2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010 Red Hat, Inc.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/cdev.h>
20 #include <linux/device.h>
21 #include <linux/err.h>
23 #include <linux/init.h>
24 #include <linux/list.h>
25 #include <linux/poll.h>
26 #include <linux/sched.h>
27 #include <linux/spinlock.h>
28 #include <linux/virtio.h>
29 #include <linux/virtio_console.h>
30 #include <linux/wait.h>
31 #include <linux/workqueue.h>
32 #include "hvc_console.h"
35 * This is a global struct for storing common data for all the devices
36 * this driver handles.
38 * Mainly, it has a linked list for all the consoles in one place so
39 * that callbacks from hvc for get_chars(), put_chars() work properly
40 * across multiple devices and multiple ports per device.
42 struct ports_driver_data {
43 /* Used for registering chardevs */
46 /* Number of devices this driver is handling */
50 * This is used to keep track of the number of hvc consoles
51 * spawned by this driver. This number is given as the first
52 * argument to hvc_alloc(). To correctly map an initial
53 * console spawned via hvc_instantiate to the console being
54 * hooked up via hvc_alloc, we need to pass the same vtermno.
56 * We also just assume the first console being initialised was
57 * the first one that got used as the initial console.
59 unsigned int next_vtermno;
61 /* All the console devices handled by this driver */
62 struct list_head consoles;
64 static struct ports_driver_data pdrvdata;
66 DEFINE_SPINLOCK(pdrvdata_lock);
68 /* This struct holds information that's relevant only for console ports */
70 /* We'll place all consoles in a list in the pdrvdata struct */
71 struct list_head list;
73 /* The hvc device associated with this console port */
74 struct hvc_struct *hvc;
77 * This number identifies the number that we used to register
78 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
79 * number passed on by the hvc callbacks to us to
80 * differentiate between the other console ports handled by
89 /* size of the buffer in *buf above */
92 /* used length of the buffer */
94 /* offset in the buf from which to consume data */
99 * This is a per-device struct that stores data common to all the
100 * ports for that device (vdev->priv).
102 struct ports_device {
104 * Workqueue handlers where we process deferred work after
107 struct work_struct control_work;
108 struct work_struct config_work;
110 struct list_head ports;
112 /* To protect the list of ports */
113 spinlock_t ports_lock;
115 /* To protect the vq operations for the control channel */
118 /* The current config space is stored here */
119 struct virtio_console_config config;
121 /* The virtio device we're associated with */
122 struct virtio_device *vdev;
125 * A couple of virtqueues for the control channel: one for
126 * guest->host transfers, one for host->guest transfers
128 struct virtqueue *c_ivq, *c_ovq;
130 /* Array of per-port IO virtqueues */
131 struct virtqueue **in_vqs, **out_vqs;
133 /* Used for numbering devices for sysfs and debugfs */
134 unsigned int drv_index;
136 /* Major number for this device. Ports will be created as minors. */
140 /* This struct holds the per-port data */
142 /* Next port in the list, head is in the ports_device */
143 struct list_head list;
145 /* Pointer to the parent virtio_console device */
146 struct ports_device *portdev;
148 /* The current buffer from which data has to be fed to readers */
149 struct port_buffer *inbuf;
152 * To protect the operations on the in_vq associated with this
153 * port. Has to be a spinlock because it can be called from
154 * interrupt context (get_char()).
