linux/drivers/cpufreq/cppc_cpufreq.c

912 lines
24 KiB

cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Force reporting values in KHz to fix user space interface When CPPC is being used by ACPI on arm64, user space tools such as cpupower report CPU frequency values from sysfs that are incorrect. What the driver was doing was reporting the values given by ACPI tables in whatever scale was used to provide them. However, the ACPI spec defines the CPPC values as unitless abstract numbers. Internal kernel structures such as struct perf_cap, in contrast, expect these values to be in KHz. When these struct values get reported via sysfs, the user space tools also assume they are in KHz, causing them to report incorrect values (for example, reporting a CPU frequency of 1MHz when it should be 1.8GHz). The downside is that this approach has some assumptions: (1) It relies on SMBIOS3 being used, *and* that the Max Frequency value for a processor is set to a non-zero value. (2) It assumes that all processors run at the same speed, or that the CPPC values have all been scaled to reflect relative speed. This patch retrieves the largest CPU Max Frequency from a type 4 DMI record that it can find. This may not be an issue, however, as a sampling of DMI data on x86 and arm64 indicates there is often only one such record regardless. Since CPPC is relatively new, it is unclear if the ACPI ASL will always be written to reflect any sort of relative performance of processors of differing speeds. (3) It assumes that performance and frequency both scale linearly. For arm64 servers, this may be sufficient, but it does rely on firmware values being set correctly. Hence, other approaches will be considered in the future. This has been tested on three arm64 servers, with and without DMI, with and without CPPC support. Signed-off-by: Al Stone <ahs3@redhat.com> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-20 15:10:04 -06:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: CPPC: add SW BOOST support To add SW BOOST support for CPPC, we need to get the max frequency of boost mode and non-boost mode. ACPI spec 6.2 section 8.4.7.1 describes the following two CPC registers. "Highest performance is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations, and may only be achievable if other platform components are in a specific state; for example, it may require other processors be in an idle state. Nominal Performance is the maximum sustained performance level of the processor, assuming ideal operating conditions. In absence of an external constraint (power, thermal, etc.) this is the performance level the platform is expected to be able to maintain continuously. All processors are expected to be able to sustain their nominal performance state simultaneously." To add SW BOOST support for CPPC, we can use Highest Performance as the max performance in boost mode and Nominal Performance as the max performance in non-boost mode. If the Highest Performance is greater than the Nominal Performance, we assume SW BOOST is supported. The current CPPC driver does not support SW BOOST and use 'Highest Performance' as the max performance the CPU can achieve. 'Nominal Performance' is used to convert 'performance' to 'frequency'. That means, if firmware enable boost and provide a value for Highest Performance which is greater than Nominal Performance, boost feature is enabled by default. Because SW BOOST is disabled by default, so, after this patch, boost feature is disabled by default even if boost is enabled by firmware. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-30 10:08:31 +08:00
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: Avoid creating excessively large stack frames In the process of modifying a cpufreq policy, the cpufreq core makes a copy of it including all of the internals which is stored on the CPU stack. Because struct cpufreq_policy is relatively large, this may cause the size of the stack frame to exceed the 2 KB limit and so the GCC complains when -Wframe-larger-than= is used. In fact, it is not necessary to copy the entire policy structure in order to modify it, however. First, because cpufreq_set_policy() obtains the min and max policy limits from frequency QoS now, it is not necessary to pass the limits to it from the callers. The only things that need to be passed to it from there are the new governor pointer or (if there is a built-in governor in the driver) the "policy" value representing the governor choice. They both can be passed as individual arguments, though, so make cpufreq_set_policy() take them this way and rework its callers accordingly. This avoids making copies of cpufreq policies in the callers of cpufreq_set_policy(). Second, cpufreq_set_policy() still needs to pass the new policy data to the ->verify() callback of the cpufreq driver whose task is to sanitize the min and max policy limits. It still does not need to make a full copy of struct cpufreq_policy for this purpose, but it needs to pass a few items from it to the driver in case they are needed (different drivers have different needs in that respect and all of them have to be covered). For this reason, introduce struct cpufreq_policy_data to hold copies of the members of struct cpufreq_policy used by the existing ->verify() driver callbacks and pass a pointer to a temporary structure of that type to ->verify() (instead of passing a pointer to full struct cpufreq_policy to it). While at it, notice that intel_pstate and longrun don't really need to verify the "policy" value in struct cpufreq_policy, so drop those check from them to avoid copying "policy" into struct cpufreq_policy_data (which allows it to be slightly smaller). Also while at it fix up white space in a couple of places and make cpufreq_set_policy() static (as it can be so). Fixes: 3000ce3c52f8 ("cpufreq: Use per-policy frequency QoS") Link: https://lore.kernel.org/linux-pm/CAMuHMdX6-jb1W8uC2_237m8ctCpsnGp=JCxqt8pCWVqNXHmkVg@mail.gmail.com Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: 5.4+ <stable@vger.kernel.org> # 5.4+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-01-26 23:40:11 +01:00
