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);
424 * Wait till the host acknowledges it pushed out the data we
425 * sent. Also ensure we return to userspace the number of
426 * bytes that were successfully consumed by the host.
428 while (!out_vq->vq_ops->get_buf(out_vq, &len))
431 /* We're expected to return the amount of data we wrote */
436 * Give out the data that's requested from the buffer that we have
439 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
442 struct port_buffer *buf;
445 if (!out_count || !port_has_data(port))
449 out_count = min(out_count, buf->len - buf->offset);
454 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
458 memcpy(out_buf, buf->buf + buf->offset, out_count);
461 buf->offset += out_count;
463 if (buf->offset == buf->len) {
465 * We're done using all the data in this buffer.
466 * Re-queue so that the Host can send us more data.
468 spin_lock_irqsave(&port->inbuf_lock, flags);
471 if (add_inbuf(port->in_vq, buf) < 0)
472 dev_warn(port->dev, "failed add_buf\n");
474 spin_unlock_irqrestore(&port->inbuf_lock, flags);
476 /* Return the number of bytes actually copied */
480 /* The condition that must be true for polling to end */
481 static bool wait_is_over(struct port *port)
483 return port_has_data(port) || !port->host_connected;
486 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
487 size_t count, loff_t *offp)
492 port = filp->private_data;
494 if (!port_has_data(port)) {
496 * If nothing's connected on the host just return 0 in
497 * case of list_empty; this tells the userspace app
498 * that there's no connection
500 if (!port->host_connected)
502 if (filp->f_flags & O_NONBLOCK)
505 ret = wait_event_interruptible(port->waitqueue,
511 * We could've received a disconnection message while we were
512 * waiting for more data.
514 * This check is not clubbed in the if() statement above as we
515 * might receive some data as well as the host could get
516 * disconnected after we got woken up from our wait. So we
517 * really want to give off whatever data we have and only then
518 * check for host_connected.
520 if (!port_has_data(port) && !port->host_connected)
523 return fill_readbuf(port, ubuf, count, true);
526 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
527 size_t count, loff_t *offp)
533 port = filp->private_data;
535 count = min((size_t)(32 * 1024), count);
537 buf = kmalloc(count, GFP_KERNEL);
541 ret = copy_from_user(buf, ubuf, count);
547 ret = send_buf(port, buf, count);
553 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
558 port = filp->private_data;
559 poll_wait(filp, &port->waitqueue, wait);
563 ret |= POLLIN | POLLRDNORM;
564 if (port->host_connected)
566 if (!port->host_connected)
572 static int port_fops_release(struct inode *inode, struct file *filp)
576 port = filp->private_data;
578 /* Notify host of port being closed */
579 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
581 spin_lock_irq(&port->inbuf_lock);
582 port->guest_connected = false;
584 discard_port_data(port);
586 spin_unlock_irq(&port->inbuf_lock);
591 static int port_fops_open(struct inode *inode, struct file *filp)
593 struct cdev *cdev = inode->i_cdev;
596 port = container_of(cdev, struct port, cdev);
597 filp->private_data = port;
600 * Don't allow opening of console port devices -- that's done
603 if (is_console_port(port))
606 /* Allow only one process to open a particular port at a time */
607 spin_lock_irq(&port->inbuf_lock);
608 if (port->guest_connected) {
609 spin_unlock_irq(&port->inbuf_lock);
613 port->guest_connected = true;
614 spin_unlock_irq(&port->inbuf_lock);
616 /* Notify host of port being opened */
617 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
623 * The file operations that we support: programs in the guest can open
624 * a console device, read from it, write to it, poll for data and
625 * close it. The devices are at
626 * /dev/vport<device number>p<port number>
628 static const struct file_operations port_fops = {
629 .owner = THIS_MODULE,
630 .open = port_fops_open,
631 .read = port_fops_read,
632 .write = port_fops_write,
633 .poll = port_fops_poll,
634 .release = port_fops_release,
638 * The put_chars() callback is pretty straightforward.
640 * We turn the characters into a scatter-gather list, add it to the
641 * output queue and then kick the Host. Then we sit here waiting for
642 * it to finish: inefficient in theory, but in practice
643 * implementations will do it immediately (lguest's Launcher does).
