linux/drivers/acpi/acpi_processor.c, branch v3.13

Merge branch 'acpi-processor'

2013-10-28T00:11:24Z

* acpi-processor: ACPI / processor: fixed a brace coding style issue ACPI / processor: Remove outdated comments ACPI / processor: remove unnecessary if (!pr) check ACPI / processor: remove some dead code in acpi_processor_get_info() x86 / ACPI: simplify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

ACPI / processor: Remove outdated comments

2013-09-23T23:39:40Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / processor: remove unnecessary if (!pr) check

2013-09-23T23:39:40Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / processor: remove some dead code in acpi_processor_get_info()

2013-09-23T23:39:40Z

errata.smp is used by nowhere, so the variable assignment is meanless, remove it. Signed-off-by: Jiang Liu Signed-off-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

ACPI / processor: use apic_id and remove duplicated _MAT evaluation

2013-09-23T23:39:39Z

Since APIC id is saved in processor struct, just use it and remove the duplicated _MAT evaluation. Signed-off-by: Jiang Liu Signed-off-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

ACPI / processor: Introduce apic_id in struct processor to save parsed APIC id

2013-09-23T23:39:39Z

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 Signed-off-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

acpi_processor: convert acpi_evaluate_object() to acpi_evaluate_integer()

2013-09-23T23:37:56Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / processor: Acquire writer lock to update CPU maps

2013-08-13T10:20:16Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / processor: move try_offline_node() after acpi_unmap_lsapic()

2013-08-07T20:18:53Z

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 Acked-by: Toshi Kani Cc: 3.9+ # 3.9+ Signed-off-by: Rafael J. Wysocki

acpi: delete __cpuinit usage from all acpi files

2013-07-14T23:36:58Z

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 Cc: "Rafael J. Wysocki" Cc: linux-acpi@vger.kernel.org Signed-off-by: Paul Gortmaker