2 files changed, 82 insertions, 7 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index e023682be2c4..3141dd3b6e53 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -666,6 +666,14 @@ config VIRTIO_CONSOLE
         help
           Virtio console for use with lguest and other hypervisors.
 
+          Also serves as a general-purpose serial device for data
+          transfer between the guest and host.  Character devices at
+          /dev/vportNpn will be created when corresponding ports are
+          found, where N is the device number and n is the port number
+          within that device.  If specified by the host, a sysfs
+          attribute called 'name' will be populated with a name for
+          the port which can be used by udev scripts to create a
+          symlink to the device.
 
 config HVCS
         tristate "IBM Hypervisor Virtual Console Server support"
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 8e447e1e12bc..64ef476d6557 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -16,6 +16,8 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
+#include <linux/cdev.h>
+#include <linux/device.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/list.h>
@@ -34,6 +36,12 @@
  * across multiple devices and multiple ports per device.
  */
 struct ports_driver_data {
+        /* Used for registering chardevs */
+        struct class *class;
+
+        /* Number of devices this driver is handling */
+        unsigned int index;
+
         /*
          * This is used to keep track of the number of hvc consoles
          * spawned by this driver.  This number is given as the first
@@ -116,6 +124,12 @@ struct ports_device {
 
         /* Array of per-port IO virtqueues */
         struct virtqueue **in_vqs, **out_vqs;
+
+        /* Used for numbering devices for sysfs and debugfs */
+        unsigned int drv_index;
+
+        /* Major number for this device.  Ports will be created as minors. */
+        int chr_major;
 };
 
 /* This struct holds the per-port data */
@@ -145,6 +159,10 @@ struct port {
          */
         struct console cons;
 
+        /* Each port associates with a separate char device */
+        struct cdev cdev;
+        struct device *dev;
+
         /* The 'id' to identify the port with the Host */
         u32 id;
 };
@@ -391,7 +409,7 @@ static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
                 port->inbuf = NULL;
 
                 if (add_inbuf(port->in_vq, buf) < 0)
-                        dev_warn(&port->portdev->vdev->dev, "failed add_buf\n");
+                        dev_warn(port->dev, "failed add_buf\n");
 
                 spin_unlock_irqrestore(&port->inbuf_lock, flags);
         }
@@ -664,6 +682,7 @@ static int add_port(struct ports_device *portdev, u32 id)
 {
         struct port *port;
         struct port_buffer *inbuf;
+        dev_t devt;
         int err;
 
         port = kmalloc(sizeof(*port), GFP_KERNEL);
@@ -681,12 +700,32 @@ static int add_port(struct ports_device *portdev, u32 id)
         port->in_vq = portdev->in_vqs[port->id];
         port->out_vq = portdev->out_vqs[port->id];
 
+        cdev_init(&port->cdev, NULL);
+
+        devt = MKDEV(portdev->chr_major, id);
+        err = cdev_add(&port->cdev, devt, 1);
+        if (err < 0) {
+                dev_err(&port->portdev->vdev->dev,
+                        "Error %d adding cdev for port %u\n", err, id);
+                goto free_port;
+        }
+        port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
+                                  devt, port, "vport%up%u",
+                                  port->portdev->drv_index, id);
+        if (IS_ERR(port->dev)) {
+                err = PTR_ERR(port->dev);
+                dev_err(&port->portdev->vdev->dev,
+                        "Error %d creating device for port %u\n",
+                        err, id);
+                goto free_cdev;
+        }
+
         spin_lock_init(&port->inbuf_lock);
 
         inbuf = alloc_buf(PAGE_SIZE);
         if (!inbuf) {
                 err = -ENOMEM;
-                goto free_port;
+                goto free_device;
         }
 
         /* Register the input buffer the first time. */
@@ -716,6 +755,10 @@ static int add_port(struct ports_device *portdev, u32 id)
 
 free_inbuf:
         free_buf(inbuf);
+free_device:
+        device_destroy(pdrvdata.class, port->dev->devt);
+free_cdev:
+        cdev_del(&port->cdev);
 free_port:
         kfree(port);
 fail:
@@ -828,6 +871,10 @@ fail:
         return err;
 }
 
+static const struct file_operations portdev_fops = {
+        .owner = THIS_MODULE,
+};
+
 /*
  * Once we're further in boot, we get probed like any other virtio
  * device.
@@ -853,6 +900,20 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
         portdev->vdev = vdev;
         vdev->priv = portdev;
 
+        spin_lock_irq(&pdrvdata_lock);
+        portdev->drv_index = pdrvdata.index++;
+        spin_unlock_irq(&pdrvdata_lock);
+
+        portdev->chr_major = register_chrdev(0, "virtio-portsdev",
+                                             &portdev_fops);
+        if (portdev->chr_major < 0) {
+                dev_err(&vdev->dev,
+                        "Error %d registering chrdev for device %u\n",
+                        portdev->chr_major, portdev->drv_index);
+                err = portdev->chr_major;
+                goto free;
+        }
+
         multiport = false;
         portdev->config.nr_ports = 1;
         portdev->config.max_nr_ports = 1;
@@ -885,7 +946,7 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
         err = init_vqs(portdev);
         if (err < 0) {
                 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
-                goto free;
+                goto free_chrdev;
         }
 
         spin_lock_init(&portdev->ports_lock);
@@ -905,10 +966,8 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
         early_put_chars = NULL;
         return 0;
 
-free_vqs:
-        vdev->config->del_vqs(vdev);
-        kfree(portdev->in_vqs);
-        kfree(portdev->out_vqs);
+free_chrdev:
+        unregister_chrdev(portdev->chr_major, "virtio-portsdev");
 free:
         kfree(portdev);
 fail:
@@ -937,6 +996,14 @@ static struct virtio_driver virtio_console = {
 
 static int __init init(void)
 {
+        int err;
+
+        pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
+        if (IS_ERR(pdrvdata.class)) {
+                err = PTR_ERR(pdrvdata.class);
+                pr_err("Error %d creating virtio-ports class\n", err);
+                return err;
+        }
         INIT_LIST_HEAD(&pdrvdata.consoles);
 
         return register_virtio_driver(&virtio_console);