/sys/devices/system/cpu/cpuX/cpuidle/stateN/power
/sys/devices/system/cpu/cpuX/cpuidle/stateN/time
/sys/devices/system/cpu/cpuX/cpuidle/stateN/usage
+ /sys/devices/system/cpu/cpuX/cpuidle/stateN/above
+ /sys/devices/system/cpu/cpuX/cpuidle/stateN/below
Date: September 2007
KernelVersion: v2.6.24
Contact: Linux power management list <linux-pm@vger.kernel.org>
usage: (RO) Number of times this state was entered (a count).
+ above: (RO) Number of times this state was entered, but the
+ observed CPU idle duration was too short for it (a count).
+
+ below: (RO) Number of times this state was entered, but the
+ observed CPU idle duration was too long for it (a count).
What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/desc
Date: February 2008
cpuidle.off=1 [CPU_IDLE]
disable the cpuidle sub-system
+ cpuidle.governor=
+ [CPU_IDLE] Name of the cpuidle governor to use.
+
cpufreq.off=1 [CPU_FREQ]
disable the cpufreq sub-system
--- /dev/null
+.. |struct cpuidle_state| replace:: :c:type:`struct cpuidle_state <cpuidle_state>`
+.. |cpufreq| replace:: :doc:`CPU Performance Scaling <cpufreq>`
+
+========================
+CPU Idle Time Management
+========================
+
+::
+
+ Copyright (c) 2018 Intel Corp., Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+
+Concepts
+========
+
+Modern processors are generally able to enter states in which the execution of
+a program is suspended and instructions belonging to it are not fetched from
+memory or executed. Those states are the *idle* states of the processor.
+
+Since part of the processor hardware is not used in idle states, entering them
+generally allows power drawn by the processor to be reduced and, in consequence,
+it is an opportunity to save energy.
+
+CPU idle time management is an energy-efficiency feature concerned about using
+the idle states of processors for this purpose.
+
+Logical CPUs
+------------
+
+CPU idle time management operates on CPUs as seen by the *CPU scheduler* (that
+is the part of the kernel responsible for the distribution of computational
+work in the system). In its view, CPUs are *logical* units. That is, they need
+not be separate physical entities and may just be interfaces appearing to
+software as individual single-core processors. In other words, a CPU is an
+entity which appears to be fetching instructions that belong to one sequence
+(program) from memory and executing them, but it need not work this way
+physically. Generally, three different cases can be consider here.
+
+First, if the whole processor can only follow one sequence of instructions (one
+program) at a time, it is a CPU. In that case, if the hardware is asked to
+enter an idle state, that applies to the processor as a whole.
+
+Second, if the processor is multi-core, each core in it is able to follow at
+least one program at a time. The cores need not be entirely independent of each
+other (for example, they may share caches), but still most of the time they
+work physically in parallel with each other, so if each of them executes only
+one program, those programs run mostly independently of each other at the same
+time. The entire cores are CPUs in that case and if the hardware is asked to
+enter an idle state, that applies to the core that asked for it in the first
+place, but it also may apply to a larger unit (say a "package" or a "cluster")
+that the core belongs to (in fact, it may apply to an entire hierarchy of larger
+units containing the core). Namely, if all of the cores in the larger unit
+except for one have been put into idle states at the "core level" and the
+remaining core asks the processor to enter an idle state, that may trigger it
+to put the whole larger unit into an idle state which also will affect the
+other cores in that unit.
+
+Finally, each core in a multi-core processor may be able to follow more than one
+program in the same time frame (that is, each core may be able to fetch
+instructions from multiple locations in memory and execute them in the same time
+frame, but not necessarily entirely in parallel with each other). In that case
+the cores present themselves to software as "bundles" each consisting of
+multiple individual single-core "processors", referred to as *hardware threads*
+(or hyper-threads specifically on Intel hardware), that each can follow one
+sequence of instructions. Then, the hardware threads are CPUs from the CPU idle
+time management perspective and if the processor is asked to enter an idle state
+by one of them, the hardware thread (or CPU) that asked for it is stopped, but
+nothing more happens, unless all of the other hardware threads within the same
+core also have asked the processor to enter an idle state. In that situation,
+the core may be put into an idle state individually or a larger unit containing
+it may be put into an idle state as a whole (if the other cores within the
+larger unit are in idle states already).
+
+Idle CPUs
+---------
+
+Logical CPUs, simply referred to as "CPUs" in what follows, are regarded as
+*idle* by the Linux kernel when there are no tasks to run on them except for the
+special "idle" task.
+
+Tasks are the CPU scheduler's representation of work. Each task consists of a
+sequence of instructions to execute, or code, data to be manipulated while
+running that code, and some context information that needs to be loaded into the
+processor every time the task's code is run by a CPU. The CPU scheduler
+distributes work by assigning tasks to run to the CPUs present in the system.
+
+Tasks can be in various states. In particular, they are *runnable* if there are
+no specific conditions preventing their code from being run by a CPU as long as
+there is a CPU available for that (for example, they are not waiting for any
+events to occur or similar). When a task becomes runnable, the CPU scheduler
+assigns it to one of the available CPUs to run and if there are no more runnable
+tasks assigned to it, the CPU will load the given task's context and run its
+code (from the instruction following the last one executed so far, possibly by
+another CPU). [If there are multiple runnable tasks assigned to one CPU
+simultaneously, they will be subject to prioritization and time sharing in order
+to allow them to make some progress over time.]
+
+The special "idle" task becomes runnable if there are no other runnable tasks
+assigned to the given CPU and the CPU is then regarded as idle. In other words,
+in Linux idle CPUs run the code of the "idle" task called *the idle loop*. That
+code may cause the processor to be put into one of its idle states, if they are
+supported, in order to save energy, but if the processor does not support any
+idle states, or there is not enough time to spend in an idle state before the
+next wakeup event, or there are strict latency constraints preventing any of the
+available idle states from being used, the CPU will simply execute more or less
+useless instructions in a loop until it is assigned a new task to run.
+
+
+.. _idle-loop:
+
+The Idle Loop
+=============
+
+The idle loop code takes two major steps in every iteration of it. First, it
+calls into a code module referred to as the *governor* that belongs to the CPU
+idle time management subsystem called ``CPUIdle`` to select an idle state for
+the CPU to ask the hardware to enter. Second, it invokes another code module
+from the ``CPUIdle`` subsystem, called the *driver*, to actually ask the
+processor hardware to enter the idle state selected by the governor.
+
+The role of the governor is to find an idle state most suitable for the
+conditions at hand. For this purpose, idle states that the hardware can be
+asked to enter by logical CPUs are represented in an abstract way independent of
+the platform or the processor architecture and organized in a one-dimensional
+(linear) array. That array has to be prepared and supplied by the ``CPUIdle``
+driver matching the platform the kernel is running on at the initialization
+time. This allows ``CPUIdle`` governors to be independent of the underlying
+hardware and to work with any platforms that the Linux kernel can run on.
+
+Each idle state present in that array is characterized by two parameters to be
+taken into account by the governor, the *target residency* and the (worst-case)
+*exit latency*. The target residency is the minimum time the hardware must
+spend in the given state, including the time needed to enter it (which may be
+substantial), in order to save more energy than it would save by entering one of
+the shallower idle states instead. [The "depth" of an idle state roughly
+corresponds to the power drawn by the processor in that state.] The exit
+latency, in turn, is the maximum time it will take a CPU asking the processor
+hardware to enter an idle state to start executing the first instruction after a
+wakeup from that state. Note that in general the exit latency also must cover
+the time needed to enter the given state in case the wakeup occurs when the
+hardware is entering it and it must be entered completely to be exited in an
+ordered manner.
+
+There are two types of information that can influence the governor's decisions.
+First of all, the governor knows the time until the closest timer event. That
+time is known exactly, because the kernel programs timers and it knows exactly
+when they will trigger, and it is the maximum time the hardware that the given
+CPU depends on can spend in an idle state, including the time necessary to enter
+and exit it. However, the CPU may be woken up by a non-timer event at any time
+(in particular, before the closest timer triggers) and it generally is not known
+when that may happen. The governor can only see how much time the CPU actually
+was idle after it has been woken up (that time will be referred to as the *idle
+duration* from now on) and it can use that information somehow along with the
+time until the closest timer to estimate the idle duration in future. How the
+governor uses that information depends on what algorithm is implemented by it
+and that is the primary reason for having more than one governor in the
+``CPUIdle`` subsystem.
+
+There are two ``CPUIdle`` governors available, ``menu`` and ``ladder``. Which
+of them is used depends on the configuration of the kernel and in particular on
+whether or not the scheduler tick can be `stopped by the idle
+loop <idle-cpus-and-tick_>`_. It is possible to change the governor at run time
+if the ``cpuidle_sysfs_switch`` command line parameter has been passed to the
+kernel, but that is not safe in general, so it should not be done on production
+systems (that may change in the future, though). The name of the ``CPUIdle``
+governor currently used by the kernel can be read from the
+:file:`current_governor_ro` (or :file:`current_governor` if
+``cpuidle_sysfs_switch`` is present in the kernel command line) file under
+:file:`/sys/devices/system/cpu/cpuidle/` in ``sysfs``.
+
+Which ``CPUIdle`` driver is used, on the other hand, usually depends on the
+platform the kernel is running on, but there are platforms with more than one
+matching driver. For example, there are two drivers that can work with the
+majority of Intel platforms, ``intel_idle`` and ``acpi_idle``, one with
+hardcoded idle states information and the other able to read that information
+from the system's ACPI tables, respectively. Still, even in those cases, the
+driver chosen at the system initialization time cannot be replaced later, so the
+decision on which one of them to use has to be made early (on Intel platforms
+the ``acpi_idle`` driver will be used if ``intel_idle`` is disabled for some
+reason or if it does not recognize the processor). The name of the ``CPUIdle``
+driver currently used by the kernel can be read from the :file:`current_driver`
+file under :file:`/sys/devices/system/cpu/cpuidle/` in ``sysfs``.
+
+
+.. _idle-cpus-and-tick:
+
+Idle CPUs and The Scheduler Tick
+================================
+
+The scheduler tick is a timer that triggers periodically in order to implement
+the time sharing strategy of the CPU scheduler. Of course, if there are
+multiple runnable tasks assigned to one CPU at the same time, the only way to
+allow them to make reasonable progress in a given time frame is to make them
+share the available CPU time. Namely, in rough approximation, each task is
+given a slice of the CPU time to run its code, subject to the scheduling class,
+prioritization and so on and when that time slice is used up, the CPU should be
+switched over to running (the code of) another task. The currently running task
+may not want to give the CPU away voluntarily, however, and the scheduler tick
+is there to make the switch happen regardless. That is not the only role of the
+tick, but it is the primary reason for using it.
+
+The scheduler tick is problematic from the CPU idle time management perspective,
+because it triggers periodically and relatively often (depending on the kernel
+configuration, the length of the tick period is between 1 ms and 10 ms).
+Thus, if the tick is allowed to trigger on idle CPUs, it will not make sense
+for them to ask the hardware to enter idle states with target residencies above
+the tick period length. Moreover, in that case the idle duration of any CPU
+will never exceed the tick period length and the energy used for entering and
+exiting idle states due to the tick wakeups on idle CPUs will be wasted.
+
+Fortunately, it is not really necessary to allow the tick to trigger on idle
+CPUs, because (by definition) they have no tasks to run except for the special
+"idle" one. In other words, from the CPU scheduler perspective, the only user
+of the CPU time on them is the idle loop. Since the time of an idle CPU need
+not be shared between multiple runnable tasks, the primary reason for using the
+tick goes away if the given CPU is idle. Consequently, it is possible to stop
+the scheduler tick entirely on idle CPUs in principle, even though that may not
+always be worth the effort.
+
+Whether or not it makes sense to stop the scheduler tick in the idle loop
+depends on what is expected by the governor. First, if there is another
+(non-tick) timer due to trigger within the tick range, stopping the tick clearly
+would be a waste of time, even though the timer hardware may not need to be
+reprogrammed in that case. Second, if the governor is expecting a non-timer
+wakeup within the tick range, stopping the tick is not necessary and it may even
+be harmful. Namely, in that case the governor will select an idle state with
+the target residency within the time until the expected wakeup, so that state is
+going to be relatively shallow. The governor really cannot select a deep idle
+state then, as that would contradict its own expectation of a wakeup in short
+order. Now, if the wakeup really occurs shortly, stopping the tick would be a
+waste of time and in this case the timer hardware would need to be reprogrammed,
+which is expensive. On the other hand, if the tick is stopped and the wakeup
+does not occur any time soon, the hardware may spend indefinite amount of time
+in the shallow idle state selected by the governor, which will be a waste of
+energy. Hence, if the governor is expecting a wakeup of any kind within the
+tick range, it is better to allow the tick trigger. Otherwise, however, the
+governor will select a relatively deep idle state, so the tick should be stopped
+so that it does not wake up the CPU too early.
+
+In any case, the governor knows what it is expecting and the decision on whether
+or not to stop the scheduler tick belongs to it. Still, if the tick has been
+stopped already (in one of the previous iterations of the loop), it is better
+to leave it as is and the governor needs to take that into account.
+
+The kernel can be configured to disable stopping the scheduler tick in the idle
+loop altogether. That can be done through the build-time configuration of it
+(by unsetting the ``CONFIG_NO_HZ_IDLE`` configuration option) or by passing
+``nohz=off`` to it in the command line. In both cases, as the stopping of the
+scheduler tick is disabled, the governor's decisions regarding it are simply
+ignored by the idle loop code and the tick is never stopped.
+
+The systems that run kernels configured to allow the scheduler tick to be
+stopped on idle CPUs are referred to as *tickless* systems and they are
+generally regarded as more energy-efficient than the systems running kernels in
+which the tick cannot be stopped. If the given system is tickless, it will use
+the ``menu`` governor by default and if it is not tickless, the default
+``CPUIdle`` governor on it will be ``ladder``.
+
+
+The ``menu`` Governor
+=====================
+
+The ``menu`` governor is the default ``CPUIdle`` governor for tickless systems.
+It is quite complex, but the basic principle of its design is straightforward.
+Namely, when invoked to select an idle state for a CPU (i.e. an idle state that
+the CPU will ask the processor hardware to enter), it attempts to predict the
+idle duration and uses the predicted value for idle state selection.
+
+It first obtains the time until the closest timer event with the assumption
+that the scheduler tick will be stopped. That time, referred to as the *sleep
+length* in what follows, is the upper bound on the time before the next CPU
+wakeup. It is used to determine the sleep length range, which in turn is needed
+to get the sleep length correction factor.
+
+The ``menu`` governor maintains two arrays of sleep length correction factors.
