*/
#define EFX_TXQ_THRESHOLD(_efx) ((_efx)->txq_entries / 2u)
-/* We need to be able to nest calls to netif_tx_stop_queue(), partly
- * because of the 2 hardware queues associated with each core queue,
- * but also so that we can inhibit TX for reasons other than a full
- * hardware queue. */
-void efx_stop_queue(struct efx_channel *channel)
-{
- struct efx_nic *efx = channel->efx;
- struct efx_tx_queue *tx_queue = efx_channel_get_tx_queue(channel, 0);
-
- if (!tx_queue)
- return;
-
- spin_lock_bh(&channel->tx_stop_lock);
- netif_vdbg(efx, tx_queued, efx->net_dev, "stop TX queue\n");
-
- atomic_inc(&channel->tx_stop_count);
- netif_tx_stop_queue(
- netdev_get_tx_queue(efx->net_dev,
- tx_queue->queue / EFX_TXQ_TYPES));
-
- spin_unlock_bh(&channel->tx_stop_lock);
-}
-
-/* Decrement core TX queue stop count and wake it if the count is 0 */
-void efx_wake_queue(struct efx_channel *channel)
-{
- struct efx_nic *efx = channel->efx;
- struct efx_tx_queue *tx_queue = efx_channel_get_tx_queue(channel, 0);
-
- if (!tx_queue)
- return;
-
- local_bh_disable();
- if (atomic_dec_and_lock(&channel->tx_stop_count,
- &channel->tx_stop_lock)) {
- netif_vdbg(efx, tx_queued, efx->net_dev, "waking TX queue\n");
- netif_tx_wake_queue(
- netdev_get_tx_queue(efx->net_dev,
- tx_queue->queue / EFX_TXQ_TYPES));
- spin_unlock(&channel->tx_stop_lock);
- }
- local_bh_enable();
-}
-
static void efx_dequeue_buffer(struct efx_tx_queue *tx_queue,
struct efx_tx_buffer *buffer)
{
* checked. Update the xmit path's
* copy of read_count.
*/
- ++tx_queue->stopped;
+ netif_tx_stop_queue(tx_queue->core_txq);
/* This memory barrier protects the
- * change of stopped from the access
+ * change of queue state from the access
* of read_count. */
smp_mb();
tx_queue->old_read_count =
- *(volatile unsigned *)
- &tx_queue->read_count;
+ ACCESS_ONCE(tx_queue->read_count);
fill_level = (tx_queue->insert_count
- tx_queue->old_read_count);
q_space = efx->txq_entries - 1 - fill_level;
- if (unlikely(q_space-- <= 0))
- goto stop;
+ if (unlikely(q_space-- <= 0)) {
+ rc = NETDEV_TX_BUSY;
+ goto unwind;
+ }
smp_mb();
- --tx_queue->stopped;
+ netif_tx_start_queue(tx_queue->core_txq);
}
insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
/* Mark the packet as transmitted, and free the SKB ourselves */
dev_kfree_skb_any(skb);
- goto unwind;
-
- stop:
- rc = NETDEV_TX_BUSY;
-
- if (tx_queue->stopped == 1)
- efx_stop_queue(tx_queue->channel);
unwind:
/* Work backwards until we hit the original insert pointer value */
efx_dequeue_buffers(tx_queue, index);
/* See if we need to restart the netif queue. This barrier
- * separates the update of read_count from the test of
- * stopped. */
+ * separates the update of read_count from the test of the
+ * queue state. */
smp_mb();
- if (unlikely(tx_queue->stopped) && likely(efx->port_enabled)) {
+ if (unlikely(netif_tx_queue_stopped(tx_queue->core_txq)) &&
+ likely(efx->port_enabled)) {
fill_level = tx_queue->insert_count - tx_queue->read_count;
if (fill_level < EFX_TXQ_THRESHOLD(efx)) {
EFX_BUG_ON_PARANOID(!efx_dev_registered(efx));
+ netif_tx_wake_queue(tx_queue->core_txq);
+ }
+ }
- /* Do this under netif_tx_lock(), to avoid racing
- * with efx_xmit(). */
- netif_tx_lock(efx->net_dev);
- if (tx_queue->stopped) {
- tx_queue->stopped = 0;
- efx_wake_queue(tx_queue->channel);
- }
- netif_tx_unlock(efx->net_dev);
+ /* Check whether the hardware queue is now empty */
+ if ((int)(tx_queue->read_count - tx_queue->old_write_count) >= 0) {
+ tx_queue->old_write_count = ACCESS_ONCE(tx_queue->write_count);
+ if (tx_queue->read_count == tx_queue->old_write_count) {
+ smp_mb();
+ tx_queue->empty_read_count =
+ tx_queue->read_count | EFX_EMPTY_COUNT_VALID;
}
}
}
tx_queue->insert_count = 0;
tx_queue->write_count = 0;
+ tx_queue->old_write_count = 0;
tx_queue->read_count = 0;
tx_queue->old_read_count = 0;
- BUG_ON(tx_queue->stopped);
+ tx_queue->empty_read_count = 0 | EFX_EMPTY_COUNT_VALID;
/* Set up TX descriptor ring */
efx_nic_init_tx(tx_queue);
/* Free up TSO header cache */
efx_fini_tso(tx_queue);
-
- /* Release queue's stop on port, if any */
- if (tx_queue->stopped) {
- tx_queue->stopped = 0;
- efx_wake_queue(tx_queue->channel);
- }
}
void efx_remove_tx_queue(struct efx_tx_queue *tx_queue)
* since the xmit path last checked. Update
* the xmit path's copy of read_count.
*/
- ++tx_queue->stopped;
+ netif_tx_stop_queue(tx_queue->core_txq);
/* This memory barrier protects the change of
- * stopped from the access of read_count. */
+ * queue state from the access of read_count. */
smp_mb();
tx_queue->old_read_count =
- *(volatile unsigned *)&tx_queue->read_count;
+ ACCESS_ONCE(tx_queue->read_count);
fill_level = (tx_queue->insert_count
- tx_queue->old_read_count);
q_space = efx->txq_entries - 1 - fill_level;
return 1;
}
smp_mb();
- --tx_queue->stopped;
+ netif_tx_start_queue(tx_queue->core_txq);
}
insert_ptr = tx_queue->insert_count & tx_queue->ptr_mask;
while (1) {
rc = tso_fill_packet_with_fragment(tx_queue, skb, &state);
- if (unlikely(rc))
- goto stop;
+ if (unlikely(rc)) {
+ rc2 = NETDEV_TX_BUSY;
+ goto unwind;
+ }
/* Move onto the next fragment? */
if (state.in_len == 0) {
netif_err(efx, tx_err, efx->net_dev,
"Out of memory for TSO headers, or PCI mapping error\n");
dev_kfree_skb_any(skb);
- goto unwind;
-
- stop:
- rc2 = NETDEV_TX_BUSY;
-
- /* Stop the queue if it wasn't stopped before. */
- if (tx_queue->stopped == 1)
- efx_stop_queue(tx_queue->channel);
unwind:
/* Free the DMA mapping we were in the process of writing out */
projects / mv-sheeva.git / blobdiff