[net-next v22 4/7] net: mtip: Add net_device_ops functions to the L2 switch driver
From: Lukasz Majewski <hidden>
Date: 2026-01-31 23:35:50
Also in:
imx, linux-devicetree, lkml
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
This patch provides callbacks for struct net_device_ops for MTIP
L2 switch.
Signed-off-by: Lukasz Majewski <redacted>
---
Changes for v13:
- New patch - created by excluding some code from large (i.e. v12 and
earlier) MTIP driver
Changes for v14:
- Add read memory barier (rmb) before reading current descriptor
- Use proper locking primitives
Changes for v15 - v15:
- None
Changes for v16:
- Enable MTIP ports to support bridge offloading
- Use dev_err_ratelimited() instead of plain dev_err()
- Move skb storage and tx ring buffer modifications after
dma mapping code.
- Do not increase tx_errors when frames are dropped after
failed dma_mapping.
- Refactor the code for better readability
- Remove legacy call to netif_trans_update()
- Remove not needed rmb() - synchronized data read already assured by
coherent DMA allocation
- Replace spin_{un}lock() with _bh variant
Changes for v17:
- Add missing _bh() variant of spin_unlock
- Avoid reverse christmas tree in swap_buffer()
- Print error message after unlock
- Add DO_ONCE() and a separate function to print state of switch HW
- Remove dev->stats.tx_errors++
Changes for v18 - v19:
- None
Changes for v20:
- Perform data swap on SKB data only when it is copied to a separate
buffer.
- Clean up the comment
- Stop both network interfaces' TX queues when no resources for
transmission available (uDMA0 descriptors)
- Do not use fep->skb_cur and fep->tx_full
Changes for v21 - v22:
- None
---
.../net/ethernet/freescale/mtipsw/mtipl2sw.c | 284 ++++++++++++++++++
1 file changed, 284 insertions(+)
diff --git a/drivers/net/ethernet/freescale/mtipsw/mtipl2sw.c b/drivers/net/ethernet/freescale/mtipsw/mtipl2sw.c
index 12df1170e394..28b04713aa0b 100644
--- a/drivers/net/ethernet/freescale/mtipsw/mtipl2sw.c
+++ b/drivers/net/ethernet/freescale/mtipsw/mtipl2sw.c@@ -43,6 +43,15 @@ #include "mtipl2sw.h" +static void swap_buffer(void *bufaddr, int len) +{ + unsigned int *buf = bufaddr; + int i; + + for (i = 0; i < len; i += 4, buf++) + swab32s(buf); +} + /* Set the last buffer to wrap */ static void mtip_set_last_buf_to_wrap(struct cbd_t *bdp) {
@@ -454,6 +463,120 @@ static void mtip_config_switch(struct switch_enet_private *fep) fep->hwp + ESW_IMR); } +static netdev_tx_t mtip_start_xmit_port(struct sk_buff *skb, + struct net_device *dev, int port) +{ + struct mtip_ndev_priv *priv = netdev_priv(dev); + struct switch_enet_private *fep = priv->fep; + unsigned short status; + unsigned int index; + struct cbd_t *bdp; + void *bufaddr; + + spin_lock_bh(&fep->hw_lock); + + if (!fep->link[0] && !fep->link[1]) { + /* Link is down or autonegotiation is in progress. */ + mtip_netif_stop_queues(fep); + spin_unlock_bh(&fep->hw_lock); + return NETDEV_TX_BUSY; + } + + /* Fill in a Tx ring entry */ + bdp = fep->cur_tx; + status = bdp->cbd_sc; + + if (status & BD_ENET_TX_READY) { + /* All transmit buffers are full. Bail out. */ + mtip_netif_stop_queues(fep); + spin_unlock_bh(&fep->hw_lock); + dev_err_ratelimited(&fep->pdev->dev, "%s: tx queue full!.