Thomas Renninger e2f74f355e [ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interface ... This interface is mainly intended (and implemented) for ACPI _PPC BIOS frequency limitations, but other cpufreq drivers can also use it for similar use-cases. Why is this needed: Currently it's not obvious why cpufreq got limited. People see cpufreq/scaling_max_freq reduced, but this could have happened by: - any userspace prog writing to scaling_max_freq - thermal limitations - hardware (_PPC in ACPI case) limitiations Therefore export bios_limit (in kHz) to: - Point the user that it's the BIOS (broken or intended) which limits frequency - Export it as a sysfs interface for userspace progs. While this was a rarely used feature on laptops, there will appear more and more server implemenations providing "Green IT" features like allowing the service processor to limit the frequency. People want to know about HW/BIOS frequency limitations. All ACPI P-state driven cpufreq drivers are covered with this patch: - powernow-k8 - powernow-k7 - acpi-cpufreq Tested with a patched DSDT which limits the first two cores (_PPC returns 1) via _PPC, exposed by bios_limit: # echo 2200000 >cpu2/cpufreq/scaling_max_freq # cat cpu*/cpufreq/scaling_max_freq 2600000 2600000 2200000 2200000 # #scaling_max_freq shows general user/thermal/BIOS limitations # cat cpu*/cpufreq/bios_limit 2600000 2600000 2800000 2800000 # #bios_limit only shows the HW/BIOS limitation CC: Pallipadi Venkatesh <venkatesh.pallipadi@intel.com> CC: Len Brown <lenb@kernel.org> CC: davej@codemonkey.org.uk CC: linux@dominikbrodowski.net Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>		2009-11-24 13:33:34 -05:00
..
ABI	[CPUFREQ] Documentation: ABI: /sys/devices/system/cpu/cpu#/cpufreq/	2009-11-24 13:33:33 -05:00
accounting	Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGS	2009-09-23 07:39:28 -07:00
acpi
aoe
arm	ARM: 5738/1: Correct TCM documentation	2009-10-01 16:26:16 +01:00
auxdisplay	includecheck fix: Documentation, cfag12864b-example.c	2009-09-24 07:20:57 -07:00
blackfin
block	Trivial typo fixes in Documentation/block/data-integrity.txt.	2009-07-01 10:56:25 +02:00
blockdev
cdrom
cgroups	cgroups: update documentation of cgroups tasks and procs files	2009-10-08 07:36:39 -07:00
connector	connector: Provide the sender's credentials to the callback	2009-10-02 10:54:01 -07:00
console
cpu-freq	[ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interface	2009-11-24 13:33:34 -05:00
cpuidle
cris
crypto	async_tx: add support for asynchronous RAID6 recovery operations	2009-08-29 19:09:27 -07:00
development-process
device-mapper
DocBook	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2009-09-22 07:51:45 -07:00
driver-model	driver model: fix show/store prototypes in doc.	2009-07-12 13:02:10 -07:00
dvb	V4L/DVB (12902): Documentation: synchronize documentation for Technisat cards	2009-09-19 00:14:32 -03:00
early-userspace
fault-injection
fb	matroxfb: make CONFIG_FB_MATROX_MULTIHEAD=y mandatory	2009-09-23 07:39:56 -07:00
filesystems	Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2	2009-11-19 20:29:05 -08:00
firmware_class
frv
hwmon	hwmon: enhance the sysfs API for power meters	2009-10-29 07:39:30 -07:00
