Merge tag 'v4.16-rc7' into x86/mm, to fix up conflict

 Conflicts:
	arch/x86/mm/init_64.c

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

12 files changed, 298 insertions, 102 deletions

diff --git a/Documentation/ABI/testing/sysfs-ata b/Documentation/ABI/testing/sysfs-ata
index aa4296498859..9ab0ef1dd1c7 100644
--- a/Documentation/ABI/testing/sysfs-ata
+++ b/Documentation/ABI/testing/sysfs-ata
@@ -1,110 +1,139 @@
 What:		/sys/class/ata_...
-Date:		August 2008
-Contact:	Gwendal Grignou<gwendal@google.com>
 Description:
-
-Provide a place in sysfs for storing the ATA topology of the system.  This allows
-retrieving various information about ATA objects.
+		Provide a place in sysfs for storing the ATA topology of the
+		system. This allows retrieving various information about ATA
+		objects.
 
 Files under /sys/class/ata_port
 -------------------------------
 
-	For each port, a directory ataX is created where X is the ata_port_id of
-	the port. The device parent is the ata host device.
+For each port, a directory ataX is created where X is the ata_port_id of the
+port. The device parent is the ata host device.
 
-idle_irq (read)
 
-	Number of IRQ received by the port while idle [some ata HBA only].
+What:		/sys/class/ata_port/ataX/nr_pmp_links
+What:		/sys/class/ata_port/ataX/idle_irq
+Date:		May, 2010
+KernelVersion:	v2.6.37
+Contact:	Gwendal Grignou <gwendal@chromium.org>
+Description:
+		nr_pmp_links:	(RO) If a SATA Port Multiplier (PM) is
+				connected, the number of links behind it.
 
-nr_pmp_links (read)
+		idle_irq:	(RO) Number of IRQ received by the port while
+				idle [some ata HBA only].
 
-	If a SATA Port Multiplier (PM) is connected, number of link behind it.
+
+What:		/sys/class/ata_port/ataX/port_no
+Date:		May, 2013
+KernelVersion:	v3.11
+Contact:	Gwendal Grignou <gwendal@chromium.org>
+Description:
+		(RO) Host local port number. While registering host controller,
+		port numbers are tracked based upon number of ports available on
+		the controller. This attribute is needed by udev for composing
+		persistent links in /dev/disk/by-path.
 
 Files under /sys/class/ata_link
 -------------------------------
 
-	Behind each port, there is a ata_link. If there is a SATA PM in the
-	topology, 15 ata_link objects are created.
-
-	If a link is behind a port, the directory name is linkX, where X is
-	ata_port_id of the port.
-	If a link is behind a PM, its name is linkX.Y where X is ata_port_id
-	of the parent port and Y the PM port.
+Behind each port, there is a ata_link. If there is a SATA PM in the topology, 15
+ata_link objects are created.
 
-hw_sata_spd_limit
+If a link is behind a port, the directory name is linkX, where X is ata_port_id
+of the port. If a link is behind a PM, its name is linkX.Y where X is
+ata_port_id of the parent port and Y the PM port.
 
-	Maximum speed supported by the connected SATA device.
 
-sata_spd_limit
+What:		/sys/class/ata_link/linkX[.Y]/hw_sata_spd_limit
+What:		/sys/class/ata_link/linkX[.Y]/sata_spd_limit
+What:		/sys/class/ata_link/linkX[.Y]/sata_spd
+Date:		May, 2010
+KernelVersion:	v2.6.37
+Contact:	Gwendal Grignou <gwendal@chromium.org>
+Description:
+		hw_sata_spd_limit:	(RO) Maximum speed supported by the
+					connected SATA device.
 
-	Maximum speed imposed by libata.
+		sata_spd_limit:		(RO) Maximum speed imposed by libata.
 
-sata_spd
+		sata_spd:		(RO) Current speed of the link
+					eg. 1.5, 3 Gbps etc.
 
-	Current speed of the link [1.5, 3Gps,...].
 
