If the smmu is enabled, the length of sg obtained from
__iommu_map_sg_attrs is not 4kB. When the IOVA is set with the sg
dma address, the IOVA will not be page continuous. so, the current
code has MTPT configuration error that probably cause dma operation
failure. In order to fix this issue, the IOVA should be calculated
based on the sg length.

Fixes: 3958cc56("RDMA/hns: Configure the MTPT in hip08")
Signed-off-by: NWei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: NShaobo Xu <xushaobo2@huawei.com>
Signed-off-by: NLijun Ou <oulijun@huawei.com>
Signed-off-by: NYixian Liu <liuyixian@huawei.com>
Signed-off-by: NXiping Zhang (Francis) <zhangxiping3@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>