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 v4: - fixed Rx buffer sizes to accomodate bigger packets, that are closer to the standard MTU size of 1500B. DSA needs extra room for tagging on top of the standard ethernet frame. Reserved a maximum overhead of 256B for DSA tagging, preserving the total packet size alignment. - addressed MAC addr propagation from DSA master eth port to the non-cpu switch ports for ports that don't have MAC addrs configured in the uboot env - added eth port aliases - fixed some in-band autoneg issues if nophy attached, in felix - dsa-uclass code cleanup - ls1028a defconfig cleanup - added missing device_compat.h (preventing build issues) - rebased on top of latest -net/master - updated copyright format and year
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 | 55 ++- arch/sandbox/dts/test.dts | 49 ++ configs/ls1028aqds_tfa_SECURE_BOOT_defconfig | 2 + configs/ls1028aqds_tfa_defconfig | 2 + configs/ls1028ardb_tfa_SECURE_BOOT_defconfig | 2 + configs/ls1028ardb_tfa_defconfig | 2 + 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 | 456 +++++++++++++++++++ include/configs/sandbox.h | 4 + include/dm/uclass-id.h | 1 + include/net.h | 6 + include/net/dsa.h | 137 ++++++ net/Makefile | 1 + net/dsa-uclass.c | 395 ++++++++++++++++ test/dm/Makefile | 1 + test/dm/dsa.c | 58 +++ test/dm/test-fdt.c | 2 +- 24 files changed, 1516 insertions(+), 2 deletions(-) create mode 100644 drivers/net/dsa_sandbox.c create mode 100644 drivers/net/mscc_eswitch/felix_switch.c create mode 100644 include/net/dsa.h create mode 100644 net/dsa-uclass.c create mode 100644 test/dm/dsa.c