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linux/net/dsa/dsa2.c
Vladimir Oltean 6dc43cd3aa net: dsa: Fix use-after-free in probing of DSA switch tree 
DSA sets up a switch tree little by little. Every switch of the N
members of the tree calls dsa_register_switch, and (N - 1) will just
touch the dst->ports list with their ports and quickly exit. Only the
last switch that calls dsa_register_switch will find all DSA links
complete in dsa_tree_setup_routing_table, and not return zero as a
result but instead go ahead and set up the entire DSA switch tree
(practically on behalf of the other switches too).

The trouble is that the (N - 1) switches don't clean up after themselves
after they get an error such as EPROBE_DEFER. Their footprint left in
dst->ports by dsa_switch_touch_ports is still there. And switch N, the
one responsible with actually setting up the tree, is going to work with
those stale dp, dp->ds and dp->ds->dev pointers. In particular ds and
ds->dev might get freed by the device driver.

Be there a 2-switch tree and the following calling order:
- Switch 1 calls dsa_register_switch
  - Calls dsa_switch_touch_ports, populates dst->ports
  - Calls dsa_port_parse_cpu, gets -EPROBE_DEFER, exits.
- Switch 2 calls dsa_register_switch
  - Calls dsa_switch_touch_ports, populates dst->ports
  - Probe doesn't get deferred, so it goes ahead.
  - Calls dsa_tree_setup_routing_table, which returns "complete == true"
    due to Switch 1 having called dsa_switch_touch_ports before.
  - Because the DSA links are complete, it calls dsa_tree_setup_switches
    now.
  - dsa_tree_setup_switches iterates through dst->ports, initializing
    the Switch 1 ds structure (invalid) and the Switch 2 ds structure
    (valid).
  - Undefined behavior (use after free, sometimes NULL pointers, etc).

Real example below (debugging prints added by me, as well as guards
against NULL pointers):

[    5.477947] dsa_tree_setup_switches: Setting up port 0 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.313002] dsa_tree_setup_switches: Setting up port 1 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.319932] dsa_tree_setup_switches: Setting up port 2 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.329693] dsa_tree_setup_switches: Setting up port 3 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.339458] dsa_tree_setup_switches: Setting up port 4 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.349226] dsa_tree_setup_switches: Setting up port 5 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.358991] dsa_tree_setup_switches: Setting up port 6 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.368758] dsa_tree_setup_switches: Setting up port 7 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.378524] dsa_tree_setup_switches: Setting up port 8 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.388291] dsa_tree_setup_switches: Setting up port 9 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.398057] dsa_tree_setup_switches: Setting up port 10 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.407912] dsa_tree_setup_switches: Setting up port 0 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.417682] dsa_tree_setup_switches: Setting up port 1 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.427446] dsa_tree_setup_switches: Setting up port 2 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.437212] dsa_tree_setup_switches: Setting up port 3 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.446979] dsa_tree_setup_switches: Setting up port 4 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.456744] dsa_tree_setup_switches: Setting up port 5 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.466512] dsa_tree_setup_switches: Setting up port 6 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.476277] dsa_tree_setup_switches: Setting up port 7 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.486043] dsa_tree_setup_switches: Setting up port 8 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.495810] dsa_tree_setup_switches: Setting up port 9 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.505577] dsa_tree_setup_switches: Setting up port 10 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.515433] dsa_tree_setup_switches: Setting up port 0 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.354120] dsa_tree_setup_switches: Setting up port 1 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.361045] dsa_tree_setup_switches: Setting up port 2 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.370805] dsa_tree_setup_switches: Setting up port 3 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.380571] dsa_tree_setup_switches: Setting up port 4 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.390337] dsa_tree_setup_switches: Setting up port 5 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.400104] dsa_tree_setup_switches: Setting up port 6 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.409872] dsa_tree_setup_switches: Setting up port 7 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.419637] dsa_tree_setup_switches: Setting up port 8 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.429403] dsa_tree_setup_switches: Setting up port 9 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.439169] dsa_tree_setup_switches: Setting up port 10 of switch ffffff803db15b80 (dev ffffff803d8e4800)

The solution is to recognize that the functions that call
dsa_switch_touch_ports (dsa_switch_parse_of, dsa_switch_parse) have side
effects, and therefore one should clean up their side effects on error
path. The cleanup of dst->ports was taken from dsa_switch_remove and
moved into a dedicated dsa_switch_release_ports function, which should
really be per-switch (free only the members of dst->ports that are also
members of ds, instead of all switch ports).

