@@ -855,31 +855,6 @@ irqreturn_t prueth_rx_irq(int irq, void *dev_id)
}
EXPORT_SYMBOL_GPL(prueth_rx_irq);
-void prueth_emac_stop(struct prueth_emac *emac)
-{
- struct prueth *prueth = emac->prueth;
- int slice;
-
- switch (emac->port_id) {
- case PRUETH_PORT_MII0:
- slice = ICSS_SLICE0;
- break;
- case PRUETH_PORT_MII1:
- slice = ICSS_SLICE1;
- break;
- default:
- netdev_err(emac->ndev, "invalid port\n");
- return;
- }
-
- emac->fw_running = 0;
- if (!emac->is_sr1)
- rproc_shutdown(prueth->txpru[slice]);
- rproc_shutdown(prueth->rtu[slice]);
- rproc_shutdown(prueth->pru[slice]);
-}
-EXPORT_SYMBOL_GPL(prueth_emac_stop);
-
void prueth_cleanup_tx_ts(struct prueth_emac *emac)
{
int i;
@@ -397,7 +397,7 @@ static int prueth_emac_buffer_setup(struct prueth_emac *emac)
return 0;
}
-static void icssg_init_emac_mode(struct prueth *prueth)
+void icssg_init_emac_mode(struct prueth *prueth)
{
/* When the device is configured as a bridge and it is being brought
* back to the emac mode, the host mac address has to be set as 0.
@@ -406,9 +406,6 @@ static void icssg_init_emac_mode(struct prueth *prueth)
int i;
u8 mac[ETH_ALEN] = { 0 };
- if (prueth->emacs_initialized)
- return;
-
/* Set VLAN TABLE address base */
regmap_update_bits(prueth->miig_rt, FDB_GEN_CFG1, SMEM_VLAN_OFFSET_MASK,
addr << SMEM_VLAN_OFFSET);
@@ -423,15 +420,13 @@ static void icssg_init_emac_mode(struct prueth *prueth)
/* Clear host MAC address */
icssg_class_set_host_mac_addr(prueth->miig_rt, mac);
}
+EXPORT_SYMBOL_GPL(icssg_init_emac_mode);
-static void icssg_init_fw_offload_mode(struct prueth *prueth)
+void icssg_init_fw_offload_mode(struct prueth *prueth)
{
u32 addr = prueth->shram.pa + EMAC_ICSSG_SWITCH_DEFAULT_VLAN_TABLE_OFFSET;
int i;
- if (prueth->emacs_initialized)
- return;
-
/* Set VLAN TABLE address base */
regmap_update_bits(prueth->miig_rt, FDB_GEN_CFG1, SMEM_VLAN_OFFSET_MASK,
addr << SMEM_VLAN_OFFSET);
@@ -448,6 +443,7 @@ static void icssg_init_fw_offload_mode(struct prueth *prueth)
icssg_class_set_host_mac_addr(prueth->miig_rt, prueth->hw_bridge_dev->dev_addr);
icssg_set_pvid(prueth, prueth->default_vlan, PRUETH_PORT_HOST);
}
+EXPORT_SYMBOL_GPL(icssg_init_fw_offload_mode);
int icssg_config(struct prueth *prueth, struct prueth_emac *emac, int slice)
{
@@ -455,11 +451,6 @@ int icssg_config(struct prueth *prueth, struct prueth_emac *emac, int slice)
struct icssg_flow_cfg __iomem *flow_cfg;
int ret;
- if (prueth->is_switch_mode || prueth->is_hsr_offload_mode)
- icssg_init_fw_offload_mode(prueth);
- else
- icssg_init_emac_mode(prueth);
-
memset_io(config, 0, TAS_GATE_MASK_LIST0);
icssg_miig_queues_init(prueth, slice);
@@ -786,3 +777,27 @@ void icssg_set_pvid(struct prueth *prueth, u8 vid, u8 port)
writel(pvid, prueth->shram.va + EMAC_ICSSG_SWITCH_PORT0_DEFAULT_VLAN_OFFSET);
}
EXPORT_SYMBOL_GPL(icssg_set_pvid);
+
+int emac_fdb_flow_id_updated(struct prueth_emac *emac)
+{
+ struct mgmt_cmd_rsp fdb_cmd_rsp = { 0 };
+ int slice = prueth_emac_slice(emac);
