Add skb_frag_size_{set|add|sub}() for Linux 3.1 and older

Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.com>

diff --git a/include/linux/compat-3.2.h b/include/linux/compat-3.2.h
index fd8d1f942a5fac6b3bedbc63770d13e476c20637..921e2888c8886ccb4347dac334dd90b6f11d7ee1 100644 (file)
--- a/include/linux/compat-3.2.h
+++ b/include/linux/compat-3.2.h
@@ -25,6 +25,48 @@ static inline struct page *skb_frag_page(const skb_frag_t *frag)
        return frag->page;
 }
 
+/**
+ * __skb_frag_set_page - sets the page contained in a paged fragment
+ * @frag: the paged fragment
+ * @page: the page to set
+ *
+ * Sets the fragment @frag to contain @page.
+ */
+static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
+{
+       frag->page = page;
+}
+
+/**
+ * skb_frag_set_page - sets the page contained in a paged fragment of an skb
+ * @skb: the buffer
+ * @f: the fragment offset
+ * @page: the page to set
+ *
+ * Sets the @f'th fragment of @skb to contain @page.
+ */
+static inline void skb_frag_set_page(struct sk_buff *skb, int f,
+                                    struct page *page)
+{
+       __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
+}
+
+/**
+ * skb_frag_address_safe - gets the address of the data contained in a paged fragment
+ * @frag: the paged fragment buffer
+ *
+ * Returns the address of the data within @frag. Checks that the page
+ * is mapped and returns %NULL otherwise.
+ */
+static inline void *skb_frag_address_safe(const skb_frag_t *frag)
+{
+       void *ptr = page_address(skb_frag_page(frag));
+       if (unlikely(!ptr))
+               return NULL;
+
+       return ptr + frag->page_offset;
+}
+
 /**
  * skb_frag_dma_map - maps a paged fragment via the DMA API
  * @device: the device to map the fragment to
@@ -52,6 +94,21 @@ static inline unsigned int skb_frag_size(const skb_frag_t *frag)
        return frag->size;
 }
 
+static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
+{
+       frag->size = size;
+}
+
+static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
+{
+       frag->size += delta;
+}
+
+static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
+{
+       frag->size -= delta;
+}
+
 static inline char *hex_byte_pack(char *buf, u8 byte)
 {
        *buf++ = hex_asc_hi(byte);