Merge tag 'v5.6-rc3' into sched/core, to pick up fixes and dependent patches

Signed-off-by: Ingo Molnar <mingo@kernel.org>

.mailmap

@@ -18,6 +18,7 @@ Aleksey Gorelov <aleksey_gorelov@phoenix.com>
 Aleksandar Markovic <aleksandar.markovic@mips.com> <aleksandar.markovic@imgtec.com>
 Alex Shi <alex.shi@linux.alibaba.com> <alex.shi@intel.com>
 Alex Shi <alex.shi@linux.alibaba.com> <alex.shi@linaro.org>
+Alexandre Belloni <alexandre.belloni@bootlin.com> <alexandre.belloni@free-electrons.com>
 Alexei Starovoitov <ast@kernel.org> <ast@plumgrid.com>
 Alexei Starovoitov <ast@kernel.org> <alexei.starovoitov@gmail.com>
 Alexei Starovoitov <ast@kernel.org> <ast@fb.com>
@@ -27,6 +28,8 @@ Andi Shyti <andi@etezian.org> <andi.shyti@samsung.com>
 Andreas Herrmann <aherrman@de.ibm.com>
 Andrey Ryabinin <ryabinin.a.a@gmail.com> <a.ryabinin@samsung.com>
 Andrew Morton <akpm@linux-foundation.org>
+Andrew Murray <amurray@thegoodpenguin.co.uk> <andrew.murray@arm.com>
+Andrew Murray <amurray@thegoodpenguin.co.uk> <amurray@embedded-bits.co.uk>
 Andrew Vasquez <andrew.vasquez@qlogic.com>
 Andy Adamson <andros@citi.umich.edu>
 Antoine Tenart <antoine.tenart@free-electrons.com>
@@ -74,6 +77,7 @@ Dmitry Safonov <0x7f454c46@gmail.com> <dima@arista.com>
 Domen Puncer <domen@coderock.org>
 Douglas Gilbert <dougg@torque.net>
 Ed L. Cashin <ecashin@coraid.com>
+Erik Kaneda <erik.kaneda@intel.com> <erik.schmauss@intel.com>
 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
 Felipe W Damasio <felipewd@terra.com.br>
 Felix Kuhling <fxkuehl@gmx.de>
@@ -99,6 +103,7 @@ Jacob Shin <Jacob.Shin@amd.com>
 Jaegeuk Kim <jaegeuk@kernel.org> <jaegeuk@google.com>
 Jaegeuk Kim <jaegeuk@kernel.org> <jaegeuk@motorola.com>
 Jaegeuk Kim <jaegeuk@kernel.org> <jaegeuk.kim@samsung.com>
+Jakub Kicinski <kuba@kernel.org> <jakub.kicinski@netronome.com>
 James Bottomley <jejb@mulgrave.(none)>
 James Bottomley <jejb@titanic.il.steeleye.com>
 James E Wilson <wilson@specifix.com>
@@ -137,6 +142,7 @@ Juha Yrjola <at solidboot.com>
 Juha Yrjola <juha.yrjola@nokia.com>
 Juha Yrjola <juha.yrjola@solidboot.com>
 Julien Thierry <julien.thierry.kdev@gmail.com> <julien.thierry@arm.com>
+Kamil Konieczny <k.konieczny@samsung.com> <k.konieczny@partner.samsung.com>
 Kay Sievers <kay.sievers@vrfy.org>
 Kenneth W Chen <kenneth.w.chen@intel.com>
 Konstantin Khlebnikov <koct9i@gmail.com> <k.khlebnikov@samsung.com>
@@ -208,6 +214,10 @@ Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
 Patrick Mochel <mochel@digitalimplant.org>
 Paul Burton <paulburton@kernel.org> <paul.burton@imgtec.com>
 Paul Burton <paulburton@kernel.org> <paul.burton@mips.com>
+Paul E. McKenney <paulmck@kernel.org> <paulmck@linux.ibm.com>
+Paul E. McKenney <paulmck@kernel.org> <paulmck@linux.vnet.ibm.com>
+Paul E. McKenney <paulmck@kernel.org> <paul.mckenney@linaro.org>
+Paul E. McKenney <paulmck@kernel.org> <paulmck@us.ibm.com>
 Peter A Jonsson <pj@ludd.ltu.se>
 Peter Oruba <peter@oruba.de>
 Peter Oruba <peter.oruba@amd.com>
@@ -216,6 +226,7 @@ Praveen BP <praveenbp@ti.com>
 Punit Agrawal <punitagrawal@gmail.com> <punit.agrawal@arm.com>
 Qais Yousef <qsyousef@gmail.com> <qais.yousef@imgtec.com>
 Quentin Perret <qperret@qperret.net> <quentin.perret@arm.com>
+Rafael J. Wysocki <rjw@rjwysocki.net> <rjw@sisk.pl>
 Rajesh Shah <rajesh.shah@intel.com>
 Ralf Baechle <ralf@linux-mips.org>
 Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
@@ -251,6 +262,7 @@ Sumit Semwal <sumit.semwal@ti.com>
 Tejun Heo <htejun@gmail.com>
 Thomas Graf <tgraf@suug.ch>
 Thomas Pedersen <twp@codeaurora.org>
+Tiezhu Yang <yangtiezhu@loongson.cn> <kernelpatch@126.com>
 Todor Tomov <todor.too@gmail.com> <todor.tomov@linaro.org>
 Tony Luck <tony.luck@intel.com>
 TripleX Chung <xxx.phy@gmail.com> <zhongyu@18mail.cn>

COPYING

@@ -16,3 +16,5 @@ In addition, other licenses may also apply. Please see:
 	Documentation/process/license-rules.rst
 
 for more details.
+
+All contributions to the Linux Kernel are subject to this COPYING file.

CREDITS

@@ -3302,7 +3302,9 @@ S: France
 N: Aleksa Sarai
 E: cyphar@cyphar.com
 W: https://www.cyphar.com/
-D: `pids` cgroup subsystem
+D: /sys/fs/cgroup/pids
+D: openat2(2)
+S: Sydney, Australia
 
 N: Dipankar Sarma
 E: dipankar@in.ibm.com

Documentation/ABI/obsolete/sysfs-selinux-disable

+What:		/sys/fs/selinux/disable
+Date:		April 2005 (predates git)
+KernelVersion:	2.6.12-rc2 (predates git)
+Contact:	selinux@vger.kernel.org
+Description:
+
+	The selinuxfs "disable" node allows SELinux to be disabled at runtime
+	prior to a policy being loaded into the kernel.  If disabled via this
+	mechanism, SELinux will remain disabled until the system is rebooted.
+
+	The preferred method of disabling SELinux is via the "selinux=0" boot
+	parameter, but the selinuxfs "disable" node was created to make it
+	easier for systems with primitive bootloaders that did not allow for
+	easy modification of the kernel command line.  Unfortunately, allowing
+	for SELinux to be disabled at runtime makes it difficult to secure the
+	kernel's LSM hooks using the "__ro_after_init" feature.
+
+	Thankfully, the need for the SELinux runtime disable appears to be
+	gone, the default Kconfig configuration disables this selinuxfs node,
+	and only one of the major distributions, Fedora, supports disabling
+	SELinux at runtime.  Fedora is in the process of removing the
+	selinuxfs "disable" node and once that is complete we will start the
+	slow process of removing this code from the kernel.
+
+	More information on /sys/fs/selinux/disable can be found under the
+	CONFIG_SECURITY_SELINUX_DISABLE Kconfig option.

Documentation/ABI/stable/sysfs-class-tpm

 What:		/sys/class/tpm/tpmX/device/
 Date:		April 2005
 KernelVersion:	2.6.12
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The device/ directory under a specific TPM instance exposes
 		the properties of that TPM chip
 
@@ -9,7 +9,7 @@ Description:	The device/ directory under a specific TPM instance exposes
 What:		/sys/class/tpm/tpmX/device/active
 Date:		April 2006
 KernelVersion:	2.6.17
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "active" property prints a '1' if the TPM chip is accepting
 		commands. An inactive TPM chip still contains all the state of
 		an active chip (Storage Root Key, NVRAM, etc), and can be
@@ -21,7 +21,7 @@ Description:	The "active" property prints a '1' if the TPM chip is accepting
 What:		/sys/class/tpm/tpmX/device/cancel
 Date:		June 2005
 KernelVersion:	2.6.13
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "cancel" property allows you to cancel the currently
 		pending TPM command. Writing any value to cancel will call the
 		TPM vendor specific cancel operation.
@@ -29,7 +29,7 @@ Description:	The "cancel" property allows you to cancel the currently
 What:		/sys/class/tpm/tpmX/device/caps
 Date:		April 2005
 KernelVersion:	2.6.12
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "caps" property contains TPM manufacturer and version info.
 
