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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-03 20:28:08 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-03 20:28:08 -0700 |
commit | 04084978003c1a1810a0b1fea581078106394a32 (patch) | |
tree | 03844f5718e1200ac7b2722edfe44e5c8b15efa4 /Documentation | |
parent | d516840629ccc1aa6b59a0886134688f9b5531a0 (diff) | |
parent | 86ba54fb0816480941cda78a99f107ab2bbd4249 (diff) | |
download | linux-04084978003c1a1810a0b1fea581078106394a32.tar.bz2 |
Merge tag 'pm-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"The most significant change here is the extension of the Energy Model
to cover non-CPU devices (as well as CPUs) from Lukasz Luba.
There is also some new hardware support (Ice Lake server idle states
table for intel_idle, Sapphire Rapids and Power Limit 4 support in the
RAPL driver), some new functionality in the existing drivers (eg. a
new switch to disable/enable CPU energy-efficiency optimizations in
intel_pstate, delayed timers in devfreq), some assorted fixes (cpufreq
core, intel_pstate, intel_idle) and cleanups (eg. cpuidle-psci,
devfreq), including the elimination of W=1 build warnings from cpufreq
done by Lee Jones.
Specifics:
- Make the Energy Model cover non-CPU devices (Lukasz Luba).
- Add Ice Lake server idle states table to the intel_idle driver and
eliminate a redundant static variable from it (Chen Yu, Rafael
Wysocki).
- Eliminate all W=1 build warnings from cpufreq (Lee Jones).
- Add support for Sapphire Rapids and for Power Limit 4 to the Intel
RAPL power capping driver (Sumeet Pawnikar, Zhang Rui).
- Fix function name in kerneldoc comments in the idle_inject power
capping driver (Yangtao Li).
- Fix locking issues with cpufreq governors and drop a redundant
"weak" function definition from cpufreq (Viresh Kumar).
- Rearrange cpufreq to register non-modular governors at the
core_initcall level and allow the default cpufreq governor to be
specified in the kernel command line (Quentin Perret).
- Extend, fix and clean up the intel_pstate driver (Srinivas
Pandruvada, Rafael Wysocki):
* Add a new sysfs attribute for disabling/enabling CPU
energy-efficiency optimizations in the processor.
* Make the driver avoid enabling HWP if EPP is not supported.
* Allow the driver to handle numeric EPP values in the sysfs
interface and fix the setting of EPP via sysfs in the active
mode.
* Eliminate a static checker warning and clean up a kerneldoc
comment.
- Clean up some variable declarations in the powernv cpufreq driver
(Wei Yongjun).
- Fix up the ->enter_s2idle callback definition to cover the case
when it points to the same function as ->idle correctly (Neal Liu).
- Rearrange and clean up the PSCI cpuidle driver (Ulf Hansson).
- Make the PM core emit "changed" uevent when adding/removing the
"wakeup" sysfs attribute of devices (Abhishek Pandit-Subedi).
- Add a helper macro for declaring PM callbacks and use it in the MMC
jz4740 driver (Paul Cercueil).
- Fix white space in some places in the hibernate code and make the
system-wide PM code use "const char *" where appropriate (Xiang
Chen, Alexey Dobriyan).
- Add one more "unsafe" helper macro to the freezer to cover the NFS
use case (He Zhe).
- Change the language in the generic PM domains framework to use
parent/child terminology and clean up a typo and some comment
fromatting in that code (Kees Cook, Geert Uytterhoeven).
- Update the operating performance points OPP framework (Lukasz Luba,
Andrew-sh.Cheng, Valdis Kletnieks):
* Refactor dev_pm_opp_of_register_em() and update related drivers.
* Add a missing function export.
* Allow disabled OPPs in dev_pm_opp_get_freq().
