net: sh_eth: add support for set_ringparam/get_ringparam

index 2dd2ff5..af0b867 100644
@@ -782,7 +782,7 @@ static void sh_eth_ring_free(struct net_device *ndev)
 
 	/* Free Rx skb ringbuffer */
 	if (mdp->rx_skbuff) {
-		for (i = 0; i < RX_RING_SIZE; i++) {
+		for (i = 0; i < mdp->num_rx_ring; i++) {
 			if (mdp->rx_skbuff[i])
 				dev_kfree_skb(mdp->rx_skbuff[i]);
 		}

@@ -792,7 +792,7 @@ static void sh_eth_ring_free(struct net_device *ndev)
 
 	/* Free Tx skb ringbuffer */
 	if (mdp->tx_skbuff) {
-		for (i = 0; i < TX_RING_SIZE; i++) {
+		for (i = 0; i < mdp->num_tx_ring; i++) {
 			if (mdp->tx_skbuff[i])
 				dev_kfree_skb(mdp->tx_skbuff[i]);
 		}

@@ -809,8 +809,8 @@ static void sh_eth_ring_format(struct net_device *ndev)
 	struct sk_buff *skb;
 	struct sh_eth_rxdesc *rxdesc = NULL;
 	struct sh_eth_txdesc *txdesc = NULL;
-	int rx_ringsize = sizeof(*rxdesc) * RX_RING_SIZE;
-	int tx_ringsize = sizeof(*txdesc) * TX_RING_SIZE;
+	int rx_ringsize = sizeof(*rxdesc) * mdp->num_rx_ring;
+	int tx_ringsize = sizeof(*txdesc) * mdp->num_tx_ring;
 
 	mdp->cur_rx = mdp->cur_tx = 0;
 	mdp->dirty_rx = mdp->dirty_tx = 0;

@@ -818,7 +818,7 @@ static void sh_eth_ring_format(struct net_device *ndev)
 	memset(mdp->rx_ring, 0, rx_ringsize);
 
 	/* build Rx ring buffer */
-	for (i = 0; i < RX_RING_SIZE; i++) {
+	for (i = 0; i < mdp->num_rx_ring; i++) {
 		/* skb */
 		mdp->rx_skbuff[i] = NULL;
 		skb = netdev_alloc_skb(ndev, mdp->rx_buf_sz);

@@ -844,7 +844,7 @@ static void sh_eth_ring_format(struct net_device *ndev)
 		}
 	}
 
-	mdp->dirty_rx = (u32) (i - RX_RING_SIZE);
+	mdp->dirty_rx = (u32) (i - mdp->num_rx_ring);
 
 	/* Mark the last entry as wrapping the ring. */
 	rxdesc->status |= cpu_to_edmac(mdp, RD_RDEL);

@@ -852,7 +852,7 @@ static void sh_eth_ring_format(struct net_device *ndev)
 	memset(mdp->tx_ring, 0, tx_ringsize);
 
 	/* build Tx ring buffer */
-	for (i = 0; i < TX_RING_SIZE; i++) {
+	for (i = 0; i < mdp->num_tx_ring; i++) {
 		mdp->tx_skbuff[i] = NULL;
 		txdesc = &mdp->tx_ring[i];
 		txdesc->status = cpu_to_edmac(mdp, TD_TFP);

@@ -886,7 +886,7 @@ static int sh_eth_ring_init(struct net_device *ndev)
 		mdp->rx_buf_sz += NET_IP_ALIGN;
 
 	/* Allocate RX and TX skb rings */
-	mdp->rx_skbuff = kmalloc(sizeof(*mdp->rx_skbuff) * RX_RING_SIZE,
+	mdp->rx_skbuff = kmalloc(sizeof(*mdp->rx_skbuff) * mdp->num_rx_ring,
 				GFP_KERNEL);
 	if (!mdp->rx_skbuff) {
 		dev_err(&ndev->dev, "Cannot allocate Rx skb\n");

@@ -894,7 +894,7 @@ static int sh_eth_ring_init(struct net_device *ndev)
 		return ret;
 	}
 
-	mdp->tx_skbuff = kmalloc(sizeof(*mdp->tx_skbuff) * TX_RING_SIZE,
+	mdp->tx_skbuff = kmalloc(sizeof(*mdp->tx_skbuff) * mdp->num_tx_ring,
 				GFP_KERNEL);
 	if (!mdp->tx_skbuff) {
 		dev_err(&ndev->dev, "Cannot allocate Tx skb\n");

@@ -903,7 +903,7 @@ static int sh_eth_ring_init(struct net_device *ndev)
 	}
 
 	/* Allocate all Rx descriptors. */
-	rx_ringsize = sizeof(struct sh_eth_rxdesc) * RX_RING_SIZE;
+	rx_ringsize = sizeof(struct sh_eth_rxdesc) * mdp->num_rx_ring;
 	mdp->rx_ring = dma_alloc_coherent(NULL, rx_ringsize, &mdp->rx_desc_dma,
 			GFP_KERNEL);
 

