Merge branch 'macb-ethtool-ringparam'

Zach Brown says:

====================
macb: Add ethtool get_ringparam and set_ringparam to cadence

There are use cases like RT that would benefit from being able to tune the
macb rx/tx ring sizes. The ethtool set_ringparam function is the standard way
of doing so.

The first patch changes the hardcoded tx/rx ring sizes to variables that are
set to a hardcoded default.

The second patch implements the get_ringparam and set_ringparam fucntions.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/macb.c

@@ -37,14 +37,21 @@
 
 #define MACB_RX_BUFFER_SIZE	128
 #define RX_BUFFER_MULTIPLE	64  /* bytes */
-#define RX_RING_SIZE		512 /* must be power of 2 */
-#define RX_RING_BYTES		(sizeof(struct macb_dma_desc) * RX_RING_SIZE)
 
-#define TX_RING_SIZE		128 /* must be power of 2 */
-#define TX_RING_BYTES		(sizeof(struct macb_dma_desc) * TX_RING_SIZE)
+#define DEFAULT_RX_RING_SIZE	512 /* must be power of 2 */
+#define MIN_RX_RING_SIZE	64
+#define MAX_RX_RING_SIZE	8192
+#define RX_RING_BYTES(bp)	(sizeof(struct macb_dma_desc)	\
+				 * (bp)->rx_ring_size)
+
+#define DEFAULT_TX_RING_SIZE	512 /* must be power of 2 */
+#define MIN_TX_RING_SIZE	64
+#define MAX_TX_RING_SIZE	4096
+#define TX_RING_BYTES(bp)	(sizeof(struct macb_dma_desc)	\
+				 * (bp)->tx_ring_size)
 
 /* level of occupied TX descriptors under which we wake up TX process */
-#define MACB_TX_WAKEUP_THRESH	(3 * TX_RING_SIZE / 4)
+#define MACB_TX_WAKEUP_THRESH(bp)	(3 * (bp)->tx_ring_size / 4)
 
 #define MACB_RX_INT_FLAGS	(MACB_BIT(RCOMP) | MACB_BIT(RXUBR)	\
 				 | MACB_BIT(ISR_ROVR))
@@ -67,45 +74,47 @@
 #define MACB_HALT_TIMEOUT	1230
 
 /* Ring buffer accessors */
-static unsigned int macb_tx_ring_wrap(unsigned int index)
+static unsigned int macb_tx_ring_wrap(struct macb *bp, unsigned int index)
 {
-	return index & (TX_RING_SIZE - 1);
+	return index & (bp->tx_ring_size - 1);
 }
 
 static struct macb_dma_desc *macb_tx_desc(struct macb_queue *queue,
 					  unsigned int index)
 {
-	return &queue->tx_ring[macb_tx_ring_wrap(index)];
+	return &queue->tx_ring[macb_tx_ring_wrap(queue->bp, index)];
 }
 
 static struct macb_tx_skb *macb_tx_skb(struct macb_queue *queue,
 				       unsigned int index)
 {
-	return &queue->tx_skb[macb_tx_ring_wrap(index)];
+	return &queue->tx_skb[macb_tx_ring_wrap(queue->bp, index)];
 }
 
 static dma_addr_t macb_tx_dma(struct macb_queue *queue, unsigned int index)
 {
 	dma_addr_t offset;
 
-	offset = macb_tx_ring_wrap(index) * sizeof(struct macb_dma_desc);
+	offset = macb_tx_ring_wrap(queue->bp, index) *
+		 sizeof(struct macb_dma_desc);
 
 	return queue->tx_ring_dma + offset;
 }
 
-static unsigned int macb_rx_ring_wrap(unsigned int index)
+static unsigned int macb_rx_ring_wrap(struct macb *bp, unsigned int index)
 {
-	return index & (RX_RING_SIZE - 1);
+	return index & (bp->rx_ring_size - 1);
 }
 
 static struct macb_dma_desc *macb_rx_desc(struct macb *bp, unsigned int index)
 {
-	return &bp->rx_ring[macb_rx_ring_wrap(index)];
+	return &bp->rx_ring[macb_rx_ring_wrap(bp, index)];
 }
 
 static void *macb_rx_buffer(struct macb *bp, unsigned int index)
 {
-	return bp->rx_buffers + bp->rx_buffer_size * macb_rx_ring_wrap(index);
+	return bp->rx_buffers + bp->rx_buffer_size *
+	       macb_rx_ring_wrap(bp, index);
 }
 
