diff --git a/drivers/net/dsa/mv88e6060.c b/drivers/net/dsa/mv88e6060.c index c29aebe1e62b..9093577755f6 100644 --- a/drivers/net/dsa/mv88e6060.c +++ b/drivers/net/dsa/mv88e6060.c @@ -26,7 +26,7 @@ static int reg_read(struct dsa_switch *ds, int addr, int reg) if (bus == NULL) return -EINVAL; - return mdiobus_read(bus, ds->pd->sw_addr + addr, reg); + return mdiobus_read_nested(bus, ds->pd->sw_addr + addr, reg); } #define REG_READ(addr, reg) \ @@ -47,7 +47,7 @@ static int reg_write(struct dsa_switch *ds, int addr, int reg, u16 val) if (bus == NULL) return -EINVAL; - return mdiobus_write(bus, ds->pd->sw_addr + addr, reg, val); + return mdiobus_write_nested(bus, ds->pd->sw_addr + addr, reg, val); } #define REG_WRITE(addr, reg, val) \ diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c index 7af96309bc07..b1b14f519d8b 100644 --- a/drivers/net/dsa/mv88e6xxx.c +++ b/drivers/net/dsa/mv88e6xxx.c @@ -24,34 +24,6 @@ #include #include "mv88e6xxx.h" -/* MDIO bus access can be nested in the case of PHYs connected to the - * internal MDIO bus of the switch, which is accessed via MDIO bus of - * the Ethernet interface. Avoid lockdep false positives by using - * mutex_lock_nested(). - */ -static int mv88e6xxx_mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) -{ - int ret; - - mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING); - ret = bus->read(bus, addr, regnum); - mutex_unlock(&bus->mdio_lock); - - return ret; -} - -static int mv88e6xxx_mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, - u16 val) -{ - int ret; - - mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING); - ret = bus->write(bus, addr, regnum, val); - mutex_unlock(&bus->mdio_lock); - - return ret; -} - /* If the switch's ADDR[4:0] strap pins are strapped to zero, it will * use all 32 SMI bus addresses on its SMI bus, and all switch registers * will be directly accessible on some {device address,register address} @@ -66,7 +38,7 @@ static int mv88e6xxx_reg_wait_ready(struct mii_bus *bus, int sw_addr) int i; for (i = 0; i < 16; i++) { - ret = mv88e6xxx_mdiobus_read(bus, sw_addr, SMI_CMD); + ret = mdiobus_read_nested(bus, sw_addr, SMI_CMD); if (ret < 0) return ret; @@ -82,7 +54,7 @@ int __mv88e6xxx_reg_read(struct mii_bus *bus, int sw_addr, int addr, int reg) int ret; if (sw_addr == 0) - return mv88e6xxx_mdiobus_read(bus, addr, reg); + return mdiobus_read_nested(bus, addr, reg); /* Wait for the bus to become free. */ ret = mv88e6xxx_reg_wait_ready(bus, sw_addr); @@ -90,8 +62,8 @@ int __mv88e6xxx_reg_read(struct mii_bus *bus, int sw_addr, int addr, int reg) return ret; /* Transmit the read command. */ - ret = mv88e6xxx_mdiobus_write(bus, sw_addr, SMI_CMD, - SMI_CMD_OP_22_READ | (addr << 5) | reg); + ret = mdiobus_write_nested(bus, sw_addr, SMI_CMD, + SMI_CMD_OP_22_READ | (addr << 5) | reg); if (ret < 0) return ret; @@ -101,7 +73,7 @@ int __mv88e6xxx_reg_read(struct mii_bus *bus, int sw_addr, int addr, int reg) return ret; /* Read the data. */ - ret = mv88e6xxx_mdiobus_read(bus, sw_addr, SMI_DATA); + ret = mdiobus_read_nested(bus, sw_addr, SMI_DATA); if (ret < 0) return ret; @@ -145,7 +117,7 @@ int __mv88e6xxx_reg_write(struct mii_bus *bus, int sw_addr, int addr, int ret; if (sw_addr == 0) - return mv88e6xxx_mdiobus_write(bus, addr, reg, val); + return mdiobus_write_nested(bus, addr, reg, val); /* Wait for the bus to become free. */ ret = mv88e6xxx_reg_wait_ready(bus, sw_addr); @@ -153,13 +125,13 @@ int __mv88e6xxx_reg_write(struct mii_bus *bus, int sw_addr, int addr, return ret; /* Transmit the data to write. */ - ret = mv88e6xxx_mdiobus_write(bus, sw_addr, SMI_DATA, val); + ret = mdiobus_write_nested(bus, sw_addr, SMI_DATA, val); if (ret < 0) return ret; /* Transmit the write command. */ - ret = mv88e6xxx_mdiobus_write(bus, sw_addr, SMI_CMD, - SMI_CMD_OP_22_WRITE | (addr << 5) | reg); + ret = mdiobus_write_nested(bus, sw_addr, SMI_CMD, + SMI_CMD_OP_22_WRITE | (addr << 5) | reg); if (ret < 0) return ret; diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 12f44c53cc8e..88cb4592b6fb 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -371,6 +371,33 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr) } EXPORT_SYMBOL(mdiobus_scan); +/** + * mdiobus_read_nested - Nested version of the mdiobus_read function + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to read + * + * In case of nested MDIO bus access avoid lockdep false positives by + * using mutex_lock_nested(). + * + * NOTE: MUST NOT be called from interrupt context, + * because the bus read/write functions may wait for an interrupt + * to conclude the operation. + */ +int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum) +{ + int retval; + + BUG_ON(in_interrupt()); + + mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING); + retval = bus->read(bus, addr, regnum); + mutex_unlock(&bus->mdio_lock); + + return retval; +} +EXPORT_SYMBOL(mdiobus_read_nested); + /** * mdiobus_read - Convenience function for reading a given MII mgmt register * @bus: the mii_bus struct @@ -395,6 +422,34 @@ int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) } EXPORT_SYMBOL(mdiobus_read); +/** + * mdiobus_write_nested - Nested version of the mdiobus_write function + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to write + * @val: value to write to @regnum + * + * In case of nested MDIO bus access avoid lockdep false positives by + * using mutex_lock_nested(). + * + * NOTE: MUST NOT be called from interrupt context, + * because the bus read/write functions may wait for an interrupt + * to conclude the operation. + */ +int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val) +{ + int err; + + BUG_ON(in_interrupt()); + + mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING); + err = bus->write(bus, addr, regnum, val); + mutex_unlock(&bus->mdio_lock); + + return err; +} +EXPORT_SYMBOL(mdiobus_write_nested); + /** * mdiobus_write - Convenience function for writing a given MII mgmt register * @bus: the mii_bus struct diff --git a/include/linux/phy.h b/include/linux/phy.h index 4c477e6ece33..05fde31b6dc6 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -213,7 +213,9 @@ static inline struct mii_bus *devm_mdiobus_alloc(struct device *dev) void devm_mdiobus_free(struct device *dev, struct mii_bus *bus); struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr); int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum); +int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum); int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val); +int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val); #define PHY_INTERRUPT_DISABLED 0x0