[PATCH net-next] net: dsa: lan9303: Protect ALR operations with mutex

From: Egil Hjelmeland
Date: Thu Dec 07 2017 - 13:56:27 EST


ALR table operations are a sequence of related register operations which
should be protected from concurrent access. The alr_cache should also be
protected. Add alr_mutex doing that.

Signed-off-by: Egil Hjelmeland <privat@xxxxxxxxxxxxxxxxxx>
---
drivers/net/dsa/lan9303-core.c | 14 ++++++++++++--
include/linux/dsa/lan9303.h | 1 +
2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
index ea59dadefb33..c1b004fa64d9 100644
--- a/drivers/net/dsa/lan9303-core.c
+++ b/drivers/net/dsa/lan9303-core.c
@@ -583,6 +583,7 @@ static void lan9303_alr_loop(struct lan9303 *chip, alr_loop_cb_t *cb, void *ctx)
{
int i;

+ mutex_lock(&chip->alr_mutex);
lan9303_write_switch_reg(chip, LAN9303_SWE_ALR_CMD,
LAN9303_ALR_CMD_GET_FIRST);
lan9303_write_switch_reg(chip, LAN9303_SWE_ALR_CMD, 0);
@@ -606,6 +607,7 @@ static void lan9303_alr_loop(struct lan9303 *chip, alr_loop_cb_t *cb, void *ctx)
LAN9303_ALR_CMD_GET_NEXT);
lan9303_write_switch_reg(chip, LAN9303_SWE_ALR_CMD, 0);
}
+ mutex_unlock(&chip->alr_mutex);
}

static void alr_reg_to_mac(u32 dat0, u32 dat1, u8 mac[6])
@@ -694,16 +696,20 @@ static int lan9303_alr_add_port(struct lan9303 *chip, const u8 *mac, int port,
{
struct lan9303_alr_cache_entry *entr;

+ mutex_lock(&chip->alr_mutex);
entr = lan9303_alr_cache_find_mac(chip, mac);
if (!entr) { /*New entry */
entr = lan9303_alr_cache_find_free(chip);
- if (!entr)
+ if (!entr) {
+ mutex_unlock(&chip->alr_mutex);
return -ENOSPC;
+ }
ether_addr_copy(entr->mac_addr, mac);
}
entr->port_map |= BIT(port);
entr->stp_override = stp_override;
lan9303_alr_set_entry(chip, mac, entr->port_map, stp_override);
+ mutex_unlock(&chip->alr_mutex);

return 0;
}
@@ -713,15 +719,18 @@ static int lan9303_alr_del_port(struct lan9303 *chip, const u8 *mac, int port)
{
struct lan9303_alr_cache_entry *entr;

+ mutex_lock(&chip->alr_mutex);
entr = lan9303_alr_cache_find_mac(chip, mac);
if (!entr)
- return 0; /* no static entry found */
+ goto out; /* no static entry found */

entr->port_map &= ~BIT(port);
if (entr->port_map == 0) /* zero means its free again */
eth_zero_addr(entr->mac_addr);
lan9303_alr_set_entry(chip, mac, entr->port_map, entr->stp_override);

+out:
+ mutex_unlock(&chip->alr_mutex);
return 0;
}

@@ -1323,6 +1332,7 @@ int lan9303_probe(struct lan9303 *chip, struct device_node *np)
int ret;

mutex_init(&chip->indirect_mutex);
+ mutex_init(&chip->alr_mutex);

lan9303_probe_reset_gpio(chip, np);

diff --git a/include/linux/dsa/lan9303.h b/include/linux/dsa/lan9303.h
index f48a85c377de..b6514c29563f 100644
--- a/include/linux/dsa/lan9303.h
+++ b/include/linux/dsa/lan9303.h
@@ -26,6 +26,7 @@ struct lan9303 {
bool phy_addr_sel_strap;
struct dsa_switch *ds;
struct mutex indirect_mutex; /* protect indexed register access */
+ struct mutex alr_mutex; /* protect ALR access */
const struct lan9303_phy_ops *ops;
bool is_bridged; /* true if port 1 and 2 are bridged */

--
2.14.1