LinuxLists.cc - [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

2015-11-10 16:14:46

Subject: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

This adds a driver for the Aurora VLSI NB8800 Ethernet controller.
It is an almost complete rewrite of a driver originally found in
a Sigma Designs 2.6.22 tree.

Signed-off-by: Mans Rullgard <[email protected]>
---
Changes:
- Refactored mdio access functions
- Refactored register access helpers
- Improved error handling in rx buffer allocation
- Optimised some fifo parameters
- Overhauled tx dma. Multiple packets are now chained in a single dma
operation if xmit_more is set, improving performance.
- Improved rx irq handling. It's not possible to disable interrupts
entirely for napi poll, but they can be slowed down a little.
- Use readx_poll_timeout in various places
- Improved error detection
- Improved statistics
- Report hardware statistics counters through ethtool
- Improved tangox-specific setup
- Support for flow control using pause frames
- Explanatory comments added
- Various minor stylistic changes
---
drivers/net/ethernet/Kconfig | 1 +
drivers/net/ethernet/Makefile | 1 +
drivers/net/ethernet/aurora/Kconfig | 20 +
drivers/net/ethernet/aurora/Makefile | 1 +
drivers/net/ethernet/aurora/nb8800.c | 1530 ++++++++++++++++++++++++++++++++++
drivers/net/ethernet/aurora/nb8800.h | 314 +++++++
6 files changed, 1867 insertions(+)
create mode 100644 drivers/net/ethernet/aurora/Kconfig
create mode 100644 drivers/net/ethernet/aurora/Makefile
create mode 100644 drivers/net/ethernet/aurora/nb8800.c
create mode 100644 drivers/net/ethernet/aurora/nb8800.h

diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
index 05aa759..8310163 100644
--- a/drivers/net/ethernet/Kconfig
+++ b/drivers/net/ethernet/Kconfig
@@ -29,6 +29,7 @@ source "drivers/net/ethernet/apm/Kconfig"
source "drivers/net/ethernet/apple/Kconfig"
source "drivers/net/ethernet/arc/Kconfig"
source "drivers/net/ethernet/atheros/Kconfig"
+source "drivers/net/ethernet/aurora/Kconfig"
source "drivers/net/ethernet/cadence/Kconfig"
source "drivers/net/ethernet/adi/Kconfig"
source "drivers/net/ethernet/broadcom/Kconfig"
diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
index ddfc808..b435fb0 100644
--- a/drivers/net/ethernet/Makefile
+++ b/drivers/net/ethernet/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_NET_XGENE) += apm/
obj-$(CONFIG_NET_VENDOR_APPLE) += apple/
obj-$(CONFIG_NET_VENDOR_ARC) += arc/
obj-$(CONFIG_NET_VENDOR_ATHEROS) += atheros/
+obj-$(CONFIG_NET_VENDOR_AURORA) += aurora/
obj-$(CONFIG_NET_CADENCE) += cadence/
obj-$(CONFIG_NET_BFIN) += adi/
obj-$(CONFIG_NET_VENDOR_BROADCOM) += broadcom/
diff --git a/drivers/net/ethernet/aurora/Kconfig b/drivers/net/ethernet/aurora/Kconfig
new file mode 100644
index 0000000..a3c7106
--- /dev/null
+++ b/drivers/net/ethernet/aurora/Kconfig
@@ -0,0 +1,20 @@
+config NET_VENDOR_AURORA
+ bool "Aurora VLSI devices"
+ help
+ If you have a network (Ethernet) device belonging to this class,
+ say Y.
+
+ Note that the answer to this question doesn't directly affect the
+ kernel: saying N will just cause the configurator to skip all
+ questions about Aurora devices. If you say Y, you will be asked
+ for your specific device in the following questions.
+
+if NET_VENDOR_AURORA
+
+config AURORA_NB8800
+ tristate "Aurora AU-NB8800 support"
+ select PHYLIB
+ help
+ Support for the AU-NB8800 gigabit Ethernet controller.
+
+endif
diff --git a/drivers/net/ethernet/aurora/Makefile b/drivers/net/ethernet/aurora/Makefile
new file mode 100644
index 0000000..6cb528a
--- /dev/null
+++ b/drivers/net/ethernet/aurora/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_AURORA_NB8800) += nb8800.o
diff --git a/drivers/net/ethernet/aurora/nb8800.c b/drivers/net/ethernet/aurora/nb8800.c
new file mode 100644
index 0000000..11cd389
--- /dev/null
+++ b/drivers/net/ethernet/aurora/nb8800.c
@@ -0,0 +1,1530 @@
+/*
+ * Copyright (C) 2015 Mans Rullgard <[email protected]>
+ *
+ * Mostly rewritten, based on driver from Sigma Designs. Original
+ * copyright notice below.
+ *
+ *
+ * Driver for tangox SMP864x/SMP865x/SMP867x/SMP868x builtin Ethernet Mac.
+ *
+ * Copyright (C) 2005 Maxime Bizon <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/etherdevice.h>
+#include <linux/delay.h>
+#include <linux/ethtool.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+#include <linux/dma-mapping.h>
+#include <linux/phy.h>
+#include <linux/cache.h>
+#include <linux/jiffies.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <asm/barrier.h>
+
+#include "nb8800.h"
+
+static int nb8800_dma_stop(struct net_device *dev);
+
+static inline u8 nb8800_readb(struct nb8800_priv *priv, int reg)
+{
+ return readb(priv->base + reg);
+}
+
+static inline u32 nb8800_readl(struct nb8800_priv *priv, int reg)
+{
+ return readl(priv->base + reg);
+}
+
+static inline void nb8800_writeb(struct nb8800_priv *priv, int reg, u8 val)
+{
+ writeb(val, priv->base + reg);
+}
+
+static inline void nb8800_writew(struct nb8800_priv *priv, int reg, u16 val)
+{
+ writew(val, priv->base + reg);
+}
+
+static inline void nb8800_writel(struct nb8800_priv *priv, int reg, u32 val)
+{
+ writel(val, priv->base + reg);
+}
+
+static inline void nb8800_maskb(struct nb8800_priv *priv, int reg,
+ u32 mask, u32 val)
+{
+ u32 old = nb8800_readb(priv, reg);
+ u32 new = (old & ~mask) | val;
+ if (new != old)
+ nb8800_writeb(priv, reg, new);
+}
+
+static inline void nb8800_maskl(struct nb8800_priv *priv, int reg,
+ u32 mask, u32 val)
+{
+ u32 old = nb8800_readl(priv, reg);
+ u32 new = (old & ~mask) | val;
+ if (new != old)
+ nb8800_writel(priv, reg, new);
+}
+
+static inline void nb8800_modb(struct nb8800_priv *priv, int reg, u8 bits,
+ bool set)
+{
+ nb8800_maskb(priv, reg, bits, set ? bits : 0);
+}
+
+static inline void nb8800_setb(struct nb8800_priv *priv, int reg, u8 bits)
+{
+ nb8800_maskb(priv, reg, bits, bits);
+}
+
+static inline void nb8800_clearb(struct nb8800_priv *priv, int reg, u8 bits)
+{
+ nb8800_maskb(priv, reg, bits, 0);
+}
+
+static inline void nb8800_modl(struct nb8800_priv *priv, int reg, u32 bits,
+ bool set)
+{
+ nb8800_maskl(priv, reg, bits, set ? bits : 0);
+}
+
+static inline void nb8800_setl(struct nb8800_priv *priv, int reg, u32 bits)
+{
+ nb8800_maskl(priv, reg, bits, bits);
+}
+
+static inline void nb8800_clearl(struct nb8800_priv *priv, int reg, u32 bits)
+{
+ nb8800_maskl(priv, reg, bits, 0);
+}
+
+static int nb8800_mdio_wait(struct mii_bus *bus)
+{
+ struct nb8800_priv *priv = bus->priv;
+ u32 val;
+
+ return readl_poll_timeout_atomic(priv->base + NB8800_MDIO_CMD,
+ val, !(val & MDIO_CMD_GO), 1, 1000);
+}
+
+static int nb8800_mdio_cmd(struct mii_bus *bus, u32 cmd)
+{
+ struct nb8800_priv *priv = bus->priv;
+ int err;
+
+ err = nb8800_mdio_wait(bus);
+ if (err)
+ return err;
+
+ nb8800_writel(priv, NB8800_MDIO_CMD, cmd);
+ udelay(10);
+ nb8800_writel(priv, NB8800_MDIO_CMD, cmd | MDIO_CMD_GO);
+
+ return nb8800_mdio_wait(bus);
+}
+
+static int nb8800_mdio_read(struct mii_bus *bus, int phy_id, int reg)
+{
+ struct nb8800_priv *priv = bus->priv;
+ u32 val;
+ int err;
+
+ err = nb8800_mdio_cmd(bus, MIIAR_ADDR(phy_id) | MIIAR_REG(reg));
+ if (err)
+ return err;
+
+ val = nb8800_readl(priv, NB8800_MDIO_STS);
+ if (val & MDIO_STS_ERR)
+ return 0xffff;
+
+ return val & 0xffff;
+}
+
+static int nb8800_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
+{
+ u32 cmd = MIIAR_DATA(val) | MIIAR_ADDR(phy_id) | MIIAR_REG(reg) |
+ MDIO_CMD_WR;
+
+ return nb8800_mdio_cmd(bus, cmd);
+}
+
+static void nb8800_mac_tx(struct net_device *dev, bool enable)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ while (nb8800_readl(priv, NB8800_TXC_CR) & TCR_EN)
+ cpu_relax();
+
+ nb8800_modb(priv, NB8800_TX_CTL1, TX_EN, enable);
+}
+
+static void nb8800_mac_rx(struct net_device *dev, bool enable)
+{
+ nb8800_modb(netdev_priv(dev), NB8800_RX_CTL, RX_EN, enable);
+}
+
+static void nb8800_mac_af(struct net_device *dev, bool enable)
+{
+ nb8800_modb(netdev_priv(dev), NB8800_RX_CTL, RX_AF_EN, enable);
+}
+
+static void nb8800_start_rx(struct net_device *dev)
+{
+ nb8800_setl(netdev_priv(dev), NB8800_RXC_CR, RCR_EN);
+}
+
+static int nb8800_alloc_rx(struct net_device *dev, int i, bool napi)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct nb8800_rx_desc *rxd = &priv->rx_descs[i];
+ struct nb8800_rx_buf *rxb = &priv->rx_bufs[i];
+ int size = L1_CACHE_ALIGN(RX_BUF_SIZE);
+ dma_addr_t dma_addr;
+ struct page *page;
+ unsigned long offset;
+ void *data;
+
+ data = napi ? napi_alloc_frag(size) : netdev_alloc_frag(size);
+ if (!data)
+ return -ENOMEM;
+
+ page = virt_to_head_page(data);
+ offset = data - page_address(page);
+
+ dma_addr = dma_map_page(&dev->dev, page, offset, RX_BUF_SIZE,
+ DMA_FROM_DEVICE);
+
+ if (dma_mapping_error(&dev->dev, dma_addr)) {
+ skb_free_frag(data);
+ return -ENOMEM;
+ }
+
+ rxb->page = page;
+ rxb->offset = offset;
+ rxd->desc.s_addr = dma_addr;
+
+ return 0;
+}
+
+static void nb8800_receive(struct net_device *dev, int i, int len)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct nb8800_rx_desc *rxd = &priv->rx_descs[i];
+ struct page *page = priv->rx_bufs[i].page;
