cxgb4: Don't assume FW_PORT_CMD reply is always port info msg

The firmware can send a set of asynchronous replies through FW_PORT_CMD
with DCBX information when that's negotiated with the Link Peer. The old
code always assumed that a FW_PORT_CMD reply was always a Get Port
Information message. This change conditionalizes the code to only handle
the Get Port Information messages and throws a warning if we don't
understand what we've been given.

Also refactor t4_handle_fw_rpl() so that core functionality performed by
t4_handle_get_port_info() for a specified port.
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -1470,6 +1470,7 @@ int t4_ctrl_eq_free(struct adapter *adap, unsigned int mbox, unsigned int pf,
 int t4_ofld_eq_free(struct adapter *adap, unsigned int mbox, unsigned int pf,
 		    unsigned int vf, unsigned int eqid);
 int t4_sge_ctxt_flush(struct adapter *adap, unsigned int mbox);
+void t4_handle_get_port_info(struct port_info *pi, const __be64 *rpl);
 int t4_handle_fw_rpl(struct adapter *adap, const __be64 *rpl);
 void t4_db_full(struct adapter *adapter);
 void t4_db_dropped(struct adapter *adapter);

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c

@@ -7103,23 +7103,20 @@ int t4_ofld_eq_free(struct adapter *adap, unsigned int mbox, unsigned int pf,
 }
 
 /**
- *	t4_handle_fw_rpl - process a FW reply message
- *	@adap: the adapter
+ *	t4_handle_get_port_info - process a FW reply message
+ *	@pi: the port info
  *	@rpl: start of the FW message
  *
- *	Processes a FW message, such as link state change messages.
+ *	Processes a GET_PORT_INFO FW reply message.
  */
-int t4_handle_fw_rpl(struct adapter *adap, const __be64 *rpl)
+void t4_handle_get_port_info(struct port_info *pi, const __be64 *rpl)
 {
-	u8 opcode = *(const u8 *)rpl;
+	const struct fw_port_cmd *p = (const void *)rpl;
+	struct adapter *adap = pi->adapter;
 
-	if (opcode == FW_PORT_CMD) {    /* link/module state change message */
+	/* link/module state change message */
 	int speed = 0, fc = 0;
-		const struct fw_port_cmd *p = (void *)rpl;
-		int chan = FW_PORT_CMD_PORTID_G(be32_to_cpu(p->op_to_portid));
-		int port = adap->chan_map[chan];
-		struct port_info *pi = adap2pinfo(adap, port);
-		struct link_config *lc = &pi->link_cfg;
+	struct link_config *lc;
 	u32 stat = be32_to_cpu(p->u.info.lstatus_to_modtype);
 	int link_ok = (stat & FW_PORT_CMD_LSTATUS_F) != 0;
 	u32 mod = FW_PORT_CMD_MODTYPE_G(stat);
@@ -7137,18 +7134,57 @@ int t4_handle_fw_rpl(struct adapter *adap, const __be64 *rpl)
 	else if (stat & FW_PORT_CMD_LSPEED_V(FW_PORT_CAP_SPEED_40G))
 		speed = 40000;
 
+	lc = &pi->link_cfg;
+
+	if (mod != pi->mod_type) {
+		pi->mod_type = mod;
+		t4_os_portmod_changed(adap, pi->port_id);
+	}
 	if (link_ok != lc->link_ok || speed != lc->speed ||
 	    fc != lc->fc) {	/* something changed */
 		lc->link_ok = link_ok;
 		lc->speed = speed;
 		lc->fc = fc;
 		lc->supported = be16_to_cpu(p->u.info.pcap);
-			t4_os_link_changed(adap, port, link_ok);
+		t4_os_link_changed(adap, pi->port_id, link_ok);
 	}
-		if (mod != pi->mod_type) {
-			pi->mod_type = mod;
-			t4_os_portmod_changed(adap, port);
+}
+
+/**
+ *      t4_handle_fw_rpl - process a FW reply message
+ *      @adap: the adapter
+ *      @rpl: start of the FW message
+ *
+ *      Processes a FW message, such as link state change messages.
+ */
+int t4_handle_fw_rpl(struct adapter *adap, const __be64 *rpl)
+{
+	u8 opcode = *(const u8 *)rpl;
+
+	/* This might be a port command ... this simplifies the following
+	 * conditionals ...  We can get away with pre-dereferencing
+	 * action_to_len16 because it's in the first 16 bytes and all messages
+	 * will be at least that long.
+	 */
+	const struct fw_port_cmd *p = (const void *)rpl;
+	unsigned int action =
+		FW_PORT_CMD_ACTION_G(be32_to_cpu(p->action_to_len16));
+
+	if (opcode == FW_PORT_CMD && action == FW_PORT_ACTION_GET_PORT_INFO) {
+		int i;
+		int chan = FW_PORT_CMD_PORTID_G(be32_to_cpu(p->op_to_portid));
+		struct port_info *pi = NULL;
+
+		for_each_port(adap, i) {
+			pi = adap2pinfo(adap, i);
+			if (pi->tx_chan == chan)
+				break;
 		}
+
+		t4_handle_get_port_info(pi, rpl);
+	} else {
+		dev_warn(adap->pdev_dev, "Unknown firmware reply %d\n", opcode);
+		return -EINVAL;
 	}
 	return 0;
 }