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-27 11:12:46 +01:00

936 lines
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/dsa/dsa2.c - Hardware switch handling, binding version 2
* Copyright (c) 2008-2009 Marvell Semiconductor
* Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
* Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/rtnetlink.h>
#include <linux/of.h>
#include <linux/of_net.h>
#include <net/devlink.h>
#include "dsa_priv.h"
static LIST_HEAD(dsa_tree_list);
static DEFINE_MUTEX(dsa2_mutex);
static const struct devlink_ops dsa_devlink_ops = {
};
static struct dsa_switch_tree *dsa_tree_find(int index)
{
struct dsa_switch_tree *dst;
list_for_each_entry(dst, &dsa_tree_list, list)
if (dst->index == index)
return dst;
return NULL;
}
static struct dsa_switch_tree *dsa_tree_alloc(int index)
{
struct dsa_switch_tree *dst;
dst = kzalloc(sizeof(*dst), GFP_KERNEL);
if (!dst)
return NULL;
dst->index = index;
INIT_LIST_HEAD(&dst->rtable);
INIT_LIST_HEAD(&dst->ports);
INIT_LIST_HEAD(&dst->list);
list_add_tail(&dst->list, &dsa_tree_list);
kref_init(&dst->refcount);
return dst;
}
static void dsa_tree_free(struct dsa_switch_tree *dst)
{
list_del(&dst->list);
kfree(dst);
}
static struct dsa_switch_tree *dsa_tree_get(struct dsa_switch_tree *dst)
{
if (dst)
kref_get(&dst->refcount);
return dst;
}
static struct dsa_switch_tree *dsa_tree_touch(int index)
{
struct dsa_switch_tree *dst;
dst = dsa_tree_find(index);
if (dst)
return dsa_tree_get(dst);
else
return dsa_tree_alloc(index);
}
static void dsa_tree_release(struct kref *ref)
{
struct dsa_switch_tree *dst;
dst = container_of(ref, struct dsa_switch_tree, refcount);
dsa_tree_free(dst);
}
static void dsa_tree_put(struct dsa_switch_tree *dst)
{
if (dst)
kref_put(&dst->refcount, dsa_tree_release);
}
static bool dsa_port_is_dsa(struct dsa_port *port)
{
return port->type == DSA_PORT_TYPE_DSA;
}
static bool dsa_port_is_cpu(struct dsa_port *port)
{
return port->type == DSA_PORT_TYPE_CPU;
}
static bool dsa_port_is_user(struct dsa_port *dp)
{
return dp->type == DSA_PORT_TYPE_USER;
}
static struct dsa_port *dsa_tree_find_port_by_node(struct dsa_switch_tree *dst,
struct device_node *dn)
{
struct dsa_port *dp;
list_for_each_entry(dp, &dst->ports, list)
if (dp->dn == dn)
return dp;
return NULL;
}
static struct dsa_link *dsa_link_touch(struct dsa_port *dp,
struct dsa_port *link_dp)
{
struct dsa_switch *ds = dp->ds;
struct dsa_switch_tree *dst;
struct dsa_link *dl;
dst = ds->dst;
list_for_each_entry(dl, &dst->rtable, list)
if (dl->dp == dp && dl->link_dp == link_dp)
return dl;
dl = kzalloc(sizeof(*dl), GFP_KERNEL);
if (!dl)
return NULL;
dl->dp = dp;
dl->link_dp = link_dp;
INIT_LIST_HEAD(&dl->list);
list_add_tail(&dl->list, &dst->rtable);
return dl;
}
static bool dsa_port_setup_routing_table(struct dsa_port *dp)
{
struct dsa_switch *ds = dp->ds;
struct dsa_switch_tree *dst = ds->dst;
struct device_node *dn = dp->dn;
struct of_phandle_iterator it;
struct dsa_port *link_dp;
