From 38fd2143fa653f80729800c1d61d4207b91dca42 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 10 May 2013 19:17:17 +0200 Subject: [PATCH] regulatory: remove reg_mutex The reg_mutex is similar to the ones I just removed in cfg80211 but even less useful since it protects global data, and we hold the RTNL in all places (except module unload) already. Signed-off-by: Johannes Berg --- net/wireless/reg.c | 76 ++++++++++++++---------------------------------------- 1 file changed, 19 insertions(+), 57 deletions(-) diff --git a/net/wireless/reg.c b/net/wireless/reg.c index 17e5ecc..e1d6749 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -81,7 +81,10 @@ static struct regulatory_request core_request_world = { .country_ie_env = ENVIRON_ANY, }; -/* Receipt of information from last regulatory request */ +/* + * Receipt of information from last regulatory request, + * protected by RTNL (and can be accessed with RCU protection) + */ static struct regulatory_request __rcu *last_request = (void __rcu *)&core_request_world; @@ -96,39 +99,25 @@ static struct device_type reg_device_type = { * Central wireless core regulatory domains, we only need two, * the current one and a world regulatory domain in case we have no * information to give us an alpha2. + * (protected by RTNL, can be read under RCU) */ const struct ieee80211_regdomain __rcu *cfg80211_regdomain; /* - * Protects static reg.c components: - * - cfg80211_regdomain (if not used with RCU) - * - cfg80211_world_regdom - * - last_request (if not used with RCU) - * - reg_num_devs_support_basehint - */ -static DEFINE_MUTEX(reg_mutex); - -/* * Number of devices that registered to the core * that support cellular base station regulatory hints + * (protected by RTNL) */ static int reg_num_devs_support_basehint; -static inline void assert_reg_lock(void) -{ - lockdep_assert_held(®_mutex); -} - static const struct ieee80211_regdomain *get_cfg80211_regdom(void) { - return rcu_dereference_protected(cfg80211_regdomain, - lockdep_is_held(®_mutex)); + return rtnl_dereference(cfg80211_regdomain); } static const struct ieee80211_regdomain *get_wiphy_regdom(struct wiphy *wiphy) { - return rcu_dereference_protected(wiphy->regd, - lockdep_is_held(®_mutex)); + return rtnl_dereference(wiphy->regd); } static void rcu_free_regdom(const struct ieee80211_regdomain *r) @@ -140,8 +129,7 @@ static void rcu_free_regdom(const struct ieee80211_regdomain *r) static struct regulatory_request *get_last_request(void) { - return rcu_dereference_check(last_request, - lockdep_is_held(®_mutex)); + return rcu_dereference_rtnl(last_request); } /* Used to queue up regulatory hints */ @@ -200,6 +188,7 @@ static const struct ieee80211_regdomain world_regdom = { } }; +/* protected by RTNL */ static const struct ieee80211_regdomain *cfg80211_world_regdom = &world_regdom; @@ -215,7 +204,7 @@ static void reset_regdomains(bool full_reset, const struct ieee80211_regdomain *r; struct regulatory_request *lr; - assert_reg_lock(); + ASSERT_RTNL(); r = get_cfg80211_regdom(); @@ -936,13 +925,7 @@ static bool reg_request_cell_base(struct regulatory_request *request) bool reg_last_request_cell_base(void) { - bool val; - - mutex_lock(®_mutex); - val = reg_request_cell_base(get_last_request()); - mutex_unlock(®_mutex); - - return val; + return reg_request_cell_base(get_last_request()); } #ifdef CONFIG_CFG80211_CERTIFICATION_ONUS @@ -1444,8 +1427,6 @@ static void reg_set_request_processed(void) * what it believes should be the current regulatory domain. * * Returns one of the different reg request treatment values. - * - * Caller must hold ®_mutex */ static enum reg_request_treatment __regulatory_hint(struct wiphy *wiphy, @@ -1622,10 +1603,8 @@ static void reg_process_pending_beacon_hints(void) static void reg_todo(struct work_struct *work) { rtnl_lock(); - mutex_lock(®_mutex); reg_process_pending_hints(); reg_process_pending_beacon_hints(); - mutex_unlock(®_mutex); rtnl_unlock(); } @@ -1851,8 +1830,6 @@ static void restore_regulatory_settings(bool reset_user) ASSERT_RTNL(); - mutex_lock(®_mutex); - reset_regdomains(true, &world_regdom); restore_alpha2(alpha2, reset_user); @@ -1906,8 +1883,6 @@ static void restore_regulatory_settings(bool reset_user) list_splice_tail_init(&tmp_reg_req_list, ®_requests_list); spin_unlock(®_requests_lock); - mutex_unlock(®_mutex); - REG_DBG_PRINT("Kicking the queue\n"); schedule_work(®_work); @@ -2222,7 +2197,6 @@ int set_regdom(const struct ieee80211_regdomain *rd) struct regulatory_request *lr; int r; - mutex_lock(®_mutex); lr = get_last_request(); /* Note that this doesn't update the wiphys, this is done below */ @@ -2232,14 +2206,12 @@ int set_regdom(const struct ieee80211_regdomain *rd) reg_set_request_processed(); kfree(rd); - goto out; + return r; } /* This would make this whole thing pointless */ - if (WARN_ON(!lr->intersect && rd != get_cfg80211_regdom())) { - r = -EINVAL; - goto out; - } + if (WARN_ON(!lr->intersect && rd != get_cfg80211_regdom())) + return -EINVAL; /* update all wiphys now with the new established regulatory domain */ update_all_wiphy_regulatory(lr->initiator); @@ -2250,10 +2222,7 @@ int set_regdom(const struct ieee80211_regdomain *rd) reg_set_request_processed(); - out: - mutex_unlock(®_mutex); - - return r; + return 0; } int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env) @@ -2278,14 +2247,10 @@ int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env) void wiphy_regulatory_register(struct wiphy *wiphy) { - mutex_lock(®_mutex); - if (!reg_dev_ignore_cell_hint(wiphy)) reg_num_devs_support_basehint++; wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE); - - mutex_unlock(®_mutex); } void wiphy_regulatory_deregister(struct wiphy *wiphy) @@ -2293,7 +2258,6 @@ void wiphy_regulatory_deregister(struct wiphy *wiphy) struct wiphy *request_wiphy = NULL; struct regulatory_request *lr; - mutex_lock(®_mutex); lr = get_last_request(); if (!reg_dev_ignore_cell_hint(wiphy)) @@ -2306,12 +2270,10 @@ void wiphy_regulatory_deregister(struct wiphy *wiphy) request_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx); if (!request_wiphy || request_wiphy != wiphy) - goto out; + return; lr->wiphy_idx = WIPHY_IDX_INVALID; lr->country_ie_env = ENVIRON_ANY; -out: - mutex_unlock(®_mutex); } static void reg_timeout_work(struct work_struct *work) @@ -2375,9 +2337,9 @@ void regulatory_exit(void) cancel_delayed_work_sync(®_timeout); /* Lock to suppress warnings */ - mutex_lock(®_mutex); + rtnl_lock(); reset_regdomains(true, NULL); - mutex_unlock(®_mutex); + rtnl_unlock(); dev_set_uevent_suppress(®_pdev->dev, true); -- 2.7.4