sfc: support RSS spreading of ethtool ntuple filters

Use a linked list to associate user-facing context IDs with FW-facing
 context IDs (since the latter can change after an MC reset).

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 59 insertions, 6 deletions

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 16757cfc5b29..7321a4cf6f4d 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -1353,12 +1353,13 @@ static void efx_fini_io(struct efx_nic *efx)
 		pci_disable_device(efx->pci_dev);
 }
 
-void efx_set_default_rx_indir_table(struct efx_nic *efx)
+void efx_set_default_rx_indir_table(struct efx_nic *efx,
+				    struct efx_rss_context *ctx)
 {
 	size_t i;
 
-	for (i = 0; i < ARRAY_SIZE(efx->rx_indir_table); i++)
-		efx->rx_indir_table[i] =
+	for (i = 0; i < ARRAY_SIZE(ctx->rx_indir_table); i++)
+		ctx->rx_indir_table[i] =
 			ethtool_rxfh_indir_default(i, efx->rss_spread);
 }
 
@@ -1739,9 +1740,9 @@ static int efx_probe_nic(struct efx_nic *efx)
 	} while (rc == -EAGAIN);
 
 	if (efx->n_channels > 1)
-		netdev_rss_key_fill(&efx->rx_hash_key,
-				    sizeof(efx->rx_hash_key));
-	efx_set_default_rx_indir_table(efx);
+		netdev_rss_key_fill(efx->rss_context.rx_hash_key,
+				    sizeof(efx->rss_context.rx_hash_key));
+	efx_set_default_rx_indir_table(efx, &efx->rss_context);
 
 	netif_set_real_num_tx_queues(efx->net_dev, efx->n_tx_channels);
 	netif_set_real_num_rx_queues(efx->net_dev, efx->n_rx_channels);
@@ -2700,6 +2701,8 @@ int efx_reset_up(struct efx_nic *efx, enum reset_type method, bool ok)
 			   " VFs may not function\n", rc);
 #endif
 
+	if (efx->type->rx_restore_rss_contexts)
+		efx->type->rx_restore_rss_contexts(efx);
 	down_read(&efx->filter_sem);
 	efx_restore_filters(efx);
 	up_read(&efx->filter_sem);
@@ -3003,6 +3006,7 @@ static int efx_init_struct(struct efx_nic *efx,
 		efx->type->rx_hash_offset - efx->type->rx_prefix_size;
 	efx->rx_packet_ts_offset =
 		efx->type->rx_ts_offset - efx->type->rx_prefix_size;
+	INIT_LIST_HEAD(&efx->rss_context.list);
 	spin_lock_init(&efx->stats_lock);
 	efx->vi_stride = EFX_DEFAULT_VI_STRIDE;
 	efx->num_mac_stats = MC_CMD_MAC_NSTATS;
@@ -3072,6 +3076,55 @@ void efx_update_sw_stats(struct efx_nic *efx, u64 *stats)
 	stats[GENERIC_STAT_rx_noskb_drops] = atomic_read(&efx->n_rx_noskb_drops);
 }
 
+/* RSS contexts.  We're using linked lists and crappy O(n) algorithms, because
+ * (a) this is an infrequent control-plane operation and (b) n is small (max 64)
+ */
+struct efx_rss_context *efx_alloc_rss_context_entry(struct list_head *head)
+{
+	struct efx_rss_context *ctx, *new;
+	u32 id = 1; /* Don't use zero, that refers to the master RSS context */
+
+	/* Search for first gap in the numbering */
+	list_for_each_entry(ctx, head, list) {
+		if (ctx->user_id != id)
+			break;
+		id++;
+		/* Check for wrap.  If this happens, we have nearly 2^32
+		 * allocated RSS contexts, which seems unlikely.
+		 */
+		if (WARN_ON_ONCE(!id))
+			return NULL;
+	}
+
+	/* Create the new entry */
+	new = kmalloc(sizeof(struct efx_rss_context), GFP_KERNEL);
+	if (!new)
+		return NULL;
+	new->context_id = EFX_EF10_RSS_CONTEXT_INVALID;
+	new->rx_hash_udp_4tuple = false;
+
+	/* Insert the new entry into the gap */
+	new->user_id = id;
+	list_add_tail(&new->list, &ctx->list);
+	return new;
+}
+
+struct efx_rss_context *efx_find_rss_context_entry(u32 id, struct list_head *head)
+{
+	struct efx_rss_context *ctx;
+
+	list_for_each_entry(ctx, head, list)
+		if (ctx->user_id == id)
+			return ctx;
+	return NULL;
+}
+
+void efx_free_rss_context_entry(struct efx_rss_context *ctx)
+{
+	list_del(&ctx->list);
+	kfree(ctx);
+}
+
 /**************************************************************************
  *
  * PCI interface