Commit Graph

38 Commits

Author SHA1 Message Date
Andrew Lunn
60045cbfc0 net: dsa: Add dsa_is_dsa_port() helper
Add an inline helper for determining is a port is a DSA port.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-18 14:17:21 -07:00
Vivien Didelot
1114953615 net: dsa: add support for switchdev VLAN objects
Add new functions in DSA drivers to access hardware VLAN entries through
SWITCHDEV_OBJ_PORT_VLAN objects:

 - port_pvid_get() and vlan_getnext() to dump a VLAN
 - port_vlan_del() to exclude a port from a VLAN
 - port_pvid_set() and port_vlan_add() to join a port to a VLAN

The DSA infrastructure will ensure that each VLAN of the given range
does not already belong to another bridge. If it does, it will fallback
to software VLAN and won't program the hardware.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-13 21:31:12 -07:00
Vivien Didelot
2a778e1b58 net: dsa: change FDB routines prototypes
Change the prototype of port_getnext to include a vid parameter.

This is necessary to introduce the support for VLAN.

Also rename the fdb_{add,del,getnext} function pointers to
port_fdb_{add,del,getnext} since they are specific to a given port.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-11 12:03:19 -07:00
David S. Miller
cdf0969763 Revert "Merge branch 'mv88e6xxx-switchdev-fdb'"
This reverts commit f1d5ca4344, reversing
changes made to 4933d85c51.

I applied v2 instead of v3.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-11 12:00:37 -07:00
Vivien Didelot
55045ddded net: dsa: add support for switchdev FDB objects
Remove the fdb_{add,del,getnext} function pointer in favor of new
port_fdb_{add,del,getnext}.

Implement the switchdev_port_obj_{add,del,dump} functions in DSA to
support the SWITCHDEV_OBJ_PORT_FDB objects.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-09 22:48:09 -07:00
Guenter Roeck
339d82626d net: dsa: Add basic framework to support ndo_fdb functions
Provide callbacks for ndo_fdb_add, ndo_fdb_del, and ndo_fdb_dump.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-29 13:23:54 -07:00
Florian Fainelli
769a020289 net: dsa: utilize of_find_net_device_by_node
Using of_find_device_by_node() restricts the search to platform_device that
match the specified device_node pointer. This is not even remotely true for
network devices backed by a pci_device for instance.

of_find_net_device_by_node() allows us to do a more thorough lookup to find the
struct net_device corresponding to a particular device_node pointer.

For symetry with the non-OF code path, we hold the net_device pointer in
dsa_probe() just like what dev_to_net_dev() does when we call this
function.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-09 23:50:21 -04:00
Florian Fainelli
5929903103 net: dsa: let switches specify their tagging protocol
In order to support the new DSA device driver model, a dsa_switch should
be able to advertise the type of tagging protocol supported by the
underlying switch device. This also removes constraints on how tagging
can be stacked to each other.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 00:18:20 -05:00
Guenter Roeck
d79d210736 net: dsa: Introduce dsa_is_port_initialized
To avoid race conditions when using the ds->ports[] array,
we need to check if the accessed port has been initialized.
Introduce and use helper function dsa_is_port_initialized
for that purpose and use it where needed.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-25 17:57:48 -05:00
Florian Fainelli
b73adef677 net: dsa: integrate with SWITCHDEV for HW bridging
In order to support bridging offloads in DSA switch drivers, select
NET_SWITCHDEV to get access to the port_stp_update and parent_get_id
NDOs that we are required to implement.

To facilitate the integratation at the DSA driver level, we implement 3
types of operations:

- port_join_bridge
- port_leave_bridge
- port_stp_update

DSA will resolve which switch ports that are currently bridge port
members as some Switch hardware/drivers need to know about that to limit
the register programming to just the relevant registers (especially for
slow MDIO buses).

We also take care of setting the correct STP state when slave network
devices are brought up/down while being bridge members.

Finally, when a port is leaving the bridge, we make sure we set in
BR_STATE_FORWARDING state, otherwise the bridge layer would leave it
disabled as a result of having left the bridge.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-25 17:03:38 -05:00
Guenter Roeck
3d762a0f0a net: dsa: Add support for reading switch registers with ethtool
Add support for reading switch registers with 'ethtool -d'.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-30 14:54:11 -04:00
Guenter Roeck
6793abb4e8 net: dsa: Add support for switch EEPROM access
On some chips it is possible to access the switch eeprom.
Add infrastructure support for it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-30 14:54:11 -04:00
Guenter Roeck
51579c3f1a net: dsa: Add support for reporting switch chip temperatures
Some switches provide chip temperature data.
Add support for reporting it through the hwmon subsystem.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-30 14:54:11 -04:00
Florian Fainelli
a28205437b net: dsa: add includes for ethtool and phy_fixed definitions
net/dsa/slave.c uses functions and structures declared in phy_fixed.h
but does not explicitely include it, while dsa.h needs structure
declarations for 'struct ethtool_wolinfo' and 'struct ethtool_eee', fix
those by including the correct header files.

