From acb99b9b2a08f439a13eafffd2a59b798d983462 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Tue, 28 Dec 2021 22:14:53 +0100 Subject: [PATCH] mac80211: Add stations iterator where the iterator function may sleep ieee80211_iterate_active_interfaces() and ieee80211_iterate_active_interfaces_atomic() already exist, where the former allows the iterator function to sleep. Add ieee80211_iterate_stations() which is similar to ieee80211_iterate_stations_atomic() but allows the iterator to sleep. This is needed for adding SDIO support to the rtw88 driver. Some interators there are reading or writing registers. With the SDIO ops (sdio_readb, sdio_writeb and friends) this means that the iterator function may sleep. Signed-off-by: Martin Blumenstingl Link: https://lore.kernel.org/r/20211228211501.468981-2-martin.blumenstingl@googlemail.com Signed-off-by: Johannes Berg --- include/net/mac80211.h | 21 +++++++++++++++++++++ net/mac80211/util.c | 13 +++++++++++++ 2 files changed, 34 insertions(+) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 8907338d52b5..c50221d7e82c 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -5614,6 +5614,9 @@ void ieee80211_iterate_active_interfaces_atomic(struct ieee80211_hw *hw, * This function iterates over the interfaces associated with a given * hardware that are currently active and calls the callback for them. * This version can only be used while holding the wiphy mutex. + * The driver must not call this with a lock held that it can also take in + * response to callbacks from mac80211, and it must not call this within + * callbacks made by mac80211 - both would result in deadlocks. * * @hw: the hardware struct of which the interfaces should be iterated over * @iter_flags: iteration flags, see &enum ieee80211_interface_iteration_flags @@ -5627,6 +5630,24 @@ void ieee80211_iterate_active_interfaces_mtx(struct ieee80211_hw *hw, struct ieee80211_vif *vif), void *data); +/** + * ieee80211_iterate_stations - iterate stations + * + * This function iterates over all stations associated with a given + * hardware that are currently uploaded to the driver and calls the callback + * function for them. + * This function allows the iterator function to sleep, when the iterator + * function is atomic @ieee80211_iterate_stations_atomic can be used. + * + * @hw: the hardware struct of which the interfaces should be iterated over + * @iterator: the iterator function to call, cannot sleep + * @data: first argument of the iterator function + */ +void ieee80211_iterate_stations(struct ieee80211_hw *hw, + void (*iterator)(void *data, + struct ieee80211_sta *sta), + void *data); + /** * ieee80211_iterate_stations_atomic - iterate stations * diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 0e4e1956bcea..f71b042a5c8b 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -862,6 +862,19 @@ static void __iterate_stations(struct ieee80211_local *local, } } +void ieee80211_iterate_stations(struct ieee80211_hw *hw, + void (*iterator)(void *data, + struct ieee80211_sta *sta), + void *data) +{ + struct ieee80211_local *local = hw_to_local(hw); + + mutex_lock(&local->sta_mtx); + __iterate_stations(local, iterator, data); + mutex_unlock(&local->sta_mtx); +} +EXPORT_SYMBOL_GPL(ieee80211_iterate_stations); + void ieee80211_iterate_stations_atomic(struct ieee80211_hw *hw, void (*iterator)(void *data, struct ieee80211_sta *sta), -- 2.39.5