From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95D4AC4167B for ; Mon, 7 Dec 2020 21:51:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 61DE523406 for ; Mon, 7 Dec 2020 21:51:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727499AbgLGVvu (ORCPT ); Mon, 7 Dec 2020 16:51:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726080AbgLGVvt (ORCPT ); Mon, 7 Dec 2020 16:51:49 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65163C061793; Mon, 7 Dec 2020 13:51:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description; bh=MApMKOSSa1wXcT7SWWTwmXRkX/JEXOq8UqusNOIGUrA=; b=FywLNEW9KC7uXtr8uTRtILsznD j/VigRjIA+fzQl017RZlHTYvrCFU0wK1z3dPrftTo5KRQ/q2F97eXw0RRn4jeE471S57LA1RCarm3 Bvbqj9UMA3vA9B7n/aT4RIh56pDvZfeLQ2FpWrV/SA+edwaWh+UGveqzBdYsZrJVopyUOtkXPBDgD FXZ7P7gpiAN5xiwo7Nau8Vdj5Xlqu8kSiO7fvql+haJQ1o409qJHaDv86BRVFZF8bnASWomW3aGAn RERkiVbssd/c2oS8Ayp87oxEx50enqmO868Z6+KRt8C9ya7ihLBr6Qjk1oMyFlgN7gOriN43aufig lvBUvBcA==; Received: from [2601:1c0:6280:3f0::1494] by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmOPS-0008Pd-DO; Mon, 07 Dec 2020 21:51:06 +0000 Subject: Re: [PATCH 18/22] xlink-core: Add xlink core driver xLink To: mgross@linux.intel.com, markgross@kernel.org, arnd@arndb.de, bp@suse.de, damien.lemoal@wdc.com, dragan.cvetic@xilinx.com, gregkh@linuxfoundation.org, corbet@lwn.net, leonard.crestez@nxp.com, palmerdabbelt@google.com, paul.walmsley@sifive.com, peng.fan@nxp.com, robh+dt@kernel.org, shawnguo@kernel.org Cc: linux-kernel@vger.kernel.org, Seamus Kelly , linux-doc@vger.kernel.org References: <20201201223511.65542-1-mgross@linux.intel.com> <20201201223511.65542-19-mgross@linux.intel.com> From: Randy Dunlap Message-ID: Date: Mon, 7 Dec 2020 13:50:59 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20201201223511.65542-19-mgross@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hi-- On 12/1/20 2:35 PM, mgross@linux.intel.com wrote: > From: Seamus Kelly > > > Cc: linux-doc@vger.kernel.org > Reviewed-by: Mark Gross > Signed-off-by: Seamus Kelly > --- > Documentation/vpu/index.rst | 1 + > Documentation/vpu/xlink-core.rst | 80 ++ > MAINTAINERS | 12 + > drivers/misc/Kconfig | 1 + > drivers/misc/Makefile | 1 + > drivers/misc/xlink-core/Kconfig | 33 + > drivers/misc/xlink-core/Makefile | 5 + > drivers/misc/xlink-core/xlink-core.c | 870 ++++++++++++++++++++ > drivers/misc/xlink-core/xlink-defs.h | 175 ++++ > drivers/misc/xlink-core/xlink-multiplexer.c | 534 ++++++++++++ > drivers/misc/xlink-core/xlink-multiplexer.h | 35 + > drivers/misc/xlink-core/xlink-platform.c | 160 ++++ > drivers/misc/xlink-core/xlink-platform.h | 65 ++ > include/linux/xlink.h | 108 +++ > include/uapi/misc/xlink_uapi.h | 145 ++++ > 15 files changed, 2225 insertions(+) > create mode 100644 Documentation/vpu/xlink-core.rst > create mode 100644 drivers/misc/xlink-core/Kconfig > create mode 100644 drivers/misc/xlink-core/Makefile > create mode 100644 drivers/misc/xlink-core/xlink-core.c > create mode 100644 drivers/misc/xlink-core/xlink-defs.h > create mode 100644 drivers/misc/xlink-core/xlink-multiplexer.c > create mode 100644 drivers/misc/xlink-core/xlink-multiplexer.h > create mode 100644 drivers/misc/xlink-core/xlink-platform.c > create mode 100644 drivers/misc/xlink-core/xlink-platform.h > create mode 100644 include/linux/xlink.h > create mode 100644 include/uapi/misc/xlink_uapi.h > diff --git a/Documentation/vpu/xlink-core.rst b/Documentation/vpu/xlink-core.rst > new file mode 100644 > index 000000000000..5410755ff13a > --- /dev/null > +++ b/Documentation/vpu/xlink-core.rst > @@ -0,0 +1,80 @@ > +.. SPDX-License-Identifier: GPL-2.0-only > + > +xLink-core software sub-system subsystem > +============================== > + > +The purpose of the xLink software sub-system is to facilitate communication subsystem {throughout/everywhere} > +between multiple users on multiple nodes in the system. > + > +There are three types of xLink nodes: > + > +1. Remote Host: this is an external IA/x86 host system that is only capable of > + communicating directly to the Local Host node on VPU 2.x products. > +2. Local Host: this is the ARM core within the VPU 2.x SoC. The Local Host can > + communicate upstream to the Remote Host node, and downstream to the VPU IP > + node. > +3. VPU IP: this is the Leon RT core within the VPU 2.x SoC. The VPU IP can only > + communicate upstream to the Local Host node. > + > +xLink provides a common API across all interfaces for