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2020-02-14PM: QoS: Make CPU latency QoS depend on CONFIG_CPU_IDLERafael J. Wysocki
Because cpuidle is the only user of the effective constraint coming from the CPU latency QoS, add #ifdef CONFIG_CPU_IDLE around that code to avoid building it unnecessarily. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-14PM: QoS: Update file information commentsRafael J. Wysocki
Update the file information comments in include/linux/pm_qos.h and kernel/power/qos.c by adding titles along with copyright and authors information to them and changing the qos.c description to better reflect its contents (outdated information is dropped from it in particular). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-14PM: QoS: Drop PM_QOS_CPU_DMA_LATENCY and rename related functionsRafael J. Wysocki
Drop the PM QoS classes enum including PM_QOS_CPU_DMA_LATENCY, drop the wrappers around pm_qos_request(), pm_qos_request_active(), and pm_qos_add/update/remove_request() introduced previously, rename these functions, respectively, to cpu_latency_qos_limit(), cpu_latency_qos_request_active(), and cpu_latency_qos_add/update/remove_request(), and update their kerneldoc comments. [While at it, drop some useless comments from these functions.] No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13PM: QoS: Add CPU latency QoS API wrappersRafael J. Wysocki
Introduce (temporary) wrappers around pm_qos_request(), pm_qos_request_active() and pm_qos_add/update/remove_request() to provide replacements for them with function signatures that will be used in the final CPU latency QoS API, so that the users of it can be switched over to the new arrangement one by one before the API is finally set. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13PM: QoS: Adjust pm_qos_request() signature and reorder pm_qos.hRafael J. Wysocki
Change the return type of pm_qos_request() to be the same as the one of pm_qos_read_value() called by it internally and stop exporting it to modules (because its only caller, cpuidle, is not modular). Also move the pm_qos_read_value() header away from the CPU latency QoS API function headers in pm_qos.h (because it technically does not belong to that API). No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13PM: QoS: Rename things related to the CPU latency QoSRafael J. Wysocki
First, rename PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE to PM_QOS_CPU_LATENCY_DEFAULT_VALUE and update all of the code referring to it accordingly. Next, rename cpu_dma_constraints to cpu_latency_constraints, move the definition of it closer to the functions referring to it and update all of them accordingly. [While at it, add a comment to mark the start of the code related to the CPU latency QoS.] Finally, rename the pm_qos_power_*() family of functions and pm_qos_power_fops to cpu_latency_qos_*() and cpu_latency_qos_fops, respectively, and update the definition of cpu_latency_qos_miscdev. [While at it, update the miscdev interface code start comment.] No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13PM: QoS: Drop PM_QOS_CPU_DMA_LATENCY notifier chainRafael J. Wysocki
Notice that pm_qos_remove_notifier() is not used at all and the only caller of pm_qos_add_notifier() is the cpuidle core, which only needs the PM_QOS_CPU_DMA_LATENCY notifier to invoke wake_up_all_idle_cpus() upon changes of the PM_QOS_CPU_DMA_LATENCY target value. First, to ensure that wake_up_all_idle_cpus() will be called whenever the PM_QOS_CPU_DMA_LATENCY target value changes, modify the pm_qos_add/update/remove_request() family of functions to check if the effective constraint for the PM_QOS_CPU_DMA_LATENCY has changed and call wake_up_all_idle_cpus() directly in that case. Next, drop the PM_QOS_CPU_DMA_LATENCY notifier from cpuidle as it is not necessary any more. Finally, drop both pm_qos_add_notifier() and pm_qos_remove_notifier(), as they have no callers now, along with cpu_dma_lat_notifier which is only used by them. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13PM: QoS: Redefine struct pm_qos_request and drop struct pm_qos_objectRafael J. Wysocki
