staging: rtl8712: use list_first_entry_or_null()

Use list_first_entry_or_null() instead of list_empty() + LIST_CONTAINOR()
to simplify the code.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/rtl871x_cmd.c

@@ -136,15 +136,12 @@ static struct cmd_obj *_dequeue_cmd(struct  __queue *queue)
 	unsigned long irqL;
 	struct cmd_obj *obj;
 
-	spin_lock_irqsave(&(queue->lock), irqL);
-	if (list_empty(&(queue->queue))) {
-		obj = NULL;
-	} else {
-		obj = LIST_CONTAINOR(queue->queue.next,
+	spin_lock_irqsave(&queue->lock, irqL);
+	obj = list_first_entry_or_null(&queue->queue,
 				       struct cmd_obj, list);
+	if (obj)
 		list_del_init(&obj->list);
-	}
-	spin_unlock_irqrestore(&(queue->lock), irqL);
+	spin_unlock_irqrestore(&queue->lock, irqL);
 	return obj;
 }
 

drivers/staging/rtl8712/rtl871x_mlme.c

@@ -87,16 +87,15 @@ struct wlan_network *_r8712_alloc_network(struct mlme_priv *pmlmepriv)
 	unsigned long irqL;
 	struct wlan_network *pnetwork;
 	struct  __queue *free_queue = &pmlmepriv->free_bss_pool;
-	struct list_head *plist = NULL;
 
-	if (list_empty(&free_queue->queue))
-		return NULL;
 	spin_lock_irqsave(&free_queue->lock, irqL);
-	plist = free_queue->queue.next;
-	pnetwork = LIST_CONTAINOR(plist, struct wlan_network, list);
+	pnetwork = list_first_entry_or_null(&free_queue->queue,
+					    struct wlan_network, list);
+	if (pnetwork) {
 		list_del_init(&pnetwork->list);
 		pnetwork->last_scanned = jiffies;
 		pmlmepriv->num_of_scanned++;
+	}
 	spin_unlock_irqrestore(&free_queue->lock, irqL);
 	return pnetwork;
 }

drivers/staging/rtl8712/rtl871x_recv.c

@@ -105,17 +105,13 @@ union recv_frame *r8712_alloc_recvframe(struct  __queue *pfree_recv_queue)
 {
 	unsigned long irqL;
 	union recv_frame  *precvframe;
-	struct list_head *plist, *phead;
 	struct _adapter *padapter;
 	struct recv_priv *precvpriv;
 
 	spin_lock_irqsave(&pfree_recv_queue->lock, irqL);
-	if (list_empty(&pfree_recv_queue->queue)) {
-		precvframe = NULL;
-	} else {
-		phead = &pfree_recv_queue->queue;
-		plist = phead->next;
-		precvframe = LIST_CONTAINOR(plist, union recv_frame, u);
+	precvframe = list_first_entry_or_null(&pfree_recv_queue->queue,
+					      union recv_frame, u.hdr.list);
+	if (precvframe) {
 		list_del_init(&precvframe->u.hdr.list);
 		padapter = precvframe->u.hdr.adapter;
 		if (padapter != NULL) {

drivers/staging/rtl8712/rtl871x_sta_mgt.c

@@ -111,13 +111,11 @@ struct sta_info *r8712_alloc_stainfo(struct sta_priv *pstapriv, u8 *hwaddr)
 	unsigned long flags;
 
