/*
* Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
- * Copyright (C) 2009, 2010 Red Hat, Inc.
+ * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
+ * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
*/
#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>
#include <linux/virtio_console.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
-#include "hvc_console.h"
+#include <linux/module.h>
+#include "../tty/hvc/hvc_console.h"
/*
* This is a global struct for storing common data for all the devices
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 {
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 */
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
*/
struct cdev *cdev;
struct device *dev;
+ /* Reference-counting to handle port hot-unplugs and file operations */
+ struct kref kref;
+
/* A waitqueue for poll() or blocking read operations */
wait_queue_head_t waitqueue;
/* The 'name' of the port that we expose via sysfs properties */
char *name;
+ /* We can notify apps of host connect / disconnect events via SIGIO */
+ struct fasync_struct *async_queue;
+
/* The 'id' to identify the port with the Host */
u32 id;
}
/* 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;
}
sg_init_one(sg, buf->buf, buf->size);
- ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
+ ret = virtqueue_add_buf(vq, sg, 0, 1, buf, GFP_ATOMIC);
virtqueue_kick(vq);
return ret;
}
static void discard_port_data(struct port *port)
{
struct port_buffer *buf;
- struct virtqueue *vq;
- unsigned int len;
- int ret;
+ unsigned int err;
- vq = port->in_vq;
- if (port->inbuf)
- buf = port->inbuf;
- else
- buf = virtqueue_get_buf(vq, &len);
+ if (!port->portdev) {
+ /* Device has been unplugged. vqs are already gone. */
+ return;
+ }
+ 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)
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;
}
vq = portdev->c_ovq;
sg_init_one(sg, &cpkt, sizeof(cpkt));
- if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
+ if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt, GFP_ATOMIC) >= 0) {
virtqueue_kick(vq);
while (!virtqueue_get_buf(vq, &len))
cpu_relax();
void *buf;
unsigned int len;
+ if (!port->portdev) {
+ /* Device has been unplugged. vqs are already gone. */
+ return;
+ }
while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
kfree(buf);
port->outvq_full = false;
reclaim_consumed_buffers(port);
sg_init_one(sg, in_buf, in_count);
- ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
+ ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf, GFP_ATOMIC);
/* Tell Host to go! */
virtqueue_kick(out_vq);
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
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;
}
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;
}
return ret;
}
+static void remove_port(struct kref *kref);
+
static int port_fops_release(struct inode *inode, struct file *filp)
{
struct port *port;
reclaim_consumed_buffers(port);
spin_unlock_irq(&port->outvq_lock);
+ /*
+ * Locks aren't necessary here as a port can't be opened after
+ * unplug, and if a port isn't unplugged, a kref would already
+ * exist for the port. Plus, taking ports_lock here would
+ * create a dependency on other locks taken by functions
+ * inside remove_port if we're the last holder of the port,
+ * creating many problems.
+ */
+ kref_put(&port->kref, remove_port);
+
return 0;
}
port = find_port_by_devt(cdev->dev);
filp->private_data = port;
+ /* Prevent against a port getting hot-unplugged at the same time */
+ spin_lock_irq(&port->portdev->ports_lock);
+ kref_get(&port->kref);
+ spin_unlock_irq(&port->portdev->ports_lock);
+
/*
* Don't allow opening of console port devices -- that's done
* via /dev/hvc
reclaim_consumed_buffers(port);
spin_unlock_irq(&port->outvq_lock);
+ nonseekable_open(inode, filp);
+
/* Notify host of port being opened */
send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
return 0;
out:
+ kref_put(&port->kref, remove_port);
return ret;
}
+static int port_fops_fasync(int fd, struct file *filp, int mode)
+{
+ struct port *port;
+
+ port = filp->private_data;
+ return fasync_helper(fd, filp, mode, &port->async_queue);
+}
+
/*
* The file operations that we support: programs in the guest can open
* a console device, read from it, write to it, poll for data and
.write = port_fops_write,
.poll = port_fops_poll,
.release = port_fops_release,
+ .fasync = port_fops_fasync,
+ .llseek = no_llseek,
};
/*
.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)
{
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,
static const struct file_operations port_debugfs_ops = {
.owner = THIS_MODULE,
- .open = debugfs_open,
+ .open = simple_open,
.read = debugfs_read,
};
return nr_added_bufs;
}
+static void send_sigio_to_port(struct port *port)
+{
+ if (port->async_queue && port->guest_connected)
+ kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
+}
+
static int add_port(struct ports_device *portdev, u32 id)
{
char debugfs_name[16];
err = -ENOMEM;
goto fail;
}
+ kref_init(&port->kref);
port->portdev = portdev;
port->id = id;
port->name = NULL;
port->inbuf = NULL;
port->cons.hvc = NULL;
+ port->async_queue = NULL;
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;
return err;
}
-/* Remove all port-specific data. */
-static void remove_port(struct port *port)
+/* No users remain, remove all port-specific data. */
+static void remove_port(struct kref *kref)
{
- struct port_buffer *buf;
-
- if (port->guest_connected) {
- port->guest_connected = false;
- port->host_connected = false;
- wake_up_interruptible(&port->waitqueue);
- send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
- }
+ struct port *port;
- spin_lock_irq(&port->portdev->ports_lock);
- list_del(&port->list);
- spin_unlock_irq(&port->portdev->ports_lock);
+ port = container_of(kref, struct port, kref);
- if (is_console_port(port)) {
- spin_lock_irq(&pdrvdata_lock);
- list_del(&port->cons.list);
- spin_unlock_irq(&pdrvdata_lock);
-#if 0
- /*
- * hvc_remove() not called as removing one hvc port
- * results in other hvc ports getting frozen.
