sky2: dynamic size transmit ring

Allocate and size transmit ring based on parameters. Saves excess
space and allows configuring larger rings for testing.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 23 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 58d35214d12d..7c1880d8b31f 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -64,10 +64,12 @@
 #define RX_MAX_PENDING          (RX_LE_SIZE/6 - 2)
 #define RX_DEF_PENDING          RX_MAX_PENDING
 
-#define TX_RING_SIZE            512
-#define TX_DEF_PENDING          128
-#define MAX_SKB_TX_LE           (4 + (sizeof(dma_addr_t)/sizeof(u32))*MAX_SKB_FRAGS)
+/* This is the worst case number of transmit list elements for a single skb:
+   VLAN + TSO + CKSUM + Data + skb_frags * DMA */
+#define MAX_SKB_TX_LE   (4 + (sizeof(dma_addr_t)/sizeof(u32))*MAX_SKB_FRAGS)
 #define TX_MIN_PENDING          (MAX_SKB_TX_LE+1)
+#define TX_MAX_PENDING          4096
+#define TX_DEF_PENDING          127
 
 #define STATUS_RING_SIZE        2048    /* 2 ports * (TX + 2*RX) */
 #define STATUS_LE_BYTES         (STATUS_RING_SIZE*sizeof(struct sky2_status_le))
@@ -1000,7 +1002,7 @@ static inline struct sky2_tx_le *get_tx_le(struct sky2_port *sky2, u16 *slot)
 {
         struct sky2_tx_le *le = sky2->tx_le + *slot;
 
-        *slot = RING_NEXT(*slot, TX_RING_SIZE);
+        *slot = RING_NEXT(*slot, sky2->tx_ring_size);
         le->ctrl = 0;
         return le;
 }
@@ -1433,13 +1435,13 @@ static int sky2_up(struct net_device *dev)
 
         /* must be power of 2 */
         sky2->tx_le = pci_alloc_consistent(hw->pdev,
-                                           TX_RING_SIZE *
+                                           sky2->tx_ring_size *
                                            sizeof(struct sky2_tx_le),
                                            &sky2->tx_le_map);
         if (!sky2->tx_le)
                 goto err_out;
 
-        sky2->tx_ring = kcalloc(TX_RING_SIZE, sizeof(struct tx_ring_info),
+        sky2->tx_ring = kcalloc(sky2->tx_ring_size, sizeof(struct tx_ring_info),
                                 GFP_KERNEL);
         if (!sky2->tx_ring)
                 goto err_out;
@@ -1491,7 +1493,7 @@ static int sky2_up(struct net_device *dev)
                 sky2_write16(hw, Q_ADDR(txqaddr[port], Q_AL), ECU_TXFF_LEV);
 
         sky2_prefetch_init(hw, txqaddr[port], sky2->tx_le_map,
-                           TX_RING_SIZE - 1);
+                           sky2->tx_ring_size - 1);
 
 #ifdef SKY2_VLAN_TAG_USED
         sky2_set_vlan_mode(hw, port, sky2->vlgrp != NULL);
@@ -1520,7 +1522,7 @@ err_out:
         }
         if (sky2->tx_le) {
                 pci_free_consistent(hw->pdev,
-                                    TX_RING_SIZE * sizeof(struct sky2_tx_le),
+                                    sky2->tx_ring_size * sizeof(struct sky2_tx_le),
                                     sky2->tx_le, sky2->tx_le_map);
                 sky2->tx_le = NULL;
         }
@@ -1533,15 +1535,15 @@ err_out:
 }
 
 /* Modular subtraction in ring */
-static inline int tx_dist(unsigned tail, unsigned head)
+static inline int tx_inuse(const struct sky2_port *sky2)
 {
-        return (head - tail) & (TX_RING_SIZE - 1);
+        return (sky2->tx_prod - sky2->tx_cons) & (sky2->tx_ring_size - 1);
 }
 
 /* Number of list elements available for next tx */
 static inline int tx_avail(const struct sky2_port *sky2)
 {
-        return sky2->tx_pending - tx_dist(sky2->tx_cons, sky2->tx_prod);
+        return sky2->tx_pending - tx_inuse(sky2);
 }
 
 /* Estimate of number of transmit list elements required */
@@ -1717,7 +1719,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
         return NETDEV_TX_OK;
 
 mapping_unwind:
-        for (i = sky2->tx_prod; i != slot; i = RING_NEXT(i, TX_RING_SIZE)) {
+        for (i = sky2->tx_prod; i != slot; i = RING_NEXT(i, sky2->tx_ring_size)) {
                 le = sky2->tx_le + i;
                 re = sky2->tx_ring + i;
 
@@ -1760,10 +1762,10 @@ static void sky2_tx_complete(struct sky2_port *sky2, u16 done)
         struct pci_dev *pdev = sky2->hw->pdev;
         unsigned idx;
 