156 spinlock_t inbuf_lock;
158 /* The IO vqs for this port */
159 struct virtqueue *in_vq, *out_vq;
162 * The entries in this struct will be valid if this port is
163 * hooked up to an hvc console
167 /* Each port associates with a separate char device */
171 /* A waitqueue for poll() or blocking read operations */
172 wait_queue_head_t waitqueue;
174 /* The 'name' of the port that we expose via sysfs properties */
177 /* The 'id' to identify the port with the Host */
180 /* Is the host device open */
183 /* We should allow only one process to open a port */
184 bool guest_connected;
187 /* This is the very early arch-specified put chars function. */
188 static int (*early_put_chars)(u32, const char *, int);
190 static struct port *find_port_by_vtermno(u32 vtermno)
193 struct console *cons;
196 spin_lock_irqsave(&pdrvdata_lock, flags);
197 list_for_each_entry(cons, &pdrvdata.consoles, list) {
198 if (cons->vtermno == vtermno) {
199 port = container_of(cons, struct port, cons);
205 spin_unlock_irqrestore(&pdrvdata_lock, flags);
209 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
214 spin_lock_irqsave(&portdev->ports_lock, flags);
215 list_for_each_entry(port, &portdev->ports, list)
220 spin_unlock_irqrestore(&portdev->ports_lock, flags);
225 static struct port *find_port_by_vq(struct ports_device *portdev,
226 struct virtqueue *vq)
231 spin_lock_irqsave(&portdev->ports_lock, flags);
232 list_for_each_entry(port, &portdev->ports, list)
233 if (port->in_vq == vq || port->out_vq == vq)
237 spin_unlock_irqrestore(&portdev->ports_lock, flags);
241 static bool is_console_port(struct port *port)
248 static inline bool use_multiport(struct ports_device *portdev)
251 * This condition can be true when put_chars is called from
256 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
259 static void free_buf(struct port_buffer *buf)
265 static struct port_buffer *alloc_buf(size_t buf_size)
267 struct port_buffer *buf;
269 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
272 buf->buf = kzalloc(buf_size, GFP_KERNEL);
277 buf->size = buf_size;
286 /* Callers should take appropriate locks */
287 static void *get_inbuf(struct port *port)
289 struct port_buffer *buf;
290 struct virtqueue *vq;
294 buf = vq->vq_ops->get_buf(vq, &len);
303 * Create a scatter-gather list representing our input buffer and put
306 * Callers should take appropriate locks.
308 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
310 struct scatterlist sg[1];
313 sg_init_one(sg, buf->buf, buf->size);
315 ret = vq->vq_ops->add_buf(vq, sg, 0, 1, buf);
316 vq->vq_ops->kick(vq);
320 /* Discard any unread data this port has. Callers lockers. */
321 static void discard_port_data(struct port *port)
323 struct port_buffer *buf;
324 struct virtqueue *vq;
331 buf = vq->vq_ops->get_buf(vq, &len);
336 if (add_inbuf(vq, buf) < 0) {
337 buf->len = buf->offset = 0;
338 dev_warn(port->dev, "Error adding buffer back to vq\n");
345 static bool port_has_data(struct port *port)
351 spin_lock_irqsave(&port->inbuf_lock, flags);
354 spin_unlock_irqrestore(&port->inbuf_lock, flags);
359 static ssize_t send_control_msg(struct port *port, unsigned int event,
362 struct scatterlist sg[1];
363 struct virtio_console_control cpkt;
364 struct virtqueue *vq;
367 if (!use_multiport(port->portdev))
374 vq = port->portdev->c_ovq;
376 sg_init_one(sg, &cpkt, sizeof(cpkt));
377 if (vq->vq_ops->add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
378 vq->vq_ops->kick(vq);
379 while (!vq->vq_ops->get_buf(vq, &len))
385 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
387 struct scatterlist sg[1];
388 struct virtqueue *out_vq;
392 out_vq = port->out_vq;
394 sg_init_one(sg, in_buf, in_count);
395 ret = out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, in_buf);
397 /* Tell Host to go! */
398 out_vq->vq_ops->kick(out_vq);
406 * Wait till the host acknowledges it pushed out the data we
407 * sent. Also ensure we return to userspace the number of
408 * bytes that were successfully consumed by the host.
410 while (!out_vq->vq_ops->get_buf(out_vq, &len))
413 /* We're expected to return the amount of data we wrote */
418 * Give out the data that's requested from the buffer that we have
421 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
424 struct port_buffer *buf;
427 if (!out_count || !port_has_data(port))
431 out_count = min(out_count, buf->len - buf->offset);
436 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
440 memcpy(out_buf, buf->buf + buf->offset, out_count);
443 buf->offset += out_count;
445 if (buf->offset == buf->len) {
447 * We're done using all the data in this buffer.
448 * Re-queue so that the Host can send us more data.
