net: Add queue state xoff flag for stack
Create separate queue state flags so that either the stack or drivers
can turn on XOFF. Added a set of functions used in the stack to determine
if a queue is really stopped (either by stack or driver)
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ac9a4b9..d19f932 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -517,11 +517,23 @@
#endif
enum netdev_queue_state_t {
- __QUEUE_STATE_XOFF,
+ __QUEUE_STATE_DRV_XOFF,
+ __QUEUE_STATE_STACK_XOFF,
__QUEUE_STATE_FROZEN,
-#define QUEUE_STATE_XOFF_OR_FROZEN ((1 << __QUEUE_STATE_XOFF) | \
- (1 << __QUEUE_STATE_FROZEN))
+#define QUEUE_STATE_ANY_XOFF ((1 << __QUEUE_STATE_DRV_XOFF) | \
+ (1 << __QUEUE_STATE_STACK_XOFF))
+#define QUEUE_STATE_ANY_XOFF_OR_FROZEN (QUEUE_STATE_ANY_XOFF | \
+ (1 << __QUEUE_STATE_FROZEN))
};
+/*
+ * __QUEUE_STATE_DRV_XOFF is used by drivers to stop the transmit queue. The
+ * netif_tx_* functions below are used to manipulate this flag. The
+ * __QUEUE_STATE_STACK_XOFF flag is used by the stack to stop the transmit
+ * queue independently. The netif_xmit_*stopped functions below are called
+ * to check if the queue has been stopped by the driver or stack (either
+ * of the XOFF bits are set in the state). Drivers should not need to call
+ * netif_xmit*stopped functions, they should only be using netif_tx_*.
+ */
struct netdev_queue {
/*
@@ -1718,7 +1730,7 @@
static inline void netif_schedule_queue(struct netdev_queue *txq)
{
- if (!test_bit(__QUEUE_STATE_XOFF, &txq->state))
+ if (!(txq->state & QUEUE_STATE_ANY_XOFF))
__netif_schedule(txq->qdisc);
}
@@ -1732,7 +1744,7 @@
static inline void netif_tx_start_queue(struct netdev_queue *dev_queue)
{
- clear_bit(__QUEUE_STATE_XOFF, &dev_queue->state);
+ clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state);
}
/**
@@ -1764,7 +1776,7 @@
return;
}
#endif
- if (test_and_clear_bit(__QUEUE_STATE_XOFF, &dev_queue->state))
+ if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state))
__netif_schedule(dev_queue->qdisc);
}
@@ -1796,7 +1808,7 @@
pr_info("netif_stop_queue() cannot be called before register_netdev()\n");
return;
}
- set_bit(__QUEUE_STATE_XOFF, &dev_queue->state);
+ set_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state);
}
/**
@@ -1823,7 +1835,7 @@
static inline int netif_tx_queue_stopped(const struct netdev_queue *dev_queue)
{
- return test_bit(__QUEUE_STATE_XOFF, &dev_queue->state);
+ return test_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state);
}
/**
@@ -1837,9 +1849,16 @@
return netif_tx_queue_stopped(netdev_get_tx_queue(dev, 0));
}
-static inline int netif_tx_queue_frozen_or_stopped(const struct netdev_queue *dev_queue)
+static inline int netif_xmit_stopped(const struct netdev_queue *dev_queue)
{
- return dev_queue->state & QUEUE_STATE_XOFF_OR_FROZEN;
+ return dev_queue->state & QUEUE_STATE_ANY_XOFF;
+}
+
+static inline int netif_xmit_frozen_or_stopped(const struct netdev_queue *dev_queue)
+{
+ return dev_queue->state & QUEUE_STATE_ANY_XOFF_OR_FROZEN;
+}
+
}
/**
@@ -1926,7 +1945,7 @@
if (netpoll_trap())
return;
#endif
- if (test_and_clear_bit(__QUEUE_STATE_XOFF, &txq->state))
+ if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &txq->state))
__netif_schedule(txq->qdisc);
}