linux/drivers/net/dsa/mv88e6060.c
Guenter Roeck b184e497f7 dsa: Fix conversion from host device to mii bus
Commit b4d2394d01 ("dsa: Replace mii_bus with a generic host device")
replaces mii_bus with a generic host_dev, and introduces
dsa_host_dev_to_mii_bus() to support conversion from host_dev to mii_bus.
However, in some cases it uses to_mii_bus to perform that conversion.
Since host_dev is not the phy bus device but typically a platform device,
this fails and results in a crash with the affected drivers.

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff81781d35>] __mutex_lock_slowpath+0x75/0x100
PGD 406783067 PUD 406784067 PMD 0
Oops: 0002 [#1] SMP
...
Call Trace:
[<ffffffff810a538b>] ? pick_next_task_fair+0x61b/0x880
[<ffffffff81781de3>] mutex_lock+0x23/0x37
[<ffffffff81533244>] mdiobus_read+0x34/0x60
[<ffffffff8153b95a>] __mv88e6xxx_reg_read+0x8a/0xa0
[<ffffffff8153b9bc>] mv88e6xxx_reg_read+0x4c/0xa0

Fixes: b4d2394d01 ("dsa: Replace mii_bus with a generic host device")
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-17 23:52:08 -04:00

300 lines
6.6 KiB
C

/*
* net/dsa/mv88e6060.c - Driver for Marvell 88e6060 switch chips
* Copyright (c) 2008-2009 Marvell Semiconductor
*
* 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/delay.h>
#include <linux/jiffies.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/phy.h>
#include <net/dsa.h>
#define REG_PORT(p) (8 + (p))
#define REG_GLOBAL 0x0f
static int reg_read(struct dsa_switch *ds, int addr, int reg)
{
struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
if (bus == NULL)
return -EINVAL;
return mdiobus_read(bus, ds->pd->sw_addr + addr, reg);
}
#define REG_READ(addr, reg) \
({ \
int __ret; \
\
__ret = reg_read(ds, addr, reg); \
if (__ret < 0) \
return __ret; \
__ret; \
})
static int reg_write(struct dsa_switch *ds, int addr, int reg, u16 val)
{
struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
if (bus == NULL)
return -EINVAL;
return mdiobus_write(bus, ds->pd->sw_addr + addr, reg, val);
}
#define REG_WRITE(addr, reg, val) \
({ \
int __ret; \
\
__ret = reg_write(ds, addr, reg, val); \
if (__ret < 0) \
return __ret; \
})
static char *mv88e6060_probe(struct device *host_dev, int sw_addr)
{
struct mii_bus *bus = dsa_host_dev_to_mii_bus(host_dev);
int ret;
if (bus == NULL)
return NULL;
ret = mdiobus_read(bus, sw_addr + REG_PORT(0), 0x03);
if (ret >= 0) {
ret &= 0xfff0;
if (ret == 0x0600)
return "Marvell 88E6060";
}
return NULL;
}
static int mv88e6060_switch_reset(struct dsa_switch *ds)
{
int i;
int ret;
unsigned long timeout;
/* Set all ports to the disabled state. */
for (i = 0; i < 6; i++) {
ret = REG_READ(REG_PORT(i), 0x04);
REG_WRITE(REG_PORT(i), 0x04, ret & 0xfffc);
}
/* Wait for transmit queues to drain. */
usleep_range(2000, 4000);
/* Reset the switch. */
REG_WRITE(REG_GLOBAL, 0x0a, 0xa130);
/* Wait up to one second for reset to complete. */
timeout = jiffies + 1 * HZ;
while (time_before(jiffies, timeout)) {
ret = REG_READ(REG_GLOBAL, 0x00);
if ((ret & 0x8000) == 0x0000)
break;
usleep_range(1000, 2000);
}
if (time_after(jiffies, timeout))
return -ETIMEDOUT;
return 0;
}
static int mv88e6060_setup_global(struct dsa_switch *ds)
{
/* Disable discarding of frames with excessive collisions,
* set the maximum frame size to 1536 bytes, and mask all
* interrupt sources.
*/
REG_WRITE(REG_GLOBAL, 0x04, 0x0800);
/* Enable automatic address learning, set the address
* database size to 1024 entries, and set the default aging
* time to 5 minutes.
*/
REG_WRITE(REG_GLOBAL, 0x0a, 0x2130);
return 0;
}
