net/smc: asymmetric link tagging

New connections must not be assigned to asymmetric links. Add asymmetric
link tagging using new link variable link_is_asym. The new helpers
smcr_lgr_set_type() and smcr_lgr_set_type_asym() are called to set the
state of the link group, and tag all links accordingly.
smcr_lgr_conn_assign_link() respects the link tagging and will not
assign new connections to links tagged as asymmetric link.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 9c19b9a..be15b30 100644 (file)
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -132,7 +132,7 @@ static int smcr_lgr_conn_assign_link(struct smc_connection *conn, bool first)
        for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
                struct smc_link *lnk = &conn->lgr->lnk[i];
 
-               if (lnk->state != expected)
+               if (lnk->state != expected || lnk->link_is_asym)
                        continue;
                if (conn->lgr->role == SMC_CLNT) {
                        conn->lnk = lnk; /* temporary, SMC server assigns link*/
@@ -143,7 +143,8 @@ static int smcr_lgr_conn_assign_link(struct smc_connection *conn, bool first)
                                struct smc_link *lnk2;
 
                                lnk2 = &conn->lgr->lnk[j];
-                               if (lnk2->state == expected) {
+                               if (lnk2->state == expected &&
+                                   !lnk2->link_is_asym) {
                                        conn->lnk = lnk2;
                                        break;
                                }
@@ -1030,6 +1031,25 @@ void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
        }
 }
 
+/* set new lgr type and clear all asymmetric link tagging */
+void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
+{
+       int i;
+
+       for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
+               if (smc_link_usable(&lgr->lnk[i]))
+                       lgr->lnk[i].link_is_asym = false;
+       lgr->type = new_type;
+}
+
+/* set new lgr type and tag a link as asymmetric */
+void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
+                           enum smc_lgr_type new_type, int asym_lnk_idx)
+{
+       smcr_lgr_set_type(lgr, new_type);
+       lgr->lnk[asym_lnk_idx].link_is_asym = true;
+}
+
 /* abort connection, abort_work scheduled from tasklet context */
 static void smc_conn_abort_work(struct work_struct *work)
 {
@@ -1123,7 +1143,7 @@ static void smcr_link_down(struct smc_link *lnk)
                smcr_link_clear(lnk);
                return;
        }
-       lgr->type = SMC_LGR_SINGLE;
+       smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
        del_link_id = lnk->link_id;
 
        if (lgr->role == SMC_SERV) {

diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 86eebba..6ed7ab6 100644 (file)
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -117,6 +117,7 @@ struct smc_link {
        u8                      peer_gid[SMC_GID_SIZE]; /* gid of peer*/
        u8                      link_id;        /* unique # within link group */
        u8                      link_idx;       /* index in lgr link array */
+       u8                      link_is_asym;   /* is link asymmetric? */
        struct smc_link_group   *lgr;           /* parent link group */
        struct work_struct      link_down_wrk;  /* wrk to bring link down */
 
@@ -380,6 +381,9 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
 void smcr_link_clear(struct smc_link *lnk);
 int smcr_buf_map_lgr(struct smc_link *lnk);
 int smcr_buf_reg_lgr(struct smc_link *lnk);
+void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type);
+void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
+                           enum smc_lgr_type new_type, int asym_lnk_idx);
 int smcr_link_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc);
 struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
                                  struct smc_link *from_lnk, bool is_dev_err);

diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 0ea7ad6..f65b2aa 100644 (file)
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -796,7 +796,11 @@ static int smc_llc_cli_conf_link(struct smc_link *link,
                return -ENOLINK;
        }
        smc_llc_link_active(link_new);
-       lgr->type = lgr_new_t;
+       if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
+           lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
+               smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
+       else
+               smcr_lgr_set_type(lgr, lgr_new_t);
        return 0;
 }
 
@@ -1038,7 +1042,11 @@ static int smc_llc_srv_conf_link(struct smc_link *link,
                return -ENOLINK;
        }
        smc_llc_link_active(link_new);
-       lgr->type = lgr_new_t;
+       if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
+           lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
+               smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
+       else
+               smcr_lgr_set_type(lgr, lgr_new_t);
        smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
        return 0;
 }
@@ -1223,9 +1231,9 @@ static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
        if (lnk_del == lnk_asym) {
                /* expected deletion of asym link, don't change lgr state */
        } else if (active_links == 1) {
-               lgr->type = SMC_LGR_SINGLE;
+               smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
        } else if (!active_links) {
-               lgr->type = SMC_LGR_NONE;
+               smcr_lgr_set_type(lgr, SMC_LGR_NONE);
                smc_lgr_terminate_sched(lgr);
        }
 out_unlock:
@@ -1314,9 +1322,9 @@ static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
 
        active_links = smc_llc_active_link_count(lgr);
        if (active_links == 1) {
-               lgr->type = SMC_LGR_SINGLE;
+               smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
        } else if (!active_links) {
-               lgr->type = SMC_LGR_NONE;
+               smcr_lgr_set_type(lgr, SMC_LGR_NONE);
                smc_lgr_terminate_sched(lgr);
        }