+One of them is used when tasks previously running on the given CPU are waiting
+for some I/O operations to complete and the other one is used when that is not
+the case. Each array contains several correction factor values that correspond
+to different sleep length ranges organized so that each range represented in the
+array is approximately 10 times wider than the previous one.
+
+The correction factor for the given sleep length range (determined before
+selecting the idle state for the CPU) is updated after the CPU has been woken
+up and the closer the sleep length is to the observed idle duration, the closer
+to 1 the correction factor becomes (it must fall between 0 and 1 inclusive).
+The sleep length is multiplied by the correction factor for the range that it
+falls into to obtain the first approximation of the predicted idle duration.
+
+Next, the governor uses a simple pattern recognition algorithm to refine its
+idle duration prediction. Namely, it saves the last 8 observed idle duration
+values and, when predicting the idle duration next time, it computes the average
+and variance of them. If the variance is small (smaller than 400 square
+milliseconds) or it is small relative to the average (the average is greater
+that 6 times the standard deviation), the average is regarded as the "typical
+interval" value. Otherwise, the longest of the saved observed idle duration
+values is discarded and the computation is repeated for the remaining ones.
+Again, if the variance of them is small (in the above sense), the average is
+taken as the "typical interval" value and so on, until either the "typical
+interval" is determined or too many data points are disregarded, in which case
+the "typical interval" is assumed to equal "infinity" (the maximum unsigned
+integer value). The "typical interval" computed this way is compared with the
+sleep length multiplied by the correction factor and the minimum of the two is
+taken as the predicted idle duration.
+
+Then, the governor computes an extra latency limit to help "interactive"
+workloads. It uses the observation that if the exit latency of the selected
+idle state is comparable with the predicted idle duration, the total time spent
+in that state probably will be very short and the amount of energy to save by
+entering it will be relatively small, so likely it is better to avoid the
+overhead related to entering that state and exiting it. Thus selecting a
+shallower state is likely to be a better option then. The first approximation
+of the extra latency limit is the predicted idle duration itself which
+additionally is divided by a value depending on the number of tasks that
+previously ran on the given CPU and now they are waiting for I/O operations to
+complete. The result of that division is compared with the latency limit coming
+from the power management quality of service, or `PM QoS <cpu-pm-qos_>`_,
+framework and the minimum of the two is taken as the limit for the idle states'
+exit latency.
+
+Now, the governor is ready to walk the list of idle states and choose one of
+them. For this purpose, it compares the target residency of each state with
+the predicted idle duration and the exit latency of it with the computed latency
+limit. It selects the state with the target residency closest to the predicted
+idle duration, but still below it, and exit latency that does not exceed the
+limit.
+
+In the final step the governor may still need to refine the idle state selection
+if it has not decided to `stop the scheduler tick <idle-cpus-and-tick_>`_. That
+happens if the idle duration predicted by it is less than the tick period and
+the tick has not been stopped already (in a previous iteration of the idle
+loop). Then, the sleep length used in the previous computations may not reflect
+the real time until the closest timer event and if it really is greater than
+that time, the governor may need to select a shallower state with a suitable
+target residency.
+
+
+.. _idle-states-representation:
+
+Representation of Idle States
+=============================
+
+For the CPU idle time management purposes all of the physical idle states
+supported by the processor have to be represented as a one-dimensional array of
+|struct cpuidle_state| objects each allowing an individual (logical) CPU to ask
+the processor hardware to enter an idle state of certain properties. If there
+is a hierarchy of units in the processor, one |struct cpuidle_state| object can
+cover a combination of idle states supported by the units at different levels of
+the hierarchy. In that case, the `target residency and exit latency parameters
+of it <idle-loop_>`_, must reflect the properties of the idle state at the
+deepest level (i.e. the idle state of the unit containing all of the other
+units).
+
+For example, take a processor with two cores in a larger unit referred to as
+a "module" and suppose that asking the hardware to enter a specific idle state
+(say "X") at the "core" level by one core will trigger the module to try to
+enter a specific idle state of its own (say "MX") if the other core is in idle
+state "X" already. In other words, asking for idle state "X" at the "core"
+level gives the hardware a license to go as deep as to idle state "MX" at the
+"module" level, but there is no guarantee that this is going to happen (the core
+asking for idle state "X" may just end up in that state by itself instead).
+Then, the target residency of the |struct cpuidle_state| object representing
+idle state "X" must reflect the minimum time to spend in idle state "MX" of
+the module (including the time needed to enter it), because that is the minimum
+time the CPU needs to be idle to save any energy in case the hardware enters
+that state. Analogously, the exit latency parameter of that object must cover
+the exit time of idle state "MX" of the module (and usually its entry time too),
+because that is the maximum delay between a wakeup signal and the time the CPU
+will start to execute the first new instruction (assuming that both cores in the
+module will always be ready to execute instructions as soon as the module
+becomes operational as a whole).
+
+There are processors without direct coordination between different levels of the
+hierarchy of units inside them, however. In those cases asking for an idle
+state at the "core" level does not automatically affect the "module" level, for
+example, in any way and the ``CPUIdle`` driver is responsible for the entire
+handling of the hierarchy. Then, the definition of the idle state objects is
+entirely up to the driver, but still the physical properties of the idle state
+that the processor hardware finally goes into must always follow the parameters
+used by the governor for idle state selection (for instance, the actual exit
+latency of that idle state must not exceed the exit latency parameter of the
+idle state object selected by the governor).
+
+In addition to the target residency and exit latency idle state parameters
+discussed above, the objects representing idle states each contain a few other
+parameters describing the idle state and a pointer to the function to run in
+order to ask the hardware to enter that state. Also, for each
+|struct cpuidle_state| object, there is a corresponding
+:c:type:`struct cpuidle_state_usage <cpuidle_state_usage>` one containing usage
+statistics of the given idle state. That information is exposed by the kernel
+via ``sysfs``.
+
+For each CPU in the system, there is a :file:`/sys/devices/system/cpu<N>/cpuidle/`
+directory in ``sysfs``, where the number ``<N>`` is assigned to the given
+CPU at the initialization time. That directory contains a set of subdirectories
+called :file:`state0`, :file:`state1` and so on, up to the number of idle state
+objects defined for the given CPU minus one. Each of these directories
+corresponds to one idle state object and the larger the number in its name, the
+deeper the (effective) idle state represented by it. Each of them contains
+a number of files (attributes) representing the properties of the idle state
+object corresponding to it, as follows:
+
+``above``
+ Total number of times this idle state had been asked for, but the
+ observed idle duration was certainly too short to match its target
+ residency.
+
+``below``
+ Total number of times this idle state had been asked for, but cerainly
+ a deeper idle state would have been a better match for the observed idle
+ duration.
+
+``desc``
+ Description of the idle state.
+
+``disable``
+ Whether or not this idle state is disabled.
+
+``latency``
+ Exit latency of the idle state in microseconds.
+
+``name``
+ Name of the idle state.
+
+``power``
+ Power drawn by hardware in this idle state in milliwatts (if specified,
+ 0 otherwise).
+
+``residency``
+ Target residency of the idle state in microseconds.
+
+``time``
+ Total time spent in this idle state by the given CPU (as measured by the
+ kernel) in microseconds.
+
+``usage``
+ Total number of times the hardware has been asked by the given CPU to
+ enter this idle state.
+
+The :file:`desc` and :file:`name` files both contain strings. The difference
+between them is that the name is expected to be more concise, while the
+description may be longer and it may contain white space or special characters.
+The other files listed above contain integer numbers.
+
+The :file:`disable` attribute is the only writeable one. If it contains 1, the
+given idle state is disabled for this particular CPU, which means that the
+governor will never select it for this particular CPU and the ``CPUIdle``
+driver will never ask the hardware to enter it for that CPU as a result.
+However, disabling an idle state for one CPU does not prevent it from being
+asked for by the other CPUs, so it must be disabled for all of them in order to
+never be asked for by any of them. [Note that, due to the way the ``ladder``
+governor is implemented, disabling an idle state prevents that governor from
+selecting any idle states deeper than the disabled one too.]
+
+If the :file:`disable` attribute contains 0, the given idle state is enabled for
+this particular CPU, but it still may be disabled for some or all of the other
+CPUs in the system at the same time. Writing 1 to it causes the idle state to
+be disabled for this particular CPU and writing 0 to it allows the governor to
+take it into consideration for the given CPU and the driver to ask for it,
+unless that state was disabled globally in the driver (in which case it cannot
+be used at all).
+
+The :file:`power` attribute is not defined very well, especially for idle state
+objects representing combinations of idle states at different levels of the
+hierarchy of units in the processor, and it generally is hard to obtain idle
+state power numbers for complex hardware, so :file:`power` often contains 0 (not
+available) and if it contains a nonzero number, that number may not be very
+accurate and it should not be relied on for anything meaningful.
+
+The number in the :file:`time` file generally may be greater than the total time
+really spent by the given CPU in the given idle state, because it is measured by
+the kernel and it may not cover the cases in which the hardware refused to enter
+this idle state and entered a shallower one instead of it (or even it did not
+enter any idle state at all). The kernel can only measure the time span between
+asking the hardware to enter an idle state and the subsequent wakeup of the CPU
+and it cannot say what really happened in the meantime at the hardware level.
+Moreover, if the idle state object in question represents a combination of idle
+states at different levels of the hierarchy of units in the processor,
+the kernel can never say how deep the hardware went down the hierarchy in any
+particular case. For these reasons, the only reliable way to find out how
+much time has been spent by the hardware in different idle states supported by
+it is to use idle state residency counters in the hardware, if available.
+
+
+.. _cpu-pm-qos:
+
+Power Management Quality of Service for CPUs
+============================================
+
+The power management quality of service (PM QoS) framework in the Linux kernel
+allows kernel code and user space processes to set constraints on various
+energy-efficiency features of the kernel to prevent performance from dropping
+below a required level. The PM QoS constraints can be set globally, in
+predefined categories referred to as PM QoS classes, or against individual
+devices.
+
+CPU idle time management can be affected by PM QoS in two ways, through the
+global constraint in the ``PM_QOS_CPU_DMA_LATENCY`` class and through the
+resume latency constraints for individual CPUs. Kernel code (e.g. device
+drivers) can set both of them with the help of special internal interfaces
+provided by the PM QoS framework. User space can modify the former by opening
+the :file:`cpu_dma_latency` special device file under :file:`/dev/` and writing
+a binary value (interpreted as a signed 32-bit integer) to it. In turn, the
+resume latency constraint for a CPU can be modified by user space by writing a
+string (representing a signed 32-bit integer) to the
+:file:`power/pm_qos_resume_latency_us` file under
+:file:`/sys/devices/system/cpu/cpu<N>/` in ``sysfs``, where the CPU number
+``<N>`` is allocated at the system initialization time. Negative values
+will be rejected in both cases and, also in both cases, the written integer
+number will be interpreted as a requested PM QoS constraint in microseconds.
+
+The requested value is not automatically applied as a new constraint, however,
+as it may be less restrictive (greater in this particular case) than another
+constraint previously requested by someone else. For this reason, the PM QoS
+framework maintains a list of requests that have been made so far in each
+global class and for each device, aggregates them and applies the effective
+(minimum in this particular case) value as the new constraint.
+
+In fact, opening the :file:`cpu_dma_latency` special device file causes a new
+PM QoS request to be created and added to the priority list of requests in the
+``PM_QOS_CPU_DMA_LATENCY`` class and the file descriptor coming from the
+"open" operation represents that request. If that file descriptor is then
+used for writing, the number written to it will be associated with the PM QoS
+request represented by it as a new requested constraint value. Next, the
+priority list mechanism will be used to determine the new effective value of
+the entire list of requests and that effective value will be set as a new
+constraint. Thus setting a new requested constraint value will only change the
+real constraint if the effective "list" value is affected by it. In particular,
+for the ``PM_QOS_CPU_DMA_LATENCY`` class it only affects the real constraint if
+it is the minimum of the requested constraints in the list. The process holding
+a file descriptor obtained by opening the :file:`cpu_dma_latency` special device
+file controls the PM QoS request associated with that file descriptor, but it
+controls this particular PM QoS request only.
+
+Closing the :file:`cpu_dma_latency` special device file or, more precisely, the
+file descriptor obtained while opening it, causes the PM QoS request associated
+with that file descriptor to be removed from the ``PM_QOS_CPU_DMA_LATENCY``
+class priority list and destroyed. If that happens, the priority list mechanism
+will be used, again, to determine the new effective value for the whole list
+and that value will become the new real constraint.
+
+In turn, for each CPU there is only one resume latency PM QoS request
+associated with the :file:`power/pm_qos_resume_latency_us` file under
+:file:`/sys/devices/system/cpu/cpu<N>/` in ``sysfs`` and writing to it causes
+this single PM QoS request to be updated regardless of which user space
+process does that. In other words, this PM QoS request is shared by the entire
+user space, so access to the file associated with it needs to be arbitrated
+to avoid confusion. [Arguably, the only legitimate use of this mechanism in
+practice is to pin a process to the CPU in question and let it use the
+``sysfs`` interface to control the resume latency constraint for it.] It
+still only is a request, however. It is a member of a priority list used to
+determine the effective value to be set as the resume latency constraint for the
+CPU in question every time the list of requests is updated this way or another
+(there may be other requests coming from kernel code in that list).
+
+CPU idle time governors are expected to regard the minimum of the global
+effective ``PM_QOS_CPU_DMA_LATENCY`` class constraint and the effective
+resume latency constraint for the given CPU as the upper limit for the exit
+latency of the idle states they can select for that CPU. They should never
+select any idle states with exit latency beyond that limit.
+
+
+Idle States Control Via Kernel Command Line
+===========================================
+
+In addition to the ``sysfs`` interface allowing individual idle states to be
+`disabled for individual CPUs <idle-states-representation_>`_, there are kernel
+command line parameters affecting CPU idle time management.
+
+The ``cpuidle.off=1`` kernel command line option can be used to disable the
+CPU idle time management entirely. It does not prevent the idle loop from
+running on idle CPUs, but it prevents the CPU idle time governors and drivers
+from being invoked. If it is added to the kernel command line, the idle loop
+will ask the hardware to enter idle states on idle CPUs via the CPU architecture
+support code that is expected to provide a default mechanism for this purpose.
+That default mechanism usually is the least common denominator for all of the
+processors implementing the architecture (i.e. CPU instruction set) in question,
+however, so it is rather crude and not very energy-efficient. For this reason,
+it is not recommended for production use.
+
+The ``cpuidle.governor=`` kernel command line switch allows the ``CPUIdle``
+governor to use to be specified. It has to be appended with a string matching
+the name of an available governor (e.g. ``cpuidle.governor=menu``) and that
+governor will be used instead of the default one. It is possible to force
+the ``menu`` governor to be used on the systems that use the ``ladder`` governor
+by default this way, for example.
