[BNX2]: Add 40-bit DMA workaround for 5708.

The internal PCIE-to-PCIX bridge of the 5708 has the same 40-bit DMA
limitation as some of the tg3 chips.  Use the same workaround used in
tg3.  On 64-bit systems without IOMMU, linearize the SKB if any
address is > 40-bit.

Signed-off-by: Michael Chan <[EMAIL PROTECTED]>

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index 6d05397..dba4088 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -4495,6 +4495,93 @@ bnx2_vlan_rx_kill_vid(struct net_device *dev, uint16_t 
vid)
 }
 #endif
 
+/* Test for DMA addresses > 40-bit.
+ * Only 64-bit systems without IOMMU require DMA address checking.
+ */
+static inline int bnx2_40bit_overflow_test(struct bnx2 *bp, dma_addr_t mapping,
+                                          int len)
+{
+#if defined(CONFIG_HIGHMEM) && (BITS_PER_LONG == 64)
+       if (CHIP_NUM(bp) == CHIP_NUM_5708)
+               return (((u64) mapping + len) > DMA_40BIT_MASK);
+       return 0;
+#else
+       return 0;
+#endif
+}
+
+#if defined(CONFIG_HIGHMEM) && (BITS_PER_LONG == 64)
+/* Workaround 40-bit hardware DMA bugs. */
+static int bnx2_dma_hwbug_workaround(struct bnx2 *bp, struct sk_buff **skb,
+                                    u16 *last_plus_one, u32 base_flags,
+                                    u32 mss)
+{
+       struct sk_buff *new_skb = skb_copy(*skb, GFP_ATOMIC);
+       dma_addr_t new_addr = 0;
+       int i, ret = 0;
+       u16 hw_prod = *last_plus_one;
+       u16 start, hw_start, prod;
+
+       prod = TX_RING_IDX(hw_prod);
+       start = prod - 1 - skb_shinfo(*skb)->nr_frags;
+       hw_start = hw_prod - 1 - skb_shinfo(*skb)->nr_frags;
+       start &= MAX_TX_DESC_CNT;
+       if (start > prod) {
+               start--;
+               hw_start--;
+       }
+
+       if (!new_skb) {
+               ret = -1;
+       } else {
+               struct tx_bd *txbd;
+
+               /* New SKB is guaranteed to be linear. */
+               new_addr = pci_map_single(bp->pdev, new_skb->data, new_skb->len,
+                                         PCI_DMA_TODEVICE);
+               txbd = &bp->tx_desc_ring[start];
+
+               txbd->tx_bd_haddr_hi = (u64) new_addr >> 32;
+               txbd->tx_bd_haddr_lo = (u64) new_addr & 0xffffffff;
+               txbd->tx_bd_mss_nbytes = new_skb->len | (mss << 16);
+               txbd->tx_bd_vlan_tag_flags = base_flags | TX_BD_FLAGS_START |
+                                            TX_BD_FLAGS_END;
+
+               *last_plus_one = NEXT_TX_BD(hw_start);
+       }
+
+       /* Now clean up the sw ring entries. */
+       i = 0;
+       while (start != prod) {
+               int len;
+
+               if (i == 0)
+                       len = skb_headlen(*skb);
+               else
+                       len = skb_shinfo(*skb)->frags[i-1].size;
+
+               pci_unmap_single(bp->pdev,
+                                pci_unmap_addr(&tp->tx_buf_ring[start],
+                                               mapping),
+                                len, PCI_DMA_TODEVICE);
+               if (i == 0) {
+                       bp->tx_buf_ring[start].skb = new_skb;
+                       pci_unmap_addr_set(&bp->tx_buf_ring[start], mapping,
+                                          new_addr);
+               }
+               hw_start = NEXT_TX_BD(hw_start);
+               start = TX_RING_IDX(hw_start);
+               i++;
+       }
+
+       dev_kfree_skb(*skb);
+
+       *skb = new_skb;
+
+       return ret;
+}
+#endif
+
 /* Called with netif_tx_lock.
  * bnx2_tx_int() runs without netif_tx_lock unless it needs to call
  * netif_wake_queue().
@@ -4508,7 +4595,7 @@ bnx2_start_xmit(struct sk_buff *skb, struct net_device 
*dev)
        struct sw_bd *tx_buf;
        u32 len, vlan_tag_flags, last_frag, mss;
        u16 prod, ring_prod;
-       int i;
+       int i, would_hit_hwbug = 0;
 
        if (unlikely(bnx2_tx_avail(bp) < (skb_shinfo(skb)->nr_frags + 1))) {
                netif_stop_queue(dev);
@@ -4598,10 +4685,25 @@ bnx2_start_xmit(struct sk_buff *skb, struct net_device 
*dev)
                txbd->tx_bd_mss_nbytes = len | (mss << 16);
                txbd->tx_bd_vlan_tag_flags = vlan_tag_flags;
 