i2c	i2c-piix4: Modify code name SB900 to Hudson-2	2009-11-07 13:10:46 +01:00
i2o
ia64	Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGS	2009-09-23 07:39:28 -07:00
ide
infiniband	IB: Fix typo in udev rule documentation	2009-10-07 15:35:55 -07:00
input	Input: add new driver for Sentelic Finger Sensing Pad	2009-08-19 21:46:09 -07:00
ioctl	drivers/char/uv_mmtimer.c: add memory mapped RTC driver for UV	2009-09-24 07:21:03 -07:00
isdn	Documentation: expand isdn/INTERFACE.CAPI document	2009-10-06 22:20:51 -07:00
ja_JP
kbuild	kbuild: introduce ld-option	2009-09-20 12:27:42 +02:00
kdump
ko_KR
kvm	KVM: Document KVM_CAP_IRQCHIP	2009-09-10 10:46:55 +03:00
laptops	Merge branch 'thinkpad-2.6.32-part2' into release	2009-09-26 01:08:55 -04:00
lguest	virtio: let header files include virtio_ids.h	2009-10-22 16:39:28 +10:30
m68k
make
mips
misc-devices	max6875: Discard obsolete detect method	2009-10-04 22:53:41 +02:00
mn10300
mtd
namespaces
netlabel
networking	pktgen: Fix multiqueue handling	2009-10-04 21:08:54 -07:00
parisc
PCI	PCI: document PCIe fundamental reset interfaces	2009-09-09 13:29:38 -07:00
pcmcia	Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGS	2009-09-23 07:39:28 -07:00
power	Merge git://git.infradead.org/battery-2.6	2009-09-23 10:11:08 -07:00
powerpc	Merge git://git.infradead.org/mtd-2.6	2009-09-23 10:07:49 -07:00
pps
prctl
RCU	rcu: Remove CONFIG_PREEMPT_RCU	2009-08-23 10:32:40 +02:00
s390	[S390] s390dbf: Add description for usage of "%s" in sprintf events	2009-09-11 10:29:53 +02:00
scheduler
scsi	[SCSI] hptiop: Add RR44xx adapter support	2009-10-02 09:45:22 -05:00
serial
sh
sound	ALSA: dummy - Fix descriptions of pcm_substreams parameter	2009-11-02 14:11:55 +01:00
sparc
spi	spi: fix spelling of `automatically' in documentation	2009-09-23 07:39:44 -07:00
sysctl	Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6	2009-09-24 07:53:22 -07:00
telephony
thermal	thermal: sysfs-api.txt - document passive attribute for thermal zones	2009-11-05 18:11:18 -05:00
timers
trace	tracing: Fix comment typo and documentation example	2009-10-24 11:07:50 +02:00
uml
usb	USB: Fix sysfs paths in documentation	2009-09-23 06:46:41 -07:00
video4linux	Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGS	2009-09-23 07:39:28 -07:00
vm	Merge branch 'hostprogs-wmissing-prototypes' of git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux-misc	2009-11-17 09:14:49 -08:00
w1	ds2482: Discard obsolete detect method	2009-10-04 22:53:41 +02:00
watchdog	Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGS	2009-09-23 07:39:28 -07:00
wimax
x86	USB: ehci-dbgp,documentation: Documentation updates for ehci-dbgp	2009-09-23 06:46:39 -07:00
zh_CN
00-INDEX	Bluetooth: Add documentation for Marvell Bluetooth driver	2009-08-22 14:25:32 -07:00
applying-patches.txt
atomic_ops.txt
bad_memory.txt
basic_profiling.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt	Bluetooth: Add documentation for Marvell Bluetooth driver	2009-08-22 14:25:32 -07:00
BUG-HUNTING
c2port.txt
cachetlb.txt
Changes
CodingStyle
cpu-hotplug.txt
cpu-load.txt
cputopology.txt	Documentation: ABI: /sys/devices/system/cpu/cpu#/ topology files	2009-10-30 14:59:52 -07:00