First, change the definition of struct pm_qos_request so that it contains a struct pm_qos_constraints pointer (called "qos") instead of a PM QoS class number (in preparation for dropping the PM QoS classes concept altogether going forward) and move its definition (along with the definition of struct pm_qos_flags_request that does not change) after the definition of struct pm_qos_constraints. Next, drop the definition of struct pm_qos_object and the null_pm_qos and cpu_dma_pm_qos variables of that type along with pm_qos_array[] holding pointers to them and change the code to refer to the pm_qos_constraints structure directly or to use the new qos pointer in struct pm_qos_request for that instead of going through pm_qos_array[] to access it. Also update kerneldoc comments that mention pm_qos_class to refer to PM_QOS_CPU_DMA_LATENCY directly instead. Finally, drop register_pm_qos_misc(), introduce cpu_latency_qos_miscdev (with the name field set to "cpu_dma_latency") to implement the CPU latency QoS interface in /dev/ and register it directly from pm_qos_power_init(). After these changes the notion of PM QoS classes remains only in the API (in the form of redundant function parameters that are ignored) and in the definitions of PM QoS trace events. While at it, some redundant local variables are dropped etc. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13PM: QoS: Drop the PM_QOS_SUM QoS typeRafael J. Wysocki
The PM_QOS_SUM QoS type is not used, so drop it along with the code referring to it in pm_qos_get_value() and the related local variables in there. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13PM: QoS: Drop pm_qos_update_request_timeout()Rafael J. Wysocki
The pm_qos_update_request_timeout() function is not called from anywhere, so drop it along with the work member in struct pm_qos_request needed by it. Also drop the useless pm_qos_update_request_timeout trace event that is only triggered by that function (so it never triggers at all) and update the trace events documentation accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2019-11-29PM / QoS: Restore DEV_PM_QOS_MIN/MAX_FREQUENCYLeonard Crestez
Support for adding per-device frequency limits was removed in commit 2aac8bdf7a0f ("PM: QoS: Drop frequency QoS types from device PM QoS") after cpufreq switched to use a new "freq_constraints" construct. Restore support for per-device freq limits but base this upon freq_constraints. This is primarily meant to be used by the devfreq subsystem. This removes the "static" marking on freq_qos_apply but does not export it for modules. Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Tested-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-29PM / QoS: Reorder pm_qos/freq_qos/dev_pm_qos structsLeonard Crestez
This allows dev_pm_qos to embed freq_qos structs, which is done in the next patch. Separate commit to make it easier to review. Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-29PM / QoS: Redefine FREQ_QOS_MAX_DEFAULT_VALUE to S32_MAXLeonard Crestez
QOS requests for DEFAULT_VALUE are supposed to be ignored but this is not the case for FREQ_QOS_MAX. Adding one request for MAX_DEFAULT_VALUE and one for a real value will cause freq_qos_read_value to unexpectedly return MAX_DEFAULT_VALUE (-1). This happens because freq_qos max value is aggregated with PM_QOS_MIN but FREQ_QOS_MAX_DEFAULT_VALUE is (-1) so it's smaller than other values. Fix this by redefining FREQ_QOS_MAX_DEFAULT_VALUE to S32_MAX. Looking at current users for freq_qos it seems that none of them create requests for FREQ_QOS_MAX_DEFAULT_VALUE. Fixes: 77751a466ebd ("PM: QoS: Introduce frequency QoS") Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Reported-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Cc: 5.4+ <stable@vger.kernel.org> # 5.4+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-21PM: QoS: Drop frequency QoS types from device PM QoSRafael J. Wysocki
There are no more active users of DEV_PM_QOS_MIN_FREQUENCY and DEV_PM_QOS_MAX_FREQUENCY device PM QoS request types, so drop them along with the code supporting them. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-10-21PM: QoS: Introduce frequency QoSRafael J. Wysocki