\n", + dev->name); + return NETDEV_TX_BUSY; + } + + /* Clear all of the status flags */ + status &= ~BD_ENET_TX_STATS; + + /* Set buffer length and buffer pointer */ + bufaddr = skb->data; + bdp->cbd_datlen = skb->len; + + index = bdp - fep->tx_bd_base; + /* On some FEC implementations data must be aligned on + * 4-byte boundaries. Use bounce buffers to copy data + * and get it aligned. + */ + if ((unsigned long)bufaddr & MTIP_ALIGNMENT || + fep->quirks & FEC_QUIRK_SWAP_FRAME) { + memcpy(fep->tx_bounce[index], skb->data, skb->len); + bufaddr = fep->tx_bounce[index]; + + if (fep->quirks & FEC_QUIRK_SWAP_FRAME) + swap_buffer(bufaddr, skb->len); + } + + /* Push the data cache so the CPM does not get stale memory + * data. + */ + bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, bufaddr, + MTIP_SWITCH_TX_FRSIZE, + DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr))) { + dev_err(&fep->pdev->dev, + "Failed to map descriptor tx buffer\n"); + dev->stats.tx_dropped++; + dev_kfree_skb_any(skb); + goto err; + } + + /* Save skb pointer. */ + fep->tx_skbuff[index] = skb; + + /* Send it on its way. Tell FEC it's ready, interrupt when done, + * it's the last BD of the frame, and to put the CRC on the end. + */ + + status |= (BD_ENET_TX_READY | BD_ENET_TX_INTR | BD_ENET_TX_LAST | + BD_ENET_TX_TC); + + /* Synchronize all descriptor writes */ + wmb(); + bdp->cbd_sc = status; + + skb_tx_timestamp(skb); + + dev->stats.tx_bytes += skb->len; + /* If this was the last BD in the ring, + * start at the beginning again. + */ + if (status & BD_ENET_TX_WRAP) + bdp = fep->tx_bd_base; + else + bdp++; + + fep->cur_tx = bdp; + /* When TX descriptors' ring buffer is full stop both interfaces */ + if (fep->cur_tx == fep->dirty_tx) + mtip_netif_stop_queues(fep); + + /* Trigger transmission start */ + writel(MCF_ESW_TDAR_X_DES_ACTIVE, fep->hwp + ESW_TDAR); + + err: + spin_unlock_bh(&fep->hw_lock); + + return NETDEV_TX_OK; +} + +static netdev_tx_t mtip_start_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct mtip_ndev_priv *priv = netdev_priv(dev); + + return mtip_start_xmit_port(skb, dev, priv->portnum); +} + static void mtip_configure_enet_mii(struct switch_enet_private *fep, int port) { struct phy_device *phydev = fep->phy_dev[port - 1];
@@ -609,6 +732,74 @@ static void mtip_switch_restart(struct net_device *dev, int duplex0, mtip_config_switch(fep); } +static void mtip_print_hw_state(struct net_device *dev) +{ + struct mtip_ndev_priv *priv = netdev_priv(dev); + struct switch_enet_private *fep = priv->fep; + struct cbd_t *bdp; + bool tx_full; + int i; + + spin_lock_bh(&fep->hw_lock); + tx_full = fep->dirty_tx == fep->cur_tx && + mtip_netif_queues_stopped(fep); + + dev_info(&dev->dev, "%s: transmit timed out.\n", dev->name); + dev_info(&dev->dev, + "Ring data: cur_tx 0x%p%s, dirty_tx 0x%p cur_rx: 0x%p\n", + fep->cur_tx, tx_full ? " (full)" : "", fep->dirty_tx, + fep->cur_rx); + + bdp = fep->tx_bd_base; + dev_info(&dev->dev, " tx: %u buffers\n", TX_RING_SIZE); + for (i = 0; i < TX_RING_SIZE; i++) { + dev_info(&dev->dev, " 0x%p: %04x %04x %08x\n", + bdp, bdp->cbd_sc, bdp->cbd_datlen, + (int)bdp->cbd_bufaddr); + bdp++; + } + + bdp = fep->rx_bd_base; + dev_info(&dev->dev, " rx: %lu buffers\n", RX_RING_SIZE); + for (i = 0 ; i < RX_RING_SIZE; i++) { + dev_info(&dev->dev, " 0x%p: %04x %04x %08x\n", + bdp, bdp->cbd_sc, bdp->cbd_datlen, + (int)bdp->cbd_bufaddr); + bdp++; + } + spin_unlock_bh(&fep->hw_lock); +} + +static void mtip_timeout(struct net_device *dev, unsigned int txqueue) +{ + struct mtip_ndev_priv *priv = netdev_priv(dev); + + dev->stats.tx_errors++; + DO_ONCE(mtip_print_hw_state, dev); + + schedule_work(&priv->tx_timeout_work); +} + +static void mtip_timeout_work(struct work_struct *work) +{ + struct mtip_ndev_priv *priv = + container_of(work, struct mtip_ndev_priv, tx_timeout_work); + struct switch_enet_private *fep = priv->fep; + struct net_device *dev = priv->dev; + + rtnl_lock(); + if (netif_device_present(dev) || netif_running(dev)) { + napi_disable(&fep->napi); + netif_tx_lock_bh(dev); + mtip_switch_restart(dev, fep->full_duplex[0], + fep->full_duplex[1]); + netif_tx_wake_all_queues(dev); + netif_tx_unlock_bh(dev); + napi_enable(&fep->napi); + } + rtnl_unlock(); +} + static irqreturn_t mtip_interrupt(int irq, void *ptr_fep) { struct switch_enet_private *fep = ptr_fep;
