2024-04-24 16:12:31

by Breno Leitao

[permalink] [raw]
Subject: [PATCH net-next] 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/[email protected]/

Signed-off-by: Breno Leitao <[email protected]>
--
PS: This was compile-tested only due to lack of hardware.
---
drivers/net/wwan/t7xx/t7xx_netdev.c | 20 ++++++++++++++++----
drivers/net/wwan/t7xx/t7xx_netdev.h | 2 +-
2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wwan/t7xx/t7xx_netdev.c b/drivers/net/wwan/t7xx/t7xx_netdev.c
index 3ef4a8a4f8fd..91fa082e9cab 100644
--- 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 f5ed6f99a145..b18312f49844 100644
--- 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;
--
2.43.0



2024-04-26 02:40:49

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH net-next] net: wwan: t7xx: Un-embed dummy device

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <[email protected]>:

On Wed, 24 Apr 2024 09:11:07 -0700 you wrote:
> 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.
>
> [...]

Here is the summary with links:
- [net-next] net: wwan: t7xx: Un-embed dummy device
https://git.kernel.org/netdev/net-next/c/c984f374aeec

You are awesome, thank you!
--
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