cpufreq / CPPC: Set platform specific transition_delay_us Add support to specify platform specific transition_delay_us instead of using the transition delay derived from PCC. With commit 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) we are setting transition_delay_us directly and not applying the LATENCY_MULTIPLIER. Because of that, on Qualcomm Centriq we can end up with a very high rate of frequency change requests when using the schedutil governor (default rate_limit_us=10 compared to an earlier value of 10000). The PCC subspace describes the rate at which the platform can accept commands on the CPPC's PCC channel. This includes read and write command on the PCC channel that can be used for reasons other than frequency transitions. Moreover the same PCC subspace can be used by multiple freq domains and deriving transition_delay_us from it as we do now can be sub-optimal. Moreover if a platform does not use PCC for desired_perf register then there is no way to compute the transition latency or the delay_us. CPPC does not have a standard defined mechanism to get the transition rate or the latency at the moment. Given the above limitations, it is simpler to have a platform specific transition_delay_us and rely on PCC derived value only if a platform specific value is not available. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Cc: 4.14+ <stable@vger.kernel.org> # 4.14+ Fixes: 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-27 11:35:27 -06:00
cpufreq / CPPC: Set platform specific transition_delay_us Add support to specify platform specific transition_delay_us instead of using the transition delay derived from PCC. With commit 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) we are setting transition_delay_us directly and not applying the LATENCY_MULTIPLIER. Because of that, on Qualcomm Centriq we can end up with a very high rate of frequency change requests when using the schedutil governor (default rate_limit_us=10 compared to an earlier value of 10000). The PCC subspace describes the rate at which the platform can accept commands on the CPPC's PCC channel. This includes read and write command on the PCC channel that can be used for reasons other than frequency transitions. Moreover the same PCC subspace can be used by multiple freq domains and deriving transition_delay_us from it as we do now can be sub-optimal. Moreover if a platform does not use PCC for desired_perf register then there is no way to compute the transition latency or the delay_us. CPPC does not have a standard defined mechanism to get the transition rate or the latency at the moment. Given the above limitations, it is simpler to have a platform specific transition_delay_us and rely on PCC derived value only if a platform specific value is not available. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Cc: 4.14+ <stable@vger.kernel.org> # 4.14+ Fixes: 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-27 11:35:27 -06:00
cpufreq / CPPC: Set platform specific transition_delay_us Add support to specify platform specific transition_delay_us instead of using the transition delay derived from PCC. With commit 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) we are setting transition_delay_us directly and not applying the LATENCY_MULTIPLIER. Because of that, on Qualcomm Centriq we can end up with a very high rate of frequency change requests when using the schedutil governor (default rate_limit_us=10 compared to an earlier value of 10000). The PCC subspace describes the rate at which the platform can accept commands on the CPPC's PCC channel. This includes read and write command on the PCC channel that can be used for reasons other than frequency transitions. Moreover the same PCC subspace can be used by multiple freq domains and deriving transition_delay_us from it as we do now can be sub-optimal. Moreover if a platform does not use PCC for desired_perf register then there is no way to compute the transition latency or the delay_us. CPPC does not have a standard defined mechanism to get the transition rate or the latency at the moment. Given the above limitations, it is simpler to have a platform specific transition_delay_us and rely on PCC derived value only if a platform specific value is not available. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Cc: 4.14+ <stable@vger.kernel.org> # 4.14+ Fixes: 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-27 11:35:27 -06:00