 /* I/O accessors */
@@ -608,7 +617,8 @@ static void macb_tx_error_task(struct work_struct *work)
 			 */
 			if (!(ctrl & MACB_BIT(TX_BUF_EXHAUSTED))) {
 				netdev_vdbg(bp->dev, "txerr skb %u (data %p) TX complete\n",
-					    macb_tx_ring_wrap(tail), skb->data);
+					    macb_tx_ring_wrap(bp, tail),
+					    skb->data);
 				bp->stats.tx_packets++;
 				bp->stats.tx_bytes += skb->len;
 			}
@@ -700,7 +710,8 @@ static void macb_tx_interrupt(struct macb_queue *queue)
 			/* First, update TX stats if needed */
 			if (skb) {
 				netdev_vdbg(bp->dev, "skb %u (data %p) TX complete\n",
-					    macb_tx_ring_wrap(tail), skb->data);
+					    macb_tx_ring_wrap(bp, tail),
+					    skb->data);
 				bp->stats.tx_packets++;
 				bp->stats.tx_bytes += skb->len;
 			}
@@ -720,7 +731,7 @@ static void macb_tx_interrupt(struct macb_queue *queue)
 	queue->tx_tail = tail;
 	if (__netif_subqueue_stopped(bp->dev, queue_index) &&
 	    CIRC_CNT(queue->tx_head, queue->tx_tail,
-		     TX_RING_SIZE) <= MACB_TX_WAKEUP_THRESH)
+		     bp->tx_ring_size) <= MACB_TX_WAKEUP_THRESH(bp))
 		netif_wake_subqueue(bp->dev, queue_index);
 }
 
@@ -731,8 +742,8 @@ static void gem_rx_refill(struct macb *bp)
 	dma_addr_t		paddr;
 
 	while (CIRC_SPACE(bp->rx_prepared_head, bp->rx_tail,
-			  RX_RING_SIZE) > 0) {
-		entry = macb_rx_ring_wrap(bp->rx_prepared_head);
+			  bp->rx_ring_size) > 0) {
+		entry = macb_rx_ring_wrap(bp, bp->rx_prepared_head);
 
 		/* Make hw descriptor updates visible to CPU */
 		rmb();
@@ -759,7 +770,7 @@ static void gem_rx_refill(struct macb *bp)
 
 			bp->rx_skbuff[entry] = skb;
 
-			if (entry == RX_RING_SIZE - 1)
+			if (entry == bp->rx_ring_size - 1)
 				paddr |= MACB_BIT(RX_WRAP);
 			macb_set_addr(&(bp->rx_ring[entry]), paddr);
 			bp->rx_ring[entry].ctrl = 0;
@@ -813,7 +824,7 @@ static int gem_rx(struct macb *bp, int budget)
 		dma_addr_t addr;
 		bool rxused;
 
-		entry = macb_rx_ring_wrap(bp->rx_tail);
+		entry = macb_rx_ring_wrap(bp, bp->rx_tail);
 		desc = &bp->rx_ring[entry];
 
 		/* Make hw descriptor updates visible to CPU */
@@ -895,8 +906,8 @@ static int macb_rx_frame(struct macb *bp, unsigned int first_frag,
 	len = desc->ctrl & bp->rx_frm_len_mask;
 
 	netdev_vdbg(bp->dev, "macb_rx_frame frags %u - %u (len %u)\n",
-		    macb_rx_ring_wrap(first_frag),
-		    macb_rx_ring_wrap(last_frag), len);
+		macb_rx_ring_wrap(bp, first_frag),
+		macb_rx_ring_wrap(bp, last_frag), len);
 
 	/* The ethernet header starts NET_IP_ALIGN bytes into the
 	 * first buffer. Since the header is 14 bytes, this makes the
@@ -969,12 +980,12 @@ static inline void macb_init_rx_ring(struct macb *bp)
 	int i;
 
 	addr = bp->rx_buffers_dma;
-	for (i = 0; i < RX_RING_SIZE; i++) {
+	for (i = 0; i < bp->rx_ring_size; i++) {
 		bp->rx_ring[i].addr = addr;
 		bp->rx_ring[i].ctrl = 0;
 		addr += bp->rx_buffer_size;
 	}
-	bp->rx_ring[RX_RING_SIZE - 1].addr |= MACB_BIT(RX_WRAP);
+	bp->rx_ring[bp->rx_ring_size - 1].addr |= MACB_BIT(RX_WRAP);
 }
 
