[NET]: Get rid of alloc_skb_from_cache

Since this was added originally for Xen, and Xen has recently (~2.6.18)
stopped using this function, we can safely get rid of it.  Good timing
too since this function has started to bit rot.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/x86_64/kernel/functionlist

@@ -514,7 +514,6 @@
 *(.text.dentry_open)
 *(.text.dentry_iput)
 *(.text.bio_alloc)
-*(.text.alloc_skb_from_cache)
 *(.text.wait_on_page_bit)
 *(.text.vfs_readdir)
 *(.text.vfs_lstat)

include/linux/skbuff.h

@@ -346,9 +346,6 @@ static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
 	return __alloc_skb(size, priority, 1, -1);
 }
 
-extern struct sk_buff *alloc_skb_from_cache(struct kmem_cache *cp,
-					    unsigned int size,
-					    gfp_t priority);
 extern void	       kfree_skbmem(struct sk_buff *skb);
 extern struct sk_buff *skb_clone(struct sk_buff *skb,
 				 gfp_t priority);

net/core/skbuff.c

@@ -196,61 +196,6 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
 	goto out;
 }
 
-/**
- *	alloc_skb_from_cache	-	allocate a network buffer
- *	@cp: kmem_cache from which to allocate the data area
- *           (object size must be big enough for @size bytes + skb overheads)
- *	@size: size to allocate
- *	@gfp_mask: allocation mask
- *
- *	Allocate a new &sk_buff. The returned buffer has no headroom and
- *	tail room of size bytes. The object has a reference count of one.
- *	The return is the buffer. On a failure the return is %NULL.
- *
- *	Buffers may only be allocated from interrupts using a @gfp_mask of
- *	%GFP_ATOMIC.
- */
-struct sk_buff *alloc_skb_from_cache(struct kmem_cache *cp,
-				     unsigned int size,
-				     gfp_t gfp_mask)
-{
-	struct sk_buff *skb;
-	u8 *data;
-
-	/* Get the HEAD */
-	skb = kmem_cache_alloc(skbuff_head_cache,
-			       gfp_mask & ~__GFP_DMA);
-	if (!skb)
-		goto out;
-
-	/* Get the DATA. */
-	size = SKB_DATA_ALIGN(size);
-	data = kmem_cache_alloc(cp, gfp_mask);
-	if (!data)
-		goto nodata;
-
-	memset(skb, 0, offsetof(struct sk_buff, truesize));
-	skb->truesize = size + sizeof(struct sk_buff);
-	atomic_set(&skb->users, 1);
-	skb->head = data;
-	skb->data = data;
-	skb->tail = data;
-	skb->end  = data + size;
-
-	atomic_set(&(skb_shinfo(skb)->dataref), 1);
-	skb_shinfo(skb)->nr_frags  = 0;
-	skb_shinfo(skb)->gso_size = 0;
-	skb_shinfo(skb)->gso_segs = 0;
-	skb_shinfo(skb)->gso_type = 0;
-	skb_shinfo(skb)->frag_list = NULL;
-out:
-	return skb;
-nodata:
-	kmem_cache_free(skbuff_head_cache, skb);
-	skb = NULL;
-	goto out;
-}
-
 /**
  *	__netdev_alloc_skb - allocate an skbuff for rx on a specific device
  *	@dev: network device to receive on