+
+The other kernel command line parameters controlling CPU idle time management
+described below are only relevant for the *x86* architecture and some of
+them affect Intel processors only.
+
+The *x86* architecture support code recognizes three kernel command line
+options related to CPU idle time management: ``idle=poll``, ``idle=halt``,
+and ``idle=nomwait``. The first two of them disable the ``acpi_idle`` and
+``intel_idle`` drivers altogether, which effectively causes the entire
+``CPUIdle`` subsystem to be disabled and makes the idle loop invoke the
+architecture support code to deal with idle CPUs. How it does that depends on
+which of the two parameters is added to the kernel command line. In the
+``idle=halt`` case, the architecture support code will use the ``HLT``
+instruction of the CPUs (which, as a rule, suspends the execution of the program
+and causes the hardware to attempt to enter the shallowest available idle state)
+for this purpose, and if ``idle=poll`` is used, idle CPUs will execute a
+more or less ``lightweight'' sequence of instructions in a tight loop. [Note
+that using ``idle=poll`` is somewhat drastic in many cases, as preventing idle
+CPUs from saving almost any energy at all may not be the only effect of it.
+For example, on Intel hardware it effectively prevents CPUs from using
+P-states (see |cpufreq|) that require any number of CPUs in a package to be
+idle, so it very well may hurt single-thread computations performance as well as
+energy-efficiency. Thus using it for performance reasons may not be a good idea
+at all.]
+
+The ``idle=nomwait`` option disables the ``intel_idle`` driver and causes
+``acpi_idle`` to be used (as long as all of the information needed by it is
+there in the system's ACPI tables), but it is not allowed to use the
+``MWAIT`` instruction of the CPUs to ask the hardware to enter idle states.
+
+In addition to the architecture-level kernel command line options affecting CPU
+idle time management, there are parameters affecting individual ``CPUIdle``
+drivers that can be passed to them via the kernel command line. Specifically,
+the ``intel_idle.max_cstate=<n>`` and ``processor.max_cstate=<n>`` parameters,
+where ``<n>`` is an idle state index also used in the name of the given
+state's directory in ``sysfs`` (see
+`Representation of Idle States <idle-states-representation_>`_), causes the
+``intel_idle`` and ``acpi_idle`` drivers, respectively, to discard all of the
+idle states deeper than idle state ``<n>``. In that case, they will never ask
+for any of those idle states or expose them to the governor. [The behavior of
+the two drivers is different for ``<n>`` equal to ``0``. Adding
+``intel_idle.max_cstate=0`` to the kernel command line disables the
+``intel_idle`` driver and allows ``acpi_idle`` to be used, whereas
+``processor.max_cstate=0`` is equivalent to ``processor.max_cstate=1``.
+Also, the ``acpi_idle`` driver is part of the ``processor`` kernel module that
+can be loaded separately and ``max_cstate=<n>`` can be passed to it as a module
+parameter when it is loaded.]
2. Each individual CPU is affected by its own per-policy limits (that is, it
cannot be requested to run faster than its own per-policy maximum and it
- cannot be requested to run slower than its own per-policy minimum).
+ cannot be requested to run slower than its own per-policy minimum). The
+ effective performance depends on whether the platform supports per core
+ P-states, hyper-threading is enabled and on current performance requests
+ from other CPUs. When platform doesn't support per core P-states, the
+ effective performance can be more than the policy limits set on a CPU, if
+ other CPUs are requesting higher performance at that moment. Even with per
+ core P-states support, when hyper-threading is enabled, if the sibling CPU
+ is requesting higher performance, the other siblings will get higher
+ performance than their policy limits.
3. The global and per-policy limits can be set independently.
.. toctree::
:maxdepth: 2
+ cpuidle
cpufreq
intel_pstate
+++ /dev/null
-
- Supporting multiple CPU idle levels in kernel
-
- cpuidle
-
-General Information:
-
-Various CPUs today support multiple idle levels that are differentiated
-by varying exit latencies and power consumption during idle.
-cpuidle is a generic in-kernel infrastructure that separates
-idle policy (governor) from idle mechanism (driver) and provides a
-standardized infrastructure to support independent development of
-governors and drivers.
-
-cpuidle resides under drivers/cpuidle.
-
-Boot options:
-"cpuidle_sysfs_switch"
-enables current_governor interface in /sys/devices/system/cpu/cpuidle/,
-which can be used to switch governors at run time. This boot option
-is meant for developer testing only. In normal usage, kernel picks the
-best governor based on governor ratings.
-SEE ALSO: sysfs.txt in this directory.
+++ /dev/null
-
-
- Supporting multiple CPU idle levels in kernel
-
- cpuidle sysfs
-
-System global cpuidle related information and tunables are under
-/sys/devices/system/cpu/cpuidle
-
-The current interfaces in this directory has self-explanatory names:
-* current_driver
-* current_governor_ro
-
-With cpuidle_sysfs_switch boot option (meant for developer testing)
-following objects are visible instead.
-* current_driver
-* available_governors
-* current_governor
-In this case users can switch the governor at run time by writing
-to current_governor.
-
-
-Per logical CPU specific cpuidle information are under
-/sys/devices/system/cpu/cpuX/cpuidle
-for each online cpu X
-
---------------------------------------------------------------------------------
-# ls -lR /sys/devices/system/cpu/cpu0/cpuidle/
-/sys/devices/system/cpu/cpu0/cpuidle/:
-total 0
-drwxr-xr-x 2 root root 0 Feb 8 10:42 state0
-drwxr-xr-x 2 root root 0 Feb 8 10:42 state1
-drwxr-xr-x 2 root root 0 Feb 8 10:42 state2
-drwxr-xr-x 2 root root 0 Feb 8 10:42 state3
-
-/sys/devices/system/cpu/cpu0/cpuidle/state0:
-total 0
--r--r--r-- 1 root root 4096 Feb 8 10:42 desc
--rw-r--r-- 1 root root 4096 Feb 8 10:42 disable
--r--r--r-- 1 root root 4096 Feb 8 10:42 latency
--r--r--r-- 1 root root 4096 Feb 8 10:42 name
--r--r--r-- 1 root root 4096 Feb 8 10:42 power
--r--r--r-- 1 root root 4096 Feb 8 10:42 residency
--r--r--r-- 1 root root 4096 Feb 8 10:42 time
--r--r--r-- 1 root root 4096 Feb 8 10:42 usage
-
-/sys/devices/system/cpu/cpu0/cpuidle/state1:
-total 0
--r--r--r-- 1 root root 4096 Feb 8 10:42 desc
--rw-r--r-- 1 root root 4096 Feb 8 10:42 disable
--r--r--r-- 1 root root 4096 Feb 8 10:42 latency
--r--r--r-- 1 root root 4096 Feb 8 10:42 name
--r--r--r-- 1 root root 4096 Feb 8 10:42 power
--r--r--r-- 1 root root 4096 Feb 8 10:42 residency
--r--r--r-- 1 root root 4096 Feb 8 10:42 time
--r--r--r-- 1 root root 4096 Feb 8 10:42 usage
-
-/sys/devices/system/cpu/cpu0/cpuidle/state2:
-total 0
--r--r--r-- 1 root root 4096 Feb 8 10:42 desc
--rw-r--r-- 1 root root 4096 Feb 8 10:42 disable
--r--r--r-- 1 root root 4096 Feb 8 10:42 latency
--r--r--r-- 1 root root 4096 Feb 8 10:42 name
--r--r--r-- 1 root root 4096 Feb 8 10:42 power
--r--r--r-- 1 root root 4096 Feb 8 10:42 residency
--r--r--r-- 1 root root 4096 Feb 8 10:42 time
--r--r--r-- 1 root root 4096 Feb 8 10:42 usage
-
-/sys/devices/system/cpu/cpu0/cpuidle/state3:
-total 0
--r--r--r-- 1 root root 4096 Feb 8 10:42 desc
--rw-r--r-- 1 root root 4096 Feb 8 10:42 disable
--r--r--r-- 1 root root 4096 Feb 8 10:42 latency
--r--r--r-- 1 root root 4096 Feb 8 10:42 name
--r--r--r-- 1 root root 4096 Feb 8 10:42 power
--r--r--r-- 1 root root 4096 Feb 8 10:42 residency
--r--r--r-- 1 root root 4096 Feb 8 10:42 time
--r--r--r-- 1 root root 4096 Feb 8 10:42 usage
---------------------------------------------------------------------------------
-
-
-* desc : Small description about the idle state (string)
-* disable : Option to disable this idle state (bool) -> see note below
-* latency : Latency to exit out of this idle state (in microseconds)
-* residency : Time after which a state becomes more effecient than any
- shallower state (in microseconds)
-* name : Name of the idle state (string)
-* power : Power consumed while in this idle state (in milliwatts)
-* time : Total time spent in this idle state (in microseconds)
-* usage : Number of times this state was entered (count)
-
-Note:
-The behavior and the effect of the disable variable depends on the
-implementation of a particular governor. In the ladder governor, for
-example, it is not coherent, i.e. if one is disabling a light state,
-then all deeper states are disabled as well, but the disable variable
-does not reflect it. Likewise, if one enables a deep state but a lighter
-state still is disabled, then this has no effect.
--- /dev/null
+Qualcomm Technologies, Inc. CPUFREQ Bindings
+
+CPUFREQ HW is a hardware engine used by some Qualcomm Technologies, Inc. (QTI)
+SoCs to manage frequency in hardware. It is capable of controlling frequency
+for multiple clusters.
+
+Properties:
+- compatible
+ Usage: required
+ Value type: <string>
+ Definition: must be "qcom,cpufreq-hw".
+
+- clocks
+ Usage: required
+ Value type: <phandle> From common clock binding.
+ Definition: clock handle for XO clock and GPLL0 clock.
+
+- clock-names
+ Usage: required
+ Value type: <string> From common clock binding.
+ Definition: must be "xo", "alternate".
+
+- reg
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: Addresses and sizes for the memory of the HW bases in
+ each frequency domain.
+- reg-names
+ Usage: Optional
+ Value type: <string>
+ Definition: Frequency domain name i.e.
+ "freq-domain0", "freq-domain1".
+
+- #freq-domain-cells:
+ Usage: required.
+ Definition: Number of cells in a freqency domain specifier.
+
+* Property qcom,freq-domain
+Devices supporting freq-domain must set their "qcom,freq-domain" property with
+phandle to a cpufreq_hw followed by the Domain ID(0/1) in the CPU DT node.
+
+
+Example:
+
+Example 1: Dual-cluster, Quad-core per cluster. CPUs within a cluster switch
+DCVS state together.
+
+/ {
+ cpus {
+ #address-cells = <2>;
+ #size-cells = <0>;
+
+ CPU0: cpu@0 {
+ device_type = "cpu";
+ compatible = "qcom,kryo385";
+ reg = <0x0 0x0>;
+ enable-method = "psci";
+ next-level-cache = <&L2_0>;
+ qcom,freq-domain = <&cpufreq_hw 0>;
+ L2_0: l2-cache {
+ compatible = "cache";
+ next-level-cache = <&L3_0>;
+ L3_0: l3-cache {
+ compatible = "cache";
+ };
+ };
+ };
+
+ CPU1: cpu@100 {
+ device_type = "cpu";
+ compatible = "qcom,kryo385";
+ reg = <0x0 0x100>;
+ enable-method = "psci";
+ next-level-cache = <&L2_100>;
+ qcom,freq-domain = <&cpufreq_hw 0>;
+ L2_100: l2-cache {
+ compatible = "cache";
+ next-level-cache = <&L3_0>;
+ };
+ };
+
+ CPU2: cpu@200 {
+ device_type = "cpu";
+ compatible = "qcom,kryo385";
+ reg = <0x0 0x200>;
+ enable-method = "psci";
+ next-level-cache = <&L2_200>;
+ qcom,freq-domain = <&cpufreq_hw 0>;
+ L2_200: l2-cache {
+ compatible = "cache";
+ next-level-cache = <&L3_0>;
+ };
+ };
+
+ CPU3: cpu@300 {
+ device_type = "cpu";
+ compatible = "qcom,kryo385";
+ reg = <0x0 0x300>;
+ enable-method = "psci";
+ next-level-cache = <&L2_300>;
+ qcom,freq-domain = <&cpufreq_hw 0>;
+ L2_300: l2-cache {
+ compatible = "cache";
+ next-level-cache = <&L3_0>;
+ };
+ };
+
+ CPU4: cpu@400 {
+ device_type = "cpu";
+ compatible = "qcom,kryo385";
+ reg = <0x0 0x400>;
+ enable-method = "psci";
+ next-level-cache = <&L2_400>;
+ qcom,freq-domain = <&cpufreq_hw 1>;
+ L2_400: l2-cache {
+ compatible = "cache";
+ next-level-cache = <&L3_0>;
+ };
+ };
+
+ CPU5: cpu@500 {
+ device_type = "cpu";
+ compatible = "qcom,kryo385";
+ reg = <0x0 0x500>;
+ enable-method = "psci";
+ next-level-cache = <&L2_500>;
+ qcom,freq-domain = <&cpufreq_hw 1>;
+ L2_500: l2-cache {
+ compatible = "cache";
+ next-level-cache = <&L3_0>;
+ };
+ };
+
+ CPU6: cpu@600 {
+ device_type = "cpu";
+ compatible = "qcom,kryo385";
+ reg = <0x0 0x600>;
+ enable-method = "psci";
+ next-level-cache = <&L2_600>;
+ qcom,freq-domain = <&cpufreq_hw 1>;
+ L2_600: l2-cache {
+ compatible = "cache";
+ next-level-cache = <&L3_0>;
+ };
+ };
+
+ CPU7: cpu@700 {
+ device_type = "cpu";
+ compatible = "qcom,kryo385";
+ reg = <0x0 0x700>;
+ enable-method = "psci";
+ next-level-cache = <&L2_700>;
+ qcom,freq-domain = <&cpufreq_hw 1>;
+ L2_700: l2-cache {
+ compatible = "cache";
+ next-level-cache = <&L3_0>;
+ };
+ };
+ };
+
+ soc {
+ cpufreq_hw: cpufreq@17d43000 {
+ compatible = "qcom,cpufreq-hw";
+ reg = <0x17d43000 0x1400>, <0x17d45800 0x1400>;
+ reg-names = "freq-domain0", "freq-domain1";
+
+ clocks = <&rpmhcc RPMH_CXO_CLK>, <&gcc GPLL0>;
+ clock-names = "xo", "alternate";
+
+ #freq-domain-cells = <1>;
+ };
+}
acpi_ec_start(first_ec, true);
}
+void acpi_ec_mark_gpe_for_wake(void)
+{
+ if (first_ec && !ec_no_wakeup)
+ acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
+}
+
+void acpi_ec_set_gpe_wake_mask(u8 action)
+{
+ if (first_ec && !ec_no_wakeup)
+ acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
+}
+
void acpi_ec_dispatch_gpe(void)
{
if (first_ec)
int acpi_ec_dsdt_probe(void);
void acpi_ec_block_transactions(void);
void acpi_ec_unblock_transactions(void);
+void acpi_ec_mark_gpe_for_wake(void);
+void acpi_ec_set_gpe_wake_mask(u8 action);
void acpi_ec_dispatch_gpe(void);
int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
acpi_handle handle, acpi_ec_query_func func,
acpi_handle_debug(adev->handle, "_DSM function mask: 0x%x\n",
bitmask);
+
+ acpi_ec_mark_gpe_for_wake();
} else {
acpi_handle_debug(adev->handle,
"_DSM function 0 evaluation failed\n");
if (lps0_device_handle) {
acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF);
acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY);
+
+ acpi_ec_set_gpe_wake_mask(ACPI_GPE_ENABLE);
}
if (acpi_sci_irq_valid())
enable_irq_wake(acpi_sci_irq);
+ /* Change the configuration of GPEs to avoid spurious wakeup. */
+ acpi_enable_all_wakeup_gpes();
+ acpi_os_wait_events_complete();
return 0;
}
static void acpi_s2idle_wake(void)
{
+ if (!lps0_device_handle)
+ return;
if (pm_debug_messages_on)
lpi_check_constraints();
* takes too much time for EC wakeup events to survive, so look
* for them now.
