Merge tag 'v6.0' into rdma.git for-next
[linux-block.git] / drivers / acpi / Kconfig
CommitLineData
b2441318 1# SPDX-License-Identifier: GPL-2.0
1da177e4
LT
2#
3# ACPI Configuration
4#
5
f5d707ed
AB
6config ARCH_SUPPORTS_ACPI
7 bool
8
3f2c48c9 9menuconfig ACPI
355ee5eb 10 bool "ACPI (Advanced Configuration and Power Interface) Support"
2c870e61 11 depends on ARCH_SUPPORTS_ACPI
243b66e7 12 select PNP
2e61069b 13 select NLS
04662bac 14 select CRC32
2c870e61 15 default y if X86
1c48aa36 16 help
1da177e4 17 Advanced Configuration and Power Interface (ACPI) support for
1c48aa36 18 Linux requires an ACPI-compliant platform (hardware/firmware),
1da177e4
LT
19 and assumes the presence of OS-directed configuration and power
20 management (OSPM) software. This option will enlarge your
21 kernel by about 70K.
22
23 Linux ACPI provides a robust functional replacement for several
24 legacy configuration and power management interfaces, including
25 the Plug-and-Play BIOS specification (PnP BIOS), the
26 MultiProcessor Specification (MPS), and the Advanced Power
27 Management (APM) specification. If both ACPI and APM support
1c48aa36 28 are configured, ACPI is used.
1da177e4 29
1c48aa36 30 The project home page for the Linux ACPI subsystem is here:
aaf3d29f 31 <https://01.org/linux-acpi>
1da177e4
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32
33 Linux support for ACPI is based on Intel Corporation's ACPI
1c48aa36
BH
34 Component Architecture (ACPI CA). For more information on the
35 ACPI CA, see:
4ce77966 36 <https://acpica.org/>
1da177e4 37
c7f5220d
HG
38 ACPI is an open industry specification originally co-developed by
39 Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba. Currently,
40 it is developed by the ACPI Specification Working Group (ASWG) under
41 the UEFI Forum and any UEFI member can join the ASWG and contribute
42 to the ACPI specification.
1c48aa36 43 The specification is available at:
0585c1c0 44 <https://uefi.org/specifications>
1da177e4 45
3e11c3ce
LB
46if ACPI
47
8a1664be
GG
48config ACPI_LEGACY_TABLES_LOOKUP
49 bool
50
46ba51ea
HG
51config ARCH_MIGHT_HAVE_ACPI_PDC
52 bool
53
d8f4f161
LP
54config ACPI_GENERIC_GSI
55 bool
56
6e0a0ea1
GG
57config ACPI_SYSTEM_POWER_STATES_SUPPORT
58 bool
59
d0562674
SS
60config ACPI_CCA_REQUIRED
61 bool
62
f64bd790
DW
63config ACPI_TABLE_LIB
64 bool
65
4d946f79 66config ACPI_DEBUGGER
8cfb0cdf 67 bool "AML debugger interface"
4d946f79
LZ
68 select ACPI_DEBUG
69 help
836d0830
LZ
70 Enable in-kernel debugging of AML facilities: statistics,
71 internal object dump, single step control method execution.
4d946f79
LZ
72 This is still under development, currently enabling this only
73 results in the compilation of the ACPICA debugger files.
74
836d0830
LZ
75if ACPI_DEBUGGER
76
77config ACPI_DEBUGGER_USER
c117dfff 78 tristate "Userspace debugger accessibility"
836d0830
LZ
79 depends on DEBUG_FS
80 help
81 Export /sys/kernel/debug/acpi/acpidbg for userspace utilities
82 to access the debugger functionalities.
83
84endif
85
ad1696f6 86config ACPI_SPCR_TABLE
0231d000
PB
87 bool "ACPI Serial Port Console Redirection Support"
88 default y if X86
89 help
90 Enable support for Serial Port Console Redirection (SPCR) Table.
91 This table provides information about the configuration of the
92 earlycon console.
ad1696f6 93
d1eb86e5
ZR
94config ACPI_FPDT
95 bool "ACPI Firmware Performance Data Table (FPDT) support"
96 depends on X86_64
97 help
98 Enable support for the Firmware Performance Data Table (FPDT).
99 This table provides information on the timing of the system
100 boot, S3 suspend and S3 resume firmware code paths.
