pch_gbe: added the process of FIFO over run error

This patch added the processing which should be done to hardware,
when a FIFO over run error occurred.

Signed-off-by: Toshiharu Okada <toshiharu-linux@dsn.okisemi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 179 insertions, 104 deletions

diff --git a/drivers/net/pch_gbe/pch_gbe.h b/drivers/net/pch_gbe/pch_gbe.h
index 59fac77d0dbb..a09a07197eb5 100644
--- a/drivers/net/pch_gbe/pch_gbe.h
+++ b/drivers/net/pch_gbe/pch_gbe.h
@@ -127,8 +127,8 @@ struct pch_gbe_regs {
 
 /* Reset */
 #define PCH_GBE_ALL_RST         0x80000000  /* All reset */
-#define PCH_GBE_TX_RST          0x40000000  /* TX MAC, TX FIFO, TX DMA reset */
-#define PCH_GBE_RX_RST          0x04000000  /* RX MAC, RX FIFO, RX DMA reset */
+#define PCH_GBE_TX_RST          0x00008000  /* TX MAC, TX FIFO, TX DMA reset */
+#define PCH_GBE_RX_RST          0x00004000  /* RX MAC, RX FIFO, RX DMA reset */
 
 /* TCP/IP Accelerator Control */
 #define PCH_GBE_EX_LIST_EN      0x00000008  /* External List Enable */
@@ -276,6 +276,9 @@ struct pch_gbe_regs {
 #define PCH_GBE_RX_DMA_EN       0x00000002   /* Enables Receive DMA */
 #define PCH_GBE_TX_DMA_EN       0x00000001   /* Enables Transmission DMA */
 
+/* RX DMA STATUS */
+#define PCH_GBE_IDLE_CHECK       0xFFFFFFFE
+
 /* Wake On LAN Status */
 #define PCH_GBE_WLS_BR          0x00000008 /* Broadcas Address */
 #define PCH_GBE_WLS_MLT         0x00000004 /* Multicast Address */
@@ -471,6 +474,7 @@ struct pch_gbe_tx_desc {
 struct pch_gbe_buffer {
         struct sk_buff *skb;
         dma_addr_t dma;
+        unsigned char *rx_buffer;
         unsigned long time_stamp;
         u16 length;
         bool mapped;
@@ -511,6 +515,9 @@ struct pch_gbe_tx_ring {
 struct pch_gbe_rx_ring {
         struct pch_gbe_rx_desc *desc;
         dma_addr_t dma;
+        unsigned char *rx_buff_pool;
+        dma_addr_t rx_buff_pool_logic;
+        unsigned int rx_buff_pool_size;
         unsigned int size;
         unsigned int count;
         unsigned int next_to_use;
@@ -622,6 +629,7 @@ struct pch_gbe_adapter {
         unsigned long rx_buffer_len;
         unsigned long tx_queue_len;
         bool have_msi;
+        bool rx_stop_flag;
 };
 
 extern const char pch_driver_version[];
diff --git a/drivers/net/pch_gbe/pch_gbe_main.c b/drivers/net/pch_gbe/pch_gbe_main.c
index 48ff87c455ae..39ce0ee44ad7 100644
--- a/drivers/net/pch_gbe/pch_gbe_main.c
+++ b/drivers/net/pch_gbe/pch_gbe_main.c
@@ -20,7 +20,6 @@
 
 #include "pch_gbe.h"
 #include "pch_gbe_api.h"
-#include <linux/prefetch.h>
 
 #define DRV_VERSION     "1.00"
 const char pch_driver_version[] = DRV_VERSION;
@@ -34,6 +33,7 @@ const char pch_driver_version[] = DRV_VERSION;
 #define PCH_GBE_WATCHDOG_PERIOD         (1 * HZ)        /* watchdog time */
 #define PCH_GBE_COPYBREAK_DEFAULT       256
 #define PCH_GBE_PCI_BAR                 1
+#define PCH_GBE_RESERVE_MEMORY          0x200000        /* 2MB */
 