cpufreq / CPPC: Set platform specific transition_delay_us Add support to specify platform specific transition_delay_us instead of using the transition delay derived from PCC. With commit 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) we are setting transition_delay_us directly and not applying the LATENCY_MULTIPLIER. Because of that, on Qualcomm Centriq we can end up with a very high rate of frequency change requests when using the schedutil governor (default rate_limit_us=10 compared to an earlier value of 10000). The PCC subspace describes the rate at which the platform can accept commands on the CPPC's PCC channel. This includes read and write command on the PCC channel that can be used for reasons other than frequency transitions. Moreover the same PCC subspace can be used by multiple freq domains and deriving transition_delay_us from it as we do now can be sub-optimal. Moreover if a platform does not use PCC for desired_perf register then there is no way to compute the transition latency or the delay_us. CPPC does not have a standard defined mechanism to get the transition rate or the latency at the moment. Given the above limitations, it is simpler to have a platform specific transition_delay_us and rely on PCC derived value only if a platform specific value is not available. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Cc: 4.14+ <stable@vger.kernel.org> # 4.14+ Fixes: 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-27 11:35:27 -06:00
cpufreq / CPPC: Set platform specific transition_delay_us Add support to specify platform specific transition_delay_us instead of using the transition delay derived from PCC. With commit 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) we are setting transition_delay_us directly and not applying the LATENCY_MULTIPLIER. Because of that, on Qualcomm Centriq we can end up with a very high rate of frequency change requests when using the schedutil governor (default rate_limit_us=10 compared to an earlier value of 10000). The PCC subspace describes the rate at which the platform can accept commands on the CPPC's PCC channel. This includes read and write command on the PCC channel that can be used for reasons other than frequency transitions. Moreover the same PCC subspace can be used by multiple freq domains and deriving transition_delay_us from it as we do now can be sub-optimal. Moreover if a platform does not use PCC for desired_perf register then there is no way to compute the transition latency or the delay_us. CPPC does not have a standard defined mechanism to get the transition rate or the latency at the moment. Given the above limitations, it is simpler to have a platform specific transition_delay_us and rely on PCC derived value only if a platform specific value is not available. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Cc: 4.14+ <stable@vger.kernel.org> # 4.14+ Fixes: 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-27 11:35:27 -06:00
cpufreq / CPPC: Set platform specific transition_delay_us Add support to specify platform specific transition_delay_us instead of using the transition delay derived from PCC. With commit 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) we are setting transition_delay_us directly and not applying the LATENCY_MULTIPLIER. Because of that, on Qualcomm Centriq we can end up with a very high rate of frequency change requests when using the schedutil governor (default rate_limit_us=10 compared to an earlier value of 10000). The PCC subspace describes the rate at which the platform can accept commands on the CPPC's PCC channel. This includes read and write command on the PCC channel that can be used for reasons other than frequency transitions. Moreover the same PCC subspace can be used by multiple freq domains and deriving transition_delay_us from it as we do now can be sub-optimal. Moreover if a platform does not use PCC for desired_perf register then there is no way to compute the transition latency or the delay_us. CPPC does not have a standard defined mechanism to get the transition rate or the latency at the moment. Given the above limitations, it is simpler to have a platform specific transition_delay_us and rely on PCC derived value only if a platform specific value is not available. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Cc: 4.14+ <stable@vger.kernel.org> # 4.14+ Fixes: 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-27 11:35:27 -06:00
cpufreq: CPPC: Add per_cpu efficiency_class In ACPI, describing power efficiency of CPUs can be done through the following arm specific field: ACPI 6.4, s5.2.12.14 'GIC CPU Interface (GICC) Structure', 'Processor Power Efficiency Class field': Describes the relative power efficiency of the associated pro- cessor. Lower efficiency class numbers are more efficient than higher ones (e.g. efficiency class 0 should be treated as more efficient than efficiency class 1). However, absolute values of this number have no meaning: 2 isn’t necessarily half as efficient as 1. The efficiency_class field is stored in the GicC structure of the ACPI MADT table and it's currently supported in Linux for arm64 only. Thus, this new functionality is introduced for arm64 only. To allow the cppc_cpufreq driver to know and preprocess the efficiency_class values of all the CPUs, add a per_cpu efficiency_class variable to store them. At least 2 different efficiency classes must be present, otherwise there is no use in creating an Energy Model. The efficiency_class values are squeezed in [0:#efficiency_class-1] while conserving the order. For instance, efficiency classes of: [111, 212, 250] will be mapped to: [0 (was 111), 1 (was 212), 2 (was 250)]. Each policy being independently registered in the driver, populating the per_cpu efficiency_class is done only once at the driver initialization. This prevents from having each policy re-searching the efficiency_class values of other CPUs. The EM will be registered in a following patch. The patch also exports acpi_cpu_get_madt_gicc() to fetch the GicC structure of the ACPI MADT table for each CPU. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:07 +02:00