users to access xLink > +functions and provides user space APIs via an IOCTL interface implemented in > +the xLink core. > + > +xLink manages communications from one interface to another and provides routing > +of data through multiple channels across a single physical interface. > + > +It exposes a common API across all interfaces at both kernel and user level for levels > +processes/applications to access. > + > +It has typical APIs types (open, close, read, write) that you would associate API types > +with a communication interface. > + > +It also has other APIs that are related to other functions that the device can > +perform e.g. boot, reset get/set device mode. perform, > +The driver is broken down into 4 source files. > + > +xlink-core: > +Contains driver initialization, driver API and IOCTL interface (for user > +space). > + > +xlink-multiplexer: > +The Multiplexer component is responsible for securely routing messages through > +multiple communication channels over a single physical interface. > + > +xlink-dispatcher: > +The Dispatcher component is responsible for queueing and handling xLink > +communication requests from all users in the system and invoking the underlying > +platform interface drivers. > + > +xlink-platform: > +provides abstraction to each interface supported (PCIe, USB, IPC, etc). > + > +Typical xLink transaction (simplified): > +When a user wants to send data across an interface via xLink it firstly calls > +xlink connect which connects to the relevant interface (PCIe, USB,IPC,etc) and USB, IPC, etc.) and > +then xlink open channel. > + > +Then it calls xlink write function, this takes the data passes it to the kernel data, passes > +which packages up the data and channel and then adds it to a tx transaction s/tx/transmit/ > +queue. > + > +A separate thread reads this transaction queue and pops off data if available > +and passes the data to the underlying interface (e.g. PCIe) write function. > +Using this thread provides serialization of transactions and decouples the user > +write from the platform write. > + > +On the other side of the interface, a thread is continually reading the > +interface (e.g. PCIe) via the platform interface read function and if it reads > +any data it adds it to channel packet container. > + > +The application at this side of the interface will have called xlink connect, > +opened the channel and called xlink read function to read data from the > +interface and if any exists for that channel , the data gets popped from the channel, > +channel packet container and copied from kernel space to user space buffer > +provided by the call. > + > +xLink can handle API requests from multi-process and multi-threaded > +application/processes. > + > +xLink maintains 4096 channels per device connected ( via xlink connect ) and (via xlink connect) and > +maintains a separate channel infrastructure for each device. > diff --git a/drivers/misc/xlink-core/Kconfig b/drivers/misc/xlink-core/Kconfig > new file mode 100644 > index 000000000000..3ae7dc01007f > --- /dev/null > +++ b/drivers/misc/xlink-core/Kconfig > @@ -0,0 +1,33 @@ > +config XLINK_CORE > + tristate "Support for XLINK CORE" > + depends on ((XLINK_PCIE_RH_DRIVER || XBAY_XLINK_PCIE_RH_DRIVER) || (XLINK_LOCAL_HOST && (XLINK_PCIE_LH_DRIVER || XBAY_XLINK_PCIE_RH_DRIVER))) > + help > + XLINK CORE enables the communication/control Sub-System. subsystem {no hyphen] > + > + If unsure, say N. > + > + To compile this driver as a module, choose M here: the > + module will be called xlink.ko. > + > +config XLINK_LOCAL_HOST > + tristate "Support for XLINK LOCAL HOST" > + depends on XLINK_IPC > + help > + XLINK LOCAL HOST enables local host functionality for > + the communication/control Sub-System. subsystem. > + > + Enable this config when building the kernel for the Inel Vision Intel > + Processing Unit (VPU) Local Host core. > + > + If building for a Remote Host kernel, say N. > + > +config XLINK_PSS > + tristate "Support for XLINK PSS" > + depends on XLINK_LOCAL_HOST > + help > + XLINK PSS enables the communication/control Sub-System on a PSS platform. subsystem Where is PSS defined? Please spell out that acronym somewhere, e.g.: tristate "Support for XLINK PSS (Please Say Something)" > + > + Enable this config when building the kernel for the Intel Vision > + Processing Unit (VPU) in a simulated env. > + > + If building for a VPU silicon, say N. -- ~Randy