/* The hvc device associated with this console port */
struct hvc_struct *hvc;
+ /* The size of the console */
+ struct winsize ws;
+
/*
* This number identifies the number that we used to register
* with hvc in hvc_instantiate() and hvc_alloc(); this is the
*/
spinlock_t inbuf_lock;
+ /* Protect the operations on the out_vq. */
+ spinlock_t outvq_lock;
+
/* The IO vqs for this port */
struct virtqueue *in_vq, *out_vq;
/* The 'id' to identify the port with the Host */
u32 id;
+ bool outvq_full;
+
/* Is the host device open */
bool host_connected;
return __send_control_msg(port->portdev, port->id, event, value);
}
-static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
+/* Callers must take the port->outvq_lock */
+static void reclaim_consumed_buffers(struct port *port)
+{
+ void *buf;
+ unsigned int len;
+
+ while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
+ kfree(buf);
+ port->outvq_full = false;
+ }
+}
+
+static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
+ bool nonblock)
{
struct scatterlist sg[1];
struct virtqueue *out_vq;
ssize_t ret;
+ unsigned long flags;
unsigned int len;
out_vq = port->out_vq;
+ spin_lock_irqsave(&port->outvq_lock, flags);
+
+ reclaim_consumed_buffers(port);
+
sg_init_one(sg, in_buf, in_count);
ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
if (ret < 0) {
in_count = 0;
- goto fail;
+ goto done;
}
- /* Wait till the host acknowledges it pushed out the data we sent. */
+ if (ret == 0)
+ port->outvq_full = true;
+
+ if (nonblock)
+ goto done;
+
+ /*
+ * Wait till the host acknowledges it pushed out the data we
+ * sent. This is done for ports in blocking mode or for data
+ * from the hvc_console; the tty operations are performed with
+ * spinlocks held so we can't sleep here.
+ */
while (!virtqueue_get_buf(out_vq, &len))
cpu_relax();
-fail:
- /* We're expected to return the amount of data we wrote */
+done:
+ spin_unlock_irqrestore(&port->outvq_lock, flags);
+ /*
+ * We're expected to return the amount of data we wrote -- all
+ * of it
+ */
return in_count;
}
}
/* The condition that must be true for polling to end */
-static bool wait_is_over(struct port *port)
+static bool will_read_block(struct port *port)
{
- return port_has_data(port) || !port->host_connected;
+ return !port_has_data(port) && port->host_connected;
+}
+
+static bool will_write_block(struct port *port)
+{
+ bool ret;
+
+ if (!port->host_connected)
+ return true;
+
+ spin_lock_irq(&port->outvq_lock);
+ /*
+ * Check if the Host has consumed any buffers since we last
+ * sent data (this is only applicable for nonblocking ports).
+ */
+ reclaim_consumed_buffers(port);
+ ret = port->outvq_full;
+ spin_unlock_irq(&port->outvq_lock);
+
+ return ret;
}
static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
return -EAGAIN;
ret = wait_event_interruptible(port->waitqueue,
- wait_is_over(port));
+ !will_read_block(port));
if (ret < 0)
return ret;
}
struct port *port;
char *buf;
ssize_t ret;
+ bool nonblock;
port = filp->private_data;
+ nonblock = filp->f_flags & O_NONBLOCK;
+
+ if (will_write_block(port)) {
+ if (nonblock)
+ return -EAGAIN;
+
+ ret = wait_event_interruptible(port->waitqueue,
+ !will_write_block(port));
+ if (ret < 0)
+ return ret;
+ }
+
count = min((size_t)(32 * 1024), count);
buf = kmalloc(count, GFP_KERNEL);
goto free_buf;
}
- ret = send_buf(port, buf, count);
+ ret = send_buf(port, buf, count, nonblock);
+
+ if (nonblock && ret > 0)
+ goto out;
+
free_buf:
kfree(buf);
+out:
return ret;
}
ret = 0;
if (port->inbuf)
ret |= POLLIN | POLLRDNORM;
- if (port->host_connected)
+ if (!will_write_block(port))
ret |= POLLOUT;
if (!port->host_connected)
ret |= POLLHUP;
spin_unlock_irq(&port->inbuf_lock);
+ spin_lock_irq(&port->outvq_lock);
+ reclaim_consumed_buffers(port);
+ spin_unlock_irq(&port->outvq_lock);
+
return 0;
}
port->guest_connected = true;
spin_unlock_irq(&port->inbuf_lock);
+ spin_lock_irq(&port->outvq_lock);
+ /*
+ * There might be a chance that we missed reclaiming a few
+ * buffers in the window of the port getting previously closed
+ * and opening now.
+ */
+ reclaim_consumed_buffers(port);
+ spin_unlock_irq(&port->outvq_lock);
+
/* Notify host of port being opened */
send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
if (!port)
return -EPIPE;
- return send_buf(port, (void *)buf, count);
+ return send_buf(port, (void *)buf, count, false);
}
/*
static void resize_console(struct port *port)
{
struct virtio_device *vdev;
- struct winsize ws;
/* The port could have been hot-unplugged */
- if (!port)
+ if (!port || !is_console_port(port))
return;
vdev = port->portdev->vdev;
- if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
- vdev->config->get(vdev,
- offsetof(struct virtio_console_config, cols),
- &ws.ws_col, sizeof(u16));
- vdev->config->get(vdev,
- offsetof(struct virtio_console_config, rows),
- &ws.ws_row, sizeof(u16));
- hvc_resize(port->cons.hvc, ws);
- }
+ if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
+ hvc_resize(port->cons.hvc, port->cons.ws);
}
/* We set the configuration at this point, since we now have a tty */
spin_unlock_irq(&pdrvdata_lock);
port->guest_connected = true;
+ /*
+ * Start using the new console output if this is the first
+ * console to come up.
+ */
+ if (early_put_chars)
+ early_put_chars = NULL;
+
/* Notify host of port being opened */
send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
"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,
+ "outvq_full: %d\n", port->outvq_full);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"is_console: %s\n",
is_console_port(port) ? "yes" : "no");
.read = debugfs_read,
};
+static void set_console_size(struct port *port, u16 rows, u16 cols)
+{
+ if (!port || !is_console_port(port))
+ return;
+
+ port->cons.ws.ws_row = rows;
+ port->cons.ws.ws_col = cols;
+}
+
static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
{
struct port_buffer *buf;
port->inbuf = NULL;
port->cons.hvc = NULL;
+ port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
+
port->host_connected = port->guest_connected = false;
+ port->outvq_full = false;
+
port->in_vq = portdev->in_vqs[port->id];
port->out_vq = portdev->out_vqs[port->id];
}
spin_lock_init(&port->inbuf_lock);
+ spin_lock_init(&port->outvq_lock);
init_waitqueue_head(&port->waitqueue);
/* Fill the in_vq with buffers so the host can send us data. */
kfree(port);
fail:
/* The host might want to notify management sw about port add failure */
- send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 0);
+ __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
return err;
}
/* Remove unused data this port might have received. */
discard_port_data(port);
+ reclaim_consumed_buffers(port);
+
/* Remove buffers we queued up for the Host to send us data in. */
while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
free_buf(buf);
switch (cpkt->event) {
case VIRTIO_CONSOLE_PORT_ADD:
if (port) {
- /*
- * This can happen for port 0: we have to
- * create a console port during probe() as was
- * the behaviour before the MULTIPORT feature.
- * On a newer host, when the host tells us
- * that a port 0 is available, we should just
- * say we have the port all set up.
- */
+ dev_dbg(&portdev->vdev->dev,
+ "Port %u already added\n", port->id);
send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
break;
}
* have to notify the host first.
*/
break;
- case VIRTIO_CONSOLE_RESIZE:
+ case VIRTIO_CONSOLE_RESIZE: {
+ struct {
+ __u16 rows;
+ __u16 cols;
+ } size;
+
if (!is_console_port(port))
break;
+
+ memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
+ sizeof(size));
+ set_console_size(port, size.rows, size.cols);
+
port->cons.hvc->irq_requested = 1;
resize_console(port);
break;
+ }
case VIRTIO_CONSOLE_PORT_OPEN:
port->host_connected = cpkt->value;
wake_up_interruptible(&port->waitqueue);
+ /*
+ * If the host port got closed and the host had any
+ * unconsumed buffers, we'll be able to reclaim them
+ * now.
+ */
+ spin_lock_irq(&port->outvq_lock);
+ reclaim_consumed_buffers(port);
+ spin_unlock_irq(&port->outvq_lock);
break;
case VIRTIO_CONSOLE_PORT_NAME:
/*
portdev = vdev->priv;
- /*
- * We'll use this way of resizing only for legacy support.
- * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
- * control messages to indicate console size changes so that
- * it can be done per-port
- */
- resize_console(find_port_by_id(portdev, 0));
+ if (!use_multiport(portdev)) {
+ struct port *port;
+ u16 rows, cols;
+
+ vdev->config->get(vdev,
+ offsetof(struct virtio_console_config, cols),
+ &cols, sizeof(u16));
+ vdev->config->get(vdev,
+ offsetof(struct virtio_console_config, rows),
+ &rows, sizeof(u16));
+
+ port = find_port_by_id(portdev, 0);
+ set_console_size(port, rows, cols);
+
+ /*
+ * We'll use this way of resizing only for legacy
+ * support. For newer userspace
+ * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
+ * to indicate console size changes so that it can be
+ * done per-port.
+ */
+ resize_console(port);
+ }
}
static int init_vqs(struct ports_device *portdev)
err = -ENOMEM;
goto free_vqs;
}
+ } else {
+ /*
+ * For backward compatibility: Create a console port
+ * if we're running on older host.
+ */
+ add_port(portdev, 0);
}
- /*
- * For backward compatibility: if we're running on an older
- * host, we always want to create a console port.
- */
- add_port(portdev, 0);
-
- /* Start using the new console output. */
- early_put_chars = NULL;
-
__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
VIRTIO_CONSOLE_DEVICE_READY, 1);
return 0;
free_vqs:
+ /* The host might want to notify mgmt sw about device add failure */
+ __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
+ VIRTIO_CONSOLE_DEVICE_READY, 0);
vdev->config->del_vqs(vdev);
kfree(portdev->in_vqs);
kfree(portdev->out_vqs);
free:
kfree(portdev);
fail:
- /* The host might want to notify mgmt sw about device add failure */
- __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
- VIRTIO_CONSOLE_DEVICE_READY, 0);
return err;
}
git.openpandora.org / pandora-kernel.git / blobdiff