 /* Macros for ML7223 */
 #define PCI_VENDOR_ID_ROHM                      0x10db
@@ -52,6 +52,7 @@ const char pch_driver_version[] = DRV_VERSION;
         )
 
 /* Ethertype field values */
+#define PCH_GBE_MAX_RX_BUFFER_SIZE      0x2880
 #define PCH_GBE_MAX_JUMBO_FRAME_SIZE    10318
 #define PCH_GBE_FRAME_SIZE_2048         2048
 #define PCH_GBE_FRAME_SIZE_4096         4096
@@ -83,10 +84,12 @@ const char pch_driver_version[] = DRV_VERSION;
 #define PCH_GBE_INT_ENABLE_MASK ( \
         PCH_GBE_INT_RX_DMA_CMPLT |    \
         PCH_GBE_INT_RX_DSC_EMP   |    \
+        PCH_GBE_INT_RX_FIFO_ERR  |    \
         PCH_GBE_INT_WOL_DET      |    \
         PCH_GBE_INT_TX_CMPLT          \
         )
 
+#define PCH_GBE_INT_DISABLE_ALL         0
 
 static unsigned int copybreak __read_mostly = PCH_GBE_COPYBREAK_DEFAULT;
 
@@ -138,6 +141,27 @@ static void pch_gbe_wait_clr_bit(void *reg, u32 bit)
         if (!tmp)
                 pr_err("Error: busy bit is not cleared\n");
 }
+
+/**
+ * pch_gbe_wait_clr_bit_irq - Wait to clear a bit for interrupt context
+ * @reg:        Pointer of register
+ * @busy:       Busy bit
+ */
+static int pch_gbe_wait_clr_bit_irq(void *reg, u32 bit)
+{
+        u32 tmp;
+        int ret = -1;
+        /* wait busy */
+        tmp = 20;
+        while ((ioread32(reg) & bit) && --tmp)
+                udelay(5);
+        if (!tmp)
+                pr_err("Error: busy bit is not cleared\n");
+        else
+                ret = 0;
+        return ret;
+}
+
 /**
  * pch_gbe_mac_mar_set - Set MAC address register
  * @hw:     Pointer to the HW structure
@@ -189,6 +213,17 @@ static void pch_gbe_mac_reset_hw(struct pch_gbe_hw *hw)
         return;
 }
 
+static void pch_gbe_mac_reset_rx(struct pch_gbe_hw *hw)
+{
+        /* Read the MAC address. and store to the private data */
+        pch_gbe_mac_read_mac_addr(hw);
+        iowrite32(PCH_GBE_RX_RST, &hw->reg->RESET);
+        pch_gbe_wait_clr_bit_irq(&hw->reg->RESET, PCH_GBE_RX_RST);
+        /* Setup the MAC address */
+        pch_gbe_mac_mar_set(hw, hw->mac.addr, 0);
+        return;
+}
+
 /**
  * pch_gbe_mac_init_rx_addrs - Initialize receive address's
  * @hw: Pointer to the HW structure
@@ -671,13 +706,8 @@ static void pch_gbe_setup_rctl(struct pch_gbe_adapter *adapter)
 
         tcpip = ioread32(&hw->reg->TCPIP_ACC);
 
-        if (netdev->features & NETIF_F_RXCSUM) {
-                tcpip &= ~PCH_GBE_RX_TCPIPACC_OFF;
-                tcpip |= PCH_GBE_RX_TCPIPACC_EN;
-        } else {
-                tcpip |= PCH_GBE_RX_TCPIPACC_OFF;
-                tcpip &= ~PCH_GBE_RX_TCPIPACC_EN;
-        }
+        tcpip |= PCH_GBE_RX_TCPIPACC_OFF;
+        tcpip &= ~PCH_GBE_RX_TCPIPACC_EN;
         iowrite32(tcpip, &hw->reg->TCPIP_ACC);
         return;
 }
@@ -1090,6 +1120,35 @@ void pch_gbe_update_stats(struct pch_gbe_adapter *adapter)
         spin_unlock_irqrestore(&adapter->stats_lock, flags);
 }
 