450 spin_lock_irqsave(&port->inbuf_lock, flags);
453 if (add_inbuf(port->in_vq, buf) < 0)
454 dev_warn(port->dev, "failed add_buf\n");
456 spin_unlock_irqrestore(&port->inbuf_lock, flags);
458 /* Return the number of bytes actually copied */
462 /* The condition that must be true for polling to end */
463 static bool wait_is_over(struct port *port)
465 return port_has_data(port) || !port->host_connected;
468 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
469 size_t count, loff_t *offp)
474 port = filp->private_data;
476 if (!port_has_data(port)) {
478 * If nothing's connected on the host just return 0 in
479 * case of list_empty; this tells the userspace app
480 * that there's no connection
482 if (!port->host_connected)
484 if (filp->f_flags & O_NONBLOCK)
487 ret = wait_event_interruptible(port->waitqueue,
493 * We could've received a disconnection message while we were
494 * waiting for more data.
496 * This check is not clubbed in the if() statement above as we
497 * might receive some data as well as the host could get
498 * disconnected after we got woken up from our wait. So we
499 * really want to give off whatever data we have and only then
500 * check for host_connected.
502 if (!port_has_data(port) && !port->host_connected)
505 return fill_readbuf(port, ubuf, count, true);
508 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
509 size_t count, loff_t *offp)
515 port = filp->private_data;
517 count = min((size_t)(32 * 1024), count);
519 buf = kmalloc(count, GFP_KERNEL);
523 ret = copy_from_user(buf, ubuf, count);
529 ret = send_buf(port, buf, count);
535 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
540 port = filp->private_data;
541 poll_wait(filp, &port->waitqueue, wait);
545 ret |= POLLIN | POLLRDNORM;
546 if (port->host_connected)
548 if (!port->host_connected)
554 static int port_fops_release(struct inode *inode, struct file *filp)
558 port = filp->private_data;
560 /* Notify host of port being closed */
561 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
563 spin_lock_irq(&port->inbuf_lock);
564 port->guest_connected = false;
566 discard_port_data(port);
568 spin_unlock_irq(&port->inbuf_lock);
573 static int port_fops_open(struct inode *inode, struct file *filp)
575 struct cdev *cdev = inode->i_cdev;
578 port = container_of(cdev, struct port, cdev);
579 filp->private_data = port;
582 * Don't allow opening of console port devices -- that's done
585 if (is_console_port(port))
588 /* Allow only one process to open a particular port at a time */
589 spin_lock_irq(&port->inbuf_lock);
590 if (port->guest_connected) {
591 spin_unlock_irq(&port->inbuf_lock);
595 port->guest_connected = true;
596 spin_unlock_irq(&port->inbuf_lock);
598 /* Notify host of port being opened */
599 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
605 * The file operations that we support: programs in the guest can open
606 * a console device, read from it, write to it, poll for data and
607 * close it. The devices are at
608 * /dev/vport<device number>p<port number>
610 static const struct file_operations port_fops = {
611 .owner = THIS_MODULE,
612 .open = port_fops_open,
613 .read = port_fops_read,
614 .write = port_fops_write,
615 .poll = port_fops_poll,
616 .release = port_fops_release,
620 * The put_chars() callback is pretty straightforward.
622 * We turn the characters into a scatter-gather list, add it to the
623 * output queue and then kick the Host. Then we sit here waiting for
624 * it to finish: inefficient in theory, but in practice
625 * implementations will do it immediately (lguest's Launcher does).
627 static int put_chars(u32 vtermno, const char *buf, int count)
631 port = find_port_by_vtermno(vtermno);
635 if (unlikely(early_put_chars))
636 return early_put_chars(vtermno, buf, count);
638 return send_buf(port, (void *)buf, count);
642 * get_chars() is the callback from the hvc_console infrastructure
643 * when an interrupt is received.
645 * We call out to fill_readbuf that gets us the required data from the
646 * buffers that are queued up.
