brcmutil: add dequeue function with filtering

Adding a packet dequeue function that will return packets that
pass the provided match function.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Piotr Haber <phaber@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/brcm80211/brcmutil/utils.c

@@ -116,6 +116,31 @@ struct sk_buff *brcmu_pktq_pdeq(struct pktq *pq, int prec)
 }
 EXPORT_SYMBOL(brcmu_pktq_pdeq);
 
+/*
+ * precedence based dequeue with match function. Passing a NULL pointer
+ * for the match function parameter is considered to be a wildcard so
+ * any packet on the queue is returned. In that case it is no different
+ * from brcmu_pktq_pdeq() above.
+ */
+struct sk_buff *brcmu_pktq_pdeq_match(struct pktq *pq, int prec,
+				      bool (*match_fn)(struct sk_buff *skb,
+						       void *arg), void *arg)
+{
+	struct sk_buff_head *q;
+	struct sk_buff *p, *next;
+
+	q = &pq->q[prec].skblist;
+	skb_queue_walk_safe(q, p, next) {
+		if (match_fn == NULL || match_fn(p, arg)) {
+			skb_unlink(p, q);
+			pq->len--;
+			return p;
+		}
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(brcmu_pktq_pdeq_match);
+
 struct sk_buff *brcmu_pktq_pdeq_tail(struct pktq *pq, int prec)
 {
 	struct sk_buff_head *q;

drivers/net/wireless/brcm80211/include/brcmu_utils.h

@@ -120,6 +120,10 @@ extern struct sk_buff *brcmu_pktq_penq_head(struct pktq *pq, int prec,
 				      struct sk_buff *p);
 extern struct sk_buff *brcmu_pktq_pdeq(struct pktq *pq, int prec);
 extern struct sk_buff *brcmu_pktq_pdeq_tail(struct pktq *pq, int prec);
+extern struct sk_buff *brcmu_pktq_pdeq_match(struct pktq *pq, int prec,
+					     bool (*match_fn)(struct sk_buff *p,
+							      void *arg),
+					     void *arg);
 
 /* packet primitives */
 extern struct sk_buff *brcmu_pkt_buf_get_skb(uint len);