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path: root/drivers/char/virtio_console.c
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Diffstat (limited to 'drivers/char/virtio_console.c')
-rw-r--r--drivers/char/virtio_console.c110
1 files changed, 77 insertions, 33 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 213373b5f17f..196428c2287a 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -25,6 +25,7 @@
#include <linux/list.h>
#include <linux/poll.h>
#include <linux/sched.h>
+#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/virtio.h>
#include <linux/virtio_console.h>
@@ -32,6 +33,35 @@
#include <linux/workqueue.h>
#include "hvc_console.h"
+/* Moved here from .h file in order to disable MULTIPORT. */
+#define VIRTIO_CONSOLE_F_MULTIPORT 1 /* Does host provide multiple ports? */
+
+struct virtio_console_multiport_conf {
+ struct virtio_console_config config;
+ /* max. number of ports this device can hold */
+ __u32 max_nr_ports;
+ /* number of ports added so far */
+ __u32 nr_ports;
+} __attribute__((packed));
+
+/*
+ * A message that's passed between the Host and the Guest for a
+ * particular port.
+ */
+struct virtio_console_control {
+ __u32 id; /* Port number */
+ __u16 event; /* The kind of control event (see below) */
+ __u16 value; /* Extra information for the key */
+};
+
+/* Some events for control messages */
+#define VIRTIO_CONSOLE_PORT_READY 0
+#define VIRTIO_CONSOLE_CONSOLE_PORT 1
+#define VIRTIO_CONSOLE_RESIZE 2
+#define VIRTIO_CONSOLE_PORT_OPEN 3
+#define VIRTIO_CONSOLE_PORT_NAME 4
+#define VIRTIO_CONSOLE_PORT_REMOVE 5
+
/*
* This is a global struct for storing common data for all the devices
* this driver handles.
@@ -120,7 +150,7 @@ struct ports_device {
spinlock_t cvq_lock;
/* The current config space is stored here */
- struct virtio_console_config config;
+ struct virtio_console_multiport_conf config;
/* The virtio device we're associated with */
struct virtio_device *vdev;
@@ -379,7 +409,7 @@ static ssize_t send_control_msg(struct port *port, unsigned int event,
struct scatterlist sg[1];
struct virtio_console_control cpkt;
struct virtqueue *vq;
- int len;
+ unsigned int len;
if (!use_multiport(port->portdev))
return 0;
@@ -415,20 +445,16 @@ static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
out_vq->vq_ops->kick(out_vq);
if (ret < 0) {
- len = 0;
+ in_count = 0;
goto fail;
}
- /*
- * Wait till the host acknowledges it pushed out the data we
- * sent. Also ensure we return to userspace the number of
- * bytes that were successfully consumed by the host.
- */
+ /* Wait till the host acknowledges it pushed out the data we sent. */
while (!out_vq->vq_ops->get_buf(out_vq, &len))
cpu_relax();
fail:
/* We're expected to return the amount of data we wrote */
- return len;
+ return in_count;
}
/*
@@ -645,13 +671,13 @@ static int put_chars(u32 vtermno, const char *buf, int count)
{
struct port *port;
+ if (unlikely(early_put_chars))
+ return early_put_chars(vtermno, buf, count);
+
port = find_port_by_vtermno(vtermno);
if (!port)
return 0;
- if (unlikely(early_put_chars))
- return early_put_chars(vtermno, buf, count);
-
return send_buf(port, (void *)buf, count);
}
@@ -681,6 +707,10 @@ static void resize_console(struct port *port)
struct virtio_device *vdev;
struct winsize ws;
+ /* The port could have been hot-unplugged */
+ if (!port)
+ return;
+
vdev = port->portdev->vdev;
if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
vdev->config->get(vdev,
@@ -947,11 +977,18 @@ static void handle_control_message(struct ports_device *portdev,
*/
err = sysfs_create_group(&port->dev->kobj,
&port_attribute_group);
- if (err)
+ if (err) {
dev_err(port->dev,
"Error %d creating sysfs device attributes\n",
err);
-
+ } else {
+ /*
+ * Generate a udev event so that appropriate
+ * symlinks can be created based on udev
+ * rules.