101
eeb2d80d
SP
102config ACPI_LPIT
103 bool
104 depends on X86_64
105 default y
106
673d5b43
LB
107config ACPI_SLEEP
108 bool
5d1e072b 109 depends on SUSPEND || HIBERNATION
6e0a0ea1 110 depends on ACPI_SYSTEM_POWER_STATES_SUPPORT
673d5b43
LB
111 default y
112
18d78b64 113config ACPI_REV_OVERRIDE_POSSIBLE
9165dabb 114 bool "Allow supported ACPI revision to be overridden"
18d78b64
RW
115 depends on X86
116 default y
117 help
118 The platform firmware on some systems expects Linux to return "5" as
119 the supported ACPI revision which makes it expose system configuration
120 information in a special way.
121
122 For example, based on what ACPI exports as the supported revision,
123 Dell XPS 13 (2015) configures its audio device to either work in HDA
124 mode or in I2S mode, where the former is supposed to be used on Linux
125 until the latter is fully supported (in the kernel as well as in user
126 space).
127
128 This option enables a DMI-based quirk for the above Dell machine (so
129 that HDA audio is exposed by the platform firmware to the kernel) and
130 makes it possible to force the kernel to return "5" as the supported
131 ACPI revision via the "acpi_rev_override" command line switch.
132
1195a098
TR
133config ACPI_EC_DEBUGFS
134 tristate "EC read/write access through /sys/kernel/debug/ec"
1195a098
TR
135 help
136 Say N to disable Embedded Controller /sys/kernel/debug interface
137
500de3dd
TR
138 Be aware that using this interface can confuse your Embedded
139 Controller in a way that a normal reboot is not enough. You then
25cb1bfd 140 have to power off your system, and remove the laptop battery for
500de3dd 141 some seconds.
1195a098
TR
142 An Embedded Controller typically is available on laptops and reads
143 sensor values like battery state and temperature.
500de3dd
TR
144 The kernel accesses the EC through ACPI parsed code provided by BIOS
145 tables. This option allows to access the EC directly without ACPI
146 code being involved.
1195a098
TR
147 Thus this option is a debug option that helps to write ACPI drivers
148 and can be used to identify ACPI code or EC firmware bugs.
149
1da177e4
LT
150config ACPI_AC
151 tristate "AC Adapter"
1b3d4c3b 152 select POWER_SUPPLY
07fefe4c 153 default y
1da177e4 154 help
1c48aa36
BH
155 This driver supports the AC Adapter object, which indicates
156 whether a system is on AC or not. If you have a system that can
07fefe4c 157 switch between A/C and battery, say Y.
1da177e4 158
1c48aa36
BH
159 To compile this driver as a module, choose M here:
160 the module will be called ac.
161
1da177e4
LT
162config ACPI_BATTERY
163 tristate "Battery"
1b3d4c3b 164 select POWER_SUPPLY
07fefe4c 165 default y
1da177e4
LT
166 help
167 This driver adds support for battery information through
168 /proc/acpi/battery. If you have a mobile system with a battery,
169 say Y.
170
1c48aa36
BH
171 To compile this driver as a module, choose M here:
172 the module will be called battery.
173
1da177e4
LT
174config ACPI_BUTTON
175 tristate "Button"
c0968f0e 176 depends on INPUT
07fefe4c 177 default y
1da177e4 178 help
1c48aa36 179 This driver handles events on the power, sleep, and lid buttons.
7d13f94c
KM
180 A daemon reads events from input devices or via netlink and
181 performs user-defined actions such as shutting down the system.
182 This is necessary for software-controlled poweroff.
1c48aa36
BH
183
184 To compile this driver as a module, choose M here:
185 the module will be called button.
1da177e4 186
a1b93e89
JT
187config ACPI_TINY_POWER_BUTTON
188 tristate "Tiny Power Button Driver"
189 depends on !ACPI_BUTTON
190 help
191 This driver provides a tiny alternative to the ACPI Button driver.
192 The tiny power button driver only handles the power button. Rather
193 than notifying userspace via the input layer or a netlink event, this
194 driver directly signals the init process to shut down.
195
196 This driver is particularly suitable for cloud and VM environments,
197 which use a simulated power button to initiate a controlled poweroff,
198 but which may not want to run a separate userspace daemon to process
199 input events.
200
201config ACPI_TINY_POWER_BUTTON_SIGNAL
202 int "Tiny Power Button Signal"
203 depends on ACPI_TINY_POWER_BUTTON
204 default 38
205 help
206 Default signal to send to init in response to the power button.
207
208 Likely values here include 38 (SIGRTMIN+4) to power off, or 2
209 (SIGINT) to simulate Ctrl+Alt+Del.
