gve: Refactor gve_open and gve_close

gve_open is rewritten to be composed of two funcs: gve_queues_mem_alloc
and gve_queues_start. The former only allocates queue resources without
doing anything to install the queues, which is taken up by the latter.
Similarly gve_close is split into gve_queues_stop and
gve_queues_mem_free.

Separating the acts of queue resource allocation and making the queue
become live help with subsequent changes that aim to not take down the
datapath when applying new configurations.

Signed-off-by: Shailend Chand <shailend@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jeroen de Borst <jeroendb@google.com>
Link: https://lore.kernel.org/r/20240122182632.1102721-5-shailend@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index 8049a47c38fc920cc783521e2c01e5978197dae6..3515484e4cead48bc531256f3d6438a3af408901 100644 (file)
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -1350,45 +1350,99 @@ static void gve_rx_stop_rings(struct gve_priv *priv, int num_rings)
        }
 }
 
-static int gve_open(struct net_device *dev)
+static void gve_queues_mem_free(struct gve_priv *priv,
+                               struct gve_qpls_alloc_cfg *qpls_alloc_cfg,
+                               struct gve_tx_alloc_rings_cfg *tx_alloc_cfg,
+                               struct gve_rx_alloc_rings_cfg *rx_alloc_cfg)
+{
+       gve_free_rings(priv, tx_alloc_cfg, rx_alloc_cfg);
+       gve_free_qpls(priv, qpls_alloc_cfg);
+}
+
+static int gve_queues_mem_alloc(struct gve_priv *priv,
+                               struct gve_qpls_alloc_cfg *qpls_alloc_cfg,
+                               struct gve_tx_alloc_rings_cfg *tx_alloc_cfg,
+                               struct gve_rx_alloc_rings_cfg *rx_alloc_cfg)
+{
+       int err;
+
+       err = gve_alloc_qpls(priv, qpls_alloc_cfg);
+       if (err) {
+               netif_err(priv, drv, priv->dev, "Failed to alloc QPLs\n");
+               return err;
+       }
+       tx_alloc_cfg->qpls = qpls_alloc_cfg->qpls;
+       rx_alloc_cfg->qpls = qpls_alloc_cfg->qpls;
+       err = gve_alloc_rings(priv, tx_alloc_cfg, rx_alloc_cfg);
+       if (err) {
+               netif_err(priv, drv, priv->dev, "Failed to alloc rings\n");
+               goto free_qpls;
+       }
+
+       return 0;
+
+free_qpls:
+       gve_free_qpls(priv, qpls_alloc_cfg);
+       return err;
+}
+
+static void gve_queues_mem_remove(struct gve_priv *priv)
 {
        struct gve_tx_alloc_rings_cfg tx_alloc_cfg = {0};
        struct gve_rx_alloc_rings_cfg rx_alloc_cfg = {0};
        struct gve_qpls_alloc_cfg qpls_alloc_cfg = {0};
-       struct gve_priv *priv = netdev_priv(dev);
+
+       gve_get_curr_alloc_cfgs(priv, &qpls_alloc_cfg,
+                               &tx_alloc_cfg, &rx_alloc_cfg);
+       gve_queues_mem_free(priv, &qpls_alloc_cfg,
+                           &tx_alloc_cfg, &rx_alloc_cfg);
+       priv->qpls = NULL;
+       priv->tx = NULL;
+       priv->rx = NULL;
+}
+
+/* The passed-in queue memory is stored into priv and the queues are made live.
+ * No memory is allocated. Passed-in memory is freed on errors.
+ */
+static int gve_queues_start(struct gve_priv *priv,
+                           struct gve_qpls_alloc_cfg *qpls_alloc_cfg,
+                           struct gve_tx_alloc_rings_cfg *tx_alloc_cfg,
+                           struct gve_rx_alloc_rings_cfg *rx_alloc_cfg)
+{
+       struct net_device *dev = priv->dev;
        int err;
 
+       /* Record new resources into priv */
+       priv->qpls = qpls_alloc_cfg->qpls;
+       priv->tx = tx_alloc_cfg->tx;
+       priv->rx = rx_alloc_cfg->rx;
+
+       /* Record new configs into priv */
+       priv->qpl_cfg = *qpls_alloc_cfg->qpl_cfg;
+       priv->tx_cfg = *tx_alloc_cfg->qcfg;
+       priv->rx_cfg = *rx_alloc_cfg->qcfg;
+       priv->tx_desc_cnt = tx_alloc_cfg->ring_size;
+       priv->rx_desc_cnt = rx_alloc_cfg->ring_size;
+
        if (priv->xdp_prog)
                priv->num_xdp_queues = priv->rx_cfg.num_queues;
        else
                priv->num_xdp_queues = 0;
 