*/
- if (lps0_device_handle)
- acpi_ec_dispatch_gpe();
+ acpi_ec_dispatch_gpe();
}
}
static void acpi_s2idle_restore(void)
{
+ acpi_enable_all_runtime_gpes();
+
if (acpi_sci_irq_valid())
disable_irq_wake(acpi_sci_irq);
if (lps0_device_handle) {
+ acpi_ec_set_gpe_wake_mask(ACPI_GPE_DISABLE);
+
acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT);
acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON);
}
static inline void genpd_update_accounting(struct generic_pm_domain *genpd) {}
#endif
+static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd,
+ unsigned int state)
+{
+ struct generic_pm_domain_data *pd_data;
+ struct pm_domain_data *pdd;
+ struct gpd_link *link;
+
+ /* New requested state is same as Max requested state */
+ if (state == genpd->performance_state)
+ return state;
+
+ /* New requested state is higher than Max requested state */
+ if (state > genpd->performance_state)
+ return state;
+
+ /* Traverse all devices within the domain */
+ list_for_each_entry(pdd, &genpd->dev_list, list_node) {
+ pd_data = to_gpd_data(pdd);
+
+ if (pd_data->performance_state > state)
+ state = pd_data->performance_state;
+ }
+
+ /*
+ * Traverse all sub-domains within the domain. This can be
+ * done without any additional locking as the link->performance_state
+ * field is protected by the master genpd->lock, which is already taken.
+ *
+ * Also note that link->performance_state (subdomain's performance state
+ * requirement to master domain) is different from
+ * link->slave->performance_state (current performance state requirement
+ * of the devices/sub-domains of the subdomain) and so can have a
+ * different value.
+ *
+ * Note that we also take vote from powered-off sub-domains into account
+ * as the same is done for devices right now.
+ */
+ list_for_each_entry(link, &genpd->master_links, master_node) {
+ if (link->performance_state > state)
+ state = link->performance_state;
+ }
+
+ return state;
+}
+
+static int _genpd_set_performance_state(struct generic_pm_domain *genpd,
+ unsigned int state, int depth)
+{
+ struct generic_pm_domain *master;
+ struct gpd_link *link;
+ int master_state, ret;
+
+ if (state == genpd->performance_state)
+ return 0;
+
+ /* Propagate to masters of genpd */
+ list_for_each_entry(link, &genpd->slave_links, slave_node) {
+ master = link->master;
+
+ if (!master->set_performance_state)
+ continue;
+
+ /* Find master's performance state */
+ ret = dev_pm_opp_xlate_performance_state(genpd->opp_table,
+ master->opp_table,
+ state);
+ if (unlikely(ret < 0))
+ goto err;
+
+ master_state = ret;
+
+ genpd_lock_nested(master, depth + 1);
+
+ link->prev_performance_state = link->performance_state;
+ link->performance_state = master_state;
+ master_state = _genpd_reeval_performance_state(master,
+ master_state);
+ ret = _genpd_set_performance_state(master, master_state, depth + 1);
+ if (ret)
+ link->performance_state = link->prev_performance_state;
+
+ genpd_unlock(master);
+
+ if (ret)
+ goto err;
+ }
+
+ ret = genpd->set_performance_state(genpd, state);
+ if (ret)
+ goto err;
+
+ genpd->performance_state = state;
+ return 0;
+
+err:
+ /* Encountered an error, lets rollback */
+ list_for_each_entry_continue_reverse(link, &genpd->slave_links,
+ slave_node) {
+ master = link->master;
+
+ if (!master->set_performance_state)
+ continue;
+
+ genpd_lock_nested(master, depth + 1);
+
+ master_state = link->prev_performance_state;
+ link->performance_state = master_state;
+
+ master_state = _genpd_reeval_performance_state(master,
+ master_state);
+ if (_genpd_set_performance_state(master, master_state, depth + 1)) {
+ pr_err("%s: Failed to roll back to %d performance state\n",
+ master->name, master_state);
+ }
+
+ genpd_unlock(master);
+ }
+
+ return ret;
+}
+
/**
* dev_pm_genpd_set_performance_state- Set performance state of device's power
* domain.
int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
{
struct generic_pm_domain *genpd;
- struct generic_pm_domain_data *gpd_data, *pd_data;
- struct pm_domain_data *pdd;
+ struct generic_pm_domain_data *gpd_data;
unsigned int prev;
- int ret = 0;
+ int ret;
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
prev = gpd_data->performance_state;
gpd_data->performance_state = state;
- /* New requested state is same as Max requested state */
- if (state == genpd->performance_state)
- goto unlock;
-
- /* New requested state is higher than Max requested state */
- if (state > genpd->performance_state)
- goto update_state;
-
- /* Traverse all devices within the domain */
- list_for_each_entry(pdd, &genpd->dev_list, list_node) {
- pd_data = to_gpd_data(pdd);
-
- if (pd_data->performance_state > state)
- state = pd_data->performance_state;
- }
-
- if (state == genpd->performance_state)
- goto unlock;
-
- /*
- * We aren't propagating performance state changes of a subdomain to its
- * masters as we don't have hardware that needs it. Over that, the
- * performance states of subdomain and its masters may not have
- * one-to-one mapping and would require additional information. We can
- * get back to this once we have hardware that needs it. For that
- * reason, we don't have to consider performance state of the subdomains
- * of genpd here.
- */
-
-update_state:
- if (genpd_status_on(genpd)) {
- ret = genpd->set_performance_state(genpd, state);
- if (ret) {
- gpd_data->performance_state = prev;
- goto unlock;
- }
- }
-
- genpd->performance_state = state;
+ state = _genpd_reeval_performance_state(genpd, state);
+ ret = _genpd_set_performance_state(genpd, state, 0);
+ if (ret)
+ gpd_data->performance_state = prev;
-unlock:
genpd_unlock(genpd);
return ret;
return ret;
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
-
- if (unlikely(genpd->set_performance_state)) {
- ret = genpd->set_performance_state(genpd, genpd->performance_state);
- if (ret) {
- pr_warn("%s: Failed to set performance state %d (%d)\n",
- genpd->name, genpd->performance_state, ret);
- }
- }
-
if (elapsed_ns <= genpd->states[state_idx].power_on_latency_ns)
return ret;
ret);
goto unlock;
}
+
+ /*
+ * Save table for faster processing while setting performance
+ * state.
+ */
+ genpd->opp_table = dev_pm_opp_get_opp_table(&genpd->dev);
+ WARN_ON(!genpd->opp_table);
}
ret = genpd_add_provider(np, genpd_xlate_simple, genpd);
if (ret) {
- if (genpd->set_performance_state)
+ if (genpd->set_performance_state) {
+ dev_pm_opp_put_opp_table(genpd->opp_table);
dev_pm_opp_of_remove_table(&genpd->dev);
+ }
goto unlock;
}
i, ret);
goto error;
}
+
+ /*
+ * Save table for faster processing while setting
+ * performance state.
+ */
+ genpd->opp_table = dev_pm_opp_get_opp_table_indexed(&genpd->dev, i);
+ WARN_ON(!genpd->opp_table);
}
genpd->provider = &np->fwnode;
genpd->provider = NULL;
genpd->has_provider = false;
- if (genpd->set_performance_state)
+ if (genpd->set_performance_state) {
+ dev_pm_opp_put_opp_table(genpd->opp_table);
dev_pm_opp_of_remove_table(&genpd->dev);
+ }
}
mutex_unlock(&gpd_list_lock);
if (!gpd->set_performance_state)
continue;
+ dev_pm_opp_put_opp_table(gpd->opp_table);
dev_pm_opp_of_remove_table(&gpd->dev);
}
}
struct device *genpd_dev_pm_attach_by_id(struct device *dev,
unsigned int index)
{
- struct device *genpd_dev;
+ struct device *virt_dev;
int num_domains;
int ret;
return NULL;
/* Allocate and register device on the genpd bus. */
- genpd_dev = kzalloc(sizeof(*genpd_dev), GFP_KERNEL);
- if (!genpd_dev)
+ virt_dev = kzalloc(sizeof(*virt_dev), GFP_KERNEL);
+ if (!virt_dev)
return ERR_PTR(-ENOMEM);
- dev_set_name(genpd_dev, "genpd:%u:%s", index, dev_name(dev));
- genpd_dev->bus = &genpd_bus_type;
- genpd_dev->release = genpd_release_dev;
+ dev_set_name(virt_dev, "genpd:%u:%s", index, dev_name(dev));
+ virt_dev->bus = &genpd_bus_type;
+ virt_dev->release = genpd_release_dev;
- ret = device_register(genpd_dev);
+ ret = device_register(virt_dev);
if (ret) {
- kfree(genpd_dev);
+ kfree(virt_dev);
return ERR_PTR(ret);
}
/* Try to attach the device to the PM domain at the specified index. */
- ret = __genpd_dev_pm_attach(genpd_dev, dev->of_node, index, false);
+ ret = __genpd_dev_pm_attach(virt_dev, dev->of_node, index, false);
if (ret < 1) {
- device_unregister(genpd_dev);
+ device_unregister(virt_dev);
return ret ? ERR_PTR(ret) : NULL;
}
- pm_runtime_enable(genpd_dev);
- genpd_queue_power_off_work(dev_to_genpd(genpd_dev));
+ pm_runtime_enable(virt_dev);
+ genpd_queue_power_off_work(dev_to_genpd(virt_dev));
- return genpd_dev;
+ return virt_dev;
}
EXPORT_SYMBOL_GPL(genpd_dev_pm_attach_by_id);
EXPORT_SYMBOL_GPL(of_genpd_parse_idle_states);
/**
- * of_genpd_opp_to_performance_state- Gets performance state of device's
- * power domain corresponding to a DT node's "required-opps" property.
+ * pm_genpd_opp_to_performance_state - Gets performance state of the genpd from its OPP node.
*
- * @dev: Device for which the performance-state needs to be found.
- * @np: DT node where the "required-opps" property is present. This can be
- * the device node itself (if it doesn't have an OPP table) or a node
- * within the OPP table of a device (if device has an OPP table).
+ * @genpd_dev: Genpd's device for which the performance-state needs to be found.
+ * @opp: struct dev_pm_opp of the OPP for which we need to find performance
+ * state.
*
- * Returns performance state corresponding to the "required-opps" property of
- * a DT node. This calls platform specific genpd->opp_to_performance_state()
- * callback to translate power domain OPP to performance state.
+ * Returns performance state encoded in the OPP of the genpd. This calls
+ * platform specific genpd->opp_to_performance_state() callback to translate
+ * power domain OPP to performance state.
*
* Returns performance state on success and 0 on failure.
