bfin_mac: convert bfin Ethernet driver to NAPI framework

Ethernet RX DMA buffers are polled in NAPI work queue other than received
directly in DMA RX interrupt handler.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 53 insertions, 32 deletions

diff --git a/drivers/net/ethernet/adi/Kconfig b/drivers/net/ethernet/adi/Kconfig
index f952fff6a9a9..c9cd3592ab73 100644
--- a/drivers/net/ethernet/adi/Kconfig
+++ b/drivers/net/ethernet/adi/Kconfig
@@ -52,8 +52,7 @@ config BFIN_TX_DESC_NUM
 config BFIN_RX_DESC_NUM
         int "Number of receive buffer packets"
         depends on BFIN_MAC
-        range 20 100 if BFIN_MAC_USE_L1
-        range 20 800
+        range 20 64
         default "20"
         ---help---
           Set the number of buffer packets used in driver.
diff --git a/drivers/net/ethernet/adi/bfin_mac.c b/drivers/net/ethernet/adi/bfin_mac.c
index 7ae74d450e8f..afa66847e10b 100644
--- a/drivers/net/ethernet/adi/bfin_mac.c
+++ b/drivers/net/ethernet/adi/bfin_mac.c
@@ -1218,11 +1218,11 @@ out:
 #define RX_ERROR_MASK (RX_LONG | RX_ALIGN | RX_CRC | RX_LEN | \
         RX_FRAG | RX_ADDR | RX_DMAO | RX_PHY | RX_LATE | RX_RANGE)
 
-static void bfin_mac_rx(struct net_device *dev)
+static void bfin_mac_rx(struct bfin_mac_local *lp)
 {
+        struct net_device *dev = lp->ndev;
         struct sk_buff *skb, *new_skb;
         unsigned short len;
-        struct bfin_mac_local *lp __maybe_unused = netdev_priv(dev);
 #if defined(BFIN_MAC_CSUM_OFFLOAD)
         unsigned int i;
         unsigned char fcs[ETH_FCS_LEN + 1];
@@ -1256,7 +1256,7 @@ static void bfin_mac_rx(struct net_device *dev)
         current_rx_ptr->skb = new_skb;
         current_rx_ptr->desc_a.start_addr = (unsigned long)new_skb->data - 2;
 
-        len = (unsigned short)((current_rx_ptr->status.status_word) & RX_FRLEN);
+        len = (unsigned short)(current_rx_ptr->status.status_word & RX_FRLEN);
         /* Deduce Ethernet FCS length from Ethernet payload length */
         len -= ETH_FCS_LEN;
         skb_put(skb, len);
@@ -1294,7 +1294,8 @@ static void bfin_mac_rx(struct net_device *dev)
         }
 #endif
 
-        netif_rx(skb);
+        napi_gro_receive(&lp->napi, skb);
+
         dev->stats.rx_packets++;
         dev->stats.rx_bytes += len;
 out:
@@ -1302,41 +1303,52 @@ out:
         current_rx_ptr = current_rx_ptr->next;
 }
 
+static int bfin_mac_poll(struct napi_struct *napi, int budget)
+{
+        int i = 0;
+        struct bfin_mac_local *lp = container_of(napi,
+                                                 struct bfin_mac_local,
+                                                 napi);
+
+        while (current_rx_ptr->status.status_word != 0 && i < budget) {
+                bfin_mac_rx(lp);
+                i++;
+        }
+
+        if (i < budget) {
+                napi_complete(napi);
+                if (test_and_clear_bit(BFIN_MAC_RX_IRQ_DISABLED, &lp->flags))
+                        enable_irq(IRQ_MAC_RX);
+        }
+
+        return i;
+}
+
 /* interrupt routine to handle rx and error signal */
 static irqreturn_t bfin_mac_interrupt(int irq, void *dev_id)
 {
-        struct net_device *dev = dev_id;
-        int number = 0;
-
-get_one_packet:
-        if (current_rx_ptr->status.status_word == 0) {
-                /* no more new packet received */
-                if (number == 0) {
-                        if (current_rx_ptr->next->status.status_word != 0) {
-                                current_rx_ptr = current_rx_ptr->next;
-                                goto real_rx;
-                        }
-                }
-                bfin_write_DMA1_IRQ_STATUS(bfin_read_DMA1_IRQ_STATUS() |
-                                           DMA_DONE | DMA_ERR);
-                return IRQ_HANDLED;
+        struct bfin_mac_local *lp = netdev_priv(dev_id);
+        u32 status;
+
+        status = bfin_read_DMA1_IRQ_STATUS();
+
+        bfin_write_DMA1_IRQ_STATUS(status | DMA_DONE | DMA_ERR);
+        if (status & DMA_DONE) {
+                disable_irq_nosync(IRQ_MAC_RX);
+                set_bit(BFIN_MAC_RX_IRQ_DISABLED, &lp->flags);
+                napi_schedule(&lp->napi);
         }
 
