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/spinlock.h>
29 #include <linux/virtio.h>
30 #include <linux/virtio_console.h>
31 #include <linux/wait.h>
32 #include <linux/workqueue.h>
33 #include "hvc_console.h"
36 * This is a global struct for storing common data for all the devices
37 * this driver handles.
39 * Mainly, it has a linked list for all the consoles in one place so
40 * that callbacks from hvc for get_chars(), put_chars() work properly
41 * across multiple devices and multiple ports per device.
43 struct ports_driver_data {
44 /* Used for registering chardevs */
47 /* Used for exporting per-port information to debugfs */
48 struct dentry *debugfs_dir;
50 /* Number of devices this driver is handling */
54 * This is used to keep track of the number of hvc consoles
55 * spawned by this driver. This number is given as the first
56 * argument to hvc_alloc(). To correctly map an initial
57 * console spawned via hvc_instantiate to the console being
58 * hooked up via hvc_alloc, we need to pass the same vtermno.
60 * We also just assume the first console being initialised was
61 * the first one that got used as the initial console.
63 unsigned int next_vtermno;
65 /* All the console devices handled by this driver */
66 struct list_head consoles;
68 static struct ports_driver_data pdrvdata;
70 DEFINE_SPINLOCK(pdrvdata_lock);
72 /* This struct holds information that's relevant only for console ports */
74 /* We'll place all consoles in a list in the pdrvdata struct */
75 struct list_head list;
77 /* The hvc device associated with this console port */
78 struct hvc_struct *hvc;
81 * This number identifies the number that we used to register
82 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
83 * number passed on by the hvc callbacks to us to
84 * differentiate between the other console ports handled by
93 /* size of the buffer in *buf above */
96 /* used length of the buffer */
98 /* offset in the buf from which to consume data */
103 * This is a per-device struct that stores data common to all the
104 * ports for that device (vdev->priv).
106 struct ports_device {
108 * Workqueue handlers where we process deferred work after
111 struct work_struct control_work;
112 struct work_struct config_work;
114 struct list_head ports;
116 /* To protect the list of ports */
117 spinlock_t ports_lock;
119 /* To protect the vq operations for the control channel */
122 /* The current config space is stored here */
123 struct virtio_console_config config;
125 /* The virtio device we're associated with */
126 struct virtio_device *vdev;
129 * A couple of virtqueues for the control channel: one for
130 * guest->host transfers, one for host->guest transfers
132 struct virtqueue *c_ivq, *c_ovq;
134 /* Array of per-port IO virtqueues */
135 struct virtqueue **in_vqs, **out_vqs;
137 /* Used for numbering devices for sysfs and debugfs */
138 unsigned int drv_index;
140 /* Major number for this device. Ports will be created as minors. */
144 /* This struct holds the per-port data */
146 /* Next port in the list, head is in the ports_device */
147 struct list_head list;
149 /* Pointer to the parent virtio_console device */
150 struct ports_device *portdev;
152 /* The current buffer from which data has to be fed to readers */
153 struct port_buffer *inbuf;
156 * To protect the operations on the in_vq associated with this
157 * port. Has to be a spinlock because it can be called from
158 * interrupt context (get_char()).
