skb: Add inline helper for getting the skb end offset from head
authorAlexander Duyck <alexander.h.duyck@intel.com>
Fri, 4 May 2012 14:26:56 +0000 (14:26 +0000)
committerDavid S. Miller <davem@davemloft.net>
Sun, 6 May 2012 17:13:19 +0000 (13:13 -0400)
With the recent changes for how we compute the skb truesize it occurs to me
we are probably going to have a lot of calls to skb_end_pointer -
skb->head.  Instead of running all over the place doing that it would make
more sense to just make it a separate inline skb_end_offset(skb) that way
we can return the correct value without having gcc having to do all the
optimization to cancel out skb->head - skb->head.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/atm/ambassador.c
drivers/atm/idt77252.c
drivers/net/wimax/i2400m/usb-rx.c
drivers/staging/octeon/ethernet-tx.c
include/linux/skbuff.h
net/core/skbuff.c

index f8f41e0e8a8c45a4cb595a6380fdb3fec9bad11d..89b30f32ba68b4f1e5cd58fc5911a95213abf163 100644 (file)
@@ -802,7 +802,7 @@ static void fill_rx_pool (amb_dev * dev, unsigned char pool,
     }
     // cast needed as there is no %? for pointer differences
     PRINTD (DBG_SKB, "allocated skb at %p, head %p, area %li",
-           skb, skb->head, (long) (skb_end_pointer(skb) - skb->head));
+           skb, skb->head, (long) skb_end_offset(skb));
     rx.handle = virt_to_bus (skb);
     rx.host_address = cpu_to_be32 (virt_to_bus (skb->data));
     if (rx_give (dev, &rx, pool))
index 1c052127548c4f18575e835591e65b7b2a7e8196..8974bd2b961e605b3b03c9c52e8dbedc897fb485 100644 (file)
@@ -1258,7 +1258,7 @@ idt77252_rx_raw(struct idt77252_dev *card)
        tail = readl(SAR_REG_RAWCT);
 
        pci_dma_sync_single_for_cpu(card->pcidev, IDT77252_PRV_PADDR(queue),
-                                   skb_end_pointer(queue) - queue->head - 16,
+                                   skb_end_offset(queue) - 16,
                                    PCI_DMA_FROMDEVICE);
 
        while (head != tail) {
index e3257681e3605a3b9659527e892b16e779718600..b78ee676e1029fc21d5ed189b118f43b62aac631 100644 (file)
@@ -277,7 +277,7 @@ retry:
                d_printf(1, dev, "RX: size changed to %d, received %d, "
                         "copied %d, capacity %ld\n",
                         rx_size, read_size, rx_skb->len,
-                        (long) (skb_end_pointer(new_skb) - new_skb->head));
+                        (long) skb_end_offset(new_skb));
                goto retry;
        }
                /* In most cases, it happens due to the hardware scheduling a
index 56d74dc2fbd5b5f3b7122371554d51647b5effb9..418ed03d0887bf1f44ee98680728541539aeec42 100644 (file)
@@ -344,7 +344,7 @@ int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev)
        }
        if (unlikely
            (skb->truesize !=
-            sizeof(*skb) + skb_end_pointer(skb) - skb->head)) {
+            sizeof(*skb) + skb_end_offset(skb))) {
                /*
                   printk("TX buffer truesize has been changed\n");
                 */
index 37f539129d8964f92595bc3c2a06ca3eebda5ad7..91ad5e227d1d1d528eb1e3ab93ebe84cb652ed9f 100644 (file)
@@ -645,11 +645,21 @@ static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
 {
        return skb->head + skb->end;
 }
+
+static inline unsigned int skb_end_offset(const struct sk_buff *skb)
+{
+       return skb->end;
+}
 #else
 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
 {
        return skb->end;
 }
+
+static inline unsigned int skb_end_offset(const struct sk_buff *skb)
+{
+       return skb->end - skb->head;
+}
 #endif
 
 /* Internal */
@@ -2558,7 +2568,7 @@ static inline bool skb_is_recycleable(const struct sk_buff *skb, int skb_size)
                return false;
 
        skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD);
-       if (skb_end_pointer(skb) - skb->head < skb_size)
+       if (skb_end_offset(skb) < skb_size)
                return false;
 
        if (skb_shared(skb) || skb_cloned(skb))
index 17e4b1e1bf2c9f6b2d218fe3cf4906c95eb3fbea..2c35da818ef9bcf0cdcbd9c1e0edb33423457c53 100644 (file)
@@ -829,7 +829,7 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask)
 {
        int headerlen = skb_headroom(skb);
-       unsigned int size = (skb_end_pointer(skb) - skb->head) + skb->data_len;
+       unsigned int size = skb_end_offset(skb) + skb->data_len;
        struct sk_buff *n = alloc_skb(size, gfp_mask);
 
        if (!n)
@@ -930,7 +930,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
 {
        int i;
        u8 *data;
-       int size = nhead + (skb_end_pointer(skb) - skb->head) + ntail;
+       int size = nhead + skb_end_offset(skb) + ntail;
        long off;
 
        BUG_ON(nhead < 0);
@@ -2727,14 +2727,13 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
                        if (unlikely(!nskb))
                                goto err;
 
-                       hsize = skb_end_pointer(nskb) - nskb->head;
+                       hsize = skb_end_offset(nskb);
                        if (skb_cow_head(nskb, doffset + headroom)) {
                                kfree_skb(nskb);
                                goto err;
                        }
 
-                       nskb->truesize += skb_end_pointer(nskb) - nskb->head -
-                                         hsize;
+                       nskb->truesize += skb_end_offset(nskb) - hsize;
                        skb_release_head_state(nskb);
                        __skb_push(nskb, doffset);
                } else {
@@ -2883,7 +2882,8 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
                skb_frag_size_sub(frag, offset);
 
                /* all fragments truesize : remove (head size + sk_buff) */
-               delta_truesize = skb->truesize - SKB_TRUESIZE(skb_end_pointer(skb) - skb->head);
+               delta_truesize = skb->truesize -
+                                SKB_TRUESIZE(skb_end_offset(skb));
 
                skb->truesize -= skb->data_len;
                skb->len -= skb->data_len;