linux/drivers/net/phy/mdio_bus.c
Anton Vorontsov 6f051069d8 phylib: Fix oops in suspend/resume paths
Suspend/resume routines check for phydrv != NULL, but that is
wrong because "phydrv" comes from container_of(drv). If drv is NULL,
then container_of(drv) will return non-NULL result, and the checks
won't work.

The Freescale TBI PHYs are driver-less, so "drv" is NULL, and that
leads to the following oops:

Unable to handle kernel paging request for data at address 0xffffffe4
Faulting instruction address: 0xc0215554
Oops: Kernel access of bad area, sig: 11 [#1]
[...]
NIP [c0215554] mdio_bus_suspend+0x34/0x70
LR [c01cc508] suspend_device+0x258/0x2bc
Call Trace:
[cfad3da0] [cfad3db8] 0xcfad3db8 (unreliable)
[cfad3db0] [c01cc508] suspend_device+0x258/0x2bc
[cfad3dd0] [c01cc62c] dpm_suspend+0xc0/0x140
[cfad3e20] [c01cc6f4] device_suspend+0x48/0x5c
[cfad3e40] [c0068dd8] suspend_devices_and_enter+0x8c/0x148
[cfad3e60] [c00690f8] enter_state+0x100/0x118
[cfad3e80] [c00691c0] state_store+0xb0/0xe4
[cfad3ea0] [c018c938] kobj_attr_store+0x24/0x3c
[cfad3eb0] [c00ea9a8] flush_write_buffer+0x58/0x7c
[cfad3ed0] [c00eadf0] sysfs_write_file+0x58/0xa0
[cfad3ef0] [c009e810] vfs_write+0xb4/0x16c
[cfad3f10] [c009ed40] sys_write+0x4c/0x90
[cfad3f40] [c0014954] ret_from_syscall+0x0/0x38
[...]

This patch fixes the issue, plus removes unneeded parentheses
and fixes indentation level in mdio_bus_suspend().