648 static int get_chars(u32 vtermno, char *buf, int count)
652 port = find_port_by_vtermno(vtermno);
656 /* If we don't have an input queue yet, we can't get input. */
657 BUG_ON(!port->in_vq);
659 return fill_readbuf(port, buf, count, false);
662 static void resize_console(struct port *port)
664 struct virtio_device *vdev;
667 vdev = port->portdev->vdev;
668 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
669 vdev->config->get(vdev,
670 offsetof(struct virtio_console_config, cols),
671 &ws.ws_col, sizeof(u16));
672 vdev->config->get(vdev,
673 offsetof(struct virtio_console_config, rows),
674 &ws.ws_row, sizeof(u16));
675 hvc_resize(port->cons.hvc, ws);
679 /* We set the configuration at this point, since we now have a tty */
680 static int notifier_add_vio(struct hvc_struct *hp, int data)
684 port = find_port_by_vtermno(hp->vtermno);
688 hp->irq_requested = 1;
689 resize_console(port);
694 static void notifier_del_vio(struct hvc_struct *hp, int data)
696 hp->irq_requested = 0;
699 /* The operations for console ports. */
700 static const struct hv_ops hv_ops = {
701 .get_chars = get_chars,
702 .put_chars = put_chars,
703 .notifier_add = notifier_add_vio,
704 .notifier_del = notifier_del_vio,
705 .notifier_hangup = notifier_del_vio,
709 * Console drivers are initialized very early so boot messages can go
710 * out, so we do things slightly differently from the generic virtio
711 * initialization of the net and block drivers.
713 * At this stage, the console is output-only. It's too early to set
714 * up a virtqueue, so we let the drivers do some boutique early-output
717 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
719 early_put_chars = put_chars;
720 return hvc_instantiate(0, 0, &hv_ops);
723 int init_port_console(struct port *port)
728 * The Host's telling us this port is a console port. Hook it
729 * up with an hvc console.
731 * To set up and manage our virtual console, we call
734 * The first argument of hvc_alloc() is the virtual console
735 * number. The second argument is the parameter for the
736 * notification mechanism (like irq number). We currently
737 * leave this as zero, virtqueues have implicit notifications.
739 * The third argument is a "struct hv_ops" containing the
740 * put_chars() get_chars(), notifier_add() and notifier_del()
741 * pointers. The final argument is the output buffer size: we
742 * can do any size, so we put PAGE_SIZE here.
744 port->cons.vtermno = pdrvdata.next_vtermno;
746 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
747 if (IS_ERR(port->cons.hvc)) {
748 ret = PTR_ERR(port->cons.hvc);
749 port->cons.hvc = NULL;
752 spin_lock_irq(&pdrvdata_lock);
753 pdrvdata.next_vtermno++;
754 list_add_tail(&port->cons.list, &pdrvdata.consoles);
755 spin_unlock_irq(&pdrvdata_lock);
756 port->guest_connected = true;
758 /* Notify host of port being opened */
759 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
764 static ssize_t show_port_name(struct device *dev,
765 struct device_attribute *attr, char *buffer)
769 port = dev_get_drvdata(dev);
771 return sprintf(buffer, "%s\n", port->name);
774 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
776 static struct attribute *port_sysfs_entries[] = {
781 static struct attribute_group port_attribute_group = {
782 .name = NULL, /* put in device directory */
783 .attrs = port_sysfs_entries,
786 /* Remove all port-specific data. */
787 static int remove_port(struct port *port)
789 spin_lock_irq(&port->portdev->ports_lock);
790 list_del(&port->list);
791 spin_unlock_irq(&port->portdev->ports_lock);
793 if (is_console_port(port)) {
794 spin_lock_irq(&pdrvdata_lock);
795 list_del(&port->cons.list);
796 spin_unlock_irq(&pdrvdata_lock);
797 hvc_remove(port->cons.hvc);
799 if (port->guest_connected)
800 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
802 while (port->in_vq->vq_ops->detach_unused_buf(port->in_vq))
805 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
806 device_destroy(pdrvdata.class, port->dev->devt);
807 cdev_del(&port->cdev);
809 discard_port_data(port);
816 /* Any private messages that the Host and Guest want to share */
817 static void handle_control_message(struct ports_device *portdev,
818 struct port_buffer *buf)
820 struct virtio_console_control *cpkt;
825 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
827 port = find_port_by_id(portdev, cpkt->id);
829 /* No valid header at start of buffer. Drop it. */
830 dev_dbg(&portdev->vdev->dev,
831 "Invalid index %u in control packet\n", cpkt->id);
835 switch (cpkt->event) {
836 case VIRTIO_CONSOLE_CONSOLE_PORT:
839 if (is_console_port(port))
842 init_port_console(port);
844 * Could remove the port here in case init fails - but
845 * have to notify the host first.
