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/debugfs.h>
21 #include <linux/device.h>
22 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/list.h>
26 #include <linux/poll.h>
27 #include <linux/sched.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/virtio.h>
31 #include <linux/virtio_console.h>
32 #include <linux/wait.h>
33 #include <linux/workqueue.h>
34 #include "hvc_console.h"
37 * This is a global struct for storing common data for all the devices
38 * this driver handles.
40 * Mainly, it has a linked list for all the consoles in one place so
41 * that callbacks from hvc for get_chars(), put_chars() work properly
42 * across multiple devices and multiple ports per device.
44 struct ports_driver_data {
45 /* Used for registering chardevs */
48 /* Used for exporting per-port information to debugfs */
49 struct dentry *debugfs_dir;
51 /* Number of devices this driver is handling */
55 * This is used to keep track of the number of hvc consoles
56 * spawned by this driver. This number is given as the first
57 * argument to hvc_alloc(). To correctly map an initial
58 * console spawned via hvc_instantiate to the console being
59 * hooked up via hvc_alloc, we need to pass the same vtermno.
61 * We also just assume the first console being initialised was
62 * the first one that got used as the initial console.
64 unsigned int next_vtermno;
66 /* All the console devices handled by this driver */
67 struct list_head consoles;
69 static struct ports_driver_data pdrvdata;
71 DEFINE_SPINLOCK(pdrvdata_lock);
73 /* This struct holds information that's relevant only for console ports */
75 /* We'll place all consoles in a list in the pdrvdata struct */
76 struct list_head list;
78 /* The hvc device associated with this console port */
79 struct hvc_struct *hvc;
82 * This number identifies the number that we used to register
83 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
84 * number passed on by the hvc callbacks to us to
85 * differentiate between the other console ports handled by
94 /* size of the buffer in *buf above */
97 /* used length of the buffer */
99 /* offset in the buf from which to consume data */
104 * This is a per-device struct that stores data common to all the
105 * ports for that device (vdev->priv).
107 struct ports_device {
109 * Workqueue handlers where we process deferred work after
112 struct work_struct control_work;
113 struct work_struct config_work;
115 struct list_head ports;
117 /* To protect the list of ports */
118 spinlock_t ports_lock;
120 /* To protect the vq operations for the control channel */
123 /* The current config space is stored here */
124 struct virtio_console_config config;
126 /* The virtio device we're associated with */
127 struct virtio_device *vdev;
130 * A couple of virtqueues for the control channel: one for
131 * guest->host transfers, one for host->guest transfers
133 struct virtqueue *c_ivq, *c_ovq;
135 /* Array of per-port IO virtqueues */
136 struct virtqueue **in_vqs, **out_vqs;
138 /* Used for numbering devices for sysfs and debugfs */
139 unsigned int drv_index;
141 /* Major number for this device. Ports will be created as minors. */
145 /* This struct holds the per-port data */
147 /* Next port in the list, head is in the ports_device */
148 struct list_head list;
150 /* Pointer to the parent virtio_console device */
151 struct ports_device *portdev;
153 /* The current buffer from which data has to be fed to readers */
154 struct port_buffer *inbuf;
157 * To protect the operations on the in_vq associated with this
158 * port. Has to be a spinlock because it can be called from
159 * interrupt context (get_char()).