+ struct mgmt_cmd fdb_cmd = { 0 };
+ int ret;
+
+ fdb_cmd.header = ICSSG_FW_MGMT_CMD_HEADER;
+ fdb_cmd.type = ICSSG_FW_MGMT_FDB_CMD_TYPE_RX_FLOW;
+ fdb_cmd.seqnum = ++(emac->prueth->icssg_hwcmdseq);
+ fdb_cmd.param = 0;
+
+ fdb_cmd.param |= (slice << 4);
+ fdb_cmd.cmd_args[0] = 0;
+
+ ret = icssg_send_fdb_msg(emac, &fdb_cmd, &fdb_cmd_rsp);
+ if (ret)
+ return ret;
+
+ WARN_ON(fdb_cmd.seqnum != fdb_cmd_rsp.seqnum);
+ return fdb_cmd_rsp.status == 1 ? 0 : -EINVAL;
+}
+EXPORT_SYMBOL_GPL(emac_fdb_flow_id_updated);
@@ -55,6 +55,7 @@ struct icssg_rxq_ctx {
#define ICSSG_FW_MGMT_FDB_CMD_TYPE 0x03
#define ICSSG_FW_MGMT_CMD_TYPE 0x04
#define ICSSG_FW_MGMT_PKT 0x80000000
+#define ICSSG_FW_MGMT_FDB_CMD_TYPE_RX_FLOW 0x05
struct icssg_r30_cmd {
u32 cmd[4];
@@ -164,11 +164,26 @@ static struct icssg_firmwares icssg_emac_firmwares[] = {
}
};
-static int prueth_emac_start(struct prueth *prueth, struct prueth_emac *emac)
+static int prueth_start(struct rproc *rproc, const char *fw_name)
+{
+ int ret;
+
+ ret = rproc_set_firmware(rproc, fw_name);
+ if (ret)
+ return ret;
+ return rproc_boot(rproc);
+}
+
+static void prueth_shutdown(struct rproc *rproc)
+{
+ rproc_shutdown(rproc);
+}
+
+static int prueth_emac_start(struct prueth *prueth)
{
struct icssg_firmwares *firmwares;
struct device *dev = prueth->dev;
- int slice, ret;
+ int ret, slice;
if (prueth->is_switch_mode)
firmwares = icssg_switch_firmwares;
@@ -177,49 +192,126 @@ static int prueth_emac_start(struct prueth *prueth, struct prueth_emac *emac)
else
firmwares = icssg_emac_firmwares;
- slice = prueth_emac_slice(emac);
- if (slice < 0) {
- netdev_err(emac->ndev, "invalid port\n");
- return -EINVAL;
+ for (slice = 0; slice < PRUETH_NUM_MACS; slice++) {
+ ret = prueth_start(prueth->pru[slice], firmwares[slice].pru);
+ if (ret) {
+ dev_err(dev, "failed to boot PRU%d: %d\n", slice, ret);
+ goto unwind_slices;
+ }
+
+ ret = prueth_start(prueth->rtu[slice], firmwares[slice].rtu);
+ if (ret) {
+ dev_err(dev, "failed to boot RTU%d: %d\n", slice, ret);
+ rproc_shutdown(prueth->pru[slice]);
+ goto unwind_slices;
+ }
+
+ ret = prueth_start(prueth->txpru[slice], firmwares[slice].txpru);
+ if (ret) {
+ dev_err(dev, "failed to boot TX_PRU%d: %d\n", slice, ret);
+ rproc_shutdown(prueth->rtu[slice]);
+ rproc_shutdown(prueth->pru[slice]);
+ goto unwind_slices;
+ }
}
- ret = icssg_config(prueth, emac, slice);
- if (ret)
- return ret;
+ return 0;
- ret = rproc_set_firmware(prueth->pru[slice], firmwares[slice].pru);
- ret = rproc_boot(prueth->pru[slice]);
- if (ret) {
- dev_err(dev, "failed to boot PRU%d: %d\n", slice, ret);
- return -EINVAL;
+unwind_slices:
+ while (--slice >= 0) {
+ prueth_shutdown(prueth->txpru[slice]);
+ prueth_shutdown(prueth->rtu[slice]);
+ prueth_shutdown(prueth->pru[slice]);
}
- ret = rproc_set_firmware(prueth->rtu[slice], firmwares[slice].rtu);
- ret = rproc_boot(prueth->rtu[slice]);
- if (ret) {
- dev_err(dev, "failed to boot RTU%d: %d\n", slice, ret);
- goto halt_pru;
+ return ret;
+}
+