- *
- * Once this is resolved in hvc, this functionality
- * will be enabled. Till that is done, the -EPIPE
- * return from get_chars() above will help
- * hvc_console.c to clean up on ports we remove here.
- */
- hvc_remove(port->cons.hvc);
-#endif
- }
sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
device_destroy(pdrvdata.class, port->dev->devt);
cdev_del(port->cdev);
+ kfree(port->name);
+
+ debugfs_remove(port->debugfs_file);
+
+ kfree(port);
+}
+
+static void remove_port_data(struct port *port)
+{
+ struct port_buffer *buf;
+
/* Remove unused data this port might have received. */
discard_port_data(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);
+}
- kfree(port->name);
+/*
+ * Port got unplugged. Remove port from portdev's list and drop the
+ * kref reference. If no userspace has this port opened, it will
+ * result in immediate removal the port.
+ */
+static void unplug_port(struct port *port)
+{
+ spin_lock_irq(&port->portdev->ports_lock);
+ list_del(&port->list);
+ spin_unlock_irq(&port->portdev->ports_lock);
- debugfs_remove(port->debugfs_file);
+ if (port->guest_connected) {
+ port->guest_connected = false;
+ port->host_connected = false;
+ wake_up_interruptible(&port->waitqueue);
- kfree(port);
+ /* Let the app know the port is going down. */
+ send_sigio_to_port(port);
+ }
+
+ if (is_console_port(port)) {
+ spin_lock_irq(&pdrvdata_lock);
+ list_del(&port->cons.list);
+ spin_unlock_irq(&pdrvdata_lock);
+ hvc_remove(port->cons.hvc);
+ }
+
+ remove_port_data(port);
+
+ /*
+ * We should just assume the device itself has gone off --
+ * else a close on an open port later will try to send out a
+ * control message.
+ */
+ port->portdev = NULL;
+
+ /*
+ * Locks around here are not necessary - a port can't be
+ * opened after we removed the port struct from ports_list
+ * above.
+ */
+ kref_put(&port->kref, remove_port);
}
/* Any private messages that the Host and Guest want to share */
add_port(portdev, cpkt->id);
break;
case VIRTIO_CONSOLE_PORT_REMOVE:
- remove_port(port);
+ unplug_port(port);
break;
case VIRTIO_CONSOLE_CONSOLE_PORT:
if (!cpkt->value)
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.
spin_lock_irq(&port->outvq_lock);
reclaim_consumed_buffers(port);
spin_unlock_irq(&port->outvq_lock);
+
+ /*
+ * If the guest is connected, it'll be interested in
+ * knowing the host connection state changed.
+ */
+ send_sigio_to_port(port);
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
*/
spin_unlock(&portdev->cvq_lock);
}
+static void out_intr(struct virtqueue *vq)
+{
+ struct port *port;
+
+ port = find_port_by_vq(vq->vdev->priv, vq);
+ if (!port)
+ return;
+
+ wake_up_interruptible(&port->waitqueue);
+}
+
static void in_intr(struct virtqueue *vq)
{
struct port *port;
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
wake_up_interruptible(&port->waitqueue);
+ /* Send a SIGIO indicating new data in case the process asked for it */
+ send_sigio_to_port(port);
+
if (is_console_port(port) && hvc_poll(port->cons.hvc))
hvc_kick();
}
nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
- if (!vqs) {
- err = -ENOMEM;
- goto fail;
- }
io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
- if (!io_callbacks) {
- err = -ENOMEM;
- goto free_vqs;
- }
io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
- if (!io_names) {
- err = -ENOMEM;
- goto free_callbacks;
- }
portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
GFP_KERNEL);
- if (!portdev->in_vqs) {
- err = -ENOMEM;
- goto free_names;
- }
portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
GFP_KERNEL);
- if (!portdev->out_vqs) {
+ if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
+ !portdev->out_vqs) {
err = -ENOMEM;
- goto free_invqs;
+ goto free;
}
/*
*/
j = 0;
io_callbacks[j] = in_intr;
- io_callbacks[j + 1] = NULL;
+ io_callbacks[j + 1] = out_intr;
io_names[j] = "input";
io_names[j + 1] = "output";
j += 2;
for (i = 1; i < nr_ports; i++) {
j += 2;
io_callbacks[j] = in_intr;
- io_callbacks[j + 1] = NULL;
+ io_callbacks[j + 1] = out_intr;
io_names[j] = "input";
io_names[j + 1] = "output";
}
io_callbacks,
(const char **)io_names);
if (err)
- goto free_outvqs;
+ goto free;
j = 0;
portdev->in_vqs[0] = vqs[0];
portdev->out_vqs[i] = vqs[j + 1];
}
}
- kfree(io_callbacks);
kfree(io_names);
+ kfree(io_callbacks);
kfree(vqs);
return 0;
-free_names:
- kfree(io_names);
-free_callbacks:
- kfree(io_callbacks);
-free_outvqs:
+free:
kfree(portdev->out_vqs);
-free_invqs:
kfree(portdev->in_vqs);
-free_vqs:
+ kfree(io_names);
+ kfree(io_callbacks);
kfree(vqs);
-fail:
+
return err;
}
.owner = THIS_MODULE,
};
+static void remove_vqs(struct ports_device *portdev)
+{
+ portdev->vdev->config->del_vqs(portdev->vdev);
+ kfree(portdev->in_vqs);
+ kfree(portdev->out_vqs);
+}
+
+static void remove_controlq_data(struct ports_device *portdev)
+{
+ struct port_buffer *buf;
+ unsigned int len;
+
+ if (!use_multiport(portdev))
+ return;
+
+ while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
+ free_buf(buf);
+
+ while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
+ free_buf(buf);
+}
+
/*
* Once we're further in boot, we get probed like any other virtio
* device.
