linux_dsm_epyc7002/Documentation
Rafael J. Wysocki 2d984ad132 PM / QoS: Introcuce latency tolerance device PM QoS type
Add a new latency tolerance device PM QoS type to be use for
specifying active state (RPM_ACTIVE) memory access (DMA) latency
tolerance requirements for devices.  It may be used to prevent
hardware from choosing overly aggressive energy-saving operation
modes (causing too much latency to appear) for the whole platform.

This feature reqiures hardware support, so it only will be
available for devices having a new .set_latency_tolerance()
callback in struct dev_pm_info populated, in which case the
routine pointed to by it should implement whatever is necessary
to transfer the effective requirement value to the hardware.

Whenever the effective latency tolerance changes for the device,
its .set_latency_tolerance() callback will be executed and the
effective value will be passed to it.  If that value is negative,
which means that the list of latency tolerance requirements for
the device is empty, the callback is expected to switch the
underlying hardware latency tolerance control mechanism to an
autonomous mode if available.  If that value is PM_QOS_LATENCY_ANY,
in turn, and the hardware supports a special "no requirement"
setting, the callback is expected to use it.  That allows software
to prevent the hardware from automatically updating the device's
latency tolerance in response to its power state changes (e.g. during
transitions from D3cold to D0), which generally may be done in the
autonomous latency tolerance control mode.

If .set_latency_tolerance() is present for the device, a new
pm_qos_latency_tolerance_us attribute will be present in the
devivce's power directory in sysfs.  Then, user space can use
that attribute to specify its latency tolerance requirement for
the device, if any.  Writing "any" to it means "no requirement, but
do not let the hardware control latency tolerance" and writing
"auto" to it allows the hardware to be switched to the autonomous
mode if there are no other requirements from the kernel side in the
device's list.