645 static int put_chars(u32 vtermno, const char *buf, int count)
649 port = find_port_by_vtermno(vtermno);
653 if (unlikely(early_put_chars))
654 return early_put_chars(vtermno, buf, count);
656 return send_buf(port, (void *)buf, count);
660 * get_chars() is the callback from the hvc_console infrastructure
661 * when an interrupt is received.
663 * We call out to fill_readbuf that gets us the required data from the
664 * buffers that are queued up.
666 static int get_chars(u32 vtermno, char *buf, int count)
670 port = find_port_by_vtermno(vtermno);
674 /* If we don't have an input queue yet, we can't get input. */
675 BUG_ON(!port->in_vq);
677 return fill_readbuf(port, buf, count, false);
680 static void resize_console(struct port *port)
682 struct virtio_device *vdev;
685 /* The port could have been hot-unplugged */
689 vdev = port->portdev->vdev;
690 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
691 vdev->config->get(vdev,
692 offsetof(struct virtio_console_config, cols),
693 &ws.ws_col, sizeof(u16));
694 vdev->config->get(vdev,
695 offsetof(struct virtio_console_config, rows),
696 &ws.ws_row, sizeof(u16));
697 hvc_resize(port->cons.hvc, ws);
701 /* We set the configuration at this point, since we now have a tty */
702 static int notifier_add_vio(struct hvc_struct *hp, int data)
706 port = find_port_by_vtermno(hp->vtermno);
710 hp->irq_requested = 1;
711 resize_console(port);
716 static void notifier_del_vio(struct hvc_struct *hp, int data)
718 hp->irq_requested = 0;
721 /* The operations for console ports. */
722 static const struct hv_ops hv_ops = {
723 .get_chars = get_chars,
724 .put_chars = put_chars,
725 .notifier_add = notifier_add_vio,
726 .notifier_del = notifier_del_vio,
727 .notifier_hangup = notifier_del_vio,
731 * Console drivers are initialized very early so boot messages can go
732 * out, so we do things slightly differently from the generic virtio
733 * initialization of the net and block drivers.
735 * At this stage, the console is output-only. It's too early to set
736 * up a virtqueue, so we let the drivers do some boutique early-output
739 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
741 early_put_chars = put_chars;
742 return hvc_instantiate(0, 0, &hv_ops);
745 int init_port_console(struct port *port)
750 * The Host's telling us this port is a console port. Hook it
751 * up with an hvc console.
753 * To set up and manage our virtual console, we call
756 * The first argument of hvc_alloc() is the virtual console
757 * number. The second argument is the parameter for the
758 * notification mechanism (like irq number). We currently
759 * leave this as zero, virtqueues have implicit notifications.
761 * The third argument is a "struct hv_ops" containing the
762 * put_chars() get_chars(), notifier_add() and notifier_del()
763 * pointers. The final argument is the output buffer size: we
764 * can do any size, so we put PAGE_SIZE here.
766 port->cons.vtermno = pdrvdata.next_vtermno;
768 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
769 if (IS_ERR(port->cons.hvc)) {
770 ret = PTR_ERR(port->cons.hvc);
772 "error %d allocating hvc for port\n", ret);
773 port->cons.hvc = NULL;
776 spin_lock_irq(&pdrvdata_lock);
777 pdrvdata.next_vtermno++;
778 list_add_tail(&port->cons.list, &pdrvdata.consoles);
779 spin_unlock_irq(&pdrvdata_lock);
780 port->guest_connected = true;
782 /* Notify host of port being opened */
783 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
788 static ssize_t show_port_name(struct device *dev,
789 struct device_attribute *attr, char *buffer)
793 port = dev_get_drvdata(dev);
795 return sprintf(buffer, "%s\n", port->name);
798 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
800 static struct attribute *port_sysfs_entries[] = {
805 static struct attribute_group port_attribute_group = {
806 .name = NULL, /* put in device directory */
807 .attrs = port_sysfs_entries,
810 static int debugfs_open(struct inode *inode, struct file *filp)
812 filp->private_data = inode->i_private;
816 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
817 size_t count, loff_t *offp)
821 ssize_t ret, out_offset, out_count;
824 buf = kmalloc(out_count, GFP_KERNEL);
828 port = filp->private_data;
830 out_offset += snprintf(buf + out_offset, out_count,
