[PATCH net-next 04/18] net/smc: support SMCv2.x supplemental features negotiation

[Wen Gu <guwen@xxxxxxxxxxxxxxxxx>]

This patch adds SMCv2.1 supplemental features negotiation. Supported
SMCv2.1 supplemental features are represented by feature_mask in FCE
header of CLC messages.

 Server                                  Client
        Proposal(features(c-mask bits))
      <-----------------------------------
         Accept(features(s-mask bits))
      ----------------------------------->
        Confirm(features(s&c-mask bits))
      <-----------------------------------

Signed-off-by: Wen Gu <guwen@xxxxxxxxxxxxxxxxx>
---
 net/smc/smc_clc.c  | 7 +++++++
 net/smc/smc_clc.h  | 6 ++++--
 net/smc/smc_core.h | 1 +
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 8deb46c..125b0d2 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -426,6 +426,7 @@ static int smc_clc_fill_fce(struct smc_clc_first_contact_ext_v2x *fce,
 	memset(fce, 0, sizeof(*fce));
 	fce->fce_v2_base.os_type = SMC_CLC_OS_LINUX;
 	fce->fce_v2_base.release = ini->release_nr;
+	fce->fce_v2_base.feature_mask = htons(ini->feature_mask);
 	memcpy(fce->fce_v2_base.hostname, smc_hostname, sizeof(smc_hostname));
 	if (ini->is_smcd && ini->release_nr < SMC_RELEASE_1) {
 		ret = sizeof(struct smc_clc_first_contact_ext);
@@ -906,6 +907,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
 		pclc_smcd->v2_ext_offset = htons(v2_ext_offset);
 		plen += sizeof(*v2_ext);
 
+		v2_ext->feature_mask = htons(ini->feature_mask);
 		read_lock(&smc_clc_eid_table.lock);
 		v2_ext->hdr.eid_cnt = smc_clc_eid_table.ueid_cnt;
 		plen += smc_clc_eid_table.ueid_cnt * SMC_MAX_EID_LEN;
@@ -1219,6 +1221,7 @@ int smc_clc_clnt_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
 			return SMC_CLC_DECL_MAXLINKERR;
 		ini->max_links = fce_v2x->max_links;
 	}
+	ini->feature_mask &= ntohs(fce->feature_mask);
 
 	return 0;
 }
@@ -1250,6 +1253,10 @@ int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
 			return SMC_CLC_DECL_MAXLINKERR;
 	}
 
+	if (~(ini->feature_mask) & ntohs(fce->feature_mask))
+		return SMC_CLC_DECL_FEATUNSUPP;
+	ini->feature_mask = ntohs(fce->feature_mask);
+
 	return 0;
 }
 
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index c5c8e7d..bcf37c8 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -48,6 +48,7 @@
 #define SMC_CLC_DECL_RELEASEERR	0x03030009  /* release version negotiate failed */
 #define SMC_CLC_DECL_MAXCONNERR	0x0303000a  /* max connections negotiate failed */
 #define SMC_CLC_DECL_MAXLINKERR	0x0303000b  /* max links negotiate failed */
+#define SMC_CLC_DECL_FEATUNSUPP	0x0303000c  /* supplemental features not supported */
 #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 */
@@ -138,7 +139,8 @@ struct smc_clc_v2_extension {
 	u8 roce[16];		/* RoCEv2 GID */
 	u8 max_conns;
 	u8 max_links;
-	u8 reserved[14];
+	__be16 feature_mask;
+	u8 reserved[12];
 	u8 user_eids[][SMC_MAX_EID_LEN];
 };
 
@@ -234,7 +236,7 @@ struct smc_clc_first_contact_ext {
 	u8 release : 4,
 	   os_type : 4;
 #endif
-	u8 reserved2[2];
+	__be16 feature_mask;
 	u8 hostname[SMC_MAX_HOSTNAME_LEN];
 };
 
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 120027d..9f65678 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -401,6 +401,7 @@ struct smc_init_info {
 	u8			max_links;
 	u8			first_contact_peer;
 	u8			first_contact_local;
+	u16			feature_mask;
 	unsigned short		vlan_id;
 	u32			rc;
 	u8			negotiated_eid[SMC_MAX_EID_LEN];
-- 
1.8.3.1