161 spinlock_t inbuf_lock;
163 /* The IO vqs for this port */
164 struct virtqueue *in_vq, *out_vq;
166 /* File in the debugfs directory that exposes this port's information */
167 struct dentry *debugfs_file;
170 * The entries in this struct will be valid if this port is
171 * hooked up to an hvc console
175 /* Each port associates with a separate char device */
179 /* A waitqueue for poll() or blocking read operations */
180 wait_queue_head_t waitqueue;
182 /* The 'name' of the port that we expose via sysfs properties */
185 /* The 'id' to identify the port with the Host */
188 /* Is the host device open */
191 /* We should allow only one process to open a port */
192 bool guest_connected;
195 /* This is the very early arch-specified put chars function. */
196 static int (*early_put_chars)(u32, const char *, int);
198 static struct port *find_port_by_vtermno(u32 vtermno)
201 struct console *cons;
204 spin_lock_irqsave(&pdrvdata_lock, flags);
205 list_for_each_entry(cons, &pdrvdata.consoles, list) {
206 if (cons->vtermno == vtermno) {
207 port = container_of(cons, struct port, cons);
213 spin_unlock_irqrestore(&pdrvdata_lock, flags);
217 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
222 spin_lock_irqsave(&portdev->ports_lock, flags);
223 list_for_each_entry(port, &portdev->ports, list)
228 spin_unlock_irqrestore(&portdev->ports_lock, flags);
233 static struct port *find_port_by_vq(struct ports_device *portdev,
234 struct virtqueue *vq)
239 spin_lock_irqsave(&portdev->ports_lock, flags);
240 list_for_each_entry(port, &portdev->ports, list)
241 if (port->in_vq == vq || port->out_vq == vq)
245 spin_unlock_irqrestore(&portdev->ports_lock, flags);
249 static bool is_console_port(struct port *port)
256 static inline bool use_multiport(struct ports_device *portdev)
259 * This condition can be true when put_chars is called from
264 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
267 static void free_buf(struct port_buffer *buf)
273 static struct port_buffer *alloc_buf(size_t buf_size)
275 struct port_buffer *buf;
277 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
280 buf->buf = kzalloc(buf_size, GFP_KERNEL);
285 buf->size = buf_size;
294 /* Callers should take appropriate locks */
295 static void *get_inbuf(struct port *port)
297 struct port_buffer *buf;
298 struct virtqueue *vq;
302 buf = vq->vq_ops->get_buf(vq, &len);
311 * Create a scatter-gather list representing our input buffer and put
314 * Callers should take appropriate locks.
316 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
318 struct scatterlist sg[1];
321 sg_init_one(sg, buf->buf, buf->size);
323 ret = vq->vq_ops->add_buf(vq, sg, 0, 1, buf);
324 vq->vq_ops->kick(vq);
328 /* Discard any unread data this port has. Callers lockers. */
329 static void discard_port_data(struct port *port)
331 struct port_buffer *buf;
332 struct virtqueue *vq;
340 buf = vq->vq_ops->get_buf(vq, &len);
344 if (add_inbuf(vq, buf) < 0) {
348 buf = vq->vq_ops->get_buf(vq, &len);
352 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
356 static bool port_has_data(struct port *port)
361 spin_lock_irqsave(&port->inbuf_lock, flags);
366 port->inbuf = get_inbuf(port);
373 spin_unlock_irqrestore(&port->inbuf_lock, flags);
377 static ssize_t send_control_msg(struct port *port, unsigned int event,
380 struct scatterlist sg[1];
381 struct virtio_console_control cpkt;
382 struct virtqueue *vq;
385 if (!use_multiport(port->portdev))
392 vq = port->portdev->c_ovq;
394 sg_init_one(sg, &cpkt, sizeof(cpkt));
395 if (vq->vq_ops->add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
396 vq->vq_ops->kick(vq);
397 while (!vq->vq_ops->get_buf(vq, &len))
403 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
405 struct scatterlist sg[1];
406 struct virtqueue *out_vq;
410 out_vq = port->out_vq;
412 sg_init_one(sg, in_buf, in_count);
413 ret = out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, in_buf);
415 /* Tell Host to go! */
416 out_vq->vq_ops->kick(out_vq);
423 /* Wait till the host acknowledges it pushed out the data we sent. */
424 while (!out_vq->vq_ops->get_buf(out_vq, &len))
427 /* We're expected to return the amount of data we wrote */
432 * Give out the data that's requested from the buffer that we have
435 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
438 struct port_buffer *buf;
441 if (!out_count || !port_has_data(port))
445 out_count = min(out_count, buf->len - buf->offset);
450 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
454 memcpy(out_buf, buf->buf + buf->offset, out_count);
457 buf->offset += out_count;
459 if (buf->offset == buf->len) {
461 * We're done using all the data in this buffer.
462 * Re-queue so that the Host can send us more data.