848 case VIRTIO_CONSOLE_RESIZE:
849 if (!is_console_port(port))
851 port->cons.hvc->irq_requested = 1;
852 resize_console(port);
854 case VIRTIO_CONSOLE_PORT_OPEN:
855 port->host_connected = cpkt->value;
856 wake_up_interruptible(&port->waitqueue);
858 case VIRTIO_CONSOLE_PORT_NAME:
860 * Skip the size of the header and the cpkt to get the size
861 * of the name that was sent
863 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
865 port->name = kmalloc(name_size, GFP_KERNEL);
868 "Not enough space to store port name\n");
871 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
873 port->name[name_size - 1] = 0;
876 * Since we only have one sysfs attribute, 'name',
877 * create it only if we have a name for the port.
879 err = sysfs_create_group(&port->dev->kobj,
880 &port_attribute_group);
883 "Error %d creating sysfs device attributes\n",
887 case VIRTIO_CONSOLE_PORT_REMOVE:
889 * Hot unplug the port. We don't decrement nr_ports
890 * since we don't want to deal with extra complexities
891 * of using the lowest-available port id: We can just
892 * pick up the nr_ports number as the id and not have
893 * userspace send it to us. This helps us in two
896 * - We don't need to have a 'port_id' field in the
897 * config space when a port is hot-added. This is a
898 * good thing as we might queue up multiple hotplug
899 * requests issued in our workqueue.
901 * - Another way to deal with this would have been to
902 * use a bitmap of the active ports and select the
903 * lowest non-active port from that map. That
904 * bloats the already tight config space and we
905 * would end up artificially limiting the
906 * max. number of ports to sizeof(bitmap). Right
907 * now we can support 2^32 ports (as the port id is
908 * stored in a u32 type).
916 static void control_work_handler(struct work_struct *work)
918 struct ports_device *portdev;
919 struct virtqueue *vq;
920 struct port_buffer *buf;
923 portdev = container_of(work, struct ports_device, control_work);
926 spin_lock(&portdev->cvq_lock);
927 while ((buf = vq->vq_ops->get_buf(vq, &len))) {
928 spin_unlock(&portdev->cvq_lock);
933 handle_control_message(portdev, buf);
935 spin_lock(&portdev->cvq_lock);
936 if (add_inbuf(portdev->c_ivq, buf) < 0) {
937 dev_warn(&portdev->vdev->dev,
938 "Error adding buffer to queue\n");
942 spin_unlock(&portdev->cvq_lock);
945 static void in_intr(struct virtqueue *vq)
950 port = find_port_by_vq(vq->vdev->priv, vq);
954 spin_lock_irqsave(&port->inbuf_lock, flags);
955 port->inbuf = get_inbuf(port);
958 * Don't queue up data when port is closed. This condition
959 * can be reached when a console port is not yet connected (no
960 * tty is spawned) and the host sends out data to console
961 * ports. For generic serial ports, the host won't
962 * (shouldn't) send data till the guest is connected.
964 if (!port->guest_connected)
965 discard_port_data(port);
967 spin_unlock_irqrestore(&port->inbuf_lock, flags);
969 wake_up_interruptible(&port->waitqueue);
971 if (is_console_port(port) && hvc_poll(port->cons.hvc))
975 static void control_intr(struct virtqueue *vq)
977 struct ports_device *portdev;
979 portdev = vq->vdev->priv;
980 schedule_work(&portdev->control_work);
983 static void config_intr(struct virtio_device *vdev)
985 struct ports_device *portdev;
987 portdev = vdev->priv;
988 if (use_multiport(portdev)) {
989 /* Handle port hot-add */
990 schedule_work(&portdev->config_work);
993 * We'll use this way of resizing only for legacy support.