831 "name: %s\n", port->name ? port->name : "");
832 out_offset += snprintf(buf + out_offset, out_count - out_offset,
833 "guest_connected: %d\n", port->guest_connected);
834 out_offset += snprintf(buf + out_offset, out_count - out_offset,
835 "host_connected: %d\n", port->host_connected);
836 out_offset += snprintf(buf + out_offset, out_count - out_offset,
838 is_console_port(port) ? "yes" : "no");
839 out_offset += snprintf(buf + out_offset, out_count - out_offset,
840 "console_vtermno: %u\n", port->cons.vtermno);
842 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
847 static const struct file_operations port_debugfs_ops = {
848 .owner = THIS_MODULE,
849 .open = debugfs_open,
850 .read = debugfs_read,
853 /* Remove all port-specific data. */
854 static int remove_port(struct port *port)
856 struct port_buffer *buf;
858 spin_lock_irq(&port->portdev->ports_lock);
859 list_del(&port->list);
860 spin_unlock_irq(&port->portdev->ports_lock);
862 if (is_console_port(port)) {
863 spin_lock_irq(&pdrvdata_lock);
864 list_del(&port->cons.list);
865 spin_unlock_irq(&pdrvdata_lock);
866 hvc_remove(port->cons.hvc);
868 if (port->guest_connected)
869 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
871 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
872 device_destroy(pdrvdata.class, port->dev->devt);
873 cdev_del(&port->cdev);
875 /* Remove unused data this port might have received. */
876 discard_port_data(port);
878 /* Remove buffers we queued up for the Host to send us data in. */
879 while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq)))
884 debugfs_remove(port->debugfs_file);
890 /* Any private messages that the Host and Guest want to share */
891 static void handle_control_message(struct ports_device *portdev,
892 struct port_buffer *buf)
894 struct virtio_console_control *cpkt;
899 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
901 port = find_port_by_id(portdev, cpkt->id);
903 /* No valid header at start of buffer. Drop it. */
904 dev_dbg(&portdev->vdev->dev,
905 "Invalid index %u in control packet\n", cpkt->id);
909 switch (cpkt->event) {
910 case VIRTIO_CONSOLE_CONSOLE_PORT:
913 if (is_console_port(port))
916 init_port_console(port);
918 * Could remove the port here in case init fails - but
919 * have to notify the host first.
922 case VIRTIO_CONSOLE_RESIZE:
923 if (!is_console_port(port))
925 port->cons.hvc->irq_requested = 1;
926 resize_console(port);
928 case VIRTIO_CONSOLE_PORT_OPEN:
929 port->host_connected = cpkt->value;
930 wake_up_interruptible(&port->waitqueue);
932 case VIRTIO_CONSOLE_PORT_NAME:
934 * Skip the size of the header and the cpkt to get the size
935 * of the name that was sent
937 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
939 port->name = kmalloc(name_size, GFP_KERNEL);
942 "Not enough space to store port name\n");
945 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
947 port->name[name_size - 1] = 0;
950 * Since we only have one sysfs attribute, 'name',
951 * create it only if we have a name for the port.
953 err = sysfs_create_group(&port->dev->kobj,
954 &port_attribute_group);
957 "Error %d creating sysfs device attributes\n",
961 * Generate a udev event so that appropriate
962 * symlinks can be created based on udev
965 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
968 case VIRTIO_CONSOLE_PORT_REMOVE:
970 * Hot unplug the port. We don't decrement nr_ports
971 * since we don't want to deal with extra complexities
972 * of using the lowest-available port id: We can just
973 * pick up the nr_ports number as the id and not have
974 * userspace send it to us. This helps us in two
977 * - We don't need to have a 'port_id' field in the
978 * config space when a port is hot-added. This is a
979 * good thing as we might queue up multiple hotplug
980 * requests issued in our workqueue.
982 * - Another way to deal with this would have been to
983 * use a bitmap of the active ports and select the
984 * lowest non-active port from that map. That
985 * bloats the already tight config space and we
986 * would end up artificially limiting the
987 * max. number of ports to sizeof(bitmap). Right
988 * now we can support 2^32 ports (as the port id is
989 * stored in a u32 type).