+ */
+ kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
+ }
break;
case VIRTIO_CONSOLE_PORT_REMOVE:
/*
@@ -1071,27 +1108,27 @@ static void config_intr(struct virtio_device *vdev)
static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
{
struct port_buffer *buf;
- unsigned int ret;
- int err;
+ unsigned int nr_added_bufs;
+ int ret;
- ret = 0;
+ nr_added_bufs = 0;
do {
buf = alloc_buf(PAGE_SIZE);
if (!buf)
break;
spin_lock_irq(lock);
- err = add_inbuf(vq, buf);
- if (err < 0) {
+ ret = add_inbuf(vq, buf);
+ if (ret < 0) {
spin_unlock_irq(lock);
free_buf(buf);
break;
}
- ret++;
+ nr_added_bufs++;
spin_unlock_irq(lock);
- } while (err > 0);
+ } while (ret > 0);
- return ret;
+ return nr_added_bufs;
}
static int add_port(struct ports_device *portdev, u32 id)
@@ -1100,6 +1137,7 @@ static int add_port(struct ports_device *portdev, u32 id)
struct port *port;
struct port_buffer *buf;
dev_t devt;
+ unsigned int nr_added_bufs;
int err;
port = kmalloc(sizeof(*port), GFP_KERNEL);
@@ -1144,8 +1182,8 @@ static int add_port(struct ports_device *portdev, u32 id)
init_waitqueue_head(&port->waitqueue);
/* Fill the in_vq with buffers so the host can send us data. */
- err = fill_queue(port->in_vq, &port->inbuf_lock);
- if (!err) {
+ nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
+ if (!nr_added_bufs) {
dev_err(port->dev, "Error allocating inbufs\n");
err = -ENOMEM;
goto free_device;
@@ -1205,7 +1243,7 @@ fail:
*/
static void config_work_handler(struct work_struct *work)
{
- struct virtio_console_config virtconconf;
+ struct virtio_console_multiport_conf virtconconf;
struct ports_device *portdev;
struct virtio_device *vdev;
int err;
@@ -1214,7 +1252,8 @@ static void config_work_handler(struct work_struct *work)
vdev = portdev->vdev;
vdev->config->get(vdev,
- offsetof(struct virtio_console_config, nr_ports),
+ offsetof(struct virtio_console_multiport_conf,
+ nr_ports),
&virtconconf.nr_ports,
sizeof(virtconconf.nr_ports));
@@ -1406,16 +1445,19 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
multiport = false;
portdev->config.nr_ports = 1;
portdev->config.max_nr_ports = 1;
+#if 0 /* Multiport is not quite ready yet --RR */
if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
multiport = true;
vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
- vdev->config->get(vdev, offsetof(struct virtio_console_config,
- nr_ports),
+ vdev->config->get(vdev,
+ offsetof(struct virtio_console_multiport_conf,
+ nr_ports),
&portdev->config.nr_ports,
sizeof(portdev->config.nr_ports));
- vdev->config->get(vdev, offsetof(struct virtio_console_config,
- max_nr_ports),
+ vdev->config->get(vdev,
+ offsetof(struct virtio_console_multiport_conf,
+ max_nr_ports),
&portdev->config.max_nr_ports,
sizeof(portdev->config.max_nr_ports));
if (portdev->config.nr_ports > portdev->config.max_nr_ports) {
@@ -1431,6 +1473,7 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
/* Let the Host know we support multiple ports.*/
vdev->config->finalize_features(vdev);
+#endif
err = init_vqs(portdev);
if (err < 0) {
@@ -1442,12 +1485,14 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
INIT_LIST_HEAD(&portdev->ports);
if (multiport) {
+ unsigned int nr_added_bufs;
+
spin_lock_init(&portdev->cvq_lock);
INIT_WORK(&portdev->control_work, &control_work_handler);
INIT_WORK(&portdev->config_work, &config_work_handler);
- err = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
- if (!err) {
+ nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
+ if (!nr_added_bufs) {
dev_err(&vdev->dev,
"Error allocating buffers for control queue\n");
err = -ENOMEM;
@@ -1511,7 +1556,6 @@ static struct virtio_device_id id_table[] = {
static unsigned int features[] = {
VIRTIO_CONSOLE_F_SIZE,
- VIRTIO_CONSOLE_F_MULTIPORT,
};
static struct virtio_driver virtio_console = {
generated by cgit v1.2.3 (git 2.39.0) at 2024-08-02 19:59:43 +0300