@@ -917,7 +917,7 @@ static int sh_eth_ring_init(struct net_device *ndev)
 	mdp->dirty_rx = 0;
 
 	/* Allocate all Tx descriptors. */
-	tx_ringsize = sizeof(struct sh_eth_txdesc) * TX_RING_SIZE;
+	tx_ringsize = sizeof(struct sh_eth_txdesc) * mdp->num_tx_ring;
 	mdp->tx_ring = dma_alloc_coherent(NULL, tx_ringsize, &mdp->tx_desc_dma,
 			GFP_KERNEL);
 	if (!mdp->tx_ring) {

@@ -946,21 +946,21 @@ static void sh_eth_free_dma_buffer(struct sh_eth_private *mdp)
 	int ringsize;
 
 	if (mdp->rx_ring) {
-		ringsize = sizeof(struct sh_eth_rxdesc) * RX_RING_SIZE;
+		ringsize = sizeof(struct sh_eth_rxdesc) * mdp->num_rx_ring;
 		dma_free_coherent(NULL, ringsize, mdp->rx_ring,
 				  mdp->rx_desc_dma);
 		mdp->rx_ring = NULL;
 	}
 
 	if (mdp->tx_ring) {
-		ringsize = sizeof(struct sh_eth_txdesc) * TX_RING_SIZE;
+		ringsize = sizeof(struct sh_eth_txdesc) * mdp->num_tx_ring;
 		dma_free_coherent(NULL, ringsize, mdp->tx_ring,
 				  mdp->tx_desc_dma);
 		mdp->tx_ring = NULL;
 	}
 }
 
-static int sh_eth_dev_init(struct net_device *ndev)
+static int sh_eth_dev_init(struct net_device *ndev, bool start)
 {
 	int ret = 0;
 	struct sh_eth_private *mdp = netdev_priv(ndev);

@@ -1008,7 +1008,8 @@ static int sh_eth_dev_init(struct net_device *ndev)
 		     RFLR);
 
 	sh_eth_write(ndev, sh_eth_read(ndev, EESR), EESR);
-	sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
+	if (start)
+		sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
 
 	/* PAUSE Prohibition */
 	val = (sh_eth_read(ndev, ECMR) & ECMR_DM) |

@@ -1023,7 +1024,8 @@ static int sh_eth_dev_init(struct net_device *ndev)
 	sh_eth_write(ndev, mdp->cd->ecsr_value, ECSR);
 
 	/* E-MAC Interrupt Enable register */
-	sh_eth_write(ndev, mdp->cd->ecsipr_value, ECSIPR);
+	if (start)
+		sh_eth_write(ndev, mdp->cd->ecsipr_value, ECSIPR);
 
 	/* Set MAC address */
 	update_mac_address(ndev);

@@ -1036,10 +1038,12 @@ static int sh_eth_dev_init(struct net_device *ndev)
 	if (mdp->cd->tpauser)
 		sh_eth_write(ndev, TPAUSER_UNLIMITED, TPAUSER);
 
-	/* Setting the Rx mode will start the Rx process. */
-	sh_eth_write(ndev, EDRRR_R, EDRRR);
+	if (start) {
+		/* Setting the Rx mode will start the Rx process. */
+		sh_eth_write(ndev, EDRRR_R, EDRRR);
 
-	netif_start_queue(ndev);
+		netif_start_queue(ndev);
+	}
 
 out:
 	return ret;

@@ -1054,7 +1058,7 @@ static int sh_eth_txfree(struct net_device *ndev)
 	int entry = 0;
 
 	for (; mdp->cur_tx - mdp->dirty_tx > 0; mdp->dirty_tx++) {
-		entry = mdp->dirty_tx % TX_RING_SIZE;
+		entry = mdp->dirty_tx % mdp->num_tx_ring;
 		txdesc = &mdp->tx_ring[entry];
 		if (txdesc->status & cpu_to_edmac(mdp, TD_TACT))
 			break;

@@ -1067,7 +1071,7 @@ static int sh_eth_txfree(struct net_device *ndev)
 			freeNum++;
 		}
 		txdesc->status = cpu_to_edmac(mdp, TD_TFP);
-		if (entry >= TX_RING_SIZE - 1)
+		if (entry >= mdp->num_tx_ring - 1)
 			txdesc->status |= cpu_to_edmac(mdp, TD_TDLE);
 
 		ndev->stats.tx_packets++;

@@ -1082,8 +1086,8 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status)
 	struct sh_eth_private *mdp = netdev_priv(ndev);
 	struct sh_eth_rxdesc *rxdesc;
 