210
1da177e4
LT
211config ACPI_VIDEO
212 tristate "Video"
038275d2 213 depends on BACKLIGHT_CLASS_DEVICE
03e2bf26 214 depends on INPUT
63c4ec90 215 select THERMAL
1da177e4 216 help
1c48aa36 217 This driver implements the ACPI Extensions For Display Adapters
1da177e4 218 for integrated graphics devices on motherboard, as specified in
1c48aa36
BH
219 ACPI 2.0 Specification, Appendix B. This supports basic operations
220 such as defining the video POST device, retrieving EDID information,
221 and setting up a video output.
222
223 To compile this driver as a module, choose M here:
224 the module will be called video.
1da177e4
LT
225
226config ACPI_FAN
227 tristate "Fan"
d8054749 228 depends on THERMAL
07fefe4c 229 default y
1da177e4 230 help
1c48aa36 231 This driver supports ACPI fan devices, allowing user-mode
1da177e4
LT
232 applications to perform basic fan control (on, off, status).
233
1c48aa36
BH
234 To compile this driver as a module, choose M here:
235 the module will be called fan.
236
95c513ec
RW
237config ACPI_TAD
238 tristate "ACPI Time and Alarm (TAD) Device Support"
239 depends on SYSFS && PM_SLEEP
240 help
241 The ACPI Time and Alarm (TAD) device is an alternative to the Real
242 Time Clock (RTC). Its wake timers allow the system to transition from
243 the S3 (or optionally S4/S5) state to S0 state after a time period
244 elapses. In comparison with the RTC Alarm, the TAD provides a larger
245 scale of flexibility in the wake timers. The time capabilities of the
246 TAD maintain the time of day information across platform power
247 transitions, and keep track of time even when the platform is turned
248 off.
249
c8f7a62c 250config ACPI_DOCK
898b054f 251 bool "Dock"
c8f7a62c 252 help
1c48aa36
BH
253 This driver supports ACPI-controlled docking stations and removable
254 drive bays such as the IBM Ultrabay and the Dell Module Bay.
01b57e73 255
239708a3
AC
256config ACPI_CPU_FREQ_PSS
257 bool
239708a3 258
35ae7133
SH
259config ACPI_PROCESSOR_CSTATE
260 def_bool y
239ed06d 261 depends on ACPI_PROCESSOR
35ae7133
SH
262 depends on IA64 || X86
263
5f05586c
AC
264config ACPI_PROCESSOR_IDLE
265 bool
266 select CPU_IDLE
267
935c760e
TN
268config ACPI_MCFG
269 bool
270
337aadff
AC
271config ACPI_CPPC_LIB
272 bool
273 depends on ACPI_PROCESSOR
337aadff
AC
274 select MAILBOX
275 select PCC
276 help
277 If this option is enabled, this file implements common functionality
278 to parse CPPC tables as described in the ACPI 5.1+ spec. The
279 routines implemented are meant to be used by other
280 drivers to control CPU performance using CPPC semantics.
281 If your platform does not support CPPC in firmware,
282 leave this option disabled.
283
1da177e4
LT
284config ACPI_PROCESSOR
285 tristate "Processor"
b1121e2a 286 depends on X86 || IA64 || ARM64 || LOONGARCH
8fc85c6a 287 select ACPI_PROCESSOR_IDLE
b1121e2a 288 select ACPI_CPU_FREQ_PSS if X86 || IA64 || LOONGARCH
7fdc74da 289 select THERMAL
07fefe4c 290 default y
1da177e4 291 help
239708a3
AC
292 This driver adds support for the ACPI Processor package. It is required
293 by several flavors of cpufreq performance-state, thermal, throttling and
294 idle drivers.
1c48aa36
BH
295
296 To compile this driver as a module, choose M here:
297 the module will be called processor.
4b88e330 298
e92b297c
ZY
299config ACPI_IPMI
300 tristate "IPMI"
50121beb 301 depends on IPMI_HANDLER
e92b297c
ZY
302 help
303 This driver enables the ACPI to access the BMC controller. And it
304 uses the IPMI request/response message to communicate with BMC
a8ab8ef4 305 controller, which can be found on the server.
e92b297c
ZY
306
307 To compile this driver as a module, choose M here:
308 the module will be called as acpi_ipmi.
