From: Haijun Liu <[email protected]>
Creates the Cross Core Modem Network Interface (CCMNI) which implements
the wwan_ops for registration with the WWAN framework, CCMNI also
implements the net_device_ops functions used by the network device.
Network device operations include open, close, start transmission, TX
timeout, change MTU, and select queue.
Signed-off-by: Haijun Liu <[email protected]>
Co-developed-by: Chandrashekar Devegowda <[email protected]>
Signed-off-by: Chandrashekar Devegowda <[email protected]>
Co-developed-by: Ricardo Martinez <[email protected]>
Signed-off-by: Ricardo Martinez <[email protected]>
---
drivers/net/wwan/t7xx/Makefile | 1 +
drivers/net/wwan/t7xx/t7xx_modem_ops.c | 11 +-
drivers/net/wwan/t7xx/t7xx_netdev.c | 433 +++++++++++++++++++++++++
drivers/net/wwan/t7xx/t7xx_netdev.h | 61 ++++
4 files changed, 505 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/wwan/t7xx/t7xx_netdev.c
create mode 100644 drivers/net/wwan/t7xx/t7xx_netdev.h
diff --git a/drivers/net/wwan/t7xx/Makefile b/drivers/net/wwan/t7xx/Makefile
index 04a9ba50dc14..dc6a7d682c15 100644
--- a/drivers/net/wwan/t7xx/Makefile
+++ b/drivers/net/wwan/t7xx/Makefile
@@ -17,3 +17,4 @@ mtk_t7xx-y:= t7xx_pci.o \
t7xx_hif_dpmaif_tx.o \
t7xx_hif_dpmaif_rx.o \
t7xx_dpmaif.o \
+ t7xx_netdev.o
diff --git a/drivers/net/wwan/t7xx/t7xx_modem_ops.c b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
index ec55845e7ac0..3680b0b8205a 100644
--- a/drivers/net/wwan/t7xx/t7xx_modem_ops.c
+++ b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
@@ -35,6 +35,7 @@
#include "t7xx_hif_cldma.h"
#include "t7xx_mhccif.h"
#include "t7xx_modem_ops.h"
+#include "t7xx_netdev.h"
#include "t7xx_pci.h"
#include "t7xx_pcie_mac.h"
#include "t7xx_port.h"
@@ -652,10 +653,14 @@ int t7xx_md_init(struct t7xx_pci_dev *t7xx_dev)
if (ret)
goto err_destroy_hswq;
- ret = t7xx_cldma_init(md, md->md_ctrl[ID_CLDMA1]);
+ ret = t7xx_ccmni_init(t7xx_dev);
if (ret)
goto err_uninit_fsm;
+ ret = t7xx_cldma_init(md, md->md_ctrl[ID_CLDMA1]);
+ if (ret)
+ goto err_uninit_ccmni;
+
ret = t7xx_port_proxy_init(md);
if (ret)
goto err_uninit_cldma;
@@ -668,6 +673,9 @@ int t7xx_md_init(struct t7xx_pci_dev *t7xx_dev)
err_uninit_cldma:
t7xx_cldma_exit(md->md_ctrl[ID_CLDMA1]);
+err_uninit_ccmni:
+ t7xx_ccmni_exit(t7xx_dev);
+
err_uninit_fsm:
t7xx_fsm_uninit(md);
@@ -689,6 +697,7 @@ void t7xx_md_exit(struct t7xx_pci_dev *t7xx_dev)
t7xx_fsm_append_cmd(md->fsm_ctl, FSM_CMD_PRE_STOP, FSM_CMD_FLAG_WAIT_FOR_COMPLETION);
t7xx_port_proxy_uninit(md->port_prox);
t7xx_cldma_exit(md->md_ctrl[ID_CLDMA1]);
+ t7xx_ccmni_exit(t7xx_dev);
t7xx_fsm_uninit(md);
destroy_workqueue(md->handshake_wq);
}
diff --git a/drivers/net/wwan/t7xx/t7xx_netdev.c b/drivers/net/wwan/t7xx/t7xx_netdev.c
new file mode 100644
index 000000000000..b4a2ef2c7b17
--- /dev/null
+++ b/drivers/net/wwan/t7xx/t7xx_netdev.c
@@ -0,0 +1,433 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, MediaTek Inc.
+ * Copyright (c) 2021, Intel Corporation.
