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-rw-r--r--include/linux/netdevice.h27
-rw-r--r--net/core/dev.c5
-rw-r--r--net/core/netpoll.c2
3 files changed, 24 insertions, 10 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d4e6e00bb90a..67e25f6d15a4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4711,7 +4711,7 @@ static inline u32 netif_msg_init(int debug_value, int default_msg_enable_bits)
static inline void __netif_tx_lock(struct netdev_queue *txq, int cpu)
{
spin_lock(&txq->_xmit_lock);
- /* Pairs with READ_ONCE() in __dev_queue_xmit() */
+ /* Pairs with READ_ONCE() in netif_tx_owned() */
WRITE_ONCE(txq->xmit_lock_owner, cpu);
}
@@ -4729,7 +4729,7 @@ static inline void __netif_tx_release(struct netdev_queue *txq)
static inline void __netif_tx_lock_bh(struct netdev_queue *txq)
{
spin_lock_bh(&txq->_xmit_lock);
- /* Pairs with READ_ONCE() in __dev_queue_xmit() */
+ /* Pairs with READ_ONCE() in netif_tx_owned() */
WRITE_ONCE(txq->xmit_lock_owner, smp_processor_id());
}
@@ -4738,7 +4738,7 @@ static inline bool __netif_tx_trylock(struct netdev_queue *txq)
bool ok = spin_trylock(&txq->_xmit_lock);
if (likely(ok)) {
- /* Pairs with READ_ONCE() in __dev_queue_xmit() */
+ /* Pairs with READ_ONCE() in netif_tx_owned() */
WRITE_ONCE(txq->xmit_lock_owner, smp_processor_id());
}
return ok;
@@ -4746,14 +4746,14 @@ static inline bool __netif_tx_trylock(struct netdev_queue *txq)
static inline void __netif_tx_unlock(struct netdev_queue *txq)
{
- /* Pairs with READ_ONCE() in __dev_queue_xmit() */
+ /* Pairs with READ_ONCE() in netif_tx_owned() */
WRITE_ONCE(txq->xmit_lock_owner, -1);
spin_unlock(&txq->_xmit_lock);
}
static inline void __netif_tx_unlock_bh(struct netdev_queue *txq)
{
- /* Pairs with READ_ONCE() in __dev_queue_xmit() */
+ /* Pairs with READ_ONCE() in netif_tx_owned() */
WRITE_ONCE(txq->xmit_lock_owner, -1);
spin_unlock_bh(&txq->_xmit_lock);
}
@@ -4846,6 +4846,23 @@ static inline void netif_tx_disable(struct net_device *dev)
local_bh_enable();
}
+#ifndef CONFIG_PREEMPT_RT
+static inline bool netif_tx_owned(struct netdev_queue *txq, unsigned int cpu)
+{
+ /* Other cpus might concurrently change txq->xmit_lock_owner
+ * to -1 or to their cpu id, but not to our id.
+ */
+ return READ_ONCE(txq->xmit_lock_owner) == cpu;
+}
+
+#else
+static inline bool netif_tx_owned(struct netdev_queue *txq, unsigned int cpu)
+{
+ return rt_mutex_owner(&txq->_xmit_lock.lock) == current;
+}
+
+#endif
+
static inline void netif_addr_lock(struct net_device *dev)
{
unsigned char nest_level = 0;
diff --git a/net/core/dev.c b/net/core/dev.c
index 20610a192ec7..14a83f2035b9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4818,10 +4818,7 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
if (dev->flags & IFF_UP) {
int cpu = smp_processor_id(); /* ok because BHs are off */
- /* Other cpus might concurrently change txq->xmit_lock_owner
- * to -1 or to their cpu id, but not to our id.
- */
- if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
+ if (!netif_tx_owned(txq, cpu)) {
bool is_list = false;
if (dev_xmit_recursion())
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index a8558a52884f..cd74beffd209 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -132,7 +132,7 @@ static int netif_local_xmit_active(struct net_device *dev)
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
- if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id())
+ if (netif_tx_owned(txq, smp_processor_id()))
return 1;
}