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2017-08-11cpufreq: intel_pstate: report correct CPU frequencies during traceDoug Smythies
The intel_pstate CPU frequency scaling driver has always calculated CPU frequency incorrectly. Recent changes have eliminted most of the issues, however the frequency reported in the trace buffer, if used, is incorrect. It remains desireable that cpu->pstate.scaling still be a nice round number for things such as when setting max and min frequencies. So the proposal is to just fix the reported frequency in the trace data. Fixes what remains of [1]. Link: https://bugzilla.kernel.org/show_bug.cgi?id=96521 # [1] Signed-off-by: Doug Smythies <dsmythies@telus.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-08-03Merge branches 'pm-cpufreq-x86', 'pm-cpufreq-docs' and 'intel_pstate'Rafael J. Wysocki
* pm-cpufreq-x86: cpufreq: x86: Make scaling_cur_freq behave more as expected * pm-cpufreq-docs: cpufreq: docs: Add missing cpuinfo_cur_freq description * intel_pstate: cpufreq: intel_pstate: Drop ->get from intel_pstate structure
2017-07-27cpufreq: intel_pstate: Drop ->get from intel_pstate structureRafael J. Wysocki
The ->get callback in the intel_pstate structure was mostly there for the scaling_cur_freq sysfs attribute to work, but after commit f8475cef9008 (x86: use common aperfmperf_khz_on_cpu() to calculate KHz using APERF/MPERF) that attribute uses arch_freq_get_on_cpu() provided by the x86 arch code on all processors supported by intel_pstate, so it doesn't need the ->get callback from the driver any more. Moreover, the very presence of the ->get callback in the intel_pstate structure causes the cpuinfo_cur_freq attribute to be present when intel_pstate operates in the active mode, which is bogus, because the role of that attribute is to return the current CPU frequency as seen by the hardware. For intel_pstate, though, this is just an average frequency and not really current, but computed for the previous sampling interval (the actual current frequency may be way different at the point this value is obtained by reading from cpuinfo_cur_freq), and after commit 82b4e03e01bc (intel_pstate: skip scheduler hook when in "performance" mode) the value in cpuinfo_cur_freq may be stale or just 0, depending on the driver's operation mode. In fact, however, on the hardware supported by intel_pstate there is no way to read the current CPU frequency from it, so the cpuinfo_cur_freq attribute should not be present at all when this driver is in use. For this reason, drop intel_pstate_get() and clear the ->get callback pointer pointing to it, so that the cpuinfo_cur_freq is not present for intel_pstate in the active mode any more. Fixes: 82b4e03e01bc (intel_pstate: skip scheduler hook when in "performance" mode) Reported-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2017-07-20Merge branches 'intel_pstate' and 'pm-domains'Rafael J. Wysocki
* intel_pstate: cpufreq: intel_pstate: Correct the busy calculation for KNL * pm-domains: PM / Domains: defer dev_pm_domain_set() until genpd->attach_dev succeeds if present
2017-07-14Merge tag 'pm-fixes-4.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These fix a recently exposed issue in the PCI device wakeup code and one older problem related to PCI device wakeup that has been reported recently, modify one more piece of computations in intel_pstate to get rid of a rounding error, fix a possible race in the schedutil cpufreq governor, fix the device PM QoS sysfs interface to correctly handle invalid user input, fix return values of two probe routines in devfreq drivers and constify an attribute_group structure in devfreq. Specifics: - Avoid clearing the PCI PME Enable bit for devices as a result of config space restoration which confuses AML executed afterward and causes wakeup events to be lost on some systems (Rafael Wysocki). - Fix the native PCIe PME interrupts handling in the cases when the PME IRQ is set up as a system wakeup one so that runtime PM remote wakeup works as expected after system resume on systems where that happens (Rafael Wysocki). - Fix the device PM QoS sysfs interface to handle invalid user input correctly instead of using an unititialized variable value as the latency tolerance for the device at hand (Dan Carpenter). - Get rid of one more rounding error from intel_pstate computations (Srinivas Pandruvada). - Fix the schedutil cpufreq governor to prevent it from possibly accessing unititialized data structures from governor callbacks in some cases on systems when multiple CPUs share a single cpufreq policy object (Vikram Mulukutla). - Fix the return values of probe routines in two devfreq drivers (Gustavo Silva). - Constify an attribute_group structure in devfreq (Arvind Yadav)" * tag 'pm-fixes-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PCI / PM: Fix native PME handling during system suspend/resume PCI / PM: Restore PME Enable after config space restoration cpufreq: schedutil: Fix sugov_start() versus sugov_update_shared() race PM / QoS: return -EINVAL for bogus strings cpufreq: intel_pstate: Fix ratio setting for min_perf_pct PM / devfreq: constify attribute_group structures. PM / devfreq: tegra: fix error return code in tegra_devfreq_probe() PM / devfreq: rk3399_dmc: fix error return code in rk3399_dmcfreq_probe()