-real_rx:
-        bfin_mac_rx(dev);
-        number++;
-        goto get_one_packet;
+        return IRQ_HANDLED;
 }
 
 #ifdef CONFIG_NET_POLL_CONTROLLER
-static void bfin_mac_poll(struct net_device *dev)
+static void bfin_mac_poll_controller(struct net_device *dev)
 {
         struct bfin_mac_local *lp = netdev_priv(dev);
 
-        disable_irq(IRQ_MAC_RX);
         bfin_mac_interrupt(IRQ_MAC_RX, dev);
         tx_reclaim_skb(lp);
-        enable_irq(IRQ_MAC_RX);
 }
 #endif                          /* CONFIG_NET_POLL_CONTROLLER */
 
@@ -1428,14 +1440,13 @@ static void bfin_mac_timeout(struct net_device *dev)
                 tx_list_head = tx_list_head->next;
         }
 
-        if (netif_queue_stopped(lp->ndev))
-                netif_wake_queue(lp->ndev);
+        if (netif_queue_stopped(dev))
+                netif_wake_queue(dev);
 
         bfin_mac_enable(lp->phydev);
 
         /* We can accept TX packets again */
         dev->trans_start = jiffies; /* prevent tx timeout */
-        netif_wake_queue(dev);
 }
 
 static void bfin_mac_multicast_hash(struct net_device *dev)
@@ -1562,6 +1573,7 @@ static int bfin_mac_open(struct net_device *dev)
                 return ret;
         pr_debug("hardware init finished\n");
 
+        napi_enable(&lp->napi);
         netif_start_queue(dev);
         netif_carrier_on(dev);
 
@@ -1579,6 +1591,7 @@ static int bfin_mac_close(struct net_device *dev)
         pr_debug("%s: %s\n", dev->name, __func__);
 
         netif_stop_queue(dev);
+        napi_disable(&lp->napi);
         netif_carrier_off(dev);
 
         phy_stop(lp->phydev);
@@ -1604,7 +1617,7 @@ static const struct net_device_ops bfin_mac_netdev_ops = {
         .ndo_validate_addr      = eth_validate_addr,
         .ndo_change_mtu         = eth_change_mtu,
 #ifdef CONFIG_NET_POLL_CONTROLLER
-        .ndo_poll_controller    = bfin_mac_poll,
+        .ndo_poll_controller    = bfin_mac_poll_controller,
 #endif
 };
 
@@ -1689,6 +1702,9 @@ static int bfin_mac_probe(struct platform_device *pdev)
         lp->tx_reclaim_timer.data = (unsigned long)lp;
         lp->tx_reclaim_timer.function = tx_reclaim_skb_timeout;
 
+        lp->flags = 0;
+        netif_napi_add(ndev, &lp->napi, bfin_mac_poll, CONFIG_BFIN_RX_DESC_NUM);
+
         spin_lock_init(&lp->lock);
 
         /* now, enable interrupts */
@@ -1723,6 +1739,7 @@ out_err_phc:
 out_err_reg_ndev:
         free_irq(IRQ_MAC_RX, ndev);
 out_err_request_irq:
+        netif_napi_del(&lp->napi);
 out_err_mii_probe:
         mdiobus_unregister(lp->mii_bus);
         mdiobus_free(lp->mii_bus);
@@ -1743,6 +1760,8 @@ static int bfin_mac_remove(struct platform_device *pdev)
 
         unregister_netdev(ndev);
 
+        netif_napi_del(&lp->napi);
+
         free_irq(IRQ_MAC_RX, ndev);
 
         free_netdev(ndev);
diff --git a/drivers/net/ethernet/adi/bfin_mac.h b/drivers/net/ethernet/adi/bfin_mac.h
index 6dec86ac97cd..d1217db70db4 100644
--- a/drivers/net/ethernet/adi/bfin_mac.h
+++ b/drivers/net/ethernet/adi/bfin_mac.h
@@ -26,6 +26,7 @@
 #endif
 
 #define TX_RECLAIM_JIFFIES (HZ / 5)
+#define BFIN_MAC_RX_IRQ_DISABLED        1
 
 struct dma_descriptor {
         struct dma_descriptor *next_dma_desc;
@@ -80,6 +81,8 @@ struct bfin_mac_local {
         int irq_wake_requested;
         struct timer_list tx_reclaim_timer;
         struct net_device *ndev;
+        struct napi_struct napi;
+        unsigned long flags;
 
         /* Data for EMAC_VLAN1 regs */
         u16 vlan1_mask, vlan2_mask;