997 static void control_work_handler(struct work_struct *work)
999 struct ports_device *portdev;
1000 struct virtqueue *vq;
1001 struct port_buffer *buf;
1004 portdev = container_of(work, struct ports_device, control_work);
1005 vq = portdev->c_ivq;
1007 spin_lock(&portdev->cvq_lock);
1008 while ((buf = vq->vq_ops->get_buf(vq, &len))) {
1009 spin_unlock(&portdev->cvq_lock);
1014 handle_control_message(portdev, buf);
1016 spin_lock(&portdev->cvq_lock);
1017 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1018 dev_warn(&portdev->vdev->dev,
1019 "Error adding buffer to queue\n");
1023 spin_unlock(&portdev->cvq_lock);
1026 static void in_intr(struct virtqueue *vq)
1029 unsigned long flags;
1031 port = find_port_by_vq(vq->vdev->priv, vq);
1035 spin_lock_irqsave(&port->inbuf_lock, flags);
1037 port->inbuf = get_inbuf(port);
1040 * Don't queue up data when port is closed. This condition
1041 * can be reached when a console port is not yet connected (no
1042 * tty is spawned) and the host sends out data to console
1043 * ports. For generic serial ports, the host won't
1044 * (shouldn't) send data till the guest is connected.
1046 if (!port->guest_connected)
1047 discard_port_data(port);
1049 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1051 wake_up_interruptible(&port->waitqueue);
1053 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1057 static void control_intr(struct virtqueue *vq)
1059 struct ports_device *portdev;
1061 portdev = vq->vdev->priv;
1062 schedule_work(&portdev->control_work);
1065 static void config_intr(struct virtio_device *vdev)
1067 struct ports_device *portdev;
1069 portdev = vdev->priv;
1070 if (use_multiport(portdev)) {
1071 /* Handle port hot-add */
1072 schedule_work(&portdev->config_work);
1075 * We'll use this way of resizing only for legacy support.
1076 * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
1077 * control messages to indicate console size changes so that
1078 * it can be done per-port
1080 resize_console(find_port_by_id(portdev, 0));
1083 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1085 struct port_buffer *buf;
1086 unsigned int nr_added_bufs;
1091 buf = alloc_buf(PAGE_SIZE);
1095 spin_lock_irq(lock);
1096 ret = add_inbuf(vq, buf);
1098 spin_unlock_irq(lock);
1103 spin_unlock_irq(lock);
1106 return nr_added_bufs;
1109 static int add_port(struct ports_device *portdev, u32 id)
1111 char debugfs_name[16];
1113 struct port_buffer *buf;
1115 unsigned int nr_added_bufs;
1118 port = kmalloc(sizeof(*port), GFP_KERNEL);
1124 port->portdev = portdev;
1129 port->cons.hvc = NULL;
1131 port->host_connected = port->guest_connected = false;
1133 port->in_vq = portdev->in_vqs[port->id];
1134 port->out_vq = portdev->out_vqs[port->id];
1136 cdev_init(&port->cdev, &port_fops);
1138 devt = MKDEV(portdev->chr_major, id);
1139 err = cdev_add(&port->cdev, devt, 1);
1141 dev_err(&port->portdev->vdev->dev,
1142 "Error %d adding cdev for port %u\n", err, id);
1145 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1146 devt, port, "vport%up%u",
1147 port->portdev->drv_index, id);
1148 if (IS_ERR(port->dev)) {
1149 err = PTR_ERR(port->dev);
1150 dev_err(&port->portdev->vdev->dev,
1151 "Error %d creating device for port %u\n",
1156 spin_lock_init(&port->inbuf_lock);
1157 init_waitqueue_head(&port->waitqueue);
1159 /* Fill the in_vq with buffers so the host can send us data. */
1160 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1161 if (!nr_added_bufs) {
1162 dev_err(port->dev, "Error allocating inbufs\n");
1168 * If we're not using multiport support, this has to be a console port
1170 if (!use_multiport(port->portdev)) {
1171 err = init_port_console(port);
1176 spin_lock_irq(&portdev->ports_lock);
1177 list_add_tail(&port->list, &port->portdev->ports);
1178 spin_unlock_irq(&portdev->ports_lock);
1181 * Tell the Host we're set so that it can send us various
1182 * configuration parameters for this port (eg, port name,
1183 * caching, whether this is a console port, etc.)