 Files under /sys/class/ata_device
 ---------------------------------
 
-	Behind each link, up to two ata device are created.
-	The name of the directory is devX[.Y].Z where:
-	- X is ata_port_id of the port where the device is connected,
-	- Y the port of the PM if any, and
-	- Z the device id: for PATA, there is usually 2 devices [0,1],
-	only 1 for SATA.
-
-class
-	Device class. Can be "ata" for disk, "atapi" for packet device,
-	"pmp" for PM, or "none" if no device was found behind the link.
-
-dma_mode
+Behind each link, up to two ata devices are created.
+The name of the directory is devX[.Y].Z where:
+- X is ata_port_id of the port where the device is connected,
+- Y the port of the PM if any, and
+- Z the device id: for PATA, there is usually 2 devices [0,1], only 1 for SATA.
+
+
+What:		/sys/class/ata_device/devX[.Y].Z/spdn_cnt
+What:		/sys/class/ata_device/devX[.Y].Z/gscr
+What:		/sys/class/ata_device/devX[.Y].Z/ering
+What:		/sys/class/ata_device/devX[.Y].Z/id
+What:		/sys/class/ata_device/devX[.Y].Z/pio_mode
+What:		/sys/class/ata_device/devX[.Y].Z/xfer_mode
+What:		/sys/class/ata_device/devX[.Y].Z/dma_mode
+What:		/sys/class/ata_device/devX[.Y].Z/class
+Date:		May, 2010
+KernelVersion:	v2.6.37
+Contact:	Gwendal Grignou <gwendal@chromium.org>
+Description:
+		spdn_cnt:	(RO) Number of times libata decided to lower the
+				speed of link due to errors.
 
-	Transfer modes supported by the device when in DMA mode.
-	Mostly used by PATA device.
+		gscr:		(RO) Cached result of the dump of PM GSCR
+				register. Valid registers are:
 
-pio_mode
+				0:      SATA_PMP_GSCR_PROD_ID,
+				1:	SATA_PMP_GSCR_REV,
+				2:      SATA_PMP_GSCR_PORT_INFO,
+				32:     SATA_PMP_GSCR_ERROR,
+				33:     SATA_PMP_GSCR_ERROR_EN,
+				64:     SATA_PMP_GSCR_FEAT,
+				96:     SATA_PMP_GSCR_FEAT_EN,
+				130:    SATA_PMP_GSCR_SII_GPIO
 
-	Transfer modes supported by the device when in PIO mode.
-	Mostly used by PATA device.
+				Only valid if the device is a PM.
 
-xfer_mode
+		ering:		(RO) Formatted output of the error ring of the
+				device.
 
-	Current transfer mode.
+		id:		(RO) Cached result of IDENTIFY command, as
+				described in ATA8 7.16 and 7.17. Only valid if
+				the device is not a PM.
 
-id
+		pio_mode:	(RO) Transfer modes supported by the device when
+				in PIO mode. Mostly used by PATA device.
 
-	Cached result of IDENTIFY command, as described in ATA8 7.16 and 7.17.
-	Only valid if the device is not a PM.
+		xfer_mode:	(RO) Current transfer mode
 
-gscr
+		dma_mode:	(RO) Transfer modes supported by the device when
+				in DMA mode. Mostly used by PATA device.
 
-	Cached result of the dump of PM GSCR register.
-	Valid registers are:
-	0: 	SATA_PMP_GSCR_PROD_ID,
-	1: 	SATA_PMP_GSCR_REV,
-	2: 	SATA_PMP_GSCR_PORT_INFO,
-	32:	SATA_PMP_GSCR_ERROR,
-	33:	SATA_PMP_GSCR_ERROR_EN,
-	64:	SATA_PMP_GSCR_FEAT,
-	96:	SATA_PMP_GSCR_FEAT_EN,
-	130:	SATA_PMP_GSCR_SII_GPIO
-	Only valid if the device is a PM.
+		class:		(RO) Device class. Can be "ata" for disk,
+				"atapi" for packet device, "pmp" for PM, or
+				"none" if no device was found behind the link.
 
-trim
 
-	Shows the DSM TRIM mode currently used by the device. Valid
-	values are:
-	unsupported:		Drive does not support DSM TRIM
-	unqueued:		Drive supports unqueued DSM TRIM only
-	queued:			Drive supports queued DSM TRIM
-	forced_unqueued:	Drive's queued DSM support is known to be
-				buggy and only unqueued TRIM commands
-				are sent
+What:		/sys/class/ata_device/devX[.Y].Z/trim
+Date:		May, 2015
+KernelVersion:	v4.10
+Contact:	Gwendal Grignou <gwendal@chromium.org>
+Description:
+		(RO) Shows the DSM TRIM mode currently used by the device. Valid
+		values are:
 
