solos: First attempt at DMA support

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

1 files changed, 90 insertions, 28 deletions

diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index b7d4af3df2a6..63c9ad03aec8 100644
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -55,6 +55,8 @@
 #define FLASH_BUSY      0x60
 #define FPGA_MODE       0x5C
 #define FLASH_MODE      0x58
+#define TX_DMA_ADDR(port)       (0x40 + (4 * (port)))
+#define RX_DMA_ADDR(port)       (0x30 + (4 * (port)))
 
 #define DATA_RAM_SIZE   32768
 #define BUF_SIZE        4096
@@ -78,6 +80,14 @@ struct pkt_hdr {
         __le16 type;
 };
 
+struct solos_skb_cb {
+        struct atm_vcc *vcc;
+        uint32_t dma_addr;
+};
+
+
+#define SKB_CB(skb)             ((struct solos_skb_cb *)skb->cb)
+
 #define PKT_DATA        0
 #define PKT_COMMAND     1
 #define PKT_POPEN       3
@@ -98,8 +108,11 @@ struct solos_card {
         struct list_head param_queue;
         struct sk_buff_head tx_queue[4];
         struct sk_buff_head cli_queue[4];
+        struct sk_buff *tx_skb[4];
+        struct sk_buff *rx_skb[4];
         wait_queue_head_t param_wq;
         wait_queue_head_t fw_wq;
+        int using_dma;
 };
 
 
@@ -588,44 +601,64 @@ void solos_bh(unsigned long card_arg)
 
         for (port = 0; port < card->nr_ports; port++) {
                 if (card_flags & (0x10 << port)) {
-                        struct pkt_hdr header;
+                        struct pkt_hdr _hdr, *header;
                         struct sk_buff *skb;
                         struct atm_vcc *vcc;
                         int size;
 
-                        rx_done |= 0x10 << port;
+                        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));
+                                }
+                                header = (void *)skb->data;
+                                size = le16_to_cpu(header->size);
+                                skb_put(skb, size + sizeof(*header));
+                                skb_pull(skb, sizeof(*header));
+                        } else {
+                                header = &_hdr;
 
-                        memcpy_fromio(&header, RX_BUF(card, port), sizeof(header));
+                                rx_done |= 0x10 << port;
 
-                        size = le16_to_cpu(header.size);
+                                memcpy_fromio(header, RX_BUF(card, port), sizeof(*header));
 
-                        skb = alloc_skb(size + 1, GFP_ATOMIC);
-                        if (!skb) {
-                                if (net_ratelimit())
-                                        dev_warn(&card->dev->dev, "Failed to allocate sk_buff for RX\n");
-                                continue;
-                        }
+                                size = le16_to_cpu(header->size);
 
-                        memcpy_fromio(skb_put(skb, size),
-                                      RX_BUF(card, port) + sizeof(header),
-                                      size);
+                                skb = alloc_skb(size + 1, GFP_ATOMIC);
+                                if (!skb) {
+                                        if (net_ratelimit())
+                                                dev_warn(&card->dev->dev, "Failed to allocate sk_buff for RX\n");
+                                        continue;
+                                }
 
+                                memcpy_fromio(skb_put(skb, size),
+                                              RX_BUF(card, port) + sizeof(*header),
+                                              size);
+                        }
                         if (atmdebug) {
                                 dev_info(&card->dev->dev, "Received: device %d\n", port);
                                 dev_info(&card->dev->dev, "size: %d VPI: %d VCI: %d\n",
-                                         size, le16_to_cpu(header.vpi),
-                                         le16_to_cpu(header.vci));
+                                         size, le16_to_cpu(header->vpi),
+                                         le16_to_cpu(header->vci));
                                 print_buffer(skb);
                         }
 
-                        switch (le16_to_cpu(header.type)) {
+                        switch (le16_to_cpu(header->type)) {
                         case PKT_DATA:
-                                vcc = find_vcc(card->atmdev[port], le16_to_cpu(header.vpi),
-                                               le16_to_cpu(header.vci));
+                                vcc = find_vcc(card->atmdev[port], le16_to_cpu(header->vpi),
+                                               le16_to_cpu(header->vci));
                                 if (!vcc) {
                                         if (net_ratelimit())
                                                 dev_warn(&card->dev->dev, "Received packet for unknown VCI.VPI %d.%d on port %d\n",
-                                                         le16_to_cpu(header.vci), le16_to_cpu(header.vpi),
+                                                         le16_to_cpu(header->vci), le16_to_cpu(header->vpi),
                                                          port);
                                         continue;
                                 }
@@ -839,7 +872,7 @@ static void fpga_queue(struct solos_card *card, int port, struct sk_buff *skb,
 {
         int old_len;
 
-        *(void **)skb->cb = vcc;
+        SKB_CB(skb)->vcc = vcc;
 
         spin_lock(&card->tx_queue_lock);
         old_len = skb_queue_len(&card->tx_queue[port]);
@@ -881,17 +914,37 @@ static int fpga_tx(struct solos_card *card)
                                          port);
                                 print_buffer(skb);
                         }
-                        memcpy_toio(TX_BUF(card, port), skb->data, skb->len);
+                        if (card->using_dma) {
+                                if (card->tx_skb[port]) {
+                                        struct sk_buff *oldskb = card->tx_skb[port];
 
-                        vcc = *(void **)skb->cb;
+                                        pci_unmap_single(card->dev, SKB_CB(oldskb)->dma_addr,
+                                                         oldskb->len, PCI_DMA_TODEVICE);
 
-                        if (vcc) {
-                                atomic_inc(&vcc->stats->tx);
-                                solos_pop(vcc, skb);
-                        } else
-                                dev_kfree_skb_irq(skb);
+                                        vcc = SKB_CB(oldskb)->vcc;
 
-                        tx_started |= 1 << port; //Set TX full flag
+                                        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(skb)->vcc;
+
+                                if (vcc) {
+                                        atomic_inc(&vcc->stats->tx);
+                                        solos_pop(vcc, skb);
+                                } else
+                                        dev_kfree_skb_irq(skb);
+                        }
                 }
         }
         if (tx_started)
@@ -999,6 +1052,12 @@ static int fpga_probe(struct pci_dev *dev, const struct pci_device_id *id)
                 goto out;
         }
 
+        err = pci_set_dma_mask(dev, DMA_32BIT_MASK);
+        if (err) {
+                dev_warn(&dev->dev, "Failed to set 32-bit DMA mask\n");
+                goto out;
+        }
+
         err = pci_request_regions(dev, "solos");
         if (err) {
                 dev_warn(&dev->dev, "Failed to request regions\n");
@@ -1035,6 +1094,9 @@ static int fpga_probe(struct pci_dev *dev, const struct pci_device_id *id)
         dev_info(&dev->dev, "Solos FPGA Version %d.%02d svn-%d\n",
                  major_ver, minor_ver, fpga_ver);
 
+        if (fpga_ver > 27)
+                card->using_dma = 1;
+
         card->nr_ports = 2; /* FIXME: Detect daughterboard */
 
         pci_set_drvdata(dev, card);