 		Example output:
@@ -46,7 +46,7 @@ Description:	The "caps" property contains TPM manufacturer and version info.
 What:		/sys/class/tpm/tpmX/device/durations
 Date:		March 2011
 KernelVersion:	3.1
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "durations" property shows the 3 vendor-specific values
 		used to wait for a short, medium and long TPM command. All
 		TPM commands are categorized as short, medium or long in
@@ -69,7 +69,7 @@ Description:	The "durations" property shows the 3 vendor-specific values
 What:		/sys/class/tpm/tpmX/device/enabled
 Date:		April 2006
 KernelVersion:	2.6.17
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "enabled" property prints a '1' if the TPM chip is enabled,
 		meaning that it should be visible to the OS. This property
 		may be visible but produce a '0' after some operation that
@@ -78,7 +78,7 @@ Description:	The "enabled" property prints a '1' if the TPM chip is enabled,
 What:		/sys/class/tpm/tpmX/device/owned
 Date:		April 2006
 KernelVersion:	2.6.17
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "owned" property produces a '1' if the TPM_TakeOwnership
 		ordinal has been executed successfully in the chip. A '0'
 		indicates that ownership hasn't been taken.
@@ -86,7 +86,7 @@ Description:	The "owned" property produces a '1' if the TPM_TakeOwnership
 What:		/sys/class/tpm/tpmX/device/pcrs
 Date:		April 2005
 KernelVersion:	2.6.12
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "pcrs" property will dump the current value of all Platform
 		Configuration Registers in the TPM. Note that since these
 		values may be constantly changing, the output is only valid
@@ -109,7 +109,7 @@ Description:	The "pcrs" property will dump the current value of all Platform
 What:		/sys/class/tpm/tpmX/device/pubek
 Date:		April 2005
 KernelVersion:	2.6.12
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "pubek" property will return the TPM's public endorsement
 		key if possible. If the TPM has had ownership established and
 		is version 1.2, the pubek will not be available without the
@@ -161,7 +161,7 @@ Description:	The "pubek" property will return the TPM's public endorsement
 What:		/sys/class/tpm/tpmX/device/temp_deactivated
 Date:		April 2006
 KernelVersion:	2.6.17
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "temp_deactivated" property returns a '1' if the chip has
 		been temporarily deactivated, usually until the next power
 		cycle. Whether a warm boot (reboot) will clear a TPM chip
@@ -170,7 +170,7 @@ Description:	The "temp_deactivated" property returns a '1' if the chip has
 What:		/sys/class/tpm/tpmX/device/timeouts
 Date:		March 2011
 KernelVersion:	3.1
-Contact:	tpmdd-devel@lists.sf.net
+Contact:	linux-integrity@vger.kernel.org
 Description:	The "timeouts" property shows the 4 vendor-specific values
 		for the TPM's interface spec timeouts. The use of these
 		timeouts is defined by the TPM interface spec that the chip
@@ -183,3 +183,14 @@ Description:	The "timeouts" property shows the 4 vendor-specific values
 		The four timeout values are shown in usecs, with a trailing
 		"[original]" or "[adjusted]" depending on whether the values
 		were scaled by the driver to be reported in usec from msecs.
+
+What:		/sys/class/tpm/tpmX/tpm_version_major
+Date:		October 2019
+KernelVersion:	5.5
+Contact:	linux-integrity@vger.kernel.org
+Description:	The "tpm_version_major" property shows the TCG spec major version
+		implemented by the TPM device.
+
+		Example output:
+
+		2

Documentation/ABI/stable/sysfs-driver-dma-idxd

+What:           sys/bus/dsa/devices/dsa<m>/cdev_major
+Date:           Oct 25, 2019
+KernelVersion: 	5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:	The major number that the character device driver assigned to
+		this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/errors
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The error information for this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/max_batch_size
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The largest number of work descriptors in a batch.
+
+What:           sys/bus/dsa/devices/dsa<m>/max_work_queues_size
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The maximum work queue size supported by this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/max_engines
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The maximum number of engines supported by this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/max_groups
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The maximum number of groups can be created under this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/max_tokens
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The total number of bandwidth tokens supported by this device.
+		The bandwidth tokens represent resources within the DSA
+		implementation, and these resources are allocated by engines to
+		support operations.
+
+What:           sys/bus/dsa/devices/dsa<m>/max_transfer_size
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The number of bytes to be read from the source address to
+		perform the operation. The maximum transfer size is dependent on
+		the workqueue the descriptor was submitted to.
+
+What:           sys/bus/dsa/devices/dsa<m>/max_work_queues
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The maximum work queue number that this device supports.
+
+What:           sys/bus/dsa/devices/dsa<m>/numa_node
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The numa node number for this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/op_cap
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The operation capability bit mask specify the operation types
+		supported by the this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/state
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The state information of this device. It can be either enabled
+		or disabled.
+
+What:           sys/bus/dsa/devices/dsa<m>/group<m>.<n>
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The assigned group under this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/engine<m>.<n>
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The assigned engine under this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/wq<m>.<n>
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The assigned work queue under this device.
+
+What:           sys/bus/dsa/devices/dsa<m>/configurable
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    To indicate if this device is configurable or not.
+
+What:           sys/bus/dsa/devices/dsa<m>/token_limit
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The maximum number of bandwidth tokens that may be in use at
+		one time by operations that access low bandwidth memory in the
+		device.
+
+What:           sys/bus/dsa/devices/wq<m>.<n>/group_id
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The group id that this work queue belongs to.
+
+What:           sys/bus/dsa/devices/wq<m>.<n>/size
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The work queue size for this work queue.
+
+What:           sys/bus/dsa/devices/wq<m>.<n>/type
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The type of this work queue, it can be "kernel" type for work
+		queue usages in the kernel space or "user" type for work queue
+		usages by applications in user space.
+
+What:           sys/bus/dsa/devices/wq<m>.<n>/cdev_minor
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The minor number assigned to this work queue by the character
+		device driver.
+
+What:           sys/bus/dsa/devices/wq<m>.<n>/mode
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The work queue mode type for this work queue.
+
+What:           sys/bus/dsa/devices/wq<m>.<n>/priority
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The priority value of this work queue, it is a vlue relative to
+		other work queue in the same group to control quality of service
+		for dispatching work from multiple workqueues in the same group.
+
+What:           sys/bus/dsa/devices/wq<m>.<n>/state
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The current state of the work queue.
+
+What:           sys/bus/dsa/devices/wq<m>.<n>/threshold
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The number of entries in this work queue that may be filled
+		via a limited portal.
+
+What:           sys/bus/dsa/devices/engine<m>.<n>/group_id
+Date:           Oct 25, 2019
+KernelVersion:  5.6.0
+Contact:        dmaengine@vger.kernel.org
+Description:    The group that this engine belongs to.

Documentation/ABI/stable/sysfs-driver-mlxreg-io

 What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/asic_health
-
 Date:		June 2018
 KernelVersion:	4.19
 Contact:	Vadim Pasternak <vadimpmellanox.com>
@@ -19,7 +18,6 @@ Description:	These files show with which CPLD versions have been burned
 		The files are read only.
 
 What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/fan_dir
-
 Date:		December 2018
 KernelVersion:	5.0
 Contact:	Vadim Pasternak <vadimpmellanox.com>
@@ -29,18 +27,16 @@ Description:	This file shows the system fans direction:
 
 		The files are read only.
 
-What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/jtag_enable
-
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/cpld3_version
 Date:		November 2018
 KernelVersion:	5.0
 Contact:	Vadim Pasternak <vadimpmellanox.com>
 Description:	These files show with which CPLD versions have been burned
-		on LED board.
+		on LED or Gearbox board.
 
 		The files are read only.
 
 What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/jtag_enable
-
 Date:		November 2018
 KernelVersion:	5.0
 Contact:	Vadim Pasternak <vadimpmellanox.com>
@@ -108,7 +104,6 @@ What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_pwr_fail
 What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_from_comex
 What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_system
 What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_voltmon_upgrade_fail
-
 Date:		November 2018
 KernelVersion:	5.0
 Contact:	Vadim Pasternak <vadimpmellanox.com>
@@ -121,6 +116,21 @@ Description:	These files show the system reset cause, as following: ComEx
 
 		The files are read only.
 
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/cpld4_version
+Date:		November 2018
+KernelVersion:	5.0
+Contact:	Vadim Pasternak <vadimpmellanox.com>
+Description:	These files show with which CPLD versions have been burned
+		on LED board.
+
+		The files are read only.
+
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_thermal
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_wd
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_from_asic
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_reload_bios
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_sff_wd
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_swb_wd
 Date:		June 2019
 KernelVersion:	5.3
 Contact:	Vadim Pasternak <vadimpmellanox.com>
@@ -134,9 +144,65 @@ Description:	These files show the system reset cause, as following:
 
 		The files are read only.
 