464 spin_lock_irqsave(&port->inbuf_lock, flags);
467 if (add_inbuf(port->in_vq, buf) < 0)
468 dev_warn(port->dev, "failed add_buf\n");
470 spin_unlock_irqrestore(&port->inbuf_lock, flags);
472 /* Return the number of bytes actually copied */
476 /* The condition that must be true for polling to end */
477 static bool wait_is_over(struct port *port)
479 return port_has_data(port) || !port->host_connected;
482 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
483 size_t count, loff_t *offp)
488 port = filp->private_data;
490 if (!port_has_data(port)) {
492 * If nothing's connected on the host just return 0 in
493 * case of list_empty; this tells the userspace app
494 * that there's no connection
496 if (!port->host_connected)
498 if (filp->f_flags & O_NONBLOCK)
501 ret = wait_event_interruptible(port->waitqueue,
507 * We could've received a disconnection message while we were
508 * waiting for more data.
510 * This check is not clubbed in the if() statement above as we
511 * might receive some data as well as the host could get
512 * disconnected after we got woken up from our wait. So we
513 * really want to give off whatever data we have and only then
514 * check for host_connected.
516 if (!port_has_data(port) && !port->host_connected)
519 return fill_readbuf(port, ubuf, count, true);
522 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
523 size_t count, loff_t *offp)
529 port = filp->private_data;
531 count = min((size_t)(32 * 1024), count);
533 buf = kmalloc(count, GFP_KERNEL);
537 ret = copy_from_user(buf, ubuf, count);
543 ret = send_buf(port, buf, count);
549 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
554 port = filp->private_data;
555 poll_wait(filp, &port->waitqueue, wait);
559 ret |= POLLIN | POLLRDNORM;
560 if (port->host_connected)
562 if (!port->host_connected)
568 static int port_fops_release(struct inode *inode, struct file *filp)
572 port = filp->private_data;
574 /* Notify host of port being closed */
575 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
577 spin_lock_irq(&port->inbuf_lock);
578 port->guest_connected = false;
580 discard_port_data(port);
582 spin_unlock_irq(&port->inbuf_lock);
587 static int port_fops_open(struct inode *inode, struct file *filp)
589 struct cdev *cdev = inode->i_cdev;
592 port = container_of(cdev, struct port, cdev);
593 filp->private_data = port;
596 * Don't allow opening of console port devices -- that's done
599 if (is_console_port(port))
602 /* Allow only one process to open a particular port at a time */
603 spin_lock_irq(&port->inbuf_lock);
604 if (port->guest_connected) {
605 spin_unlock_irq(&port->inbuf_lock);
609 port->guest_connected = true;
610 spin_unlock_irq(&port->inbuf_lock);
612 /* Notify host of port being opened */
613 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
619 * The file operations that we support: programs in the guest can open
620 * a console device, read from it, write to it, poll for data and
621 * close it. The devices are at
622 * /dev/vport<device number>p<port number>
624 static const struct file_operations port_fops = {
625 .owner = THIS_MODULE,
626 .open = port_fops_open,
627 .read = port_fops_read,
628 .write = port_fops_write,
629 .poll = port_fops_poll,
630 .release = port_fops_release,
634 * The put_chars() callback is pretty straightforward.
636 * We turn the characters into a scatter-gather list, add it to the
637 * output queue and then kick the Host. Then we sit here waiting for
638 * it to finish: inefficient in theory, but in practice
639 * implementations will do it immediately (lguest's Launcher does).
641 static int put_chars(u32 vtermno, const char *buf, int count)
645 if (unlikely(early_put_chars))
646 return early_put_chars(vtermno, buf, count);
648 port = find_port_by_vtermno(vtermno);
652 return send_buf(port, (void *)buf, count);
656 * get_chars() is the callback from the hvc_console infrastructure
657 * when an interrupt is received.
659 * We call out to fill_readbuf that gets us the required data from the
660 * buffers that are queued up.
