[PATCH V2 net-next 06/15] smc: connection and link group creation

Ursula Braun
2016-09-27T16:41:47Z

* create smc_connection for SMC-sockets
* determine suitable link group for a connection
* create a new link group if necessary

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
---
net/smc/Makefile | 2 +-
net/smc/af_smc.c | 103 +++++++++++++--
net/smc/smc.h | 35 ++++++
net/smc/smc_clc.c | 31 ++++-
net/smc/smc_clc.h | 2 +-
net/smc/smc_core.c | 359 +++++++++++++++++++++++++++++++++++++++++++++++++++++
net/smc/smc_core.h | 105 ++++++++++++++++
7 files changed, 621 insertions(+), 16 deletions(-)
create mode 100644 net/smc/smc_core.c
create mode 100644 net/smc/smc_core.h

diff --git a/net/smc/Makefile b/net/smc/Makefile
index c0ad588..cb8bcd9 100644
--- a/net/smc/Makefile
+++ b/net/smc/Makefile
@@ -1,2 +1,2 @@
obj-$(CONFIG_SMC) += smc.o
-smc-y := af_smc.o smc_pnet.o smc_ib.o smc_clc.o
+smc-y := af_smc.o smc_pnet.o smc_ib.o smc_clc.o smc_core.o
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index f8c60db..d1e9098 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -31,9 +31,19 @@

#include "smc.h"
#include "smc_clc.h"
+#include "smc_core.h"
#include "smc_ib.h"
#include "smc_pnet.h"

+static DEFINE_MUTEX(smc_create_lgr_pending); /* serialize link group
+ * creation
+ */
+
+struct smc_lgr_list smc_lgr_list = { /* established link groups */
+ .lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
+ .list = LIST_HEAD_INIT(smc_lgr_list.list),
+};
+
static void smc_tcp_listen_work(struct work_struct *);

static void smc_set_keepalive(struct sock *sk, int val)
@@ -107,6 +117,7 @@ static struct sock *smc_sock_alloc(struct net *net, struct socket *sock)
smc = smc_sk(sk);
smc->clcsock = NULL;
smc->use_fallback = 0;
+ memset(&smc->conn, 0, sizeof(smc->conn));
smc->addr = NULL;
smc->listen_smc = NULL;
INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
@@ -241,11 +252,31 @@ out:
return rc;
}

+static void smc_conn_save_peer_info(struct smc_sock *smc,
+ struct smc_clc_msg_accept_confirm *clc)
+{
+ smc->conn.peer_conn_idx = clc->conn_idx;
+}
+
+static void smc_link_save_peer_info(struct smc_link *link,
+ struct smc_clc_msg_accept_confirm *clc)
+{
+ link->peer_qpn = ntoh24(clc->qpn);
+ memcpy(link->peer_gid, clc->lcl.gid.raw, SMC_GID_SIZE);
+ memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
+ link->peer_psn = ntoh24(clc->psn);
+ link->peer_mtu = clc->qp_mtu;
+}
+
/* setup for RDMA connection of client */
static int smc_connect_rdma(struct smc_sock *smc)
{
+ struct sockaddr_in *inaddr = (struct sockaddr_in *)smc->addr;
struct smc_clc_msg_accept_confirm aclc;
+ int local_contact = SMC_FIRST_CONTACT;
struct smc_ib_device *smcibdev;
+ struct smc_link *link;
+ u8 srv_first_contact;
int reason_code = 0;
int rc = 0;
u8 ibport;
@@ -288,26 +319,43 @@ static int smc_connect_rdma(struct smc_sock *smc)
if (reason_code > 0)
goto decline_rdma;

