net: lan966x: Update FDMA to change MTU.

When changing the MTU, it is required to change also the size of the
DBs. In case those frames will arrive to CPU.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index f5fdb74..9e2a732 100644 (file)
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -336,6 +336,20 @@ static void lan966x_fdma_wakeup_netdev(struct lan966x *lan966x)
        }
 }
 
+static void lan966x_fdma_stop_netdev(struct lan966x *lan966x)
+{
+       struct lan966x_port *port;
+       int i;
+
+       for (i = 0; i < lan966x->num_phys_ports; ++i) {
+               port = lan966x->ports[i];
+               if (!port)
+                       continue;
+
+               netif_stop_queue(port->dev);
+       }
+}
+
 static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight)
 {
        struct lan966x_tx *tx = &lan966x->tx;
@@ -644,6 +658,126 @@ release:
        return err;
 }
 
+static int lan966x_fdma_get_max_mtu(struct lan966x *lan966x)
+{
+       int max_mtu = 0;
+       int i;
+
+       for (i = 0; i < lan966x->num_phys_ports; ++i) {
+               int mtu;
+
+               if (!lan966x->ports[i])
+                       continue;
+
+               mtu = lan966x->ports[i]->dev->mtu;
+               if (mtu > max_mtu)
+                       max_mtu = mtu;
+       }
+
+       return max_mtu;
+}
+
+static int lan966x_qsys_sw_status(struct lan966x *lan966x)
+{
+       return lan_rd(lan966x, QSYS_SW_STATUS(CPU_PORT));
+}
+
+static int lan966x_fdma_reload(struct lan966x *lan966x, int new_mtu)
+{
+       void *rx_dcbs, *tx_dcbs, *tx_dcbs_buf;
+       dma_addr_t rx_dma, tx_dma;
+       u32 size;
+       int err;
+
+       /* Store these for later to free them */
+       rx_dma = lan966x->rx.dma;
+       tx_dma = lan966x->tx.dma;
+       rx_dcbs = lan966x->rx.dcbs;
+       tx_dcbs = lan966x->tx.dcbs;
+       tx_dcbs_buf = lan966x->tx.dcbs_buf;
+
+       napi_synchronize(&lan966x->napi);
+       napi_disable(&lan966x->napi);
+       lan966x_fdma_stop_netdev(lan966x);
+
+       lan966x_fdma_rx_disable(&lan966x->rx);
+       lan966x_fdma_rx_free_pages(&lan966x->rx);
+       lan966x->rx.page_order = round_up(new_mtu, PAGE_SIZE) / PAGE_SIZE - 1;
+       err = lan966x_fdma_rx_alloc(&lan966x->rx);
+       if (err)
+               goto restore;
+       lan966x_fdma_rx_start(&lan966x->rx);
+
+       size = sizeof(struct lan966x_rx_dcb) * FDMA_DCB_MAX;
+       size = ALIGN(size, PAGE_SIZE);
+       dma_free_coherent(lan966x->dev, size, rx_dcbs, rx_dma);
+
+       lan966x_fdma_tx_disable(&lan966x->tx);
+       err = lan966x_fdma_tx_alloc(&lan966x->tx);
+       if (err)
+               goto restore_tx;
+
+       size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
+       size = ALIGN(size, PAGE_SIZE);
+       dma_free_coherent(lan966x->dev, size, tx_dcbs, tx_dma);
+
+       kfree(tx_dcbs_buf);
+
+       lan966x_fdma_wakeup_netdev(lan966x);
+       napi_enable(&lan966x->napi);
+
+       return err;
+restore:
+       lan966x->rx.dma = rx_dma;
+       lan966x->tx.dma = tx_dma;
+       lan966x_fdma_rx_start(&lan966x->rx);
+
+restore_tx:
+       lan966x->rx.dcbs = rx_dcbs;
+       lan966x->tx.dcbs = tx_dcbs;
+       lan966x->tx.dcbs_buf = tx_dcbs_buf;
+
+       return err;
+}
+
+int lan966x_fdma_change_mtu(struct lan966x *lan966x)
+{
+       int max_mtu;
+       int err;
+       u32 val;
+
+       max_mtu = lan966x_fdma_get_max_mtu(lan966x);
+       max_mtu += IFH_LEN * sizeof(u32);
+
+       if (round_up(max_mtu, PAGE_SIZE) / PAGE_SIZE - 1 ==
+           lan966x->rx.page_order)
+               return 0;
+
+       /* Disable the CPU port */
+       lan_rmw(QSYS_SW_PORT_MODE_PORT_ENA_SET(0),
+               QSYS_SW_PORT_MODE_PORT_ENA,
+               lan966x, QSYS_SW_PORT_MODE(CPU_PORT));
+
+       /* Flush the CPU queues */
+       readx_poll_timeout(lan966x_qsys_sw_status, lan966x,
+                          val, !(QSYS_SW_STATUS_EQ_AVAIL_GET(val)),
+                          READL_SLEEP_US, READL_TIMEOUT_US);
+
+       /* Add a sleep in case there are frames between the queues and the CPU
+        * port
+        */
+       usleep_range(1000, 2000);
+
+       err = lan966x_fdma_reload(lan966x, max_mtu);
+
+       /* Enable back the CPU port */
+       lan_rmw(QSYS_SW_PORT_MODE_PORT_ENA_SET(1),
+               QSYS_SW_PORT_MODE_PORT_ENA,
+               lan966x,  QSYS_SW_PORT_MODE(CPU_PORT));
+
+       return err;
+}
+
 void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev)
 {
        if (lan966x->fdma_ndev)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index d7134a4..e875197 100644 (file)
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -354,12 +354,24 @@ static int lan966x_port_change_mtu(struct net_device *dev, int new_mtu)
 {
        struct lan966x_port *port = netdev_priv(dev);
        struct lan966x *lan966x = port->lan966x;
+       int old_mtu = dev->mtu;
+       int err;
 
        lan_wr(DEV_MAC_MAXLEN_CFG_MAX_LEN_SET(new_mtu),
               lan966x, DEV_MAC_MAXLEN_CFG(port->chip_port));
        dev->mtu = new_mtu;
 
-       return 0;
+       if (!lan966x->fdma)
+               return 0;
+
+       err = lan966x_fdma_change_mtu(lan966x);
+       if (err) {
+               lan_wr(DEV_MAC_MAXLEN_CFG_MAX_LEN_SET(old_mtu),
+                      lan966x, DEV_MAC_MAXLEN_CFG(port->chip_port));
+               dev->mtu = old_mtu;
+       }
+
+       return err;
 }
 
 static int lan966x_mc_unsync(struct net_device *dev, const unsigned char *addr)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index 1ab20b6..5213263 100644 (file)
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -394,6 +394,7 @@ void lan966x_ptp_txtstamp_release(struct lan966x_port *port,
 irqreturn_t lan966x_ptp_irq_handler(int irq, void *args);
 
 int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev);
+int lan966x_fdma_change_mtu(struct lan966x *lan966x);
 void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev);
 void lan966x_fdma_netdev_deinit(struct lan966x *lan966x, struct net_device *dev);
 int lan966x_fdma_init(struct lan966x *lan966x);