-What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_thermal
-What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_wd
-What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_from_asic
-What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_reload_bios
-What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_sff_wd
-What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_swb_wd
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/config1
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/config2
+Date:		January 2020
+KernelVersion:	5.6
+Contact:	Vadim Pasternak <vadimpmellanox.com>
+Description:	These files show system static topology identification
+		like system's static I2C topology, number and type of FPGA
+		devices within the system and so on.
+
+		The files are read only.
+
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_ac_pwr_fail
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_platform
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_soc
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_sw_pwr_off
+Date:		January 2020
+KernelVersion:	5.6
+Contact:	Vadim Pasternak <vadimpmellanox.com>
+Description:	These files show the system reset causes, as following: reset
+		due to AC power failure, reset invoked from software by
+		assertion reset signal through CPLD. reset caused by signal
+		asserted by SOC through ACPI register, reset invoked from
+		software by assertion power off signal through CPLD.
+
+		The files are read only.
+
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/pcie_asic_reset_dis
+Date:		January 2020
+KernelVersion:	5.6
+Contact:	Vadim Pasternak <vadimpmellanox.com>
+Description:	This file allows to retain ASIC up during PCIe root complex
+		reset, when attribute is set 1.
+
+		The file is read/write.
+
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/vpd_wp
+Date:		January 2020
+KernelVersion:	5.6
+Contact:	Vadim Pasternak <vadimpmellanox.com>
+Description:	This file allows to overwrite system VPD hardware wrtie
+		protection when attribute is set 1.
+
+		The file is read/write.
+
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/voltreg_update_status
+Date:		January 2020
+KernelVersion:	5.6
+Contact:	Vadim Pasternak <vadimpmellanox.com>
+Description:	This file exposes the configuration update status of burnable
+		voltage regulator devices. The status values are as following:
+		0 - OK; 1 - CRC failure; 2 = I2C failure; 3 - in progress.
+
+		The file is read only.
+
+What:		/sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/ufm_version
+Date:		January 2020
+KernelVersion:	5.6
+Contact:	Vadim Pasternak <vadimpmellanox.com>
+Description:	This file exposes the firmware version of burnable voltage
+		regulator devices.
+
+		The file is read only.

Documentation/ABI/testing/configfs-usb-gadget

@@ -16,6 +16,10 @@ Description:
 				write UDC's name found in /sys/class/udc/*
 				to bind a gadget, empty string "" to unbind.
 
+		max_speed	- maximum speed the driver supports. Valid
+				names are super-speed-plus, super-speed,
+				high-speed, full-speed, and low-speed.
+
 		bDeviceClass	- USB device class code
 		bDeviceSubClass	- USB device subclass code
 		bDeviceProtocol	- USB device protocol code

Documentation/ABI/testing/ima_policy

@@ -25,11 +25,11 @@ Description:
 			lsm:	[[subj_user=] [subj_role=] [subj_type=]
 				 [obj_user=] [obj_role=] [obj_type=]]
 			option:	[[appraise_type=]] [template=] [permit_directio]
-				[appraise_flag=]
+				[appraise_flag=] [keyrings=]
 		base: 	func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK][MODULE_CHECK]
 				[FIRMWARE_CHECK]
 				[KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
-				[KEXEC_CMDLINE]
+				[KEXEC_CMDLINE] [KEY_CHECK]
 			mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
 			       [[^]MAY_EXEC]
 			fsmagic:= hex value
@@ -42,6 +42,9 @@ Description:
 			appraise_flag:= [check_blacklist]
 			Currently, blacklist check is only for files signed with appended
 			signature.
+			keyrings:= list of keyrings
+			(eg, .builtin_trusted_keys|.ima). Only valid
+			when action is "measure" and func is KEY_CHECK.
 			template:= name of a defined IMA template type
 			(eg, ima-ng). Only valid when action is "measure".
 			pcr:= decimal value
@@ -113,3 +116,12 @@ Description:
 		Example of appraise rule allowing modsig appended signatures:
 
 			appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig
+
+		Example of measure rule using KEY_CHECK to measure all keys:
+
+			measure func=KEY_CHECK
+
+		Example of measure rule using KEY_CHECK to only measure
+		keys added to .builtin_trusted_keys or .ima keyring:
+
+			measure func=KEY_CHECK keyrings=.builtin_trusted_keys|.ima

Documentation/ABI/testing/rtc-cdev

@@ -33,6 +33,14 @@ Description:
 		  Requires a separate RTC_PIE_ON call to enable the periodic
 		  interrupts.
 
+		* RTC_VL_READ: Read the voltage inputs status of the RTC when
+		  supported. The value is a bit field of RTC_VL_*, giving the
+		  status of the main and backup voltages.
+
+		* RTC_VL_CLEAR: Clear the voltage status of the RTC. Some RTCs
+		  need user interaction when the backup power provider is
+		  replaced or charged to be able to clear the status.
+
 		The ioctl() calls supported by the older /dev/rtc interface are
 		also supported by the newer RTC class framework. However,
 		because the chips and systems are not standardized, some PC/AT

Documentation/ABI/testing/sysfs-bus-iio

@@ -1726,3 +1726,16 @@ Contact:	linux-iio@vger.kernel.org
 Description:
 		List of valid periods (in seconds) for which the light intensity
 		must be above the threshold level before interrupt is asserted.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_filter_notch_center_frequency
+KernelVersion:	5.5
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Center frequency in Hz for a notch filter. Used i.e. for line
+		noise suppression.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_temp_thermocouple_type
+KernelVersion:	5.5
+Contact:	linux-iio@vger.kernel.org
+Description:
+		One of the following thermocouple types: B, E, J, K, N, R, S, T.

Documentation/ABI/testing/sysfs-bus-iio-dma-buffer

+What:		/sys/bus/iio/devices/iio:deviceX/buffer/length_align_bytes
+KernelVersion:	5.4
+Contact:	linux-iio@vger.kernel.org
+Description:
+		DMA buffers tend to have a alignment requirement for the
+		buffers. If this alignment requirement is not met samples might
+		be dropped from the buffer.
+
+		This property reports the alignment requirements in bytes.
+		This means that the buffer size in bytes needs to be a integer
+		multiple of the number reported by this file.
+
+		The alignment requirements in number of sample sets will depend
+		on the enabled channels and the bytes per channel. This means
+		that the alignment requirement in samples sets might change
+		depending on which and how many channels are enabled. Whereas
+		the alignment requirement reported in bytes by this property
+		will remain static and does not depend on which channels are
+		enabled.

Documentation/ABI/testing/sysfs-bus-mdio

+What:          /sys/bus/mdio_bus/devices/.../statistics/
+Date:          January 2020
+KernelVersion: 5.6
+Contact:       netdev@vger.kernel.org
+Description:
+		This folder contains statistics about global and per
+		MDIO bus address statistics.
+
+What:          /sys/bus/mdio_bus/devices/.../statistics/transfers
+Date:          January 2020
+KernelVersion: 5.6
+Contact:       netdev@vger.kernel.org
+Description:
+		Total number of transfers for this MDIO bus.
+
+What:          /sys/bus/mdio_bus/devices/.../statistics/errors
+Date:          January 2020
+KernelVersion: 5.6
+Contact:       netdev@vger.kernel.org
+Description:
+		Total number of transfer errors for this MDIO bus.
+
+What:          /sys/bus/mdio_bus/devices/.../statistics/writes
+Date:          January 2020
+KernelVersion: 5.6
+Contact:       netdev@vger.kernel.org
+Description:
+		Total number of write transactions for this MDIO bus.
+
+What:          /sys/bus/mdio_bus/devices/.../statistics/reads
+Date:          January 2020
+KernelVersion: 5.6
+Contact:       netdev@vger.kernel.org
+Description:
+		Total number of read transactions for this MDIO bus.
+
+What:          /sys/bus/mdio_bus/devices/.../statistics/transfers_<addr>
+Date:          January 2020
+KernelVersion: 5.6
+Contact:       netdev@vger.kernel.org
+Description:
+		Total number of transfers for this MDIO bus address.
+
+What:          /sys/bus/mdio_bus/devices/.../statistics/errors_<addr>
+Date:          January 2020
+KernelVersion: 5.6
+Contact:       netdev@vger.kernel.org
+Description:
+		Total number of transfer errors for this MDIO bus address.
+
+What:          /sys/bus/mdio_bus/devices/.../statistics/writes_<addr>
+Date:          January 2020
+KernelVersion: 5.6
+Contact:       netdev@vger.kernel.org
+Description:
+		Total number of write transactions for this MDIO bus address.
+
+What:          /sys/bus/mdio_bus/devices/.../statistics/reads_<addr>
+Date:          January 2020
+KernelVersion: 5.6
+Contact:       netdev@vger.kernel.org
+Description:
+		Total number of read transactions for this MDIO bus address.

Documentation/ABI/testing/sysfs-class-devfreq

@@ -7,6 +7,13 @@ Description:
 		The name of devfreq object denoted as ... is same as the
 		name of device using devfreq.
 
