[PATCH net-next 05/10] net/smc: register RMB-related memory region

Ursula Braun
2017-07-28T11:56:17Z

A memory region created for a new RMB must be registered explicitly,
before the peer can make use of it for remote DMA transfer.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
---
net/smc/af_smc.c | 38 ++++++++++++++++++++++++++++++++
net/smc/smc_core.c | 1 -
net/smc/smc_core.h | 12 +++++++++++
net/smc/smc_ib.c | 2 +-
net/smc/smc_wr.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
net/smc/smc_wr.h | 1 +
6 files changed, 115 insertions(+), 2 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 120a7b9b4d8e..e0a95d50bf87 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -338,6 +338,12 @@ static int smc_clnt_conf_first_link(struct smc_sock *smc, union ib_gid *gid)
return SMC_CLC_DECL_INTERR;

smc_wr_remember_qp_attr(link);
+
+ rc = smc_wr_reg_send(link,
+ smc->conn.rmb_desc->mr_rx[SMC_SINGLE_LINK]);
+ if (rc)
+ return SMC_CLC_DECL_INTERR;
+
/* send CONFIRM LINK response over RoCE fabric */
rc = smc_llc_send_confirm_link(link,
link->smcibdev->mac[link->ibport - 1],
@@ -459,6 +465,18 @@ static int smc_connect_rdma(struct smc_sock *smc)
reason_code = SMC_CLC_DECL_INTERR;
goto decline_rdma_unlock;
}
+ } else {
+ struct smc_buf_desc *buf_desc = smc->conn.rmb_desc;
+
+ if (!buf_desc->reused) {
+ /* register memory region for new rmb */
+ rc = smc_wr_reg_send(link,
+ buf_desc->mr_rx[SMC_SINGLE_LINK]);
+ if (rc) {
+ reason_code = SMC_CLC_DECL_INTERR;
+ goto decline_rdma_unlock;
+ }
+ }
}

rc = smc_clc_send_confirm(smc);
@@ -692,6 +710,12 @@ static int smc_serv_conf_first_link(struct smc_sock *smc)
int rc;

link = &lgr->lnk[SMC_SINGLE_LINK];
+
+ rc = smc_wr_reg_send(link,
+ smc->conn.rmb_desc->mr_rx[SMC_SINGLE_LINK]);
+ if (rc)
+ return SMC_CLC_DECL_INTERR;
+
/* send CONFIRM LINK request to client over the RoCE fabric */
rc = smc_llc_send_confirm_link(link,
link->smcibdev->mac[link->ibport - 1],
@@ -803,6 +827,20 @@ static void smc_listen_work(struct work_struct *work)
smc_close_init(new_smc);
smc_rx_init(new_smc);

+ if (local_contact != SMC_FIRST_CONTACT) {
+ struct smc_buf_desc *buf_desc = new_smc->conn.rmb_desc;
+
+ if (!buf_desc->reused) {
+ /* register memory region for new rmb */
+ rc = smc_wr_reg_send(link,
+ buf_desc->mr_rx[SMC_SINGLE_LINK]);
+ if (rc) {
+ reason_code = SMC_CLC_DECL_INTERR;
+ goto decline_rdma;
+ }
+ }
+ }
+
rc = smc_clc_send_accept(new_smc, local_contact);
if (rc)
goto out_err;
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index f1dd4e1cd3e1..87bb3e4771a8 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -175,7 +175,6 @@ static int smc_lgr_create(struct smc_sock *smc, __be32 peer_in_addr,
rc = smc_wr_alloc_link_mem(lnk);
if (rc)
goto free_lgr;
- init_waitqueue_head(&lnk->wr_tx_wait);
rc = smc_ib_create_protection_domain(lnk);
if (rc)
goto free_link_mem;
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 17b5fea09901..f7b40bdbf24c 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -37,6 +37,14 @@ struct smc_wr_buf {
u8 raw[SMC_WR_BUF_SIZE];
};

+#define SMC_WR_REG_MR_WAIT_TIME (5 * HZ)/* wait time for ib_wr_reg_mr result */
+
+enum smc_wr_reg_state {
+ POSTED, /* ib_wr_reg_mr request posted */
+ CONFIRMED, /* ib_wr_reg_mr response: successful */
+ FAILED /* ib_wr_reg_mr response: failure */
+};
+
struct smc_link {
struct smc_ib_device *smcibdev; /* ib-device */
u8 ibport; /* port - values 1 | 2 */
@@ -65,6 +73,10 @@ struct smc_link {
u64 wr_rx_id; /* seq # of last recv WR */
u32 wr_rx_cnt; /* number of WR recv buffers */

