net: dsa: mv88e6xxx: Split mv88e6xxx_reg_read and mv88e6xxx_reg_write

Split mv88e6xxx_reg_read and mv88e6xxx_reg_write into two functions each,
one to acquire smi_mutex and one to get struct mii_bus *bus from
struct dsa_switch *ds and to call the actual read/write function.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx.c

@@ -72,19 +72,16 @@ int __mv88e6xxx_reg_read(struct mii_bus *bus, int sw_addr, int addr, int reg)
 	return ret & 0xffff;
 }
 
-int mv88e6xxx_reg_read(struct dsa_switch *ds, int addr, int reg)
+/* Must be called with SMI mutex held */
+static int _mv88e6xxx_reg_read(struct dsa_switch *ds, int addr, int reg)
 {
-	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
 	struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
 	int ret;
 
 	if (bus == NULL)
 		return -EINVAL;
 
-	mutex_lock(&ps->smi_mutex);
 	ret = __mv88e6xxx_reg_read(bus, ds->pd->sw_addr, addr, reg);
-	mutex_unlock(&ps->smi_mutex);
-
 	if (ret < 0)
 		return ret;
 
@@ -94,6 +91,18 @@ int mv88e6xxx_reg_read(struct dsa_switch *ds, int addr, int reg)
 	return ret;
 }
 
+int mv88e6xxx_reg_read(struct dsa_switch *ds, int addr, int reg)
+{
+	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+	int ret;
+
+	mutex_lock(&ps->smi_mutex);
+	ret = _mv88e6xxx_reg_read(ds, addr, reg);
+	mutex_unlock(&ps->smi_mutex);
+
+	return ret;
+}
+
 int __mv88e6xxx_reg_write(struct mii_bus *bus, int sw_addr, int addr,
 			  int reg, u16 val)
 {
@@ -125,20 +134,28 @@ int __mv88e6xxx_reg_write(struct mii_bus *bus, int sw_addr, int addr,
 	return 0;
 }
 
-int mv88e6xxx_reg_write(struct dsa_switch *ds, int addr, int reg, u16 val)
+/* Must be called with SMI mutex held */
+static int _mv88e6xxx_reg_write(struct dsa_switch *ds, int addr, int reg,
+				u16 val)
 {
-	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
 	struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
-	int ret;
 
 	if (bus == NULL)
 		return -EINVAL;
 
 	dev_dbg(ds->master_dev, "-> addr: 0x%.2x reg: 0x%.2x val: 0x%.4x\n",
 		addr, reg, val);
 
+	return __mv88e6xxx_reg_write(bus, ds->pd->sw_addr, addr, reg, val);
+}
+
+int mv88e6xxx_reg_write(struct dsa_switch *ds, int addr, int reg, u16 val)
+{
+	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+	int ret;
+
 	mutex_lock(&ps->smi_mutex);
-	ret = __mv88e6xxx_reg_write(bus, ds->pd->sw_addr, addr, reg, val);
+	ret = _mv88e6xxx_reg_write(ds, addr, reg, val);
 	mutex_unlock(&ps->smi_mutex);
 
 	return ret;