160 spinlock_t inbuf_lock;
162 /* The IO vqs for this port */
163 struct virtqueue *in_vq, *out_vq;
165 /* File in the debugfs directory that exposes this port's information */
166 struct dentry *debugfs_file;
169 * The entries in this struct will be valid if this port is
170 * hooked up to an hvc console
174 /* Each port associates with a separate char device */
178 /* A waitqueue for poll() or blocking read operations */
179 wait_queue_head_t waitqueue;
181 /* The 'name' of the port that we expose via sysfs properties */
184 /* The 'id' to identify the port with the Host */
187 /* Is the host device open */
190 /* We should allow only one process to open a port */
191 bool guest_connected;
194 /* This is the very early arch-specified put chars function. */
195 static int (*early_put_chars)(u32, const char *, int);
197 static struct port *find_port_by_vtermno(u32 vtermno)
200 struct console *cons;
203 spin_lock_irqsave(&pdrvdata_lock, flags);
204 list_for_each_entry(cons, &pdrvdata.consoles, list) {
205 if (cons->vtermno == vtermno) {
206 port = container_of(cons, struct port, cons);
212 spin_unlock_irqrestore(&pdrvdata_lock, flags);
216 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
221 spin_lock_irqsave(&portdev->ports_lock, flags);
222 list_for_each_entry(port, &portdev->ports, list)
227 spin_unlock_irqrestore(&portdev->ports_lock, flags);
232 static struct port *find_port_by_vq(struct ports_device *portdev,
233 struct virtqueue *vq)
238 spin_lock_irqsave(&portdev->ports_lock, flags);
239 list_for_each_entry(port, &portdev->ports, list)
240 if (port->in_vq == vq || port->out_vq == vq)
244 spin_unlock_irqrestore(&portdev->ports_lock, flags);
248 static bool is_console_port(struct port *port)
255 static inline bool use_multiport(struct ports_device *portdev)
258 * This condition can be true when put_chars is called from
263 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
266 static void free_buf(struct port_buffer *buf)
272 static struct port_buffer *alloc_buf(size_t buf_size)
274 struct port_buffer *buf;
276 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
279 buf->buf = kzalloc(buf_size, GFP_KERNEL);
284 buf->size = buf_size;
293 /* Callers should take appropriate locks */
294 static void *get_inbuf(struct port *port)
296 struct port_buffer *buf;
297 struct virtqueue *vq;
301 buf = vq->vq_ops->get_buf(vq, &len);
310 * Create a scatter-gather list representing our input buffer and put
313 * Callers should take appropriate locks.
315 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
317 struct scatterlist sg[1];
320 sg_init_one(sg, buf->buf, buf->size);
322 ret = vq->vq_ops->add_buf(vq, sg, 0, 1, buf);
323 vq->vq_ops->kick(vq);
327 /* Discard any unread data this port has. Callers lockers. */
328 static void discard_port_data(struct port *port)
330 struct port_buffer *buf;
331 struct virtqueue *vq;
338 buf = vq->vq_ops->get_buf(vq, &len);
343 if (add_inbuf(vq, buf) < 0) {
344 buf->len = buf->offset = 0;
345 dev_warn(port->dev, "Error adding buffer back to vq\n");
352 static bool port_has_data(struct port *port)
358 spin_lock_irqsave(&port->inbuf_lock, flags);
361 spin_unlock_irqrestore(&port->inbuf_lock, flags);
366 static ssize_t send_control_msg(struct port *port, unsigned int event,
369 struct scatterlist sg[1];
370 struct virtio_console_control cpkt;
371 struct virtqueue *vq;
374 if (!use_multiport(port->portdev))
381 vq = port->portdev->c_ovq;
383 sg_init_one(sg, &cpkt, sizeof(cpkt));
384 if (vq->vq_ops->add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
385 vq->vq_ops->kick(vq);
386 while (!vq->vq_ops->get_buf(vq, &len))
392 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
394 struct scatterlist sg[1];
395 struct virtqueue *out_vq;
399 out_vq = port->out_vq;
401 sg_init_one(sg, in_buf, in_count);
402 ret = out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, in_buf);
404 /* Tell Host to go! */
405 out_vq->vq_ops->kick(out_vq);
413 * Wait till the host acknowledges it pushed out the data we
414 * sent. Also ensure we return to userspace the number of
415 * bytes that were successfully consumed by the host.
417 while (!out_vq->vq_ops->get_buf(out_vq, &len))
420 /* We're expected to return the amount of data we wrote */
425 * Give out the data that's requested from the buffer that we have
428 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
431 struct port_buffer *buf;
434 if (!out_count || !port_has_data(port))
438 out_count = min(out_count, buf->len - buf->offset);
443 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
447 memcpy(out_buf, buf->buf + buf->offset, out_count);
450 buf->offset += out_count;
452 if (buf->offset == buf->len) {
454 * We're done using all the data in this buffer.