credentials.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt	ieee1394: update URLs in debugging-via-ohci1394.txt	2009-10-03 09:28:11 +02:00
dell_rbu.txt
devices.txt
DMA-API.txt
DMA-attributes.txt
DMA-ISA-LPC.txt
DMA-mapping.txt
dmaengine.txt
dontdiff	sparc: Kill PROM console driver.	2009-09-15 17:04:38 -07:00
dynamic-debug-howto.txt
edac.txt
eisa.txt
email-clients.txt
feature-removal-schedule.txt	inotify: deprecate the inotify kernel interface	2009-10-18 15:49:38 -04:00
flexible-arrays.txt	Update flex_arrays.txt	2009-10-15 07:25:20 -06:00
futex-requeue-pi.txt
gcov.txt	trivial: fix typo in CONFIG_DEBUG_FS in gcov doc	2009-09-21 15:14:56 +02:00
gpio.txt	gpiolib: allow poll() on value	2009-09-23 07:39:48 -07:00
highuid.txt
HOWTO
hw_random.txt
ics932s401
initrd.txt
Intel-IOMMU.txt	intel-iommu: Kill DMAR_BROKEN_GFX_WA option.	2009-09-19 09:37:23 -07:00
intel_txt.txt	x86, intel_txt: Intel TXT boot support	2009-07-21 11:49:06 -07:00
io-mapping.txt
IO-mapping.txt
io_ordering.txt
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt	kernel-doc: allow multi-line declaration purpose descriptions	2009-09-18 09:48:52 -07:00
kernel-docs.txt
kernel-parameters.txt	x86: earlyprintk: Fix regression to handle serial,ttySn as 1 arg	2009-10-01 10:34:16 +02:00
keys-request-key.txt
keys.txt	KEYS: Add a keyctl to install a process's session keyring on its parent [try #6]	2009-09-02 21:29:22 +10:00
kmemcheck.txt	kmemcheck: update documentation	2009-07-01 22:36:22 +02:00
kmemleak.txt	kmemleak: add clear command support	2009-09-08 16:36:08 +01:00
kobject.txt
kprobes.txt
kref.txt	kref: double kref_put() in my_data_handler()	2009-09-18 09:48:52 -07:00
ldm.txt
leds-class.txt	led: document sysfs interface	2009-08-28 15:21:12 -04:00
leds-lp3944.txt
local_ops.txt
lockdep-design.txt	lockdep: Fix typos in documentation	2009-08-07 12:03:46 +02:00
lockstat.txt
logo.gif
logo.txt
magic-number.txt
Makefile
ManagementStyle
mca.txt
md.txt
memory-barriers.txt
memory-hotplug.txt
memory.txt	Documentation/memory.txt: remove some very outdated recommendations	2009-09-22 07:17:26 -07:00
mono.txt
mutex-design.txt
nmi_watchdog.txt
nommu-mmap.txt
numastat.txt	mm: fix NUMA accounting in numastat.txt	2009-09-22 07:17:39 -07:00
oops-tracing.txt
parport-lowlevel.txt
parport.txt
pi-futex.txt
pnp.txt
preempt-locking.txt
printk-formats.txt
prio_tree.txt
rbtree.txt
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rt-mutex-design.txt
rt-mutex.txt
rtc.txt	rtc: add boot_timesource sysfs attribute	2009-09-23 07:39:46 -07:00
SAK.txt
SecurityBugs
SELinux.txt
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
slow-work.txt
SM501.txt
Smack.txt
sparse.txt
spinlocks.txt
stable_api_nonsense.txt
stable_kernel_rules.txt
SubmitChecklist
SubmittingDrivers
SubmittingPatches	docs: update patch size in SubmittingPatches	2009-10-01 16:11:12 -07:00
svga.txt
sysfs-rules.txt
sysrq.txt	sysrq, kdump: make sysrq-c consistent	2009-07-29 19:10:36 -07:00
tomoyo.txt
unaligned-memory-access.txt
unicode.txt
unshare.txt
VGA-softcursor.txt
vgaarbiter.txt	PCI/VGA: add VGA arbitration documentation	2009-09-09 13:29:42 -07:00
video-output.txt
volatile-considered-harmful.txt
voyager.txt
zorro.txt