2 files changed, 447 insertions, 21 deletions

diff --git a/drivers/net/ks8842.c b/drivers/net/ks8842.c
index 289b0bee3462..3fe38c787f29 100644
--- a/drivers/net/ks8842.c
+++ b/drivers/net/ks8842.c
@@ -30,6 +30,9 @@
 #include <linux/etherdevice.h>
 #include <linux/ethtool.h>
 #include <linux/ks8842.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
 
 #define DRV_NAME "ks8842"
 
@@ -82,6 +85,15 @@
 #define IRQ_RX_ERROR    0x0080
 #define ENABLED_IRQS    (IRQ_LINK_CHANGE | IRQ_TX | IRQ_RX | IRQ_RX_STOPPED | \
                 IRQ_TX_STOPPED | IRQ_RX_OVERRUN | IRQ_RX_ERROR)
+/* When running via timberdale in DMA mode, the RX interrupt should be
+   enabled in the KS8842, but not in the FPGA IP, since the IP handles
+   RX DMA internally.
+   TX interrupts are not needed it is handled by the FPGA the driver is
+   notified via DMA callbacks.
+*/
+#define ENABLED_IRQS_DMA_IP     (IRQ_LINK_CHANGE | IRQ_RX_STOPPED | \
+        IRQ_TX_STOPPED | IRQ_RX_OVERRUN | IRQ_RX_ERROR)
+#define ENABLED_IRQS_DMA        (ENABLED_IRQS_DMA_IP | IRQ_RX)
 #define REG_ISR         0x02
 #define REG_RXSR        0x04
 #define RXSR_VALID      0x8000
@@ -124,6 +136,28 @@
 #define MICREL_KS884X           0x01    /* 0=Timeberdale(FPGA), 1=Micrel */
 #define KS884X_16BIT            0x02    /*  1=16bit, 0=32bit */
 
+#define DMA_BUFFER_SIZE         2048
+
+struct ks8842_tx_dma_ctl {
+        struct dma_chan *chan;
+        struct dma_async_tx_descriptor *adesc;
+        void *buf;
+        struct scatterlist sg;
+        int channel;
+};
+
+struct ks8842_rx_dma_ctl {
+        struct dma_chan *chan;
+        struct dma_async_tx_descriptor *adesc;
+        struct sk_buff  *skb;
+        struct scatterlist sg;
+        struct tasklet_struct tasklet;
+        int channel;
+};
+
+#define KS8842_USE_DMA(adapter) (((adapter)->dma_tx.channel != -1) && \
+         ((adapter)->dma_rx.channel != -1))
+
 struct ks8842_adapter {
         void __iomem    *hw_addr;
         int             irq;
@@ -132,8 +166,19 @@ struct ks8842_adapter {
         spinlock_t      lock; /* spinlock to be interrupt safe */
         struct work_struct timeout_work;
         struct net_device *netdev;
+        struct device *dev;
+        struct ks8842_tx_dma_ctl        dma_tx;
+        struct ks8842_rx_dma_ctl        dma_rx;
 };
 
+static void ks8842_dma_rx_cb(void *data);
+static void ks8842_dma_tx_cb(void *data);
+
+static inline void ks8842_resume_dma(struct ks8842_adapter *adapter)
+{
+        iowrite32(1, adapter->hw_addr + REQ_TIMB_DMA_RESUME);
+}
+
 static inline void ks8842_select_bank(struct ks8842_adapter *adapter, u16 bank)
 {
         iowrite16(bank, adapter->hw_addr + REG_SELECT_BANK);
@@ -297,8 +342,19 @@ static void ks8842_reset_hw(struct ks8842_adapter *adapter)
         ks8842_write16(adapter, 18, 0xffff, REG_ISR);
 
