IB/iser: Support T10-PI operations

Add logic to initialize protection information entities.  Upon each
iSCSI task, we keep the scsi_cmnd in order to query the scsi
protection operations and reference to protection buffers.

Modify iser_fast_reg_mr to receive indication whether it is
registering the data or protection buffers.

In addition introduce iser_reg_sig_mr which performs fast registration
work-request for a signature enabled memory region
(IB_WR_REG_SIG_MR).  In this routine we set all the protection
relevants for the device to offload protection data-transfer and
verification.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Alex Tabachnik <alext@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

4 files changed, 304 insertions, 27 deletions

diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index cfa952e9ac90..a64b87811915 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -184,6 +184,8 @@ iscsi_iser_task_init(struct iscsi_task *task)
 
         iser_task->command_sent = 0;
         iser_task_rdma_init(iser_task);
+        iser_task->sc = task->sc;
+
         return 0;
 }
 
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h
index 99fc8b899648..fce54092d300 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.h
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
@@ -46,6 +46,8 @@
 #include <linux/printk.h>
 #include <scsi/libiscsi.h>
 #include <scsi/scsi_transport_iscsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
 
 #include <linux/interrupt.h>
 #include <linux/wait.h>
@@ -289,6 +291,10 @@ struct iser_device {
                                                             enum iser_data_dir cmd_dir);
 };
 
+#define ISER_CHECK_GUARD        0xc0
+#define ISER_CHECK_REFTAG       0x0f
+#define ISER_CHECK_APPTAG       0x30
+
 enum iser_reg_indicator {
         ISER_DATA_KEY_VALID     = 1 << 0,
         ISER_PROT_KEY_VALID     = 1 << 1,
@@ -361,11 +367,14 @@ struct iscsi_iser_task {
         struct iser_tx_desc          desc;
         struct iscsi_iser_conn       *iser_conn;
         enum iser_task_status        status;
+        struct scsi_cmnd             *sc;
         int                          command_sent;  /* set if command  sent  */
         int                          dir[ISER_DIRS_NUM];      /* set if dir use*/
         struct iser_regd_buf         rdma_regd[ISER_DIRS_NUM];/* regd rdma buf */
         struct iser_data_buf         data[ISER_DIRS_NUM];     /* orig. data des*/
         struct iser_data_buf         data_copy[ISER_DIRS_NUM];/* contig. copy  */
+        struct iser_data_buf         prot[ISER_DIRS_NUM];     /* prot desc     */
+        struct iser_data_buf         prot_copy[ISER_DIRS_NUM];/* prot copy     */
 };
 
 struct iser_page_vec {
diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c
index 58e14c7705c6..7fd95fe6d989 100644
--- a/drivers/infiniband/ulp/iser/iser_initiator.c
+++ b/drivers/infiniband/ulp/iser/iser_initiator.c
@@ -62,6 +62,17 @@ static int iser_prepare_read_cmd(struct iscsi_task *task,
         if (err)
                 return err;
 
+        if (scsi_prot_sg_count(iser_task->sc)) {
+                struct iser_data_buf *pbuf_in = &iser_task->prot[ISER_DIR_IN];
+
+                err = iser_dma_map_task_data(iser_task,
+                                             pbuf_in,
+                                             ISER_DIR_IN,
+                                             DMA_FROM_DEVICE);
+                if (err)
+                        return err;
+        }
+
         if (edtl > iser_task->data[ISER_DIR_IN].data_len) {
                 iser_err("Total data length: %ld, less than EDTL: "
                          "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
@@ -113,6 +124,17 @@ iser_prepare_write_cmd(struct iscsi_task *task,
         if (err)
                 return err;
 