Fixes: ec9436baed ("net: dsa: allow drivers to do link adjustment")
Fixes: ce31b31c68 ("net: dsa: allow updating fixed PHY link information")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-17 23:54:46 -04:00
Florian Fainelli
7905288f09 net: dsa: allow switches driver to implement get/set EEE
Allow switches driver to query and enable/disable EEE on a per-port
basis by implementing the ethtool_{get,set}_eee settings and delegating
these operations to the switch driver.

set_eee() will need to coordinate with the PHY driver to make sure that
EEE is enabled, the link-partner supports it and the auto-negotiation
result is satisfactory.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 17:14:09 -04:00
Florian Fainelli
b2f2af21e3 net: dsa: allow enabling and disable switch ports
Whenever a per-port network device is used/unused, invoke the switch
driver port_enable/port_disable callbacks to allow saving as much power
as possible by disabling unused parts of the switch (RX/TX logic, memory
arrays, PHYs...). We supply a PHY device argument to make sure the
switch driver can act on the PHY device if needed (like putting/taking
the PHY out of deep low power mode).

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 17:14:08 -04:00
Florian Fainelli
19e57c4e6d net: dsa: add {get, set}_wol callbacks to slave devices
Allow switch drivers to implement per-port Wake-on-LAN getter and
setters.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-22 14:41:23 -04:00
Florian Fainelli
2446254915 net: dsa: allow switch drivers to implement suspend/resume hooks
Add an abstraction layer to suspend/resume switch devices, doing the
following split:

- suspend/resume the slave network devices and their corresponding PHY
  devices
- suspend/resume the switch hardware using switch driver callbacks

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-22 14:41:23 -04:00
Florian Fainelli
6819563e64 net: dsa: allow switch drivers to specify phy_device::dev_flags
Some switch drivers (e.g: bcm_sf2) may have to communicate specific
workarounds or flags towards the PHY device driver. Allow switches
driver to be delegated that task by introducing a get_phy_flags()
callback which will do just that.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 16:27:07 -04:00
Alexander Duyck
b4d2394d01 dsa: Replace mii_bus with a generic host device
This change makes it so that instead of passing and storing a mii_bus we
instead pass and store a host_dev.  From there we can test to determine the
exact type of device, and can verify it is the correct device for our switch.

So for example it would be possible to pass a device pointer from a pci_dev
and instead of checking for a PHY ID we could check for a vendor and/or device
ID.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-15 17:24:20 -04:00
Alexander Duyck
5075314e4e dsa: Split ops up, and avoid assigning tag_protocol and receive separately
This change addresses several issues.

First, it was possible to set tag_protocol without setting the ops pointer.
To correct that I have reordered things so that rcv is now populated before
we set tag_protocol.

Second, it didn't make much sense to keep setting the device ops each time a
new slave was registered.  So by moving the receive portion out into root
switch initialization that issue should be addressed.

Third, I wanted to avoid sending tags if the rcv pointer was not registered
so I changed the tag check to verify if the rcv function pointer is set on
the root tree.  If it is then we start sending DSA tagged frames.

Finally I split the device ops pointer in the structures into two spots.  I
placed the rcv function pointer in the root switch since this makes it
easiest to access from there, and I placed the xmit function pointer in the
slave for the same reason.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-15 17:24:20 -04:00
Florian Fainelli
ac7a04c33d net: dsa: change tag_protocol to an enum
Now that we introduced an additional multiplexing/demultiplexing layer
with commit 3e8a72d1da ("net: dsa: reduce number of protocol hooks")
that lives within the DSA code, we no longer need to have a given switch
driver tag_protocol be an actual ethertype value, instead, we can
replace it with an enum: dsa_tag_protocol.

Do this replacement in the drivers, which allows us to get rid of the
cpu_to_be16()/htons() dance, and remove ETH_P_BRCMTAG since we do not
need it anymore.

Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-13 17:04:35 -04:00
Florian Fainelli
5037d532b8 net: dsa: add Broadcom tag RX/TX handler
Add support for the 4-bytes Broadcom tag that built-in switches such as
the Starfighter 2 might insert when receiving packets, or that we need
to insert while targetting specific switch ports. We use a fake local
EtherType value for this 4-bytes switch tag: ETH_P_BRCMTAG to make sure
we can assign DSA-specific network operations within the DSA drivers.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 22:59:40 -07:00
Florian Fainelli
ce31b31c68 net: dsa: allow updating fixed PHY link information
Allow switch drivers to hook a PHY link update callback to perform
port-specific link work.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 22:59:40 -07:00
Florian Fainelli
ec9436baed net: dsa: allow drivers to do link adjustment
Whenever libphy determines that the link status of a given PHY/port has
changed, allow to call into the switch driver link adjustment callback
so proper actions can be taken care of by the switch driver upon link
notification.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 22:59:40 -07:00
Florian Fainelli
5aed85cec2 net: dsa: allow switches to work without tagging
In case switch port tagging is disabled (voluntarily, or the switch just
does not support it), allow us to continue using the defined set of
dsa_device_ops in net/dsa/slave.c.

