[PATCH v4 net-next 11/15] nfp: sync ring state during FW reconfiguration

[Jakub Kicinski]

FW reconfiguration in .ndo_open()/.ndo_stop() should reset/
restore queue state.  Since we need IRQs to be disabled when
filling rings on RX path we have to move disable_irq() from
.ndo_open() all the way up to IRQ allocation.

nfp_net_start_vec() becomes trivial now so it's inlined.

Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
---
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 45 ++++++++--------------
 1 file changed, 16 insertions(+), 29 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c 
b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index f171a7da8931..2878ac021eda 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -1520,6 +1520,7 @@ nfp_net_prepare_vector(struct nfp_net *nn, struct 
nfp_net_r_vector *r_vec,
                nn_err(nn, "Error requesting IRQ %d\n", entry->vector);
                return err;
        }
+       disable_irq(entry->vector);
 
        /* Setup NAPI */
        netif_napi_add(nn->netdev, &r_vec->napi,
@@ -1648,13 +1649,14 @@ static void nfp_net_clear_config_and_disable(struct 
nfp_net *nn)
 
        nn_writel(nn, NFP_NET_CFG_CTRL, new_ctrl);
        err = nfp_net_reconfig(nn, update);
-       if (err) {
+       if (err)
                nn_err(nn, "Could not disable device: %d\n", err);
-               return;
-       }
 
-       for (r = 0; r < nn->num_r_vecs; r++)
+       for (r = 0; r < nn->num_r_vecs; r++) {
+               nfp_net_rx_ring_reset(nn->r_vecs[r].rx_ring);
+               nfp_net_tx_ring_reset(nn, nn->r_vecs[r].tx_ring);
                nfp_net_vec_clear_ring_data(nn, r);
+       }
 
        nn->ctrl = new_ctrl;
 }
@@ -1722,6 +1724,9 @@ static int __nfp_net_set_config_and_enable(struct nfp_net 
*nn)
 
        nn->ctrl = new_ctrl;
 
+       for (r = 0; r < nn->num_r_vecs; r++)
+               nfp_net_rx_ring_fill_freelist(nn->r_vecs[r].rx_ring);
+
        /* Since reconfiguration requests while NFP is down are ignored we
         * have to wipe the entire VXLAN configuration and reinitialize it.
         */
@@ -1750,26 +1755,6 @@ static int nfp_net_set_config_and_enable(struct nfp_net 
*nn)
 }
 
 /**
- * nfp_net_start_vec() - Start ring vector
- * @nn:      NFP Net device structure
- * @r_vec:   Ring vector to be started
- */
-static void
-nfp_net_start_vec(struct nfp_net *nn, struct nfp_net_r_vector *r_vec)
-{
-       unsigned int irq_vec;
-
-       irq_vec = nn->irq_entries[r_vec->irq_idx].vector;
-
-       disable_irq(irq_vec);
-
-       nfp_net_rx_ring_fill_freelist(r_vec->rx_ring);
-       napi_enable(&r_vec->napi);
-
-       enable_irq(irq_vec);
-}
-
-/**
  * nfp_net_open_stack() - Start the device from stack's perspective
  * @nn:      NFP Net device to reconfigure
  */
@@ -1777,8 +1762,10 @@ static void nfp_net_open_stack(struct nfp_net *nn)
 {
        unsigned int r;
 
-       for (r = 0; r < nn->num_r_vecs; r++)
-               nfp_net_start_vec(nn, &nn->r_vecs[r]);
+       for (r = 0; r < nn->num_r_vecs; r++) {
+               napi_enable(&nn->r_vecs[r].napi);
+               enable_irq(nn->irq_entries[nn->r_vecs[r].irq_idx].vector);
+       }
 
        netif_tx_wake_all_queues(nn->netdev);
 
@@ -1903,8 +1890,10 @@ static void nfp_net_close_stack(struct nfp_net *nn)
        netif_carrier_off(nn->netdev);
        nn->link_up = false;
 
-       for (r = 0; r < nn->num_r_vecs; r++)
+       for (r = 0; r < nn->num_r_vecs; r++) {
+               disable_irq(nn->irq_entries[nn->r_vecs[r].irq_idx].vector);
                napi_disable(&nn->r_vecs[r].napi);
+       }
 
        netif_tx_disable(nn->netdev);
 }
@@ -1918,9 +1907,7 @@ static void nfp_net_close_free_all(struct nfp_net *nn)
        unsigned int r;
 
        for (r = 0; r < nn->num_r_vecs; r++) {
-               nfp_net_rx_ring_reset(nn->r_vecs[r].rx_ring);
                nfp_net_rx_ring_bufs_free(nn, nn->r_vecs[r].rx_ring);
-               nfp_net_tx_ring_reset(nn, nn->r_vecs[r].tx_ring);
                nfp_net_rx_ring_free(nn->r_vecs[r].rx_ring);
                nfp_net_tx_ring_free(nn->r_vecs[r].tx_ring);
                nfp_net_cleanup_vector(nn, &nn->r_vecs[r]);
-- 
1.9.1