455 * Re-queue so that the Host can send us more data.
457 spin_lock_irqsave(&port->inbuf_lock, flags);
460 if (add_inbuf(port->in_vq, buf) < 0)
461 dev_warn(port->dev, "failed add_buf\n");
463 spin_unlock_irqrestore(&port->inbuf_lock, flags);
465 /* Return the number of bytes actually copied */
469 /* The condition that must be true for polling to end */
470 static bool wait_is_over(struct port *port)
472 return port_has_data(port) || !port->host_connected;
475 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
476 size_t count, loff_t *offp)
481 port = filp->private_data;
483 if (!port_has_data(port)) {
485 * If nothing's connected on the host just return 0 in
486 * case of list_empty; this tells the userspace app
487 * that there's no connection
489 if (!port->host_connected)
491 if (filp->f_flags & O_NONBLOCK)
494 ret = wait_event_interruptible(port->waitqueue,
500 * We could've received a disconnection message while we were
501 * waiting for more data.
503 * This check is not clubbed in the if() statement above as we
504 * might receive some data as well as the host could get
505 * disconnected after we got woken up from our wait. So we
506 * really want to give off whatever data we have and only then
507 * check for host_connected.
509 if (!port_has_data(port) && !port->host_connected)
512 return fill_readbuf(port, ubuf, count, true);
515 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
516 size_t count, loff_t *offp)
522 port = filp->private_data;
524 count = min((size_t)(32 * 1024), count);
526 buf = kmalloc(count, GFP_KERNEL);
530 ret = copy_from_user(buf, ubuf, count);
536 ret = send_buf(port, buf, count);
542 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
547 port = filp->private_data;
548 poll_wait(filp, &port->waitqueue, wait);
552 ret |= POLLIN | POLLRDNORM;
553 if (port->host_connected)
555 if (!port->host_connected)
561 static int port_fops_release(struct inode *inode, struct file *filp)
565 port = filp->private_data;
567 /* Notify host of port being closed */
568 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
570 spin_lock_irq(&port->inbuf_lock);
571 port->guest_connected = false;
573 discard_port_data(port);
575 spin_unlock_irq(&port->inbuf_lock);
580 static int port_fops_open(struct inode *inode, struct file *filp)
582 struct cdev *cdev = inode->i_cdev;
585 port = container_of(cdev, struct port, cdev);
586 filp->private_data = port;
589 * Don't allow opening of console port devices -- that's done
592 if (is_console_port(port))
595 /* Allow only one process to open a particular port at a time */
596 spin_lock_irq(&port->inbuf_lock);
597 if (port->guest_connected) {
598 spin_unlock_irq(&port->inbuf_lock);
602 port->guest_connected = true;
603 spin_unlock_irq(&port->inbuf_lock);
605 /* Notify host of port being opened */
606 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
612 * The file operations that we support: programs in the guest can open
613 * a console device, read from it, write to it, poll for data and
614 * close it. The devices are at
615 * /dev/vport<device number>p<port number>
617 static const struct file_operations port_fops = {
618 .owner = THIS_MODULE,
619 .open = port_fops_open,
620 .read = port_fops_read,
621 .write = port_fops_write,
622 .poll = port_fops_poll,
623 .release = port_fops_release,
627 * The put_chars() callback is pretty straightforward.
629 * We turn the characters into a scatter-gather list, add it to the
630 * output queue and then kick the Host. Then we sit here waiting for
631 * it to finish: inefficient in theory, but in practice
632 * implementations will do it immediately (lguest's Launcher does).
634 static int put_chars(u32 vtermno, const char *buf, int count)
638 port = find_port_by_vtermno(vtermno);
642 if (unlikely(early_put_chars))
643 return early_put_chars(vtermno, buf, count);
645 return send_buf(port, (void *)buf, count);
649 * get_chars() is the callback from the hvc_console infrastructure
650 * when an interrupt is received.