- /* tbd in follow-on patch: more steps to setup RDMA communcication,
- * create connection, link group, link
- */
+ srv_first_contact = aclc.hdr.flag;
+ mutex_lock(&smc_create_lgr_pending);
+ local_contact = smc_conn_create(smc, inaddr->sin_addr.s_addr, smcibdev,
+ ibport, &aclc.lcl, srv_first_contact);
+ if (local_contact < 0) {
+ rc = local_contact;
+ if (rc == -ENOMEM)
+ reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
+ else if (rc == -ENOLINK)
+ reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
+ goto decline_rdma_unlock;
+ }
+ link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];

+ smc_conn_save_peer_info(smc, &aclc);
+ if (local_contact == SMC_FIRST_CONTACT)
+ smc_link_save_peer_info(link, &aclc);
/* tbd in follow-on patch: more steps to setup RDMA communcication,
* create rmbs, map rmbs, rtoken_handling, modify_qp
*/

rc = smc_clc_send_confirm(smc);
if (rc)
- goto out_err;
+ goto out_err_unlock;

/* tbd in follow-on patch: llc_confirm */

+ mutex_unlock(&smc_create_lgr_pending);
out_connected:
smc_copy_sock_settings_to_clc(smc);
smc->sk.sk_state = SMC_ACTIVE;

- return rc;
+ return rc ? rc : local_contact;

+decline_rdma_unlock:
+ mutex_unlock(&smc_create_lgr_pending);
+ smc_conn_free(&smc->conn);
decline_rdma:
/* RDMA setup failed, switch back to TCP */
smc->use_fallback = 1;
@@ -318,6 +366,9 @@ decline_rdma:
}
goto out_connected;

+out_err_unlock:
+ mutex_unlock(&smc_create_lgr_pending);
+ smc_conn_free(&smc->conn);
out_err:
return rc;
}
@@ -486,10 +537,12 @@ static void smc_listen_work(struct work_struct *work)
struct socket *newclcsock = new_smc->clcsock;
struct smc_sock *lsmc = new_smc->listen_smc;
struct smc_clc_msg_accept_confirm cclc;
+ int local_contact = SMC_REUSE_CONTACT;
struct sock *newsmcsk = &new_smc->sk;
struct smc_clc_msg_proposal pclc;
struct smc_ib_device *smcibdev;
struct sockaddr_in peeraddr;
+ struct smc_link *link;
int reason_code = 0;
int rc = 0, len;
__be32 subnet;
@@ -537,15 +590,30 @@ static void smc_listen_work(struct work_struct *work)
/* get address of the peer connected to the internal TCP socket */
kernel_getpeername(newclcsock, (struct sockaddr *)&peeraddr, &len);

- /* tbd in follow-on patch: more steps to setup RDMA communcication,
- * create connection, link_group, link
- */
+ /* allocate connection / link group */
+ mutex_lock(&smc_create_lgr_pending);
+ local_contact = smc_conn_create(new_smc, peeraddr.sin_addr.s_addr,
+ smcibdev, ibport, &pclc.lcl, 0);
+ if (local_contact == SMC_REUSE_CONTACT)
+ /* lock no longer needed, free it due to following
+ * smc_clc_wait_msg() call
+ */
+ mutex_unlock(&smc_create_lgr_pending);
+ if (local_contact < 0) {
+ rc = local_contact;
+ if (rc == -ENOMEM)
+ reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
+ else if (rc == -ENOLINK)
+ reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
+ goto decline_rdma;
+ }
+ link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];

/* tbd in follow-on patch: more steps to setup RDMA communcication,
* create rmbs, map rmbs
*/

- rc = smc_clc_send_accept(new_smc);
+ rc = smc_clc_send_accept(new_smc, local_contact);
if (rc)
goto out_err;

@@ -556,6 +624,9 @@ static void smc_listen_work(struct work_struct *work)
goto out_err;
if (reason_code > 0)
goto decline_rdma;
+ smc_conn_save_peer_info(new_smc, &cclc);
+ if (local_contact == SMC_FIRST_CONTACT)
+ smc_link_save_peer_info(link, &cclc);

