static inline void isert_link_send_pdu_wrs(struct isert_cmnd *from_pdu,
struct isert_cmnd *to_pdu,
int wr_cnt)
{
isert_link_send_wrs(&from_pdu->wr[wr_cnt - 1], &to_pdu->wr[0]);
to_pdu->wr[0].send_wr.next = NULL;
}
int isert_prepare_rdma(struct isert_cmnd *isert_pdu,
struct isert_connection *isert_conn,
enum isert_wr_op op)
{
struct isert_buf *isert_buf = &isert_pdu->rdma_buf;
struct isert_device *isert_dev = isert_conn->isert_dev;
struct ib_device *ib_dev = isert_dev->ib_dev;
int err;
int buff_offset;
int sg_offset, sg_cnt;
int wr_cnt, i;
isert_buf_init_sg(isert_buf, isert_pdu->iscsi.sg,
isert_pdu->iscsi.sg_cnt,
isert_pdu->iscsi.bufflen);
if (op == ISER_WR_RDMA_WRITE)
isert_buf->dma_dir = DMA_TO_DEVICE;
else
isert_buf->dma_dir = DMA_FROM_DEVICE;
if (unlikely(isert_buf->sg_cnt > isert_pdu->n_sge)) {
wr_cnt = isert_alloc_for_rdma(isert_pdu, isert_buf->sg_cnt, isert_conn);
if (unlikely(wr_cnt))
goto out;
}
err = ib_dma_map_sg(ib_dev, isert_buf->sg, isert_buf->sg_cnt,
isert_buf->dma_dir);
if (unlikely(!err)) {
pr_err("Failed to DMA map iser sg:%p len:%d\n",
isert_buf->sg, isert_buf->sg_cnt);
wr_cnt = -EFAULT;
goto out;
}
buff_offset = 0;
sg_cnt = 0;
for (wr_cnt = 0, sg_offset = 0; sg_offset < isert_buf->sg_cnt; ++wr_cnt) {
sg_cnt = min((int)isert_conn->max_sge,
isert_buf->sg_cnt - sg_offset);
err = isert_wr_init(&isert_pdu->wr[wr_cnt], op, isert_buf,
isert_conn, isert_pdu, isert_pdu->sg_pool,
sg_offset, sg_cnt, buff_offset);
if (unlikely(err < 0)) {
wr_cnt = err;
goto out;
}
buff_offset = err;
sg_offset += sg_cnt;
}
for (i = 1; i < wr_cnt; ++i)
isert_link_send_wrs(&isert_pdu->wr[i - 1], &isert_pdu->wr[i]);
out:
TRACE_EXIT_RES(wr_cnt);
return wr_cnt;
}
