solos-pci: ensure all TX packets are aligned to 4 bytes

The FPGA can't handled unaligned DMA (yet). So copy into an aligned buffer,
if skb->data isn't suitably aligned.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index aa4f35d52a92b9acc46af8913e7cb4d4bd30e2e5..d70abe77f737591c236e8b711aef14a4ca37826a 100644 (file)
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -128,9 +128,11 @@ struct solos_card {
        struct sk_buff_head cli_queue[4];
        struct sk_buff *tx_skb[4];
        struct sk_buff *rx_skb[4];
+       unsigned char *dma_bounce;
        wait_queue_head_t param_wq;
        wait_queue_head_t fw_wq;
        int using_dma;
+       int dma_alignment;
        int fpga_version;
        int buffer_size;
        int atmel_flash;
@@ -1083,7 +1085,12 @@ static uint32_t fpga_tx(struct solos_card *card)
                                tx_started |= 1 << port;
                                oldskb = skb; /* We're done with this skb already */
                        } else if (skb && card->using_dma) {
-                               SKB_CB(skb)->dma_addr = pci_map_single(card->dev, skb->data,
+                               unsigned char *data = skb->data;
+                               if ((unsigned long)data & card->dma_alignment) {
+                                       data = card->dma_bounce + (BUF_SIZE * port);
+                                       memcpy(data, skb->data, skb->len);
+                               }
+                               SKB_CB(skb)->dma_addr = pci_map_single(card->dev, data,
                                                                       skb->len, PCI_DMA_TODEVICE);
                                card->tx_skb[port] = skb;
                                iowrite32(SKB_CB(skb)->dma_addr,
@@ -1261,18 +1268,27 @@ static int fpga_probe(struct pci_dev *dev, const struct pci_device_id *id)
        else
                card->atmel_flash = 0;
 
+       data32 = ioread32(card->config_regs + PORTS);
+       card->nr_ports = (data32 & 0x000000FF);
+
        if (card->fpga_version >= DMA_SUPPORTED) {
                pci_set_master(dev);
                card->using_dma = 1;
+               if (1) { /* All known FPGA versions so far */
+                       card->dma_alignment = 3;
+                       card->dma_bounce = kmalloc(card->nr_ports * BUF_SIZE, GFP_KERNEL);
+                       if (!card->dma_bounce) {
+                               dev_warn(&card->dev->dev, "Failed to allocate DMA bounce buffers\n");
+                               /* Fallback to MMIO doesn't work */
+                               goto out_unmap_both;
+                       }
+               }
        } else {
                card->using_dma = 0;
                /* Set RX empty flag for all ports */
                iowrite32(0xF0, card->config_regs + FLAGS_ADDR);
        }
 
-       data32 = ioread32(card->config_regs + PORTS);
-       card->nr_ports = (data32 & 0x000000FF);
-
        pci_set_drvdata(dev, card);
 
        tasklet_init(&card->tlet, solos_bh, (unsigned long)card);
@@ -1319,6 +1335,7 @@ static int fpga_probe(struct pci_dev *dev, const struct pci_device_id *id)
        tasklet_kill(&card->tlet);
        
  out_unmap_both:
+       kfree(card->dma_bounce);
        pci_set_drvdata(dev, NULL);
        pci_iounmap(dev, card->buffers);
  out_unmap_config:
@@ -1429,6 +1446,8 @@ static void fpga_remove(struct pci_dev *dev)
        free_irq(dev->irq, card);
        tasklet_kill(&card->tlet);
 
+       kfree(card->dma_bounce);
+
        /* Release device from reset */
        iowrite32(0, card->config_regs + FPGA_MODE);
        (void)ioread32(card->config_regs + FPGA_MODE);