struct dsa_link *dl;
int err;
of_for_each_phandle(&it, err, dn, "link", NULL, 0) {
link_dp = dsa_tree_find_port_by_node(dst, it.node);
if (!link_dp) {
of_node_put(it.node);
return false;
}
dl = dsa_link_touch(dp, link_dp);
if (!dl) {
of_node_put(it.node);
return false;
}
}
return true;
}
static bool dsa_tree_setup_routing_table(struct dsa_switch_tree *dst)
{
bool complete = true;
struct dsa_port *dp;
list_for_each_entry(dp, &dst->ports, list) {
if (dsa_port_is_dsa(dp)) {
complete = dsa_port_setup_routing_table(dp);
if (!complete)
break;
}
}
return complete;
}
static struct dsa_port *dsa_tree_find_first_cpu(struct dsa_switch_tree *dst)
{
struct dsa_port *dp;
list_for_each_entry(dp, &dst->ports, list)
if (dsa_port_is_cpu(dp))
return dp;
return NULL;
}
static int dsa_tree_setup_default_cpu(struct dsa_switch_tree *dst)
{
struct dsa_port *cpu_dp, *dp;
cpu_dp = dsa_tree_find_first_cpu(dst);
if (!cpu_dp) {
pr_err("DSA: tree %d has no CPU port\n", dst->index);
return -EINVAL;
}
/* Assign the default CPU port to all ports of the fabric */
list_for_each_entry(dp, &dst->ports, list)
if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
dp->cpu_dp = cpu_dp;
return 0;
}
static void dsa_tree_teardown_default_cpu(struct dsa_switch_tree *dst)
{
struct dsa_port *dp;
list_for_each_entry(dp, &dst->ports, list)
if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
dp->cpu_dp = NULL;
}
static int dsa_port_setup(struct dsa_port *dp)
{
struct dsa_switch *ds = dp->ds;
struct dsa_switch_tree *dst = ds->dst;
const unsigned char *id = (const unsigned char *)&dst->index;
const unsigned char len = sizeof(dst->index);
struct devlink_port *dlp = &dp->devlink_port;
bool dsa_port_link_registered = false;
bool devlink_port_registered = false;
struct devlink *dl = ds->devlink;
bool dsa_port_enabled = false;
int err = 0;
if (dp->setup)
return 0;
switch (dp->type) {
case DSA_PORT_TYPE_UNUSED:
dsa_port_disable(dp);
break;
case DSA_PORT_TYPE_CPU:
memset(dlp, 0, sizeof(*dlp));
devlink_port_attrs_set(dlp, DEVLINK_PORT_FLAVOUR_CPU,
dp->index, false, 0, id, len);
err = devlink_port_register(dl, dlp, dp->index);
if (err)
break;
devlink_port_registered = true;
err = dsa_port_link_register_of(dp);
if (err)
break;
dsa_port_link_registered = true;
err = dsa_port_enable(dp, NULL);
if (err)
break;
dsa_port_enabled = true;
break;
case DSA_PORT_TYPE_DSA:
memset(dlp, 0, sizeof(*dlp));
devlink_port_attrs_set(dlp, DEVLINK_PORT_FLAVOUR_DSA,
dp->index, false, 0, id, len);
err = devlink_port_register(dl, dlp, dp->index);
if (err)
break;
devlink_port_registered = true;
err = dsa_port_link_register_of(dp);
if (err)
break;
dsa_port_link_registered = true;
err = dsa_port_enable(dp, NULL);
if (err)
break;
dsa_port_enabled = true;
break;
case DSA_PORT_TYPE_USER:
memset(dlp, 0, sizeof(*dlp));
devlink_port_attrs_set(dlp, DEVLINK_PORT_FLAVOUR_PHYSICAL,
dp->index, false, 0, id, len);
err = devlink_port_register(dl, dlp, dp->index);
if (err)
break;
devlink_port_registered = true;
