Introduce Work Queue object and its verbs

Introduce Work Queue object and its create/destroy/modify verbs.

QP can be created without internal WQs "packaged" inside it,
this QP can be configured to use "external" WQ object as its
receive/send queue.

WQ is a necessary component for RSS technology since RSS mechanism
is supposed to distribute the traffic between multiple Receive Work
Queues.

WQ associated (many to one) with Completion Queue and it owns WQ
properties (PD, WQ size, etc.).
WQ has a type, this patch introduces the IBV_WQT_RQ (i.e.receive
queue), it may be extend to others such as IBV_WQT_SQ. (send queue).

WQ from type IBV_WQT_RQ contains receive work requests and as such
exposes post receive function to be used to post a list of work
requests (WRs) to its receive queue.

PD is an attribute of a work queue (i.e. send/receive queue), it's
used by the hardware for security validation before scattering to a
memory region which is pointed by the WQ. For that, an external WQ
object
needs a PD, letting the hardware makes that validation.

When accessing a memory region that is pointed by the WQ its PD
is used and not the QP's PD, this behavior is similar to a SRQ and a QP.

WQ context is subject to a well-defined state transitions done by
the modify_wq verb.
When WQ is created its initial state becomes IBV_WQS_RESET.
>From IBV_WQS_RESET it can be modified to itself or to IBV_WQS_RDY.
>From IBV_WQS_RDY it can be modified to itself, to IBV_WQS_RESET
      or to IBV_WQS_ERR.
>From IBV_WQS_ERR it can be modified to IBV_WQS_RESET.

Note: transition to IBV_WQS_ERR might occur implicitly in case there
      was some HW error.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
5 files changed