[PATCH net-next 11/12] net/smc: create improved SMC-R link_uid

Karsten Graul
2020-05-04T12:19:17Z

The link_uid of an SMC-R link is exchanged between SMC peers and its
value can be used for debugging purposes. Create a unique link_uid
during link initialization and use it in communication with SMC-R peers.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
---
net/smc/smc_core.c | 1 +
net/smc/smc_core.h | 4 +++-
net/smc/smc_llc.c | 18 ++++++++++++++----
net/smc/smc_llc.h | 1 +
4 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index fb391bc6781e..fb5f685ff494 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -331,6 +331,7 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
lnk->smcibdev = ini->ib_dev;
lnk->ibport = ini->ib_port;
lnk->path_mtu = ini->ib_dev->pattr[ini->ib_port - 1].active_mtu;
+ smc_llc_link_set_uid(lnk);
INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
if (!ini->ib_dev->initialized) {
rc = (int)smc_ib_setup_per_ibdev(ini->ib_dev);
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 32bc45af9a1a..e2ace20db7fd 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -70,6 +70,8 @@ struct smc_rdma_wr { /* work requests per message
struct ib_rdma_wr wr_tx_rdma[SMC_MAX_RDMA_WRITES];
};

+#define SMC_LGR_ID_SIZE 4
+
struct smc_link {
struct smc_ib_device *smcibdev; /* ib-device */
u8 ibport; /* port - values 1 | 2 */
@@ -116,6 +118,7 @@ struct smc_link {
u8 peer_mac[ETH_ALEN]; /* = gid[8:10||13:15] */
u8 peer_gid[SMC_GID_SIZE]; /* gid of peer*/
u8 link_id; /* unique # within link group */
+ u8 link_uid[SMC_LGR_ID_SIZE]; /* unique lnk id */
u8 link_idx; /* index in lgr link array */
u8 link_is_asym; /* is link asymmetric? */
struct smc_link_group *lgr; /* parent link group */
@@ -178,7 +181,6 @@ struct smc_rtoken { /* address/key of remote RMB */
u32 rkey;
};

-#define SMC_LGR_ID_SIZE 4
#define SMC_BUF_MIN_SIZE 16384 /* minimum size of an RMB */
#define SMC_RMBE_SIZES 16 /* number of distinct RMBE sizes */
/* theoretically, the RFC states that largest size would be 512K,
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 482acf80e26e..afb889d60881 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -361,7 +361,6 @@ static int smc_llc_add_pending_send(struct smc_link *link,
int smc_llc_send_confirm_link(struct smc_link *link,
enum smc_llc_reqresp reqresp)
{
- struct smc_link_group *lgr = smc_get_lgr(link);
struct smc_llc_msg_confirm_link *confllc;
struct smc_wr_tx_pend_priv *pend;
struct smc_wr_buf *wr_buf;
@@ -382,7 +381,7 @@ int smc_llc_send_confirm_link(struct smc_link *link,
memcpy(confllc->sender_gid, link->gid, SMC_GID_SIZE);
hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
confllc->link_num = link->link_id;
- memcpy(confllc->link_uid, lgr->id, SMC_LGR_ID_SIZE);
+ memcpy(confllc->link_uid, link->link_uid, SMC_LGR_ID_SIZE);
confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS;
/* send llc message */
rc = smc_wr_tx_send(link, pend);
@@ -845,7 +844,8 @@ int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
if (rc)
goto out_reject;
smc_llc_save_add_link_info(lnk_new, llc);
- lnk_new->link_id = llc->link_num;
+ lnk_new->link_id = llc->link_num; /* SMC server assigns link id */
+ smc_llc_link_set_uid(lnk_new);

rc = smc_ib_ready_link(lnk_new);
if (rc)
@@ -1775,12 +1775,22 @@ int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
return rc;
}

+void smc_llc_link_set_uid(struct smc_link *link)
+{
+ __be32 link_uid;
+
+ link_uid = htonl(*((u32 *)link->lgr->id) + link->link_id);
+ memcpy(link->link_uid, &link_uid, SMC_LGR_ID_SIZE);
+}
+
/* evaluate confirm link request or response */
int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
enum smc_llc_reqresp type)
{
- if (type == SMC_LLC_REQ) /* SMC server assigns link_id */
+ if (type == SMC_LLC_REQ) { /* SMC server assigns link_id */
qentry->link->link_id = qentry->msg.confirm_link.link_num;
+ smc_llc_link_set_uid(qentry->link);
+ }
if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
return -ENOTSUPP;
return 0;
diff --git a/net/smc/smc_llc.h b/net/smc/smc_llc.h
index f5882ebf357b..1b68f229cb99 100644
--- a/net/smc/smc_llc.h
+++ b/net/smc/smc_llc.h
@@ -92,6 +92,7 @@ int smc_llc_flow_initiate(struct smc_link_group *lgr,
void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow);
int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
enum smc_llc_reqresp type);
+void smc_llc_link_set_uid(struct smc_link *link);
struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr,
struct smc_link *lnk,
int time_out, u8 exp_msg);
--
2.17.1