net: dsa: bcm_sf2: Do not clobber b53_switch_ops

We make the bcm_sf2 driver override ds->ops which points to
b53_switch_ops since b53_switch_alloc() did the assignent. This is all
well and good until a second b53 switch comes in, and ends up using the
bcm_sf2 operations. Make a proper local copy, substitute the ds->ops
pointer and then override the operations.

Fixes: f458995b ("net: dsa: bcm_sf2: Utilize core B53 driver when possible")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/bcm_sf2.c

@@ -982,6 +982,7 @@ static int bcm_sf2_sw_probe(struct platform_device *pdev)
 	const char *reg_names[BCM_SF2_REGS_NUM] = BCM_SF2_REGS_NAME;
 	struct device_node *dn = pdev->dev.of_node;
 	struct b53_platform_data *pdata;
+	struct dsa_switch_ops *ops;
 	struct bcm_sf2_priv *priv;
 	struct b53_device *dev;
 	struct dsa_switch *ds;
@@ -995,6 +996,10 @@ static int bcm_sf2_sw_probe(struct platform_device *pdev)
 	if (!priv)
 		return -ENOMEM;
 
+	ops = devm_kzalloc(&pdev->dev, sizeof(*ops), GFP_KERNEL);
+	if (!ops)
+		return -ENOMEM;
+
 	dev = b53_switch_alloc(&pdev->dev, &bcm_sf2_io_ops, priv);
 	if (!dev)
 		return -ENOMEM;
@@ -1014,6 +1019,8 @@ static int bcm_sf2_sw_probe(struct platform_device *pdev)
 	ds = dev->ds;
 
 	/* Override the parts that are non-standard wrt. normal b53 devices */
+	memcpy(ops, ds->ops, sizeof(*ops));
+	ds->ops = ops;
 	ds->ops->get_tag_protocol = bcm_sf2_sw_get_tag_protocol;
 	ds->ops->setup = bcm_sf2_sw_setup;
 	ds->ops->get_phy_flags = bcm_sf2_sw_get_phy_flags;