2 files changed, 128 insertions, 8 deletions

diff --git a/drivers/net/b44.c b/drivers/net/b44.c
index d27e870e59ab..282ebd15f011 100644
--- a/drivers/net/b44.c
+++ b/drivers/net/b44.c
@@ -106,6 +106,29 @@ static int b44_poll(struct net_device *dev, int *budget);
 static void b44_poll_controller(struct net_device *dev);
 #endif
 
+static int dma_desc_align_mask;
+static int dma_desc_sync_size;
+
+static inline void b44_sync_dma_desc_for_device(struct pci_dev *pdev,
+                                                dma_addr_t dma_base,
+                                                unsigned long offset,
+                                                enum dma_data_direction dir)
+{
+        dma_sync_single_range_for_device(&pdev->dev, dma_base,
+                                         offset & dma_desc_align_mask,
+                                         dma_desc_sync_size, dir);
+}
+
+static inline void b44_sync_dma_desc_for_cpu(struct pci_dev *pdev,
+                                             dma_addr_t dma_base,
+                                             unsigned long offset,
+                                             enum dma_data_direction dir)
+{
+        dma_sync_single_range_for_cpu(&pdev->dev, dma_base,
+                                      offset & dma_desc_align_mask,
+                                      dma_desc_sync_size, dir);
+}
+
 static inline unsigned long br32(const struct b44 *bp, unsigned long reg)
 {
         return readl(bp->regs + reg);
@@ -668,6 +691,11 @@ static int b44_alloc_rx_skb(struct b44 *bp, int src_idx, u32 dest_idx_unmasked)
         dp->ctrl = cpu_to_le32(ctrl);
         dp->addr = cpu_to_le32((u32) mapping + bp->rx_offset + bp->dma_offset);
 
+        if (bp->flags & B44_FLAG_RX_RING_HACK)
+                b44_sync_dma_desc_for_device(bp->pdev, bp->rx_ring_dma,
+                                             dest_idx * sizeof(dp),
+                                             DMA_BIDIRECTIONAL);
+
         return RX_PKT_BUF_SZ;
 }
 
@@ -692,6 +720,11 @@ static void b44_recycle_rx(struct b44 *bp, int src_idx, u32 dest_idx_unmasked)
         pci_unmap_addr_set(dest_map, mapping,
                            pci_unmap_addr(src_map, mapping));
 
+        if (bp->flags & B44_FLAG_RX_RING_HACK)
+                b44_sync_dma_desc_for_cpu(bp->pdev, bp->rx_ring_dma,
+                                          src_idx * sizeof(src_desc),
+                                          DMA_BIDIRECTIONAL);
+
         ctrl = src_desc->ctrl;
         if (dest_idx == (B44_RX_RING_SIZE - 1))
                 ctrl |= cpu_to_le32(DESC_CTRL_EOT);
@@ -700,8 +733,14 @@ static void b44_recycle_rx(struct b44 *bp, int src_idx, u32 dest_idx_unmasked)
 
         dest_desc->ctrl = ctrl;
         dest_desc->addr = src_desc->addr;
+
         src_map->skb = NULL;
 
+        if (bp->flags & B44_FLAG_RX_RING_HACK)
+                b44_sync_dma_desc_for_device(bp->pdev, bp->rx_ring_dma,
+                                             dest_idx * sizeof(dest_desc),
+                                             DMA_BIDIRECTIONAL);
+
         pci_dma_sync_single_for_device(bp->pdev, src_desc->addr,
                                        RX_PKT_BUF_SZ,
                                        PCI_DMA_FROMDEVICE);
@@ -959,6 +998,11 @@ static int b44_start_xmit(struct sk_buff *skb, struct net_device *dev)
         bp->tx_ring[entry].ctrl = cpu_to_le32(ctrl);
         bp->tx_ring[entry].addr = cpu_to_le32((u32) mapping+bp->dma_offset);
 
+        if (bp->flags & B44_FLAG_TX_RING_HACK)
+                b44_sync_dma_desc_for_device(bp->pdev, bp->tx_ring_dma,
+                                             entry * sizeof(bp->tx_ring[0]),
+                                             DMA_TO_DEVICE);
+
         entry = NEXT_TX(entry);
 
         bp->tx_prod = entry;
@@ -1064,6 +1108,16 @@ static void b44_init_rings(struct b44 *bp)
         memset(bp->rx_ring, 0, B44_RX_RING_BYTES);
         memset(bp->tx_ring, 0, B44_TX_RING_BYTES);
 