*/
-unsigned int of_genpd_opp_to_performance_state(struct device *dev,
- struct device_node *np)
+unsigned int pm_genpd_opp_to_performance_state(struct device *genpd_dev,
+ struct dev_pm_opp *opp)
{
- struct generic_pm_domain *genpd;
- struct dev_pm_opp *opp;
- int state = 0;
+ struct generic_pm_domain *genpd = NULL;
+ int state;
- genpd = dev_to_genpd(dev);
- if (IS_ERR(genpd))
- return 0;
+ genpd = container_of(genpd_dev, struct generic_pm_domain, dev);
- if (unlikely(!genpd->set_performance_state))
+ if (unlikely(!genpd->opp_to_performance_state))
return 0;
genpd_lock(genpd);
-
- opp = of_dev_pm_opp_find_required_opp(&genpd->dev, np);
- if (IS_ERR(opp)) {
- dev_err(dev, "Failed to find required OPP: %ld\n",
- PTR_ERR(opp));
- goto unlock;
- }
-
state = genpd->opp_to_performance_state(genpd, opp);
- dev_pm_opp_put(opp);
-
-unlock:
genpd_unlock(genpd);
return state;
}
-EXPORT_SYMBOL_GPL(of_genpd_opp_to_performance_state);
+EXPORT_SYMBOL_GPL(pm_genpd_opp_to_performance_state);
static int __init genpd_bus_init(void)
{
return 0;
}
-static int genpd_summary_show(struct seq_file *s, void *data)
+static int summary_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd;
int ret = 0;
return ret;
}
-static int genpd_status_show(struct seq_file *s, void *data)
+static int status_show(struct seq_file *s, void *data)
{
static const char * const status_lookup[] = {
[GPD_STATE_ACTIVE] = "on",
return ret;
}
-static int genpd_sub_domains_show(struct seq_file *s, void *data)
+static int sub_domains_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
struct gpd_link *link;
return ret;
}
-static int genpd_idle_states_show(struct seq_file *s, void *data)
+static int idle_states_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
unsigned int i;
return ret;
}
-static int genpd_active_time_show(struct seq_file *s, void *data)
+static int active_time_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
ktime_t delta = 0;
return ret;
}
-static int genpd_total_idle_time_show(struct seq_file *s, void *data)
+static int total_idle_time_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
ktime_t delta = 0, total = 0;
}
-static int genpd_devices_show(struct seq_file *s, void *data)
+static int devices_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
struct pm_domain_data *pm_data;
return ret;
}
-static int genpd_perf_state_show(struct seq_file *s, void *data)
+static int perf_state_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
return 0;
}
-#define define_genpd_open_function(name) \
-static int genpd_##name##_open(struct inode *inode, struct file *file) \
-{ \
- return single_open(file, genpd_##name##_show, inode->i_private); \
-}
-
-define_genpd_open_function(summary);
-define_genpd_open_function(status);
-define_genpd_open_function(sub_domains);
-define_genpd_open_function(idle_states);
-define_genpd_open_function(active_time);
-define_genpd_open_function(total_idle_time);
-define_genpd_open_function(devices);
-define_genpd_open_function(perf_state);
-
-#define define_genpd_debugfs_fops(name) \
-static const struct file_operations genpd_##name##_fops = { \
- .open = genpd_##name##_open, \
- .read = seq_read, \
- .llseek = seq_lseek, \
- .release = single_release, \
-}
-
-define_genpd_debugfs_fops(summary);
-define_genpd_debugfs_fops(status);
-define_genpd_debugfs_fops(sub_domains);
-define_genpd_debugfs_fops(idle_states);
-define_genpd_debugfs_fops(active_time);
-define_genpd_debugfs_fops(total_idle_time);
-define_genpd_debugfs_fops(devices);
-define_genpd_debugfs_fops(perf_state);
+DEFINE_SHOW_ATTRIBUTE(summary);
+DEFINE_SHOW_ATTRIBUTE(status);
+DEFINE_SHOW_ATTRIBUTE(sub_domains);
+DEFINE_SHOW_ATTRIBUTE(idle_states);
+DEFINE_SHOW_ATTRIBUTE(active_time);
+DEFINE_SHOW_ATTRIBUTE(total_idle_time);
+DEFINE_SHOW_ATTRIBUTE(devices);
+DEFINE_SHOW_ATTRIBUTE(perf_state);
static int __init genpd_debug_init(void)
{
return -ENOMEM;
d = debugfs_create_file("pm_genpd_summary", S_IRUGO,
- genpd_debugfs_dir, NULL, &genpd_summary_fops);
+ genpd_debugfs_dir, NULL, &summary_fops);
if (!d)
return -ENOMEM;
return -ENOMEM;
debugfs_create_file("current_state", 0444,
- d, genpd, &genpd_status_fops);
+ d, genpd, &status_fops);
debugfs_create_file("sub_domains", 0444,
- d, genpd, &genpd_sub_domains_fops);
+ d, genpd, &sub_domains_fops);
debugfs_create_file("idle_states", 0444,
- d, genpd, &genpd_idle_states_fops);
+ d, genpd, &idle_states_fops);
debugfs_create_file("active_time", 0444,
- d, genpd, &genpd_active_time_fops);
+ d, genpd, &active_time_fops);
debugfs_create_file("total_idle_time", 0444,
- d, genpd, &genpd_total_idle_time_fops);
+ d, genpd, &total_idle_time_fops);
debugfs_create_file("devices", 0444,
- d, genpd, &genpd_devices_fops);
+ d, genpd, &devices_fops);
if (genpd->set_performance_state)
debugfs_create_file("perf_state", 0444,
- d, genpd, &genpd_perf_state_fops);
+ d, genpd, &perf_state_fops);
}
return 0;
If in doubt, say N.
+config ARM_QCOM_CPUFREQ_HW
+ tristate "QCOM CPUFreq HW driver"
+ depends on ARCH_QCOM || COMPILE_TEST
+ help
+ Support for the CPUFreq HW driver.
+ Some QCOM chipsets have a HW engine to offload the steps
+ necessary for changing the frequency of the CPUs. Firmware loaded
+ in this engine exposes a programming interface to the OS.
+ The driver implements the cpufreq interface for this HW engine.
+ Say Y if you want to support CPUFreq HW.
+
config ARM_S3C_CPUFREQ
bool
help
obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o
obj-$(CONFIG_ARM_PXA2xx_CPUFREQ) += pxa2xx-cpufreq.o
obj-$(CONFIG_PXA3xx) += pxa3xx-cpufreq.o
+obj-$(CONFIG_ARM_QCOM_CPUFREQ_HW) += qcom-cpufreq-hw.o
obj-$(CONFIG_ARM_QCOM_CPUFREQ_KRYO) += qcom-cpufreq-kryo.o
obj-$(CONFIG_ARM_S3C2410_CPUFREQ) += s3c2410-cpufreq.o
obj-$(CONFIG_ARM_S3C2412_CPUFREQ) += s3c2412-cpufreq.o
/* Now write the value in all 64 registers */
for (temp = 0; temp <= 0x3f; temp++)
pci_write_config_dword(nforce2_dev, NFORCE2_PLLREG, pll);
-
- return;
}
/**
module_init(nforce2_init);
module_exit(nforce2_exit);
-
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
#include <asm/io.h>
#include <linux/uaccess.h>
#include <asm/pal.h>
MODULE_DESCRIPTION("ACPI Processor P-States Driver");
MODULE_LICENSE("GPL");
-
struct cpufreq_acpi_io {
struct acpi_processor_performance acpi_data;
unsigned int resume;
pr_debug("acpi_cpufreq_exit\n");
cpufreq_unregister_driver(&acpi_cpufreq_driver);
- return;
}
-
late_initcall(acpi_cpufreq_init);
module_exit(acpi_cpufreq_exit);
-
/* scaling down? scale voltage after frequency */
if (new_freq < old_freq) {
ret = regulator_set_voltage_tol(arm_reg, volt, 0);
- if (ret) {
+ if (ret)
dev_warn(cpu_dev,
"failed to scale vddarm down: %d\n", ret);
- ret = 0;
- }
ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
- if (ret) {
+ if (ret)
dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret);
- ret = 0;
- }
if (!IS_ERR(pu_reg)) {
ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
- if (ret) {
+ if (ret)
dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret);
- ret = 0;
- }
}
}
if (of_machine_is_compatible("fsl,imx6ul") ||
of_machine_is_compatible("fsl,imx6ull")) {
ret = imx6ul_opp_check_speed_grading(cpu_dev);
- if (ret == -EPROBE_DEFER)
- return ret;
if (ret) {
+ if (ret == -EPROBE_DEFER)
+ return ret;
+
dev_err(cpu_dev, "failed to read ocotp: %d\n",
ret);
return ret;
wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
}
+static void intel_pstate_hwp_force_min_perf(int cpu)
+{
+ u64 value;
+ int min_perf;
+
+ value = all_cpu_data[cpu]->hwp_req_cached;
+ value &= ~GENMASK_ULL(31, 0);
+ min_perf = HWP_LOWEST_PERF(all_cpu_data[cpu]->hwp_cap_cached);
+
+ /* Set hwp_max = hwp_min */
+ value |= HWP_MAX_PERF(min_perf);
+ value |= HWP_MIN_PERF(min_perf);
+
+ /* Set EPP/EPB to min */
+ if (static_cpu_has(X86_FEATURE_HWP_EPP))
+ value |= HWP_ENERGY_PERF_PREFERENCE(HWP_EPP_POWERSAVE);
+ else
+ intel_pstate_set_epb(cpu, HWP_EPP_BALANCE_POWERSAVE);
+
+ wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
+}
+
static int intel_pstate_hwp_save_state(struct cpufreq_policy *policy)
{
struct cpudata *cpu_data = all_cpu_data[policy->cpu];
pr_debug("CPU %d exiting\n", policy->cpu);
intel_pstate_clear_update_util_hook(policy->cpu);
- if (hwp_active)
+ if (hwp_active) {
intel_pstate_hwp_save_state(policy);
- else
+ intel_pstate_hwp_force_min_perf(policy->cpu);
+ } else {
intel_cpufreq_stop_cpu(policy);
+ }
}
static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
pfunc_vdnap0_complete =
pmf_find_function(root, "slewing-done");
+ of_node_put(root);
if (pfunc_set_vdnap0 == NULL ||
pfunc_vdnap0_complete == NULL) {
pr_err("Can't find required platform function\n");
if (of_property_read_u32(power_mgt, "ibm,pstate-min", &pstate_min)) {
pr_warn("ibm,pstate-min node not found\n");
- return -ENODEV;
+ goto out;
}
if (of_property_read_u32(power_mgt, "ibm,pstate-max", &pstate_max)) {
pr_warn("ibm,pstate-max node not found\n");
- return -ENODEV;
+ goto out;
}
if (of_property_read_u32(power_mgt, "ibm,pstate-nominal",
&pstate_nominal)) {
pr_warn("ibm,pstate-nominal not found\n");
- return -ENODEV;
+ goto out;
}
if (of_property_read_u32(power_mgt, "ibm,pstate-ultra-turbo",
pstate_ids = of_get_property(power_mgt, "ibm,pstate-ids", &len_ids);
if (!pstate_ids) {
pr_warn("ibm,pstate-ids not found\n");
- return -ENODEV;
+ goto out;
}
pstate_freqs = of_get_property(power_mgt, "ibm,pstate-frequencies-mhz",
&len_freqs);
if (!pstate_freqs) {
pr_warn("ibm,pstate-frequencies-mhz not found\n");
- return -ENODEV;
+ goto out;
}
if (len_ids != len_freqs) {
nr_pstates = min(len_ids, len_freqs) / sizeof(u32);
if (!nr_pstates) {
pr_warn("No PStates found\n");
- return -ENODEV;
+ goto out;
}
powernv_pstate_info.nr_pstates = nr_pstates;
/* End of list marker entry */
powernv_freqs[i].frequency = CPUFREQ_TABLE_END;
+
+ of_node_put(power_mgt);
return 0;
+out:
+ of_node_put(power_mgt);
+ return -ENODEV;
}
/* Returns the CPU frequency corresponding to the pstate_id. */
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/cpufreq.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+
+#define LUT_MAX_ENTRIES 40U
+#define LUT_SRC GENMASK(31, 30)
+#define LUT_L_VAL GENMASK(7, 0)
+#define LUT_CORE_COUNT GENMASK(18, 16)
+#define LUT_ROW_SIZE 32
+#define CLK_HW_DIV 2
+
+/* Register offsets */
+#define REG_ENABLE 0x0
+#define REG_LUT_TABLE 0x110
+#define REG_PERF_STATE 0x920
+
+static unsigned long cpu_hw_rate, xo_rate;
+static struct platform_device *global_pdev;
+
+static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
+ unsigned int index)
+{
+ void __iomem *perf_state_reg = policy->driver_data;
+
+ writel_relaxed(index, perf_state_reg);
+
+ return 0;
+}
+
+static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
+{
+ void __iomem *perf_state_reg;
+ struct cpufreq_policy *policy;
+ unsigned int index;
+
+ policy = cpufreq_cpu_get_raw(cpu);
+ if (!policy)
+ return 0;
+
+ perf_state_reg = policy->driver_data;
+
+ index = readl_relaxed(perf_state_reg);
+ index = min(index, LUT_MAX_ENTRIES - 1);
+
+ return policy->freq_table[index].frequency;
+}
+
+static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ void __iomem *perf_state_reg = policy->driver_data;
+ int index;
+
+ index = policy->cached_resolved_idx;
+ if (index < 0)
+ return 0;
+
+ writel_relaxed(index, perf_state_reg);
+
+ return policy->freq_table[index].frequency;
+}
+
+static int qcom_cpufreq_hw_read_lut(struct device *dev,
+ struct cpufreq_policy *policy,
+ void __iomem *base)
+{
+ u32 data, src, lval, i, core_count, prev_cc = 0, prev_freq = 0, freq;
+ unsigned int max_cores = cpumask_weight(policy->cpus);
+ struct cpufreq_frequency_table *table;
+
+ table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
+ if (!table)
+ return -ENOMEM;
+
+ for (i = 0; i < LUT_MAX_ENTRIES; i++) {
+ data = readl_relaxed(base + REG_LUT_TABLE + i * LUT_ROW_SIZE);
+ src = FIELD_GET(LUT_SRC, data);
+ lval = FIELD_GET(LUT_L_VAL, data);
+ core_count = FIELD_GET(LUT_CORE_COUNT, data);
+
+ if (src)
+ freq = xo_rate * lval / 1000;
+ else
+ freq = cpu_hw_rate / 1000;
+
+ /* Ignore boosts in the middle of the table */
+ if (core_count != max_cores) {
+ table[i].frequency = CPUFREQ_ENTRY_INVALID;
+ } else {
+ table[i].frequency = freq;
+ dev_dbg(dev, "index=%d freq=%d, core_count %d\n", i,
+ freq, core_count);
+ }
+
+ /*
+ * Two of the same frequencies with the same core counts means
+ * end of table
+ */
+ if (i > 0 && prev_freq == freq && prev_cc == core_count) {
+ struct cpufreq_frequency_table *prev = &table[i - 1];
+
+ /*
+ * Only treat the last frequency that might be a boost
+ * as the boost frequency
+ */
+ if (prev_cc != max_cores) {
+ prev->frequency = prev_freq;
+ prev->flags = CPUFREQ_BOOST_FREQ;
+ }
+
+ break;
+ }
+
+ prev_cc = core_count;
+ prev_freq = freq;
+ }
+
+ table[i].frequency = CPUFREQ_TABLE_END;
+ policy->freq_table = table;
+
+ return 0;
+}
+
+static void qcom_get_related_cpus(int index, struct cpumask *m)
+{
+ struct device_node *cpu_np;
+ struct of_phandle_args args;
+ int cpu, ret;
+
+ for_each_possible_cpu(cpu) {
+ cpu_np = of_cpu_device_node_get(cpu);
+ if (!cpu_np)
+ continue;
+
+ ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
+ "#freq-domain-cells", 0,
+ &args);
+ of_node_put(cpu_np);
+ if (ret < 0)
+ continue;
+
