IB/ehca: Use remap_4k_pfn() to map firmware contexts to user space

Use Paul's new remap_4k_pfn() function to map our 4K firmware contexts
into user space on 64K-page machines without exposing neighboring
firmware contexts. Return the context's offset within a 64K page to
user space so it can determine the proper virtual address.

For details about remap_4k_pfn(), see commit 721151d0 or
http://patchwork.ozlabs.org/linuxppc/patch?id=10281

Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ehca/ehca_classes.h

@@ -338,6 +338,8 @@ struct ehca_create_cq_resp {
 	u32 cq_number;
 	u32 token;
 	struct ipzu_queue_resp ipz_queue;
+	u32 fw_handle_ofs;
+	u32 dummy;
 };
 
 struct ehca_create_qp_resp {
@@ -348,7 +350,7 @@ struct ehca_create_qp_resp {
 	u32 qkey;
 	/* qp_num assigned by ehca: sqp0/1 may have got different numbers */
 	u32 real_qp_num;
-	u32 dummy; /* padding for 8 byte alignment */
+	u32 fw_handle_ofs;
 	struct ipzu_queue_resp ipz_squeue;
 	struct ipzu_queue_resp ipz_rqueue;
 };