662 static int get_chars(u32 vtermno, char *buf, int count)
666 port = find_port_by_vtermno(vtermno);
670 /* If we don't have an input queue yet, we can't get input. */
671 BUG_ON(!port->in_vq);
673 return fill_readbuf(port, buf, count, false);
676 static void resize_console(struct port *port)
678 struct virtio_device *vdev;
681 /* The port could have been hot-unplugged */
685 vdev = port->portdev->vdev;
686 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
687 vdev->config->get(vdev,
688 offsetof(struct virtio_console_config, cols),
689 &ws.ws_col, sizeof(u16));
690 vdev->config->get(vdev,
691 offsetof(struct virtio_console_config, rows),
692 &ws.ws_row, sizeof(u16));
693 hvc_resize(port->cons.hvc, ws);
697 /* We set the configuration at this point, since we now have a tty */
698 static int notifier_add_vio(struct hvc_struct *hp, int data)
702 port = find_port_by_vtermno(hp->vtermno);
706 hp->irq_requested = 1;
707 resize_console(port);
712 static void notifier_del_vio(struct hvc_struct *hp, int data)
714 hp->irq_requested = 0;
717 /* The operations for console ports. */
718 static const struct hv_ops hv_ops = {
719 .get_chars = get_chars,
720 .put_chars = put_chars,
721 .notifier_add = notifier_add_vio,
722 .notifier_del = notifier_del_vio,
723 .notifier_hangup = notifier_del_vio,
727 * Console drivers are initialized very early so boot messages can go
728 * out, so we do things slightly differently from the generic virtio
729 * initialization of the net and block drivers.
731 * At this stage, the console is output-only. It's too early to set
732 * up a virtqueue, so we let the drivers do some boutique early-output
735 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
737 early_put_chars = put_chars;
738 return hvc_instantiate(0, 0, &hv_ops);
741 int init_port_console(struct port *port)
746 * The Host's telling us this port is a console port. Hook it
747 * up with an hvc console.
749 * To set up and manage our virtual console, we call
752 * The first argument of hvc_alloc() is the virtual console
753 * number. The second argument is the parameter for the
754 * notification mechanism (like irq number). We currently
755 * leave this as zero, virtqueues have implicit notifications.
757 * The third argument is a "struct hv_ops" containing the
758 * put_chars() get_chars(), notifier_add() and notifier_del()
759 * pointers. The final argument is the output buffer size: we
760 * can do any size, so we put PAGE_SIZE here.
762 port->cons.vtermno = pdrvdata.next_vtermno;
764 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
765 if (IS_ERR(port->cons.hvc)) {
766 ret = PTR_ERR(port->cons.hvc);
768 "error %d allocating hvc for port\n", ret);
769 port->cons.hvc = NULL;
772 spin_lock_irq(&pdrvdata_lock);
773 pdrvdata.next_vtermno++;
774 list_add_tail(&port->cons.list, &pdrvdata.consoles);
775 spin_unlock_irq(&pdrvdata_lock);
776 port->guest_connected = true;
778 /* Notify host of port being opened */
779 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
784 static ssize_t show_port_name(struct device *dev,
785 struct device_attribute *attr, char *buffer)
789 port = dev_get_drvdata(dev);
791 return sprintf(buffer, "%s\n", port->name);
794 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
796 static struct attribute *port_sysfs_entries[] = {
801 static struct attribute_group port_attribute_group = {
802 .name = NULL, /* put in device directory */
803 .attrs = port_sysfs_entries,
806 static int debugfs_open(struct inode *inode, struct file *filp)
808 filp->private_data = inode->i_private;
812 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
813 size_t count, loff_t *offp)
817 ssize_t ret, out_offset, out_count;
820 buf = kmalloc(out_count, GFP_KERNEL);
824 port = filp->private_data;
826 out_offset += snprintf(buf + out_offset, out_count,
827 "name: %s\n", port->name ? port->name : "");
828 out_offset += snprintf(buf + out_offset, out_count - out_offset,
829 "guest_connected: %d\n", port->guest_connected);
830 out_offset += snprintf(buf + out_offset, out_count - out_offset,
831 "host_connected: %d\n", port->host_connected);
832 out_offset += snprintf(buf + out_offset, out_count - out_offset,
834 is_console_port(port) ? "yes" : "no");
835 out_offset += snprintf(buf + out_offset, out_count - out_offset,
836 "console_vtermno: %u\n", port->cons.vtermno);
838 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
843 static const struct file_operations port_debugfs_ops = {
844 .owner = THIS_MODULE,
845 .open = debugfs_open,
846 .read = debugfs_read,
849 /* Remove all port-specific data. */