+static void pch_gbe_stop_receive(struct pch_gbe_adapter *adapter)
+{
+        struct pch_gbe_hw *hw = &adapter->hw;
+        u32 rxdma;
+        u16 value;
+        int ret;
+
+        /* Disable Receive DMA */
+        rxdma = ioread32(&hw->reg->DMA_CTRL);
+        rxdma &= ~PCH_GBE_RX_DMA_EN;
+        iowrite32(rxdma, &hw->reg->DMA_CTRL);
+        /* Wait Rx DMA BUS is IDLE */
+        ret = pch_gbe_wait_clr_bit_irq(&hw->reg->RX_DMA_ST, PCH_GBE_IDLE_CHECK);
+        if (ret) {
+                /* Disable Bus master */
+                pci_read_config_word(adapter->pdev, PCI_COMMAND, &value);
+                value &= ~PCI_COMMAND_MASTER;
+                pci_write_config_word(adapter->pdev, PCI_COMMAND, value);
+                /* Stop Receive */
+                pch_gbe_mac_reset_rx(hw);
+                /* Enable Bus master */
+                value |= PCI_COMMAND_MASTER;
+                pci_write_config_word(adapter->pdev, PCI_COMMAND, value);
+        } else {
+                /* Stop Receive */
+                pch_gbe_mac_reset_rx(hw);
+        }
+}
+
 static void pch_gbe_start_receive(struct pch_gbe_hw *hw)
 {
         u32 rxdma;
@@ -1129,7 +1188,15 @@ static irqreturn_t pch_gbe_intr(int irq, void *data)
         if (int_st & PCH_GBE_INT_RX_FRAME_ERR)
                 adapter->stats.intr_rx_frame_err_count++;
         if (int_st & PCH_GBE_INT_RX_FIFO_ERR)
-                adapter->stats.intr_rx_fifo_err_count++;
+                if (!adapter->rx_stop_flag) {
+                        adapter->stats.intr_rx_fifo_err_count++;
+                        pr_debug("Rx fifo over run\n");
+                        adapter->rx_stop_flag = true;
+                        int_en = ioread32(&hw->reg->INT_EN);
+                        iowrite32((int_en & ~PCH_GBE_INT_RX_FIFO_ERR),
+                                  &hw->reg->INT_EN);
+                        pch_gbe_stop_receive(adapter);
+                }
         if (int_st & PCH_GBE_INT_RX_DMA_ERR)
                 adapter->stats.intr_rx_dma_err_count++;
         if (int_st & PCH_GBE_INT_TX_FIFO_ERR)
@@ -1141,7 +1208,7 @@ static irqreturn_t pch_gbe_intr(int irq, void *data)
         /* When Rx descriptor is empty  */
         if ((int_st & PCH_GBE_INT_RX_DSC_EMP)) {
                 adapter->stats.intr_rx_dsc_empty_count++;
-                pr_err("Rx descriptor is empty\n");
+                pr_debug("Rx descriptor is empty\n");
                 int_en = ioread32(&hw->reg->INT_EN);
                 iowrite32((int_en & ~PCH_GBE_INT_RX_DSC_EMP), &hw->reg->INT_EN);
                 if (hw->mac.tx_fc_enable) {
@@ -1191,29 +1258,23 @@ pch_gbe_alloc_rx_buffers(struct pch_gbe_adapter *adapter,
         unsigned int i;
         unsigned int bufsz;
 
-        bufsz = adapter->rx_buffer_len + PCH_GBE_DMA_ALIGN;
+        bufsz = adapter->rx_buffer_len + NET_IP_ALIGN;
         i = rx_ring->next_to_use;
 