652 * We call out to fill_readbuf that gets us the required data from the
653 * buffers that are queued up.
655 static int get_chars(u32 vtermno, char *buf, int count)
659 port = find_port_by_vtermno(vtermno);
663 /* If we don't have an input queue yet, we can't get input. */
664 BUG_ON(!port->in_vq);
666 return fill_readbuf(port, buf, count, false);
669 static void resize_console(struct port *port)
671 struct virtio_device *vdev;
674 vdev = port->portdev->vdev;
675 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
676 vdev->config->get(vdev,
677 offsetof(struct virtio_console_config, cols),
678 &ws.ws_col, sizeof(u16));
679 vdev->config->get(vdev,
680 offsetof(struct virtio_console_config, rows),
681 &ws.ws_row, sizeof(u16));
682 hvc_resize(port->cons.hvc, ws);
686 /* We set the configuration at this point, since we now have a tty */
687 static int notifier_add_vio(struct hvc_struct *hp, int data)
691 port = find_port_by_vtermno(hp->vtermno);
695 hp->irq_requested = 1;
696 resize_console(port);
701 static void notifier_del_vio(struct hvc_struct *hp, int data)
703 hp->irq_requested = 0;
706 /* The operations for console ports. */
707 static const struct hv_ops hv_ops = {
708 .get_chars = get_chars,
709 .put_chars = put_chars,
710 .notifier_add = notifier_add_vio,
711 .notifier_del = notifier_del_vio,
712 .notifier_hangup = notifier_del_vio,
716 * Console drivers are initialized very early so boot messages can go
717 * out, so we do things slightly differently from the generic virtio
718 * initialization of the net and block drivers.
720 * At this stage, the console is output-only. It's too early to set
721 * up a virtqueue, so we let the drivers do some boutique early-output
724 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
726 early_put_chars = put_chars;
727 return hvc_instantiate(0, 0, &hv_ops);
730 int init_port_console(struct port *port)
735 * The Host's telling us this port is a console port. Hook it
736 * up with an hvc console.
738 * To set up and manage our virtual console, we call
741 * The first argument of hvc_alloc() is the virtual console
742 * number. The second argument is the parameter for the
743 * notification mechanism (like irq number). We currently
744 * leave this as zero, virtqueues have implicit notifications.
746 * The third argument is a "struct hv_ops" containing the
747 * put_chars() get_chars(), notifier_add() and notifier_del()
748 * pointers. The final argument is the output buffer size: we
749 * can do any size, so we put PAGE_SIZE here.
751 port->cons.vtermno = pdrvdata.next_vtermno;
753 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
754 if (IS_ERR(port->cons.hvc)) {
755 ret = PTR_ERR(port->cons.hvc);
757 "error %d allocating hvc for port\n", ret);
758 port->cons.hvc = NULL;
761 spin_lock_irq(&pdrvdata_lock);
762 pdrvdata.next_vtermno++;
763 list_add_tail(&port->cons.list, &pdrvdata.consoles);
764 spin_unlock_irq(&pdrvdata_lock);
765 port->guest_connected = true;
767 /* Notify host of port being opened */
768 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
773 static ssize_t show_port_name(struct device *dev,
774 struct device_attribute *attr, char *buffer)
778 port = dev_get_drvdata(dev);
780 return sprintf(buffer, "%s\n", port->name);
783 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
785 static struct attribute *port_sysfs_entries[] = {
790 static struct attribute_group port_attribute_group = {
791 .name = NULL, /* put in device directory */
792 .attrs = port_sysfs_entries,
795 static int debugfs_open(struct inode *inode, struct file *filp)
797 filp->private_data = inode->i_private;
801 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
802 size_t count, loff_t *offp)
806 ssize_t ret, out_offset, out_count;
809 buf = kmalloc(out_count, GFP_KERNEL);
813 port = filp->private_data;
815 out_offset += snprintf(buf + out_offset, out_count,
