[SCSI] libfc: Add support for FDMI

This patch adds support for Fabric Device Management
Interface as per FC-GS-4 spec. in libfc. Any driver
making use of libfc can enable fdmi state machine
for a given lport.

If lport has enabled FDMI support the lport state
machine will transition into FDMI after completing
the DNS states and before entering the SCR state.
The FDMI state transition is such that if there is an
error, it won't stop the lport state machine from
transitioning and the it will behave as if there was
no FDMI support.

The FDMI HBA attributes are registed with the Management
server via Register HBA (RHBA) command and the port
attributes are reigstered using the Register Port(RPA)
command.

Signed-off-by: Neerav Parikh <neerav.parikh@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Acked-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 224 insertions, 3 deletions

diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index 83750ebb527f..9a0b2a9caad6 100644
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -116,6 +116,8 @@ static void fc_lport_enter_ns(struct fc_lport *, enum fc_lport_state);
 static void fc_lport_enter_scr(struct fc_lport *);
 static void fc_lport_enter_ready(struct fc_lport *);
 static void fc_lport_enter_logo(struct fc_lport *);
+static void fc_lport_enter_fdmi(struct fc_lport *lport);
+static void fc_lport_enter_ms(struct fc_lport *, enum fc_lport_state);
 
 static const char *fc_lport_state_names[] = {
 	[LPORT_ST_DISABLED] = "disabled",
@@ -126,6 +128,11 @@ static const char *fc_lport_state_names[] = {
 	[LPORT_ST_RSPN_ID] =  "RSPN_ID",
 	[LPORT_ST_RFT_ID] =   "RFT_ID",
 	[LPORT_ST_RFF_ID] =   "RFF_ID",
+	[LPORT_ST_FDMI] =     "FDMI",
+	[LPORT_ST_RHBA] =     "RHBA",
+	[LPORT_ST_RPA] =      "RPA",
+	[LPORT_ST_DHBA] =     "DHBA",
+	[LPORT_ST_DPRT] =     "DPRT",
 	[LPORT_ST_SCR] =      "SCR",
 	[LPORT_ST_READY] =    "Ready",
 	[LPORT_ST_LOGO] =     "LOGO",
@@ -183,11 +190,14 @@ static void fc_lport_rport_callback(struct fc_lport *lport,
 		if (lport->state == LPORT_ST_DNS) {
 			lport->dns_rdata = rdata;
 			fc_lport_enter_ns(lport, LPORT_ST_RNN_ID);
+		} else if (lport->state == LPORT_ST_FDMI) {
+			lport->ms_rdata = rdata;
+			fc_lport_enter_ms(lport, LPORT_ST_DHBA);
 		} else {
 			FC_LPORT_DBG(lport, "Received an READY event "
 				     "on port (%6.6x) for the directory "
 				     "server, but the lport is not "
-				     "in the DNS state, it's in the "
+				     "in the DNS or FDMI state, it's in the "
 				     "%d state", rdata->ids.port_id,
 				     lport->state);
 			lport->tt.rport_logoff(rdata);
@@ -196,7 +206,10 @@ static void fc_lport_rport_callback(struct fc_lport *lport,
 	case RPORT_EV_LOGO:
 	case RPORT_EV_FAILED:
 	case RPORT_EV_STOP:
-		lport->dns_rdata = NULL;
+		if (rdata->ids.port_id == FC_FID_DIR_SERV)
+			lport->dns_rdata = NULL;
+		else if (rdata->ids.port_id == FC_FID_MGMT_SERV)
+			lport->ms_rdata = NULL;
 		break;
 	case RPORT_EV_NONE:
 		break;
@@ -1148,7 +1161,10 @@ static void fc_lport_ns_resp(struct fc_seq *sp, struct fc_frame *fp,
 			fc_lport_enter_ns(lport, LPORT_ST_RFF_ID);
 			break;
 		case LPORT_ST_RFF_ID:
-			fc_lport_enter_scr(lport);
+			if (lport->fdmi_enabled)
+				fc_lport_enter_fdmi(lport);
+			else
+				fc_lport_enter_scr(lport);
 			break;
 		default:
 			/* should have already been caught by state checks */
@@ -1163,6 +1179,85 @@ err:
 }
 