+ if (index == args.args[0])
+ cpumask_set_cpu(cpu, m);
+ }
+}
+
+static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
+{
+ struct device *dev = &global_pdev->dev;
+ struct of_phandle_args args;
+ struct device_node *cpu_np;
+ struct resource *res;
+ void __iomem *base;
+ int ret, index;
+
+ cpu_np = of_cpu_device_node_get(policy->cpu);
+ if (!cpu_np)
+ return -EINVAL;
+
+ ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
+ "#freq-domain-cells", 0, &args);
+ of_node_put(cpu_np);
+ if (ret)
+ return ret;
+
+ index = args.args[0];
+
+ res = platform_get_resource(global_pdev, IORESOURCE_MEM, index);
+ if (!res)
+ return -ENODEV;
+
+ base = devm_ioremap(dev, res->start, resource_size(res));
+ if (!base)
+ return -ENOMEM;
+
+ /* HW should be in enabled state to proceed */
+ if (!(readl_relaxed(base + REG_ENABLE) & 0x1)) {
+ dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
+ ret = -ENODEV;
+ goto error;
+ }
+
+ qcom_get_related_cpus(index, policy->cpus);
+ if (!cpumask_weight(policy->cpus)) {
+ dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
+ ret = -ENOENT;
+ goto error;
+ }
+
+ policy->driver_data = base + REG_PERF_STATE;
+
+ ret = qcom_cpufreq_hw_read_lut(dev, policy, base);
+ if (ret) {
+ dev_err(dev, "Domain-%d failed to read LUT\n", index);
+ goto error;
+ }
+
+ policy->fast_switch_possible = true;
+
+ return 0;
+error:
+ devm_iounmap(dev, base);
+ return ret;
+}
+
+static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
+{
+ void __iomem *base = policy->driver_data - REG_PERF_STATE;
+
+ kfree(policy->freq_table);
+ devm_iounmap(&global_pdev->dev, base);
+
+ return 0;
+}
+
+static struct freq_attr *qcom_cpufreq_hw_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ &cpufreq_freq_attr_scaling_boost_freqs,
+ NULL
+};
+
+static struct cpufreq_driver cpufreq_qcom_hw_driver = {
+ .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK |
+ CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
+ .verify = cpufreq_generic_frequency_table_verify,
+ .target_index = qcom_cpufreq_hw_target_index,
+ .get = qcom_cpufreq_hw_get,
+ .init = qcom_cpufreq_hw_cpu_init,
+ .exit = qcom_cpufreq_hw_cpu_exit,
+ .fast_switch = qcom_cpufreq_hw_fast_switch,
+ .name = "qcom-cpufreq-hw",
+ .attr = qcom_cpufreq_hw_attr,
+};
+
+static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
+{
+ struct clk *clk;
+ int ret;
+
+ clk = clk_get(&pdev->dev, "xo");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ xo_rate = clk_get_rate(clk);
+ clk_put(clk);
+
+ clk = clk_get(&pdev->dev, "alternate");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
+ clk_put(clk);
+
+ global_pdev = pdev;
+
+ ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
+ if (ret)
+ dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
+ else
+ dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");
+
+ return ret;
+}
+
+static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
+{
+ return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
+}
+
+static const struct of_device_id qcom_cpufreq_hw_match[] = {
+ { .compatible = "qcom,cpufreq-hw" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);
+
+static struct platform_driver qcom_cpufreq_hw_driver = {
+ .probe = qcom_cpufreq_hw_driver_probe,
+ .remove = qcom_cpufreq_hw_driver_remove,
+ .driver = {
+ .name = "qcom-cpufreq-hw",
+ .of_match_table = qcom_cpufreq_hw_match,
+ },
+};
+
+static int __init qcom_cpufreq_hw_init(void)
+{
+ return platform_driver_register(&qcom_cpufreq_hw_driver);
+}
+subsys_initcall(qcom_cpufreq_hw_init);
+
+static void __exit qcom_cpufreq_hw_exit(void)
+{
+ platform_driver_unregister(&qcom_cpufreq_hw_driver);
+}
+module_exit(qcom_cpufreq_hw_exit);
+
+MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
+MODULE_LICENSE("GPL v2");
return 0;
}
-static int fops_board_open(struct inode *inode, struct file *file)
-{
- return single_open(file, board_show, NULL);
-}
-
-static const struct file_operations fops_board = {
- .open = fops_board_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
- .owner = THIS_MODULE,
-};
+DEFINE_SHOW_ATTRIBUTE(board);
static int info_show(struct seq_file *seq, void *p)
{
return 0;
}
-static int fops_info_open(struct inode *inode, struct file *file)
-{
- return single_open(file, info_show, NULL);
-}
-
-static const struct file_operations fops_info = {
- .open = fops_info_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
- .owner = THIS_MODULE,
-};
+DEFINE_SHOW_ATTRIBUTE(info);
static int io_show(struct seq_file *seq, void *p)
{
return 0;
}
-static int fops_io_open(struct inode *inode, struct file *file)
-{
- return single_open(file, io_show, NULL);
-}
-
-static const struct file_operations fops_io = {
- .open = fops_io_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
- .owner = THIS_MODULE,
-};
-
+DEFINE_SHOW_ATTRIBUTE(io);
static int __init s3c_freq_debugfs_init(void)
{
}
dbgfs_file_io = debugfs_create_file("io-timing", S_IRUGO, dbgfs_root,
- NULL, &fops_io);
+ NULL, &io_fops);
dbgfs_file_info = debugfs_create_file("info", S_IRUGO, dbgfs_root,
- NULL, &fops_info);
+ NULL, &info_fops);
dbgfs_file_board = debugfs_create_file("board", S_IRUGO, dbgfs_root,
- NULL, &fops_board);
+ NULL, &board_fops);
return 0;
}
{
int ret;
struct device_node *root = of_find_node_by_path("/");
+ const struct of_device_id *match_id;
if (!root)
return -ENODEV;
/*
* Initialize the driver just for a compliant set of machines
*/
- if (!of_match_node(compatible_machine_match, root))
+ match_id = of_match_node(compatible_machine_match, root);
+
+ of_node_put(root);
+
+ if (!match_id)
return -ENODEV;
if (!mcpm_is_available())
struct cpuidle_state *target_state = &drv->states[index];
bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP);
ktime_t time_start, time_end;
- s64 diff;
/*
* Tell the time framework to switch to a broadcast timer because our
local_irq_enable();
if (entered_state >= 0) {
+ s64 diff, delay = drv->states[entered_state].exit_latency;
+ int i;
+
/*
* Update cpuidle counters
* This can be moved to within driver enter routine,
dev->last_residency = (int)diff;
dev->states_usage[entered_state].time += dev->last_residency;
dev->states_usage[entered_state].usage++;
+
+ if (diff < drv->states[entered_state].target_residency) {
+ for (i = entered_state - 1; i >= 0; i--) {
+ if (drv->states[i].disabled ||
+ dev->states_usage[i].disable)
+ continue;
+
+ /* Shallower states are enabled, so update. */
+ dev->states_usage[entered_state].above++;
+ break;
+ }
+ } else if (diff > delay) {
+ for (i = entered_state + 1; i < drv->state_count; i++) {
+ if (drv->states[i].disabled ||
+ dev->states_usage[i].disable)
+ continue;
+
+ /*
+ * Update if a deeper state would have been a
+ * better match for the observed idle duration.
+ */
+ if (diff - delay >= drv->states[i].target_residency)
+ dev->states_usage[entered_state].below++;
+
+ break;
+ }
+ }
} else {
dev->last_residency = 0;
}
}
module_param(off, int, 0444);
+module_param_string(governor, param_governor, CPUIDLE_NAME_LEN, 0444);
core_initcall(cpuidle_init);
#define __DRIVER_CPUIDLE_H
/* For internal use only */
+extern char param_governor[];
extern struct cpuidle_governor *cpuidle_curr_governor;
extern struct list_head cpuidle_governors;
extern struct list_head cpuidle_detected_devices;
#include <linux/cpu.h>
#include <linux/cpuidle.h>
#include <linux/mutex.h>
+#include <linux/module.h>
#include <linux/pm_qos.h>
#include "cpuidle.h"
+char param_governor[CPUIDLE_NAME_LEN];
+
LIST_HEAD(cpuidle_governors);
struct cpuidle_governor *cpuidle_curr_governor;
mutex_lock(&cpuidle_lock);
if (__cpuidle_find_governor(gov->name) == NULL) {
ret = 0;
- list_add_tail(&gov->governor_list, &cpuidle_governors);
if (!cpuidle_curr_governor ||
- cpuidle_curr_governor->rating < gov->rating)
+ !strncasecmp(param_governor, gov->name, CPUIDLE_NAME_LEN) ||
+ (cpuidle_curr_governor->rating < gov->rating &&
+ strncasecmp(param_governor, cpuidle_curr_governor->name,
+ CPUIDLE_NAME_LEN)))
cpuidle_switch_governor(gov);
}
mutex_unlock(&cpuidle_lock);
local_irq_enable();
if (!current_set_polling_and_test()) {
- u64 limit = (u64)drv->states[1].target_residency * NSEC_PER_USEC;
unsigned int loop_count = 0;
+ u64 limit = TICK_USEC;
+ int i;
+
+ for (i = 1; i < drv->state_count; i++) {
+ if (drv->states[i].disabled || dev->states_usage[i].disable)
+ continue;
+
+ limit = (u64)drv->states[i].target_residency * NSEC_PER_USEC;
+ break;
+ }
while (!need_resched()) {
cpu_relax();
define_show_state_str_function(desc)
define_show_state_ull_function(disable)
define_store_state_ull_function(disable)
+define_show_state_ull_function(above)
+define_show_state_ull_function(below)
define_one_state_ro(name, show_state_name);
define_one_state_ro(desc, show_state_desc);
define_one_state_ro(usage, show_state_usage);
define_one_state_ro(time, show_state_time);
define_one_state_rw(disable, show_state_disable, store_state_disable);
+define_one_state_ro(above, show_state_above);
+define_one_state_ro(below, show_state_below);
static struct attribute *cpuidle_state_default_attrs[] = {
&attr_name.attr,
&attr_usage.attr,
&attr_time.attr,
&attr_disable.attr,
+ &attr_above.attr,
+ &attr_below.attr,
NULL
};
if (IS_ERR(opp_table))
return 0;
- count = opp_table->regulator_count;
-
/* Regulator may not be required for the device */
- if (!count)
+ if (!opp_table->regulators)
goto put_opp_table;
+ count = opp_table->regulator_count;
+
uV = kmalloc_array(count, sizeof(*uV), GFP_KERNEL);
if (!uV)
goto put_opp_table;
return ret;
}
-static inline int
-_generic_set_opp_domain(struct device *dev, struct clk *clk,
- unsigned long old_freq, unsigned long freq,
- unsigned int old_pstate, unsigned int new_pstate)
-{
- int ret;
-
- /* Scaling up? Scale domain performance state before frequency */
- if (freq > old_freq) {
- ret = dev_pm_genpd_set_performance_state(dev, new_pstate);
- if (ret)
- return ret;
- }
-
- ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
- if (ret)
- goto restore_domain_state;
-
- /* Scaling down? Scale domain performance state after frequency */
- if (freq < old_freq) {
- ret = dev_pm_genpd_set_performance_state(dev, new_pstate);
- if (ret)
- goto restore_freq;
- }
-
- return 0;
-
-restore_freq:
- if (_generic_set_opp_clk_only(dev, clk, freq, old_freq))
- dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
- __func__, old_freq);
-restore_domain_state:
- if (freq > old_freq)
- dev_pm_genpd_set_performance_state(dev, old_pstate);
-
- return ret;
-}
-
static int _generic_set_opp_regulator(const struct opp_table *opp_table,
struct device *dev,
unsigned long old_freq,
return ret;
}
+static int _set_opp_custom(const struct opp_table *opp_table,
+ struct device *dev, unsigned long old_freq,
+ unsigned long freq,
+ struct dev_pm_opp_supply *old_supply,
+ struct dev_pm_opp_supply *new_supply)
+{
+ struct dev_pm_set_opp_data *data;
+ int size;
+
+ data = opp_table->set_opp_data;
+ data->regulators = opp_table->regulators;
+ data->regulator_count = opp_table->regulator_count;
+ data->clk = opp_table->clk;
+ data->dev = dev;
+
+ data->old_opp.rate = old_freq;
+ size = sizeof(*old_supply) * opp_table->regulator_count;
+ if (IS_ERR(old_supply))
+ memset(data->old_opp.supplies, 0, size);
+ else
+ memcpy(data->old_opp.supplies, old_supply, size);
+
+ data->new_opp.rate = freq;
+ memcpy(data->new_opp.supplies, new_supply, size);
+
+ return opp_table->set_opp(data);
+}
+
+/* This is only called for PM domain for now */
+static int _set_required_opps(struct device *dev,
+ struct opp_table *opp_table,
+ struct dev_pm_opp *opp)
+{
+ struct opp_table **required_opp_tables = opp_table->required_opp_tables;
+ struct device **genpd_virt_devs = opp_table->genpd_virt_devs;
+ unsigned int pstate;
+ int i, ret = 0;
+
+ if (!required_opp_tables)
+ return 0;
+
+ /* Single genpd case */
+ if (!genpd_virt_devs) {
+ pstate = opp->required_opps[0]->pstate;
+ ret = dev_pm_genpd_set_performance_state(dev, pstate);
+ if (ret) {
+ dev_err(dev, "Failed to set performance state of %s: %d (%d)\n",
+ dev_name(dev), pstate, ret);
+ }
+ return ret;
+ }
+
+ /* Multiple genpd case */
+
+ /*
+ * Acquire genpd_virt_dev_lock to make sure we don't use a genpd_dev
+ * after it is freed from another thread.
+ */
+ mutex_lock(&opp_table->genpd_virt_dev_lock);
+
+ for (i = 0; i < opp_table->required_opp_count; i++) {
+ pstate = opp->required_opps[i]->pstate;
+
+ if (!genpd_virt_devs[i])
+ continue;
+
+ ret = dev_pm_genpd_set_performance_state(genpd_virt_devs[i], pstate);
+ if (ret) {
+ dev_err(dev, "Failed to set performance rate of %s: %d (%d)\n",
+ dev_name(genpd_virt_devs[i]), pstate, ret);
+ break;
+ }
+ }
+ mutex_unlock(&opp_table->genpd_virt_dev_lock);
+
+ return ret;
+}
+
/**
* dev_pm_opp_set_rate() - Configure new OPP based on frequency
* @dev: device for which we do this operation
unsigned long freq, old_freq;
struct dev_pm_opp *old_opp, *opp;
struct clk *clk;
- int ret, size;
+ int ret;
if (unlikely(!target_freq)) {
dev_err(dev, "%s: Invalid target frequency %lu\n", __func__,
dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n", __func__,
old_freq, freq);
- /* Only frequency scaling */
- if (!opp_table->regulators) {
- /*
- * We don't support devices with both regulator and
- * domain performance-state for now.