-spdn_cnt
+		unsupported:		Drive does not support DSM TRIM
 
-	Number of time libata decided to lower the speed of link due to errors.
+		unqueued:               Drive supports unqueued DSM TRIM only
 
-ering
+		queued:                 Drive supports queued DSM TRIM
 
-	Formatted output of the error ring of the device.
+		forced_unqueued:	Drive's queued DSM support is known to
+					be buggy and only unqueued TRIM commands
+					are sent
diff --git a/Documentation/ABI/testing/sysfs-block-device b/Documentation/ABI/testing/sysfs-block-device
new file mode 100644
index 000000000000..82ef6eab042d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-block-device
@@ -0,0 +1,58 @@
+What:		/sys/block/*/device/sw_activity
+Date:		Jun, 2008
+KernelVersion:	v2.6.27
+Contact:	linux-ide@vger.kernel.org
+Description:
+		(RW) Used by drivers which support software controlled activity
+		LEDs.
+
+		It has the following valid values:
+
+		0	OFF - the LED is not activated on activity
+		1	BLINK_ON - the LED blinks on every 10ms when activity is
+			detected.
+		2	BLINK_OFF - the LED is on when idle, and blinks off
+			every 10ms when activity is detected.
+
+		Note that the user must turn sw_activity OFF it they wish to
+		control the activity LED via the em_message file.
+
+
+What:		/sys/block/*/device/unload_heads
+Date:		Sep, 2008
+KernelVersion:	v2.6.28
+Contact:	linux-ide@vger.kernel.org
+Description:
+		(RW) Hard disk shock protection
+
+		Writing an integer value to this file will take the heads of the
+		respective drive off the platter and block all I/O operations
+		for the specified number of milliseconds.
+
+		- If the device does not support the unload heads feature,
+		  access is denied with -EOPNOTSUPP.
+		- The maximal value accepted for a timeout is 30000
+		  milliseconds.
+		- A previously set timeout can be cancelled and disk can resume
+		  normal operation immediately by specifying a timeout of 0.
+		- Some hard drives only comply with an earlier version of the
+		  ATA standard, but support the unload feature nonetheless.
+		  There is no safe way Linux can detect these devices, so this
+		  is not enabled by default. If it is known that your device
+		  does support the unload feature, then you can tell the kernel
+		  to enable it by writing -1. It can be disabled again by
+		  writing -2.
+		- Values below -2 are rejected with -EINVAL
+
+		For more information, see
+		Documentation/laptops/disk-shock-protection.txt
+
+
+What:		/sys/block/*/device/ncq_prio_enable
+Date:		Oct, 2016
+KernelVersion:	v4.10
+Contact:	linux-ide@vger.kernel.org
+Description:
+		(RW) Write to the file to turn on or off the SATA ncq (native
+		command queueing) support. By default this feature is turned
+		off.
diff --git a/Documentation/ABI/testing/sysfs-class-scsi_host b/Documentation/ABI/testing/sysfs-class-scsi_host
index 0eb255e7db12..bafc59fd7b69 100644
--- a/Documentation/ABI/testing/sysfs-class-scsi_host
+++ b/Documentation/ABI/testing/sysfs-class-scsi_host
@@ -27,3 +27,92 @@ Description:	This file contains the current status of the "SSD Smart Path"
 		the direct i/o path to physical devices.  This setting is
 		controller wide, affecting all configured logical drives on the
 		controller.  This file is readable and writable.
+
+What:		/sys/class/scsi_host/hostX/link_power_management_policy
+Date:		Oct, 2007
+KernelVersion:	v2.6.24
+Contact:	linux-ide@vger.kernel.org
+Description:
+		(RW) This parameter allows the user to read and set the link
+		(interface) power management.