- Update devfreq core and drivers (Chanwoo Choi, Lukasz Luba, Enric
Balletbo i Serra, Dmitry Osipenko, Kieran Bingham, Marc Zyngier):
* Add support for delayed timers to the devfreq core and make the
Samsung exynos5422-dmc driver use it.
* Unify sysfs interface to use "df-" as a prefix in instance
names consistently.
* Fix devfreq_summary debugfs node indentation.
* Add the rockchip,pmu phandle to the rk3399_dmc driver DT
bindings.
* List Dmitry Osipenko as the Tegra devfreq driver maintainer.
* Fix typos in the core devfreq code.
- Update the pm-graph utility to version 5.7 including a number of
fixes related to suspend-to-idle (Todd Brandt).
- Fix coccicheck errors and warnings in the cpupower utility (Shuah
Khan).
- Replace HTTP links with HTTPs ones in multiple places (Alexander A.
Klimov)"
* tag 'pm-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (71 commits)
cpuidle: ACPI: fix 'return' with no value build warning
cpufreq: intel_pstate: Fix EPP setting via sysfs in active mode
cpufreq: intel_pstate: Rearrange the storing of new EPP values
intel_idle: Customize IceLake server support
PM / devfreq: Fix the wrong end with semicolon
PM / devfreq: Fix indentaion of devfreq_summary debugfs node
PM / devfreq: Clean up the devfreq instance name in sysfs attr
memory: samsung: exynos5422-dmc: Add module param to control IRQ mode
memory: samsung: exynos5422-dmc: Adjust polling interval and uptreshold
memory: samsung: exynos5422-dmc: Use delayed timer as default
PM / devfreq: Add support delayed timer for polling mode
dt-bindings: devfreq: rk3399_dmc: Add rockchip,pmu phandle
PM / devfreq: tegra: Add Dmitry as a maintainer
PM / devfreq: event: Fix trivial spelling
PM / devfreq: rk3399_dmc: Fix kernel oops when rockchip,pmu is absent
cpuidle: change enter_s2idle() prototype
cpuidle: psci: Prevent domain idlestates until consumers are ready
cpuidle: psci: Convert PM domain to platform driver
cpuidle: psci: Fix error path via converting to a platform driver
cpuidle: psci: Fail cpuidle registration if set OSI mode failed
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/ABI/testing/sysfs-class-devfreq | 12 | ||||
-rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 | ||||
-rw-r--r-- | Documentation/admin-guide/pm/cpufreq.rst | 6 | ||||
-rw-r--r-- | Documentation/admin-guide/pm/intel_pstate.rst | 17 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt | 2 | ||||
-rw-r--r-- | Documentation/power/energy-model.rst | 135 | ||||
-rw-r--r-- | Documentation/power/powercap/powercap.rst | 15 |
7 files changed, 123 insertions, 69 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq index 9758eb85ade3..deefffb3bbe4 100644 --- a/Documentation/ABI/testing/sysfs-class-devfreq +++ b/Documentation/ABI/testing/sysfs-class-devfreq @@ -108,3 +108,15 @@ Description: frequency requested by governors and min_freq. The max_freq overrides min_freq because max_freq may be used to throttle devices to avoid overheating. + +What: /sys/class/devfreq/.../timer +Date: July 2020 +Contact: Chanwoo Choi <cw00.choi@samsung.com> +Description: + This ABI shows and stores the kind of work timer by users. + This work timer is used by devfreq workqueue in order to + monitor the device status such as utilization. The user + can change the work timer on runtime according to their demand + as following: + echo deferrable > /sys/class/devfreq/.../timer + echo delayed > /sys/class/devfreq/.../timer diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index d35fd3ced0db..9e74ffd377f0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -703,6 +703,11 @@ cpufreq.off=1 [CPU_FREQ] disable the cpufreq sub-system + cpufreq.default_governor= + [CPU_FREQ] Name of the default cpufreq governor or + policy to use. This governor must be registered in the + kernel before the cpufreq driver probes. + cpu_init_udelay=N [X86] Delay for N microsec between assert and de-assert of APIC INIT to start processors. This delay occurs diff --git a/Documentation/admin-guide/pm/cpufreq.rst b/Documentation/admin-guide/pm/cpufreq.rst index 