tg3: Add tx BD budgeting code

[pandora-kernel.git] / drivers / net / tg3.c

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 7f816a0..b93ba3d 100644 (file)
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -5924,7 +5924,7 @@ static inline void tg3_tx_set_bd(struct tg3_tx_buffer_desc *txbd,
        txbd->vlan_tag = (mss << TXD_MSS_SHIFT) | (vlan << TXD_VLAN_TAG_SHIFT);
 }
 
-static bool tg3_tx_frag_set(struct tg3_napi *tnapi, u32 entry,
+static bool tg3_tx_frag_set(struct tg3_napi *tnapi, u32 *entry, u32 *budget,
                            dma_addr_t map, u32 len, u32 flags,
                            u32 mss, u32 vlan)
 {
@@ -5940,7 +5940,14 @@ static bool tg3_tx_frag_set(struct tg3_napi *tnapi, u32 entry,
        if (tg3_40bit_overflow_test(tp, map, len))
                hwbug = 1;
 
-       tg3_tx_set_bd(&tnapi->tx_ring[entry], map, len, flags, mss, vlan);
+       if (*budget) {
+               tg3_tx_set_bd(&tnapi->tx_ring[*entry], map,
+                             len, flags, mss, vlan);
+               (*budget)--;
+       } else
+               hwbug = 1;
+
+       *entry = NEXT_TX(*entry);
 
        return hwbug;
 }
@@ -5986,12 +5993,12 @@ static void tg3_tx_skb_unmap(struct tg3_napi *tnapi, u32 entry, int last)
 /* Workaround 4GB and 40-bit hardware DMA bugs. */
 static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi,
                                       struct sk_buff *skb,
+                                      u32 *entry, u32 *budget,
                                       u32 base_flags, u32 mss, u32 vlan)
 {
        struct tg3 *tp = tnapi->tp;
        struct sk_buff *new_skb;
        dma_addr_t new_addr = 0;
-       u32 entry = tnapi->tx_prod;
        int ret = 0;
 
        if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5701)
@@ -6017,14 +6024,14 @@ static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi,
                } else {
                        base_flags |= TXD_FLAG_END;
 
-                       tnapi->tx_buffers[entry].skb = new_skb;
-                       dma_unmap_addr_set(&tnapi->tx_buffers[entry],
+                       tnapi->tx_buffers[*entry].skb = new_skb;
+                       dma_unmap_addr_set(&tnapi->tx_buffers[*entry],
                                           mapping, new_addr);
 
-                       if (tg3_tx_frag_set(tnapi, entry, new_addr,
+                       if (tg3_tx_frag_set(tnapi, entry, budget, new_addr,
                                            new_skb->len, base_flags,
                                            mss, vlan)) {
-                               tg3_tx_skb_unmap(tnapi, entry, 0);
+                               tg3_tx_skb_unmap(tnapi, *entry, 0);
                                dev_kfree_skb(new_skb);
                                ret = -1;
                        }
@@ -6086,6 +6093,7 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct tg3 *tp = netdev_priv(dev);
        u32 len, entry, base_flags, mss, vlan = 0;
+       u32 budget;
        int i = -1, would_hit_hwbug;
        dma_addr_t mapping;
        struct tg3_napi *tnapi;
@@ -6097,12 +6105,14 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
        if (tg3_flag(tp, ENABLE_TSS))
                tnapi++;
 
+       budget = tg3_tx_avail(tnapi);
+
        /* We are running in BH disabled context with netif_tx_lock
         * and TX reclaim runs via tp->napi.poll inside of a software
         * interrupt.  Furthermore, IRQ processing runs lockless so we have
         * no IRQ context deadlocks to worry about either.  Rejoice!
         */
-       if (unlikely(tg3_tx_avail(tnapi) <= (skb_shinfo(skb)->nr_frags + 1))) {
+       if (unlikely(budget <= (skb_shinfo(skb)->nr_frags + 1))) {
                if (!netif_tx_queue_stopped(txq)) {
                        netif_tx_stop_queue(txq);
 
@@ -6214,13 +6224,11 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
        if (tg3_flag(tp, 5701_DMA_BUG))
                would_hit_hwbug = 1;
 
-       if (tg3_tx_frag_set(tnapi, entry, mapping, len, base_flags |
+       if (tg3_tx_frag_set(tnapi, &entry, &budget, mapping, len, base_flags |
                          ((skb_shinfo(skb)->nr_frags == 0) ? TXD_FLAG_END : 0),
                            mss, vlan))
                would_hit_hwbug = 1;
 
-       entry = NEXT_TX(entry);
-
        /* Now loop through additional data fragments, and queue them. */
        if (skb_shinfo(skb)->nr_frags > 0) {
                u32 tmp_mss = mss;
@@ -6246,12 +6254,11 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
                        if (pci_dma_mapping_error(tp->pdev, mapping))
                                goto dma_error;
 
-                       if (tg3_tx_frag_set(tnapi, entry, mapping, len,
-                                 base_flags | ((i == last) ? TXD_FLAG_END : 0),
+                       if (tg3_tx_frag_set(tnapi, &entry, &budget, mapping,
+                                           len, base_flags |
+                                           ((i == last) ? TXD_FLAG_END : 0),
                                            tmp_mss, vlan))
                                would_hit_hwbug = 1;
-
-                       entry = NEXT_TX(entry);
                }
        }
 
@@ -6261,11 +6268,11 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
                /* If the workaround fails due to memory/mapping
                 * failure, silently drop this packet.
                 */
-               if (tigon3_dma_hwbug_workaround(tnapi, skb, base_flags,
-                                               mss, vlan))
+               entry = tnapi->tx_prod;
+               budget = tg3_tx_avail(tnapi);
+               if (tigon3_dma_hwbug_workaround(tnapi, skb, &entry, &budget,
+                                               base_flags, mss, vlan))
                        goto out_unlock;
-
-               entry = NEXT_TX(tnapi->tx_prod);
        }
 
        skb_tx_timestamp(skb);
@@ -11206,6 +11213,7 @@ static int tg3_run_loopback(struct tg3 *tp, u32 pktsz, int loopback_mode)
 {
        u32 mac_mode, rx_start_idx, rx_idx, tx_idx, opaque_key;
        u32 base_flags = 0, mss = 0, desc_idx, coal_now, data_off, val;
+       u32 budget;
        struct sk_buff *skb, *rx_skb;
        u8 *tx_data;
        dma_addr_t map;
@@ -11376,7 +11384,8 @@ static int tg3_run_loopback(struct tg3 *tp, u32 pktsz, int loopback_mode)
 
        rx_start_idx = rnapi->hw_status->idx[0].rx_producer;
 
-       if (tg3_tx_frag_set(tnapi, tnapi->tx_prod, map, tx_len,
+       budget = tg3_tx_avail(tnapi);
+       if (tg3_tx_frag_set(tnapi, &val, &budget, map, tx_len,
                            base_flags | TXD_FLAG_END, mss, 0)) {
                tnapi->tx_buffers[val].skb = NULL;
                dev_kfree_skb(skb);