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It is possible to provide hints to the HWP algorithms in the processor to be more performance centric to more energy centric. These hints are provided by using HWP energy performance preference (EPP) or energy performance bias (EPB) settings. The scope of these settings is per logical processor, which means that each of the logical processors in the package can be programmed with a different value. This change provides cpufreq sysfs interface to provide hint. For each policy, two additional attributes will be available to check and provide hint. These attributes will only be present when the intel_pstate driver is using HWP mode. These attributes are: - energy_performance_available_preferences - energy_performance_preference To get list of supported hints: $ cat energy_performance_available_preferences default performance balance_performance balance_power power The current preference can be read or changed via cpufreq sysfs attribute "energy_performance_preference". Reading from this attribute will display current effective setting changed via any method. User can write any of the valid preference string to this attribute. User can always restore to power-on default by writing "default". Implementation Since these hints can be provided by direct MSR write or using some tools like x86_energy_perf_policy, the driver internally doesn't maintain any state. The user operation will result in direct read/write of MSR: 0x774 (HWP_REQUEST_MSR). Also driver use read modify write to update other fields in this MSR. Summary of changes: - struct cpudata field epp_saved is renamed to epp_powersave, as this stores the value to restore once policy is switched from performance to powersave to restore original powersave EPP value. - A new struct cpudata field epp_saved is used to store the raw MSR EPP/EPB value when a CPU goes offline or on suspend and restore on online/resume. This ensures that EPP value is restored to correct value irrespective of the means used to set. - EPP/EPB value ranges are fixed for each preference, which can be set for the cpufreq sysfs, so user request is mapped to/from this range. - New attributes are only added when HWP is present. - Since EPP value of 0 is valid the fields are initialized to -EINVAL when not valid. The field epp_default is read only once after powerup to avoid reading on subsequent CPU online operation - New suspend callback to store epp on suspend operation - Don't invalidate old epp_saved field on resume and online as now we can restore last epp value on suspend and this field can still have old EPP value sampled during switch to performance from powersave. - While here optimized setting of cpu_data->epp_powersave = epp in intel_pstate_hwp_set() as this was done in both true and false paths. - epp/epb set function returns error to caller on failure to pass on to user space for display. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
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| .. | ||
| acpi-cpufreq.c | ||
| amd_freq_sensitivity.c | ||
| arm_big_little.c | ||
| arm_big_little.h | ||
| arm_big_little_dt.c | ||
| at32ap-cpufreq.c | ||
| blackfin-cpufreq.c | ||
| brcmstb-avs-cpufreq.c | ||
| cppc_cpufreq.c | ||
| cpufreq-dt-platdev.c | ||
| cpufreq-dt.c | ||
| cpufreq-dt.h | ||
| cpufreq-nforce2.c | ||
| cpufreq.c | ||
| cpufreq_conservative.c | ||
| cpufreq_governor.c | ||
| cpufreq_governor.h | ||
| cpufreq_governor_attr_set.c | ||
| cpufreq_ondemand.c | ||
| cpufreq_ondemand.h | ||
| cpufreq_performance.c | ||
| cpufreq_powersave.c | ||
| cpufreq_stats.c | ||
| cpufreq_userspace.c | ||
| cris-artpec3-cpufreq.c | ||
| cris-etraxfs-cpufreq.c | ||
| davinci-cpufreq.c | ||
| dbx500-cpufreq.c | ||
| e_powersaver.c | ||
| elanfreq.c | ||
| exynos5440-cpufreq.c | ||
| freq_table.c | ||
| gx-suspmod.c | ||
| highbank-cpufreq.c | ||
| ia64-acpi-cpufreq.c | ||
| imx6q-cpufreq.c | ||
| intel_pstate.c | ||
| Kconfig | ||
| Kconfig.arm | ||
| Kconfig.powerpc | ||
| Kconfig.x86 | ||
| kirkwood-cpufreq.c | ||
| longhaul.c | ||
| longhaul.h | ||
| longrun.c | ||
| loongson1-cpufreq.c | ||
| loongson2_cpufreq.c | ||
| Makefile | ||
| maple-cpufreq.c | ||
| mt8173-cpufreq.c | ||
| mvebu-cpufreq.c | ||
| omap-cpufreq.c | ||
| p4-clockmod.c | ||
| pasemi-cpufreq.c | ||
| pcc-cpufreq.c | ||
| pmac32-cpufreq.c | ||
| pmac64-cpufreq.c | ||
| powernow-k6.c | ||
| powernow-k7.c | ||
| powernow-k7.h | ||
| powernow-k8.c | ||
| powernow-k8.h | ||
| powernv-cpufreq.c | ||
| ppc_cbe_cpufreq.c | ||
| ppc_cbe_cpufreq.h | ||
| ppc_cbe_cpufreq_pervasive.c | ||
| ppc_cbe_cpufreq_pmi.c | ||
| pxa2xx-cpufreq.c | ||
| pxa3xx-cpufreq.c | ||
| qoriq-cpufreq.c | ||
| s3c24xx-cpufreq-debugfs.c | ||
| s3c24xx-cpufreq.c | ||
| s3c64xx-cpufreq.c | ||
| s3c2410-cpufreq.c | ||
| s3c2412-cpufreq.c | ||
| s3c2416-cpufreq.c | ||
| s3c2440-cpufreq.c | ||
| s5pv210-cpufreq.c | ||
| sa1100-cpufreq.c | ||
| sa1110-cpufreq.c | ||
| sc520_freq.c | ||
| scpi-cpufreq.c | ||
| sfi-cpufreq.c | ||
| sh-cpufreq.c | ||
| sparc-us2e-cpufreq.c | ||
| sparc-us3-cpufreq.c | ||
| spear-cpufreq.c | ||
| speedstep-centrino.c | ||
| speedstep-ich.c | ||
| speedstep-lib.c | ||
| speedstep-lib.h | ||
| speedstep-smi.c | ||
| sti-cpufreq.c | ||
| tegra20-cpufreq.c | ||
| tegra124-cpufreq.c | ||
| unicore2-cpufreq.c | ||
| vexpress-spc-cpufreq.c | ||