07 Apr, 2011

1 commit


09 Oct, 2008

2 commits

  • Add support for the Marvell 88E6131 switch chip. This chip only
    supports the original (ethertype-less) DSA tagging format.

    On the 88E6131, there is a PHY Polling Unit (PPU) which has exclusive
    access to each of the PHYs's MII management registers. If we want to
    talk to the PHYs from software, we have to disable the PPU and wait
    for it to complete its current transaction before we can do so, and we
    need to re-enable the PPU afterwards to make sure that the switch will
    notice changes in link state and speed on the individual ports as they
    occur.

    Since disabling the PPU is rather slow, and since MII management
    accesses are typically done in bursts, this patch keeps the PPU disabled
    for 10ms after a software access completes. This makes handling the
    PPU slightly more complex, but speeds up something like running ethtool
    on one of the switch slave interfaces from ~300ms to ~30ms on typical
    hardware.

    Signed-off-by: Lennert Buytenhek
    Tested-by: Nicolas Pitre
    Tested-by: Peter van Valderen
    Tested-by: Dirk Teurlings
    Signed-off-by: David S. Miller

    Lennert Buytenhek
     
  • 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
    Tested-by: Nicolas Pitre
    Tested-by: Byron Bradley
    Tested-by: Tim Ellis
    Tested-by: Peter van Valderen
    Tested-by: Dirk Teurlings
    Signed-off-by: David S. Miller

    Lennert Buytenhek