2017-07-14Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux Pull thermal management updates from Zhang Rui: - Improve thermal cpu_cooling interaction with cpufreq core. The cpu_cooling driver is designed to use CPU frequency scaling to avoid high thermal states for a platform. But it wasn't glued really well with cpufreq core. For example clipped-cpus is copied from the policy structure and its much better to use the policy->cpus (or related_cpus) fields directly as they may have got updated. Not that things were broken before this series, but they can be optimized a bit more. This series tries to improve interactions between cpufreq core and cpu_cooling driver and does some fixes/cleanups to the cpu_cooling driver. (Viresh Kumar) - A couple of fixes and cleanups in thermal core and imx, hisilicon, bcm_2835, int340x thermal drivers. (Arvind Yadav, Dan Carpenter, Sumeet Pawnikar, Srinivas Pandruvada, Willy WOLFF) * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: (24 commits) thermal: bcm2835: fix an error code in probe() thermal: hisilicon: Handle return value of clk_prepare_enable thermal: imx: Handle return value of clk_prepare_enable thermal: int340x: check for sensor when PTYP is missing Thermal/int340x: Fix few typos and kernel-doc style thermal: fix source code documentation for parameters thermal: cpu_cooling: Replace kmalloc with kmalloc_array thermal: cpu_cooling: Rearrange struct cpufreq_cooling_device thermal: cpu_cooling: 'freq' can't be zero in cpufreq_state2power() thermal: cpu_cooling: don't store cpu_dev in cpufreq_cdev thermal: cpu_cooling: get_level() can't fail thermal: cpu_cooling: create structure for idle time stats thermal: cpu_cooling: merge frequency and power tables thermal: cpu_cooling: get rid of 'allowed_cpus' thermal: cpu_cooling: OPPs are registered for all CPUs thermal: cpu_cooling: store cpufreq policy cpufreq: create cpufreq_table_count_valid_entries() thermal: cpu_cooling: use cpufreq_policy to register cooling device thermal: cpu_cooling: get rid of a variable in cpufreq_set_cur_state() thermal: cpu_cooling: remove cpufreq_cooling_get_level() ...
2017-07-14Merge branches 'pm-cpufreq-sched' and 'intel_pstate'Rafael J. Wysocki
* pm-cpufreq-sched: cpufreq: schedutil: Fix sugov_start() versus sugov_update_shared() race * intel_pstate: cpufreq: intel_pstate: Fix ratio setting for min_perf_pct
2017-07-14cpufreq: intel_pstate: Correct the busy calculation for KNLSrinivas Pandruvada
The busy percent calculated for the Knights Landing (KNL) platform is 1024 times smaller than the correct busy value. This causes performance to get stuck at the lowest ratio. The scaling algorithm used for KNL is performance-based, but it still looks at the CPU load to set the scaled busy factor to 0 when the load is less than 1 percent. In this case, since the computed load is 1024x smaller than it should be, the scaled busy factor will always be 0, irrespective of CPU business. This needs a fix similar to the turbostat one in commit b2b34dfe4d9a (tools/power turbostat: KNL workaround for %Busy and Avg_MHz). For this reason, add one more callback to processor-specific callbacks to specify an MPERF multiplier represented by a number of bit positions to shift the value of that register to the left to copmensate for its rate difference with respect to the TSC. This shift value is used during CPU busy calculations. Fixes: ffb810563c (intel_pstate: Avoid getting stuck in high P-states when idle) Reported-and-tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: 4.6+ <stable@vger.kernel.org> # 4.6+ [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-07-12cpufreq: intel_pstate: Fix ratio setting for min_perf_pctSrinivas Pandruvada
When the minimum performance limit percentage is set to the power-up default, it is possible that minimum performance ratio is off by one. In the set_policy() callback the minimum ratio is calculated by applying global.min_perf_pct to turbo_ratio and rounding up, but the power-up default global.min_perf_pct is already rounded up to the next percent in min_perf_pct_min(). That results in two round up operations, so for the default min_perf_pct one of them is not required. It is better to remove rounding up in min_perf_pct_min() as this matches the displayed min_perf_pct prior to commit c5a2ee7dde89 (cpufreq: intel_pstate: Active mode P-state limits rework) in 4.12. For example on a platform with max turbo ratio of 37 and minimum ratio of 10, the min_perf_pct resulted in 28 with the above commit. Before this commit it was 27 and it will be the same after this change. Fixes: 1a4fe38add8b (cpufreq: intel_pstate: Remove max/min fractions to limit performance) Reported-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-07-10Merge tag 'pm-extra-4.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "These revert one recent change in the generic power domains framework, fix a recently introduced build issue in there and constify attribute_group structures in some places. Specifics: - Revert a recent change in the generic power domains (genpd) framework that led to regressions and turned out the be misguided (Rafael Wysocki). - Fix a recently introduced build issue in the generic power domains (genpd) framework (Arnd Bergmann). - Constify attribute_group structures in the PM core, the cpufreq stats code and in intel_pstate (Arvind Yadav)" * tag 'pm-extra-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpufreq: intel_pstate: constify attribute_group structures cpufreq: cpufreq_stats: constify attribute_group structures PM / sleep: constify attribute_group structures PM / Domains: provide pm_genpd_poweroff_noirq() stub Revert "PM / Domains: Handle safely genpd_syscore_switch() call on non-genpd device"
