Re: [PATCH 1/1] mac80211: restructure __ieee80211_rx

[Johannes Berg <johannes@sipsolutions.net>]

[-- Attachment #1: Type: text/plain, Size: 6104 bytes --]


On Mon, 2007-12-24 at 13:36 +0200, Ron Rindjunsky wrote:
> This patch makes a separation between Rx frame pre-handling which stays in
> __ieee80211_rx and Rx frame handlers, moving to __ieee80211_rx_handle_packet.
> Although this separation has no affect in regular mode of operation, this kind
> of mechanism will be used in A-MPDU frames reordering as it allows accumulation
> of frames during pre-handling, dispatching them to later handling when necessary.
> 
> Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>

That looks really good to me. I'll remove the qos pre-handler too after
you get your a-mpdu patches into the tree.

Acked-by: Johannes Berg <johannes@sipsolutions.net>

> ---
>  net/mac80211/rx.c |   86 ++++++++++++++++++++++++++++++----------------------
>  1 files changed, 50 insertions(+), 36 deletions(-)
> 
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index e94cf30..bcc232c 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -272,11 +272,11 @@ ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
>  	return TXRX_CONTINUE;
>  }
>  
> -static ieee80211_txrx_result
> -ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
> +
> +u32 ieee80211_rx_load_stats(struct ieee80211_local *local,
> +			      struct sk_buff *skb,
> +			      struct ieee80211_rx_status *status)
>  {
> -	struct ieee80211_local *local = rx->local;
> -	struct sk_buff *skb = rx->skb;
>  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
>  	u32 load = 0, hdrtime;
>  	struct ieee80211_rate *rate;
> @@ -290,7 +290,7 @@ ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
>  
>  	rate = &mode->rates[0];
>  	for (i = 0; i < mode->num_rates; i++) {
> -		if (mode->rates[i].val == rx->u.rx.status->rate) {
> +		if (mode->rates[i].val == status->rate) {
>  			rate = &mode->rates[i];
>  			break;
>  		}
> @@ -315,15 +315,13 @@ ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
>  	/* Divide channel_use by 8 to avoid wrapping around the counter */
>  	load >>= CHAN_UTIL_SHIFT;
>  	local->channel_use_raw += load;
> -	rx->u.rx.load = load;
>  
> -	return TXRX_CONTINUE;
> +	return load;
>  }
>  
>  ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
>  {
>  	ieee80211_rx_h_parse_qos,
> -	ieee80211_rx_h_load_stats,
>  	NULL
>  };
>  
> @@ -1594,11 +1592,11 @@ static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
>  }
>  
>  /*
> - * This is the receive path handler. It is called by a low level driver when an
> - * 802.11 MPDU is received from the hardware.
> + * This is the actual Rx frames handler. as it blongs to Rx path it must
> + * be called with rcu_read_lock protection.
>   */
> -void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
> -		    struct ieee80211_rx_status *status)
> +void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw, struct sk_buff *skb,
> +			    struct ieee80211_rx_status *status, u32 load)
>  {
>  	struct ieee80211_local *local = hw_to_local(hw);
>  	struct ieee80211_sub_if_data *sdata;
> @@ -1606,36 +1604,18 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
>  	struct ieee80211_hdr *hdr;
>  	struct ieee80211_txrx_data rx;
>  	u16 type;
> -	int prepres;
> +	int prepares;
>  	struct ieee80211_sub_if_data *prev = NULL;
>  	struct sk_buff *skb_new;
>  	u8 *bssid;
>  
> -	/*
> -	 * key references and virtual interfaces are protected using RCU
> -	 * and this requires that we are in a read-side RCU section during
> -	 * receive processing
> -	 */
> -	rcu_read_lock();
> -
> -	/*
> -	 * Frames with failed FCS/PLCP checksum are not returned,
> -	 * all other frames are returned without radiotap header
> -	 * if it was previously present.
> -	 * Also, frames with less than 16 bytes are dropped.
> -	 */
> -	skb = ieee80211_rx_monitor(local, skb, status);
> -	if (!skb) {
> -		rcu_read_unlock();
> -		return;
> -	}
> -
>  	hdr = (struct ieee80211_hdr *) skb->data;
>  	memset(&rx, 0, sizeof(rx));
>  	rx.skb = skb;
>  	rx.local = local;
>  
>  	rx.u.rx.status = status;
> +	rx.u.rx.load = load;
>  	rx.fc = le16_to_cpu(hdr->frame_control);
>  	type = rx.fc & IEEE80211_FCTL_FTYPE;
>  
> @@ -1682,11 +1662,11 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
>  			continue;
>  
>  		rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
> -		prepres = prepare_for_handlers(sdata, bssid, &rx, hdr);
> +		prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
>  		/* prepare_for_handlers can change sta */
>  		sta = rx.sta;
>  
> -		if (!prepres)
> +		if (!prepares)
>  			continue;
>  
>  		/*
> @@ -1731,11 +1711,45 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
>  		dev_kfree_skb(skb);
>  
>   end:
> -	rcu_read_unlock();
> -
>  	if (sta)
>  		sta_info_put(sta);
>  }
> +
> +/*
> + * This is the receive path handler. It is called by a low level driver when an
> + * 802.11 MPDU is received from the hardware.
> + */
> +void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
> +		    struct ieee80211_rx_status *status)
> +{
> +	struct ieee80211_local *local = hw_to_local(hw);
> +	u32 pkt_load;
> +
> +	/*
> +	 * key references and virtual interfaces are protected using RCU
> +	 * and this requires that we are in a read-side RCU section during
> +	 * receive processing
> +	 */
> +	rcu_read_lock();
> +
> +	/*
> +	 * Frames with failed FCS/PLCP checksum are not returned,
> +	 * all other frames are returned without radiotap header
> +	 * if it was previously present.
> +	 * Also, frames with less than 16 bytes are dropped.
> +	 */
> +	skb = ieee80211_rx_monitor(local, skb, status);
> +	if (!skb) {
> +		rcu_read_unlock();
> +		return;
> +	}
> +
> +	pkt_load = ieee80211_rx_load_stats(local, skb, status);
> +
> +	__ieee80211_rx_handle_packet(hw, skb, status, pkt_load);
> +
> +	rcu_read_unlock();
> +}
>  EXPORT_SYMBOL(__ieee80211_rx);
>  
>  /* This is a version of the rx handler that can be called from hard irq

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 828 bytes --]