 static int macb_rx(struct macb *bp, int budget)
@@ -1228,7 +1239,7 @@ static unsigned int macb_tx_map(struct macb *bp,
 	offset = 0;
 	while (len) {
 		size = min(len, bp->max_tx_length);
-		entry = macb_tx_ring_wrap(tx_head);
+		entry = macb_tx_ring_wrap(bp, tx_head);
 		tx_skb = &queue->tx_skb[entry];
 
 		mapping = dma_map_single(&bp->pdev->dev,
@@ -1257,7 +1268,7 @@ static unsigned int macb_tx_map(struct macb *bp,
 		offset = 0;
 		while (len) {
 			size = min(len, bp->max_tx_length);
-			entry = macb_tx_ring_wrap(tx_head);
+			entry = macb_tx_ring_wrap(bp, tx_head);
 			tx_skb = &queue->tx_skb[entry];
 
 			mapping = skb_frag_dma_map(&bp->pdev->dev, frag,
@@ -1295,14 +1306,14 @@ static unsigned int macb_tx_map(struct macb *bp,
 	 * to set the end of TX queue
 	 */
 	i = tx_head;
-	entry = macb_tx_ring_wrap(i);
+	entry = macb_tx_ring_wrap(bp, i);
 	ctrl = MACB_BIT(TX_USED);
 	desc = &queue->tx_ring[entry];
 	desc->ctrl = ctrl;
 
 	do {
 		i--;
-		entry = macb_tx_ring_wrap(i);
+		entry = macb_tx_ring_wrap(bp, i);
 		tx_skb = &queue->tx_skb[entry];
 		desc = &queue->tx_ring[entry];
 
@@ -1311,7 +1322,7 @@ static unsigned int macb_tx_map(struct macb *bp,
 			ctrl |= MACB_BIT(TX_LAST);
 			eof = 0;
 		}
-		if (unlikely(entry == (TX_RING_SIZE - 1)))
+		if (unlikely(entry == (bp->tx_ring_size - 1)))
 			ctrl |= MACB_BIT(TX_WRAP);
 
 		/* Set TX buffer descriptor */
@@ -1388,7 +1399,8 @@ static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	spin_lock_irqsave(&bp->lock, flags);
 
 	/* This is a hard error, log it. */
-	if (CIRC_SPACE(queue->tx_head, queue->tx_tail, TX_RING_SIZE) < count) {
+	if (CIRC_SPACE(queue->tx_head, queue->tx_tail,
+		       bp->tx_ring_size) < count) {
 		netif_stop_subqueue(dev, queue_index);
 		spin_unlock_irqrestore(&bp->lock, flags);
 		netdev_dbg(bp->dev, "tx_head = %u, tx_tail = %u\n",
@@ -1414,7 +1426,7 @@ static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART));
 
-	if (CIRC_SPACE(queue->tx_head, queue->tx_tail, TX_RING_SIZE) < 1)
+	if (CIRC_SPACE(queue->tx_head, queue->tx_tail, bp->tx_ring_size) < 1)
 		netif_stop_subqueue(dev, queue_index);
 
 unlock:
@@ -1453,7 +1465,7 @@ static void gem_free_rx_buffers(struct macb *bp)
 	if (!bp->rx_skbuff)
 		return;
 
-	for (i = 0; i < RX_RING_SIZE; i++) {
+	for (i = 0; i < bp->rx_ring_size; i++) {
 		skb = bp->rx_skbuff[i];
 
 		if (!skb)
@@ -1478,7 +1490,7 @@ static void macb_free_rx_buffers(struct macb *bp)
 {
 	if (bp->rx_buffers) {
 		dma_free_coherent(&bp->pdev->dev,
-				  RX_RING_SIZE * bp->rx_buffer_size,
+				  bp->rx_ring_size * bp->rx_buffer_size,
 				  bp->rx_buffers, bp->rx_buffers_dma);
 		bp->rx_buffers = NULL;
 	}
@@ -1491,7 +1503,7 @@ static void macb_free_consistent(struct macb *bp)
 
 	bp->macbgem_ops.mog_free_rx_buffers(bp);
 	if (bp->rx_ring) {
-		dma_free_coherent(&bp->pdev->dev, RX_RING_BYTES,
+		dma_free_coherent(&bp->pdev->dev, RX_RING_BYTES(bp),
 				  bp->rx_ring, bp->rx_ring_dma);
 		bp->rx_ring = NULL;
 	}
@@ -1500,7 +1512,7 @@ static void macb_free_consistent(struct macb *bp)
 		kfree(queue->tx_skb);
 		queue->tx_skb = NULL;
 		if (queue->tx_ring) {
-			dma_free_coherent(&bp->pdev->dev, TX_RING_BYTES,
+			dma_free_coherent(&bp->pdev->dev, TX_RING_BYTES(bp),
 					  queue->tx_ring, queue->tx_ring_dma);
 			queue->tx_ring = NULL;
 		}
@@ -1511,14 +1523,14 @@ static int gem_alloc_rx_buffers(struct macb *bp)
 {
 	int size;
 
