net: macb: Add ethtool get_ringparam and set_ringparam functionality

Some applications want to tune the size of the macb rx/tx ring buffers.
The ethtool set_ringparam function is the standard way of doing it.

Signed-off-by: Zach Brown <zach.brown@ni.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index 644975da2857e8b92b34a8df67d1e0061eed6e53..e1847ce6308deba39998fcdd81e9d3d272a23873 100644 (file)
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -37,11 +37,16 @@
 
 #define MACB_RX_BUFFER_SIZE    128
 #define RX_BUFFER_MULTIPLE     64  /* bytes */
+
 #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)
 
@@ -2211,6 +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,
@@ -2220,6 +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 = {
@@ -2232,6 +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)