T3 hardware doorbell FIFO overflows can cause application stalls due
to lost doorbell ring events.  This has been seen when running large
NP IMB alltoall MPI jobs.  The T3 hardware supports an xon/xoff-type
flow control mechanism to help avoid overflowing the HW doorbell FIFO.

This patch uses these interrupts to disable RDMA QP doorbell rings
when we near an overflow condition, and then turn them back on (and
ring all the active QP doorbells) when when the doorbell FIFO empties
out.  In addition if an doorbell ring is dropped by the hardware, the
code will now recover.

Design:

cxgb3:
- enable these DB interrupts
- in the interrupt handler, schedule work tasks to call the ULPs event
  handlers with the new events.
- ring all the qset txqs when an overflow is detected.

iw_cxgb3:
- disable db ringing on all active qps when we get the DB_FULL event
- enable db ringing on all active qps and ring all active dbs when we get
  the DB_EMPTY event
- On DB_DROP event:
       - disable db rings in the event handler
       - delay-schedule a work task which rings and enables the dbs on
         all active qps.
- in post_send and post_recv logic, don't ring the db if it's disabled.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

Massage the err_handler upcall into an event handler upcall, pass
netdev port events to the cxgb3 ULPs and generate RDMA port events
based on LLD port events.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

Pre-allocate a skb at init time to be used for control messages to the HW
if skb allocation fails.

Tolerate failures to send messages initializing some memories at the cost of
parity error detection for these memories.
Retry sending connection id release messages if both alloc_skb(GFP_ATOMIC)
and alloc_skb(GFP_KERNEL) fail.
Do not bring the interface up if messages binding queue set to port fail to
be sent.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Set up a notification mechanism to inform upper layer modules
(iWARP, iSCSI) of a chip reset due to an EEH event or a fatal error.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Update copyright banner to 2008.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

cxgb3 used netdev_priv() and dev->priv for different purposes.
In 2.6.23, netdev_priv() == dev->priv, cxgb3 needs a fix.
This patch is a partial backport of Dave Miller's changes in the
net-2.6.24 git branch.

Without this fix, cxgb3 crashes on 2.6.23.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

Fix copyrights in the cxgb3 driver.

Remove the Open Grid Computing copyright.  It shouldn't be there.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

Dual licensing, needed for OFED 1.2

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

This driver is required by the Chelsio T3 RDMA driver posted by
Steve Wise.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>