+static void prueth_emac_stop(struct prueth *prueth)
+{
+ int slice;
+
+ for (slice = 0; slice < PRUETH_NUM_MACS; slice++) {
+ prueth_shutdown(prueth->txpru[slice]);
+ prueth_shutdown(prueth->rtu[slice]);
+ prueth_shutdown(prueth->pru[slice]);
}
+}
+
+static int prueth_emac_common_start(struct prueth *prueth)
+{
+ struct prueth_emac *emac;
+ int ret = 0;
+ int slice;
+
+ if (!prueth->emac[ICSS_SLICE0] && !prueth->emac[ICSS_SLICE1])
+ return -EINVAL;
+
+ /* clear SMEM and MSMC settings for all slices */
+ memset_io(prueth->msmcram.va, 0, prueth->msmcram.size);
+ memset_io(prueth->shram.va, 0, ICSSG_CONFIG_OFFSET_SLICE1 * PRUETH_NUM_MACS);
+
+ icssg_class_default(prueth->miig_rt, ICSS_SLICE0, 0, false);
+ icssg_class_default(prueth->miig_rt, ICSS_SLICE1, 0, false);
+
+ if (prueth->is_switch_mode || prueth->is_hsr_offload_mode)
+ icssg_init_fw_offload_mode(prueth);
+ else
+ icssg_init_emac_mode(prueth);
+
+ for (slice = 0; slice < PRUETH_NUM_MACS; slice++) {
+ emac = prueth->emac[slice];
+ if (!emac)
+ continue;
+ ret = icssg_config(prueth, emac, slice);
+ if (ret)
+ goto disable_class;
+ }
+
+ ret = prueth_emac_start(prueth);
+ if (ret)
+ goto disable_class;
- ret = rproc_set_firmware(prueth->txpru[slice], firmwares[slice].txpru);
- ret = rproc_boot(prueth->txpru[slice]);
+ emac = prueth->emac[ICSS_SLICE0] ? prueth->emac[ICSS_SLICE0] :
+ prueth->emac[ICSS_SLICE1];
+ ret = icss_iep_init(emac->iep, &prueth_iep_clockops,
+ emac, IEP_DEFAULT_CYCLE_TIME_NS);
if (ret) {
- dev_err(dev, "failed to boot TX_PRU%d: %d\n", slice, ret);
- goto halt_rtu;
+ dev_err(prueth->dev, "Failed to initialize IEP module\n");
+ goto stop_pruss;
}
- emac->fw_running = 1;
return 0;
-halt_rtu:
- rproc_shutdown(prueth->rtu[slice]);
+stop_pruss:
+ prueth_emac_stop(prueth);
-halt_pru:
- rproc_shutdown(prueth->pru[slice]);
+disable_class:
+ icssg_class_disable(prueth->miig_rt, ICSS_SLICE0);
+ icssg_class_disable(prueth->miig_rt, ICSS_SLICE1);
return ret;
}
+static int prueth_emac_common_stop(struct prueth *prueth)
+{
+ struct prueth_emac *emac;
+
+ if (!prueth->emac[ICSS_SLICE0] && !prueth->emac[ICSS_SLICE1])
+ return -EINVAL;
+
+ icssg_class_disable(prueth->miig_rt, ICSS_SLICE0);
+ icssg_class_disable(prueth->miig_rt, ICSS_SLICE1);
+
+ prueth_emac_stop(prueth);
+
+ emac = prueth->emac[ICSS_SLICE0] ? prueth->emac[ICSS_SLICE0] :
+ prueth->emac[ICSS_SLICE1];
+ icss_iep_exit(emac->iep);
+
+ return 0;
+}
+
/* called back by PHY layer if there is change in link state of hw port*/
static void emac_adjust_link(struct net_device *ndev)
{
@@ -374,9 +466,6 @@ static void prueth_iep_settime(void *clockops_data, u64 ns)
u32 cycletime;
int timeout;
- if (!emac->fw_running)
- return;
-
sc_descp = emac->prueth->shram.va + TIMESYNC_FW_WC_SETCLOCK_DESC_OFFSET;
cycletime = IEP_DEFAULT_CYCLE_TIME_NS;
@@ -543,23 +632,17 @@ static int emac_ndo_open(struct net_device *ndev)
{
struct prueth_emac *emac = netdev_priv(ndev);
int ret, i, num_data_chn = emac->tx_ch_num;
+ struct icssg_flow_cfg __iomem *flow_cfg;
