net: enetc: implement software lockstep for port MAC registers

Currently the enetc driver duplicates its writes to the PM0 registers
also to PM1, but it doesn't do this consistently - for example we write
to ENETC_PM0_MAXFRM but not to ENETC_PM1_MAXFRM.

Create enetc_port_mac_wr() which writes both the PM0 and PM1 register
with the same value (if frame preemption is supported on this port).
Also create enetc_port_mac_rd() which reads from PM0 - the assumption
being that PM1 contains just the same value.

This will be necessary when we enable the MAC Merge layer properly, and
the pMAC becomes operational.

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

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index cb227c93a07b..1fe8dfd6b6d4 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -397,6 +397,8 @@ struct enetc_msg_cmd_set_primary_mac {
 extern int enetc_phc_index;
 
 /* SI common */
+u32 enetc_port_mac_rd(struct enetc_si *si, u32 reg);
+void enetc_port_mac_wr(struct enetc_si *si, u32 reg, u32 val);
 int enetc_pci_probe(struct pci_dev *pdev, const char *name, int sizeof_priv);
 void enetc_pci_remove(struct pci_dev *pdev);
 int enetc_alloc_msix(struct enetc_ndev_priv *priv);