be2net: fix bug in rx page posting

Pages are posted to the rxq in such a way that more than one frag
can share the page. The last frag that uses the page unmaps the
page.  In the case when a page is not fully used (due to lack of space in rxq)
the last frag that uses the page is not being set as a "last_page_user";
instead, the next frag in the rxq is incorrectly being set.

The fix has also been tested on ppc64 with 64k pages...

Signed-off-by: Sathya Perla <sathyap@serverengines.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/benet/be_main.c

@@ -910,7 +910,7 @@ static inline struct page *be_alloc_pages(u32 size)
 static void be_post_rx_frags(struct be_adapter *adapter)
 {
 	struct be_rx_page_info *page_info_tbl = adapter->rx_obj.page_info_tbl;
-	struct be_rx_page_info *page_info = NULL;
+	struct be_rx_page_info *page_info = NULL, *prev_page_info = NULL;
 	struct be_queue_info *rxq = &adapter->rx_obj.q;
 	struct page *pagep = NULL;
 	struct be_eth_rx_d *rxd;
@@ -941,18 +941,20 @@ static void be_post_rx_frags(struct be_adapter *adapter)
 		rxd = queue_head_node(rxq);
 		rxd->fragpa_lo = cpu_to_le32(frag_dmaaddr & 0xFFFFFFFF);
 		rxd->fragpa_hi = cpu_to_le32(upper_32_bits(frag_dmaaddr));
-		queue_head_inc(rxq);
 
 		/* Any space left in the current big page for another frag? */
 		if ((page_offset + rx_frag_size + rx_frag_size) >
 					adapter->big_page_size) {
 			pagep = NULL;
 			page_info->last_page_user = true;
 		}
+
+		prev_page_info = page_info;
+		queue_head_inc(rxq);
 		page_info = &page_info_tbl[rxq->head];
 	}
 	if (pagep)
-		page_info->last_page_user = true;
+		prev_page_info->last_page_user = true;
 
 	if (posted) {
 		atomic_add(posted, &rxq->used);