816 "name: %s\n", port->name ? port->name : "");
817 out_offset += snprintf(buf + out_offset, out_count - out_offset,
818 "guest_connected: %d\n", port->guest_connected);
819 out_offset += snprintf(buf + out_offset, out_count - out_offset,
820 "host_connected: %d\n", port->host_connected);
821 out_offset += snprintf(buf + out_offset, out_count - out_offset,
823 is_console_port(port) ? "yes" : "no");
824 out_offset += snprintf(buf + out_offset, out_count - out_offset,
825 "console_vtermno: %u\n", port->cons.vtermno);
827 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
832 static const struct file_operations port_debugfs_ops = {
833 .owner = THIS_MODULE,
834 .open = debugfs_open,
835 .read = debugfs_read,
838 /* Remove all port-specific data. */
839 static int remove_port(struct port *port)
841 spin_lock_irq(&port->portdev->ports_lock);
842 list_del(&port->list);
843 spin_unlock_irq(&port->portdev->ports_lock);
845 if (is_console_port(port)) {
846 spin_lock_irq(&pdrvdata_lock);
847 list_del(&port->cons.list);
848 spin_unlock_irq(&pdrvdata_lock);
849 hvc_remove(port->cons.hvc);
851 if (port->guest_connected)
852 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
854 while (port->in_vq->vq_ops->detach_unused_buf(port->in_vq))
857 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
858 device_destroy(pdrvdata.class, port->dev->devt);
859 cdev_del(&port->cdev);
861 discard_port_data(port);
864 debugfs_remove(port->debugfs_file);
870 /* Any private messages that the Host and Guest want to share */
871 static void handle_control_message(struct ports_device *portdev,
872 struct port_buffer *buf)
874 struct virtio_console_control *cpkt;
879 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
881 port = find_port_by_id(portdev, cpkt->id);
883 /* No valid header at start of buffer. Drop it. */
884 dev_dbg(&portdev->vdev->dev,
885 "Invalid index %u in control packet\n", cpkt->id);
889 switch (cpkt->event) {
890 case VIRTIO_CONSOLE_CONSOLE_PORT:
893 if (is_console_port(port))
896 init_port_console(port);
898 * Could remove the port here in case init fails - but
899 * have to notify the host first.
902 case VIRTIO_CONSOLE_RESIZE:
903 if (!is_console_port(port))
905 port->cons.hvc->irq_requested = 1;
906 resize_console(port);
908 case VIRTIO_CONSOLE_PORT_OPEN:
909 port->host_connected = cpkt->value;
910 wake_up_interruptible(&port->waitqueue);
912 case VIRTIO_CONSOLE_PORT_NAME:
914 * Skip the size of the header and the cpkt to get the size
915 * of the name that was sent
917 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
919 port->name = kmalloc(name_size, GFP_KERNEL);
922 "Not enough space to store port name\n");
925 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
927 port->name[name_size - 1] = 0;
930 * Since we only have one sysfs attribute, 'name',
931 * create it only if we have a name for the port.
933 err = sysfs_create_group(&port->dev->kobj,
934 &port_attribute_group);
937 "Error %d creating sysfs device attributes\n",
941 case VIRTIO_CONSOLE_PORT_REMOVE:
943 * Hot unplug the port. We don't decrement nr_ports
944 * since we don't want to deal with extra complexities
945 * of using the lowest-available port id: We can just
946 * pick up the nr_ports number as the id and not have
947 * userspace send it to us. This helps us in two
950 * - We don't need to have a 'port_id' field in the
951 * config space when a port is hot-added. This is a
952 * good thing as we might queue up multiple hotplug
953 * requests issued in our workqueue.
955 * - Another way to deal with this would have been to
956 * use a bitmap of the active ports and select the
957 * lowest non-active port from that map. That
958 * bloats the already tight config space and we
959 * would end up artificially limiting the
960 * max. number of ports to sizeof(bitmap). Right
961 * now we can support 2^32 ports (as the port id is
962 * stored in a u32 type).