+        if (scsi_prot_sg_count(iser_task->sc)) {
+                struct iser_data_buf *pbuf_out = &iser_task->prot[ISER_DIR_OUT];
+
+                err = iser_dma_map_task_data(iser_task,
+                                             pbuf_out,
+                                             ISER_DIR_OUT,
+                                             DMA_TO_DEVICE);
+                if (err)
+                        return err;
+        }
+
         if (edtl > iser_task->data[ISER_DIR_OUT].data_len) {
                 iser_err("Total data length: %ld, less than EDTL: %d, "
                          "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
@@ -368,7 +390,7 @@ int iser_send_command(struct iscsi_conn *conn,
         struct iscsi_iser_task *iser_task = task->dd_data;
         unsigned long edtl;
         int err;
-        struct iser_data_buf *data_buf;
+        struct iser_data_buf *data_buf, *prot_buf;
         struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
         struct scsi_cmnd *sc  =  task->sc;
         struct iser_tx_desc *tx_desc = &iser_task->desc;
@@ -379,18 +401,26 @@ int iser_send_command(struct iscsi_conn *conn,
         tx_desc->type = ISCSI_TX_SCSI_COMMAND;
         iser_create_send_desc(iser_conn->ib_conn, tx_desc);
 
-        if (hdr->flags & ISCSI_FLAG_CMD_READ)
+        if (hdr->flags & ISCSI_FLAG_CMD_READ) {
                 data_buf = &iser_task->data[ISER_DIR_IN];
-        else
+                prot_buf = &iser_task->prot[ISER_DIR_IN];
+        } else {
                 data_buf = &iser_task->data[ISER_DIR_OUT];
+                prot_buf = &iser_task->prot[ISER_DIR_OUT];
+        }
 
         if (scsi_sg_count(sc)) { /* using a scatter list */
                 data_buf->buf  = scsi_sglist(sc);
                 data_buf->size = scsi_sg_count(sc);
         }
-
         data_buf->data_len = scsi_bufflen(sc);
 
+        if (scsi_prot_sg_count(sc)) {
+                prot_buf->buf  = scsi_prot_sglist(sc);
+                prot_buf->size = scsi_prot_sg_count(sc);
+                prot_buf->data_len = sc->prot_sdb->length;
+        }
+
         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
                 err = iser_prepare_read_cmd(task, edtl);
                 if (err)
@@ -635,6 +665,9 @@ void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
         iser_task->data[ISER_DIR_IN].data_len  = 0;
         iser_task->data[ISER_DIR_OUT].data_len = 0;
 
+        iser_task->prot[ISER_DIR_IN].data_len  = 0;
+        iser_task->prot[ISER_DIR_OUT].data_len = 0;
+
         memset(&iser_task->rdma_regd[ISER_DIR_IN], 0,
                sizeof(struct iser_regd_buf));
         memset(&iser_task->rdma_regd[ISER_DIR_OUT], 0,
@@ -645,6 +678,8 @@ void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 {
         struct iser_device *device = iser_task->iser_conn->ib_conn->device;
         int is_rdma_data_aligned = 1;
+        int is_rdma_prot_aligned = 1;
+        int prot_count = scsi_prot_sg_count(iser_task->sc);
 
         /* if we were reading, copy back to unaligned sglist,
          * anyway dma_unmap and free the copy
@@ -665,12 +700,30 @@ void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
                                                 ISER_DIR_OUT);
         }
 
+        if (iser_task->prot_copy[ISER_DIR_IN].copy_buf != NULL) {
+                is_rdma_prot_aligned = 0;
+                iser_finalize_rdma_unaligned_sg(iser_task,
+                                                &iser_task->prot[ISER_DIR_IN],
+                                                &iser_task->prot_copy[ISER_DIR_IN],
+                                                ISER_DIR_IN);
+        }
+
+        if (iser_task->prot_copy[ISER_DIR_OUT].copy_buf != NULL) {
+                is_rdma_prot_aligned = 0;
+                iser_finalize_rdma_unaligned_sg(iser_task,
+                                                &iser_task->prot[ISER_DIR_OUT],
+                                                &iser_task->prot_copy[ISER_DIR_OUT],
+                                                ISER_DIR_OUT);
+        }
+
         if (iser_task->dir[ISER_DIR_IN]) {
                 device->iser_unreg_rdma_mem(iser_task, ISER_DIR_IN);
                 if (is_rdma_data_aligned)
                         iser_dma_unmap_task_data(iser_task,
                                                  &iser_task->data[ISER_DIR_IN]);
-
+                if (prot_count && is_rdma_prot_aligned)
+                        iser_dma_unmap_task_data(iser_task,
+                                                 &iser_task->prot[ISER_DIR_IN]);
         }
 