+ int offset = priv->rx_bufs[i].offset;
+ void *data = page_address(page) + offset;
+ dma_addr_t dma = rxd->desc.s_addr;
+ struct sk_buff *skb;
+ int size;
+ int err;
+
+ size = len <= RX_COPYBREAK ? len : RX_COPYHDR;
+
+ skb = napi_alloc_skb(&priv->napi, size);
+ if (!skb) {
+ netdev_err(dev, "rx skb allocation failed\n");
+ dev->stats.rx_dropped++;
+ return;
+ }
+
+ if (len <= RX_COPYBREAK) {
+ dma_sync_single_for_cpu(&dev->dev, dma, len, DMA_FROM_DEVICE);
+ memcpy(skb_put(skb, len), data, len);
+ dma_sync_single_for_device(&dev->dev, dma, len,
+ DMA_FROM_DEVICE);
+ } else {
+ err = nb8800_alloc_rx(dev, i, true);
+ if (err) {
+ netdev_err(dev, "rx buffer allocation failed\n");
+ dev->stats.rx_dropped++;
+ return;
+ }
+
+ dma_unmap_page(&dev->dev, dma, RX_BUF_SIZE, DMA_FROM_DEVICE);
+ memcpy(skb_put(skb, RX_COPYHDR), data, RX_COPYHDR);
+ skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
+ offset + RX_COPYHDR, len - RX_COPYHDR,
+ RX_BUF_SIZE);
+ }
+
+ skb->protocol = eth_type_trans(skb, dev);
+ netif_receive_skb(skb);
+}
+
+static void nb8800_rx_error(struct net_device *dev, u32 report)
+{
+ if (report & RX_LENGTH_ERR)
+ dev->stats.rx_length_errors++;
+
+ if (report & RX_FCS_ERR)
+ dev->stats.rx_crc_errors++;
+
+ if (report & RX_FIFO_OVERRUN)
+ dev->stats.rx_fifo_errors++;
+
+ if (report & RX_ALIGNMENT_ERROR)
+ dev->stats.rx_frame_errors++;
+
+ dev->stats.rx_errors++;
+}
+
+static int nb8800_poll(struct napi_struct *napi, int budget)
+{
+ struct net_device *dev = napi->dev;
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct nb8800_rx_desc *rxd;
+ int work = 0;
+ int last = priv->rx_eoc;
+ int next;
+
+again:
+ while (work < budget) {
+ struct nb8800_rx_buf *rxb;
+ int len;
+
+ next = (last + 1) % RX_DESC_COUNT;
+
+ rxb = &priv->rx_bufs[next];
+ rxd = &priv->rx_descs[next];
+
+ if (!rxd->report)
+ break;
+
+ len = RX_BYTES_TRANSFERRED(rxd->report);
+
+ if (IS_RX_ERROR(rxd->report))
+ nb8800_rx_error(dev, rxd->report);
+ else
+ nb8800_receive(dev, next, len);
+
+ dev->stats.rx_packets++;
+ dev->stats.rx_bytes += len;
+
+ if (rxd->report & RX_MULTICAST_PKT)
+ dev->stats.multicast++;
+
+ rxd->report = 0;
+ last = next;
+ work++;
+ }
+
+ if (work) {
+ priv->rx_descs[last].desc.config |= DESC_EOC;
+ wmb(); /* ensure new EOC is written before clearing old */
+ priv->rx_descs[priv->rx_eoc].desc.config &= ~DESC_EOC;
+ priv->rx_eoc = last;
+ nb8800_start_rx(dev);
+ }
+
+ if (work < budget) {
+ nb8800_writel(priv, NB8800_RX_ITR, priv->rx_itr_irq);
+
+ /* If a packet arrived after we last checked but
+ * before writing RX_ITR, the interrupt will be
+ * delayed, so we retrieve it now. */
+ if (priv->rx_descs[next].report)
+ goto again;
+
+ napi_complete_done(napi, work);
+ }
+
+ return work;
+}
+
+static void nb8800_tx_dma_start(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct nb8800_tx_buf *txb;
+ u32 txc_cr;
+
+ txb = &priv->tx_bufs[priv->tx_queue];
+ if (!txb->ready)
+ return;
+
+ txc_cr = nb8800_readl(priv, NB8800_TXC_CR);
+ if (txc_cr & TCR_EN)
+ return;
+
+ nb8800_writel(priv, NB8800_TX_DESC_ADDR, txb->dma_desc);
+ wmb(); /* ensure desc addr is written before starting DMA */
+ nb8800_writel(priv, NB8800_TXC_CR, txc_cr | TCR_EN);
+
+ priv->tx_queue = (priv->tx_queue + txb->chain_len) % TX_DESC_COUNT;
+}
+
+static void nb8800_tx_dma_start_irq(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ spin_lock(&priv->tx_lock);
+ nb8800_tx_dma_start(dev);
+ spin_unlock(&priv->tx_lock);
+}
+
+static int nb8800_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct nb8800_tx_desc *txd;
+ struct nb8800_tx_buf *txb;
+ struct nb8800_dma_desc *dma;
+ dma_addr_t dma_addr;
+ unsigned int dma_len;
+ unsigned long flags;
+ int align;
+ int next;
+
+ if (atomic_read(&priv->tx_free) <= NB8800_DESC_LOW) {
+ netif_stop_queue(dev);
+ return NETDEV_TX_BUSY;
+ }
+
+ align = (8 - (uintptr_t)skb->data) & 7;
+
+ dma_len = skb->len - align;
+ dma_addr = dma_map_single(&dev->dev, skb->data + align,
+ dma_len, DMA_TO_DEVICE);
+
+ if (dma_mapping_error(&dev->dev, dma_addr)) {
+ netdev_err(dev, "tx dma mapping error\n");
+ kfree_skb(skb);
+ dev->stats.tx_dropped++;
+ return NETDEV_TX_OK;
+ }
+
+ if (atomic_dec_return(&priv->tx_free) <= NB8800_DESC_LOW)
+ netif_stop_queue(dev);
+
+ next = priv->tx_next;
+ txb = &priv->tx_bufs[next];
+ txd = &priv->tx_descs[next];
+ dma = &txd->desc[0];
+
+ next = (next + 1) % TX_DESC_COUNT;
+
+ if (align) {
+ memcpy(txd->buf, skb->data, align);
+
+ dma->s_addr =
+ txb->dma_desc + offsetof(struct nb8800_tx_desc, buf);
+ dma->n_addr = txb->dma_desc + sizeof(txd->desc[0]);
+ dma->config = DESC_BTS(2) | DESC_DS | align;
+
+ dma++;
+ }
+
+ dma->s_addr = dma_addr;
+ dma->n_addr = priv->tx_bufs[next].dma_desc;
+ dma->config = DESC_BTS(2) | DESC_DS | DESC_EOF | dma_len;
+
+ if (!skb->xmit_more)
+ dma->config |= DESC_EOC;
+
+ txb->skb = skb;
+ txb->dma_addr = dma_addr;
+ txb->dma_len = dma_len;
+
+ if (!priv->tx_chain) {
+ txb->chain_len = 1;
+ priv->tx_chain = txb;
+ } else {
+ priv->tx_chain->chain_len++;
+ }
+
+ netdev_sent_queue(dev, skb->len);
+
+ smp_mb__before_spinlock();
+ spin_lock_irqsave(&priv->tx_lock, flags);
+
+ if (!skb->xmit_more) {
+ priv->tx_chain->ready = true;
+ priv->tx_chain = NULL;
+ nb8800_tx_dma_start(dev);
+ }
+
+ spin_unlock_irqrestore(&priv->tx_lock, flags);
+
+ priv->tx_next = next;
+
+ return NETDEV_TX_OK;
+}
+
+static void nb8800_tx_error(struct net_device *dev, u32 report)
+{
+ if (report & TX_LATE_COLLISION)
+ dev->stats.collisions++;
+
+ if (report & TX_PACKET_DROPPED)
+ dev->stats.tx_dropped++;
+
+ if (report & TX_FIFO_UNDERRUN)
+ dev->stats.tx_fifo_errors++;
+
+ dev->stats.tx_errors++;
+}
+
+static void nb8800_tx_done(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ int limit = priv->tx_next;
+ int done = priv->tx_done;
+ unsigned int packets = 0;
+ unsigned int len = 0;
+
+ while (done != limit) {
+ struct nb8800_tx_desc *txd = &priv->tx_descs[done];
+ struct nb8800_tx_buf *txb = &priv->tx_bufs[done];
+ struct sk_buff *skb;
+
+ if (!txd->report)
+ break;
+
+ skb = txb->skb;
+ len += skb->len;
+
+ dma_unmap_single(&dev->dev, txb->dma_addr, txb->dma_len,
+ DMA_TO_DEVICE);
+
+ if (IS_TX_ERROR(txd->report)) {
+ nb8800_tx_error(dev, txd->report);
+ dev_kfree_skb_irq(skb);
+ } else {
+ dev_consume_skb_irq(skb);
+ }
+
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += TX_BYTES_TRANSFERRED(txd->report);
+ dev->stats.collisions += TX_EARLY_COLLISIONS(txd->report);
+
+ txb->skb = NULL;
+ txb->ready = false;
+ txd->report = 0;
+
+ done = (done + 1) % TX_DESC_COUNT;
+ packets++;
+ }
+
+ if (packets) {
+ smp_mb__before_atomic();
+ atomic_add(packets, &priv->tx_free);
+ netdev_completed_queue(dev, packets, len);
+ netif_wake_queue(dev);
+ priv->tx_done = done;
+ }
+}
+
+static irqreturn_t nb8800_irq(int irq, void *dev_id)
+{
+ struct net_device *dev = dev_id;
+ struct nb8800_priv *priv = netdev_priv(dev);
+ u32 val;
+
+ /* tx interrupt */
+ val = nb8800_readl(priv, NB8800_TXC_SR);
+ if (val) {
+ nb8800_writel(priv, NB8800_TXC_SR, val);
+
+ if (val & TSR_DI)
+ nb8800_tx_dma_start_irq(dev);
+
+ if (val & TSR_TI)
+ nb8800_tx_done(dev);
+
+ if (unlikely(val & TSR_DE))
+ netdev_err(dev, "TX DMA error\n");
+
+ /* should never happen with automatic status retrieval */
+ if (unlikely(val & TSR_TO))
+ netdev_err(dev, "TX Status FIFO overflow\n");
+ }
+
+ /* rx interrupt */
+ val = nb8800_readl(priv, NB8800_RXC_SR);
+ if (val) {
+ nb8800_writel(priv, NB8800_RXC_SR, val);
+
+ if (likely(val & (RSR_RI | RSR_DI))) {
