cxgb3: map entire Rx page, feed map+offset to Rx ring.

DMA mapping can be expensive in the presence of iommus.
Reduce the Rx iommu activity by mapping an entire page, and provide the H/W
the mapped address + offset of the current page chunk.
Reserve bits at the end of the page to track mapping references, so the page
can be unmapped.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/cxgb3/adapter.h b/drivers/net/cxgb3/adapter.h
index 2cf6c92..714df2b 100644
--- a/drivers/net/cxgb3/adapter.h
+++ b/drivers/net/cxgb3/adapter.h
@@ -85,6 +85,8 @@
 	struct page *page;
 	void *va;
 	unsigned int offset;
+	u64 *p_cnt;
+	DECLARE_PCI_UNMAP_ADDR(mapping);
 };
 
 struct rx_desc;
@@ -101,6 +103,7 @@
 	struct fl_pg_chunk pg_chunk;/* page chunk cache */
 	unsigned int use_pages;     /* whether FL uses pages or sk_buffs */
 	unsigned int order;	    /* order of page allocations */
+	unsigned int alloc_size;    /* size of allocated buffer */
 	struct rx_desc *desc;       /* address of HW Rx descriptor ring */
 	struct rx_sw_desc *sdesc;   /* address of SW Rx descriptor ring */
 	dma_addr_t   phys_addr;     /* physical address of HW ring start */