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2009-03-21dsa: add switch chip cascading supportLennert Buytenhek1-9/+33
The initial version of the DSA driver only supported a single switch chip per network interface, while DSA-capable switch chips can be interconnected to form a tree of switch chips. This patch adds support for multiple switch chips on a network interface. An example topology for a 16-port device with an embedded CPU is as follows: +-----+ +--------+ +--------+ | |eth0 10| switch |9 10| switch | | CPU +----------+ +-------+ | | | | chip 0 | | chip 1 | +-----+ +---++---+ +---++---+ || || || || ||1000baseT ||1000baseT ||ports 1-8 ||ports 9-16 This requires a couple of interdependent changes in the DSA layer: - The dsa platform driver data needs to be extended: there is still only one netdevice per DSA driver instance (eth0 in the example above), but each of the switch chips in the tree needs its own mii_bus device pointer, MII management bus address, and port name array. (include/net/dsa.h) The existing in-tree dsa users need some small changes to deal with this. (arch/arm) - The DSA and Ethertype DSA tagging modules need to be extended to use the DSA device ID field on receive and demultiplex the packet accordingly, and fill in the DSA device ID field on transmit according to which switch chip the packet is heading to. (net/dsa/tag_{dsa,edsa}.c) - The concept of "CPU port", which is the switch chip port that the CPU is connected to (port 10 on switch chip 0 in the example), needs to be extended with the concept of "upstream port", which is the port on the switch chip that will bring us one hop closer to the CPU (port 10 for both switch chips in the example above). - The dsa platform data needs to specify which ports on which switch chips are links to other switch chips, so that we can enable DSA tagging mode on them. (For inter-switch links, we always use non-EtherType DSA tagging, since it has lower overhead. The CPU link uses dsa or edsa tagging depending on what the 'root' switch chip supports.) This is done by specifying "dsa" for the given port in the port array. - The dsa platform data needs to be extended with information on via which port to reach any given switch chip from any given switch chip. This info is specified via the per-switch chip data struct ->rtable[] array, which gives the nexthop ports for each of the other switches in the tree. For the example topology above, the dsa platform data would look something like this: static struct dsa_chip_data sw[2] = { { .mii_bus = &foo, .sw_addr = 1, .port_names[0] = "p1", .port_names[1] = "p2", .port_names[2] = "p3", .port_names[3] = "p4", .port_names[4] = "p5", .port_names[5] = "p6", .port_names[6] = "p7", .port_names[7] = "p8", .port_names[9] = "dsa", .port_names[10] = "cpu", .rtable = (s8 []){ -1, 9, }, }, { .mii_bus = &foo, .sw_addr = 2, .port_names[0] = "p9", .port_names[1] = "p10", .port_names[2] = "p11", .port_names[3] = "p12", .port_names[4] = "p13", .port_names[5] = "p14", .port_names[6] = "p15", .port_names[7] = "p16", .port_names[10] = "dsa", .rtable = (s8 []){ 10, -1, }, }, }, static struct dsa_platform_data pd = { .netdev = &foo, .nr_switches = 2, .sw = sw, }; Signed-off-by: Lennert Buytenhek <buytenh@marvell.com> Tested-by: Gary Thomas <gary@mlbassoc.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08dsa: add support for Trailer tagging formatLennert Buytenhek1-0/+1
This adds support for the Trailer switch tagging format. This is another tagging that doesn't explicitly mark tagged packets with a distinct ethertype, so that we need to add a similar hack in the receive path as for the Original DSA tagging format. Signed-off-by: Lennert Buytenhek <buytenh@marvell.com> Tested-by: Byron Bradley <byron.bbradley@gmail.com> Tested-by: Tim Ellis <tim.ellis@mac.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08dsa: add support for original DSA tagging formatLennert Buytenhek1-0/+2
Most of the DSA switches currently in the field do not support the Ethertype DSA tagging format that one of the previous patches added support for, but only the original DSA tagging format. The original DSA tagging format carries the same information as the Ethertype DSA tagging format, but with the difference that it does not have an ethertype field. In other words, when receiving a packet that is tagged with an original DSA tag, there is no way of telling in eth_type_trans() that this packet is in fact a DSA-tagged packet. This patch adds a hook into eth_type_trans() which is only compiled in if support for a switch chip that doesn't support Ethertype DSA is selected, and which checks whether there is a DSA switch driver instance attached to this network device which uses the old tag format. If so, it sets the protocol field to ETH_P_DSA without looking at the packet, so that the packet ends up in the right place. Signed-off-by: Lennert Buytenhek <buytenh@marvell.com> Tested-by: Nicolas Pitre <nico@marvell.com> Tested-by: Peter van Valderen <linux@ddcrew.com> Tested-by: Dirk Teurlings <dirk@upexia.nl> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08net: Distributed Switch Architecture protocol supportLennert Buytenhek1-0/+34
Distributed Switch Architecture is a protocol for managing hardware switch chips. It consists of a set of MII management registers and commands to configure the switch, and an ethernet header format to signal which of the ports of the switch a packet was received from or is intended to be sent to. The switches that this driver supports are typically embedded in access points and routers, and a typical setup with a DSA switch looks something like this: +-----------+ +-----------+ | | RGMII | | | +-------+ +------ 1000baseT MDI ("WAN") | | | 6-port +------ 1000baseT MDI ("LAN1") | CPU | | ethernet +------ 1000baseT MDI ("LAN2") | |MIImgmt| switch +------ 1000baseT MDI ("LAN3") | +-------+ w/5 PHYs +------ 1000baseT MDI ("LAN4") | | | | +-----------+ +-----------+ The switch driver presents each port on the switch as a separate network interface to Linux, polls the switch to maintain software link state of those ports, forwards MII management interface accesses to those network interfaces (e.g. as done by ethtool) to the switch, and exposes the switch's hardware statistics counters via the appropriate Linux kernel interfaces. This initial patch supports the MII management interface register layout of the Marvell 88E6123, 88E6161 and 88E6165 switch chips, and supports the "Ethertype DSA" packet tagging format. (There is no officially registered ethertype for the Ethertype DSA packet format, so we just grab a random one. The ethertype to use is programmed into the switch, and the switch driver uses the value of ETH_P_EDSA for this, so this define can be changed at any time in the future if the one we chose is allocated to another protocol or if Ethertype DSA gets its own officially registered ethertype, and everything will continue to work.) Signed-off-by: Lennert Buytenhek <buytenh@marvell.com> Tested-by: Nicolas Pitre <nico@marvell.com> Tested-by: Byron Bradley <byron.bbradley@gmail.com> Tested-by: Tim Ellis <tim.ellis@mac.com> Tested-by: Peter van Valderen <linux@ddcrew.com> Tested-by: Dirk Teurlings <dirk@upexia.nl> Signed-off-by: David S. Miller <davem@davemloft.net>