+What:		/sys/class/devfreq/.../name
+Date:		November 2019
+Contact:	Chanwoo Choi <cw00.choi@samsung.com>
+Description:
+		The /sys/class/devfreq/.../name shows the name of device
+		of the corresponding devfreq object.
+
 What:		/sys/class/devfreq/.../governor
 Date:		September 2011
 Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
@@ -48,12 +55,15 @@ What:		/sys/class/devfreq/.../trans_stat
 Date:		October 2012
 Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
 Description:
-		This ABI shows the statistics of devfreq behavior on a
-		specific device. It shows the time spent in each state and
-		the number of transitions between states.
+		This ABI shows or clears the statistics of devfreq behavior
+		on a specific device. It shows the time spent in each state
+		and the number of transitions between states.
 		In order to activate this ABI, the devfreq target device
 		driver should provide the list of available frequencies
-		with its profile.
+		with its profile. If need to reset the statistics of devfreq
+		behavior on a specific device, enter 0(zero) to 'trans_stat'
+		as following:
+			echo 0 > /sys/class/devfreq/.../trans_stat
 
 What:		/sys/class/devfreq/.../userspace/set_freq
 Date:		September 2011

Documentation/ABI/testing/sysfs-class-power

@@ -189,7 +189,8 @@ Description:
 		Access: Read
 		Valid values: "Unknown", "Good", "Overheat", "Dead",
 			      "Over voltage", "Unspecified failure", "Cold",
-			      "Watchdog timer expire", "Safety timer expire"
+			      "Watchdog timer expire", "Safety timer expire",
+			      "Over current"
 
 What:		/sys/class/power_supply/<supply_name>/precharge_current
 Date:		June 2017

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -196,6 +196,12 @@ Description:
 		does not reflect it. Likewise, if one enables a deep state but a
 		lighter state still is disabled, then this has no effect.
 
+What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/default_status
+Date:		December 2019
+KernelVersion:	v5.6
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:
+		(RO) The default status of this state, "enabled" or "disabled".
 
 What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/residency
 Date:		March 2014

Documentation/ABI/testing/sysfs-driver-pciback

@@ -11,3 +11,16 @@ Description:
                 #echo 00:19.0-E0:2:FF > /sys/bus/pci/drivers/pciback/quirks
                 will allow the guest to read and write to the configuration
                 register 0x0E.
+
+What:           /sys/bus/pci/drivers/pciback/allow_interrupt_control
+Date:           Jan 2020
+KernelVersion:  5.6
+Contact:        xen-devel@lists.xenproject.org
+Description:
+                List of devices which can have interrupt control flag (INTx,
+                MSI, MSI-X) set by a connected guest. It is meant to be set
+                only when the guest is a stubdomain hosting device model (qemu)
+                and the actual device is assigned to a HVM. It is not safe
+                (similar to permissive attribute) to set for a devices assigned
+                to a PV guest. The device is automatically removed from this
+                list when the connected pcifront terminates.

Documentation/ABI/testing/sysfs-driver-xen-blkback

@@ -25,3 +25,13 @@ Description:
                 allocated without being in use. The time is in
                 seconds, 0 means indefinitely long.
                 The default is 60 seconds.
+
+What:           /sys/module/xen_blkback/parameters/buffer_squeeze_duration_ms
+Date:           December 2019
+KernelVersion:  5.6
+Contact:        SeongJae Park <sjpark@amazon.de>
+Description:
+                When memory pressure is reported to blkback this option
+                controls the duration in milliseconds that blkback will not
+                cache any page not backed by a grant mapping.
+                The default is 10ms.

Documentation/ABI/testing/sysfs-platform-asus-wmi

@@ -46,3 +46,13 @@ Description:
 			* 0 - normal,
 			* 1 - overboost,
 			* 2 - silent
+
+What:		/sys/devices/platform/<platform>/throttle_thermal_policy
+Date:		Dec 2019
+KernelVersion:	5.6
+Contact:	"Leonid Maksymchuk" <leonmaxx@gmail.com>
+Description:
+		Throttle thermal policy mode:
+			* 0 - default,
+			* 1 - overboost,
+			* 2 - silent

Documentation/ABI/testing/sysfs-power

@@ -407,3 +407,16 @@ Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
 Description:
 		The /sys/power/suspend_stats/last_failed_step file contains
 		the last failed step in the suspend/resume path.
+
+What:		/sys/power/sync_on_suspend
+Date:		October 2019
+Contact:	Jonas Meurer <jonas@freesources.org>
+Description:
+		This file controls whether or not the kernel will sync()
+		filesystems during system suspend (after freezing user space
+		and before suspending devices).
+
+		Writing a "1" to this file enables the sync() and writing a "0"
+		disables it.  Reads from the file return the current value.
+		The default is "1" if the build-time "SUSPEND_SKIP_SYNC" config
+		flag is unset, or "0" otherwise.

Documentation/ABI/testing/usb-charger-uevent

+What:		Raise a uevent when a USB charger is inserted or removed
+Date:		2020-01-14
+KernelVersion:	5.6
+Contact:	linux-usb@vger.kernel.org
+Description:	There are two USB charger states:
+		USB_CHARGER_ABSENT
+		USB_CHARGER_PRESENT
+		There are five USB charger types:
+		USB_CHARGER_UNKNOWN_TYPE: Charger type is unknown
+		USB_CHARGER_SDP_TYPE: Standard Downstream Port
+		USB_CHARGER_CDP_TYPE: Charging Downstream Port
+		USB_CHARGER_DCP_TYPE: Dedicated Charging Port
+		USB_CHARGER_ACA_TYPE: Accessory Charging Adapter
+		https://www.usb.org/document-library/battery-charging-v12-spec-and-adopters-agreement
+
+		Here are two examples taken using udevadm monitor -p when
+		USB charger is online:
+		UDEV  change   /devices/soc0/usbphynop1 (platform)
+		ACTION=change
+		DEVPATH=/devices/soc0/usbphynop1
+		DRIVER=usb_phy_generic
+		MODALIAS=of:Nusbphynop1T(null)Cusb-nop-xceiv
+		OF_COMPATIBLE_0=usb-nop-xceiv
+		OF_COMPATIBLE_N=1
+		OF_FULLNAME=/usbphynop1
+		OF_NAME=usbphynop1
+		SEQNUM=2493
+		SUBSYSTEM=platform
+		USB_CHARGER_STATE=USB_CHARGER_PRESENT
+		USB_CHARGER_TYPE=USB_CHARGER_SDP_TYPE
+		USEC_INITIALIZED=227422826
+
+		USB charger is offline:
+		KERNEL change   /devices/soc0/usbphynop1 (platform)
+		ACTION=change
+		DEVPATH=/devices/soc0/usbphynop1
+		DRIVER=usb_phy_generic
+		MODALIAS=of:Nusbphynop1T(null)Cusb-nop-xceiv
+		OF_COMPATIBLE_0=usb-nop-xceiv
+		OF_COMPATIBLE_N=1
+		OF_FULLNAME=/usbphynop1
+		OF_NAME=usbphynop1
+		SEQNUM=2494
+		SUBSYSTEM=platform
+		USB_CHARGER_STATE=USB_CHARGER_ABSENT
+		USB_CHARGER_TYPE=USB_CHARGER_UNKNOWN_TYPE

Documentation/PCI/msi-howto.rst

@@ -283,5 +283,5 @@ or disabled (0).  If 0 is found in any of the msi_bus files belonging
 to bridges between the PCI root and the device, MSIs are disabled.
 
 It is also worth checking the device driver to see whether it supports MSIs.
-For example, it may contain calls to pci_irq_alloc_vectors() with the
+For example, it may contain calls to pci_alloc_irq_vectors() with the
 PCI_IRQ_MSI or PCI_IRQ_MSIX flags.

Documentation/RCU/NMI-RCU.rst

+.. _NMI_rcu_doc:
+
+Using RCU to Protect Dynamic NMI Handlers
+=========================================
+
+
+Although RCU is usually used to protect read-mostly data structures,
+it is possible to use RCU to provide dynamic non-maskable interrupt
+handlers, as well as dynamic irq handlers.  This document describes
+how to do this, drawing loosely from Zwane Mwaikambo's NMI-timer
+work in "arch/x86/oprofile/nmi_timer_int.c" and in
+"arch/x86/kernel/traps.c".
+
+The relevant pieces of code are listed below, each followed by a
+brief explanation::
+
+	static int dummy_nmi_callback(struct pt_regs *regs, int cpu)
+	{
+		return 0;
+	}
+
+The dummy_nmi_callback() function is a "dummy" NMI handler that does
+nothing, but returns zero, thus saying that it did nothing, allowing
+the NMI handler to take the default machine-specific action::
+
+	static nmi_callback_t nmi_callback = dummy_nmi_callback;
+
+This nmi_callback variable is a global function pointer to the current
+NMI handler::
+
+	void do_nmi(struct pt_regs * regs, long error_code)
+	{
+		int cpu;
+
+		nmi_enter();
+
+		cpu = smp_processor_id();
+		++nmi_count(cpu);
+
+		if (!rcu_dereference_sched(nmi_callback)(regs, cpu))
+			default_do_nmi(regs);
+
+		nmi_exit();
+	}
+
+The do_nmi() function processes each NMI.  It first disables preemption
+in the same way that a hardware irq would, then increments the per-CPU
+count of NMIs.  It then invokes the NMI handler stored in the nmi_callback
+function pointer.  If this handler returns zero, do_nmi() invokes the
+default_do_nmi() function to handle a machine-specific NMI.  Finally,
+preemption is restored.
+
+In theory, rcu_dereference_sched() is not needed, since this code runs
+only on i386, which in theory does not need rcu_dereference_sched()
+anyway.  However, in practice it is a good documentation aid, particularly
+for anyone attempting to do something similar on Alpha or on systems
+with aggressive optimizing compilers.
+
+Quick Quiz:
+		Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only?
+
+:ref:`Answer to Quick Quiz <answer_quick_quiz_NMI>`
+
+Back to the discussion of NMI and RCU::
+
+	void set_nmi_callback(nmi_callback_t callback)
+	{
+		rcu_assign_pointer(nmi_callback, callback);
+	}
+
+The set_nmi_callback() function registers an NMI handler.  Note that any
+data that is to be used by the callback must be initialized up -before-
+the call to set_nmi_callback().  On architectures that do not order
+writes, the rcu_assign_pointer() ensures that the NMI handler sees the
+initialized values::
+
+	void unset_nmi_callback(void)
+	{
+		rcu_assign_pointer(nmi_callback, dummy_nmi_callback);
+	}
+
+This function unregisters an NMI handler, restoring the original
+dummy_nmi_handler().  However, there may well be an NMI handler
+currently executing on some other CPU.  We therefore cannot free
+up any data structures used by the old NMI handler until execution
+of it completes on all other CPUs.
+
+One way to accomplish this is via synchronize_rcu(), perhaps as
+follows::
+
+	unset_nmi_callback();
+	synchronize_rcu();
+	kfree(my_nmi_data);
+
+This works because (as of v4.20) synchronize_rcu() blocks until all
+CPUs complete any preemption-disabled segments of code that they were
+executing.
+Since NMI handlers disable preemption, synchronize_rcu() is guaranteed
+not to return until all ongoing NMI handlers exit.  It is therefore safe
+to free up the handler's data as soon as synchronize_rcu() returns.
+
+Important note: for this to work, the architecture in question must
+invoke nmi_enter() and nmi_exit() on NMI entry and exit, respectively.
+
+.. _answer_quick_quiz_NMI:
+
+Answer to Quick Quiz:
+	Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only?
+
+	The caller to set_nmi_callback() might well have
+	initialized some data that is to be used by the new NMI
+	handler.  In this case, the rcu_dereference_sched() would
+	be needed, because otherwise a CPU that received an NMI
+	just after the new handler was set might see the pointer
+	to the new NMI handler, but the old pre-initialized
+	version of the handler's data.
+
+	This same sad story can happen on other CPUs when using
+	a compiler with aggressive pointer-value speculation
+	optimizations.
+
+	More important, the rcu_dereference_sched() makes it
+	clear to someone reading the code that the pointer is
+	being protected by RCU-sched.

Documentation/RCU/NMI-RCU.txt

-Using RCU to Protect Dynamic NMI Handlers
-
-
-Although RCU is usually used to protect read-mostly data structures,
-it is possible to use RCU to provide dynamic non-maskable interrupt
-handlers, as well as dynamic irq handlers.  This document describes
-how to do this, drawing loosely from Zwane Mwaikambo's NMI-timer
-work in "arch/x86/oprofile/nmi_timer_int.c" and in
-"arch/x86/kernel/traps.c".
-
-The relevant pieces of code are listed below, each followed by a
-brief explanation.
-
-	static int dummy_nmi_callback(struct pt_regs *regs, int cpu)
-	{
-		return 0;
-	}
-
-The dummy_nmi_callback() function is a "dummy" NMI handler that does
-nothing, but returns zero, thus saying that it did nothing, allowing
-the NMI handler to take the default machine-specific action.
-
-	static nmi_callback_t nmi_callback = dummy_nmi_callback;
-
-This nmi_callback variable is a global function pointer to the current
-NMI handler.
-
-	void do_nmi(struct pt_regs * regs, long error_code)
-	{
-		int cpu;
-
-		nmi_enter();
-
-		cpu = smp_processor_id();
-		++nmi_count(cpu);
-
-		if (!rcu_dereference_sched(nmi_callback)(regs, cpu))
-			default_do_nmi(regs);
-
-		nmi_exit();
-	}
-
-The do_nmi() function processes each NMI.  It first disables preemption
-in the same way that a hardware irq would, then increments the per-CPU
-count of NMIs.  It then invokes the NMI handler stored in the nmi_callback
-function pointer.  If this handler returns zero, do_nmi() invokes the
-default_do_nmi() function to handle a machine-specific NMI.  Finally,
-preemption is restored.
-
-In theory, rcu_dereference_sched() is not needed, since this code runs
-only on i386, which in theory does not need rcu_dereference_sched()
-anyway.  However, in practice it is a good documentation aid, particularly
-for anyone attempting to do something similar on Alpha or on systems
-with aggressive optimizing compilers.
-
-Quick Quiz:  Why might the rcu_dereference_sched() be necessary on Alpha,
-	     given that the code referenced by the pointer is read-only?
-
-
-Back to the discussion of NMI and RCU...
-
-	void set_nmi_callback(nmi_callback_t callback)
-	{
-		rcu_assign_pointer(nmi_callback, callback);
-	}
-
-The set_nmi_callback() function registers an NMI handler.  Note that any
-data that is to be used by the callback must be initialized up -before-
-the call to set_nmi_callback().  On architectures that do not order
-writes, the rcu_assign_pointer() ensures that the NMI handler sees the
-initialized values.
-
-	void unset_nmi_callback(void)
-	{
-		rcu_assign_pointer(nmi_callback, dummy_nmi_callback);
-	}
-
-This function unregisters an NMI handler, restoring the original
-dummy_nmi_handler().  However, there may well be an NMI handler
-currently executing on some other CPU.  We therefore cannot free
-up any data structures used by the old NMI handler until execution
-of it completes on all other CPUs.
-
-One way to accomplish this is via synchronize_rcu(), perhaps as
-follows:
-
-	unset_nmi_callback();
-	synchronize_rcu();
-	kfree(my_nmi_data);
-
-This works because (as of v4.20) synchronize_rcu() blocks until all
-CPUs complete any preemption-disabled segments of code that they were
-executing.
-Since NMI handlers disable preemption, synchronize_rcu() is guaranteed
-not to return until all ongoing NMI handlers exit.  It is therefore safe
-to free up the handler's data as soon as synchronize_rcu() returns.
-
-Important note: for this to work, the architecture in question must
-invoke nmi_enter() and nmi_exit() on NMI entry and exit, respectively.
-
-
-Answer to Quick Quiz
-
-	Why might the rcu_dereference_sched() be necessary on Alpha, given
-	that the code referenced by the pointer is read-only?
-
-	Answer: The caller to set_nmi_callback() might well have
-		initialized some data that is to be used by the new NMI
-		handler.  In this case, the rcu_dereference_sched() would
-		be needed, because otherwise a CPU that received an NMI
-		just after the new handler was set might see the pointer
-		to the new NMI handler, but the old pre-initialized
-		version of the handler's data.
-
-		This same sad story can happen on other CPUs when using
-		a compiler with aggressive pointer-value speculation
-		optimizations.
-
-		More important, the rcu_dereference_sched() makes it
-		clear to someone reading the code that the pointer is
-		being protected by RCU-sched.

