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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-04-28 02:10:46 +0200 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-04-28 02:10:46 +0200 |
commit | 885f925eef411f549f17bc64dd054a3269cf66cd (patch) | |
tree | 6bac783d573a51e497ad28c19b5a71defac85f39 /Documentation | |
parent | e4f5a3adc454745fea35f1c312e14cbeba6e0ea4 (diff) | |
parent | 45c009a9a447655aecbdb06c86126f05d0272171 (diff) | |
download | linux-885f925eef411f549f17bc64dd054a3269cf66cd.tar.bz2 |
Merge branch 'pm-cpufreq'
* pm-cpufreq: (57 commits)
cpufreq: MAINTAINERS: Add co-maintainer
cpufreq: pxa2xx: initialize variables
ARM: S5pv210: compiling issue, ARM_S5PV210_CPUFREQ needs CONFIG_CPU_FREQ_TABLE=y
cpufreq: cpu0: Put cpu parent node after using it
cpufreq: ARM big LITTLE: Adapt to latest cpufreq updates
cpufreq: ARM big LITTLE: put DT nodes after using them
cpufreq: Don't call __cpufreq_governor() for drivers without target()
cpufreq: exynos5440: Protect OPP search calls with RCU lock
cpufreq: dbx500: Round to closest available freq
cpufreq: Call __cpufreq_governor() with correct policy->cpus mask
cpufreq / intel_pstate: Optimize intel_pstate_set_policy
cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver
arm: exynos: Enable OPP library support for exynos5440
cpufreq: exynos: Remove error return even if no soc is found
cpufreq: exynos: Add cpufreq driver for exynos5440
cpufreq: AMD "frequency sensitivity feedback" powersave bias for ondemand governor
cpufreq: ondemand: allow custom powersave_bias_target handler to be registered
cpufreq: convert cpufreq_driver to using RCU
cpufreq: powerpc/platforms/cell: move cpufreq driver to drivers/cpufreq
cpufreq: sparc: move cpufreq driver to drivers/cpufreq
...
Conflicts:
MAINTAINERS (with commit a8e39c3 from pm-cpuidle)
drivers/cpufreq/cpufreq_governor.h (with commit beb0ff3)
Diffstat (limited to 'Documentation')
5 files changed, 126 insertions, 5 deletions
diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.txt index 72f70b16d299..a3585eac83b6 100644 --- a/Documentation/cpu-freq/cpu-drivers.txt +++ b/Documentation/cpu-freq/cpu-drivers.txt @@ -108,8 +108,9 @@ policy->governor must contain the "default policy" for cpufreq_driver.target is called with these values. -For setting some of these values, the frequency table helpers might be -helpful. See the section 2 for more information on them. +For setting some of these values (cpuinfo.min[max]_freq, policy->min[max]), the +frequency table helpers might be helpful. See the section 2 for more information +on them. SMP systems normally have same clock source for a group of cpus. For these the .init() would be called only once for the first online cpu. Here the .init() @@ -184,10 +185,10 @@ the reference implementation in drivers/cpufreq/longrun.c As most cpufreq processors only allow for being set to a few specific frequencies, a "frequency table" with some functions might assist in some work of the processor driver. Such a "frequency table" consists -of an array of struct cpufreq_freq_table entries, with any value in +of an array of struct cpufreq_frequency_table entries, with any value in "index" you want to use, and the corresponding frequency in "frequency". At the end of the table, you need to add a -cpufreq_freq_table entry with frequency set to CPUFREQ_TABLE_END. And +cpufreq_frequency_table entry with frequency set to CPUFREQ_TABLE_END. And if you want to skip one entry in the table, set the frequency to CPUFREQ_ENTRY_INVALID. The entries don't need to be in ascending order. diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt index c7a2eb8450c2..66f9cc310686 100644 --- a/Documentation/cpu-freq/governors.txt +++ b/Documentation/cpu-freq/governors.txt @@ -167,6 +167,27 @@ of load evaluation and helping the CPU stay at its top speed when truly busy, rather than shifting back and forth in speed. This tunable has no effect on behavior at lower speeds/lower CPU loads. +powersave_bias: this parameter takes a value between 0 to 1000. It +defines the percentage (times 10) value of the target frequency that +will be shaved off of the target. For example, when set to 100 -- 10%, +when ondemand governor would have targeted 1000 MHz, it will target +1000 MHz - (10% of 1000 MHz) = 900 MHz instead. This is set to 0 +(disabled) by default. +When AMD frequency sensitivity powersave bias driver -- +drivers/cpufreq/amd_freq_sensitivity.c