/* tbd in follow-on patch: more steps to setup RDMA communcication,
* rtoken_handling, modify_qp
@@ -565,6 +636,8 @@ out_connected:
sk_refcnt_debug_inc(newsmcsk);
newsmcsk->sk_state = SMC_ACTIVE;
enqueue:
+ if (local_contact == SMC_FIRST_CONTACT)
+ mutex_unlock(&smc_create_lgr_pending);
lock_sock(&lsmc->sk);
if (lsmc->sk.sk_state == SMC_LISTEN) {
smc_accept_enqueue(&lsmc->sk, newsmcsk);
@@ -580,6 +653,7 @@ enqueue:

decline_rdma:
/* RDMA setup failed, switch back to TCP */
+ smc_conn_free(&new_smc->conn);
new_smc->use_fallback = 1;
if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
rc = smc_clc_send_decline(new_smc, reason_code, 0);
@@ -1034,6 +1108,17 @@ out_pnet:

static void __exit smc_exit(void)
{
+ struct smc_link_group *lgr, *lg;
+ LIST_HEAD(lgr_freeing_list);
+
+ spin_lock_bh(&smc_lgr_list.lock);
+ if (!list_empty(&smc_lgr_list.list))
+ list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
+ spin_unlock_bh(&smc_lgr_list.lock);
+ list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
+ list_del_init(&lgr->list);
+ smc_lgr_free(lgr); /* free link group */
+ }
smc_ib_unregister_client();
sock_unregister(PF_SMC);
proto_unregister(&smc_proto);
diff --git a/net/smc/smc.h b/net/smc/smc.h
index 707e4f8..e7ebc26 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -14,6 +14,8 @@
#include <linux/types.h>
#include <net/sock.h>

+#include "smc_ib.h"
+
#define SMCPROTO_SMC 0 /* SMC protocol */

enum smc_state { /* possible states of an SMC socket */
@@ -23,9 +25,19 @@ enum smc_state { /* possible states of an SMC socket */
SMC_LISTEN = 10,
};

+struct smc_link_group;
+
+struct smc_connection {
+ struct rb_node alert_node;
+ struct smc_link_group *lgr; /* link group of connection */
+ u32 alert_token_local; /* unique conn. id */
+ u8 peer_conn_idx; /* from tcp handshake */
+};
+
struct smc_sock { /* smc sock container */
struct sock sk;
struct socket *clcsock; /* internal tcp socket */
+ struct smc_connection conn; /* smc connection */
struct sockaddr *addr; /* inet connect address */
struct smc_sock *listen_smc; /* listen parent */
struct work_struct tcp_listen_work;/* handle tcp socket accepts */
@@ -45,6 +57,24 @@ static inline struct smc_sock *smc_sk(const struct sock *sk)

extern u8 local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */

+/* convert an u32 value into network byte order, store it into a 3 byte field */
+static inline void hton24(u8 *net, u32 host)
+{
+ __be32 t;
+
+ t = cpu_to_be32(host);
+ memcpy(net, ((u8 *)&t) + 1, 3);
+}
+
+/* convert a received 3 byte field into host byte order*/
+static inline u32 ntoh24(u8 *net)
+{
+ __be32 t = 0;
+
+ memcpy(((u8 *)&t) + 1, net, 3);
+ return be32_to_cpu(t);
+}
+
#ifdef CONFIG_XFRM
static inline bool using_ipsec(struct smc_sock *smc)
{
@@ -58,6 +88,11 @@ static inline bool using_ipsec(struct smc_sock *smc)
}
#endif

+struct smc_clc_msg_local;
+
int smc_netinfo_by_tcpsk(struct socket *, __be32 *, u8 *);
+void smc_conn_free(struct smc_connection *);
+int smc_conn_create(struct smc_sock *, __be32, struct smc_ib_device *, u8,
+ struct smc_clc_msg_local *, int);

#endif /* _SMC_H */
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index cbc02a8..298fb1e 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -13,6 +13,7 @@
#include <net/tcp.h>

