[PATCH v3 0/6] Introduce DSA Ethernet switch class and Felix driver
Alexandru Marginean
alexm.osslist at gmail.com
Tue Mar 17 10:58:53 CET 2020
On 2/8/2020 2:19 PM, Vladimir Oltean wrote:
> On Tue, 3 Dec 2019 at 18:18, Alex Marginean <alexandru.marginean at nxp.com> wrote:
>>
>> DSA stands for Distributed Switch Architecture and it is a subsystem
>> introduced in the Linux kernel to support switches that:
>> - have an Ethernet link up to the CPU
>> - use some form of tagging to identify the source/destination port for
>> Rx/Tx
>> - may be cascaded in tree-like structures.
>>
>> DSA is described in depth here:
>> https://www.kernel.org/doc/Documentation/networking/dsa/dsa.txt
>>
>> From the doc:
>>
>> Summarized, this is basically how DSA looks like from a network device
>> perspective:
>>
>>
>> |---------------------------
>> | CPU network device (eth0)|
>> ----------------------------
>> | <tag added by switch |
>> | |
>> | |
>> | tag added by CPU> |
>> |--------------------------------------------|
>> | Switch driver |
>> |--------------------------------------------|
>> || || ||
>> |-------| |-------| |-------|
>> | sw0p0 | | sw0p1 | | sw0p2 |
>> |-------| |-------| |-------|
>>
>> This patch set introduces a DSA class in U-Boot to support drivers of such
>> switches. DSA drivers have to implement the following ops:
>> - enable/disable of switch ports,
>> - insert a tag in frames being transmitted, used by the switch to select
>> the egress port,
>> - parse a tag in frames being received, used for Rx traffic.
>>
>> DSA class code deals with presentation of switch ports as Ethernet
>> interfaces, deals with the master Ethernet device for I/O and helps with
>> parsing of the DT assuming the structure follows the DSA kernel binding.
>>
>> Support for switch cascading is not included yet.
>>
>> This patch set also introduces a driver for the Ethernet switch integrated
>> into NXP LS1028A, called Felix. The switch has 4 front panel ports, I/O
>> to/fom it is done though an ENETC Ethernet interface and meta-data is
>> carried between the switch and the driver though an additional header
>> pre-pended to the original frame.
>> Network commands like tftp can be used on these front panel ports. The
>> ports are disabled unless used so they do not cause issues on network
>> topologies that include loops.
>>
>> Felix as seen on LS1028A RDB:
>> => dm tree
>> Class Index Probed Driver Name
>> -----------------------------------------------------------
>> ......
>> dsa 0 [ + ] felix-switch | |-- felix-switch
>> eth 4 [ + ] dsa-port | | |-- swp0
>> eth 5 [ + ] dsa-port | | |-- swp1
>> eth 6 [ + ] dsa-port | | |-- swp2
>> eth 7 [ + ] dsa-port | | `-- swp3
>>
>> => mdio list
>> ......
>> 10 - Vitesse VSC8514 <--> swp0
>> 11 - Vitesse VSC8514 <--> swp1
>> 12 - Vitesse VSC8514 <--> swp2
>> 13 - Vitesse VSC8514 <--> swp3
>>
>> => tftp 80000000 test
>> Using swp2 device
>> TFTP from server 192.168.100.1; our IP address is 192.168.100.100
>> Filename 'test'.
>> Load address: 0x80000000
>> Loading: #################################################################
>> #################################################################
>> ########################################################
>> 6.8 MiB/s
>> done
>> Bytes transferred = 949880 (e7e78 hex)
>>
>> Changes in v3:
>> - fix Felix platdata size
>> - move include/dsa.h to include/net/dsa.h
>> - updated TODO in dsa.h
>> - other minor fixes
>>
>> Changes in v2:
>> - Don't use NULL PHY in Felix driver
>> - guard dsa.h with #ifndef __DSA__H__, somehow I missed that in v1
>> - added a TODO for setting master Eth in promiscuous mode
>> - Minor fixes in patch descriptions, API comments
>> - Added address/size-cells to LS1028A DT ports node
>>
>> This patch set replaces v2:
>> https://patchwork.ozlabs.org/project/uboot/list/?series=144912
>> and depends on:
>> https://patchwork.ozlabs.org/project/uboot/list/?series=144907
>> https://patchwork.ozlabs.org/project/uboot/list/?series=142879
>>
>> Alex Marginean (6):
>> net: introduce DSA class for Ethernet switches
>> drivers: net: add a DSA sandbox driver
>> test: dm: add a simple unit test for DSA class
>> drivers: net: add Felix DSA switch driver
>> arm: dts: ls1028a: adds Ethernet switch node and its dependencies
>> configs: ls1028a: enable the Ethernet switch driver in defconfig
>>
>> arch/Kconfig | 1 +
>> arch/arm/dts/fsl-ls1028a-rdb.dts | 36 ++
>> arch/arm/dts/fsl-ls1028a.dtsi | 44 +-
>> arch/sandbox/dts/test.dts | 49 ++
>> configs/ls1028aqds_tfa_SECURE_BOOT_defconfig | 3 +-
>> configs/ls1028aqds_tfa_defconfig | 3 +-
>> configs/ls1028ardb_tfa_SECURE_BOOT_defconfig | 3 +-
>> configs/ls1028ardb_tfa_defconfig | 3 +-
>> drivers/net/Kconfig | 21 +
>> drivers/net/Makefile | 1 +
>> drivers/net/dsa_sandbox.c | 272 +++++++++++
>> drivers/net/fsl_enetc.h | 5 +
>> drivers/net/mscc_eswitch/Kconfig | 8 +
>> drivers/net/mscc_eswitch/Makefile | 1 +
>> drivers/net/mscc_eswitch/felix_switch.c | 454 +++++++++++++++++++
>> include/configs/sandbox.h | 4 +
>> include/dm/uclass-id.h | 1 +
>> include/dsa.h | 140 ++++++
>> net/Makefile | 1 +
>> net/dsa-uclass.c | 369 +++++++++++++++
>> test/dm/Makefile | 1 +
>> test/dm/dsa.c | 58 +++
>> test/dm/test-fdt.c | 2 +-
>> 23 files changed, 1474 insertions(+), 6 deletions(-)
>> create mode 100644 drivers/net/dsa_sandbox.c
>> create mode 100644 drivers/net/mscc_eswitch/felix_switch.c
>> create mode 100644 include/dsa.h
>> create mode 100644 net/dsa-uclass.c
>> create mode 100644 test/dm/dsa.c
>>
>> --
>> 2.17.1
>>
>
> For the entire series, you are free to add my:
>
> Tested-by: Vladimir Oltean <vladimir.oltean at nxp.com>
>
> I think this looks good enough for now. I've even been able to create
> another DSA driver based on this framework. Improvements (and getting
> rid of the TODOs) can come further along the way, but this has been
> lingering for a while now. Joe, if there aren't any complaints, do you
> think you could let this in?
>
> Thanks,
> -Vladimir
>
Yeah, this has been sitting here for some time and I didn't get to work
on it more. One thing I think it would be worth including early is
dealing with MAC addresses for switch ports. Linux DSA uses the MAC
address of master Eth and we should do the same in U-Boot. That's not
just for consistency with Linux but also to make this work on arbitrary
mixes of switches and Eth ports without having to set master Eth in
promisc mode.
It's not really a big change, I'll try to look into it in the next
couple of weeks.
Thanks!
Alex
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