Currently, the USB hub core waits for 50 ms after enumerating the
device. This was added to help "some high speed devices" to
enumerate (b789696a "[PATCH] USB: relax usbcore reset timings").

On some devices, the time-to-active is important, so we provide
a per-port option to reduce the time to what the USB specification
requires: 10 ms.
Signed-off-by: NNicolas Boichat <drinkcat@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The "old" enumeration scheme is considerably faster (it takes
~244ms instead of ~356ms to get the descriptor).

It is currently only possible to use the old scheme globally
(/sys/module/usbcore/parameters/old_scheme_first), which is not
desirable as the new scheme was introduced to increase compatibility
with more devices.

However, in our case, we care about time-to-active for a specific
USB device (which we make the firmware for), on a specific port
(that is pogo-pin based: not a standard USB port). This new
sysfs option makes it possible to use the old scheme on a single
port only.
Signed-off-by: NNicolas Boichat <drinkcat@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Failure to synchronize the tunneled operations does not prevent
the initialization of the cxl card. This patch reports the tunneled
operations status via /sys.
Signed-off-by: NPhilippe Bergheaud <felix@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

In 4.9 kernel, the sysfs files for Hyper-V VMBus changed name but
the documentation files were not updated. The current sysfs file
names are /sys/bus/vmbus/devices/<UUID>/...

See commit 9a56e5d6a0ba ("Drivers: hv: make VMBus bus ids persistent")
and commit f6b2db08 ("vmbus: make sysfs names consistent with PCI")
Reported-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the sysfs file for the new vulerability. It does not do much except
show the words 'Vulnerable' for recent x86 cores.

Intel cores prior to family 6 are known not to be vulnerable, and so are
some Atoms and some Xeon Phi.

It assumes that older Cyrix, Centaur, etc. cores are immune.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>

Several documents in Documentation/vm fit quite well into the "admin/user
guide" category. The documents that don't overload the reader with lots of
implementation details and provide coherent description of certain feature
can be moved to Documentation/admin-guide/mm.
Signed-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

This commit adds the 'usb_type' property to represent USB supplies
which can report a number of different types based on a connection
event.

Examples of this already exist in drivers whereby the existing 'type'
property is updated, based on an event, to represent what was
connected (e.g. USB, USB_DCP, USB_ACA, ...). Current implementations
however don't show all supported connectable types, so this knowledge
has to be exlicitly known for each driver that supports this.

The 'usb_type' property is intended to fill this void and show users
all possible USB types supported by a driver. The property, when read,
shows all available types for the driver, and the one currently chosen
is highlighted/bracketed. It is expected that the 'type' property
would then just show the top-level type 'USB', and this would be
static.

Currently the 'usb_type' enum contains all of the USB variant types
that exist for the 'type' enum at this time, and in addition has
SDP and PPS types. The mirroring is intentional so as to not impact
existing usage of the 'type' property.
Signed-off-by: NAdam Thomson <Adam.Thomson.Opensource@diasemi.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit adds generic ABI information regarding power_supply
properties. This is an initial attempt to try and align the usage
of these properties between drivers. As part of this commit,
common Battery and USB related properties have been listed.
Signed-off-by: NAdam Thomson <Adam.Thomson.Opensource@diasemi.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

rx_lanes and tx_lanes sysfs entries show the number of lanes in use by a
device.
USB 3.2 adds support for Dual-lane (symmetrical), using 2 rx lanes and
2 tx lanes for normal non Inter-Chip SSIC devices.
USB 3.1 and older are all single lane.

SSIC devices can have up to 4 lanes per direction in use,
with different number of rx and tx lanes.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Currently the only way to specify a hibernate offset for a
swap file is on the kernel command line.

Add a new /sys/power/resume_offset that lets userspace
specify the offset and disk to use when initiating a hibernate
cycle.
Signed-off-by: NMario Limonciello <mario.limonciello@dell.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add a new attribute group called "s2idle" under the sysfs directory
of each cpuidle state that supports the ->enter_s2idle callback
and put two new attributes, "usage" and "time", into that group to
represent the number of times the given state was requested for
suspend-to-idle and the total time spent in suspend-to-idle after
requesting that state, respectively.

That will allow diagnostic information related to suspend-to-idle
to be collected without enabling advanced debug features and
analyzing dmesg output.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The existing BPRM_CHECK functionality in IMA validates against the
credentials of the existing process, not any new credentials that the
child process may transition to. Add an additional CREDS_CHECK target
and refactor IMA to pass the appropriate creds structure. In
ima_bprm_check(), check with both the existing process credentials and
the credentials that will be committed when the new process is started.
This will not change behaviour unless the system policy is extended to
include CREDS_CHECK targets - BPRM_CHECK will continue to check the same
credentials that it did previously.