850 static int remove_port(struct port *port)
852 struct port_buffer *buf;
854 spin_lock_irq(&port->portdev->ports_lock);
855 list_del(&port->list);
856 spin_unlock_irq(&port->portdev->ports_lock);
858 if (is_console_port(port)) {
859 spin_lock_irq(&pdrvdata_lock);
860 list_del(&port->cons.list);
861 spin_unlock_irq(&pdrvdata_lock);
862 hvc_remove(port->cons.hvc);
864 if (port->guest_connected)
865 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
867 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
868 device_destroy(pdrvdata.class, port->dev->devt);
869 cdev_del(&port->cdev);
871 /* Remove unused data this port might have received. */
872 discard_port_data(port);
874 /* Remove buffers we queued up for the Host to send us data in. */
875 while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq)))
880 debugfs_remove(port->debugfs_file);
886 /* Any private messages that the Host and Guest want to share */
887 static void handle_control_message(struct ports_device *portdev,
888 struct port_buffer *buf)
890 struct virtio_console_control *cpkt;
895 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
897 port = find_port_by_id(portdev, cpkt->id);
899 /* No valid header at start of buffer. Drop it. */
900 dev_dbg(&portdev->vdev->dev,
901 "Invalid index %u in control packet\n", cpkt->id);
905 switch (cpkt->event) {
906 case VIRTIO_CONSOLE_CONSOLE_PORT:
909 if (is_console_port(port))
912 init_port_console(port);
914 * Could remove the port here in case init fails - but
915 * have to notify the host first.
918 case VIRTIO_CONSOLE_RESIZE:
919 if (!is_console_port(port))
921 port->cons.hvc->irq_requested = 1;
922 resize_console(port);
924 case VIRTIO_CONSOLE_PORT_OPEN:
925 port->host_connected = cpkt->value;
926 wake_up_interruptible(&port->waitqueue);
928 case VIRTIO_CONSOLE_PORT_NAME:
930 * Skip the size of the header and the cpkt to get the size
931 * of the name that was sent
933 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
935 port->name = kmalloc(name_size, GFP_KERNEL);
938 "Not enough space to store port name\n");
941 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
943 port->name[name_size - 1] = 0;
946 * Since we only have one sysfs attribute, 'name',
947 * create it only if we have a name for the port.
949 err = sysfs_create_group(&port->dev->kobj,
950 &port_attribute_group);
953 "Error %d creating sysfs device attributes\n",
957 * Generate a udev event so that appropriate
958 * symlinks can be created based on udev
961 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
964 case VIRTIO_CONSOLE_PORT_REMOVE:
966 * Hot unplug the port. We don't decrement nr_ports
967 * since we don't want to deal with extra complexities
968 * of using the lowest-available port id: We can just
969 * pick up the nr_ports number as the id and not have
970 * userspace send it to us. This helps us in two
973 * - We don't need to have a 'port_id' field in the
974 * config space when a port is hot-added. This is a
975 * good thing as we might queue up multiple hotplug
976 * requests issued in our workqueue.
978 * - Another way to deal with this would have been to
979 * use a bitmap of the active ports and select the
980 * lowest non-active port from that map. That
981 * bloats the already tight config space and we
982 * would end up artificially limiting the
983 * max. number of ports to sizeof(bitmap). Right
984 * now we can support 2^32 ports (as the port id is
985 * stored in a u32 type).
993 static void control_work_handler(struct work_struct *work)
995 struct ports_device *portdev;
996 struct virtqueue *vq;
997 struct port_buffer *buf;
1000 portdev = container_of(work, struct ports_device, control_work);
1001 vq = portdev->c_ivq;
1003 spin_lock(&portdev->cvq_lock);
1004 while ((buf = vq->vq_ops->get_buf(vq, &len))) {
1005 spin_unlock(&portdev->cvq_lock);
1010 handle_control_message(portdev, buf);
1012 spin_lock(&portdev->cvq_lock);
1013 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1014 dev_warn(&portdev->vdev->dev,
1015 "Error adding buffer to queue\n");
1019 spin_unlock(&portdev->cvq_lock);
1022 static void in_intr(struct virtqueue *vq)
1025 unsigned long flags;
1027 port = find_port_by_vq(vq->vdev->priv, vq);
1031 spin_lock_irqsave(&port->inbuf_lock, flags);
1033 port->inbuf = get_inbuf(port);
1036 * Don't queue up data when port is closed. This condition
1037 * can be reached when a console port is not yet connected (no
1038 * tty is spawned) and the host sends out data to console
1039 * ports. For generic serial ports, the host won't
1040 * (shouldn't) send data till the guest is connected.