is loaded, this parameter +defines the workload frequency sensitivity threshold in which a lower +frequency is chosen instead of ondemand governor's original target. +The frequency sensitivity is a hardware reported (on AMD Family 16h +Processors and above) value between 0 to 100% that tells software how +the performance of the workload running on a CPU will change when +frequency changes. A workload with sensitivity of 0% (memory/IO-bound) +will not perform any better on higher core frequency, whereas a +workload with sensitivity of 100% (CPU-bound) will perform better +higher the frequency. When the driver is loaded, this is set to 400 +by default -- for CPUs running workloads with sensitivity value below +40%, a lower frequency is chosen. Unloading the driver or writing 0 +will disable this feature. + 2.5 Conservative ---------------- @@ -191,6 +212,12 @@ governor but for the opposite direction. For example when set to its default value of '20' it means that if the CPU usage needs to be below 20% between samples to have the frequency decreased. +sampling_down_factor: similar functionality as in "ondemand" governor. +But in "conservative", it controls the rate at which the kernel makes +a decision on when to decrease the frequency while running in any +speed. Load for frequency increase is still evaluated every +sampling rate. + 3. The Governor Interface in the CPUfreq Core ============================================= diff --git a/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt b/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt new file mode 100644 index 000000000000..0715695e94a9 --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt @@ -0,0 +1,65 @@ +Generic ARM big LITTLE cpufreq driver's DT glue +----------------------------------------------- + +This is DT specific glue layer for generic cpufreq driver for big LITTLE +systems. + +Both required and optional properties listed below must be defined +under node /cpus/cpu@x. Where x is the first cpu inside a cluster. + +FIXME: Cpus should boot in the order specified in DT and all cpus for a cluster +must be present contiguously. Generic DT driver will check only node 'x' for +cpu:x. + +Required properties: +- operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt + for details + +Optional properties: +- clock-latency: Specify the possible maximum transition latency for clock, + in unit of nanoseconds. + +Examples: + +cpus { + #address-cells = <1>; + #size-cells = <0>; + + cpu@0 { + compatible = "arm,cortex-a15"; + reg = <0>; + next-level-cache = <&L2>; + operating-points = < + /* kHz uV */ + 792000 1100000 + 396000 950000 + 198000 850000 + >; + clock-latency = <61036>; /* two CLK32 periods */ + }; + + cpu@1 { + compatible = "arm,cortex-a15"; + reg = <1>; + next-level-cache = <&L2>; + }; + + cpu@100 { + compatible = "arm,cortex-a7"; + reg = <100>; + next-level-cache = <&L2>; + operating-points = < + /* kHz uV */ + 792000 950000 + 396000 750000 + 198000 450000 + >; + clock-latency = <61036>; /* two CLK32 periods */ + }; + + cpu@101 { + compatible = "arm,cortex-a7"; + reg = <101>; + next-level-cache = <&L2>; + }; +}; diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt index 4416ccc33472..051f764bedb8 100644 --- a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt @@ -32,7 +32,7 @@ cpus { 396000 950000 198000 850000 >; - transition-latency = <61036>; /* two CLK32 periods */ + clock-latency = <61036>; /* two CLK32 periods */ }; cpu@1 { diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt new file mode 100644 index 000000000000..caff1a57436f --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt @@ -0,0 +1,28 @@ + +Exynos5440 cpufreq driver +------------------- + +Exynos5440 SoC cpufreq driver for CPU frequency scaling. + +Required properties: +- interrupts: Interrupt to know the completion of cpu frequency change. +- operating-points: Table of frequencies and voltage CPU could be transitioned into, + in the decreasing order. Frequency should be in KHz units and voltage + should be in microvolts. + +Optional properties: +- clock-latency: Clock monitor latency in microsecond. + +All the required listed above must be defined under node cpufreq. + +Example: +-------- + cpufreq@160000 { + compatible = "samsung,exynos5440-cpufreq"; + reg = <0x160000 0x1000>; + interrupts = <0 57 0>; + operating-points = < + 1000000 975000 + 800000 925000>; + clock-latency = <100000>; + }; |