Thread (19 messages) 19 messages, 3 authors, 2023-08-30
STALE1014d REVIEWED: 1 (1M)
Revisions (3)
  1. v2 current
  2. v1 [diff vs current]
  3. v2 [diff vs current]

[RFC PATCH v2 net-next 4/6] net/smc: support max connections per lgr negotiation

From: Guangguan Wang <hidden>
Date: 2023-08-07 06:27:47
Also in: linux-s390, lkml
Subsystem: networking [general], shared memory communications (smc) sockets, the rest · Maintainers: "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, D. Wythe, Dust Li, Sidraya Jayagond, Wenjia Zhang, Linus Torvalds

Support max connections per lgr negotiation for SMCR v2.1,
which is one of smc v2.1 features.

Signed-off-by: Guangguan Wang <redacted>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
---
 net/smc/af_smc.c   |  1 +
 net/smc/smc_clc.c  | 41 +++++++++++++++++++++++++++++++++++++++--
 net/smc/smc_clc.h  |  7 +++++--
 net/smc/smc_core.c |  4 +++-
 net/smc/smc_core.h |  5 +++++
 net/smc/smc_llc.c  |  6 +++++-
 6 files changed, 58 insertions(+), 6 deletions(-)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index fd58e25beddf..b95d3fd48c28 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1214,6 +1214,7 @@ static int smc_connect_rdma(struct smc_sock *smc,
 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
+	ini->max_conns = SMC_RMBS_PER_LGR_MAX;
 
 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
 	if (reason_code)
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 4f6b69af2b80..e2b224063dcc 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -427,9 +427,17 @@ static int smc_clc_fill_fce(struct smc_clc_first_contact_ext_v2x *fce,
 	fce->fce_v20.os_type = SMC_CLC_OS_LINUX;
 	fce->fce_v20.release = ini->release_ver;
 	memcpy(fce->fce_v20.hostname, smc_hostname, sizeof(smc_hostname));
-	if (ini->is_smcd && ini->release_ver < SMC_RELEASE_1)
+	if (ini->is_smcd && ini->release_ver < SMC_RELEASE_1) {
 		ret = sizeof(struct smc_clc_first_contact_ext);
+		goto out;
+	}
+
+	if (ini->release_ver >= SMC_RELEASE_1) {
+		if (!ini->is_smcd)
+			fce->max_conns = ini->max_conns;
+	}
 
+out:
 	return ret;
 }
 
@@ -931,8 +939,10 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
 				sizeof(struct smc_clc_smcd_gid_chid);
 		}
 	}
-	if (smcr_indicated(ini->smc_type_v2))
+	if (smcr_indicated(ini->smc_type_v2)) {
 		memcpy(v2_ext->roce, ini->smcrv2.ib_gid_v2, SMC_GID_SIZE);
+		v2_ext->max_conns = SMC_CONN_PER_LGR_MAX;
+	}
 
 	pclc_base->hdr.length = htons(plen);
 	memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
@@ -1163,6 +1173,11 @@ int smc_clc_srv_v2x_features_validate(struct smc_clc_msg_proposal *pclc,
 {
 	struct smc_clc_v2_extension *pclc_v2_ext;
 
+	/* default max conn is SMC_RMBS_PER_LGR_MAX(255),
+	 * which is the default value in smc v1 and v2.0.
+	 */
+	ini->max_conns = SMC_RMBS_PER_LGR_MAX;
+
 	if ((!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) ||
 	    ini->release_ver < SMC_RELEASE_1)
 		return 0;
@@ -1171,15 +1186,30 @@ int smc_clc_srv_v2x_features_validate(struct smc_clc_msg_proposal *pclc,
 	if (!pclc_v2_ext)
 		return SMC_CLC_DECL_NOV2EXT;
 
+	if (ini->smcr_version & SMC_V2) {
+		ini->max_conns = min_t(u8, pclc_v2_ext->max_conns, SMC_CONN_PER_LGR_MAX);
+		if (ini->max_conns < SMC_CONN_PER_LGR_MIN)
+			return SMC_CLC_DECL_MAXCONNERR;
+	}
+
 	return 0;
 }
 
 int smc_clc_cli_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
 				      struct smc_init_info *ini)
 {
+	struct smc_clc_first_contact_ext_v2x *fce_v2x =
+		(struct smc_clc_first_contact_ext_v2x *)fce;
+
 	if (ini->release_ver < SMC_RELEASE_1)
 		return 0;
 
+	if (!ini->is_smcd) {
+		if (fce_v2x->max_conns < SMC_CONN_PER_LGR_MIN)
+			return SMC_CLC_DECL_MAXCONNERR;
+		ini->max_conns = fce_v2x->max_conns;
+	}
+
 	return 0;
 }
 
@@ -1190,6 +1220,8 @@ int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
 		(struct smc_clc_msg_accept_confirm_v2 *)cclc;
 	struct smc_clc_first_contact_ext *fce =
 		smc_get_clc_first_contact_ext(clc_v2, ini->is_smcd);
+	struct smc_clc_first_contact_ext_v2x *fce_v2x =
+		(struct smc_clc_first_contact_ext_v2x *)fce;
 
 	if (cclc->hdr.version == SMC_V1 ||
 	    !(cclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
@@ -1201,6 +1233,11 @@ int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
 	if (fce->release < SMC_RELEASE_1)
 		return 0;
 
