commit 52033cfb5aab2a54e238e93c9e52f61c2c5708aa
author Matan Barak <matanb@mellanox.com> Thu Jun 11 16:35:26 2015 +0300
committer Doug Ledford <dledford@redhat.com> Fri Jun 12 14:49:10 2015 -0400
tree 2fa1c99afee51a719b168c7b3175cdce25bb4090
parent 2528e33e680921d95092f83c4a64046744f111b3

IB/mlx4: Add mmap call to map the hardware clock

In order to read the HCA's cycle counter efficiently in
user space, we need to map the HCA's register.
This is done through mmap call.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx4/main.c

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 6cd8cd5..2b10707 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -716,8 +716,24 @@
 				       dev->dev->caps.num_uars,
 				       PAGE_SIZE, vma->vm_page_prot))
 			return -EAGAIN;
-	} else
+	} else if (vma->vm_pgoff == 3) {
+		struct mlx4_clock_params params;
+		int ret = mlx4_get_internal_clock_params(dev->dev, &params);
+
+		if (ret)
+			return ret;
+
+		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+		if (io_remap_pfn_range(vma, vma->vm_start,
+				       (pci_resource_start(dev->dev->persist->pdev,
+							   params.bar) +
+					params.offset)
+				       >> PAGE_SHIFT,
+				       PAGE_SIZE, vma->vm_page_prot))
+			return -EAGAIN;
+	} else {
 		return -EINVAL;
+	}
 
 	return 0;
 }