[PATCH v4 net-next 08/15] nfp: preallocate RX buffers early in .ndo_open

[Jakub Kicinski]

We want the .ndo_open() to have following structure:
 - allocate resources;
 - configure HW/FW;
 - enable the device from stack perspective.
Therefore filling RX rings needs to be moved to the beginning
of .ndo_open().

Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
---
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 34 +++++++---------------
 1 file changed, 11 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c 
b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index b057102769f9..c04706cd7d51 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -1667,28 +1667,19 @@ static void nfp_net_clear_config_and_disable(struct 
nfp_net *nn)
  * @nn:      NFP Net device structure
  * @r_vec:   Ring vector to be started
  */
-static int nfp_net_start_vec(struct nfp_net *nn, struct nfp_net_r_vector 
*r_vec)
+static void
+nfp_net_start_vec(struct nfp_net *nn, struct nfp_net_r_vector *r_vec)
 {
        unsigned int irq_vec;
-       int err = 0;
 
        irq_vec = nn->irq_entries[r_vec->irq_idx].vector;
 
        disable_irq(irq_vec);
 
-       err = nfp_net_rx_ring_bufs_alloc(r_vec->nfp_net, r_vec->rx_ring);
-       if (err) {
-               nn_err(nn, "RV%02d: couldn't allocate enough buffers\n",
-                      r_vec->irq_idx);
-               goto out;
-       }
        nfp_net_rx_ring_fill_freelist(r_vec->rx_ring);
-
        napi_enable(&r_vec->napi);
-out:
-       enable_irq(irq_vec);
 
-       return err;
+       enable_irq(irq_vec);
 }
 
 static int nfp_net_netdev_open(struct net_device *netdev)
@@ -1743,6 +1734,10 @@ static int nfp_net_netdev_open(struct net_device *netdev)
                err = nfp_net_rx_ring_alloc(nn->r_vecs[r].rx_ring);
                if (err)
                        goto err_free_tx_ring_p;
+
+               err = nfp_net_rx_ring_bufs_alloc(nn, nn->r_vecs[r].rx_ring);
+               if (err)
+                       goto err_flush_rx_ring_p;
        }
 
        err = netif_set_real_num_tx_queues(netdev, nn->num_tx_rings);
@@ -1815,11 +1810,8 @@ static int nfp_net_netdev_open(struct net_device *netdev)
         * - enable all TX queues
         * - set link state
         */
-       for (r = 0; r < nn->num_r_vecs; r++) {
-               err = nfp_net_start_vec(nn, &nn->r_vecs[r]);
-               if (err)
-                       goto err_disable_napi;
-       }
+       for (r = 0; r < nn->num_r_vecs; r++)
+               nfp_net_start_vec(nn, &nn->r_vecs[r]);
 
        netif_tx_wake_all_queues(netdev);
 
@@ -1828,18 +1820,14 @@ static int nfp_net_netdev_open(struct net_device 
*netdev)
 
        return 0;
 
-err_disable_napi:
-       while (r--) {
-               napi_disable(&nn->r_vecs[r].napi);
-               nfp_net_rx_ring_reset(nn->r_vecs[r].rx_ring);
-               nfp_net_rx_ring_bufs_free(nn, nn->r_vecs[r].rx_ring);
-       }
 err_clear_config:
        nfp_net_clear_config_and_disable(nn);
 err_free_rings:
        r = nn->num_r_vecs;
 err_free_prev_vecs:
        while (r--) {
+               nfp_net_rx_ring_bufs_free(nn, nn->r_vecs[r].rx_ring);
+err_flush_rx_ring_p:
                nfp_net_rx_ring_free(nn->r_vecs[r].rx_ring);
 err_free_tx_ring_p:
                nfp_net_tx_ring_free(nn->r_vecs[r].tx_ring);
-- 
1.9.1