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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>
This commit is contained in:
David S. Miller 2015-10-23 05:57:53 -07:00
parent 6fb3b6b57a f050561050
commit 654c9c543a
4 changed files with 68 additions and 39 deletions
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4
drivers/net/dsa/mv88e6060.c
View File

@ -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) \

46
drivers/net/dsa/mv88e6xxx.c
View File

@ -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);
@ -90,8 +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;

55
drivers/net/phy/mdio_bus.c
View File

@ -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

2
include/linux/phy.h
View File

@ -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