linux-kernel - [PATCH net-next v3 04/11] net: phy: make the "prevent_c45

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Message-Id: <20230620-feature-c45-over-c22-v3-4-9eb37edf7be0@kernel.org>
Date:   Wed, 12 Jul 2023 17:07:04 +0200
From:   Michael Walle <mwalle@...nel.org>
To:     Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Russell King <linux@...linux.org.uk>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Yisen Zhuang <yisen.zhuang@...wei.com>,
        Salil Mehta <salil.mehta@...wei.com>,
        Florian Fainelli <florian.fainelli@...adcom.com>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@...adcom.com>,
        Marek Behún <kabel@...nel.org>,
        Xu Liang <lxu@...linear.com>
Cc:     netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Simon Horman <simon.horman@...igine.com>,
        Michael Walle <mwalle@...nel.org>
Subject: [PATCH net-next v3 04/11] net: phy: make the "prevent_c45_scan" a
 property of the MII bus

The blacklist will also be used elsewhere in the kernel, e.g. in the
DT scanning code. Make it a property of mii_bus and export the function.

Signed-off-by: Michael Walle <mwalle@...nel.org>
---
v3:
 - add missing EXPORT_SYMBOL_GPL() for
   mdiobus_scan_for_broken_c45_access()
---
 drivers/net/phy/mdio_bus.c | 18 +++++++++---------
 include/linux/phy.h        |  5 +++++
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index a31eb1204f63..29ad9302fe11 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -613,9 +613,9 @@ static int mdiobus_scan_bus_c45(struct mii_bus *bus)
  * stomping over the true devices reply, to performing a write to
  * themselves which was intended for another device. Now that C22
  * devices have been found, see if any of them are bad for C45, and if we
- * should skip the C45 scan.
+ * should prohibit any C45 transactions.
  */
-static bool mdiobus_prevent_c45_scan(struct mii_bus *bus)
+void mdiobus_scan_for_broken_c45_access(struct mii_bus *bus)
 {
 	int i;
 
@@ -628,11 +628,13 @@ static bool mdiobus_prevent_c45_scan(struct mii_bus *bus)
 			continue;
 		oui = phydev->phy_id >> 10;
 
-		if (oui == MICREL_OUI)
-			return true;
+		if (oui == MICREL_OUI) {
+			bus->prevent_c45_access = true;
+			break;
+		}
 	}
-	return false;
 }
+EXPORT_SYMBOL_GPL(mdiobus_scan_for_broken_c45_access);
 
 /**
  * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
@@ -652,7 +654,6 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 {
 	struct mdio_device *mdiodev;
 	struct gpio_desc *gpiod;
-	bool prevent_c45_scan;
 	int i, err;
 
 	if (!bus || !bus->name)
@@ -724,9 +725,8 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 			goto error;
 	}
 
-	prevent_c45_scan = mdiobus_prevent_c45_scan(bus);
-
-	if (!prevent_c45_scan && bus->read_c45) {
+	mdiobus_scan_for_broken_c45_access(bus);
+	if (!bus->prevent_c45_access && bus->read_c45) {
 		err = mdiobus_scan_bus_c45(bus);
 		if (err)
 			goto error;
diff --git a/include/linux/phy.h b/include/linux/phy.h
index fb7481715c3b..cd67887a7289 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -410,6 +410,9 @@ struct mii_bus {
 	/** @phy_ignore_ta_mask: PHY addresses to ignore the TA/read failure */
 	u32 phy_ignore_ta_mask;
 
+	/** @prevent_c45_access: Don't do any C45 transactions on the bus */
+	unsigned prevent_c45_access:1;
+
 	/**
 	 * @irq: An array of interrupts, each PHY's interrupt at the index
 	 * matching its address
@@ -462,6 +465,8 @@ static inline struct mii_bus *devm_mdiobus_alloc(struct device *dev)
 struct mii_bus *mdio_find_bus(const char *mdio_name);
 struct phy_device *mdiobus_scan_c22(struct mii_bus *bus, int addr);
 
+void mdiobus_scan_for_broken_c45_access(struct mii_bus *bus);
+
 #define PHY_INTERRUPT_DISABLED	false
 #define PHY_INTERRUPT_ENABLED	true
 

-- 
2.39.2