 /**
+ * fc_lport_ms_resp() - Handle response to a management server
+ *			exchange
+ * @sp:	    current sequence in exchange
+ * @fp:	    response frame
+ * @lp_arg: Fibre Channel host port instance
+ *
+ * Locking Note: This function will be called without the lport lock
+ * held, but it will lock, call an _enter_* function or fc_lport_error()
+ * and then unlock the lport.
+ */
+static void fc_lport_ms_resp(struct fc_seq *sp, struct fc_frame *fp,
+			     void *lp_arg)
+{
+	struct fc_lport *lport = lp_arg;
+	struct fc_frame_header *fh;
+	struct fc_ct_hdr *ct;
+
+	FC_LPORT_DBG(lport, "Received a ms %s\n", fc_els_resp_type(fp));
+
+	if (fp == ERR_PTR(-FC_EX_CLOSED))
+		return;
+
+	mutex_lock(&lport->lp_mutex);
+
+	if (lport->state < LPORT_ST_RHBA || lport->state > LPORT_ST_DPRT) {
+		FC_LPORT_DBG(lport, "Received a management server response, "
+			     "but in state %s\n", fc_lport_state(lport));
+		if (IS_ERR(fp))
+			goto err;
+		goto out;
+	}
+
+	if (IS_ERR(fp)) {
+		fc_lport_error(lport, fp);
+		goto err;
+	}
+
+	fh = fc_frame_header_get(fp);
+	ct = fc_frame_payload_get(fp, sizeof(*ct));
+
+	if (fh && ct && fh->fh_type == FC_TYPE_CT &&
+	    ct->ct_fs_type == FC_FST_MGMT &&
+	    ct->ct_fs_subtype == FC_FDMI_SUBTYPE) {
+		FC_LPORT_DBG(lport, "Received a management server response, "
+				    "reason=%d explain=%d\n",
+				    ct->ct_reason,
+				    ct->ct_explan);
+
+		switch (lport->state) {
+		case LPORT_ST_RHBA:
+			if (ntohs(ct->ct_cmd) == FC_FS_ACC)
+				fc_lport_enter_ms(lport, LPORT_ST_RPA);
+			else /* Error Skip RPA */
+				fc_lport_enter_scr(lport);
+			break;
+		case LPORT_ST_RPA:
+			fc_lport_enter_scr(lport);
+			break;
+		case LPORT_ST_DPRT:
+			fc_lport_enter_ms(lport, LPORT_ST_RHBA);
+			break;
+		case LPORT_ST_DHBA:
+			fc_lport_enter_ms(lport, LPORT_ST_DPRT);
+			break;
+		default:
+			/* should have already been caught by state checks */
+			break;
+		}
+	} else {
+		/* Invalid Frame? */
+		fc_lport_error(lport, fp);
+	}
+out:
+	fc_frame_free(fp);
+err:
+	mutex_unlock(&lport->lp_mutex);
+}
+
+/**
  * fc_lport_scr_resp() - Handle response to State Change Register (SCR) request
  * @sp:	    current sequence in SCR exchange
  * @fp:	    response frame
@@ -1339,6 +1434,123 @@ err:
 }
 