 	pfree_sta_queue = &pstapriv->free_sta_queue;
-	spin_lock_irqsave(&(pfree_sta_queue->lock), flags);
-	if (list_empty(&pfree_sta_queue->queue)) {
-		psta = NULL;
-	} else {
-		psta = LIST_CONTAINOR(pfree_sta_queue->queue.next,
+	spin_lock_irqsave(&pfree_sta_queue->lock, flags);
+	psta = list_first_entry_or_null(&pfree_sta_queue->queue,
 					struct sta_info, list);
-		list_del_init(&(psta->list));
+	if (psta) {
+		list_del_init(&psta->list);
 		_init_stainfo(psta);
 		memcpy(psta->hwaddr, hwaddr, ETH_ALEN);
 		index = wifi_mac_hash(hwaddr);
@@ -125,7 +123,7 @@ struct sta_info *r8712_alloc_stainfo(struct sta_priv *pstapriv, u8 *hwaddr)
 			psta = NULL;
 			goto exit;
 		}
-		phash_list = &(pstapriv->sta_hash[index]);
+		phash_list = &pstapriv->sta_hash[index];
 		list_add_tail(&psta->hash_list, phash_list);
 		pstapriv->asoc_sta_count++;
 
@@ -149,7 +147,7 @@ struct sta_info *r8712_alloc_stainfo(struct sta_priv *pstapriv, u8 *hwaddr)
 		}
 	}
 exit:
-	spin_unlock_irqrestore(&(pfree_sta_queue->lock), flags);
+	spin_unlock_irqrestore(&pfree_sta_queue->lock, flags);
 	return psta;
 }
 

drivers/staging/rtl8712/rtl871x_xmit.c

@@ -741,21 +741,16 @@ void r8712_update_protection(struct _adapter *padapter, u8 *ie, uint ie_len)
 struct xmit_buf *r8712_alloc_xmitbuf(struct xmit_priv *pxmitpriv)
 {
 	unsigned long irqL;
-	struct xmit_buf *pxmitbuf =  NULL;
-	struct list_head *plist, *phead;
+	struct xmit_buf *pxmitbuf;
 	struct  __queue *pfree_xmitbuf_queue = &pxmitpriv->free_xmitbuf_queue;
 
 	spin_lock_irqsave(&pfree_xmitbuf_queue->lock, irqL);
-	if (list_empty(&pfree_xmitbuf_queue->queue)) {
-		pxmitbuf = NULL;
-	} else {
-		phead = &pfree_xmitbuf_queue->queue;
-		plist = phead->next;
-		pxmitbuf = LIST_CONTAINOR(plist, struct xmit_buf, list);
-		list_del_init(&(pxmitbuf->list));
-	}
-	if (pxmitbuf !=  NULL)
+	pxmitbuf = list_first_entry_or_null(&pfree_xmitbuf_queue->queue,
+					    struct xmit_buf, list);
+	if (pxmitbuf) {
+		list_del_init(&pxmitbuf->list);
 		pxmitpriv->free_xmitbuf_cnt--;
+	}
 	spin_unlock_irqrestore(&pfree_xmitbuf_queue->lock, irqL);
 	return pxmitbuf;
 }
@@ -795,20 +790,14 @@ struct xmit_frame *r8712_alloc_xmitframe(struct xmit_priv *pxmitpriv)
 		pfree_xmit_queue
 	*/
 	unsigned long irqL;
-	struct xmit_frame *pxframe = NULL;
-	struct list_head *plist, *phead;
+	struct xmit_frame *pxframe;
 	struct  __queue *pfree_xmit_queue = &pxmitpriv->free_xmit_queue;
 
 	spin_lock_irqsave(&pfree_xmit_queue->lock, irqL);
-	if (list_empty(&pfree_xmit_queue->queue)) {
-		pxframe =  NULL;
-	} else {
-		phead = &pfree_xmit_queue->queue;
-		plist = phead->next;
-		pxframe = LIST_CONTAINOR(plist, struct xmit_frame, list);
-		list_del_init(&(pxframe->list));
-	}
-	if (pxframe !=  NULL) {
+	pxframe = list_first_entry_or_null(&pfree_xmit_queue->queue,
+					   struct xmit_frame, list);
+	if (pxframe) {
+		list_del_init(&pxframe->list);
 		pxmitpriv->free_xmitframe_cnt--;
 		pxframe->buf_addr = NULL;
 		pxframe->pxmitbuf = NULL;