@@ -1091,6 +1282,92 @@ static int mtip_close(struct net_device *dev) return 0; } +#define FEC_HASH_BITS 6 /* #bits in hash */ +static void mtip_set_multicast_list(struct net_device *dev) +{ + struct mtip_ndev_priv *priv = netdev_priv(dev); + unsigned int hash_high = 0, hash_low = 0, crc; + struct switch_enet_private *fep = priv->fep; + void __iomem *enet_addr = fep->enet_addr; + struct netdev_hw_addr *ha; + unsigned char hash; + + if (priv->portnum == 2) + enet_addr += MCF_ESW_ENET_PORT_OFFSET; + + if (dev->flags & IFF_PROMISC) { + /* Promisc mode is required for switch - it is + * already enabled during driver's probe. + */ + dev_dbg(&dev->dev, "%s: IFF_PROMISC\n", __func__); + return; + } + + if (dev->flags & IFF_ALLMULTI) { + dev_dbg(&dev->dev, "%s: IFF_ALLMULTI\n", __func__); + + /* Allow all multicast addresses */ + writel(0xFFFFFFFF, enet_addr + MCF_FEC_GRP_HASH_TABLE_HIGH); + writel(0xFFFFFFFF, enet_addr + MCF_FEC_GRP_HASH_TABLE_LOW); + + return; + } + + netdev_for_each_mc_addr(ha, dev) { + /* Calculate crc32 value of mac address */ + crc = ether_crc_le(dev->addr_len, ha->addr); + + /* Only upper 6 bits (FEC_HASH_BITS) are used + * which point to specific bit in the hash registers + */ + hash = (crc >> (32 - FEC_HASH_BITS)) & 0x3F; + + if (hash > 31) + hash_high |= 1 << (hash - 32); + else + hash_low |= 1 << hash; + } + + writel(hash_high, enet_addr + MCF_FEC_GRP_HASH_TABLE_HIGH); + writel(hash_low, enet_addr + MCF_FEC_GRP_HASH_TABLE_LOW); +} + +static int mtip_set_mac_address(struct net_device *dev, void *p) +{ + struct mtip_ndev_priv *priv = netdev_priv(dev); + struct switch_enet_private *fep = priv->fep; + void __iomem *enet_addr = fep->enet_addr; + struct sockaddr *addr = p; + + if (!is_valid_ether_addr(addr->sa_data)) + return -EADDRNOTAVAIL; + eth_hw_addr_set(dev, addr->sa_data); + + if (priv->portnum == 2) + enet_addr += MCF_ESW_ENET_PORT_OFFSET; + + writel(dev->dev_addr[3] | (dev->dev_addr[2] << 8) | + (dev->dev_addr[1] << 16) | (dev->dev_addr[0] << 24), + enet_addr + MCF_FEC_PALR); + writel((dev->dev_addr[5] << 16) | (dev->dev_addr[4] << 24), + enet_addr + MCF_FEC_PAUR); + + return mtip_update_atable_static((unsigned char *)dev->dev_addr, + 7, 7, fep); +} + +static int mtip_get_port_parent_id(struct net_device *ndev, + struct netdev_phys_item_id *ppid) +{ + struct mtip_ndev_priv *priv = netdev_priv(ndev); + struct switch_enet_private *fep = priv->fep; + + ppid->id_len = sizeof(fep->mac[0]); + memcpy(&ppid->id, &fep->mac[0], ppid->id_len); + + return 0; +} + static const struct ethtool_ops mtip_ethtool_ops = { .get_link_ksettings = phy_ethtool_get_link_ksettings, .set_link_ksettings = phy_ethtool_set_link_ksettings,
@@ -1102,6 +1379,11 @@ static const struct ethtool_ops mtip_ethtool_ops = { static const struct net_device_ops mtip_netdev_ops = { .ndo_open = mtip_open, .ndo_stop = mtip_close, + .ndo_start_xmit = mtip_start_xmit, + .ndo_set_rx_mode = mtip_set_multicast_list, + .ndo_tx_timeout = mtip_timeout, + .ndo_set_mac_address = mtip_set_mac_address, + .ndo_get_port_parent_id = mtip_get_port_parent_id, }; bool mtip_is_switch_netdev_port(const struct net_device *ndev)
@@ -1206,6 +1488,8 @@ static int mtip_ndev_init(struct switch_enet_private *fep, goto cleanup_created_ndev; } + INIT_WORK(&priv->tx_timeout_work, mtip_timeout_work); + dev_dbg(&fep->ndev[i]->dev, "%s: MTIP eth L2 switch %pM\n", fep->ndev[i]->name, fep->ndev[i]->dev_addr); }
--
2.39.5