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Date:   Thu, 18 Aug 2022 16:34:24 -0700
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Subject: Re: [PATCH 37/50] wifi: ath12k: add peer.c
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To:     Kalle Valo <kvalo@kernel.org>, <linux-wireless@vger.kernel.org>
CC:     <ath12k@lists.infradead.org>
References: <20220812161003.27279-1-kvalo@kernel.org>
 <20220812161003.27279-38-kvalo@kernel.org>
From:   Jeff Johnson <quic_jjohnson@quicinc.com>
In-Reply-To: <20220812161003.27279-38-kvalo@kernel.org>
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On 8/12/2022 9:09 AM, Kalle Valo wrote:
> From: Kalle Valo <quic_kvalo@quicinc.com>
> 
> (Patches split into one patch per file for easier review, but the final
> commit will be one big patch. See the cover letter for more info.)
> 
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
> ---
>   drivers/net/wireless/ath/ath12k/peer.c | 343 +++++++++++++++++++++++++++++++++
>   1 file changed, 343 insertions(+)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/peer.c b/drivers/net/wireless/ath/ath12k/peer.c
> new file mode 100644
> index 000000000000..30ffdbbdcc7f
> --- /dev/null
> +++ b/drivers/net/wireless/ath/ath12k/peer.c
> @@ -0,0 +1,343 @@
> +// SPDX-License-Identifier: BSD-3-Clause-Clear
> +/*
> + * Copyright (c) 2018-2021 The Linux Foundation. All rights reserved.
> + * Copyright (c) 2021-2022 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include "core.h"
> +#include "peer.h"
> +#include "debug.h"
> +
> +struct ath12k_peer *ath12k_peer_find(struct ath12k_base *ab, int vdev_id,
> +				     const u8 *addr)
> +{
> +	struct ath12k_peer *peer;
> +
> +	lockdep_assert_held(&ab->base_lock);
> +
> +	list_for_each_entry(peer, &ab->peers, list) {
> +		if (peer->vdev_id != vdev_id)
> +			continue;
> +		if (!ether_addr_equal(peer->addr, addr))
> +			continue;
> +
> +		return peer;
> +	}
> +
> +	return NULL;
> +}
> +
> +static struct ath12k_peer *ath12k_peer_find_by_pdev_idx(struct ath12k_base *ab,
> +							u8 pdev_idx, const u8 *addr)
> +{
> +	struct ath12k_peer *peer;
> +
> +	lockdep_assert_held(&ab->base_lock);
> +
> +	list_for_each_entry(peer, &ab->peers, list) {
> +		if (peer->pdev_idx != pdev_idx)
> +			continue;
> +		if (!ether_addr_equal(peer->addr, addr))
> +			continue;
> +
> +		return peer;
> +	}
> +
> +	return NULL;
> +}
> +
> +struct ath12k_peer *ath12k_peer_find_by_addr(struct ath12k_base *ab,
> +					     const u8 *addr)
> +{
> +	struct ath12k_peer *peer;
> +
> +	lockdep_assert_held(&ab->base_lock);
> +
> +	list_for_each_entry(peer, &ab->peers, list) {
> +		if (!ether_addr_equal(peer->addr, addr))
> +			continue;
> +
> +		return peer;
> +	}
> +
> +	return NULL;
> +}
> +
> +struct ath12k_peer *ath12k_peer_find_by_id(struct ath12k_base *ab,
> +					   int peer_id)
> +{
> +	struct ath12k_peer *peer;
> +
> +	lockdep_assert_held(&ab->base_lock);
> +
> +	list_for_each_entry(peer, &ab->peers, list)
> +		if (peer_id == peer->peer_id)
> +			return peer;
> +
> +	return NULL;
> +}
> +
> +struct ath12k_peer *ath12k_peer_find_by_vdev_id(struct ath12k_base *ab,
> +						int vdev_id)
> +{
> +	struct ath12k_peer *peer;
> +
> +	spin_lock_bh(&ab->base_lock);

the other ath12k_peer_find_*() functions expect the caller to take the 
lock, but in this one the function itself takes the lock. why the 
discrepancy? should these have a consistent interface? note that the 
returned peer won't be protected by the lock.

note i see this is only used in one place, and there it doesn't use the 
peer, it just checks if it exists.

perhaps rename this to bool ath12k_peer_exists_by_vdev() to justify the 
difference in locking?


> +
> +	list_for_each_entry(peer, &ab->peers, list) {
> +		if (vdev_id == peer->vdev_id) {
> +			spin_unlock_bh(&ab->base_lock);
> +			return peer;
> +		}
> +	}
> +	spin_unlock_bh(&ab->base_lock);
> +	return NULL;
> +}

[...]