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;
 };

drivers/infiniband/hw/ehca/ehca_cq.c

@@ -281,6 +281,8 @@ struct ib_cq *ehca_create_cq(struct ib_device *device, int cqe, int comp_vector,
 		resp.ipz_queue.queue_length = ipz_queue->queue_length;
 		resp.ipz_queue.pagesize = ipz_queue->pagesize;
 		resp.ipz_queue.toggle_state = ipz_queue->toggle_state;
+		resp.fw_handle_ofs = (u32)
+			(my_cq->galpas.user.fw_handle & (PAGE_SIZE - 1));
 		if (ib_copy_to_udata(udata, &resp, sizeof(resp))) {
 			ehca_err(device, "Copy to udata failed.");
 			goto create_cq_exit4;

drivers/infiniband/hw/ehca/ehca_qp.c

@@ -749,6 +749,8 @@ static struct ehca_qp *internal_create_qp(
 			queue2resp(&resp.ipz_squeue, &my_qp->ipz_squeue);
 		if (HAS_RQ(my_qp))
 			queue2resp(&resp.ipz_rqueue, &my_qp->ipz_rqueue);
+		resp.fw_handle_ofs = (u32)
+			(my_qp->galpas.user.fw_handle & (PAGE_SIZE - 1));
 
 		if (ib_copy_to_udata(udata, &resp, sizeof resp)) {
 			ehca_err(pd->device, "Copy to udata failed");

drivers/infiniband/hw/ehca/ehca_uverbs.c

@@ -109,7 +109,7 @@ static int ehca_mmap_fw(struct vm_area_struct *vma, struct h_galpas *galpas,
 	u64 vsize, physical;
 
 	vsize = vma->vm_end - vma->vm_start;
-	if (vsize != EHCA_PAGESIZE) {
+	if (vsize < EHCA_PAGESIZE) {
 		ehca_gen_err("invalid vsize=%lx", vma->vm_end - vma->vm_start);
 		return -EINVAL;
 	}
@@ -118,8 +118,8 @@ static int ehca_mmap_fw(struct vm_area_struct *vma, struct h_galpas *galpas,
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 	ehca_gen_dbg("vsize=%lx physical=%lx", vsize, physical);
 	/* VM_IO | VM_RESERVED are set by remap_pfn_range() */
-	ret = remap_pfn_range(vma, vma->vm_start, physical >> PAGE_SHIFT,
-			      vsize, vma->vm_page_prot);
+	ret = remap_4k_pfn(vma, vma->vm_start, physical >> EHCA_PAGESHIFT,
+			   vma->vm_page_prot);
 	if (unlikely(ret)) {
 		ehca_gen_err("remap_pfn_range() failed ret=%x", ret);
 		return -ENOMEM;