diff options
| -rw-r--r-- | drivers/char/virtio_console.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 9f20fda9c56f..2a04daa9189e 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -17,6 +17,7 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/cdev.h> +#include <linux/debugfs.h> #include <linux/device.h> #include <linux/err.h> #include <linux/fs.h> @@ -43,6 +44,9 @@ struct ports_driver_data { /* Used for registering chardevs */ struct class *class; + /* Used for exporting per-port information to debugfs */ + struct dentry *debugfs_dir; + /* Number of devices this driver is handling */ unsigned int index; @@ -158,6 +162,9 @@ struct port { /* The IO vqs for this port */ struct virtqueue *in_vq, *out_vq; + /* File in the debugfs directory that exposes this port's information */ + struct dentry *debugfs_file; + /* * The entries in this struct will be valid if this port is * hooked up to an hvc console @@ -783,6 +790,49 @@ static struct attribute_group port_attribute_group = { .attrs = port_sysfs_entries, }; +static int debugfs_open(struct inode *inode, struct file *filp) +{ + filp->private_data = inode->i_private; + return 0; +} + +static ssize_t debugfs_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *offp) +{ + struct port *port; + char *buf; + ssize_t ret, out_offset, out_count; + + out_count = 1024; + buf = kmalloc(out_count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + port = filp->private_data; + out_offset = 0; + out_offset += snprintf(buf + out_offset, out_count, + "name: %s\n", port->name ? port->name : ""); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "guest_connected: %d\n", port->guest_connected); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "host_connected: %d\n", port->host_connected); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "is_console: %s\n", + is_console_port(port) ? "yes" : "no"); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "console_vtermno: %u\n", port->cons.vtermno); + + ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset); + kfree(buf); + return ret; +} + +static const struct file_operations port_debugfs_ops = { + .owner = THIS_MODULE, + .open = debugfs_open, + .read = debugfs_read, +}; + /* Remove all port-specific data. */ static int remove_port(struct port *port) { @@ -809,6 +859,8 @@ static int remove_port(struct port *port) discard_port_data(port); kfree(port->name); + debugfs_remove(port->debugfs_file); + kfree(port); return 0; } @@ -1021,6 +1073,7 @@ static void fill_queue(struct virtqueue *vq, spinlock_t *lock) static int add_port(struct ports_device *portdev, u32 id) { + char debugfs_name[16]; struct port *port; struct port_buffer *inbuf; dev_t devt; @@ -1096,6 +1149,18 @@ static int add_port(struct ports_device *portdev, u32 id) */ send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); + if (pdrvdata.debugfs_dir) { + /* + * Finally, create the debugfs file that we can use to + * inspect a port's state at any time + */ + sprintf(debugfs_name, "vport%up%u", + port->portdev->drv_index, id); + port->debugfs_file = debugfs_create_file(debugfs_name, 0444, + pdrvdata.debugfs_dir, + port, + &port_debugfs_ops); + } return 0; free_inbuf: @@ -1406,6 +1471,12 @@ static int __init init(void) pr_err("Error %d creating virtio-ports class\n", err); return err; } + + pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL); + if (!pdrvdata.debugfs_dir) { + pr_warning("Error %ld creating debugfs dir for virtio-ports\n", + PTR_ERR(pdrvdata.debugfs_dir)); + } INIT_LIST_HEAD(&pdrvdata.consoles); return register_virtio_driver(&virtio_console); |