kernel/arch/arm/include/asm/topology.h, branch linux-6.2.y

arch_topology: Remove unused topology_set_thermal_pressure() and related

2021-11-23T09:40:26Z

There is no need of this function (and related) since code has been converted to use the new arch_update_thermal_pressure() API. The old code can be removed. Signed-off-by: Lukasz Luba Signed-off-by: Viresh Kumar

arch_topology: Introduce thermal pressure update function

2021-11-23T09:40:26Z

The thermal pressure is a mechanism which is used for providing information about reduced CPU performance to the scheduler. Usually code has to convert the value from frequency units into capacity units, which are understandable by the scheduler. Create a common conversion code which can be just used via a handy API. Internally, the topology_update_thermal_pressure() operates on frequency in MHz and max CPU frequency is taken from 'freq_factor' (per-cpu). Signed-off-by: Lukasz Luba Reviewed-by: Thara Gopinath Signed-off-by: Viresh Kumar

arm: disable frequency invariance for CONFIG_BL_SWITCHER

2020-10-08T15:17:27Z

big.LITTLE switching complicates the setting of a correct cpufreq-based frequency invariance scale factor due to (as observed in drivers/cpufreq/vexpress-spc-cpufreq.c): - Incorrect current and maximum frequencies as a result of the exposure of a virtual frequency table to the cpufreq core, - Missed updates as a result of asynchronous frequency adjustments caused by frequency changes in other CPU pairs. Given that its functionality is atypical in regards to frequency invariance and this is an old technology, disable frequency invariance for when big.LITTLE switching is configured in to prevent incorrect scale setting. Signed-off-by: Ionela Voinescu Suggested-by: Dietmar Eggemann Acked-by: Viresh Kumar Acked-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki

cpufreq,arm,arm64: restructure definitions of arch_set_freq_scale()

2020-10-08T15:17:27Z

Compared to other arch_* functions, arch_set_freq_scale() has an atypical weak definition that can be replaced by a strong architecture specific implementation. The more typical support for architectural functions involves defining an empty stub in a header file if the symbol is not already defined in architecture code. Some examples involve: - #define arch_scale_freq_capacity topology_get_freq_scale - #define arch_scale_freq_invariant topology_scale_freq_invariant - #define arch_scale_cpu_capacity topology_get_cpu_scale - #define arch_update_cpu_topology topology_update_cpu_topology - #define arch_scale_thermal_pressure topology_get_thermal_pressure - #define arch_set_thermal_pressure topology_set_thermal_pressure Bring arch_set_freq_scale() in line with these functions by renaming it to topology_set_freq_scale() in the arch topology driver, and by defining the arch_set_freq_scale symbol to point to the new function for arm and arm64. While there are other users of the arch_topology driver, this patch defines arch_set_freq_scale for arm and arm64 only, due to their existing definitions of arch_scale_freq_capacity. This is the getter function of the frequency invariance scale factor and without a getter function, the setter function - arch_set_freq_scale() has not purpose. Signed-off-by: Ionela Voinescu Acked-by: Viresh Kumar Acked-by: Catalin Marinas Acked-by: Sudeep Holla (BL_SWITCHER and topology parts) Signed-off-by: Rafael J. Wysocki

arch_topology, arm, arm64: define arch_scale_freq_invariant()

2020-09-18T17:11:20Z

arch_scale_freq_invariant() is used by schedutil to determine whether the scheduler's load-tracking signals are frequency invariant. Its definition is overridable, though by default it is hardcoded to 'true' if arch_scale_freq_capacity() is defined ('false' otherwise). This behaviour is not overridden on arm, arm64 and other users of the generic arch topology driver, which is somewhat precarious: arch_scale_freq_capacity() will always be defined, yet not all cpufreq drivers are guaranteed to drive the frequency invariance scale factor setting. In other words, the load-tracking signals may very well *not* be frequency invariant. Now that cpufreq can be queried on whether the current driver is driving the Frequency Invariance (FI) scale setting, the current situation can be improved. This combines the query of whether cpufreq supports the setting of the frequency scale factor, with whether all online CPUs are counter-based FI enabled. While cpufreq FI enablement applies at system level, for all CPUs, counter-based FI support could also be used for only a subset of CPUs to set the invariance scale factor. Therefore, if cpufreq-based FI support is present, we consider the system to be invariant. If missing, we require all online CPUs to be counter-based FI enabled in order for the full system to be considered invariant. If the system ends up not being invariant, a new condition is needed in the counter initialization code that disables all scale factor setting based on counters. Precedence of counters over cpufreq use is not important here. The invariant status is only given to the system if all CPUs have at least one method of setting the frequency scale factor. Signed-off-by: Valentin Schneider Signed-off-by: Ionela Voinescu Acked-by: Catalin Marinas Acked-by: Viresh Kumar Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki

arch_topology, sched/core: Cleanup thermal pressure definition

2020-07-22T08:22:05Z

The following commit: 14533a16c46d ("thermal/cpu-cooling, sched/core: Move the arch_set_thermal_pressure() API to generic scheduler code") moved the definition of arch_set_thermal_pressure() to sched/core.c, but kept its declaration in linux/arch_topology.h. When building e.g. an x86 kernel with CONFIG_SCHED_THERMAL_PRESSURE=y, cpufreq_cooling.c ends up getting the declaration of arch_set_thermal_pressure() from include/linux/arch_topology.h, which is somewhat awkward. On top of this, sched/core.c unconditionally defines o The thermal_pressure percpu variable o arch_set_thermal_pressure() while arch_scale_thermal_pressure() does nothing unless redefined by the architecture. arch_*() functions are meant to be defined by architectures, so revert the aforementioned commit and re-implement it in a way that keeps arch_set_thermal_pressure() architecture-definable, and doesn't define the thermal pressure percpu variable for kernels that don't need it (CONFIG_SCHED_THERMAL_PRESSURE=n). Signed-off-by: Valentin Schneider Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200712165917.9168-2-valentin.schneider@arm.com

arm/topology: Populate arch_scale_thermal_pressure() for ARM platforms

2020-03-06T11:57:19Z

Hook up topology_get_thermal_pressure to arch_scale_thermal_pressure thus enabling scheduler to retrieve instantaneous thermal pressure of a CPU. Signed-off-by: Thara Gopinath Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20200222005213.3873-6-thara.gopinath@linaro.org

arm: Use common cpu_topology structure and functions.

2019-07-22T16:36:18Z

Currently, ARM32 and ARM64 uses different data structures to represent their cpu topologies. Since, we are moving the ARM64 topology to common code to be used by other architectures, we can reuse that for ARM32 as well. Take this opprtunity to remove the redundant functions from ARM32 and reuse the common code instead. To: Russell King Signed-off-by: Atish Patra Tested-by: Sudeep Holla (on TC2) Reviewed-by: Sudeep Holla Signed-off-by: Paul Walmsley

sched/topology, arch/arm: Rebuild sched_domain hierarchy when CPU capacity changes

2018-09-10T09:05:48Z

Asymmetric CPU capacity can not necessarily be determined accurately at the time the initial sched_domain hierarchy is built during boot. It is therefore necessary to be able to force a full rebuild of the hierarchy later triggered by the arch_topology driver. A full rebuild requires the arch-code to implement arch_update_cpu_topology() which isn't yet implemented for arm. This patch points the arm implementation to arch_topology driver to ensure that full hierarchy rebuild happens when needed. Signed-off-by: Morten Rasmussen Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Russell King Cc: Thomas Gleixner Cc: dietmar.eggemann@arm.com Cc: valentin.schneider@arm.com Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/1532093554-30504-5-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar

Merge branch 'pm-cpufreq'

2017-11-13T00:34:49Z

* pm-cpufreq: (22 commits) cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZE cpufreq: arm_big_little: make cpufreq_arm_bL_ops structures const cpufreq: arm_big_little: make function arguments and structure pointer const cpufreq: pxa: convert to clock API cpufreq: speedstep-lib: mark expected switch fall-through cpufreq: ti-cpufreq: add missing of_node_put() cpufreq: dt: Remove support for Exynos4212 SoCs cpufreq: imx6q: Move speed grading check to cpufreq driver cpufreq: ti-cpufreq: kfree opp_data when failure cpufreq: SPEAr: pr_err() strings should end with newlines cpufreq: powernow-k8: pr_err() strings should end with newlines cpufreq: dt-platdev: drop socionext,uniphier-ld6b from whitelist arm64: wire cpu-invariant accounting support up to the task scheduler arm64: wire frequency-invariant accounting support up to the task scheduler arm: wire cpu-invariant accounting support up to the task scheduler arm: wire frequency-invariant accounting support up to the task scheduler drivers base/arch_topology: allow inlining cpu-invariant accounting support drivers base/arch_topology: provide frequency-invariant accounting support cpufreq: dt: invoke frequency-invariance setter function cpufreq: arm_big_little: invoke frequency-invariance setter function ...