dp->mac = of_get_mac_address(dp->dn);
err = dsa_slave_create(dp);
if (err)
break;
devlink_port_type_eth_set(dlp, dp->slave);
break;
}
if (err && dsa_port_enabled)
dsa_port_disable(dp);
if (err && dsa_port_link_registered)
dsa_port_link_unregister_of(dp);
if (err && devlink_port_registered)
devlink_port_unregister(dlp);
if (err)
return err;
dp->setup = true;
return 0;
}
static void dsa_port_teardown(struct dsa_port *dp)
{
struct devlink_port *dlp = &dp->devlink_port;
if (!dp->setup)
return;
switch (dp->type) {
case DSA_PORT_TYPE_UNUSED:
break;
case DSA_PORT_TYPE_CPU:
dsa_port_disable(dp);
dsa_tag_driver_put(dp->tag_ops);
devlink_port_unregister(dlp);
dsa_port_link_unregister_of(dp);
break;
case DSA_PORT_TYPE_DSA:
dsa_port_disable(dp);
devlink_port_unregister(dlp);
dsa_port_link_unregister_of(dp);
break;
case DSA_PORT_TYPE_USER:
devlink_port_unregister(dlp);
if (dp->slave) {
dsa_slave_destroy(dp->slave);
dp->slave = NULL;
}
break;
}
dp->setup = false;
}
static int dsa_switch_setup(struct dsa_switch *ds)
{
struct dsa_devlink_priv *dl_priv;
int err;
if (ds->setup)
return 0;
/* Initialize ds->phys_mii_mask before registering the slave MDIO bus
* driver and before ops->setup() has run, since the switch drivers and
* the slave MDIO bus driver rely on these values for probing PHY
* devices or not
*/
ds->phys_mii_mask |= dsa_user_ports(ds);
/* Add the switch to devlink before calling setup, so that setup can
* add dpipe tables
*/
ds->devlink = devlink_alloc(&dsa_devlink_ops, sizeof(*dl_priv));
if (!ds->devlink)
return -ENOMEM;
dl_priv = devlink_priv(ds->devlink);
dl_priv->ds = ds;
err = devlink_register(ds->devlink, ds->dev);
if (err)
goto free_devlink;
err = dsa_switch_register_notifier(ds);
if (err)
goto unregister_devlink;
err = ds->ops->setup(ds);
if (err < 0)
goto unregister_notifier;
devlink_params_publish(ds->devlink);
if (!ds->slave_mii_bus && ds->ops->phy_read) {
ds->slave_mii_bus = devm_mdiobus_alloc(ds->dev);
if (!ds->slave_mii_bus) {
err = -ENOMEM;
goto unregister_notifier;
}
dsa_slave_mii_bus_init(ds);
err = mdiobus_register(ds->slave_mii_bus);
if (err < 0)
goto unregister_notifier;
}
ds->setup = true;
return 0;
unregister_notifier:
dsa_switch_unregister_notifier(ds);
unregister_devlink:
devlink_unregister(ds->devlink);
free_devlink:
devlink_free(ds->devlink);
ds->devlink = NULL;
return err;
}
static void dsa_switch_teardown(struct dsa_switch *ds)
{
if (!ds->setup)
return;
if (ds->slave_mii_bus && ds->ops->phy_read)
mdiobus_unregister(ds->slave_mii_bus);
dsa_switch_unregister_notifier(ds);
if (ds->ops->teardown)
ds->ops->teardown(ds);
if (ds->devlink) {
devlink_unregister(ds->devlink);
devlink_free(ds->devlink);
ds->devlink = NULL;
}
ds->setup = false;
}
static int dsa_tree_setup_switches(struct dsa_switch_tree *dst)
{
struct dsa_port *dp;
int err;
list_for_each_entry(dp, &dst->ports, list) {
err = dsa_switch_setup(dp->ds);
if (err)
goto teardown;
}
list_for_each_entry(dp, &dst->ports, list) {
err = dsa_port_setup(dp);
