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smc: connection and link group creation

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* 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>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ursula Braun 2017-01-09 16:55:17 +01:00 committed by David S. Miller
parent a046d57da1
commit 0cfdd8f92c
7 changed files with 605 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/smc/Makefile
View File

@ -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

102
net/smc/af_smc.c
View File

@ -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)
@ -235,11 +245,31 @@ 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, 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;
@ -278,26 +308,43 @@ 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 = true;
@ -308,6 +355,9 @@ decline_rdma:
}
goto out_connected;
out_err_unlock:
mutex_unlock(&smc_create_lgr_pending);
smc_conn_free(&smc->conn);
out_err:
return rc;
}
@ -476,10 +526,12 @@ 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;
@ -527,15 +579,30 @@ 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;
@ -546,6 +613,9 @@ 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
@ -555,6 +625,8 @@ 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);
@ -570,6 +642,7 @@ enqueue:
decline_rdma:
/* RDMA setup failed, switch back to TCP */
smc_conn_free(&new_smc->conn);
new_smc->use_fallback = true;
if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
rc = smc_clc_send_decline(new_smc, reason_code, 0);
@ -1024,6 +1097,17 @@ 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);

36
net/smc/smc.h
View File

@ -14,6 +14,8 @@
#include <linux/types.h>
#include <net/sock.h>
#include "smc_ib.h"
#define SMCPROTO_SMC 0 /* SMC protocol */
#define SMC_MAX_PORTS 2 /* Max # of ports */
@ -25,9 +27,19 @@ 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 */
@ -46,6 +58,24 @@ 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)
{
@ -59,7 +89,13 @@ static inline bool using_ipsec(struct smc_sock *smc)
}
#endif
struct smc_clc_msg_local;
int smc_netinfo_by_tcpsk(struct socket *clcsock, __be32 *subnet,
u8 *prefix_len);
void smc_conn_free(struct smc_connection *conn);
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);
#endif /* __SMC_H */

38
net/smc/smc_clc.c
View File

@ -14,6 +14,7 @@
#include <net/tcp.h>
#include "smc.h"
#include "smc_core.h"
#include "smc_clc.h"
#include "smc_ib.h"
@ -89,8 +90,13 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
reason_code = -EPROTO;
goto out;
}
if (clcm->type == SMC_CLC_DECLINE)
if (clcm->type == SMC_CLC_DECLINE) {
reason_code = SMC_CLC_DECL_REPLY;
if (ntohl(((struct smc_clc_msg_decline *)buf)->peer_diagnosis)
== SMC_CLC_DECL_SYNCERR)
smc->conn.lgr->sync_err = true;
}
out:
return reason_code;
}
@ -175,12 +181,15 @@ 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));
@ -188,12 +197,18 @@ 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));
@ -214,26 +229,37 @@ 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));

2
net/smc/smc_clc.h
View File

@ -109,6 +109,6 @@ int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info,
int smc_clc_send_proposal(struct smc_sock *smc, struct smc_ib_device *smcibdev,
u8 ibport);
int smc_clc_send_confirm(struct smc_sock *smc);
int smc_clc_send_accept(struct smc_sock *smc);
int smc_clc_send_accept(struct smc_sock *smc, int srv_first_contact);
#endif

336
net/smc/smc_core.c Normal file
View File

@ -0,0 +1,336 @@
/*
* 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;
int reduced = 0;
write_lock_bh(&lgr->conns_lock);
if (conn->alert_token_local) {
reduced = 1;
__smc_lgr_unregister_conn(conn);
}
write_unlock_bh(&lgr->conns_lock);
if (reduced && !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->sync_err = false;
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(&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);
}
/* 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;
role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id);
if (rc)
return rc;
if ((role == SMC_CLNT) && srv_first_contact)
/* create new link group as well */
goto create;
/* 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->sync_err &&
(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 && !srv_first_contact &&
(local_contact == SMC_FIRST_CONTACT)) {
/* Server reuses a link group, but Client wants to start
* a new one
* send out_of_sync decline, reason synchr. error
*/
return -ENOLINK;
}
create:
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;
}

106
net/smc/smc_core.h Normal file
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@ -0,0 +1,106 @@
/*
* 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 */
bool sync_err; /* lgr no longer fits to peer */
};
/* 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 *lgr);
void smc_lgr_terminate(struct smc_link_group *lgr);
#endif