-	int entry = mdp->cur_rx % RX_RING_SIZE;
-	int boguscnt = (mdp->dirty_rx + RX_RING_SIZE) - mdp->cur_rx;
+	int entry = mdp->cur_rx % mdp->num_rx_ring;
+	int boguscnt = (mdp->dirty_rx + mdp->num_rx_ring) - mdp->cur_rx;
 	struct sk_buff *skb;
 	u16 pkt_len = 0;
 	u32 desc_status;

@@ -1134,13 +1138,13 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status)
 			ndev->stats.rx_bytes += pkt_len;
 		}
 		rxdesc->status |= cpu_to_edmac(mdp, RD_RACT);
-		entry = (++mdp->cur_rx) % RX_RING_SIZE;
+		entry = (++mdp->cur_rx) % mdp->num_rx_ring;
 		rxdesc = &mdp->rx_ring[entry];
 	}
 
 	/* Refill the Rx ring buffers. */
 	for (; mdp->cur_rx - mdp->dirty_rx > 0; mdp->dirty_rx++) {
-		entry = mdp->dirty_rx % RX_RING_SIZE;
+		entry = mdp->dirty_rx % mdp->num_rx_ring;
 		rxdesc = &mdp->rx_ring[entry];
 		/* The size of the buffer is 16 byte boundary. */
 		rxdesc->buffer_length = ALIGN(mdp->rx_buf_sz, 16);

@@ -1157,7 +1161,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status)
 			skb_checksum_none_assert(skb);
 			rxdesc->addr = virt_to_phys(PTR_ALIGN(skb->data, 4));
 		}
-		if (entry >= RX_RING_SIZE - 1)
+		if (entry >= mdp->num_rx_ring - 1)
 			rxdesc->status | 				cpu_to_edmac(mdp, RD_RACT | RD_RFP | RD_RDEL);
 		else

@@ -1557,6 +1561,71 @@ static void sh_eth_get_strings(struct net_device *ndev, u32 stringset, u8 *data)
 	}
 }
 
+static void sh_eth_get_ringparam(struct net_device *ndev,
+				 struct ethtool_ringparam *ring)
+{
+	struct sh_eth_private *mdp = netdev_priv(ndev);
+
+	ring->rx_max_pending = RX_RING_MAX;
+	ring->tx_max_pending = TX_RING_MAX;
+	ring->rx_pending = mdp->num_rx_ring;
+	ring->tx_pending = mdp->num_tx_ring;
+}
+
+static int sh_eth_set_ringparam(struct net_device *ndev,
+				struct ethtool_ringparam *ring)
+{
+	struct sh_eth_private *mdp = netdev_priv(ndev);
+	int ret;
+
+	if (ring->tx_pending > TX_RING_MAX ||
+	    ring->rx_pending > RX_RING_MAX ||
+	    ring->tx_pending < TX_RING_MIN ||
+	    ring->rx_pending < RX_RING_MIN)
+		return -EINVAL;
+	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
+		return -EINVAL;
+
+	if (netif_running(ndev)) {
+		netif_tx_disable(ndev);
+		/* Disable interrupts by clearing the interrupt mask. */
+		sh_eth_write(ndev, 0x0000, EESIPR);
+		/* Stop the chip's Tx and Rx processes. */
+		sh_eth_write(ndev, 0, EDTRR);
+		sh_eth_write(ndev, 0, EDRRR);
+		synchronize_irq(ndev->irq);
+	}
+
+	/* Free all the skbuffs in the Rx queue. */
+	sh_eth_ring_free(ndev);
+	/* Free DMA buffer */
+	sh_eth_free_dma_buffer(mdp);
+
+	/* Set new parameters */
+	mdp->num_rx_ring = ring->rx_pending;
+	mdp->num_tx_ring = ring->tx_pending;
+
+	ret = sh_eth_ring_init(ndev);
+	if (ret < 0) {
+		dev_err(&ndev->dev, "%s: sh_eth_ring_init failed.\n", __func__);
+		return ret;
+	}
+	ret = sh_eth_dev_init(ndev, false);
+	if (ret < 0) {
+		dev_err(&ndev->dev, "%s: sh_eth_dev_init failed.\n", __func__);
+		return ret;
+	}
+
+	if (netif_running(ndev)) {
+		sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
+		/* Setting the Rx mode will start the Rx process. */
+		sh_eth_write(ndev, EDRRR_R, EDRRR);
+		netif_wake_queue(ndev);
+	}
+
+	return 0;
+}
+
 static const struct ethtool_ops sh_eth_ethtool_ops = {
 	.get_settings	= sh_eth_get_settings,
 	.set_settings	= sh_eth_set_settings,

