On 10/1/2021 11:22 AM, Apeksha Gupta wrote: >> -----Original Message----- >> From: Ferruh Yigit <ferruh.yi...@intel.com> >> Sent: Thursday, September 23, 2021 3:40 PM >> To: Apeksha Gupta <apeksha.gu...@nxp.com>; >> david.march...@redhat.com; andrew.rybche...@oktetlabs.ru; >> ferruh.yi...@intel.com >> Cc: dev@dpdk.org; Sachin Saxena <sachin.sax...@nxp.com>; Hemant >> Agrawal <hemant.agra...@nxp.com> >> Subject: [EXT] Re: [dpdk-dev] [PATCH v3 1/5] net/enetfec: introduce NXP >> ENETFEC driver >> >> Caution: EXT Email >> >> On 9/9/2021 9:43 PM, Apeksha Gupta wrote: >>> ENETFEC (Fast Ethernet Controller) is a network poll mode driver >>> for NXP SoC i.MX 8M Mini. >>> >> >> Hi Apeksha, >> >> Before going into details, I have some high level comments to start with, >> please >> find comments below. >> >>> This patch adds skeleton for enetfec driver with probe function. >>> >>> Signed-off-by: Sachin Saxena <sachin.sax...@nxp.com> >>> Signed-off-by: Apeksha Gupta <apeksha.gu...@nxp.com> >> >> <...> >> >>> +++ b/doc/guides/nics/enetfec.rst >>> @@ -0,0 +1,122 @@ >>> +.. SPDX-License-Identifier: BSD-3-Clause >>> + Copyright 2021 NXP >>> + >>> +ENETFEC Poll Mode Driver >>> +======================== >>> + >>> +The ENETFEC NIC PMD (**librte_net_enetfec**) provides poll mode >> driver >>> +support for the inbuilt NIC found in the ** NXP i.MX 8M Mini** SoC. >>> + >>> +More information can be found at NXP Official Website >>> >> +<https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fw >> ww.nxp.com%2Fproducts%2Fprocessors-and-microcontrollers%2Farm- >> processors%2Fi-mx-applications-processors%2Fi-mx-8-processors%2Fi-mx- >> 8m-mini-arm-cortex-a53-cortex-m4-audio-voice- >> video%3Ai.MX8MMINI&data=04%7C01%7Capeksha.gupta%40nxp.com >> %7C74fdc59c47574d828f7608d97e7a4df3%7C686ea1d3bc2b4c6fa92cd99c5c30 >> 1635%7C0%7C1%7C637679886024819097%7CUnknown%7CTWFpbGZsb3d8ey >> JWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D% >> 7C3000&sdata=TjuqIfC8yXwBa3DLCgA7djItfV0UmZ6lA3uLDQ7TFwY%3D >> &reserved=0> >>> + >>> +ENETFEC >>> +------- >>> + >>> +This section provides an overview of the NXP ENETFEC and how it is >>> +integrated into the DPDK. >>> + >>> +Contents summary >>> + >>> +- ENETFEC overview >>> +- ENETFEC features >>> +- Supported ENETFEC SoCs >>> +- Prerequisites >>> +- Driver compilation and testing >>> +- Limitations >>> + >>> +ENETFEC Overview >>> +~~~~~~~~~~~~~~~~ >>> +The i.MX 8M Mini Media Applications Processor is built to achieve both >> high >>> +performance and low power consumption. ENETFEC is a hardware >> programmable >>> +packet forwarding engine to provide high performance Ethernet interface. >> >> It has 1Gbps interface, right? It can be good to give more details on the >> Ethernet interface. > [Apeksha] Okay. >> >>> +The diagram below shows a system level overview of ENETFEC: >>> + >>> + >> ====================================================+===== >> ========== >>> + US +-----------------------------------------+ | Kernel Space >>> + | | | >>> + | ENETFEC Driver | | >>> + +-----------------------------------------+ | >>> + ^ | | >>> + ENETFEC RXQ | | TXQ | >>> + PMD | | | >>> + | v | +----------+ >>> + +-------------+ | | fec-uio | >>> + | net_enetfec | | +----------+ >>> + +-------------+ | >>> + ^ | | >>> + TXQ | | RXQ | >>> + | | | >>> + | v | >>> + >> ===================================================+====== >> ========= >>> + +----------------------------------------+ >>> + | | HW >>> + | i.MX 8M MINI EVK | >>> + | +-----+ | >>> + | | MAC | | >>> + +---------------+-----+------------------+ >>> + | PHY | >>> + +-----+ >>> + >>> +ENETFEC Ethernet driver is traditional DPDK PMD driver running in the >> userspace. >>> +The MAC and PHY are the hardware blocks. 'fec-uio' is the UIO driver, >> ENETFEC PMD >>> +uses UIO interface to interact with kernel for PHY initialisation and for >> mapping >>> +the allocated memory of register & BD in kernel with DPDK which gives >> access to >>> +non-cacheable memory for BD. >> >> Why a specific uio driver, 'fec-uio', is required? I think this is the major >> issue to clarify to proceed. >> >> In DPDK we have full framework to support uio, to do the all memory >> mapping, >> interrupt configuration etc..., common to all drivers. >> But in this case driver is implemented as virtual driver and it handles its >> own >> uoi handling itself. Why the driver can't use existing support and >> implemented >> as physical driver? > [Apeksha] Yes you are correct. As per our knowledge, UIO framework is there > for VM & PCI bus devices and not for vdev bus devices.
That is part of the comment, why driver implemented as vdev instead of physical device? What is the actual device bus?
