tree 4a3b63aedd212e74fa67ee95b9ad5afab39c434c
parent e657571b76faf96a1de1aaf40b2111adcf76c673
author Sagi Grimberg <sagig@mellanox.com> 1375004142 +0300
committer Roland Dreier <roland@purestorage.com> 1376093890 -0700

IB/iser: Introduce fast memory registration model (FRWR)

Newer HCAs and Virtual functions may not support FMRs but rather a fast
registration model, which we call FRWR - "Fast Registration Work Requests".

This model was introduced in 00f7ec36c ("RDMA/core: Add memory management
extensions support") and works when the IB device supports the
IB_DEVICE_MEM_MGT_EXTENSIONS capability.

Upon creating the iser device iser will test whether the HCA supports
FMRs.  If no support for FMRs, check if IB_DEVICE_MEM_MGT_EXTENSIONS
is supported and assign function pointers that handle fast
registration and allocation of appropriate resources (fast_reg
descriptors).

Registration is done using posting IB_WR_FAST_REG_MR to the QP and
invalidations using posting IB_WR_LOCAL_INV.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>