994 * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
995 * control messages to indicate console size changes so that
996 * it can be done per-port
998 resize_console(find_port_by_id(portdev, 0));
1001 static void fill_queue(struct virtqueue *vq, spinlock_t *lock)
1003 struct port_buffer *buf;
1007 buf = alloc_buf(PAGE_SIZE);
1011 spin_lock_irq(lock);
1012 ret = add_inbuf(vq, buf);
1014 spin_unlock_irq(lock);
1018 spin_unlock_irq(lock);
1022 static int add_port(struct ports_device *portdev, u32 id)
1025 struct port_buffer *inbuf;
1029 port = kmalloc(sizeof(*port), GFP_KERNEL);
1035 port->portdev = portdev;
1040 port->cons.hvc = NULL;
1042 port->host_connected = port->guest_connected = false;
1044 port->in_vq = portdev->in_vqs[port->id];
1045 port->out_vq = portdev->out_vqs[port->id];
1047 cdev_init(&port->cdev, &port_fops);
1049 devt = MKDEV(portdev->chr_major, id);
1050 err = cdev_add(&port->cdev, devt, 1);
1052 dev_err(&port->portdev->vdev->dev,
1053 "Error %d adding cdev for port %u\n", err, id);
1056 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1057 devt, port, "vport%up%u",
1058 port->portdev->drv_index, id);
1059 if (IS_ERR(port->dev)) {
1060 err = PTR_ERR(port->dev);
1061 dev_err(&port->portdev->vdev->dev,
1062 "Error %d creating device for port %u\n",
1067 spin_lock_init(&port->inbuf_lock);
1068 init_waitqueue_head(&port->waitqueue);
1070 inbuf = alloc_buf(PAGE_SIZE);
1076 /* Register the input buffer the first time. */
1077 add_inbuf(port->in_vq, inbuf);
1080 * If we're not using multiport support, this has to be a console port
1082 if (!use_multiport(port->portdev)) {
1083 err = init_port_console(port);
1088 spin_lock_irq(&portdev->ports_lock);
1089 list_add_tail(&port->list, &port->portdev->ports);
1090 spin_unlock_irq(&portdev->ports_lock);
1093 * Tell the Host we're set so that it can send us various
1094 * configuration parameters for this port (eg, port name,
1095 * caching, whether this is a console port, etc.)
1097 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1104 device_destroy(pdrvdata.class, port->dev->devt);
1106 cdev_del(&port->cdev);
1114 * The workhandler for config-space updates.
1116 * This is called when ports are hot-added.
1118 static void config_work_handler(struct work_struct *work)
1120 struct virtio_console_config virtconconf;
1121 struct ports_device *portdev;
1122 struct virtio_device *vdev;
1125 portdev = container_of(work, struct ports_device, config_work);
1127 vdev = portdev->vdev;
1128 vdev->config->get(vdev,
1129 offsetof(struct virtio_console_config, nr_ports),
1130 &virtconconf.nr_ports,
1131 sizeof(virtconconf.nr_ports));
1133 if (portdev->config.nr_ports == virtconconf.nr_ports) {
1135 * Port 0 got hot-added. Since we already did all the
1136 * other initialisation for it, just tell the Host
1137 * that the port is ready if we find the port. In
1138 * case the port was hot-removed earlier, we call
1139 * add_port to add the port.
1143 port = find_port_by_id(portdev, 0);
1145 add_port(portdev, 0);
1147 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1150 if (virtconconf.nr_ports > portdev->config.max_nr_ports) {
1151 dev_warn(&vdev->dev,
1152 "More ports specified (%u) than allowed (%u)",
1153 portdev->config.nr_ports + 1,
1154 portdev->config.max_nr_ports);
1157 if (virtconconf.nr_ports < portdev->config.nr_ports)
1161 while (virtconconf.nr_ports - portdev->config.nr_ports) {
1162 err = add_port(portdev, portdev->config.nr_ports);
1165 portdev->config.nr_ports++;
1169 static int init_vqs(struct ports_device *portdev)
1171 vq_callback_t **io_callbacks;
1173 struct virtqueue **vqs;
1174 u32 i, j, nr_ports, nr_queues;
1177 nr_ports = portdev->config.max_nr_ports;
1178 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1180 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1185 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1186 if (!io_callbacks) {
1190 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1193 goto free_callbacks;
1195 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1197 if (!portdev->in_vqs) {
1201 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1203 if (!portdev->out_vqs) {
1209 * For backward compat (newer host but older guest), the host
1210 * spawns a console port first and also inits the vqs for port
1214 io_callbacks[j] = in_intr;
1215 io_callbacks[j + 1] = NULL;
1216 io_names[j] = "input";
1217 io_names[j + 1] = "output";
1220 if (use_multiport(portdev)) {
1221 io_callbacks[j] = control_intr;
1222 io_callbacks[j + 1] = NULL;
1223 io_names[j] = "control-i";
1224 io_names[j + 1] = "control-o";
1226 for (i = 1; i < nr_ports; i++) {
1228 io_callbacks[j] = in_intr;
1229 io_callbacks[j + 1] = NULL;
1230 io_names[j] = "input";
1231 io_names[j + 1] = "output";
1234 /* Find the queues. */
1235 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1237 (const char **)io_names);
1242 portdev->in_vqs[0] = vqs[0];
1243 portdev->out_vqs[0] = vqs[1];
1245 if (use_multiport(portdev)) {
1246 portdev->c_ivq = vqs[j];
1247 portdev->c_ovq = vqs[j + 1];
1249 for (i = 1; i < nr_ports; i++) {
1251 portdev->in_vqs[i] = vqs[j];
1252 portdev->out_vqs[i] = vqs[j + 1];
1255 kfree(io_callbacks);
1264 kfree(io_callbacks);
1266 kfree(portdev->out_vqs);
1268 kfree(portdev->in_vqs);
1275 static const struct file_operations portdev_fops = {
1276 .owner = THIS_MODULE,
1280 * Once we're further in boot, we get probed like any other virtio
1283 * If the host also supports multiple console ports, we check the
1284 * config space to see how many ports the host has spawned. We
1285 * initialize each port found.