cpufreq: CPPC: Register EM based on efficiency class information Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. This patch also populates the (struct cpufreq_driver).register_em callback if the valid efficiency_class ACPI values are provided. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:08 +02:00
cpufreq: CPPC: Register EM based on efficiency class information Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. This patch also populates the (struct cpufreq_driver).register_em callback if the valid efficiency_class ACPI values are provided. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:08 +02:00
cpufreq: CPPC: Register EM based on efficiency class information Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. This patch also populates the (struct cpufreq_driver).register_em callback if the valid efficiency_class ACPI values are provided. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:08 +02:00
cpufreq: CPPC: Register EM based on efficiency class information Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. This patch also populates the (struct cpufreq_driver).register_em callback if the valid efficiency_class ACPI values are provided. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:08 +02:00
cpufreq: CPPC: Register EM based on efficiency class information Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. This patch also populates the (struct cpufreq_driver).register_em callback if the valid efficiency_class ACPI values are provided. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:08 +02:00
cpufreq: CPPC: Register EM based on efficiency class information Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. This patch also populates the (struct cpufreq_driver).register_em callback if the valid efficiency_class ACPI values are provided. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:08 +02:00
cpufreq: CPPC: Register EM based on efficiency class information Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. This patch also populates the (struct cpufreq_driver).register_em callback if the valid efficiency_class ACPI values are provided. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:08 +02:00
cpufreq: CPPC: Add per_cpu efficiency_class In ACPI, describing power efficiency of CPUs can be done through the following arm specific field: ACPI 6.4, s5.2.12.14 'GIC CPU Interface (GICC) Structure', 'Processor Power Efficiency Class field': Describes the relative power efficiency of the associated pro- cessor. Lower efficiency class numbers are more efficient than higher ones (e.g. efficiency class 0 should be treated as more efficient than efficiency class 1). However, absolute values of this number have no meaning: 2 isn’t necessarily half as efficient as 1. The efficiency_class field is stored in the GicC structure of the ACPI MADT table and it's currently supported in Linux for arm64 only. Thus, this new functionality is introduced for arm64 only. To allow the cppc_cpufreq driver to know and preprocess the efficiency_class values of all the CPUs, add a per_cpu efficiency_class variable to store them. At least 2 different efficiency classes must be present, otherwise there is no use in creating an Energy Model. The efficiency_class values are squeezed in [0:#efficiency_class-1] while conserving the order. For instance, efficiency classes of: [111, 212, 250] will be mapped to: [0 (was 111), 1 (was 212), 2 (was 250)]. Each policy being independently registered in the driver, populating the per_cpu efficiency_class is done only once at the driver initialization. This prevents from having each policy re-searching the efficiency_class values of other CPUs. The EM will be registered in a following patch. The patch also exports acpi_cpu_get_madt_gicc() to fetch the GicC structure of the ACPI MADT table for each CPU. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:07 +02:00
cpufreq: CPPC: Register EM based on efficiency class information Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. This patch also populates the (struct cpufreq_driver).register_em callback if the valid efficiency_class ACPI values are provided. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:08 +02:00
cpufreq: CPPC: Add per_cpu efficiency_class In ACPI, describing power efficiency of CPUs can be done through the following arm specific field: ACPI 6.4, s5.2.12.14 'GIC CPU Interface (GICC) Structure', 'Processor Power Efficiency Class field': Describes the relative power efficiency of the associated pro- cessor. Lower efficiency class numbers are more efficient than higher ones (e.g. efficiency class 0 should be treated as more efficient than efficiency class 1). However, absolute values of this number have no meaning: 2 isn’t necessarily half as efficient as 1. The efficiency_class field is stored in the GicC structure of the ACPI MADT table and it's currently supported in Linux for arm64 only. Thus, this new functionality is introduced for arm64 only. To allow the cppc_cpufreq driver to know and preprocess the efficiency_class values of all the CPUs, add a per_cpu efficiency_class variable to store them. At least 2 different efficiency classes must be present, otherwise there is no use in creating an Energy Model. The efficiency_class values are squeezed in [0:#efficiency_class-1] while conserving the order. For instance, efficiency classes of: [111, 212, 250] will be mapped to: [0 (was 111), 1 (was 212), 2 (was 250)]. Each policy being independently registered in the driver, populating the per_cpu efficiency_class is done only once at the driver initialization. This prevents from having each policy re-searching the efficiency_class values of other CPUs. The EM will be registered in a following patch. The patch also exports acpi_cpu_get_madt_gicc() to fetch the GicC structure of the ACPI MADT table for each CPU. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:07 +02:00
