K 10
svn:author
V 2
np
K 8
svn:date
V 27
2011-05-05T02:38:08.864421Z
K 7
svn:log
V 443
T4 packet timestamps.

Reference code that shows how to get a packet's timestamp out of
cxgbe(4).  Disabled by default because we don't have a standard way
today to pass this information up the stack.

The timestamp is 60 bits wide and each increment represents 1 tick of
the T4's core clock.  As an example, the timestamp granularity is ~4.4ns
for this card:

# sysctl dev.t4nex.0.core_clock
dev.t4nex.0.core_clock: 228125

MFC after:	1 week

END