Commit e3669129 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

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



This patch introduces helpers to allow set and get device status.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-7-jasowang@redhat.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 1a5c85f1

drivers/virtio/virtio_pci_modern.c

+29 −8
Original line number Diff line number Diff line
@@ -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);