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authorThomas Gleixner <tglx@linutronix.de>2014-03-18 17:19:12 +0000
committerMarc Kleine-Budde <mkl@pengutronix.de>2014-04-01 11:55:00 +0200
commitbf88a20611d5a62119a02da4eba95b461ec692c8 (patch)
treef1ee16ea5621c98799fdf17f5b102474a77b4e8e /drivers
parent710c56105dfd10e32a89086cf78cc1c8433f6a7a (diff)
can: c_can: Provide protection in the xmit path
The network core does not serialize the access to the hardware. The xmit related code lets the following happen: CPU0 CPU1 interrupt() do_poll() c_can_do_tx() Fiddle with HW and xmit() internal data Fiddle with HW and internal data due the complete lack of serialization. Add proper locking. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/can/c_can/c_can.c9
-rw-r--r--drivers/net/can/c_can/c_can.h1
2 files changed, 9 insertions, 1 deletions
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 30a85aa81d45..1fe79ce50c5a 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -549,6 +549,7 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb,
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
+ spin_lock_bh(&priv->xmit_lock);
msg_obj_no = get_tx_next_msg_obj(priv);
/* prepare message object for transmission */
@@ -563,6 +564,7 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb,
if (c_can_is_next_tx_obj_busy(priv, get_tx_next_msg_obj(priv)) ||
(priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) == 0)
netif_stop_queue(dev);
+ spin_unlock_bh(&priv->xmit_lock);
return NETDEV_TX_OK;
}
@@ -787,7 +789,9 @@ static void c_can_do_tx(struct net_device *dev)
struct c_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
- for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
+ spin_lock_bh(&priv->xmit_lock);
+
+ for (; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
msg_obj_no = get_tx_echo_msg_obj(priv);
val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG);
if (!(val & (1 << (msg_obj_no - 1)))) {
@@ -809,6 +813,8 @@ static void c_can_do_tx(struct net_device *dev)
if (((priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) != 0) ||
((priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) == 0))
netif_wake_queue(dev);
+
+ spin_unlock_bh(&priv->xmit_lock);
}
/*
@@ -1262,6 +1268,7 @@ struct net_device *alloc_c_can_dev(void)
return NULL;
priv = netdev_priv(dev);
+ spin_lock_init(&priv->xmit_lock);
netif_napi_add(dev, &priv->napi, c_can_poll, C_CAN_NAPI_WEIGHT);
priv->dev = dev;
diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index d2e1c21b143f..5097c802a61e 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -156,6 +156,7 @@ struct c_can_priv {
struct napi_struct napi;
struct net_device *dev;
struct device *device;
+ spinlock_t xmit_lock;
int tx_object;
int current_status;
int last_status;