         if (iser_task->dir[ISER_DIR_OUT]) {
diff --git a/drivers/infiniband/ulp/iser/iser_memory.c b/drivers/infiniband/ulp/iser/iser_memory.c
index 2c3f4b144a1a..0995565f5dda 100644
--- a/drivers/infiniband/ulp/iser/iser_memory.c
+++ b/drivers/infiniband/ulp/iser/iser_memory.c
@@ -440,15 +440,180 @@ int iser_reg_rdma_mem_fmr(struct iscsi_iser_task *iser_task,
         return 0;
 }
 
+static inline enum ib_t10_dif_type
+scsi2ib_prot_type(unsigned char prot_type)
+{
+        switch (prot_type) {
+        case SCSI_PROT_DIF_TYPE0:
+                return IB_T10DIF_NONE;
+        case SCSI_PROT_DIF_TYPE1:
+                return IB_T10DIF_TYPE1;
+        case SCSI_PROT_DIF_TYPE2:
+                return IB_T10DIF_TYPE2;
+        case SCSI_PROT_DIF_TYPE3:
+                return IB_T10DIF_TYPE3;
+        default:
+                return IB_T10DIF_NONE;
+        }
+}
+
+
+static int
+iser_set_sig_attrs(struct scsi_cmnd *sc, struct ib_sig_attrs *sig_attrs)
+{
+        unsigned char scsi_ptype = scsi_get_prot_type(sc);
+
+        sig_attrs->mem.sig_type = IB_SIG_TYPE_T10_DIF;
+        sig_attrs->wire.sig_type = IB_SIG_TYPE_T10_DIF;
+        sig_attrs->mem.sig.dif.pi_interval = sc->device->sector_size;
+        sig_attrs->wire.sig.dif.pi_interval = sc->device->sector_size;
+
+        switch (scsi_get_prot_op(sc)) {
+        case SCSI_PROT_WRITE_INSERT:
+        case SCSI_PROT_READ_STRIP:
+                sig_attrs->mem.sig.dif.type = IB_T10DIF_NONE;
+                sig_attrs->wire.sig.dif.type = scsi2ib_prot_type(scsi_ptype);
+                sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
+                sig_attrs->wire.sig.dif.ref_tag = scsi_get_lba(sc) &
+                                                  0xffffffff;
+                break;
+        case SCSI_PROT_READ_INSERT:
+        case SCSI_PROT_WRITE_STRIP:
+                sig_attrs->mem.sig.dif.type = scsi2ib_prot_type(scsi_ptype);
+                sig_attrs->mem.sig.dif.bg_type = IB_T10DIF_CRC;
+                sig_attrs->mem.sig.dif.ref_tag = scsi_get_lba(sc) &
+                                                 0xffffffff;
+                sig_attrs->wire.sig.dif.type = IB_T10DIF_NONE;
+                break;
+        case SCSI_PROT_READ_PASS:
+        case SCSI_PROT_WRITE_PASS:
+                sig_attrs->mem.sig.dif.type = scsi2ib_prot_type(scsi_ptype);
+                sig_attrs->mem.sig.dif.bg_type = IB_T10DIF_CRC;
+                sig_attrs->mem.sig.dif.ref_tag = scsi_get_lba(sc) &
+                                                 0xffffffff;
+                sig_attrs->wire.sig.dif.type = scsi2ib_prot_type(scsi_ptype);
+                sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
+                sig_attrs->wire.sig.dif.ref_tag = scsi_get_lba(sc) &
+                                                  0xffffffff;
+                break;
+        default:
+                iser_err("Unsupported PI operation %d\n",
+                         scsi_get_prot_op(sc));
+                return -EINVAL;
+        }
+        return 0;
+}
+
+
+static int
+iser_set_prot_checks(struct scsi_cmnd *sc, u8 *mask)
+{
+        switch (scsi_get_prot_type(sc)) {
+        case SCSI_PROT_DIF_TYPE0:
+                *mask = 0x0;
+                break;
+        case SCSI_PROT_DIF_TYPE1:
+        case SCSI_PROT_DIF_TYPE2:
+                *mask = ISER_CHECK_GUARD | ISER_CHECK_REFTAG;
+                break;
+        case SCSI_PROT_DIF_TYPE3:
+                *mask = ISER_CHECK_GUARD;
+                break;
+        default:
+                iser_err("Unsupported protection type %d\n",
+                         scsi_get_prot_type(sc));
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int
+iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
+                struct fast_reg_descriptor *desc, struct ib_sge *data_sge,
+                struct ib_sge *prot_sge, struct ib_sge *sig_sge)
+{
+        struct iser_conn *iser_conn = iser_task->iser_conn->ib_conn;
+        struct iser_pi_context *pi_ctx = desc->pi_ctx;
+        struct ib_send_wr sig_wr, inv_wr;
+        struct ib_send_wr *bad_wr, *wr = NULL;
+        struct ib_sig_attrs sig_attrs;
+        int ret;
+        u32 key;
+
+        memset(&sig_attrs, 0, sizeof(sig_attrs));
+        ret = iser_set_sig_attrs(iser_task->sc, &sig_attrs);
+        if (ret)
+                goto err;
+
+        ret = iser_set_prot_checks(iser_task->sc, &sig_attrs.check_mask);
+        if (ret)
+                goto err;
+
+        if (!(desc->reg_indicators & ISER_SIG_KEY_VALID)) {
+                memset(&inv_wr, 0, sizeof(inv_wr));
+                inv_wr.opcode = IB_WR_LOCAL_INV;
+                inv_wr.wr_id = ISER_FASTREG_LI_WRID;
+                inv_wr.ex.invalidate_rkey = pi_ctx->sig_mr->rkey;
+                wr = &inv_wr;
+                /* Bump the key */
+                key = (u8)(pi_ctx->sig_mr->rkey & 0x000000FF);
+                ib_update_fast_reg_key(pi_ctx->sig_mr, ++key);
+        }
+
+        memset(&sig_wr, 0, sizeof(sig_wr));
+        sig_wr.opcode = IB_WR_REG_SIG_MR;
+        sig_wr.wr_id = ISER_FASTREG_LI_WRID;
+        sig_wr.sg_list = data_sge;
+        sig_wr.num_sge = 1;
+        sig_wr.wr.sig_handover.sig_attrs = &sig_attrs;
+        sig_wr.wr.sig_handover.sig_mr = pi_ctx->sig_mr;
+        if (scsi_prot_sg_count(iser_task->sc))
+                sig_wr.wr.sig_handover.prot = prot_sge;
+        sig_wr.wr.sig_handover.access_flags = IB_ACCESS_LOCAL_WRITE |
+                                              IB_ACCESS_REMOTE_READ |
+                                              IB_ACCESS_REMOTE_WRITE;
+
+        if (!wr)
+                wr = &sig_wr;
+        else
+                wr->next = &sig_wr;
+
+        ret = ib_post_send(iser_conn->qp, wr, &bad_wr);
+        if (ret) {
+                iser_err("reg_sig_mr failed, ret:%d\n", ret);
+                goto err;
+        }
+        desc->reg_indicators &= ~ISER_SIG_KEY_VALID;
+
+        sig_sge->lkey = pi_ctx->sig_mr->lkey;
+        sig_sge->addr = 0;
+        sig_sge->length = data_sge->length + prot_sge->length;
+        if (scsi_get_prot_op(iser_task->sc) == SCSI_PROT_WRITE_INSERT ||
+            scsi_get_prot_op(iser_task->sc) == SCSI_PROT_READ_STRIP) {
+                sig_sge->length += (data_sge->length /
+                                   iser_task->sc->device->sector_size) * 8;
+        }
+
+        iser_dbg("sig_sge: addr: 0x%llx  length: %u lkey: 0x%x\n",
+                 sig_sge->addr, sig_sge->length,
+                 sig_sge->lkey);
+err:
+        return ret;
+}
+
 static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
                             struct iser_regd_buf *regd_buf,
                             struct iser_data_buf *mem,
+                            enum iser_reg_indicator ind,
                             struct ib_sge *sge)
 {
         struct fast_reg_descriptor *desc = regd_buf->reg.mem_h;
         struct iser_conn *ib_conn = iser_task->iser_conn->ib_conn;
         struct iser_device *device = ib_conn->device;
         struct ib_device *ibdev = device->ib_device;
+        struct ib_mr *mr;
+        struct ib_fast_reg_page_list *frpl;
         struct ib_send_wr fastreg_wr, inv_wr;
         struct ib_send_wr *bad_wr, *wr = NULL;
         u8 key;
@@ -467,35 +632,42 @@ static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
                 return 0;
         }
 
