On Mon, Sep 13, 2021 at 07:19:17PM +1000, Alexey Kardashevskiy wrote:
>
>
> On 26/07/2021 14:51, Viresh Kumar wrote:
> > Bind the virtio devices with their of_node. This will help users of the
> > virtio devices to mention their dependencies on the device in the DT
> > itself. Like GPIO pin users can use the phandle of the device node, or
> > the node may contain more subnodes to add i2c or spi eeproms and other
> > users.
> >
> > Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
> > Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> > ---
> > drivers/virtio/virtio.c | 57 ++++++++++++++++++++++++++++++++++++++---
> > 1 file changed, 54 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> > index 4b15c00c0a0a..d001e84a5b23 100644
> > --- a/drivers/virtio/virtio.c
> > +++ b/drivers/virtio/virtio.c
> > @@ -4,6 +4,7 @@
> > #include <linux/virtio_config.h>
> > #include <linux/module.h>
> > #include <linux/idr.h>
> > +#include <linux/of.h>
> > #include <uapi/linux/virtio_ids.h>
> >
> > /* Unique numbering for virtio devices. */
> > @@ -292,6 +293,9 @@ static int virtio_dev_remove(struct device *_d)
> >
> > /* Acknowledge the device's existence again. */
> > virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
> > +
> > + of_node_put(dev->dev.of_node);
> > +
> > return 0;
> > }
> >
> > @@ -319,6 +323,43 @@ void unregister_virtio_driver(struct virtio_driver *driver)
> > }
> > EXPORT_SYMBOL_GPL(unregister_virtio_driver);
> >
> > +static int virtio_device_of_init(struct virtio_device *dev)
> > +{
> > + struct device_node *np, *pnode = dev_of_node(dev->dev.parent);
> > + char compat[] = "virtio,XXXXXXXX"; /* Reserve enough space 32-bit id */
> > + int ret, count;
> > +
> > + if (!pnode)
> > + return 0;
> > +
> > + count = of_get_available_child_count(pnode);
> > + if (!count)
> > + return 0;
> > +
> > + /* There can be only 1 child node */
> > + if (WARN_ON(count > 1))
> > + return -EINVAL;
> > +
> > + np = of_get_next_available_child(pnode, NULL);
> > + if (WARN_ON(!np))
> > + return -ENODEV;
> > +
> > + BUG_ON(snprintf(compat, sizeof(compat), "virtio,%x", dev->id.device) >=
> > + sizeof(compat));
> > +
> > + if (!of_device_is_compatible(np, compat)) {
>
>
> This broke powerpc/pseries as there these virtio devices are PCI so
> there is no "compat" - PCI vendor id/device ids play role of "compat".
> Thanks,
Hmm now that you say this I wonder why do we bother
with this check, too. When can this be invoked for something
that is not a virtio device? And is it enough to just
skip of_node initialization then?
>
>
>
> > + ret = -EINVAL;
So basically ret = 0 above?
> > + goto out;
> > + }
> > +
> > + dev->dev.of_node = np;
> > + return 0;
> > +
> > +out:
> > + of_node_put(np);
> > + return ret;
> > +}
> > +
> > /**
> > * register_virtio_device - register virtio device
> > * @dev : virtio device to be registered
> > @@ -343,6 +384,10 @@ int register_virtio_device(struct virtio_device *dev)
> > dev->index = err;
> > dev_set_name(&dev->dev, "virtio%u", dev->index);
> >
> > + err = virtio_device_of_init(dev);
> > + if (err)
> > + goto out_ida_remove;
> > +
> > spin_lock_init(&dev->config_lock);
> > dev->config_enabled = false;
> > dev->config_change_pending = false;
> > @@ -362,10 +407,16 @@ int register_virtio_device(struct virtio_device *dev)
> > */
> > err = device_add(&dev->dev);
> > if (err)
> > - ida_simple_remove(&virtio_index_ida, dev->index);
> > + goto out_of_node_put;
> > +
> > + return 0;
> > +
> > +out_of_node_put:
> > + of_node_put(dev->dev.of_node);
> > +out_ida_remove:
> > + ida_simple_remove(&virtio_index_ida, dev->index);
> > out:
> > - if (err)
> > - virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
> > + virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
> > return err;
> > }
> > EXPORT_SYMBOL_GPL(register_virtio_device);
> >
>
> --
> Alexey