1185 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1187 if (pdrvdata.debugfs_dir) {
1189 * Finally, create the debugfs file that we can use to
1190 * inspect a port's state at any time
1192 sprintf(debugfs_name, "vport%up%u",
1193 port->portdev->drv_index, id);
1194 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1195 pdrvdata.debugfs_dir,
1202 while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq)))
1205 device_destroy(pdrvdata.class, port->dev->devt);
1207 cdev_del(&port->cdev);
1215 * The workhandler for config-space updates.
1217 * This is called when ports are hot-added.
1219 static void config_work_handler(struct work_struct *work)
1221 struct virtio_console_config virtconconf;
1222 struct ports_device *portdev;
1223 struct virtio_device *vdev;
1226 portdev = container_of(work, struct ports_device, config_work);
1228 vdev = portdev->vdev;
1229 vdev->config->get(vdev,
1230 offsetof(struct virtio_console_config, nr_ports),
1231 &virtconconf.nr_ports,
1232 sizeof(virtconconf.nr_ports));
1234 if (portdev->config.nr_ports == virtconconf.nr_ports) {
1236 * Port 0 got hot-added. Since we already did all the
1237 * other initialisation for it, just tell the Host
1238 * that the port is ready if we find the port. In
1239 * case the port was hot-removed earlier, we call
1240 * add_port to add the port.
1244 port = find_port_by_id(portdev, 0);
1246 add_port(portdev, 0);
1248 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1251 if (virtconconf.nr_ports > portdev->config.max_nr_ports) {
1252 dev_warn(&vdev->dev,
1253 "More ports specified (%u) than allowed (%u)",
1254 portdev->config.nr_ports + 1,
1255 portdev->config.max_nr_ports);
1258 if (virtconconf.nr_ports < portdev->config.nr_ports)
1262 while (virtconconf.nr_ports - portdev->config.nr_ports) {
1263 err = add_port(portdev, portdev->config.nr_ports);
1266 portdev->config.nr_ports++;
1270 static int init_vqs(struct ports_device *portdev)
1272 vq_callback_t **io_callbacks;
1274 struct virtqueue **vqs;
1275 u32 i, j, nr_ports, nr_queues;
1278 nr_ports = portdev->config.max_nr_ports;
1279 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1281 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1286 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1287 if (!io_callbacks) {
1291 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1294 goto free_callbacks;
1296 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1298 if (!portdev->in_vqs) {
1302 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1304 if (!portdev->out_vqs) {
1310 * For backward compat (newer host but older guest), the host
1311 * spawns a console port first and also inits the vqs for port
1315 io_callbacks[j] = in_intr;
1316 io_callbacks[j + 1] = NULL;
1317 io_names[j] = "input";
1318 io_names[j + 1] = "output";
1321 if (use_multiport(portdev)) {
1322 io_callbacks[j] = control_intr;
1323 io_callbacks[j + 1] = NULL;
1324 io_names[j] = "control-i";
1325 io_names[j + 1] = "control-o";
1327 for (i = 1; i < nr_ports; i++) {
1329 io_callbacks[j] = in_intr;
1330 io_callbacks[j + 1] = NULL;
1331 io_names[j] = "input";
1332 io_names[j + 1] = "output";
1335 /* Find the queues. */
1336 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1338 (const char **)io_names);
1343 portdev->in_vqs[0] = vqs[0];
1344 portdev->out_vqs[0] = vqs[1];
1346 if (use_multiport(portdev)) {
1347 portdev->c_ivq = vqs[j];
1348 portdev->c_ovq = vqs[j + 1];
1350 for (i = 1; i < nr_ports; i++) {
1352 portdev->in_vqs[i] = vqs[j];
1353 portdev->out_vqs[i] = vqs[j + 1];
1356 kfree(io_callbacks);
1365 kfree(io_callbacks);
1367 kfree(portdev->out_vqs);
1369 kfree(portdev->in_vqs);
1376 static const struct file_operations portdev_fops = {
1377 .owner = THIS_MODULE,
1381 * Once we're further in boot, we get probed like any other virtio
1384 * If the host also supports multiple console ports, we check the
1385 * config space to see how many ports the host has spawned. We
1386 * initialize each port found.
