net: dsa: mt7530: introduce mutex helpers

As the MDIO bus lock only needs to be involved if actually operating
on an MDIO-connected switch we will need to skip locking for built-in
switches which are accessed via MMIO.
Create helper functions which simplify that upcoming change.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mt7530.c

@@ -143,31 +143,40 @@ core_write_mmd_indirect(struct mt7530_priv *priv, int prtad,
 }
 
 static void
-core_write(struct mt7530_priv *priv, u32 reg, u32 val)
+mt7530_mutex_lock(struct mt7530_priv *priv)
 {
-	struct mii_bus *bus = priv->bus;
+	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
+}
 
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+static void
+mt7530_mutex_unlock(struct mt7530_priv *priv)
+{
+	mutex_unlock(&priv->bus->mdio_lock);
+}
+
+static void
+core_write(struct mt7530_priv *priv, u32 reg, u32 val)
+{
+	mt7530_mutex_lock(priv);
 
 	core_write_mmd_indirect(priv, reg, MDIO_MMD_VEND2, val);
 
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 }
 
 static void
 core_rmw(struct mt7530_priv *priv, u32 reg, u32 mask, u32 set)
 {
-	struct mii_bus *bus = priv->bus;
 	u32 val;
 
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 
 	val = core_read_mmd_indirect(priv, reg, MDIO_MMD_VEND2);
 	val &= ~mask;
 	val |= set;
 	core_write_mmd_indirect(priv, reg, MDIO_MMD_VEND2, val);
 
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 }
 
 static void
@@ -264,13 +273,11 @@ mt7530_mii_read(struct mt7530_priv *priv, u32 reg)
 static void
 mt7530_write(struct mt7530_priv *priv, u32 reg, u32 val)
 {
-	struct mii_bus *bus = priv->bus;
-
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 
 	mt7530_mii_write(priv, reg, val);
 
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 }
 
 static u32
@@ -282,14 +289,13 @@ _mt7530_unlocked_read(struct mt7530_dummy_poll *p)
 static u32
 _mt7530_read(struct mt7530_dummy_poll *p)
 {
-	struct mii_bus		*bus = p->priv->bus;
 	u32 val;
 
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(p->priv);
 
 	val = mt7530_mii_read(p->priv, p->reg);
 
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(p->priv);
 
 	return val;
 }
@@ -307,13 +313,11 @@ static void
 mt7530_rmw(struct mt7530_priv *priv, u32 reg,
 	   u32 mask, u32 set)
 {
-	struct mii_bus *bus = priv->bus;
-
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 
 	regmap_update_bits(priv->regmap, reg, mask, set);
 
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 }
 
 static void
@@ -657,14 +661,13 @@ static int
 mt7531_ind_c45_phy_read(struct mt7530_priv *priv, int port, int devad,
 			int regnum)
 {
-	struct mii_bus *bus = priv->bus;
 	struct mt7530_dummy_poll p;
 	u32 reg, val;
 	int ret;
 
 	INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
 
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 
 	ret = readx_poll_timeout(_mt7530_unlocked_read, &p, val,
 				 !(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -697,7 +700,7 @@ mt7531_ind_c45_phy_read(struct mt7530_priv *priv, int port, int devad,
 
 	ret = val & MT7531_MDIO_RW_DATA_MASK;
 out:
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 
 	return ret;
 }
@@ -706,14 +709,13 @@ static int
 mt7531_ind_c45_phy_write(struct mt7530_priv *priv, int port, int devad,
 			 int regnum, u16 data)
 {
-	struct mii_bus *bus = priv->bus;
 	struct mt7530_dummy_poll p;
 	u32 val, reg;
 	int ret;
 
 	INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
 
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 
 	ret = readx_poll_timeout(_mt7530_unlocked_read, &p, val,
 				 !(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -745,7 +747,7 @@ mt7531_ind_c45_phy_write(struct mt7530_priv *priv, int port, int devad,
 	}
 
 out:
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 
 	return ret;
 }
@@ -753,14 +755,13 @@ mt7531_ind_c45_phy_write(struct mt7530_priv *priv, int port, int devad,
 static int
 mt7531_ind_c22_phy_read(struct mt7530_priv *priv, int port, int regnum)
 {
-	struct mii_bus *bus = priv->bus;
 	struct mt7530_dummy_poll p;
 	int ret;
 	u32 val;
 
 	INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
 
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 
 	ret = readx_poll_timeout(_mt7530_unlocked_read, &p, val,
 				 !(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -783,7 +784,7 @@ mt7531_ind_c22_phy_read(struct mt7530_priv *priv, int port, int regnum)
 
 	ret = val & MT7531_MDIO_RW_DATA_MASK;
 out:
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 
 	return ret;
 }
@@ -792,14 +793,13 @@ static int
 mt7531_ind_c22_phy_write(struct mt7530_priv *priv, int port, int regnum,
 			 u16 data)
 {
-	struct mii_bus *bus = priv->bus;
 	struct mt7530_dummy_poll p;
 	int ret;
 	u32 reg;
 
 	INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
 
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 
 	ret = readx_poll_timeout(_mt7530_unlocked_read, &p, reg,
 				 !(reg & MT7531_PHY_ACS_ST), 20, 100000);
@@ -821,7 +821,7 @@ mt7531_ind_c22_phy_write(struct mt7530_priv *priv, int port, int regnum,
 	}
 
 out:
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 
 	return ret;
 }
@@ -1102,7 +1102,6 @@ static int
 mt7530_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
 {
 	struct mt7530_priv *priv = ds->priv;
-	struct mii_bus *bus = priv->bus;
 	int length;
 	u32 val;
 
@@ -1113,7 +1112,7 @@ mt7530_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
 	if (!dsa_is_cpu_port(ds, port))
 		return 0;
 
-	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 
 	val = mt7530_mii_read(priv, MT7530_GMACCR);
 	val &= ~MAX_RX_PKT_LEN_MASK;
@@ -1134,7 +1133,7 @@ mt7530_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
 
 	mt7530_mii_write(priv, MT7530_GMACCR, val);
 
-	mutex_unlock(&bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 
 	return 0;
 }
@@ -1935,10 +1934,10 @@ mt7530_irq_thread_fn(int irq, void *dev_id)
 	u32 val;
 	int p;
 
-	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 	val = mt7530_mii_read(priv, MT7530_SYS_INT_STS);
 	mt7530_mii_write(priv, MT7530_SYS_INT_STS, val);
-	mutex_unlock(&priv->bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 
 	for (p = 0; p < MT7530_NUM_PHYS; p++) {
 		if (BIT(p) & val) {
@@ -1974,7 +1973,7 @@ mt7530_irq_bus_lock(struct irq_data *d)
 {
 	struct mt7530_priv *priv = irq_data_get_irq_chip_data(d);
 
-	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mt7530_mutex_lock(priv);
 }
 
 static void
@@ -1983,7 +1982,7 @@ mt7530_irq_bus_sync_unlock(struct irq_data *d)
 	struct mt7530_priv *priv = irq_data_get_irq_chip_data(d);
 
 	mt7530_mii_write(priv, MT7530_SYS_INT_EN, priv->irq_enable);
-	mutex_unlock(&priv->bus->mdio_lock);
+	mt7530_mutex_unlock(priv);
 }
 
 static struct irq_chip mt7530_irq_chip = {