net: enetc: create a common enetc_pf_to_port helper

Even though ENETC interfaces are exposed as individual PCIe PFs with
their own driver instances, the ENETC is still fundamentally a
multi-port Ethernet controller, and some parts of the IP take a port
number (as can be seen in the PSFP implementation).

Create a common helper that can be used outside of the TSN code for
retrieving the ENETC port number based on the PF number. This is only
correct for LS1028A, the only Linux-capable instantiation of ENETC thus
far.

Note that ENETC port 3 is PF 6. The TSN code did not care about this
because ENETC port 3 does not support TSN, so the wrong mapping done by
enetc_get_port for PF 6 could have never been hit.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 3de71669e317..08b283347d9c 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -237,6 +237,22 @@ static inline bool enetc_si_is_pf(struct enetc_si *si)
 	return !!(si->hw.port);
 }
 
+static inline int enetc_pf_to_port(struct pci_dev *pf_pdev)
+{
+	switch (pf_pdev->devfn) {
+	case 0:
+		return 0;
+	case 1:
+		return 1;
+	case 2:
+		return 2;
+	case 6:
+		return 3;
+	default:
+		return -1;
+	}
+}
+
 #define ENETC_MAX_NUM_TXQS	8
 #define ENETC_INT_NAME_MAX	(IFNAMSIZ + 8)