net: wwan: t7xx: Un-embed dummy device

Embedding net_device into structures prohibits the usage of flexible
arrays in the net_device structure. For more details, see the discussion
at [1].

Un-embed the net_device from the private struct by converting it
into a pointer. Then use the leverage the new alloc_netdev_dummy()
helper to allocate and initialize dummy devices.

[1] https://lore.kernel.org/all/20240229225910.79e224cf@kernel.org/

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240424161108.3397057-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/wwan/t7xx/t7xx_netdev.c b/drivers/net/wwan/t7xx/t7xx_netdev.c
index 3ef4a8a4f8fdbced3b31115db04136292e9269c8..91fa082e9cab80f51936fd35ac32e78e126eea33 100644 (file)
--- a/drivers/net/wwan/t7xx/t7xx_netdev.c
+++ b/drivers/net/wwan/t7xx/t7xx_netdev.c
@@ -253,22 +253,27 @@ static void t7xx_ccmni_wwan_setup(struct net_device *dev)
        dev->netdev_ops = &ccmni_netdev_ops;
 }
 
-static void t7xx_init_netdev_napi(struct t7xx_ccmni_ctrl *ctlb)
+static int t7xx_init_netdev_napi(struct t7xx_ccmni_ctrl *ctlb)
 {
        int i;
 
        /* one HW, but shared with multiple net devices,
         * so add a dummy device for NAPI.
         */
-       init_dummy_netdev(&ctlb->dummy_dev);
+       ctlb->dummy_dev = alloc_netdev_dummy(0);
+       if (!ctlb->dummy_dev)
+               return -ENOMEM;
+
        atomic_set(&ctlb->napi_usr_refcnt, 0);
        ctlb->is_napi_en = false;
 
        for (i = 0; i < RXQ_NUM; i++) {
                ctlb->napi[i] = &ctlb->hif_ctrl->rxq[i].napi;
-               netif_napi_add_weight(&ctlb->dummy_dev, ctlb->napi[i], t7xx_dpmaif_napi_rx_poll,
+               netif_napi_add_weight(ctlb->dummy_dev, ctlb->napi[i], t7xx_dpmaif_napi_rx_poll,
                                      NIC_NAPI_POLL_BUDGET);
        }
+
+       return 0;
 }
 
 static void t7xx_uninit_netdev_napi(struct t7xx_ccmni_ctrl *ctlb)
@@ -279,6 +284,7 @@ static void t7xx_uninit_netdev_napi(struct t7xx_ccmni_ctrl *ctlb)
                netif_napi_del(ctlb->napi[i]);
                ctlb->napi[i] = NULL;
        }
+       free_netdev(ctlb->dummy_dev);
 }
 
 static int t7xx_ccmni_wwan_newlink(void *ctxt, struct net_device *dev, u32 if_id,
@@ -480,6 +486,7 @@ 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)
@@ -495,7 +502,12 @@ int t7xx_ccmni_init(struct t7xx_pci_dev *t7xx_dev)
        if (!ctlb->hif_ctrl)
                return -ENOMEM;
 
-       t7xx_init_netdev_napi(ctlb);
+       ret = t7xx_init_netdev_napi(ctlb);
+       if (ret) {
+               t7xx_dpmaif_hif_exit(ctlb->hif_ctrl);
+               return ret;
+       }
+
        init_md_status_notifier(t7xx_dev);
        return 0;
 }

diff --git a/drivers/net/wwan/t7xx/t7xx_netdev.h b/drivers/net/wwan/t7xx/t7xx_netdev.h
index f5ed6f99a1454cd03db3779fa706c0e942ec33f3..b18312f498440dcc74b26c00a899fe0ed87ee536 100644 (file)
--- a/drivers/net/wwan/t7xx/t7xx_netdev.h
+++ b/drivers/net/wwan/t7xx/t7xx_netdev.h
@@ -48,7 +48,7 @@ struct t7xx_ccmni_ctrl {
        unsigned int                    md_sta;
        struct t7xx_fsm_notifier        md_status_notify;
        bool                            wwan_is_registered;
-       struct net_device               dummy_dev;
+       struct net_device               *dummy_dev;
        struct napi_struct              *napi[RXQ_NUM];
        atomic_t                        napi_usr_refcnt;
        bool                            is_napi_en;