solos: Tidy up DMA handling a little. Still untested

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index 63c9ad0..acba08d 100644 (file)
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -68,6 +68,8 @@
 #define RX_BUF(card, nr) ((card->buffers) + (nr)*BUF_SIZE*2)
 #define TX_BUF(card, nr) ((card->buffers) + (nr)*BUF_SIZE*2 + BUF_SIZE)
 
+#define RX_DMA_SIZE    2048
+
 static int debug = 0;
 static int atmdebug = 0;
 static int firmware_upgrade = 0;
@@ -608,17 +610,11 @@ void solos_bh(unsigned long card_arg)
 
                        if (card->using_dma) {
                                skb = card->rx_skb[port];
-                               pci_unmap_single(card->dev, SKB_CB(skb)->dma_addr, skb->len,
-                                                PCI_DMA_FROMDEVICE);
-
-                               card->rx_skb[port] = alloc_skb(2048, GFP_ATOMIC);
-                               if (card->rx_skb[port]) {
-                                       SKB_CB(card->rx_skb[port])->dma_addr =
-                                               pci_map_single(card->dev, skb->data, skb->len,
-                                                              PCI_DMA_FROMDEVICE);
-                                       iowrite32(SKB_CB(card->rx_skb[port])->dma_addr,
-                                                 card->config_regs + RX_DMA_ADDR(port));
-                               }
+                               card->rx_skb[port] = NULL;
+
+                               pci_unmap_single(card->dev, SKB_CB(skb)->dma_addr,
+                                                RX_DMA_SIZE, PCI_DMA_FROMDEVICE);
+
                                header = (void *)skb->data;
                                size = le16_to_cpu(header->size);
                                skb_put(skb, size + sizeof(*header));
@@ -669,7 +665,7 @@ void solos_bh(unsigned long card_arg)
 
                        case PKT_STATUS:
                                process_status(card, port, skb);
-                               dev_kfree_skb(skb);
+                               dev_kfree_skb_any(skb);
                                break;
 
                        case PKT_COMMAND:
@@ -681,12 +677,32 @@ void solos_bh(unsigned long card_arg)
                                        if (net_ratelimit())
                                                dev_warn(&card->dev->dev, "Dropping console response on port %d\n",
                                                         port);
+                                       dev_kfree_skb_any(skb);
                                } else
                                        skb_queue_tail(&card->cli_queue[port], skb);
                                spin_unlock(&card->cli_queue_lock);
                                break;
                        }
                }
+               /* Allocate RX skbs for any ports which need them */
+               if (card->using_dma && card->atmdev[port] &&
+                   !card->rx_skb[port]) {
+                       struct sk_buff *skb = alloc_skb(RX_DMA_SIZE, GFP_ATOMIC);
+                       if (skb) {
+                               SKB_CB(skb)->dma_addr =
+                                       pci_map_single(card->dev, skb->data,
+                                                      RX_DMA_SIZE, PCI_DMA_FROMDEVICE);
+                               iowrite32(SKB_CB(skb)->dma_addr,
+                                         card->config_regs + RX_DMA_ADDR(port));
+                               card->rx_skb[port] = skb;
+                       } else {
+                               if (net_ratelimit())
+                                       dev_warn(&card->dev->dev, "Failed to allocate RX skb");
+
+                               /* We'll have to try again later */
+                               tasklet_schedule(&card->tlet);
+                       }
+               }
        }
        if (rx_done)
                iowrite32(rx_done, card->config_regs + FLAGS_ADDR);
@@ -901,50 +917,45 @@ static int fpga_tx(struct solos_card *card)
 
        for (port = 0; port < card->nr_ports; port++) {
                if (card->atmdev[port] && !(tx_pending & (1 << port))) {
+                       struct sk_buff *oldskb = card->tx_skb[port];
 
+                       if (oldskb)
+                               pci_unmap_single(card->dev, SKB_CB(oldskb)->dma_addr,
+                                                oldskb->len, PCI_DMA_TODEVICE);
+                       
                        spin_lock(&card->tx_queue_lock);
                        skb = skb_dequeue(&card->tx_queue[port]);
                        spin_unlock(&card->tx_queue_lock);
 
-                       if (!skb)
+                       if (skb && !card->using_dma) {
+                               memcpy_toio(TX_BUF(card, port), skb->data, skb->len);
+                               tx_started |= 1 << port; //Set TX full flag
+                               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,
+                                                                      skb->len, PCI_DMA_TODEVICE);
+                               iowrite32(SKB_CB(skb)->dma_addr,
+                                         card->config_regs + TX_DMA_ADDR(port));
+                       }
+
+                       if (!oldskb)
                                continue;
 
+                       /* Clean up and free oldskb now it's gone */
                        if (atmdebug) {
                                dev_info(&card->dev->dev, "Transmitted: port %d\n",
                                         port);
-                               print_buffer(skb);
+                               print_buffer(oldskb);
                        }
-                       if (card->using_dma) {
-                               if (card->tx_skb[port]) {
-                                       struct sk_buff *oldskb = card->tx_skb[port];
-
-                                       pci_unmap_single(card->dev, SKB_CB(oldskb)->dma_addr,
-                                                        oldskb->len, PCI_DMA_TODEVICE);
-
-                                       vcc = SKB_CB(oldskb)->vcc;
-
-                                       if (vcc) {
-                                               atomic_inc(&vcc->stats->tx);
-                                               solos_pop(vcc, oldskb);
-                                       } else
-                                               dev_kfree_skb_irq(oldskb);
-                               }
 
-                               SKB_CB(skb)->dma_addr = pci_map_single(card->dev, skb->data,
-                                                              skb->len, PCI_DMA_TODEVICE);
-                               iowrite32(SKB_CB(skb)->dma_addr, card->config_regs + TX_DMA_ADDR(port));
-                       } else {
-                               memcpy_toio(TX_BUF(card, port), skb->data, skb->len);
-                               tx_started |= 1 << port; //Set TX full flag
+                       vcc = SKB_CB(oldskb)->vcc;
 
-                               vcc = SKB_CB(skb)->vcc;
+                       if (vcc) {
+                               atomic_inc(&vcc->stats->tx);
+                               solos_pop(vcc, oldskb);
+                       } else
+                               dev_kfree_skb_irq(oldskb);
 
-                               if (vcc) {
-                                       atomic_inc(&vcc->stats->tx);
-                                       solos_pop(vcc, skb);
-                               } else
-                                       dev_kfree_skb_irq(skb);
-                       }
                }
        }
        if (tx_started)