         while ((cleaned_count--)) {
                 buffer_info = &rx_ring->buffer_info[i];
-                skb = buffer_info->skb;
-                if (skb) {
-                        skb_trim(skb, 0);
-                } else {
-                        skb = netdev_alloc_skb(netdev, bufsz);
-                        if (unlikely(!skb)) {
-                                /* Better luck next round */
-                                adapter->stats.rx_alloc_buff_failed++;
-                                break;
-                        }
-                        /* 64byte align */
-                        skb_reserve(skb, PCH_GBE_DMA_ALIGN);
-
-                        buffer_info->skb = skb;
-                        buffer_info->length = adapter->rx_buffer_len;
+                skb = netdev_alloc_skb(netdev, bufsz);
+                if (unlikely(!skb)) {
+                        /* Better luck next round */
+                        adapter->stats.rx_alloc_buff_failed++;
+                        break;
                 }
+                /* align */
+                skb_reserve(skb, NET_IP_ALIGN);
+                buffer_info->skb = skb;
+
                 buffer_info->dma = dma_map_single(&pdev->dev,
-                                                  skb->data,
+                                                  buffer_info->rx_buffer,
                                                   buffer_info->length,
                                                   DMA_FROM_DEVICE);
                 if (dma_mapping_error(&adapter->pdev->dev, buffer_info->dma)) {
@@ -1246,6 +1307,36 @@ pch_gbe_alloc_rx_buffers(struct pch_gbe_adapter *adapter,
         return;
 }
 
+static int
+pch_gbe_alloc_rx_buffers_pool(struct pch_gbe_adapter *adapter,
+                         struct pch_gbe_rx_ring *rx_ring, int cleaned_count)
+{
+        struct pci_dev *pdev = adapter->pdev;
+        struct pch_gbe_buffer *buffer_info;
+        unsigned int i;
+        unsigned int bufsz;
+        unsigned int size;
+
+        bufsz = adapter->rx_buffer_len;
+
+        size = rx_ring->count * bufsz + PCH_GBE_RESERVE_MEMORY;
+        rx_ring->rx_buff_pool = dma_alloc_coherent(&pdev->dev, size,
+                                                &rx_ring->rx_buff_pool_logic,
+                                                GFP_KERNEL);
+        if (!rx_ring->rx_buff_pool) {
+                pr_err("Unable to allocate memory for the receive poll buffer\n");
+                return -ENOMEM;
+        }
+        memset(rx_ring->rx_buff_pool, 0, size);
+        rx_ring->rx_buff_pool_size = size;
+        for (i = 0; i < rx_ring->count; i++) {
+                buffer_info = &rx_ring->buffer_info[i];
+                buffer_info->rx_buffer = rx_ring->rx_buff_pool + bufsz * i;
+                buffer_info->length = bufsz;
+        }
+        return 0;
+}
+
 /**
  * pch_gbe_alloc_tx_buffers - Allocate transmit buffers
  * @adapter:   Board private structure
@@ -1386,7 +1477,7 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter,
         unsigned int i;
         unsigned int cleaned_count = 0;
         bool cleaned = false;
-        struct sk_buff *skb, *new_skb;
+        struct sk_buff *skb;
         u8 dma_status;
         u16 gbec_status;
         u32 tcp_ip_status;
@@ -1407,13 +1498,12 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter,
                 rx_desc->gbec_status = DSC_INIT16;
                 buffer_info = &rx_ring->buffer_info[i];
                 skb = buffer_info->skb;
+                buffer_info->skb = NULL;
 
                 /* unmap dma */
                 dma_unmap_single(&pdev->dev, buffer_info->dma,
                                    buffer_info->length, DMA_FROM_DEVICE);
                 buffer_info->mapped = false;
-                /* Prefetch the packet */
-                prefetch(skb->data);
 