+ nb8800_writel(priv, NB8800_RX_ITR, priv->rx_itr_poll);
+ napi_schedule_irqoff(&priv->napi);
+ }
+
+ if (unlikely(val & RSR_DE))
+ netdev_err(dev, "RX DMA error\n");
+
+ /* should never happen with automatic status retrieval */
+ if (unlikely(val & RSR_RO))
+ netdev_err(dev, "RX Status FIFO overflow\n");
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void nb8800_mac_config(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ bool gigabit = priv->speed == SPEED_1000;
+ u32 mac_mode_mask = RGMII_MODE | HALF_DUPLEX | GMAC_MODE;
+ u32 mac_mode = 0;
+ u32 slot_time;
+ u32 phy_clk;
+ u32 ict;
+
+ if (!priv->duplex)
+ mac_mode |= HALF_DUPLEX;
+
+ if (gigabit) {
+ if (priv->phy_mode == PHY_INTERFACE_MODE_RGMII)
+ mac_mode |= RGMII_MODE;
+
+ mac_mode |= GMAC_MODE;
+ phy_clk = 125000000;
+
+ /* Should be 512 but register is only 8 bits */
+ slot_time = 255;
+ } else {
+ phy_clk = 25000000;
+ slot_time = 128;
+ }
+
+ ict = DIV_ROUND_UP(phy_clk, clk_get_rate(priv->clk));
+
+ nb8800_writeb(priv, NB8800_IC_THRESHOLD, ict);
+ nb8800_writeb(priv, NB8800_SLOT_TIME, slot_time);
+ nb8800_maskb(priv, NB8800_MAC_MODE, mac_mode_mask, mac_mode);
+}
+
+static void nb8800_pause_config(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct phy_device *phydev = priv->phydev;
+ u32 rxcr;
+
+ if (priv->pause_aneg) {
+ if (!phydev || !phydev->link)
+ return;
+
+ priv->pause_rx = phydev->pause;
+ priv->pause_tx = phydev->pause ^ phydev->asym_pause;
+ }
+
+ nb8800_modb(priv, NB8800_RX_CTL, RX_PAUSE_EN, priv->pause_rx);
+
+ rxcr = nb8800_readl(priv, NB8800_RXC_CR);
+ if (!!(rxcr & RCR_FL) == priv->pause_tx)
+ return;
+
+ if (netif_running(dev)) {
+ napi_disable(&priv->napi);
+ netif_tx_lock_bh(dev);
+ nb8800_dma_stop(dev);
+ nb8800_modl(priv, NB8800_RXC_CR, RCR_FL, priv->pause_tx);
+ nb8800_start_rx(dev);
+ netif_tx_unlock_bh(dev);
+ napi_enable(&priv->napi);
+ } else {
+ nb8800_modl(priv, NB8800_RXC_CR, RCR_FL, priv->pause_tx);
+ }
+}
+
+static void nb8800_link_reconfigure(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct phy_device *phydev = priv->phydev;
+ int change = 0;
+
+ if (phydev->link) {
+ if (phydev->speed != priv->speed) {
+ priv->speed = phydev->speed;
+ change = 1;
+ }
+
+ if (phydev->duplex != priv->duplex) {
+ priv->duplex = phydev->duplex;
+ change = 1;
+ }
+
+ if (change)
+ nb8800_mac_config(dev);
+
+ nb8800_pause_config(dev);
+ }
+
+ if (phydev->link != priv->link) {
+ priv->link = phydev->link;
+ change = 1;
+ }
+
+ if (change)
+ phy_print_status(priv->phydev);
+}
+
+static void nb8800_update_mac_addr(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ int i;
+
+ for (i = 0; i < ETH_ALEN; i++)
+ nb8800_writeb(priv, NB8800_SRC_ADDR(i), dev->dev_addr[i]);
+
+ for (i = 0; i < ETH_ALEN; i++)
+ nb8800_writeb(priv, NB8800_UC_ADDR(i), dev->dev_addr[i]);
+}
+
+static int nb8800_set_mac_address(struct net_device *dev, void *addr)
+{
+ struct sockaddr *sock = addr;
+
+ if (netif_running(dev))
+ return -EBUSY;
+
+ ether_addr_copy(dev->dev_addr, sock->sa_data);
+ nb8800_update_mac_addr(dev);
+
+ return 0;
+}
+
+static void nb8800_mc_init(struct net_device *dev, int val)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ nb8800_writeb(priv, NB8800_MC_INIT, val);
+ readb_poll_timeout_atomic(priv->base + NB8800_MC_INIT, val, !val,
+ 1, 1000);
+}
+
+static void nb8800_set_rx_mode(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct netdev_hw_addr *ha;
+ int i;
+
+ if (dev->flags & (IFF_PROMISC | IFF_ALLMULTI)) {
+ nb8800_mac_af(dev, false);
+ return;
+ }
+
+ nb8800_mac_af(dev, true);
+ nb8800_mc_init(dev, 0);
+
+ netdev_for_each_mc_addr(ha, dev) {
+ for (i = 0; i < ETH_ALEN; i++)
+ nb8800_writeb(priv, NB8800_MC_ADDR(i), ha->addr[i]);
+
+ nb8800_mc_init(dev, 0xff);
+ }
+}
+
+#define RX_DESC_SIZE (RX_DESC_COUNT * sizeof(struct nb8800_rx_desc))
+#define TX_DESC_SIZE (TX_DESC_COUNT * sizeof(struct nb8800_tx_desc))
+
+static void nb8800_dma_free(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ int i;
+
+ if (priv->rx_bufs) {
+ for (i = 0; i < RX_DESC_COUNT; i++)
+ if (priv->rx_bufs[i].page)
+ put_page(priv->rx_bufs[i].page);
+
+ kfree(priv->rx_bufs);
+ priv->rx_bufs = NULL;
+ }
+
+ if (priv->tx_bufs) {
+ for (i = 0; i < TX_DESC_COUNT; i++)
+ kfree_skb(priv->tx_bufs[i].skb);
+
+ kfree(priv->tx_bufs);
+ priv->tx_bufs = NULL;
+ }
+
+ if (priv->rx_descs) {
+ dma_free_coherent(dev->dev.parent, RX_DESC_SIZE, priv->rx_descs,
+ priv->rx_desc_dma);
+ priv->rx_descs = NULL;
+ }
+
+ if (priv->tx_descs) {
+ dma_free_coherent(dev->dev.parent, TX_DESC_SIZE, priv->tx_descs,
+ priv->tx_desc_dma);
+ priv->tx_descs = NULL;
+ }
+}
+
+static void nb8800_dma_reset(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct nb8800_rx_desc *rxd;
+ struct nb8800_tx_desc *txd;
+ int i;
+
+ for (i = 0; i < RX_DESC_COUNT; i++) {
+ dma_addr_t rx_dma = priv->rx_desc_dma + i * sizeof(*rxd);
+
+ rxd = &priv->rx_descs[i];
+ rxd->desc.n_addr = rx_dma + sizeof(*rxd);
+ rxd->desc.r_addr =
+ rx_dma + offsetof(struct nb8800_rx_desc, report);
+ rxd->desc.config = priv->rx_dma_config;
+ rxd->report = 0;
+ }
+
+ rxd->desc.n_addr = priv->rx_desc_dma;
+ rxd->desc.config |= DESC_EOC;
+
+ priv->rx_eoc = RX_DESC_COUNT - 1;
+
+ for (i = 0; i < TX_DESC_COUNT; i++) {
+ struct nb8800_tx_buf *txb = &priv->tx_bufs[i];
+ dma_addr_t r_dma = txb->dma_desc +
+ offsetof(struct nb8800_tx_desc, report);
+
+ txd = &priv->tx_descs[i];
+ txd->desc[0].r_addr = r_dma;
+ txd->desc[1].r_addr = r_dma;
+ txd->report = 0;
+ }
+
+ priv->tx_next = 0;
+ priv->tx_queue = 0;
+ priv->tx_done = 0;
+ atomic_set(&priv->tx_free, TX_DESC_COUNT);
+
+ nb8800_writel(priv, NB8800_RX_DESC_ADDR, priv->rx_desc_dma);
+
+ wmb(); /* ensure all setup is written before starting */
+}
+
+static int nb8800_dma_init(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ int n_rx = RX_DESC_COUNT;
+ int n_tx = TX_DESC_COUNT;
+ int err;
+ int i;
+
+ priv->rx_descs = dma_alloc_coherent(dev->dev.parent, RX_DESC_SIZE,
+ &priv->rx_desc_dma, GFP_KERNEL);
+ if (!priv->rx_descs)
+ goto err_out;
+
+ priv->rx_bufs = kcalloc(n_rx, sizeof(*priv->rx_bufs), GFP_KERNEL);
+ if (!priv->rx_bufs)
+ goto err_out;
+
+ for (i = 0; i < n_rx; i++) {
+ err = nb8800_alloc_rx(dev, i, false);
+ if (err)
+ goto err_out;
+ }
+
+ priv->tx_descs = dma_alloc_coherent(dev->dev.parent, TX_DESC_SIZE,
+ &priv->tx_desc_dma, GFP_KERNEL);
+ if (!priv->tx_descs)
+ goto err_out;
+
+ priv->tx_bufs = kcalloc(n_tx, sizeof(*priv->tx_bufs), GFP_KERNEL);
+ if (!priv->tx_bufs)
+ goto err_out;
+
+ for (i = 0; i < n_tx; i++)
+ priv->tx_bufs[i].dma_desc =
+ priv->tx_desc_dma + i * sizeof(struct nb8800_tx_desc);
+
+ nb8800_dma_reset(dev);
+
+ return 0;
+
+err_out:
+ nb8800_dma_free(dev);
+
+ return -ENOMEM;
+}
+
+static int nb8800_dma_stop(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ struct nb8800_tx_buf *txb = &priv->tx_bufs[0];
+ struct nb8800_tx_desc *txd = &priv->tx_descs[0];
+ int retry = 5;
+ u32 txcr;
+ u32 rxcr;
+ int err;
+ int i;
+
+ /* wait for tx to finish */
+ err = readl_poll_timeout_atomic(priv->base + NB8800_TXC_CR, txcr,
+ !(txcr & TCR_EN) &&
+ priv->tx_done == priv->tx_next,
+ 1000, 1000000);
+ if (err)
+ return err;
+
+ /* The rx DMA only stops if it reaches the end of chain.
+ * To make this happen, we set the EOC flag on all rx
+ * descriptors, put the device in loopback mode, and send
+ * a few dummy frames. The interrupt handler will ignore
+ * these since NAPI is disabled and no real frames are in
+ * the tx queue. */
+
+ for (i = 0; i < RX_DESC_COUNT; i++)
