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Subject[PATCH V2 4/4] mic: vop: copy data to kernel space then write to io memory
Date
Read and write io memory should address align on ARCH ARM. Change to use
memcpy_toio to avoid kernel panic caused by the address un-align issue.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
drivers/misc/mic/vop/vop_vringh.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
index 45fdb394de11..7014ffe88632 100644
--- a/drivers/misc/mic/vop/vop_vringh.c
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -602,6 +602,7 @@ static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf,
size_t partlen;
bool dma = VOP_USE_DMA && vi->dma_ch;
int err = 0;
+ size_t offset = 0;

if (dma) {
dma_alignment = 1 << vi->dma_ch->device->copy_align;
@@ -655,13 +656,20 @@ static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf,
* We are copying to IO below and should ideally use something
* like copy_from_user_toio(..) if it existed.
*/
- if (copy_from_user((void __force *)dbuf, ubuf, len)) {
- err = -EFAULT;
- dev_err(vop_dev(vdev), "%s %d err %d\n",
- __func__, __LINE__, err);
- goto err;
+ while (len) {
+ partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
+
+ if (copy_from_user(vvr->buf, ubuf + offset, partlen)) {
+ err = -EFAULT;
+ dev_err(vop_dev(vdev), "%s %d err %d\n",
+ __func__, __LINE__, err);
+ goto err;
+ }
+ memcpy_toio(dbuf + offset, vvr->buf, partlen);
+ offset += partlen;
+ vdev->out_bytes += partlen;
+ len -= partlen;
}
- vdev->out_bytes += len;
err = 0;
err:
vpdev->hw_ops->unmap(vpdev, dbuf);
--
2.17.1
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