Documentation/RCU/arrayRCU.rst

+.. _array_rcu_doc:
+
+Using RCU to Protect Read-Mostly Arrays
+=======================================
+
+Although RCU is more commonly used to protect linked lists, it can
+also be used to protect arrays.  Three situations are as follows:
+
+1.  :ref:`Hash Tables <hash_tables>`
+
+2.  :ref:`Static Arrays <static_arrays>`
+
+3.  :ref:`Resizable Arrays <resizable_arrays>`
+
+Each of these three situations involves an RCU-protected pointer to an
+array that is separately indexed.  It might be tempting to consider use
+of RCU to instead protect the index into an array, however, this use
+case is **not** supported.  The problem with RCU-protected indexes into
+arrays is that compilers can play way too many optimization games with
+integers, which means that the rules governing handling of these indexes
+are far more trouble than they are worth.  If RCU-protected indexes into
+arrays prove to be particularly valuable (which they have not thus far),
+explicit cooperation from the compiler will be required to permit them
+to be safely used.
+
+That aside, each of the three RCU-protected pointer situations are
+described in the following sections.
+
+.. _hash_tables:
+
+Situation 1: Hash Tables
+------------------------
+
+Hash tables are often implemented as an array, where each array entry
+has a linked-list hash chain.  Each hash chain can be protected by RCU
+as described in the listRCU.txt document.  This approach also applies
+to other array-of-list situations, such as radix trees.
+
+.. _static_arrays:
+
+Situation 2: Static Arrays
+--------------------------
+
+Static arrays, where the data (rather than a pointer to the data) is
+located in each array element, and where the array is never resized,
+have not been used with RCU.  Rik van Riel recommends using seqlock in
+this situation, which would also have minimal read-side overhead as long
+as updates are rare.
+
+Quick Quiz:
+		Why is it so important that updates be rare when using seqlock?
+
+:ref:`Answer to Quick Quiz <answer_quick_quiz_seqlock>`
+
+.. _resizable_arrays:
+
+Situation 3: Resizable Arrays
+------------------------------
+
+Use of RCU for resizable arrays is demonstrated by the grow_ary()
+function formerly used by the System V IPC code.  The array is used
+to map from semaphore, message-queue, and shared-memory IDs to the data
+structure that represents the corresponding IPC construct.  The grow_ary()
+function does not acquire any locks; instead its caller must hold the
+ids->sem semaphore.
+
+The grow_ary() function, shown below, does some limit checks, allocates a
+new ipc_id_ary, copies the old to the new portion of the new, initializes
+the remainder of the new, updates the ids->entries pointer to point to
+the new array, and invokes ipc_rcu_putref() to free up the old array.
+Note that rcu_assign_pointer() is used to update the ids->entries pointer,
+which includes any memory barriers required on whatever architecture
+you are running on::
+
+	static int grow_ary(struct ipc_ids* ids, int newsize)
+	{
+		struct ipc_id_ary* new;
+		struct ipc_id_ary* old;
+		int i;
+		int size = ids->entries->size;
+
+		if(newsize > IPCMNI)
+			newsize = IPCMNI;
+		if(newsize <= size)
+			return newsize;
+
+		new = ipc_rcu_alloc(sizeof(struct kern_ipc_perm *)*newsize +
+				    sizeof(struct ipc_id_ary));
+		if(new == NULL)
+			return size;
+		new->size = newsize;
+		memcpy(new->p, ids->entries->p,
+		       sizeof(struct kern_ipc_perm *)*size +
+		       sizeof(struct ipc_id_ary));
+		for(i=size;i<newsize;i++) {
+			new->p[i] = NULL;
+		}
+		old = ids->entries;
+
+		/*
+		 * Use rcu_assign_pointer() to make sure the memcpyed
+		 * contents of the new array are visible before the new
+		 * array becomes visible.
+		 */
+		rcu_assign_pointer(ids->entries, new);
+
+		ipc_rcu_putref(old);
+		return newsize;
+	}
+
+The ipc_rcu_putref() function decrements the array's reference count
+and then, if the reference count has dropped to zero, uses call_rcu()
+to free the array after a grace period has elapsed.
+
+The array is traversed by the ipc_lock() function.  This function
+indexes into the array under the protection of rcu_read_lock(),
+using rcu_dereference() to pick up the pointer to the array so
+that it may later safely be dereferenced -- memory barriers are
+required on the Alpha CPU.  Since the size of the array is stored
+with the array itself, there can be no array-size mismatches, so
+a simple check suffices.  The pointer to the structure corresponding
+to the desired IPC object is placed in "out", with NULL indicating
+a non-existent entry.  After acquiring "out->lock", the "out->deleted"
+flag indicates whether the IPC object is in the process of being
+deleted, and, if not, the pointer is returned::
+
+	struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id)
+	{
+		struct kern_ipc_perm* out;
+		int lid = id % SEQ_MULTIPLIER;
+		struct ipc_id_ary* entries;
+
+		rcu_read_lock();
+		entries = rcu_dereference(ids->entries);
+		if(lid >= entries->size) {
+			rcu_read_unlock();
+			return NULL;
+		}
+		out = entries->p[lid];
+		if(out == NULL) {
+			rcu_read_unlock();
+			return NULL;
+		}
+		spin_lock(&out->lock);
+
+		/* ipc_rmid() may have already freed the ID while ipc_lock
+		 * was spinning: here verify that the structure is still valid
+		 */
+		if (out->deleted) {
+			spin_unlock(&out->lock);
+			rcu_read_unlock();
+			return NULL;
+		}
+		return out;
+	}
+
+.. _answer_quick_quiz_seqlock:
+
+Answer to Quick Quiz:
+	Why is it so important that updates be rare when using seqlock?
+
+	The reason that it is important that updates be rare when
+	using seqlock is that frequent updates can livelock readers.
+	One way to avoid this problem is to assign a seqlock for
+	each array entry rather than to the entire array.

Documentation/RCU/arrayRCU.txt

-Using RCU to Protect Read-Mostly Arrays
-
-
-Although RCU is more commonly used to protect linked lists, it can
-also be used to protect arrays.  Three situations are as follows:
-
-1.  Hash Tables
-
-2.  Static Arrays
-
-3.  Resizeable Arrays
-
-Each of these three situations involves an RCU-protected pointer to an
-array that is separately indexed.  It might be tempting to consider use
-of RCU to instead protect the index into an array, however, this use
-case is -not- supported.  The problem with RCU-protected indexes into
-arrays is that compilers can play way too many optimization games with
-integers, which means that the rules governing handling of these indexes
-are far more trouble than they are worth.  If RCU-protected indexes into
-arrays prove to be particularly valuable (which they have not thus far),
-explicit cooperation from the compiler will be required to permit them
-to be safely used.
-
-That aside, each of the three RCU-protected pointer situations are
-described in the following sections.
-
-
-Situation 1: Hash Tables
-
-Hash tables are often implemented as an array, where each array entry
-has a linked-list hash chain.  Each hash chain can be protected by RCU
-as described in the listRCU.txt document.  This approach also applies
-to other array-of-list situations, such as radix trees.
-
-
-Situation 2: Static Arrays
-
-Static arrays, where the data (rather than a pointer to the data) is
-located in each array element, and where the array is never resized,
-have not been used with RCU.  Rik van Riel recommends using seqlock in
-this situation, which would also have minimal read-side overhead as long
-as updates are rare.
-
-Quick Quiz:  Why is it so important that updates be rare when
-	     using seqlock?
-
-
-Situation 3: Resizeable Arrays
-
-Use of RCU for resizeable arrays is demonstrated by the grow_ary()
-function formerly used by the System V IPC code.  The array is used
-to map from semaphore, message-queue, and shared-memory IDs to the data
-structure that represents the corresponding IPC construct.  The grow_ary()
-function does not acquire any locks; instead its caller must hold the
-ids->sem semaphore.
-
-The grow_ary() function, shown below, does some limit checks, allocates a
-new ipc_id_ary, copies the old to the new portion of the new, initializes
-the remainder of the new, updates the ids->entries pointer to point to
-the new array, and invokes ipc_rcu_putref() to free up the old array.
-Note that rcu_assign_pointer() is used to update the ids->entries pointer,
-which includes any memory barriers required on whatever architecture
-you are running on.
-
-	static int grow_ary(struct ipc_ids* ids, int newsize)
-	{
-		struct ipc_id_ary* new;
-		struct ipc_id_ary* old;
-		int i;
-		int size = ids->entries->size;
-
-		if(newsize > IPCMNI)
-			newsize = IPCMNI;
-		if(newsize <= size)
-			return newsize;
-
-		new = ipc_rcu_alloc(sizeof(struct kern_ipc_perm *)*newsize +
-				    sizeof(struct ipc_id_ary));
-		if(new == NULL)
-			return size;
-		new->size = newsize;
-		memcpy(new->p, ids->entries->p,
-		       sizeof(struct kern_ipc_perm *)*size +
-		       sizeof(struct ipc_id_ary));
-		for(i=size;i<newsize;i++) {
-			new->p[i] = NULL;
-		}
-		old = ids->entries;
-
-		/*
-		 * Use rcu_assign_pointer() to make sure the memcpyed
-		 * contents of the new array are visible before the new
-		 * array becomes visible.
-		 */
-		rcu_assign_pointer(ids->entries, new);
-
-		ipc_rcu_putref(old);
-		return newsize;
-	}
-
-The ipc_rcu_putref() function decrements the array's reference count
-and then, if the reference count has dropped to zero, uses call_rcu()
-to free the array after a grace period has elapsed.
-
-The array is traversed by the ipc_lock() function.  This function
-indexes into the array under the protection of rcu_read_lock(),
-using rcu_dereference() to pick up the pointer to the array so
-that it may later safely be dereferenced -- memory barriers are
-required on the Alpha CPU.  Since the size of the array is stored
-with the array itself, there can be no array-size mismatches, so
-a simple check suffices.  The pointer to the structure corresponding
-to the desired IPC object is placed in "out", with NULL indicating
-a non-existent entry.  After acquiring "out->lock", the "out->deleted"
-flag indicates whether the IPC object is in the process of being
-deleted, and, if not, the pointer is returned.
-
-	struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id)
-	{
-		struct kern_ipc_perm* out;
-		int lid = id % SEQ_MULTIPLIER;
-		struct ipc_id_ary* entries;
-
-		rcu_read_lock();
-		entries = rcu_dereference(ids->entries);
-		if(lid >= entries->size) {
-			rcu_read_unlock();
-			return NULL;
-		}
-		out = entries->p[lid];
-		if(out == NULL) {
-			rcu_read_unlock();
-			return NULL;
-		}
-		spin_lock(&out->lock);
-
-		/* ipc_rmid() may have already freed the ID while ipc_lock
-		 * was spinning: here verify that the structure is still valid
-		 */
-		if (out->deleted) {
-			spin_unlock(&out->lock);
-			rcu_read_unlock();
-			return NULL;
-		}
-		return out;
-	}
-
-
-Answer to Quick Quiz:
-
-	The reason that it is important that updates be rare when
-	using seqlock is that frequent updates can livelock readers.
-	One way to avoid this problem is to assign a seqlock for
-	each array entry rather than to the entire array.