-	size = RX_RING_SIZE * sizeof(struct sk_buff *);
+	size = bp->rx_ring_size * sizeof(struct sk_buff *);
 	bp->rx_skbuff = kzalloc(size, GFP_KERNEL);
 	if (!bp->rx_skbuff)
 		return -ENOMEM;
-
+	else
 		netdev_dbg(bp->dev,
 			   "Allocated %d RX struct sk_buff entries at %p\n",
-		   RX_RING_SIZE, bp->rx_skbuff);
+			   bp->rx_ring_size, bp->rx_skbuff);
 	return 0;
 }
 
@@ -1526,7 +1538,7 @@ static int macb_alloc_rx_buffers(struct macb *bp)
 {
 	int size;
 
-	size = RX_RING_SIZE * bp->rx_buffer_size;
+	size = bp->rx_ring_size * bp->rx_buffer_size;
 	bp->rx_buffers = dma_alloc_coherent(&bp->pdev->dev, size,
 					    &bp->rx_buffers_dma, GFP_KERNEL);
 	if (!bp->rx_buffers)
@@ -1545,7 +1557,7 @@ static int macb_alloc_consistent(struct macb *bp)
 	int size;
 
 	for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
-		size = TX_RING_BYTES;
+		size = TX_RING_BYTES(bp);
 		queue->tx_ring = dma_alloc_coherent(&bp->pdev->dev, size,
 						    &queue->tx_ring_dma,
 						    GFP_KERNEL);
@@ -1556,13 +1568,13 @@ static int macb_alloc_consistent(struct macb *bp)
 			   q, size, (unsigned long)queue->tx_ring_dma,
 			   queue->tx_ring);
 
-		size = TX_RING_SIZE * sizeof(struct macb_tx_skb);
+		size = bp->tx_ring_size * sizeof(struct macb_tx_skb);
 		queue->tx_skb = kmalloc(size, GFP_KERNEL);
 		if (!queue->tx_skb)
 			goto out_err;
 	}
 
-	size = RX_RING_BYTES;
+	size = RX_RING_BYTES(bp);
 	bp->rx_ring = dma_alloc_coherent(&bp->pdev->dev, size,
 					 &bp->rx_ring_dma, GFP_KERNEL);
 	if (!bp->rx_ring)
@@ -1588,11 +1600,11 @@ static void gem_init_rings(struct macb *bp)
 	int i;
 
 	for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
-		for (i = 0; i < TX_RING_SIZE; i++) {
-			macb_set_addr(&(queue->tx_ring[i]), 0);
+		for (i = 0; i < bp->tx_ring_size; i++) {
+			queue->tx_ring[i].addr = 0;
 			queue->tx_ring[i].ctrl = MACB_BIT(TX_USED);
 		}
-		queue->tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP);
+		queue->tx_ring[bp->tx_ring_size - 1].ctrl |= MACB_BIT(TX_WRAP);
 		queue->tx_head = 0;
 		queue->tx_tail = 0;
 	}
@@ -1609,13 +1621,13 @@ static void macb_init_rings(struct macb *bp)
 
 	macb_init_rx_ring(bp);
 
-	for (i = 0; i < TX_RING_SIZE; i++) {
+	for (i = 0; i < bp->tx_ring_size; i++) {
 		bp->queues[0].tx_ring[i].addr = 0;
 		bp->queues[0].tx_ring[i].ctrl = MACB_BIT(TX_USED);
 	}
 	bp->queues[0].tx_head = 0;
 	bp->queues[0].tx_tail = 0;
-	bp->queues[0].tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP);
+	bp->queues[0].tx_ring[bp->tx_ring_size - 1].ctrl |= MACB_BIT(TX_WRAP);
 
 	bp->rx_tail = 0;
 }
@@ -2148,8 +2160,8 @@ static void macb_get_regs(struct net_device *dev, struct ethtool_regs *regs,
 	regs->version = (macb_readl(bp, MID) & ((1 << MACB_REV_SIZE) - 1))
 			| MACB_GREGS_VERSION;
 
