-/**
- * srpt_unmap_sg_to_ib_sge() - Unmap an IB SGE list.
- */
-static void srpt_unmap_sg_to_ib_sge(struct srpt_rdma_ch *ch,
- struct srpt_send_ioctx *ioctx)
-{
- struct scatterlist *sg;
- enum dma_data_direction dir;
-
- BUG_ON(!ch);
- BUG_ON(!ioctx);
- BUG_ON(ioctx->n_rdma && !ioctx->rdma_wrs);
-
- while (ioctx->n_rdma)
- kfree(ioctx->rdma_wrs[--ioctx->n_rdma].wr.sg_list);
-
- kfree(ioctx->rdma_wrs);
- ioctx->rdma_wrs = NULL;
-
- if (ioctx->mapped_sg_count) {
- sg = ioctx->sg;
- WARN_ON(!sg);
- dir = ioctx->cmd.data_direction;
- BUG_ON(dir == DMA_NONE);
- ib_dma_unmap_sg(ch->sport->sdev->device, sg, ioctx->sg_cnt,
- target_reverse_dma_direction(&ioctx->cmd));
- ioctx->mapped_sg_count = 0;
- }
-}
-
-/**
- * srpt_map_sg_to_ib_sge() - Map an SG list to an IB SGE list.
- */
-static int srpt_map_sg_to_ib_sge(struct srpt_rdma_ch *ch,
- struct srpt_send_ioctx *ioctx)
-{
- struct ib_device *dev = ch->sport->sdev->device;
- struct se_cmd *cmd;
- struct scatterlist *sg, *sg_orig;
- int sg_cnt;
- enum dma_data_direction dir;
- struct ib_rdma_wr *riu;
- struct srp_direct_buf *db;
- dma_addr_t dma_addr;
- struct ib_sge *sge;
- u64 raddr;
- u32 rsize;
- u32 tsize;
- u32 dma_len;
- int count, nrdma;
- int i, j, k;
-
- BUG_ON(!ch);
- BUG_ON(!ioctx);
- cmd = &ioctx->cmd;
- dir = cmd->data_direction;
- BUG_ON(dir == DMA_NONE);
-
- ioctx->sg = sg = sg_orig = cmd->t_data_sg;
- ioctx->sg_cnt = sg_cnt = cmd->t_data_nents;
-
- count = ib_dma_map_sg(ch->sport->sdev->device, sg, sg_cnt,
- target_reverse_dma_direction(cmd));
- if (unlikely(!count))
- return -EAGAIN;
-
- ioctx->mapped_sg_count = count;
-
- if (ioctx->rdma_wrs && ioctx->n_rdma_wrs)
- nrdma = ioctx->n_rdma_wrs;
- else {
- nrdma = (count + SRPT_DEF_SG_PER_WQE - 1) / SRPT_DEF_SG_PER_WQE
- + ioctx->n_rbuf;
-
- ioctx->rdma_wrs = kcalloc(nrdma, sizeof(*ioctx->rdma_wrs),
- GFP_KERNEL);
- if (!ioctx->rdma_wrs)
- goto free_mem;
-
- ioctx->n_rdma_wrs = nrdma;
- }
-
- db = ioctx->rbufs;
- tsize = cmd->data_length;
- dma_len = ib_sg_dma_len(dev, &sg[0]);
- riu = ioctx->rdma_wrs;
-
- /*
- * For each remote desc - calculate the #ib_sge.
- * If #ib_sge < SRPT_DEF_SG_PER_WQE per rdma operation then
- * each remote desc rdma_iu is required a rdma wr;
- * else
- * we need to allocate extra rdma_iu to carry extra #ib_sge in
- * another rdma wr
- */
- for (i = 0, j = 0;
- j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
- rsize = be32_to_cpu(db->len);
- raddr = be64_to_cpu(db->va);
- riu->remote_addr = raddr;
- riu->rkey = be32_to_cpu(db->key);
- riu->wr.num_sge = 0;
-
- /* calculate how many sge required for this remote_buf */
- while (rsize > 0 && tsize > 0) {
-
- if (rsize >= dma_len) {
- tsize -= dma_len;
- rsize -= dma_len;
- raddr += dma_len;
-
- if (tsize > 0) {
- ++j;
- if (j < count) {
- sg = sg_next(sg);
- dma_len = ib_sg_dma_len(
- dev, sg);
- }
- }
- } else {
- tsize -= rsize;
- dma_len -= rsize;
- rsize = 0;
- }
-
- ++riu->wr.num_sge;
-
- if (rsize > 0 &&
- riu->wr.num_sge == SRPT_DEF_SG_PER_WQE) {
- ++ioctx->n_rdma;
- riu->wr.sg_list = kmalloc_array(riu->wr.num_sge,
- sizeof(*riu->wr.sg_list),
- GFP_KERNEL);
- if (!riu->wr.sg_list)
- goto free_mem;
-
- ++riu;
- riu->wr.num_sge = 0;
- riu->remote_addr = raddr;
- riu->rkey = be32_to_cpu(db->key);
- }
- }
-
- ++ioctx->n_rdma;
- riu->wr.sg_list = kmalloc_array(riu->wr.num_sge,
- sizeof(*riu->wr.sg_list),
- GFP_KERNEL);
- if (!riu->wr.sg_list)
- goto free_mem;
- }
-
- db = ioctx->rbufs;
- tsize = cmd->data_length;
- riu = ioctx->rdma_wrs;
- sg = sg_orig;
- dma_len = ib_sg_dma_len(dev, &sg[0]);
- dma_addr = ib_sg_dma_address(dev, &sg[0]);
-
- /* this second loop is really mapped sg_addres to rdma_iu->ib_sge */
- for (i = 0, j = 0;
- j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
- rsize = be32_to_cpu(db->len);
- sge = riu->wr.sg_list;
- k = 0;
-
- while (rsize > 0 && tsize > 0) {
- sge->addr = dma_addr;
- sge->lkey = ch->sport->sdev->pd->local_dma_lkey;
-
- if (rsize >= dma_len) {
- sge->length =
- (tsize < dma_len) ? tsize : dma_len;
- tsize -= dma_len;
- rsize -= dma_len;
-
- if (tsize > 0) {
- ++j;
- if (j < count) {
- sg = sg_next(sg);
- dma_len = ib_sg_dma_len(
- dev, sg);
- dma_addr = ib_sg_dma_address(
- dev, sg);
- }
- }
- } else {
- sge->length = (tsize < rsize) ? tsize : rsize;
- tsize -= rsize;
- dma_len -= rsize;
- dma_addr += rsize;
- rsize = 0;
- }
-
- ++k;
- if (k == riu->wr.num_sge && rsize > 0 && tsize > 0) {
- ++riu;
- sge = riu->wr.sg_list;
- k = 0;
- } else if (rsize > 0 && tsize > 0)
- ++sge;
- }
- }
-
- return 0;
-
-free_mem:
- srpt_unmap_sg_to_ib_sge(ch, ioctx);
-
- return -ENOMEM;
-}
-