virtio-pci-modern: introduce helpers for setting and getting status

stable inclusion
from stable-v5.12
commit e3669129
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5WXCZ
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e3669129fdcd2494e6991bd4111e090551087e16

----------------------------------------------------------------------

This patch introduces helpers to allow set and get device status.
Signed-off-by: NJason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-7-jasowang@redhat.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NPengyuan Zhao <zhaopengyuan@hisilicon.com>

drivers/virtio/virtio_pci_modern.c

@@ -275,41 +275,62 @@ static u32 vp_generation(struct virtio_device *vdev)
 	return vp_ioread8(&cfg->config_generation);
 }
 
+/*
+ * vp_modern_get_status - get the device status
+ * @mdev: the modern virtio-pci device
+ *
+ * Returns the status read from device
+ */
+static u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
+{
+	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
+
+	return vp_ioread8(&cfg->device_status);
+}
+
 /* config->{get,set}_status() implementations */
 static u8 vp_get_status(struct virtio_device *vdev)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+
+	return vp_modern_get_status(&vp_dev->mdev);
+}
+
+/*
+ * vp_modern_set_status - set status to device
+ * @mdev: the modern virtio-pci device
+ * @status: the status set to device
+ */
+static void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
+				 u8 status)
+{
 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 
-	return vp_ioread8(&cfg->device_status);
+	vp_iowrite8(status, &cfg->device_status);
 }
 
 static void vp_set_status(struct virtio_device *vdev, u8 status)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
-	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 
 	/* We should never be setting status to 0. */
 	BUG_ON(status == 0);
-	vp_iowrite8(status, &cfg->device_status);
+	vp_modern_set_status(&vp_dev->mdev, status);
 }
 
 static void vp_reset(struct virtio_device *vdev)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
-	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
 
 	/* 0 status means a reset. */
-	vp_iowrite8(0, &cfg->device_status);
+	vp_modern_set_status(mdev, 0);
 	/* After writing 0 to device_status, the driver MUST wait for a read of
 	 * device_status to return 0 before reinitializing the device.
 	 * This will flush out the status write, and flush in device writes,
 	 * including MSI-X interrupts, if any.
 	 */
-	while (vp_ioread8(&cfg->device_status))
+	while (vp_modern_get_status(mdev))
 		msleep(1);
 	/* Flush pending VQ/configuration callbacks. */
 	vp_synchronize_vectors(vdev);