+               if (bnx2_40bit_overflow_test(bp, mapping, len))
+                       would_hit_hwbug = 1;
        }
        txbd->tx_bd_vlan_tag_flags |= TX_BD_FLAGS_END;
 
        prod = NEXT_TX_BD(prod);
+
+#if defined(CONFIG_HIGHMEM) && (BITS_PER_LONG == 64)
+       if (unlikely(would_hit_hwbug)) {
+               /* If the workaround fails due to memory/mapping
+                * failure, silently drop this packet.
+                */
+               if (bnx2_dma_hwbug_workaround(bp, &skb, &prod,
+                                             vlan_tag_flags, mss))
+                       return NETDEV_TX_OK;
+
+       }
+#endif
+
        bp->tx_prod_bseq += skb->len;
 
        REG_WR16(bp, bp->tx_bidx_addr, prod);
@@ -5711,6 +5813,7 @@ bnx2_init_board(struct pci_dev *pdev, struct net_device 
*dev)
        unsigned long mem_len;
        int rc;
        u32 reg;
+       u64 dma_mask, persist_dma_mask;
 
        SET_MODULE_OWNER(dev);
        SET_NETDEV_DEV(dev, &pdev->dev);
@@ -5749,21 +5852,6 @@ bnx2_init_board(struct pci_dev *pdev, struct net_device 
*dev)
                goto err_out_release;
        }
 
-       if (pci_set_dma_mask(pdev, DMA_64BIT_MASK) == 0) {
-               bp->flags |= USING_DAC_FLAG;
-               if (pci_set_consistent_dma_mask(pdev, DMA_64BIT_MASK) != 0) {
-                       dev_err(&pdev->dev,
-                               "pci_set_consistent_dma_mask failed, 
aborting.\n");
-                       rc = -EIO;
-                       goto err_out_release;
-               }
-       }
-       else if (pci_set_dma_mask(pdev, DMA_32BIT_MASK) != 0) {
-               dev_err(&pdev->dev, "System does not support DMA, aborting.\n");
-               rc = -EIO;
-               goto err_out_release;
-       }
-
        bp->dev = dev;
        bp->pdev = pdev;
 
@@ -5805,6 +5893,33 @@ bnx2_init_board(struct pci_dev *pdev, struct net_device 
*dev)
                }
        }
 
+       /* 5708 cannot support DMA addresses > 40-bit.
+        * On 64-bit systems with IOMMU, use 40-bit dma_mask.
+        * On 64-bit systems without IOMMU, use 64-bit dma_mask and
+        * do DMA address check in bnx2_start_xmit().
+        */
+       if (CHIP_NUM(bp) == CHIP_NUM_5708) {
+               persist_dma_mask = dma_mask = DMA_40BIT_MASK;
+#ifdef CONFIG_HIGHMEM
+               dma_mask = DMA_64BIT_MASK;
+#endif
+       } else
+               persist_dma_mask = dma_mask = DMA_64BIT_MASK;
+
+       /* Configure DMA attributes. */
+       if (pci_set_dma_mask(pdev, dma_mask) == 0) {
+               dev->features |= NETIF_F_HIGHDMA;
+               rc = pci_set_consistent_dma_mask(pdev, persist_dma_mask);
+               if (rc) {
+                       dev_err(&pdev->dev,
+                               "pci_set_consistent_dma_mask failed, 
aborting.\n");
+                       goto err_out_unmap;
+               }
+       } else if ((rc = pci_set_dma_mask(pdev, DMA_32BIT_MASK)) != 0) {
+               dev_err(&pdev->dev, "System does not support DMA, aborting.\n");
+               goto err_out_unmap;
+       }
+
        /* Get bus information. */
        reg = REG_RD(bp, BNX2_PCICFG_MISC_STATUS);
        if (reg & BNX2_PCICFG_MISC_STATUS_PCIX_DET) {
@@ -6114,8 +6229,6 @@ bnx2_init_one(struct pci_dev *pdev, const struct 
pci_device_id *ent)
        printk("\n");
 
        dev->features |= NETIF_F_SG;
-       if (bp->flags & USING_DAC_FLAG)
-               dev->features |= NETIF_F_HIGHDMA;
        dev->features |= NETIF_F_IP_CSUM;
 #ifdef BCM_VLAN
        dev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
diff --git a/drivers/net/bnx2.h b/drivers/net/bnx2.h
index 878eee5..8e7b29a 100644
--- a/drivers/net/bnx2.h
+++ b/drivers/net/bnx2.h
@@ -6433,7 +6433,6 @@ struct bnx2 {
 #define PCI_32BIT_FLAG                 2
 #define ONE_TDMA_FLAG                  4       /* no longer used */
 #define NO_WOL_FLAG                    8
-#define USING_DAC_FLAG                 0x10
 #define USING_MSI_FLAG                 0x20
 #define ASF_ENABLE_FLAG                        0x40
 


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