Introduce frequency QoS, based on the "raw" low-level PM QoS, to represent min and max frequency requests and aggregate constraints. The min and max frequency requests are to be represented by struct freq_qos_request objects and the aggregate constraints are to be represented by struct freq_constraints objects. The latter are expected to be initialized with the help of freq_constraints_init(). The freq_qos_read_value() helper is defined to retrieve the aggregate constraints values from a given struct freq_constraints object and there are the freq_qos_add_request(), freq_qos_update_request() and freq_qos_remove_request() helpers to manipulate the min and max frequency requests. It is assumed that the the helpers will not run concurrently with each other for the same struct freq_qos_request object, so if that may be the case, their uses must ensure proper synchronization between them (e.g. through locking). In addition, freq_qos_add_notifier() and freq_qos_remove_notifier() are provided to add and remove notifiers that will trigger on aggregate constraint changes to and from a given struct freq_constraints object, respectively. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-08-21PM: QoS: Get rid of unused flagsAmit Kucheria
The network_latency and network_throughput flags for PM-QoS have not found much use in drivers or in userspace since they were introduced. Commit 4a733ef1bea7 ("mac80211: remove PM-QoS listener") removed the only user PM_QOS_NETWORK_LATENCY in the kernel a while ago and there don't seem to be any userspace tools using the character device files either. PM_QOS_MEMORY_BANDWIDTH was never even added to the trace events. Remove all the flags except cpu_dma_latency. Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-04PM / QoS: Add support for MIN/MAX frequency constraintsViresh Kumar
This patch introduces the min-frequency and max-frequency device constraints, which will be used by the cpufreq core to begin with. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-04PM / QOS: Pass request type to dev_pm_qos_read_value()Viresh Kumar
In order to allow dev_pm_qos_read_value() to read values for different QoS requests, pass request type as a parameter to these routines. For now, it only supports resume-latency request type but will be extended to frequency limit (min/max) constraints later on. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-04PM / QOS: Rename __dev_pm_qos_read_value() and dev_pm_qos_raw_read_value()Viresh Kumar
dev_pm_qos_read_value() will soon need to support more constraint types (min/max frequency) and will have another argument to it, i.e. type of the constraint. While that is fine for the existing users of dev_pm_qos_read_value(), but not that optimal for the callers of __dev_pm_qos_read_value() and dev_pm_qos_raw_read_value() as all the callers of these two routines are only looking for resume latency constraint. Lets make these two routines care only about the resume latency constraint and rename them to __dev_pm_qos_resume_latency() and dev_pm_qos_raw_resume_latency(). Suggested-by: Rafael J. Wysocki <rjw@rjwysocki.net> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-04PM / QOS: Pass request type to dev_pm_qos_{add|remove}_notifier()Viresh Kumar
In order to use the same set of routines to register notifiers for different request types, update the existing dev_pm_qos_{add|remove}_notifier() routines with an additional parameter: request-type. For now, it only supports resume-latency request type but will be extended to frequency limit (min/max) constraints later on. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-11-13Merge branch 'pm-qos'Rafael J. Wysocki
* pm-qos: PM / QoS: Fix device resume latency framework PM / QoS: Drop PM_QOS_FLAG_REMOTE_WAKEUP
2017-11-08PM / QoS: Fix device resume latency frameworkRafael J. Wysocki
The special value of 0 for device resume latency PM QoS means "no restriction", but there are two problems with that. First, device resume latency PM QoS requests with 0 as the value are always put in front of requests with positive values in the priority lists used internally by the PM QoS framework, causing 0 to be chosen as an effective constraint value. However, that 0 is then interpreted as "no restriction" effectively overriding the other requests with specific restrictions which is incorrect. Second, the users of device resume latency PM QoS have no way to specify that *any* resume latency at all should be avoided, which is an artificial limitation in general. To address these issues, modify device resume latency PM QoS to use S32_MAX as the "no constraint" value and 0 as the "no latency at all" one and rework its users (the cpuidle menu governor, the genpd QoS governor and the runtime PM framework) to follow these changes. Also add a special "n/a" value to the corresponding user space I/F to allow user space to indicate that it cannot accept any resume latencies at all for the given device. Fixes: 85dc0b8a4019 (PM / QoS: Make it possible to expose PM QoS latency constraints) Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323 Reported-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Tero Kristo <t-kristo@ti.com> Reviewed-by: Ramesh Thomas <ramesh.thomas@intel.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-14PM / QoS: Drop PM_QOS_FLAG_REMOTE_WAKEUPRafael J. Wysocki
