On Wed, Feb 12, 2014 at 10:38 PM, Johannes Berg
<johannes@xxxxxxxxxxxxxxxx> wrote:
> From: Johannes Berg <johannes.berg@xxxxxxxxx>
>
> NAPI was originally added to mac80211 a long time ago (by John in
> commit 4e6cbfd09c66 in July 2010), but then removed years later
> (by Stanislaw in commit 30c97120c6c7 in February 2013). No driver
> ever used it, so that was fine.
>
> Now I'm adding support for NAPI to our driver, so add some code
> to mac80211 again to support NAPI. John was originally wrapping
> some (but not nearly all NAPI-related functions), but that doesn't
> scale very well with the number of functions that are there, some
> of which are even only inlines. Thus, instead of doing that, let
> the drivers manage the NAPI struct, except for napi_add() which is
> needed so mac80211 knows how to call napi_gro_receive().
>
> Also remove some no longer needed definitions that were left when
> NAPI support was removed.
>
> Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
> Reviewed-by: Eyal Shapira <eyal@xxxxxxxxxx>
> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
> ---
> include/net/mac80211.h | 34 +++++++++++++---------------------
> net/mac80211/ieee80211_i.h | 2 ++
> net/mac80211/main.c | 12 ++++++++++++
> net/mac80211/rx.c | 5 ++++-
> 4 files changed, 31 insertions(+), 22 deletions(-)
>
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index 4005c5b..2d4d312 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -1642,10 +1642,6 @@ enum ieee80211_hw_flags {
> * the hw can report back.
> * @max_rate_tries: maximum number of tries for each stage
> *
> - * @napi_weight: weight used for NAPI polling. You must specify an
> - * appropriate value here if a napi_poll operation is provided
> - * by your driver.
> - *
> * @max_rx_aggregation_subframes: maximum buffer size (number of
> * sub-frames) to be used for A-MPDU block ack receiver
> * aggregation.
> @@ -1699,7 +1695,6 @@ struct ieee80211_hw {
> int vif_data_size;
> int sta_data_size;
> int chanctx_data_size;
> - int napi_weight;
> u16 queues;
> u16 max_listen_interval;
> s8 max_signal;
> @@ -2622,8 +2617,6 @@ enum ieee80211_roc_type {
> * callback. They must then call ieee80211_chswitch_done() to indicate
> * completion of the channel switch.
> *
> - * @napi_poll: Poll Rx queue for incoming data frames.
> - *
> * @set_antenna: Set antenna configuration (tx_ant, rx_ant) on the device.
> * Parameters are bitmaps of allowed antennas to use for TX/RX. Drivers may
> * reject TX/RX mask combinations they cannot support by returning -EINVAL
> @@ -2882,7 +2875,6 @@ struct ieee80211_ops {
> void (*flush)(struct ieee80211_hw *hw, u32 queues, bool drop);
> void (*channel_switch)(struct ieee80211_hw *hw,
> struct ieee80211_channel_switch *ch_switch);
> - int (*napi_poll)(struct ieee80211_hw *hw, int budget);
> int (*set_antenna)(struct ieee80211_hw *hw, u32 tx_ant, u32 rx_ant);
> int (*get_antenna)(struct ieee80211_hw *hw, u32 *tx_ant, u32 *rx_ant);
>
> @@ -3164,21 +3156,21 @@ void ieee80211_free_hw(struct ieee80211_hw *hw);
> */
> void ieee80211_restart_hw(struct ieee80211_hw *hw);
>
> -/** ieee80211_napi_schedule - schedule NAPI poll
> - *
> - * Use this function to schedule NAPI polling on a device.
> - *
> - * @hw: the hardware to start polling
> - */
> -void ieee80211_napi_schedule(struct ieee80211_hw *hw);
> -
> -/** ieee80211_napi_complete - complete NAPI polling
> - *
> - * Use this function to finish NAPI polling on a device.
> +/**
> + * ieee80211_napi_add - initialize mac80211 NAPI context
> + * @hw: the hardware to initialize the NAPI context on
> + * @napi: the NAPI context to initialize
> + * @napi_dev: dummy NAPI netdevice, here to not waste the space if the
> + * driver doesn't use NAPI
> + * @poll: poll function
> + * @weight: default weight
> *
> - * @hw: the hardware to stop polling
> + * See also netif_napi_add().
> */
> -void ieee80211_napi_complete(struct ieee80211_hw *hw);
> +void ieee80211_napi_add(struct ieee80211_hw *hw, struct napi_struct *napi,
> + struct net_device *napi_dev,
> + int (*poll)(struct napi_struct *, int),
> + int weight);
>
> /**
> * ieee80211_rx - receive frame
> diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
> index 0014b53..8603dfb 100644
> --- a/net/mac80211/ieee80211_i.h
> +++ b/net/mac80211/ieee80211_i.h
> @@ -1242,6 +1242,8 @@ struct ieee80211_local {
>
> struct ieee80211_sub_if_data __rcu *p2p_sdata;
>
> + struct napi_struct *napi;
> +
> /* virtual monitor interface */
> struct ieee80211_sub_if_data __rcu *monitor_sdata;
> struct cfg80211_chan_def monitor_chandef;
> diff --git a/net/mac80211/main.c b/net/mac80211/main.c
> index 1f7d842..b055f6a5 100644
> --- a/net/mac80211/main.c
> +++ b/net/mac80211/main.c
> @@ -1076,6 +1076,18 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
> }
> EXPORT_SYMBOL(ieee80211_register_hw);
>
> +void ieee80211_napi_add(struct ieee80211_hw *hw, struct napi_struct *napi,
> + struct net_device *napi_dev,
> + int (*poll)(struct napi_struct *, int),
> + int weight)
> +{
> + struct ieee80211_local *local = hw_to_local(hw);
> +
> + netif_napi_add(napi_dev, napi, poll, weight);
> + local->napi = napi;
I'm not really familiar with NAPI, but shouldn't netif_napi_del be
called at some point? And if so, it will leave mac80211 in an
inconsistent state.
Maybe if we make it part of ieee80211_register/unregister_hw the
scoping of local->napi will be nicer?
Arik
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