1287 static int __devinit virtcons_probe(struct virtio_device *vdev)
1289 struct ports_device *portdev;
1294 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1300 /* Attach this portdev to this virtio_device, and vice-versa. */
1301 portdev->vdev = vdev;
1302 vdev->priv = portdev;
1304 spin_lock_irq(&pdrvdata_lock);
1305 portdev->drv_index = pdrvdata.index++;
1306 spin_unlock_irq(&pdrvdata_lock);
1308 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1310 if (portdev->chr_major < 0) {
1312 "Error %d registering chrdev for device %u\n",
1313 portdev->chr_major, portdev->drv_index);
1314 err = portdev->chr_major;
1319 portdev->config.nr_ports = 1;
1320 portdev->config.max_nr_ports = 1;
1321 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1323 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1325 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1327 &portdev->config.nr_ports,
1328 sizeof(portdev->config.nr_ports));
1329 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1331 &portdev->config.max_nr_ports,
1332 sizeof(portdev->config.max_nr_ports));
1333 if (portdev->config.nr_ports > portdev->config.max_nr_ports) {
1334 dev_warn(&vdev->dev,
1335 "More ports (%u) specified than allowed (%u). Will init %u ports.",
1336 portdev->config.nr_ports,
1337 portdev->config.max_nr_ports,
1338 portdev->config.max_nr_ports);
1340 portdev->config.nr_ports = portdev->config.max_nr_ports;
1344 /* Let the Host know we support multiple ports.*/
1345 vdev->config->finalize_features(vdev);
1347 err = init_vqs(portdev);
1349 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1353 spin_lock_init(&portdev->ports_lock);
1354 INIT_LIST_HEAD(&portdev->ports);
1357 spin_lock_init(&portdev->cvq_lock);
1358 INIT_WORK(&portdev->control_work, &control_work_handler);
1359 INIT_WORK(&portdev->config_work, &config_work_handler);
1361 fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1364 for (i = 0; i < portdev->config.nr_ports; i++)
1365 add_port(portdev, i);
1367 /* Start using the new console output. */
1368 early_put_chars = NULL;
1372 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1379 static struct virtio_device_id id_table[] = {
1380 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1384 static unsigned int features[] = {
1385 VIRTIO_CONSOLE_F_SIZE,
1386 VIRTIO_CONSOLE_F_MULTIPORT,
1389 static struct virtio_driver virtio_console = {
1390 .feature_table = features,
1391 .feature_table_size = ARRAY_SIZE(features),
1392 .driver.name = KBUILD_MODNAME,
1393 .driver.owner = THIS_MODULE,
1394 .id_table = id_table,
1395 .probe = virtcons_probe,
1396 .config_changed = config_intr,
1399 static int __init init(void)
1403 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1404 if (IS_ERR(pdrvdata.class)) {
1405 err = PTR_ERR(pdrvdata.class);
1406 pr_err("Error %d creating virtio-ports class\n", err);
1409 INIT_LIST_HEAD(&pdrvdata.consoles);
1411 return register_virtio_driver(&virtio_console);
1415 MODULE_DEVICE_TABLE(virtio, id_table);
1416 MODULE_DESCRIPTION("Virtio console driver");
1417 MODULE_LICENSE("GPL");