Commit 079c1812 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki

Merge branches 'intel_pstate', 'pm-cpufreq' and 'pm-cpufreq-sched'

* intel_pstate:
  cpufreq: intel_pstate: Document the current behavior and user interface

* pm-cpufreq:
  cpufreq: dbx500: add a Kconfig symbol

* pm-cpufreq-sched:
  cpufreq: schedutil: use now as reference when aggregating shared policy requests
.. |struct cpufreq_policy| replace:: :c:type:`struct cpufreq_policy <cpufreq_policy>`
.. |intel_pstate| replace:: :doc:`intel_pstate <intel_pstate>`
=======================
CPU Performance Scaling
......@@ -75,7 +76,7 @@ feedback registers, as that information is typically specific to the hardware
interface it comes from and may not be easily represented in an abstract,
platform-independent way. For this reason, ``CPUFreq`` allows scaling drivers
to bypass the governor layer and implement their own performance scaling
algorithms. That is done by the ``intel_pstate`` scaling driver.
algorithms. That is done by the |intel_pstate| scaling driver.
``CPUFreq`` Policy Objects
......@@ -174,13 +175,13 @@ necessary to restart the scaling governor so that it can take the new online CPU
into account. That is achieved by invoking the governor's ``->stop`` and
``->start()`` callbacks, in this order, for the entire policy.
As mentioned before, the ``intel_pstate`` scaling driver bypasses the scaling
As mentioned before, the |intel_pstate| scaling driver bypasses the scaling
governor layer of ``CPUFreq`` and provides its own P-state selection algorithms.
Consequently, if ``intel_pstate`` is used, scaling governors are not attached to
Consequently, if |intel_pstate| is used, scaling governors are not attached to
new policy objects. Instead, the driver's ``->setpolicy()`` callback is invoked
to register per-CPU utilization update callbacks for each policy. These
callbacks are invoked by the CPU scheduler in the same way as for scaling
governors, but in the ``intel_pstate`` case they both determine the P-state to
governors, but in the |intel_pstate| case they both determine the P-state to
use and change the hardware configuration accordingly in one go from scheduler
context.
......@@ -257,7 +258,7 @@ are the following:
``scaling_available_governors``
List of ``CPUFreq`` scaling governors present in the kernel that can
be attached to this policy or (if the ``intel_pstate`` scaling driver is
be attached to this policy or (if the |intel_pstate| scaling driver is
in use) list of scaling algorithms provided by the driver that can be
applied to this policy.
......@@ -274,7 +275,7 @@ are the following:
the CPU is actually running at (due to hardware design and other
limitations).
Some scaling drivers (e.g. ``intel_pstate``) attempt to provide
Some scaling drivers (e.g. |intel_pstate|) attempt to provide
information more precisely reflecting the current CPU frequency through
this attribute, but that still may not be the exact current CPU
frequency as seen by the hardware at the moment.
......@@ -284,13 +285,13 @@ are the following:
``scaling_governor``
The scaling governor currently attached to this policy or (if the
``intel_pstate`` scaling driver is in use) the scaling algorithm
|intel_pstate| scaling driver is in use) the scaling algorithm
provided by the driver that is currently applied to this policy.
This attribute is read-write and writing to it will cause a new scaling
governor to be attached to this policy or a new scaling algorithm
provided by the scaling driver to be applied to it (in the
``intel_pstate`` case), as indicated by the string written to this
|intel_pstate| case), as indicated by the string written to this
attribute (which must be one of the names listed by the
``scaling_available_governors`` attribute described above).
......@@ -619,7 +620,7 @@ This file is located under :file:`/sys/devices/system/cpu/cpufreq/` and controls
the "boost" setting for the whole system. It is not present if the underlying
scaling driver does not support the frequency boost mechanism (or supports it,
but provides a driver-specific interface for controlling it, like
``intel_pstate``).
|intel_pstate|).
If the value in this file is 1, the frequency boost mechanism is enabled. This
means that either the hardware can be put into states in which it is able to
......
......@@ -6,6 +6,7 @@ Power Management
:maxdepth: 2
cpufreq
intel_pstate
.. only:: subproject and html
......
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This diff is collapsed.
......@@ -71,6 +71,15 @@ config ARM_HIGHBANK_CPUFREQ
If in doubt, say N.
config ARM_DB8500_CPUFREQ
tristate "ST-Ericsson DB8500 cpufreq" if COMPILE_TEST && !ARCH_U8500
default ARCH_U8500
depends on HAS_IOMEM
depends on !CPU_THERMAL || THERMAL
help
This adds the CPUFreq driver for ST-Ericsson Ux500 (DB8500) SoC
series.
config ARM_IMX6Q_CPUFREQ
tristate "Freescale i.MX6 cpufreq support"
depends on ARCH_MXC
......
......@@ -53,7 +53,7 @@ obj-$(CONFIG_ARM_DT_BL_CPUFREQ) += arm_big_little_dt.o
obj-$(CONFIG_ARM_BRCMSTB_AVS_CPUFREQ) += brcmstb-avs-cpufreq.o
obj-$(CONFIG_ARCH_DAVINCI) += davinci-cpufreq.o
obj-$(CONFIG_UX500_SOC_DB8500) += dbx500-cpufreq.o
obj-$(CONFIG_ARM_DB8500_CPUFREQ) += dbx500-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS5440_CPUFREQ) += exynos5440-cpufreq.o
obj-$(CONFIG_ARM_HIGHBANK_CPUFREQ) += highbank-cpufreq.o
obj-$(CONFIG_ARM_IMX6Q_CPUFREQ) += imx6q-cpufreq.o
......
......@@ -245,11 +245,10 @@ static void sugov_update_single(struct update_util_data *hook, u64 time,
sugov_update_commit(sg_policy, time, next_f);
}
static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu)
static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
{
struct sugov_policy *sg_policy = sg_cpu->sg_policy;
struct cpufreq_policy *policy = sg_policy->policy;
u64 last_freq_update_time = sg_policy->last_freq_update_time;
unsigned long util = 0, max = 1;
unsigned int j;
......@@ -265,7 +264,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu)
* enough, don't take the CPU into account as it probably is
* idle now (and clear iowait_boost for it).
*/
delta_ns = last_freq_update_time - j_sg_cpu->last_update;
delta_ns = time - j_sg_cpu->last_update;
if (delta_ns > TICK_NSEC) {
j_sg_cpu->iowait_boost = 0;
continue;
......@@ -309,7 +308,7 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time,
if (flags & SCHED_CPUFREQ_RT_DL)
next_f = sg_policy->policy->cpuinfo.max_freq;
else
next_f = sugov_next_freq_shared(sg_cpu);
next_f = sugov_next_freq_shared(sg_cpu, time);
sugov_update_commit(sg_policy, time, next_f);
}
......
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