After this patch, an IMA policy rule along the lines of:

measure func=CREDS_CHECK subj_type=unconfined_t

will trigger if a process is executed and runs as unconfined_t, ignoring
the context of the parent process. This is in contrast to:

measure func=BPRM_CHECK subj_type=unconfined_t

which will trigger if the process that calls exec() is already executing
in unconfined_t, ignoring the context that the child process executes
into.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Changelog:
- initialize ima_creds_status

Document the core of the debugfs CEC error injection ABI.

The driver specific commands are documented elsewhere and
this file points to that documentation.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

USB role switch is a device that can be used to choose the
data role for USB connector. With dual-role capable USB
controllers, the controller itself will be the switch, but
on some platforms the USB host and device controllers are
separate IPs and there is a mux between them and the
connector. On those platforms the mux driver will need to
register the switch.

With USB Type-C connectors, the host-to-device relationship
is negotiated over the Configuration Channel (CC). That
means the USB Type-C drivers need to be in control of the
role switch. The class provides a simple API for the USB
Type-C drivers for the control.

For other types of USB connectors (mainly microAB) the class
provides user space control via sysfs attribute file that
can be used to request role swapping from the switch.
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For some userspace applications information on the number of
over-current conditions at specific USB hub ports is relevant.

In our case we have a series of USB hardware (using the cp210x driver)
which communicates using a proprietary protocol. These devices sometimes
trigger an over-current situation on some hubs. In case of such an
over-current situation the USB devices offer an interface for reducing
the max used power. As these conditions are quite rare and imply
performance reductions of the device we don't want to reduce the max
power always.

Therefore give user-space applications the possibility to react
adequately by introducing an over_current_counter in the usb port struct
which is exported via sysfs.
Signed-off-by: NRichard Leitner <richard.leitner@skidata.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

UFS host controllers may support an autonomous power management feature
called the Auto-Hibernate Idle Timer. The timer is set to the number of
microseconds of idle time before the UFS host controller will autonomously
put the link into Hibernate state. That will save power at the expense of
increased latency. Any access to the host controller interface registers
will automatically put the link out of Hibernate state. So once configured,
the feature is transparent to the driver.

Expose the Auto-Hibernate Idle Timer value via SysFS to allow users to
choose between power efficiency or lower latency. Set a default value of
150 ms.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NStanislav Nijnikov <stanislav.nijnikov@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Read from these files will return the integer value of the chosen power
management level now. Separate entries were added to show the target UFS
device and UIC link states. The description of the possible power
managements levels was added to the ABI file. The on-write behaviour of
these entries wasn't changed.

[mkp: typo]
Signed-off-by: NStanislav Nijnikov <stanislav.nijnikov@wdc.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Descriptions have been collected from git commit logs, code commits and
the TrackPoint System Version 4.0 Engineering Specification.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Descriptions have collected from code comments and by reading through
code.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

This is an attempt to document the nfit sysfs interface. The
descriptions have been collected from git commit logs and the ACPI
specification 6.2.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

The existing sysfs interface has been updated to be in the same format
as described in Documentation/ABI/README. This will be useful for
scripting and tracking changes in the ABI. Attributes have been grouped
by functionality and/or the date on which they were added.

There are a couple of more changes:
- The attributes have been annotated with file permissions RO/RW/WO.
- Added description of the bus attribute supported_features
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Introduce a driver for the ACPI Time and Alarm Device (TAD) based on
Section 9.18 of ACPI 6.2.

This driver only supports the system wakeup capabilities of the TAD
which are mandatory.  Support for the RTC capabilities of the TAD
will be added to it in the future.

This driver is entirely sysfs-based.  It provides attributes (under
the TAD platform device) to allow user space to manage the AC and DC
wakeup timers of the TAD: set and read their values, set and check
their expire timer wake policies, check and clear their status and
check the capabilities of the TAD reported by AML.  The DC timer
attributes are only present if the TAD supports a separate DC alarm
timer.

The wakeup events handling and power management of the TAD is
expected to be taken care of by the ACPI PM domain attached to its
platform device.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Add a way for drivers to inform the core of the supported date/time range.
The core can then check whether the date/time or alarm is in the range
before calling ->set_time, ->set_mmss or ->set_alarm. It returns -ERANGE
when the time is out of range.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>

Limit the number of queued writes per client.
Writes above this threshold are blocked till place
in the transmit queue is available.
The limit is configurable via sysfs and defaults to 50.
The implementation should provide blocking I/O behavior.
Prior to this change one would end up in the hands of OOM.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This change introduces an 'external mode' for GPIO-based FSI masters,
allowing the clock and data lines to be driven by an external source.
For example, external mode is selected by a user when an external debug
device is attached to the FSI pins.

