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

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

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-7-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Jason Wang 2021-01-04 14:54:50 +08:00 committed by Michael S. Tsirkin
parent 1a5c85f165
commit e3669129fd
1 changed files with 31 additions and 10 deletions
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41
drivers/virtio/virtio_pci_modern.c
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@ -275,41 +275,62 @@ static u32 vp_generation(struct virtio_device *vdev)
return vp_ioread8(&cfg->config_generation);
}
/* config->{get,set}_status() implementations */
static u8 vp_get_status(struct virtio_device *vdev)
/*
* 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_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;
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);
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;
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);