[PATCH] ehca: map 4k firmware context of cq, qp to user space

[Hoang-Nam Nguyen]

From: Hoang-Nam Nguyen <hnguyen at de.ibm.com>
Date: Thu, 2 Aug 2007 10:08:30 +0200
Subject: [PATCH] ehca: map 4k firmware context of cq, qp to user space
This patch utilizes remap_4k_pfn() as introduced by Paul M.,
for details see http://patchwork.ozlabs.org/linuxppc/patch?id=10281,
to map ehca cq, qp firmware context (4k) to user space if kernel page
size is 64k. For reason, why this is required, see also Paul's patch.
In addition to that the kernel page offset of firmware context needs
to be set in cq and qp response block so that user space can assemble
the proper virtual address to use.
An appropriate patch for libehca will follow for ofed-1.3.

Signed-off-by: Hoang-Nam Nguyen <hnguyen at de.ibm.com>
---
 drivers/infiniband/hw/ehca/ehca_classes.h |    4 +++-
 drivers/infiniband/hw/ehca/ehca_cq.c      |    2 ++
 drivers/infiniband/hw/ehca/ehca_qp.c      |    2 ++
 drivers/infiniband/hw/ehca/ehca_uverbs.c  |    8 +++++++-
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/ehca/ehca_classes.h b/drivers/infiniband/hw/ehca/ehca_classes.h
index b5e9603..206d4eb 100644
--- a/drivers/infiniband/hw/ehca/ehca_classes.h
+++ b/drivers/infiniband/hw/ehca/ehca_classes.h
@@ -337,6 +337,8 @@ 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 {
@@ -347,7 +349,7 @@ 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 81aff36..ed5d67f 100644
--- a/drivers/infiniband/hw/ehca/ehca_cq.c
+++ b/drivers/infiniband/hw/ehca/ehca_cq.c
@@ -276,6 +276,8 @@ 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 b178cba..66f632c 100644
--- a/drivers/infiniband/hw/ehca/ehca_qp.c
+++ b/drivers/infiniband/hw/ehca/ehca_qp.c
@@ -745,6 +745,8 @@ 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 4bc687f..1308efa 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 +118,14 @@ 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() */
+#ifdef CONFIG_PPC_64K_PAGES
+	/* make sure we map only 4k for fw context */
+	ret = remap_4k_pfn(vma, vma->vm_start, physical >> EHCA_PAGESHIFT,
+			   vma->vm_page_prot);
+#else
 	ret = remap_pfn_range(vma, vma->vm_start, physical >> PAGE_SHIFT,
 			      vsize, vma->vm_page_prot);
+#endif
 	if (unlikely(ret)) {
 		ehca_gen_err("remap_pfn_range() failed ret=%x", ret);
 		return -ENOMEM;
-- 
1.5.2