cpus(); However, this lock has no protection with CPU hotplug since the ACPI processor handler does not use the writer lock when it updates cpu_possible_mask. The reader lock does not serialize within the readers. This patch protects them with the writer lock with cpu_hotplug_begin() along with cpu_maps_update_begin(), which must be held before calling cpu_hotplug_begin(). It also protects arch_register_cpu() / arch_unregister_cpu(), which creates / deletes a sysfs cpu device interface. For this purpose it changes cpu_hotplug_begin() and cpu_hotplug_done() to global and exports them in cpu.h. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07ACPI / processor: move try_offline_node() after acpi_unmap_lsapic()Yasuaki Ishimatsu
try_offline_node() checks that all CPUs associated with the given node have been removed by using cpu_present_bits. If all cpus related to that node have been removed, try_offline_node() clears the node information. However, try_offline_node() called from acpi_processor_remove() never clears the node information. For disabling cpu_present_bits, acpi_unmap_lsapic() needs be called. Yet, acpi_unmap_lsapic() is called after try_offline_node() has run. So when try_offline_node() runs, the CPU's cpu_present_bits is always set. Fix the issue by moving try_offline_node() after acpi_unmap_lsapic(). The problem fixed here was uncovered by commit cecdb19 "ACPI / scan: Change the implementation of acpi_bus_trim()". [rjw: Changelog] Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: 3.9+ <stable@vger.kernel.org> # 3.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-14acpi: delete __cpuinit usage from all acpi filesPaul Gortmaker
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 drivers/acpi uses of the __cpuinit macros from all C files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Len Brown <lenb@kernel.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: linux-acpi@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-06-01ACPI / processor: Fix potential NULL pointer dereference in acpi_processor_add()Hanjun Guo
In acpi_processor_add(), get_cpu_device() may return NULL in some cases which is then passed to acpi_bind_one() and that will case a NULL pointer dereference to occur. Add a check to prevent that from happening. [rjw: Changelog] Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-01ACPI / processor: Pass processor object handle to acpi_bind_one()Rafael J. Wysocki
Make acpi_processor_add() pass the ACPI handle of the processor namespace object to acpi_bind_one() instead of setting it directly to allow acpi_bind_one() to catch possible bugs causing the ACPI handle of the processor device to be set earlier. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Toshi Kani <toshi.kani@hp.com>
2013-05-30ACPI / processor: Initialize per_cpu(processors, pr->id) properlyRafael J. Wysocki
Commit ac212b6 (ACPI / processor: Use common hotplug infrastructure) forgot about initializing the per-CPU 'processors' variables which lead to ACPI cpuidle failure to use C-states and caused boot slowdown on multi-CPU machines. Fix the problem by adding per_cpu(processors, pr->id) initialization to acpi_processor_add() and add make acpi_processor_remove() clean it up as appropriate. Also modify acpi_processor_stop() so that it doesn't clear per_cpu(processors, pr->id) on processor driver removal which would then cause problems to happen when the driver is loaded again. This version of the patch contains fixes from Yinghai Lu. Reported-and-tested-by: Yinghai Lu <yinghai@kernel.org> Reported-and-tested-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12ACPI / processor: Use common hotplug infrastructureRafael J. Wysocki
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 <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Toshi Kani <toshi.kani@hp.com>