Subject: Re: [PATCH V2 net-next 2/8] net: hns3: Add support of the HNAE3 framework

From: Andrew Lunn <[email-masked]>
Date: Wed, 14 Jun 2017 03:32:23 +0200

On Wed, Jun 14, 2017 at 12:10:29AM +0100, Salil Mehta wrote:
> This patch adds the support of the HNAE3 (Hisilicon Network
> Acceleration Engine 3) framework support to the HNS3 driver.
> 
> Framework facilitates clients like ENET(HNS3 Ethernet Driver), RoCE
> and user-space Ethernet drivers (like ODP etc.) to register with HNAE3
> devices and their associated operations.
> 
> Signed-off-by: Daode Huang <[email-masked]>
> Signed-off-by: lipeng <[email-masked]>
> Signed-off-by: Salil Mehta <[email-masked]>
> Signed-off-by: Yisen Zhuang <[email-masked]>
> ---
>  drivers/net/ethernet/hisilicon/hns3/hnae3.c | 305 +++++++++++++++++++
>  drivers/net/ethernet/hisilicon/hns3/hnae3.h | 449 ++++++++++++++++++++++++++++
>  2 files changed, 754 insertions(+)
>  create mode 100644 drivers/net/ethernet/hisilicon/hns3/hnae3.c
>  create mode 100644 drivers/net/ethernet/hisilicon/hns3/hnae3.h
> 
> diff --git a/drivers/net/ethernet/hisilicon/hns3/hnae3.c b/drivers/net/ethernet/hisilicon/hns3/hnae3.c
> new file mode 100644
> index 0000000..f133e1d
> --- /dev/null
> +++ b/drivers/net/ethernet/hisilicon/hns3/hnae3.c
> @@ -0,0 +1,305 @@
> +/*
> + * Copyright (c) 2016-2017 Hisilicon Limited.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/slab.h>
> +#include <linux/list.h>
> +#include <linux/spinlock.h>
> +
> +#include "hnae3.h"
> +
> +static LIST_HEAD(hnae3_ae_algo_list);
> +static LIST_HEAD(hnae3_client_list);
> +static LIST_HEAD(hnae3_ae_dev_list);
> +
> +static DEFINE_SPINLOCK(hnae3_list_ae_algo_lock);
> +static DEFINE_SPINLOCK(hnae3_list_client_lock);
> +static DEFINE_SPINLOCK(hnae3_list_ae_dev_lock);
> +
> +static void hnae3_list_add(spinlock_t *lock, struct list_head *node,
> +			   struct list_head *head)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(lock, flags);
> +	list_add_tail_rcu(node, head);
> +	spin_unlock_irqrestore(lock, flags);
> +}
> +
> +static void hnae3_list_del(spinlock_t *lock, struct list_head *node)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(lock, flags);
> +	list_del_rcu(node);
> +	spin_unlock_irqrestore(lock, flags);
> +}

You have these two _rcu operations here, and no others. I don't see
any rcu_read_lock(), or call_rcu(), etc.

I'm not an RCU expert, but this looks odd to me.

    Andrew