struct prueth *prueth = emac->prueth;
int slice = prueth_emac_slice(emac);
struct device *dev = prueth->dev;
int max_rx_flows;
int rx_flow;
- /* clear SMEM and MSMC settings for all slices */
- if (!prueth->emacs_initialized) {
- memset_io(prueth->msmcram.va, 0, prueth->msmcram.size);
- memset_io(prueth->shram.va, 0, ICSSG_CONFIG_OFFSET_SLICE1 * PRUETH_NUM_MACS);
- }
-
/* set h/w MAC as user might have re-configured */
ether_addr_copy(emac->mac_addr, ndev->dev_addr);
icssg_class_set_mac_addr(prueth->miig_rt, slice, emac->mac_addr);
- icssg_class_default(prueth->miig_rt, slice, 0, false);
icssg_ft1_set_mac_addr(prueth->miig_rt, slice, emac->mac_addr);
/* Notify the stack of the actual queue counts. */
@@ -597,18 +680,23 @@ static int emac_ndo_open(struct net_device *ndev)
goto cleanup_napi;
}
- /* reset and start PRU firmware */
- ret = prueth_emac_start(prueth, emac);
- if (ret)
- goto free_rx_irq;
+ if (!prueth->emacs_initialized) {
+ ret = prueth_emac_common_start(prueth);
+ if (ret)
+ goto free_rx_irq;
+ }
- icssg_mii_update_mtu(prueth->mii_rt, slice, ndev->max_mtu);
+ flow_cfg = emac->dram.va + ICSSG_CONFIG_OFFSET + PSI_L_REGULAR_FLOW_ID_BASE_OFFSET;
+ writew(emac->rx_flow_id_base, &flow_cfg->rx_base_flow);
+ ret = emac_fdb_flow_id_updated(emac);
- if (!prueth->emacs_initialized) {
- ret = icss_iep_init(emac->iep, &prueth_iep_clockops,
- emac, IEP_DEFAULT_CYCLE_TIME_NS);
+ if (ret) {
+ netdev_err(ndev, "Failed to update Rx Flow ID %d", ret);
+ goto stop;
}
+ icssg_mii_update_mtu(prueth->mii_rt, slice, ndev->max_mtu);
+
ret = request_threaded_irq(emac->tx_ts_irq, NULL, prueth_tx_ts_irq,
IRQF_ONESHOT, dev_name(dev), emac);
if (ret)
@@ -653,7 +741,8 @@ static int emac_ndo_open(struct net_device *ndev)
free_tx_ts_irq:
free_irq(emac->tx_ts_irq, emac);
stop:
- prueth_emac_stop(emac);
+ if (!prueth->emacs_initialized)
+ prueth_emac_common_stop(prueth);
free_rx_irq:
free_irq(emac->rx_chns.irq[rx_flow], emac);
cleanup_napi:
@@ -689,8 +778,6 @@ static int emac_ndo_stop(struct net_device *ndev)
if (ndev->phydev)
phy_stop(ndev->phydev);
- icssg_class_disable(prueth->miig_rt, prueth_emac_slice(emac));
-
if (emac->prueth->is_hsr_offload_mode)
__dev_mc_unsync(ndev, icssg_prueth_hsr_del_mcast);
else
@@ -728,11 +815,9 @@ static int emac_ndo_stop(struct net_device *ndev)
/* Destroying the queued work in ndo_stop() */
cancel_delayed_work_sync(&emac->stats_work);
- if (prueth->emacs_initialized == 1)
- icss_iep_exit(emac->iep);
-
/* stop PRUs */
- prueth_emac_stop(emac);
+ if (prueth->emacs_initialized == 1)
+ prueth_emac_common_stop(prueth);
free_irq(emac->tx_ts_irq, emac);
@@ -1053,10 +1138,11 @@ static void prueth_offload_fwd_mark_update(struct prueth *prueth)
}
}
-static void prueth_emac_restart(struct prueth *prueth)
+static int prueth_emac_restart(struct prueth *prueth)
{
struct prueth_emac *emac0 = prueth->emac[PRUETH_MAC0];
struct prueth_emac *emac1 = prueth->emac[PRUETH_MAC1];
+ int ret;
/* Detach the net_device for both PRUeth ports*/
