diff options
Diffstat (limited to 'Documentation')
67 files changed, 2708 insertions, 299 deletions
diff --git a/Documentation/ABI/testing/sysfs-driver-samsung-laptop b/Documentation/ABI/testing/sysfs-driver-samsung-laptop index 63c1ad0212fc..34d3a3359cf4 100644 --- a/Documentation/ABI/testing/sysfs-driver-samsung-laptop +++ b/Documentation/ABI/testing/sysfs-driver-samsung-laptop @@ -3,7 +3,7 @@ Date: January 1, 2010 KernelVersion: 2.6.33 Contact: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Description: Some Samsung laptops have different "performance levels" - that are can be modified by a function key, and by this + that can be modified by a function key, and by this sysfs file. These values don't always make a whole lot of sense, but some users like to modify them to keep their fans quiet at all costs. Reading from this file diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 512ccafa45b1..39ac9d4fad7f 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3711,7 +3711,11 @@ [KNL, SMP] Set scheduler's default relax_domain_level. See Documentation/cgroup-v1/cpusets.txt. - reserve= [KNL,BUGS] Force the kernel to ignore some iomem area + reserve= [KNL,BUGS] Force kernel to ignore I/O ports or memory + Format: <base1>,<size1>[,<base2>,<size2>,...] + Reserve I/O ports or memory so the kernel won't use + them. If <base> is less than 0x10000, the region + is assumed to be I/O ports; otherwise it is memory. reservetop= [X86-32] Format: nn[KMG] diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst index 9b55952039a6..9948ec36a204 100644 --- a/Documentation/admin-guide/thunderbolt.rst +++ b/Documentation/admin-guide/thunderbolt.rst @@ -3,13 +3,13 @@ ============= The interface presented here is not meant for end users. Instead there should be a userspace tool that handles all the low-level details, keeps -database of the authorized devices and prompts user for new connections. +a database of the authorized devices and prompts users for new connections. More details about the sysfs interface for Thunderbolt devices can be found in ``Documentation/ABI/testing/sysfs-bus-thunderbolt``. Those users who just want to connect any device without any sort of -manual work, can add following line to +manual work can add following line to ``/etc/udev/rules.d/99-local.rules``:: ACTION=="add", SUBSYSTEM=="thunderbolt", ATTR{authorized}=="0", ATTR{authorized}="1" @@ -20,7 +20,7 @@ vulnerable to DMA attacks. Security levels and how to use them ----------------------------------- -Starting from Intel Falcon Ridge Thunderbolt controller there are 4 +Starting with Intel Falcon Ridge Thunderbolt controller there are 4 security levels available. The reason for these is the fact that the connected devices can be DMA masters and thus read contents of the host memory without CPU and OS knowing about it. There are ways to prevent @@ -37,14 +37,14 @@ The security levels are as follows: user User is asked whether the device is allowed to be connected. Based on the device identification information available through - ``/sys/bus/thunderbolt/devices``. user then can do the decision. + ``/sys/bus/thunderbolt/devices``, the user then can make the decision. In BIOS settings this is typically called *Unique ID*. secure User is asked whether the device is allowed to be connected. In addition to UUID the device (if it supports secure connect) is sent a challenge that should match the expected one based on a random key - written to ``key`` sysfs attribute. In BIOS settings this is + written to the ``key`` sysfs attribute. In BIOS settings this is typically called *One time saved key*. dponly @@ -78,7 +78,7 @@ When a device is plugged in it will appear in sysfs as follows:: /sys/bus/thunderbolt/devices/0-1/unique_id - e0376f00-0300-0100-ffff-ffffffffffff The ``authorized`` attribute reads 0 which means no PCIe tunnels are -created yet. The user can authorize the device by simply:: +created yet. The user can authorize the device by simply entering:: # echo 1 > /sys/bus/thunderbolt/devices/0-1/authorized @@ -86,7 +86,7 @@ This will create the PCIe tunnels and the device is now connected. If the device supports secure connect, and the domain security level is set to ``secure``, it has an additional attribute ``key`` which can hold -a random 32 byte value used for authorization and challenging the device in +a random 32-byte value used for authorization and challenging the device in future connects:: /sys/bus/thunderbolt/devices/0-3/authorized - 0 @@ -99,12 +99,12 @@ future connects:: Notice the key is empty by default. -If the user does not want to use secure connect it can just ``echo 1`` +If the user does not want to use secure connect they can just ``echo 1`` to the ``authorized`` attribute and the PCIe tunnels will be created in -the same way than in ``user`` security level. +the same way as in the ``user`` security level. If the user wants to use secure connect, the first time the device is -plugged a key needs to be created and send to the device:: +plugged a key needs to be created and sent to the device:: # key=$(openssl rand -hex 32) # echo $key > /sys/bus/thunderbolt/devices/0-3/key @@ -121,27 +121,27 @@ device using the same key:: If the challenge the device returns back matches the one we expect based on the key, the device is connected and the PCIe tunnels are created. -However, if the challenge failed no tunnels are created and error is +However, if the challenge fails no tunnels are created and error is returned to the user. -If the user still wants to connect the device it can either approve -the device without a key or write new key and write 1 to the +If the user still wants to connect the device they can either approve +the device without a key or write a new key and write 1 to the ``authorized`` file to get the new key stored on the device NVM. Upgrading NVM on Thunderbolt device or host ------------------------------------------- -Since most of the functionality is handled in a firmware running on a +Since most of the functionality is handled in firmware running on a host controller or a device, it is important that the firmware can be upgraded to the latest where possible bugs in it have been fixed. Typically OEMs provide this firmware from their support site. -There is also a central site which has links where to download firmwares +There is also a central site which has links where to download firmware for some machines: `Thunderbolt Updates <https://thunderbolttechnology.net/updates>`_ -Before you upgrade firmware on a device or host, please make sure it is -the suitable. Failing to do that may render the device (or host) in a +Before you upgrade firmware on a device or host, please make sure it is a +suitable upgrade. Failing to do that may render the device (or host) in a state where it cannot be used properly anymore without special tools! Host NVM upgrade on Apple Macs is not supported. @@ -151,7 +151,7 @@ Thunderbolt device so that the host controller appears. It does not matter which device is connected (unless you are upgrading NVM on a device - then you need to connect that particular device). -Note OEM-specific method to power the controller up ("force power") may +Note an OEM-specific method to power the controller up ("force power") may be available for your system in which case there is no need to plug in a Thunderbolt device. @@ -171,7 +171,7 @@ it comes back the driver notices it and initiates a full power cycle. After a while the host controller appears again and this time it should be fully functional. -We can verify that the new NVM firmware is active by running following +We can verify that the new NVM firmware is active by running the following commands:: # cat /sys/bus/thunderbolt/devices/0-0/nvm_authenticate @@ -179,38 +179,38 @@ commands:: # cat /sys/bus/thunderbolt/devices/0-0/nvm_version 18.0 -If ``nvm_authenticate`` contains anything else than 0x0 it is the error +If ``nvm_authenticate`` contains anything other than 0x0 it is the error code from the last authentication cycle, which means the authentication of the NVM image failed. Note names of the NVMem devices ``nvm_activeN`` and ``nvm_non_activeN`` -depends on the order they are registered in the NVMem subsystem. N in +depend on the order they are registered in the NVMem subsystem. N in the name is the identifier added by the NVMem subsystem. Upgrading NVM when host controller is in safe mode -------------------------------------------------- If the existing NVM is not properly authenticated (or is missing) the -host controller goes into safe mode which means that only available -functionality is flashing new NVM image. When in this mode the reading +host controller goes into safe mode which means that the only available +functionality is flashing a new NVM image. When in this mode, reading ``nvm_version`` fails with ``ENODATA`` and the device identification information is missing. To recover from this mode, one needs to flash a valid NVM image to the -host host controller in the same way it is done in the previous chapter. +host controller in the same way it is done in the previous chapter. Networking over Thunderbolt cable --------------------------------- -Thunderbolt technology allows software communication across two hosts +Thunderbolt technology allows software communication between two hosts connected by a Thunderbolt cable. -It is possible to tunnel any kind of traffic over Thunderbolt link but +It is possible to tunnel any kind of traffic over a Thunderbolt link but currently we only support Apple ThunderboltIP protocol. -If the other host is running Windows or macOS only thing you need to -do is to connect Thunderbolt cable between the two hosts, the -``thunderbolt-net`` is loaded automatically. If the other host is also -Linux you should load ``thunderbolt-net`` manually on one host (it does -not matter which one):: +If the other host is running Windows or macOS, the only thing you need to +do is to connect a Thunderbolt cable between the two hosts; the +``thunderbolt-net`` driver is loaded automatically. If the other host is +also Linux you should load ``thunderbolt-net`` manually on one host (it +does not matter which one):: # modprobe thunderbolt-net @@ -220,12 +220,12 @@ is built-in to the kernel image, there is no need to do anything. The driver will create one virtual ethernet interface per Thunderbolt port which are named like ``thunderbolt0`` and so on. From this point you can either use standard userspace tools like ``ifconfig`` to -configure the interface or let your GUI to handle it automatically. +configure the interface or let your GUI handle it automatically. Forcing power ------------- Many OEMs include a method that can be used to force the power of a -thunderbolt controller to an "On" state even if nothing is connected. +Thunderbolt controller to an "On" state even if nothing is connected. If supported by your machine this will be exposed by the WMI bus with a sysfs attribute called "force_power". diff --git a/Documentation/bpf/bpf_devel_QA.txt b/Documentation/bpf/bpf_devel_QA.txt index cefef855dea4..84cbb302f2b5 100644 --- a/Documentation/bpf/bpf_devel_QA.txt +++ b/Documentation/bpf/bpf_devel_QA.txt @@ -516,4 +516,35 @@ A: LLVM has a -mcpu selector for the BPF back end in order to allow the By the way, the BPF kernel selftests run with -mcpu=probe for better test coverage. +Q: In some cases clang flag "-target bpf" is used but in other cases the + default clang target, which matches the underlying architecture, is used. + What is the difference and when I should use which? + +A: Although LLVM IR generation and optimization try to stay architecture + independent, "-target <arch>" still has some impact on generated code: + + - BPF program may recursively include header file(s) with file scope + inline assembly codes. The default target can handle this well, + while bpf target may fail if bpf backend assembler does not + understand these assembly codes, which is true in most cases. + + - When compiled without -g, additional elf sections, e.g., + .eh_frame and .rela.eh_frame, may be present in the object file + with default target, but not with bpf target. + + - The default target may turn a C switch statement into a switch table + lookup and jump operation. Since the switch table is placed + in the global readonly section, the bpf program will fail to load. + The bpf target does not support switch table optimization. + The clang option "-fno-jump-tables" can be used to disable + switch table generation. + + You should use default target when: + + - Your program includes a header file, e.g., ptrace.h, which eventually + pulls in some header files containing file scope host assembly codes. + - You can add "-fno-jump-tables" to work around the switch table issue. + + Otherwise, you can use bpf target. + Happy BPF hacking! diff --git a/Documentation/devicetree/bindings/media/cec-gpio.txt b/Documentation/devicetree/bindings/media/cec-gpio.txt index 46a0bac8b3b9..12fcd55ed153 100644 --- a/Documentation/devicetree/bindings/media/cec-gpio.txt +++ b/Documentation/devicetree/bindings/media/cec-gpio.txt @@ -4,6 +4,10 @@ The HDMI CEC GPIO module supports CEC implementations where the CEC line is hooked up to a pull-up GPIO line and - optionally - the HPD line is hooked up to another GPIO line. +Please note: the maximum voltage for the CEC line is 3.63V, for the HPD +line it is 5.3V. So you may need some sort of level conversion circuitry +when connecting them to a GPIO line. + Required properties: - compatible: value must be "cec-gpio". - cec-gpios: gpio that the CEC line is connected to. The line should be @@ -21,7 +25,7 @@ the following property is optional: Example for the Raspberry Pi 3 where the CEC line is connected to pin 26 aka BCM7 aka CE1 on the GPIO pin header and the HPD line is -connected to pin 11 aka BCM17: +connected to pin 11 aka BCM17 (some level shifter is needed for this!): #include <dt-bindings/gpio/gpio.h> diff --git a/Documentation/devicetree/bindings/media/i2c/mt9m111.txt b/Documentation/devicetree/bindings/media/i2c/mt9m111.txt index ed5a334b1e57..6b910036b57e 100644 --- a/Documentation/devicetree/bindings/media/i2c/mt9m111.txt +++ b/Documentation/devicetree/bindings/media/i2c/mt9m111.txt @@ -6,6 +6,8 @@ interface. Required Properties: - compatible: value should be "micron,mt9m111" +- clocks: reference to the master clock. +- clock-names: shall be "mclk". For further reading on port node refer to Documentation/devicetree/bindings/media/video-interfaces.txt. @@ -16,6 +18,8 @@ Example: mt9m111@5d { compatible = "micron,mt9m111"; reg = <0x5d>; + clocks = <&mclk>; + clock-names = "mclk"; remote = <&pxa_camera>; port { diff --git a/Documentation/devicetree/bindings/media/i2c/ov5640.txt b/Documentation/devicetree/bindings/media/i2c/ov5640.txt index 540b36c4b1f2..8e36da0d8406 100644 --- a/Documentation/devicetree/bindings/media/i2c/ov5640.txt +++ b/Documentation/devicetree/bindings/media/i2c/ov5640.txt @@ -1,4 +1,4 @@ -* Omnivision OV5640 MIPI CSI-2 sensor +* Omnivision OV5640 MIPI CSI-2 / parallel sensor Required Properties: - compatible: should be "ovti,ov5640" @@ -18,7 +18,25 @@ The device node must contain one 'port' child node for its digital output video port, in accordance with the video interface bindings defined in Documentation/devicetree/bindings/media/video-interfaces.txt. -Example: +OV5640 can be connected to a MIPI CSI-2 bus or a parallel bus endpoint. + +Endpoint node required properties for CSI-2 connection are: +- remote-endpoint: a phandle to the bus receiver's endpoint node. +- clock-lanes: should be set to <0> (clock lane on hardware lane 0) +- data-lanes: should be set to <1> or <1 2> (one or two CSI-2 lanes supported) + +Endpoint node required properties for parallel connection are: +- remote-endpoint: a phandle to the bus receiver's endpoint node. +- bus-width: shall be set to <8> for 8 bits parallel bus + or <10> for 10 bits parallel bus +- data-shift: shall be set to <2> for 8 bits parallel bus + (lines 9:2 are used) or <0> for 10 bits parallel bus +- hsync-active: active state of the HSYNC signal, 0/1 for LOW/HIGH respectively. +- vsync-active: active state of the VSYNC signal, 0/1 for LOW/HIGH respectively. +- pclk-sample: sample data on rising (1) or falling (0) edge of the pixel clock + signal. + +Examples: &i2c1 { ov5640: camera@3c { @@ -35,6 +53,7 @@ Example: reset-gpios = <&gpio1 20 GPIO_ACTIVE_LOW>; port { + /* MIPI CSI-2 bus endpoint */ ov5640_to_mipi_csi2: endpoint { remote-endpoint = <&mipi_csi2_from_ov5640>; clock-lanes = <0>; @@ -43,3 +62,26 @@ Example: }; }; }; + +&i2c1 { + ov5640: camera@3c { + compatible = "ovti,ov5640"; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_ov5640>; + reg = <0x3c>; + clocks = <&clk_ext_camera>; + clock-names = "xclk"; + + port { + /* Parallel bus endpoint */ + ov5640_to_parallel: endpoint { + remote-endpoint = <¶llel_from_ov5640>; + bus-width = <8>; + data-shift = <2>; /* lines 9:2 are used */ + hsync-active = <0>; + vsync-active = <0>; + pclk-sample = <1>; + }; + }; + }; +}; diff --git a/Documentation/devicetree/bindings/media/i2c/ov7740.txt b/Documentation/devicetree/bindings/media/i2c/ov7740.txt new file mode 100644 index 000000000000..af781c3a5f0e --- /dev/null +++ b/Documentation/devicetree/bindings/media/i2c/ov7740.txt @@ -0,0 +1,47 @@ +* Omnivision OV7740 CMOS image sensor + +The Omnivision OV7740 image sensor supports multiple output image +size, such as VGA, and QVGA, CIF and any size smaller. It also +supports the RAW RGB and YUV output formats. + +The common video interfaces bindings (see video-interfaces.txt) should +be used to specify link to the image data receiver. The OV7740 device +node should contain one 'port' child node with an 'endpoint' subnode. + +Required Properties: +- compatible: "ovti,ov7740". +- reg: I2C slave address of the sensor. +- clocks: Reference to the xvclk input clock. +- clock-names: "xvclk". + +Optional Properties: +- reset-gpios: Rreference to the GPIO connected to the reset_b pin, + if any. Active low with pull-ip resistor. +- powerdown-gpios: Reference to the GPIO connected to the pwdn pin, + if any. Active high with pull-down resistor. + +Endpoint node mandatory properties: +- remote-endpoint: A phandle to the bus receiver's endpoint node. + +Example: + + i2c1: i2c@fc028000 { + ov7740: camera@21 { + compatible = "ovti,ov7740"; + reg = <0x21>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_sensor_power &pinctrl_sensor_reset>; + clocks = <&isc>; + clock-names = "xvclk"; + assigned-clocks = <&isc>; + assigned-clock-rates = <24000000>; + reset-gpios = <&pioA 43 GPIO_ACTIVE_LOW>; + powerdown-gpios = <&pioA 44 GPIO_ACTIVE_HIGH>; + + port { + ov7740_0: endpoint { + remote-endpoint = <&isc_0>; + }; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/media/i2c/toshiba,et8ek8.txt b/Documentation/devicetree/bindings/media/i2c/toshiba,et8ek8.txt index 0b7b6a4d84ff..e80d5891b7ed 100644 --- a/Documentation/devicetree/bindings/media/i2c/toshiba,et8ek8.txt +++ b/Documentation/devicetree/bindings/media/i2c/toshiba,et8ek8.txt @@ -20,6 +20,13 @@ Mandatory properties is in hardware standby mode when the signal is in the low state. +Optional properties +------------------- + +- flash-leds: See ../video-interfaces.txt +- lens-focus: See ../video-interfaces.txt + + Endpoint node mandatory properties ---------------------------------- diff --git a/Documentation/devicetree/bindings/media/nvidia,tegra-vde.txt b/Documentation/devicetree/bindings/media/nvidia,tegra-vde.txt new file mode 100644 index 000000000000..470237ed6fe5 --- /dev/null +++ b/Documentation/devicetree/bindings/media/nvidia,tegra-vde.txt @@ -0,0 +1,55 @@ +NVIDIA Tegra Video Decoder Engine + +Required properties: +- compatible : Must contain one of the following values: + - "nvidia,tegra20-vde" + - "nvidia,tegra30-vde" + - "nvidia,tegra114-vde" + - "nvidia,tegra124-vde" + - "nvidia,tegra132-vde" +- reg : Must contain an entry for each entry in reg-names. +- reg-names : Must include the following entries: + - sxe + - bsev + - mbe + - ppe + - mce + - tfe + - ppb + - vdma + - frameid +- iram : Must contain phandle to the mmio-sram device node that represents + IRAM region used by VDE. +- interrupts : Must contain an entry for each entry in interrupt-names. +- interrupt-names : Must include the following entries: + - sync-token + - bsev + - sxe +- clocks : Must include the following entries: + - vde +- resets : Must include the following entries: + - vde + +Example: + +video-codec@6001a000 { + compatible = "nvidia,tegra20-vde"; + reg = <0x6001a000 0x1000 /* Syntax Engine */ + 0x6001b000 0x1000 /* Video Bitstream Engine */ + 0x6001c000 0x100 /* Macroblock Engine */ + 0x6001c200 0x100 /* Post-processing Engine */ + 0x6001c400 0x100 /* Motion Compensation Engine */ + 0x6001c600 0x100 /* Transform Engine */ + 0x6001c800 0x100 /* Pixel prediction block */ + 0x6001ca00 0x100 /* Video DMA */ + 0x6001d800 0x300 /* Video frame controls */>; + reg-names = "sxe", "bsev", "mbe", "ppe", "mce", + "tfe", "ppb", "vdma", "frameid"; + iram = <&vde_pool>; /* IRAM region */ + interrupts = <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>, /* Sync token interrupt */ + <GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>, /* BSE-V interrupt */ + <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>; /* SXE interrupt */ + interrupt-names = "sync-token", "bsev", "sxe"; + clocks = <&tegra_car TEGRA20_CLK_VDE>; + resets = <&tegra_car 61>; +}; diff --git a/Documentation/devicetree/bindings/media/xilinx/xlnx,v-tpg.txt b/Documentation/devicetree/bindings/media/xilinx/xlnx,v-tpg.txt index 9dd86b3db937..439351ab2a79 100644 --- a/Documentation/devicetree/bindings/media/xilinx/xlnx,v-tpg.txt +++ b/Documentation/devicetree/bindings/media/xilinx/xlnx,v-tpg.txt @@ -66,6 +66,6 @@ Example: tpg1_out: endpoint { remote-endpoint = <&switch_in0>; }; - }: + }; }; }; diff --git a/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt b/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt index 4e4aee4439ea..979dc7b6cfe8 100644 --- a/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt +++ b/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt @@ -4,7 +4,10 @@ This PCIe host controller is based on the Synopsys DesignWare PCIe IP and thus inherits all the common properties defined in designware-pcie.txt. Required properties: -- compatible: "axis,artpec6-pcie", "snps,dw-pcie" +- compatible: "axis,artpec6-pcie", "snps,dw-pcie" for ARTPEC-6 in RC mode; + "axis,artpec6-pcie-ep", "snps,dw-pcie" for ARTPEC-6 in EP mode; + "axis,artpec7-pcie", "snps,dw-pcie" for ARTPEC-7 in RC mode; + "axis,artpec7-pcie-ep", "snps,dw-pcie" for ARTPEC-7 in EP mode; - reg: base addresses and lengths of the PCIe controller (DBI), the PHY controller, and configuration address space. - reg-names: Must include the following entries: diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.txt b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.txt new file mode 100644 index 000000000000..9a305237fa6e --- /dev/null +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.txt @@ -0,0 +1,22 @@ +* Cadence PCIe endpoint controller + +Required properties: +- compatible: Should contain "cdns,cdns-pcie-ep" to identify the IP used. +- reg: Should contain the controller register base address and AXI interface + region base address respectively. +- reg-names: Must be "reg" and "mem" respectively. +- cdns,max-outbound-regions: Set to maximum number of outbound regions + +Optional properties: +- max-functions: Maximum number of functions that can be configured (default 1). + +Example: + +pcie@fc000000 { + compatible = "cdns,cdns-pcie-ep"; + reg = <0x0 0xfc000000 0x0 0x01000000>, + <0x0 0x80000000 0x0 0x40000000>; + reg-names = "reg", "mem"; + cdns,max-outbound-regions = <16>; + max-functions = /bits/ 8 <8>; +}; diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.txt b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.txt new file mode 100644 index 000000000000..20a33f38f69d --- /dev/null +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.txt @@ -0,0 +1,60 @@ +* Cadence PCIe host controller + +This PCIe controller inherits the base properties defined in +host-generic-pci.txt. + +Required properties: +- compatible: Should contain "cdns,cdns-pcie-host" to identify the IP used. +- reg: Should contain the controller register base address, PCIe configuration + window base address, and AXI interface region base address respectively. +- reg-names: Must be "reg", "cfg" and "mem" respectively. +- #address-cells: Set to <3> +- #size-cells: Set to <2> +- device_type: Set to "pci" +- ranges: Ranges for the PCI memory and I/O regions +- #interrupt-cells: Set to <1> +- interrupt-map-mask and interrupt-map: Standard PCI properties to define the + mapping of the PCIe interface to interrupt numbers. + +Optional properties: +- cdns,max-outbound-regions: Set to maximum number of outbound regions + (default 32) +- cdns,no-bar-match-nbits: Set into the no BAR match register to configure the + number of least significant bits kept during inbound (PCIe -> AXI) address + translations (default 32) +- vendor-id: The PCI vendor ID (16 bits, default is design dependent) +- device-id: The PCI device ID (16 bits, default is design dependent) + +Example: + +pcie@fb000000 { + compatible = "cdns,cdns-pcie-host"; + device_type = "pci"; + #address-cells = <3>; + #size-cells = <2>; + bus-range = <0x0 0xff>; + linux,pci-domain = <0>; + cdns,max-outbound-regions = <16>; + cdns,no-bar-match-nbits = <32>; + vendor-id = /bits/ 16 <0x17cd>; + device-id = /bits/ 16 <0x0200>; + + reg = <0x0 0xfb000000 0x0 0x01000000>, + <0x0 0x41000000 0x0 0x00001000>, + <0x0 0x40000000 0x0 0x04000000>; + reg-names = "reg", "cfg", "mem"; + + ranges = <0x02000000 0x0 0x42000000 0x0 0x42000000 0x0 0x1000000>, + <0x01000000 0x0 0x43000000 0x0 0x43000000 0x0 0x0010000>; + + #interrupt-cells = <0x1>; + + interrupt-map = <0x0 0x0 0x0 0x1 &gic 0x0 0x0 0x0 14 0x1 + 0x0 0x0 0x0 0x2 &gic 0x0 0x0 0x0 15 0x1 + 0x0 0x0 0x0 0x3 &gic 0x0 0x0 0x0 16 0x1 + 0x0 0x0 0x0 0x4 &gic 0x0 0x0 0x0 17 0x1>; + + interrupt-map-mask = <0x0 0x0 0x0 0x7>; + + msi-parent = <&its_pci>; +}; diff --git a/Documentation/devicetree/bindings/pci/samsung,exynos5440-pcie.txt b/Documentation/devicetree/bindings/pci/samsung,exynos5440-pcie.txt index 34a11bfbfb60..651d957d1051 100644 --- a/Documentation/devicetree/bindings/pci/samsung,exynos5440-pcie.txt +++ b/Documentation/devicetree/bindings/pci/samsung,exynos5440-pcie.txt @@ -6,9 +6,6 @@ and thus inherits all the common properties defined in designware-pcie.txt. Required properties: - compatible: "samsung,exynos5440-pcie" - reg: base addresses and lengths of the PCIe controller, - the PHY controller, additional register for the PHY controller. - (Registers for the PHY controller are DEPRECATED. - Use the PHY framework.) - reg-names : First name should be set to "elbi". And use the "config" instead of getting the configuration address space from "ranges". @@ -23,49 +20,8 @@ For other common properties, refer to Example: -SoC-specific DT Entry: +SoC-specific DT Entry (with using PHY framework): - pcie@290000 { - compatible = "samsung,exynos5440-pcie", "snps,dw-pcie"; - reg = <0x290000 0x1000 - 0x270000 0x1000 - 0x271000 0x40>; - interrupts = <0 20 0>, <0 21 0>, <0 22 0>; - clocks = <&clock 28>, <&clock 27>; - clock-names = "pcie", "pcie_bus"; - #address-cells = <3>; - #size-cells = <2>; - device_type = "pci"; - ranges = <0x00000800 0 0x40000000 0x40000000 0 0x00001000 /* configuration space */ - 0x81000000 0 0 0x40001000 0 0x00010000 /* downstream I/O */ - 0x82000000 0 0x40011000 0x40011000 0 0x1ffef000>; /* non-prefetchable memory */ - #interrupt-cells = <1>; - interrupt-map-mask = <0 0 0 0>; - interrupt-map = <0 0 0 0 &gic GIC_SPI 21 IRQ_TYPE_LEVEL_HIGH>; - num-lanes = <4>; - }; - - pcie@2a0000 { - compatible = "samsung,exynos5440-pcie", "snps,dw-pcie"; - reg = <0x2a0000 0x1000 - 0x272000 0x1000 - 0x271040 0x40>; - interrupts = <0 23 0>, <0 24 0>, <0 25 0>; - clocks = <&clock 29>, <&clock 27>; - clock-names = "pcie", "pcie_bus"; - #address-cells = <3>; - #size-cells = <2>; - device_type = "pci"; - ranges = <0x00000800 0 0x60000000 0x60000000 0 0x00001000 /* configuration space */ - 0x81000000 0 0 0x60001000 0 0x00010000 /* downstream I/O */ - 0x82000000 0 0x60011000 0x60011000 0 0x1ffef000>; /* non-prefetchable memory */ - #interrupt-cells = <1>; - interrupt-map-mask = <0 0 0 0>; - interrupt-map = <0 0 0 0 &gic GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>; - num-lanes = <4>; - }; - -With using PHY framework: pcie_phy0: pcie-phy@270000 { ... reg = <0x270000 0x1000>, <0x271000 0x40>; @@ -74,13 +30,21 @@ With using PHY framework: }; pcie@290000 { - ... + compatible = "samsung,exynos5440-pcie", "snps,dw-pcie"; reg = <0x290000 0x1000>, <0x40000000 0x1000>; reg-names = "elbi", "config"; + clocks = <&clock 28>, <&clock 27>; + clock-names = "pcie", "pcie_bus"; + #address-cells = <3>; + #size-cells = <2>; + device_type = "pci"; phys = <&pcie_phy0>; ranges = <0x81000000 0 0 0x60001000 0 0x00010000 0x82000000 0 0x60011000 0x60011000 0 0x1ffef000>; - ... + #interrupt-cells = <1>; + interrupt-map-mask = <0 0 0 0>; + interrupt-map = <0 0 0 0 &gic GIC_SPI 21 IRQ_TYPE_LEVEL_HIGH>; + num-lanes = <4>; }; Board-specific DT Entry: diff --git a/Documentation/devicetree/bindings/pwm/pwm-meson.txt b/Documentation/devicetree/bindings/pwm/pwm-meson.txt index 1ee81321c35e..1fa3f7182133 100644 --- a/Documentation/devicetree/bindings/pwm/pwm-meson.txt +++ b/Documentation/devicetree/bindings/pwm/pwm-meson.txt @@ -5,6 +5,8 @@ Required properties: - compatible: Shall contain "amlogic,meson8b-pwm" or "amlogic,meson-gxbb-pwm" or "amlogic,meson-gxbb-ao-pwm" + or "amlogic,meson-axg-ee-pwm" + or "amlogic,meson-axg-ao-pwm" - #pwm-cells: Should be 3. See pwm.txt in this directory for a description of the cells format. diff --git a/Documentation/devicetree/bindings/thermal/armada-thermal.txt b/Documentation/devicetree/bindings/thermal/armada-thermal.txt index 24aacf8948c5..e0d013a2e66d 100644 --- a/Documentation/devicetree/bindings/thermal/armada-thermal.txt +++ b/Documentation/devicetree/bindings/thermal/armada-thermal.txt @@ -2,22 +2,35 @@ Required properties: -- compatible: Should be set to one of the following: - marvell,armada370-thermal - marvell,armada375-thermal - marvell,armada380-thermal - marvell,armadaxp-thermal +- compatible: Should be set to one of the following: + * marvell,armada370-thermal + * marvell,armada375-thermal + * marvell,armada380-thermal + * marvell,armadaxp-thermal + * marvell,armada-ap806-thermal + * marvell,armada-cp110-thermal -- reg: Device's register space. - Two entries are expected, see the examples below. - The first one is required for the sensor register; - the second one is required for the control register - to be used for sensor initialization (a.k.a. calibration). +- reg: Device's register space. + Two entries are expected, see the examples below. The first one points + to the status register (4B). The second one points to the control + registers (8B). + Note: The compatibles marvell,armada370-thermal, + marvell,armada380-thermal, and marvell,armadaxp-thermal must point to + "control MSB/control 1", with size of 4 (deprecated binding), or point + to "control LSB/control 0" with size of 8 (current binding). All other + compatibles must point to "control LSB/control 0" with size of 8. -Example: +Examples: + /* Legacy bindings */ thermal@d0018300 { compatible = "marvell,armada370-thermal"; - reg = <0xd0018300 0x4 + reg = <0xd0018300 0x4 0xd0018304 0x4>; }; + + ap_thermal: thermal@6f8084 { + compatible = "marvell,armada-ap806-thermal"; + reg = <0x6f808C 0x4>, + <0x6f8084 0x8>; + }; diff --git a/Documentation/devicetree/bindings/thermal/rcar-thermal.txt b/Documentation/devicetree/bindings/thermal/rcar-thermal.txt index a8e52c8ccfcc..349e635f2d87 100644 --- a/Documentation/devicetree/bindings/thermal/rcar-thermal.txt +++ b/Documentation/devicetree/bindings/thermal/rcar-thermal.txt @@ -6,6 +6,7 @@ Required properties: "renesas,rcar-thermal" (without thermal-zone) as fallback. Examples with soctypes are: - "renesas,thermal-r8a73a4" (R-Mobile APE6) + - "renesas,thermal-r8a7743" (RZ/G1M) - "renesas,thermal-r8a7779" (R-Car H1) - "renesas,thermal-r8a7790" (R-Car H2) - "renesas,thermal-r8a7791" (R-Car M2-W) diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt index b1fa64a1d4d0..ae850d6c0ad3 100644 --- a/Documentation/devicetree/bindings/vendor-prefixes.txt +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt @@ -125,6 +125,7 @@ focaltech FocalTech Systems Co.,Ltd friendlyarm Guangzhou FriendlyARM Computer Tech Co., Ltd fsl Freescale Semiconductor fujitsu Fujitsu Ltd. +gcw Game Consoles Worldwide ge General Electric Company geekbuying GeekBuying gef GE Fanuc Intelligent Platforms Embedded Systems, Inc. diff --git a/Documentation/devicetree/bindings/watchdog/cortina,gemini-watchdog.txt b/Documentation/devicetree/bindings/watchdog/cortina,gemini-watchdog.txt deleted file mode 100644 index bc4b865d178b..000000000000 --- a/Documentation/devicetree/bindings/watchdog/cortina,gemini-watchdog.txt +++ /dev/null @@ -1,17 +0,0 @@ -Cortina Systems Gemini SoC Watchdog - -Required properties: -- compatible : must be "cortina,gemini-watchdog" -- reg : shall contain base register location and length -- interrupts : shall contain the interrupt for the watchdog - -Optional properties: -- timeout-sec : the default watchdog timeout in seconds. - -Example: - -watchdog@41000000 { - compatible = "cortina,gemini-watchdog"; - reg = <0x41000000 0x1000>; - interrupts = <3 IRQ_TYPE_LEVEL_HIGH>; -}; diff --git a/Documentation/devicetree/bindings/watchdog/cortina,gemin-watchdog.txt b/Documentation/devicetree/bindings/watchdog/faraday,ftwdt010.txt index bc4b865d178b..9ecdb502e605 100644 --- a/Documentation/devicetree/bindings/watchdog/cortina,gemin-watchdog.txt +++ b/Documentation/devicetree/bindings/watchdog/faraday,ftwdt010.txt @@ -1,7 +1,12 @@ -Cortina Systems Gemini SoC Watchdog +Faraday Technology FTWDT010 watchdog + +This is an IP part from Faraday Technology found in the Gemini +SoCs and others. Required properties: -- compatible : must be "cortina,gemini-watchdog" +- compatible : must be one of + "faraday,ftwdt010" + "cortina,gemini-watchdog", "faraday,ftwdt010" - reg : shall contain base register location and length - interrupts : shall contain the interrupt for the watchdog @@ -11,7 +16,7 @@ Optional properties: Example: watchdog@41000000 { - compatible = "cortina,gemini-watchdog"; + compatible = "faraday,ftwdt010"; reg = <0x41000000 0x1000>; interrupts = <3 IRQ_TYPE_LEVEL_HIGH>; }; diff --git a/Documentation/devicetree/bindings/watchdog/ingenic,jz4740-wdt.txt b/Documentation/devicetree/bindings/watchdog/ingenic,jz4740-wdt.txt index 3c7a1cd13b10..cb44918f01a8 100644 --- a/Documentation/devicetree/bindings/watchdog/ingenic,jz4740-wdt.txt +++ b/Documentation/devicetree/bindings/watchdog/ingenic,jz4740-wdt.txt @@ -1,7 +1,7 @@ -Ingenic Watchdog Timer (WDT) Controller for JZ4740 +Ingenic Watchdog Timer (WDT) Controller for JZ4740 & JZ4780 Required properties: -compatible: "ingenic,jz4740-watchdog" +compatible: "ingenic,jz4740-watchdog" or "ingenic,jz4780-watchdog" reg: Register address and length for watchdog registers Example: diff --git a/Documentation/devicetree/bindings/watchdog/realtek,rtd119x.txt b/Documentation/devicetree/bindings/watchdog/realtek,rtd119x.txt new file mode 100644 index 000000000000..05653054bd5b --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/realtek,rtd119x.txt @@ -0,0 +1,17 @@ +Realtek RTD1295 Watchdog +======================== + +Required properties: + +- compatible : Should be "realtek,rtd1295-watchdog" +- reg : Specifies the physical base address and size of registers +- clocks : Specifies one clock input + + +Example: + + watchdog@98007680 { + compatible = "realtek,rtd1295-watchdog"; + reg = <0x98007680 0x100>; + clocks = <&osc27M>; + }; diff --git a/Documentation/devicetree/bindings/watchdog/renesas-wdt.txt b/Documentation/devicetree/bindings/watchdog/renesas-wdt.txt index bf6d1ca58af7..74b2f03c1515 100644 --- a/Documentation/devicetree/bindings/watchdog/renesas-wdt.txt +++ b/Documentation/devicetree/bindings/watchdog/renesas-wdt.txt @@ -4,10 +4,11 @@ Required properties: - compatible : Should be "renesas,<soctype>-wdt", and "renesas,rcar-gen3-wdt" or "renesas,rza-wdt" as fallback. Examples with soctypes are: + - "renesas,r7s72100-wdt" (RZ/A1) - "renesas,r8a7795-wdt" (R-Car H3) - "renesas,r8a7796-wdt" (R-Car M3-W) + - "renesas,r8a77970-wdt" (R-Car V3M) - "renesas,r8a77995-wdt" (R-Car D3) - - "renesas,r7s72100-wdt" (RZ/A1) When compatible with the generic version, nodes must list the SoC-specific version corresponding to the platform first, followed by the generic diff --git a/Documentation/devicetree/bindings/watchdog/sprd-wdt.txt b/Documentation/devicetree/bindings/watchdog/sprd-wdt.txt new file mode 100644 index 000000000000..aeaf3e0caf47 --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/sprd-wdt.txt @@ -0,0 +1,19 @@ +Spreadtrum SoCs Watchdog timer + +Required properties: +- compatible : Should be "sprd,sp9860-wdt". +- reg : Specifies base physical address and size of the registers. +- interrupts : Exactly one interrupt specifier. +- timeout-sec : Contain the default watchdog timeout in seconds. +- clock-names : Contain the input clock names. +- clocks : Phandles to input clocks. + +Example: + watchdog: watchdog@40310000 { + compatible = "sprd,sp9860-wdt"; + reg = <0 0x40310000 