970 static void control_work_handler(struct work_struct *work)
972 struct ports_device *portdev;
973 struct virtqueue *vq;
974 struct port_buffer *buf;
977 portdev = container_of(work, struct ports_device, control_work);
980 spin_lock(&portdev->cvq_lock);
981 while ((buf = vq->vq_ops->get_buf(vq, &len))) {
982 spin_unlock(&portdev->cvq_lock);
987 handle_control_message(portdev, buf);
989 spin_lock(&portdev->cvq_lock);
990 if (add_inbuf(portdev->c_ivq, buf) < 0) {
991 dev_warn(&portdev->vdev->dev,
992 "Error adding buffer to queue\n");
996 spin_unlock(&portdev->cvq_lock);
999 static void in_intr(struct virtqueue *vq)
1002 unsigned long flags;
1004 port = find_port_by_vq(vq->vdev->priv, vq);
1008 spin_lock_irqsave(&port->inbuf_lock, flags);
1009 port->inbuf = get_inbuf(port);
1012 * Don't queue up data when port is closed. This condition
1013 * can be reached when a console port is not yet connected (no
1014 * tty is spawned) and the host sends out data to console
1015 * ports. For generic serial ports, the host won't
1016 * (shouldn't) send data till the guest is connected.
1018 if (!port->guest_connected)
1019 discard_port_data(port);
1021 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1023 wake_up_interruptible(&port->waitqueue);
1025 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1029 static void control_intr(struct virtqueue *vq)
1031 struct ports_device *portdev;
1033 portdev = vq->vdev->priv;
1034 schedule_work(&portdev->control_work);
1037 static void config_intr(struct virtio_device *vdev)
1039 struct ports_device *portdev;
1041 portdev = vdev->priv;
1042 if (use_multiport(portdev)) {
1043 /* Handle port hot-add */
1044 schedule_work(&portdev->config_work);
1047 * We'll use this way of resizing only for legacy support.
1048 * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
1049 * control messages to indicate console size changes so that
1050 * it can be done per-port
1052 resize_console(find_port_by_id(portdev, 0));
1055 static void fill_queue(struct virtqueue *vq, spinlock_t *lock)
1057 struct port_buffer *buf;
1061 buf = alloc_buf(PAGE_SIZE);
1065 spin_lock_irq(lock);
1066 ret = add_inbuf(vq, buf);
1068 spin_unlock_irq(lock);
1072 spin_unlock_irq(lock);
1076 static int add_port(struct ports_device *portdev, u32 id)
1078 char debugfs_name[16];
1080 struct port_buffer *inbuf;
1084 port = kmalloc(sizeof(*port), GFP_KERNEL);
1090 port->portdev = portdev;
1095 port->cons.hvc = NULL;
1097 port->host_connected = port->guest_connected = false;
1099 port->in_vq = portdev->in_vqs[port->id];
1100 port->out_vq = portdev->out_vqs[port->id];
1102 cdev_init(&port->cdev, &port_fops);
1104 devt = MKDEV(portdev->chr_major, id);
1105 err = cdev_add(&port->cdev, devt, 1);
1107 dev_err(&port->portdev->vdev->dev,
1108 "Error %d adding cdev for port %u\n", err, id);
1111 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1112 devt, port, "vport%up%u",
1113 port->portdev->drv_index, id);
1114 if (IS_ERR(port->dev)) {
1115 err = PTR_ERR(port->dev);
1116 dev_err(&port->portdev->vdev->dev,
1117 "Error %d creating device for port %u\n",
1122 spin_lock_init(&port->inbuf_lock);
1123 init_waitqueue_head(&port->waitqueue);
1125 inbuf = alloc_buf(PAGE_SIZE);
1131 /* Register the input buffer the first time. */
1132 add_inbuf(port->in_vq, inbuf);
1135 * If we're not using multiport support, this has to be a console port
1137 if (!use_multiport(port->portdev)) {
1138 err = init_port_console(port);
1143 spin_lock_irq(&portdev->ports_lock);
1144 list_add_tail(&port->list, &port->portdev->ports);
1145 spin_unlock_irq(&portdev->ports_lock);
1148 * Tell the Host we're set so that it can send us various
1149 * configuration parameters for this port (eg, port name,
1150 * caching, whether this is a console port, etc.)
1152 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1154 if (pdrvdata.debugfs_dir) {
1156 * Finally, create the debugfs file that we can use to
1157 * inspect a port's state at any time
1159 sprintf(debugfs_name, "vport%up%u",
1160 port->portdev->drv_index, id);
1161 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1162 pdrvdata.debugfs_dir,
1171 device_destroy(pdrvdata.class, port->dev->devt);
1173 cdev_del(&port->cdev);
1181 * The workhandler for config-space updates.
1183 * This is called when ports are hot-added.
1185 static void config_work_handler(struct work_struct *work)
1187 struct virtio_console_config virtconconf;
1188 struct ports_device *portdev;
1189 struct virtio_device *vdev;
1192 portdev = container_of(work, struct ports_device, config_work);
1194 vdev = portdev->vdev;
1195 vdev->config->get(vdev,
1196 offsetof(struct virtio_console_config, nr_ports),
1197 &virtconconf.nr_ports,
1198 sizeof(virtconconf.nr_ports));
1200 if (portdev->config.nr_ports == virtconconf.nr_ports) {
1202 * Port 0 got hot-added. Since we already did all the
1203 * other initialisation for it, just tell the Host
1204 * that the port is ready if we find the port. In
1205 * case the port was hot-removed earlier, we call
1206 * add_port to add the port.
1210 port = find_port_by_id(portdev, 0);
1212 add_port(portdev, 0);
1214 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1217 if (virtconconf.nr_ports > portdev->config.max_nr_ports) {
1218 dev_warn(&vdev->dev,
1219 "More ports specified (%u) than allowed (%u)",
1220 portdev->config.nr_ports + 1,
1221 portdev->config.max_nr_ports);
1224 if (virtconconf.nr_ports < portdev->config.nr_ports)
1228 while (virtconconf.nr_ports - portdev->config.nr_ports) {
1229 err = add_port(portdev, portdev->config.nr_ports);
1232 portdev->config.nr_ports++;
1236 static int init_vqs(struct ports_device *portdev)
1238 vq_callback_t **io_callbacks;
1240 struct virtqueue **vqs;
1241 u32 i, j, nr_ports, nr_queues;
1244 nr_ports = portdev->config.max_nr_ports;
1245 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1247 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1252 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1253 if (!io_callbacks) {
1257 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1260 goto free_callbacks;
1262 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1264 if (!portdev->in_vqs) {
1268 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1270 if (!portdev->out_vqs) {
1276 * For backward compat (newer host but older guest), the host
1277 * spawns a console port first and also inits the vqs for port
1281 io_callbacks[j] = in_intr;
1282 io_callbacks[j + 1] = NULL;
1283 io_names[j] = "input";
1284 io_names[j + 1] = "output";
1287 if (use_multiport(portdev)) {
1288 io_callbacks[j] = control_intr;
1289 io_callbacks[j + 1] = NULL;
1290 io_names[j] = "control-i";
1291 io_names[j + 1] = "control-o";
1293 for (i = 1; i < nr_ports; i++) {
1295 io_callbacks[j] = in_intr;
1296 io_callbacks[j + 1] = NULL;
1297 io_names[j] = "input";
1298 io_names[j + 1] = "output";
1301 /* Find the queues. */
1302 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1304 (const char **)io_names);
1309 portdev->in_vqs[0] = vqs[0];
1310 portdev->out_vqs[0] = vqs[1];
1312 if (use_multiport(portdev)) {
1313 portdev->c_ivq = vqs[j];
1314 portdev->c_ovq = vqs[j + 1];
1316 for (i = 1; i < nr_ports; i++) {
1318 portdev->in_vqs[i] = vqs[j];
1319 portdev->out_vqs[i] = vqs[j + 1];
1322 kfree(io_callbacks);
1331 kfree(io_callbacks);
1333 kfree(portdev->out_vqs);
1335 kfree(portdev->in_vqs);
1342 static const struct file_operations portdev_fops = {
1343 .owner = THIS_MODULE,
1347 * Once we're further in boot, we get probed like any other virtio
1350 * If the host also supports multiple console ports, we check the
1351 * config space to see how many ports the host has spawned. We
1352 * initialize each port found.
1354 static int __devinit virtcons_probe(struct virtio_device *vdev)
1356 struct ports_device *portdev;
1361 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1367 /* Attach this portdev to this virtio_device, and vice-versa. */
1368 portdev->vdev = vdev;
1369 vdev->priv = portdev;
1371 spin_lock_irq(&pdrvdata_lock);
1372 portdev->drv_index = pdrvdata.index++;
1373 spin_unlock_irq(&pdrvdata_lock);
1375 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1377 if (portdev->chr_major < 0) {
1379 "Error %d registering chrdev for device %u\n",
1380 portdev->chr_major, portdev->drv_index);
1381 err = portdev->chr_major;
1386 portdev->config.nr_ports = 1;
1387 portdev->config.max_nr_ports = 1;
1388 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1390 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1392 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1394 &portdev->config.nr_ports,
1395 sizeof(portdev->config.nr_ports));
1396 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1398 &portdev->config.max_nr_ports,
1399 sizeof(portdev->config.max_nr_ports));
1400 if (portdev->config.nr_ports > portdev->config.max_nr_ports) {
1401 dev_warn(&vdev->dev,
1402 "More ports (%u) specified than allowed (%u). Will init %u ports.",
1403 portdev->config.nr_ports,
1404 portdev->config.max_nr_ports,
1405 portdev->config.max_nr_ports);
1407 portdev->config.nr_ports = portdev->config.max_nr_ports;
1411 /* Let the Host know we support multiple ports.*/
1412 vdev->config->finalize_features(vdev);
1414 err = init_vqs(portdev);
1416 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1420 spin_lock_init(&portdev->ports_lock);
1421 INIT_LIST_HEAD(&portdev->ports);
1424 spin_lock_init(&portdev->cvq_lock);
1425 INIT_WORK(&portdev->control_work, &control_work_handler);
1426 INIT_WORK(&portdev->config_work, &config_work_handler);
1428 fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1431 for (i = 0; i < portdev->config.nr_ports; i++)
1432 add_port(portdev, i);
1434 /* Start using the new console output. */
1435 early_put_chars = NULL;
1439 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1446 static struct virtio_device_id id_table[] = {
1447 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1451 static unsigned int features[] = {
1452 VIRTIO_CONSOLE_F_SIZE,
1453 VIRTIO_CONSOLE_F_MULTIPORT,
1456 static struct virtio_driver virtio_console = {
1457 .feature_table = features,
1458 .feature_table_size = ARRAY_SIZE(features),
1459 .driver.name = KBUILD_MODNAME,
1460 .driver.owner = THIS_MODULE,
1461 .id_table = id_table,
1462 .probe = virtcons_probe,
1463 .config_changed = config_intr,
1466 static int __init init(void)
1470 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1471 if (IS_ERR(pdrvdata.class)) {
1472 err = PTR_ERR(pdrvdata.class);
1473 pr_err("Error %d creating virtio-ports class\n", err);
1477 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1478 if (!pdrvdata.debugfs_dir) {
1479 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1480 PTR_ERR(pdrvdata.debugfs_dir));
1482 INIT_LIST_HEAD(&pdrvdata.consoles);
1484 return register_virtio_driver(&virtio_console);
1488 MODULE_DEVICE_TABLE(virtio, id_table);
1489 MODULE_DESCRIPTION("Virtio console driver");
1490 MODULE_LICENSE("GPL");