-        plen = iser_sg_to_page_vec(mem, device->ib_device,
-                                   desc->data_frpl->page_list,
+        if (ind == ISER_DATA_KEY_VALID) {
+                mr = desc->data_mr;
+                frpl = desc->data_frpl;
+        } else {
+                mr = desc->pi_ctx->prot_mr;
+                frpl = desc->pi_ctx->prot_frpl;
+        }
+
+        plen = iser_sg_to_page_vec(mem, device->ib_device, frpl->page_list,
                                    &offset, &size);
         if (plen * SIZE_4K < size) {
                 iser_err("fast reg page_list too short to hold this SG\n");
                 return -EINVAL;
         }
 
-        if (!(desc->reg_indicators & ISER_DATA_KEY_VALID)) {
+        if (!(desc->reg_indicators & ind)) {
                 memset(&inv_wr, 0, sizeof(inv_wr));
                 inv_wr.wr_id = ISER_FASTREG_LI_WRID;
                 inv_wr.opcode = IB_WR_LOCAL_INV;
-                inv_wr.ex.invalidate_rkey = desc->data_mr->rkey;
+                inv_wr.ex.invalidate_rkey = mr->rkey;
                 wr = &inv_wr;
                 /* Bump the key */
-                key = (u8)(desc->data_mr->rkey & 0x000000FF);
-                ib_update_fast_reg_key(desc->data_mr, ++key);
+                key = (u8)(mr->rkey & 0x000000FF);
+                ib_update_fast_reg_key(mr, ++key);
         }
 
         /* Prepare FASTREG WR */
         memset(&fastreg_wr, 0, sizeof(fastreg_wr));
         fastreg_wr.wr_id = ISER_FASTREG_LI_WRID;
         fastreg_wr.opcode = IB_WR_FAST_REG_MR;
-        fastreg_wr.wr.fast_reg.iova_start = desc->data_frpl->page_list[0] + offset;
-        fastreg_wr.wr.fast_reg.page_list = desc->data_frpl;
+        fastreg_wr.wr.fast_reg.iova_start = frpl->page_list[0] + offset;
+        fastreg_wr.wr.fast_reg.page_list = frpl;
         fastreg_wr.wr.fast_reg.page_list_len = plen;
         fastreg_wr.wr.fast_reg.page_shift = SHIFT_4K;
         fastreg_wr.wr.fast_reg.length = size;
-        fastreg_wr.wr.fast_reg.rkey = desc->data_mr->rkey;
+        fastreg_wr.wr.fast_reg.rkey = mr->rkey;
         fastreg_wr.wr.fast_reg.access_flags = (IB_ACCESS_LOCAL_WRITE  |
                                                IB_ACCESS_REMOTE_WRITE |
                                                IB_ACCESS_REMOTE_READ);
@@ -510,10 +682,10 @@ static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
                 iser_err("fast registration failed, ret:%d\n", ret);
                 return ret;
         }
-        desc->reg_indicators &= ~ISER_DATA_KEY_VALID;
+        desc->reg_indicators &= ~ind;
 