0c74a7784964..368e612145d2 100644 --- a/Documentation/admin-guide/pm/cpufreq.rst +++ b/Documentation/admin-guide/pm/cpufreq.rst @@ -147,9 +147,9 @@ CPUs in it. The next major initialization step for a new policy object is to attach a scaling governor to it (to begin with, that is the default scaling governor -determined by the kernel configuration, but it may be changed later -via ``sysfs``). First, a pointer to the new policy object is passed to the -governor's ``->init()`` callback which is expected to initialize all of the +determined by the kernel command line or configuration, but it may be changed +later via ``sysfs``). First, a pointer to the new policy object is passed to +the governor's ``->init()`` callback which is expected to initialize all of the data structures necessary to handle the given policy and, possibly, to add a governor ``sysfs`` interface to it. Next, the governor is started by invoking its ``->start()`` callback. diff --git a/Documentation/admin-guide/pm/intel_pstate.rst b/Documentation/admin-guide/pm/intel_pstate.rst index 39d80bc29ccd..40d481cca368 100644 --- a/Documentation/admin-guide/pm/intel_pstate.rst +++ b/Documentation/admin-guide/pm/intel_pstate.rst @@ -431,6 +431,17 @@ argument is passed to the kernel in the command line. supported in the current configuration, writes to this attribute will fail with an appropriate error. +``energy_efficiency`` + This attribute is only present on platforms, which have CPUs matching + Kaby Lake or Coffee Lake desktop CPU model. By default + energy efficiency optimizations are disabled on these CPU models in HWP + mode by this driver. Enabling energy efficiency may limit maximum + operating frequency in both HWP and non HWP mode. In non HWP mode, + optimizations are done only in the turbo frequency range. In HWP mode, + optimizations are done in the entire frequency range. Setting this + attribute to "1" enables energy efficiency optimizations and setting + to "0" disables energy efficiency optimizations. + Interpretation of Policy Attributes ----------------------------------- @@ -554,7 +565,11 @@ somewhere between the two extremes: Strings written to the ``energy_performance_preference`` attribute are internally translated to integer values written to the processor's Energy-Performance Preference (EPP) knob (if supported) or its -Energy-Performance Bias (EPB) knob. +Energy-Performance Bias (EPB) knob. It is also possible to write a positive +integer value between 0 to 255, if the EPP feature is present. If the EPP +feature is not present, writing integer value to this attribute is not +supported. In this case, user can use + "/sys/devices/system/cpu/cpu*/power/energy_perf_bias" interface. [Note that tasks may by migrated from one CPU to another by the scheduler's load-balancing algorithm and if different energy vs performance hints are diff --git a/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt index 0ec68141f85a..a10d1f6d85c6 100644 --- a/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt +++ b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt @@ -18,6 +18,8 @@ Optional properties: format depends on the interrupt controller. It should be a DCF interrupt. When DDR DVFS finishes a DCF interrupt is triggered. +- rockchip,pmu: Phandle to the syscon managing the "PMU general register + files". Following properties relate to DDR timing: diff --git a/Documentation/power/energy-model.rst b/Documentation/power/energy-model.rst index 90a345d57ae9..a6fb986abe3c 100644 --- a/Documentation/power/energy-model.rst +++ b/Documentation/power/energy-model.rst @@ -1,15 +1,17 @@ -==================== -Energy Model of CPUs -==================== +.. SPDX-License-Identifier: GPL-2.0 + +======================= +Energy Model of devices +======================= 1. Overview ----------- The Energy Model (EM) framework serves as an interface between drivers knowing -the power consumed by CPUs at various performance levels, and the kernel +the power consumed by devices at various performance levels, and the kernel subsystems willing to use that information to make energy-aware decisions. -The source of the information about the power consumed by CPUs can vary greatly +The source of the information about the power consumed by devices can vary greatly from one platform to another. These power costs can be estimated using devicetree data in some cases. In others, the firmware will know better. Alternatively, userspace might be best positioned. And so on. In order to avoid @@ -25,7 +27,7 @@ framework, and interested clients reading the data from it:: +---------------+ +-----------------+ +---------------+ | Thermal (IPA) | | Scheduler (EAS) | | Other | +---------------+ +-----------------+ +---------------+ - | | em_pd_energy() | + | | em_cpu_energy() | | | em_cpu_get() | +---------+ | +---------+ | | | @@ -35,7 +37,7 @@ framework, and interested clients reading the data from it:: | Framework | +---------------------+ ^ ^ ^ - | | | em_register_perf_domain() + | | | em_dev_register_perf_domain() +----------+ | +---------+ | | | +---------------+ +---------------+ +--------------+ @@ -47,12 +49,12 @@ framework, and interested clients reading the data from it:: | Device Tree | | Firmware | | ? | +--------------+ +---------------+ +--------------+ -The EM framework manages power cost tables per 'performance domain' in the -system. A performance domain is a group of CPUs whose performance is scaled -together. Performance domains generally have a 1-to-1 mapping with CPUFreq -policies. All CPUs in a performance domain are required to have the same -micro-architecture. CPUs in different performance domains can have different -micro-architectures. +In case of CPU devices the EM framework manages power cost tables per +'performance domain' in the system. A performance domain is a group of CPUs +whose performance is scaled together. Performance domains generally have a +1-to-1 mapping with CPUFreq policies. All CPUs in a performance domain are +required to have the same micro-architecture. CPUs in different performance +domains can have different micro-architectures. 2. Core APIs @@ -70,14 +72,16 @@ CONFIG_ENERGY_MODEL must be enabled to use the EM framework. Drivers are expected to register performance domains into the EM framework by calling the following API:: - int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, - struct em_data_callback *cb); + int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, + struct em_data_callback *cb, cpumask_t *cpus); -Drivers must specify the CPUs of the performance domains using the cpumask -argument, and provide a callback function returning <frequency, power> tuples -for each capacity state. The callback function provided by the driver is free +Drivers must provide a callback function returning <frequency, power> tuples +for each performance state. The callback function provided by the driver is free to fetch data from any relevant location (DT, firmware, ...), and by any mean -deemed necessary. See Section 3. for an example of driver implementing this +deemed necessary. Only for CPU devices, drivers must specify the CPUs of the +performance domains using cpumask. For other devices than CPUs the last +argument must be set to NULL. +See Section 3. for an example of driver implementing this callback, and kernel/power/energy_model.c for further documentation on this API. @@ -85,13 +89,20 @@ API. 2.3 Accessing performance domains ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +There are two API functions which provide the access to the energy model: +em_cpu_get() which takes CPU id as an argument and em_pd_get() with device +pointer as an argument. It depends on the subsystem which interface it is +going to use, but in case of CPU devices both functions return the same +performance domain. + Subsystems interested in the energy model of a CPU can retrieve it using the em_cpu_get() API. The energy model tables are allocated once upon creation of the performance domains, and kept in memory untouched. The energy consumed by a performance domain can be estimated