This driver supports both NTB-to-NTB and NTB-to-Root Port modes (though
the second with predictable complications on hot-plug and reboot events).
I tested it with PEX 8717 and PEX 8733 chips, but expect it should work
with many other compatible ones too. It supports up to two NT bridges
per chip, each of which can have up to 2 64-bit or 4 32-bit memory windows,
6 or 12 scratchpad registers and 16 doorbells. There are also 4 DMA engines
in those chips, but they are not yet supported.
While there, rename Intel NTB driver from generic ntb_hw(4) to more specific
ntb_hw_intel(4), so now it is on par with this new ntb_hw_plx(4) driver and
alike to Linux naming.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
The NTB allows you to connect two systems with this device using a PCI-e
link. The driver is made of two modules:
- ntb_hw which is a basic hardware abstraction layer for the device.
- if_ntb which implements the ntb network device and the communication
protocol.
The driver is limited at the moment to CPU memcpy instead of using DMA, and
only Back-to-Back mode is supported. Also the network device isn't full
featured yet. These changes will be coming soon. The DMA change will also
bring in the ioat driver from the project branch it is on now.
This is an initial port of the GPL/BSD Linux driver contributed by Jon Mason
from Intel. Any bugs are my contributions.
Sponsored by: Intel
Reviewed by: jimharris, joel (man page only)
Approved by: jimharris (mentor)
