net: phy: let genphy_c45_read_link manage the devices to check

Let genphy_c45_read_link manage the devices to check, this removes
overhead from callers. Add C22EXT to the list of excluded devices
because it doesn't implement the status register. According to the
802.3 clause 45 spec registers 29.0 - 29.4 are reserved.

At the moment we have very few clause 45 PHY drivers, so we are
lacking experience whether other drivers will have to exclude further
devices, or may need to check PHY XS. If we should figure out that
list of devices to check needs to be configurable, I think best will
be to add a device list member to struct phy_driver.

v2:
- adjusted commit message
- exclude also device C22EXT from link checking

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: hkallweit

drivers/net/phy/marvell10g.c

@@ -428,16 +428,8 @@ static int mv3310_read_10gbr_status(struct phy_device *phydev)
 
 static int mv3310_read_status(struct phy_device *phydev)
 {
-	u32 mmd_mask = phydev->c45_ids.devices_in_package;
 	int val;
 
-	/* The vendor devads do not report link status.  Avoid the PHYXS
-	 * instance as there are three, and its status depends on the MAC
-	 * being appropriately configured for the negotiated speed.
-	 */
-	mmd_mask &= ~(BIT(MDIO_MMD_VEND1) | BIT(MDIO_MMD_VEND2) |
-		      BIT(MDIO_MMD_PHYXS));
-
 	phydev->speed = SPEED_UNKNOWN;
 	phydev->duplex = DUPLEX_UNKNOWN;
 	linkmode_zero(phydev->lp_advertising);
@@ -453,7 +445,7 @@ static int mv3310_read_status(struct phy_device *phydev)
 	if (val & MDIO_STAT1_LSTATUS)
 		return mv3310_read_10gbr_status(phydev);
 
-	val = genphy_c45_read_link(phydev, mmd_mask);
+	val = genphy_c45_read_link(phydev);
 	if (val < 0)
 		return val;
 

drivers/net/phy/phy-c45.c

@@ -118,17 +118,24 @@ EXPORT_SYMBOL_GPL(genphy_c45_aneg_done);
 /**
  * genphy_c45_read_link - read the overall link status from the MMDs
  * @phydev: target phy_device struct
- * @mmd_mask: MMDs to read status from
  *
  * Read the link status from the specified MMDs, and if they all indicate
  * that the link is up, set phydev->link to 1.  If an error is encountered,
  * a negative errno will be returned, otherwise zero.
  */
-int genphy_c45_read_link(struct phy_device *phydev, u32 mmd_mask)
+int genphy_c45_read_link(struct phy_device *phydev)
 {
+	u32 mmd_mask = phydev->c45_ids.devices_in_package;
 	int val, devad;
 	bool link = true;
 
+	/* The vendor devads and C22EXT do not report link status. Avoid the
+	 * PHYXS instance as its status may depend on the MAC being
+	 * appropriately configured for the negotiated speed.
+	 */
+	mmd_mask &= ~(MDIO_DEVS_VEND1 | MDIO_DEVS_VEND2 | MDIO_DEVS_C22EXT |
+		      MDIO_DEVS_PHYXS);
+
 	while (mmd_mask && link) {
 		devad = __ffs(mmd_mask);
 		mmd_mask &= ~BIT(devad);
@@ -266,16 +273,11 @@ EXPORT_SYMBOL_GPL(gen10g_config_aneg);
 
 int gen10g_read_status(struct phy_device *phydev)
 {
-	u32 mmd_mask = phydev->c45_ids.devices_in_package;
-
 	/* For now just lie and say it's 10G all the time */
 	phydev->speed = SPEED_10000;
 	phydev->duplex = DUPLEX_FULL;
 
-	/* Avoid reading the vendor MMDs */
-	mmd_mask &= ~(BIT(MDIO_MMD_VEND1) | BIT(MDIO_MMD_VEND2));
-
-	return genphy_c45_read_link(phydev, mmd_mask);
+	return genphy_c45_read_link(phydev);
 }
 EXPORT_SYMBOL_GPL(gen10g_read_status);
 

include/linux/phy.h

@@ -1094,7 +1094,7 @@ int genphy_write_mmd_unsupported(struct phy_device *phdev, int devnum,
 /* Clause 45 PHY */
 int genphy_c45_restart_aneg(struct phy_device *phydev);
 int genphy_c45_aneg_done(struct phy_device *phydev);
-int genphy_c45_read_link(struct phy_device *phydev, u32 mmd_mask);
+int genphy_c45_read_link(struct phy_device *phydev);
 int genphy_c45_read_lpa(struct phy_device *phydev);
 int genphy_c45_read_pma(struct phy_device *phydev);
 int genphy_c45_pma_setup_forced(struct phy_device *phydev);

include/uapi/linux/mdio.h

@@ -123,6 +123,8 @@
 #define MDIO_DEVS_TC			MDIO_DEVS_PRESENT(MDIO_MMD_TC)
 #define MDIO_DEVS_AN			MDIO_DEVS_PRESENT(MDIO_MMD_AN)
 #define MDIO_DEVS_C22EXT		MDIO_DEVS_PRESENT(MDIO_MMD_C22EXT)
+#define MDIO_DEVS_VEND1			MDIO_DEVS_PRESENT(MDIO_MMD_VEND1)
+#define MDIO_DEVS_VEND2			MDIO_DEVS_PRESENT(MDIO_MMD_VEND2)
 
 /* Control register 2. */
 #define MDIO_PMA_CTRL2_TYPE		0x000f	/* PMA/PMD type selection */