using the -em_pd_energy() API. The estimation is performed assuming that the schedutil -CPUfreq governor is in use. +em_cpu_energy() API. The estimation is performed assuming that the schedutil +CPUfreq governor is in use in case of CPU device. Currently this calculation is +not provided for other type of devices. More details about the above APIs can be found in include/linux/energy_model.h. @@ -106,42 +117,46 @@ EM framework:: -> drivers/cpufreq/foo_cpufreq.c - 01 static int est_power(unsigned long *mW, unsigned long *KHz, int cpu) - 02 { - 03 long freq, power; - 04 - 05 /* Use the 'foo' protocol to ceil the frequency */ - 06 freq = foo_get_freq_ceil(cpu, *KHz); - 07 if (freq < 0); - 08 return freq; - 09 - 10 /* Estimate the power cost for the CPU at the relevant freq. */ - 11 power = foo_estimate_power(cpu, freq); - 12 if (power < 0); - 13 return power; - 14 - 15 /* Return the values to the EM framework */ - 16 *mW = power; - 17 *KHz = freq; - 18 - 19 return 0; - 20 } - 21 - 22 static int foo_cpufreq_init(struct cpufreq_policy *policy) - 23 { - 24 struct em_data_callback em_cb = EM_DATA_CB(est_power); - 25 int nr_opp, ret; - 26 - 27 /* Do the actual CPUFreq init work ... */ - 28 ret = do_foo_cpufreq_init(policy); - 29 if (ret) - 30 return ret; - 31 - 32 /* Find the number of OPPs for this policy */ - 33 nr_opp = foo_get_nr_opp(policy); - 34 - 35 /* And register the new performance domain */ - 36 em_register_perf_domain(policy->cpus, nr_opp, &em_cb); - 37 - 38 return 0; - 39 } + 01 static int est_power(unsigned long *mW, unsigned long *KHz, + 02 struct device *dev) + 03 { + 04 long freq, power; + 05 + 06 /* Use the 'foo' protocol to ceil the frequency */ + 07 freq = foo_get_freq_ceil(dev, *KHz); + 08 if (freq < 0); + 09 return freq; + 10 + 11 /* Estimate the power cost for the dev at the relevant freq. */ + 12 power = foo_estimate_power(dev, freq); + 13 if (power < 0); + 14 return power; + 15 + 16 /* Return the values to the EM framework */ + 17 *mW = power; + 18 *KHz = freq; + 19 + 20 return 0; + 21 } + 22 + 23 static int foo_cpufreq_init(struct cpufreq_policy *policy) + 24 { + 25 struct em_data_callback em_cb = EM_DATA_CB(est_power); + 26 struct device *cpu_dev; + 27 int nr_opp, ret; + 28 + 29 cpu_dev = get_cpu_device(cpumask_first(policy->cpus)); + 30 + 31 /* Do the actual CPUFreq init work ... */ + 32 ret = do_foo_cpufreq_init(policy); + 33 if (ret) + 34 return ret; + 35 + 36 /* Find the number of OPPs for this policy */ + 37 nr_opp = foo_get_nr_opp(policy); + 38 + 39 /* And register the new performance domain */ + 40 em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, policy->cpus); + 41 + 42 return 0; + 43 } diff --git a/Documentation/power/powercap/powercap.rst b/Documentation/power/powercap/powercap.rst index 7ae3b44c7624..e75d12596dac 100644 --- a/Documentation/power/powercap/powercap.rst +++ b/Documentation/power/powercap/powercap.rst @@ -167,11 +167,13 @@ For example:: package-0 --------- -The Intel RAPL technology allows two constraints, short term and long term, -with two different time windows to be applied to each power zone. Thus for -each zone there are 2 attributes representing the constraint names, 2 power -limits and 2 attributes representing the sizes of the time windows. Such that, -constraint_j_* attributes correspond to the jth constraint (j = 0,1). +Depending on different power zones, the Intel RAPL technology allows +one or multiple constraints like short term, long term and peak power, +with different time windows to be applied to each power zone. +All the zones contain attributes representing the constraint names, +power limits and the sizes of the time windows. Note that time window +is not applicable to peak power. Here, constraint_j_* attributes +correspond to the jth constraint (j = 0,1,2). For example:: @@ -181,6 +183,9 @@ For example:: constraint_1_name constraint_1_power_limit_uw constraint_1_time_window_us + constraint_2_name + constraint_2_power_limit_uw + constraint_2_time_window_us Power Zone Attributes ===================== |