1da177e4
LT
309
310config ACPI_HOTPLUG_CPU
cbfc1bae 311 bool
f756f28b 312 depends on ACPI_PROCESSOR && HOTPLUG_CPU
1da177e4 313 select ACPI_CONTAINER
cbfc1bae 314 default y
1da177e4 315
8e0af514
SL
316config ACPI_PROCESSOR_AGGREGATOR
317 tristate "Processor Aggregator"
318 depends on ACPI_PROCESSOR
d91f79eb 319 depends on X86
8e0af514
SL
320 help
321 ACPI 4.0 defines processor Aggregator, which enables OS to perform
c4c4e2a5 322 specific processor configuration and control that applies to all
8e0af514
SL
323 processors in the platform. Currently only logical processor idling
324 is defined, which is to reduce power consumption. This driver
c4c4e2a5 325 supports the new device.
8e0af514 326
1da177e4
LT
327config ACPI_THERMAL
328 tristate "Thermal Zone"
329 depends on ACPI_PROCESSOR
3f655ef8 330 select THERMAL
07fefe4c 331 default y
1da177e4 332 help
1c48aa36 333 This driver supports ACPI thermal zones. Most mobile and
1da177e4
LT
334 some desktop systems support ACPI thermal zones. It is HIGHLY
335 recommended that this option be enabled, as your processor(s)
336 may be damaged without it.
337
1c48aa36
BH
338 To compile this driver as a module, choose M here:
339 the module will be called thermal.
340
a2ff95e0 341config ACPI_PLATFORM_PROFILE
21f05a43 342 tristate
a2ff95e0 343
7ce9573e
RD
344config ACPI_CUSTOM_DSDT_FILE
345 string "Custom DSDT Table file to include"
346 default ""
1da177e4 347 depends on !STANDALONE
1da177e4 348 help
d89e9d6b 349 This option supports a custom DSDT by linking it into the kernel.
cb1aaebe 350 See Documentation/admin-guide/acpi/dsdt-override.rst
d89e9d6b 351
c30fe7f7 352 Enter the full path name to the file which includes the AmlCode
82e4eb4e 353 or dsdt_aml_code declaration.
1da177e4 354
7ce9573e
RD
355 If unsure, don't enter a file name.
356
357config ACPI_CUSTOM_DSDT
358 bool
359 default ACPI_CUSTOM_DSDT_FILE != ""
360
91dda51a
AM
361config ARCH_HAS_ACPI_TABLE_UPGRADE
362 def_bool n
363
5d881327
LZ
364config ACPI_TABLE_UPGRADE
365 bool "Allow upgrading ACPI tables via initrd"
91dda51a 366 depends on BLK_DEV_INITRD && ARCH_HAS_ACPI_TABLE_UPGRADE
5d881327 367 default y
53aac44c 368 help
5d881327 369 This option provides functionality to upgrade arbitrary ACPI tables
53aac44c
TR
370 via initrd. No functional change if no ACPI tables are passed via
371 initrd, therefore it's safe to say Y.
cb1aaebe 372 See Documentation/admin-guide/acpi/initrd_table_override.rst for details
53aac44c 373
98a455d9
SY
374config ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD
375 bool "Override ACPI tables from built-in initrd"
376 depends on ACPI_TABLE_UPGRADE
d2cbbf1f 377 depends on INITRAMFS_SOURCE!="" && INITRAMFS_COMPRESSION_NONE
98a455d9
SY
378 help
379 This option provides functionality to override arbitrary ACPI tables
380 from built-in uncompressed initrd.
381
cb1aaebe 382 See Documentation/admin-guide/acpi/initrd_table_override.rst for details
98a455d9 383
1da177e4
LT
384config ACPI_DEBUG
385 bool "Debug Statements"
1da177e4 386 help
a0d84a92
BH
387 The ACPI subsystem can produce debug output. Saying Y enables this
388 output and increases the kernel size by around 50K.
389
390 Use the acpi.debug_layer and acpi.debug_level kernel command-line
cb1aaebe 391 parameters documented in Documentation/firmware-guide/acpi/debug.rst and
8c27ceff 392 Documentation/admin-guide/kernel-parameters.rst to control the type and
a0d84a92 393 amount of debug output.
1da177e4 394
8344b568 395config ACPI_PCI_SLOT
ab1a2e03 396 bool "PCI slot detection driver"
5c6a1177 397 depends on SYSFS && PCI
8344b568 398 help
1c48aa36
BH
399 This driver creates entries in /sys/bus/pci/slots/ for all PCI
400 slots in the system. This can help correlate PCI bus addresses,
401 i.e., segment/bus/device/function tuples, with physical slots in
402 the system. If you are unsure, say N.
