wireless: get rid of pointless request list

We really only need to know the last request at each point in time.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/wireless/reg.c

@@ -44,14 +44,13 @@
 
 /* wiphy is set if this request's initiator is REGDOM_SET_BY_DRIVER */
 struct regulatory_request {
-	struct list_head list;
 	struct wiphy *wiphy;
 	int granted;
 	enum reg_set_by initiator;
 	char alpha2[2];
 };
 
-static LIST_HEAD(regulatory_requests);
+static struct regulatory_request *last_request;
 
 /* To trigger userspace events */
 static struct platform_device *reg_pdev;
@@ -201,7 +200,7 @@ static void reset_regdomains(void)
  * core upon initialization */
 static void update_world_regdomain(const struct ieee80211_regdomain *rd)
 {
-	BUG_ON(list_empty(&regulatory_requests));
+	BUG_ON(!last_request);
 
 	reset_regdomains();
 
@@ -302,15 +301,10 @@ static int call_crda(const char *alpha2)
 static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
 	char *alpha2, struct ieee80211_regdomain *rd)
 {
-	struct regulatory_request *last_request = NULL;
-
 	/* All initial requests are respected */
-	if (list_empty(&regulatory_requests))
+	if (!last_request)
 		return 0;
 
-	last_request = list_first_entry(&regulatory_requests,
-		struct regulatory_request, list);
-
 	switch (set_by) {
 	case REGDOM_SET_BY_INIT:
 		return -EINVAL;
@@ -320,7 +314,7 @@ static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
 		 * anyway */
 		return 0;
 	case REGDOM_SET_BY_COUNTRY_IE:
-		if (last_request->initiator == set_by) {
+		if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
 			if (last_request->wiphy != wiphy) {
 				/* Two cards with two APs claiming different
 				 * different Country IE alpha2s!
@@ -350,7 +344,7 @@ static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
 		return 1;
 	case REGDOM_SET_BY_DRIVER:
 		BUG_ON(!wiphy);
-		if (last_request->initiator == set_by) {
+		if (last_request->initiator == REGDOM_SET_BY_DRIVER) {
 			/* Two separate drivers hinting different things,
 			 * this is possible if you have two devices present
 			 * on a system with different EEPROM regulatory
@@ -376,7 +370,7 @@ static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
 			return 0;
 		return 0;
 	case REGDOM_SET_BY_USER:
-		if (last_request->initiator == set_by ||
+		if (last_request->initiator == REGDOM_SET_BY_USER ||
 		    last_request->initiator == REGDOM_SET_BY_CORE)
 			return 0;
 		/* Drivers can use their wiphy's reg_notifier()
@@ -392,26 +386,13 @@ static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
 	}
 }
 
-static bool __reg_is_valid_request(const char *alpha2,
-	struct regulatory_request **request)
-{
-	struct regulatory_request *req;
-	if (list_empty(&regulatory_requests))
-		return false;
-	list_for_each_entry(req, &regulatory_requests, list) {
-		if (alpha2_equal(req->alpha2, alpha2)) {
-			*request = req;
-			return true;
-		}
-	}
-	return false;
-}
-
 /* Used by nl80211 before kmalloc'ing our regulatory domain */
 bool reg_is_valid_request(const char *alpha2)
 {
-	struct regulatory_request *request = NULL;
-	return  __reg_is_valid_request(alpha2, &request);
+	if (!last_request)
+		return false;
+
+	return alpha2_equal(last_request->alpha2, alpha2);
 }
 
 /* Sanity check on a regulatory rule */
@@ -607,7 +588,8 @@ int __regulatory_hint(struct wiphy *wiphy, enum reg_set_by set_by,
 		request->initiator = set_by;
 		request->wiphy = wiphy;
 
-		list_add_tail(&request->list, &regulatory_requests);
+		kfree(last_request);
+		last_request = request;
 		if (rd)
 			break;
 		r = call_crda(alpha2);
@@ -711,12 +693,10 @@ void print_regdomain_info(const struct ieee80211_regdomain *rd)
 
 static int __set_regdom(const struct ieee80211_regdomain *rd)
 {
-	struct regulatory_request *request = NULL;
-
 	/* Some basic sanity checks first */
 
 	if (is_world_regdom(rd->alpha2)) {
-		if (WARN_ON(!__reg_is_valid_request(rd->alpha2, &request)))
+		if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
 			return -EINVAL;
 		update_world_regdomain(rd);
 		return 0;
@@ -726,7 +706,7 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
 			!is_unknown_alpha2(rd->alpha2))
 		return -EINVAL;
 
-	if (list_empty(&regulatory_requests))
+	if (!last_request)
 		return -EINVAL;
 
 	/* allow overriding the static definitions if CRDA is present */
@@ -739,13 +719,13 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
 	 * to review or adjust their own settings based on their own
 	 * internal EEPROM data */
 
-	if (WARN_ON(!__reg_is_valid_request(rd->alpha2, &request)))
+	if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
 		return -EINVAL;
 
 	reset_regdomains();
 
 	/* Country IE parsing coming soon */
-	switch (request->initiator) {
+	switch (last_request->initiator) {
 	case REGDOM_SET_BY_CORE:
 	case REGDOM_SET_BY_DRIVER:
 	case REGDOM_SET_BY_USER:
@@ -764,7 +744,7 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
 
 	/* Tada! */
 	cfg80211_regdomain = rd;
-	request->granted = 1;
+	last_request->granted = 1;
 
 	return 0;
 }
@@ -776,42 +756,18 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
  * the passed rd. Caller must hold cfg80211_drv_mutex */
 int set_regdom(const struct ieee80211_regdomain *rd)
 {
-	struct regulatory_request *this_request = NULL, *prev_request = NULL;
 	int r;
 
-	if (!list_empty(&regulatory_requests))
-		prev_request = list_first_entry(&regulatory_requests,
-			struct regulatory_request, list);
-
 	/* Note that this doesn't update the wiphys, this is done below */
 	r = __set_regdom(rd);
 	if (r)
 		return r;
 
-	BUG_ON((!__reg_is_valid_request(rd->alpha2, &this_request)));
-
-	/* The initial standard core update of the world regulatory domain, no
-	 * need to keep that request info around if it didn't fail. */
-	if (is_world_regdom(rd->alpha2) &&
-			this_request->initiator == REGDOM_SET_BY_CORE &&
-			this_request->granted) {
-		list_del(&this_request->list);
-		kfree(this_request);
-		this_request = NULL;
-	}
-
-	/* Remove old requests, we only leave behind the last one */
-	if (prev_request) {
-		list_del(&prev_request->list);
-		kfree(prev_request);
-		prev_request = NULL;
-	}
-
 	/* This would make this whole thing pointless */
 	BUG_ON(rd != cfg80211_regdomain);
 
 	/* update all wiphys now with the new established regulatory domain */
-	update_all_wiphy_regulatory(this_request->initiator);
+	update_all_wiphy_regulatory(last_request->initiator);
 
 	print_regdomain(rd);
 
@@ -853,16 +809,12 @@ int regulatory_init(void)
 
 void regulatory_exit(void)
 {
-	struct regulatory_request *req, *req_tmp;
-
 	mutex_lock(&cfg80211_drv_mutex);
 
 	reset_regdomains();
 
-	list_for_each_entry_safe(req, req_tmp, &regulatory_requests, list) {
-		list_del(&req->list);
-		kfree(req);
-	}
+	kfree(last_request);
+
 	platform_device_unregister(reg_pdev);
 
 	mutex_unlock(&cfg80211_drv_mutex);