Data offset are intended to correspond to DATAO in NVMe/TCP and
Buffer Offset in iSCSI.
Previously for iSCSI, buffer offset had been merged to start block
address, but passing buffer offset separately from start block address
clarifies the logic more.
On the other hand, for NVMe/TCP, passing DATAO separately from start
block address will be critically important because DATAO will bave any
alignment and will be necessary to use for not only reference tag
but also guard computation.
This patch adds data_offset to struct spdk_dif_ctx and adds it to the
parameters of spdk_dif_ctx_init(). ref_tag_offset is also added to struct
spdk_dif_ctx and it is computed by dividing data_offset by data_block_size
and is used to compute reference tag.
The next patch will use this change when getting DIF context in SCSI.
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: Id0e12ca9b1dc75d0589787520feb0c2ee0f844a5
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/457540
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
73204fe2e5