if (netif_running(emac0->ndev))
@@ -1065,36 +1151,46 @@ static void prueth_emac_restart(struct prueth *prueth)
netif_device_detach(emac1->ndev);
/* Disable both PRUeth ports */
- icssg_set_port_state(emac0, ICSSG_EMAC_PORT_DISABLE);
- icssg_set_port_state(emac1, ICSSG_EMAC_PORT_DISABLE);
+ ret = icssg_set_port_state(emac0, ICSSG_EMAC_PORT_DISABLE);
+ ret |= icssg_set_port_state(emac1, ICSSG_EMAC_PORT_DISABLE);
+ if (ret)
+ return ret;
/* Stop both pru cores for both PRUeth ports*/
- prueth_emac_stop(emac0);
- prueth->emacs_initialized--;
- prueth_emac_stop(emac1);
- prueth->emacs_initialized--;
+ ret = prueth_emac_common_stop(prueth);
+ if (ret) {
+ dev_err(prueth->dev, "Failed to stop the firmwares");
+ return ret;
+ }
/* Start both pru cores for both PRUeth ports */
- prueth_emac_start(prueth, emac0);
- prueth->emacs_initialized++;
- prueth_emac_start(prueth, emac1);
- prueth->emacs_initialized++;
+ ret = prueth_emac_common_start(prueth);
+ if (ret) {
+ dev_err(prueth->dev, "Failed to start the firmwares");
+ return ret;
+ }
/* Enable forwarding for both PRUeth ports */
- icssg_set_port_state(emac0, ICSSG_EMAC_PORT_FORWARD);
- icssg_set_port_state(emac1, ICSSG_EMAC_PORT_FORWARD);
+ ret = icssg_set_port_state(emac0, ICSSG_EMAC_PORT_FORWARD);
+ ret |= icssg_set_port_state(emac1, ICSSG_EMAC_PORT_FORWARD);
/* Attache net_device for both PRUeth ports */
netif_device_attach(emac0->ndev);
netif_device_attach(emac1->ndev);
+
+ return ret;
}
static void icssg_change_mode(struct prueth *prueth)
{
struct prueth_emac *emac;
- int mac;
+ int mac, ret;
- prueth_emac_restart(prueth);
+ ret = prueth_emac_restart(prueth);
+ if (ret) {
+ dev_err(prueth->dev, "Failed to restart the firmwares, aborting the process");
+ return;
+ }
for (mac = PRUETH_MAC0; mac < PRUETH_NUM_MACS; mac++) {
emac = prueth->emac[mac];
@@ -1173,13 +1269,18 @@ static void prueth_netdevice_port_unlink(struct net_device *ndev)
{
struct prueth_emac *emac = netdev_priv(ndev);
struct prueth *prueth = emac->prueth;
+ int ret;
prueth->br_members &= ~BIT(emac->port_id);
if (prueth->is_switch_mode) {
prueth->is_switch_mode = false;
emac->port_vlan = 0;
- prueth_emac_restart(prueth);
+ ret = prueth_emac_restart(prueth);
+ if (ret) {
+ dev_err(prueth->dev, "Failed to restart the firmwares, aborting the process");
+ return;
+ }
}
prueth_offload_fwd_mark_update(prueth);
@@ -1228,6 +1329,7 @@ static void prueth_hsr_port_unlink(struct net_device *ndev)
struct prueth *prueth = emac->prueth;
struct prueth_emac *emac0;
struct prueth_emac *emac1;
+ int ret;
emac0 = prueth->emac[PRUETH_MAC0];
emac1 = prueth->emac[PRUETH_MAC1];
@@ -1238,7 +1340,11 @@ static void prueth_hsr_port_unlink(struct net_device *ndev)
emac0->port_vlan = 0;
emac1->port_vlan = 0;
prueth->hsr_dev = NULL;
- prueth_emac_restart(prueth);
+ ret = prueth_emac_restart(prueth);
+ if (ret) {
+ dev_err(prueth->dev, "Failed to restart the firmwares, aborting the process");
+ return;
+ }
netdev_dbg(ndev, "Disabling HSR Offload mode\n");