403
1da177e4 404config ACPI_CONTAINER
06991c28 405 bool "Container and Module Devices"
ea6a4581 406 default (ACPI_HOTPLUG_MEMORY || ACPI_HOTPLUG_CPU)
1c48aa36
BH
407 help
408 This driver supports ACPI Container and Module devices (IDs
409 ACPI0004, PNP0A05, and PNP0A06).
45b1b196 410
1c48aa36
BH
411 This helps support hotplug of nodes, CPUs, and memory.
412
1da177e4 413config ACPI_HOTPLUG_MEMORY
0a347644 414 bool "Memory Hotplug"
bc02af93 415 depends on MEMORY_HOTPLUG
1da177e4 416 help
1c48aa36
BH
417 This driver supports ACPI memory hotplug. The driver
418 fields notifications on ACPI memory devices (PNP0C80),
419 which represent memory ranges that may be onlined or
420 offlined during runtime.
1da177e4 421
1c48aa36
BH
422 If your hardware and firmware do not support adding or
423 removing memory devices at runtime, you need not enable
424 this driver.
1da177e4 425
c183619b
JL
426config ACPI_HOTPLUG_IOAPIC
427 bool
428 depends on PCI
429 depends on X86_IO_APIC
430 default y
431
3f86b832 432config ACPI_SBS
94f6c086 433 tristate "Smart Battery System"
b4150fc4 434 depends on X86
1b3d4c3b 435 select POWER_SUPPLY
3f86b832 436 help
1c48aa36 437 This driver supports the Smart Battery System, another
94f6c086 438 type of access to battery information, found on some laptops.
3f86b832 439
1c48aa36
BH
440 To compile this driver as a module, choose M here:
441 the modules will be called sbs and sbshc.
442
801eab81
HY
443config ACPI_HED
444 tristate "Hardware Error Device"
445 help
446 This driver supports the Hardware Error Device (PNP0C33),
447 which is used to report some hardware errors notified via
448 SCI, mainly the corrected errors.
449
526b4af4
TR
450config ACPI_CUSTOM_METHOD
451 tristate "Allow ACPI methods to be inserted/replaced at run time"
452 depends on DEBUG_FS
526b4af4 453 help
bd1b2a55 454 This debug facility allows ACPI AML methods to be inserted and/or
526b4af4 455 replaced without rebooting the system. For details refer to:
cb1aaebe 456 Documentation/firmware-guide/acpi/method-customizing.rst.
526b4af4
TR
457
458 NOTE: This option is security sensitive, because it allows arbitrary
459 kernel memory to be written to by root (uid=0) users, allowing them
460 to bypass certain security measures (e.g. if root is not allowed to
461 load additional kernel modules after boot, this feature may be used
462 to override that restriction).
463
d1ff4b1c 464config ACPI_BGRT
2223af38 465 bool "Boottime Graphics Resource Table support"
6e7300cf 466 depends on EFI && (X86 || ARM64)
feb17406 467 help
d1ff4b1c
MG
468 This driver adds support for exposing the ACPI Boottime Graphics
469 Resource Table, which allows the operating system to obtain
470 data from the firmware boot splash. It will appear under
471 /sys/firmware/acpi/bgrt/ .
472
af1ae78a
AS
473config ACPI_REDUCED_HARDWARE_ONLY
474 bool "Hardware-reduced ACPI support only" if EXPERT
475 def_bool n
af1ae78a 476 help
99a33ffc
HG
477 This config item changes the way the ACPI code is built. When this
478 option is selected, the kernel will use a specialized version of
479 ACPICA that ONLY supports the ACPI "reduced hardware" mode. The
480 resulting kernel will be smaller but it will also be restricted to
481 running in ACPI reduced hardware mode ONLY.
af1ae78a 482
99a33ffc 483 If you are unsure what to do, do not enable this option.
af1ae78a 484
bdf97013 485source "drivers/acpi/nfit/Kconfig"
c710fcc5 486source "drivers/acpi/numa/Kconfig"
a643ce20 487source "drivers/acpi/apei/Kconfig"
6256ebd5 488source "drivers/acpi/dptf/Kconfig"
a643ce20 489
058dfc76
MW
490config ACPI_WATCHDOG
491 bool
492
4b3db708
CG
493config ACPI_EXTLOG
494 tristate "Extended Error Log support"
9613916b 495 depends on X86_MCE && X86_LOCAL_APIC && EDAC
7ea6c6c1 496 select UEFI_CPER
4b3db708
CG
497 help
498 Certain usages such as Predictive Failure Analysis (PFA) require
499 more information about the error than what can be described in
500 processor machine check banks. Most server processors log
501 additional information about the error in processor uncore
502 registers. Since the addresses and layout of these registers vary
503 widely from one processor to another, system software cannot
504 readily make use of them. To complicate matters further, some of
505 the additional error information cannot be constructed without
506 detailed knowledge about platform topology.
