RDMA/cxgb3: Fix page shift calculation in build_phys_page_list()

The existing logic incorrectly maps this buffer list:

    0: addr 0x10001000, size 0x1000
    1: addr 0x10002000, size 0x1000

To this bogus page list:

    0: 0x10000000
    1: 0x10002000

The shift calculation must also take into account the address of the
first entry masked by the page_mask as well as the last address+size
rounded up to the next page size.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/cxgb3/iwch_mem.c

@@ -122,6 +122,13 @@ int build_phys_page_list(struct ib_phys_buf *buffer_list,
 		*total_size += buffer_list[i].size;
 		if (i > 0)
 			mask |= buffer_list[i].addr;
+		else
+			mask |= buffer_list[i].addr & PAGE_MASK;
+		if (i != num_phys_buf - 1)
+			mask |= buffer_list[i].addr + buffer_list[i].size;
+		else
+			mask |= (buffer_list[i].addr + buffer_list[i].size +
+				PAGE_SIZE - 1) & PAGE_MASK;
 	}
 
 	if (*total_size > 0xFFFFFFFFULL)