@@ -1567,6 +1636,8 @@ static const struct ethtool_ops sh_eth_ethtool_ops = {
 	.get_strings	= sh_eth_get_strings,
 	.get_ethtool_stats  = sh_eth_get_ethtool_stats,
 	.get_sset_count     = sh_eth_get_sset_count,
+	.get_ringparam	= sh_eth_get_ringparam,
+	.set_ringparam	= sh_eth_set_ringparam,
 };
 
 /* network device open function */

@@ -1597,7 +1668,7 @@ static int sh_eth_open(struct net_device *ndev)
 		goto out_free_irq;
 
 	/* device init */
-	ret = sh_eth_dev_init(ndev);
+	ret = sh_eth_dev_init(ndev, true);
 	if (ret)
 		goto out_free_irq;
 

@@ -1631,7 +1702,7 @@ static void sh_eth_tx_timeout(struct net_device *ndev)
 	ndev->stats.tx_errors++;
 
 	/* Free all the skbuffs in the Rx queue. */
-	for (i = 0; i < RX_RING_SIZE; i++) {
+	for (i = 0; i < mdp->num_rx_ring; i++) {
 		rxdesc = &mdp->rx_ring[i];
 		rxdesc->status = 0;
 		rxdesc->addr = 0xBADF00D0;

@@ -1639,14 +1710,14 @@ static void sh_eth_tx_timeout(struct net_device *ndev)
 			dev_kfree_skb(mdp->rx_skbuff[i]);
 		mdp->rx_skbuff[i] = NULL;
 	}
-	for (i = 0; i < TX_RING_SIZE; i++) {
+	for (i = 0; i < mdp->num_tx_ring; i++) {
 		if (mdp->tx_skbuff[i])
 			dev_kfree_skb(mdp->tx_skbuff[i]);
 		mdp->tx_skbuff[i] = NULL;
 	}
 
 	/* device init */
-	sh_eth_dev_init(ndev);
+	sh_eth_dev_init(ndev, true);
 }
 
 /* Packet transmit function */

@@ -1658,7 +1729,7 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	unsigned long flags;
 
 	spin_lock_irqsave(&mdp->lock, flags);
-	if ((mdp->cur_tx - mdp->dirty_tx) >= (TX_RING_SIZE - 4)) {
+	if ((mdp->cur_tx - mdp->dirty_tx) >= (mdp->num_tx_ring - 4)) {
 		if (!sh_eth_txfree(ndev)) {
 			if (netif_msg_tx_queued(mdp))
 				dev_warn(&ndev->dev, "TxFD exhausted.\n");

@@ -1669,7 +1740,7 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	}
 	spin_unlock_irqrestore(&mdp->lock, flags);
 
-	entry = mdp->cur_tx % TX_RING_SIZE;
+	entry = mdp->cur_tx % mdp->num_tx_ring;
 	mdp->tx_skbuff[entry] = skb;
 	txdesc = &mdp->tx_ring[entry];
 	/* soft swap. */

@@ -1683,7 +1754,7 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	else
 		txdesc->buffer_length = skb->len;
 
-	if (entry >= TX_RING_SIZE - 1)
+	if (entry >= mdp->num_tx_ring - 1)
 		txdesc->status |= cpu_to_edmac(mdp, TD_TACT | TD_TDLE);
 	else
 		txdesc->status |= cpu_to_edmac(mdp, TD_TACT);

@@ -2313,6 +2384,8 @@ static int sh_eth_drv_probe(struct platform_device *pdev)
 	ether_setup(ndev);
 
 	mdp = netdev_priv(ndev);
+	mdp->num_tx_ring = TX_RING_SIZE;
+	mdp->num_rx_ring = RX_RING_SIZE;
 	mdp->addr = ioremap(res->start, resource_size(res));
 	if (mdp->addr = NULL) {
 		ret = -ENOMEM;

index 37a0702..bae84fd 100644
@@ -27,6 +27,10 @@
 #define TX_TIMEOUT	(5*HZ)
 #define TX_RING_SIZE	64	/* Tx ring size */
 #define RX_RING_SIZE	64	/* Rx ring size */
+#define TX_RING_MIN	64
+#define RX_RING_MIN	64
+#define TX_RING_MAX	1024
+#define RX_RING_MAX	1024
 #define ETHERSMALL		60
 #define PKT_BUF_SZ		1538
 #define SH_ETH_TSU_TIMEOUT_MS	500

@@ -701,6 +705,8 @@ struct sh_eth_private {
 	const u16 *reg_offset;
 	void __iomem *addr;
 	void __iomem *tsu_addr;
+	u32 num_rx_ring;
+	u32 num_tx_ring;
 	dma_addr_t rx_desc_dma;
 	dma_addr_t tx_desc_dma;
 	struct sh_eth_rxdesc *rx_ring;