+ *
+ * Authors:
+ * Chandrashekar Devegowda <[email protected]>
+ * Haijun Liu <[email protected]>
+ * Ricardo Martinez<[email protected]>
+ *
+ * Contributors:
+ * Amir Hanania <[email protected]>
+ * Andy Shevchenko <[email protected]>
+ * Chiranjeevi Rapolu <[email protected]>
+ * Eliot Lee <[email protected]>
+ * Moises Veleta <[email protected]>
+ * Sreehari Kancharla <[email protected]>
+ */
+
+#include <linux/atomic.h>
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/gfp.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/netdev_features.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+#include <linux/wwan.h>
+#include <net/pkt_sched.h>
+
+#include "t7xx_common.h"
+#include "t7xx_hif_dpmaif_rx.h"
+#include "t7xx_hif_dpmaif_tx.h"
+#include "t7xx_netdev.h"
+#include "t7xx_pci.h"
+#include "t7xx_state_monitor.h"
+
+#define IP_MUX_SESSION_DEFAULT 0
+
+static u16 t7xx_ccmni_select_queue(struct net_device *dev, struct sk_buff *skb,
+ struct net_device *sb_dev)
+{
+ return TXQ_TYPE_DEFAULT;
+}
+
+static int t7xx_ccmni_open(struct net_device *dev)
+{
+ struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
+
+ netif_carrier_on(dev);
+ netif_tx_start_all_queues(dev);
+ atomic_inc(&ccmni->usage);
+ return 0;
+}
+
+static int t7xx_ccmni_close(struct net_device *dev)
+{
+ struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
+
+ if (atomic_dec_return(&ccmni->usage) < 0)
+ return -EINVAL;
+
+ netif_carrier_off(dev);
+ netif_tx_disable(dev);
+ return 0;
+}
+
+static int t7xx_ccmni_send_packet(struct t7xx_ccmni *ccmni, struct sk_buff *skb,
+ unsigned int txqt)
+{
+ struct t7xx_ccmni_ctrl *ctlb = ccmni->ctlb;
+
+ skb->cb[TX_CB_NETIF_IDX] = ccmni->index;
+
+ if (t7xx_dpmaif_tx_send_skb(ctlb->hif_ctrl, txqt, skb))
+ return NETDEV_TX_BUSY;
+
+ return 0;
+}
+
+static int t7xx_ccmni_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
+ int skb_len = skb->len;
+
+ /* If MTU is changed or there is no headroom, drop the packet */
+ if (skb->len > dev->mtu || skb_headroom(skb) < sizeof(struct ccci_header)) {
+ dev_kfree_skb(skb);
+ dev->stats.tx_dropped++;
+ return NETDEV_TX_OK;
+ }
+
+ if (t7xx_ccmni_send_packet(ccmni, skb, TXQ_TYPE_DEFAULT))
+ return NETDEV_TX_BUSY;
+
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb_len;
+
+ return NETDEV_TX_OK;
+}
+
+static void t7xx_ccmni_tx_timeout(struct net_device *dev, unsigned int __always_unused txqueue)
+{
+ struct t7xx_ccmni *ccmni = netdev_priv(dev);
+
+ dev->stats.tx_errors++;
+
+ if (atomic_read(&ccmni->usage) > 0)
+ netif_tx_wake_all_queues(dev);
+}
+
+static const struct net_device_ops ccmni_netdev_ops = {
+ .ndo_open = t7xx_ccmni_open,
+ .ndo_stop = t7xx_ccmni_close,
+ .ndo_start_xmit = t7xx_ccmni_start_xmit,
+ .ndo_tx_timeout = t7xx_ccmni_tx_timeout,
+ .ndo_select_queue = t7xx_ccmni_select_queue,
+};
+
+static void t7xx_ccmni_start(struct t7xx_ccmni_ctrl *ctlb)
+{
+ struct t7xx_ccmni *ccmni;
+ int i;
+
+ for (i = 0; i < ctlb->nic_dev_num; i++) {
+ ccmni = ctlb->ccmni_inst[i];
+ if (!ccmni)
+ continue;
+
+ if (atomic_read(&ccmni->usage) > 0) {
+ netif_tx_start_all_queues(ccmni->dev);
+ netif_carrier_on(ccmni->dev);
+ }