2017-07-10Merge branches 'pm-domains', 'pm-sleep' and 'pm-cpufreq'Rafael J. Wysocki
* pm-domains: PM / Domains: provide pm_genpd_poweroff_noirq() stub Revert "PM / Domains: Handle safely genpd_syscore_switch() call on non-genpd device" * pm-sleep: PM / sleep: constify attribute_group structures * pm-cpufreq: cpufreq: intel_pstate: constify attribute_group structures cpufreq: cpufreq_stats: constify attribute_group structures
2017-07-05Merge branch 'linus' of ↵Zhang Rui
git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal into thermal-soc
2017-07-04Merge tag 'armsoc-drivers' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC driver updates from Arnd Bergmann: "New SoC specific drivers: - NVIDIA Tegra PM Domain support for newer SoCs (Tegra186 and later) based on the "BPMP" firmware - Clocksource and system controller drivers for the newly added Action Semi platforms (both arm and arm64). Reset subsystem, merged through arm-soc by tradition: - New drivers for Altera Stratix10, TI Keystone and Cortina Gemini SoCs - Various subsystem-wide cleanups Updates for existing SoC-specific drivers - TI GPMC (General Purpose Memory Controller) - Mediatek "scpsys" system controller support for MT6797 - Broadcom "brcmstb_gisb" bus arbitrer - ARM SCPI firmware - Renesas "SYSC" system controller One more driver update was submitted for the Freescale/NXP DPAA data path acceleration that has previously been used on PowerPC chips. I ended up postponing the merge until some API questions for its unusual MMIO access are resolved" * tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (35 commits) clocksource: owl: Add S900 support clocksource: Add Owl timer soc: renesas: rcar-sysc: Use GENPD_FLAG_ALWAYS_ON firmware: tegra: Fix locking bugs in BPMP soc/tegra: flowctrl: Fix error handling soc/tegra: bpmp: Implement generic PM domains soc/tegra: bpmp: Update ABI header PM / Domains: Allow overriding the ->xlate() callback soc: brcmstb: enable drivers for ARM64 and BMIPS soc: renesas: Rework Kconfig and Makefile logic reset: Add the TI SCI reset driver dt-bindings: reset: Add TI SCI reset binding reset: use kref for reference counting soc: qcom: smsm: Improve error handling, quiesce probe deferral cpufreq: scpi: use new scpi_ops functions to remove duplicate code firmware: arm_scpi: add support to populate OPPs and get transition latency dt-bindings: reset: Add reset manager offsets for Stratix10 memory: omap-gpmc: add error message if bank-width property is absent memory: omap-gpmc: make dts snippet include semicolon reset: Add a Gemini reset controller ...
2017-07-04Merge tag 'pm-4.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "The big ticket items here are the rework of suspend-to-idle in order to add proper support for power button wakeup from it on recent Dell laptops and the rework of interfaces exporting the current CPU frequency on x86. In addition to that, support for a few new pieces of hardware is added, the PCI/ACPI device wakeup infrastructure is simplified significantly and the wakeup IRQ framework is fixed to unbreak the IRQ bus locking infrastructure. Also, there are some functional improvements for intel_pstate, tools updates and small fixes and cleanups all over. Specifics: - Rework suspend-to-idle to allow it to take wakeup events signaled by the EC into account on ACPI-based platforms in order to properly support power button wakeup from suspend-to-idle on recent Dell laptops (Rafael Wysocki). That includes the core suspend-to-idle code rework, support for the Low Power S0 _DSM interface, and support for the ACPI INT0002 Virtual GPIO device from Hans de Goede (required for USB keyboard wakeup from suspend-to-idle to work on some machines). - Stop trying to export the current CPU frequency via /proc/cpuinfo on x86 as that is inaccurate and confusing (Len Brown). - Rework the way in which the current CPU frequency is exported by the kernel (over the cpufreq sysfs interface) on x86 systems with the APERF and MPERF registers by always using values read from these registers, when available, to compute the current frequency regardless of which cpufreq driver is in use (Len Brown). - Rework the PCI/ACPI device wakeup infrastructure to remove the questionable and artificial distinction between "devices that can wake up the system from sleep states" and "devices that can generate wakeup signals in the working state" from it, which allows the code to be simplified quite a bit (Rafael Wysocki). - Fix the wakeup IRQ framework by making it use SRCU instead of RCU which doesn't allow sleeping in the read-side critical sections, but which in turn is expected to be allowed by the IRQ bus locking infrastructure (Thomas Gleixner). - Modify some computations in the intel_pstate driver to avoid rounding errors resulting from them (Srinivas Pandruvada). - Reduce the overhead of the intel_pstate driver in the HWP (hardware-managed P-states) mode and when the "performance" P-state selection algorithm is in use by making it avoid registering scheduler callbacks in those cases (Len Brown). - Rework the energy_performance_preference sysfs knob in intel_pstate by changing the values that correspond to different symbolic hint