if (err)
goto teardown;
}
return 0;
teardown:
list_for_each_entry(dp, &dst->ports, list)
dsa_port_teardown(dp);
list_for_each_entry(dp, &dst->ports, list)
dsa_switch_teardown(dp->ds);
return err;
}
static void dsa_tree_teardown_switches(struct dsa_switch_tree *dst)
{
struct dsa_port *dp;
list_for_each_entry(dp, &dst->ports, list)
dsa_port_teardown(dp);
list_for_each_entry(dp, &dst->ports, list)
dsa_switch_teardown(dp->ds);
}
static int dsa_tree_setup_master(struct dsa_switch_tree *dst)
{
struct dsa_port *dp;
int err;
list_for_each_entry(dp, &dst->ports, list) {
if (dsa_port_is_cpu(dp)) {
err = dsa_master_setup(dp->master, dp);
if (err)
return err;
}
}
return 0;
}
static void dsa_tree_teardown_master(struct dsa_switch_tree *dst)
{
struct dsa_port *dp;
list_for_each_entry(dp, &dst->ports, list)
if (dsa_port_is_cpu(dp))
dsa_master_teardown(dp->master);
}
static int dsa_tree_setup(struct dsa_switch_tree *dst)
{
bool complete;
int err;
if (dst->setup) {
pr_err("DSA: tree %d already setup! Disjoint trees?\n",
dst->index);
return -EEXIST;
}
complete = dsa_tree_setup_routing_table(dst);
if (!complete)
return 0;
err = dsa_tree_setup_default_cpu(dst);
if (err)
return err;
err = dsa_tree_setup_switches(dst);
if (err)
goto teardown_default_cpu;
err = dsa_tree_setup_master(dst);
if (err)
goto teardown_switches;
dst->setup = true;
pr_info("DSA: tree %d setup\n", dst->index);
return 0;
teardown_switches:
dsa_tree_teardown_switches(dst);
teardown_default_cpu:
dsa_tree_teardown_default_cpu(dst);
return err;
}
static void dsa_tree_teardown(struct dsa_switch_tree *dst)
{
struct dsa_link *dl, *next;
if (!dst->setup)
return;
dsa_tree_teardown_master(dst);
dsa_tree_teardown_switches(dst);
dsa_tree_teardown_default_cpu(dst);
list_for_each_entry_safe(dl, next, &dst->rtable, list) {
list_del(&dl->list);
kfree(dl);
}
pr_info("DSA: tree %d torn down\n", dst->index);
dst->setup = false;
}
static struct dsa_port *dsa_port_touch(struct dsa_switch *ds, int index)
{
struct dsa_switch_tree *dst = ds->dst;
struct dsa_port *dp;
list_for_each_entry(dp, &dst->ports, list)
if (dp->ds == ds && dp->index == index)
return dp;
dp = kzalloc(sizeof(*dp), GFP_KERNEL);
if (!dp)
return NULL;
dp->ds = ds;
dp->index = index;
INIT_LIST_HEAD(&dp->list);
list_add_tail(&dp->list, &dst->ports);
return dp;
}
static int dsa_port_parse_user(struct dsa_port *dp, const char *name)
{
if (!name)
name = "eth%d";
dp->type = DSA_PORT_TYPE_USER;
dp->name = name;
return 0;
}
static int dsa_port_parse_dsa(struct dsa_port *dp)
{
dp->type = DSA_PORT_TYPE_DSA;
return 0;
}
static enum dsa_tag_protocol dsa_get_tag_protocol(struct dsa_port *dp,
struct net_device *master)
{
enum dsa_tag_protocol tag_protocol = DSA_TAG_PROTO_NONE;
struct dsa_switch *mds, *ds = dp->ds;
unsigned int mdp_upstream;
struct dsa_port *mdp;
/* It is possible to stack DSA switches onto one another when that
* happens the switch driver may want to know if its tagging protocol
* is going to work in such a configuration.