#include "smc.h"
+#include "smc_core.h"
#include "smc_clc.h"
#include "smc_ib.h"

@@ -174,12 +175,15 @@ int smc_clc_send_proposal(struct smc_sock *smc,
/* send CLC CONFIRM message across internal TCP socket */
int smc_clc_send_confirm(struct smc_sock *smc)
{
+ struct smc_connection *conn = &smc->conn;
struct smc_clc_msg_accept_confirm cclc;
+ struct smc_link *link;
int reason_code = 0;
struct msghdr msg;
struct kvec vec;
int len;

+ link = &conn->lgr->lnk[SMC_SINGLE_LINK];
/* send SMC Confirm CLC msg */
memset(&cclc, 0, sizeof(cclc));
memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
@@ -187,12 +191,18 @@ int smc_clc_send_confirm(struct smc_sock *smc)
cclc.hdr.length = htons(sizeof(cclc));
cclc.hdr.version = SMC_CLC_V1; /* SMC version */
memcpy(cclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
-
- /* tbd in follow-on patch: fill in link-related values */
+ memcpy(&cclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
+ SMC_GID_SIZE);
+ memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
+ sizeof(link->smcibdev->mac));

/* tbd in follow-on patch: fill in rmb-related values */

+ hton24(cclc.qpn, link->roce_qp->qp_num);
cclc.conn_idx = 1; /* for now: 1 RMB = 1 RMBE */
+ cclc.rmbe_alert_token = htonl(conn->alert_token_local);
+ cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
+ hton24(cclc.psn, link->psn_initial);

memcpy(cclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));

@@ -213,26 +223,37 @@ int smc_clc_send_confirm(struct smc_sock *smc)
}

/* send CLC ACCEPT message across internal TCP socket */
-int smc_clc_send_accept(struct smc_sock *new_smc)
+int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
{
+ struct smc_connection *conn = &new_smc->conn;
struct smc_clc_msg_accept_confirm aclc;
+ struct smc_link *link;
struct msghdr msg;
struct kvec vec;
int rc = 0;
int len;

+ link = &conn->lgr->lnk[SMC_SINGLE_LINK];
memset(&aclc, 0, sizeof(aclc));
memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
aclc.hdr.type = SMC_CLC_ACCEPT;
aclc.hdr.length = htons(sizeof(aclc));
aclc.hdr.version = SMC_CLC_V1; /* SMC version */
+ if (srv_first_contact)
+ aclc.hdr.flag = 1;
memcpy(aclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
-
- /* tbd in follow-on patch: fill in link-related values */
+ memcpy(&aclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
+ SMC_GID_SIZE);
+ memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1],
+ sizeof(link->smcibdev->mac[link->ibport - 1]));

/* tbd in follow-on patch: fill in rmb-related values */

+ hton24(aclc.qpn, link->roce_qp->qp_num);
aclc.conn_idx = 1; /* as long as 1 RMB = 1 RMBE */
+ aclc.rmbe_alert_token = htonl(conn->alert_token_local);
+ aclc.qp_mtu = link->path_mtu;
+ hton24(aclc.psn, link->psn_initial);
memcpy(aclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));

memset(&msg, 0, sizeof(msg));
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 565c62a..ba42f7b 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -106,6 +106,6 @@ int smc_clc_wait_msg(struct smc_sock *, void *, int, u8);
int smc_clc_send_decline(struct smc_sock *, u32, u8);
int smc_clc_send_proposal(struct smc_sock *, struct smc_ib_device *, u8);
int smc_clc_send_confirm(struct smc_sock *);
-int smc_clc_send_accept(struct smc_sock *);
+int smc_clc_send_accept(struct smc_sock *, int);

