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Commit 654c9c54 authored Oct 23, 2015 by David S. Miller

Merge branch 'mdiobus_nested_read_write'



Neil Armstrong says:

====================
Refactor nested mdiobus read/write functions

In order to avoid locked signal false positive for nested mdiobus
read/write calls, nested code was introduced in mv88e6xxx and
mdio-mux.
But mv88e6060 also needs such nested mdiobus read/write calls.
For sake of refactoring, introduce nested variants of mdiobus read/write
and make them used by mv88e6xxx and mv88e6060.
In a next patch, mdio-mux should also use these variant calls.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

parents 6fb3b6b5 f0505610

drivers/net/dsa/mv88e6060.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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) \

drivers/net/dsa/mv88e6xxx.c

+9 −37

Original line number	Diff line number	Diff line
		@@ -24,34 +24,6 @@
		#include <net/switchdev.h>
		#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);
		@@ -90,7 +62,7 @@ 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,
		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);
		@@ -153,12 +125,12 @@ 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,
		ret = mdiobus_write_nested(bus, sw_addr, SMI_CMD,
		SMI_CMD_OP_22_WRITE \| (addr << 5) \| reg);
		if (ret < 0)
		return ret;

drivers/net/phy/mdio_bus.c

+55 −0

Original line number	Diff line number	Diff line
		@@ -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

include/linux/phy.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -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