+ }
+}
+
+static void t7xx_ccmni_pre_stop(struct t7xx_ccmni_ctrl *ctlb)
+{
+ struct t7xx_ccmni *ccmni;
+ int i;
+
+ for (i = 0; i < ctlb->nic_dev_num; i++) {
+ ccmni = ctlb->ccmni_inst[i];
+ if (!ccmni)
+ continue;
+
+ if (atomic_read(&ccmni->usage) > 0)
+ netif_tx_disable(ccmni->dev);
+ }
+}
+
+static void t7xx_ccmni_post_stop(struct t7xx_ccmni_ctrl *ctlb)
+{
+ struct t7xx_ccmni *ccmni;
+ int i;
+
+ for (i = 0; i < ctlb->nic_dev_num; i++) {
+ ccmni = ctlb->ccmni_inst[i];
+ if (!ccmni)
+ continue;
+
+ if (atomic_read(&ccmni->usage) > 0)
+ netif_carrier_off(ccmni->dev);
+ }
+}
+
+static void t7xx_ccmni_wwan_setup(struct net_device *dev)
+{
+ dev->header_ops = NULL;
+ dev->hard_header_len += sizeof(struct ccci_header);
+
+ dev->mtu = ETH_DATA_LEN;
+ dev->max_mtu = CCMNI_MTU_MAX;
+ dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
+ dev->watchdog_timeo = CCMNI_NETDEV_WDT_TO;
+ /* CCMNI is a pure IP device */
+ dev->flags = IFF_POINTOPOINT | IFF_NOARP;
+
+ /* Not supporting VLAN */
+ dev->features = NETIF_F_VLAN_CHALLENGED;
+
+ dev->features |= NETIF_F_SG;
+ dev->hw_features |= NETIF_F_SG;
+
+ /* Uplink checksum offload */
+ dev->features |= NETIF_F_HW_CSUM;
+ dev->hw_features |= NETIF_F_HW_CSUM;
+
+ /* Downlink checksum offload */
+ dev->features |= NETIF_F_RXCSUM;
+ dev->hw_features |= NETIF_F_RXCSUM;
+
+ /* Use kernel default free_netdev() function */
+ dev->needs_free_netdev = true;
+
+ /* No need to free again because of free_netdev() */
+ dev->priv_destructor = NULL;
+ dev->type = ARPHRD_NONE;
+
+ dev->netdev_ops = &ccmni_netdev_ops;
+}
+
+static int t7xx_ccmni_wwan_newlink(void *ctxt, struct net_device *dev, u32 if_id,
+ struct netlink_ext_ack *extack)
+{
+ struct t7xx_ccmni_ctrl *ctlb = ctxt;
+ struct t7xx_ccmni *ccmni;
+ int ret;
+
+ if (if_id >= ARRAY_SIZE(ctlb->ccmni_inst))
+ return -EINVAL;
+
+ ccmni = wwan_netdev_drvpriv(dev);
+ ccmni->index = if_id;
+ ccmni->ctlb = ctlb;
+ ccmni->dev = dev;
+ atomic_set(&ccmni->usage, 0);
+ ctlb->ccmni_inst[if_id] = ccmni;
+
+ ret = register_netdevice(dev);
+ if (ret)
+ return ret;
+
+ netif_device_attach(dev);
+ return 0;
+}
+
+static void t7xx_ccmni_wwan_dellink(void *ctxt, struct net_device *dev, struct list_head *head)
+{
+ struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
+ struct t7xx_ccmni_ctrl *ctlb = ctxt;
+ u8 if_id = ccmni->index;
+
+ if (if_id >= ARRAY_SIZE(ctlb->ccmni_inst))
+ return;
+
+ if (WARN_ON(ctlb->ccmni_inst[if_id] != ccmni))
+ return;
+
+ unregister_netdevice(dev);
+}
+
+static const struct wwan_ops ccmni_wwan_ops = {
+ .priv_size = sizeof(struct t7xx_ccmni),
+ .setup = t7xx_ccmni_wwan_setup,
+ .newlink = t7xx_ccmni_wwan_newlink,
+ .dellink = t7xx_ccmni_wwan_dellink,
+};
+
+static int t7xx_ccmni_md_state_callback(enum md_state state, void *para)
+{
+ struct t7xx_ccmni_ctrl *ctlb = para;
+ int ret = 0;
+
+ ctlb->md_sta = state;
+
+ switch (state) {
+ case MD_STATE_READY:
+ t7xx_ccmni_start(ctlb);
+ break;
+
+ case MD_STATE_EXCEPTION:
+ case MD_STATE_STOPPED:
+ t7xx_ccmni_pre_stop(ctlb);
+
+ ret = t7xx_dpmaif_md_state_callback(ctlb->hif_ctrl, state);
+ if (ret < 0)
+ dev_err(ctlb->hif_ctrl->dev,