}
}
@@ -1413,13 +1519,10 @@ static int prueth_probe(struct platform_device *pdev)
prueth->pa_stats = NULL;
}
- if (eth0_node) {
+ if (eth0_node || eth1_node) {
ret = prueth_get_cores(prueth, ICSS_SLICE0, false);
if (ret)
goto put_cores;
- }
-
- if (eth1_node) {
ret = prueth_get_cores(prueth, ICSS_SLICE1, false);
if (ret)
goto put_cores;
@@ -1618,14 +1721,12 @@ static int prueth_probe(struct platform_device *pdev)
pruss_put(prueth->pruss);
put_cores:
- if (eth1_node) {
- prueth_put_cores(prueth, ICSS_SLICE1);
- of_node_put(eth1_node);
- }
-
- if (eth0_node) {
+ if (eth0_node || eth1_node) {
prueth_put_cores(prueth, ICSS_SLICE0);
of_node_put(eth0_node);
+
+ prueth_put_cores(prueth, ICSS_SLICE1);
+ of_node_put(eth1_node);
}
return ret;
@@ -140,7 +140,6 @@ struct prueth_rx_chn {
/* data for each emac port */
struct prueth_emac {
bool is_sr1;
- bool fw_running;
struct prueth *prueth;
struct net_device *ndev;
u8 mac_addr[6];
@@ -361,6 +360,8 @@ int icssg_set_port_state(struct prueth_emac *emac,
enum icssg_port_state_cmd state);
void icssg_config_set_speed(struct prueth_emac *emac);
void icssg_config_half_duplex(struct prueth_emac *emac);
+void icssg_init_emac_mode(struct prueth *prueth);
+void icssg_init_fw_offload_mode(struct prueth *prueth);
/* Buffer queue helpers */
int icssg_queue_pop(struct prueth *prueth, u8 queue);
@@ -377,6 +378,7 @@ void icssg_vtbl_modify(struct prueth_emac *emac, u8 vid, u8 port_mask,
u8 untag_mask, bool add);
u16 icssg_get_pvid(struct prueth_emac *emac);
void icssg_set_pvid(struct prueth *prueth, u8 vid, u8 port);
+int emac_fdb_flow_id_updated(struct prueth_emac *emac);
#define prueth_napi_to_tx_chn(pnapi) \
container_of(pnapi, struct prueth_tx_chn, napi_tx)
@@ -407,7 +409,6 @@ void emac_rx_timestamp(struct prueth_emac *emac,
struct sk_buff *skb, u32 *psdata);
enum netdev_tx icssg_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev);
irqreturn_t prueth_rx_irq(int irq, void *dev_id);
-void prueth_emac_stop(struct prueth_emac *emac);
void prueth_cleanup_tx_ts(struct prueth_emac *emac);
int icssg_napi_rx_poll(struct napi_struct *napi_rx, int budget);
int prueth_prepare_rx_chan(struct prueth_emac *emac,
@@ -440,7 +440,6 @@ static int prueth_emac_start(struct prueth *prueth, struct prueth_emac *emac)
goto halt_pru;
}
- emac->fw_running = 1;
return 0;
halt_pru:
@@ -449,6 +448,29 @@ static int prueth_emac_start(struct prueth *prueth, struct prueth_emac *emac)
return ret;
}
+static void prueth_emac_stop(struct prueth_emac *emac)
+{
+ struct prueth *prueth = emac->prueth;
+ int slice;
+
+ switch (emac->port_id) {
+ case PRUETH_PORT_MII0:
+ slice = ICSS_SLICE0;
+ break;
+ case PRUETH_PORT_MII1:
+ slice = ICSS_SLICE1;
+ break;
+ default:
+ netdev_err(emac->ndev, "invalid port\n");
+ return;
+ }
+
+ if (!emac->is_sr1)
+ rproc_shutdown(prueth->txpru[slice]);
+ rproc_shutdown(prueth->rtu[slice]);
+ rproc_shutdown(prueth->pru[slice]);
+}
+
/**
* emac_ndo_open - EMAC device open
* @ndev: network adapter device