Documentation/RCU/index.rst

@@ -7,8 +7,13 @@ RCU concepts
 .. toctree::
    :maxdepth: 3
 
+   arrayRCU
+   rcubarrier
+   rcu_dereference
+   whatisRCU
    rcu
    listRCU
+   NMI-RCU
    UP
 
    Design/Memory-Ordering/Tree-RCU-Memory-Ordering

Documentation/RCU/lockdep-splat.txt

@@ -99,7 +99,7 @@ With this change, the rcu_dereference() is always within an RCU
 read-side critical section, which again would have suppressed the
 above lockdep-RCU splat.
 
-But in this particular case, we don't actually deference the pointer
+But in this particular case, we don't actually dereference the pointer
 returned from rcu_dereference().  Instead, that pointer is just compared
 to the cic pointer, which means that the rcu_dereference() can be replaced
 by rcu_access_pointer() as follows:

Documentation/RCU/stallwarn.txt

@@ -225,18 +225,13 @@ an estimate of the total number of RCU callbacks queued across all CPUs
 In kernels with CONFIG_RCU_FAST_NO_HZ, more information is printed
 for each CPU:
 
-	0: (64628 ticks this GP) idle=dd5/3fffffffffffffff/0 softirq=82/543 last_accelerate: a345/d342 Nonlazy posted: ..D
+	0: (64628 ticks this GP) idle=dd5/3fffffffffffffff/0 softirq=82/543 last_accelerate: a345/d342 dyntick_enabled: 1
 
 The "last_accelerate:" prints the low-order 16 bits (in hex) of the
 jiffies counter when this CPU last invoked rcu_try_advance_all_cbs()
 from rcu_needs_cpu() or last invoked rcu_accelerate_cbs() from
-rcu_prepare_for_idle().  The "Nonlazy posted:" indicates lazy-callback
-status, so that an "l" indicates that all callbacks were lazy at the start
-of the last idle period and an "L" indicates that there are currently
-no non-lazy callbacks (in both cases, "." is printed otherwise, as
-shown above) and "D" indicates that dyntick-idle processing is enabled
-("." is printed otherwise, for example, if disabled via the "nohz="
-kernel boot parameter).
+rcu_prepare_for_idle(). "dyntick_enabled: 1" indicates that dyntick-idle
+processing is enabled.
 
 If the grace period ends just as the stall warning starts printing,
 there will be a spurious stall-warning message, which will include

Documentation/admin-guide/acpi/fan_performance_states.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+ACPI Fan Performance States
+===========================
+
+When the optional _FPS object is present under an ACPI device representing a
+fan (for example, PNP0C0B or INT3404), the ACPI fan driver creates additional
+"state*" attributes in the sysfs directory of the ACPI device in question.
+These attributes list properties of fan performance states.
+
+For more information on _FPS refer to the ACPI specification at:
+
+http://uefi.org/specifications
+
+For instance, the contents of the INT3404 ACPI device sysfs directory
+may look as follows::
+
+ $ ls -l /sys/bus/acpi/devices/INT3404:00/
+ total 0
+...
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state0
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state1
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state10
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state11
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state2
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state3
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state4
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state5
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state6
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state7
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state8
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state9
+ -r--r--r-- 1 root root 4096 Dec 13 01:00 status
+ ...
+
+where each of the "state*" files represents one performance state of the fan
+and contains a colon-separated list of 5 integer numbers (fields) with the
+following interpretation::
+
+control_percent:trip_point_index:speed_rpm:noise_level_mdb:power_mw
+
+* ``control_percent``: The percent value to be used to set the fan speed to a
+  specific level using the _FSL object (0-100).
+
+* ``trip_point_index``: The active cooling trip point number that corresponds
+  to this performance state (0-9).
+
+* ``speed_rpm``: Speed of the fan in rotations per minute.
+
+* ``noise_level_mdb``: Audible noise emitted by the fan in this state in
+  millidecibels.
+
+* ``power_mw``: Power draw of the fan in this state in milliwatts.
+
+For example::
+
+ $cat /sys/bus/acpi/devices/INT3404:00/state1
+ 25:0:3200:12500:1250
+
+When a given field is not populated or its value provided by the platform
+firmware is invalid, the "not-defined" string is shown instead of the value.

Documentation/admin-guide/acpi/index.rst

@@ -12,3 +12,4 @@ the Linux ACPI support.
    dsdt-override
    ssdt-overlays
    cppc_sysfs
+   fan_performance_states

Documentation/admin-guide/blockdev/zram.rst

 ========================================
-zram: Compressed RAM based block devices
+zram: Compressed RAM-based block devices
 ========================================
 
 Introduction
 ============
 
-The zram module creates RAM based block devices named /dev/zram<id>
+The zram module creates RAM-based block devices named /dev/zram<id>
 (<id> = 0, 1, ...). Pages written to these disks are compressed and stored
 in memory itself. These disks allow very fast I/O and compression provides
-good amounts of memory savings. Some of the usecases include /tmp storage,
-use as swap disks, various caches under /var and maybe many more :)
+good amounts of memory savings. Some of the use cases include /tmp storage,
+use as swap disks, various caches under /var and maybe many more. :)
 
 Statistics for individual zram devices are exported through sysfs nodes at
 /sys/block/zram<id>/
@@ -43,17 +43,17 @@ The list of possible return codes:
 
 ========  =============================================================
 -EBUSY	  an attempt to modify an attribute that cannot be changed once
-	  the device has been initialised. Please reset device first;
+	  the device has been initialised. Please reset device first.
 -ENOMEM	  zram was not able to allocate enough memory to fulfil your
-	  needs;
+	  needs.
 -EINVAL	  invalid input has been provided.
 ========  =============================================================
 
-If you use 'echo', the returned value that is changed by 'echo' utility,
+If you use 'echo', the returned value is set by the 'echo' utility,
 and, in general case, something like::
 
 	echo 3 > /sys/block/zram0/max_comp_streams
-	if [ $? -ne 0 ];
+	if [ $? -ne 0 ]; then
 		handle_error
 	fi
 
@@ -65,7 +65,8 @@ should suffice.
 ::
 
 	modprobe zram num_devices=4
-	This creates 4 devices: /dev/zram{0,1,2,3}
+
+This creates 4 devices: /dev/zram{0,1,2,3}
 
 num_devices parameter is optional and tells zram how many devices should be
 pre-created. Default: 1.
@@ -73,12 +74,12 @@ pre-created. Default: 1.
 2) Set max number of compression streams
 ========================================
 
-Regardless the value passed to this attribute, ZRAM will always
-allocate multiple compression streams - one per online CPUs - thus
+Regardless of the value passed to this attribute, ZRAM will always
+allocate multiple compression streams - one per online CPU - thus
 allowing several concurrent compression operations. The number of
 allocated compression streams goes down when some of the CPUs
 become offline. There is no single-compression-stream mode anymore,
-unless you are running a UP system or has only 1 CPU online.
+unless you are running a UP system or have only 1 CPU online.
 
 To find out how many streams are currently available::
 
@@ -89,7 +90,7 @@ To find out how many streams are currently available::
 
 Using comp_algorithm device attribute one can see available and
 currently selected (shown in square brackets) compression algorithms,
-change selected compression algorithm (once the device is initialised
+or change the selected compression algorithm (once the device is initialised
 there is no way to change compression algorithm).
 
 Examples::
@@ -167,9 +168,9 @@ Examples::
 zram provides a control interface, which enables dynamic (on-demand) device
 addition and removal.
 
-In order to add a new /dev/zramX device, perform read operation on hot_add
-attribute. This will return either new device's device id (meaning that you
-can use /dev/zram<id>) or error code.
+In order to add a new /dev/zramX device, perform a read operation on the hot_add
+attribute. This will return either the new device's device id (meaning that you
+can use /dev/zram<id>) or an error code.
 
 Example::
 
@@ -186,8 +187,8 @@ execute::
 
 Per-device statistics are exported as various nodes under /sys/block/zram<id>/
 
-A brief description of exported device attributes. For more details please
-read Documentation/ABI/testing/sysfs-block-zram.
+A brief description of exported device attributes follows. For more details
+please read Documentation/ABI/testing/sysfs-block-zram.
 