cpufreq: CPPC: Register EM based on efficiency class information Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. This patch also populates the (struct cpufreq_driver).register_em callback if the valid efficiency_class ACPI values are provided. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:08 +02:00
cpufreq / CPPC: Set platform specific transition_delay_us Add support to specify platform specific transition_delay_us instead of using the transition delay derived from PCC. With commit 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) we are setting transition_delay_us directly and not applying the LATENCY_MULTIPLIER. Because of that, on Qualcomm Centriq we can end up with a very high rate of frequency change requests when using the schedutil governor (default rate_limit_us=10 compared to an earlier value of 10000). The PCC subspace describes the rate at which the platform can accept commands on the CPPC's PCC channel. This includes read and write command on the PCC channel that can be used for reasons other than frequency transitions. Moreover the same PCC subspace can be used by multiple freq domains and deriving transition_delay_us from it as we do now can be sub-optimal. Moreover if a platform does not use PCC for desired_perf register then there is no way to compute the transition latency or the delay_us. CPPC does not have a standard defined mechanism to get the transition rate or the latency at the moment. Given the above limitations, it is simpler to have a platform specific transition_delay_us and rely on PCC derived value only if a platform specific value is not available. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Cc: 4.14+ <stable@vger.kernel.org> # 4.14+ Fixes: 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-27 11:35:27 -06:00
cpufreq: CPPC: Add per_cpu efficiency_class In ACPI, describing power efficiency of CPUs can be done through the following arm specific field: ACPI 6.4, s5.2.12.14 'GIC CPU Interface (GICC) Structure', 'Processor Power Efficiency Class field': Describes the relative power efficiency of the associated pro- cessor. Lower efficiency class numbers are more efficient than higher ones (e.g. efficiency class 0 should be treated as more efficient than efficiency class 1). However, absolute values of this number have no meaning: 2 isn’t necessarily half as efficient as 1. The efficiency_class field is stored in the GicC structure of the ACPI MADT table and it's currently supported in Linux for arm64 only. Thus, this new functionality is introduced for arm64 only. To allow the cppc_cpufreq driver to know and preprocess the efficiency_class values of all the CPUs, add a per_cpu efficiency_class variable to store them. At least 2 different efficiency classes must be present, otherwise there is no use in creating an Energy Model. The efficiency_class values are squeezed in [0:#efficiency_class-1] while conserving the order. For instance, efficiency classes of: [111, 212, 250] will be mapped to: [0 (was 111), 1 (was 212), 2 (was 250)]. Each policy being independently registered in the driver, populating the per_cpu efficiency_class is done only once at the driver initialization. This prevents from having each policy re-searching the efficiency_class values of other CPUs. The EM will be registered in a following patch. The patch also exports acpi_cpu_get_madt_gicc() to fetch the GicC structure of the ACPI MADT table for each CPU. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:07 +02:00
cpufreq / CPPC: Set platform specific transition_delay_us Add support to specify platform specific transition_delay_us instead of using the transition delay derived from PCC. With commit 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) we are setting transition_delay_us directly and not applying the LATENCY_MULTIPLIER. Because of that, on Qualcomm Centriq we can end up with a very high rate of frequency change requests when using the schedutil governor (default rate_limit_us=10 compared to an earlier value of 10000). The PCC subspace describes the rate at which the platform can accept commands on the CPPC's PCC channel. This includes read and write command on the PCC channel that can be used for reasons other than frequency transitions. Moreover the same PCC subspace can be used by multiple freq domains and deriving transition_delay_us from it as we do now can be sub-optimal. Moreover if a platform does not use PCC for desired_perf register then there is no way to compute the transition latency or the delay_us. CPPC does not have a standard defined mechanism to get the transition rate or the latency at the moment. Given the above limitations, it is simpler to have a platform specific transition_delay_us and rely on PCC derived value only if a platform specific value is not available. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Cc: 4.14+ <stable@vger.kernel.org> # 4.14+ Fixes: 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-27 11:35:27 -06:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: CPPC: Force reporting values in KHz to fix user space interface When CPPC is being used by ACPI on arm64, user space tools such as cpupower report CPU frequency values from sysfs that are incorrect. What the driver was doing was reporting the values given by ACPI tables in whatever scale was used to provide them. However, the ACPI spec defines the CPPC values as unitless abstract numbers. Internal kernel structures such as struct perf_cap, in contrast, expect these values to be in KHz. When these struct values get reported via sysfs, the user space tools also assume they are in KHz, causing them to report incorrect values (for example, reporting a CPU frequency of 1MHz when it should be 1.8GHz). The downside is that this approach has some assumptions: (1) It relies on SMBIOS3 being used, *and* that the Max Frequency value for a processor is set to a non-zero value. (2) It assumes that all processors run at the same speed, or that the CPPC values have all been scaled to reflect relative speed. This patch retrieves the largest CPU Max Frequency from a type 4 DMI record that it can find. This may not be an issue, however, as a sampling of DMI data on x86 and arm64 indicates there is often only one such record regardless. Since CPPC is relatively new, it is unclear if the ACPI ASL will always be written to reflect any sort of relative performance of processors of differing speeds. (3) It assumes that performance and frequency both scale linearly. For arm64 servers, this may be sufficient, but it does rely on firmware values being set correctly. Hence, other approaches will be considered in the future. This has been tested on three arm64 servers, with and without DMI, with and without CPPC support. Signed-off-by: Al Stone <ahs3@redhat.com> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-20 15:10:04 -06:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: CPPC: add SW BOOST support To add SW BOOST support for CPPC, we need to get the max frequency of boost mode and non-boost mode. ACPI spec 6.2 section 8.4.7.1 describes the following two CPC registers. "Highest performance is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations, and may only be achievable if other platform components are in a specific state; for example, it may require other processors be in an idle state. Nominal Performance is the maximum sustained performance level of the processor, assuming ideal operating conditions. In absence of an external constraint (power, thermal, etc.) this is the performance level the platform is expected to be able to maintain continuously. All processors are expected to be able to sustain their nominal performance state simultaneously." To add SW BOOST support for CPPC, we can use Highest Performance as the max performance in boost mode and Nominal Performance as the max performance in non-boost mode. If the Highest Performance is greater than the Nominal Performance, we assume SW BOOST is supported. The current CPPC driver does not support SW BOOST and use 'Highest Performance' as the max performance the CPU can achieve. 'Nominal Performance' is used to convert 'performance' to 'frequency'. That means, if firmware enable boost and provide a value for Highest Performance which is greater than Nominal Performance, boost feature is enabled by default. Because SW BOOST is disabled by default, so, after this patch, boost feature is disabled by default even if boost is enabled by firmware. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-30 10:08:31 +08:00
cpufreq: CPPC: add SW BOOST support To add SW BOOST support for CPPC, we need to get the max frequency of boost mode and non-boost mode. ACPI spec 6.2 section 8.4.7.1 describes the following two CPC registers. "Highest performance is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations, and may only be achievable if other platform components are in a specific state; for example, it may require other processors be in an idle state. Nominal Performance is the maximum sustained performance level of the processor, assuming ideal operating conditions. In absence of an external constraint (power, thermal, etc.) this is the performance level the platform is expected to be able to maintain continuously. All processors are expected to be able to sustain their nominal performance state simultaneously." To add SW BOOST support for CPPC, we can use Highest Performance as the max performance in boost mode and Nominal Performance as the max performance in non-boost mode. If the Highest Performance is greater than the Nominal Performance, we assume SW BOOST is supported. The current CPPC driver does not support SW BOOST and use 'Highest Performance' as the max performance the CPU can achieve. 'Nominal Performance' is used to convert 'performance' to 'frequency'. That means, if firmware enable boost and provide a value for Highest Performance which is greater than Nominal Performance, boost feature is enabled by default. Because SW BOOST is disabled by default, so, after this patch, boost feature is disabled by default even if boost is enabled by firmware. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-30 10:08:31 +08:00
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: add SW BOOST support To add SW BOOST support for CPPC, we need to get the max frequency of boost mode and non-boost mode. ACPI spec 6.2 section 8.4.7.1 describes the following two CPC registers. "Highest performance is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations, and may only be achievable if other platform components are in a specific state; for example, it may require other processors be in an idle state. Nominal Performance is the maximum sustained performance level of the processor, assuming ideal operating conditions. In absence of an external constraint (power, thermal, etc.) this is the performance level the platform is expected to be able to maintain continuously. All processors are expected to be able to sustain their nominal performance state simultaneously." To add SW BOOST support for CPPC, we can use Highest Performance as the max performance in boost mode and Nominal Performance as the max performance in non-boost mode. If the Highest Performance is greater than the Nominal Performance, we assume SW BOOST is supported. The current CPPC driver does not support SW BOOST and use 'Highest Performance' as the max performance the CPU can achieve. 'Nominal Performance' is used to convert 'performance' to 'frequency'. That means, if firmware enable boost and provide a value for Highest Performance which is greater than Nominal Performance, boost feature is enabled by default. Because SW BOOST is disabled by default, so, after this patch, boost feature is disabled by default even if boost is enabled by firmware. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-30 10:08:31 +08:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: CPPC: add SW BOOST support To add SW BOOST support for CPPC, we need to get the max frequency of boost mode and non-boost mode. ACPI spec 6.2 section 8.4.7.1 describes the following two CPC registers. "Highest performance is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations, and may only be achievable if other platform components are in a specific state; for example, it may require other processors be in an idle state. Nominal Performance is the maximum sustained performance level of the processor, assuming ideal operating conditions. In absence of an external constraint (power, thermal, etc.) this is the performance level the platform is expected to be able to maintain continuously. All processors are expected to be able to sustain their nominal performance state simultaneously." To add SW BOOST support for CPPC, we can use Highest Performance as the max performance in boost mode and Nominal Performance as the max performance in non-boost mode. If the Highest Performance is greater than the Nominal Performance, we assume SW BOOST is supported. The current CPPC driver does not support SW BOOST and use 'Highest Performance' as the max performance the CPU can achieve. 'Nominal Performance' is used to convert 'performance' to 'frequency'. That means, if firmware enable boost and provide a value for Highest Performance which is greater than Nominal Performance, boost feature is enabled by default. Because SW BOOST is disabled by default, so, after this patch, boost feature is disabled by default even if boost is enabled by firmware. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-30 10:08:31 +08:00
cpufreq: CPPC: add SW BOOST support To add SW BOOST support for CPPC, we need to get the max frequency of boost mode and non-boost mode. ACPI spec 6.2 section 8.4.7.1 describes the following two CPC registers. "Highest performance is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations, and may only be achievable if other platform components are in a specific state; for example, it may require other processors be in an idle state. Nominal Performance is the maximum sustained performance level of the processor, assuming ideal operating conditions. In absence of an external constraint (power, thermal, etc.) this is the performance level the platform is expected to be able to maintain continuously. All processors are expected to be able to sustain their nominal performance state simultaneously." To add SW BOOST support for CPPC, we can use Highest Performance as the max performance in boost mode and Nominal Performance as the max performance in non-boost mode. If the Highest Performance is greater than the Nominal Performance, we assume SW BOOST is supported. The current CPPC driver does not support SW BOOST and use 'Highest Performance' as the max performance the CPU can achieve. 'Nominal Performance' is used to convert 'performance' to 'frequency'. That means, if firmware enable boost and provide a value for Highest Performance which is greater than Nominal Performance, boost feature is enabled by default. Because SW BOOST is disabled by default, so, after this patch, boost feature is disabled by default even if boost is enabled by firmware. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-30 10:08:31 +08:00
cpufreq: CPPC: add SW BOOST support To add SW BOOST support for CPPC, we need to get the max frequency of boost mode and non-boost mode. ACPI spec 6.2 section 8.4.7.1 describes the following two CPC registers. "Highest performance is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations, and may only be achievable if other platform components are in a specific state; for example, it may require other processors be in an idle state. Nominal Performance is the maximum sustained performance level of the processor, assuming ideal operating conditions. In absence of an external constraint (power, thermal, etc.) this is the performance level the platform is expected to be able to maintain continuously. All processors are expected to be able to sustain their nominal performance state simultaneously." To add SW BOOST support for CPPC, we can use Highest Performance as the max performance in boost mode and Nominal Performance as the max performance in non-boost mode. If the Highest Performance is greater than the Nominal Performance, we assume SW BOOST is supported. The current CPPC driver does not support SW BOOST and use 'Highest Performance' as the max performance the CPU can achieve. 