gve: Switch to config-aware queue allocation

The new config-aware functions will help achieve the goal of being able
to allocate resources for new queues while there already are active
queues serving traffic.

These new functions work off of arbitrary queue allocation configs
rather than just the currently active config in priv, and they return
the newly allocated resources instead of writing them into priv.

Signed-off-by: Shailend Chand <shailend@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jeroen de Borst <jeroendb@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240122182632.1102721-4-shailend@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 89 insertions, 39 deletions

diff --git a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c
index 07ba124780df..4b9853adc113 100644
--- a/drivers/net/ethernet/google/gve/gve_tx.c
+++ b/drivers/net/ethernet/google/gve/gve_tx.c
@@ -196,29 +196,36 @@ static int gve_clean_xdp_done(struct gve_priv *priv, struct gve_tx_ring *tx,
 static int gve_clean_tx_done(struct gve_priv *priv, struct gve_tx_ring *tx,
 			     u32 to_do, bool try_to_wake);
 
-static void gve_tx_free_ring(struct gve_priv *priv, int idx)
+void gve_tx_stop_ring_gqi(struct gve_priv *priv, int idx)
 {
+	int ntfy_idx = gve_tx_idx_to_ntfy(priv, idx);
 	struct gve_tx_ring *tx = &priv->tx[idx];
+
+	if (!gve_tx_was_added_to_block(priv, idx))
+		return;
+
+	gve_remove_napi(priv, ntfy_idx);
+	gve_clean_tx_done(priv, tx, priv->tx_desc_cnt, false);
+	netdev_tx_reset_queue(tx->netdev_txq);
+	gve_tx_remove_from_block(priv, idx);
+}
+
+static void gve_tx_free_ring_gqi(struct gve_priv *priv, struct gve_tx_ring *tx,
+				 struct gve_tx_alloc_rings_cfg *cfg)
+{
 	struct device *hdev = &priv->pdev->dev;
+	int idx = tx->q_num;
 	size_t bytes;
 	u32 slots;
 
-	gve_tx_remove_from_block(priv, idx);
 	slots = tx->mask + 1;
-	if (tx->q_num < priv->tx_cfg.num_queues) {
-		gve_clean_tx_done(priv, tx, priv->tx_desc_cnt, false);
-		netdev_tx_reset_queue(tx->netdev_txq);
-	} else {
-		gve_clean_xdp_done(priv, tx, priv->tx_desc_cnt);
-	}
-
 	dma_free_coherent(hdev, sizeof(*tx->q_resources),
 			  tx->q_resources, tx->q_resources_bus);
 	tx->q_resources = NULL;
 
 	if (!tx->raw_addressing) {
 		gve_tx_fifo_release(priv, &tx->tx_fifo);
-		gve_unassign_qpl(priv, tx->tx_fifo.qpl->id);
+		gve_unassign_qpl(cfg->qpl_cfg, tx->tx_fifo.qpl->id);
 		tx->tx_fifo.qpl = NULL;
 	}
 
@@ -232,11 +239,23 @@ static void gve_tx_free_ring(struct gve_priv *priv, int idx)
 	netif_dbg(priv, drv, priv->dev, "freed tx queue %d\n", idx);
 }
 
-static int gve_tx_alloc_ring(struct gve_priv *priv, int idx)
+void gve_tx_start_ring_gqi(struct gve_priv *priv, int idx)
 {
+	int ntfy_idx = gve_tx_idx_to_ntfy(priv, idx);
 	struct gve_tx_ring *tx = &priv->tx[idx];
+
+	gve_tx_add_to_block(priv, idx);
+
+	tx->netdev_txq = netdev_get_tx_queue(priv->dev, idx);
+	gve_add_napi(priv, ntfy_idx, gve_napi_poll);
+}
+
+static int gve_tx_alloc_ring_gqi(struct gve_priv *priv,
+				 struct gve_tx_alloc_rings_cfg *cfg,
+				 struct gve_tx_ring *tx,
+				 int idx)
+{
 	struct device *hdev = &priv->pdev->dev;
-	u32 slots = priv->tx_desc_cnt;
 	size_t bytes;
 
 	/* Make sure everything is zeroed to start */
@@ -245,23 +264,23 @@ static int gve_tx_alloc_ring(struct gve_priv *priv, int idx)
 	spin_lock_init(&tx->xdp_lock);
 	tx->q_num = idx;
 
-	tx->mask = slots - 1;
+	tx->mask = cfg->ring_size - 1;
 
 	/* alloc metadata */
-	tx->info = vcalloc(slots, sizeof(*tx->info));
+	tx->info = vcalloc(cfg->ring_size, sizeof(*tx->info));
 	if (!tx->info)
 		return -ENOMEM;
 
 	/* alloc tx queue */
-	bytes = sizeof(*tx->desc) * slots;
+	bytes = sizeof(*tx->desc) * cfg->ring_size;
 	tx->desc = dma_alloc_coherent(hdev, bytes, &tx->bus, GFP_KERNEL);
 	if (!tx->desc)
 		goto abort_with_info;
 