names used by it (Len Brown). - Make it possible to use more than one cpuidle driver at the same time on ARM (Daniel Lezcano). - Make it possible to prevent the cpuidle menu governor from using the 0 state by disabling it via sysfs (Nicholas Piggin). - Add support for FFH (Fixed Functional Hardware) MWAIT in ACPI C1 on AMD systems (Yazen Ghannam). - Make the CPPC cpufreq driver take the lowest nonlinear performance information into account (Prashanth Prakash). - Add support for hi3660 to the cpufreq-dt driver, fix the imx6q driver and clean up the sfi, exynos5440 and intel_pstate drivers (Colin Ian King, Krzysztof Kozlowski, Octavian Purdila, Rafael Wysocki, Tao Wang). - Fix a few minor issues in the generic power domains (genpd) framework and clean it up somewhat (Krzysztof Kozlowski, Mikko Perttunen, Viresh Kumar). - Fix a couple of minor issues in the operating performance points (OPP) framework and clean it up somewhat (Viresh Kumar). - Fix a CONFIG dependency in the hibernation core and clean it up slightly (Balbir Singh, Arvind Yadav, BaoJun Luo). - Add rk3228 support to the rockchip-io adaptive voltage scaling (AVS) driver (David Wu). - Fix an incorrect bit shift operation in the RAPL power capping driver (Adam Lessnau). - Add support for the EPP field in the HWP (hardware managed P-states) control register, HWP.EPP, to the x86_energy_perf_policy tool and update msr-index.h with HWP.EPP values (Len Brown). - Fix some minor issues in the turbostat tool (Len Brown). - Add support for AMD family 0x17 CPUs to the cpupower tool and fix a minor issue in it (Sherry Hurwitz). - Assorted cleanups, mostly related to the constification of some data structures (Arvind Yadav, Joe Perches, Kees Cook, Krzysztof Kozlowski)" * tag 'pm-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (69 commits) cpufreq: Update scaling_cur_freq documentation cpufreq: intel_pstate: Clean up after performance governor changes PM: hibernate: constify attribute_group structures. cpuidle: menu: allow state 0 to be disabled intel_idle: Use more common logging style PM / Domains: Fix missing default_power_down_ok comment PM / Domains: Fix unsafe iteration over modified list of domains PM / Domains: Fix unsafe iteration over modified list of domain providers PM / Domains: Fix unsafe iteration over modified list of device links PM / Domains: Handle safely genpd_syscore_switch() call on non-genpd device PM / Domains: Call driver's noirq callbacks PM / core: Drop run_wake flag from struct dev_pm_info PCI / PM: Simplify device wakeup settings code PCI / PM: Drop pme_interrupt flag from struct pci_dev ACPI / PM: Consolidate device wakeup settings code ACPI / PM: Drop run_wake from struct acpi_device_wakeup_flags PM / QoS: constify *_attribute_group. PM / AVS: rockchip-io: add io selectors and supplies for rk3228 powercap/RAPL: prevent overridding bits outside of the mask PM / sysfs: Constify attribute groups ...
2017-07-04cpufreq: intel_pstate: constify attribute_group structuresArvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 15197 2552 40 17789 457d drivers/cpufreq/intel_pstate.o File size After adding 'const': text data bss dec hex filename 15261 2488 40 17789 457d drivers/cpufreq/intel_pstate.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-07-04cpufreq: cpufreq_stats: constify attribute_group structuresArvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 1655 256 4 1915 77b drivers/cpufreq/cpufreq_stats.o File size After adding 'const': text data bss dec hex filename 1695 192 4 1891 763 drivers/cpufreq/cpufreq_stats.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-07-03Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP hotplug updates from Thomas Gleixner: "This update is primarily a cleanup of the CPU hotplug locking code. The hotplug locking mechanism is an open coded RWSEM, which allows recursive locking. The main problem with that is the recursive nature as it evades the full lockdep coverage and hides potential deadlocks. The rework replaces the open coded RWSEM with a percpu RWSEM and establishes full lockdep coverage that way. The bulk of the changes fix up recursive locking issues and address the now fully reported potential deadlocks all over the place. Some of these deadlocks have been observed in the RT tree, but on mainline the probability was low enough to hide them away." * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) cpu/hotplug: Constify attribute_group structures powerpc: Only obtain cpu_hotplug_lock if called by rtasd ARM/hw_breakpoint: Fix possible recursive locking for arch_hw_breakpoint_init cpu/hotplug: Remove unused check_for_tasks() function perf/core: Don't release cred_guard_mutex if not taken cpuhotplug: Link lock stacks for hotplug callbacks acpi/processor: Prevent cpu hotplug deadlock sched: Provide is_percpu_thread() helper cpu/hotplug: Convert hotplug locking to percpu rwsem s390: Prevent hotplug rwsem recursion arm: Prevent hotplug rwsem recursion arm64: Prevent cpu hotplug rwsem recursion kprobes: Cure hotplug lock ordering issues jump_label: Reorder hotplug lock and jump_label_lock perf/tracing/cpuhotplug: Fix locking order ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus() PCI: Replace the racy recursion prevention PCI: Use cpu_hotplug_disable() instead of get_online_cpus() perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode() x86/perf: Drop EXPORT of perf_check_microcode ...
