qcacld-3.0: Create new hdd_adapter_iterate() function

Currently, there is a problem in hdd_for_each_adapter(), as it is
checking for the NDI adapter only in an infinite loop. Create
hdd_adapter_iterate() in order to iterate through all adapters properly.

Change-Id: Ib0e22d0f46d6311d44de3ee48b3202376a42f209
CRs-Fixed: 2568906

core/hdd/inc/wlan_hdd_main.h

@@ -2049,6 +2049,44 @@ QDF_STATUS hdd_add_adapter_back(struct hdd_context *hdd_ctx,
 QDF_STATUS hdd_add_adapter_front(struct hdd_context *hdd_ctx,
 				 struct hdd_adapter *adapter);
 
+/**
+ * typedef hdd_adapter_iterate_cb() – Iteration callback function
+ * @adapter: current adapter of interest
+ * @context: user context supplied to the iterator
+ *
+ * This specifies the type of a callback function to supply to
+ * hdd_adapter_iterate().
+ *
+ * Return:
+ * * QDF_STATUS_SUCCESS if further iteration should continue
+ * * QDF_STATUS_E_ABORTED if further iteration should be aborted
+ */
+typedef QDF_STATUS (*hdd_adapter_iterate_cb)(struct hdd_adapter *adapter,
+					     void *context);
+
+/**
+ * hdd_adapter_iterate() – Safely iterate over all adapters
+ * @cb: callback function to invoke for each adapter
+ * @context: user-supplied context to pass to @cb
+ *
+ * This function will iterate over all of the adapters known to the system in
+ * a safe manner, invoking the callback function for each adapter.
+ * The callback function will be invoked in the same context/thread as the
+ * caller without any additional locks in force.
+ * Iteration continues until either the callback has been invoked for all
+ * adapters or a callback returns a value of QDF_STATUS_E_ABORTED to indicate
+ * that further iteration should cease.
+ *
+ * Return:
+ * * QDF_STATUS_E_ABORTED if any callback function returns that value
+ * * QDF_STATUS_E_FAILURE if the callback was not invoked for all adapters due
+ * to concurrency (i.e. adapter was deleted while iterating)
+ * * QDF_STATUS_SUCCESS if @cb was invoked for each adapter and none returned
+ * an error
+ */
+QDF_STATUS hdd_adapter_iterate(hdd_adapter_iterate_cb cb,
+			       void *context);
+
 /**
  * hdd_for_each_adapter - adapter iterator macro
  * @hdd_ctx: the global HDD context

core/hdd/src/wlan_hdd_main.c

@@ -7160,6 +7160,49 @@ QDF_STATUS hdd_add_adapter_front(struct hdd_context *hdd_ctx,
 	return status;
 }
 
+QDF_STATUS hdd_adapter_iterate(hdd_adapter_iterate_cb cb, void *context)
+{
+	struct hdd_context *hdd_ctx;
+	struct hdd_adapter *cache[HDD_MAX_ADAPTERS];
+	struct hdd_adapter *adapter;
+	uint32_t n_cache = 0;
+	QDF_STATUS ret = QDF_STATUS_SUCCESS;
+	QDF_STATUS status;
+	int i;
+
+	hdd_ctx = cds_get_context(QDF_MODULE_ID_HDD);
+	if (unlikely(!hdd_ctx)) {
+		hdd_err("HDD context is Null");
+		return QDF_STATUS_E_FAILURE;
+	}
+
+	qdf_spin_lock_bh(&hdd_ctx->hdd_adapter_lock);
+	for (hdd_get_front_adapter_no_lock(hdd_ctx, &adapter); adapter;
+	     hdd_get_next_adapter_no_lock(hdd_ctx, adapter, &adapter)) {
+		cache[n_cache++] = adapter;
+	}
+	qdf_spin_unlock_bh(&hdd_ctx->hdd_adapter_lock);
+
+	for (i = 0; i < n_cache - 1; i++) {
+		adapter = hdd_adapter_get_by_reference(hdd_ctx, cache[i]);
+		if (!adapter) {
+			/*
+			 * detected remove while iterating
+			 * concurrency failure
+			 */
+			ret = QDF_STATUS_E_FAILURE;
+			continue;
+		}
+
+		status = cb(adapter, context);
+		hdd_adapter_put(adapter);
+		if (status != QDF_STATUS_SUCCESS)
+			return status;
+	}
+
+	return ret;
+}
+
 struct hdd_adapter *hdd_get_adapter_by_rand_macaddr(
 	struct hdd_context *hdd_ctx, tSirMacAddr mac_addr)
 {