'Nominal Performance' is used to convert 'performance' to 'frequency'. That means, if firmware enable boost and provide a value for Highest Performance which is greater than Nominal Performance, boost feature is enabled by default. Because SW BOOST is disabled by default, so, after this patch, boost feature is disabled by default even if boost is enabled by firmware. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-30 10:08:31 +08:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: CPPC: add SW BOOST support To add SW BOOST support for CPPC, we need to get the max frequency of boost mode and non-boost mode. ACPI spec 6.2 section 8.4.7.1 describes the following two CPC registers. "Highest performance is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations, and may only be achievable if other platform components are in a specific state; for example, it may require other processors be in an idle state. Nominal Performance is the maximum sustained performance level of the processor, assuming ideal operating conditions. In absence of an external constraint (power, thermal, etc.) this is the performance level the platform is expected to be able to maintain continuously. All processors are expected to be able to sustain their nominal performance state simultaneously." To add SW BOOST support for CPPC, we can use Highest Performance as the max performance in boost mode and Nominal Performance as the max performance in non-boost mode. If the Highest Performance is greater than the Nominal Performance, we assume SW BOOST is supported. The current CPPC driver does not support SW BOOST and use 'Highest Performance' as the max performance the CPU can achieve. 'Nominal Performance' is used to convert 'performance' to 'frequency'. That means, if firmware enable boost and provide a value for Highest Performance which is greater than Nominal Performance, boost feature is enabled by default. Because SW BOOST is disabled by default, so, after this patch, boost feature is disabled by default even if boost is enabled by firmware. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-30 10:08:31 +08:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cpufreq: CPPC: Add per_cpu efficiency_class In ACPI, describing power efficiency of CPUs can be done through the following arm specific field: ACPI 6.4, s5.2.12.14 'GIC CPU Interface (GICC) Structure', 'Processor Power Efficiency Class field': Describes the relative power efficiency of the associated pro- cessor. Lower efficiency class numbers are more efficient than higher ones (e.g. efficiency class 0 should be treated as more efficient than efficiency class 1). However, absolute values of this number have no meaning: 2 isn’t necessarily half as efficient as 1. The efficiency_class field is stored in the GicC structure of the ACPI MADT table and it's currently supported in Linux for arm64 only. Thus, this new functionality is introduced for arm64 only. To allow the cppc_cpufreq driver to know and preprocess the efficiency_class values of all the CPUs, add a per_cpu efficiency_class variable to store them. At least 2 different efficiency classes must be present, otherwise there is no use in creating an Energy Model. The efficiency_class values are squeezed in [0:#efficiency_class-1] while conserving the order. For instance, efficiency classes of: [111, 212, 250] will be mapped to: [0 (was 111), 1 (was 212), 2 (was 250)]. Each policy being independently registered in the driver, populating the per_cpu efficiency_class is done only once at the driver initialization. This prevents from having each policy re-searching the efficiency_class values of other CPUs. The EM will be registered in a following patch. The patch also exports acpi_cpu_get_madt_gicc() to fetch the GicC structure of the ACPI MADT table for each CPU. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-25 14:38:07 +02:00
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
cpufreq: CPPC: Add support for frequency invariance The Frequency Invariance Engine (FIE) is providing a frequency scaling correction factor that helps achieve more accurate load-tracking. Normally, this scaling factor can be obtained directly with the help of the cpufreq drivers as they know the exact frequency the hardware is running at. But that isn't the case for CPPC cpufreq driver. Another way of obtaining that is using the arch specific counter support, which is already present in kernel, but that hardware is optional for platforms. This patch updates the CPPC driver to register itself with the topology core to provide its own implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which gets called by the scheduler on every tick. Note that the arch specific counters have higher priority than CPPC counters, if available, though the CPPC driver doesn't need to have any special handling for that. On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we reach here from hard-irq context), which then schedules a normal work item and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable based on the counter updates since the last tick. To allow platforms to disable this CPPC counter-based frequency invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE, which is enabled by default. This also exports sched_setattr_nocheck() as the CPPC driver can be built as a module. Cc: linux-acpi@vger.kernel.org Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-06-23 15:49:40 +05:30
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00