0 0x1000>; + interrupts = <GIC_SPI 61 IRQ_TYPE_LEVEL_HIGH>; + timeout-sec = <12>; + clock-names = "enable", "rtc_enable"; + clocks = <&clk_aon_apb_gates1 8>, <&clk_aon_apb_rtc_gates 9>; + }; diff --git a/Documentation/filesystems/overlayfs.txt b/Documentation/filesystems/overlayfs.txt index e6a5f4912b6d..6ea1e64d1464 100644 --- a/Documentation/filesystems/overlayfs.txt +++ b/Documentation/filesystems/overlayfs.txt @@ -190,6 +190,20 @@ Mount options: Redirects are not created and not followed (equivalent to "redirect_dir=off" if "redirect_always_follow" feature is not enabled). +When the NFS export feature is enabled, every copied up directory is +indexed by the file handle of the lower inode and a file handle of the +upper directory is stored in a "trusted.overlay.upper" extended attribute +on the index entry. On lookup of a merged directory, if the upper +directory does not match the file handle stores in the index, that is an +indication that multiple upper directories may be redirected to the same +lower directory. In that case, lookup returns an error and warns about +a possible inconsistency. + +Because lower layer redirects cannot be verified with the index, enabling +NFS export support on an overlay filesystem with no upper layer requires +turning off redirect follow (e.g. "redirect_dir=nofollow"). + + Non-directories --------------- @@ -281,9 +295,9 @@ filesystem, so both st_dev and st_ino of the file may change. Any open files referring to this inode will access the old data. -If a file with multiple hard links is copied up, then this will -"break" the link. Changes will not be propagated to other names -referring to the same inode. +Unless "inode index" feature is enabled, if a file with multiple hard +links is copied up, then this will "break" the link. Changes will not be +propagated to other names referring to the same inode. Unless "redirect_dir" feature is enabled, rename(2) on a lower or merged directory will fail with EXDEV. @@ -299,6 +313,92 @@ filesystem are not allowed. If the underlying filesystem is changed, the behavior of the overlay is undefined, though it will not result in a crash or deadlock. +When the overlay NFS export feature is enabled, overlay filesystems +behavior on offline changes of the underlying lower layer is different +than the behavior when NFS export is disabled. + +On every copy_up, an NFS file handle of the lower inode, along with the +UUID of the lower filesystem, are encoded and stored in an extended +attribute "trusted.overlay.origin" on the upper inode. + +When the NFS export feature is enabled, a lookup of a merged directory, +that found a lower directory at the lookup path or at the path pointed +to by the "trusted.overlay.redirect" extended attribute, will verify +that the found lower directory file handle and lower filesystem UUID +match the origin file handle that was stored at copy_up time. If a +found lower directory does not match the stored origin, that directory +will not be merged with the upper directory. + + + +NFS export +---------- + +When the underlying filesystems supports NFS export and the "nfs_export" +feature is enabled, an overlay filesystem may be exported to NFS. + +With the "nfs_export" feature, on copy_up of any lower object, an index +entry is created under the index directory. The index entry name is the +hexadecimal representation of the copy up origin file handle. For a +non-directory object, the index entry is a hard link to the upper inode. +For a directory object, the index entry has an extended attribute +"trusted.overlay.upper" with an encoded file handle of the upper +directory inode. + +When encoding a file handle from an overlay filesystem object, the +following rules apply: + +1. For a non-upper object, encode a lower file handle from lower inode +2. For an indexed object, encode a lower file handle from copy_up origin +3. For a pure-upper object and for an existing non-indexed upper object, + encode an upper file handle from upper inode + +The encoded overlay file handle includes: + - Header including path type information (e.g. lower/upper) + - UUID of the underlying filesystem + - Underlying filesystem encoding of underlying inode + +This encoding format is identical to the encoding format file handles that +are stored in extended attribute "trusted.overlay.origin". + +When decoding an overlay file handle, the following steps are followed: + +1. Find underlying layer by UUID and path type information. +2. Decode the underlying filesystem file handle to underlying dentry. +3. For a lower file handle, lookup the handle in index directory by name. +4. If a whiteout is found in index, return ESTALE. This represents an + overlay object that was deleted after its file handle was encoded. +5. For a non-directory, instantiate a disconnected overlay dentry from the + decoded underlying dentry, the path type and index inode, if found. +6. For a directory, use the connected underlying decoded dentry, path type + and index, to lookup a connected overlay dentry. + +Decoding a non-directory file handle may return a disconnected dentry. +copy_up of that disconnected dentry will create an upper index entry with +no upper alias. + +When overlay filesystem has multiple lower layers, a middle layer +directory may have a "redirect" to lower directory. Because middle layer +"redirects" are not indexed, a lower file handle that was encoded from the +"redirect" origin directory, cannot be used to find the middle or upper +layer directory. Similarly, a lower file handle that was encoded from a +descendant of the "redirect" origin directory, cannot be used to +reconstruct a connected overlay path. To mitigate the cases of +directories that cannot be decoded from a lower file handle, these +directories are copied up on encode and encoded as an upper file handle. +On an overlay filesystem with no upper layer this mitigation cannot be +used NFS export in this setup requires turning off redirect follow (e.g. +"redirect_dir=nofollow"). + +The overlay filesystem does not support non-directory connectable file +handles, so exporting with the 'subtree_check' exportfs configuration will +cause failures to lookup files over NFS. + +When the NFS export feature is enabled, all directory index entries are +verified on mount time to check that upper file handles are not stale. +This verification may cause significant overhead in some cases. + + Testsuite --------- diff --git a/Documentation/infiniband/user_verbs.txt b/Documentation/infiniband/user_verbs.txt index e5092d696da2..df049b9f5b6e 100644 --- a/Documentation/infiniband/user_verbs.txt +++ b/Documentation/infiniband/user_verbs.txt @@ -5,7 +5,7 @@ USERSPACE VERBS ACCESS described in chapter 11 of the InfiniBand Architecture Specification. To use the verbs, the libibverbs library, available from - http://www.openfabrics.org/, is required. libibverbs contains a + https://github.com/linux-rdma/rdma-core, is required. libibverbs contains a device-independent API for using the ib_uverbs interface. libibverbs also requires appropriate device-dependent kernel and userspace driver for your InfiniBand hardware. For example, to use diff --git a/Documentation/media/dmx.h.rst.exceptions b/Documentation/media/dmx.h.rst.exceptions index 629db384104a..63f55a9ae2b1 100644 --- a/Documentation/media/dmx.h.rst.exceptions +++ b/Documentation/media/dmx.h.rst.exceptions @@ -54,3 +54,5 @@ ignore symbol DMX_OUT_DECODER ignore symbol DMX_OUT_TAP ignore symbol DMX_OUT_TS_TAP ignore symbol DMX_OUT_TSDEMUX_TAP + +replace ioctl DMX_DQBUF dmx_qbuf diff --git a/Documentation/media/kapi/cec-core.rst b/Documentation/media/kapi/cec-core.rst index d37e107f2fde..62b9a1448177 100644 --- a/Documentation/media/kapi/cec-core.rst +++ b/Documentation/media/kapi/cec-core.rst @@ -103,6 +103,7 @@ your driver: /* Low-level callbacks */ int (*adap_enable)(struct cec_adapter *adap, bool enable); int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); + int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable); int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, u32 signal_free_time, struct cec_msg *msg); @@ -144,6 +145,19 @@ called if the CEC_CAP_MONITOR_ALL capability is set. This callback is optional Note that adap_monitor_all_enable must return 0 if enable is false. +To enable/disable the 'monitor pin' mode: + +.. c:function:: + int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable); + +If enabled, then the adapter should be put in a mode to also monitor CEC pin +changes. Not all hardware supports this and this function is only called if +the CEC_CAP_MONITOR_PIN capability is set. This callback is optional +(some hardware may always be in 'monitor pin' mode). + +Note that adap_monitor_pin_enable must return 0 if enable is false. + + To program a new logical address: .. c:function:: diff --git a/Documentation/media/kapi/dtv-ca.rst b/Documentation/media/kapi/dtv-ca.rst index a4dd700189b0..fded096b937c 100644 --- a/Documentation/media/kapi/dtv-ca.rst +++ b/Documentation/media/kapi/dtv-ca.rst @@ -1,4 +1,4 @@ Digital TV Conditional Access kABI ---------------------------------- -.. kernel-doc:: drivers/media/dvb-core/dvb_ca_en50221.h +.. kernel-doc:: include/media/dvb_ca_en50221.h diff --git a/Documentation/media/kapi/dtv-common.rst b/Documentation/media/kapi/dtv-common.rst index 40cf1033b5e1..7a9574f03190 100644 --- a/Documentation/media/kapi/dtv-common.rst +++ b/Documentation/media/kapi/dtv-common.rst @@ -7,7 +7,7 @@ Math functions Provide some commonly-used math functions, usually required in order to estimate signal strength and signal to noise measurements in dB. -.. kernel-doc:: drivers/media/dvb-core/dvb_math.h +.. kernel-doc:: include/media/dvb_math.h DVB devices @@ -15,7 +15,7 @@ DVB devices Those functions are responsible for handling the DVB device nodes. -.. kernel-doc:: drivers/media/dvb-core/dvbdev.h +.. kernel-doc:: include/media/dvbdev.h Digital TV Ring buffer ~~~~~~~~~~~~~~~~~~~~~~ @@ -52,4 +52,9 @@ copy it from/to userspace. Resetting the buffer counts as a read and write operation. Two or more writers must be locked against each other. -.. kernel-doc:: drivers/media/dvb-core/dvb_ringbuffer.h +.. kernel-doc:: include/media/dvb_ringbuffer.h + +Digital TV VB2 handler +~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/media/dvb_vb2.h diff --git a/Documentation/media/kapi/dtv-demux.rst b/Documentation/media/kapi/dtv-demux.rst index 7aa865a2b43f..24857133e4e8 100644 --- a/Documentation/media/kapi/dtv-demux.rst +++ b/Documentation/media/kapi/dtv-demux.rst @@ -8,7 +8,7 @@ The Kernel Digital TV Demux kABI defines a driver-internal interface for registering low-level, hardware specific driver to a hardware independent demux layer. It is only of interest for Digital TV device driver writers. The header file for this kABI is named ``demux.h`` and located in -``drivers/media/dvb-core``. +``include/media``. The demux kABI should be implemented for each demux in the system. It is used to select the TS source of a demux and to manage the demux resources. @@ -69,14 +69,14 @@ callbacks. Digital TV Demux device registration functions and data structures ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.. kernel-doc:: drivers/media/dvb-core/dmxdev.h +.. kernel-doc:: include/media/dmxdev.h High-level Digital TV demux interface ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.. kernel-doc:: drivers/media/dvb-core/dvb_demux.h +.. kernel-doc:: include/media/dvb_demux.h Driver-internal low-level hardware specific driver demux interface ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.. kernel-doc:: drivers/media/dvb-core/demux.h +.. kernel-doc:: include/media/demux.h diff --git a/Documentation/media/kapi/dtv-frontend.rst b/Documentation/media/kapi/dtv-frontend.rst index f1a2fdaab5ba..472650cdb100 100644 --- a/Documentation/media/kapi/dtv-frontend.rst +++ b/Documentation/media/kapi/dtv-frontend.rst @@ -8,7 +8,7 @@ The Digital TV Frontend kABI defines a driver-internal interface for registering low-level, hardware specific driver to a hardware independent frontend layer. It is only of interest for Digital TV device driver writers. The header file for this API is named ``dvb_frontend.h`` and located in -``drivers/media/dvb-core``. +``include/media/``. Demodulator driver ^^^^^^^^^^^^^^^^^^ @@ -17,7 +17,7 @@ The demodulator driver is responsible to talk with the decoding part of the hardware. Such driver should implement :c:type:`dvb_frontend_ops`, with tells what type of digital TV standards are supported, and points to a series of functions that allow the DVB core to command the hardware via -the code under ``drivers/media/dvb-core/dvb_frontend.c``. +the code under ``include/media/dvb_frontend.c``. A typical example of such struct in a driver ``foo`` is:: @@ -118,7 +118,7 @@ Satellite TV reception is:: .. |delta| unicode:: U+00394 -The ``drivers/media/dvb-core/dvb_frontend.c`` has a kernel thread with is +The ``include/media/dvb_frontend.c`` has a kernel thread with is responsible for tuning the device. It supports multiple algorithms to detect a channel, as defined at enum :c:func:`dvbfe_algo`. @@ -440,4 +440,4 @@ monotonic stats at the right time. Digital TV Frontend functions and types ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.. kernel-doc:: drivers/media/dvb-core/dvb_frontend.h +.. kernel-doc:: include/media/dvb_frontend.h diff --git a/Documentation/media/kapi/dtv-net.rst b/Documentation/media/kapi/dtv-net.rst index ced991b73d69..158c7cbd7600 100644 --- a/Documentation/media/kapi/dtv-net.rst +++ b/Documentation/media/kapi/dtv-net.rst @@ -1,4 +1,4 @@ Digital TV Network kABI ----------------------- -.. kernel-doc:: drivers/media/dvb-core/dvb_net.h +.. kernel-doc:: include/media/dvb_net.h diff --git a/Documentation/media/kapi/rc-core.rst b/Documentation/media/kapi/rc-core.rst index a45895886257..4759f020d6b2 100644 --- a/Documentation/media/kapi/rc-core.rst +++ b/Documentation/media/kapi/rc-core.rst @@ -4,11 +4,83 @@ Remote Controller devices Remote Controller core ~~~~~~~~~~~~~~~~~~~~~~ -.. kernel-doc:: include/media/rc-core.h +The remote controller core implements infrastructure to receive and send +remote controller keyboard keystrokes and mouse events. -.. kernel-doc:: include/media/rc-map.h +Every time a key is pressed on a remote controller, a scan code is produced. +Also, on most hardware, keeping a key pressed for more than a few dozens of +milliseconds produce a repeat key event. That's somewhat similar to what +a normal keyboard or mouse is handled internally on Linux\ [#f1]_. So, the +remote controller core is implemented on the top of the linux input/evdev +interface. + +.. [#f1] + + The main difference is that, on keyboard events, the keyboard controller + produces one event for a key press and another one for key release. On + infrared-based remote controllers, there's no key release event. Instead, + an extra code is produced to indicate key repeats. + +However, most of the remote controllers use infrared (IR) to transmit signals. +As there are several protocols used to modulate infrared signals, one +important part of the core is dedicated to adjust the driver and the core +system to support the infrared protocol used by the emitter. + +The infrared transmission is done by blinking a infrared emitter using a +carrier. The carrier can be switched on or off by the IR transmitter +hardware. When the carrier is switched on, it is called *PULSE*. +When the carrier is switched off, it is called *SPACE*. + +In other words, a typical IR transmission can be viewed as a sequence of +*PULSE* and *SPACE* events, each with a given duration. + +The carrier parameters (frequency, duty cycle) and the intervals for +*PULSE* and *SPACE* events depend on the protocol. +For example, the NEC protocol uses a carrier of 38kHz, and transmissions +start with a 9ms *PULSE* and a 4.5ms SPACE. It then transmits 16 bits of +scan code, being 8 bits for address (usually it is a fixed number for a +given remote controller), followed by 8 bits of code. A bit "1" is modulated +with 560µs *PULSE* followed by 1690µs *SPACE* and a bit "0" is modulated +with 560µs *PULSE* followed by 560µs *SPACE*. + +At receiver, a simple low-pass filter can be used to convert the received +signal in a sequence of *PULSE/SPACE* events, filtering out the carrier +frequency. Due to that, the receiver doesn't care about the carrier's +actual frequency parameters: all it has to do is to measure the amount +of time it receives *PULSE/SPACE* events. +So, a simple IR receiver hardware will just provide a sequence of timings +for those events to the Kernel. The drivers for hardware with such kind of +receivers are identified by ``RC_DRIVER_IR_RAW``, as defined by +:c:type:`rc_driver_type`\ [#f2]_. Other hardware come with a +microcontroller that decode the *PULSE/SPACE* sequence and return scan +codes to the Kernel. Such kind of receivers are identified +by ``RC_DRIVER_SCANCODE``. -LIRC -~~~~ +.. [#f2] -.. kernel-doc:: include/media/lirc_dev.h + The RC core also supports devices that have just IR emitters, + without any receivers. Right now, all such devices work only in + raw TX mode. Such kind of hardware is identified as + ``RC_DRIVER_IR_RAW_TX``. + +When the RC core receives events produced by ``RC_DRIVER_IR_RAW`` IR +receivers, it needs to decode the IR protocol, in order to obtain the +corresponding scan code. The protocols supported by the RC core are +defined at enum :c:type:`rc_proto`. + +When the RC code receives a scan code (either directly, by a driver +of the type ``RC_DRIVER_SCANCODE``, or via its IR decoders), it needs +to convert into a Linux input event code. This is done via a mapping +table. + +The Kernel has support for mapping tables available on most media +devices. It also supports loading a table in runtime, via some +sysfs nodes. See the :ref:`RC userspace API <Remote_controllers_Intro>` +for more details. + +Remote controller data structures and functions +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/rc-core.h + +.. kernel-doc:: include/media/rc-map.h diff --git a/Documentation/media/kapi/v4l2-dev.rst b/Documentation/media/kapi/v4l2-dev.rst index b29aa616c267..7bb0505b60f1 100644 --- a/Documentation/media/kapi/v4l2-dev.rst +++ b/Documentation/media/kapi/v4l2-dev.rst @@ -196,11 +196,18 @@ device. Which device is registered depends on the type argument. The following types exist: -- ``VFL_TYPE_GRABBER``: ``/dev/videoX`` for video input/output devices -- ``VFL_TYPE_VBI``: ``/dev/vbiX`` for vertical blank data (i.e. closed captions, teletext) -- ``VFL_TYPE_RADIO``: ``/dev/radioX`` for radio tuners -- ``VFL_TYPE_SDR``: ``/dev/swradioX`` for Software Defined Radio tuners -- ``VFL_TYPE_TOUCH``: ``/dev/v4l-touchX`` for touch sensors +========================== ==================== ============================== +:c:type:`vfl_devnode_type` Device name Usage +========================== ==================== ============================== +``VFL_TYPE_GRABBER`` ``/dev/videoX`` for video input/output devices +``VFL_TYPE_VBI`` ``/dev/vbiX`` for vertical blank data (i.e. + closed captions, teletext) +``VFL_TYPE_RADIO`` ``/dev/radioX`` for radio tuners +``VFL_TYPE_SUBDEV`` ``/dev/v4l-subdevX`` for V4L2 subdevices +``VFL_TYPE_SDR`` ``/dev/swradioX`` for Software Defined Radio + (SDR) tuners +``VFL_TYPE_TOUCH`` ``/dev/v4l-touchX`` for touch sensors +========================== ==================== ============================== The last argument gives you a certain amount of control over the device device node number used (i.e. the X in ``videoX``). Normally you will pass -1 diff --git a/Documentation/media/kapi/v4l2-event.rst b/Documentation/media/kapi/v4l2-event.rst index 9938d21ef4d1..5c7e31224ddc 100644 --- a/Documentation/media/kapi/v4l2-event.rst +++ b/Documentation/media/kapi/v4l2-event.rst @@ -5,27 +5,68 @@ V4L2 events The V4L2 events provide a generic way to pass events to user space. The driver must use :c:type:`v4l2_fh` to be able to support V4L2 events. -Events are defined by a type and an optional ID. The ID may refer to a V4L2 -object such as a control ID. If unused, then the ID is 0. +Events are subscribed per-filehandle. An event specification consists of a +``type`` and is optionally associated with an object identified through the +``id`` field. If unused, then the ``id`` is 0. So an event is uniquely +identified by the ``(type, id)`` tuple. -When the user subscribes to an event the driver will allocate a number of -kevent structs for that event. So every (type, ID) event tuple will have -its own set of kevent structs. This guarantees that if a driver is generating -lots of events of one type in a short time, then that will not overwrite -events of another type. +The :c:type:`v4l2_fh` struct has a list of subscribed events on its +``subscribed`` field. -But if you get more events of one type than the number of kevents that were -reserved, then the oldest event will be dropped and the new one added. +When the user subscribes to an event, a :c:type:`v4l2_subscribed_event` +struct is added to :c:type:`v4l2_fh`\ ``.subscribed``, one for every +subscribed event. + +Each :c:type:`v4l2_subscribed_event` struct ends with a +:c:type:`v4l2_kevent` ringbuffer, with the size given by the caller +of :c:func:`v4l2_event_subscribe`. This ringbuffer is used to store any events +raised by the driver. + +So every ``(type, ID)`` event tuple will have its own +:c:type:`v4l2_kevent` ringbuffer. This guarantees that if a driver is +generating lots of events of one type in a short time, then that will +not overwrite events of another type. + +But if you get more events of one type than the size of the +:c:type:`v4l2_kevent` ringbuffer, then the oldest event will be dropped +and the new one added. + +The :c:type:`v4l2_kevent` struct links into the ``available`` +list of the :c:type:`v4l2_fh` struct so :ref:`VIDIOC_DQEVENT` will +know which event to dequeue first. + +Finally, if the event subscription is associated with a particular object +such as a V4L2 control, then that object needs to know about that as well +so that an event can be raised by that object. So the ``node`` field can +be used to link the :c:type:`v4l2_subscribed_event` struct into a list of +such objects. + +So to summarize: + +- struct :c:type:`v4l2_fh` has two lists: one of the ``subscribed`` events, + and one of the ``available`` events. + +- struct :c:type:`v4l2_subscribed_event` has a ringbuffer of raised + (pending) events of that particular type. + +- If struct :c:type:`v4l2_subscribed_event` is associated with a specific + object, then that object will have an internal list of + struct :c:type:`v4l2_subscribed_event` so it knows who subscribed an + event to that object. Furthermore, the internal struct :c:type:`v4l2_subscribed_event` has ``merge()`` and ``replace()`` callbacks which drivers can set. These callbacks are called when a new event is raised and there is no more room. + The ``replace()`` callback allows you to replace the payload of the old event with that of the new event, merging any relevant data from the old payload into the new payload that replaces it. It is called when this event type has -only one kevent struct allocated. The ``merge()`` callback allows you to merge -the oldest event payload into that of the second-oldest event payload. It is -called when there are two or more kevent structs allocated. +a ringbuffer with size is one, i.e. only one event can be stored in the +ringbuffer. + +The ``merge()`` callback allows you to merge the oldest event payload into +that of the second-oldest event payload. It is called when +the ringbuffer has size is greater than one. This way no status information is lost, just the intermediate steps leading up to that state. @@ -73,7 +114,7 @@ The ops argument allows the driver to specify a number of callbacks: Callback Description ======== ============================================================== add called when a new listener gets added (subscribing to the same - event twice will only cause this callback to get called once) + event twice will only cause this callback to get called once) del called when a listener stops listening replace replace event 'old' with event 'new'. merge merge event 'old' into event 'new'. diff --git a/Documentation/media/lirc.h.rst.exceptions b/Documentation/media/lirc.h.rst.exceptions index c130617a9986..c6e3a35d2c4e 100644 --- a/Documentation/media/lirc.h.rst.exceptions +++ b/Documentation/media/lirc.h.rst.exceptions @@ -28,6 +28,36 @@ ignore define LIRC_CAN_SEND_MASK ignore define LIRC_CAN_REC_MASK ignore define LIRC_CAN_SET_REC_DUTY_CYCLE +# Obsolete ioctls + +ignore ioctl LIRC_GET_LENGTH + +# rc protocols + +ignore symbol RC_PROTO_UNKNOWN +ignore symbol RC_PROTO_OTHER +ignore symbol RC_PROTO_RC5 +ignore symbol RC_PROTO_RC5X_20 +ignore symbol RC_PROTO_RC5_SZ +ignore symbol RC_PROTO_JVC +ignore symbol RC_PROTO_SONY12 +ignore symbol RC_PROTO_SONY15 +ignore symbol RC_PROTO_SONY20 +ignore symbol RC_PROTO_NEC +ignore symbol RC_PROTO_NECX +ignore symbol RC_PROTO_NEC32 +ignore symbol RC_PROTO_SANYO +ignore symbol RC_PROTO_MCIR2_KBD +ignore symbol RC_PROTO_MCIR2_MSE +ignore symbol RC_PROTO_RC6_0 +ignore symbol RC_PROTO_RC6_6A_20 +ignore symbol RC_PROTO_RC6_6A_24 +ignore symbol RC_PROTO_RC6_6A_32 +ignore symbol RC_PROTO_RC6_MCE +ignore symbol RC_PROTO_SHARP +ignore symbol RC_PROTO_XMP +ignore symbol RC_PROTO_CEC + # Undocumented macros ignore define PULSE_BIT @@ -40,3 +70,4 @@ ignore define LIRC_VALUE_MASK ignore define LIRC_MODE2_MASK ignore define LIRC_MODE_RAW +ignore define LIRC_MODE_LIRCCODE diff --git a/Documentation/media/uapi/dvb/dmx-expbuf.rst b/Documentation/media/uapi/dvb/dmx-expbuf.rst new file mode 100644 index 000000000000..2d96cfe891df --- /dev/null +++ b/Documentation/media/uapi/dvb/dmx-expbuf.rst @@ -0,0 +1,88 @@ +.. _DMX_EXPBUF: + +**************** +ioctl DMX_EXPBUF +**************** + +Name +==== + +DMX_EXPBUF - Export a buffer as a DMABUF file descriptor. + +.. warning:: this API is still experimental + + +Synopsis +======== + +.. c:function:: int ioctl( int fd, DMX_EXPBUF, struct dmx_exportbuffer *argp ) + :name: DMX_EXPBUF + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <dmx_fopen>`. + +``argp`` + Pointer to struct :c:type:`dmx_exportbuffer`. + + +Description +=========== + +This ioctl is an extension to the memory mapping I/O method. +It can be used to export a buffer as a DMABUF file at any time after +buffers have been allocated with the :ref:`DMX_REQBUFS` ioctl. + +To export a buffer, applications fill struct :c:type:`dmx_exportbuffer`. +Applications must set the ``index`` field. Valid index numbers +range from zero to the number of buffers allocated with :ref:`DMX_REQBUFS` +(struct :c:type:`dmx_requestbuffers` ``count``) minus one. +Additional flags may be posted in the ``flags`` field. Refer to a manual +for open() for details. Currently only O_CLOEXEC, O_RDONLY, O_WRONLY, +and O_RDWR are supported. +All other fields must be set to zero. In the +case of multi-planar API, every plane is exported separately using +multiple :ref:`DMX_EXPBUF` calls. + +After calling :ref:`DMX_EXPBUF` the ``fd`` field will be set by a +driver, on success. This is a DMABUF file descriptor. The application may +pass it to other DMABUF-aware devices. It is recommended to close a DMABUF +file when it is no longer used to allow the associated memory to be reclaimed. + + +Examples +======== + + +.. code-block:: c + + int buffer_export(int v4lfd, enum dmx_buf_type bt, int index, int *dmafd) + { + struct dmx_exportbuffer expbuf; + + memset(&expbuf, 0, sizeof(expbuf)); + expbuf.type = bt; + expbuf.index = index; + if (ioctl(v4lfd, DMX_EXPBUF, &expbuf) == -1) { + perror("DMX_EXPBUF"); + return -1; + } + + *dmafd = expbuf.fd; + + return 0; + } + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +EINVAL + A queue is not in MMAP mode or DMABUF exporting is not supported or + ``flags`` or ``index`` fields are invalid. diff --git a/Documentation/media/uapi/dvb/dmx-mmap.rst b/Documentation/media/uapi/dvb/dmx-mmap.rst new file mode 100644 index 000000000000..15d107348b9f --- /dev/null +++ b/Documentation/media/uapi/dvb/dmx-mmap.rst @@ -0,0 +1,116 @@ +.. _dmx-mmap: + +***************** +Digital TV mmap() +***************** + +Name +==== + +dmx-mmap - Map device memory into application address space + +.. warning:: this API is still experimental + +Synopsis +======== + +.. code-block:: c + + #include <unistd.h> + #include <sys/mman.h> + + +.. c:function:: void *mmap( void *start, size_t length, int prot, int flags, int fd, off_t offset ) + :name: dmx-mmap + +Arguments +========= + +``start`` + Map the buffer to this address in the application's address space. + When the ``MAP_FIXED`` flag is specified, ``start`` must be a + multiple of the pagesize and mmap will fail when the specified + address cannot be used. Use of this option is discouraged; + applications should just specify a ``NULL`` pointer here. + +``length`` + Length of the memory area to map. This must be a multiple of the + DVB packet length (188, on most drivers). + +``prot`` + The ``prot`` argument describes the desired memory protection. + Regardless of the device type and the direction of data exchange it + should be set to ``PROT_READ`` | ``PROT_WRITE``, permitting read + and write access to image buffers. Drivers should support at least + this combination of flags. + +``flags`` + The ``flags`` parameter specifies the type of the mapped object, + mapping options and whether modifications made to the mapped copy of + the page are private to the process or are to be shared with other + references. + + ``MAP_FIXED`` requests that the driver selects no other address than + the one specified. If the specified address cannot be used, + :ref:`mmap() <dmx-mmap>` will fail. If ``MAP_FIXED`` is specified, + ``start`` must be a multiple of the pagesize. Use of this option is + discouraged. + + One of the ``MAP_SHARED`` or ``MAP_PRIVATE`` flags must be set. + ``MAP_SHARED`` allows applications to share the mapped memory with + other (e. g. child-) processes. + + .. note:: + + The Linux Digital TV applications should not set the + ``MAP_PRIVATE``, ``MAP_DENYWRITE``, ``MAP_EXECUTABLE`` or ``MAP_ANON`` + flags. + +``fd`` + File descriptor returned by :ref:`open() <dmx_fopen>`. + +``offset`` + Offset of the buffer in device memory, as returned by + :ref:`DMX_QUERYBUF` ioctl. + + +Description +=========== + +The :ref:`mmap() <dmx-mmap>` function asks to map ``length`` bytes starting at +``offset`` in the memory of the device specified by ``fd`` into the +application address space, preferably at address ``start``. This latter +address is a hint only, and is usually specified as 0. + +Suitable length and offset parameters are queried with the +:ref:`DMX_QUERYBUF` ioctl. Buffers must be allocated with the +:ref:`DMX_REQBUFS` ioctl before they can be queried. + +To unmap buffers the :ref:`munmap() <dmx-munmap>` function is used. + + +Return Value +============ + +On success :ref:`mmap() <dmx-mmap>` returns a pointer to the mapped buffer. On +error ``MAP_FAILED`` (-1) is returned, and the ``errno`` variable is set +appropriately. Possible error codes are: + +EBADF + ``fd`` is not a valid file descriptor. + +EACCES + ``fd`` is not open for reading and writing. + +EINVAL + The ``start`` or ``length`` or ``offset`` are not suitable. (E. g. + they are too large, or not aligned on a ``PAGESIZE`` boundary.) + + The ``flags`` or ``prot`` value is not supported. + + No buffers have been allocated with the + :ref:`DMX_REQBUFS` ioctl. + +ENOMEM + Not enough physical or virtual memory was available to complete the + request. diff --git a/Documentation/media/uapi/dvb/dmx-munmap.rst b/Documentation/media/uapi/dvb/dmx-munmap.rst new file mode 100644 index 000000000000..d77218732bb6 --- /dev/null +++ b/Documentation/media/uapi/dvb/dmx-munmap.rst @@ -0,0 +1,54 @@ +.. _dmx-munmap: + +************ +DVB munmap() +************ + +Name +==== + +dmx-munmap - Unmap device memory + +.. warning:: This API is still experimental. + + +Synopsis +======== + +.. code-block:: c + + #include <unistd.h> + #include <sys/mman.h> + + +.. c:function:: int munmap( void *start, size_t length ) + :name: dmx-munmap + +Arguments +========= + +``start`` + Address of the mapped buffer as returned by the + :ref:`mmap() <dmx-mmap>` function. + +``length`` + Length of the mapped buffer. This must be the same value as given to + :ref:`mmap() <dmx-mmap>`. + + +Description +=========== + +Unmaps a previously with the :ref:`mmap() <dmx-mmap>` function mapped +buffer and frees it, if possible. + + +Return Value +============ + +On success :ref:`munmap() <dmx-munmap>` returns 0, on failure -1 and the +``errno`` variable is set appropriately: + +EINVAL + The ``start`` or ``length`` is incorrect, or no buffers have been + mapped yet. diff --git a/Documentation/media/uapi/dvb/dmx-qbuf.rst b/Documentation/media/uapi/dvb/dmx-qbuf.rst new file mode 100644 index 000000000000..b48c4931658e --- /dev/null +++ b/Documentation/media/uapi/dvb/dmx-qbuf.rst @@ -0,0 +1,83 @@ +.. _DMX_QBUF: + +************************* +ioctl DMX_QBUF, DMX_DQBUF +************************* + +Name +==== + +DMX_QBUF - DMX_DQBUF - Exchange a buffer with the driver + +.. warning:: this API is still experimental + + +Synopsis +======== + +.. c:function:: int ioctl( int fd, DMX_QBUF, struct dmx_buffer *argp ) + :name: DMX_QBUF + +.. c:function:: int ioctl( int fd, DMX_DQBUF, struct dmx_buffer *argp ) + :name: DMX_DQBUF + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <dmx_fopen>`. + +``argp`` + Pointer to struct :c:type:`dmx_buffer`. + + +Description +=========== + +Applications call the ``DMX_QBUF`` ioctl to enqueue an empty +(capturing) or filled (output) buffer in the driver's incoming queue. +The semantics depend on the selected I/O method. + +To enqueue a buffer applications set the ``index`` field. Valid index +numbers range from zero to the number of buffers allocated with +:ref:`DMX_REQBUFS` (struct :c:type:`dmx_requestbuffers` ``count``) minus +one. The contents of the struct :c:type:`dmx_buffer` returned +by a :ref:`DMX_QUERYBUF` ioctl will do as well. + +When ``DMX_QBUF`` is called with a pointer to this structure, it locks the +memory pages of the buffer in physical memory, so they cannot be swapped +out to disk. Buffers remain locked until dequeued, until the +the device is closed. + +Applications call the ``DMX_DQBUF`` ioctl to dequeue a filled +(capturing) buffer from the driver's outgoing queue. They just set the ``reserved`` field array to zero. When ``DMX_DQBUF`` is called with a +pointer to this structure, the driver fills the remaining fields or +returns an error code. + +By default ``DMX_DQBUF`` blocks when no buffer is in the outgoing +queue. When the ``O_NONBLOCK`` flag was given to the +:ref:`open() <dmx_fopen>` function, ``DMX_DQBUF`` returns +immediately with an ``EAGAIN`` error code when no buffer is available. + +The struct :c:type:`dmx_buffer` structure is specified in +:ref:`buffer`. + + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +EAGAIN + Non-blocking I/O has been selected using ``O_NONBLOCK`` and no + buffer was in the outgoing queue. + +EINVAL + The ``index`` is out of bounds, or no buffers have been allocated yet. + +EIO + ``DMX_DQBUF`` failed due to an internal error. Can also indicate + temporary problems like signal loss or CRC errors. diff --git a/Documentation/media/uapi/dvb/dmx-querybuf.rst b/Documentation/media/uapi/dvb/dmx-querybuf.rst new file mode 100644 index 000000000000..89481e24bb86 --- /dev/null +++ b/Documentation/media/uapi/dvb/dmx-querybuf.rst @@ -0,0 +1,63 @@ +.. _DMX_QUERYBUF: + +****************** +ioctl DMX_QUERYBUF +****************** + +Name +==== + +DMX_QUERYBUF - Query the status of a buffer + +.. warning:: this API is still experimental + + +Synopsis +======== + +.. c:function:: int ioctl( int fd, DMX_QUERYBUF, struct dvb_buffer *argp ) + :name: DMX_QUERYBUF + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <dmx_fopen>`. + +``argp`` + Pointer to struct :c:type:`dvb_buffer`. + + +Description +=========== + +This ioctl is part of the mmap streaming I/O method. It can +be used to query the status of a buffer at any time after buffers have +been allocated with the :ref:`DMX_REQBUFS` ioctl. + +Applications set the ``index`` field. Valid index numbers range from zero +to the number of buffers allocated with :ref:`DMX_REQBUFS` +(struct :c:type:`dvb_requestbuffers` ``count``) minus one. + +After calling :ref:`DMX_QUERYBUF` with a pointer to this structure, +drivers return an error code or fill the rest of the structure. + +On success, the ``offset`` will contain the offset of the buffer from the +start of the device memory, the ``length`` field its size, and the +``bytesused`` the number of bytes occupied by data in the buffer (payload). + +Return Value +============ + +On success 0 is returned, the ``offset`` will contain the offset of the +buffer from the start of the device memory, the ``length`` field its size, +and the ``bytesused`` the number of bytes occupied by data in the buffer +(payload). + +On error it returns -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +EINVAL + The ``index`` is out of bounds. diff --git a/Documentation/media/uapi/dvb/dmx-reqbufs.rst b/Documentation/media/uapi/dvb/dmx-reqbufs.rst new file mode 100644 index 000000000000..14b80d60bf35 --- /dev/null +++ b/Documentation/media/uapi/dvb/dmx-reqbufs.rst @@ -0,0 +1,74 @@ +.. _DMX_REQBUFS: + +***************** +ioctl DMX_REQBUFS +***************** + +Name +==== + +DMX_REQBUFS - Initiate Memory Mapping and/or DMA buffer I/O + +.. warning:: this API is still experimental + + +Synopsis +======== + +.. c:function:: int ioctl( int fd, DMX_REQBUFS, struct dmx_requestbuffers *argp ) + :name: DMX_REQBUFS + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <dmx_fopen>`. + +``argp`` + Pointer to struct :c:type:`dmx_requestbuffers`. + +Description +=========== + +This ioctl is used to initiate a memory mapped or DMABUF based demux I/O. + +Memory mapped buffers are located in device memory and must be allocated +with this ioctl before they can be mapped into the application's address +space. User buffers are allocated by applications themselves, and this +ioctl is merely used to switch the driver into user pointer I/O mode and +to setup some internal structures. Similarly, DMABUF buffers are +allocated by applications through a device driver, and this ioctl only +configures the driver into DMABUF I/O mode without performing any direct +allocation. + +To allocate device buffers applications initialize all fields of the +struct :c:type:`dmx_requestbuffers` structure. They set the ``count`` field +to the desired number of buffers, and ``size`` to the size of each +buffer. + +When the ioctl is called with a pointer to this structure, the driver will +attempt to allocate the requested number of buffers and it stores the actual +number allocated in the ``count`` field. The ``count`` can be smaller than the number requested, even zero, when the driver runs out of free memory. A larger +number is also possible when the driver requires more buffers to +function correctly. The actual allocated buffer size can is returned +at ``size``, and can be smaller than what's requested. + +When this I/O method is not supported, the ioctl returns an ``EOPNOTSUPP`` +error code. + +Applications can call :ref:`DMX_REQBUFS` again to change the number of +buffers, however this cannot succeed when any buffers are still mapped. +A ``count`` value of zero frees all buffers, after aborting or finishing +any DMA in progress. + + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +EOPNOTSUPP + The the requested I/O method is not supported. diff --git a/Documentation/media/uapi/dvb/dmx_fcalls.rst b/Documentation/media/uapi/dvb/dmx_fcalls.rst index a17289143220..4c391cf2554f 100644 --- a/Documentation/media/uapi/dvb/dmx_fcalls.rst +++ b/Documentation/media/uapi/dvb/dmx_fcalls.rst @@ -13,6 +13,8 @@ Demux Function Calls dmx-fclose dmx-fread dmx-fwrite + dmx-mmap + dmx-munmap dmx-start dmx-stop dmx-set-filter @@ -22,3 +24,7 @@ Demux Function Calls dmx-get-pes-pids dmx-add-pid dmx-remove-pid + dmx-reqbufs + dmx-querybuf + dmx-expbuf + dmx-qbuf diff --git a/Documentation/media/uapi/dvb/fe_property_parameters.rst b/Documentation/media/uapi/dvb/fe_property_parameters.rst index 6eef507fea50..3524dcae4604 100644 --- a/Documentation/media/uapi/dvb/fe_property_parameters.rst +++ b/Documentation/media/uapi/dvb/fe_property_parameters.rst @@ -987,3 +987,21 @@ Possible values: 0, 1, LNA_AUTO 1, LNA on use the special macro LNA_AUTO to set LNA auto + + +.. _DTV-SCRAMBLING-SEQUENCE-INDEX: + +DTV_SCRAMBLING_SEQUENCE_INDEX +============================= + +Used on DVB-S2. + +This 18 bit field, when present, carries the index of the DVB-S2 physical +layer scrambling sequence as defined in clause 5.5.4 of EN 302 307. +There is no explicit signalling method to convey scrambling sequence index +to the receiver. If S2 satellite delivery system descriptor is available +it can be used to read the scrambling sequence index (EN 300 468 table 41). + +By default, gold scrambling sequence index 0 is used. + +The valid scrambling sequence index range is from 0 to 262142. diff --git a/Documentation/media/uapi/dvb/frontend-property-satellite-systems.rst b/Documentation/media/uapi/dvb/frontend-property-satellite-systems.rst index 1f40399c68ff..2929e6999a7a 100644 --- a/Documentation/media/uapi/dvb/frontend-property-satellite-systems.rst +++ b/Documentation/media/uapi/dvb/frontend-property-satellite-systems.rst @@ -60,6 +60,8 @@ following parameters: - :ref:`DTV_STREAM_ID <DTV-STREAM-ID>` +- :ref:`DTV_SCRAMBLING_SEQUENCE_INDEX <DTV-SCRAMBLING-SEQUENCE-INDEX>` + In addition, the :ref:`DTV QoS statistics <frontend-stat-properties>` are also valid. diff --git a/Documentation/media/uapi/rc/lirc-dev-intro.rst b/Documentation/media/uapi/rc/lirc-dev-intro.rst index d1936eeb9ce0..3a74fec66d69 100644 --- a/Documentation/media/uapi/rc/lirc-dev-intro.rst +++ b/Documentation/media/uapi/rc/lirc-dev-intro.rst @@ -6,11 +6,12 @@ Introduction ************ -The LIRC device interface is a bi-directional interface for transporting -raw IR data between userspace and kernelspace. Fundamentally, it is just -a chardev (/dev/lircX, for X = 0, 1, 2, ...), with a number of standard -struct file_operations defined on it. With respect to transporting raw -IR data to and fro, the essential fops are read, write and ioctl. +LIRC stands for Linux Infrared Remote Control. The LIRC device interface is +a bi-directional interface for transporting raw IR and decoded scancodes +data between userspace and kernelspace. Fundamentally, it is just a chardev +(/dev/lircX, for X = 0, 1, 2, ...), with a number of standard struct +file_operations defined on it. With respect to transporting raw IR and +decoded scancodes to and fro, the essential fops are read, write and ioctl. Example dmesg output upon a driver registering w/LIRC: @@ -18,7 +19,7 @@ Example dmesg output upon a driver registering w/LIRC: $ dmesg |grep lirc_dev lirc_dev: IR Remote Control driver registered, major 248 - rc rc0: lirc_dev: driver ir-lirc-codec (mceusb) registered at minor = 0 + rc rc0: lirc_dev: driver mceusb registered at minor = 0 What you should see for a chardev: @@ -36,6 +37,43 @@ LIRC modes LIRC supports some modes of receiving and sending IR codes, as shown on the following table. +.. _lirc-mode-scancode: +.. _lirc-scancode-flag-toggle: +.. _lirc-scancode-flag-repeat: + +``LIRC_MODE_SCANCODE`` + + This mode is for both sending and receiving IR. + + For transmitting (aka sending), create a ``struct lirc_scancode`` with + the desired scancode set in the ``scancode`` member, :c:type:`rc_proto` + set the IR protocol, and all other members set to 0. Write this struct to + the lirc device. + + For receiving, you read ``struct lirc_scancode`` from the lirc device, + with ``scancode`` set to the received scancode and the IR protocol + :c:type:`rc_proto`. If the scancode maps to a valid key code, this is set + in the ``keycode`` field, else it is set to ``KEY_RESERVED``. + + The ``flags`` can have ``LIRC_SCANCODE_FLAG_TOGGLE`` set if the toggle + bit is set in protocols that support it (e.g. rc-5 and rc-6), or + ``LIRC_SCANCODE_FLAG_REPEAT`` for when a repeat is received for protocols + that support it (e.g. nec). + + In the Sanyo and NEC protocol, if you hold a button on remote, rather than + repeating the entire scancode, the remote sends a shorter message with + no scancode, which just means button is held, a "repeat". When this is + received, the ``LIRC_SCANCODE_FLAG_REPEAT`` is set and the scancode and + keycode is repeated. + + With nec, there is no way to distinguish "button hold" from "repeatedly + pressing the same button". The rc-5 and rc-6 protocols have a toggle bit. + When a button is released and pressed again, the toggle bit is inverted. + If the toggle bit is set, the ``LIRC_SCANCODE_FLAG_TOGGLE`` is set. + + The ``timestamp`` field is filled with the time nanoseconds + (in ``CLOCK_MONOTONIC``) when the scancode was decoded. + .. _lirc-mode-mode2: ``LIRC_MODE_MODE2`` @@ -72,21 +110,6 @@ on the following table. this packet will be sent, with the number of microseconds with no IR. -.. _lirc-mode-lirccode: - -``LIRC_MODE_LIRCCODE`` - - This mode can be used for IR receive and send. - - The IR signal is decoded internally by the receiver, or encoded by the - transmitter. The LIRC interface represents the scancode as byte string, - which might not be a u32, it can be any length. The value is entirely - driver dependent. This mode is used by some older lirc drivers. - - The length of each code depends on the driver, which can be retrieved - with :ref:`lirc_get_length`. This length is used both - for transmitting and receiving IR. - .. _lirc-mode-pulse: ``LIRC_MODE_PULSE`` @@ -99,3 +122,13 @@ on the following table. of entries. This mode is used only for IR send. + + +************************** +Remote Controller protocol +************************** + +An enum :c:type:`rc_proto` in the :ref:`lirc_header` lists all the +supported IR protocols: + +.. kernel-doc:: include/uapi/linux/lirc.h diff --git a/Documentation/media/uapi/rc/lirc-func.rst b/Documentation/media/uapi/rc/lirc-func.rst index 9b5a772ec96c..ddb4620de294 100644 --- a/Documentation/media/uapi/rc/lirc-func.rst +++ b/Documentation/media/uapi/rc/lirc-func.rst @@ -18,7 +18,6 @@ LIRC Function Reference lirc-set-send-duty-cycle lirc-get-timeout lirc-set-rec-timeout - lirc-get-length lirc-set-rec-carrier lirc-set-rec-carrier-range lirc-set-send-carrier diff --git a/Documentation/media/uapi/rc/lirc-get-features.rst b/Documentation/media/uapi/rc/lirc-get-features.rst index 64f89a4f9d9c..889a8807037b 100644 --- a/Documentation/media/uapi/rc/lirc-get-features.rst +++ b/Documentation/media/uapi/rc/lirc-get-features.rst @@ -55,15 +55,24 @@ LIRC features ``LIRC_CAN_REC_MODE2`` - The driver is capable of receiving using - :ref:`LIRC_MODE_MODE2 <lirc-mode-MODE2>`. + This is raw IR driver for receiving. This means that + :ref:`LIRC_MODE_MODE2 <lirc-mode-MODE2>` is used. This also implies + that :ref:`LIRC_MODE_SCANCODE <lirc-mode-SCANCODE>` is also supported, + as long as the kernel is recent enough. Use the + :ref:`lirc_set_rec_mode` to switch modes. .. _LIRC-CAN-REC-LIRCCODE: ``LIRC_CAN_REC_LIRCCODE`` - The driver is capable of receiving using - :ref:`LIRC_MODE_LIRCCODE <lirc-mode-LIRCCODE>`. + Unused. Kept just to avoid breaking uAPI. + +.. _LIRC-CAN-REC-SCANCODE: + +``LIRC_CAN_REC_SCANCODE`` + + This is a scancode driver for receiving. This means that + :ref:`LIRC_MODE_SCANCODE <lirc-mode-SCANCODE>` is used. .. _LIRC-CAN-SET-SEND-CARRIER: @@ -157,7 +166,10 @@ LIRC features ``LIRC_CAN_SEND_PULSE`` The driver supports sending (also called as IR blasting or IR TX) using - :ref:`LIRC_MODE_PULSE <lirc-mode-pulse>`. + :ref:`LIRC_MODE_PULSE <lirc-mode-pulse>`. This implies that + :ref:`LIRC_MODE_SCANCODE <lirc-mode-SCANCODE>` is also supported for + transmit, as long as the kernel is recent enough. Use the + :ref:`lirc_set_send_mode` to switch modes. .. _LIRC-CAN-SEND-MODE2: @@ -170,8 +182,7 @@ LIRC features ``LIRC_CAN_SEND_LIRCCODE`` - The driver supports sending (also called as IR blasting or IR TX) using - :ref:`LIRC_MODE_LIRCCODE <lirc-mode-LIRCCODE>`. + Unused. Kept just to avoid breaking uAPI. Return Value diff --git a/Documentation/media/uapi/rc/lirc-get-length.rst b/Documentation/media/uapi/rc/lirc-get-length.rst deleted file mode 100644 index 3990af5de0e9..000000000000 --- a/Documentation/media/uapi/rc/lirc-get-length.rst +++ /dev/null @@ -1,44 +0,0 @@ -.. -*- coding: utf-8; mode: rst -*- - -.. _lirc_get_length: - -********************* -ioctl LIRC_GET_LENGTH -********************* - -Name -==== - -LIRC_GET_LENGTH - Retrieves the code length in bits. - -Synopsis -======== - -.. c:function:: int ioctl( int fd, LIRC_GET_LENGTH, __u32 *length ) - :name: LIRC_GET_LENGTH - -Arguments -========= - -``fd`` - File descriptor returned by open(). - -``length`` - length, in bits - - -Description -=========== - -Retrieves the code length in bits (only for -:ref:`LIRC_MODE_LIRCCODE <lirc-mode-lirccode>`). -Reads on the device must be done in blocks matching the bit count. -The bit could should be rounded up so that it matches full bytes. - - -Return Value -============ - -On success 0 is returned, on error -1 and the ``errno`` variable is set -appropriately. The generic error codes are described at the -:ref:`Generic Error Codes <gen-errors>` chapter. diff --git a/Documentation/media/uapi/rc/lirc-get-rec-mode.rst b/Documentation/media/uapi/rc/lirc-get-rec-mode.rst index a4eb6c0a26e9..2722118484fa 100644 --- a/Documentation/media/uapi/rc/lirc-get-rec-mode.rst +++ b/Documentation/media/uapi/rc/lirc-get-rec-mode.rst @@ -10,15 +10,15 @@ ioctls LIRC_GET_REC_MODE and LIRC_SET_REC_MODE Name ==== -LIRC_GET_REC_MODE/LIRC_SET_REC_MODE - Get/set supported receive modes. +LIRC_GET_REC_MODE/LIRC_SET_REC_MODE - Get/set current receive mode. Synopsis ======== -.. c:function:: int ioctl( int fd, LIRC_GET_REC_MODE, __u32 rx_modes) +.. c:function:: int ioctl( int fd, LIRC_GET_REC_MODE, __u32 *mode) :name: LIRC_GET_REC_MODE -.. c:function:: int ioctl( int fd, LIRC_SET_REC_MODE, __u32 rx_modes) +.. c:function:: int ioctl( int fd, LIRC_SET_REC_MODE, __u32 *mode) :name: LIRC_SET_REC_MODE Arguments @@ -27,20 +27,41 @@ Arguments ``fd`` File descriptor returned by open(). -``rx_modes`` - Bitmask with the supported transmit modes. +``mode`` + Mode used for receive. Description =========== -Get/set supported receive modes. Only :ref:`LIRC_MODE_MODE2 <lirc-mode-mode2>` -and :ref:`LIRC_MODE_LIRCCODE <lirc-mode-lirccode>` are supported for IR -receive. Use :ref:`lirc_get_features` to find out which modes the driver -supports. +Get and set the current receive mode. Only +:ref:`LIRC_MODE_MODE2 <lirc-mode-mode2>` and +:ref:`LIRC_MODE_SCANCODE <lirc-mode-scancode>` are supported. +Use :ref:`lirc_get_features` to find out which modes the driver supports. Return Value ============ -On success 0 is returned, on error -1 and the ``errno`` variable is set -appropriately. The generic error codes are described at the -:ref:`Generic Error Codes <gen-errors>` chapter. +.. tabularcolumns:: |p{2.5cm}|p{15.0cm}| + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + + + - .. row 1 + + - ``ENODEV`` + + - Device not available. + + - .. row 2 + + - ``ENOTTY`` + + - Device does not support receiving. + + - .. row 3 + + - ``EINVAL`` + + - Invalid mode or invalid mode for this device. diff --git a/Documentation/media/uapi/rc/lirc-get-send-mode.rst b/Documentation/media/uapi/rc/lirc-get-send-mode.rst index a169b234290e..c44e61a79ad1 100644 --- a/Documentation/media/uapi/rc/lirc-get-send-mode.rst +++ b/Documentation/media/uapi/rc/lirc-get-send-mode.rst @@ -10,15 +10,15 @@ ioctls LIRC_GET_SEND_MODE and LIRC_SET_SEND_MODE Name ==== -LIRC_GET_SEND_MODE/LIRC_SET_SEND_MODE - Get/set supported transmit mode. +LIRC_GET_SEND_MODE/LIRC_SET_SEND_MODE - Get/set current transmit mode. Synopsis ======== -.. c:function:: int ioctl( int fd, LIRC_GET_SEND_MODE, __u32 *tx_modes ) +.. c:function:: int ioctl( int fd, LIRC_GET_SEND_MODE, __u32 *mode ) :name: LIRC_GET_SEND_MODE -.. c:function:: int ioctl( int fd, LIRC_SET_SEND_MODE, __u32 *tx_modes ) +.. c:function:: int ioctl( int fd, LIRC_SET_SEND_MODE, __u32 *mode ) :name: LIRC_SET_SEND_MODE Arguments @@ -27,8 +27,8 @@ Arguments ``fd`` File descriptor returned by open(). -``tx_modes`` - Bitmask with the supported transmit modes. +``mode`` + The mode used for transmitting. Description @@ -37,13 +37,35 @@ Description Get/set current transmit mode. Only :ref:`LIRC_MODE_PULSE <lirc-mode-pulse>` and -:ref:`LIRC_MODE_LIRCCODE <lirc-mode-lirccode>` is supported by for IR send, +:ref:`LIRC_MODE_SCANCODE <lirc-mode-scancode>` are supported by for IR send, depending on the driver. Use :ref:`lirc_get_features` to find out which modes the driver supports. Return Value ============ -On success 0 is returned, on error -1 and the ``errno`` variable is set -appropriately. The generic error codes are described at the -:ref:`Generic Error Codes <gen-errors>` chapter. + +.. tabularcolumns:: |p{2.5cm}|p{15.0cm}| + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + + + - .. row 1 + + - ``ENODEV`` + + - Device not available. + + - .. row 2 + + - ``ENOTTY`` + + - Device does not support transmitting. + + - .. row 3 + + - ``EINVAL`` + + - Invalid mode or invalid mode for this device. diff --git a/Documentation/media/uapi/rc/lirc-read.rst b/Documentation/media/uapi/rc/lirc-read.rst index ff14a69104e5..c024aaffb8ad 100644 --- a/Documentation/media/uapi/rc/lirc-read.rst +++ b/Documentation/media/uapi/rc/lirc-read.rst @@ -45,13 +45,20 @@ descriptor ``fd`` into the buffer starting at ``buf``. If ``count`` is zero, is greater than ``SSIZE_MAX``, the result is unspecified. The exact format of the data depends on what :ref:`lirc_modes` a driver -uses. Use :ref:`lirc_get_features` to get the supported mode. +uses. Use :ref:`lirc_get_features` to get the supported mode, and use +:ref:`lirc_set_rec_mode` set the current active mode. -The generally preferred mode for receive is -:ref:`LIRC_MODE_MODE2 <lirc-mode-mode2>`, -in which packets containing an int value describing an IR signal are +The mode :ref:`LIRC_MODE_MODE2 <lirc-mode-mode2>` is for raw IR, +in which packets containing an unsigned int value describing an IR signal are read from the chardev. +Alternatively, :ref:`LIRC_MODE_SCANCODE <lirc-mode-scancode>` can be available, +in this mode scancodes which are either decoded by software decoders, or +by hardware decoders. The :c:type:`rc_proto` member is set to the +protocol used for transmission, and ``scancode`` to the decoded scancode, +and the ``keycode`` set to the keycode or ``KEY_RESERVED``. + + Return Value ============ diff --git a/Documentation/media/uapi/rc/lirc-write.rst b/Documentation/media/uapi/rc/lirc-write.rst index 2aad0fef4a5b..d4566b0a2015 100644 --- a/Documentation/media/uapi/rc/lirc-write.rst +++ b/Documentation/media/uapi/rc/lirc-write.rst @@ -42,21 +42,32 @@ Description referenced by the file descriptor ``fd`` from the buffer starting at ``buf``. -The exact format of the data depends on what mode a driver uses, use -:ref:`lirc_get_features` to get the supported mode. +The exact format of the data depends on what mode a driver is in, use +:ref:`lirc_get_features` to get the supported modes and use +:ref:`lirc_set_send_mode` set the mode. When in :ref:`LIRC_MODE_PULSE <lirc-mode-PULSE>` mode, the data written to the chardev is a pulse/space sequence of integer values. Pulses and spaces are only marked implicitly by their position. The data must start and end with a pulse, therefore, the data must always include an uneven number of -samples. The write function must block until the data has been transmitted +samples. The write function blocks until the data has been transmitted by the hardware. If more data is provided than the hardware can send, the driver returns ``EINVAL``. +When in :ref:`LIRC_MODE_SCANCODE <lirc-mode-scancode>` mode, one +``struct lirc_scancode`` must be written to the chardev at a time, else +``EINVAL`` is returned. Set the desired scancode in the ``scancode`` member, +and the protocol in the :c:type:`rc_proto`: member. All other members must be +set to 0, else ``EINVAL`` is returned. If there is no protocol encoder +for the protocol or the scancode is not valid for the specified protocol, +``EINVAL`` is returned. The write function blocks until the scancode +is transmitted by the hardware. + + Return Value ============ -On success, the number of bytes read is returned. It is not an error if +On success, the number of bytes written is returned. It is not an error if this number is smaller than the number of bytes requested, or the amount of data required for one frame. On error, -1 is returned, and the ``errno`` variable is set appropriately. The generic error codes are described at the diff --git a/Documentation/media/uapi/v4l/meta-formats.rst b/Documentation/media/uapi/v4l/meta-formats.rst index 01e24e3df571..0c4e1ecf5879 100644 --- a/Documentation/media/uapi/v4l/meta-formats.rst +++ b/Documentation/media/uapi/v4l/meta-formats.rst @@ -12,5 +12,6 @@ These formats are used for the :ref:`metadata` interface only. .. toctree:: :maxdepth: 1 + pixfmt-meta-uvc pixfmt-meta-vsp1-hgo pixfmt-meta-vsp1-hgt diff --git a/Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst b/Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst new file mode 100644 index 000000000000..b5165dc090c2 --- /dev/null +++ b/Documentation/media/uapi/v4l/pixfmt-meta-uvc.rst @@ -0,0 +1,51 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _v4l2-meta-fmt-uvc: + +******************************* +V4L2_META_FMT_UVC ('UVCH') +******************************* + +UVC Payload Header Data + + +Description +=========== + +This format describes standard UVC metadata, extracted from UVC packet headers +and provided by the UVC driver through metadata video nodes. That data includes +exact copies of the standard part of UVC Payload Header contents and auxiliary +timing information, required for precise interpretation of timestamps, contained +in those headers. See section "2.4.3.3 Video and Still Image Payload Headers" of +the "UVC 1.5 Class specification" for details. + +Each UVC payload header can be between 2 and 12 bytes large. Buffers can +contain multiple headers, if multiple such headers have been transmitted by the +camera for the respective frame. However, the driver may drop headers when the +buffer is full, when they contain no useful information (e.g. those without the +SCR field or with that field identical to the previous header), or generally to +perform rate limiting when the device sends a large number of headers. + +Each individual block contains the following fields: + +.. flat-table:: UVC Metadata Block + :widths: 1 4 + :header-rows: 1 + :stub-columns: 0 + + * - Field + - Description + * - __u64 ts; + - system timestamp in host byte order, measured by the driver upon + reception of the payload + * - __u16 sof; + - USB Frame Number in host byte order, also obtained by the driver as + close as possible to the above timestamp to enable correlation between + them + * - :cspan:`1` *The rest is an exact copy of the UVC payload header:* + * - __u8 length; + - length of the rest of the block, including this field + * - __u8 flags; + - Flags, indicating presence of other standard UVC fields + * - __u8 buf[]; + - The rest of the header, possibly including UVC PTS and SCR fields diff --git a/Documentation/media/uapi/v4l/pixfmt-rgb.rst b/Documentation/media/uapi/v4l/pixfmt-rgb.rst index 4cc27195dc79..cf2ef7df9616 100644 --- a/Documentation/media/uapi/v4l/pixfmt-rgb.rst +++ b/Documentation/media/uapi/v4l/pixfmt-rgb.rst @@ -16,6 +16,7 @@ RGB Formats pixfmt-srggb10p pixfmt-srggb10alaw8 pixfmt-srggb10dpcm8 + pixfmt-srggb10-ipu3 pixfmt-srggb12 pixfmt-srggb12p pixfmt-srggb16 diff --git a/Documentation/media/uapi/v4l/pixfmt-srggb10-ipu3.rst b/Documentation/media/uapi/v4l/pixfmt-srggb10-ipu3.rst new file mode 100644 index 000000000000..99cde5077519 --- /dev/null +++ b/Documentation/media/uapi/v4l/pixfmt-srggb10-ipu3.rst @@ -0,0 +1,335 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _v4l2-pix-fmt-ipu3-sbggr10: +.. _v4l2-pix-fmt-ipu3-sgbrg10: +.. _v4l2-pix-fmt-ipu3-sgrbg10: +.. _v4l2-pix-fmt-ipu3-srggb10: + +********************************************************************************************************************************************** +V4L2_PIX_FMT_IPU3_SBGGR10 ('ip3b'), V4L2_PIX_FMT_IPU3_SGBRG10 ('ip3g'), V4L2_PIX_FMT_IPU3_SGRBG10 ('ip3G'), V4L2_PIX_FMT_IPU3_SRGGB10 ('ip3r') +********************************************************************************************************************************************** + +10-bit Bayer formats + +Description +=========== + +These four pixel formats are used by Intel IPU3 driver, they are raw +sRGB / Bayer formats with 10 bits per sample with every 25 pixels packed +to 32 bytes leaving 6 most significant bits padding in the last byte. +The format is little endian. + +In other respects this format is similar to :ref:`V4L2-PIX-FMT-SRGGB10`. +Below is an example of a small image in V4L2_PIX_FMT_IPU3_SBGGR10 format. + +**Byte Order.** +Each cell is one byte. + +.. tabularcolumns:: |p{0.8cm}|p{4.0cm}|p{4.0cm}|p{4.0cm}|p{4.0cm}| + +.. flat-table:: + + * - start + 0: + - B\ :sub:`0000low` + - G\ :sub:`0001low`\ (bits 7--2) + + B\ :sub:`0000high`\ (bits 1--0) + - B\ :sub:`0002low`\ (bits 7--4) + + G\ :sub:`0001high`\ (bits 3--0) + - G\ :sub:`0003low`\ (bits 7--6) + + B\ :sub:`0002high`\ (bits 5--0) + * - start + 4: + - G\ :sub:`0003high` + - B\ :sub:`0004low` + - G\ :sub:`0005low`\ (bits 7--2) + + B\ :sub:`0004high`\ (bits 1--0) + - B\ :sub:`0006low`\ (bits 7--4) + + G\ :sub:`0005high`\ (bits 3--0) + * - start + 8: + - G\ :sub:`0007low`\ (bits 7--6) + + B\ :sub:`0006high`\ (bits 5--0) + - G\ :sub:`0007high` + - B\ :sub:`0008low` + - G\ :sub:`0009low`\ (bits 7--2) + + B\ :sub:`0008high`\ (bits 1--0) + * - start + 12: + - B\ :sub:`0010low`\ (bits 7--4) + + G\ :sub:`0009high`\ (bits 3--0) + - G\ :sub:`0011low`\ (bits 7--6) + + B\ :sub:`0010high`\ (bits 5--0) + - G\ :sub:`0011high` + - B\ :sub:`0012low` + * - start + 16: + - G\ :sub:`0013low`\ (bits 7--2) + + B\ :sub:`0012high`\ (bits 1--0) + - B\ :sub:`0014low`\ (bits 7--4) + + G\ :sub:`0013high`\ (bits 3--0) + - G\ :sub:`0015low`\ (bits 7--6) + + B\ :sub:`0014high`\ (bits 5--0) + - G\ :sub:`0015high` + * - start + 20 + - B\ :sub:`0016low` + - G\ :sub:`0017low`\ (bits 7--2) + + B\ :sub:`0016high`\ (bits 1--0) + - B\ :sub:`0018low`\ (bits 7--4) + + G\ :sub:`0017high`\ (bits 3--0) + - G\ :sub:`0019low`\ (bits 7--6) + + B\ :sub:`0018high`\ (bits 5--0) + * - start + 24: + - G\ :sub:`0019high` + - B\ :sub:`0020low` + - G\ :sub:`0021low`\ (bits 7--2) + + B\ :sub:`0020high`\ (bits 1--0) + - B\ :sub:`0022low`\ (bits 7--4) + + G\ :sub:`0021high`\ (bits 3--0) + * - start + 28: + - G\ :sub:`0023low`\ (bits 7--6) + + B\ :sub:`0022high`\ (bits 5--0) + - G\ :sub:`0023high` + - B\ :sub:`0024low` + - B\ :sub:`0024high`\ (bits 1--0) + * - start + 32: + - G\ :sub:`0100low` + - R\ :sub:`0101low`\ (bits 7--2) + + G\ :sub:`0100high`\ (bits 1--0) + - G\ :sub:`0102low`\ (bits 7--4) + + R\ :sub:`0101high`\ (bits 3--0) + - R\ :sub:`0103low`\ (bits 7--6) + + G\ :sub:`0102high`\ (bits 5--0) + * - start + 36: + - R\ :sub:`0103high` + - G\ :sub:`0104low` + - R\ :sub:`0105low`\ (bits 7--2) + + G\ :sub:`0104high`\ (bits 1--0) + - G\ :sub:`0106low`\ (bits 7--4) + + R\ :sub:`0105high`\ (bits 3--0) + * - start + 40: + - R\ :sub:`0107low`\ (bits 7--6) + + G\ :sub:`0106high`\ (bits 5--0) + - R\ :sub:`0107high` + - G\ :sub:`0108low` + - R\ :sub:`0109low`\ (bits 7--2) + + G\ :sub:`0108high`\ (bits 1--0) + * - start + 44: + - G\ :sub:`0110low`\ (bits 7--4) + + R\ :sub:`0109high`\ (bits 3--0) + - R\ :sub:`0111low`\ (bits 7--6) + + G\ :sub:`0110high`\ (bits 5--0) + - R\ :sub:`0111high` + - G\ :sub:`0112low` + * - start + 48: + - R\ :sub:`0113low`\ (bits 7--2) + + G\ :sub:`0112high`\ (bits 1--0) + - G\ :sub:`0114low`\ (bits 7--4) + + R\ :sub:`0113high`\ (bits 3--0) + - R\ :sub:`0115low`\ (bits 7--6) + + G\ :sub:`0114high`\ (bits 5--0) + - R\ :sub:`0115high` + * - start + 52: + - G\ :sub:`0116low` + - R\ :sub:`0117low`\ (bits 7--2) + + G\ :sub:`0116high`\ (bits 1--0) + - G\ :sub:`0118low`\ (bits 7--4) + + R\ :sub:`0117high`\ (bits 3--0) + - R\ :sub:`0119low`\ (bits 7--6) + + G\ :sub:`0118high`\ (bits 5--0) + * - start + 56: + - R\ :sub:`0119high` + - G\ :sub:`0120low` + - R\ :sub:`0121low`\ (bits 7--2) + + G\ :sub:`0120high`\ (bits 1--0) + - G\ :sub:`0122low`\ (bits 7--4) + + R\ :sub:`0121high`\ (bits 3--0) + * - start + 60: + - R\ :sub:`0123low`\ (bits 7--6) + + G\ :sub:`0122high`\ (bits 5--0) + - R\ :sub:`0123high` + - G\ :sub:`0124low` + - G\ :sub:`0124high`\ (bits 1--0) + * - start + 64: + - B\ :sub:`0200low` + - G\ :sub:`0201low`\ (bits 7--2) + + B\ :sub:`0200high`\ (bits 1--0) + - B\ :sub:`0202low`\ (bits 7--4) + + G\ :sub:`0201high`\ (bits 3--0) + - G\ :sub:`0203low`\ (bits 7--6) + + B\ :sub:`0202high`\ (bits 5--0) + * - start + 68: + - G\ :sub:`0203high` + - B\ :sub:`0204low` + - G\ :sub:`0205low`\ (bits 7--2) + + B\ :sub:`0204high`\ (bits 1--0) + - B\ :sub:`0206low`\ (bits 7--4) + + G\ :sub:`0205high`\ (bits 3--0) + * - start + 72: + - G\ :sub:`0207low`\ (bits 7--6) + + B\ :sub:`0206high`\ (bits 5--0) + - G\ :sub:`0207high` + - B\ :sub:`0208low` + - G\ :sub:`0209low`\ (bits 7--2) + + B\ :sub:`0208high`\ (bits 1--0) + * - start + 76: + - B\ :sub:`0210low`\ (bits 7--4) + + G\ :sub:`0209high`\ (bits 3--0) + - G\ :sub:`0211low`\ (bits 7--6) + + B\ :sub:`0210high`\ (bits 5--0) + - G\ :sub:`0211high` + - B\ :sub:`0212low` + * - start + 80: + - G\ :sub:`0213low`\ (bits 7--2) + + B\ :sub:`0212high`\ (bits 1--0) + - B\ :sub:`0214low`\ (bits 7--4) + + G\ :sub:`0213high`\ (bits 3--0) + - G\ :sub:`0215low`\ (bits 7--6) + + B\ :sub:`0214high`\ (bits 5--0) + - G\ :sub:`0215high` + * - start + 84: + - B\ :sub:`0216low` + - G\ :sub:`0217low`\ (bits 7--2) + + B\ :sub:`0216high`\ (bits 1--0) + - B\ :sub:`0218low`\ (bits 7--4) + + G\ :sub:`0217high`\ (bits 3--0) + - G\ :sub:`0219low`\ (bits 7--6) + + B\ :sub:`0218high`\ (bits 5--0) + * - start + 88: + - G\ :sub:`0219high` + - B\ :sub:`0220low` + - G\ :sub:`0221low`\ (bits 7--2) + + B\ :sub:`0220high`\ (bits 1--0) + - B\ :sub:`0222low`\ (bits 7--4) + + G\ :sub:`0221high`\ (bits 3--0) + * - start + 92: + - G\ :sub:`0223low`\ (bits 7--6) + + B\ :sub:`0222high`\ (bits 5--0) + - G\ :sub:`0223high` + - B\ :sub:`0224low` + - B\ :sub:`0224high`\ (bits 1--0) + * - start + 96: + - G\ :sub:`0300low` + - R\ :sub:`0301low`\ (bits 7--2) + + G\ :sub:`0300high`\ (bits 1--0) + - G\ :sub:`0302low`\ (bits 7--4) + + R\ :sub:`0301high`\ (bits 3--0) + - R\ :sub:`0303low`\ (bits 7--6) + + G\ :sub:`0302high`\ (bits 5--0) + * - start + 100: + - R\ :sub:`0303high` + - G\ :sub:`0304low` + - R\ :sub:`0305low`\ (bits 7--2) + + G\ :sub:`0304high`\ (bits 1--0) + - G\ :sub:`0306low`\ (bits 7--4) + + R\ :sub:`0305high`\ (bits 3--0) + * - start + 104: + - R\ :sub:`0307low`\ (bits 7--6) + + G\ :sub:`0306high`\ (bits 5--0) + - R\ :sub:`0307high` + - G\ :sub:`0308low` + - R\ :sub:`0309low`\ (bits 7--2) + + G\ :sub:`0308high`\ (bits 1--0) + * - start + 108: + - G\ :sub:`0310low`\ (bits 7--4) + + R\ :sub:`0309high`\ (bits 3--0) + - R\ :sub:`0311low`\ (bits 7--6) + + G\ :sub:`0310high`\ (bits 5--0) + - R\ :sub:`0311high` + - G\ :sub:`0312low` + * - start + 112: + - R\ :sub:`0313low`\ (bits 7--2) + + G\ :sub:`0312high`\ (bits 1--0) + - G\ :sub:`0314low`\ (bits 7--4) + + R\ :sub:`0313high`\ (bits 3--0) + - R\ :sub:`0315low`\ (bits 7--6) + + G\ :sub:`0314high`\ (bits 5--0) + - R\ :sub:`0315high` + * - start + 116: + - G\ :sub:`0316low` + - R\ :sub:`0317low`\ (bits 7--2) + + G\ :sub:`0316high`\ (bits 1--0) + - G\ :sub:`0318low`\ (bits 7--4) + + R\ :sub:`0317high`\ (bits 3--0) + - R\ :sub:`0319low`\ (bits 7--6) + + G\ :sub:`0318high`\ (bits 5--0) + * - start + 120: + - R\ :sub:`0319high` + - G\ :sub:`0320low` + - R\ :sub:`0321low`\ (bits 7--2) + + G\ :sub:`0320high`\ (bits 1--0) + - G\ :sub:`0322low`\ (bits 7--4) + + R\ :sub:`0321high`\ (bits 3--0) + * - start + 124: + - R\ :sub:`0323low`\ (bits 7--6) + + G\ :sub:`0322high`\ (bits 5--0) + - R\ :sub:`0323high` + - G\ :sub:`0324low` + - G\ :sub:`0324high`\ (bits 1--0) diff --git a/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst b/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst index 2696380626d4..1a034e825161 100644 --- a/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst +++ b/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst @@ -267,7 +267,7 @@ EBUSY will also be cleared. * - ``V4L2_DV_FL_HALF_LINE`` - Specific to interlaced formats: if set, then the vertical - frontporch of field 1 (aka the odd field) is really one half-line + backporch of field 1 (aka the odd field) is really one half-line longer and the vertical backporch of field 2 (aka the even field) is really one half-line shorter, so each field has exactly the same number of half-lines. Whether half-lines can be detected or diff --git a/Documentation/mips/AU1xxx_IDE.README b/Documentation/mips/AU1xxx_IDE.README index 52844a58cc8a..ff675a1b1422 100644 --- a/Documentation/mips/AU1xxx_IDE.README +++ b/Documentation/mips/AU1xxx_IDE.README @@ -56,8 +56,6 @@ Following extra configs variables are introduced: CONFIG_BLK_DEV_IDE_AU1XXX_PIO_DBDMA - enable the PIO+DBDMA mode CONFIG_BLK_DEV_IDE_AU1XXX_MDMA2_DBDMA - enable the MWDMA mode - CONFIG_BLK_DEV_IDE_AU1XXX_BURSTABLE_ON - set Burstable FIFO in DBDMA - controller SUPPORTED IDE MODES @@ -82,11 +80,9 @@ CONFIG_IDE_GENERIC=y CONFIG_BLK_DEV_IDEPCI=y CONFIG_BLK_DEV_GENERIC=y CONFIG_BLK_DEV_IDEDMA_PCI=y -CONFIG_IDEDMA_PCI_AUTO=y CONFIG_BLK_DEV_IDE_AU1XXX=y CONFIG_BLK_DEV_IDE_AU1XXX_MDMA2_DBDMA=y CONFIG_BLK_DEV_IDEDMA=y -CONFIG_IDEDMA_AUTO=y Also define 'IDE_AU1XXX_BURSTMODE' in 'drivers/ide/mips/au1xxx-ide.c' to enable the burst support on DBDMA controller. @@ -94,16 +90,13 @@ the burst support on DBDMA controller. If the used system need the USB support enable the following kernel configs for high IDE to USB throughput. -CONFIG_BLK_DEV_IDEDISK=y CONFIG_IDE_GENERIC=y CONFIG_BLK_DEV_IDEPCI=y CONFIG_BLK_DEV_GENERIC=y CONFIG_BLK_DEV_IDEDMA_PCI=y -CONFIG_IDEDMA_PCI_AUTO=y CONFIG_BLK_DEV_IDE_AU1XXX=y CONFIG_BLK_DEV_IDE_AU1XXX_MDMA2_DBDMA=y CONFIG_BLK_DEV_IDEDMA=y -CONFIG_IDEDMA_AUTO=y Also undefine 'IDE_AU1XXX_BURSTMODE' in 'drivers/ide/mips/au1xxx-ide.c' to disable the burst support on DBDMA controller. diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 3f2c40d8e6aa..a553d4e4a0fb 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -508,7 +508,7 @@ tcp_rmem - vector of 3 INTEGERs: min, default, max min: Minimal size of receive buffer used by TCP sockets. It is guaranteed to each TCP socket, even under moderate memory pressure. - Default: 1 page + Default: 4K default: initial size of receive buffer used by TCP sockets. This value overrides net.core.rmem_default used by other protocols. @@ -667,7 +667,7 @@ tcp_window_scaling - BOOLEAN tcp_wmem - vector of 3 INTEGERs: min, default, max min: Amount of memory reserved for send buffers for TCP sockets. Each TCP socket has rights to use it due to fact of its birth. - Default: 1 page + Default: 4K default: initial size of send buffer used by TCP sockets. This value overrides net.core.wmem_default used by other protocols. diff --git a/Documentation/process/index.rst b/Documentation/process/index.rst index a430f6eee756..1c9fe657ed01 100644 --- a/Documentation/process/index.rst +++ b/Documentation/process/index.rst @@ -24,6 +24,7 @@ Below are the essential guides that every developer should read. development-process submitting-patches coding-style + maintainer-pgp-guide email-clients kernel-enforcement-statement kernel-driver-statement diff --git a/Documentation/process/kernel-docs.rst b/Documentation/process/kernel-docs.rst index b8cac85a4001..3fb28de556e4 100644 --- a/Documentation/process/kernel-docs.rst +++ b/Documentation/process/kernel-docs.rst @@ -58,7 +58,7 @@ On-line docs * Title: **Linux Kernel Mailing List Glossary** :Author: various - :URL: http://kernelnewbies.org/glossary/ + :URL: https://kernelnewbies.org/KernelGlossary :Date: rolling version :Keywords: glossary, terms, linux-kernel. :Description: From the introduction: "This glossary is intended as diff --git a/Documentation/process/maintainer-pgp-guide.rst b/Documentation/process/maintainer-pgp-guide.rst new file mode 100644 index 000000000000..b453561a7148 --- /dev/null +++ b/Documentation/process/maintainer-pgp-guide.rst @@ -0,0 +1,929 @@ +.. _pgpguide: + +=========================== +Kernel Maintainer PGP guide +=========================== + +:Author: Konstantin Ryabitsev <konstantin@linuxfoundation.org> + +This document is aimed at Linux kernel developers, and especially at +subsystem maintainers. It contains a subset of information discussed in +the more general "`Protecting Code Integrity`_" guide published by the +Linux Foundation. Please read that document for more in-depth discussion +on some of the topics mentioned in this guide. + +.. _`Protecting Code Integrity`: https://github.com/lfit/itpol/blob/master/protecting-code-integrity.md + +The role of PGP in Linux Kernel development +=========================================== + +PGP helps ensure the integrity of the code that is produced by the Linux +kernel development community and, to a lesser degree, establish trusted +communication channels between developers via PGP-signed email exchange. + +The Linux kernel source code is available in two main formats: + +- Distributed source repositories (git) +- Periodic release snapshots (tarballs) + +Both git repositories and tarballs carry PGP signatures of the kernel +developers who create official kernel releases. These signatures offer a +cryptographic guarantee that downloadable versions made available via +kernel.org or any other mirrors are identical to what these developers +have on their workstations. To this end: + +- git repositories provide PGP signatures on all tags +- tarballs provide detached PGP signatures with all downloads + +.. _devs_not_infra: + +Trusting the developers, not infrastructure +------------------------------------------- + +Ever since the 2011 compromise of core kernel.org systems, the main +operating principle of the Kernel Archives project has been to assume +that any part of the infrastructure can be compromised at any time. For +this reason, the administrators have taken deliberate steps to emphasize +that trust must always be placed with developers and never with the code +hosting infrastructure, regardless of how good the security practices +for the latter may be. + +The above guiding principle is the reason why this guide is needed. We +want to make sure that by placing trust into developers we do not simply +shift the blame for potential future