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-22 13:51:24 -08:00

344 lines
7.7 KiB
C

/*
* drivers/net/phy/mdio_bus.c
*
* MDIO Bus interface
*
* Author: Andy Fleming
*
* Copyright (c) 2004 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/phy.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
/**
* mdiobus_alloc - allocate a mii_bus structure
*
* Description: called by a bus driver to allocate an mii_bus
* structure to fill in.
*/
struct mii_bus *mdiobus_alloc(void)
{
struct mii_bus *bus;
bus = kzalloc(sizeof(*bus), GFP_KERNEL);
if (bus != NULL)
bus->state = MDIOBUS_ALLOCATED;
return bus;
}
EXPORT_SYMBOL(mdiobus_alloc);
/**
* mdiobus_release - mii_bus device release callback
* @d: the target struct device that contains the mii_bus
*
* Description: called when the last reference to an mii_bus is
* dropped, to free the underlying memory.
*/
static void mdiobus_release(struct device *d)
{
struct mii_bus *bus = to_mii_bus(d);
BUG_ON(bus->state != MDIOBUS_RELEASED &&
/* for compatibility with error handling in drivers */
bus->state != MDIOBUS_ALLOCATED);
kfree(bus);
}
static struct class mdio_bus_class = {
.name = "mdio_bus",
.dev_release = mdiobus_release,
};
/**
* mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
* @bus: target mii_bus
*
* Description: Called by a bus driver to bring up all the PHYs
* on a given bus, and attach them to the bus.
*
* Returns 0 on success or < 0 on error.
*/
int mdiobus_register(struct mii_bus *bus)
{
int i, err;
if (NULL == bus || NULL == bus->name ||
NULL == bus->read ||
NULL == bus->write)
return -EINVAL;
BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
bus->state != MDIOBUS_UNREGISTERED);
bus->dev.parent = bus->parent;
bus->dev.class = &mdio_bus_class;
bus->dev.groups = NULL;
dev_set_name(&bus->dev, bus->id);
err = device_register(&bus->dev);
if (err) {
printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
return -EINVAL;
}
mutex_init(&bus->mdio_lock);
if (bus->reset)
bus->reset(bus);
for (i = 0; i < PHY_MAX_ADDR; i++) {
bus->phy_map[i] = NULL;
if ((bus->phy_mask & (1 << i)) == 0) {
struct phy_device *phydev;
phydev = mdiobus_scan(bus, i);
if (IS_ERR(phydev)) {
err = PTR_ERR(phydev);
goto error;
}
}
}
bus->state = MDIOBUS_REGISTERED;
pr_info("%s: probed\n", bus->name);
return 0;
error:
while (--i >= 0) {
if (bus->phy_map[i])
device_unregister(&bus->phy_map[i]->dev);
}
device_del(&bus->dev);
return err;
}
EXPORT_SYMBOL(mdiobus_register);
void mdiobus_unregister(struct mii_bus *bus)
{
int i;
BUG_ON(bus->state != MDIOBUS_REGISTERED);
bus->state = MDIOBUS_UNREGISTERED;
device_del(&bus->dev);
for (i = 0; i < PHY_MAX_ADDR; i++) {
if (bus->phy_map[i])
device_unregister(&bus->phy_map[i]->dev);
}
}
EXPORT_SYMBOL(mdiobus_unregister);
/**
* mdiobus_free - free a struct mii_bus
* @bus: mii_bus to free
*
* This function releases the reference to the underlying device
* object in the mii_bus. If this is the last reference, the mii_bus
* will be freed.
*/
void mdiobus_free(struct mii_bus *bus)
{
/*
* For compatibility with error handling in drivers.
*/
if (bus->state == MDIOBUS_ALLOCATED) {
kfree(bus);
return;
}
BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
bus->state = MDIOBUS_RELEASED;
put_device(&bus->dev);
}
EXPORT_SYMBOL(mdiobus_free);
struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
{
struct phy_device *phydev;
int err;
phydev = get_phy_device(bus, addr);
if (IS_ERR(phydev) || phydev == NULL)
return phydev;
/* There's a PHY at this address
* We need to set:
* 1) IRQ
* 2) bus_id
* 3) parent
* 4) bus
* 5) mii_bus
* And, we need to register it */
phydev->irq = bus->irq != NULL ? bus->irq[addr] : PHY_POLL;
phydev->dev.parent = bus->parent;
phydev->dev.bus = &mdio_bus_type;
dev_set_name(&phydev->dev, PHY_ID_FMT, bus->id, addr);
phydev->bus = bus;
/* Run all of the fixups for this PHY */
phy_scan_fixups(phydev);
err = device_register(&phydev->dev);
if (err) {
printk(KERN_ERR "phy %d failed to register\n", addr);
phy_device_free(phydev);
phydev = NULL;
}
bus->phy_map[addr] = phydev;
return phydev;
}
EXPORT_SYMBOL(mdiobus_scan);
/**
* mdiobus_read - Convenience function for reading a given MII mgmt register
* @bus: the mii_bus struct
* @addr: the phy address
* @regnum: register number to read
*
* 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(struct mii_bus *bus, int addr, u16 regnum)
{
int retval;
BUG_ON(in_interrupt());
mutex_lock(&bus->mdio_lock);
retval = bus->read(bus, addr, regnum);
mutex_unlock(&bus->mdio_lock);
return retval;
}
EXPORT_SYMBOL(mdiobus_read);
/**
* mdiobus_write - Convenience function for writing a given MII mgmt register
* @bus: the mii_bus struct
* @addr: the phy address
* @regnum: register number to write
* @val: value to write to @regnum
*
* 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(struct mii_bus *bus, int addr, u16 regnum, u16 val)
{
int err;
BUG_ON(in_interrupt());
mutex_lock(&bus->mdio_lock);
err = bus->write(bus, addr, regnum, val);
mutex_unlock(&bus->mdio_lock);
return err;
}
EXPORT_SYMBOL(mdiobus_write);
/**
* mdio_bus_match - determine if given PHY driver supports the given PHY device
* @dev: target PHY device
* @drv: given PHY driver
*
* Description: Given a PHY device, and a PHY driver, return 1 if
* the driver supports the device. Otherwise, return 0.
*/
static int mdio_bus_match(struct device *dev, struct device_driver *drv)
{
struct phy_device *phydev = to_phy_device(dev);
struct phy_driver *phydrv = to_phy_driver(drv);
return ((phydrv->phy_id & phydrv->phy_id_mask) ==
(phydev->phy_id & phydrv->phy_id_mask));
}
/* Suspend and resume. Copied from platform_suspend and
* platform_resume
*/
static int mdio_bus_suspend(struct device * dev, pm_message_t state)
{
int ret = 0;
struct device_driver *drv = dev->driver;
struct phy_driver *phydrv = to_phy_driver(drv);
struct phy_device *phydev = to_phy_device(dev);
if (drv && phydrv->suspend && !device_may_wakeup(phydev->dev.parent))
ret = phydrv->suspend(phydev);
return ret;
}
static int mdio_bus_resume(struct device * dev)
{
int ret = 0;
struct device_driver *drv = dev->driver;
struct phy_driver *phydrv = to_phy_driver(drv);
struct phy_device *phydev = to_phy_device(dev);
if (drv && phydrv->resume && !device_may_wakeup(phydev->dev.parent))
ret = phydrv->resume(phydev);
return ret;
}
struct bus_type mdio_bus_type = {
.name = "mdio_bus",
.match = mdio_bus_match,
.suspend = mdio_bus_suspend,
.resume = mdio_bus_resume,
};
EXPORT_SYMBOL(mdio_bus_type);
int __init mdio_bus_init(void)
{
int ret;
ret = class_register(&mdio_bus_class);
if (!ret) {
ret = bus_register(&mdio_bus_type);
if (ret)
class_unregister(&mdio_bus_class);
}
return ret;
}
void mdio_bus_exit(void)
{
class_unregister(&mdio_bus_class);
bus_unregister(&mdio_bus_type);
}