+	if (!ini->is_smcd) {
+		if (fce_v2x->max_conns != ini->max_conns)
+			return SMC_CLC_DECL_MAXCONNERR;
+	}
+
 	return 0;
 }
 
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 66932bfdc6d0..54077e50c368 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -46,6 +46,7 @@
 #define SMC_CLC_DECL_NOSMCD2DEV	0x03030007  /* no SMC-Dv2 device found	      */
 #define SMC_CLC_DECL_NOUEID	0x03030008  /* peer sent no UEID	      */
 #define SMC_CLC_DECL_RELEASEERR	0x03030009  /* release version negotiate failed */
+#define SMC_CLC_DECL_MAXCONNERR	0x0303000a  /* max connections negotiate failed */
 #define SMC_CLC_DECL_MODEUNSUPP	0x03040000  /* smc modes do not match (R or D)*/
 #define SMC_CLC_DECL_RMBE_EC	0x03050000  /* peer has eyecatcher in RMBE    */
 #define SMC_CLC_DECL_OPTUNSUPP	0x03060000  /* fastopen sockopt not supported */
@@ -134,7 +135,8 @@ struct smc_clc_smcd_gid_chid {
 struct smc_clc_v2_extension {
 	struct smc_clnt_opts_area_hdr hdr;
 	u8 roce[16];		/* RoCEv2 GID */
-	u8 reserved[16];
+	u8 max_conns;
+	u8 reserved[15];
 	u8 user_eids[][SMC_MAX_EID_LEN];
 };
 
@@ -236,7 +238,8 @@ struct smc_clc_first_contact_ext {
 
 struct smc_clc_first_contact_ext_v2x {
 	struct smc_clc_first_contact_ext fce_v20;
-	u8 reserved3[4];
+	u8 max_conns; /* for SMC-R only */
+	u8 reserved3[3];
 	__be32 vendor_exp_options;
 	u8 reserved4[8];
 } __packed;		/* format defined in
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 6aa3db47a956..5de1fbaa6e28 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -895,9 +895,11 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
 			lgr->uses_gateway = ini->smcrv2.uses_gateway;
 			memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
 			       ETH_ALEN);
+			lgr->max_conns = ini->max_conns;
 		} else {
 			ibdev = ini->ib_dev;
 			ibport = ini->ib_port;
+			lgr->max_conns = SMC_RMBS_PER_LGR_MAX;
 		}
 		memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
 		       SMC_MAX_PNETID_LEN);
@@ -1890,7 +1892,7 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
 		    (ini->smcd_version == SMC_V2 ||
 		     lgr->vlan_id == ini->vlan_id) &&
 		    (role == SMC_CLNT || ini->is_smcd ||
-		    (lgr->conns_num < SMC_RMBS_PER_LGR_MAX &&
+		    (lgr->conns_num < lgr->max_conns &&
 		      !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) {
 			/* link group found */
 			ini->first_contact_local = 0;
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 1a97fef39127..f4f7299c810a 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -22,6 +22,8 @@
 #include "smc_ib.h"
 
 #define SMC_RMBS_PER_LGR_MAX	255	/* max. # of RMBs per link group */
+#define SMC_CONN_PER_LGR_MAX	255	/* max. # of connections per link group */
+#define SMC_CONN_PER_LGR_MIN	16	/* min. # of connections per link group */
 
 struct smc_lgr_list {			/* list of link group definition */
 	struct list_head	list;
@@ -331,6 +333,8 @@ struct smc_link_group {
 			__be32			saddr;
 						/* net namespace */
 			struct net		*net;
+			u8			max_conns;
+						/* max conn can be assigned to lgr */
 		};
 		struct { /* SMC-D */
 			u64			peer_gid;
@@ -375,6 +379,7 @@ struct smc_init_info {
 	u8			smc_type_v1;
 	u8			smc_type_v2;
 	u8			release_ver;
+	u8			max_conns;
 	u8			first_contact_peer;
 	u8			first_contact_local;
 	unsigned short		vlan_id;
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 90f0b60b196a..5347b62f1518 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -52,7 +52,8 @@ struct smc_llc_msg_confirm_link {	/* type 0x01 */
 	u8 link_num;
 	u8 link_uid[SMC_LGR_ID_SIZE];
 	u8 max_links;
-	u8 reserved[9];
+	u8 max_conns;
+	u8 reserved[8];
 };
 
 #define SMC_LLC_FLAG_ADD_LNK_REJ	0x40
@@ -472,6 +473,9 @@ int smc_llc_send_confirm_link(struct smc_link *link,
 	confllc->link_num = link->link_id;
 	memcpy(confllc->link_uid, link->link_uid, SMC_LGR_ID_SIZE);
 	confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS;
+	if (link->lgr->smc_version == SMC_V2 &&
+	    link->lgr->peer_smc_release >= SMC_RELEASE_1)
+		confllc->max_conns = link->lgr->max_conns;
 	/* send llc message */
 	rc = smc_wr_tx_send(link, pend);
 put_out:
-- 
2.24.3 (Apple Git-128)
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