+        if (bp->flags & B44_FLAG_RX_RING_HACK)
+                dma_sync_single_for_device(&bp->pdev->dev, bp->rx_ring_dma,
+                                           DMA_TABLE_BYTES,
+                                           PCI_DMA_BIDIRECTIONAL);
+
+        if (bp->flags & B44_FLAG_TX_RING_HACK)
+                dma_sync_single_for_device(&bp->pdev->dev, bp->tx_ring_dma,
+                                           DMA_TABLE_BYTES,
+                                           PCI_DMA_TODEVICE);
+
         for (i = 0; i < bp->rx_pending; i++) {
                 if (b44_alloc_rx_skb(bp, -1, i) < 0)
                         break;
@@ -1085,14 +1139,28 @@ static void b44_free_consistent(struct b44 *bp)
                 bp->tx_buffers = NULL;
         }
         if (bp->rx_ring) {
-                pci_free_consistent(bp->pdev, DMA_TABLE_BYTES,
-                                    bp->rx_ring, bp->rx_ring_dma);
+                if (bp->flags & B44_FLAG_RX_RING_HACK) {
+                        dma_unmap_single(&bp->pdev->dev, bp->rx_ring_dma,
+                                         DMA_TABLE_BYTES,
+                                         DMA_BIDIRECTIONAL);
+                        kfree(bp->rx_ring);
+                } else
+                        pci_free_consistent(bp->pdev, DMA_TABLE_BYTES,
+                                            bp->rx_ring, bp->rx_ring_dma);
                 bp->rx_ring = NULL;
+                bp->flags &= ~B44_FLAG_RX_RING_HACK;
         }
         if (bp->tx_ring) {
-                pci_free_consistent(bp->pdev, DMA_TABLE_BYTES,
-                                    bp->tx_ring, bp->tx_ring_dma);
+                if (bp->flags & B44_FLAG_TX_RING_HACK) {
+                        dma_unmap_single(&bp->pdev->dev, bp->tx_ring_dma,
+                                         DMA_TABLE_BYTES,
+                                         DMA_TO_DEVICE);
+                        kfree(bp->tx_ring);
+                } else
+                        pci_free_consistent(bp->pdev, DMA_TABLE_BYTES,
+                                            bp->tx_ring, bp->tx_ring_dma);
                 bp->tx_ring = NULL;
+                bp->flags &= ~B44_FLAG_TX_RING_HACK;
         }
 }
 
@@ -1118,12 +1186,56 @@ static int b44_alloc_consistent(struct b44 *bp)
 
         size = DMA_TABLE_BYTES;
         bp->rx_ring = pci_alloc_consistent(bp->pdev, size, &bp->rx_ring_dma);
-        if (!bp->rx_ring)
-                goto out_err;
+        if (!bp->rx_ring) {
+                /* Allocation may have failed due to pci_alloc_consistent
+                   insisting on use of GFP_DMA, which is more restrictive
+                   than necessary...  */
+                struct dma_desc *rx_ring;
+                dma_addr_t rx_ring_dma;
+
+                if (!(rx_ring = (struct dma_desc *)kmalloc(size, GFP_KERNEL)))
+                        goto out_err;
+
+                memset(rx_ring, 0, size);
+                rx_ring_dma = dma_map_single(&bp->pdev->dev, rx_ring,
+                                             DMA_TABLE_BYTES,
+                                             DMA_BIDIRECTIONAL);
+
+                if (rx_ring_dma + size > B44_DMA_MASK) {
+                        kfree(rx_ring);
+                        goto out_err;
+                }
+
+                bp->rx_ring = rx_ring;
+                bp->rx_ring_dma = rx_ring_dma;
+                bp->flags |= B44_FLAG_RX_RING_HACK;
+        }
 
         bp->tx_ring = pci_alloc_consistent(bp->pdev, size, &bp->tx_ring_dma);
-        if (!bp->tx_ring)
-                goto out_err;
+        if (!bp->tx_ring) {
+                /* Allocation may have failed due to pci_alloc_consistent
+                   insisting on use of GFP_DMA, which is more restrictive
+                   than necessary...  */
+                struct dma_desc *tx_ring;
+                dma_addr_t tx_ring_dma;
+
+                if (!(tx_ring = (struct dma_desc *)kmalloc(size, GFP_KERNEL)))
+                        goto out_err;
+
+                memset(tx_ring, 0, size);
+                tx_ring_dma = dma_map_single(&bp->pdev->dev, tx_ring,
+                                             DMA_TABLE_BYTES,
+                                             DMA_TO_DEVICE);
+
+                if (tx_ring_dma + size > B44_DMA_MASK) {
+                        kfree(tx_ring);
+                        goto out_err;
+                }
+
+                bp->tx_ring = tx_ring;
+                bp->tx_ring_dma = tx_ring_dma;
+                bp->flags |= B44_FLAG_TX_RING_HACK;
+        }
 
         return 0;
 
@@ -1973,6 +2085,12 @@ static struct pci_driver b44_driver = {
 
 static int __init b44_init(void)
 {
+        unsigned int dma_desc_align_size = dma_get_cache_alignment();
+
+        /* Setup paramaters for syncing RX/TX DMA descriptors */
+        dma_desc_align_mask = ~(dma_desc_align_size - 1);
+        dma_desc_sync_size = max(dma_desc_align_size, sizeof(struct dma_desc));
+
         return pci_module_init(&b44_driver);
 }
 
diff --git a/drivers/net/b44.h b/drivers/net/b44.h
index 11c40a2e71c7..593cb0ad4100 100644
--- a/drivers/net/b44.h
+++ b/drivers/net/b44.h
@@ -400,6 +400,8 @@ struct b44 {
 #define B44_FLAG_ADV_100HALF    0x04000000
 #define B44_FLAG_ADV_100FULL    0x08000000
 #define B44_FLAG_INTERNAL_PHY   0x10000000
+#define B44_FLAG_RX_RING_HACK   0x20000000
+#define B44_FLAG_TX_RING_HACK   0x40000000
 
         u32                     rx_offset;