 /**
+ * fc_lport_enter_ms() - management server commands
+ * @lport: Fibre Channel local port to register
+ *
+ * Locking Note: The lport lock is expected to be held before calling
+ * this routine.
+ */
+static void fc_lport_enter_ms(struct fc_lport *lport, enum fc_lport_state state)
+{
+	struct fc_frame *fp;
+	enum fc_fdmi_req cmd;
+	int size = sizeof(struct fc_ct_hdr);
+	size_t len;
+	int numattrs;
+
+	FC_LPORT_DBG(lport, "Entered %s state from %s state\n",
+		     fc_lport_state_names[state],
+		     fc_lport_state(lport));
+
+	fc_lport_state_enter(lport, state);
+
+	switch (state) {
+	case LPORT_ST_RHBA:
+		cmd = FC_FDMI_RHBA;
+		/* Number of HBA Attributes */
+		numattrs = 10;
+		len = sizeof(struct fc_fdmi_rhba);
+		len -= sizeof(struct fc_fdmi_attr_entry);
+		len += (numattrs * FC_FDMI_ATTR_ENTRY_HEADER_LEN);
+		len += FC_FDMI_HBA_ATTR_NODENAME_LEN;
+		len += FC_FDMI_HBA_ATTR_MANUFACTURER_LEN;
+		len += FC_FDMI_HBA_ATTR_SERIALNUMBER_LEN;
+		len += FC_FDMI_HBA_ATTR_MODEL_LEN;
+		len += FC_FDMI_HBA_ATTR_MODELDESCR_LEN;
+		len += FC_FDMI_HBA_ATTR_HARDWAREVERSION_LEN;
+		len += FC_FDMI_HBA_ATTR_DRIVERVERSION_LEN;
+		len += FC_FDMI_HBA_ATTR_OPTIONROMVERSION_LEN;
+		len += FC_FDMI_HBA_ATTR_FIRMWAREVERSION_LEN;
+		len += FC_FDMI_HBA_ATTR_OSNAMEVERSION_LEN;
+
+		size += len;
+		break;
+	case LPORT_ST_RPA:
+		cmd = FC_FDMI_RPA;
+		/* Number of Port Attributes */
+		numattrs = 6;
+		len = sizeof(struct fc_fdmi_rpa);
+		len -= sizeof(struct fc_fdmi_attr_entry);
+		len += (numattrs * FC_FDMI_ATTR_ENTRY_HEADER_LEN);
+		len += FC_FDMI_PORT_ATTR_FC4TYPES_LEN;
+		len += FC_FDMI_PORT_ATTR_SUPPORTEDSPEED_LEN;
+		len += FC_FDMI_PORT_ATTR_CURRENTPORTSPEED_LEN;
+		len += FC_FDMI_PORT_ATTR_MAXFRAMESIZE_LEN;
+		len += FC_FDMI_PORT_ATTR_OSDEVICENAME_LEN;
+		len += FC_FDMI_PORT_ATTR_HOSTNAME_LEN;
+
+		size += len;
+		break;
+	case LPORT_ST_DPRT:
+		cmd = FC_FDMI_DPRT;
+		len = sizeof(struct fc_fdmi_dprt);
+		size += len;
+		break;
+	case LPORT_ST_DHBA:
+		cmd = FC_FDMI_DHBA;
+		len = sizeof(struct fc_fdmi_dhba);
+		size += len;
+		break;
+	default:
+		fc_lport_error(lport, NULL);
+		return;
+	}
+
+	FC_LPORT_DBG(lport, "Cmd=0x%x Len %d size %d\n",
+			     cmd, (int)len, size);
+	fp = fc_frame_alloc(lport, size);
+	if (!fp) {
+		fc_lport_error(lport, fp);
+		return;
+	}
+
+	if (!lport->tt.elsct_send(lport, FC_FID_MGMT_SERV, fp, cmd,
+				  fc_lport_ms_resp,
+				  lport, 3 * lport->r_a_tov))
+		fc_lport_error(lport, fp);
+}
+
+/**
+ * fc_rport_enter_fdmi() - Create a fc_rport for the management server
+ * @lport: The local port requesting a remote port for the management server
+ *
+ * Locking Note: The lport lock is expected to be held before calling
+ * this routine.
+ */
+static void fc_lport_enter_fdmi(struct fc_lport *lport)
+{
+	struct fc_rport_priv *rdata;
+
+	FC_LPORT_DBG(lport, "Entered FDMI state from %s state\n",
+		     fc_lport_state(lport));
+
+	fc_lport_state_enter(lport, LPORT_ST_FDMI);
+
+	mutex_lock(&lport->disc.disc_mutex);
+	rdata = lport->tt.rport_create(lport, FC_FID_MGMT_SERV);
+	mutex_unlock(&lport->disc.disc_mutex);
+	if (!rdata)
+		goto err;
+
+	rdata->ops = &fc_lport_rport_ops;
+	lport->tt.rport_login(rdata);
+	return;
+
+err:
+	fc_lport_error(lport, NULL);
+}
+
+/**
  * fc_lport_timeout() - Handler for the retry_work timer
  * @work: The work struct of the local port
  */
@@ -1371,6 +1583,15 @@ static void fc_lport_timeout(struct work_struct *work)
 	case LPORT_ST_RFF_ID:
 		fc_lport_enter_ns(lport, lport->state);
 		break;
+	case LPORT_ST_FDMI:
+		fc_lport_enter_fdmi(lport);
+		break;
+	case LPORT_ST_RHBA:
+	case LPORT_ST_RPA:
+	case LPORT_ST_DHBA:
+	case LPORT_ST_DPRT:
+		fc_lport_enter_ms(lport, lport->state);
+		break;
 	case LPORT_ST_SCR:
 		fc_lport_enter_scr(lport);
 		break;