static int mv88e6060_setup_port(struct dsa_switch *ds, int p)
{
int addr = REG_PORT(p);
/* Do not force flow control, disable Ingress and Egress
* Header tagging, disable VLAN tunneling, and set the port
* state to Forwarding. Additionally, if this is the CPU
* port, enable Ingress and Egress Trailer tagging mode.
*/
REG_WRITE(addr, 0x04, dsa_is_cpu_port(ds, p) ? 0x4103 : 0x0003);
/* Port based VLAN map: give each port its own address
* database, allow the CPU port to talk to each of the 'real'
* ports, and allow each of the 'real' ports to only talk to
* the CPU port.
*/
REG_WRITE(addr, 0x06,
((p & 0xf) << 12) |
(dsa_is_cpu_port(ds, p) ?
ds->phys_port_mask :
(1 << ds->dst->cpu_port)));
/* Port Association Vector: when learning source addresses
* of packets, add the address to the address database using
* a port bitmap that has only the bit for this port set and
* the other bits clear.
*/
REG_WRITE(addr, 0x0b, 1 << p);
return 0;
}
static int mv88e6060_setup(struct dsa_switch *ds)
{
int i;
int ret;
ret = mv88e6060_switch_reset(ds);
if (ret < 0)
return ret;
/* @@@ initialise atu */
ret = mv88e6060_setup_global(ds);
if (ret < 0)
return ret;
for (i = 0; i < 6; i++) {
ret = mv88e6060_setup_port(ds, i);
if (ret < 0)
return ret;
}
return 0;
}
static int mv88e6060_set_addr(struct dsa_switch *ds, u8 *addr)
{
REG_WRITE(REG_GLOBAL, 0x01, (addr[0] << 8) | addr[1]);
REG_WRITE(REG_GLOBAL, 0x02, (addr[2] << 8) | addr[3]);
REG_WRITE(REG_GLOBAL, 0x03, (addr[4] << 8) | addr[5]);
return 0;
}
static int mv88e6060_port_to_phy_addr(int port)
{
if (port >= 0 && port <= 5)
return port;
return -1;
}
static int mv88e6060_phy_read(struct dsa_switch *ds, int port, int regnum)
{
int addr;
addr = mv88e6060_port_to_phy_addr(port);
if (addr == -1)
return 0xffff;
return reg_read(ds, addr, regnum);
}
static int
mv88e6060_phy_write(struct dsa_switch *ds, int port, int regnum, u16 val)
{
int addr;
addr = mv88e6060_port_to_phy_addr(port);
if (addr == -1)
return 0xffff;
return reg_write(ds, addr, regnum, val);
}
static void mv88e6060_poll_link(struct dsa_switch *ds)
{
int i;
for (i = 0; i < DSA_MAX_PORTS; i++) {
struct net_device *dev;
int uninitialized_var(port_status);
int link;
int speed;
int duplex;
int fc;
dev = ds->ports[i];
if (dev == NULL)
continue;
link = 0;
if (dev->flags & IFF_UP) {
port_status = reg_read(ds, REG_PORT(i), 0x00);
if (port_status < 0)
continue;
link = !!(port_status & 0x1000);
}
if (!link) {
if (netif_carrier_ok(dev)) {
netdev_info(dev, "link down\n");
netif_carrier_off(dev);
}
continue;
}
speed = (port_status & 0x0100) ? 100 : 10;
duplex = (port_status & 0x0200) ? 1 : 0;
fc = ((port_status & 0xc000) == 0xc000) ? 1 : 0;
if (!netif_carrier_ok(dev)) {
netdev_info(dev,
"link up, %d Mb/s, %s duplex, flow control %sabled\n",
speed,
duplex ? "full" : "half",
fc ? "en" : "dis");
netif_carrier_on(dev);
}
}
}
static struct dsa_switch_driver mv88e6060_switch_driver = {
.tag_protocol = DSA_TAG_PROTO_TRAILER,
.probe = mv88e6060_probe,
.setup = mv88e6060_setup,
.set_addr = mv88e6060_set_addr,
.phy_read = mv88e6060_phy_read,
.phy_write = mv88e6060_phy_write,
.poll_link = mv88e6060_poll_link,
};
static int __init mv88e6060_init(void)
{
register_switch_driver(&mv88e6060_switch_driver);
return 0;
}
module_init(mv88e6060_init);
static void __exit mv88e6060_cleanup(void)
{
unregister_switch_driver(&mv88e6060_switch_driver);
}
module_exit(mv88e6060_cleanup);
MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
MODULE_DESCRIPTION("Driver for Marvell 88E6060 ethernet switch chip");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mv88e6060");