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) {
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->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
-
- vdev->config->get(vdev, offsetof(struct virtio_console_config,
- max_nr_ports),
- &portdev->config.max_nr_ports,
- sizeof(portdev->config.max_nr_ports));
- }
-
- /* Let the Host know we support multiple ports.*/
- vdev->config->finalize_features(vdev);
err = init_vqs(portdev);
if (err < 0) {
__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:
/* 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);
+ remove_vqs(portdev);
free_chrdev:
unregister_chrdev(portdev->chr_major, "virtio-portsdev");
free:
cancel_work_sync(&portdev->control_work);
list_for_each_entry_safe(port, port2, &portdev->ports, list)
- remove_port(port);
+ unplug_port(port);
unregister_chrdev(portdev->chr_major, "virtio-portsdev");
- if (use_multiport(portdev)) {
- struct port_buffer *buf;
- unsigned int len;
-
- while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
- free_buf(buf);
-
- while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
- free_buf(buf);
- }
-
- vdev->config->del_vqs(vdev);
- kfree(portdev->in_vqs);
- kfree(portdev->out_vqs);
-
+ /*
+ * When yanking out a device, we immediately lose the
+ * (device-side) queues. So there's no point in keeping the
+ * guest side around till we drop our final reference. This
+ * also means that any ports which are in an open state will
+ * have to just stop using the port, as the vqs are going
+ * away.
+ */
+ remove_controlq_data(portdev);
+ remove_vqs(portdev);
kfree(portdev);
}
VIRTIO_CONSOLE_F_MULTIPORT,
};
+#ifdef CONFIG_PM
+static int virtcons_freeze(struct virtio_device *vdev)
+{
+ struct ports_device *portdev;
+ struct port *port;
+
+ portdev = vdev->priv;
+
+ vdev->config->reset(vdev);
+
+ virtqueue_disable_cb(portdev->c_ivq);
+ cancel_work_sync(&portdev->control_work);
+ /*
+ * Once more: if control_work_handler() was running, it would
+ * enable the cb as the last step.
+ */
+ virtqueue_disable_cb(portdev->c_ivq);
+ remove_controlq_data(portdev);
+
+ list_for_each_entry(port, &portdev->ports, list) {
+ virtqueue_disable_cb(port->in_vq);
+ virtqueue_disable_cb(port->out_vq);
+ /*
+ * We'll ask the host later if the new invocation has
+ * the port opened or closed.
+ */
+ port->host_connected = false;
+ remove_port_data(port);
+ }
+ remove_vqs(portdev);
+
+ return 0;
+}
+
+static int virtcons_restore(struct virtio_device *vdev)
+{
+ struct ports_device *portdev;
+ struct port *port;
+ int ret;
+
+ portdev = vdev->priv;
+
+ ret = init_vqs(portdev);
+ if (ret)
+ return ret;
+
+ if (use_multiport(portdev))
+ fill_queue(portdev->c_ivq, &portdev->cvq_lock);
+
+ list_for_each_entry(port, &portdev->ports, list) {
+ port->in_vq = portdev->in_vqs[port->id];
+ port->out_vq = portdev->out_vqs[port->id];
+
+ fill_queue(port->in_vq, &port->inbuf_lock);
+
+ /* Get port open/close status on the host */
+ send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
+
+ /*
+ * If a port was open at the time of suspending, we
+ * have to let the host know that it's still open.
+ */
+ if (port->guest_connected)
+ send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
+ }
+ return 0;
+}
+#endif
+
static struct virtio_driver virtio_console = {
.feature_table = features,
.feature_table_size = ARRAY_SIZE(features),
.probe = virtcons_probe,
.remove = virtcons_remove,
.config_changed = config_intr,
+#ifdef CONFIG_PM
+ .freeze = virtcons_freeze,
+ .restore = virtcons_restore,
+#endif
};
static int __init init(void)