Merge branch 'siw' into rdma.git for-next

Bernard Metzler says:

====================
This patch set contributes the SoftiWarp driver rebased for latest
rdma-next. SoftiWarp (siw) implements the iWarp RDMA protocol over kernel
TCP sockets. The driver integrates with the linux-rdma framework.

A matching userlevel driver is available as PR at
https://github.com/linux-rdma/rdma-core/pull/536

Many thanks for reviewing and testing the driver, especially to Leon,
Jason, Steve, Doug, Olga, Dennis, Gal. You all helped to significantly
improve the driver over the last year.

Please find below a list of changes and comments, compared to older
versions of the siw driver.

Many thanks!
Bernard.

CHANGES:
========

v3 (this version)
-----------------

- Rebased to rdma-next

- Removed unneccessary initialization of enums in siw-abi.h

- Added comment on sizing of all work queues to power of two.

v2
-----------------

- Changed recieve path CRC calculation to compute CRC32c not
  on target buffer after placement, but on original skbuf.
  This change severely hurts performance, if CRC is switched
  on, since skb must now be walked twice. It is planned to
  work on an extension to skb_copy_bits() to fold in CRC
  computation.

- Moved debugging to using ibdev_dbg().

- Dropped detailed packet debug printing.

- Removed siw_debug.[ch] files.

- Removed resource tracking, code now relies on restrack of
  RDMA midlayer. Only object counting to enforce reported
  device limits is left in place.

- Removed all nested switch-case statements.

- Cleaned up header file #include's

- Moved CQ create/destroy to new semantics,
  where midlayer creates/destroys containing object.

- Set siw's ABI version to 1 (was 0 before)

- Removed all enum initialization where not needed.

- Fixed MAINTANERS entry for siw driver

- This version stays with the current siw specific
  management of user memory (siw_umem_get() vs.
  ib_umem_get(), etc.). This, since the current ib_umem
  implementation is less efficient for user page lookup
  on the fast path, where effciency is important for a
  SW RDMA driver.
  It is planned to contribute enhancements to the ib_umem
  framework, wich makes it suitable for SW drivers as well.

v1 (first version after v9 of siw RFC)
--------------------------------------

- Rebased to 5.2-rc1

- All IDR code got removed.

- Both MR and QP deallocation verbs now synchronously
  free the resources referenced by the RDMA mid-layer.

- IPv6 support was added.

- For compatibility with Chelsio iWarp hardware, the RX
  path was slightly reworked. It now allows packet intersection
  between tagged and untagged RDMAP operations. While not
  a defined behavior as of IETF RFC 5040/5041, some RDMA hardware
  may intersect an ongoing outbound (large) tagged message, such
  as an multisegment RDMA Read Response with sending an untagged
  message, such as an RDMA Send frame. This behavior was only
  detected in an NVMeF setup, where siw was used at target side,
  and RDMA hardware at client side (during file write). siw now
  implements two input paths for tagged and untagged messages each,
  and allows the intersected placement of both messages.

- The siw kernel abi file got renamed from siw_user.h to siw-abi.h.
====================

* branch 'siw':
  SIW addition to kernel build environment
  SIW completion queue methods
  SIW receive path
  SIW transmit path
  SIW queue pair methods
  SIW application buffer management
  SIW application interface
  SIW connection management
  SIW network and RDMA core interface
  SIW main include file
  iWarp wire packet format