1 files changed, 80 insertions, 41 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index fb68b1295373..8e3c46d67cb3 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -19,8 +19,10 @@
  */
 #include <linux/cdev.h>
 #include <linux/debugfs.h>
+#include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/err.h>
+#include <linux/freezer.h>
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/list.h>
@@ -32,6 +34,7 @@
 #include <linux/virtio_console.h>
 #include <linux/wait.h>
 #include <linux/workqueue.h>
+#include <linux/module.h>
 #include "../tty/hvc/hvc_console.h"
 
 /*
@@ -73,6 +76,7 @@ struct ports_driver_data {
 static struct ports_driver_data pdrvdata;
 
 DEFINE_SPINLOCK(pdrvdata_lock);
+DECLARE_COMPLETION(early_console_added);
 
 /* This struct holds information that's relevant only for console ports */
 struct console {
@@ -151,6 +155,10 @@ struct ports_device {
 	int chr_major;
 };
 
+struct port_stats {
+	unsigned long bytes_sent, bytes_received, bytes_discarded;
+};
+
 /* This struct holds the per-port data */
 struct port {
 	/* Next port in the list, head is in the ports_device */
@@ -179,6 +187,13 @@ struct port {
 	struct dentry *debugfs_file;
 
 	/*
+	 * Keep count of the bytes sent, received and discarded for
+	 * this port for accounting and debugging purposes.  These
+	 * counts are not reset across port open / close events.
+	 */
+	struct port_stats stats;
+
+	/*
 	 * The entries in this struct will be valid if this port is
 	 * hooked up to an hvc console
 	 */
@@ -347,17 +362,19 @@ fail:
 }
 
 /* Callers should take appropriate locks */
-static void *get_inbuf(struct port *port)
+static struct port_buffer *get_inbuf(struct port *port)
 {
 	struct port_buffer *buf;
-	struct virtqueue *vq;
 	unsigned int len;
 
-	vq = port->in_vq;
-	buf = virtqueue_get_buf(vq, &len);
+	if (port->inbuf)
+		return port->inbuf;
+
+	buf = virtqueue_get_buf(port->in_vq, &len);
 	if (buf) {
 		buf->len = len;
 		buf->offset = 0;
+		port->stats.bytes_received += len;
 	}
 	return buf;
 }
@@ -384,32 +401,27 @@ static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
 static void discard_port_data(struct port *port)
 {
 	struct port_buffer *buf;
-	struct virtqueue *vq;
-	unsigned int len;
-	int ret;
+	unsigned int err;
 
 	if (!port->portdev) {
 		/* Device has been unplugged.  vqs are already gone. */
 		return;
 	}
-	vq = port->in_vq;
-	if (port->inbuf)
-		buf = port->inbuf;
-	else
-		buf = virtqueue_get_buf(vq, &len);
+	buf = get_inbuf(port);
 
-	ret = 0;
+	err = 0;
 	while (buf) {
-		if (add_inbuf(vq, buf) < 0) {
-			ret++;
+		port->stats.bytes_discarded += buf->len - buf->offset;
+		if (add_inbuf(port->in_vq, buf) < 0) {
+			err++;
 			free_buf(buf);
 		}
-		buf = virtqueue_get_buf(vq, &len);
+		port->inbuf = NULL;
+		buf = get_inbuf(port);
 	}
-	port->inbuf = NULL;
-	if (ret)
+	if (err)
 		dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
-			 ret);
+			 err);
 }
 
 static bool port_has_data(struct port *port)
@@ -417,18 +429,12 @@ static bool port_has_data(struct port *port)
 	unsigned long flags;
 	bool ret;
 
+	ret = false;
 	spin_lock_irqsave(&port->inbuf_lock, flags);
-	if (port->inbuf) {
-		ret = true;
-		goto out;
-	}
 	port->inbuf = get_inbuf(port);
-	if (port->inbuf) {
+	if (port->inbuf)
 		ret = true;
-		goto out;
-	}
-	ret = false;
-out:
+
 	spin_unlock_irqrestore(&port->inbuf_lock, flags);
 	return ret;
 }
@@ -529,6 +535,8 @@ static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
 		cpu_relax();
 done:
 	spin_unlock_irqrestore(&port->outvq_lock, flags);
+
+	port->stats.bytes_sent += in_count;
 	/*
 	 * We're expected to return the amount of data we wrote -- all
 	 * of it
@@ -633,8 +641,8 @@ static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
 		if (filp->f_flags & O_NONBLOCK)
 			return -EAGAIN;
 
