brcm80211: util: use sk_buff_head in precedence queue functions

Instead of dealing with sk_buff prev pointers the queue functions
now make use of the sk_buff_head functions provided by the kernel.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Alwin Beukers <alwin@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 39 insertions, 98 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmutil/utils.c b/drivers/net/wireless/brcm80211/brcmutil/utils.c
index 12b795ffd369..57e656f987ad 100644
--- a/drivers/net/wireless/brcm80211/brcmutil/utils.c
+++ b/drivers/net/wireless/brcm80211/brcmutil/utils.c
@@ -86,21 +86,13 @@ EXPORT_SYMBOL(brcmu_pkttotlen);
 struct sk_buff *brcmu_pktq_penq(struct pktq *pq, int prec,
                                       struct sk_buff *p)
 {
-        struct pktq_prec *q;
+        struct sk_buff_head *q;
 
         if (pktq_full(pq) || pktq_pfull(pq, prec))
                 return NULL;
 
-        q = &pq->q[prec];
-
-        if (q->head)
-                q->tail->prev = p;
-        else
-                q->head = p;
-
-        q->tail = p;
-        q->len++;
-
+        q = &pq->q[prec].skblist;
+        skb_queue_tail(q, p);
         pq->len++;
 
         if (pq->hi_prec < prec)
@@ -113,20 +105,13 @@ EXPORT_SYMBOL(brcmu_pktq_penq);
 struct sk_buff *brcmu_pktq_penq_head(struct pktq *pq, int prec,
                                            struct sk_buff *p)
 {
-        struct pktq_prec *q;
+        struct sk_buff_head *q;
 
         if (pktq_full(pq) || pktq_pfull(pq, prec))
                 return NULL;
 
-        q = &pq->q[prec];
-
-        if (q->head == NULL)
-                q->tail = p;
-
-        p->prev = q->head;
-        q->head = p;
-        q->len++;
-
+        q = &pq->q[prec].skblist;
+        skb_queue_head(q, p);
         pq->len++;
 
         if (pq->hi_prec < prec)
@@ -138,53 +123,30 @@ EXPORT_SYMBOL(brcmu_pktq_penq_head);
 
 struct sk_buff *brcmu_pktq_pdeq(struct pktq *pq, int prec)
 {
-        struct pktq_prec *q;
+        struct sk_buff_head *q;
         struct sk_buff *p;
 
-        q = &pq->q[prec];
-
-        p = q->head;
+        q = &pq->q[prec].skblist;
+        p = skb_dequeue(q);
         if (p == NULL)
                 return NULL;
 
-        q->head = p->prev;
-        if (q->head == NULL)
-                q->tail = NULL;
-
-        q->len--;
-
         pq->len--;
-
-        p->prev = NULL;
-
         return p;
 }
 EXPORT_SYMBOL(brcmu_pktq_pdeq);
 
 struct sk_buff *brcmu_pktq_pdeq_tail(struct pktq *pq, int prec)
 {
-        struct pktq_prec *q;
-        struct sk_buff *p, *prev;
-
-        q = &pq->q[prec];
+        struct sk_buff_head *q;
+        struct sk_buff *p;
 
-        p = q->head;
+        q = &pq->q[prec].skblist;
+        p = skb_dequeue_tail(q);
         if (p == NULL)
                 return NULL;
 
-        for (prev = NULL; p != q->tail; p = p->prev)
-                prev = p;
-
-        if (prev)
-                prev->prev = NULL;
-        else
-                q->head = NULL;
-
-        q->tail = prev;
-        q->len--;
-
         pq->len--;
-
         return p;
 }
 EXPORT_SYMBOL(brcmu_pktq_pdeq_tail);
@@ -193,31 +155,17 @@ void
 brcmu_pktq_pflush(struct pktq *pq, int prec, bool dir,
                   bool (*fn)(struct sk_buff *, void *), void *arg)
 {
-        struct pktq_prec *q;
-        struct sk_buff *p, *prev = NULL;
+        struct sk_buff_head *q;
+        struct sk_buff *p, *next;
 
-        q = &pq->q[prec];
-        p = q->head;
-        while (p) {
+        q = &pq->q[prec].skblist;
+        skb_queue_walk_safe(q, p, next) {
                 if (fn == NULL || (*fn) (p, arg)) {
-                        bool head = (p == q->head);
-                        if (head)
-                                q->head = p->prev;
-                        else
-                                prev->prev = p->prev;
-                        p->prev = NULL;
+                        skb_unlink(p, q);
                         brcmu_pkt_buf_free_skb(p);
-                        q->len--;
                         pq->len--;
-                        p = (head ? q->head : prev->prev);
-                } else {
-                        prev = p;
-                        p = p->prev;
                 }
         }
-
-        if (q->head == NULL)
-                q->tail = NULL;
 }
 EXPORT_SYMBOL(brcmu_pktq_pflush);
 
@@ -242,8 +190,10 @@ void brcmu_pktq_init(struct pktq *pq, int num_prec, int max_len)
 
         pq->max = (u16) max_len;
 
-        for (prec = 0; prec < num_prec; prec++)
+        for (prec = 0; prec < num_prec; prec++) {
                 pq->q[prec].max = pq->max;
+                skb_queue_head_init(&pq->q[prec].skblist);
+        }
 }
 EXPORT_SYMBOL(brcmu_pktq_init);
 
@@ -255,13 +205,13 @@ struct sk_buff *brcmu_pktq_peek_tail(struct pktq *pq, int *prec_out)
                 return NULL;
 
         for (prec = 0; prec < pq->hi_prec; prec++)
-                if (pq->q[prec].head)
+                if (!skb_queue_empty(&pq->q[prec].skblist))
                         break;
 
         if (prec_out)
                 *prec_out = prec;
 
-        return pq->q[prec].tail;
+        return skb_peek_tail(&pq->q[prec].skblist);
 }
 EXPORT_SYMBOL(brcmu_pktq_peek_tail);
 
@@ -274,7 +224,7 @@ int brcmu_pktq_mlen(struct pktq *pq, uint prec_bmp)
 
         for (prec = 0; prec <= pq->hi_prec; prec++)
                 if (prec_bmp & (1 << prec))
-                        len += pq->q[prec].len;
+                        len += pq->q[prec].skblist.qlen;
 
         return len;
 }
@@ -284,39 +234,32 @@ EXPORT_SYMBOL(brcmu_pktq_mlen);
 struct sk_buff *brcmu_pktq_mdeq(struct pktq *pq, uint prec_bmp,
                                       int *prec_out)
 {
-        struct pktq_prec *q;
+        struct sk_buff_head *q;
         struct sk_buff *p;
         int prec;
 
         if (pq->len == 0)
                 return NULL;
 
-        while ((prec = pq->hi_prec) > 0 && pq->q[prec].head == NULL)
+        while ((prec = pq->hi_prec) > 0 &&
+               skb_queue_empty(&pq->q[prec].skblist))
                 pq->hi_prec--;
 
-        while ((prec_bmp & (1 << prec)) == 0 || pq->q[prec].head == NULL)
+        while ((prec_bmp & (1 << prec)) == 0 ||
+               skb_queue_empty(&pq->q[prec].skblist))
                 if (prec-- == 0)
                         return NULL;
 
-        q = &pq->q[prec];
-
-        p = q->head;
+        q = &pq->q[prec].skblist;
+        p = skb_dequeue(q);
         if (p == NULL)
                 return NULL;
 
-        q->head = p->prev;
-        if (q->head == NULL)
-                q->tail = NULL;
-
-        q->len--;
+        pq->len--;
 
         if (prec_out)
                 *prec_out = prec;
 
-        pq->len--;
-
-        p->prev = NULL;
-
         return p;
 }
 EXPORT_SYMBOL(brcmu_pktq_mdeq);
diff --git a/drivers/net/wireless/brcm80211/include/brcmu_utils.h b/drivers/net/wireless/brcm80211/include/brcmu_utils.h
index ccf60151953c..cae4e519d187 100644
--- a/drivers/net/wireless/brcm80211/include/brcmu_utils.h
+++ b/drivers/net/wireless/brcm80211/include/brcmu_utils.h
@@ -65,9 +65,7 @@
 #define ETHER_ADDR_STR_LEN      18
 
 struct pktq_prec {
-        struct sk_buff *head;   /* first packet to dequeue */
-        struct sk_buff *tail;   /* last packet to dequeue */
-        u16 len;                /* number of queued packets */
+        struct sk_buff_head skblist;
         u16 max;                /* maximum number of queued packets */
 };
 
@@ -88,32 +86,32 @@ struct pktq {
 
 static inline int pktq_plen(struct pktq *pq, int prec)
 {
-        return pq->q[prec].len;
+        return pq->q[prec].skblist.qlen;
 }
 
 static inline int pktq_pavail(struct pktq *pq, int prec)
 {
-        return pq->q[prec].max - pq->q[prec].len;
+        return pq->q[prec].max - pq->q[prec].skblist.qlen;
 }
 
 static inline bool pktq_pfull(struct pktq *pq, int prec)
 {
-        return pq->q[prec].len >= pq->q[prec].max;
+        return pq->q[prec].skblist.qlen >= pq->q[prec].max;
 }
 
 static inline bool pktq_pempty(struct pktq *pq, int prec)
 {
-        return pq->q[prec].len == 0;
+        return skb_queue_empty(&pq->q[prec].skblist);
 }
 
 static inline struct sk_buff *pktq_ppeek(struct pktq *pq, int prec)
 {
-        return pq->q[prec].head;
+        return skb_peek(&pq->q[prec].skblist);
 }
 
 static inline struct sk_buff *pktq_ppeek_tail(struct pktq *pq, int prec)
 {
-        return pq->q[prec].tail;
+        return skb_peek_tail(&pq->q[prec].skblist);
 }
 
 extern struct sk_buff *brcmu_pktq_penq(struct pktq *pq, int prec,