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linux
1# SPDX-License-Identifier: GPL-2.0-only
2menu "CPU Frequency scaling"
3
4config CPU_FREQ
5 bool "CPU Frequency scaling"
6 help
7 CPU Frequency scaling allows you to change the clock speed of
8 CPUs on the fly. This is a nice method to save power, because
9 the lower the CPU clock speed, the less power the CPU consumes.
10
11 Note that this driver doesn't automatically change the CPU
12 clock speed, you need to either enable a dynamic cpufreq governor
13 (see below) after boot, or use a userspace tool.
14
15 For details, take a look at
16 <file:Documentation/admin-guide/pm/cpufreq.rst>.
17
18 If in doubt, say N.
19
20if CPU_FREQ
21
22config CPU_FREQ_GOV_ATTR_SET
23 bool
24
25config CPU_FREQ_GOV_COMMON
26 select CPU_FREQ_GOV_ATTR_SET
27 select IRQ_WORK
28 bool
29
30config CPU_FREQ_STAT
31 bool "CPU frequency transition statistics"
32 help
33 Export CPU frequency statistics information through sysfs.
34
35 If in doubt, say N.
36
37choice
38 prompt "Default CPUFreq governor"
39 default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1110_CPUFREQ
40 default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if ARM64 || ARM
41 default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if (X86_INTEL_PSTATE || X86_AMD_PSTATE) && SMP
42 default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
43 help
44 This option sets which CPUFreq governor shall be loaded at
45 startup. If in doubt, use the default setting.
46
47config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
48 bool "performance"
49 select CPU_FREQ_GOV_PERFORMANCE
50 help
51 Use the CPUFreq governor 'performance' as default. This sets
52 the frequency statically to the highest frequency supported by
53 the CPU.
54
55config CPU_FREQ_DEFAULT_GOV_POWERSAVE
56 bool "powersave"
57 select CPU_FREQ_GOV_POWERSAVE
58 help
59 Use the CPUFreq governor 'powersave' as default. This sets
60 the frequency statically to the lowest frequency supported by
61 the CPU.
62
63config CPU_FREQ_DEFAULT_GOV_USERSPACE
64 bool "userspace"
65 select CPU_FREQ_GOV_USERSPACE
66 help
67 Use the CPUFreq governor 'userspace' as default. This allows
68 you to set the CPU frequency manually or when a userspace
69 program shall be able to set the CPU dynamically without having
70 to enable the userspace governor manually.
71
72config CPU_FREQ_DEFAULT_GOV_ONDEMAND
73 bool "ondemand"
74 depends on !(X86_INTEL_PSTATE && SMP)
75 select CPU_FREQ_GOV_ONDEMAND
76 select CPU_FREQ_GOV_PERFORMANCE
77 help
78 Use the CPUFreq governor 'ondemand' as default. This allows
79 you to get a full dynamic frequency capable system by simply
80 loading your cpufreq low-level hardware driver.
81 Be aware that not all cpufreq drivers support the ondemand
82 governor. If unsure have a look at the help section of the
83 driver. Fallback governor will be the performance governor.
84
85config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
86 bool "conservative"
87 depends on !(X86_INTEL_PSTATE && SMP)
88 select CPU_FREQ_GOV_CONSERVATIVE
89 select CPU_FREQ_GOV_PERFORMANCE
90 help
91 Use the CPUFreq governor 'conservative' as default. This allows
92 you to get a full dynamic frequency capable system by simply
93 loading your cpufreq low-level hardware driver.
94 Be aware that not all cpufreq drivers support the conservative
95 governor. If unsure have a look at the help section of the
96 driver. Fallback governor will be the performance governor.
97
98config CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
99 bool "schedutil"
100 depends on SMP
101 select CPU_FREQ_GOV_SCHEDUTIL
102 select CPU_FREQ_GOV_PERFORMANCE
103 help
104 Use the 'schedutil' CPUFreq governor by default. If unsure,
105 have a look at the help section of that governor. The fallback
106 governor will be 'performance'.
107
108endchoice
109
110config CPU_FREQ_GOV_PERFORMANCE
111 tristate "'performance' governor"
112 help
113 This cpufreq governor sets the frequency statically to the
114 highest available CPU frequency.
115
116 To compile this driver as a module, choose M here: the
117 module will be called cpufreq_performance.
118
119 If in doubt, say Y.
120
121config CPU_FREQ_GOV_POWERSAVE
122 tristate "'powersave' governor"
123 help
124 This cpufreq governor sets the frequency statically to the
125 lowest available CPU frequency.