+ struct ib_reg_wr wr_reg; /* WR register memory region */
+ wait_queue_head_t wr_reg_wait; /* wait for wr_reg result */
+ enum smc_wr_reg_state wr_reg_state; /* state of wr_reg request */
+
union ib_gid gid; /* gid matching used vlan id */
u32 peer_qpn; /* QP number of peer */
enum ib_mtu path_mtu; /* used mtu */
diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
index 08233492ec45..85e1831f591e 100644
--- a/net/smc/smc_ib.c
+++ b/net/smc/smc_ib.c
@@ -231,10 +231,10 @@ int smc_ib_create_queue_pair(struct smc_link *lnk)
.recv_cq = lnk->smcibdev->roce_cq_recv,
.srq = NULL,
.cap = {
- .max_send_wr = SMC_WR_BUF_CNT,
/* include unsolicited rdma_writes as well,
* there are max. 2 RDMA_WRITE per 1 WR_SEND
*/
+ .max_send_wr = SMC_WR_BUF_CNT * 3,
.max_recv_wr = SMC_WR_BUF_CNT * 3,
.max_send_sge = SMC_IB_MAX_SEND_SGE,
.max_recv_sge = 1,
diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c
index 874ee9f9d796..ab56bda66783 100644
--- a/net/smc/smc_wr.c
+++ b/net/smc/smc_wr.c
@@ -68,6 +68,16 @@ static inline void smc_wr_tx_process_cqe(struct ib_wc *wc)
int i;

link = wc->qp->qp_context;
+
+ if (wc->opcode == IB_WC_REG_MR) {
+ if (wc->status)
+ link->wr_reg_state = FAILED;
+ else
+ link->wr_reg_state = CONFIRMED;
+ wake_up(&link->wr_reg_wait);
+ return;
+ }
+
pnd_snd_idx = smc_wr_tx_find_pending_index(link, wc->wr_id);
if (pnd_snd_idx == link->wr_tx_cnt)
return;
@@ -243,6 +253,52 @@ int smc_wr_tx_send(struct smc_link *link, struct smc_wr_tx_pend_priv *priv)
return rc;
}

+/* Register a memory region and wait for result. */
+int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr)
+{
+ struct ib_send_wr *failed_wr = NULL;
+ int rc;
+
+ ib_req_notify_cq(link->smcibdev->roce_cq_send,
+ IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
+ link->wr_reg_state = POSTED;
+ link->wr_reg.wr.wr_id = (u64)(uintptr_t)mr;
+ link->wr_reg.mr = mr;
+ link->wr_reg.key = mr->rkey;
+ failed_wr = &link->wr_reg.wr;
+ rc = ib_post_send(link->roce_qp, &link->wr_reg.wr, &failed_wr);
+ WARN_ON(failed_wr != &link->wr_reg.wr);
+ if (rc)
+ return rc;
+
+ rc = wait_event_interruptible_timeout(link->wr_reg_wait,
+ (link->wr_reg_state != POSTED),
+ SMC_WR_REG_MR_WAIT_TIME);
+ if (!rc) {
+ /* timeout - terminate connections */
+ struct smc_link_group *lgr;
+
+ lgr = container_of(link, struct smc_link_group,
+ lnk[SMC_SINGLE_LINK]);
+ smc_lgr_terminate(lgr);
+ return -EPIPE;
+ }
+ if (rc == -ERESTARTSYS)
+ return -EINTR;
+ switch (link->wr_reg_state) {
+ case CONFIRMED:
+ rc = 0;
+ break;
+ case FAILED:
+ rc = -EIO;
+ break;
+ case POSTED:
+ rc = -EPIPE;
+ break;
+ }
+ return rc;
+}
+
void smc_wr_tx_dismiss_slots(struct smc_link *link, u8 wr_rx_hdr_type,
smc_wr_tx_filter filter,
smc_wr_tx_dismisser dismisser,
@@ -458,6 +514,11 @@ static void smc_wr_init_sge(struct smc_link *lnk)
lnk->wr_rx_ibs[i].sg_list = &lnk->wr_rx_sges[i];
lnk->wr_rx_ibs[i].num_sge = 1;
}
+ lnk->wr_reg.wr.next = NULL;
+ lnk->wr_reg.wr.num_sge = 0;
+ lnk->wr_reg.wr.send_flags = IB_SEND_SIGNALED;
+ lnk->wr_reg.wr.opcode = IB_WR_REG_MR;
+ lnk->wr_reg.access = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE;
}

void smc_wr_free_link(struct smc_link *lnk)
@@ -602,6 +663,8 @@ int smc_wr_create_link(struct smc_link *lnk)
smc_wr_init_sge(lnk);
memset(lnk->wr_tx_mask, 0,
BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*lnk->wr_tx_mask));
+ init_waitqueue_head(&lnk->wr_tx_wait);
+ init_waitqueue_head(&lnk->wr_reg_wait);
return rc;

dma_unmap:
diff --git a/net/smc/smc_wr.h b/net/smc/smc_wr.h
index 0b9beeda6053..45eb53833052 100644
--- a/net/smc/smc_wr.h
+++ b/net/smc/smc_wr.h
@@ -102,5 +102,6 @@ void smc_wr_tx_dismiss_slots(struct smc_link *lnk, u8 wr_rx_hdr_type,
int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler);
int smc_wr_rx_post_init(struct smc_link *link);
void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
+int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr);

#endif /* SMC_WR_H */
--
2.11.2