2017-07-03Merge branches 'pm-cpufreq', 'intel_pstate' and 'pm-cpuidle'Rafael J. Wysocki
* pm-cpufreq: cpufreq / CPPC: Initialize policy->min to lowest nonlinear performance cpufreq: sfi: make freq_table static cpufreq: exynos5440: Fix inconsistent indenting cpufreq: imx6q: imx6ull should use the same flow as imx6ul cpufreq: dt: Add support for hi3660 * intel_pstate: cpufreq: Update scaling_cur_freq documentation cpufreq: intel_pstate: Clean up after performance governor changes intel_pstate: skip scheduler hook when in "performance" mode intel_pstate: delete scheduler hook in HWP mode x86: use common aperfmperf_khz_on_cpu() to calculate KHz using APERF/MPERF cpufreq: intel_pstate: Remove max/min fractions to limit performance x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz" * pm-cpuidle: cpuidle: menu: allow state 0 to be disabled intel_idle: Use more common logging style x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD systems ARM: cpuidle: Support asymmetric idle definition
2017-07-03Merge branch 'pm-tools'Rafael J. Wysocki
* pm-tools: cpupower: Add support for new AMD family 0x17 cpupower: Fix bug where return value was not used tools/power turbostat: update version number tools/power turbostat: decode MSR_IA32_MISC_ENABLE only on Intel tools/power turbostat: stop migrating, unless '-m' tools/power turbostat: if --debug, print sampling overhead tools/power turbostat: hide SKL counters, when not requested intel_pstate: use updated msr-index.h HWP.EPP values tools/power x86_energy_perf_policy: support HWP.EPP x86: msr-index.h: fix shifts to ULL results in HWP macros. x86: msr-index.h: define HWP.EPP values x86: msr-index.h: define EPB mid-points
2017-06-29cpufreq: intel_pstate: Clean up after performance governor changesRafael J. Wysocki
After commit 82b4e03e01bc (intel_pstate: skip scheduler hook when in "performance" mode) get_target_pstate_use_performance() and get_target_pstate_use_cpu_load() are never called if scaling_governor is "performance", so drop the CPUFREQ_POLICY_PERFORMANCE checks from them as they will never trigger anyway. Moreover, the documentation needs to be updated to reflect the change made by the above commit, so do that too. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
2017-06-27cpufreq / CPPC: Initialize policy->min to lowest nonlinear performancePrakash, Prashanth
Description of Lowest Perfomance in ACPI 6.1 specification states: "Lowest Performance is the absolute lowest performance level of the platform. Selecting a performance level lower than the lowest nonlinear performance level may actually cause an efficiency penalty, but should reduce the instantaneous power consumption of the processor. In traditional terms, this represents the T-state range of performance levels." Set the default value of policy->min to Lowest Nonlinear Performance to avoid any potential efficiency penalty. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Alexey Klimov <alexey.klimov@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-27intel_pstate: skip scheduler hook when in "performance" modeLen Brown
When the governor is set to "performance", intel_pstate does not need the scheduler hook for doing any calculations. Under these conditions, its only purpose is to continue to maintain cpufreq/scaling_cur_freq. The cpufreq/scaling_cur_freq sysfs attribute is now provided by shared x86 cpufreq code on modern x86 systems, including all systems supported by the intel_pstate driver. So in "performance" governor mode, the scheduler hook can be skipped. This applies to both in Software and Hardware P-state control modes. Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-27intel_pstate: delete scheduler hook in HWP modeLen Brown
The cpufreq/scaling_cur_freq sysfs attribute is now provided by shared x86 cpufreq code on modern x86 systems, including all systems supported by the intel_pstate driver. In HWP mode, maintaining that value was the sole purpose of the scheduler hook, intel_pstate_update_util_hwp(), so it can now be removed. Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-27x86: use common aperfmperf_khz_on_cpu() to calculate KHz using APERF/MPERFLen Brown
The goal of this change is to give users a uniform and meaningful result when they read /sys/...cpufreq/scaling_cur_freq on modern x86 hardware, as compared to what they get today. Modern x86 processors include the hardware needed to accurately calculate frequency over an interval -- APERF, MPERF, and the TSC. Here we provide an x86 routine to make this calculation on supported hardware, and use it in preference to any driver driver-specific cpufreq_driver.get() routine. MHz is computed like so: MHz = base_MHz * delta_APERF / delta_MPERF MHz is the average frequency of the busy processor over a measurement interval. The interval is defined to be the time between successive invocations of aperfmperf_khz_on_cpu(), which are expected to to happen on-demand when users read sysfs attribute cpufreq/scaling_cur_freq. As with previous methods of calculating MHz, idle time is excluded. base_MHz above is from TSC calibration global "cpu_khz". This x86 native method to calculate MHz returns a meaningful result no matter if P-states are controlled by hardware or firmware and/or if the Linux cpufreq sub-system is or is-not installed. When this routine is invoked more frequently, the measurement interval becomes shorter. However, the code limits re-computation to 10ms intervals so that average frequency remains meaningful. Discerning users are encouraged to take advantage of the turbostat(8) utility, which can gracefully handle concurrent measurement intervals of arbitrary length. Signed-off-by: Len Brown <len.brown@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-27Merge back PM tools material for v4.13.Rafael J. Wysocki
2017-06-24cpufreq: intel_pstate: Remove max/min fractions to limit performanceSrinivas Pandruvada
In the current model the max/min perf limits are a fraction of current user space limits to the allowed max_freq or 100% for global limits. This results in wrong ratio limits calculation because of rounding issues for some user space limits. Initially we tried to solve this issue by issue by having more shift bits to increase precision. Still there are isolated cases where we still have error. This can be avoided by using ratios all together. Since the way we get cpuinfo.max_freq is by multiplying scaling factor to max ratio, we can easily keep the max/min ratios in terms of ratios and not fractions. For example: if the max ratio = 36 cpuinfo.max_freq = 36 * 100000 = 3600000 Suppose user space sets a limit of 1200000, then we can calculate max ratio limit as = 36 * 1200000 / 3600000 = 12 This will be correct for any user limits. The other advantage is that, we don't need to do any calculation in the fast path as ratio limit is already calculated via set_policy() callback. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-24cpufreq: sfi: make freq_table staticColin Ian King
pointer freq_table can be made static as it does not need to be in global scope. Cleans up sparse warning: "symbol 'freq_table' was not declared. Should it be static?" Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-24cpufreq: exynos5440: Fix inconsistent indentingKrzysztof Kozlowski
Fix inconsistent indenting and unneeded white space in assignment. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-24cpufreq: imx6q: imx6ull should use the same flow as imx6ulOctavian Purdila
This fixes an issue with imx6ull where setting the frequency to 528Mhz would actually set the ARM clock to 324Mhz. Signed-off-by: Octavian Purdila <octavian.purdila@nxp.com> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-24cpufreq: dt: Add support for hi3660Tao Wang
Add the compatible string for supporting the generic device tree cpufreq-dt driver on Hisilicon's 3660 SoC. Signed-off-by: Tao Wang <kevin.wangtao@hisilicon.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-20Merge branch 'WIP.sched/core' into sched/coreIngo Molnar
Conflicts: kernel/sched/Makefile Pick up the waitqueue related renames - it didn't get much feedback, so it appears to be uncontroversial. Famous last words? ;-) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-18Merge tag 'scpi-updates-4.13' of ↵Olof Johansson
git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into next/drivers SCPI update for v4.13 Adds support to get DVFS transition latency and OPP for any device whose DVFS are managed by SCPI. This avoids code duplication in both cpufreq and devfreq SCPI drivers. * tag 'scpi-updates-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux: cpufreq: scpi: use new scpi_ops functions to remove duplicate code firmware: arm_scpi: add support to populate OPPs and get transition latency Signed-off-by: Olof Johansson <olof@lixom.net>
2017-06-15Merge branches 'pm-cpufreq', 'pm-cpuidle' and 'pm-devfreq'Rafael J. Wysocki
* pm-cpufreq: cpufreq: conservative: Allow down_threshold to take values from 1 to 10 Revert "cpufreq: schedutil: Reduce frequencies slower" * pm-cpuidle: cpuidle: dt: Add missing 'of_node_put()' * pm-devfreq: PM / devfreq: exynos-ppmu: Staticize event list PM / devfreq: exynos-ppmu: Handle return value of clk_prepare_enable PM / devfreq: exynos-nocp: Handle return value of clk_prepare_enable
2017-06-12cpufreq: conservative: Allow down_threshold to take values from 1 to 10Tomasz Wilczyński
Commit 27ed3cd2ebf4 (cpufreq: conservative: Fix the logic in frequency decrease checking) removed the 10 point substraction when comparing the load against down_threshold but did not remove the related limit for the down_threshold value. As a result, down_threshold lower than 11 is not allowed even though values from 1 to 10 do work correctly too. The comment ("cannot be lower than 11 otherwise freq will not fall") also does not apply after removing the substraction. For this reason, allow down_threshold to take any value from 1 to 99 and fix the related comment. Fixes: 27ed3cd2ebf4 (cpufreq: conservative: Fix the logic in frequency decrease checking) Signed-off-by: Tomasz Wilczyński <twilczynski@naver.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 3.10+ <stable@vger.kernel.org> # 3.10+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-09Merge branches 'intel_pstate' and 'pm-sleep'Rafael J. Wysocki
* intel_pstate: cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min() * pm-sleep: Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
2017-06-05cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()Rafael J. Wysocki
Commit c5a2ee7dde89 (cpufreq: intel_pstate: Active mode P-state limits rework) incorrectly assumed that pstate.turbo_pstate would always be nonzero for CPU0 in min_perf_pct_min() if cpufreq_register_driver() had succeeded which may not be the case in virtualized environments. If that assumption doesn't hold, it leads to an early crash on boot in intel_pstate_register_driver(), so add a sanity check to min_perf_pct_min() to prevent the crash from happening. Fixes: c5a2ee7dde89 (cpufreq: intel_pstate: Active mode P-state limits rework) Reported-and-tested-by: Jongman Heo <jongman.heo@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-05cpufreq: scpi: use new scpi_ops functions to remove duplicate codeSudeep Holla
scpi_ops now provide APIs to get the transition_latency and to add OPPs to the devices making those logic redundant here. This patch makes use of those APIs and removes the redundant code in this driver. Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2017-06-03Merge branch 'pm-cpufreq'Rafael J. Wysocki
* pm-cpufreq: cpufreq: kirkwood-cpufreq:- Handle return value of clk_prepare_enable() cpufreq: cpufreq_register_driver() should return -ENODEV if init fails
2017-05-30cpufreq: kirkwood-cpufreq:- Handle return value of clk_prepare_enable()Arvind Yadav
clk_prepare_enable() can fail here and we must check its return value. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-30cpufreq: cpufreq_register_driver() should return -ENODEV if init failsDavid Arcari
For a driver that does not set the CPUFREQ_STICKY flag, if all of the ->init() calls fail, cpufreq_register_driver() should return an error. This will prevent the driver from loading. Fixes: ce1bcfe94db8 (cpufreq: check cpufreq_policy_list instead of scanning policies for all CPUs) Cc: 4.0+ <stable@vger.kernel.org> # 4.0+ Signed-off-by: David Arcari <darcari@redhat.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-27cpufreq: create cpufreq_table_count_valid_entries()Viresh Kumar
