[ofa-general] EQ creation in ConnectX

[Ramachandra K]

Hi,

I had a query related to EQ creation in the Connect X driver.

Please correct me if I am wrong, but as I understand it, the driver
has to do the following things for creating
an EQ:

1. Allocate ICM space for EQ Context table
2. Allocate CMPT space for the EQ
3. Create an MTT entry to describe the physical address of the EQ buffer.
4. Use the SW2HW_EQ command to transfer ownership to hardware and passing
   the EQ context table entry to HW.

I have a few questions related to these steps:

1. Is mtt_base_addr_h/l in the EQC entry used in SW2HW_EQ command, the
offset of the MTT entry in the MTT
   made for this EQ describing the EQ buffer physical address ?

2. The Programmer's reference manual states that "The underlying MTTs
are allocated and populated by the driver through
   the WRITE_MTT command". But I do not see a WRITE_MTT command being
used in the Connect X driver. Is the EQ buffer information
   being directly written to the MTT table by the driver instead of
using the WRITE_MTT command ?

3. Is the MTT entry just the physical address of the EQ buffer (and
the present bit) or is there more significance
   to the MTT entry ?

4. Does the driver need do anything with the CMPT entries or are they
completely handled by the hardware ?

Regards,
Ram