*/
if (dsa_slave_dev_check(master)) {
mdp = dsa_slave_to_port(master);
mds = mdp->ds;
mdp_upstream = dsa_upstream_port(mds, mdp->index);
tag_protocol = mds->ops->get_tag_protocol(mds, mdp_upstream,
DSA_TAG_PROTO_NONE);
}
/* If the master device is not itself a DSA slave in a disjoint DSA
* tree, then return immediately.
*/
return ds->ops->get_tag_protocol(ds, dp->index, tag_protocol);
}
static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
{
struct dsa_switch *ds = dp->ds;
struct dsa_switch_tree *dst = ds->dst;
const struct dsa_device_ops *tag_ops;
enum dsa_tag_protocol tag_protocol;
tag_protocol = dsa_get_tag_protocol(dp, master);
tag_ops = dsa_tag_driver_get(tag_protocol);
if (IS_ERR(tag_ops)) {
if (PTR_ERR(tag_ops) == -ENOPROTOOPT)
return -EPROBE_DEFER;
dev_warn(ds->dev, "No tagger for this switch\n");
dp->master = NULL;
return PTR_ERR(tag_ops);
}
dp->master = master;
dp->type = DSA_PORT_TYPE_CPU;
dp->filter = tag_ops->filter;
dp->rcv = tag_ops->rcv;
dp->tag_ops = tag_ops;
dp->dst = dst;
return 0;
}
static int dsa_port_parse_of(struct dsa_port *dp, struct device_node *dn)
{
struct device_node *ethernet = of_parse_phandle(dn, "ethernet", 0);
const char *name = of_get_property(dn, "label", NULL);
bool link = of_property_read_bool(dn, "link");
dp->dn = dn;
if (ethernet) {
struct net_device *master;
master = of_find_net_device_by_node(ethernet);
if (!master)
return -EPROBE_DEFER;
return dsa_port_parse_cpu(dp, master);
}
if (link)
return dsa_port_parse_dsa(dp);
return dsa_port_parse_user(dp, name);
}
static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
struct device_node *dn)
{
struct device_node *ports, *port;
struct dsa_port *dp;
int err = 0;
u32 reg;
ports = of_get_child_by_name(dn, "ports");
if (!ports) {
dev_err(ds->dev, "no ports child node found\n");
return -EINVAL;
}
for_each_available_child_of_node(ports, port) {
err = of_property_read_u32(port, "reg", &reg);
if (err)
goto out_put_node;
if (reg >= ds->num_ports) {
err = -EINVAL;
goto out_put_node;
}
dp = dsa_to_port(ds, reg);
err = dsa_port_parse_of(dp, port);
if (err)
goto out_put_node;
}
out_put_node:
of_node_put(ports);
return err;
}
static int dsa_switch_parse_member_of(struct dsa_switch *ds,
struct device_node *dn)
{
u32 m[2] = { 0, 0 };
int sz;
/* Don't error out if this optional property isn't found */
sz = of_property_read_variable_u32_array(dn, "dsa,member", m, 2, 2);
if (sz < 0 && sz != -EINVAL)
return sz;
ds->index = m[1];
ds->dst = dsa_tree_touch(m[0]);
if (!ds->dst)
return -ENOMEM;
return 0;
}
static int dsa_switch_touch_ports(struct dsa_switch *ds)
{
struct dsa_port *dp;
int port;
for (port = 0; port < ds->num_ports; port++) {
dp = dsa_port_touch(ds, port);
if (!dp)
return -ENOMEM;
}
return 0;
}
static int dsa_switch_parse_of(struct dsa_switch *ds, struct device_node *dn)
{
int err;
err = dsa_switch_parse_member_of(ds, dn);
