diff options
author | Paolo Abeni | 2022-09-08 18:34:54 +0200 |
---|---|---|
committer | Paolo Abeni | 2022-09-08 18:38:30 +0200 |
commit | 9f8f1933dce555d3c246f447f54fca8de8889da9 (patch) | |
tree | dc447d0174473de8385d47eb8aedc058a336e4a9 /Documentation | |
parent | 75554fe00f941c3c3d9344e88708093a14d2b4b8 (diff) | |
parent | 26b1224903b3fb66e8aa564868d0d57648c32b15 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/ethernet/freescale/fec.h
7d650df99d52 ("net: fec: add pm_qos support on imx6q platform")
40c79ce13b03 ("net: fec: add stop mode support for imx8 platform")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/block/index.rst | 1 | ||||
-rw-r--r-- | Documentation/block/ublk.rst | 253 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml | 2 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/input/touchscreen/goodix.yaml | 1 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml | 1 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/usb/qcom,dwc3.yaml | 6 | ||||
-rw-r--r-- | Documentation/input/joydev/joystick.rst | 1 | ||||
-rw-r--r-- | Documentation/networking/rxrpc.rst | 11 |
8 files changed, 265 insertions, 11 deletions
diff --git a/Documentation/block/index.rst b/Documentation/block/index.rst index 68f115f2b1c6..c4c73db748a8 100644 --- a/Documentation/block/index.rst +++ b/Documentation/block/index.rst @@ -23,3 +23,4 @@ Block stat switching-sched writeback_cache_control + ublk diff --git a/Documentation/block/ublk.rst b/Documentation/block/ublk.rst new file mode 100644 index 000000000000..2122d1a4a541 --- /dev/null +++ b/Documentation/block/ublk.rst @@ -0,0 +1,253 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=========================================== +Userspace block device driver (ublk driver) +=========================================== + +Overview +======== + +ublk is a generic framework for implementing block device logic from userspace. +The motivation behind it is that moving virtual block drivers into userspace, +such as loop, nbd and similar can be very helpful. It can help to implement +new virtual block device such as ublk-qcow2 (there are several attempts of +implementing qcow2 driver in kernel). + +Userspace block devices are attractive because: + +- They can be written many programming languages. +- They can use libraries that are not available in the kernel. +- They can be debugged with tools familiar to application developers. +- Crashes do not kernel panic the machine. +- Bugs are likely to have a lower security impact than bugs in kernel + code. +- They can be installed and updated independently of the kernel. +- They can be used to simulate block device easily with user specified + parameters/setting for test/debug purpose + +ublk block device (``/dev/ublkb*``) is added by ublk driver. Any IO request +on the device will be forwarded to ublk userspace program. For convenience, +in this document, ``ublk server`` refers to generic ublk userspace +program. ``ublksrv`` [#userspace]_ is one of such implementation. It +provides ``libublksrv`` [#userspace_lib]_ library for developing specific +user block device conveniently, while also generic type block device is +included, such as loop and null. Richard W.M. Jones wrote userspace nbd device +``nbdublk`` [#userspace_nbdublk]_ based on ``libublksrv`` [#userspace_lib]_. + +After the IO is handled by userspace, the result is committed back to the +driver, thus completing the request cycle. This way, any specific IO handling +logic is totally done by userspace, such as loop's IO handling, NBD's IO +communication, or qcow2's IO mapping. + +``/dev/ublkb*`` is driven by blk-mq request-based driver. Each request is +assigned by one queue wide unique tag. ublk server assigns unique tag to each +IO too, which is 1:1 mapped with IO of ``/dev/ublkb*``. + +Both the IO request forward and IO handling result committing are done via +``io_uring`` passthrough command; that is why ublk is also one io_uring based +block driver. It has been observed that using io_uring passthrough command can +give better IOPS than block IO; which is why ublk is one of high performance +implementation of userspace block device: not only IO request communication is +done by io_uring, but also the preferred IO handling in ublk server is io_uring +based approach too. + +ublk provides control interface to set/get ublk block device parameters. +The interface is extendable and kabi compatible: basically any ublk request +queue's parameter or ublk generic feature parameters can be set/get via the +interface. Thus, ublk is generic userspace block device framework. +For example, it is easy to setup a ublk device with specified block +parameters from userspace. + +Using ublk +========== + +ublk requires userspace ublk server to handle real block device logic. + +Below is example of using ``ublksrv`` to provide ublk-based loop device. + +- add a device:: + + ublk add -t loop -f ublk-loop.img + +- format with xfs, then use it:: + + mkfs.xfs /dev/ublkb0 + mount /dev/ublkb0 /mnt + # do anything. all IOs are handled by io_uring + ... + umount /mnt + +- list the devices with their info:: + + ublk list + +- delete the device:: + + ublk del -a + ublk del -n $ublk_dev_id + +See usage details in README of ``ublksrv`` [#userspace_readme]_. + +Design +====== + +Control plane +------------- + +ublk driver provides global misc device node (``/dev/ublk-control``) for +managing and controlling ublk devices with help of several control commands: + +- ``UBLK_CMD_ADD_DEV`` + + Add a ublk char device (``/dev/ublkc*``) which is talked with ublk server + WRT IO command communication. Basic device info is sent together with this + command. It sets UAPI structure of ``ublksrv_ctrl_dev_info``, + such as ``nr_hw_queues``, ``queue_depth``, and max IO request buffer size, + for which the info is negotiated with the driver and sent back to the server. + When this command is completed, the basic device info is immutable. + +- ``UBLK_CMD_SET_PARAMS`` / ``UBLK_CMD_GET_PARAMS`` + + Set or get parameters of the device, which can be either generic feature + related, or request queue limit related, but can't be IO logic specific, + because the driver does not handle any IO logic. This command has to be + sent before sending ``UBLK_CMD_START_DEV``. + +- ``UBLK_CMD_START_DEV`` + + After the server prepares userspace resources (such as creating per-queue + pthread & io_uring for handling ublk IO), this command is sent to the + driver for allocating & exposing ``/dev/ublkb*``. Parameters set via + ``UBLK_CMD_SET_PARAMS`` are applied for creating the device. + +- ``UBLK_CMD_STOP_DEV`` + + Halt IO on ``/dev/ublkb*`` and remove the device. When this command returns, + ublk server will release resources (such as destroying per-queue pthread & + io_uring). + +- ``UBLK_CMD_DEL_DEV`` + + Remove ``/dev/ublkc*``. When this command returns, the allocated ublk device + number can be reused. + +- ``UBLK_CMD_GET_QUEUE_AFFINITY`` + + When ``/dev/ublkc`` is added, the driver creates block layer tagset, so + that each queue's affinity info is available. The server sends + ``UBLK_CMD_GET_QUEUE_AFFINITY`` to retrieve queue affinity info. It can + set up the per-queue context efficiently, such as bind affine CPUs with IO + pthread and try to allocate buffers in IO thread context. + +- ``UBLK_CMD_GET_DEV_INFO`` + + For retrieving device info via ``ublksrv_ctrl_dev_info``. It is the server's + responsibility to save IO target specific info in userspace. + +Data plane +---------- + +ublk server needs to create per-queue IO pthread & io_uring for handling IO +commands via io_uring passthrough. The per-queue IO pthread +focuses on IO handling and shouldn't handle any control & management +tasks. + +The's IO is assigned by a unique tag, which is 1:1 mapping with IO +request of ``/dev/ublkb*``. + +UAPI structure of ``ublksrv_io_desc`` is defined for describing each IO from +the driver. A fixed mmaped area (array) on ``/dev/ublkc*`` is provided for +exporting IO info to the server; such as IO offset, length, OP/flags and +buffer address. Each ``ublksrv_io_desc`` instance can be indexed via queue id +and IO tag directly. + +The following IO commands are communicated via io_uring passthrough command, +and each command is only for forwarding the IO and committing the result +with specified IO tag in the command data: + +- ``UBLK_IO_FETCH_REQ`` + + Sent from the server IO pthread for fetching future incoming IO requests + destined to ``/dev/ublkb*``. This command is sent only once from the server + IO pthread for ublk driver to setup IO forward environment. + +- ``UBLK_IO_COMMIT_AND_FETCH_REQ`` + + When an IO request is destined to ``/dev/ublkb*``, the driver stores + the IO's ``ublksrv_io_desc`` to the specified mapped area; then the + previous received IO command of this IO tag (either ``UBLK_IO_FETCH_REQ`` + or ``UBLK_IO_COMMIT_AND_FETCH_REQ)`` is completed, so the server gets + the IO notification via io_uring. + + After the server handles the IO, its result is committed back to the + driver by sending ``UBLK_IO_COMMIT_AND_FETCH_REQ`` back. Once ublkdrv + received this command, it parses the result and complete the request to + ``/dev/ublkb*``. In the meantime setup environment for fetching future + requests with the same IO tag. That is, ``UBLK_IO_COMMIT_AND_FETCH_REQ`` + is reused for both fetching request and committing back IO result. + +- ``UBLK_IO_NEED_GET_DATA`` + + With ``UBLK_F_NEED_GET_DATA`` enabled, the WRITE request will be firstly + issued to ublk server without data copy. Then, IO backend of ublk server + receives the request and it can allocate data buffer and embed its addr + inside this new io command. After the kernel driver gets the command, + data copy is done from request pages to this backend's buffer. Finally, + backend receives the request again with data to be written and it can + truly handle the request. + + ``UBLK_IO_NEED_GET_DATA`` adds one additional round-trip and one + io_uring_enter() syscall. Any user thinks that it may lower performance + should not enable UBLK_F_NEED_GET_DATA. ublk server pre-allocates IO + buffer for each IO by default. Any new project should try to use this + buffer to communicate with ublk driver. However, existing project may + break or not able to consume the new buffer interface; that's why this + command is added for backwards compatibility so that existing projects + can still consume existing buffers. + +- data copy between ublk server IO buffer and ublk block IO request + + The driver needs to copy the block IO request pages into the server buffer + (pages) first for WRITE before notifying the server of the coming IO, so + that the server can handle WRITE request. + + When the server handles READ request and sends + ``UBLK_IO_COMMIT_AND_FETCH_REQ`` to the server, ublkdrv needs to copy + the server buffer (pages) read to the IO request pages. + +Future development +================== + +Container-aware ublk deivice +---------------------------- + +ublk driver doesn't handle any IO logic. Its function is well defined +for now and very limited userspace interfaces are needed, which is also +well defined too. It is possible to make ublk devices container-aware block +devices in future as Stefan Hajnoczi suggested [#stefan]_, by removing +ADMIN privilege. + +Zero copy +--------- + +Zero copy is a generic requirement for nbd, fuse or similar drivers. A +problem [#xiaoguang]_ Xiaoguang mentioned is that pages mapped to userspace +can't be remapped any more in kernel with existing mm interfaces. This can +occurs when destining direct IO to ``/dev/ublkb*``. Also, he reported that +big requests (IO size >= 256 KB) may benefit a lot from zero copy. + + +References +========== + +.. [#userspace] https://github.com/ming1/ubdsrv + +.. [#userspace_lib] https://github.com/ming1/ubdsrv/tree/master/lib + +.. [#userspace_nbdublk] https://gitlab.com/rwmjones/libnbd/-/tree/nbdublk + +.. [#userspace_readme] https://github.com/ming1/ubdsrv/blob/master/README + +.. [#stefan] https://lore.kernel.org/linux-block/YoOr6jBfgVm8GvWg@stefanha-x1.localdomain/ + +.. [#xiaoguang] https://lore.kernel.org/linux-block/YoOr6jBfgVm8GvWg@stefanha-x1.localdomain/ diff --git a/Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml b/Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml index b6bbc312a7cf..1414ba9977c1 100644 --- a/Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml +++ b/Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml @@ -24,8 +24,10 @@ properties: interrupts: minItems: 1 + maxItems: 2 description: Should be configured with type IRQ_TYPE_EDGE_RISING. + If two interrupts are provided, expected order is INT1 and INT2. required: - compatible diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml b/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml index 93f2ce3130ae..19ac9da421df 100644 --- a/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml +++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml @@ -16,6 +16,7 @@ properties: compatible: enum: - goodix,gt1151 + - goodix,gt1158 - goodix,gt5663 - goodix,gt5688 - goodix,gt911 diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml index e63b66545317..b019d490170d 100644 --- a/Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml +++ b/Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml @@ -24,6 +24,7 @@ properties: - mediatek,mt2712-mtu3 - mediatek,mt8173-mtu3 - mediatek,mt8183-mtu3 + - mediatek,mt8188-mtu3 - mediatek,mt8192-mtu3 - mediatek,mt8195-mtu3 - const: mediatek,mtu3 diff --git a/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml b/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml index fea3e7092ace..cd2f7cb6745a 100644 --- a/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml +++ b/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml @@ -33,6 +33,7 @@ properties: - qcom,sm6115-dwc3 - qcom,sm6125-dwc3 - qcom,sm6350-dwc3 + - qcom,sm6375-dwc3 - qcom,sm8150-dwc3 - qcom,sm8250-dwc3 - qcom,sm8350-dwc3 @@ -108,12 +109,17 @@ properties: HS/FS/LS modes are supported. type: boolean + wakeup-source: true + # Required child node: patternProperties: "^usb@[0-9a-f]+$": $ref: snps,dwc3.yaml# + properties: + wakeup-source: false + required: - compatible - reg diff --git a/Documentation/input/joydev/joystick.rst b/Documentation/input/joydev/joystick.rst index f615906a0821..6d721396717a 100644 --- a/Documentation/input/joydev/joystick.rst +++ b/Documentation/input/joydev/joystick.rst @@ -517,6 +517,7 @@ All I-Force devices are supported by the iforce module. This includes: * AVB Mag Turbo Force * AVB Top Shot Pegasus * AVB Top Shot Force Feedback Racing Wheel +* Boeder Force Feedback Wheel * Logitech WingMan Force * Logitech WingMan Force Wheel * Guillemot Race Leader Force Feedback diff --git a/Documentation/networking/rxrpc.rst b/Documentation/networking/rxrpc.rst index 39c2249c7aa7..39494a6ea739 100644 --- a/Documentation/networking/rxrpc.rst +++ b/Documentation/networking/rxrpc.rst @@ -1055,17 +1055,6 @@ The kernel interface functions are as follows: first function to change. Note that this must be called in TASK_RUNNING state. - (#) Get reply timestamp:: - - bool rxrpc_kernel_get_reply_time(struct socket *sock, - struct rxrpc_call *call, - ktime_t *_ts) - - This allows the timestamp on the first DATA packet of the reply of a - client call to be queried, provided that it is still in the Rx ring. If - successful, the timestamp will be stored into ``*_ts`` and true will be - returned; false will be returned otherwise. - (#) Get remote client epoch:: u32 rxrpc_kernel_get_epoch(struct socket *sock, |