qcacmn: Drop beacon/probe frames posted on Scan Queue if queue is full

Drop beacon/probe frames before posting on Scan queue if the queue
already has too many beacon/probes to process.

Also add scheduler API to get the queue size given the module ID.

Change-Id: I9153c7e77e74377863774b68e8163839e992358d
CRs-Fixed: 2298584

scheduler/inc/scheduler_api.h

@@ -283,4 +283,14 @@ QDF_STATUS scheduler_deregister_wma_legacy_handler(void);
  */
 void scheduler_mc_timer_callback(unsigned long data);
 
+/**
+ * scheduler_get_queue_size() - Get the current size of the scheduler queue
+ * @qid: Queue ID for which the size is requested
+ * @size: Pointer to size where the size would be returned to the caller
+ *
+ * This API finds the size of the scheduler queue for the given Queue ID
+ *
+ * Return: QDF Status
+ */
+QDF_STATUS scheduler_get_queue_size(QDF_MODULE_ID qid, uint32_t *size);
 #endif

scheduler/src/scheduler_api.c

@@ -619,3 +619,30 @@ void scheduler_mc_timer_callback(unsigned long data)
 	if (QDF_IS_STATUS_ERROR(status))
 		sched_err("Could not enqueue timer to timer queue");
 }
+
+QDF_STATUS scheduler_get_queue_size(QDF_MODULE_ID qid, uint32_t *size)
+{
+	uint8_t qidx;
+	struct scheduler_mq_type *target_mq;
+	struct scheduler_ctx *sched_ctx;
+
+	sched_ctx = scheduler_get_context();
+	if (!sched_ctx)
+		return QDF_STATUS_E_INVAL;
+
+	/* WMA also uses the target_if queue, so replace the QID */
+	if (QDF_MODULE_ID_WMA == qid)
+		qid = QDF_MODULE_ID_TARGET_IF;
+
+	qidx = sched_ctx->queue_ctx.scheduler_msg_qid_to_qidx[qid];
+	if (qidx >= SCHEDULER_NUMBER_OF_MSG_QUEUE) {
+		sched_err("Scheduler is deinitialized");
+		return QDF_STATUS_E_FAILURE;
+	}
+
+	target_mq = &(sched_ctx->queue_ctx.sch_msg_q[qidx]);
+
+	*size = qdf_list_size(&target_mq->mq_list);
+
+	return QDF_STATUS_SUCCESS;
+}

umac/scan/core/src/wlan_scan_main.h

@@ -44,6 +44,18 @@
 #define scm_debug(params...) \
 	QDF_TRACE_DEBUG(QDF_MODULE_ID_SCAN, params)
 
+/* Rate Limited Logs */
+#define scm_alert_rl(params...) \
+	QDF_TRACE_FATAL_RL(QDF_MODULE_ID_SCAN, params)
+#define scm_err_rl(params...) \
+	QDF_TRACE_ERROR_RL(QDF_MODULE_ID_SCAN, params)
+#define scm_warn_rl(params...) \
+	QDF_TRACE_WARN_RL(QDF_MODULE_ID_SCAN, params)
+#define scm_info_rl(params...) \
+	QDF_TRACE_INFO_RL(QDF_MODULE_ID_SCAN, params)
+#define scm_debug_rl(params...) \
+	QDF_TRACE_DEBUG_RL(QDF_MODULE_ID_SCAN, params)
+
 #define scm_nofl_alert(params...) \
 	QDF_TRACE_FATAL_NO_FL(QDF_MODULE_ID_SCAN, params)
 #define scm_nofl_err(params...) \

umac/scan/dispatcher/inc/wlan_scan_public_structs.h

@@ -69,6 +69,12 @@ typedef uint32_t wlan_scan_id;
 #define MAX_INDEX_SCORE 100
 #define MAX_INDEX_PER_INI 4
 
