cpufreq: intel_pstate: Add base_frequency attribute
authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Mon, 15 Oct 2018 17:37:20 +0000 (10:37 -0700)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tue, 16 Oct 2018 08:33:39 +0000 (10:33 +0200)
commit86d333a8cc7f66c2314ab1e147834a1cd95ec2de
tree136188373a393aee5ecea86119fa20275716d5bf
parent29523f095397637edca60c627bc3e5c25a02c40f
cpufreq: intel_pstate: Add base_frequency attribute

Expose base_frequency to user space via cpufreq sysfs when HWP is in
use.

This HWP base frequency is read from the ACPI _CPC object if present,
or from the HWP Capabilities MSR otherwise.

On the majority of the HWP platforms the _CPC object will point to
the HWP Capabilities MSR using the "Functional Fixed Hardware"
address space type.  The address space type also can simply be
ACPI_TYPE_INTEGER, however, in which case the platform firmware
can set its value at the initialization time based on the system
constraints.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/cpufreq/intel_pstate.c