Re: [PATCH net-next v3 2/3] dinghai: add MSI-X interrupt pools

[Simon Horman <horms@kernel.org>]

On Mon, Sep 21, 2026 at 02:59:46PM +0800, han.junyang@zte.com.cn wrote:
> From: Junyang Han <han.junyang@zte.com.cn>
> 
> Allocate the fixed MSI-X vector layout of the device and manage the
> vectors in per-purpose pools: the async event queues first, a range
> reserved for RDMA in between and the vq queue pairs last. This series
> wires up the async pool; the vq pool comes with the netdev series.
> 
> IRQs are reference counted so that several event queues can share one
> vector. The pool hands out the least loaded matching IRQ once it passes
> the pool minimum threshold, and binds newly created IRQs to the least
> loaded CPU of the requested affinity mask. Interrupt delivery fans out
> through an atomic notifier chain attached to each IRQ, which the async
> event queue setup posted later in this series hooks into.
> 
> Signed-off-by: Junyang Han <han.junyang@zte.com.cn>

...

> @@ -516,10 +604,24 @@ static int zxdh_pf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  		goto err_modern_cfg;
>  	}
> 
> +	ret = zxdh_pf_irq_table_init(zxdh_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "zxdh_pf_irq_table_init failed: %d\n", ret);
> +		goto err_modern_cfg;
> +	}
> +
> +	ret = zxdh_pf_irq_table_create(zxdh_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "zxdh_pf_irq_table_create failed: %d\n", ret);
> +		goto err_irq_table;
> +	}

I am wondering if you considered calling zxdh_pf_irq_table_create()
from zxdh_pf_irq_table_init(). And likewise for
zxdh_pf_eq_table_init()/zxdh_pf_eq_table_create() in patch 3/3.

I mainly ask because it seems like it would simplify zxdh_pf_probe()
slightly. But I don't feel strongly about this.

> +
>  	devlink_register(devlink);
> 
>  	return 0;
> 
> +err_irq_table:
> +	kvfree(zxdh_dev->irq_table.priv);

As a counter to my previous comment: I see the line is changed to call
zxdh_pf_irq_table_destroy() in patch 3/3. But I'm wondering if it should be
(or would be nicer if it was) zxdh_pf_irq_table_destroy() in this patch.

>  err_modern_cfg:
>  	zxdh_pf_modern_cfg_uninit(zxdh_dev);
>  err_cfg_init:

...

> diff --git a/drivers/net/ethernet/zte/dinghai/zxdh_irq.c b/drivers/net/ethernet/zte/dinghai/zxdh_irq.c

...

> +static struct zxdh_irq *zxdh_irq_alloc(struct zxdh_irq_pool *pool, int vecidx,
> +				       const struct cpumask *affinity)
> +{
> +	struct zxdh_core_dev *zxdh_dev = pool->dev;
> +	struct zxdh_irq *irq;
> +	int err;
> +	int cpu;
> +
> +	irq = kzalloc_obj(*irq, GFP_KERNEL);
> +	if (!irq)
> +		return ERR_PTR(-ENOMEM);
> +
> +	irq->pool = pool;
> +	irq->irqn = pci_irq_vector(zxdh_dev->pdev, vecidx);
> +	if (irq->irqn < 0) {
> +		err = irq->irqn;
> +		goto err_irqn;
> +	}
> +
> +	ATOMIC_INIT_NOTIFIER_HEAD(&irq->nh);
> +	snprintf(irq->name, ZXDH_MAX_IRQ_NAME, "%s_%d@pci:%s", pool->name,
> +		 vecidx, pci_name(zxdh_dev->pdev));

W=1 builds complain about this. E.g. GCC 16.2.0 on x86_64 says:

  CC [M]  drivers/net/ethernet/zte/dinghai/zxdh_irq.o
drivers/net/ethernet/zte/dinghai/zxdh_irq.c: In function 'zxdh_irq_alloc':
drivers/net/ethernet/zte/dinghai/zxdh_irq.c:94:52: warning: '%d' directive output may be truncated writing between 1 and 11 bytes into a region of size between 0 and 99 [-Wformat-truncation=]
   94 |         snprintf(irq->name, ZXDH_MAX_IRQ_NAME, "%s_%d@pci:%s", pool->name,
      |                                                    ^~
drivers/net/ethernet/zte/dinghai/zxdh_irq.c:94:9: note: 'snprintf' output 8 or more bytes (assuming 107) into a destination of size 100
   94 |         snprintf(irq->name, ZXDH_MAX_IRQ_NAME, "%s_%d@pci:%s", pool->name,
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   95 |                  vecidx, pci_name(zxdh_dev->pdev));
      |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

...