1042 if (!port->guest_connected)
1043 discard_port_data(port);
1045 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1047 wake_up_interruptible(&port->waitqueue);
1049 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1053 static void control_intr(struct virtqueue *vq)
1055 struct ports_device *portdev;
1057 portdev = vq->vdev->priv;
1058 schedule_work(&portdev->control_work);
1061 static void config_intr(struct virtio_device *vdev)
1063 struct ports_device *portdev;
1065 portdev = vdev->priv;
1066 if (use_multiport(portdev)) {
1067 /* Handle port hot-add */
1068 schedule_work(&portdev->config_work);
1071 * We'll use this way of resizing only for legacy support.
1072 * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
1073 * control messages to indicate console size changes so that
1074 * it can be done per-port
1076 resize_console(find_port_by_id(portdev, 0));
1079 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1081 struct port_buffer *buf;
1082 unsigned int nr_added_bufs;
1087 buf = alloc_buf(PAGE_SIZE);
1091 spin_lock_irq(lock);
1092 ret = add_inbuf(vq, buf);
1094 spin_unlock_irq(lock);
1099 spin_unlock_irq(lock);
1102 return nr_added_bufs;
1105 static int add_port(struct ports_device *portdev, u32 id)
1107 char debugfs_name[16];
1109 struct port_buffer *buf;
1111 unsigned int nr_added_bufs;
1114 port = kmalloc(sizeof(*port), GFP_KERNEL);
1120 port->portdev = portdev;
1125 port->cons.hvc = NULL;
1127 port->host_connected = port->guest_connected = false;
1129 port->in_vq = portdev->in_vqs[port->id];
1130 port->out_vq = portdev->out_vqs[port->id];
1132 cdev_init(&port->cdev, &port_fops);
1134 devt = MKDEV(portdev->chr_major, id);
1135 err = cdev_add(&port->cdev, devt, 1);
1137 dev_err(&port->portdev->vdev->dev,
1138 "Error %d adding cdev for port %u\n", err, id);
1141 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1142 devt, port, "vport%up%u",
1143 port->portdev->drv_index, id);
1144 if (IS_ERR(port->dev)) {
1145 err = PTR_ERR(port->dev);
1146 dev_err(&port->portdev->vdev->dev,
1147 "Error %d creating device for port %u\n",
1152 spin_lock_init(&port->inbuf_lock);
1153 init_waitqueue_head(&port->waitqueue);
1155 /* Fill the in_vq with buffers so the host can send us data. */
1156 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1157 if (!nr_added_bufs) {
1158 dev_err(port->dev, "Error allocating inbufs\n");
1164 * If we're not using multiport support, this has to be a console port
1166 if (!use_multiport(port->portdev)) {
1167 err = init_port_console(port);
1172 spin_lock_irq(&portdev->ports_lock);
1173 list_add_tail(&port->list, &port->portdev->ports);
1174 spin_unlock_irq(&portdev->ports_lock);
1177 * Tell the Host we're set so that it can send us various
1178 * configuration parameters for this port (eg, port name,
1179 * caching, whether this is a console port, etc.)
1181 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1183 if (pdrvdata.debugfs_dir) {
1185 * Finally, create the debugfs file that we can use to
1186 * inspect a port's state at any time
1188 sprintf(debugfs_name, "vport%up%u",
1189 port->portdev->drv_index, id);
1190 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1191 pdrvdata.debugfs_dir,
1198 while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq)))
1201 device_destroy(pdrvdata.class, port->dev->devt);
1203 cdev_del(&port->cdev);
1211 * The workhandler for config-space updates.