+ priv->rx_descs[i].desc.config |= DESC_EOC;
+
+ txd->desc[0].s_addr =
+ txb->dma_desc + offsetof(struct nb8800_tx_desc, buf);
+ txd->desc[0].config = DESC_BTS(2) | DESC_DS | DESC_EOF | DESC_EOC | 8;
+ memset(txd->buf, 0, sizeof(txd->buf));
+
+ nb8800_mac_af(dev, false);
+ nb8800_setb(priv, NB8800_MAC_MODE, LOOPBACK_EN);
+
+ do {
+ nb8800_writel(priv, NB8800_TX_DESC_ADDR, txb->dma_desc);
+ wmb();
+ nb8800_writel(priv, NB8800_TXC_CR, txcr | TCR_EN);
+
+ err = readl_poll_timeout_atomic(priv->base + NB8800_RXC_CR,
+ rxcr, !(rxcr & RCR_EN),
+ 1000, 100000);
+ } while (err && --retry);
+
+ nb8800_mac_af(dev, true);
+ nb8800_clearb(priv, NB8800_MAC_MODE, LOOPBACK_EN);
+ nb8800_dma_reset(dev);
+
+ return retry ? 0 : -ETIMEDOUT;
+}
+
+static void nb8800_pause_adv(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ u32 adv = 0;
+
+ if (!priv->phydev)
+ return;
+
+ if (priv->pause_rx)
+ adv |= ADVERTISED_Pause | ADVERTISED_Asym_Pause;
+ if (priv->pause_tx)
+ adv ^= ADVERTISED_Asym_Pause;
+
+ priv->phydev->supported |= adv;
+ priv->phydev->advertising |= adv;
+
+}
+
+static int nb8800_open(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ int err;
+
+ /* clear any pending interrupts */
+ nb8800_writel(priv, NB8800_RXC_SR, 0xf);
+ nb8800_writel(priv, NB8800_TXC_SR, 0xf);
+
+ err = nb8800_dma_init(dev);
+ if (err)
+ return err;
+
+ err = request_irq(dev->irq, nb8800_irq, 0, dev_name(&dev->dev), dev);
+ if (err)
+ goto err_free_dma;
+
+ nb8800_mac_rx(dev, true);
+ nb8800_mac_tx(dev, true);
+
+ priv->phydev = of_phy_connect(dev, priv->phy_node,
+ nb8800_link_reconfigure, 0,
+ priv->phy_mode);
+ if (!priv->phydev)
+ goto err_free_irq;
+
+ nb8800_pause_adv(dev);
+
+ netdev_reset_queue(dev);
+ napi_enable(&priv->napi);
+ netif_start_queue(dev);
+
+ nb8800_start_rx(dev);
+ phy_start(priv->phydev);
+
+ return 0;
+
+err_free_irq:
+ free_irq(dev->irq, dev);
+err_free_dma:
+ nb8800_dma_free(dev);
+
+ return err;
+}
+
+static int nb8800_stop(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ phy_stop(priv->phydev);
+
+ netif_stop_queue(dev);
+ napi_disable(&priv->napi);
+
+ nb8800_dma_stop(dev);
+ nb8800_mac_rx(dev, false);
+ nb8800_mac_tx(dev, false);
+
+ phy_disconnect(priv->phydev);
+ priv->phydev = NULL;
+
+ free_irq(dev->irq, dev);
+
+ nb8800_dma_free(dev);
+
+ return 0;
+}
+
+static int nb8800_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ return phy_mii_ioctl(priv->phydev, rq, cmd);
+}
+
+static const struct net_device_ops nb8800_netdev_ops = {
+ .ndo_open = nb8800_open,
+ .ndo_stop = nb8800_stop,
+ .ndo_start_xmit = nb8800_xmit,
+ .ndo_set_mac_address = nb8800_set_mac_address,
+ .ndo_set_rx_mode = nb8800_set_rx_mode,
+ .ndo_do_ioctl = nb8800_ioctl,
+ .ndo_change_mtu = eth_change_mtu,
+ .ndo_validate_addr = eth_validate_addr,
+};
+
+static int nb8800_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ if (!priv->phydev)
+ return -ENODEV;
+
+ return phy_ethtool_gset(priv->phydev, cmd);
+}
+
+static int nb8800_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ if (!priv->phydev)
+ return -ENODEV;
+
+ return phy_ethtool_sset(priv->phydev, cmd);
+}
+
+static int nb8800_nway_reset(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ if (!priv->phydev)
+ return -ENODEV;
+
+ return genphy_restart_aneg(priv->phydev);
+}
+
+static void nb8800_get_pauseparam(struct net_device *dev,
+ struct ethtool_pauseparam *pp)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ pp->autoneg = priv->pause_aneg;
+ pp->rx_pause = priv->pause_rx;
+ pp->tx_pause = priv->pause_tx;
+}
+
+static int nb8800_set_pauseparam(struct net_device *dev,
+ struct ethtool_pauseparam *pp)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ priv->pause_aneg = pp->autoneg;
+ priv->pause_rx = pp->rx_pause;
+ priv->pause_tx = pp->tx_pause;
+
+ nb8800_pause_adv(dev);
+
+ if (!priv->pause_aneg)
+ nb8800_pause_config(dev);
+ else if (priv->phydev)
+ phy_start_aneg(priv->phydev);
+
+ return 0;
+}
+
+static const char nb8800_stats_names[][ETH_GSTRING_LEN] = {
+ "rx_bytes_ok",
+ "rx_frames_ok",
+ "rx_undersize_frames",
+ "rx_fragment_frames",
+ "rx_64_byte_frames",
+ "rx_127_byte_frames",
+ "rx_255_byte_frames",
+ "rx_511_byte_frames",
+ "rx_1023_byte_frames",
+ "rx_max_size_frames",
+ "rx_oversize_frames",
+ "rx_bad_fcs_frames",
+ "rx_broadcast_frames",
+ "rx_multicast_frames",
+ "rx_control_frames",
+ "rx_pause_frames",
+ "rx_unsup_control_frames",
+ "rx_align_error_frames",
+ "rx_overrun_frames",
+ "rx_jabber_frames",
+ "rx_bytes",
+ "rx_frames",
+
+ "tx_bytes_ok",
+ "tx_frames_ok",
+ "tx_64_byte_frames",
+ "tx_127_byte_frames",
+ "tx_255_byte_frames",
+ "tx_511_byte_frames",
+ "tx_1023_byte_frames",
+ "tx_max_size_frames",
+ "tx_oversize_frames",
+ "tx_broadcast_frames",
+ "tx_multicast_frames",
+ "tx_control_frames",
+ "tx_pause_frames",
+ "tx_underrun_frames",
+ "tx_single_collision_frames",
+ "tx_multi_collision_frames",
+ "tx_deferred_collision_frames",
+ "tx_late_collision_frames",
+ "tx_excessive_collision_frames",
+ "tx_bytes",
+ "tx_frames",
+ "tx_collisions",
+};
+
+#define NB8800_NUM_STATS ARRAY_SIZE(nb8800_stats_names)
+
+static int nb8800_get_sset_count(struct net_device *dev, int sset)
+{
+ if (sset == ETH_SS_STATS)
+ return NB8800_NUM_STATS;
+
+ return -EOPNOTSUPP;
+}
+
+static void nb8800_get_strings(struct net_device *dev, u32 sset, u8 *buf)
+{
+ if (sset == ETH_SS_STATS)
+ memcpy(buf, &nb8800_stats_names, sizeof(nb8800_stats_names));
+}
+
+static u32 nb8800_read_stat(struct net_device *dev, int index)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+
+ nb8800_writeb(priv, NB8800_STAT_INDEX, index);
+
+ return nb8800_readl(priv, NB8800_STAT_DATA);
+}
+
+static void nb8800_get_ethtool_stats(struct net_device *dev,
+ struct ethtool_stats *estats, u64 *st)
+{
+ u32 rx, tx;
+ int i;
+
+ for (i = 0; i < NB8800_NUM_STATS / 2; i++) {
+ rx = nb8800_read_stat(dev, i);
+ tx = nb8800_read_stat(dev, i | 0x80);
+ st[i] = rx;
+ st[i + NB8800_NUM_STATS / 2] = tx;
+ }
+}
+
+static const struct ethtool_ops nb8800_ethtool_ops = {
+ .get_settings = nb8800_get_settings,
+ .set_settings = nb8800_set_settings,
+ .nway_reset = nb8800_nway_reset,
+ .get_link = ethtool_op_get_link,
+ .get_pauseparam = nb8800_get_pauseparam,
+ .set_pauseparam = nb8800_set_pauseparam,
+ .get_sset_count = nb8800_get_sset_count,
+ .get_strings = nb8800_get_strings,
+ .get_ethtool_stats = nb8800_get_ethtool_stats,
+};
+
+static int nb8800_hw_init(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ u32 val;
+
+ val = TX_RETRY_EN | TX_PAD_EN | TX_APPEND_FCS;
+ nb8800_writeb(priv, NB8800_TX_CTL1, val);
+
+ /* Collision retry count */
+ nb8800_writeb(priv, NB8800_TX_CTL2, 5);
+
+ val = RX_PAD_STRIP | RX_AF_EN;
+ nb8800_writeb(priv, NB8800_RX_CTL, val);
+
+ /* Chosen by fair dice roll */
+ nb8800_writeb(priv, NB8800_RANDOM_SEED, 4);
+
+ /* TX cycles per deferral period */
+ nb8800_writeb(priv, NB8800_TX_SDP, 12);
+
+ /* The following three threshold values have been
+ * experimentally determined for good results. */
+
+ /* RX/TX FIFO threshold for partial empty (64-bit entries) */
+ nb8800_writeb(priv, NB8800_PE_THRESHOLD, 0);
+
+ /* RX/TX FIFO threshold for partial full (64-bit entries) */
+ nb8800_writeb(priv, NB8800_PF_THRESHOLD, 255);
+
+ /* Buffer size for transmit (64-bit entries) */
+ nb8800_writeb(priv, NB8800_TX_BUFSIZE, 64);
+
+ /* Configure tx DMA */
+
+ val = nb8800_readl(priv, NB8800_TXC_CR);
+ val &= TCR_LE; /* keep endian setting */
+ val |= TCR_DM; /* DMA descriptor mode */
+ val |= TCR_RS; /* automatically store tx status */
