octeontx2-pf: Receive side scaling support

Adds receive side scaling (RSS) support to distribute
pkts/flows across multiple queues. Sets up key, indirection
table etc. Also added extraction of HW calculated rxhash and
adding to same to SKB ie NETIF_F_RXHASH offload support.
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c

@@ -106,6 +106,126 @@ int otx2_hw_set_mtu(struct otx2_nic *pfvf, int mtu)
 	return err;
 }
 
+static int otx2_set_flowkey_cfg(struct otx2_nic *pfvf)
+{
+	struct otx2_rss_info *rss = &pfvf->hw.rss_info;
+	struct nix_rss_flowkey_cfg *req;
+	int err;
+
+	otx2_mbox_lock(&pfvf->mbox);
+	req = otx2_mbox_alloc_msg_nix_rss_flowkey_cfg(&pfvf->mbox);
+	if (!req) {
+		otx2_mbox_unlock(&pfvf->mbox);
+		return -ENOMEM;
+	}
+	req->mcam_index = -1; /* Default or reserved index */
+	req->flowkey_cfg = rss->flowkey_cfg;
+	req->group = DEFAULT_RSS_CONTEXT_GROUP;
+
+	err = otx2_sync_mbox_msg(&pfvf->mbox);
+	otx2_mbox_unlock(&pfvf->mbox);
+	return err;
+}
+
+static int otx2_set_rss_table(struct otx2_nic *pfvf)
+{
+	struct otx2_rss_info *rss = &pfvf->hw.rss_info;
+	struct mbox *mbox = &pfvf->mbox;
+	struct nix_aq_enq_req *aq;
+	int idx, err;
+
+	otx2_mbox_lock(mbox);
+	/* Get memory to put this msg */
+	for (idx = 0; idx < rss->rss_size; idx++) {
+		aq = otx2_mbox_alloc_msg_nix_aq_enq(mbox);
+		if (!aq) {
+			/* The shared memory buffer can be full.
+			 * Flush it and retry
+			 */
+			err = otx2_sync_mbox_msg(mbox);
+			if (err) {
+				otx2_mbox_unlock(mbox);
+				return err;
+			}
+			aq = otx2_mbox_alloc_msg_nix_aq_enq(mbox);
+			if (!aq) {
+				otx2_mbox_unlock(mbox);
+				return -ENOMEM;
+			}
+		}
+
+		aq->rss.rq = rss->ind_tbl[idx];
+
+		/* Fill AQ info */
+		aq->qidx = idx;
+		aq->ctype = NIX_AQ_CTYPE_RSS;
+		aq->op = NIX_AQ_INSTOP_INIT;
+	}
+	err = otx2_sync_mbox_msg(mbox);
+	otx2_mbox_unlock(mbox);
+	return err;
+}
+
+static void otx2_set_rss_key(struct otx2_nic *pfvf)
+{
+	struct otx2_rss_info *rss = &pfvf->hw.rss_info;
+	u64 *key = (u64 *)&rss->key[4];
+	int idx;
+
+	/* 352bit or 44byte key needs to be configured as below
+	 * NIX_LF_RX_SECRETX0 = key<351:288>
+	 * NIX_LF_RX_SECRETX1 = key<287:224>
+	 * NIX_LF_RX_SECRETX2 = key<223:160>
+	 * NIX_LF_RX_SECRETX3 = key<159:96>
+	 * NIX_LF_RX_SECRETX4 = key<95:32>
+	 * NIX_LF_RX_SECRETX5<63:32> = key<31:0>
+	 */
+	otx2_write64(pfvf, NIX_LF_RX_SECRETX(5),
+		     (u64)(*((u32 *)&rss->key)) << 32);
+	idx = sizeof(rss->key) / sizeof(u64);
+	while (idx > 0) {
+		idx--;
+		otx2_write64(pfvf, NIX_LF_RX_SECRETX(idx), *key++);
+	}
+}
+
+int otx2_rss_init(struct otx2_nic *pfvf)
+{
+	struct otx2_rss_info *rss = &pfvf->hw.rss_info;
+	int idx, ret = 0;
+
+	rss->rss_size = sizeof(rss->ind_tbl);
+
+	/* Init RSS key if it is not setup already */
+	if (!rss->enable)
+		netdev_rss_key_fill(rss->key, sizeof(rss->key));
+	otx2_set_rss_key(pfvf);
+
+	if (!netif_is_rxfh_configured(pfvf->netdev)) {
+		/* Default indirection table */
+		for (idx = 0; idx < rss->rss_size; idx++)
+			rss->ind_tbl[idx] =
+				ethtool_rxfh_indir_default(idx,
+							   pfvf->hw.rx_queues);
+	}
+	ret = otx2_set_rss_table(pfvf);
+	if (ret)
+		return ret;
+
+	/* Flowkey or hash config to be used for generating flow tag */
+	rss->flowkey_cfg = rss->enable ? rss->flowkey_cfg :
+			   NIX_FLOW_KEY_TYPE_IPV4 | NIX_FLOW_KEY_TYPE_IPV6 |
+			   NIX_FLOW_KEY_TYPE_TCP | NIX_FLOW_KEY_TYPE_UDP |
+			   NIX_FLOW_KEY_TYPE_SCTP;
+
+	ret = otx2_set_flowkey_cfg(pfvf);
+	if (ret)
+		return ret;
+
+	rss->enable = true;
+	return 0;
+}
+
 void otx2_config_irq_coalescing(struct otx2_nic *pfvf, int qidx)
 {
 	/* Configure CQE interrupt coalescing parameters
@@ -608,6 +728,8 @@ int otx2_config_nix(struct otx2_nic *pfvf)
 	nixlf->rq_cnt = pfvf->hw.rx_queues;
 	nixlf->sq_cnt = pfvf->hw.tx_queues;
 	nixlf->cq_cnt = pfvf->qset.cq_cnt;
+	nixlf->rss_sz = MAX_RSS_INDIR_TBL_SIZE;
+	nixlf->rss_grps = 1; /* Single RSS indir table supported, for now */
 	nixlf->xqe_sz = NIX_XQESZ_W16;
 	/* We don't know absolute NPA LF idx attached.
 	 * AF will replace 'RVU_DEFAULT_PF_FUNC' with

drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h

@@ -41,6 +41,16 @@ enum arua_mapped_qtypes {
 #define NIX_LF_ERR_VEC				0x81
 #define NIX_LF_POISON_VEC			0x82
 
+/* RSS configuration */
+struct otx2_rss_info {
+	u8 enable;
+	u32 flowkey_cfg;
+	u16 rss_size;
+	u8  ind_tbl[MAX_RSS_INDIR_TBL_SIZE];
+#define RSS_HASH_KEY_SIZE	44   /* 352 bit key */
+	u8  key[RSS_HASH_KEY_SIZE];
+};
+
 /* NIX (or NPC) RX errors */
 enum otx2_errlvl {
 	NPC_ERRLVL_RE,
@@ -95,6 +105,7 @@ struct mbox {
 
 struct otx2_hw {
 	struct pci_dev		*pdev;
+	struct otx2_rss_info	rss_info;
 	u16                     rx_queues;
 	u16                     tx_queues;
 	u16			max_queues;
@@ -510,6 +521,9 @@ void otx2_ctx_disable(struct mbox *mbox, int type, bool npa);
 void otx2_cleanup_rx_cqes(struct otx2_nic *pfvf, struct otx2_cq_queue *cq);
 void otx2_cleanup_tx_cqes(struct otx2_nic *pfvf, struct otx2_cq_queue *cq);
 
+/* RSS configuration APIs*/
+int otx2_rss_init(struct otx2_nic *pfvf);
+
 /* Mbox handlers */
 void mbox_handler_msix_offset(struct otx2_nic *pfvf,
 			      struct msix_offset_rsp *rsp);

drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c

@@ -838,6 +838,11 @@ int otx2_open(struct net_device *netdev)
 	if (err)
 		goto err_disable_napi;
 
+	/* Initialize RSS */
+	err = otx2_rss_init(pf);
+	if (err)
+		goto err_disable_napi;
+
 	/* Register Queue IRQ handlers */
 	vec = pf->hw.nix_msixoff + NIX_LF_QINT_VEC_START;
 	irq_name = &pf->hw.irq_name[vec * NAME_SIZE];
@@ -1237,7 +1242,8 @@ static int otx2_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	pf->iommu_domain = iommu_get_domain_for_dev(dev);
 
 	netdev->hw_features = (NETIF_F_RXCSUM | NETIF_F_IP_CSUM |
-			       NETIF_F_IPV6_CSUM | NETIF_F_SG);
+			       NETIF_F_IPV6_CSUM | NETIF_F_RXHASH |
+			       NETIF_F_SG);
 	netdev->features |= netdev->hw_features;
 
 	netdev->hw_features |= NETIF_F_LOOPBACK | NETIF_F_RXALL;

drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c

@@ -115,6 +115,28 @@ static void otx2_skb_add_frag(struct otx2_nic *pfvf, struct sk_buff *skb,
 			    pfvf->rbsize, DMA_FROM_DEVICE);
 }
 
+static void otx2_set_rxhash(struct otx2_nic *pfvf,
+			    struct nix_cqe_rx_s *cqe, struct sk_buff *skb)
+{
+	enum pkt_hash_types hash_type = PKT_HASH_TYPE_NONE;
+	struct otx2_rss_info *rss;
+	u32 hash = 0;
+
+	if (!(pfvf->netdev->features & NETIF_F_RXHASH))
+		return;
+
+	rss = &pfvf->hw.rss_info;
+	if (rss->flowkey_cfg) {
+		if (rss->flowkey_cfg &
+		    ~(NIX_FLOW_KEY_TYPE_IPV4 | NIX_FLOW_KEY_TYPE_IPV6))
+			hash_type = PKT_HASH_TYPE_L4;
+		else
+			hash_type = PKT_HASH_TYPE_L3;
+		hash = cqe->hdr.flow_tag;
+	}
+	skb_set_hash(skb, hash, hash_type);
+}
+
 static bool otx2_check_rcv_errors(struct otx2_nic *pfvf,
 				  struct nix_cqe_rx_s *cqe, int qidx)
 {
@@ -194,6 +216,8 @@ static void otx2_rcv_pkt_handler(struct otx2_nic *pfvf,
 	otx2_skb_add_frag(pfvf, skb, cqe->sg.seg_addr, cqe->sg.seg_size);
 	cq->pool_ptrs++;
 
+	otx2_set_rxhash(pfvf, cqe, skb);
+
 	skb_record_rx_queue(skb, cq->cq_idx);
 	if (pfvf->netdev->features & NETIF_F_RXCSUM)
 		skb->ip_summed = CHECKSUM_UNNECESSARY;