We need such a routine at two places already, lets create one. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Tested-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2017-05-27thermal: cpu_cooling: use cpufreq_policy to register cooling deviceViresh Kumar
The CPU cooling driver uses the cpufreq policy, to get clip_cpus, the frequency table, etc. Most of the callers of CPU cooling driver's registration routines have the cpufreq policy with them, but they only pass the policy->related_cpus cpumask. The __cpufreq_cooling_register() routine then gets the policy by itself and uses it. It would be much better if the callers can pass the policy instead directly. This also fixes a basic design flaw, where the policy can be freed while the CPU cooling driver is still active. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Tested-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2017-05-26cpufreq: Use cpuhp_setup_state_nocalls_cpuslocked()Sebastian Andrzej Siewior
cpufreq holds get_online_cpus() while invoking cpuhp_setup_state_nocalls() to make subsys_interface_register() and the registration of hotplug calls atomic versus cpu hotplug. cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is correct, but prevents the conversion of the hotplug locking to a percpu rwsem. Use cpuhp_setup/remove_state_nocalls_cpuslocked() to avoid the nested call. Convert *_online_cpus() to the new interfaces while at it. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linux-pm@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170524081547.731628408@linutronix.de
2017-05-23cpufreq/pasemi: Adjust system_state checkThomas Gleixner
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in pas_cpufreq_cpu_exit() to handle the extra states. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20170516184735.620023128@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-22Merge branches 'intel_pstate', 'pm-cpufreq' and 'pm-cpufreq-sched'Rafael J. Wysocki
* intel_pstate: cpufreq: intel_pstate: Document the current behavior and user interface * pm-cpufreq: cpufreq: dbx500: add a Kconfig symbol * pm-cpufreq-sched: cpufreq: schedutil: use now as reference when aggregating shared policy requests
2017-05-16Merge branch 'utilities' of ↵Rafael J. Wysocki
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux Pull power management utilities updates from Len Brown. * 'utilities' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: intel_pstate: use updated msr-index.h HWP.EPP values tools/power x86_energy_perf_policy: support HWP.EPP x86: msr-index.h: fix shifts to ULL results in HWP macros. x86: msr-index.h: define HWP.EPP values x86: msr-index.h: define EPB mid-points
2017-05-14cpufreq: dbx500: add a Kconfig symbolArnd Bergmann
Moving the cooling code into the cpufreq driver caused a possible build failure when the cpu_thermal helper code is a loadable module or disabled: drivers/cpufreq/dbx500-cpufreq.o: In function `dbx500_cpufreq_ready': dbx500-cpufreq.c:(.text.dbx500_cpufreq_ready+0x4): undefined reference to `cpufreq_cooling_register' This adds the same dependency that we have in other cpufreq drivers, forcing the driver to be disabled when we can't possibly link it. Fixes: 19678ffb9fd6 (cpufreq: dbx500: Manage cooling device from cpufreq driver) Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-12Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from James Hogan: "math-emu: - Add missing clearing of BLTZALL and BGEZALL emulation counters - Fix BC1EQZ and BC1NEZ condition handling - Fix BLEZL and BGTZL identification BPF: - Add JIT support for SKF_AD_HATYPE - Use unsigned access for unsigned SKB fields - Quit clobbering callee saved registers in JIT code - Fix multiple problems in JIT skb access helpers Loongson 3: - Select MIPS_L1_CACHE_SHIFT_6 Octeon: - Remove vestiges of CONFIG_CAVIUM_OCTEON_2ND_KERNEL - Remove unused L2C types and macros. - Remove unused SLI types and macros. - Fix compile error when USB is not enabled. - Octeon: Remove unused PCIERCX types and macros. - Octeon: Clean up platform code. SNI: - Remove recursive include of cpu-feature-overrides.h Sibyte: - Export symbol periph_rev to sb1250-mac network driver. - Fix Kconfig warning. Generic platform: - Enable Root FS on NFS in generic_defconfig SMP-MT: - Use CPU interrupt controller IPI IRQ domain support UASM: - Add support for LHU for uasm. - Remove needless ISA abstraction mm: - Add 48-bit VA space and 4-level page tables for 4K pages. PCI: - Add controllers before the specified head irqchip driver for MIPS CPU: - Replace magic 0x100 with IE_SW0 - Prepare for non-legacy IRQ domains - Introduce IPI IRQ domain support MAINTAINERS: - Update email-id of Rahul Bedarkar NET: - sb1250-mac: Add missing MODULE_LICENSE() CPUFREQ: - Loongson2: drop set_cpus_allowed_ptr() Misc: - Disable Werror when W= is set - Opt into HAVE_COPY_THREAD_TLS - Enable GENERIC_CPU_AUTOPROBE - Use common outgoing-CPU-notification code - Remove dead define of ST_OFF - Remove CONFIG_ARCH_HAS_ILOG2_U{32,64} - Stengthen IPI IRQ domain sanity check - Remove confusing else statement in __do_page_fault() - Don't unnecessarily include kmalloc.h into <asm/cache.h>. - Delete unused definition of SMP_CACHE_SHIFT. - Delete redundant definition of SMP_CACHE_BYTES" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (39 commits) MIPS: Sibyte: Fix Kconfig warning. MIPS: Sibyte: Export symbol periph_rev to sb1250-mac network driver. NET: sb1250-mac: Add missing MODULE_LICENSE() MAINTAINERS: Update email-id of Rahul Bedarkar MIPS: Remove confusing else statement in __do_page_fault() MIPS: Stengthen IPI IRQ domain sanity check MIPS: smp-mt: Use CPU interrupt controller IPI IRQ domain support irqchip: mips-cpu: Introduce IPI IRQ domain support irqchip: mips-cpu: Prepare for non-legacy IRQ domains irqchip: mips-cpu: Replace magic 0x100 with IE_SW0 MIPS: Remove CONFIG_ARCH_HAS_ILOG2_U{32,64} MIPS: generic: Enable Root FS on NFS in generic_defconfig MIPS: mach-rm: Remove recursive include of cpu-feature-overrides.h MIPS: Opt into HAVE_COPY_THREAD_TLS CPUFREQ: Loongson2: drop set_cpus_allowed_ptr() MIPS: uasm: Remove needless ISA abstraction MIPS: Remove dead define of ST_OFF MIPS: Use common outgoing-CPU-notification code MIPS: math-emu: Fix BC1EQZ and BC1NEZ condition handling MIPS: r2-on-r6-emu: Clear BLTZALL and BGEZALL debugfs counters ...
