Address Lookup Table (A-LUT) being enabled allows to specify separate
translation for each 1/128th or 1/256th of the BAR2. Previously it was
used only to limit effective window size by blocking access through some
of A-LUT elements. This change allows A-LUT elements to also point
different memory locations, providing to upper layers several (up to 128)
independent memory windows. A-LUT hardware allows even more flexible
configurations than this, but NTB KPI have no way to manage that now.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
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.
