Jason Wang
2022-Jan-12 02:32 UTC
[PATCH 1/4] vdpa: Avoid taking cf_mutex lock on get status
On Wed, Jan 12, 2022 at 2:34 AM Eli Cohen <elic at nvidia.com> wrote:> > Avoid the wrapper holding cf_mutex since it is not protecting anything. > To avoid confusion and unnecessary overhead incurred by it, remove. > > Fixes: f489f27bc0ab ("vdpa: Sync calls set/get config/status with cf_mutex") > Signed-off-by: Eli Cohen <elic at nvidia.com>Acked-by: Jason Wang <jasowang at redhat.com>> --- > drivers/vdpa/vdpa.c | 11 ----------- > drivers/vhost/vdpa.c | 5 +++-- > include/linux/vdpa.h | 1 - > 3 files changed, 3 insertions(+), 14 deletions(-) > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index 4380367d00b5..9846c9de4bfa 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -21,17 +21,6 @@ static LIST_HEAD(mdev_head); > static DEFINE_MUTEX(vdpa_dev_mutex); > static DEFINE_IDA(vdpa_index_ida); > > -u8 vdpa_get_status(struct vdpa_device *vdev) > -{ > - u8 status; > - > - mutex_lock(&vdev->cf_mutex); > - status = vdev->config->get_status(vdev); > - mutex_unlock(&vdev->cf_mutex); > - return status; > -} > -EXPORT_SYMBOL(vdpa_get_status); > - > void vdpa_set_status(struct vdpa_device *vdev, u8 status) > { > mutex_lock(&vdev->cf_mutex); > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 6e7edaf2472b..0ed6cbadb52d 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -142,9 +142,10 @@ static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp) > static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp) > { > struct vdpa_device *vdpa = v->vdpa; > + const struct vdpa_config_ops *ops = vdpa->config; > u8 status; > > - status = vdpa_get_status(vdpa); > + status = ops->get_status(vdpa); > > if (copy_to_user(statusp, &status, sizeof(status))) > return -EFAULT; > @@ -163,7 +164,7 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp) > if (copy_from_user(&status, statusp, sizeof(status))) > return -EFAULT; > > - status_old = vdpa_get_status(vdpa); > + status_old = ops->get_status(vdpa); > > /* > * Userspace shouldn't remove status bits unless reset the > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h > index a6047fd6cf12..2de442ececae 100644 > --- a/include/linux/vdpa.h > +++ b/include/linux/vdpa.h > @@ -421,7 +421,6 @@ void vdpa_get_config(struct vdpa_device *vdev, unsigned int offset, > void *buf, unsigned int len); > void vdpa_set_config(struct vdpa_device *dev, unsigned int offset, > const void *buf, unsigned int length); > -u8 vdpa_get_status(struct vdpa_device *vdev); > void vdpa_set_status(struct vdpa_device *vdev, u8 status); > > /** > -- > 2.34.1 >