linux/net
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
..
9p 9p: fix sparse warning: cast adds address space 2009-02-26 23:13:32 -08:00
802 snap: use const for descriptor 2009-03-21 19:06:50 -07:00
8021q gro: Fix vlan/netpoll check again 2009-03-17 13:10:52 -07:00
appletalk net: convert usage of packet_type to read_mostly 2009-03-10 05:22:43 -07:00
atm atm: lec use dev_change_mtu 2009-03-21 13:37:28 -07:00
ax25 ax25: zero length frame filtering in AX25 2009-03-21 13:33:55 -07:00
bluetooth Bluetooth: Remove some pointless conditionals before kfree_skb() 2009-02-27 06:14:49 +01:00
bridge netlink: change nlmsg_notify() return value logic 2009-02-24 23:18:28 -08:00
can can: remove some pointless conditionals before kfree_skb() 2009-02-26 23:07:35 -08:00
core net: remove useless prefetch() call 2009-03-21 13:42:55 -07:00
dcb DCB: fix kfree(skb) 2009-01-04 17:29:21 -08:00
dccp dccp: Do not let initial option overhead shrink the MPS 2009-03-02 03:07:23 -08:00
decnet net/*: use linux/kernel.h swap() 2009-03-21 13:36:17 -07:00
dsa dsa: add switch chip cascading support 2009-03-21 19:06:54 -07:00
econet net: convert usage of packet_type to read_mostly 2009-03-10 05:22:43 -07:00
ethernet eth: Declare an optimized compare_ether_addr_64bits() function 2008-11-23 23:24:32 -08:00
ipv4 net/*: use linux/kernel.h swap() 2009-03-21 13:36:17 -07:00
ipv6 net/*: use linux/kernel.h swap() 2009-03-21 13:36:17 -07:00
ipx ipx: use constant for strings and desciptor 2009-03-21 19:06:51 -07:00
irda net: convert usage of packet_type to read_mostly 2009-03-10 05:22:43 -07:00
iucv iucv: remove some pointless conditionals before kfree_skb() 2009-02-26 23:07:37 -08:00
key af_key: remove some pointless conditionals before kfree_skb() 2009-02-26 23:07:32 -08:00
lapb
llc net: convert usage of packet_type to read_mostly 2009-03-10 05:22:43 -07:00
mac80211 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 2009-03-17 15:04:31 -07:00
netfilter Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-03-17 15:01:30 -07:00
netlabel netlabel: Update kernel configuration API 2008-12-31 12:54:11 -05:00
netlink Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-03-05 02:06:47 -08:00
netrom netrom: zero length frame filtering in NetRom 2009-03-21 13:34:20 -07:00
packet Network Drop Monitor: Adding kfree_skb_clean for non-drops and modifying end-of-line points for skbs 2009-03-13 12:09:28 -07:00
phonet net: convert usage of packet_type to read_mostly 2009-03-10 05:22:43 -07:00
rds rds: fix iband RDMA dependencies 2009-03-03 21:39:40 -08:00
rfkill net/rfkill/rfkill.c: fix unused rfkill_led_trigger() warning 2009-01-04 17:11:24 -08:00
rose rose: convert to network_device_ops 2009-01-21 14:02:04 -08:00
rxrpc RxRPC: Fix a potential NULL dereference 2009-02-06 21:50:52 -08:00
sched net/*: use linux/kernel.h swap() 2009-03-21 13:36:17 -07:00
sctp sctp: Clean up TEST_FRAME hacks. 2009-03-21 13:41:09 -07:00
sunrpc net/sunrpc/xprtsock.c: some common code found 2009-02-06 23:48:33 -08:00
tipc tipc: fix non-const printf format arguments 2009-03-18 19:11:29 -07:00
unix unix: remove some pointless conditionals before kfree_skb() 2009-02-26 23:07:34 -08:00
wanrouter wanrouter: fix sparse warnings: context imbalance 2009-02-26 23:13:36 -08:00
wimax Merge branch 'master' of /home/davem/src/GIT/linux-2.6/ 2009-02-14 23:12:00 -08:00
wireless Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 2009-03-17 15:04:31 -07:00
x25 x25: '< 0' and '>= 0' test on unsigned 2009-03-13 16:04:12 -07:00
xfrm xfrm: Fix xfrm_state_find() wrt. wildcard source address. 2009-03-13 14:22:40 -07:00
compat.c net: socket infrastructure for SO_TIMESTAMPING 2009-02-15 22:43:35 -08:00
Kconfig Network Drop Monitor: Adding Build changes to enable drop monitor 2009-03-13 12:09:29 -07:00
Makefile RDS: Kconfig and Makefile 2009-02-26 23:43:35 -08:00
nonet.c
socket.c net: socket infrastructure for SO_TIMESTAMPING 2009-02-15 22:43:35 -08:00
sysctl_net.c missing bits of net-namespace / sysctl 2008-07-27 09:45:34 -07:00
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