From: Eli Cohen <elic@nvidia.com>
Date: Tue, 11 Jan 2022 20:33:57 +0200
Subject: vdpa: Avoid taking cf_mutex lock on get status
Patch-mainline: v5.17-rc1
Git-commit: f6d955d80830b6e6f6a170be68cc3628f36365dd
References: jsc#PED-1549
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@nvidia.com>
Link: https://lore.kernel.org/r/20220111183400.38418-2-elic@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Si-Wei Liu<si-wei.liu@oracle.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/vdpa/vdpa.c | 11 -----------
drivers/vhost/vdpa.c | 5 +++--
include/linux/vdpa.h | 1 -
3 files changed, 3 insertions(+), 14 deletions(-)
--- 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);
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -142,9 +142,10 @@ static long vhost_vdpa_get_device_id(str
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
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
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -421,7 +421,6 @@ void vdpa_get_config(struct vdpa_device
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);
/**