- */
- if (opp_table->genpd_performance_state)
- ret = _generic_set_opp_domain(dev, clk, old_freq, freq,
- IS_ERR(old_opp) ? 0 : old_opp->pstate,
- opp->pstate);
- else
- ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
- } else if (!opp_table->set_opp) {
+ /* Scaling up? Configure required OPPs before frequency */
+ if (freq > old_freq) {
+ ret = _set_required_opps(dev, opp_table, opp);
+ if (ret)
+ goto put_opp;
+ }
+
+ if (opp_table->set_opp) {
+ ret = _set_opp_custom(opp_table, dev, old_freq, freq,
+ IS_ERR(old_opp) ? NULL : old_opp->supplies,
+ opp->supplies);
+ } else if (opp_table->regulators) {
ret = _generic_set_opp_regulator(opp_table, dev, old_freq, freq,
IS_ERR(old_opp) ? NULL : old_opp->supplies,
opp->supplies);
} else {
- struct dev_pm_set_opp_data *data;
-
- data = opp_table->set_opp_data;
- data->regulators = opp_table->regulators;
- data->regulator_count = opp_table->regulator_count;
- data->clk = clk;
- data->dev = dev;
-
- data->old_opp.rate = old_freq;
- size = sizeof(*opp->supplies) * opp_table->regulator_count;
- if (IS_ERR(old_opp))
- memset(data->old_opp.supplies, 0, size);
- else
- memcpy(data->old_opp.supplies, old_opp->supplies, size);
-
- data->new_opp.rate = freq;
- memcpy(data->new_opp.supplies, opp->supplies, size);
+ /* Only frequency scaling */
+ ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
+ }
- ret = opp_table->set_opp(data);
+ /* Scaling down? Configure required OPPs after frequency */
+ if (!ret && freq < old_freq) {
+ ret = _set_required_opps(dev, opp_table, opp);
+ if (ret)
+ dev_err(dev, "Failed to set required opps: %d\n", ret);
}
+put_opp:
dev_pm_opp_put(opp);
put_old_opp:
if (!IS_ERR(old_opp))
return NULL;
mutex_init(&opp_table->lock);
+ mutex_init(&opp_table->genpd_virt_dev_lock);
INIT_LIST_HEAD(&opp_table->dev_list);
+ /* Mark regulator count uninitialized */
+ opp_table->regulator_count = -1;
+
opp_dev = _add_opp_dev(dev, opp_table);
if (!opp_dev) {
kfree(opp_table);
struct opp_table *opp_table = container_of(kref, struct opp_table, kref);
struct opp_device *opp_dev, *temp;
+ _of_clear_opp_table(opp_table);
+
/* Release clk */
if (!IS_ERR(opp_table->clk))
clk_put(opp_table->clk);
_remove_opp_dev(opp_dev, opp_table);
}
+ mutex_destroy(&opp_table->genpd_virt_dev_lock);
mutex_destroy(&opp_table->lock);
list_del(&opp_table->node);
kfree(opp_table);
* frequency/voltage list.
*/
blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_REMOVE, opp);
+ _of_opp_free_required_opps(opp_table, opp);
opp_debug_remove_one(opp);
list_del(&opp->node);
kfree(opp);
int count, supply_size;
/* Allocate space for at least one supply */
- count = table->regulator_count ? table->regulator_count : 1;
+ count = table->regulator_count > 0 ? table->regulator_count : 1;
supply_size = sizeof(*opp->supplies) * count;
/* allocate new OPP node and supplies structures */
struct regulator *reg;
int i;
+ if (!opp_table->regulators)
+ return true;
+
for (i = 0; i < opp_table->regulator_count; i++) {
reg = opp_table->regulators[i];
struct dev_pm_set_opp_data *data;
int len, count = opp_table->regulator_count;
- if (WARN_ON(!count))
+ if (WARN_ON(!opp_table->regulators))
return -EINVAL;
/* space for set_opp_data */
kfree(opp_table->regulators);
opp_table->regulators = NULL;
- opp_table->regulator_count = 0;
+ opp_table->regulator_count = -1;
err:
dev_pm_opp_put_opp_table(opp_table);
kfree(opp_table->regulators);
opp_table->regulators = NULL;
- opp_table->regulator_count = 0;
+ opp_table->regulator_count = -1;
put_opp_table:
dev_pm_opp_put_opp_table(opp_table);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_unregister_set_opp_helper);
+/**
+ * dev_pm_opp_set_genpd_virt_dev - Set virtual genpd device for an index
+ * @dev: Consumer device for which the genpd device is getting set.
+ * @virt_dev: virtual genpd device.
+ * @index: index.
+ *
+ * Multiple generic power domains for a device are supported with the help of
+ * virtual genpd devices, which are created for each consumer device - genpd
+ * pair. These are the device structures which are attached to the power domain
+ * and are required by the OPP core to set the performance state of the genpd.
+ *
+ * This helper will normally be called by the consumer driver of the device
+ * "dev", as only that has details of the genpd devices.
+ *
+ * This helper needs to be called once for each of those virtual devices, but
+ * only if multiple domains are available for a device. Otherwise the original
+ * device structure will be used instead by the OPP core.
+ */
+struct opp_table *dev_pm_opp_set_genpd_virt_dev(struct device *dev,
+ struct device *virt_dev,
+ int index)
+{
+ struct opp_table *opp_table;
+
+ opp_table = dev_pm_opp_get_opp_table(dev);
+ if (!opp_table)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_lock(&opp_table->genpd_virt_dev_lock);
+
+ if (unlikely(!opp_table->genpd_virt_devs ||
+ index >= opp_table->required_opp_count ||
+ opp_table->genpd_virt_devs[index])) {
+
+ dev_err(dev, "Invalid request to set required device\n");
+ dev_pm_opp_put_opp_table(opp_table);
+ mutex_unlock(&opp_table->genpd_virt_dev_lock);
+
+ return ERR_PTR(-EINVAL);
+ }
+
+ opp_table->genpd_virt_devs[index] = virt_dev;
+ mutex_unlock(&opp_table->genpd_virt_dev_lock);
+
+ return opp_table;
+}
+
+/**
+ * dev_pm_opp_put_genpd_virt_dev() - Releases resources blocked for genpd device.
+ * @opp_table: OPP table returned by dev_pm_opp_set_genpd_virt_dev().
+ * @virt_dev: virtual genpd device.
+ *
+ * This releases the resource previously acquired with a call to
+ * dev_pm_opp_set_genpd_virt_dev(). The consumer driver shall call this helper
+ * if it doesn't want OPP core to update performance state of a power domain
+ * anymore.
+ */
+void dev_pm_opp_put_genpd_virt_dev(struct opp_table *opp_table,
+ struct device *virt_dev)
+{
+ int i;
+
+ /*
+ * Acquire genpd_virt_dev_lock to make sure virt_dev isn't getting
+ * used in parallel.
+ */
+ mutex_lock(&opp_table->genpd_virt_dev_lock);
+
+ for (i = 0; i < opp_table->required_opp_count; i++) {
+ if (opp_table->genpd_virt_devs[i] != virt_dev)
+ continue;
+
+ opp_table->genpd_virt_devs[i] = NULL;
+ dev_pm_opp_put_opp_table(opp_table);
+
+ /* Drop the vote */
+ dev_pm_genpd_set_performance_state(virt_dev, 0);
+ break;
+ }
+
+ mutex_unlock(&opp_table->genpd_virt_dev_lock);
+
+ if (unlikely(i == opp_table->required_opp_count))
+ dev_err(virt_dev, "Failed to find required device entry\n");
+}
+
+/**
+ * dev_pm_opp_xlate_performance_state() - Find required OPP's pstate for src_table.
+ * @src_table: OPP table which has dst_table as one of its required OPP table.
+ * @dst_table: Required OPP table of the src_table.
+ * @pstate: Current performance state of the src_table.
+ *
+ * This Returns pstate of the OPP (present in @dst_table) pointed out by the
+ * "required-opps" property of the OPP (present in @src_table) which has
+ * performance state set to @pstate.
+ *
+ * Return: Zero or positive performance state on success, otherwise negative
+ * value on errors.
+ */
+int dev_pm_opp_xlate_performance_state(struct opp_table *src_table,
+ struct opp_table *dst_table,
+ unsigned int pstate)
+{
+ struct dev_pm_opp *opp;
+ int dest_pstate = -EINVAL;
+ int i;
+
+ if (!pstate)
+ return 0;
+
+ /*
+ * Normally the src_table will have the "required_opps" property set to
+ * point to one of the OPPs in the dst_table, but in some cases the
+ * genpd and its master have one to one mapping of performance states
+ * and so none of them have the "required-opps" property set. Return the
+ * pstate of the src_table as it is in such cases.
+ */
+ if (!src_table->required_opp_count)
+ return pstate;
+
+ for (i = 0; i < src_table->required_opp_count; i++) {
+ if (src_table->required_opp_tables[i]->np == dst_table->np)
+ break;
+ }
+
+ if (unlikely(i == src_table->required_opp_count)) {
+ pr_err("%s: Couldn't find matching OPP table (%p: %p)\n",
+ __func__, src_table, dst_table);
+ return -EINVAL;
+ }
+
+ mutex_lock(&src_table->lock);
+
+ list_for_each_entry(opp, &src_table->opp_list, node) {
+ if (opp->pstate == pstate) {
+ dest_pstate = opp->required_opps[i]->pstate;
+ goto unlock;
+ }
+ }
+
+ pr_err("%s: Couldn't find matching OPP (%p: %p)\n", __func__, src_table,
+ dst_table);
+
+unlock:
+ mutex_unlock(&src_table->lock);
+
+ return dest_pstate;
+}
+
/**
* dev_pm_opp_add() - Add an OPP table from a table definitions
* @dev: device for which we do this operation
if (!opp_table)
return -ENOMEM;
+ /* Fix regulator count for dynamic OPPs */
+ opp_table->regulator_count = 1;
+
ret = _opp_add_v1(opp_table, dev, freq, u_volt, true);
if (ret)
dev_pm_opp_put_opp_table(opp_table);
return managed_table;
}
+/* The caller must call dev_pm_opp_put() after the OPP is used */
+static struct dev_pm_opp *_find_opp_of_np(struct opp_table *opp_table,
+ struct device_node *opp_np)
+{
+ struct dev_pm_opp *opp;
+
+ lockdep_assert_held(&opp_table_lock);
+
+ mutex_lock(&opp_table->lock);
+
+ list_for_each_entry(opp, &opp_table->opp_list, node) {
+ if (opp->np == opp_np) {
+ dev_pm_opp_get(opp);
+ mutex_unlock(&opp_table->lock);
+ return opp;
+ }
+ }
+
+ mutex_unlock(&opp_table->lock);
+
+ return NULL;
+}
+
+static struct device_node *of_parse_required_opp(struct device_node *np,
+ int index)
+{
+ struct device_node *required_np;
+
+ required_np = of_parse_phandle(np, "required-opps", index);
+ if (unlikely(!required_np)) {
+ pr_err("%s: Unable to parse required-opps: %pOF, index: %d\n",
+ __func__, np, index);
+ }
+
+ return required_np;
+}
+
+/* The caller must call dev_pm_opp_put_opp_table() after the table is used */
+static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
+{
+ struct opp_table *opp_table;
+ struct device_node *opp_table_np;
+
+ lockdep_assert_held(&opp_table_lock);
+
+ opp_table_np = of_get_parent(opp_np);
+ if (!opp_table_np)
+ goto err;
+
+ /* It is safe to put the node now as all we need now is its address */
+ of_node_put(opp_table_np);
+
+ list_for_each_entry(opp_table, &opp_tables, node) {
+ if (opp_table_np == opp_table->np) {
+ _get_opp_table_kref(opp_table);
+ return opp_table;
+ }
+ }
+
+err:
+ return ERR_PTR(-ENODEV);
+}
+
+/* Free resources previously acquired by _opp_table_alloc_required_tables() */
+static void _opp_table_free_required_tables(struct opp_table *opp_table)
+{
+ struct opp_table **required_opp_tables = opp_table->required_opp_tables;
+ struct device **genpd_virt_devs = opp_table->genpd_virt_devs;
+ int i;
+
+ if (!required_opp_tables)
+ return;
+
+ for (i = 0; i < opp_table->required_opp_count; i++) {
+ if (IS_ERR_OR_NULL(required_opp_tables[i]))
+ break;
+
+ dev_pm_opp_put_opp_table(required_opp_tables[i]);
+ }
+
+ kfree(required_opp_tables);
+ kfree(genpd_virt_devs);
+
+ opp_table->required_opp_count = 0;
+ opp_table->genpd_virt_devs = NULL;
+ opp_table->required_opp_tables = NULL;
+}
+
+/*
+ * Populate all devices and opp tables which are part of "required-opps" list.
+ * Checking only the first OPP node should be enough.
+ */
+static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
+ struct device *dev,
+ struct device_node *opp_np)
+{
+ struct opp_table **required_opp_tables;
+ struct device **genpd_virt_devs = NULL;
+ struct device_node *required_np, *np;
+ int count, i;
+
+ /* Traversing the first OPP node is all we need */
+ np = of_get_next_available_child(opp_np, NULL);
+ if (!np) {
+ dev_err(dev, "Empty OPP table\n");
+ return;
+ }
+
+ count = of_count_phandle_with_args(np, "required-opps", NULL);
+ if (!count)
+ goto put_np;
+
+ if (count > 1) {
+ genpd_virt_devs = kcalloc(count, sizeof(*genpd_virt_devs),
+ GFP_KERNEL);
+ if (!genpd_virt_devs)
+ goto put_np;
+ }
+
+ required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),
+ GFP_KERNEL);
+ if (!required_opp_tables) {
+ kfree(genpd_virt_devs);
+ goto put_np;
+ }
+
+ opp_table->genpd_virt_devs = genpd_virt_devs;
+ opp_table->required_opp_tables = required_opp_tables;
+ opp_table->required_opp_count = count;
+
+ for (i = 0; i < count; i++) {
+ required_np = of_parse_required_opp(np, i);
+ if (!required_np)
+ goto free_required_tables;
+
+ required_opp_tables[i] = _find_table_of_opp_np(required_np);
+ of_node_put(required_np);
+
+ if (IS_ERR(required_opp_tables[i]))
+ goto free_required_tables;
+
+ /*
+ * We only support genpd's OPPs in the "required-opps" for now,
+ * as we don't know how much about other cases. Error out if the
+ * required OPP doesn't belong to a genpd.
+ */
+ if (!required_opp_tables[i]->is_genpd) {
+ dev_err(dev, "required-opp doesn't belong to genpd: %pOF\n",
+ required_np);
+ goto free_required_tables;
+ }
+ }
+
+ goto put_np;
+
+free_required_tables:
+ _opp_table_free_required_tables(opp_table);
+put_np:
+ of_node_put(np);
+}
+
void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
int index)
{
of_property_read_u32(np, "voltage-tolerance",
&opp_table->voltage_tolerance_v1);
+ if (of_find_property(np, "#power-domain-cells", NULL))
+ opp_table->is_genpd = true;
+
/* Get OPP table node */
opp_np = _opp_of_get_opp_desc_node(np, index);
of_node_put(np);
opp_table->np = opp_np;
+ _opp_table_alloc_required_tables(opp_table, dev, opp_np);
of_node_put(opp_np);
}
+void _of_clear_opp_table(struct opp_table *opp_table)
+{
+ _opp_table_free_required_tables(opp_table);
+}
+
+/*
+ * Release all resources previously acquired with a call to
+ * _of_opp_alloc_required_opps().