+#ifdef CONFIG_MCL
+#define MAX_BCN_PROBE_IN_SCAN_QUEUE 150
+#else
+#define MAX_BCN_PROBE_IN_SCAN_QUEUE 2000
+#endif
+
 #define WLAN_GET_BITS(_val, _index, _num_bits) \
 	(((_val) >> (_index)) & ((1 << (_num_bits)) - 1))
 

umac/scan/dispatcher/src/wlan_scan_tgt_api.c

@@ -257,29 +257,29 @@ QDF_STATUS tgt_scan_bcn_probe_rx_callback(struct wlan_objmgr_psoc *psoc,
 	enum mgmt_frame_type frm_type)
 {
 	struct scheduler_msg msg = {0};
-	struct scan_bcn_probe_event *bcn;
+	struct scan_bcn_probe_event *bcn = NULL;
 	QDF_STATUS status;
+	uint32_t scan_queue_size = 0;
 
 	if ((frm_type != MGMT_PROBE_RESP) &&
 	   (frm_type != MGMT_BEACON)) {
 		scm_err("frame is not beacon or probe resp");
-		qdf_nbuf_free(buf);
-		return QDF_STATUS_E_INVAL;
+		status = QDF_STATUS_E_INVAL;
+		goto free;
 	}
 	bcn = qdf_mem_malloc_atomic(sizeof(*bcn));
 
 	if (!bcn) {
 		scm_err("Failed to allocate memory for bcn");
-		qdf_nbuf_free(buf);
-		return QDF_STATUS_E_NOMEM;
+		status = QDF_STATUS_E_NOMEM;
+		goto free;
 	}
 	bcn->rx_data =
 		qdf_mem_malloc_atomic(sizeof(*rx_param));
 	if (!bcn->rx_data) {
 		scm_err("Failed to allocate memory for rx_data");
-		qdf_mem_free(bcn);
-		qdf_nbuf_free(buf);
-		return QDF_STATUS_E_NOMEM;
+		status = QDF_STATUS_E_NOMEM;
+		goto free;
 	}
 
 	if (frm_type == MGMT_PROBE_RESP)
@@ -287,13 +287,20 @@ QDF_STATUS tgt_scan_bcn_probe_rx_callback(struct wlan_objmgr_psoc *psoc,
 	else
 		bcn->frm_type = MGMT_SUBTYPE_BEACON;
 
+	/* Check if the beacon/probe frame can be posted in the scan queue */
+	status = scheduler_get_queue_size(QDF_MODULE_ID_SCAN, &scan_queue_size);
+	if (!QDF_IS_STATUS_SUCCESS(status) ||
+	    scan_queue_size > MAX_BCN_PROBE_IN_SCAN_QUEUE) {
+		scm_debug_rl("Dropping beacon/probe frame, queue size %d",
+			     scan_queue_size);
+		status = QDF_STATUS_E_FAILURE;
+		goto free;
+	}
+
 	status = wlan_objmgr_psoc_try_get_ref(psoc, WLAN_SCAN_ID);
 	if (QDF_IS_STATUS_ERROR(status)) {
 		scm_info("unable to get reference");
-		qdf_mem_free(bcn->rx_data);
-		qdf_mem_free(bcn);
-		qdf_nbuf_free(buf);
-		return status;
+		goto free;
 	}
 
 	bcn->psoc = psoc;
@@ -306,13 +313,19 @@ QDF_STATUS tgt_scan_bcn_probe_rx_callback(struct wlan_objmgr_psoc *psoc,
 
 	status = scheduler_post_msg(QDF_MODULE_ID_SCAN, &msg);
 
-	if (!QDF_IS_STATUS_SUCCESS(status)) {
+	if (QDF_IS_STATUS_SUCCESS(status))
+		return status;
+
 	wlan_objmgr_psoc_release_ref(psoc, WLAN_SCAN_ID);
 	scm_err("failed to post to QDF_MODULE_ID_SCAN");
+
+free:
+	if (bcn && bcn->rx_data)
 		qdf_mem_free(bcn->rx_data);
+	if (bcn)
 		qdf_mem_free(bcn);
+	if (buf)
 		qdf_nbuf_free(buf);
-	}
 
 	return status;
 }