+
+		There are four possible options:
+
+		min_power: Tell the controller to try to make the link use the
+		least possible power when possible. This may sacrifice some
+		performance due to increased latency when coming out of lower
+		power states.
+
+		max_performance: Generally, this means no power management.
+		Tell the controller to have performance be a priority over power
+		management.
+
+		medium_power: Tell the controller to enter a lower power state
+		when possible, but do not enter the lowest power state, thus
+		improving latency over min_power setting.
+
+		med_power_with_dipm: Identical to the existing medium_power
+		setting except that it enables dipm (device initiated power
+		management) on top, which makes it match the Windows IRST (Intel
+		Rapid Storage Technology) driver settings. This setting is also
+		close to min_power, except that:
+		a) It does not use host-initiated slumber mode, but it does
+		allow device-initiated slumber
+		b) It does not enable low power device sleep mode (DevSlp).
+
+What:		/sys/class/scsi_host/hostX/em_message
+What:		/sys/class/scsi_host/hostX/em_message_type
+Date:		Jun, 2008
+KernelVersion:	v2.6.27
+Contact:	linux-ide@vger.kernel.org
+Description:
+		em_message: (RW) Enclosure management support. For the LED
+		protocol, writes and reads correspond to the LED message format
+		as defined in the AHCI spec.
+
+		The user must turn sw_activity (under /sys/block/*/device/) OFF
+		it they wish to control the activity LED via the em_message
+		file.
+
+		em_message_type: (RO) Displays the current enclosure management
+		protocol that is being used by the driver (for eg. LED, SAF-TE,
+		SES-2, SGPIO etc).
+
+What:		/sys/class/scsi_host/hostX/ahci_port_cmd
+What:		/sys/class/scsi_host/hostX/ahci_host_caps
+What:		/sys/class/scsi_host/hostX/ahci_host_cap2
+Date:		Mar, 2010
+KernelVersion:	v2.6.35
+Contact:	linux-ide@vger.kernel.org
+Description:
+		[to be documented]
+
+What:		/sys/class/scsi_host/hostX/ahci_host_version
+Date:		Mar, 2010
+KernelVersion:	v2.6.35
+Contact:	linux-ide@vger.kernel.org
+Description:
+		(RO) Display the version of the AHCI spec implemented by the
+		host.
+
+What:		/sys/class/scsi_host/hostX/em_buffer
+Date:		Apr, 2010
+KernelVersion:	v2.6.35
+Contact:	linux-ide@vger.kernel.org
+Description:
+		(RW) Allows access to AHCI EM (enclosure management) buffer
+		directly if the host supports EM.
+
+		For eg. the AHCI driver supports SGPIO EM messages but the
+		SATA/AHCI specs do not define the SGPIO message format of the EM
+		buffer. Different hardware(HW) vendors may have different
+		definitions. With the em_buffer attribute, this issue can be
+		solved by allowing HW vendors to provide userland drivers and
+		tools for their SGPIO initiators.
+
+What:		/sys/class/scsi_host/hostX/em_message_supported
+Date:		Oct, 2009
+KernelVersion:	v2.6.39
+Contact:	linux-ide@vger.kernel.org
+Description:
+		(RO) Displays supported enclosure management message types.
diff --git a/Documentation/devicetree/bindings/display/exynos/exynos_hdmi.txt b/Documentation/devicetree/bindings/display/exynos/exynos_hdmi.txt
index 6394ea9e3b9e..58b12e25bbb1 100644
--- a/Documentation/devicetree/bindings/display/exynos/exynos_hdmi.txt
+++ b/Documentation/devicetree/bindings/display/exynos/exynos_hdmi.txt
@@ -16,6 +16,7 @@ Required properties:
 - ddc: phandle to the hdmi ddc node
 - phy: phandle to the hdmi phy node
 - samsung,syscon-phandle: phandle for system controller node for PMU.
+- #sound-dai-cells: should be 0.
 