                 pr_debug("RxDecNo = 0x%04x  Status[DMA:0x%02x GBE:0x%04x "
                          "TCP:0x%08x]  BufInf = 0x%p\n",
@@ -1433,70 +1523,16 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter,
                         pr_err("Receive CRC Error\n");
                 } else {
                         /* get receive length */
-                        /* length convert[-3] */
-                        length = (rx_desc->rx_words_eob) - 3;
-
-                        /* Decide the data conversion method */
-                        if (!(netdev->features & NETIF_F_RXCSUM)) {
-                                /* [Header:14][payload] */
-                                if (NET_IP_ALIGN) {
-                                        /* Because alignment differs,
-                                         * the new_skb is newly allocated,
-                                         * and data is copied to new_skb.*/
-                                        new_skb = netdev_alloc_skb(netdev,
-                                                         length + NET_IP_ALIGN);
-                                        if (!new_skb) {
-                                                /* dorrop error */
-                                                pr_err("New skb allocation "
-                                                        "Error\n");
-                                                goto dorrop;
-                                        }
-                                        skb_reserve(new_skb, NET_IP_ALIGN);
-                                        memcpy(new_skb->data, skb->data,
-                                               length);
-                                        skb = new_skb;
-                                } else {
-                                        /* DMA buffer is used as SKB as it is.*/
-                                        buffer_info->skb = NULL;
-                                }
-                        } else {
-                                /* [Header:14][padding:2][payload] */
-                                /* The length includes padding length */
-                                length = length - PCH_GBE_DMA_PADDING;
-                                if ((length < copybreak) ||
-                                    (NET_IP_ALIGN != PCH_GBE_DMA_PADDING)) {
-                                        /* Because alignment differs,
-                                         * the new_skb is newly allocated,
-                                         * and data is copied to new_skb.
-                                         * Padding data is deleted
-                                         * at the time of a copy.*/
-                                        new_skb = netdev_alloc_skb(netdev,
-                                                         length + NET_IP_ALIGN);
-                                        if (!new_skb) {
-                                                /* dorrop error */
-                                                pr_err("New skb allocation "
-                                                        "Error\n");
-                                                goto dorrop;
-                                        }
-                                        skb_reserve(new_skb, NET_IP_ALIGN);
-                                        memcpy(new_skb->data, skb->data,
-                                               ETH_HLEN);
-                                        memcpy(&new_skb->data[ETH_HLEN],
-                                               &skb->data[ETH_HLEN +
-                                               PCH_GBE_DMA_PADDING],
-                                               length - ETH_HLEN);
-                                        skb = new_skb;
-                                } else {
-                                        /* Padding data is deleted
-                                         * by moving header data.*/
-                                        memmove(&skb->data[PCH_GBE_DMA_PADDING],
-                                                &skb->data[0], ETH_HLEN);
-                                        skb_reserve(skb, NET_IP_ALIGN);
-                                        buffer_info->skb = NULL;
-                                }
-                        }
-                        /* The length includes FCS length */
-                        length = length - ETH_FCS_LEN;
+                        /* length convert[-3], length includes FCS length */
+                        length = (rx_desc->rx_words_eob) - 3 - ETH_FCS_LEN;
+                        if (rx_desc->rx_words_eob & 0x02)
+                                length = length - 4;
+                        /*
+                         * buffer_info->rx_buffer: [Header:14][payload]
+                         * skb->data: [Reserve:2][Header:14][payload]
+                         */
+                        memcpy(skb->data, buffer_info->rx_buffer, length);
+
                         /* update status of driver */
                         adapter->stats.rx_bytes += length;
                         adapter->stats.rx_packets++;
@@ -1515,7 +1551,6 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter,
                         pr_debug("Receive skb->ip_summed: %d length: %d\n",
                                  skb->ip_summed, length);
                 }
-dorrop:
                 /* return some buffers to hardware, one at a time is too slow */
                 if (unlikely(cleaned_count >= PCH_GBE_RX_BUFFER_WRITE)) {
                         pch_gbe_alloc_rx_buffers(adapter, rx_ring,
@@ -1720,6 +1755,11 @@ int pch_gbe_up(struct pch_gbe_adapter *adapter)
                 pr_err("Error: can't bring device up\n");
                 return err;
         }
+        err = pch_gbe_alloc_rx_buffers_pool(adapter, rx_ring, rx_ring->count);
+        if (err) {
+                pr_err("Error: can't bring device up\n");
+                return err;
+        }
         pch_gbe_alloc_tx_buffers(adapter, tx_ring);
         pch_gbe_alloc_rx_buffers(adapter, rx_ring, rx_ring->count);
         adapter->tx_queue_len = netdev->tx_queue_len;
@@ -1741,6 +1781,7 @@ int pch_gbe_up(struct pch_gbe_adapter *adapter)
 void pch_gbe_down(struct pch_gbe_adapter *adapter)
 {
         struct net_device *netdev = adapter->netdev;
+        struct pch_gbe_rx_ring *rx_ring = adapter->rx_ring;
 