+ "dpmaif md state callback err, md_sta=%d\n", state);
+
+ t7xx_ccmni_post_stop(ctlb);
+ break;
+
+ case MD_STATE_WAITING_FOR_HS1:
+ case MD_STATE_WAITING_TO_STOP:
+ ret = t7xx_dpmaif_md_state_callback(ctlb->hif_ctrl, state);
+ if (ret < 0)
+ dev_err(ctlb->hif_ctrl->dev,
+ "dpmaif md state callback err, md_sta=%d\n", state);
+
+ break;
+
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+static void init_md_status_notifier(struct t7xx_pci_dev *t7xx_dev)
+{
+ struct t7xx_ccmni_ctrl *ctlb = t7xx_dev->ccmni_ctlb;
+ struct t7xx_fsm_notifier *md_status_notifier;
+
+ md_status_notifier = &ctlb->md_status_notify;
+ INIT_LIST_HEAD(&md_status_notifier->entry);
+ md_status_notifier->notifier_fn = t7xx_ccmni_md_state_callback;
+ md_status_notifier->data = ctlb;
+
+ t7xx_fsm_notifier_register(t7xx_dev->md, md_status_notifier);
+}
+
+static void t7xx_ccmni_recv_skb(struct t7xx_pci_dev *t7xx_dev, struct sk_buff *skb)
+{
+ struct t7xx_ccmni *ccmni;
+ struct net_device *net_dev;
+ int pkt_type, skb_len;
+ u8 netif_id;
+
+ netif_id = skb->cb[RX_CB_NETIF_IDX];
+ ccmni = t7xx_dev->ccmni_ctlb->ccmni_inst[netif_id];
+ if (!ccmni) {
+ dev_kfree_skb(skb);
+ return;
+ }
+
+ net_dev = ccmni->dev;
+ skb->dev = net_dev;
+
+ pkt_type = skb->cb[RX_CB_PKT_TYPE];
+ if (pkt_type == PKT_TYPE_IP6)
+ skb->protocol = htons(ETH_P_IPV6);
+ else
+ skb->protocol = htons(ETH_P_IP);
+
+ skb_len = skb->len;
+ netif_rx_any_context(skb);
+ net_dev->stats.rx_packets++;
+ net_dev->stats.rx_bytes += skb_len;
+}
+
+static void t7xx_ccmni_queue_tx_irq_notify(struct t7xx_ccmni_ctrl *ctlb, int qno)
+{
+ struct t7xx_ccmni *ccmni = ctlb->ccmni_inst[0];
+ struct netdev_queue *net_queue;
+
+ if (netif_running(ccmni->dev) && atomic_read(&ccmni->usage) > 0) {
+ if (ctlb->capability & NIC_CAP_CCMNI_MQ) {
+ net_queue = netdev_get_tx_queue(ccmni->dev, qno);
+ if (netif_tx_queue_stopped(net_queue))
+ netif_tx_wake_queue(net_queue);
+ } else if (netif_queue_stopped(ccmni->dev)) {
+ netif_wake_queue(ccmni->dev);
+ }
+ }
+}
+
+static void t7xx_ccmni_queue_tx_full_notify(struct t7xx_ccmni_ctrl *ctlb, int qno)
+{
+ struct t7xx_ccmni *ccmni = ctlb->ccmni_inst[0];
+ struct netdev_queue *net_queue;
+
+ if (atomic_read(&ccmni->usage) > 0) {
+ netdev_err(ccmni->dev, "TX queue %d is full\n", qno);
+
+ if (ctlb->capability & NIC_CAP_CCMNI_MQ) {
+ net_queue = netdev_get_tx_queue(ccmni->dev, qno);
+ netif_tx_stop_queue(net_queue);
+ } else {
+ netif_stop_queue(ccmni->dev);
+ }
+ }
+}
+
+static void t7xx_ccmni_queue_state_notify(struct t7xx_pci_dev *t7xx_dev,
+ enum dpmaif_txq_state state, int qno)
+{
+ struct t7xx_ccmni_ctrl *ctlb = t7xx_dev->ccmni_ctlb;
+
+ if (!(ctlb->capability & NIC_CAP_TXBUSY_STOP) ||
+ ctlb->md_sta != MD_STATE_READY)
+ return;
+
+ if (!ctlb->ccmni_inst[0]) {
+ dev_warn(&t7xx_dev->pdev->dev, "No netdev registered yet\n");
+ return;
+ }
+
+ if (state == DMPAIF_TXQ_STATE_IRQ)
+ t7xx_ccmni_queue_tx_irq_notify(ctlb, qno);
+ else if (state == DMPAIF_TXQ_STATE_FULL)
+ t7xx_ccmni_queue_tx_full_notify(ctlb, qno);
+}
+
+int t7xx_ccmni_init(struct t7xx_pci_dev *t7xx_dev)
+{
+ struct device *dev = &t7xx_dev->pdev->dev;
+ struct t7xx_ccmni_ctrl *ctlb;
