bnxt_en: export a common switchdev PARENT_ID for all reps of an adapter

Currently the driver exports different switchdev PARENT_IDs for
representors belonging to different SR-IOV PF-pools of an adapter.
This is not correct as the adapter can switch across all vports
of an adapter. This patch fixes this by exporting a common switchdev
PARENT_ID for all reps of an adapter. The PCIE DSN is used as the id.

Signed-off-by: Sathya Perla <sathya.perla@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -8149,12 +8149,8 @@ int bnxt_port_attr_get(struct bnxt *bp, struct switchdev_attr *attr)
 
 	switch (attr->id) {
 	case SWITCHDEV_ATTR_ID_PORT_PARENT_ID:
-		/* In SRIOV each PF-pool (PF + child VFs) serves as a
-		 * switching domain, the PF's perm mac-addr can be used
-		 * as the unique parent-id
-		 */
-		attr->u.ppid.id_len = ETH_ALEN;
-		ether_addr_copy(attr->u.ppid.id, bp->pf.mac_addr);
+		attr->u.ppid.id_len = sizeof(bp->switch_id);
+		memcpy(attr->u.ppid.id, bp->switch_id, attr->u.ppid.id_len);
 		break;
 	default:
 		return -EOPNOTSUPP;

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -1371,6 +1371,7 @@ struct bnxt {
 	enum devlink_eswitch_mode eswitch_mode;
 	struct bnxt_vf_rep	**vf_reps; /* array of vf-rep ptrs */
 	u16			*cfa_code_map; /* cfa_code -> vf_idx map */
+	u8			switch_id[8];
 	struct bnxt_tc_info	*tc_info;
 };
 

drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c

@@ -43,7 +43,7 @@ static u16 bnxt_flow_get_dst_fid(struct bnxt *pf_bp, struct net_device *dev)
 	}
 
 	/* Is dev a VF-rep? */
-	if (dev != pf_bp->dev)
+	if (bnxt_dev_is_vf_rep(dev))
 		return bnxt_vf_rep_get_fid(dev);
 
 	bp = netdev_priv(dev);

drivers/net/ethernet/broadcom/bnxt/bnxt_vfr.c

@@ -241,6 +241,11 @@ static const struct net_device_ops bnxt_vf_rep_netdev_ops = {
 	.ndo_get_phys_port_name = bnxt_vf_rep_get_phys_port_name
 };
 
+bool bnxt_dev_is_vf_rep(struct net_device *dev)
+{
+	return dev->netdev_ops == &bnxt_vf_rep_netdev_ops;
+}
+
 /* Called when the parent PF interface is closed:
  * As the mode transition from SWITCHDEV to LEGACY
  * happens under the rtnl_lock() this routine is safe
@@ -376,6 +381,26 @@ static void bnxt_vf_rep_netdev_init(struct bnxt *bp, struct bnxt_vf_rep *vf_rep,
 	ether_addr_copy(dev->dev_addr, dev->perm_addr);
 }
 
+static int bnxt_pcie_dsn_get(struct bnxt *bp, u8 dsn[])
+{
+	struct pci_dev *pdev = bp->pdev;
+	int pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DSN);
+	u32 dw;
+
+	if (!pos) {
+		netdev_info(bp->dev, "Unable do read adapter's DSN");
+		return -EOPNOTSUPP;
+	}
+
+	/* DSN (two dw) is at an offset of 4 from the cap pos */
+	pos += 4;
+	pci_read_config_dword(pdev, pos, &dw);
+	put_unaligned_le32(dw, &dsn[0]);
+	pci_read_config_dword(pdev, pos + 4, &dw);
+	put_unaligned_le32(dw, &dsn[4]);
+	return 0;
+}
+
 static int bnxt_vf_reps_create(struct bnxt *bp)
 {
 	u16 *cfa_code_map = NULL, num_vfs = pci_num_vf(bp->pdev);
@@ -440,6 +465,11 @@ static int bnxt_vf_reps_create(struct bnxt *bp)
 		}
 	}
 
+	/* Read the adapter's DSN to use as the eswitch switch_id */
+	rc = bnxt_pcie_dsn_get(bp, bp->switch_id);
+	if (rc)
+		goto err;
+
 	/* publish cfa_code_map only after all VF-reps have been initialized */
 	bp->cfa_code_map = cfa_code_map;
 	bp->eswitch_mode = DEVLINK_ESWITCH_MODE_SWITCHDEV;

drivers/net/ethernet/broadcom/bnxt/bnxt_vfr.h

@@ -28,6 +28,7 @@ static inline u16 bnxt_vf_rep_get_fid(struct net_device *dev)
 	return bp->pf.vf[vf_rep->vf_idx].fw_fid;
 }
 
+bool bnxt_dev_is_vf_rep(struct net_device *dev);
 int bnxt_dl_eswitch_mode_get(struct devlink *devlink, u16 *mode);
 int bnxt_dl_eswitch_mode_set(struct devlink *devlink, u16 mode);
 
@@ -54,5 +55,10 @@ static inline u16 bnxt_vf_rep_get_fid(struct net_device *dev)
 {
 	return 0;
 }
+
+static inline bool bnxt_dev_is_vf_rep(struct net_device *dev)
+{
+	return false;
+}
 #endif /* CONFIG_BNXT_SRIOV */
 #endif /* BNXT_VFR_H */