#endif
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
new file mode 100644
index 0000000..e81c718
--- /dev/null
+++ b/net/smc/smc_core.c
@@ -0,0 +1,359 @@
+/*
+ * Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ * Basic Transport Functions exploiting Infiniband API
+ *
+ * Copyright IBM Corp. 2016
+ *
+ * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
+ */
+
+#include <linux/socket.h>
+#include <linux/if_vlan.h>
+#include <linux/random.h>
+#include <linux/workqueue.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <rdma/ib_verbs.h>
+
+#include "smc.h"
+#include "smc_clc.h"
+#include "smc_core.h"
+#include "smc_ib.h"
+
+#define SMC_LGR_FREE_DELAY (600 * HZ)
+
+/* Register connection's alert token in our lookup structure.
+ * To use rbtrees we have to implement our own insert core.
+ * Requires @conns_lock
+ * @smc connection to register
+ * Returns 0 on success, != otherwise.
+ */
+static void smc_lgr_add_alert_token(struct smc_connection *conn)
+{
+ struct rb_node **link, *parent = NULL;
+ u32 token = conn->alert_token_local;
+
+ link = &conn->lgr->conns_all.rb_node;
+ while (*link) {
+ struct smc_connection *cur = rb_entry(*link,
+ struct smc_connection, alert_node);
+
+ parent = *link;
+ if (cur->alert_token_local > token)
+ link = &parent->rb_left;
+ else
+ link = &parent->rb_right;
+ }
+ /* Put the new node there */
+ rb_link_node(&conn->alert_node, parent, link);
+ rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
+}
+
+/* Register connection in link group by assigning an alert token
+ * registered in a search tree.
+ * Requires @conns_lock
+ * Note that '0' is a reserved value and not assigned.
+ */
+static void smc_lgr_register_conn(struct smc_connection *conn)
+{
+ struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
+ static atomic_t nexttoken = ATOMIC_INIT(0);
+
+ /* find a new alert_token_local value not yet used by some connection
+ * in this link group
+ */
+ sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
+ while (!conn->alert_token_local) {
+ conn->alert_token_local = atomic_inc_return(&nexttoken);
+ if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
+ conn->alert_token_local = 0;
+ }
+ smc_lgr_add_alert_token(conn);
+ conn->lgr->conns_num++;
+}
+
+/* Unregister connection and reset the alert token of the given connection<
+ */
+static void __smc_lgr_unregister_conn(struct smc_connection *conn)
+{
+ struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
+ struct smc_link_group *lgr = conn->lgr;
+
+ rb_erase(&conn->alert_node, &lgr->conns_all);
+ lgr->conns_num--;
+ conn->alert_token_local = 0;
+ conn->lgr = NULL;
+ sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
+}
+
+/* Unregister connection and trigger lgr freeing if applicable
+ */
+static void smc_lgr_unregister_conn(struct smc_connection *conn)
+{
+ struct smc_link_group *lgr = conn->lgr;
+
+ if (!conn->alert_token_local)
+ return;
+
+ write_lock_bh(&lgr->conns_lock);
+ __smc_lgr_unregister_conn(conn);
+ write_unlock_bh(&lgr->conns_lock);
+ if (!lgr->conns_num)
+ schedule_delayed_work(&lgr->free_work, SMC_LGR_FREE_DELAY);
+}
+
+static void smc_lgr_free_work(struct work_struct *work)
+{
+ struct smc_link_group *lgr = container_of(to_delayed_work(work),
+ struct smc_link_group,
+ free_work);
+ bool conns;