security incidents to someone else. +The goal is to provide a set of guidelines developers can use to create +a secure working environment and safeguard the PGP keys used to +establish the integrity of the Linux kernel itself. + +.. _pgp_tools: + +PGP tools +========= + +Use GnuPG v2 +------------ + +Your distro should already have GnuPG installed by default, you just +need to verify that you are using version 2.x and not the legacy 1.4 +release -- many distributions still package both, with the default +``gpg`` command invoking GnuPG v.1. To check, run:: + + $ gpg --version | head -n1 + +If you see ``gpg (GnuPG) 1.4.x``, then you are using GnuPG v.1. Try the +``gpg2`` command (if you don't have it, you may need to install the +gnupg2 package):: + + $ gpg2 --version | head -n1 + +If you see ``gpg (GnuPG) 2.x.x``, then you are good to go. This guide +will assume you have the version 2.2 of GnuPG (or later). If you are +using version 2.0 of GnuPG, then some of the commands in this guide will +not work, and you should consider installing the latest 2.2 version of +GnuPG. Versions of gnupg-2.1.11 and later should be compatible for the +purposes of this guide as well. + +If you have both ``gpg`` and ``gpg2`` commands, you should make sure you +are always using GnuPG v2, not the legacy version. You can enforce this +by setting the appropriate alias:: + + $ alias gpg=gpg2 + +You can put that in your ``.bashrc`` to make sure it's always the case. + +Configure gpg-agent options +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The GnuPG agent is a helper tool that will start automatically whenever +you use the ``gpg`` command and run in the background with the purpose +of caching the private key passphrase. There are two options you should +know in order to tweak when the passphrase should be expired from cache: + +- ``default-cache-ttl`` (seconds): If you use the same key again before + the time-to-live expires, the countdown will reset for another period. + The default is 600 (10 minutes). +- ``max-cache-ttl`` (seconds): Regardless of how recently you've used + the key since initial passphrase entry, if the maximum time-to-live + countdown expires, you'll have to enter the passphrase again. The + default is 30 minutes. + +If you find either of these defaults too short (or too long), you can +edit your ``~/.gnupg/gpg-agent.conf`` file to set your own values:: + + # set to 30 minutes for regular ttl, and 2 hours for max ttl + default-cache-ttl 1800 + max-cache-ttl 7200 + +.. note:: + + It is no longer necessary to start gpg-agent manually at the + beginning of your shell session. You may want to check your rc files + to remove anything you had in place for older versions of GnuPG, as + it may not be doing the right thing any more. + +Set up a refresh cronjob +~~~~~~~~~~~~~~~~~~~~~~~~ + +You will need to regularly refresh your keyring in order to get the +latest changes on other people's public keys, which is best done with a +daily cronjob:: + + @daily /usr/bin/gpg2 --refresh >/dev/null 2>&1 + +Check the full path to your ``gpg`` or ``gpg2`` command and use the +``gpg2`` command if regular ``gpg`` for you is the legacy GnuPG v.1. + +.. _master_key: + +Protect your master PGP key +=========================== + +This guide assumes that you already have a PGP key that you use for Linux +kernel development purposes. If you do not yet have one, please see the +"`Protecting Code Integrity`_" document mentioned earlier for guidance +on how to create a new one. + +You should also make a new key if your current one is weaker than 2048 bits +(RSA). + +Master key vs. Subkeys +---------------------- + +Subkeys are fully independent PGP keypairs that are tied to the "master" +key using certifying key signatures (certificates). It is important to +understand the following: + +1. There are no technical differences between the "master key" and "subkeys." +2. At creation time, we assign functional limitations to each key by + giving it specific capabilities. +3. A PGP key can have 4 capabilities: + + - **[S]** key can be used for signing + - **[E]** key can be used for encryption + - **[A]** key can be used for authentication + - **[C]** key can be used for certifying other keys + +4. A single key may have multiple capabilities. +5. A subkey is fully independent from the master key. A message + encrypted to a subkey cannot be decrypted with the master key. If you + lose your private subkey, it cannot be recreated from the master key + in any way. + +The key carrying the **[C]** (certify) capability is considered the +"master" key because it is the only key that can be used to indicate +relationship with other keys. Only the **[C]** key can be used to: + +- add or revoke other keys (subkeys) with S/E/A capabilities +- add, change or revoke identities (uids) associated with the key +- add or change the expiration date on itself or any subkey +- sign other people's keys for web of trust purposes + +By default, GnuPG creates the following when generating new keys: + +- A master key carrying both Certify and Sign capabilities (**[SC]**) +- A separate subkey with the Encryption capability (**[E]**) + +If you used the default parameters when generating your key, then that +is what you will have. You can verify by running ``gpg --list-secret-keys``, +for example:: + + sec rsa2048 2018-01-23 [SC] [expires: 2020-01-23] + 000000000000000000000000AAAABBBBCCCCDDDD + uid [ultimate] Alice Dev <adev@kernel.org> + ssb rsa2048 2018-01-23 [E] [expires: 2020-01-23] + +Any key carrying the **[C]** capability is your master key, regardless +of any other capabilities it may have assigned to it. + +The long line under the ``sec`` entry is your key fingerprint -- +whenever you see ``[fpr]`` in the examples below, that 40-character +string is what it refers to. + +Ensure your passphrase is strong +-------------------------------- + +GnuPG uses passphrases to encrypt your private keys before storing them on +disk. This way, even if your ``.gnupg`` directory is leaked or stolen in +its entirety, the attackers cannot use your private keys without first +obtaining the passphrase to decrypt them. + +It is absolutely essential that your private keys are protected by a +strong passphrase. To set it or change it, use:: + + $ gpg --change-passphrase [fpr] + +Create a separate Signing subkey +-------------------------------- + +Our goal is to protect your master key by moving it to offline media, so +if you only have a combined **[SC]** key, then you should create a separate +signing subkey:: + + $ gpg --quick-add-key [fpr] ed25519 sign + +Remember to tell the keyservers about this change, so others can pull down +your new subkey:: + + $ gpg --send-key [fpr] + +.. note:: ECC support in GnuPG + + GnuPG 2.1 and later has full support for Elliptic Curve + Cryptography, with ability to combine ECC subkeys with traditional + RSA master keys. The main upside of ECC cryptography is that it is + much faster computationally and creates much smaller signatures when + compared byte for byte with 2048+ bit RSA keys. Unless you plan on + using a smartcard device that does not support ECC operations, we + recommend that you create an ECC signing subkey for your kernel + work. + + If for some reason you prefer to stay with RSA subkeys, just replace + "ed25519" with "rsa2048" in the above command. + + +Back up your master key for disaster recovery +--------------------------------------------- + +The more signatures you have on your PGP key from other developers, the +more reasons you have to create a backup version that lives on something +other than digital media, for disaster recovery reasons. + +The best way to create a printable hardcopy of your private key is by +using the ``paperkey`` software written for this very purpose. See ``man +paperkey`` for more details on the output format and its benefits over +other solutions. Paperkey should already be packaged for most +distributions. + +Run the following command to create a hardcopy backup of your private +key:: + + $ gpg --export-secret-key [fpr] | paperkey -o /tmp/key-backup.txt + +Print out that file (or pipe the output straight to lpr), then take a +pen and write your passphrase on the margin of the paper. **This is +strongly recommended** because the key printout is still encrypted with +that passphrase, and if you ever change it you will not remember what it +used to be when you had created the backup -- *guaranteed*. + +Put the resulting printout and the hand-written passphrase into an envelope +and store in a secure and well-protected place, preferably away from your +home, such as your bank vault. + +.. note:: + + Your printer is probably no longer a simple dumb device connected to + your parallel port, but since the output is still encrypted with + your passphrase, printing out even to "cloud-integrated" modern + printers should remain a relatively safe operation. One option is to + change the passphrase on your master key immediately after you are + done with paperkey. + +Back up your whole GnuPG directory +---------------------------------- + +.. warning:: + + **!!!Do not skip this step!!!** + +It is important to have a readily available backup of your PGP keys +should you need to recover them. This is different from the +disaster-level preparedness we did with ``paperkey``. You will also rely +on these external copies whenever you need to use your Certify key -- +such as when making changes to your own key or signing other people's +keys after conferences and summits. + +Start by getting a small USB "thumb" drive (preferably two!) that you +will use for backup purposes. You will need to encrypt them using LUKS +-- refer to your distro's documentation on how to accomplish this. + +For the encryption passphrase, you can use the same one as on your +master key. + +Once the encryption process is over, re-insert the USB drive and make +sure it gets properly mounted. Copy your entire ``.gnupg`` directory +over to the encrypted storage:: + + $ cp -a ~/.gnupg /media/disk/foo/gnupg-backup + +You should now test to make sure everything still works:: + + $ gpg --homedir=/media/disk/foo/gnupg-backup --list-key [fpr] + +If you don't get any errors, then you should be good to go. Unmount the +USB drive, distinctly label it so you don't blow it away next time you +need to use a random USB drive, and put in a safe place -- but not too +far away, because you'll need to use it every now and again for things +like editing identities, adding or revoking subkeys, or signing other +people's keys. + +Remove the master key from your homedir +---------------------------------------- + +The files in our home directory are not as well protected as we like to +think. They can be leaked or stolen via many different means: + +- by accident when making quick homedir copies to set up a new workstation +- by systems administrator negligence or malice +- via poorly secured backups +- via malware in desktop apps (browsers, pdf viewers, etc) +- via coercion when crossing international borders + +Protecting your key with a good passphrase greatly helps reduce the risk +of any of the above, but passphrases can be discovered via keyloggers, +shoulder-surfing, or any number of other means. For this reason, the +recommended setup is to remove your master key from your home directory +and store it on offline storage. + +.. warning:: + + Please see the previous section and make sure you have backed up + your GnuPG directory in its entirety. What we are about to do will + render your key useless if you do not have a usable backup! + +First, identify the keygrip of your master key:: + + $ gpg --with-keygrip --list-key [fpr] + +The output will be something like this:: + + pub rsa2048 2018-01-24 [SC] [expires: 2020-01-24] + 000000000000000000000000AAAABBBBCCCCDDDD + Keygrip = 1111000000000000000000000000000000000000 + uid [ultimate] Alice Dev <adev@kernel.org> + sub rsa2048 2018-01-24 [E] [expires: 2020-01-24] + Keygrip = 2222000000000000000000000000000000000000 + sub ed25519 2018-01-24 [S] + Keygrip = 3333000000000000000000000000000000000000 + +Find the keygrip entry that is beneath the ``pub`` line (right under the +master key fingerprint). This will correspond directly to a file in your +``~/.gnupg`` directory:: + + $ cd ~/.gnupg/private-keys-v1.d + $ ls + 1111000000000000000000000000000000000000.key + 2222000000000000000000000000000000000000.key + 3333000000000000000000000000000000000000.key + +All you have to do is simply remove the .key file that corresponds to +the master keygrip:: + + $ cd ~/.gnupg/private-keys-v1.d + $ rm 1111000000000000000000000000000000000000.key + +Now, if you issue the ``--list-secret-keys`` command, it will show that +the master key is missing (the ``#`` indicates it is not available):: + + $ gpg --list-secret-keys + sec# rsa2048 2018-01-24 [SC] [expires: 2020-01-24] + 000000000000000000000000AAAABBBBCCCCDDDD + uid [ultimate] Alice Dev <adev@kernel.org> + ssb rsa2048 2018-01-24 [E] [expires: 2020-01-24] + ssb ed25519 2018-01-24 [S] + +You should also remove any ``secring.gpg`` files in the ``~/.gnupg`` +directory, which are left over from earlier versions of GnuPG. + +If you don't have the "private-keys-v1.d" directory +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +If you do not have a ``~/.gnupg/private-keys-v1.d`` directory, then your +secret keys are still stored in the legacy ``secring.gpg`` file used by +GnuPG v1. Making any changes to your key, such as changing the +passphrase or adding a subkey, should automatically convert the old +``secring.gpg`` format to use ``private-keys-v1.d`` instead. + +Once you get that done, make sure to delete the obsolete ``secring.gpg`` +file, which still contains your private keys. + +.. _smartcards: + +Move the subkeys to a dedicated crypto device +============================================= + +Even though the master key is now safe from being leaked or stolen, the +subkeys are still in your home directory. Anyone who manages to get +their hands on those will be able to decrypt your communication or fake +your signatures (if they know the passphrase). Furthermore, each time a +GnuPG operation is performed, the keys are loaded into system memory and +can be stolen from there by sufficiently advanced malware (think +Meltdown and Spectre). + +The best way to completely protect your keys is to move them to a +specialized hardware device that is capable of smartcard operations. + +The benefits of smartcards +-------------------------- + +A smartcard contains a cryptographic chip that is capable of storing +private keys and performing crypto operations directly on the card +itself. Because the key contents never leave the smartcard, the +operating system of the computer into which you plug in the hardware +device is not able to retrieve the private keys themselves. This is very +different from the encrypted USB storage device we used earlier for +backup purposes -- while that USB device is plugged in and mounted, the +operating system is able to access the private key contents. + +Using external encrypted USB media is not a substitute to having a +smartcard-capable device. + +Available smartcard devices +--------------------------- + +Unless all your laptops and workstations have smartcard readers, the +easiest is to get a specialized USB device that implements smartcard +functionality. There are several options available: + +- `Nitrokey Start`_: Open hardware and Free Software, based on FSI + Japan's `Gnuk`_. Offers support for ECC keys, but fewest security + features (such as resistance to tampering or some side-channel + attacks). +- `Nitrokey Pro`_: Similar to the Nitrokey Start, but more + tamper-resistant and offers more security features, but no ECC + support. +- `Yubikey 4`_: proprietary hardware and software, but cheaper than + Nitrokey Pro and comes available in the USB-C form that is more useful + with newer laptops. Offers additional security features such as FIDO + U2F, but no ECC. + +`LWN has a good review`_ of some of the above models, as well as several +others. If you want to use ECC keys, your best bet among commercially +available devices is the Nitrokey Start. + +.. _`Nitrokey Start`: https://shop.nitrokey.com/shop/product/nitrokey-start-6 +.. _`Nitrokey Pro`: https://shop.nitrokey.com/shop/product/nitrokey-pro-3 +.. _`Yubikey 4`: https://www.yubico.com/product/yubikey-4-series/ +.. _Gnuk: http://www.fsij.org/doc-gnuk/ +.. _`LWN has a good review`: https://lwn.net/Articles/736231/ + +Configure your smartcard device +------------------------------- + +Your smartcard device should Just Work (TM) the moment you plug it into +any modern Linux workstation. You can verify it by running:: + + $ gpg --card-status + +If you see full smartcard details, then you are good to go. +Unfortunately, troubleshooting all possible reasons why things may not +be working for you is way beyond the scope of this guide. If you are +having trouble getting the card to work with GnuPG, please seek help via +usual support channels. + +To configure your smartcard, you will need to use the GnuPG menu system, as +there are no convenient command-line switches:: + + $ gpg --card-edit + [...omitted...] + gpg/card> admin + Admin commands are allowed + gpg/card> passwd + +You should set the user PIN (1), Admin PIN (3), and the Reset Code (4). +Please make sure to record and store these in a safe place -- especially +the Admin PIN and the Reset Code (which allows you to completely wipe +the smartcard). You so rarely need to use the Admin PIN, that you will +inevitably forget what it is if you do not record it. + +Getting back to the main card menu, you can also set other values (such +as name, sex, login data, etc), but it's not necessary and will +additionally leak information about your smartcard should you lose it. + +.. note:: + + Despite having the name "PIN", neither the user PIN nor the admin + PIN on the card need to be numbers. + +Move the subkeys to your smartcard +---------------------------------- + +Exit the card menu (using "q") and save all changes. Next, let's move +your subkeys onto the smartcard. You will need both your PGP key +passphrase and the admin PIN of the card for most operations:: + + $ gpg --edit-key [fpr] + + Secret subkeys are available. + + pub rsa2048/AAAABBBBCCCCDDDD + created: 2018-01-23 expires: 2020-01-23 usage: SC + trust: ultimate validity: ultimate + ssb rsa2048/1111222233334444 + created: 2018-01-23 expires: never usage: E + ssb ed25519/5555666677778888 + created: 2017-12-07 expires: never usage: S + [ultimate] (1). Alice Dev <adev@kernel.org> + + gpg> + +Using ``--edit-key`` puts us into the menu mode again, and you will +notice that the key listing is a little different. From here on, all +commands are done from inside this menu mode, as indicated by ``gpg>``. + +First, let's select the key we'll be putting onto the card -- you do +this by typing ``key 1`` (it's the first one in the listing, the **[E]** +subkey):: + + gpg> key 1 + +In the output, you should now see ``ssb*`` on the **[E]** key. The ``*`` +indicates which key is currently "selected." It works as a *toggle*, +meaning that if you type ``key 1`` again, the ``*`` will disappear and +the key will not be selected any more. + +Now, let's move that key onto the smartcard:: + + gpg> keytocard + Please select where to store the key: + (2) Encryption key + Your selection? 