[PATCH net-next 02/10] net/smc: register new rmbs with the peer

Ursula Braun
2018-05-15T15:04:55Z

Register new rmb buffers with the remote peer by exchanging a
confirm_rkey llc message.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
net/smc/af_smc.c | 20 ++++++++++++++------
net/smc/smc_core.c | 1 +
net/smc/smc_core.h | 2 ++
net/smc/smc_llc.c | 47 +++++++++++++++++++++++++++++++++++++++++++++--
net/smc/smc_llc.h | 2 ++
5 files changed, 64 insertions(+), 8 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 83403be46a4a..397ba2182453 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -293,14 +293,22 @@ static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
}

-/* register a new rmb */
-static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc)
+/* register a new rmb, optionally send confirm_rkey msg to register with peer */
+static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
+ bool conf_rkey)
{
/* register memory region for new rmb */
if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
rmb_desc->regerr = 1;
return -EFAULT;
}
+ if (!conf_rkey)
+ return 0;
+ /* exchange confirm_rkey msg with peer */
+ if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
+ rmb_desc->regerr = 1;
+ return -EFAULT;
+ }
return 0;
}

@@ -334,7 +342,7 @@ static int smc_clnt_conf_first_link(struct smc_sock *smc)

smc_wr_remember_qp_attr(link);

- if (smc_reg_rmb(link, smc->conn.rmb_desc))
+ if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
return SMC_CLC_DECL_INTERR;

/* send CONFIRM LINK response over RoCE fabric */
@@ -488,7 +496,7 @@ static int smc_connect_rdma(struct smc_sock *smc)
}
} else {
if (!smc->conn.rmb_desc->reused) {
- if (smc_reg_rmb(link, smc->conn.rmb_desc)) {
+ if (smc_reg_rmb(link, smc->conn.rmb_desc, true)) {
reason_code = SMC_CLC_DECL_INTERR;
goto decline_rdma_unlock;
}
@@ -729,7 +737,7 @@ static int smc_serv_conf_first_link(struct smc_sock *smc)

link = &lgr->lnk[SMC_SINGLE_LINK];

- if (smc_reg_rmb(link, smc->conn.rmb_desc))
+ if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
return SMC_CLC_DECL_INTERR;

/* send CONFIRM LINK request to client over the RoCE fabric */
@@ -866,7 +874,7 @@ static void smc_listen_work(struct work_struct *work)

if (local_contact != SMC_FIRST_CONTACT) {
if (!new_smc->conn.rmb_desc->reused) {
- if (smc_reg_rmb(link, new_smc->conn.rmb_desc)) {
+ if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true)) {
reason_code = SMC_CLC_DECL_INTERR;
goto decline_rdma_unlock;
}
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 9c74844e2008..29ae077b0ec9 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -210,6 +210,7 @@ static int smc_lgr_create(struct smc_sock *smc,
init_completion(&lnk->llc_confirm_resp);
init_completion(&lnk->llc_add);
init_completion(&lnk->llc_add_resp);
+ init_completion(&lnk->llc_confirm_rkey);

smc->conn.lgr = lgr;
rwlock_init(&lgr->conns_lock);
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index fca8624e5e71..9398e235d74b 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -105,6 +105,8 @@ struct smc_link {
struct delayed_work llc_testlink_wrk; /* testlink worker */
struct completion llc_testlink_resp; /* wait for rx of testlink */
int llc_testlink_time; /* testlink interval */
+ struct completion llc_confirm_rkey; /* wait 4 rx of cnf rkey */
+ int llc_confirm_rkey_rc; /* rc from cnf rkey msg */
};

/* For now we just allow one parallel link per link group. The SMC protocol
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 33b4d856f4c6..b118f80b9c41 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -214,6 +214,31 @@ int smc_llc_send_confirm_link(struct smc_link *link, u8 mac[],
return rc;
}

+/* send LLC confirm rkey request */
+static int smc_llc_send_confirm_rkey(struct smc_link *link,
+ struct smc_buf_desc *rmb_desc)
+{
+ struct smc_llc_msg_confirm_rkey *rkeyllc;
+ struct smc_wr_tx_pend_priv *pend;
+ struct smc_wr_buf *wr_buf;
+ int rc;
+
+ rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
+ if (rc)
+ return rc;
+ rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
+ memset(rkeyllc, 0, sizeof(*rkeyllc));
+ rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY;
+ rkeyllc->hd.length = sizeof(struct smc_llc_msg_confirm_rkey);
+ rkeyllc->rtoken[0].rmb_key =
+ htonl(rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
+ rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
+ (u64)sg_dma_address(rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
+ /* send llc message */
+ rc = smc_wr_tx_send(link, pend);
+ return rc;
+}
+
/* send ADD LINK request or response */
int smc_llc_send_add_link(struct smc_link *link, u8 mac[],
union ib_gid *gid,
@@ -413,7 +438,9 @@ static void smc_llc_rx_confirm_rkey(struct smc_link *link,
lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);

if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
- /* unused as long as we don't send this type of msg */
+ link->llc_confirm_rkey_rc = llc->hd.flags &
+ SMC_LLC_FLAG_RKEY_NEG;
+ complete(&link->llc_confirm_rkey);
} else {
rc = smc_rtoken_add(lgr,
llc->rtoken[0].rmb_vaddr,
@@ -503,7 +530,7 @@ static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
}
}

-/***************************** worker ****************************************/
+/***************************** worker, utils *********************************/

static void smc_llc_testlink_work(struct work_struct *work)
{
@@ -562,6 +589,22 @@ void smc_llc_link_flush(struct smc_link *link)
cancel_delayed_work_sync(&link->llc_testlink_wrk);
}

+/* register a new rtoken at the remote peer */
+int smc_llc_do_confirm_rkey(struct smc_link *link,
+ struct smc_buf_desc *rmb_desc)
+{
+ int rc;
+
+ reinit_completion(&link->llc_confirm_rkey);
+ smc_llc_send_confirm_rkey(link, rmb_desc);
+ /* receive CONFIRM RKEY response from server over RoCE fabric */
+ rc = wait_for_completion_interruptible_timeout(&link->llc_confirm_rkey,
+ SMC_LLC_WAIT_TIME);
+ if (rc <= 0 || link->llc_confirm_rkey_rc)
+ return -EFAULT;
+ return 0;
+}
+
/***************************** init, exit, misc ******************************/

static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
diff --git a/net/smc/smc_llc.h b/net/smc/smc_llc.h
index d6e42116485e..728823dd8ae5 100644
--- a/net/smc/smc_llc.h
+++ b/net/smc/smc_llc.h
@@ -47,6 +47,8 @@ int smc_llc_send_test_link(struct smc_link *lnk, u8 user_data[16],
void smc_llc_link_active(struct smc_link *link, int testlink_time);
void smc_llc_link_inactive(struct smc_link *link);
void smc_llc_link_flush(struct smc_link *link);
+int smc_llc_do_confirm_rkey(struct smc_link *link,
+ struct smc_buf_desc *rmb_desc);
int smc_llc_init(void) __init;

#endif /* SMC_LLC_H */
--
2.16.3