+ val |= TCR_DIE; /* interrupt on DMA chain completion */
+ val |= TCR_TFI(7); /* interrupt after 7 frames transmitted */
+ val |= TCR_BTS(2); /* 32-byte bus transaction size */
+ nb8800_writel(priv, NB8800_TXC_CR, val);
+
+ /* TX complete interrupt after 10 ms or 7 frames (see above) */
+ val = clk_get_rate(priv->clk) / 100;
+ nb8800_writel(priv, NB8800_TX_ITR, val);
+
+ /* Configure rx DMA */
+
+ val = nb8800_readl(priv, NB8800_RXC_CR);
+ val &= RCR_LE; /* keep endian setting */
+ val |= RCR_DM; /* DMA descriptor mode */
+ val |= RCR_RS; /* automatically store rx status */
+ val |= RCR_DIE; /* interrupt at end of DMA chain */
+ val |= RCR_RFI(7); /* interrupt after 7 frames received */
+ val |= RCR_BTS(2); /* 32-byte bus transaction size */
+ nb8800_writel(priv, NB8800_RXC_CR, val);
+
+ /* The rx interrupt can fire before the DMA has completed
+ * unless a small delay is added. 50 us is hopefully enough. */
+ priv->rx_itr_irq = clk_get_rate(priv->clk) / 20000;
+
+ /* In NAPI poll mode we want to disable interrupts, but the
+ * hardware does not permit this. Delay 10 ms instead. */
+ priv->rx_itr_poll = clk_get_rate(priv->clk) / 100;
+
+ nb8800_writel(priv, NB8800_RX_ITR, priv->rx_itr_irq);
+
+ priv->rx_dma_config = RX_BUF_SIZE | DESC_BTS(2) | DESC_DS | DESC_EOF;
+
+ /* Flow control settings */
+
+ /* Pause time of 0.1 ms */
+ val = 100000 / 512;
+ nb8800_writeb(priv, NB8800_PQ1, val >> 8);
+ nb8800_writeb(priv, NB8800_PQ2, val & 0xff);
+
+ /* Auto-negotiate by default */
+ priv->pause_aneg = true;
+ priv->pause_rx = true;
+ priv->pause_tx = true;
+
+ nb8800_mc_init(dev, 0);
+
+ return 0;
+}
+
+static int nb8800_tangox_init(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ u32 pad_mode = PAD_MODE_MII;
+
+ switch (priv->phy_mode) {
+ case PHY_INTERFACE_MODE_MII:
+ case PHY_INTERFACE_MODE_GMII:
+ pad_mode = PAD_MODE_MII;
+ break;
+
+ case PHY_INTERFACE_MODE_RGMII:
+ pad_mode = PAD_MODE_RGMII;
+ break;
+
+ case PHY_INTERFACE_MODE_RGMII_TXID:
+ pad_mode = PAD_MODE_RGMII | PAD_MODE_GTX_CLK_DELAY;
+ break;
+
+ default:
+ dev_err(dev->dev.parent, "unsupported phy mode %s\n",
+ phy_modes(priv->phy_mode));
+ return -EINVAL;
+ }
+
+ nb8800_writeb(priv, NB8800_TANGOX_PAD_MODE, pad_mode);
+
+ return 0;
+}
+
+static int nb8800_tangox_reset(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ int clk_div;
+
+ nb8800_writeb(priv, NB8800_TANGOX_RESET, 0);
+ usleep_range(1000, 10000);
+ nb8800_writeb(priv, NB8800_TANGOX_RESET, 1);
+
+ wmb(); /* ensure reset is cleared before proceeding */
+
+ clk_div = DIV_ROUND_UP(clk_get_rate(priv->clk), 2 * MAX_MDC_CLOCK);
+ nb8800_writew(priv, NB8800_TANGOX_MDIO_CLKDIV, clk_div);
+
+ return 0;
+}
+
+static const struct nb8800_ops nb8800_tangox_ops = {
+ .init = nb8800_tangox_init,
+ .reset = nb8800_tangox_reset,
+};
+
+static int nb8800_tango4_init(struct net_device *dev)
+{
+ struct nb8800_priv *priv = netdev_priv(dev);
+ int err;
+
+ err = nb8800_tangox_init(dev);
+ if (err)
+ return err;
+
+ /* On tango4 interrupt on DMA completion per frame works and gives
+ * better performance despite generating more rx interrupts. */
+
+ /* Disable unnecessary interrupt on rx completion */
+ nb8800_clearl(priv, NB8800_RXC_CR, RCR_RFI(7));
+
+ /* Request interrupt on descriptor DMA completion */
+ priv->rx_dma_config |= DESC_ID;
+
+ return 0;
+}
+
+static const struct nb8800_ops nb8800_tango4_ops = {
+ .init = nb8800_tango4_init,
+ .reset = nb8800_tangox_reset,
+};
+
+static const struct of_device_id nb8800_dt_ids[] = {
+ {
+ .compatible = "aurora,nb8800",
+ },
+ {
+ .compatible = "sigma,smp8642-ethernet",
+ .data = &nb8800_tangox_ops,
+ },
+ {
+ .compatible = "sigma,smp8734-ethernet",
+ .data = &nb8800_tango4_ops,
+ },
+ { }
+};
+
+static int nb8800_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+ const struct nb8800_ops *ops = NULL;
+ struct nb8800_priv *priv;
+ struct resource *res;
+ struct net_device *dev;
+ struct mii_bus *bus;
+ const unsigned char *mac;
+ void __iomem *base;
+ int irq;
+ int ret;
+
+ match = of_match_device(nb8800_dt_ids, &pdev->dev);
+ if (match)
+ ops = match->data;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq <= 0) {
+ dev_err(&pdev->dev, "No IRQ\n");
+ return -EINVAL;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ dev_dbg(&pdev->dev, "AU-NB8800 Ethernet at %pa\n", &res->start);
+
+ dev = alloc_etherdev(sizeof(*priv));
+ if (!dev)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, dev);
+ SET_NETDEV_DEV(dev, &pdev->dev);
+
+ priv = netdev_priv(dev);
+ priv->base = base;
+
+ priv->phy_mode = of_get_phy_mode(pdev->dev.of_node);
+ if (priv->phy_mode < 0)
+ priv->phy_mode = PHY_INTERFACE_MODE_RGMII;
+
+ priv->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(priv->clk)) {
+ dev_err(&pdev->dev, "failed to get clock\n");
+ ret = PTR_ERR(priv->clk);
+ goto err_free_dev;
+ }
+
+ ret = clk_prepare_enable(priv->clk);
+ if (ret)
+ goto err_free_dev;
+
+ spin_lock_init(&priv->tx_lock);
+
+ if (ops && ops->reset) {
+ ret = ops->reset(dev);
+ if (ret)
+ goto err_free_dev;
+ }
+
+ bus = devm_mdiobus_alloc(&pdev->dev);
+ if (!bus) {
+ ret = -ENOMEM;
+ goto err_disable_clk;
+ }
+
+ bus->name = "nb8800-mii";
+ bus->read = nb8800_mdio_read;
+ bus->write = nb8800_mdio_write;
+ bus->parent = &pdev->dev;
+ snprintf(bus->id, MII_BUS_ID_SIZE, "%lx.nb8800-mii",
+ (unsigned long)res->start);
+ bus->priv = priv;
+
+ ret = of_mdiobus_register(bus, pdev->dev.of_node);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register MII bus\n");
+ goto err_disable_clk;
+ }
+
+ priv->phy_node = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
+ if (!priv->phy_node) {
+ dev_err(&pdev->dev, "no PHY specified\n");
+ ret = -ENODEV;
+ goto err_free_bus;
+ }
+
+ priv->mii_bus = bus;
+
+ ret = nb8800_hw_init(dev);
+ if (ret)
+ goto err_free_bus;
+
+ if (ops && ops->init) {
+ ret = ops->init(dev);
+ if (ret)
+ goto err_free_bus;
+ }
+
+ dev->netdev_ops = &nb8800_netdev_ops;
+ dev->ethtool_ops = &nb8800_ethtool_ops;
+ dev->flags |= IFF_MULTICAST;
+ dev->irq = irq;
+
+ mac = of_get_mac_address(pdev->dev.of_node);
+ if (mac)
+ ether_addr_copy(dev->dev_addr, mac);
+
+ if (!is_valid_ether_addr(dev->dev_addr))
+ eth_hw_addr_random(dev);
+
+ nb8800_update_mac_addr(dev);
+
+ netif_carrier_off(dev);
+
+ ret = register_netdev(dev);
+ if (ret) {
+ netdev_err(dev, "failed to register netdev\n");
+ goto err_free_dma;
+ }
+
+ netif_napi_add(dev, &priv->napi, nb8800_poll, NAPI_POLL_WEIGHT);
+
+ netdev_info(dev, "MAC address %pM\n", dev->dev_addr);
+
+ return 0;
+
+err_free_dma:
+ nb8800_dma_free(dev);
+err_free_bus:
+ mdiobus_unregister(bus);
+err_disable_clk:
+ clk_disable_unprepare(priv->clk);
+err_free_dev:
+ free_netdev(dev);
+
+ return ret;
+}
+
+static int nb8800_remove(struct platform_device *pdev)
+{
+ struct net_device *ndev = platform_get_drvdata(pdev);
+ struct nb8800_priv *priv = netdev_priv(ndev);
+
+ unregister_netdev(ndev);
+
+ mdiobus_unregister(priv->mii_bus);
+
+ clk_disable_unprepare(priv->clk);
+
+ nb8800_dma_free(ndev);
+ free_netdev(ndev);
+
+ return 0;
+}
+
+static struct platform_driver nb8800_driver = {
+ .driver = {
+ .name = "nb8800",
+ .of_match_table = nb8800_dt_ids,
+ },
+ .probe = nb8800_probe,
+ .remove = nb8800_remove,
+};
+
+module_platform_driver(nb8800_driver);
+
+MODULE_DESCRIPTION("Aurora AU-NB8800 Ethernet driver");
+MODULE_AUTHOR("Mans Rullgard <[email protected]>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/net/ethernet/aurora/nb8800.h b/drivers/net/ethernet/aurora/nb8800.h
new file mode 100644
