solos: Tidy up DMA handling a little. Still untested

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

1 files changed, 53 insertions, 42 deletions

diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index 63c9ad03aec8..acba08df5eb0 100644
--- 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)