2017-05-11intel_pstate: use updated msr-index.h HWP.EPP valuesLen Brown
intel_pstate exports sysfs attributes for setting and observing HWP.EPP. These attributes use strings to describe 4 operating states, and inside the driver, these strings are mapped to numerical register values. The authorative mapping between the strings and numerical HWP.EPP values are now globally defined in msr-index.h, replacing the out-dated mapping that were open-coded into intel_pstate.c new old string --- --- ------ 0 0 performance 128 64 balance_performance 192 128 balance_power 255 192 power Note that the HW and BIOS default value on most system is 128, which intel_pstate will now call "balance_performance" while it used to call it "balance_power". Signed-off-by: Len Brown <len.brown@intel.com>
2017-05-10Merge tag 'hwparam-20170420' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull hw lockdown support from David Howells: "Annotation of module parameters that configure hardware resources including ioports, iomem addresses, irq lines and dma channels. This allows a future patch to prohibit the use of such module parameters to prevent that hardware from being abused to gain access to the running kernel image as part of locking the kernel down under UEFI secure boot conditions. Annotations are made by changing: module_param(n, t, p) module_param_named(n, v, t, p) module_param_array(n, t, m, p) to: module_param_hw(n, t, hwtype, p) module_param_hw_named(n, v, t, hwtype, p) module_param_hw_array(n, t, hwtype, m, p) where the module parameter refers to a hardware setting hwtype specifies the type of the resource being configured. This can be one of: ioport Module parameter configures an I/O port iomem Module parameter configures an I/O mem address ioport_or_iomem Module parameter could be either (runtime set) irq Module parameter configures an I/O port dma Module parameter configures a DMA channel dma_addr Module parameter configures a DMA buffer address other Module parameter configures some other value Note that the hwtype is compile checked, but not currently stored (the lockdown code probably won't require it). It is, however, there for future use. A bonus is that the hwtype can also be used for grepping. The intention is for the kernel to ignore or reject attempts to set annotated module parameters if lockdown is enabled. This applies to options passed on the boot command line, passed to insmod/modprobe or direct twiddling in /sys/module/ parameter files. The module initialisation then needs to handle the parameter not being set, by (1) giving an error, (2) probing for a value or (3) using a reasonable default. What I can't do is just reject a module out of hand because it may take a hardware setting in the module parameters. Some important modules, some ipmi stuff for instance, both probe for hardware and allow hardware to be manually specified; if the driver is aborts with any error, you don't get any ipmi hardware. Further, trying to do this entirely in the module initialisation code doesn't protect against sysfs twiddling. [!] Note that in and of itself, this series of patches should have no effect on the the size of the kernel or code execution - that is left to a patch in the next series to effect. It does mark annotated kernel parameters with a KERNEL_PARAM_FL_HWPARAM flag in an already existing field" * tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (38 commits) Annotate hardware config module parameters in sound/pci/ Annotate hardware config module parameters in sound/oss/ Annotate hardware config module parameters in sound/isa/ Annotate hardware config module parameters in sound/drivers/ Annotate hardware config module parameters in fs/pstore/ Annotate hardware config module parameters in drivers/watchdog/ Annotate hardware config module parameters in drivers/video/ Annotate hardware config module parameters in drivers/tty/ Annotate hardware config module parameters in drivers/staging/vme/ Annotate hardware config module parameters in drivers/staging/speakup/ Annotate hardware config module parameters in drivers/staging/media/ Annotate hardware config module parameters in drivers/scsi/ Annotate hardware config module parameters in drivers/pcmcia/ Annotate hardware config module parameters in drivers/pci/hotplug/ Annotate hardware config module parameters in drivers/parport/ Annotate hardware config module parameters in drivers/net/wireless/ Annotate hardware config module parameters in drivers/net/wan/ Annotate hardware config module parameters in drivers/net/irda/ Annotate hardware config module parameters in drivers/net/hamradio/ Annotate hardware config module parameters in drivers/net/ethernet/ ...