+ int ret;
+
+ ctlb = devm_kzalloc(dev, sizeof(*ctlb), GFP_KERNEL);
+ if (!ctlb)
+ return -ENOMEM;
+
+ t7xx_dev->ccmni_ctlb = ctlb;
+ ctlb->t7xx_dev = t7xx_dev;
+ ctlb->callbacks.state_notify = t7xx_ccmni_queue_state_notify;
+ ctlb->callbacks.recv_skb = t7xx_ccmni_recv_skb;
+ ctlb->nic_dev_num = NIC_DEV_DEFAULT;
+ ctlb->capability = NIC_CAP_TXBUSY_STOP | NIC_CAP_SGIO |
+ NIC_CAP_DATA_ACK_DVD | NIC_CAP_CCMNI_MQ;
+
+ ctlb->hif_ctrl = t7xx_dpmaif_hif_init(t7xx_dev, &ctlb->callbacks);
+ if (!ctlb->hif_ctrl)
+ return -ENOMEM;
+
+ /* WWAN core will create a netdev for the default IP MUX channel */
+ ret = wwan_register_ops(dev, &ccmni_wwan_ops, ctlb, IP_MUX_SESSION_DEFAULT);
+ if (ret)
+ goto err_unregister_ops;
+
+ init_md_status_notifier(t7xx_dev);
+
+ return 0;
+
+err_unregister_ops:
+ wwan_unregister_ops(dev);
+
+ return ret;
+}
+
+void t7xx_ccmni_exit(struct t7xx_pci_dev *t7xx_dev)
+{
+ struct t7xx_ccmni_ctrl *ctlb = t7xx_dev->ccmni_ctlb;
+
+ t7xx_fsm_notifier_unregister(t7xx_dev->md, &ctlb->md_status_notify);
+ wwan_unregister_ops(&t7xx_dev->pdev->dev);
+ t7xx_dpmaif_hif_exit(ctlb->hif_ctrl);
+}
diff --git a/drivers/net/wwan/t7xx/t7xx_netdev.h b/drivers/net/wwan/t7xx/t7xx_netdev.h
new file mode 100644
index 000000000000..2553c050fca4
--- /dev/null
+++ b/drivers/net/wwan/t7xx/t7xx_netdev.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (c) 2021, MediaTek Inc.
+ * Copyright (c) 2021, Intel Corporation.
+ *
+ * Authors:
+ * Haijun Liu <[email protected]>
+ * Moises Veleta <[email protected]>
+ *
+ * Contributors:
+ * Amir Hanania <[email protected]>
+ * Chiranjeevi Rapolu <[email protected]>
+ * Ricardo Martinez<[email protected]>
+ */
+
+#ifndef __T7XX_NETDEV_H__
+#define __T7XX_NETDEV_H__
+
+#include <linux/bits.h>
+#include <linux/netdevice.h>
+#include <linux/types.h>
+
+#include "t7xx_common.h"
+#include "t7xx_hif_dpmaif.h"
+#include "t7xx_pci.h"
+#include "t7xx_state_monitor.h"
+
+#define RXQ_NUM DPMAIF_RXQ_NUM
+#define NIC_DEV_MAX 21
+#define NIC_DEV_DEFAULT 2
+#define NIC_CAP_TXBUSY_STOP BIT(0)
+#define NIC_CAP_SGIO BIT(1)
+#define NIC_CAP_DATA_ACK_DVD BIT(2)
+#define NIC_CAP_CCMNI_MQ BIT(3)
+
+/* Must be less than DPMAIF_HW_MTU_SIZE (3*1024 + 8) */
+#define CCMNI_MTU_MAX 3000
+#define CCMNI_NETDEV_WDT_TO (1 * HZ)
+
+struct t7xx_ccmni {
+ u8 index;
+ atomic_t usage;
+ struct net_device *dev;
+ struct t7xx_ccmni_ctrl *ctlb;
+};
+
+struct t7xx_ccmni_ctrl {
+ struct t7xx_pci_dev *t7xx_dev;
+ struct dpmaif_ctrl *hif_ctrl;
+ struct t7xx_ccmni *ccmni_inst[NIC_DEV_MAX];
+ struct dpmaif_callbacks callbacks;
+ unsigned int nic_dev_num;
+ unsigned int md_sta;
+ unsigned int capability;
+ struct t7xx_fsm_notifier md_status_notify;
+};
+
+int t7xx_ccmni_init(struct t7xx_pci_dev *t7xx_dev);
+void t7xx_ccmni_exit(struct t7xx_pci_dev *t7xx_dev);
+
+#endif /* __T7XX_NETDEV_H__ */
--
2.17.1
On Thu, 13 Jan 2022, Ricardo Martinez wrote:
> From: Haijun Liu <[email protected]>
>
> Creates the Cross Core Modem Network Interface (CCMNI) which implements
> the wwan_ops for registration with the WWAN framework, CCMNI also
> implements the net_device_ops functions used by the network device.
