/*
* removes a virtio device if a hot remove event has been
* requested by the host.
*/
static int _vop_remove_device(struct mic_device_desc __iomem *d,
unsigned int offset, struct vop_device *vpdev)
{
struct mic_device_ctrl __iomem *dc
= (void __iomem *)d + _vop_aligned_desc_size(d);
struct _vop_vdev *vdev = (struct _vop_vdev *)readq(&dc->vdev);
u8 status;
int ret = -1;
if (ioread8(&dc->config_change) == MIC_VIRTIO_PARAM_DEV_REMOVE) {
dev_dbg(&vpdev->dev,
"%s %d config_change %d type %d vdev %p\n",
__func__, __LINE__,
ioread8(&dc->config_change), ioread8(&d->type), vdev);
status = ioread8(&d->status);
reinit_completion(&vdev->reset_done);
unregister_virtio_device(&vdev->vdev);
vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
iowrite8(-1, &dc->h2c_vdev_db);
if (status & VIRTIO_CONFIG_S_DRIVER_OK)
wait_for_completion(&vdev->reset_done);
kfree(vdev);
iowrite8(1, &dc->guest_ack);
dev_dbg(&vpdev->dev, "%s %d guest_ack %d\n",
__func__, __LINE__, ioread8(&dc->guest_ack));
iowrite8(-1, &d->type);
ret = 0;
}
return ret;
}
/*
* adds a new device and register it with virtio
* appropriate drivers are loaded by the device model
*/
static int _vop_add_device(struct mic_device_desc __iomem *d,
unsigned int offset, struct vop_device *vpdev,
int dnode)
{
struct _vop_vdev *vdev, *reg_dev = NULL;
int ret;
u8 type = ioread8(&d->type);
vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
if (!vdev)
return -ENOMEM;
vdev->vpdev = vpdev;
vdev->vdev.dev.parent = &vpdev->dev;
vdev->vdev.dev.release = vop_virtio_release_dev;
vdev->vdev.id.device = type;
vdev->vdev.config = &vop_vq_config_ops;
vdev->desc = d;
vdev->dc = (void __iomem *)d + _vop_aligned_desc_size(d);
vdev->dnode = dnode;
vdev->vdev.priv = (void *)(unsigned long)dnode;
init_completion(&vdev->reset_done);
vdev->h2c_vdev_db = vpdev->hw_ops->next_db(vpdev);
vdev->virtio_cookie = vpdev->hw_ops->request_irq(vpdev,
vop_virtio_intr_handler, "virtio intr",
vdev, vdev->h2c_vdev_db);
if (IS_ERR(vdev->virtio_cookie)) {
ret = PTR_ERR(vdev->virtio_cookie);
goto kfree;
}
iowrite8((u8)vdev->h2c_vdev_db, &vdev->dc->h2c_vdev_db);
vdev->c2h_vdev_db = ioread8(&vdev->dc->c2h_vdev_db);
ret = register_virtio_device(&vdev->vdev);
reg_dev = vdev;
if (ret) {
dev_err(_vop_dev(vdev),
"Failed to register vop device %u type %u\n",
offset, type);
goto free_irq;
}
writeq((unsigned long)vdev, &vdev->dc->vdev);
dev_dbg(_vop_dev(vdev), "%s: registered vop device %u type %u vdev %p\n",
__func__, offset, type, vdev);
return 0;
free_irq:
vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
kfree:
if (reg_dev)
put_device(&vdev->vdev.dev);
else
kfree(vdev);
return ret;
}
static void _vop_scan_devices(void __iomem *dp, struct vop_device *vpdev,
bool remove, int dnode)
{
s8 type;
unsigned int i;
struct mic_device_desc __iomem *d;
struct mic_device_ctrl __iomem *dc;
struct device *dev;
int ret;
for (i = sizeof(struct mic_bootparam);
i < MIC_DP_SIZE; i += _vop_total_desc_size(d)) {
d = dp + i;
dc = (void __iomem *)d + _vop_aligned_desc_size(d);
/*
* This read barrier is paired with the corresponding write
* barrier on the host which is inserted before adding or
* removing a virtio device descriptor, by updating the type.
*/
rmb();
type = ioread8(&d->type);
/* end of list */
if (type == 0)
break;
if (type == -1)
continue;
/* device already exists */
dev = device_find_child(&vpdev->dev, (void __force *)d,
vop_match_desc);
if (dev) {
if (remove)
iowrite8(MIC_VIRTIO_PARAM_DEV_REMOVE,
&dc->config_change);
put_device(dev);
_vop_handle_config_change(d, i, vpdev);
ret = _vop_remove_device(d, i, vpdev);
if (remove) {
iowrite8(0, &dc->config_change);
iowrite8(0, &dc->guest_ack);
}
continue;
}
/* new device */
dev_dbg(&vpdev->dev, "%s %d Adding new virtio device %p\n",
__func__, __LINE__, d);
if (!remove)
_vop_add_device(d, i, vpdev, dnode);
}
}
static void _vop_handle_config_change(struct mic_device_desc __iomem *d,
unsigned int offset,
struct vop_device *vpdev)
{
struct mic_device_ctrl __iomem *dc
= (void __iomem *)d + _vop_aligned_desc_size(d);
struct _vop_vdev *vdev = (struct _vop_vdev *)readq(&dc->vdev);
if (ioread8(&dc->config_change) != MIC_VIRTIO_PARAM_CONFIG_CHANGED)
return;
dev_dbg(&vpdev->dev, "%s %d\n", __func__, __LINE__);
virtio_config_changed(&vdev->vdev);
iowrite8(1, &dc->guest_ack);
}
static inline unsigned
_vop_total_desc_size(struct mic_device_desc __iomem *desc)
{
return _vop_aligned_desc_size(desc) + sizeof(struct mic_device_ctrl);
}
