[PATCH 5/5] misc: vop: mapping kernel memory to user space as noncached

[Sherry Sun]

Mapping kernel space memory to user space as noncached for noncoherent
platform, since user space need check avail_idx and device page flags
timely.

Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
---
 drivers/misc/mic/vop/vop_vringh.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
index aa2dd240c11e..9850515e8d21 100644
--- a/drivers/misc/mic/vop/vop_vringh.c
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -1139,7 +1139,9 @@ static int vop_mmap(struct file *f, struct vm_area_struct *vma)
 		}
 		err = remap_pfn_range(vma, vma->vm_start + offset,
 				      pa >> PAGE_SHIFT, size,
-				      vma->vm_page_prot);
+				      dev_is_dma_coherent(vop_dev(vdev)) ? vma->vm_page_prot :
+							  pgprot_noncached(vma->vm_page_prot));
+
 		if (err)
 			goto ret;
 		size_rem -= size;
-- 
2.17.1