+
+ spin_lock_bh(&smc_lgr_list.lock);
+ read_lock_bh(&lgr->conns_lock);
+ conns = RB_EMPTY_ROOT(&lgr->conns_all);
+ read_unlock_bh(&lgr->conns_lock);
+ if (!conns) { /* number of lgr connections is no longer zero */
+ spin_unlock_bh(&smc_lgr_list.lock);
+ return;
+ }
+ list_del_init(&lgr->list); /* remove from smc_lgr_list */
+ spin_unlock_bh(&smc_lgr_list.lock);
+ smc_lgr_free(lgr);
+}
+
+/* create a new SMC link group */
+static int smc_lgr_create(struct smc_sock *smc, __be32 peer_in_addr,
+ struct smc_ib_device *smcibdev, u8 ibport,
+ char *peer_systemid, unsigned short vlan_id)
+{
+ struct smc_link_group *lgr;
+ struct smc_link *lnk;
+ u8 rndvec[3];
+ int rc = 0;
+
+ lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
+ if (!lgr) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
+ lgr->daddr = peer_in_addr;
+ memcpy(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN);
+ lgr->vlan_id = vlan_id;
+ INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
+ lgr->conns_all = RB_ROOT;
+
+ lnk = &lgr->lnk[SMC_SINGLE_LINK];
+ /* initialize link */
+ lnk->smcibdev = smcibdev;
+ lnk->ibport = ibport;
+ lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu;
+ get_random_bytes(rndvec, sizeof(rndvec));
+ lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) + (rndvec[2] << 16);
+
+ smc->conn.lgr = lgr;
+ rwlock_init(&lgr->conns_lock);
+ spin_lock_bh(&smc_lgr_list.lock);
+ list_add_tail(&lgr->list, &smc_lgr_list.list);
+ spin_unlock_bh(&smc_lgr_list.lock);
+out:
+ return rc;
+}
+
+/* remove a finished connection from its link group */
+void smc_conn_free(struct smc_connection *conn)
+{
+ struct smc_link_group *lgr = conn->lgr;
+
+ if (!lgr)
+ return;
+ smc_lgr_unregister_conn(conn);
+}
+
+static void smc_link_clear(struct smc_link *lnk)
+{
+ lnk->peer_qpn = 0;
+}
+
+/* remove a link group */
+void smc_lgr_free(struct smc_link_group *lgr)
+{
+ smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
+ kfree(lgr);
+}
+
+/* terminate linkgroup abnormally */
+void smc_lgr_terminate(struct smc_link_group *lgr)
+{
+ struct smc_connection *conn;
+ struct rb_node *node;
+
+ spin_lock_bh(&smc_lgr_list.lock);
+ if (list_empty(&lgr->list)) {
+ /* termination already triggered */
+ spin_unlock_bh(&smc_lgr_list.lock);
+ return;
+ }
+ /* do not use this link group for new connections */
+ list_del_init(&lgr->list);
+ spin_unlock_bh(&smc_lgr_list.lock);
+
+ write_lock_bh(&lgr->conns_lock);
+ node = rb_first(&lgr->conns_all);
+ while (node) {
+ conn = rb_entry(node, struct smc_connection, alert_node);
+ __smc_lgr_unregister_conn(conn);
+ node = rb_first(&lgr->conns_all);
+ }
+ write_unlock_bh(&lgr->conns_lock);
+ schedule_delayed_work(&lgr->free_work, SMC_LGR_FREE_DELAY);
+}
+
+/* Client checks if creation / reuse of a link group happens
+ * synchronously with Server.
+ * Returns true iff client and server disagree.
+ */
+static bool smc_lgr_clt_srv_disagree(struct smc_connection *conn, int new_lgr,
+ int srv_first_contact)
+{
+ if (!srv_first_contact && new_lgr) {
+ /* Server reuses a link group, but Client wants to start
+ * a new one
+ */
+ return true;
+ }
+ if (srv_first_contact && !new_lgr) {
+ /* Server starts a new link group, but Client wants to reuse
+ * an existing link group
+ */
+ spin_lock_bh(&smc_lgr_list.lock);