To do this, we need to set specific states for the trans, mux and enable
GPIOs, and prevent access to clk & data from the FSI core code (by
returning EBUSY).

External mode is controlled by a sysfs attribute, so add the relevant
information to Documentation/ABI/
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch supports to recognize hot file extension in f2fs, so that we
can allocate proper hot segment location for its data, which can lead to
better hot/cold seperation in filesystem.

In addition, we changes a bit on query/add/del operation method for
extension_list sysfs entry as below:

- Query: cat /sys/fs/f2fs/<disk>/extension_list
- Add: echo 'extension' > /sys/fs/f2fs/<disk>/extension_list
- Del: echo '!extension' > /sys/fs/f2fs/<disk>/extension_list
- Add: echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list
- Del: echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_list
- [h] means add/del hot file extension
- [c] means add/del cold file extension
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds a sysfs entry 'extension_list' to support
query/add/del item in extension list.

Query:
cat /sys/fs/f2fs/<device>/extension_list

Add:
echo 'extension' > /sys/fs/f2fs/<device>/extension_list

Del:
echo '!extension' > /sys/fs/f2fs/<device>/extension_list
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This new security level works so that it creates one PCIe tunnel to the
connected Thunderbolt dock, removing PCIe links downstream of the dock.
This leaves only the internal USB controller visible.

Display Port tunnels are created normally.

While there make sure security sysfs attribute returns "unknown" for any
future security level.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>

Preboot ACL is a mechanism that allows connecting Thunderbolt devices
boot time in more secure way than the legacy Thunderbolt boot support.
As with the legacy boot option, this also needs to be enabled from the
BIOS before booting is allowed. Difference to the legacy mode is that
the userspace software explicitly adds device UUIDs by sending a special
message to the ICM firmware. Only the devices listed in the boot ACL are
connected automatically during the boot. This works in both "user" and
"secure" security levels.

We implement this in Linux by exposing a new sysfs attribute (boot_acl)
below each Thunderbolt domain. The userspace software can then update
the full list as needed.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>

In various cases, Thunderbolt device can be connected by ICM on boot
without waiting for approval from user. Most cases are related to
OEM-specific BIOS configurations. This information is interesting for
user-space as if the device isn't in SW ACL, it may create a friction in
the user experience where the device is automatically authorized if it's
connected on boot but requires an explicit user action if connected
after OS is up. User-space can use this information to suggest adding
the device to SW ACL for auto-authorization on later connections.
Signed-off-by: NYehezkel Bernat <yehezkel.bernat@intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>

Add sysfs documentation for N-Trig touchscreens under Documentation/ABI.
Descriptions have been collected from code comments.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Use sysfs to allow supporting sub-channels. The userspace application
makes request to host to create sub-channels and the UIO kernel
driver populates the sysfs per-channel directory with a binary
attribute file that can be used to read/write ring.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Descriptions have been collected from git commit logs.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Switch the parent of the nvmem device to the parent of the rtc device so it
can be registered before the RTC.

This is a small change in the ABI as the nvmem moves out of the
/sys/class/rtc/rtcX folder to be under the parent device folder (that is
where the previous nvram files where registered).

However, it is still available under its correct location,
/sys/bus/nvmem/devices which is the one that should be used by userspace
applications.

The other benefit is that the nvmem device can stay registered even if the
rtc registration fails. Or it is possible to not register the rtc if the
nvmem registration failed.

Finally, it makes a lot of sense for devices that actually have different
i2c or spi addresses for the RTC and the EEPROM. That is basically how it
would end up when using MFD or even completely separate devices.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>

Surprisingly there is no simple way to see if the IRQ line in question
is wakeup source or not.

Note that wakeup might be an OOB (out-of-band) source like GPIO line
which makes things slightly more complicated.

Add a sysfs node to cover this case.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NTony Lindgren <tony@atomide.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20180226155043.67937-1-andriy.shevchenko@linux.intel.com

This is an attempt to document the sysfs interface for the IPMI drivers.
Descriptions were collected from v2.0 of the IPMI specification and from
code comments.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Signed-off-by: NCorey Minyard <cminyard@mvista.com>

Right now, the description of the rapidio sysfs interfaces is in
Documentation/rapidio/sysfs.txt. Since these are a part of the ABI, they
should be in Documentation/ABI along with the rest.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Acked-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Add documentation for sysfs interface of adp8860 series backlight
devices by reading through code and git commits.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Acked-by: NMichael Hennerich <michael.hennerich@analog.com>
Acked-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Add documentation for sysfs interface of adp5520/adp5501 analog devices
backlight driver by reading code and looking through git commit logs.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Acked-by: NMichael Hennerich <michael.hennerich@analog.com>
Acked-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>