126
127 To compile this driver as a module, choose M here: the
128 module will be called cpufreq_powersave.
129
130 If in doubt, say Y.
131
132config CPU_FREQ_GOV_USERSPACE
133 tristate "'userspace' governor for userspace frequency scaling"
134 help
135 Enable this cpufreq governor when you either want to set the
136 CPU frequency manually or when a userspace program shall
137 be able to set the CPU dynamically, like on LART
138 <http://www.lartmaker.nl/>.
139
140 To compile this driver as a module, choose M here: the
141 module will be called cpufreq_userspace.
142
143 If in doubt, say Y.
144
145config CPU_FREQ_GOV_ONDEMAND
146 tristate "'ondemand' cpufreq policy governor"
147 select CPU_FREQ_GOV_COMMON
148 help
149 'ondemand' - This driver adds a dynamic cpufreq policy governor.
150 The governor does a periodic polling and
151 changes frequency based on the CPU utilization.
152 The support for this governor depends on CPU capability to
153 do fast frequency switching (i.e, very low latency frequency
154 transitions).
155
156 To compile this driver as a module, choose M here: the
157 module will be called cpufreq_ondemand.
158
159 For details, take a look at
160 <file:Documentation/admin-guide/pm/cpufreq.rst>.
161
162 If in doubt, say N.
163
164config CPU_FREQ_GOV_CONSERVATIVE
165 tristate "'conservative' cpufreq governor"
166 depends on CPU_FREQ
167 select CPU_FREQ_GOV_COMMON
168 help
169 'conservative' - this driver is rather similar to the 'ondemand'
170 governor both in its source code and its purpose, the difference is
171 its optimisation for better suitability in a battery powered
172 environment. The frequency is gracefully increased and decreased
173 rather than jumping to 100% when speed is required.
174
175 If you have a desktop machine then you should really be considering
176 the 'ondemand' governor instead, however if you are using a laptop,
177 PDA or even an AMD64 based computer (due to the unacceptable
178 step-by-step latency issues between the minimum and maximum frequency
179 transitions in the CPU) you will probably want to use this governor.
180
181 To compile this driver as a module, choose M here: the
182 module will be called cpufreq_conservative.
183
184 For details, take a look at
185 <file:Documentation/admin-guide/pm/cpufreq.rst>.
186
187 If in doubt, say N.
188
189config CPU_FREQ_GOV_SCHEDUTIL
190 bool "'schedutil' cpufreq policy governor"
191 depends on CPU_FREQ && SMP
192 select CPU_FREQ_GOV_ATTR_SET
193 select IRQ_WORK
194 help
195 This governor makes decisions based on the utilization data provided
196 by the scheduler. It sets the CPU frequency to be proportional to
197 the utilization/capacity ratio coming from the scheduler. If the
198 utilization is frequency-invariant, the new frequency is also
199 proportional to the maximum available frequency. If that is not the
200 case, it is proportional to the current frequency of the CPU. The
201 frequency tipping point is at utilization/capacity equal to 80% in
202 both cases.
203
204 If in doubt, say N.
205
206comment "CPU frequency scaling drivers"
207
208config CPUFREQ_DT
209 tristate "Generic DT based cpufreq driver"
210 depends on HAVE_CLK && OF
211 select CPUFREQ_DT_PLATDEV
212 select PM_OPP
213 help
214 This adds a generic DT based cpufreq driver for frequency management.
215 It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
216 systems.
217
218 If in doubt, say N.
219
220config CPUFREQ_DT_RUST
221 tristate "Rust based Generic DT based cpufreq driver"
222 depends on HAVE_CLK && OF && RUST
223 select CPUFREQ_DT_PLATDEV
224 select PM_OPP
225 help
226 This adds a Rust based generic DT based cpufreq driver for frequency
227 management. It supports both uniprocessor (UP) and symmetric
228 multiprocessor (SMP) systems.
229
230 If in doubt, say N.
231
232config CPUFREQ_VIRT
233 tristate "Virtual cpufreq driver"
234 depends on GENERIC_ARCH_TOPOLOGY
235 help
236 This adds a virtualized cpufreq driver for guest kernels that
237 read/writes to a MMIO region for a virtualized cpufreq device to
238 communicate with the host. It sends performance requests to the host
239 which gets used as a hint to schedule vCPU threads and select CPU
240 frequency. If a VM does not support a virtualized FIE such as AMUs,
241 it updates the frequency scaling factor by polling host CPU frequency
242 to enable accurate Per-Entity Load Tracking for tasks running in the guest.