         /* signal that we're down so the interrupt handler does not
          * reschedule our watchdog timer */
@@ -1759,6 +1800,12 @@ void pch_gbe_down(struct pch_gbe_adapter *adapter)
         pch_gbe_reset(adapter);
         pch_gbe_clean_tx_ring(adapter, adapter->tx_ring);
         pch_gbe_clean_rx_ring(adapter, adapter->rx_ring);
+
+        pci_free_consistent(adapter->pdev, rx_ring->rx_buff_pool_size,
+                            rx_ring->rx_buff_pool, rx_ring->rx_buff_pool_logic);
+        rx_ring->rx_buff_pool_logic = 0;
+        rx_ring->rx_buff_pool_size = 0;
+        rx_ring->rx_buff_pool = NULL;
 }
 
 /**
@@ -2011,6 +2058,8 @@ static int pch_gbe_change_mtu(struct net_device *netdev, int new_mtu)
 {
         struct pch_gbe_adapter *adapter = netdev_priv(netdev);
         int max_frame;
+        unsigned long old_rx_buffer_len = adapter->rx_buffer_len;
+        int err;
 
         max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN;
         if ((max_frame < ETH_ZLEN + ETH_FCS_LEN) ||
@@ -2025,14 +2074,24 @@ static int pch_gbe_change_mtu(struct net_device *netdev, int new_mtu)
         else if (max_frame <= PCH_GBE_FRAME_SIZE_8192)
                 adapter->rx_buffer_len = PCH_GBE_FRAME_SIZE_8192;
         else
-                adapter->rx_buffer_len = PCH_GBE_MAX_JUMBO_FRAME_SIZE;
-        netdev->mtu = new_mtu;
-        adapter->hw.mac.max_frame_size = max_frame;
+                adapter->rx_buffer_len = PCH_GBE_MAX_RX_BUFFER_SIZE;
 
-        if (netif_running(netdev))
-                pch_gbe_reinit_locked(adapter);
-        else
+        if (netif_running(netdev)) {
+                pch_gbe_down(adapter);
+                err = pch_gbe_up(adapter);
+                if (err) {
+                        adapter->rx_buffer_len = old_rx_buffer_len;
+                        pch_gbe_up(adapter);
+                        return -ENOMEM;
+                } else {
+                        netdev->mtu = new_mtu;
+                        adapter->hw.mac.max_frame_size = max_frame;
+                }
+        } else {
                 pch_gbe_reset(adapter);
+                netdev->mtu = new_mtu;
+                adapter->hw.mac.max_frame_size = max_frame;
+        }
 
         pr_debug("max_frame : %d  rx_buffer_len : %d  mtu : %d  max_frame_size : %d\n",
                  max_frame, (u32) adapter->rx_buffer_len, netdev->mtu,
@@ -2110,6 +2169,7 @@ static int pch_gbe_napi_poll(struct napi_struct *napi, int budget)
         int work_done = 0;
         bool poll_end_flag = false;
         bool cleaned = false;
+        u32 int_en;
 
         pr_debug("budget : %d\n", budget);
 
@@ -2117,8 +2177,15 @@ static int pch_gbe_napi_poll(struct napi_struct *napi, int budget)
         if (!netif_carrier_ok(netdev)) {
                 poll_end_flag = true;
         } else {
-                cleaned = pch_gbe_clean_tx(adapter, adapter->tx_ring);
                 pch_gbe_clean_rx(adapter, adapter->rx_ring, &work_done, budget);
+                if (adapter->rx_stop_flag) {
+                        adapter->rx_stop_flag = false;
+                        pch_gbe_start_receive(&adapter->hw);
+                        int_en = ioread32(&adapter->hw.reg->INT_EN);
+                        iowrite32((int_en | PCH_GBE_INT_RX_FIFO_ERR),
+                                        &adapter->hw.reg->INT_EN);
+                }
+                cleaned = pch_gbe_clean_tx(adapter, adapter->tx_ring);
 
                 if (cleaned)
                         work_done = budget;