+ list_del_init(&conn->lgr->list);
+ spin_unlock_bh(&smc_lgr_list.lock);
+ smc_lgr_unregister_conn(conn); /* takes conns_lock */
+ /* tbd: terminate existing connections */
+ return true;
+ }
+ return false;
+}
+
+/* Determine vlan of internal TCP socket.
+ * @vlan_id: address to store the determined vlan id into
+ */
+static int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id)
+{
+ struct dst_entry *dst = sk_dst_get(clcsock->sk);
+ int rc = 0;
+
+ *vlan_id = 0;
+ if (!dst) {
+ rc = -ENOTCONN;
+ goto out;
+ }
+ if (!dst->dev) {
+ rc = -ENODEV;
+ goto out_rel;
+ }
+
+ if (is_vlan_dev(dst->dev))
+ *vlan_id = vlan_dev_vlan_id(dst->dev);
+
+out_rel:
+ dst_release(dst);
+out:
+ return rc;
+}
+
+/* determine the link gid matching the vlan id of the link group */
+static int smc_link_determine_gid(struct smc_link_group *lgr)
+{
+ struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
+ struct ib_gid_attr gattr;
+ union ib_gid gid;
+ int i;
+
+ if (!lgr->vlan_id) {
+ lnk->gid = lnk->smcibdev->gid[lnk->ibport - 1];
+ return 0;
+ }
+
+ for (i = 0; i < lnk->smcibdev->pattr[lnk->ibport - 1].gid_tbl_len;
+ i++) {
+ if (ib_query_gid(lnk->smcibdev->ibdev, lnk->ibport, i, &gid,
+ &gattr))
+ continue;
+ if (gattr.ndev &&
+ (vlan_dev_vlan_id(gattr.ndev) == lgr->vlan_id)) {
+ lnk->gid = gid;
+ return 0;
+ }
+ }
+ return -ENODEV;
+}
+
+/* create a new SMC connection (and a new link group if necessary) */
+int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr,
+ struct smc_ib_device *smcibdev, u8 ibport,
+ struct smc_clc_msg_local *lcl, int srv_first_contact)
+{
+ struct smc_connection *conn = &smc->conn;
+ struct smc_link_group *lgr;
+ unsigned short vlan_id;
+ enum smc_lgr_role role;
+ int local_contact = SMC_FIRST_CONTACT;
+ int rc = 0;
+
+ /* wait when another process is already creating a connection
+ * till either this process can reuse an existing link group or
+ * till this process has finished creating a new link group
+ */
+ role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
+ rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id);
+ if (rc)
+ return rc;
+
+ /* determine if an existing link group can be reused */
+ spin_lock_bh(&smc_lgr_list.lock);
+ list_for_each_entry(lgr, &smc_lgr_list.list, list) {
+ write_lock_bh(&lgr->conns_lock);
+ if (!memcmp(lgr->peer_systemid, lcl->id_for_peer,
+ SMC_SYSTEMID_LEN) &&
+ !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid,
+ SMC_GID_SIZE) &&
+ !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac,
+ sizeof(lcl->mac)) &&
+ (lgr->role == role) &&
+ (lgr->vlan_id == vlan_id)) {
+ /* link group found */
+ local_contact = SMC_REUSE_CONTACT;
+ conn->lgr = lgr;
+ smc_lgr_register_conn(conn); /* add smc conn to lgr */
+ write_unlock_bh(&lgr->conns_lock);
+ break;
+ }
+ write_unlock_bh(&lgr->conns_lock);
+ }
+ spin_unlock_bh(&smc_lgr_list.lock);
+
+ if (role == SMC_CLNT) {
+ if (smc_lgr_clt_srv_disagree(conn, local_contact,
+ srv_first_contact)) {
+ /* send out_of_sync decline, reason synchr. error */
+ smc->sk.sk_err = ENOLINK;
+ return -ENOLINK;
+ }
+ }
+
+ if (local_contact == SMC_FIRST_CONTACT) {
+ rc = smc_lgr_create(smc, peer_in_addr, smcibdev, ibport,
+ lcl->id_for_peer, vlan_id);
+ if (rc)
+ goto out;
+ smc_lgr_register_conn(conn); /* add smc conn to lgr */