1213 * This is called when ports are hot-added.
1215 static void config_work_handler(struct work_struct *work)
1217 struct virtio_console_config virtconconf;
1218 struct ports_device *portdev;
1219 struct virtio_device *vdev;
1222 portdev = container_of(work, struct ports_device, config_work);
1224 vdev = portdev->vdev;
1225 vdev->config->get(vdev,
1226 offsetof(struct virtio_console_config, nr_ports),
1227 &virtconconf.nr_ports,
1228 sizeof(virtconconf.nr_ports));
1230 if (portdev->config.nr_ports == virtconconf.nr_ports) {
1232 * Port 0 got hot-added. Since we already did all the
1233 * other initialisation for it, just tell the Host
1234 * that the port is ready if we find the port. In
1235 * case the port was hot-removed earlier, we call
1236 * add_port to add the port.
1240 port = find_port_by_id(portdev, 0);
1242 add_port(portdev, 0);
1244 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1247 if (virtconconf.nr_ports > portdev->config.max_nr_ports) {
1248 dev_warn(&vdev->dev,
1249 "More ports specified (%u) than allowed (%u)",
1250 portdev->config.nr_ports + 1,
1251 portdev->config.max_nr_ports);
1254 if (virtconconf.nr_ports < portdev->config.nr_ports)
1258 while (virtconconf.nr_ports - portdev->config.nr_ports) {
1259 err = add_port(portdev, portdev->config.nr_ports);
1262 portdev->config.nr_ports++;
1266 static int init_vqs(struct ports_device *portdev)
1268 vq_callback_t **io_callbacks;
1270 struct virtqueue **vqs;
1271 u32 i, j, nr_ports, nr_queues;
1274 nr_ports = portdev->config.max_nr_ports;
1275 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1277 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1282 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1283 if (!io_callbacks) {
1287 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1290 goto free_callbacks;
1292 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1294 if (!portdev->in_vqs) {
1298 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1300 if (!portdev->out_vqs) {
1306 * For backward compat (newer host but older guest), the host
1307 * spawns a console port first and also inits the vqs for port
1311 io_callbacks[j] = in_intr;
1312 io_callbacks[j + 1] = NULL;
1313 io_names[j] = "input";
1314 io_names[j + 1] = "output";
1317 if (use_multiport(portdev)) {
1318 io_callbacks[j] = control_intr;
1319 io_callbacks[j + 1] = NULL;
1320 io_names[j] = "control-i";
1321 io_names[j + 1] = "control-o";
1323 for (i = 1; i < nr_ports; i++) {
1325 io_callbacks[j] = in_intr;
1326 io_callbacks[j + 1] = NULL;
1327 io_names[j] = "input";
1328 io_names[j + 1] = "output";
1331 /* Find the queues. */
1332 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1334 (const char **)io_names);
1339 portdev->in_vqs[0] = vqs[0];
1340 portdev->out_vqs[0] = vqs[1];
1342 if (use_multiport(portdev)) {
1343 portdev->c_ivq = vqs[j];
1344 portdev->c_ovq = vqs[j + 1];
1346 for (i = 1; i < nr_ports; i++) {
1348 portdev->in_vqs[i] = vqs[j];
1349 portdev->out_vqs[i] = vqs[j + 1];
1352 kfree(io_callbacks);
1361 kfree(io_callbacks);
1363 kfree(portdev->out_vqs);
1365 kfree(portdev->in_vqs);
1372 static const struct file_operations portdev_fops = {
1373 .owner = THIS_MODULE,
1377 * Once we're further in boot, we get probed like any other virtio
1380 * If the host also supports multiple console ports, we check the
1381 * config space to see how many ports the host has spawned. We
1382 * initialize each port found.