-       gve_get_curr_alloc_cfgs(priv, &qpls_alloc_cfg,
-                               &tx_alloc_cfg, &rx_alloc_cfg);
-       err = gve_alloc_qpls(priv, &qpls_alloc_cfg);
-       if (err)
-               return err;
-       priv->qpls = qpls_alloc_cfg.qpls;
-       tx_alloc_cfg.qpls = priv->qpls;
-       rx_alloc_cfg.qpls = priv->qpls;
-       err = gve_alloc_rings(priv, &tx_alloc_cfg, &rx_alloc_cfg);
-       if (err)
-               goto free_qpls;
-
-       gve_tx_start_rings(priv, 0, tx_alloc_cfg.num_rings);
-       gve_rx_start_rings(priv, rx_alloc_cfg.qcfg->num_queues);
+       gve_tx_start_rings(priv, 0, tx_alloc_cfg->num_rings);
+       gve_rx_start_rings(priv, rx_alloc_cfg->qcfg->num_queues);
        gve_init_sync_stats(priv);
 
        err = netif_set_real_num_tx_queues(dev, priv->tx_cfg.num_queues);
        if (err)
-               goto free_rings;
+               goto stop_and_free_rings;
        err = netif_set_real_num_rx_queues(dev, priv->rx_cfg.num_queues);
        if (err)
-               goto free_rings;
+               goto stop_and_free_rings;
 
        err = gve_reg_xdp_info(priv, dev);
        if (err)
-               goto free_rings;
+               goto stop_and_free_rings;
 
        err = gve_register_qpls(priv);
        if (err)
@@ -1416,29 +1470,22 @@ static int gve_open(struct net_device *dev)
        priv->interface_up_cnt++;
        return 0;
 
-free_rings:
-       gve_tx_stop_rings(priv, 0, tx_alloc_cfg.num_rings);
-       gve_rx_stop_rings(priv, rx_alloc_cfg.qcfg->num_queues);
-       gve_free_rings(priv, &tx_alloc_cfg, &rx_alloc_cfg);
-free_qpls:
-       gve_free_qpls(priv, &qpls_alloc_cfg);
-       return err;
-
 reset:
-       /* This must have been called from a reset due to the rtnl lock
-        * so just return at this point.
-        */
        if (gve_get_reset_in_progress(priv))
-               return err;
-       /* Otherwise reset before returning */
+               goto stop_and_free_rings;
        gve_reset_and_teardown(priv, true);
        /* if this fails there is nothing we can do so just ignore the return */
        gve_reset_recovery(priv, false);
        /* return the original error */
        return err;
+stop_and_free_rings:
+       gve_tx_stop_rings(priv, 0, gve_num_tx_queues(priv));
+       gve_rx_stop_rings(priv, priv->rx_cfg.num_queues);
+       gve_queues_mem_remove(priv);
+       return err;
 }
 
-static int gve_close(struct net_device *dev)
+static int gve_open(struct net_device *dev)
 {
        struct gve_tx_alloc_rings_cfg tx_alloc_cfg = {0};
        struct gve_rx_alloc_rings_cfg rx_alloc_cfg = {0};
@@ -1446,7 +1493,30 @@ static int gve_close(struct net_device *dev)
        struct gve_priv *priv = netdev_priv(dev);
        int err;
 
-       netif_carrier_off(dev);
+       gve_get_curr_alloc_cfgs(priv, &qpls_alloc_cfg,
+                               &tx_alloc_cfg, &rx_alloc_cfg);
+
+       err = gve_queues_mem_alloc(priv, &qpls_alloc_cfg,
+                                  &tx_alloc_cfg, &rx_alloc_cfg);
+       if (err)
+               return err;
+
+       /* No need to free on error: ownership of resources is lost after
+        * calling gve_queues_start.
+        */
+       err = gve_queues_start(priv, &qpls_alloc_cfg,
+                              &tx_alloc_cfg, &rx_alloc_cfg);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static int gve_queues_stop(struct gve_priv *priv)
+{
+       int err;
+
+       netif_carrier_off(priv->dev);
        if (gve_get_device_rings_ok(priv)) {
                gve_turndown(priv);
                gve_drain_page_cache(priv);
@@ -1462,12 +1532,8 @@ static int gve_close(struct net_device *dev)
 
        gve_unreg_xdp_info(priv);
 
-       gve_get_curr_alloc_cfgs(priv, &qpls_alloc_cfg,
-                               &tx_alloc_cfg, &rx_alloc_cfg);
-       gve_tx_stop_rings(priv, 0, tx_alloc_cfg.num_rings);
-       gve_rx_stop_rings(priv, rx_alloc_cfg.qcfg->num_queues);
-       gve_free_rings(priv, &tx_alloc_cfg, &rx_alloc_cfg);
-       gve_free_qpls(priv, &qpls_alloc_cfg);
+       gve_tx_stop_rings(priv, 0, gve_num_tx_queues(priv));
+       gve_rx_stop_rings(priv, priv->rx_cfg.num_queues);
 
        priv->interface_down_cnt++;
        return 0;
@@ -1483,6 +1549,19 @@ err:
        return gve_reset_recovery(priv, false);
 }
 
+static int gve_close(struct net_device *dev)
+{
+       struct gve_priv *priv = netdev_priv(dev);
+       int err;
+
+       err = gve_queues_stop(priv);
+       if (err)
+               return err;
+
+       gve_queues_mem_remove(priv);
+       return 0;
+}
+
 static int gve_remove_xdp_queues(struct gve_priv *priv)
 {
        int qpl_start_id;