-        sge->lkey = desc->data_mr->lkey;
-        sge->addr = desc->data_frpl->page_list[0] + offset;
+        sge->lkey = mr->lkey;
+        sge->addr = frpl->page_list[0] + offset;
         sge->length = size;
 
         return ret;
@@ -550,7 +722,8 @@ int iser_reg_rdma_mem_fastreg(struct iscsi_iser_task *iser_task,
                 mem = &iser_task->data_copy[cmd_dir];
         }
 
-        if (mem->dma_nents != 1) {
+        if (mem->dma_nents != 1 ||
+            scsi_get_prot_op(iser_task->sc) != SCSI_PROT_NORMAL) {
                 spin_lock_irqsave(&ib_conn->lock, flags);
                 desc = list_first_entry(&ib_conn->fastreg.pool,
                                         struct fast_reg_descriptor, list);
@@ -559,21 +732,61 @@ int iser_reg_rdma_mem_fastreg(struct iscsi_iser_task *iser_task,
                 regd_buf->reg.mem_h = desc;
         }
 
-        err = iser_fast_reg_mr(iser_task, regd_buf, mem, &data_sge);
+        err = iser_fast_reg_mr(iser_task, regd_buf, mem,
+                               ISER_DATA_KEY_VALID, &data_sge);
         if (err)
                 goto err_reg;
 
-        if (desc) {
-                regd_buf->reg.rkey = desc->data_mr->rkey;
+        if (scsi_get_prot_op(iser_task->sc) != SCSI_PROT_NORMAL) {
+                struct ib_sge prot_sge, sig_sge;
+
+                memset(&prot_sge, 0, sizeof(prot_sge));
+                if (scsi_prot_sg_count(iser_task->sc)) {
+                        mem = &iser_task->prot[cmd_dir];
+                        aligned_len = iser_data_buf_aligned_len(mem, ibdev);
+                        if (aligned_len != mem->dma_nents) {
+                                err = fall_to_bounce_buf(iser_task, ibdev, mem,
+                                                         &iser_task->prot_copy[cmd_dir],
+                                                         cmd_dir, aligned_len);
+                                if (err) {
+                                        iser_err("failed to allocate bounce buffer\n");
+                                        return err;
+                                }
+                                mem = &iser_task->prot_copy[cmd_dir];
+                        }
+
+                        err = iser_fast_reg_mr(iser_task, regd_buf, mem,
+                                               ISER_PROT_KEY_VALID, &prot_sge);
+                        if (err)
+                                goto err_reg;
+                }
+
+                err = iser_reg_sig_mr(iser_task, desc, &data_sge,
+                                      &prot_sge, &sig_sge);
+                if (err) {
+                        iser_err("Failed to register signature mr\n");
+                        return err;
+                }
+                desc->reg_indicators |= ISER_FASTREG_PROTECTED;
+
+                regd_buf->reg.lkey = sig_sge.lkey;
+                regd_buf->reg.rkey = desc->pi_ctx->sig_mr->rkey;
+                regd_buf->reg.va = sig_sge.addr;
+                regd_buf->reg.len = sig_sge.length;
                 regd_buf->reg.is_mr = 1;
         } else {
-                regd_buf->reg.rkey = device->mr->rkey;
-                regd_buf->reg.is_mr = 0;
-        }
+                if (desc) {
+                        regd_buf->reg.rkey = desc->data_mr->rkey;
+                        regd_buf->reg.is_mr = 1;
+                } else {
+                        regd_buf->reg.rkey = device->mr->rkey;
+                        regd_buf->reg.is_mr = 0;
+                }
 
-        regd_buf->reg.lkey = data_sge.lkey;
-        regd_buf->reg.va = data_sge.addr;
-        regd_buf->reg.len = data_sge.length;
+                regd_buf->reg.lkey = data_sge.lkey;
+                regd_buf->reg.va = data_sge.addr;
+                regd_buf->reg.len = data_sge.length;
+        }
 
         return 0;
 err_reg: