embryonic connection has been setup and never attempt to abort a tid
before this is done. This fixes a bad race where a listening socket is
closed when the driver is in the middle of step (b) here. The symptom
of this were "ARP miss" errors from the driver followed by tid leaks.
A hardware-offloaded passive open works this way:
a) A SYN "hits" the TCAM entry for a server tid and the chip delivers it
to the queue associated with the server tid (say, queue A). It waits
for a response from the driver telling it what to do.
b) The driver decides it is ok to proceed. It adds the new tid to the
list of embryonic connections associated with the server tid and then
hands off the SYN to the kernel's syncache to make sure that the kernel
okays it too. If it does then the driver provides an L2 table entry,
queue id (say, queue B), etc. and instructs the chip to send the SYN/ACK
response.
c) The chip delivers a status to queue B depending on how the third step
of the 3-way handshake goes. The driver removes the tid from its list
of embryonic connections and either expands the syncache entry or
destroys the tid. In any case all subsequent messages for the new tid
will be delivered to queue B, not queue A. Anything running in queue B
knows that the L2 entry has long been setup and the new flag is of no
interest from here on. If the listener is closed it will deal with
so_comp as normal.
MFC after: 1 week
counter) when the syncache doesn't want the driver to reply to an
incoming SYN. This fixes a harmless bug where tids_in_use would
go out of sync with the hardware counter.
MFC after: 3 days
This lets userspace read arbitrary information from the SFP+ modules
etc. on this bus.
Reading multiple bytes in the same transaction isn't possible right now.
I'll update the driver once the chip's firmware supports this.
MFC after: 3 days
#defines. This also has the advantage that it makes the names more
compact, iand also allows us to correct the non-uniform naming of
the PCIM_LINK_* defines, making them all consistent amongst themselves.
This is a mostly mechanical rename:
s/PCIR_EXPRESS_/PCIER_/g
s/PCIM_EXP_/PCIEM_/g
s/PCIM_LINK_/PCIEM_LINK_/g
When this is MFC'd, #defines will be added for the old names to assist
out-of-tree drivers.
Discussed with: jhb
MFC after: 1 week
evicted from the syncache but a later syncache_expand succeeds because
of syncookies. The TOE driver has to resort to more direct means to
install its hooks in the socket in this case.
the TOE driver reports that an active open failed. toe_connect_failed is
supposed to handle this but it should be provided the inpcb instead of the
tcpcb which may no longer be around.
Basically, this is automatic rx zero copy when feasible. TCP payload is
DMA'd directly into the userspace buffer described by the uio submitted
in soreceive by an application.
- Works with sockets that are being handled by the TCP offload engine
of a T4 chip (you need t4_tom.ko module loaded after cxgbe, and an
"ifconfig +toe" on the cxgbe interface).
- Does not require any modification to the application.
- Not enabled by default. Use hw.t4nex.<X>.toe.ddp="1" to enable it.
- Setup multiple DDP page sizes. When the driver attempts DDP it will
try to combine physically contiguous pages into regions of these sizes.
- Set the indicate size such that the payload carried in the indicate can
be copied in the header mbuf (and the 16K rx buffer can be recycled).
- Set DDP threshold to the max payload that the chip will coalesce and
deliver to the driver (this is ~16K by default, which is also why the
offload rx queue is backed by 16K buffers). If the chip is able to
coalesce up to the max it's allowed to, it's a good sign that the peer
is transmitting in bulk without any TCP PSH.
MFC after: 2 weeks
TCB. Filters are programmed by modifying the TCB too (via a different
routine) and the reply to any TCB update is delivered via a
CPL_SET_TCB_RPL. Figure out whether the reply is for a filter-write or
something else and route it appropriately.
MFC after: 2 weeks
interface's MTU. Initialize such freelists with correct values.
This wasn't a problem for common MTUs (1500 and 9000) as the buffers (2048
and 9216 in size) happened to have enough spare room. I ran into it when
playing around with unusual MTUs.
MFC after: 2 weeks
values).
- cong_drop specifies what to do on congestion: nothing, backpressure,
or drop.
- fl_pktshift specifies the padding before Ethernet payload.
- fl_pad specifies the boundary upto which to pad Ethernet payload.
- spg_len controls the length of the status page.
MFC after: 2 weeks
'fw_hdr_intfver' into an anonymous enum, which avoids a clang 3.2
warning about all the enum values being the same value.
Reviewed by: np
MFC after: 1 week
exported via PCI passthrough.
- Do not check for a specific physical function (PF) before claiming a device.
Different PFs have different device-ids so this check is redundant anyway.
- Obtain the PF# from the WHOAMI register instead of pci_get_function().
- Setup the memory windows using the real BAR0 address, not what the VM says it
is.
Obtained from: Chelsio Communications
- Stateful TCP offload drivers for Terminator 3 and 4 (T3 and T4) ASICs.
These are available as t3_tom and t4_tom modules that augment cxgb(4)
and cxgbe(4) respectively. The cxgb/cxgbe drivers continue to work as
usual with or without these extra features.
- iWARP driver for Terminator 3 ASIC (kernel verbs). T4 iWARP in the
works and will follow soon.
Build-tested with make universe.
30s overview
============
What interfaces support TCP offload? Look for TOE4 and/or TOE6 in the
capabilities of an interface:
# ifconfig -m | grep TOE
Enable/disable TCP offload on an interface (just like any other ifnet
capability):
# ifconfig cxgbe0 toe
# ifconfig cxgbe0 -toe
Which connections are offloaded? Look for toe4 and/or toe6 in the
output of netstat and sockstat:
# netstat -np tcp | grep toe
# sockstat -46c | grep toe
Reviewed by: bz, gnn
Sponsored by: Chelsio communications.
MFC after: ~3 months (after 9.1, and after ensuring MFC is feasible)
Significantly update tcp_lro for mostly two things:
1) introduce basic support for IPv6 without extension headers.
2) try hard to also get the incremental checksum updates right,
especially also in the IPv4 case for the IP and TCP header.
Move variables around for better locality, factor things out into
functions, allow checksum updates to be compiled out, ...
Leave a few comments on further things to look at in the future,
though that is not the full list.
Update drivers with appropriate #includes as needed for IPv6 data
type in LRO.
Sponsored by: The FreeBSD Foundation
Sponsored by: iXsystems
Reviewed by: gnn (as part of the whole)
MFC After: 3 days