 Required properties for Exynos 4210, 4212, 5420 and 5433:
 - clocks: list of clock IDs from SoC clock driver.
diff --git a/Documentation/devicetree/bindings/iio/adc/sigma-delta-modulator.txt b/Documentation/devicetree/bindings/iio/adc/sigma-delta-modulator.txt
index e9ebb8a20e0d..ba24ca7ba95e 100644
--- a/Documentation/devicetree/bindings/iio/adc/sigma-delta-modulator.txt
+++ b/Documentation/devicetree/bindings/iio/adc/sigma-delta-modulator.txt
@@ -3,11 +3,11 @@ Device-Tree bindings for sigma delta modulator
 Required properties:
 - compatible: should be "ads1201", "sd-modulator". "sd-modulator" can be use
 	as a generic SD modulator if modulator not specified in compatible list.
-- #io-channel-cells = <1>: See the IIO bindings section "IIO consumers".
+- #io-channel-cells = <0>: See the IIO bindings section "IIO consumers".
 
 Example node:
 
 	ads1202: adc@0 {
 		compatible = "sd-modulator";
-		#io-channel-cells = <1>;
+		#io-channel-cells = <0>;
 	};
diff --git a/Documentation/devicetree/bindings/net/dsa/marvell.txt b/Documentation/devicetree/bindings/net/dsa/marvell.txt
index 1d4d0f49c9d0..8c033d48e2ba 100644
--- a/Documentation/devicetree/bindings/net/dsa/marvell.txt
+++ b/Documentation/devicetree/bindings/net/dsa/marvell.txt
@@ -50,14 +50,15 @@ Example:
 			compatible = "marvell,mv88e6085";
 			reg = <0>;
 			reset-gpios = <&gpio5 1 GPIO_ACTIVE_LOW>;
-		};
-		mdio {
-			#address-cells = <1>;
-			#size-cells = <0>;
-			switch1phy0: switch1phy0@0 {
-				reg = <0>;
-				interrupt-parent = <&switch0>;
-				interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+
+			mdio {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				switch1phy0: switch1phy0@0 {
+					reg = <0>;
+					interrupt-parent = <&switch0>;
+					interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+				};
 			};
 		};
 	};
@@ -74,23 +75,24 @@ Example:
 			compatible = "marvell,mv88e6390";
 			reg = <0>;
 			reset-gpios = <&gpio5 1 GPIO_ACTIVE_LOW>;
-		};
-		mdio {
-			#address-cells = <1>;
-			#size-cells = <0>;
-			switch1phy0: switch1phy0@0 {
-				reg = <0>;
-				interrupt-parent = <&switch0>;
-				interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+
+			mdio {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				switch1phy0: switch1phy0@0 {
+					reg = <0>;
+					interrupt-parent = <&switch0>;
+					interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+				};
 			};
-		};
 
-		mdio1 {
-			compatible = "marvell,mv88e6xxx-mdio-external";
-			#address-cells = <1>;
-			#size-cells = <0>;
-			switch1phy9: switch1phy0@9 {
-				reg = <9>;
+			mdio1 {
+				compatible = "marvell,mv88e6xxx-mdio-external";
+				#address-cells = <1>;
+				#size-cells = <0>;
+				switch1phy9: switch1phy0@9 {
+					reg = <9>;
+				};
 			};
 		};
 	};
diff --git a/Documentation/devicetree/bindings/net/renesas,ravb.txt b/Documentation/devicetree/bindings/net/renesas,ravb.txt
index 92fd4b2f17b2..b4dc455eb155 100644
--- a/Documentation/devicetree/bindings/net/renesas,ravb.txt
+++ b/Documentation/devicetree/bindings/net/renesas,ravb.txt
@@ -27,7 +27,11 @@ Required properties:
 	SoC-specific version corresponding to the platform first followed by
 	the generic version.
 
-- reg: offset and length of (1) the register block and (2) the stream buffer.
+- reg: Offset and length of (1) the register block and (2) the stream buffer.
+       The region for the register block is mandatory.
+       The region for the stream buffer is optional, as it is only present on
+       R-Car Gen2 and RZ/G1 SoCs, and on R-Car H3 (R8A7795), M3-W (R8A7796),
+       and M3-N (R8A77965).
 - interrupts: A list of interrupt-specifiers, one for each entry in
 	      interrupt-names.
 	      If interrupt-names is not present, an interrupt specifier
diff --git a/Documentation/devicetree/bindings/usb/dwc2.txt b/Documentation/devicetree/bindings/usb/dwc2.txt
index e64d903bcbe8..46da5f184460 100644
--- a/Documentation/devicetree/bindings/usb/dwc2.txt
+++ b/Documentation/devicetree/bindings/usb/dwc2.txt
@@ -19,7 +19,7 @@ Required properties:
   configured in FS mode;
   - "st,stm32f4x9-hsotg": The DWC2 USB HS controller instance in STM32F4x9 SoCs
   configured in HS mode;
-  - "st,stm32f7xx-hsotg": The DWC2 USB HS controller instance in STM32F7xx SoCs
+  - "st,stm32f7-hsotg": The DWC2 USB HS controller instance in STM32F7 SoCs
     configured in HS mode;
 - reg : Should contain 1 register range (address and length)
 - interrupts : Should contain 1 interrupt
diff --git a/Documentation/devicetree/bindings/usb/renesas_usb3.txt b/Documentation/devicetree/bindings/usb/renesas_usb3.txt
index 87a45e2f9b7f..2c071bb5801e 100644
--- a/Documentation/devicetree/bindings/usb/renesas_usb3.txt
+++ b/Documentation/devicetree/bindings/usb/renesas_usb3.txt
@@ -4,6 +4,7 @@ Required properties:
   - compatible: Must contain one of the following:
 	- "renesas,r8a7795-usb3-peri"
 	- "renesas,r8a7796-usb3-peri"
+	- "renesas,r8a77965-usb3-peri"
 	- "renesas,rcar-gen3-usb3-peri" for a generic R-Car Gen3 compatible
 	  device
 
