Commit 654c9c54 authored by David S. Miller's avatar David S. Miller
Browse files

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: default avatarDavid 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

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