-        BUG_ON(done >= TX_RING_SIZE);
+        BUG_ON(done >= sky2->tx_ring_size);
 
         for (idx = sky2->tx_cons; idx != done;
-             idx = RING_NEXT(idx, TX_RING_SIZE)) {
+             idx = RING_NEXT(idx, sky2->tx_ring_size)) {
                 struct sky2_tx_le *le = sky2->tx_le + idx;
                 struct tx_ring_info *re = sky2->tx_ring + idx;
 
@@ -1799,7 +1801,7 @@ static void sky2_tx_complete(struct sky2_port *sky2, u16 done)
                         else
                                 dev_kfree_skb_any(skb);
 
-                        sky2->tx_next = RING_NEXT(idx, TX_RING_SIZE);
+                        sky2->tx_next = RING_NEXT(idx, sky2->tx_ring_size);
                 }
         }
 
@@ -1907,7 +1909,7 @@ static int sky2_down(struct net_device *dev)
         kfree(sky2->rx_ring);
 
         pci_free_consistent(hw->pdev,
-                            TX_RING_SIZE * sizeof(struct sky2_tx_le),
+                            sky2->tx_ring_size * sizeof(struct sky2_tx_le),
                             sky2->tx_le, sky2->tx_le_map);
         kfree(sky2->tx_ring);
 
@@ -2517,7 +2519,6 @@ static int sky2_status_intr(struct sky2_hw *hw, int to_do, u16 idx)
 
                 case OP_TXINDEXLE:
                         /* TX index reports status for both ports */
-                        BUILD_BUG_ON(TX_RING_SIZE > 0x1000);
                         sky2_tx_done(hw->dev[0], status & 0xfff);
                         if (hw->dev[1])
                                 sky2_tx_done(hw->dev[1],
@@ -3669,7 +3670,7 @@ static int sky2_set_coalesce(struct net_device *dev,
             ecmd->rx_coalesce_usecs_irq > tmax)
                 return -EINVAL;
 
-        if (ecmd->tx_max_coalesced_frames >= TX_RING_SIZE-1)
+        if (ecmd->tx_max_coalesced_frames >= sky2->tx_ring_size-1)
                 return -EINVAL;
         if (ecmd->rx_max_coalesced_frames > RX_MAX_PENDING)
                 return -EINVAL;
@@ -3713,7 +3714,7 @@ static void sky2_get_ringparam(struct net_device *dev,
         ering->rx_max_pending = RX_MAX_PENDING;
         ering->rx_mini_max_pending = 0;
         ering->rx_jumbo_max_pending = 0;
-        ering->tx_max_pending = TX_RING_SIZE - 1;
+        ering->tx_max_pending = TX_MAX_PENDING;
 
         ering->rx_pending = sky2->rx_pending;
         ering->rx_mini_pending = 0;
@@ -3728,14 +3729,15 @@ static int sky2_set_ringparam(struct net_device *dev,
 
         if (ering->rx_pending > RX_MAX_PENDING ||
             ering->rx_pending < 8 ||
-            ering->tx_pending < MAX_SKB_TX_LE ||
-            ering->tx_pending > TX_RING_SIZE - 1)
+            ering->tx_pending < TX_MIN_PENDING ||
+            ering->tx_pending > TX_MAX_PENDING)
                 return -EINVAL;
 
         sky2_detach(dev);
 
         sky2->rx_pending = ering->rx_pending;
         sky2->tx_pending = ering->tx_pending;
+        sky2->tx_ring_size = roundup_pow_of_two(sky2->tx_pending+1);
 
         return sky2_reattach(dev);
 }
@@ -4105,8 +4107,8 @@ static int sky2_debug_show(struct seq_file *seq, void *v)
 
         /* Dump contents of tx ring */
         sop = 1;
-        for (idx = sky2->tx_next; idx != sky2->tx_prod && idx < TX_RING_SIZE;
-             idx = RING_NEXT(idx, TX_RING_SIZE)) {
+        for (idx = sky2->tx_next; idx != sky2->tx_prod && idx < sky2->tx_ring_size;
+             idx = RING_NEXT(idx, sky2->tx_ring_size)) {
                 const struct sky2_tx_le *le = sky2->tx_le + idx;
                 u32 a = le32_to_cpu(le->addr);
 
@@ -4315,7 +4317,9 @@ static __devinit struct net_device *sky2_init_netdev(struct sky2_hw *hw,
         sky2->wol = wol;
 
         spin_lock_init(&sky2->phy_lock);
+
         sky2->tx_pending = TX_DEF_PENDING;
+        sky2->tx_ring_size = roundup_pow_of_two(TX_DEF_PENDING+1);
         sky2->rx_pending = RX_DEF_PENDING;
 
         hw->dev[port] = dev;