+ rc = smc_link_determine_gid(conn->lgr);
+ }
+
+out:
+ return rc ? rc : local_contact;
+}
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
new file mode 100644
index 0000000..c43c6f5
--- /dev/null
+++ b/net/smc/smc_core.h
@@ -0,0 +1,105 @@
+/*
+ * Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ * Definitions for SMC Connections, Link Groups and Links
+ *
+ * Copyright IBM Corp. 2016
+ *
+ * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
+ */
+
+#ifndef _SMC_CORE_H
+#define _SMC_CORE_H
+
+#include <rdma/ib_verbs.h>
+
+#include "smc.h"
+#include "smc_ib.h"
+
+struct smc_lgr_list { /* list of link group definition */
+ struct list_head list;
+ spinlock_t lock; /* protects list of link groups */
+};
+
+extern struct smc_lgr_list smc_lgr_list; /* list of link groups */
+
+enum smc_lgr_role { /* possible roles of a link group */
+ SMC_CLNT, /* client */
+ SMC_SERV /* server */
+};
+
+struct smc_link {
+ struct smc_ib_device *smcibdev; /* ib-device */
+ u8 ibport; /* port - values 1 | 2 */
+ struct ib_qp *roce_qp; /* IB queue pair */
+ struct ib_qp_attr qp_attr; /* IB queue pair attributes */
+ union ib_gid gid; /* gid matching used vlan id */
+ u32 peer_qpn; /* QP number of peer */
+ enum ib_mtu path_mtu; /* used mtu */
+ enum ib_mtu peer_mtu; /* mtu size of peer */
+ u32 psn_initial; /* QP tx initial packet seqno */
+ u32 peer_psn; /* QP rx initial packet seqno */
+ u8 peer_mac[ETH_ALEN]; /* = gid[8:10||13:15] */
+ u8 peer_gid[sizeof(union ib_gid)]; /* gid of peer*/
+};
+
+/* For now we just allow one parallel link per link group. The SMC protocol
+ * allows more (up to 8).
+ */
+#define SMC_LINKS_PER_LGR_MAX 1
+#define SMC_SINGLE_LINK 0
+
+#define SMC_FIRST_CONTACT 1 /* first contact to a peer */
+#define SMC_REUSE_CONTACT 0 /* follow-on contact to a peer*/
+
+struct smc_link_group {
+ struct list_head list;
+ enum smc_lgr_role role; /* client or server */
+ __be32 daddr; /* destination ip address */
+ struct smc_link lnk[SMC_LINKS_PER_LGR_MAX]; /* smc link */
+ char peer_systemid[SMC_SYSTEMID_LEN];
+ /* unique system_id of peer */
+ struct rb_root conns_all; /* connection tree */
+ rwlock_t conns_lock; /* protects conns_all */
+ unsigned int conns_num; /* current # of connections */
+ unsigned short vlan_id; /* vlan id of link group */
+ struct delayed_work free_work; /* delayed freeing of an lgr */
+};
+
+/* Find the connection associated with the given alert token in the link group.
+ * To use rbtrees we have to implement our own search core.
+ * Requires @conns_lock
+ * @token alert token to search for
+ * @lgr link group to search in
+ * Returns connection associated with token if found, NULL otherwise.
+ */
+static inline struct smc_connection *smc_lgr_find_conn(
+ u32 token, struct smc_link_group *lgr)
+{
+ struct smc_connection *res = NULL;
+ struct rb_node *node;
+
+ node = lgr->conns_all.rb_node;
+ while (node) {
+ struct smc_connection *cur = rb_entry(node,
+ struct smc_connection, alert_node);
+
+ if (cur->alert_token_local > token) {
+ node = node->rb_left;
+ } else {
+ if (cur->alert_token_local < token) {
+ node = node->rb_right;
+ } else {
+ res = cur;
+ break;
+ }
+ }
+ }
+
+ return res;
+}
+
+void smc_lgr_free(struct smc_link_group *);
+void smc_lgr_terminate(struct smc_link_group *);
+
+#endif
--
2.8.4