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;
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 = virtqueue_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 = virtqueue_add_buf(vq, sg, 0, 1, buf);
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;
339 buf = virtqueue_get_buf(vq, &len);
343 if (add_inbuf(vq, buf) < 0) {
347 buf = virtqueue_get_buf(vq, &len);
351 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
355 static bool port_has_data(struct port *port)
360 spin_lock_irqsave(&port->inbuf_lock, flags);
365 port->inbuf = get_inbuf(port);
372 spin_unlock_irqrestore(&port->inbuf_lock, flags);
376 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
377 unsigned int event, unsigned int value)
379 struct scatterlist sg[1];
380 struct virtio_console_control cpkt;
381 struct virtqueue *vq;
384 if (!use_multiport(portdev))
393 sg_init_one(sg, &cpkt, sizeof(cpkt));
394 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
396 while (!virtqueue_get_buf(vq, &len))
402 static ssize_t send_control_msg(struct port *port, unsigned int event,
405 return __send_control_msg(port->portdev, port->id, event, value);
408 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
410 struct scatterlist sg[1];
411 struct virtqueue *out_vq;
415 out_vq = port->out_vq;
417 sg_init_one(sg, in_buf, in_count);
418 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
420 /* Tell Host to go! */
421 virtqueue_kick(out_vq);
428 /* Wait till the host acknowledges it pushed out the data we sent. */
429 while (!virtqueue_get_buf(out_vq, &len))
432 /* We're expected to return the amount of data we wrote */
437 * Give out the data that's requested from the buffer that we have
440 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
443 struct port_buffer *buf;
446 if (!out_count || !port_has_data(port))
450 out_count = min(out_count, buf->len - buf->offset);
455 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
459 memcpy(out_buf, buf->buf + buf->offset, out_count);
462 buf->offset += out_count;
464 if (buf->offset == buf->len) {
466 * We're done using all the data in this buffer.
467 * Re-queue so that the Host can send us more data.
469 spin_lock_irqsave(&port->inbuf_lock, flags);
472 if (add_inbuf(port->in_vq, buf) < 0)
473 dev_warn(port->dev, "failed add_buf\n");
475 spin_unlock_irqrestore(&port->inbuf_lock, flags);
477 /* Return the number of bytes actually copied */
481 /* The condition that must be true for polling to end */
482 static bool will_read_block(struct port *port)
484 return !port_has_data(port) && port->host_connected;
487 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
488 size_t count, loff_t *offp)
493 port = filp->private_data;
495 if (!port_has_data(port)) {
497 * If nothing's connected on the host just return 0 in
498 * case of list_empty; this tells the userspace app
499 * that there's no connection
501 if (!port->host_connected)
503 if (filp->f_flags & O_NONBLOCK)
506 ret = wait_event_interruptible(port->waitqueue,
507 !will_read_block(port));
512 * We could've received a disconnection message while we were
513 * waiting for more data.
515 * This check is not clubbed in the if() statement above as we
516 * might receive some data as well as the host could get
517 * disconnected after we got woken up from our wait. So we
518 * really want to give off whatever data we have and only then
519 * check for host_connected.
521 if (!port_has_data(port) && !port->host_connected)
524 return fill_readbuf(port, ubuf, count, true);
527 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
528 size_t count, loff_t *offp)
534 port = filp->private_data;
536 count = min((size_t)(32 * 1024), count);
538 buf = kmalloc(count, GFP_KERNEL);
542 ret = copy_from_user(buf, ubuf, count);
548 ret = send_buf(port, buf, count);
554 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
559 port = filp->private_data;
560 poll_wait(filp, &port->waitqueue, wait);
564 ret |= POLLIN | POLLRDNORM;
565 if (port->host_connected)
567 if (!port->host_connected)
573 static int port_fops_release(struct inode *inode, struct file *filp)
577 port = filp->private_data;
579 /* Notify host of port being closed */
580 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
582 spin_lock_irq(&port->inbuf_lock);
583 port->guest_connected = false;
585 discard_port_data(port);
587 spin_unlock_irq(&port->inbuf_lock);
592 static int port_fops_open(struct inode *inode, struct file *filp)
594 struct cdev *cdev = inode->i_cdev;
597 port = container_of(cdev, struct port, cdev);
598 filp->private_data = port;
601 * Don't allow opening of console port devices -- that's done
604 if (is_console_port(port))
607 /* Allow only one process to open a particular port at a time */
608 spin_lock_irq(&port->inbuf_lock);
609 if (port->guest_connected) {
610 spin_unlock_irq(&port->inbuf_lock);
614 port->guest_connected = true;
615 spin_unlock_irq(&port->inbuf_lock);
617 /* Notify host of port being opened */
618 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
624 * The file operations that we support: programs in the guest can open
625 * a console device, read from it, write to it, poll for data and
626 * close it. The devices are at
627 * /dev/vport<device number>p<port number>
629 static const struct file_operations port_fops = {
630 .owner = THIS_MODULE,
631 .open = port_fops_open,
632 .read = port_fops_read,
633 .write = port_fops_write,
634 .poll = port_fops_poll,
635 .release = port_fops_release,
639 * The put_chars() callback is pretty straightforward.