This changeset includes a fix from Mika Westerberg.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 00:35:38 +01:00
..
ABI PM / QoS: Introcuce latency tolerance device PM QoS type 2014-02-11 00:35:38 +01:00
accounting
acpi ACPI and power management updates for 3.14-rc1 2014-01-24 15:51:02 -08:00
aoe
arm ARM: SoC platform changes for 3.14 2014-01-23 18:40:49 -08:00
arm64
auxdisplay
backlight
blackfin
block
blockdev zram: remove old private project comment 2014-01-30 16:56:55 -08:00
bus-devices
cdrom
cgroups Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2014-01-31 09:31:14 -08:00
connector
console
cpu-freq Documentation: cpufreq / boost: Update BOOST documentation 2014-01-17 02:00:45 +01:00
cpuidle
cris
crypto
development-process
device-mapper dm cache: add policy name to status output 2014-01-16 13:44:11 -05:00
devicetree Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-02-05 16:02:53 -08:00
DocBook Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2014-01-31 09:31:14 -08:00
driver-model Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-01-22 21:21:55 -08:00
dvb [media] update Michael Krufky's email address 2014-02-04 06:34:21 -02:00
early-userspace
EDID
extcon extcon: fix switch class porting guide (Documentation) 2014-01-07 11:54:28 +09:00
fault-injection
fb
filesystems Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-01-30 20:08:20 -08:00
firmware_class
fmc
frv
gpio
hid
hwmon Update Jean Delvare's e-mail address 2014-01-29 20:40:08 +01:00
i2c Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2014-01-29 19:56:20 -08:00
i2o
ia64
ide
infiniband
input
ioctl s390/hypfs: add interface for diagnose 0x304 2014-01-24 09:40:59 +01:00
isdn
ja_JP
kbuild
kdump
ko_KR Documentation: HOWTO: Updates on subsystem trees, patchwork, -next (vs. -mm) in ko_KR 2014-01-08 15:32:51 -08:00
laptops
leds leds: lp5523: Support LED MUX configuration on running a pattern 2014-01-27 17:28:48 -08:00
m68k
make
memory-devices
metag
mic
mips
misc-devices Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging 2014-01-29 18:56:27 -08:00
mmc
mn10300
mtd
namespaces
netlabel
networking net: Document promote_secondaries 2014-01-27 20:39:21 -08:00
nfc
parisc
PCI Merge branch 'pci/msi' into next 2014-01-07 17:34:39 -07:00
pcmcia
power PM / QoS: Introcuce latency tolerance device PM QoS type 2014-02-11 00:35:38 +01:00
powerpc
pps
prctl
pti
ptp
rapidio
RCU
s390 qeth: bridgeport support - address notifications 2014-01-15 14:48:01 -08:00
scheduler sched/deadline: Add sched_dl documentation 2014-01-28 13:08:40 +01:00
scsi Main batch of InfiniBand/RDMA changes for 3.14: 2014-01-24 17:18:32 -08:00
security
serial
sh
sound ASoC: docs: Update the Overview document 2014-01-07 17:56:32 +00:00
spi
sysctl Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-01-31 08:59:46 -08:00
target
thermal
timers
tpm
trace PM / QoS: Rename device resume latency QoS items 2014-02-11 00:35:23 +01:00
usb doc: Fix typo in USB Gadget Documentation 2014-01-10 15:33:54 +01:00
vDSO
video4linux
virtual Merge branch 'kvm-ppc-next' of git://github.com/agraf/linux-2.6 into kvm-queue 2014-01-29 18:29:01 +01:00
vm mm: documentation: remove hopelessly out-of-date locking doc 2014-01-23 16:36:50 -08:00
w1
watchdog
wimax
x86 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-01-22 21:21:55 -08:00
xtensa xtensa: remap io area defined in device tree 2014-01-15 00:25:14 +04:00
zh_CN
.gitignore
00-INDEX
applying-patches.txt
assoc_array.txt
atomic_ops.txt
bad_memory.txt
basic_profiling.txt
bcache.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt
Changes
circular-buffers.txt
clk.txt clk: Add set_rate_and_parent() op 2014-01-16 12:00:57 -08:00
coccinelle.txt
CodingStyle
cpu-hotplug.txt Documentation/cpu-hotplug.txt: fix a typo in example code 2014-01-23 16:37:01 -08:00
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt firewire: Enable remote DMA above 4 GB 2014-01-20 01:11:13 +01:00
dell_rbu.txt
devices.txt
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt
DMA-attributes.txt
dma-buf-sharing.txt
DMA-ISA-LPC.txt
dmaengine.txt
dmatest.txt
dontdiff
dynamic-debug-howto.txt dynamic-debug-howto.txt: update since new wildcard support 2014-01-23 16:36:55 -08:00
edac.txt
efi-stub.txt
eisa.txt
email-clients.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcov.txt
highuid.txt
HOWTO
hw_random.txt
hwspinlock.txt
init.txt
initrd.txt
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt
kernel-docs.txt
kernel-parameters.txt Documentation/kernel-parameters.txt: fix memmap= language 2014-02-06 13:48:51 -08:00
kernel-per-CPU-kthreads.txt
kmemcheck.txt
kmemleak.txt
kobject.txt
kprobes.txt
kref.txt
ldm.txt
local_ops.txt
lockdep-design.txt
lockstat.txt
lockup-watchdogs.txt
logo.gif
logo.txt
magic-number.txt
Makefile
ManagementStyle
md.txt
media-framework.txt
memory-barriers.txt locking/doc: Rename LOCK/UNLOCK to ACQUIRE/RELEASE 2014-01-12 10:37:13 +01:00
memory-hotplug.txt
module-signing.txt
mono.txt
mutex-design.txt
nommu-mmap.txt
numastat.txt
oops-tracing.txt
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt
pinctrl.txt pinctrl: Fix some typos and grammar issues in the documentation 2014-01-15 13:59:50 +01:00
pnp.txt
preempt-locking.txt
printk-formats.txt vsprintf: add %pad extension for dma_addr_t use 2014-01-23 16:36:56 -08:00
pwm.txt
ramoops.txt
rbtree.txt
remoteproc.txt
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rt-mutex-design.txt
rt-mutex.txt
rtc.txt
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
SM501.txt
smsc_ece1099.txt
sparse.txt
spinlocks.txt
stable_api_nonsense.txt
stable_kernel_rules.txt
static-keys.txt
SubmitChecklist
SubmittingDrivers
SubmittingPatches
svga.txt
sysfs-rules.txt
sysrq.txt
this_cpu_ops.txt
unaligned-memory-access.txt
unicode.txt
unshare.txt
vfio.txt
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
vme_api.txt
volatile-considered-harmful.txt
workqueue.txt
ww-mutex-design.txt
xz.txt
zorro.txt