-	tail = macb_tx_ring_wrap(bp->queues[0].tx_tail);
-	head = macb_tx_ring_wrap(bp->queues[0].tx_head);
+	tail = macb_tx_ring_wrap(bp, bp->queues[0].tx_tail);
+	head = macb_tx_ring_wrap(bp, bp->queues[0].tx_head);
 
 	regs_buff[0]  = macb_readl(bp, NCR);
 	regs_buff[1]  = macb_or_gem_readl(bp, NCFGR);
@@ -2204,6 +2216,56 @@ static int macb_set_wol(struct net_device *netdev, struct ethtool_wolinfo *wol)
 	return 0;
 }
 
+static void macb_get_ringparam(struct net_device *netdev,
+			       struct ethtool_ringparam *ring)
+{
+	struct macb *bp = netdev_priv(netdev);
+
+	ring->rx_max_pending = MAX_RX_RING_SIZE;
+	ring->tx_max_pending = MAX_TX_RING_SIZE;
+
+	ring->rx_pending = bp->rx_ring_size;
+	ring->tx_pending = bp->tx_ring_size;
+}
+
+static int macb_set_ringparam(struct net_device *netdev,
+			      struct ethtool_ringparam *ring)
+{
+	struct macb *bp = netdev_priv(netdev);
+	u32 new_rx_size, new_tx_size;
+	unsigned int reset = 0;
+
+	if ((ring->rx_mini_pending) || (ring->rx_jumbo_pending))
+		return -EINVAL;
+
+	new_rx_size = clamp_t(u32, ring->rx_pending,
+			      MIN_RX_RING_SIZE, MAX_RX_RING_SIZE);
+	new_rx_size = roundup_pow_of_two(new_rx_size);
+
+	new_tx_size = clamp_t(u32, ring->tx_pending,
+			      MIN_TX_RING_SIZE, MAX_TX_RING_SIZE);
+	new_tx_size = roundup_pow_of_two(new_tx_size);
+
+	if ((new_tx_size == bp->tx_ring_size) &&
+	    (new_rx_size == bp->rx_ring_size)) {
+		/* nothing to do */
+		return 0;
+	}
+
+	if (netif_running(bp->dev)) {
+		reset = 1;
+		macb_close(bp->dev);
+	}
+
+	bp->rx_ring_size = new_rx_size;
+	bp->tx_ring_size = new_tx_size;
+
+	if (reset)
+		macb_open(bp->dev);
+
+	return 0;
+}
+
 static const struct ethtool_ops macb_ethtool_ops = {
 	.get_regs_len		= macb_get_regs_len,
 	.get_regs		= macb_get_regs,
@@ -2213,6 +2275,8 @@ static const struct ethtool_ops macb_ethtool_ops = {
 	.set_wol		= macb_set_wol,
 	.get_link_ksettings     = phy_ethtool_get_link_ksettings,
 	.set_link_ksettings     = phy_ethtool_set_link_ksettings,
+	.get_ringparam		= macb_get_ringparam,
+	.set_ringparam		= macb_set_ringparam,
 };
 
 static const struct ethtool_ops gem_ethtool_ops = {
@@ -2225,6 +2289,8 @@ static const struct ethtool_ops gem_ethtool_ops = {
 	.get_sset_count		= gem_get_sset_count,
 	.get_link_ksettings     = phy_ethtool_get_link_ksettings,
 	.set_link_ksettings     = phy_ethtool_set_link_ksettings,
+	.get_ringparam		= macb_get_ringparam,
+	.set_ringparam		= macb_set_ringparam,
 };
 
 static int macb_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
@@ -2419,6 +2485,9 @@ static int macb_init(struct platform_device *pdev)
 	int err;
 	u32 val;
 
+	bp->tx_ring_size = DEFAULT_TX_RING_SIZE;
+	bp->rx_ring_size = DEFAULT_RX_RING_SIZE;
+
 	/* set the queue register mapping once for all: queue0 has a special
 	 * register mapping but we don't want to test the queue index then
 	 * compute the corresponding register offset at run time.

drivers/net/ethernet/cadence/macb.h

@@ -811,6 +811,9 @@ struct macb {
 	void			*rx_buffers;
 	size_t			rx_buffer_size;
 
+	unsigned int		rx_ring_size;
+	unsigned int		tx_ring_size;
+
 	unsigned int		num_queues;
 	unsigned int		queue_mask;
 	struct macb_queue	queues[MACB_MAX_QUEUES];