qcacld-3.0: Use request manager for Class A stats

We are transitioning to the new request manager framework. Change
wlan_hdd_get_class_astats() and hdd_get_class_a_statistics_cb() to
this framework.

Change-Id: I6cfa2155187e3d9ac4099f1e4480835917fd9ca6
CRs-Fixed: 2005302

core/hdd/src/wlan_hdd_wext.c

@@ -94,6 +94,7 @@
 #endif
 #include "wlan_hdd_lro.h"
 #include "cds_utils.h"
+#include "wlan_hdd_request_manager.h"
 
 #define HDD_FINISH_ULA_TIME_OUT         800
 #define HDD_SET_MCBC_FILTERS_TO_FW      1
@@ -4219,60 +4220,43 @@ static int iw_get_range(struct net_device *dev, struct iw_request_info *info,
 	return ret;
 }
 
+struct class_a_stats {
+	tCsrGlobalClassAStatsInfo class_a_stats;
+};
+
 /**
  * hdd_get_class_a_statistics_cb() - Get Class A stats callback function
- * @pStats: pointer to Class A stats
- * @pContext: user context originally registered with SME
+ * @stats: pointer to Class A stats
+ * @context: user context originally registered with SME (always the
+ *	cookie from the request context)
  *
  * Return: None
  */
-static void hdd_get_class_a_statistics_cb(void *pStats, void *pContext)
+static void hdd_get_class_a_statistics_cb(void *stats, void *context)
 {
-	struct statsContext *pStatsContext;
-	tCsrGlobalClassAStatsInfo *pClassAStats;
-	hdd_adapter_t *pAdapter;
+	struct hdd_request *request;
+	struct class_a_stats *priv;
+	tCsrGlobalClassAStatsInfo *returned_stats;
 
-	if ((NULL == pStats) || (NULL == pContext)) {
-		hdd_err("Bad param, pStats [%p] pContext [%p]",
-			pStats, pContext);
+	ENTER();
+	if ((NULL == stats) || (NULL == context)) {
+		hdd_err("Bad param, stats [%p] context [%p]",
+			stats, context);
 		return;
 	}
 
-	pClassAStats = pStats;
-	pStatsContext = pContext;
-	pAdapter = pStatsContext->pAdapter;
-
-	/* there is a race condition that exists between this callback
-	 * function and the caller since the caller could time out
-	 * either before or while this code is executing.  we use a
-	 * spinlock to serialize these actions
-	 */
-	spin_lock(&hdd_context_lock);
-
-	if ((NULL == pAdapter) ||
-	    (STATS_CONTEXT_MAGIC != pStatsContext->magic)) {
-		/* the caller presumably timed out so there is nothing
-		 * we can do
-		 */
-		spin_unlock(&hdd_context_lock);
-		hdd_warn("Invalid context, pAdapter [%p] magic [%08x]",
-			 pAdapter, pStatsContext->magic);
+	request = hdd_request_get(context);
+	if (!request) {
+		hdd_err("Obsolete request");
 		return;
 	}
 
-	/* context is valid so caller is still waiting */
-
-	/* paranoia: invalidate the magic */
-	pStatsContext->magic = 0;
-
-	/* copy over the stats. do so as a struct copy */
-	pAdapter->hdd_stats.ClassA_stat = *pClassAStats;
-
-	/* notify the caller */
-	complete(&pStatsContext->completion);
-
-	/* serialization is complete */
-	spin_unlock(&hdd_context_lock);
+	returned_stats = stats;
+	priv = hdd_request_priv(request);
+	priv->class_a_stats = *returned_stats;
+	hdd_request_complete(request);
+	hdd_request_put(request);
+	EXIT();
 }
 
 /**
@@ -4285,8 +4269,14 @@ QDF_STATUS wlan_hdd_get_class_astats(hdd_adapter_t *pAdapter)
 {
 	hdd_station_ctx_t *pHddStaCtx = WLAN_HDD_GET_STATION_CTX_PTR(pAdapter);
 	QDF_STATUS hstatus;
-	unsigned long rc;
-	static struct statsContext context;
+	int ret;
+	void *cookie;
+	struct hdd_request *request;
+	struct class_a_stats *priv;
+	static const struct hdd_request_params params = {
+		.priv_size = sizeof(*priv),
+		.timeout_ms = WLAN_WAIT_TIME_STATS,
+	};
 
 	if (NULL == pAdapter) {
 		hdd_err("pAdapter is NULL");
@@ -4298,10 +4288,13 @@ QDF_STATUS wlan_hdd_get_class_astats(hdd_adapter_t *pAdapter)
 		return QDF_STATUS_SUCCESS;
 	}
 
-	/* we are connected so prepare our callback context */
-	init_completion(&context.completion);
-	context.pAdapter = pAdapter;
-	context.magic = STATS_CONTEXT_MAGIC;
+	request = hdd_request_alloc(&params);
+	if (!request) {
+		hdd_err("Request allocation failure");
+		return QDF_STATUS_E_NOMEM;
+	}
+	cookie = hdd_request_cookie(request);
+
 	/* query only for Class A statistics (which include link speed) */
 	hstatus = sme_get_statistics(WLAN_HDD_GET_HAL_CTX(pAdapter),
 				     eCSR_HDD, SME_GLOBAL_CLASSA_STATS,
@@ -4309,38 +4302,31 @@ QDF_STATUS wlan_hdd_get_class_astats(hdd_adapter_t *pAdapter)
 				     0, /* not periodic */
 				     false, /* non-cached results */
 				     pHddStaCtx->conn_info.staId[0],
-				     &context, pAdapter->sessionId);
+				     cookie, pAdapter->sessionId);
 	if (QDF_STATUS_SUCCESS != hstatus) {
 		hdd_warn("Unable to retrieve Class A statistics");
-		/* we'll returned a cached value below */
-	} else {
-		/* request was sent -- wait for the response */
-		rc = wait_for_completion_timeout
-			(&context.completion,
-			 msecs_to_jiffies(WLAN_WAIT_TIME_STATS));
-		if (!rc) {
-			hdd_warn("SME timed out while retrieving Class A statistics");
-		}
+		goto return_cached_results;
 	}
 
-	/* either we never sent a request, we sent a request and
-	 * received a response or we sent a request and timed out.  if
-	 * we never sent a request or if we sent a request and got a
-	 * response, we want to clear the magic out of paranoia.  if
-	 * we timed out there is a race condition such that the
-	 * callback function could be executing at the same time we
-	 * are. of primary concern is if the callback function had
-	 * already verified the "magic" but had not yet set the
-	 * completion variable when a timeout occurred. we serialize
-	 * these activities by invalidating the magic while holding a
-	 * shared spinlock which will cause us to block if the
-	 * callback is currently executing
-	 */
-	spin_lock(&hdd_context_lock);
-	context.magic = 0;
-	spin_unlock(&hdd_context_lock);
+	/* request was sent -- wait for the response */
+	ret = hdd_request_wait_for_response(request);
+	if (ret) {
+		hdd_warn("SME timed out while retrieving Class A statistics");
+		goto return_cached_results;
+	}
+
+	/* update the adapter with the fresh results */
+	priv = hdd_request_priv(request);
+	pAdapter->hdd_stats.ClassA_stat = priv->class_a_stats;
+
+return_cached_results:
+	/*
+	 * either we never sent a request, we sent a request and
+	 * received a response or we sent a request and timed out.
+	 * regardless we are done with the request.
+	 */
+	hdd_request_put(request);
 
-	/* either callback updated pAdapter stats or it has cached data */
 	return QDF_STATUS_SUCCESS;
 }