From: Parav Pandit <parav@mellanox.com>
To: Jason Gunthorpe <jgg@ziepe.ca>, Greg KH <gregkh@linuxfoundation.org>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
"davem@davemloft.net" <davem@davemloft.net>,
Dave Ertman <david.m.ertman@intel.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
"nhorman@redhat.com" <nhorman@redhat.com>,
"sassmann@redhat.com" <sassmann@redhat.com>,
Kiran Patil <kiran.patil@intel.com>
Subject: RE: [net-next 1/1] virtual-bus: Implementation of Virtual Bus
Date: Wed, 13 Nov 2019 01:03:44 +0000 [thread overview]
Message-ID: <AM0PR05MB48662DEDDE4750D399B8181ED1760@AM0PR05MB4866.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <20191113000819.GB19615@ziepe.ca>
Hi Jason,
> From: Jason Gunthorpe <jgg@ziepe.ca>
> Sent: Tuesday, November 12, 2019 6:08 PM
>
> On Tue, Nov 12, 2019 at 10:28:26PM +0100, Greg KH wrote:
>
> > > + */
> > > +struct virtbus_device {
> > > + const char *name;
> > > + int id;
> > > + const struct virtbus_dev_id *dev_id;
> > > + struct device dev;
> > > + void *data;
> > > +};
> > > +
> > > +struct virtbus_driver {
> > > + int (*probe)(struct virtbus_device *);
> > > + int (*remove)(struct virtbus_device *);
> > > + void (*shutdown)(struct virtbus_device *);
> > > + int (*suspend)(struct virtbus_device *, pm_message_t state);
> > > + int (*resume)(struct virtbus_device *);
> > > + struct device_driver driver;
> > > + const struct virtbus_dev_id *id_table; };
> > > +
> > > +#define virtbus_get_dev_id(vdev) ((vdev)->id_entry)
> > > +#define virtbus_get_devdata(dev) ((dev)->devdata)
> >
> > What are these for?
>
> As far as I can see, the scheme here, using the language from the most
> recent discussion is:
>
> // in core or netdev module
> int mlx5_core_create()
> {
> struct mlx5_core_dev *core = kzalloc(..)
>
> [..]
>
> core->vdev = virtbus_dev_alloc("mlx5_core", core);
> }
>
>
> // in rdma module
> static int mlx5_rdma_probe(struct virtbus_device *dev)
> {
> // Get the value passed to virtbus_dev_alloc()
> struct mlx5_core_dev *core = virtbus_get_devdata(dev)
>
> // Use the huge API surrounding struct mlx5_core_dev
> qp = mlx5_core_create_qp(core, ...);
> }
>
> static struct virtbus_driver mlx5_rdma_driver = {
> .probe = mlx5_rdma_probe,
> .match = {"mlx5_core"}
> }
>
> Drivers that match "mlx5_core" know that the opaque
> 'virtbus_get_devdata()' is a 'struct mlx5_core_dev *' and use that access the
> core driver.
>
> A "ice_core" would know it is some 'struct ice_core_dev *' for Intel and uses
> that pointer, etc.
>
> ie it is just a way to a pass a 'void *' from one module to another while using
> the driver core to manage module autoloading and binding.
A small improvement below, because get_drvdata() and set_drvdata() is supposed to be called by the bus driver, not its creator.
And below data structure achieve strong type checks, no void* casts, and exactly achieves the foo_device example.
Isn't it better?
mlx5_virtbus_device {
struct virtbus_device dev;
struct mlx5_core_dev *dev;
};
mlx5_core_create(const struct mlx5_core_dev *coredev)
{
struct mlx5_virtbus_device *dev;
dev = virtdev_alloc(sizeof(*dev));
dev->core = coredev; /* this should not be stored in drvdata */
virtdev_register(dev);
}
mlx5_rdma_probe(struct virtbus_device *dev)
{
struct mlx5_core_dev *coredev;
struct mlx5_virtdev *virtdev;
struct mlx5_ib_dev *ibdev;
virtdev = container_of(virtdev, struct mlx5_virtdev, dev);
coredev = virtdev->coredev;
ibdev = ib_alloc_dev();
if (!bdev)
return -ENOMEM;
virtdev_set_drvdata(dev, ibdev);
/* setup.. */
return 0;
}
mlx5_rdma_remove(struct virtbus_device *dev)
{
struct mlx5_ib_dev *ibdev;
ibdev = virtdev_get_drvdata(dev);
/* previous load failed */
if(!ibdev)
return;
[..]
/* mirror of probe */
}
next prev parent reply other threads:[~2019-11-13 1:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-11 19:22 [net-next 1/1] virtual-bus: Implementation of Virtual Bus Jeff Kirsher
2019-11-12 20:59 ` Jason Gunthorpe
2019-11-12 21:18 ` Ertman, David M
2019-11-12 21:28 ` Greg KH
2019-11-13 0:08 ` Jason Gunthorpe
2019-11-13 1:03 ` Parav Pandit [this message]
2019-11-13 1:10 ` Jason Gunthorpe
2019-11-13 6:44 ` Parav Pandit
2019-11-13 1:09 ` Ertman, David M
2019-11-13 7:03 ` Parav Pandit
2019-11-15 21:17 ` Ertman, David M
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=AM0PR05MB48662DEDDE4750D399B8181ED1760@AM0PR05MB4866.eurprd05.prod.outlook.com \
--to=parav@mellanox.com \
--cc=davem@davemloft.net \
--cc=david.m.ertman@intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=jeffrey.t.kirsher@intel.com \
--cc=jgg@ziepe.ca \
--cc=kiran.patil@intel.com \
--cc=linux-rdma@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=nhorman@redhat.com \
--cc=sassmann@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).