 ======================  ======  ===============================================
 Name            	access            description
@@ -245,7 +246,7 @@ whitespace:
 
 File /sys/block/zram<id>/mm_stat
 
-The stat file represents device's mm statistics. It consists of a single
+The mm_stat file represents the device's mm statistics. It consists of a single
 line of text and contains the following stats separated by whitespace:
 
  ================ =============================================================
@@ -261,7 +262,7 @@ line of text and contains the following stats separated by whitespace:
                   Unit: bytes
  mem_limit        the maximum amount of memory ZRAM can use to store
                   the compressed data
- mem_used_max     the maximum amount of memory zram have consumed to
+ mem_used_max     the maximum amount of memory zram has consumed to
                   store the data
  same_pages       the number of same element filled pages written to this disk.
                   No memory is allocated for such pages.
@@ -271,7 +272,7 @@ line of text and contains the following stats separated by whitespace:
 
 File /sys/block/zram<id>/bd_stat
 
-The stat file represents device's backing device statistics. It consists of
+The bd_stat file represents a device's backing device statistics. It consists of
 a single line of text and contains the following stats separated by whitespace:
 
  ============== =============================================================
@@ -316,9 +317,9 @@ To use the feature, admin should set up backing device via::
 	echo /dev/sda5 > /sys/block/zramX/backing_dev
 
 before disksize setting. It supports only partition at this moment.
-If admin want to use incompressible page writeback, they could do via::
+If admin wants to use incompressible page writeback, they could do via::
 
-	echo huge > /sys/block/zramX/write
+	echo huge > /sys/block/zramX/writeback
 
 To use idle page writeback, first, user need to declare zram pages
 as idle::
@@ -326,7 +327,7 @@ as idle::
 	echo all > /sys/block/zramX/idle
 
 From now on, any pages on zram are idle pages. The idle mark
-will be removed until someone request access of the block.
+will be removed until someone requests access of the block.
 IOW, unless there is access request, those pages are still idle pages.
 
 Admin can request writeback of those idle pages at right timing via::
@@ -341,16 +342,16 @@ to guarantee storage health for entire product life.
 
 To overcome the concern, zram supports "writeback_limit" feature.
 The "writeback_limit_enable"'s default value is 0 so that it doesn't limit
-any writeback. IOW, if admin want to apply writeback budget, he should
+any writeback. IOW, if admin wants to apply writeback budget, he should
 enable writeback_limit_enable via::
 
 	$ echo 1 > /sys/block/zramX/writeback_limit_enable
 
 Once writeback_limit_enable is set, zram doesn't allow any writeback
-until admin set the budget via /sys/block/zramX/writeback_limit.
+until admin sets the budget via /sys/block/zramX/writeback_limit.
 
 (If admin doesn't enable writeback_limit_enable, writeback_limit's value
-assigned via /sys/block/zramX/writeback_limit is meaninless.)
+assigned via /sys/block/zramX/writeback_limit is meaningless.)
 
 If admin want to limit writeback as per-day 400M, he could do it
 like below::
@@ -361,13 +362,13 @@ like below::
 		/sys/block/zram0/writeback_limit.
 	$ echo 1 > /sys/block/zram0/writeback_limit_enable
 
-If admin want to allow further write again once the bugdet is exausted,
+If admins want to allow further write again once the bugdet is exhausted,
 he could do it like below::
 
 	$ echo $((400<<MB_SHIFT>>4K_SHIFT)) > \
 		/sys/block/zram0/writeback_limit
 
-If admin want to see remaining writeback budget since he set::
+If admin wants to see remaining writeback budget since last set::
 
 	$ cat /sys/block/zramX/writeback_limit
 
@@ -375,12 +376,12 @@ If admin want to disable writeback limit, he could do::
 
 	$ echo 0 > /sys/block/zramX/writeback_limit_enable
 
-The writeback_limit count will reset whenever you reset zram(e.g.,
+The writeback_limit count will reset whenever you reset zram (e.g.,
 system reboot, echo 1 > /sys/block/zramX/reset) so keeping how many of
 writeback happened until you reset the zram to allocate extra writeback
 budget in next setting is user's job.
 
-If admin want to measure writeback count in a certain period, he could
+If admin wants to measure writeback count in a certain period, he could
 know it via /sys/block/zram0/bd_stat's 3rd column.
 
 memory tracking

Documentation/admin-guide/cgroup-v2.rst

@@ -61,6 +61,8 @@ v1 is available under Documentation/admin-guide/cgroup-v1/.
      5-6. Device
      5-7. RDMA
        5-7-1. RDMA Interface Files
+     5-8. HugeTLB
+       5.8-1. HugeTLB Interface Files
      5-8. Misc
        5-8-1. perf_event
      5-N. Non-normative information
@@ -2056,6 +2058,33 @@ RDMA Interface Files
 	  mlx4_0 hca_handle=1 hca_object=20
 	  ocrdma1 hca_handle=1 hca_object=23
 
+HugeTLB
+-------
+
+The HugeTLB controller allows to limit the HugeTLB usage per control group and
+enforces the controller limit during page fault.
+
+HugeTLB Interface Files
+~~~~~~~~~~~~~~~~~~~~~~~
+
+  hugetlb.<hugepagesize>.current
+	Show current usage for "hugepagesize" hugetlb.  It exists for all
+	the cgroup except root.
+
+  hugetlb.<hugepagesize>.max
+	Set/show the hard limit of "hugepagesize" hugetlb usage.
+	The default value is "max".  It exists for all the cgroup except root.
+
+  hugetlb.<hugepagesize>.events
+	A read-only flat-keyed file which exists on non-root cgroups.
+
+	  max
+		The number of allocation failure due to HugeTLB limit
+
+  hugetlb.<hugepagesize>.events.local
+	Similar to hugetlb.<hugepagesize>.events but the fields in the file
+	are local to the cgroup i.e. not hierarchical. The file modified event
+	generated on this file reflects only the local events.
 
 Misc
 ----

Documentation/admin-guide/device-mapper/dm-raid.rst

@@ -419,3 +419,5 @@ Version History
 	rebuild errors.
  1.15.0 Fix size extensions not being synchronized in case of new MD bitmap
         pages allocated;  also fix those not occuring after previous reductions
+ 1.15.1 Fix argument count and arguments for rebuild/write_mostly/journal_(dev|mode)
+        on the status line.

Documentation/admin-guide/devices.txt

@@ -319,7 +319,7 @@
 		182 = /dev/perfctr	Performance-monitoring counters
 		183 = /dev/hwrng	Generic random number generator
 		184 = /dev/cpu/microcode CPU microcode update interface
-		186 = /dev/atomicps	Atomic shapshot of process state data
+		186 = /dev/atomicps	Atomic snapshot of process state data
 		187 = /dev/irnet	IrNET device
 		188 = /dev/smbusbios	SMBus BIOS
 		189 = /dev/ussp_ctl	User space serial port control

Documentation/admin-guide/ext4.rst

@@ -92,6 +92,8 @@ Currently Available
 * efficient new ordered mode in JBD2 and ext4 (avoid using buffer head to force
   the ordering)
 * Case-insensitive file name lookups
+* file-based encryption support (fscrypt)
+* file-based verity support (fsverity)
 
 [1] Filesystems with a block size of 1k may see a limit imposed by the
 directory hash tree having a maximum depth of two.

Documentation/admin-guide/index.rst

@@ -64,6 +64,7 @@ configure specific aspects of kernel behavior to your liking.
    binderfs
    binfmt-misc
    blockdev/index
+   bootconfig
    braille-console
    btmrvl
    cgroup-v1/index
@@ -76,6 +77,7 @@ configure specific aspects of kernel behavior to your liking.
    device-mapper/index
    efi-stub
    ext4
+   nfs/index
    gpio/index
    highuid
    hw_random

Documentation/admin-guide/nfs/index.rst

+=============
+NFS
+=============
+
+.. toctree::
+    :maxdepth: 1
+
+    nfs-client
+    nfsroot
+    nfs-rdma
+    nfsd-admin-interfaces
+    nfs-idmapper
+    pnfs-block-server
+    pnfs-scsi-server
+    fault_injection

Documentation/admin-guide/nfs/nfsd-admin-interfaces.rst

+==================================
+Administrative interfaces for nfsd
+==================================
+
+Note that normally these interfaces are used only by the utilities in
+nfs-utils.
+
+nfsd is controlled mainly by pseudofiles under the "nfsd" filesystem,
+which is normally mounted at /proc/fs/nfsd/.
+
+The server is always started by the first write of a nonzero value to
+nfsd/threads.
+
+Before doing that, NFSD can be told which sockets to listen on by
+writing to nfsd/portlist; that write may be:
+
+	-  an ascii-encoded file descriptor, which should refer to a
+	   bound (and listening, for tcp) socket, or
+	-  "transportname port", where transportname is currently either
+	   "udp", "tcp", or "rdma".
+
+If nfsd is started without doing any of these, then it will create one
+udp and one tcp listener at port 2049 (see nfsd_init_socks).
+
+On startup, nfsd and lockd grace periods start. nfsd is shut down by a write of
+0 to nfsd/threads.  All locks and state are thrown away at that point.
+
+Between startup and shutdown, the number of threads may be adjusted up
+or down by additional writes to nfsd/threads or by writes to
+nfsd/pool_threads.
+
+For more detail about files under nfsd/ and what they control, see
+fs/nfsd/nfsctl.c; most of them have detailed comments.
+
+Implementation notes
+====================
+
+Note that the rpc server requires the caller to serialize addition and
+removal of listening sockets, and startup and shutdown of the server.
+For nfsd this is done using nfsd_mutex.

Documentation/admin-guide/pm/working-state.rst

@@ -8,6 +8,7 @@ Working-State Power Management
    :maxdepth: 2
 
    cpuidle
+   intel_idle
    cpufreq
    intel_pstate
    intel_epb