diff --git a/Documentation/devicetree/bindings/usb/renesas_usbhs.txt b/Documentation/devicetree/bindings/usb/renesas_usbhs.txt
index d060172f1529..43960faf5a88 100644
--- a/Documentation/devicetree/bindings/usb/renesas_usbhs.txt
+++ b/Documentation/devicetree/bindings/usb/renesas_usbhs.txt
@@ -12,6 +12,7 @@ Required properties:
 	- "renesas,usbhs-r8a7794" for r8a7794 (R-Car E2) compatible device
 	- "renesas,usbhs-r8a7795" for r8a7795 (R-Car H3) compatible device
 	- "renesas,usbhs-r8a7796" for r8a7796 (R-Car M3-W) compatible device
+	- "renesas,usbhs-r8a77965" for r8a77965 (R-Car M3-N) compatible device
 	- "renesas,usbhs-r8a77995" for r8a77995 (R-Car D3) compatible device
 	- "renesas,usbhs-r7s72100" for r7s72100 (RZ/A1) compatible device
 	- "renesas,rcar-gen2-usbhs" for R-Car Gen2 or RZ/G1 compatible devices
diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
index e2ea59bbca93..1651483a7048 100644
--- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
@@ -13,6 +13,7 @@ Required properties:
     - "renesas,xhci-r8a7793" for r8a7793 SoC
     - "renesas,xhci-r8a7795" for r8a7795 SoC
     - "renesas,xhci-r8a7796" for r8a7796 SoC
+    - "renesas,xhci-r8a77965" for r8a77965 SoC
     - "renesas,rcar-gen2-xhci" for a generic R-Car Gen2 or RZ/G1 compatible
       device
     - "renesas,rcar-gen3-xhci" for a generic R-Car Gen3 compatible device
diff --git a/Documentation/networking/segmentation-offloads.txt b/Documentation/networking/segmentation-offloads.txt
index d47480b61ac6..aca542ec125c 100644
--- a/Documentation/networking/segmentation-offloads.txt
+++ b/Documentation/networking/segmentation-offloads.txt
@@ -20,8 +20,8 @@ TCP Segmentation Offload
 
 TCP segmentation allows a device to segment a single frame into multiple
 frames with a data payload size specified in skb_shinfo()->gso_size.
-When TCP segmentation requested the bit for either SKB_GSO_TCP or
-SKB_GSO_TCP6 should be set in skb_shinfo()->gso_type and
+When TCP segmentation requested the bit for either SKB_GSO_TCPV4 or
+SKB_GSO_TCPV6 should be set in skb_shinfo()->gso_type and
 skb_shinfo()->gso_size should be set to a non-zero value.
 
 TCP segmentation is dependent on support for the use of partial checksum
@@ -153,8 +153,18 @@ To signal this, gso_size is set to the special value GSO_BY_FRAGS.
 
 Therefore, any code in the core networking stack must be aware of the
 possibility that gso_size will be GSO_BY_FRAGS and handle that case
-appropriately. (For size checks, the skb_gso_validate_*_len family of
-helpers do this automatically.)
+appropriately.
+
+There are some helpers to make this easier:
+
+ - skb_is_gso(skb) && skb_is_gso_sctp(skb) is the best way to see if
+   an skb is an SCTP GSO skb.
+
+ - For size checks, the skb_gso_validate_*_len family of helpers correctly
+   considers GSO_BY_FRAGS.
+
+ - For manipulating packets, skb_increase_gso_size and skb_decrease_gso_size
+   will check for GSO_BY_FRAGS and WARN if asked to manipulate these skbs.
 
 This also affects drivers with the NETIF_F_FRAGLIST & NETIF_F_GSO_SCTP bits
 set. Note also that NETIF_F_GSO_SCTP is included in NETIF_F_GSO_SOFTWARE.