+ */
+void _of_opp_free_required_opps(struct opp_table *opp_table,
+ struct dev_pm_opp *opp)
+{
+ struct dev_pm_opp **required_opps = opp->required_opps;
+ int i;
+
+ if (!required_opps)
+ return;
+
+ for (i = 0; i < opp_table->required_opp_count; i++) {
+ if (!required_opps[i])
+ break;
+
+ /* Put the reference back */
+ dev_pm_opp_put(required_opps[i]);
+ }
+
+ kfree(required_opps);
+ opp->required_opps = NULL;
+}
+
+/* Populate all required OPPs which are part of "required-opps" list */
+static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
+ struct dev_pm_opp *opp)
+{
+ struct dev_pm_opp **required_opps;
+ struct opp_table *required_table;
+ struct device_node *np;
+ int i, ret, count = opp_table->required_opp_count;
+
+ if (!count)
+ return 0;
+
+ required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
+ if (!required_opps)
+ return -ENOMEM;
+
+ opp->required_opps = required_opps;
+
+ for (i = 0; i < count; i++) {
+ required_table = opp_table->required_opp_tables[i];
+
+ np = of_parse_required_opp(opp->np, i);
+ if (unlikely(!np)) {
+ ret = -ENODEV;
+ goto free_required_opps;
+ }
+
+ required_opps[i] = _find_opp_of_np(required_table, np);
+ of_node_put(np);
+
+ if (!required_opps[i]) {
+ pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
+ __func__, opp->np, i);
+ ret = -ENODEV;
+ goto free_required_opps;
+ }
+ }
+
+ return 0;
+
+free_required_opps:
+ _of_opp_free_required_opps(opp_table, opp);
+
+ return ret;
+}
+
static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
struct device_node *np)
{
struct opp_table *opp_table)
{
u32 *microvolt, *microamp = NULL;
- int supplies, vcount, icount, ret, i, j;
+ int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
struct property *prop = NULL;
char name[NAME_MAX];
- supplies = opp_table->regulator_count ? opp_table->regulator_count : 1;
-
/* Search for "opp-microvolt-<name>" */
if (opp_table->prop_name) {
snprintf(name, sizeof(name), "opp-microvolt-%s",
/* Missing property isn't a problem, but an invalid entry is */
if (!prop) {
- if (!opp_table->regulator_count)
+ if (unlikely(supplies == -1)) {
+ /* Initialize regulator_count */
+ opp_table->regulator_count = 0;
+ return 0;
+ }
+
+ if (!supplies)
return 0;
dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
}
}
+ if (unlikely(supplies == -1)) {
+ /* Initialize regulator_count */
+ supplies = opp_table->regulator_count = 1;
+ } else if (unlikely(!supplies)) {
+ dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
+ return -EINVAL;
+ }
+
vcount = of_property_count_u32_elems(opp->np, name);
if (vcount < 0) {
dev_err(dev, "%s: Invalid %s property (%d)\n",
ret = of_property_read_u64(np, "opp-hz", &rate);
if (ret < 0) {
/* "opp-hz" is optional for devices like power domains. */
- if (!of_find_property(dev->of_node, "#power-domain-cells",
- NULL)) {
+ if (!opp_table->is_genpd) {
dev_err(dev, "%s: opp-hz not found\n", __func__);
goto free_opp;
}
new_opp->dynamic = false;
new_opp->available = true;
+ ret = _of_opp_alloc_required_opps(opp_table, new_opp);
+ if (ret)
+ goto free_opp;
+
if (!of_property_read_u32(np, "clock-latency-ns", &val))
new_opp->clock_latency_ns = val;
- new_opp->pstate = of_genpd_opp_to_performance_state(dev, np);
-
ret = opp_parse_supplies(new_opp, dev, opp_table);
if (ret)
- goto free_opp;
+ goto free_required_opps;
+
+ if (opp_table->is_genpd)
+ new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
if (ret) {
/* Don't return error for duplicate OPPs */
if (ret == -EBUSY)
ret = 0;
- goto free_opp;
+ goto free_required_opps;
}
/* OPP to select on device suspend */
blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
return new_opp;
+free_required_opps:
+ _of_opp_free_required_opps(opp_table, new_opp);
free_opp:
_opp_free(new_opp);
EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
/**
- * of_dev_pm_opp_find_required_opp() - Search for required OPP.
- * @dev: The device whose OPP node is referenced by the 'np' DT node.
+ * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
* @np: Node that contains the "required-opps" property.
+ * @index: Index of the phandle to parse.
*
- * Returns the OPP of the device 'dev', whose phandle is present in the "np"
- * node. Although the "required-opps" property supports having multiple
- * phandles, this helper routine only parses the very first phandle in the list.
- *
- * Return: Matching opp, else returns ERR_PTR in case of error and should be
- * handled using IS_ERR.
+ * Returns the performance state of the OPP pointed out by the "required-opps"
+ * property at @index in @np.
*
- * The callers are required to call dev_pm_opp_put() for the returned OPP after
- * use.
+ * Return: Zero or positive performance state on success, otherwise negative
+ * value on errors.
*/
-struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev,
- struct device_node *np)
+int of_get_required_opp_performance_state(struct device_node *np, int index)
{
- struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ENODEV);
+ struct dev_pm_opp *opp;
struct device_node *required_np;
struct opp_table *opp_table;
+ int pstate = -EINVAL;
- opp_table = _find_opp_table(dev);
- if (IS_ERR(opp_table))
- return ERR_CAST(opp_table);
+ required_np = of_parse_required_opp(np, index);
+ if (!required_np)
+ return -EINVAL;
- required_np = of_parse_phandle(np, "required-opps", 0);
- if (unlikely(!required_np)) {
- dev_err(dev, "Unable to parse required-opps\n");
- goto put_opp_table;
+ opp_table = _find_table_of_opp_np(required_np);
+ if (IS_ERR(opp_table)) {
+ pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
+ __func__, np, PTR_ERR(opp_table));
+ goto put_required_np;
}
- mutex_lock(&opp_table->lock);
-
- list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
- if (temp_opp->available && temp_opp->np == required_np) {
- opp = temp_opp;
-
- /* Increment the reference count of OPP */
- dev_pm_opp_get(opp);
- break;
- }
+ opp = _find_opp_of_np(opp_table, required_np);
+ if (opp) {
+ pstate = opp->pstate;
+ dev_pm_opp_put(opp);
}
- mutex_unlock(&opp_table->lock);
+ dev_pm_opp_put_opp_table(opp_table);
+put_required_np:
of_node_put(required_np);
-put_opp_table:
- dev_pm_opp_put_opp_table(opp_table);
- return opp;
+ return pstate;
}
-EXPORT_SYMBOL_GPL(of_dev_pm_opp_find_required_opp);
+EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);
/**
* dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
* @supplies: Power supplies voltage/current values
* @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
* frequency from any other OPP's frequency.
+ * @required_opps: List of OPPs that are required by this OPP.
* @opp_table: points back to the opp_table struct this opp belongs to
* @np: OPP's device node.
* @dentry: debugfs dentry pointer (per opp)
unsigned long clock_latency_ns;
+ struct dev_pm_opp **required_opps;
struct opp_table *opp_table;
struct device_node *np;
* @parsed_static_opps: True if OPPs are initialized from DT.
* @shared_opp: OPP is shared between multiple devices.
* @suspend_opp: Pointer to OPP to be used during device suspend.
+ * @genpd_virt_dev_lock: Mutex protecting the genpd virtual device pointers.
+ * @genpd_virt_devs: List of virtual devices for multiple genpd support.
+ * @required_opp_tables: List of device OPP tables that are required by OPPs in
+ * this table.
+ * @required_opp_count: Number of required devices.
* @supported_hw: Array of version number to support.
* @supported_hw_count: Number of elements in supported_hw array.
* @prop_name: A name to postfix to many DT properties, while parsing them.
* @clk: Device's clock handle
* @regulators: Supply regulators
- * @regulator_count: Number of power supply regulators
+ * @regulator_count: Number of power supply regulators. Its value can be -1
+ * (uninitialized), 0 (no opp-microvolt property) or > 0 (has opp-microvolt
+ * property).
* @genpd_performance_state: Device's power domain support performance state.
+ * @is_genpd: Marks if the OPP table belongs to a genpd.
* @set_opp: Platform specific set_opp callback
* @set_opp_data: Data to be passed to set_opp callback
* @dentry: debugfs dentry pointer of the real device directory (not links).
enum opp_table_access shared_opp;
struct dev_pm_opp *suspend_opp;
+ struct mutex genpd_virt_dev_lock;
+ struct device **genpd_virt_devs;
+ struct opp_table **required_opp_tables;
+ unsigned int required_opp_count;
+
unsigned int *supported_hw;
unsigned int supported_hw_count;
const char *prop_name;
struct clk *clk;
struct regulator **regulators;
- unsigned int regulator_count;
+ int regulator_count;
bool genpd_performance_state;
+ bool is_genpd;
int (*set_opp)(struct dev_pm_set_opp_data *data);
struct dev_pm_set_opp_data *set_opp_data;
#ifdef CONFIG_OF
void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index);
+void _of_clear_opp_table(struct opp_table *opp_table);
struct opp_table *_managed_opp(struct device *dev, int index);
+void _of_opp_free_required_opps(struct opp_table *opp_table,
+ struct dev_pm_opp *opp);
#else
static inline void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index) {}
+static inline void _of_clear_opp_table(struct opp_table *opp_table) {}
static inline struct opp_table *_managed_opp(struct device *dev, int index) { return NULL; }
+static inline void _of_opp_free_required_opps(struct opp_table *opp_table,
+ struct dev_pm_opp *opp) {}
#endif
#ifdef CONFIG_DEBUG_FS
unsigned long long disable;
unsigned long long usage;
unsigned long long time; /* in US */
+ unsigned long long above; /* Number of times it's been too deep */
+ unsigned long long below; /* Number of times it's been too shallow */
#ifdef CONFIG_SUSPEND
unsigned long long s2idle_usage;
unsigned long long s2idle_time; /* in US */
struct genpd_lock_ops;
struct dev_pm_opp;
+struct opp_table;
struct generic_pm_domain {
struct device dev;
unsigned int performance_state; /* Aggregated max performance state */
int (*power_off)(struct generic_pm_domain *domain);
int (*power_on)(struct generic_pm_domain *domain);
+ struct opp_table *opp_table; /* OPP table of the genpd */
unsigned int (*opp_to_performance_state)(struct generic_pm_domain *genpd,
struct dev_pm_opp *opp);
int (*set_performance_state)(struct generic_pm_domain *genpd,
struct list_head master_node;
struct generic_pm_domain *slave;
struct list_head slave_node;
+
+ /* Sub-domain's per-master domain performance state */
+ unsigned int performance_state;
+ unsigned int prev_performance_state;
};
struct gpd_timing_data {
struct generic_pm_domain *of_genpd_remove_last(struct device_node *np);
int of_genpd_parse_idle_states(struct device_node *dn,
struct genpd_power_state **states, int *n);
-unsigned int of_genpd_opp_to_performance_state(struct device *dev,
- struct device_node *np);
+unsigned int pm_genpd_opp_to_performance_state(struct device *genpd_dev,
+ struct dev_pm_opp *opp);
int genpd_dev_pm_attach(struct device *dev);
struct device *genpd_dev_pm_attach_by_id(struct device *dev,
}
static inline unsigned int
-of_genpd_opp_to_performance_state(struct device *dev,
- struct device_node *np)
+pm_genpd_opp_to_performance_state(struct device *genpd_dev,
+ struct dev_pm_opp *opp)
{
return 0;
}
void dev_pm_opp_put_clkname(struct opp_table *opp_table);
struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev, int (*set_opp)(struct dev_pm_set_opp_data *data));
void dev_pm_opp_unregister_set_opp_helper(struct opp_table *opp_table);
+struct opp_table *dev_pm_opp_set_genpd_virt_dev(struct device *dev, struct device *virt_dev, int index);
+void dev_pm_opp_put_genpd_virt_dev(struct opp_table *opp_table, struct device *virt_dev);
+int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate);
int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq);
int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, const struct cpumask *cpumask);
int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask);
static inline void dev_pm_opp_put_clkname(struct opp_table *opp_table) {}
+static inline struct opp_table *dev_pm_opp_set_genpd_virt_dev(struct device *dev, struct device *virt_dev, int index)
+{
+ return ERR_PTR(-ENOTSUPP);
+}
+
+static inline void dev_pm_opp_put_genpd_virt_dev(struct opp_table *opp_table, struct device *virt_dev) {}
+
+static inline int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate)
+{
+ return -ENOTSUPP;
+}
+
static inline int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
{
return -ENOTSUPP;
void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask);
int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask);
struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev);
-struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev, struct device_node *np);
struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp);
+int of_get_required_opp_performance_state(struct device_node *np, int index);
#else
static inline int dev_pm_opp_of_add_table(struct device *dev)
{
return NULL;
}
-static inline struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev, struct device_node *np)
+static inline struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
{
return NULL;
}
-static inline struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
+static inline int of_get_required_opp_performance_state(struct device_node *np, int index)
{
- return NULL;
+ return -ENOTSUPP;
}
#endif
return 0;
}
-
-static int suspend_stats_open(struct inode *inode, struct file *file)
-{
- return single_open(file, suspend_stats_show, NULL);
-}
-
-static const struct file_operations suspend_stats_operations = {
- .open = suspend_stats_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(suspend_stats);
static int __init pm_debugfs_init(void)
{
debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
- NULL, NULL, &suspend_stats_operations);
+ NULL, NULL, &suspend_stats_fops);
return 0;
}
c->target_value = value;
}
-static int pm_qos_dbg_show_requests(struct seq_file *s, void *unused)
+static int pm_qos_debug_show(struct seq_file *s, void *unused)
{
struct pm_qos_object *qos = (struct pm_qos_object *)s->private;
struct pm_qos_constraints *c;
return 0;
}
-static int pm_qos_dbg_open(struct inode *inode, struct file *file)
-{
- return single_open(file, pm_qos_dbg_show_requests,
- inode->i_private);
-}
-
-static const struct file_operations pm_qos_debug_fops = {
- .open = pm_qos_dbg_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(pm_qos_debug);
/**
* pm_qos_update_target - manages the constraints list and calls the notifiers
+// SPDX-License-Identifier: GPL-2.0
/*
* Scheduler code and data structures related to cpufreq.
*
* Copyright (C) 2016, Intel Corporation
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*/
#include "sched.h"
+// SPDX-License-Identifier: GPL-2.0
/*
* CPUFreq governor based on scheduler-provided CPU utilization data.
*
* Copyright (C) 2016, Intel Corporation
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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