2 + +Since it's our **[E]** key, it makes sense to put it into the Encryption +slot. When you submit your selection, you will be prompted first for +your PGP key passphrase, and then for the admin PIN. If the command +returns without an error, your key has been moved. + +**Important**: Now type ``key 1`` again to unselect the first key, and +``key 2`` to select the **[S]** key:: + + gpg> key 1 + gpg> key 2 + gpg> keytocard + Please select where to store the key: + (1) Signature key + (3) Authentication key + Your selection? 1 + +You can use the **[S]** key both for Signature and Authentication, but +we want to make sure it's in the Signature slot, so choose (1). Once +again, if your command returns without an error, then the operation was +successful:: + + gpg> q + Save changes? (y/N) y + +Saving the changes will delete the keys you moved to the card from your +home directory (but it's okay, because we have them in our backups +should we need to do this again for a replacement smartcard). + +Verifying that the keys were moved +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +If you perform ``--list-secret-keys`` now, you will see a subtle +difference in the output:: + + $ gpg --list-secret-keys + sec# rsa2048 2018-01-24 [SC] [expires: 2020-01-24] + 000000000000000000000000AAAABBBBCCCCDDDD + uid [ultimate] Alice Dev <adev@kernel.org> + ssb> rsa2048 2018-01-24 [E] [expires: 2020-01-24] + ssb> ed25519 2018-01-24 [S] + +The ``>`` in the ``ssb>`` output indicates that the subkey is only +available on the smartcard. If you go back into your secret keys +directory and look at the contents there, you will notice that the +``.key`` files there have been replaced with stubs:: + + $ cd ~/.gnupg/private-keys-v1.d + $ strings *.key | grep 'private-key' + +The output should contain ``shadowed-private-key`` to indicate that +these files are only stubs and the actual content is on the smartcard. + +Verifying that the smartcard is functioning +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +To verify that the smartcard is working as intended, you can create a +signature:: + + $ echo "Hello world" | gpg --clearsign > /tmp/test.asc + $ gpg --verify /tmp/test.asc + +This should ask for your smartcard PIN on your first command, and then +show "Good signature" after you run ``gpg --verify``. + +Congratulations, you have successfully made it extremely difficult to +steal your digital developer identity! + +Other common GnuPG operations +----------------------------- + +Here is a quick reference for some common operations you'll need to do +with your PGP key. + +Mounting your master key offline storage +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +You will need your master key for any of the operations below, so you +will first need to mount your backup offline storage and tell GnuPG to +use it:: + + $ export GNUPGHOME=/media/disk/foo/gnupg-backup + $ gpg --list-secret-keys + +You want to make sure that you see ``sec`` and not ``sec#`` in the +output (the ``#`` means the key is not available and you're still using +your regular home directory location). + +Extending key expiration date +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The master key has the default expiration date of 2 years from the date +of creation. This is done both for security reasons and to make obsolete +keys eventually disappear from keyservers. + +To extend the expiration on your key by a year from current date, just +run:: + + $ gpg --quick-set-expire [fpr] 1y + +You can also use a specific date if that is easier to remember (e.g. +your birthday, January 1st, or Canada Day):: + + $ gpg --quick-set-expire [fpr] 2020-07-01 + +Remember to send the updated key back to keyservers:: + + $ gpg --send-key [fpr] + +Updating your work directory after any changes +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +After you make any changes to your key using the offline storage, you will +want to import these changes back into your regular working directory:: + + $ gpg --export | gpg --homedir ~/.gnupg --import + $ unset GNUPGHOME + + +Using PGP with Git +================== + +One of the core features of Git is its decentralized nature -- once a +repository is cloned to your system, you have full history of the +project, including all of its tags, commits and branches. However, with +hundreds of cloned repositories floating around, how does anyone verify +that their copy of linux.git has not been tampered with by a malicious +third party? + +Or what happens if a backdoor is discovered in the code and the "Author" +line in the commit says it was done by you, while you're pretty sure you +had `nothing to do with it`_? + +To address both of these issues, Git introduced PGP integration. Signed +tags prove the repository integrity by assuring that its contents are +exactly the same as on the workstation of the developer who created the +tag, while signed commits make it nearly impossible for someone to +impersonate you without having access to your PGP keys. + +.. _`nothing to do with it`: https://github.com/jayphelps/git-blame-someone-else + +Configure git to use your PGP key +--------------------------------- + +If you only have one secret key in your keyring, then you don't really +need to do anything extra, as it becomes your default key. However, if +you happen to have multiple secret keys, you can tell git which key +should be used (``[fpr]`` is the fingerprint of your key):: + + $ git config --global user.signingKey [fpr] + +**IMPORTANT**: If you have a distinct ``gpg2`` command, then you should +tell git to always use it instead of the legacy ``gpg`` from version 1:: + + $ git config --global gpg.program gpg2 + +How to work with signed tags +---------------------------- + +To create a signed tag, simply pass the ``-s`` switch to the tag +command:: + + $ git tag -s [tagname] + +Our recommendation is to always sign git tags, as this allows other +developers to ensure that the git repository they are pulling from has +not been maliciously altered. + +How to verify signed tags +~~~~~~~~~~~~~~~~~~~~~~~~~ + +To verify a signed tag, simply use the ``verify-tag`` command:: + + $ git verify-tag [tagname] + +If you are pulling a tag from another fork of the project repository, +git should automatically verify the signature at the tip you're pulling +and show you the results during the merge operation:: + + $ git pull [url] tags/sometag + +The merge message will contain something like this:: + + Merge tag 'sometag' of [url] + + [Tag message] + + # gpg: Signature made [...] + # gpg: Good signature from [...] + +If you are verifying someone else's git tag, then you will need to +import their PGP key. Please refer to the +":ref:`verify_identities`" section below. + +Configure git to always sign annotated tags +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Chances are, if you're creating an annotated tag, you'll want to sign +it. To force git to always sign annotated tags, you can set a global +configuration option:: + + $ git config --global tag.forceSignAnnotated true + +How to work with signed commits +------------------------------- + +It is easy to create signed commits, but it is much more difficult to +use them in Linux kernel development, since it relies on patches sent to +the mailing list, and this workflow does not preserve PGP commit +signatures. Furthermore, when rebasing your repository to match +upstream, even your own PGP commit signatures will end up discarded. For +this reason, most kernel developers don't bother signing their commits +and will ignore signed commits in any external repositories that they +rely upon in their work. + +However, if you have your working git tree publicly available at some +git hosting service (kernel.org, infradead.org, ozlabs.org, or others), +then the recommendation is that you sign all your git commits even if +upstream developers do not directly benefit from this practice. + +We recommend this for the following reasons: + +1. Should there ever be a need to perform code forensics or track code + provenance, even externally maintained trees carrying PGP commit + signatures will be valuable for such purposes. +2. If you ever need to re-clone your local repository (for example, + after a disk failure), this lets you easily verify the repository + integrity before resuming your work. +3. If someone needs to cherry-pick your commits, this allows them to + quickly verify their integrity before applying them. + +Creating signed commits +~~~~~~~~~~~~~~~~~~~~~~~ + +To create a signed commit, you just need to pass the ``-S`` flag to the +``git commit`` command (it's capital ``-S`` due to collision with +another flag):: + + $ git commit -S + +Configure git to always sign commits +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +You can tell git to always sign commits:: + + git config --global commit.gpgSign true + +.. note:: + + Make sure you configure ``gpg-agent`` before you turn this on. + +.. _verify_identities: + +How to verify kernel developer identities +========================================= + +Signing tags and commits is easy, but how does one go about verifying +that the key used to sign something belongs to the actual kernel +developer and not to a malicious imposter? + +Configure auto-key-retrieval using WKD and DANE +----------------------------------------------- + +If you are not already someone with an extensive collection of other +developers' public keys, then you can jumpstart your keyring by relying +on key auto-discovery and auto-retrieval. GnuPG can piggyback on other +delegated trust technologies, namely DNSSEC and TLS, to get you going if +the prospect of starting your own Web of Trust from scratch is too +daunting. + +Add the following to your ``~/.gnupg/gpg.conf``:: + + auto-key-locate wkd,dane,local + auto-key-retrieve + +DNS-Based Authentication of Named Entities ("DANE") is a method for +publishing public keys in DNS and securing them using DNSSEC signed +zones. Web Key Directory ("WKD") is the alternative method that uses +https lookups for the same purpose. When using either DANE or WKD for +looking up public keys, GnuPG will validate DNSSEC or TLS certificates, +respectively, before adding auto-retrieved public keys to your local +keyring. + +Kernel.org publishes the WKD for all developers who have kernel.org +accounts. Once you have the above changes in your ``gpg.conf``, you can +auto-retrieve the keys for Linus Torvalds and Greg Kroah-Hartman (if you +don't already have them):: + + $ gpg --locate-keys torvalds@kernel.org gregkh@kernel.org + +If you have a kernel.org account, then you should `add the kernel.org +UID to your key`_ to make WKD more useful to other kernel developers. + +.. _`add the kernel.org UID to your key`: https://korg.wiki.kernel.org/userdoc/mail#adding_a_kernelorg_uid_to_your_pgp_key + +Web of Trust (WOT) vs. Trust on First Use (TOFU) +------------------------------------------------ + +PGP incorporates a trust delegation mechanism known as the "Web of +Trust." At its core, this is an attempt to replace the need for +centralized Certification Authorities of the HTTPS/TLS world. Instead of +various software makers dictating who should be your trusted certifying +entity, PGP leaves this responsibility to each user. + +Unfortunately, very few people understand how the Web of Trust works. +While it remains an important aspect of the OpenPGP specification, +recent versions of GnuPG (2.2 and above) have implemented an alternative +mechanism called "Trust on First Use" (TOFU). You can think of TOFU as +"the SSH-like approach to trust." With SSH, the first time you connect +to a remote system, its key fingerprint is recorded and remembered. If +the key changes in the future, the SSH client will alert you and refuse +to connect, forcing you to make a decision on whether you choose to +trust the changed key or not. Similarly, the first time you import +someone's PGP key, it is assumed to be valid. If at any point in the +future GnuPG comes across another key with the same identity, both the +previously imported key and the new key will be marked as invalid and +you will need to manually figure out which one to keep. + +We recommend that you use the combined TOFU+PGP trust model (which is +the new default in GnuPG v2). To set it, add (or modify) the +``trust-model`` setting in ``~/.gnupg/gpg.conf``:: + + trust-model tofu+pgp + +How to use keyservers (more) safely +----------------------------------- + +If you get a "No public key" error when trying to validate someone's +tag, then you should attempt to lookup that key using a keyserver. It is +important to keep in mind that there is absolutely no guarantee that the +key you retrieve from PGP keyservers belongs to the actual person -- +that much is by design. You are supposed to use the Web of Trust to +establish key validity. + +How to properly maintain the Web of Trust is beyond the scope of this +document, simply because doing it properly requires both effort and +dedication that tends to be beyond the caring threshold of most human +beings. Here are some shortcuts that will help you reduce the risk of +importing a malicious key. + +First, let's say you've tried to run ``git verify-tag`` but it returned +an error saying the key is not found:: + + $ git verify-tag sunxi-fixes-for-4.15-2 + gpg: Signature made Sun 07 Jan 2018 10:51:55 PM EST + gpg: using RSA key DA73759BF8619E484E5A3B47389A54219C0F2430 + gpg: issuer "wens@...org" + gpg: Can't check signature: No public key + +Let's query the keyserver for more info about that key fingerprint (the +fingerprint probably belongs to a subkey, so we can't use it directly +without finding out the ID of the master key it is associated with):: + + $ gpg --search DA73759BF8619E484E5A3B47389A54219C0F2430 + gpg: data source: hkp://keys.gnupg.net + (1) Chen-Yu Tsai <wens@...org> + 4096 bit RSA key C94035C21B4F2AEB, created: 2017-03-14, expires: 2019-03-15 + Keys 1-1 of 1 for "DA73759BF8619E484E5A3B47389A54219C0F2430". Enter number(s), N)ext, or Q)uit > q + +Locate the ID of the master key in the output, in our example +``C94035C21B4F2AEB``. Now display the key of Linus Torvalds that you +have on your keyring:: + + $ gpg --list-key torvalds@kernel.org + pub rsa2048 2011-09-20 [SC] + ABAF11C65A2970B130ABE3C479BE3E4300411886 + uid [ unknown] Linus Torvalds <torvalds@kernel.org> + sub rsa2048 2011-09-20 [E] + +Next, open the `PGP pathfinder`_. In the "From" field, paste the key +fingerprint of Linus Torvalds from the output above. In the "To" field, +paste they key-id you found via ``gpg --search`` of the unknown key, and +check the results: + +- `Finding paths to Linus`_ + +If you get a few decent trust paths, then it's a pretty good indication +that it is a valid key. You can add it to your keyring from the +keyserver now:: + + $ gpg --recv-key C94035C21B4F2AEB + +This process is not perfect, and you are obviously trusting the +administrators of the PGP Pathfinder service to not be malicious (in +fact, this goes against :ref:`devs_not_infra`). However, if you +do not carefully maintain your own web of trust, then it is a marked +improvement over blindly trusting keyservers. + +.. _`PGP pathfinder`: https://pgp.cs.uu.nl/ +.. _`Finding paths to Linus`: https://pgp.cs.uu.nl/paths/79BE3E4300411886/to/C94035C21B4F2AEB.html diff --git a/Documentation/sysctl/user.txt b/Documentation/sysctl/user.txt index 1291c498f78f..a5882865836e 100644 --- a/Documentation/sysctl/user.txt +++ b/Documentation/sysctl/user.txt @@ -3,7 +3,7 @@ Documentation for /proc/sys/user/* kernel version 4.9.0 ============================================================== -This file contains the documetation for the sysctl files in +This file contains the documentation for the sysctl files in /proc/sys/user. The files in this directory can be used to override the default diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt index 6f9d7b418917..beea975980f6 100644 --- a/Documentation/watchdog/watchdog-parameters.txt +++ b/Documentation/watchdog/watchdog-parameters.txt @@ -40,11 +40,6 @@ margin: Watchdog margin in seconds (default=60) nowayout: Disable watchdog shutdown on close (default=kernel config parameter) ------------------------------------------------- -at32ap700x_wdt: -timeout: Timeout value. Limited to be 1 or 2 seconds. (default=2) -nowayout: Watchdog cannot be stopped once started - (default=kernel config parameter) -------------------------------------------------- at91rm9200_wdt: wdt_time: Watchdog time in seconds. (default=5) nowayout: Watchdog cannot be stopped once started @@ -162,11 +157,6 @@ testmode: Watchdog test mode (1 = no reboot), default=0 nowayout: Watchdog cannot be stopped once started (default=kernel config parameter) ------------------------------------------------- -ixp2000_wdt: -heartbeat: Watchdog heartbeat in seconds (default 60s) -nowayout: Watchdog cannot be stopped once started - (default=kernel config parameter) -------------------------------------------------- ixp4xx_wdt: heartbeat: Watchdog heartbeat in seconds (default 60s) nowayout: Watchdog cannot be stopped once started @@ -381,19 +371,6 @@ timeout: Watchdog timeout in seconds. 1 <= timeout <= 255, default=60. nowayout: Watchdog cannot be stopped once started (default=kernel config parameter) ------------------------------------------------- -w83697hf_wdt: -wdt_io: w83697hf/hg WDT io port (default 0x2e, 0 = autodetect) -timeout: Watchdog timeout in seconds. 1<= timeout <=255 (default=60) -nowayout: Watchdog cannot be stopped once started - (default=kernel config parameter) -early_disable: Watchdog gets disabled at boot time (default=1) -------------------------------------------------- -w83697ug_wdt: -wdt_io: w83697ug/uf WDT io port (default 0x2e) -timeout: Watchdog timeout in seconds. 1<= timeout <=255 (default=60) -nowayout: Watchdog cannot be stopped once started - (default=kernel config parameter) -------------------------------------------------- w83877f_wdt: timeout: Watchdog timeout in seconds. (1<=timeout<=3600, default=30) nowayout: Watchdog cannot be stopped once started |