index 0000000..e108d01
--- /dev/null
+++ b/drivers/net/ethernet/aurora/nb8800.h
@@ -0,0 +1,314 @@
+#ifndef _NB8800_H_
+#define _NB8800_H_
+
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <linux/phy.h>
+#include <linux/clk.h>
+#include <linux/bitops.h>
+
+#define RX_DESC_COUNT 256
+#define TX_DESC_COUNT 256
+
+#define NB8800_DESC_LOW 4
+
+#define RX_BUF_SIZE 1552
+
+#define RX_COPYBREAK 256
+#define RX_COPYHDR 128
+
+#define MAX_MDC_CLOCK 2500000
+
+/* Stargate Solutions SSN8800 core registers */
+#define NB8800_TX_CTL1 0x000
+#define TX_TPD BIT(5)
+#define TX_APPEND_FCS BIT(4)
+#define TX_PAD_EN BIT(3)
+#define TX_RETRY_EN BIT(2)
+#define TX_EN BIT(0)
+
+#define NB8800_TX_CTL2 0x001
+
+#define NB8800_RX_CTL 0x004
+#define RX_BC_DISABLE BIT(7)
+#define RX_RUNT BIT(6)
+#define RX_AF_EN BIT(5)
+#define RX_PAUSE_EN BIT(3)
+#define RX_SEND_CRC BIT(2)
+#define RX_PAD_STRIP BIT(1)
+#define RX_EN BIT(0)
+
+#define NB8800_RANDOM_SEED 0x008
+#define NB8800_TX_SDP 0x14
+#define NB8800_TX_TPDP1 0x18
+#define NB8800_TX_TPDP2 0x19
+#define NB8800_SLOT_TIME 0x1c
+
+#define NB8800_MDIO_CMD 0x020
+#define MIIAR_ADDR(x) ((x) << 21)
+#define MIIAR_REG(x) ((x) << 16)
+#define MIIAR_DATA(x) ((x) << 0)
+#define MDIO_CMD_GO BIT(31)
+#define MDIO_CMD_WR BIT(26)
+
+#define NB8800_MDIO_STS 0x024
+#define MDIO_STS_ERR BIT(31)
+
+#define NB8800_MC_ADDR(i) (0x028 + (i))
+#define NB8800_MC_INIT 0x02e
+#define NB8800_UC_ADDR(i) (0x03c + (i))
+
+#define NB8800_MAC_MODE 0x044
+#define RGMII_MODE BIT(7)
+#define HALF_DUPLEX BIT(4)
+#define BURST_EN BIT(3)
+#define LOOPBACK_EN BIT(2)
+#define GMAC_MODE BIT(0)
+
+#define NB8800_IC_THRESHOLD 0x050
+#define NB8800_PE_THRESHOLD 0x051
+#define NB8800_PF_THRESHOLD 0x052
+#define NB8800_TX_BUFSIZE 0x054
+#define NB8800_FIFO_CTL 0x056
+#define NB8800_PQ1 0x060
+#define NB8800_PQ2 0x061
+#define NB8800_SRC_ADDR(i) (0x06a + (i))
+#define NB8800_STAT_DATA 0x078
+#define NB8800_STAT_INDEX 0x07c
+#define NB8800_STAT_CLEAR 0x07d
+
+#define NB8800_SLEEP_MODE 0x07e
+#define SLEEP_MODE BIT(0)
+
+#define NB8800_WAKEUP 0x07f
+#define WAKEUP BIT(0)
+
+/* Aurora NB8800 host interface registers */
+#define NB8800_TXC_CR 0x100
+#define TCR_LK BIT(12)
+#define TCR_DS BIT(11)
+#define TCR_BTS(x) (((x) & 0x7) << 8)
+#define TCR_DIE BIT(7)
+#define TCR_TFI(x) (((x) & 0x7) << 4)
+#define TCR_LE BIT(3)
+#define TCR_RS BIT(2)
+#define TCR_DM BIT(1)
+#define TCR_EN BIT(0)
+
+#define NB8800_TXC_SR 0x104
+#define TSR_DE BIT(3)
+#define TSR_DI BIT(2)
+#define TSR_TO BIT(1)
+#define TSR_TI BIT(0)
+
+#define NB8800_TX_SAR 0x108
+#define NB8800_TX_DESC_ADDR 0x10c
+
+#define NB8800_TX_REPORT_ADDR 0x110
+#define TX_BYTES_TRANSFERRED(x) (((x) >> 16) & 0xffff)
+#define TX_FIRST_DEFERRAL BIT(7)
+#define TX_EARLY_COLLISIONS(x) (((x) >> 3) & 0xf)
+#define TX_LATE_COLLISION BIT(2)
+#define TX_PACKET_DROPPED BIT(1)
+#define TX_FIFO_UNDERRUN BIT(0)
+#define IS_TX_ERROR(r) ((r) & 0x07)
+
+#define NB8800_TX_FIFO_SR 0x114
+#define NB8800_TX_ITR 0x118
+
+#define NB8800_RXC_CR 0x200
+#define RCR_FL BIT(13)
+#define RCR_LK BIT(12)
+#define RCR_DS BIT(11)
+#define RCR_BTS(x) (((x) & 7) << 8)
+#define RCR_DIE BIT(7)
+#define RCR_RFI(x) (((x) & 7) << 4)
+#define RCR_LE BIT(3)
+#define RCR_RS BIT(2)
+#define RCR_DM BIT(1)
+#define RCR_EN BIT(0)
+
+#define NB8800_RXC_SR 0x204
+#define RSR_DE BIT(3)
+#define RSR_DI BIT(2)
+#define RSR_RO BIT(1)
+#define RSR_RI BIT(0)
+
+#define NB8800_RX_SAR 0x208
+#define NB8800_RX_DESC_ADDR 0x20c
+
+#define NB8800_RX_REPORT_ADDR 0x210
+#define RX_BYTES_TRANSFERRED(x) (((x) >> 16) & 0xFFFF)
+#define RX_MULTICAST_PKT BIT(9)
+#define RX_BROADCAST_PKT BIT(8)
+#define RX_LENGTH_ERR BIT(7)
+#define RX_FCS_ERR BIT(6)
+#define RX_RUNT_PKT BIT(5)
+#define RX_FIFO_OVERRUN BIT(4)
+#define RX_LATE_COLLISION BIT(3)
+#define RX_ALIGNMENT_ERROR BIT(2)
+#define RX_ERROR_MASK 0xfc
+#define IS_RX_ERROR(r) ((r) & RX_ERROR_MASK)
+
+#define NB8800_RX_FIFO_SR 0x214
+#define NB8800_RX_ITR 0x218
+
+/* Sigma Designs SMP86xx additional registers */
+#define NB8800_TANGOX_PAD_MODE 0x400
+#define PAD_MODE_MASK 0x7
+#define PAD_MODE_MII 0x0
+#define PAD_MODE_RGMII 0x1
+#define PAD_MODE_GTX_CLK_INV BIT(3)
+#define PAD_MODE_GTX_CLK_DELAY BIT(4)
+
+#define NB8800_TANGOX_MDIO_CLKDIV 0x420
+#define NB8800_TANGOX_RESET 0x424
+
+/* Hardware DMA descriptor */
+struct nb8800_dma_desc {
+ u32 s_addr; /* start address */
+ u32 n_addr; /* next descriptor address */
+ u32 r_addr; /* report address */
+ u32 config;
+} __aligned(8);
+
+#define DESC_ID BIT(23)
+#define DESC_EOC BIT(22)
+#define DESC_EOF BIT(21)
+#define DESC_LK BIT(20)
+#define DESC_DS BIT(19)
+#define DESC_BTS(x) (((x) & 0x7) << 16)
+
+/* DMA descriptor and associated data for rx.
+ * Allocated from coherent memory.
+ */
+struct nb8800_rx_desc {
+ /* DMA descriptor */
+ struct nb8800_dma_desc desc;
+
+ /* Status report filled in by hardware */
+ u32 report;
+};
+
+/* Address of buffer on rx ring */
+struct nb8800_rx_buf {
+ struct page *page;
+ unsigned long offset;
+};
+
+/* DMA descriptors and associated data for tx.
+ * Allocated from coherent memory.
+ */
+struct nb8800_tx_desc {
+ /* DMA descriptor. The second descriptor is used if packet
+ * data is unaligned. */
+ struct nb8800_dma_desc desc[2];
+
+ /* Status report filled in by hardware */
+ u32 report;
+
+ /* Bounce buffer for initial unaligned part of packet */
+ u8 buf[8] __aligned(8);
+};
+
+/* Packet in tx queue */
+struct nb8800_tx_buf {
+ /* Currently queued skb */
+ struct sk_buff *skb;
+
+ /* DMA address of the first descriptor */
+ dma_addr_t dma_desc;
+
+ /* DMA address of packet data */
+ dma_addr_t dma_addr;
+
+ /* Length of DMA mapping, less than skb->len if alignment
+ * buffer is used. */
+ unsigned int dma_len;
+
+ /* Number of packets in chain starting here */
+ unsigned int chain_len;
+
+ /* Packet chain ready to be submitted to hardware */
+ bool ready;
+};
+
+struct nb8800_priv {
+ struct napi_struct napi;
+
+ void __iomem *base;
+
+ /* RX DMA descriptors */
+ struct nb8800_rx_desc *rx_descs;
+
+ /* RX buffers referenced by DMA descriptors */
+ struct nb8800_rx_buf *rx_bufs;
+
+ /* Current end of chain */
+ u32 rx_eoc;
+
+ /* Value for rx interrupt time register in NAPI interrupt mode */
+ u32 rx_itr_irq;
+
+ /* Value for rx interrupt time register in NAPI poll mode */
+ u32 rx_itr_poll;
+
+ /* Value for config field of rx DMA descriptors */
+ u32 rx_dma_config;
+
+ /* TX DMA descriptors */
+ struct nb8800_tx_desc *tx_descs;
+
+ /* TX packet queue */
+ struct nb8800_tx_buf *tx_bufs;
+
+ /* Number of free tx queue entries */
+ atomic_t tx_free;
+
+ /* First free tx queue entry */
+ u32 tx_next;
+
+ /* Next buffer to transmit */
+ u32 tx_queue;
+
+ /* Start of current packet chain */
+ struct nb8800_tx_buf *tx_chain;
+
+ /* Next buffer to reclaim */
+ u32 tx_done;
+
+ /* Lock for DMA activation */
+ spinlock_t tx_lock;
+
+ struct mii_bus *mii_bus;
+ struct device_node *phy_node;
+ struct phy_device *phydev;
+
+ /* PHY connection type from DT */
+ int phy_mode;
+
+ /* Current link status */
+ int speed;
+ int duplex;
+ int link;
+
+ /* Pause settings */
+ bool pause_aneg;
+ bool pause_rx;
+ bool pause_tx;
+
+ /* DMA base address of rx descriptors, see rx_descs above */
+ dma_addr_t rx_desc_dma;
+
+ /* DMA base address of tx descriptors, see tx_descs above */
+ dma_addr_t tx_desc_dma;
+
+ struct clk *clk;
+};
+
+struct nb8800_ops {
+ int (*init)(struct net_device *dev);
+ int (*reset)(struct net_device *dev);
+};
+
+#endif /* _NB8800_H_ */
--
2.6.3