1388 static int __devinit virtcons_probe(struct virtio_device *vdev)
1390 struct ports_device *portdev;
1395 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1401 /* Attach this portdev to this virtio_device, and vice-versa. */
1402 portdev->vdev = vdev;
1403 vdev->priv = portdev;
1405 spin_lock_irq(&pdrvdata_lock);
1406 portdev->drv_index = pdrvdata.index++;
1407 spin_unlock_irq(&pdrvdata_lock);
1409 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1411 if (portdev->chr_major < 0) {
1413 "Error %d registering chrdev for device %u\n",
1414 portdev->chr_major, portdev->drv_index);
1415 err = portdev->chr_major;
1420 portdev->config.nr_ports = 1;
1421 portdev->config.max_nr_ports = 1;
1422 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1424 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1426 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1428 &portdev->config.nr_ports,
1429 sizeof(portdev->config.nr_ports));
1430 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1432 &portdev->config.max_nr_ports,
1433 sizeof(portdev->config.max_nr_ports));
1434 if (portdev->config.nr_ports > portdev->config.max_nr_ports) {
1435 dev_warn(&vdev->dev,
1436 "More ports (%u) specified than allowed (%u). Will init %u ports.",
1437 portdev->config.nr_ports,
1438 portdev->config.max_nr_ports,
1439 portdev->config.max_nr_ports);
1441 portdev->config.nr_ports = portdev->config.max_nr_ports;
1445 /* Let the Host know we support multiple ports.*/
1446 vdev->config->finalize_features(vdev);
1448 err = init_vqs(portdev);
1450 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1454 spin_lock_init(&portdev->ports_lock);
1455 INIT_LIST_HEAD(&portdev->ports);
1458 unsigned int nr_added_bufs;
1460 spin_lock_init(&portdev->cvq_lock);
1461 INIT_WORK(&portdev->control_work, &control_work_handler);
1462 INIT_WORK(&portdev->config_work, &config_work_handler);
1464 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1465 if (!nr_added_bufs) {
1467 "Error allocating buffers for control queue\n");
1473 for (i = 0; i < portdev->config.nr_ports; i++)
1474 add_port(portdev, i);
1476 /* Start using the new console output. */
1477 early_put_chars = NULL;
1481 vdev->config->del_vqs(vdev);
1482 kfree(portdev->in_vqs);
1483 kfree(portdev->out_vqs);
1485 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1492 static void virtcons_remove(struct virtio_device *vdev)
1494 struct ports_device *portdev;
1495 struct port *port, *port2;
1496 struct port_buffer *buf;
1499 portdev = vdev->priv;
1501 cancel_work_sync(&portdev->control_work);
1502 cancel_work_sync(&portdev->config_work);
1504 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1507 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1509 while ((buf = portdev->c_ivq->vq_ops->get_buf(portdev->c_ivq, &len)))
1512 while ((buf = portdev->c_ivq->vq_ops->detach_unused_buf(portdev->c_ivq)))
1515 vdev->config->del_vqs(vdev);
1516 kfree(portdev->in_vqs);
1517 kfree(portdev->out_vqs);
1522 static struct virtio_device_id id_table[] = {
1523 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1527 static unsigned int features[] = {
1528 VIRTIO_CONSOLE_F_SIZE,
1529 VIRTIO_CONSOLE_F_MULTIPORT,
1532 static struct virtio_driver virtio_console = {
1533 .feature_table = features,
1534 .feature_table_size = ARRAY_SIZE(features),
1535 .driver.name = KBUILD_MODNAME,
1536 .driver.owner = THIS_MODULE,
1537 .id_table = id_table,
1538 .probe = virtcons_probe,
1539 .remove = virtcons_remove,
1540 .config_changed = config_intr,
1543 static int __init init(void)
1547 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1548 if (IS_ERR(pdrvdata.class)) {
1549 err = PTR_ERR(pdrvdata.class);
1550 pr_err("Error %d creating virtio-ports class\n", err);
1554 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1555 if (!pdrvdata.debugfs_dir) {
1556 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1557 PTR_ERR(pdrvdata.debugfs_dir));
1559 INIT_LIST_HEAD(&pdrvdata.consoles);
1561 return register_virtio_driver(&virtio_console);
1564 static void __exit fini(void)
1566 unregister_virtio_driver(&virtio_console);
1568 class_destroy(pdrvdata.class);
1569 if (pdrvdata.debugfs_dir)
1570 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1575 MODULE_DEVICE_TABLE(virtio, id_table);
1576 MODULE_DESCRIPTION("Virtio console driver");
1577 MODULE_LICENSE("GPL");