1384 static int __devinit virtcons_probe(struct virtio_device *vdev)
1386 struct ports_device *portdev;
1391 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1397 /* Attach this portdev to this virtio_device, and vice-versa. */
1398 portdev->vdev = vdev;
1399 vdev->priv = portdev;
1401 spin_lock_irq(&pdrvdata_lock);
1402 portdev->drv_index = pdrvdata.index++;
1403 spin_unlock_irq(&pdrvdata_lock);
1405 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1407 if (portdev->chr_major < 0) {
1409 "Error %d registering chrdev for device %u\n",
1410 portdev->chr_major, portdev->drv_index);
1411 err = portdev->chr_major;
1416 portdev->config.nr_ports = 1;
1417 portdev->config.max_nr_ports = 1;
1418 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1420 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1422 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1424 &portdev->config.nr_ports,
1425 sizeof(portdev->config.nr_ports));
1426 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1428 &portdev->config.max_nr_ports,
1429 sizeof(portdev->config.max_nr_ports));
1430 if (portdev->config.nr_ports > portdev->config.max_nr_ports) {
1431 dev_warn(&vdev->dev,
1432 "More ports (%u) specified than allowed (%u). Will init %u ports.",
1433 portdev->config.nr_ports,
1434 portdev->config.max_nr_ports,
1435 portdev->config.max_nr_ports);
1437 portdev->config.nr_ports = portdev->config.max_nr_ports;
1441 /* Let the Host know we support multiple ports.*/
1442 vdev->config->finalize_features(vdev);
1444 err = init_vqs(portdev);
1446 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1450 spin_lock_init(&portdev->ports_lock);
1451 INIT_LIST_HEAD(&portdev->ports);
1454 unsigned int nr_added_bufs;
1456 spin_lock_init(&portdev->cvq_lock);
1457 INIT_WORK(&portdev->control_work, &control_work_handler);
1458 INIT_WORK(&portdev->config_work, &config_work_handler);
1460 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1461 if (!nr_added_bufs) {
1463 "Error allocating buffers for control queue\n");
1469 for (i = 0; i < portdev->config.nr_ports; i++)
1470 add_port(portdev, i);
1472 /* Start using the new console output. */
1473 early_put_chars = NULL;
1477 vdev->config->del_vqs(vdev);
1478 kfree(portdev->in_vqs);
1479 kfree(portdev->out_vqs);
1481 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1488 static void virtcons_remove(struct virtio_device *vdev)
1490 struct ports_device *portdev;
1491 struct port *port, *port2;
1492 struct port_buffer *buf;
1495 portdev = vdev->priv;
1497 cancel_work_sync(&portdev->control_work);
1498 cancel_work_sync(&portdev->config_work);
1500 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1503 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1505 while ((buf = portdev->c_ivq->vq_ops->get_buf(portdev->c_ivq, &len)))
1508 while ((buf = portdev->c_ivq->vq_ops->detach_unused_buf(portdev->c_ivq)))
1511 vdev->config->del_vqs(vdev);
1512 kfree(portdev->in_vqs);
1513 kfree(portdev->out_vqs);
1518 static struct virtio_device_id id_table[] = {
1519 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1523 static unsigned int features[] = {
1524 VIRTIO_CONSOLE_F_SIZE,
1525 VIRTIO_CONSOLE_F_MULTIPORT,
1528 static struct virtio_driver virtio_console = {
1529 .feature_table = features,
1530 .feature_table_size = ARRAY_SIZE(features),
1531 .driver.name = KBUILD_MODNAME,
1532 .driver.owner = THIS_MODULE,
1533 .id_table = id_table,
1534 .probe = virtcons_probe,
1535 .remove = virtcons_remove,
1536 .config_changed = config_intr,
1539 static int __init init(void)
1543 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1544 if (IS_ERR(pdrvdata.class)) {
1545 err = PTR_ERR(pdrvdata.class);
1546 pr_err("Error %d creating virtio-ports class\n", err);
1550 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1551 if (!pdrvdata.debugfs_dir) {
1552 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1553 PTR_ERR(pdrvdata.debugfs_dir));
1555 INIT_LIST_HEAD(&pdrvdata.consoles);
1557 return register_virtio_driver(&virtio_console);
1560 static void __exit fini(void)
1562 unregister_virtio_driver(&virtio_console);
1564 class_destroy(pdrvdata.class);
1565 if (pdrvdata.debugfs_dir)
1566 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1571 MODULE_DEVICE_TABLE(virtio, id_table);
1572 MODULE_DESCRIPTION("Virtio console driver");
1573 MODULE_LICENSE("GPL");