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net: Add queue state xoff flag for stack

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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>
This commit is contained in:
Tom Herbert
2011-11-28 16:32:44 +00:00
committed by David S. Miller
parent 75957ba36c
commit 7346649826
7 changed files with 46 additions and 25 deletions
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41
include/linux/netdevice.h
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@@ -517,11 +517,23 @@ static inline void napi_synchronize(const struct napi_struct *n)
#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 @@ extern void __netif_schedule(struct Qdisc *q);
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_schedule_all(struct net_device *dev)
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 @@ static inline void netif_tx_wake_queue(struct netdev_queue *dev_queue)
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 @@ static inline void netif_tx_stop_queue(struct netdev_queue *dev_queue)
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 void netif_tx_stop_all_queues(struct net_device *dev)
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 @@ static inline int netif_queue_stopped(const struct net_device *dev)
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 @@ static inline void netif_wake_subqueue(struct net_device *dev, u16 queue_index)
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);
}