-	tx->raw_addressing = priv->queue_format == GVE_GQI_RDA_FORMAT;
-	tx->dev = &priv->pdev->dev;
+	tx->raw_addressing = cfg->raw_addressing;
+	tx->dev = hdev;
 	if (!tx->raw_addressing) {
-		tx->tx_fifo.qpl = gve_assign_tx_qpl(priv, idx);
+		tx->tx_fifo.qpl = gve_assign_tx_qpl(cfg, idx);
 		if (!tx->tx_fifo.qpl)
 			goto abort_with_desc;
 		/* map Tx FIFO */
@@ -277,12 +296,6 @@ static int gve_tx_alloc_ring(struct gve_priv *priv, int idx)
 	if (!tx->q_resources)
 		goto abort_with_fifo;
 
-	netif_dbg(priv, drv, priv->dev, "tx[%d]->bus=%lx\n", idx,
-		  (unsigned long)tx->bus);
-	if (idx < priv->tx_cfg.num_queues)
-		tx->netdev_txq = netdev_get_tx_queue(priv->dev, idx);
-	gve_tx_add_to_block(priv, idx);
-
 	return 0;
 
 abort_with_fifo:
@@ -290,7 +303,7 @@ abort_with_fifo:
 		gve_tx_fifo_release(priv, &tx->tx_fifo);
 abort_with_qpl:
 	if (!tx->raw_addressing)
-		gve_unassign_qpl(priv, tx->tx_fifo.qpl->id);
+		gve_unassign_qpl(cfg->qpl_cfg, tx->tx_fifo.qpl->id);
 abort_with_desc:
 	dma_free_coherent(hdev, bytes, tx->desc, tx->bus);
 	tx->desc = NULL;
@@ -300,36 +313,73 @@ abort_with_info:
 	return -ENOMEM;
 }
 
-int gve_tx_alloc_rings(struct gve_priv *priv, int start_id, int num_rings)
+int gve_tx_alloc_rings_gqi(struct gve_priv *priv,
+			   struct gve_tx_alloc_rings_cfg *cfg)
 {
+	struct gve_tx_ring *tx = cfg->tx;
 	int err = 0;
-	int i;
+	int i, j;
+
+	if (!cfg->raw_addressing && !cfg->qpls) {
+		netif_err(priv, drv, priv->dev,
+			  "Cannot alloc QPL ring before allocing QPLs\n");
+		return -EINVAL;
+	}
+
+	if (cfg->start_idx + cfg->num_rings > cfg->qcfg->max_queues) {
+		netif_err(priv, drv, priv->dev,
+			  "Cannot alloc more than the max num of Tx rings\n");
+		return -EINVAL;
+	}
+
+	if (cfg->start_idx == 0) {
+		tx = kvcalloc(cfg->qcfg->max_queues, sizeof(struct gve_tx_ring),
+			      GFP_KERNEL);
+		if (!tx)
+			return -ENOMEM;
+	} else if (!tx) {
+		netif_err(priv, drv, priv->dev,
+			  "Cannot alloc tx rings from a nonzero start idx without tx array\n");
+		return -EINVAL;
+	}
 
-	for (i = start_id; i < start_id + num_rings; i++) {
-		err = gve_tx_alloc_ring(priv, i);
+	for (i = cfg->start_idx; i < cfg->start_idx + cfg->num_rings; i++) {
+		err = gve_tx_alloc_ring_gqi(priv, cfg, &tx[i], i);
 		if (err) {
 			netif_err(priv, drv, priv->dev,
 				  "Failed to alloc tx ring=%d: err=%d\n",
 				  i, err);
-			break;
+			goto cleanup;
 		}
 	}
-	/* Unallocate if there was an error */
-	if (err) {
-		int j;
 
-		for (j = start_id; j < i; j++)
-			gve_tx_free_ring(priv, j);
-	}
+	cfg->tx = tx;
+	return 0;
+
+cleanup:
+	for (j = 0; j < i; j++)
+		gve_tx_free_ring_gqi(priv, &tx[j], cfg);
+	if (cfg->start_idx == 0)
+		kvfree(tx);
 	return err;
 }
 
-void gve_tx_free_rings_gqi(struct gve_priv *priv, int start_id, int num_rings)
+void gve_tx_free_rings_gqi(struct gve_priv *priv,
+			   struct gve_tx_alloc_rings_cfg *cfg)
 {
+	struct gve_tx_ring *tx = cfg->tx;
 	int i;
 
-	for (i = start_id; i < start_id + num_rings; i++)
-		gve_tx_free_ring(priv, i);
+	if (!tx)
+		return;
+
+	for (i = cfg->start_idx; i < cfg->start_idx + cfg->num_rings; i++)
+		gve_tx_free_ring_gqi(priv, &tx[i], cfg);
+
+	if (cfg->start_idx == 0) {
+		kvfree(tx);
+		cfg->tx = NULL;
+	}
 }
 
 /* gve_tx_avail - Calculates the number of slots available in the ring