sfc: Use a global count of active queues instead of pending drains

On EF10, the firmware will initiate a queue flush in certain
error cases.  We need to accept that flush events might appear
at any time after a queue has been initialised, not just when
we try to flush them.

We can handle Falcon-architecture in just the same way.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index b483223..34788fb 100644 (file)
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -631,11 +631,14 @@ static void efx_start_datapath(struct efx_nic *efx)
 
        /* Initialise the channels */
        efx_for_each_channel(channel, efx) {
-               efx_for_each_channel_tx_queue(tx_queue, channel)
+               efx_for_each_channel_tx_queue(tx_queue, channel) {
                        efx_init_tx_queue(tx_queue);
+                       atomic_inc(&efx->active_queues);
+               }
 
                efx_for_each_channel_rx_queue(rx_queue, channel) {
                        efx_init_rx_queue(rx_queue);
+                       atomic_inc(&efx->active_queues);
                        efx_nic_generate_fill_event(rx_queue);
                }
 

diff --git a/drivers/net/ethernet/sfc/farch.c b/drivers/net/ethernet/sfc/farch.c
index eb754cf..842f92e 100644 (file)
--- a/drivers/net/ethernet/sfc/farch.c
+++ b/drivers/net/ethernet/sfc/farch.c
@@ -594,7 +594,7 @@ static bool efx_farch_flush_wake(struct efx_nic *efx)
        /* Ensure that all updates are visible to efx_farch_flush_queues() */
        smp_mb();
 
-       return (atomic_read(&efx->drain_pending) == 0 ||
+       return (atomic_read(&efx->active_queues) == 0 ||
                (atomic_read(&efx->rxq_flush_outstanding) < EFX_RX_FLUSH_COUNT
                 && atomic_read(&efx->rxq_flush_pending) > 0));
 }
@@ -626,7 +626,7 @@ static bool efx_check_tx_flush_complete(struct efx_nic *efx)
                                netif_dbg(efx, hw, efx->net_dev,
                                          "flush complete on TXQ %d, so drain "
                                          "the queue\n", tx_queue->queue);
-                               /* Don't need to increment drain_pending as it
+                               /* Don't need to increment active_queues as it
                                 * has already been incremented for the queues
                                 * which did not drain
                                 */
@@ -653,17 +653,15 @@ static int efx_farch_do_flush(struct efx_nic *efx)
 
        efx_for_each_channel(channel, efx) {
                efx_for_each_channel_tx_queue(tx_queue, channel) {
-                       atomic_inc(&efx->drain_pending);
                        efx_farch_flush_tx_queue(tx_queue);
                }
                efx_for_each_channel_rx_queue(rx_queue, channel) {
-                       atomic_inc(&efx->drain_pending);
                        rx_queue->flush_pending = true;
                        atomic_inc(&efx->rxq_flush_pending);
                }
        }
 
-       while (timeout && atomic_read(&efx->drain_pending) > 0) {
+       while (timeout && atomic_read(&efx->active_queues) > 0) {
                /* If SRIOV is enabled, then offload receive queue flushing to
                 * the firmware (though we will still have to poll for
                 * completion). If that fails, fall back to the old scheme.
@@ -699,15 +697,15 @@ static int efx_farch_do_flush(struct efx_nic *efx)
                                             timeout);
        }
 
-       if (atomic_read(&efx->drain_pending) &&
+       if (atomic_read(&efx->active_queues) &&
            !efx_check_tx_flush_complete(efx)) {
                netif_err(efx, hw, efx->net_dev, "failed to flush %d queues "
-                         "(rx %d+%d)\n", atomic_read(&efx->drain_pending),
+                         "(rx %d+%d)\n", atomic_read(&efx->active_queues),
                          atomic_read(&efx->rxq_flush_outstanding),
                          atomic_read(&efx->rxq_flush_pending));
                rc = -ETIMEDOUT;
 
-               atomic_set(&efx->drain_pending, 0);
+               atomic_set(&efx->active_queues, 0);
                atomic_set(&efx->rxq_flush_pending, 0);
                atomic_set(&efx->rxq_flush_outstanding, 0);
        }
@@ -1123,8 +1121,8 @@ efx_farch_handle_drain_event(struct efx_channel *channel)
 {
        struct efx_nic *efx = channel->efx;
 
-       WARN_ON(atomic_read(&efx->drain_pending) == 0);
-       atomic_dec(&efx->drain_pending);
+       WARN_ON(atomic_read(&efx->active_queues) == 0);
+       atomic_dec(&efx->active_queues);
        if (efx_farch_flush_wake(efx))
                wake_up(&efx->flush_wq);
 }

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 5341c76..c9b6f2d 100644 (file)
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -723,7 +723,7 @@ struct vfdi_status;
  * @rps_flow_id: Flow IDs of filters allocated for accelerated RFS,
  *     indexed by filter ID
  * @rps_expire_index: Next index to check for expiry in @rps_flow_id
- * @drain_pending: Count of RX and TX queues that haven't been flushed and drained.
+ * @active_queues: Count of RX and TX queues that haven't been flushed and drained.
  * @rxq_flush_pending: Count of number of receive queues that need to be flushed.
  *     Decremented when the efx_flush_rx_queue() is called.
  * @rxq_flush_outstanding: Count of number of RX flushes started but not yet
@@ -864,7 +864,7 @@ struct efx_nic {
        unsigned int rps_expire_index;
 #endif
 
-       atomic_t drain_pending;
+       atomic_t active_queues;
        atomic_t rxq_flush_pending;
        atomic_t rxq_flush_outstanding;
        wait_queue_head_t flush_wq;