octeontx2-pf: Change receive buffer size using ethtool

ethtool rx-buf-len is for setting receive buffer size,
support setting it via ethtool -G parameter and getting
it via ethtool -g parameter.
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
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

@@ -222,8 +222,11 @@ EXPORT_SYMBOL(otx2_set_mac_address);
 int otx2_hw_set_mtu(struct otx2_nic *pfvf, int mtu)
 {
 	struct nix_frs_cfg *req;
+	u16 maxlen;
 	int err;
 
+	maxlen = otx2_get_max_mtu(pfvf) + OTX2_ETH_HLEN + OTX2_HW_TIMESTAMP_LEN;
+
 	mutex_lock(&pfvf->mbox.lock);
 	req = otx2_mbox_alloc_msg_nix_set_hw_frs(&pfvf->mbox);
 	if (!req) {
@@ -233,6 +236,10 @@ int otx2_hw_set_mtu(struct otx2_nic *pfvf, int mtu)
 
 	req->maxlen = pfvf->netdev->mtu + OTX2_ETH_HLEN + OTX2_HW_TIMESTAMP_LEN;
 
+	/* Use max receive length supported by hardware for loopback devices */
+	if (is_otx2_lbkvf(pfvf->pdev))
+		req->maxlen = maxlen;
+
 	err = otx2_sync_mbox_msg(&pfvf->mbox);
 	mutex_unlock(&pfvf->mbox.lock);
 	return err;

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

@@ -178,6 +178,9 @@ struct otx2_hw {
 	u16			rqpool_cnt;
 	u16			sqpool_cnt;
 
+#define OTX2_DEFAULT_RBUF_LEN	2048
+	u16			rbuf_len;
+
 	/* NPA */
 	u32			stack_pg_ptrs;  /* No of ptrs per stack page */
 	u32			stack_pg_bytes; /* Size of stack page */

drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c

@@ -371,6 +371,7 @@ static void otx2_get_ringparam(struct net_device *netdev,
 	ring->rx_pending = qs->rqe_cnt ? qs->rqe_cnt : Q_COUNT(Q_SIZE_256);
 	ring->tx_max_pending = Q_COUNT(Q_SIZE_MAX);
 	ring->tx_pending = qs->sqe_cnt ? qs->sqe_cnt : Q_COUNT(Q_SIZE_4K);
+	kernel_ring->rx_buf_len = pfvf->hw.rbuf_len;
 }
 
 static int otx2_set_ringparam(struct net_device *netdev,
@@ -379,6 +380,8 @@ static int otx2_set_ringparam(struct net_device *netdev,
 			      struct netlink_ext_ack *extack)
 {
 	struct otx2_nic *pfvf = netdev_priv(netdev);
+	u32 rx_buf_len = kernel_ring->rx_buf_len;
+	u32 old_rx_buf_len = pfvf->hw.rbuf_len;
 	bool if_up = netif_running(netdev);
 	struct otx2_qset *qs = &pfvf->qset;
 	u32 rx_count, tx_count;
@@ -386,6 +389,15 @@ static int otx2_set_ringparam(struct net_device *netdev,
 	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
 		return -EINVAL;
 
+	/* Hardware supports max size of 32k for a receive buffer
+	 * and 1536 is typical ethernet frame size.
+	 */
+	if (rx_buf_len && (rx_buf_len < 1536 || rx_buf_len > 32768)) {
+		netdev_err(netdev,
+			   "Receive buffer range is 1536 - 32768");
+		return -EINVAL;
+	}
+
 	/* Permitted lengths are 16 64 256 1K 4K 16K 64K 256K 1M  */
 	rx_count = ring->rx_pending;
 	/* On some silicon variants a skid or reserved CQEs are
@@ -403,7 +415,8 @@ static int otx2_set_ringparam(struct net_device *netdev,
 			   Q_COUNT(Q_SIZE_4K), Q_COUNT(Q_SIZE_MAX));
 	tx_count = Q_COUNT(Q_SIZE(tx_count, 3));
 
-	if (tx_count == qs->sqe_cnt && rx_count == qs->rqe_cnt)
+	if (tx_count == qs->sqe_cnt && rx_count == qs->rqe_cnt &&
+	    rx_buf_len == old_rx_buf_len)
 		return 0;
 
 	if (if_up)
@@ -413,6 +426,8 @@ static int otx2_set_ringparam(struct net_device *netdev,
 	qs->sqe_cnt = tx_count;
 	qs->rqe_cnt = rx_count;
 
+	pfvf->hw.rbuf_len = rx_buf_len;
+
 	if (if_up)
 		return netdev->netdev_ops->ndo_open(netdev);
 
@@ -1207,6 +1222,7 @@ static int otx2_set_link_ksettings(struct net_device *netdev,
 static const struct ethtool_ops otx2_ethtool_ops = {
 	.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
 				     ETHTOOL_COALESCE_MAX_FRAMES,
+	.supported_ring_params  = ETHTOOL_RING_USE_RX_BUF_LEN,
 	.get_link		= otx2_get_link,
 	.get_drvinfo		= otx2_get_drvinfo,
 	.get_strings		= otx2_get_strings,
@@ -1326,6 +1342,7 @@ static int otx2vf_get_link_ksettings(struct net_device *netdev,
 static const struct ethtool_ops otx2vf_ethtool_ops = {
 	.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
 				     ETHTOOL_COALESCE_MAX_FRAMES,
+	.supported_ring_params  = ETHTOOL_RING_USE_RX_BUF_LEN,
 	.get_link		= otx2_get_link,
 	.get_drvinfo		= otx2vf_get_drvinfo,
 	.get_strings		= otx2vf_get_strings,

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

@@ -1311,6 +1311,9 @@ static int otx2_get_rbuf_size(struct otx2_nic *pf, int mtu)
 	int total_size;
 	int rbuf_size;
 
+	if (pf->hw.rbuf_len)
+		return ALIGN(pf->hw.rbuf_len, OTX2_ALIGN) + OTX2_HEAD_ROOM;
+
 	/* The data transferred by NIX to memory consists of actual packet
 	 * plus additional data which has timestamp and/or EDSA/HIGIG2
 	 * headers if interface is configured in corresponding modes.
@@ -2625,6 +2628,7 @@ static int otx2_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	hw->tx_queues = qcount;
 	hw->tot_tx_queues = qcount;
 	hw->max_queues = qcount;
+	hw->rbuf_len = OTX2_DEFAULT_RBUF_LEN;
 
 	num_vec = pci_msix_vec_count(pdev);
 	hw->irq_name = devm_kmalloc_array(&hw->pdev->dev, num_vec, NAME_SIZE,

drivers/net/ethernet/marvell/octeontx2/nic/otx2_vf.c

@@ -586,6 +586,7 @@ static int otx2vf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	hw->tx_queues = qcount;
 	hw->max_queues = qcount;
 	hw->tot_tx_queues = qcount;
+	hw->rbuf_len = OTX2_DEFAULT_RBUF_LEN;
 
 	hw->irq_name = devm_kmalloc_array(&hw->pdev->dev, num_vec, NAME_SIZE,
 					  GFP_KERNEL);