if (err)
return err;
err = dsa_switch_touch_ports(ds);
if (err)
return err;
return dsa_switch_parse_ports_of(ds, dn);
}
static int dsa_port_parse(struct dsa_port *dp, const char *name,
struct device *dev)
{
if (!strcmp(name, "cpu")) {
struct net_device *master;
master = dsa_dev_to_net_device(dev);
if (!master)
return -EPROBE_DEFER;
dev_put(master);
return dsa_port_parse_cpu(dp, master);
}
if (!strcmp(name, "dsa"))
return dsa_port_parse_dsa(dp);
return dsa_port_parse_user(dp, name);
}
static int dsa_switch_parse_ports(struct dsa_switch *ds,
struct dsa_chip_data *cd)
{
bool valid_name_found = false;
struct dsa_port *dp;
struct device *dev;
const char *name;
unsigned int i;
int err;
for (i = 0; i < DSA_MAX_PORTS; i++) {
name = cd->port_names[i];
dev = cd->netdev[i];
dp = dsa_to_port(ds, i);
if (!name)
continue;
err = dsa_port_parse(dp, name, dev);
if (err)
return err;
valid_name_found = true;
}
if (!valid_name_found && i == DSA_MAX_PORTS)
return -EINVAL;
return 0;
}
static int dsa_switch_parse(struct dsa_switch *ds, struct dsa_chip_data *cd)
{
int err;
ds->cd = cd;
/* We don't support interconnected switches nor multiple trees via
* platform data, so this is the unique switch of the tree.
*/
ds->index = 0;
ds->dst = dsa_tree_touch(0);
if (!ds->dst)
return -ENOMEM;
err = dsa_switch_touch_ports(ds);
if (err)
return err;
return dsa_switch_parse_ports(ds, cd);
}
static void dsa_switch_release_ports(struct dsa_switch *ds)
{
struct dsa_switch_tree *dst = ds->dst;
struct dsa_port *dp, *next;
list_for_each_entry_safe(dp, next, &dst->ports, list) {
if (dp->ds != ds)
continue;
list_del(&dp->list);
kfree(dp);
}
}
static int dsa_switch_probe(struct dsa_switch *ds)
{
struct dsa_switch_tree *dst;
struct dsa_chip_data *pdata;
struct device_node *np;
int err;
if (!ds->dev)
return -ENODEV;
pdata = ds->dev->platform_data;
np = ds->dev->of_node;
if (!ds->num_ports)
return -EINVAL;
if (np) {
err = dsa_switch_parse_of(ds, np);
if (err)
dsa_switch_release_ports(ds);
} else if (pdata) {
err = dsa_switch_parse(ds, pdata);
if (err)
dsa_switch_release_ports(ds);
} else {
err = -ENODEV;
}
if (err)
return err;
dst = ds->dst;
dsa_tree_get(dst);
err = dsa_tree_setup(dst);
if (err) {
dsa_switch_release_ports(ds);
dsa_tree_put(dst);
}
return err;
}
int dsa_register_switch(struct dsa_switch *ds)
{
int err;
mutex_lock(&dsa2_mutex);
err = dsa_switch_probe(ds);
dsa_tree_put(ds->dst);
mutex_unlock(&dsa2_mutex);
return err;
}
EXPORT_SYMBOL_GPL(dsa_register_switch);
static void dsa_switch_remove(struct dsa_switch *ds)
{
struct dsa_switch_tree *dst = ds->dst;
dsa_tree_teardown(dst);
dsa_switch_release_ports(ds);
dsa_tree_put(dst);
}
void dsa_unregister_switch(struct dsa_switch *ds)
{
mutex_lock(&dsa2_mutex);
dsa_switch_remove(ds);
mutex_unlock(&dsa2_mutex);
}
EXPORT_SYMBOL_GPL(dsa_unregister_switch);
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