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: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Johannes Berg 2012-09-11 17:57:42 +02:00
parent 04ecd2578e
commit 3448c00583
2 changed files with 41 additions and 2 deletions

View File

@ -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().

View File

@ -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);