sfc: Allow driver to cope with a lower number of VIs than it needs for RSS

[linux-drm-fsl-dcu.git] / drivers / net / ethernet / sfc / efx.c

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 03bc03b67f08b3224f6e0d13b1fc0c189780c1af..974637d3ae2526427e82997203fdd811215e3692 100644 (file)
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -115,9 +115,9 @@ static struct workqueue_struct *reset_workqueue;
  *
  * This is only used in MSI-X interrupt mode
  */
-static bool separate_tx_channels;
-module_param(separate_tx_channels, bool, 0444);
-MODULE_PARM_DESC(separate_tx_channels,
+bool efx_separate_tx_channels;
+module_param(efx_separate_tx_channels, bool, 0444);
+MODULE_PARM_DESC(efx_separate_tx_channels,
                 "Use separate channels for TX and RX");
 
 /* This is the weight assigned to each of the (per-channel) virtual
@@ -1391,7 +1391,7 @@ static int efx_probe_interrupts(struct efx_nic *efx)
                unsigned int n_channels;
 
                n_channels = efx_wanted_parallelism(efx);
-               if (separate_tx_channels)
+               if (efx_separate_tx_channels)
                        n_channels *= 2;
                n_channels += extra_channels;
                n_channels = min(n_channels, efx->max_channels);
@@ -1418,13 +1418,16 @@ static int efx_probe_interrupts(struct efx_nic *efx)
                        efx->n_channels = n_channels;
                        if (n_channels > extra_channels)
                                n_channels -= extra_channels;
-                       if (separate_tx_channels) {
-                               efx->n_tx_channels = max(n_channels / 2, 1U);
+                       if (efx_separate_tx_channels) {
+                               efx->n_tx_channels = min(max(n_channels / 2,
+                                                            1U),
+                                                        efx->max_tx_channels);
                                efx->n_rx_channels = max(n_channels -
                                                         efx->n_tx_channels,
                                                         1U);
                        } else {
-                               efx->n_tx_channels = n_channels;
+                               efx->n_tx_channels = min(n_channels,
+                                                        efx->max_tx_channels);
                                efx->n_rx_channels = n_channels;
                        }
                        for (i = 0; i < efx->n_channels; i++)
@@ -1450,7 +1453,7 @@ static int efx_probe_interrupts(struct efx_nic *efx)
 
        /* Assume legacy interrupts */
        if (efx->interrupt_mode == EFX_INT_MODE_LEGACY) {
-               efx->n_channels = 1 + (separate_tx_channels ? 1 : 0);
+               efx->n_channels = 1 + (efx_separate_tx_channels ? 1 : 0);
                efx->n_rx_channels = 1;
                efx->n_tx_channels = 1;
                efx->legacy_irq = efx->pci_dev->irq;
@@ -1624,7 +1627,8 @@ static void efx_set_channels(struct efx_nic *efx)
        struct efx_tx_queue *tx_queue;
 
        efx->tx_channel_offset =
-               separate_tx_channels ? efx->n_channels - efx->n_tx_channels : 0;
+               efx_separate_tx_channels ?
+               efx->n_channels - efx->n_tx_channels : 0;
 
        /* We need to mark which channels really have RX and TX
         * queues, and adjust the TX queue numbers if we have separate
@@ -1653,17 +1657,34 @@ static int efx_probe_nic(struct efx_nic *efx)
        if (rc)
                return rc;
 
-       /* Determine the number of channels and queues by trying to hook
-        * in MSI-X interrupts. */
-       rc = efx_probe_interrupts(efx);
-       if (rc)
-               goto fail1;
+       do {
+               if (!efx->max_channels || !efx->max_tx_channels) {
+                       netif_err(efx, drv, efx->net_dev,
+                                 "Insufficient resources to allocate"
+                                 " any channels\n");
+                       rc = -ENOSPC;
+                       goto fail1;
+               }
 
-       efx_set_channels(efx);
+               /* Determine the number of channels and queues by trying
+                * to hook in MSI-X interrupts.
+                */
+               rc = efx_probe_interrupts(efx);
+               if (rc)
+                       goto fail1;
 
-       rc = efx->type->dimension_resources(efx);
-       if (rc)
-               goto fail2;
+               efx_set_channels(efx);
+
+               /* dimension_resources can fail with EAGAIN */
+               rc = efx->type->dimension_resources(efx);
+               if (rc != 0 && rc != -EAGAIN)
+                       goto fail2;
+
+               if (rc == -EAGAIN)
+                       /* try again with new max_channels */
+                       efx_remove_interrupts(efx);
+
+       } while (rc == -EAGAIN);
 
        if (efx->n_channels > 1)
                netdev_rss_key_fill(&efx->rx_hash_key,