-		ret = wait_event_interruptible(port->waitqueue,
-					       !will_read_block(port));
+		ret = wait_event_freezable(port->waitqueue,
+					   !will_read_block(port));
 		if (ret < 0)
 			return ret;
 	}
@@ -677,8 +685,8 @@ static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
 		if (nonblock)
 			return -EAGAIN;
 
-		ret = wait_event_interruptible(port->waitqueue,
-					       !will_write_block(port));
+		ret = wait_event_freezable(port->waitqueue,
+					   !will_write_block(port));
 		if (ret < 0)
 			return ret;
 	}
@@ -1059,6 +1067,14 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
 	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,
+			       "bytes_sent: %lu\n", port->stats.bytes_sent);
+	out_offset += snprintf(buf + out_offset, out_count - out_offset,
+			       "bytes_received: %lu\n",
+			       port->stats.bytes_received);
+	out_offset += snprintf(buf + out_offset, out_count - out_offset,
+			       "bytes_discarded: %lu\n",
+			       port->stats.bytes_discarded);
+	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,
@@ -1143,6 +1159,7 @@ static int add_port(struct ports_device *portdev, u32 id)
 	port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
 
 	port->host_connected = port->guest_connected = false;
+	port->stats = (struct port_stats) { 0 };
 
 	port->outvq_full = false;
 
@@ -1352,6 +1369,7 @@ static void handle_control_message(struct ports_device *portdev,
 			break;
 
 		init_port_console(port);
+		complete(&early_console_added);
 		/*
 		 * Could remove the port here in case init fails - but
 		 * have to notify the host first.
@@ -1394,6 +1412,13 @@ static void handle_control_message(struct ports_device *portdev,
 		break;
 	case VIRTIO_CONSOLE_PORT_NAME:
 		/*
+		 * If we woke up after hibernation, we can get this
+		 * again.  Skip it in that case.
+		 */
+		if (port->name)
+			break;
+
+		/*
 		 * Skip the size of the header and the cpkt to get the size
 		 * of the name that was sent
 		 */
@@ -1481,8 +1506,7 @@ static void in_intr(struct virtqueue *vq)
 		return;
 
 	spin_lock_irqsave(&port->inbuf_lock, flags);
-	if (!port->inbuf)
-		port->inbuf = get_inbuf(port);
+	port->inbuf = get_inbuf(port);
 
 	/*
 	 * Don't queue up data when port is closed.  This condition
@@ -1563,7 +1587,7 @@ static int init_vqs(struct ports_device *portdev)
 	portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
 				   GFP_KERNEL);
 	if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
-			!portdev->out_vqs) {
+	    !portdev->out_vqs) {
 		err = -ENOMEM;
 		goto free;
 	}
@@ -1648,6 +1672,10 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
 	struct ports_device *portdev;
 	int err;
 	bool multiport;
+	bool early = early_put_chars != NULL;
+
+	/* Ensure to read early_put_chars now */
+	barrier();
 
 	portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
 	if (!portdev) {
@@ -1675,13 +1703,11 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
 
 	multiport = false;
 	portdev->config.max_nr_ports = 1;
-	if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
+	if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
+			      offsetof(struct virtio_console_config,
+				       max_nr_ports),
+			      &portdev->config.max_nr_ports) == 0)
 		multiport = true;
-		vdev->config->get(vdev, offsetof(struct virtio_console_config,
-						 max_nr_ports),
-				  &portdev->config.max_nr_ports,
-				  sizeof(portdev->config.max_nr_ports));
-	}
 
 	err = init_vqs(portdev);
 	if (err < 0) {
@@ -1719,6 +1745,19 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
 
 	__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
 			   VIRTIO_CONSOLE_DEVICE_READY, 1);
+
+	/*
+	 * If there was an early virtio console, assume that there are no
+	 * other consoles. We need to wait until the hvc_alloc matches the
+	 * hvc_instantiate, otherwise tty_open will complain, resulting in
+	 * a "Warning: unable to open an initial console" boot failure.
+	 * Without multiport this is done in add_port above. With multiport
+	 * this might take some host<->guest communication - thus we have to
+	 * wait.
+	 */
+	if (multiport && early)
+		wait_for_completion(&early_console_added);
+
 	return 0;
 
 free_vqs: