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>

4 files changed, 10 insertions, 4 deletions

diff --git a/drivers/infiniband/hw/ehca/ehca_classes.h b/drivers/infiniband/hw/ehca/ehca_classes.h
index 0d69f0f001d9..0942a173881c 100644
--- a/drivers/infiniband/hw/ehca/ehca_classes.h
+++ b/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;
 };
diff --git a/drivers/infiniband/hw/ehca/ehca_cq.c b/drivers/infiniband/hw/ehca/ehca_cq.c
index a6f17e488c77..d68603ddfc2c 100644
--- a/drivers/infiniband/hw/ehca/ehca_cq.c
+++ b/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;
diff --git a/drivers/infiniband/hw/ehca/ehca_qp.c b/drivers/infiniband/hw/ehca/ehca_qp.c
index bfae1c228b2f..e89fdca7fa19 100644
--- a/drivers/infiniband/hw/ehca/ehca_qp.c
+++ b/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");
diff --git a/drivers/infiniband/hw/ehca/ehca_uverbs.c b/drivers/infiniband/hw/ehca/ehca_uverbs.c
index 3340f49f0211..84a16bcfd536 100644
--- a/drivers/infiniband/hw/ehca/ehca_uverbs.c
+++ b/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;