507
508 Enhanced MCA Logging allows firmware to provide additional error
509 information to system software, synchronous with MCE or CMCI. This
2dfb7d51
CG
510 driver adds support for that functionality with corresponding
511 tracepoint which carries that information to userspace.
4b3db708 512
4cf841e3
TL
513config ACPI_ADXL
514 bool
515
0bf54fcd
OP
516config ACPI_CONFIGFS
517 tristate "ACPI configfs support"
518 select CONFIGFS_FS
519 help
520 Select this option to enable support for ACPI configuration from
521 userspace. The configurable ACPI groups will be visible under
522 /config/acpi, assuming configfs is mounted under /config.
523
0db89fa2
CY
524config ACPI_PFRUT
525 tristate "ACPI Platform Firmware Runtime Update and Telemetry"
526 depends on 64BIT
527 help
528 This mechanism allows certain pieces of the platform firmware
529 to be updated on the fly while the system is running (runtime)
530 without the need to restart it, which is key in the cases when
531 the system needs to be available 100% of the time and it cannot
532 afford the downtime related to restarting it, or when the work
533 carried out by the system is particularly important, so it cannot
534 be interrupted, and it is not practical to wait until it is complete.
535
536 The existing firmware code can be modified (driver update) or
537 extended by adding new code to the firmware (code injection).
538
b0013e03
CY
539 Besides, the telemetry driver allows user space to fetch telemetry
540 data from the firmware with the help of the Platform Firmware Runtime
541 Telemetry interface.
542
543 To compile the drivers as modules, choose M here:
544 the modules will be called pfr_update and pfr_telemetry.
0db89fa2 545
88ef16d8
TN
546if ARM64
547source "drivers/acpi/arm64/Kconfig"
0ce82232
JL
548
549config ACPI_PPTT
550 bool
88ef16d8
TN
551endif
552
77e2a047
SH
553config ACPI_PCC
554 bool "ACPI PCC Address Space"
555 depends on PCC
556 default y
557 help
558 The PCC Address Space also referred as PCC Operation Region pertains
559 to the region of PCC subspace that succeeds the PCC signature.
560
561 The PCC Operation Region works in conjunction with the PCC Table
562 (Platform Communications Channel Table). PCC subspaces that are
563 marked for use as PCC Operation Regions must not be used as PCC
564 subspaces for the standard ACPI features such as CPPC, RASF, PDTT and
565 MPST. These standard features must always use the PCC Table instead.
566
567 Enable this feature if you want to set up and install the PCC Address
568 Space handler to handle PCC OpRegion in the firmware.
569
fa870509
AS
570source "drivers/acpi/pmic/Kconfig"
571
3cf48554
JPB
572config ACPI_VIOT
573 bool
574
e3435fff
SH
575config ACPI_PRMT
576 bool "Platform Runtime Mechanism Support"
577 depends on EFI && (X86_64 || ARM64)
578 default y
579 help
580 Platform Runtime Mechanism (PRM) is a firmware interface exposing a
581 set of binary executables that can be called from the AML interpreter
582 or directly from device drivers.
583
584 Say Y to enable the AML interpreter to execute the PRM code.
585
586 While this feature is optional in principle, leaving it out may
587 substantially increase computational overhead related to the
588 initialization of some server systems.
589
1da177e4 590endif # ACPI
87e65d05
JK
591
592config X86_PM_TIMER
593 bool "Power Management Timer Support" if EXPERT
594 depends on X86 && (ACPI || JAILHOUSE_GUEST)
595 default y
596 help
597 The Power Management Timer is available on all ACPI-capable,
598 in most cases even if ACPI is unusable or blacklisted.
599
600 This timing source is not affected by power management features
601 like aggressive processor idling, throttling, frequency and/or
602 voltage scaling, unlike the commonly used Time Stamp Counter
603 (TSC) timing source.
604
605 You should nearly always say Y here because many modern
606 systems require this timer.