The PM QoS flag PM_QOS_FLAG_REMOTE_WAKEUP is not used consistently and the vast majority of code simply assumes that remote wakeup should be enabled for devices in runtime suspend if they can generate wakeup signals, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2017-03-03Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep'Rafael J. Wysocki
* pm-cpuidle: intel_idle: stop exposing platform acronyms in sysfs cpuidle: menu: Avoid taking spinlock for accessing QoS values * pm-cpufreq: cpufreq: intel_pstate: Fix limits issue with operation mode switching cpufreq: qoriq: clean up unused code * pm-sleep: PM / hibernate: Define pr_fmt() and use pr_*() instead of printk() PM / hibernate: Untangle power_down()
2017-02-27cpuidle: menu: Avoid taking spinlock for accessing QoS valuesRafael J. Wysocki
After commit 9908859acaa9 (cpuidle/menu: add per CPU PM QoS resume latency consideration) the cpuidle menu governor calls dev_pm_qos_read_value() on CPU devices to read the current resume latency QoS constraint values for them. That function takes a spinlock to prevent the device's power.qos pointer from becoming NULL during the access which is a problem for the RT patchset where spinlocks are converted into mutexes and the idle loop stops working. However, it is not even necessary for the menu governor to take that spinlock, because the power.qos pointer accessed under it cannot be modified during the access anyway. For this reason, introduce a "raw" routine for accessing device QoS resume latency constraints without locking and use it in the menu governor. Fixes: 9908859acaa9 (cpuidle/menu: add per CPU PM QoS resume latency consideration) Acked-by: Alex Shi <alex.shi@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-02-23PM / QoS: Remove global notifiersViresh Kumar
They were never used in the kernel, so get rid of them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-01-27PM / QoS: Remove unneeded linux/miscdevice.h includeCorentin LABBE
pm_qos.h does not use any miscdevice, so this patch remove this unnecessary inclusion. Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-28PM / QoS: Make it possible to expose device latency tolerance to userspaceMika Westerberg
Typically when a device is created the bus core it belongs to (for example PCI) does not know if the device supports things like latency tolerance. This is left to the driver that binds to the device in question. However, at that time the device has already been created and there is no way to set its dev->power.set_latency_tolerance anymore. So follow what has been done for other PM QoS attributes as well and allow drivers to expose and hide latency tolerance from userspace, if the device supports it. Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-12-04PM: Drop CONFIG_PM_RUNTIME from the driver coreRafael J. Wysocki
After commit b2b49ccbdd54 (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is selected) PM_RUNTIME is always set if PM is set, so quite a few depend on CONFIG_PM or even may be dropped entirely in some cases. Replace CONFIG_PM_RUNTIME with CONFIG_PM in the PM core code. Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-25PM / QoS: Add PM_QOS_MEMORY_BANDWIDTH classTomeu Vizoso
Also adds a class type PM_QOS_SUM that aggregates the values by summing them. It can be used by memory controllers to calculate the optimum clock frequency based on the bandwidth needs of the different memory clients. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11PM / QoS: Add type to dev_pm_qos_add_ancestor_request() argumentsRafael J. Wysocki
Rework dev_pm_qos_add_ancestor_request() so that device PM QoS type is passed to it as the third argument and make it support the DEV_PM_QOS_LATENCY_TOLERANCE device PM QoS type (in addition to DEV_PM_QOS_RESUME_LATENCY). That will allow the drivers of devices without latency tolerance hardware support to use their ancestors having it as proxies for their latency tolerance requirements. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11PM / QoS: Introcuce latency tolerance device PM QoS typeRafael J. Wysocki
Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11PM / QoS: Add no_constraints_value field to struct pm_qos_constraintsRafael J. Wysocki
Add a new field, no_constraints_value, to struct pm_qos_constraints representing a list of PM QoS constraint requests to be returned by pm_qos_get_value() when that list of requests is empty. That field will be equal to default_value for all of the existing global PM QoS classes and for the resume latency device PM QoS type, but it will be different from default_value for the new latency tolerance device PM QoS type introduced by the next changeset. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11PM / QoS: Rename device resume latency QoS itemsRafael J. Wysocki
Rename symbols, variables, functions and structure fields related do the resume latency device PM QoS type so that it is clear where they belong (in particular, to avoid confusion with the latency tolerance device PM QoS type introduced by a subsequent changeset). Update the PM QoS documentation to better reflect its current state. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-24PM / QoS: Make it possible to expose PM QoS device flags to user spaceRafael J. Wysocki
Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the caller to expose those two flags to user space or to hide them from it, respectively. After the flags have been exposed, user space will see two additional sysfs attributes, pm_qos_no_power_off and pm_qos_remote_wakeup, under the device's /sys/devices/.../power/ directory. Then, writing 1 to one of them will update the PM QoS flags request owned by user space so that the corresponding flag is requested to be set. In turn, writing 0 to one of them will cause the corresponding flag in the user space's request to be cleared (however, the owners of the other PM QoS flags requests for the same device may still request the flag to be set and it may be effectively set even if user space doesn't request that). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Acked-by: mark gross <markgross@thegnar.org>
2012-10-23PM / QoS: Introduce PM QoS device flags supportRafael J. Wysocki
Modify the device PM QoS core code to support PM QoS flags requests. First, add a new field of type struct pm_qos_flags called "flags" to struct dev_pm_qos for representing the list of PM QoS flags requests for the given device. Accordingly, add a new "type" field to struct dev_pm_qos_request (along with an enum for representing request types) and a new member called "flr" to its data union for representig flags requests. Second, modify dev_pm_qos_add_request(), dev_pm_qos_update_request(), the internal routine apply_constraint() used by them and their existing callers to cover flags requests as well as latency requests. In particular, dev_pm_qos_add_request() gets a new argument called "type" for specifying the type of a request to be added. Finally, introduce two routines, __dev_pm_qos_flags() and dev_pm_qos_flags(), allowing their callers to check which PM QoS flags have been requested for the given device (the caller is supposed to pass the mask of flags to check as the routine's second argument and examine its return value for the result). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: mark gross <markgross@thegnar.org>
2012-10-23PM / QoS: Prepare struct dev_pm_qos_request for more request typesRafael J. Wysocki
The subsequent patches will use struct dev_pm_qos_request for representing both latency requests and flags requests. To make that easier, put the node member of struct dev_pm_qos_request (under the name "pnode") into a union called "data" that will represent the request's value and list node depending on its type. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: mark gross <markgross@thegnar.org>
2012-10-23PM / QoS: Introduce request and constraint data types for PM QoS flagsRafael J. Wysocki
Introduce struct pm_qos_flags_request and struct pm_qos_flags representing PM QoS flags request type and PM QoS flags constraint type, respectively. With these definitions the data structures will be arranged so that the list member of a struct pm_qos_flags object will contain the head of a list of struct pm_qos_flags_request objects representing all of the "flags" requests present for the given device. Then, the effective_flags member of a struct pm_qos_flags object will contain the bitwise OR of the flags members of all the struct pm_qos_flags_request objects in the list. Additionally, introduce helper function pm_qos_update_flags() allowing the caller to manage the list of struct pm_qos_flags_request pointed to by the list member of struct pm_qos_flags. The flags are of type s32 so that the request's "value" field is always of the same type regardless of what kind of request it is (latency requests already have value fields of type s32). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Acked-by: mark gross <markgross@thegnar.org>
2012-10-23PM / QoS: Prepare device structure for adding more constraint typesRafael J. Wysocki
Currently struct dev_pm_info contains only one PM QoS constraints pointer reserved for latency requirements. Since one more device constraints type (i.e. flags) will be necessary, introduce a new structure, struct dev_pm_qos, that eventually will contain all of the available device PM QoS constraints and replace the "constraints" pointer in struct dev_pm_info with a pointer to the new structure called "qos". Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com>
2012-07-19PM / QoS: Use NULL pointer instead of plain integer in pm_qos.hSachin Kamat
Fix the following sparse warning: include/linux/pm_qos.h:69:28: warning: Using plain integer as NULL pointer Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-28PM / QoS: add pm_qos_update_request_timeout() APIMyungJoo Ham
The new API, pm_qos_update_request_timeout() is to provide a timeout with pm_qos_update_request. For example, pm_qos_update_request_timeout(req, 100, 1000), means that QoS request on req with value 100 will be active for 1000 microseconds. After 1000 microseconds, the QoS request thru req is reset. If there were another pm_qos_update_request(req, x) during the 1000 us, this new request with value x will override as this is another request on the same req handle. A new request on the same req handle will always override the previous request whether it is the conventional request or it is the new timeout request. Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Mark Gross <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-13PM / QoS: Make it possible to expose PM QoS latency constraintsRafael J. Wysocki
A runtime suspend of a device (e.g. an MMC controller) belonging to a power domain or, in a more complicated scenario, a runtime suspend of another device in the same power domain, may cause power to be removed from the entire domain. In that case, the amount of time necessary to runtime-resume the given device (e.g. the MMC controller) is often substantially greater than the time needed to run its driver's runtime resume callback. That may hurt performance in some situations, because user data may need to wait for the device to become operational, so we should make it possible to prevent that from happening. For this reason, introduce a new sysfs attribute for devices, power/pm_qos_resume_latency_us, allowing user space to specify the upper bound of the time necessary to bring the (runtime-suspended) device up after the resume of it has been requested. However, make that attribute appear only for the devices whose drivers declare support for it by calling the (new) dev_pm_qos_expose_latency_limit() helper function with the appropriate initial value of the attribute. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-13PM / QoS: unconditionally build the featureJean Pihet
The PM QoS feature originally didn't depend on CONFIG_PM, which was mistakenly changed by commit e8db0be1245de16a6cc6365506abc392c3c212d4 PM QoS: Move and rename the implementation files Later, commit d020283dc694c9ec31b410f522252f7a8397e67d PM / QoS: CPU C-state breakage with PM Qos change partially fixed that by introducing a static inline definition of pm_qos_request(), but that still didn't allow user space to use the PM QoS interface if CONFIG_PM was unset (which had been possible before). For this reason, remove the dependency of PM QoS on CONFIG_PM to make it work (as intended) with CONFIG_PM unset. [rjw: Replaced the original changelog with a new one.] Signed-off-by: Jean Pihet <j-pihet@ti.com> Reported-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-13Merge commit 'pm-fixes-for-3.3-rc3' into pm-qosRafael J. Wysocki
New material in the pm-qos branch depends on recent power management fixes.
