openwrt/target/linux/generic/backport-5.10/735-v5.14-03-net-dsa-qca8k-improve-qca8k-read-write-rmw-bus-acces.patch

From 504bf65931824eda83494e5b5d75686e27ace03e Mon Sep 17 00:00:00 2001
From: Ansuel Smith <ansuelsmth@gmail.com>
Date: Fri, 14 May 2021 22:59:53 +0200
Subject: [PATCH] net: dsa: qca8k: improve qca8k read/write/rmw bus access

Put bus in local variable to improve faster access to the mdio bus.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/dsa/qca8k.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -142,17 +142,18 @@ qca8k_set_page(struct mii_bus *bus, u16
 static u32
 qca8k_read(struct qca8k_priv *priv, u32 reg)
 {
+	struct mii_bus *bus = priv->bus;
 	u16 r1, r2, page;
 	u32 val;
 
 	qca8k_split_addr(reg, &r1, &r2, &page);
 
-	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
 
-	qca8k_set_page(priv->bus, page);
-	val = qca8k_mii_read32(priv->bus, 0x10 | r2, r1);
+	qca8k_set_page(bus, page);
+	val = qca8k_mii_read32(bus, 0x10 | r2, r1);
 
-	mutex_unlock(&priv->bus->mdio_lock);
+	mutex_unlock(&bus->mdio_lock);
 
 	return val;
 }
@@ -160,35 +161,37 @@ qca8k_read(struct qca8k_priv *priv, u32
 static void
 qca8k_write(struct qca8k_priv *priv, u32 reg, u32 val)
 {
+	struct mii_bus *bus = priv->bus;
 	u16 r1, r2, page;
 
 	qca8k_split_addr(reg, &r1, &r2, &page);
 
-	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
 
-	qca8k_set_page(priv->bus, page);
-	qca8k_mii_write32(priv->bus, 0x10 | r2, r1, val);
+	qca8k_set_page(bus, page);
+	qca8k_mii_write32(bus, 0x10 | r2, r1, val);
 
-	mutex_unlock(&priv->bus->mdio_lock);
+	mutex_unlock(&bus->mdio_lock);
 }
 
 static u32
 qca8k_rmw(struct qca8k_priv *priv, u32 reg, u32 mask, u32 val)
 {
+	struct mii_bus *bus = priv->bus;
 	u16 r1, r2, page;
 	u32 ret;
 
 	qca8k_split_addr(reg, &r1, &r2, &page);
 
-	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
+	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
 
-	qca8k_set_page(priv->bus, page);
-	ret = qca8k_mii_read32(priv->bus, 0x10 | r2, r1);
+	qca8k_set_page(bus, page);
+	ret = qca8k_mii_read32(bus, 0x10 | r2, r1);
 	ret &= ~mask;
 	ret |= val;
-	qca8k_mii_write32(priv->bus, 0x10 | r2, r1, ret);
+	qca8k_mii_write32(bus, 0x10 | r2, r1, ret);
 
-	mutex_unlock(&priv->bus->mdio_lock);
+	mutex_unlock(&bus->mdio_lock);
 
 	return ret;
 }