> Network device operations include open, close, start transmission, TX
> timeout, change MTU, and select queue.
>
> Signed-off-by: Haijun Liu <[email protected]>
> Co-developed-by: Chandrashekar Devegowda <[email protected]>
> Signed-off-by: Chandrashekar Devegowda <[email protected]>
> Co-developed-by: Ricardo Martinez <[email protected]>
> Signed-off-by: Ricardo Martinez <[email protected]>
> ---
> +static int t7xx_ccmni_open(struct net_device *dev)
> +{
> + struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
> +
> + netif_carrier_on(dev);
> + netif_tx_start_all_queues(dev);
> + atomic_inc(&ccmni->usage);
> + return 0;
> +}
> +
> +static int t7xx_ccmni_close(struct net_device *dev)
> +{
> + struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
> +
> + if (atomic_dec_return(&ccmni->usage) < 0)
> + return -EINVAL;
I'm certainly way out of my expertize here in knowing how/when these open
and close can be called. That kept in mind, I wonder if there's need to do
rollback for the atomic dec.
> +static void t7xx_ccmni_wwan_setup(struct net_device *dev)
> +{
> + dev->header_ops = NULL;
> + dev->hard_header_len += sizeof(struct ccci_header);
> +
> + dev->mtu = ETH_DATA_LEN;
> + dev->max_mtu = CCMNI_MTU_MAX;
> + dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
> + dev->watchdog_timeo = CCMNI_NETDEV_WDT_TO;
> + /* CCMNI is a pure IP device */
> + dev->flags = IFF_POINTOPOINT | IFF_NOARP;
> +
> + /* Not supporting VLAN */
> + dev->features = NETIF_F_VLAN_CHALLENGED;
> +
> + dev->features |= NETIF_F_SG;
> + dev->hw_features |= NETIF_F_SG;
> +
> + /* Uplink checksum offload */
> + dev->features |= NETIF_F_HW_CSUM;
> + dev->hw_features |= NETIF_F_HW_CSUM;
> +
> + /* Downlink checksum offload */
> + dev->features |= NETIF_F_RXCSUM;
> + dev->hw_features |= NETIF_F_RXCSUM;
> +
> + /* Use kernel default free_netdev() function */
> + dev->needs_free_netdev = true;
> +
> + /* No need to free again because of free_netdev() */
> + dev->priv_destructor = NULL;
Isn't the struct zeroed for you?
Maybe some of those comments are not that useful?
> + ctlb->capability = NIC_CAP_TXBUSY_STOP | NIC_CAP_SGIO |
> + NIC_CAP_DATA_ACK_DVD | NIC_CAP_CCMNI_MQ;
Is capability going to remain constant? And some of these are
not used at all.
Related to this, e.g., the NETIF_F_SG setting above doesn't seem to care
about what is in capability (assuming SGIO means what I think it does),
should it?
> + /* WWAN core will create a netdev for the default IP MUX channel */
> + ret = wwan_register_ops(dev, &ccmni_wwan_ops, ctlb, IP_MUX_SESSION_DEFAULT);
> + if (ret)
> + goto err_unregister_ops;
> +
> + init_md_status_notifier(t7xx_dev);
> +
> + return 0;
> +
> +err_unregister_ops:
> + wwan_unregister_ops(dev);
If wwan_register_ops fails, why is wwan_unregister_ops needed?
> +/* Must be less than DPMAIF_HW_MTU_SIZE (3*1024 + 8) */
This could be enforced with BUILD_BUG_ON if you want.
--
i.