243
244 If in doubt, say N.
245
246config CPUFREQ_DT_PLATDEV
247 bool "Generic DT based cpufreq platdev driver"
248 depends on OF
249 help
250 This adds a generic DT based cpufreq platdev driver for frequency
251 management. This creates a 'cpufreq-dt' platform device, on the
252 supported platforms.
253
254 If in doubt, say N.
255
256if X86
257source "drivers/cpufreq/Kconfig.x86"
258endif
259
260source "drivers/cpufreq/Kconfig.arm"
261
262if PPC32 || PPC64
263source "drivers/cpufreq/Kconfig.powerpc"
264endif
265
266if MIPS
267config BMIPS_CPUFREQ
268 tristate "BMIPS CPUfreq Driver"
269 help
270 This option adds a CPUfreq driver for BMIPS processors with
271 support for configurable CPU frequency.
272
273 For now, BMIPS5 chips are supported (such as the Broadcom 7425).
274
275 If in doubt, say N.
276
277config LOONGSON2_CPUFREQ
278 tristate "Loongson2 CPUFreq Driver"
279 depends on LEMOTE_MACH2F
280 help
281 This option adds a CPUFreq driver for loongson processors which
282 support software configurable cpu frequency.
283
284 Loongson2F and its successors support this feature.
285
286 If in doubt, say N.
287endif
288
289if LOONGARCH
290config LOONGSON3_CPUFREQ
291 tristate "Loongson3 CPUFreq Driver"
292 help
293 This option adds a CPUFreq driver for Loongson processors which
294 support software configurable cpu frequency.
295
296 Loongson-3 family processors support this feature.
297
298 If in doubt, say N.
299endif
300
301if SPARC64
302config SPARC_US3_CPUFREQ
303 tristate "UltraSPARC-III CPU Frequency driver"
304 help
305 This adds the CPUFreq driver for UltraSPARC-III processors.
306
307 If in doubt, say N.
308
309config SPARC_US2E_CPUFREQ
310 tristate "UltraSPARC-IIe CPU Frequency driver"
311 help
312 This adds the CPUFreq driver for UltraSPARC-IIe processors.
313
314 If in doubt, say N.
315endif
316
317if SUPERH
318config SH_CPU_FREQ
319 tristate "SuperH CPU Frequency driver"
320 help
321 This adds the cpufreq driver for SuperH. Any CPU that supports
322 clock rate rounding through the clock framework can use this
323 driver. While it will make the kernel slightly larger, this is
324 harmless for CPUs that don't support rate rounding. The driver
325 will also generate a notice in the boot log before disabling
326 itself if the CPU in question is not capable of rate rounding.
327
328 If unsure, say N.
329endif
330
331config QORIQ_CPUFREQ
332 tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
333 depends on OF && COMMON_CLK
334 depends on PPC_E500MC || SOC_LS1021A || ARCH_LAYERSCAPE || COMPILE_TEST
335 select CLK_QORIQ
336 help
337 This adds the CPUFreq driver support for Freescale QorIQ SoCs
338 which are capable of changing the CPU's frequency dynamically.
339
340config ACPI_CPPC_CPUFREQ
341 tristate "CPUFreq driver based on the ACPI CPPC spec"
342 depends on ACPI_PROCESSOR
343 depends on ARM || ARM64 || RISCV
344 select ACPI_CPPC_LIB
345 help
346 This adds a CPUFreq driver which uses CPPC methods
347 as described in the ACPIv5.1 spec. CPPC stands for
348 Collaborative Processor Performance Controls. It
349 is based on an abstract continuous scale of CPU
350 performance values which allows the remote power
351 processor to flexibly optimize for power and
352 performance. CPPC relies on power management firmware
353 support for its operation.
354
355 If in doubt, say N.
356
357config ACPI_CPPC_CPUFREQ_FIE
358 bool "Frequency Invariance support for CPPC cpufreq driver"
359 depends on ACPI_CPPC_CPUFREQ && GENERIC_ARCH_TOPOLOGY
360 depends on ARM || ARM64 || RISCV
361 default y
362 help
363 This extends frequency invariance support in the CPPC cpufreq driver,
364 by using CPPC delivered and reference performance counters.
365
366 If in doubt, say N.
367
368endif
369
370endmenu