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path: root/drivers/cpufreq/acpi-cpufreq.c
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2012-09-09acpi-cpufreq: Add compatibility for legacy AMD cpb sysfs knobAndre Przywara
The powernow-k8 driver supported a sysfs knob called "cpb", which was instantiated per CPU, but actually acted globally for the whole system. To keep some compatibility with this feature, we re-introduce this behavior here, but: a) only enable it on AMD CPUs and b) protect it with a Kconfig switch I'd like to consider this feature obsolete. Lets keep it around for some kernel versions and then phase it out. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-09acpi-cpufreq: Add support for disabling dynamic overclockingAndre Przywara
One feature present in powernow-k8 that isn't present in acpi-cpufreq is support for enabling or disabling AMD's core performance boost technology. This patch adds support to acpi-cpufreq, but also includes support for Intel's dynamic acceleration. The original boost disabling sysfs file was per CPU, but acted globally. Also the naming (cpb) was at least not intuitive. So lets introduce a single file simply called "boost", which sits once in /sys/devices/system/cpu/cpufreq. This should be the only way of using this feature, so add documentation about the rationale and the usage. A following patch will re-introduce the cpb knob for compatibility reasons on AMD CPUs. Per-CPU boost switching is possible, but not trivial and is thus postponed to a later patch series. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-09acpi-cpufreq: Add quirk to disable _PSD usage on all AMD CPUsAndre Przywara
To workaround some Windows specific behavior, the ACPI _PSD table on AMD desktop boards advertises all cores as dependent, meaning that they all can only use the same P-state. acpi-cpufreq strictly obeys this description, instantiating one CPU only and symlinking the others. But the hardware can have distinct frequencies for each core and powernow-k8 did it that way. So, in order to use the hardware to its full potential and keep the original powernow-k8 behavior, lets override the _PSD table setting on AMD hardware. We use the siblings table, as it matches the current hardware behavior. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-09acpi-cpufreq: Add support for modern AMD CPUsMatthew Garrett
The programming model for P-states on modern AMD CPUs is very similar to that of Intel and VIA. It makes sense to consolidate this support into one driver rather than duplicating functionality between two of them. This patch adds support for AMDs with hardware P-state control to acpi-cpufreq. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-13[CPUFREQ] Handle CPUs with different capabilities in acpi-cpufreqMatthew Garrett
acpi-cpufreq checks each CPU for aperf/mperf support, but only sets a global flag. This will cause errors if some CPUs in the system don't support the feature. Check boot_cpu_has() instead in order to make sure that all CPUs support it. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Dave Jones <davej@redhat.com>
2011-07-10[CPUFREQ] fix cpumask memory leak in acpi-cpufreq on cpu hotplug.Luming Yu
I came across a memory leak during a cyclic cpu-online-offline test. Signed-off-by: Yu Luming <luming.yu@intel.com> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
2011-05-19[CPUFREQ] Move x86 drivers to drivers/cpufreq/Dave Jones
Signed-off-by: Dave Jones <davej@redhat.com>