[RFC PATCH v4 0/2] RDMA/rxe: Add dma-buf support

[Shunsuke Mie <mie@igel.co.jp>]

This patch series add a dma-buf support for rxe driver.

A dma-buf based memory registering has beed introduced to use the memory
region that lack of associated page structures (e.g. device memory and CMA
managed memory) [1]. However, to use the dma-buf based memory, each rdma
device drivers require add some implementation. The rxe driver has not
support yet.

[1] https://www.spinics.net/lists/linux-rdma/msg98592.html

To enable to use the dma-buf memory in rxe rdma device, add some changes
and implementation in this patch series.

This series consists of two patches. The first patch changes the IB core
to support for rdma drivers that has not dma device. The secound patch adds
the dma-buf support to rxe driver.

Related user space RDMA library changes are provided as a separate patch.

v4:
* Fix warnings, unused variable and casting
v3: https://www.spinics.net/lists/linux-rdma/msg106776.html
* Rebase to the latest linux-rdma 'for-next' branch (5.15.0-rc6+)
* Fix to use dma-buf-map helpers
v2: https://www.spinics.net/lists/linux-rdma/msg105928.html
* Rebase to the latest linux-rdma 'for-next' branch (5.15.0-rc1+)
* Instead of using a dummy dma_device to attach dma-buf, just store
  dma-buf to use software RDMA driver
* Use dma-buf vmap() interface
* Check to pass tests of rdma-core
v1: https://www.spinics.net/lists/linux-rdma/msg105376.html
* The initial patch set
* Use ib_device as dma_device.
* Use dma-buf dynamic attach interface
* Add dma-buf support to rxe device

Shunsuke Mie (2):
  RDMA/umem: Change for rdma devices has not dma device
  RDMA/rxe: Add dma-buf support

 drivers/infiniband/core/umem_dmabuf.c |  20 ++++-
 drivers/infiniband/sw/rxe/rxe_loc.h   |   2 +
 drivers/infiniband/sw/rxe/rxe_mr.c    | 113 ++++++++++++++++++++++++++
 drivers/infiniband/sw/rxe/rxe_verbs.c |  34 ++++++++
 include/rdma/ib_umem.h                |   1 +
 5 files changed, 166 insertions(+), 4 deletions(-)

-- 
2.17.1