         /* enable interrupts */
-        ks8842_write16(adapter, 18, ENABLED_IRQS, REG_IER);
-
+        if (KS8842_USE_DMA(adapter)) {
+                /* When running in DMA Mode the RX interrupt is not enabled in
+                   timberdale because RX data is received by DMA callbacks
+                   it must still be enabled in the KS8842 because it indicates
+                   to timberdale when there is RX data for it's DMA FIFOs */
+                iowrite16(ENABLED_IRQS_DMA_IP, adapter->hw_addr + REG_TIMB_IER);
+                ks8842_write16(adapter, 18, ENABLED_IRQS_DMA, REG_IER);
+        } else {
+                if (!(adapter->conf_flags & MICREL_KS884X))
+                        iowrite16(ENABLED_IRQS,
+                                adapter->hw_addr + REG_TIMB_IER);
+                ks8842_write16(adapter, 18, ENABLED_IRQS, REG_IER);
+        }
         /* enable the switch */
         ks8842_write16(adapter, 32, 0x1, REG_SW_ID_AND_ENABLE);
 }
@@ -371,6 +427,53 @@ static inline u16 ks8842_tx_fifo_space(struct ks8842_adapter *adapter)
         return ks8842_read16(adapter, 16, REG_TXMIR) & 0x1fff;
 }
 
+static int ks8842_tx_frame_dma(struct sk_buff *skb, struct net_device *netdev)
+{
+        struct ks8842_adapter *adapter = netdev_priv(netdev);
+        struct ks8842_tx_dma_ctl *ctl = &adapter->dma_tx;
+        u8 *buf = ctl->buf;
+
+        if (ctl->adesc) {
+                netdev_dbg(netdev, "%s: TX ongoing\n", __func__);
+                /* transfer ongoing */
+                return NETDEV_TX_BUSY;
+        }
+
+        sg_dma_len(&ctl->sg) = skb->len + sizeof(u32);
+
+        /* copy data to the TX buffer */
+        /* the control word, enable IRQ, port 1 and the length */
+        *buf++ = 0x00;
+        *buf++ = 0x01; /* Port 1 */
+        *buf++ = skb->len & 0xff;
+        *buf++ = (skb->len >> 8) & 0xff;
+        skb_copy_from_linear_data(skb, buf, skb->len);
+
+        dma_sync_single_range_for_device(adapter->dev,
+                sg_dma_address(&ctl->sg), 0, sg_dma_len(&ctl->sg),
+                DMA_TO_DEVICE);
+
+        /* make sure the length is a multiple of 4 */
+        if (sg_dma_len(&ctl->sg) % 4)
+                sg_dma_len(&ctl->sg) += 4 - sg_dma_len(&ctl->sg) % 4;
+
+        ctl->adesc = ctl->chan->device->device_prep_slave_sg(ctl->chan,
+                &ctl->sg, 1, DMA_TO_DEVICE,
+                DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_SRC_UNMAP);
+        if (!ctl->adesc)
+                return NETDEV_TX_BUSY;
+
+        ctl->adesc->callback_param = netdev;
+        ctl->adesc->callback = ks8842_dma_tx_cb;
+        ctl->adesc->tx_submit(ctl->adesc);
+
+        netdev->stats.tx_bytes += skb->len;
+
+        dev_kfree_skb(skb);
+
+        return NETDEV_TX_OK;
+}
+
 static int ks8842_tx_frame(struct sk_buff *skb, struct net_device *netdev)
 {
         struct ks8842_adapter *adapter = netdev_priv(netdev);
@@ -422,6 +525,121 @@ static int ks8842_tx_frame(struct sk_buff *skb, struct net_device *netdev)
         return NETDEV_TX_OK;
 }
 
+static void ks8842_update_rx_err_counters(struct net_device *netdev, u32 status)
+{
+        netdev_dbg(netdev, "RX error, status: %x\n", status);
+
+        netdev->stats.rx_errors++;
+        if (status & RXSR_TOO_LONG)
+                netdev->stats.rx_length_errors++;
+        if (status & RXSR_CRC_ERROR)
+                netdev->stats.rx_crc_errors++;
+        if (status & RXSR_RUNT)
+                netdev->stats.rx_frame_errors++;
+}
+
+static void ks8842_update_rx_counters(struct net_device *netdev, u32 status,
+        int len)
+{
+        netdev_dbg(netdev, "RX packet, len: %d\n", len);
+
+        netdev->stats.rx_packets++;
+        netdev->stats.rx_bytes += len;
+        if (status & RXSR_MULTICAST)
+                netdev->stats.multicast++;
+}
+
+static int __ks8842_start_new_rx_dma(struct net_device *netdev)
+{
+        struct ks8842_adapter *adapter = netdev_priv(netdev);
+        struct ks8842_rx_dma_ctl *ctl = &adapter->dma_rx;
+        struct scatterlist *sg = &ctl->sg;
+        int err;
+
+        ctl->skb = netd