We introduce dsa_protocol_is_tagged() to check whether we need to
override skb->protocol and go through the DSA-specifif packet_type
function, or if we just go on and receive the SKB through the normal
path.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 22:59:40 -07:00
Florian Fainelli
0d8bcdd383 net: dsa: allow for more complex PHY setups
Modify the DSA slave interface to be bound to an arbitray PHY, not just
the ones that are available as child PHY devices of the switch MDIO bus.

This allows us for instance to have external PHYs connected to a
separate MDIO bus, but yet also connected to a given switch port.

Under certain configurations, the physical port mask might not be a 1:1
mapping to the MII PHYs mask. This is the case, if e.g: Port 1 of the
switch is used and connects to a PHY at a MDIO address different than 1.

Introduce a phys_mii_mask variable which allows driver to implement and
divert their own MDIO read/writes operations for a subset of the MDIO
PHY addresses.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 22:59:40 -07:00
Florian Fainelli
bd47497a01 net: dsa: retain a per-port device_node pointer
We will later use the per-port device_node pointer to fetch a bunch of
port-specific properties.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 22:59:40 -07:00
Florian Fainelli
fa981d9af8 net: dsa: provide a switch device device tree node pointer
We might need to fetch additional resources from the device tree node
pointer, such as register ranges or other properties. Keep a device_node
pointer around for this.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 22:59:39 -07:00
Florian Fainelli
3e8a72d1da net: dsa: reduce number of protocol hooks
DSA is currently registering one packet_type function per EtherType it
needs to intercept in the receive path of a DSA-enabled Ethernet device.
Right now we have three of them: trailer, DSA and eDSA, and there might
be more in the future, this will not scale to the addition of new
protocols.

This patch proceeds with adding a new layer of abstraction and two new
functions:

dsa_switch_rcv() which will dispatch into the tag-protocol specific
receive function implemented by net/dsa/tag_*.c

dsa_slave_xmit() which will dispatch into the tag-protocol specific
transmit function implemented by net/dsa/tag_*.c

When we do create the per-port slave network devices, we iterate over
the switch protocol to assign the DSA-specific receive and transmit
operations.

A new fake ethertype value is used: ETH_P_XDSA to illustrate the fact
that this is no longer going to look like ETH_P_DSA or ETH_P_TRAILER
like it used to be.

This allows us to greatly simplify the check in eth_type_trans() and
always override the skb->protocol with ETH_P_XDSA for Ethernet switches
tagged protocol, while also reducing the number repetitive slave
netdevice_ops assignments.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 22:59:39 -07:00
Florian Fainelli
7fa857ed04 net: dsa: add ds_to_priv
DSA drivers have a trick which consists in allocating "priv_size" more
bytes to account for the DSA driver private context. Add a helper
function to access that private context instead of open-coding it in
drivers with (void *)(ds + 1).

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-30 13:31:25 -04:00
Axel Lin
ea1f51beff dsa: Include linux/if_ether.h to fix build error
Include linux/if_ether.h to fix below build errors:

  CC      arch/arm/mach-kirkwood/common.o
In file included from arch/arm/mach-kirkwood/common.c:19:
include/net/dsa.h: In function 'dsa_uses_dsa_tags':
include/net/dsa.h:192: error: 'ETH_P_DSA' undeclared (first use in this function)
include/net/dsa.h:192: error: (Each undeclared identifier is reported only once
include/net/dsa.h:192: error: for each function it appears in.)
include/net/dsa.h: In function 'dsa_uses_trailer_tags':
include/net/dsa.h:197: error: 'ETH_P_TRAILER' undeclared (first use in this function)
make[1]: *** [arch/arm/mach-kirkwood/common.o] Error 1
make: *** [arch/arm/mach-kirkwood] Error 2

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-01 11:41:06 -05:00
Ben Hutchings
c8f0b86996 dsa: Move all definitions needed by drivers into <net/dsa.h>
Any headers included by drivers should be under include/, and
any definitions they use are not really private to the core as
the name "dsa_priv.h" suggests.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29 00:21:36 -05:00
Ben Hutchings
cf50dcc24f dsa: Change dsa_uses_{dsa, trailer}_tags() into inline functions
eth_type_trans() will use these functions if DSA is enabled, which
blocks building DSA as a module.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-26 14:48:14 -05:00
Lennert Buytenhek
e84665c9cb dsa: add switch chip cascading support
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>
2009-03-21 19:06:54 -07:00
Lennert Buytenhek
396138f03f dsa: add support for Trailer tagging format
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>
2008-10-08 17:24:16 -07:00
Lennert Buytenhek
cf85d08fdf dsa: add support for original DSA tagging format
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>
2008-10-08 17:19:56 -07:00
Lennert Buytenhek
91da11f870 net: Distributed Switch Architecture protocol support
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>
2008-10-08 17:15:19 -07:00