2015-11-10 17:55:50

by Eric Dumazet

[permalink] [raw]

Subject: Re: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

On Tue, 2015-11-10 at 16:14 +0000, Mans Rullgard wrote:
> This adds a driver for the Aurora VLSI NB8800 Ethernet controller.
> It is an almost complete rewrite of a driver originally found in
> a Sigma Designs 2.6.22 tree.

...

> +
> +static void nb8800_receive(struct net_device *dev, int i, int len)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_rx_desc *rxd = &priv->rx_descs[i];
> + struct page *page = priv->rx_bufs[i].page;
> + int offset = priv->rx_bufs[i].offset;
> + void *data = page_address(page) + offset;
> + dma_addr_t dma = rxd->desc.s_addr;
> + struct sk_buff *skb;
> + int size;
> + int err;
> +
> + size = len <= RX_COPYBREAK ? len : RX_COPYHDR;
> +
> + skb = napi_alloc_skb(&priv->napi, size);
> + if (!skb) {
> + netdev_err(dev, "rx skb allocation failed\n");
> + dev->stats.rx_dropped++;
> + return;
> + }
> +
> + if (len <= RX_COPYBREAK) {
> + dma_sync_single_for_cpu(&dev->dev, dma, len, DMA_FROM_DEVICE);
> + memcpy(skb_put(skb, len), data, len);
> + dma_sync_single_for_device(&dev->dev, dma, len,
> + DMA_FROM_DEVICE);
> + } else {
> + err = nb8800_alloc_rx(dev, i, true);
> + if (err) {
> + netdev_err(dev, "rx buffer allocation failed\n");
> + dev->stats.rx_dropped++;
> + return;
> + }
> +
> + dma_unmap_page(&dev->dev, dma, RX_BUF_SIZE, DMA_FROM_DEVICE);
> + memcpy(skb_put(skb, RX_COPYHDR), data, RX_COPYHDR);
> + skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
> + offset + RX_COPYHDR, len - RX_COPYHDR,
> + RX_BUF_SIZE);
> + }
> +
> + skb->protocol = eth_type_trans(skb, dev);
> + netif_receive_skb(skb);
> +}
> +

Any reason you do not use napi_gro_receive(&priv->napi, skb) instead of
netif_receive_skb() ?

I see you correctly use late napi_complete_done(napi, work), but this
matters only if napi_gro_receive() was used.

2015-11-10 17:58:17

by Eric Dumazet

[permalink] [raw]

Subject: Re: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

On Tue, 2015-11-10 at 16:14 +0000, Mans Rullgard wrote:
> This adds a driver for the Aurora VLSI NB8800 Ethernet controller.
> It is an almost complete rewrite of a driver originally found in
> a Sigma Designs 2.6.22 tree.

...

> +
> +static int nb8800_xmit(struct sk_buff *skb, struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_tx_desc *txd;
> + struct nb8800_tx_buf *txb;
> + struct nb8800_dma_desc *dma;
> + dma_addr_t dma_addr;
> + unsigned int dma_len;
> + unsigned long flags;
> + int align;
> + int next;
> +
> + if (atomic_read(&priv->tx_free) <= NB8800_DESC_LOW) {
> + netif_stop_queue(dev);
> + return NETDEV_TX_BUSY;
> + }
> +
> + align = (8 - (uintptr_t)skb->data) & 7;
> +
> + dma_len = skb->len - align;
> + dma_addr = dma_map_single(&dev->dev, skb->data + align,
> + dma_len, DMA_TO_DEVICE);
> +
> + if (dma_mapping_error(&dev->dev, dma_addr)) {
> + netdev_err(dev, "tx dma mapping error\n");
> + kfree_skb(skb);
> + dev->stats.tx_dropped++;
> + return NETDEV_TX_OK;
> + }
> +
> + if (atomic_dec_return(&priv->tx_free) <= NB8800_DESC_LOW)
> + netif_stop_queue(dev);

You probably also want to clear skb->xmit_more or risk a stall

xmit_more is tricky ;)

> +
> + next = priv->tx_next;
> + txb = &priv->tx_bufs[next];
> + txd = &priv->tx_descs[next];
> + dma = &txd->desc[0];
> +
> + next = (next + 1) % TX_DESC_COUNT;
> +
> + if (align) {
> + memcpy(txd->buf, skb->data, align);
> +
> + dma->s_addr =
> + txb->dma_desc + offsetof(struct nb8800_tx_desc, buf);
> + dma->n_addr = txb->dma_desc + sizeof(txd->desc[0]);
> + dma->config = DESC_BTS(2) | DESC_DS | align;
> +
> + dma++;
> + }
> +
> + dma->s_addr = dma_addr;
> + dma->n_addr = priv->tx_bufs[next].dma_desc;
> + dma->config = DESC_BTS(2) | DESC_DS | DESC_EOF | dma_len;
> +
> + if (!skb->xmit_more)
> + dma->config |= DESC_EOC;
> +
> + txb->skb = skb;
> + txb->dma_addr = dma_addr;
> + txb->dma_len = dma_len;
> +
> + if (!priv->tx_chain) {
> + txb->chain_len = 1;
> + priv->tx_chain = txb;
> + } else {
> + priv->tx_chain->chain_len++;
> + }
> +
> + netdev_sent_queue(dev, skb->len);
> +
> + smp_mb__before_spinlock();
> + spin_lock_irqsave(&priv->tx_lock, flags);
> +
> + if (!skb->xmit_more) {
> + priv->tx_chain->ready = true;
> + priv->tx_chain = NULL;
> + nb8800_tx_dma_start(dev);
> + }
> +
> + spin_unlock_irqrestore(&priv->tx_lock, flags);
> +
> + priv->tx_next = next;
> +
> + return NETDEV_TX_OK;
> +}
> +

2015-11-10 18:05:28