2012-02-04PM / QoS: CPU C-state breakage with PM Qos changeVenkatesh Pallipadi
Looks like change "PM QoS: Move and rename the implementation files" merged during the 3.2 development cycle made PM QoS depend on CONFIG_PM which depends on (PM_SLEEP || PM_RUNTIME). That breaks CPU C-states with kernels not having these CONFIGs, causing CPUs to spend time in Polling loop idle instead of going into deep C-states, consuming way way more power. This is with either acpi idle or intel idle enabled. Either CONFIG_PM should be enabled with any pm_qos users or the !CONFIG_PM pm_qos_request() should return sane defaults not to break the existing users. Here's is the patch for the latter option. [rjw: Modified the changelog slightly.] Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@vger.kernel.org
2012-01-29PM / QoS: Simplify PM QoS expansion/mergeAlex Frid
- Replace class ID #define with enumeration - Loop through PM QoS objects during initialization (rather than initializing them one-by-one) Signed-off-by: Alex Frid <afrid@nvidia.com> Reviewed-by: Antti Miettinen <amiettinen@nvidia.com> Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com> Reviewed-by: Scott Williams <scwilliams@nvidia.com> Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com> Acked-by: markgross <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-25Merge branch 'pm-domains' into pm-for-linusRafael J. Wysocki
* pm-domains: PM / shmobile: Allow the A4R domain to be turned off at run time PM / input / touchscreen: Make st1232 use device PM QoS constraints PM / QoS: Introduce dev_pm_qos_add_ancestor_request() PM / shmobile: Remove the stay_on flag from SH7372's PM domains PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode ARM: S3C64XX: Implement basic power domain support PM / shmobile: Use common always on power domain governor PM / Domains: Provide an always on power domain governor PM / Domains: Fix default system suspend/resume operations PM / Domains: Make it possible to assign names to generic PM domains PM / Domains: fix compilation failure for CONFIG_PM_GENERIC_DOMAINS unset PM / Domains: Automatically update overoptimistic latency information PM / Domains: Add default power off governor function (v4) PM / Domains: Add device stop governor function (v4) PM / Domains: Rework system suspend callback routines (v2) PM / Domains: Introduce "save/restore state" device callbacks PM / Domains: Make it possible to use per-device domain callbacks
2011-12-25PM / QoS: Introduce dev_pm_qos_add_ancestor_request()Rafael J. Wysocki
Some devices, like the I2C controller on SH7372, are not necessary for providing power to their children or forwarding wakeup signals (and generally interrupts) from them. They are only needed by their children when there's some data to transfer, so they may be suspended for the majority of time and resumed on demand, when the children have data to send or receive. For this purpose, however, their power.ignore_children flags have to be set, or the PM core wouldn't allow them to be suspended while their children were active. Unfortunately, in some situations it may take too much time to resume such devices so that they can assist their children in transferring data. For example, if such a device belongs to a PM domain which goes to the "power off" state when that device is suspended, it may take too much time to restore power to the domain in response to the request from one of the device's children. In that case, if the parent's resume time is critical, the domain should stay in the "power on" state, although it still may be desirable to power manage the parent itself (e.g. by manipulating its clock). In general, device PM QoS may be used to address this problem. Namely, if the device's children added PM QoS latency constraints for it, they would be able to prevent it from being put into an overly deep low-power state. However, in some cases the devices needing to be serviced are not the immediate children of a "children-ignoring" device, but its grandchildren or even less direct descendants. In those cases, the entity wanting to add a PM QoS request for a given device's ancestor that ignores its children will have to find it in the first place, so introduce a new helper function that may be used to achieve that. This function, dev_pm_qos_add_ancestor_request(), will search for the first ancestor of the given device whose power.ignore_children flag is set and will add a device PM QoS latency request for that ancestor on behalf of the caller. The request added this way may be removed with the help of dev_pm_qos_remove_request() in the future, like any other device PM QoS latency request. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-01PM / Runtime: Use device PM QoS constraints (v2)Rafael J. Wysocki
Make the runtime PM core use device PM QoS constraints to check if it is allowed to suspend a given device, so that an error code is returned if the device's own PM QoS constraint is negative or one of its children has already been suspended for too long. If this is not the case, the maximum estimated time the device is allowed to be suspended, computed as the minimum of the device's PM QoS constraint and the PM QoS constraints of its children (reduced by the difference between the current time and their suspend times) is stored in a new device's PM field power.max_time_suspended_ns that can be used by the device's subsystem or PM domain to decide whether or not to put the device into lower-power (and presumably higher-latency) states later (if the constraint is 0, which means "no constraint", the power.max_time_suspended_ns is set to -1). Additionally, the time of execution of the subsystem-level .runtime_suspend() callback for the device is recorded in the new power.suspend_time field for later use by the device's subsystem or PM domain along with power.max_time_suspended_ns (it also is used by the core code when the device's parent is suspended). Introduce a new helper function, pm_runtime_update_max_time_suspended(), allowing subsystems and PM domains (or device drivers) to update the power.max_time_suspended_ns field, for example after changing the power state of a suspended device. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>