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2015-01-23PM / QoS: Add debugfs support to view the list of constraintsNishanth Menon
PM QoS requests are notoriously hard to debug and made even more so due to their highly dynamic nature. Having visibility into the internal data representation per constraint allows us to have much better appreciation of potential issues or bad usage by drivers in the system. So introduce for all classes of PM QoS, an entry in /sys/kernel/debug/pm_qos that shall show all the current requests as well as the snapshot of the value these requests boil down to. For example: ==> /sys/kernel/debug/pm_qos/cpu_dma_latency <== 1: 4444: Active 2: 2000000000: Default 3: 2000000000: Default 4: 2000000000: Default Type=Minimum, Value=4444, Requests: active=1 / total=4 ==> /sys/kernel/debug/pm_qos/memory_bandwidth <== Empty! ... The actual value listed will have their meaning based on the QoS it is on, the 'Type' indicates what logic it would use to collate the information - Minimum, Maximum, or Sum. Value is the collation of all requests. This interface also compares the values with the defaults for the QoS class and marks the ones that are currently active. Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Dave Gerlach <d-gerlach@ti.com> 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: 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>
2013-10-17PM / QoS: simplify pm_qos_power_write()Andy Shevchenko
Let kstrtos32_from_user() do the necessary calls and checks. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-14PM / QoS: Fix workqueue deadlock when using pm_qos_update_request_timeout()Stephen Boyd
pm_qos_update_request_timeout() updates a qos and then schedules a delayed work item to bring the qos back down to the default after the timeout. When the work item runs, pm_qos_work_fn() will call pm_qos_update_request() and deadlock because it tries to cancel itself via cancel_delayed_work_sync(). Future callers of that qos will also hang waiting to cancel the work that is canceling itself. Let's extract the little bit of code that does the real work of pm_qos_update_request() and call it from the work function so that we don't deadlock. Before ed1ac6e (PM: don't use [delayed_]work_pending()) this didn't happen because the work function wouldn't try to cancel itself. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: 3.9+ <stable@vger.kernel.org> # 3.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-24PM / QoS: Add pm_qos_request tracepointsSahara
Adds tracepoints to pm_qos_add_request, pm_qos_update_request, pm_qos_remove_request, and pm_qos_update_request_timeout. It's useful for checking pm_qos_class, value, and timeout_us. Signed-off-by: Sahara <keun-o.park@windriver.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-24PM / QoS: Add pm_qos_update_target/flags tracepointsSahara
This patch adds tracepoints to pm_qos_update_target and pm_qos_update_flags. It's useful for checking pm qos action, previous value and current value. Signed-off-by: Sahara <keun-o.park@windriver.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-21PM / QoS: correct the valid range of pm_qos_classSahara
The valid start index for pm_qos_array is not 0, but PM_QOS_CPU_DMA_LATENCY. There is a null_pm_qos at index 0 of pm_qos_array. However, null_pm_qos is not created as misc device so that inclusion of 0 index for checking pm_qos_class especially for file operations is not proper here. [rjw: Changelog, a bit] Signed-off-by: Sahara <keun-o.park@windriver.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-01-26PM: don't use [delayed_]work_pending()Tejun Heo
There's no need to test whether a (delayed) work item is pending before queueing, flushing or cancelling it, so remove work_pending() tests used in those cases. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-29Merge branch 'pm-sleep'Rafael J. Wysocki
* pm-sleep: PM / Freezer: Fixup compile error of try_to_freeze_nowarn() driver core / PM: move the calling to device_pm_remove behind the calling to bus_remove_device PM / Hibernate: use rb_entry PM / sysfs: replace strict_str* with kstrto*
2012-11-15PM / sysfs: replace strict_str* with kstrto*Daniel Walter
Replace strict_strtoul() with kstrtoul() in pm_async_store() and pm_qos_power_write(). [rjw: Modified subject and changelog.] Signed-off-by: Daniel Walter <sahne@0x90.at> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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>
2012-09-07PM / QoS: Add return code to pm_qos_get_value function.Luis Gonzalez Fernandez
pm_qos_get_value don't return a return code in all cases. It's sure that anything interesting happend after BUG() but this prevent any compilation warning. [rjw: Chaneged the new return value to PM_QOS_DEFAULT_VALUE.] Signed-off-by: Luis Gonzalez Fernandez <luisgf@gmail.com> 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>
2012-01-29PM / 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>
2011-11-07PM / QoS: Set cpu_dma_pm_qos->nameDominik Brodowski
Since commit 4a31a334, the name of this misc device is not initialized, which leads to a funny device named /dev/(null) being created and /proc/misc containing an entry with just a number but no name. The latter leads to complaints by cryptsetup, which caused me to investigate this matter. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-11-06Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
2011-11-04PM / QoS: Remove redundant checkGuennadi Liakhovetski
Remove an "if" check, that repeats an equivalent one 6 lines above. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-10-31kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructurePaul Gortmaker
These files were getting <linux/module.h> via an implicit non-obvious path, but we want to crush those out of existence since they cost time during compiles of processing thousands of lines of headers for no reason. Give them the lightweight header that just contains the EXPORT_SYMBOL infrastructure. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-08-25PM QoS: Add global notification mechanism for device constraintsJean Pihet
Add a global notification chain that gets called upon changes to the aggregated constraint value for any device. The notification callbacks are passing the full constraint request data in order for the callees to have access to it. The current use is for the platform low-level code to access the target device of the constraint. Signed-off-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Generalize and export constraints management codeJean Pihet
In preparation for the per-device constratins support: - rename update_target to pm_qos_update_target - generalize and export pm_qos_update_target for usage by the upcoming per-device latency constraints framework: * operate on struct pm_qos_constraints for constraints management, * introduce an 'action' parameter for constraints add/update/remove, * the return value indicates if the aggregated constraint value has changed, - update the internal code to operate on struct pm_qos_constraints - add a NULL pointer check in the API functions Signed-off-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Reorganize data structsJean Pihet
In preparation for the per-device constratins support, re-organize the data strctures: - add a struct pm_qos_constraints which contains the constraints related data - update struct pm_qos_object contents to the PM QoS internal object data. Add a pointer to struct pm_qos_constraints - update the internal code to use the new data structs. Signed-off-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Code reorganizationJean Pihet
Move around the PM QoS misc devices management code for better readability. Signed-off-by: Jean Pihet <j-pihet@ti.com> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Minor clean-upsJean Pihet
- Misc fixes to improve code readability: * rename struct pm_qos_request_list to struct pm_qos_request, * rename pm_qos_req parameter to req in internal code, consistenly use req in the API parameters, * update the in-kernel API callers to the new parameters names, * rename of fields names (requests, list, node, constraints) Signed-off-by: Jean Pihet <j-pihet@ti.com> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Move and rename the implementation filesJean Pihet
The PM QoS implementation files are better named kernel/power/qos.c and include/linux/pm_qos.h. The PM QoS support is compiled under the CONFIG_PM option. Signed-off-by: Jean Pihet <j-pihet@ti.com> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>