Commit 3448c005 authored by Johannes Berg's avatar Johannes Berg
Browse files

mac80211: add channel context iterator 



Drivers may need to iterate the active channel
contexts, export an iterator function to allow
that. To make it possible, use RCU-safe list
functions.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 04ecd257

include/net/mac80211.h

+21 −0
Original line number Diff line number Diff line
@@ -3596,6 +3596,27 @@ void ieee80211_iter_keys(struct ieee80211_hw *hw, 
				      void *data),

			 void *iter_data);



/**

 * ieee80211_iter_chan_contexts_atomic - iterate channel contexts

 * @hw: pointre obtained from ieee80211_alloc_hw().

 * @iter: iterator function

 * @iter_data: data passed to iterator function

 *

 * Iterate all active channel contexts. This function is atomic and

 * doesn't acquire any locks internally that might be held in other

 * places while calling into the driver.

 *

 * The iterator will not find a context that's being added (during

 * the driver callback to add it) but will find it while it's being

 * removed.

 */

void ieee80211_iter_chan_contexts_atomic(

	struct ieee80211_hw *hw,

	void (*iter)(struct ieee80211_hw *hw,

		     struct ieee80211_chanctx_conf *chanctx_conf,

		     void *data),

	void *iter_data);



/**

 * ieee80211_ap_probereq_get - retrieve a Probe Request template

 * @hw: pointer obtained from ieee80211_alloc_hw().

net/mac80211/chan.c

+20 −2
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 */



#include <linux/nl80211.h>

#include <linux/export.h>

#include <net/cfg80211.h>

#include "ieee80211_i.h"

#include "driver-ops.h"
@@ -134,7 +135,7 @@ ieee80211_new_chanctx(struct ieee80211_local *local, 
		}

	}



	list_add(&ctx->list, &local->chanctx_list);

	list_add_rcu(&ctx->list, &local->chanctx_list);



	return ctx;

}
@@ -153,7 +154,7 @@ static void ieee80211_free_chanctx(struct ieee80211_local *local, 
		drv_remove_chanctx(local, ctx);

	}



	list_del(&ctx->list);

	list_del_rcu(&ctx->list);

	kfree_rcu(ctx, rcu_head);

}
@@ -379,3 +380,20 @@ void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata) 
	__ieee80211_vif_release_channel(sdata);

	mutex_unlock(&sdata->local->chanctx_mtx);

}



void ieee80211_iter_chan_contexts_atomic(

	struct ieee80211_hw *hw,

	void (*iter)(struct ieee80211_hw *hw,

		     struct ieee80211_chanctx_conf *chanctx_conf,

		     void *data),

	void *iter_data)

{

	struct ieee80211_local *local = hw_to_local(hw);

	struct ieee80211_chanctx *ctx;



	rcu_read_lock();

	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)

		iter(hw, &ctx->conf, iter_data);

	rcu_read_unlock();

}

EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);