[CASSINI]: Revert 'dont touch page_count'.

This reverts changeset fa4f0774d7c6cccb4d1fda76b91dd8eddcb2dd6a
([CASSINI]: dont touch page_count) because it breaks the driver.

The local page counting added by this changeset did not account
for the asynchronous page count changes done by kfree_skb()
and friends.

The change adds extra atomics and on top of it all appears to be
totally unnecessary as well.

Signed-off-by: David S. Miller <[e-mail]>
Acked-by: Nick Piggin <[e-mail]>

drivers/net/cassini.c

···
 		cas_disable_irq(cp, i);
 }
 
-static inline void cas_buffer_init(cas_page_t *cp)
-{
-	struct page *page = cp->buffer;
-	atomic_set((atomic_t *)&page->lru.next, 1);
-}
-
-static inline int cas_buffer_count(cas_page_t *cp)
-{
-	struct page *page = cp->buffer;
-	return atomic_read((atomic_t *)&page->lru.next);
-}
-
-static inline void cas_buffer_inc(cas_page_t *cp)
-{
-	struct page *page = cp->buffer;
-	atomic_inc((atomic_t *)&page->lru.next);
-}
-
-static inline void cas_buffer_dec(cas_page_t *cp)
-{
-	struct page *page = cp->buffer;
-	atomic_dec((atomic_t *)&page->lru.next);
-}
-
 static void cas_enable_irq(struct cas *cp, const int ring)
 {
 	if (ring == 0) { /* all but TX_DONE */
···
 {
 	pci_unmap_page(cp->pdev, page->dma_addr, cp->page_size,
 		       PCI_DMA_FROMDEVICE);
-	cas_buffer_dec(page);
 	__free_pages(page->buffer, cp->page_order);
 	kfree(page);
 	return 0;
···
 	page->buffer = alloc_pages(flags, cp->page_order);
 	if (!page->buffer)
 		goto page_err;
-	cas_buffer_init(page);
 	page->dma_addr = pci_map_page(cp->pdev, page->buffer, 0,
 				      cp->page_size, PCI_DMA_FROMDEVICE);
 	return page;
···
 	list_for_each_safe(elem, tmp, &list) {
 		cas_page_t *page = list_entry(elem, cas_page_t, list);
 
-		if (cas_buffer_count(page) > 1)
+		if (page_count(page->buffer) > 1)
 			continue;
 
 		list_del(elem);
···
 	cas_page_t *page = cp->rx_pages[1][index];
 	cas_page_t *new;
 
-	if (cas_buffer_count(page) == 1)
+	if (page_count(page->buffer) == 1)
 		return page;
 
 	new = cas_page_dequeue(cp);
···
 	cas_page_t **page1 = cp->rx_pages[1];
 
 	/* swap if buffer is in use */
-	if (cas_buffer_count(page0[index]) > 1) {
+	if (page_count(page0[index]->buffer) > 1) {
 		cas_page_t *new = cas_page_spare(cp, index);
 		if (new) {
 			page1[index] = page0[index];
···
 		skb->len      += hlen - swivel;
 
 		get_page(page->buffer);
-		cas_buffer_inc(page);
 		frag->page = page->buffer;
 		frag->page_offset = off;
 		frag->size = hlen - swivel;
···
 			frag++;
 
 			get_page(page->buffer);
-			cas_buffer_inc(page);
 			frag->page = page->buffer;
 			frag->page_offset = 0;
 			frag->size = hlen;
···
 	released = 0;
 	while (entry != last) {
 		/* make a new buffer if it's still in use */
-		if (cas_buffer_count(page[entry]) > 1) {
+		if (page_count(page[entry]->buffer) > 1) {
 			cas_page_t *new = cas_page_dequeue(cp);
 			if (!new) {
 				/* let the timer know that we need to