641 * We turn the characters into a scatter-gather list, add it to the
642 * output queue and then kick the Host. Then we sit here waiting for
643 * it to finish: inefficient in theory, but in practice
644 * implementations will do it immediately (lguest's Launcher does).
646 static int put_chars(u32 vtermno, const char *buf, int count)
650 if (unlikely(early_put_chars))
651 return early_put_chars(vtermno, buf, count);
653 port = find_port_by_vtermno(vtermno);
657 return send_buf(port, (void *)buf, count);
661 * get_chars() is the callback from the hvc_console infrastructure
662 * when an interrupt is received.
664 * We call out to fill_readbuf that gets us the required data from the
665 * buffers that are queued up.
667 static int get_chars(u32 vtermno, char *buf, int count)
671 /* If we've not set up the port yet, we have no input to give. */
672 if (unlikely(early_put_chars))
675 port = find_port_by_vtermno(vtermno);
679 /* If we don't have an input queue yet, we can't get input. */
680 BUG_ON(!port->in_vq);
682 return fill_readbuf(port, buf, count, false);
685 static void resize_console(struct port *port)
687 struct virtio_device *vdev;
690 /* The port could have been hot-unplugged */
694 vdev = port->portdev->vdev;
695 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
696 vdev->config->get(vdev,
697 offsetof(struct virtio_console_config, cols),
698 &ws.ws_col, sizeof(u16));
699 vdev->config->get(vdev,
700 offsetof(struct virtio_console_config, rows),
701 &ws.ws_row, sizeof(u16));
702 hvc_resize(port->cons.hvc, ws);
706 /* We set the configuration at this point, since we now have a tty */
707 static int notifier_add_vio(struct hvc_struct *hp, int data)
711 port = find_port_by_vtermno(hp->vtermno);
715 hp->irq_requested = 1;
716 resize_console(port);
721 static void notifier_del_vio(struct hvc_struct *hp, int data)
723 hp->irq_requested = 0;
726 /* The operations for console ports. */
727 static const struct hv_ops hv_ops = {
728 .get_chars = get_chars,
729 .put_chars = put_chars,
730 .notifier_add = notifier_add_vio,
731 .notifier_del = notifier_del_vio,
732 .notifier_hangup = notifier_del_vio,
736 * Console drivers are initialized very early so boot messages can go
737 * out, so we do things slightly differently from the generic virtio
738 * initialization of the net and block drivers.
740 * At this stage, the console is output-only. It's too early to set
741 * up a virtqueue, so we let the drivers do some boutique early-output
744 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
746 early_put_chars = put_chars;
747 return hvc_instantiate(0, 0, &hv_ops);
750 int init_port_console(struct port *port)
755 * The Host's telling us this port is a console port. Hook it
756 * up with an hvc console.
758 * To set up and manage our virtual console, we call
761 * The first argument of hvc_alloc() is the virtual console
762 * number. The second argument is the parameter for the
763 * notification mechanism (like irq number). We currently
764 * leave this as zero, virtqueues have implicit notifications.
766 * The third argument is a "struct hv_ops" containing the
767 * put_chars() get_chars(), notifier_add() and notifier_del()
768 * pointers. The final argument is the output buffer size: we
769 * can do any size, so we put PAGE_SIZE here.
771 port->cons.vtermno = pdrvdata.next_vtermno;
773 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
774 if (IS_ERR(port->cons.hvc)) {
775 ret = PTR_ERR(port->cons.hvc);
777 "error %d allocating hvc for port\n", ret);
778 port->cons.hvc = NULL;
781 spin_lock_irq(&pdrvdata_lock);
782 pdrvdata.next_vtermno++;
783 list_add_tail(&port->cons.list, &pdrvdata.consoles);
784 spin_unlock_irq(&pdrvdata_lock);
785 port->guest_connected = true;
788 * Start using the new console output if this is the first
789 * console to come up.
792 early_put_chars = NULL;
794 /* Notify host of port being opened */
795 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
800 static ssize_t show_port_name(struct device *dev,
801 struct device_attribute *attr, char *buffer)
805 port = dev_get_drvdata(dev);
807 return sprintf(buffer, "%s\n", port->name);
810 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
812 static struct attribute *port_sysfs_entries[] = {
817 static struct attribute_group port_attribute_group = {
818 .name = NULL, /* put in device directory */
819 .attrs = port_sysfs_entries,
822 static int debugfs_open(struct inode *inode, struct file *filp)
824 filp->private_data = inode->i_private;
828 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
829 size_t count, loff_t *offp)
833 ssize_t ret, out_offset, out_count;
836 buf = kmalloc(out_count, GFP_KERNEL);
840 port = filp->private_data;
842 out_offset += snprintf(buf + out_offset, out_count,
843 "name: %s\n", port->name ? port->name : "");
844 out_offset += snprintf(buf + out_offset, out_count - out_offset,
845 "guest_connected: %d\n", port->guest_connected);
846 out_offset += snprintf(buf + out_offset, out_count - out_offset,
847 "host_connected: %d\n", port->host_connected);
848 out_offset += snprintf(buf + out_offset, out_count - out_offset,
850 is_console_port(port) ? "yes" : "no");
851 out_offset += snprintf(buf + out_offset, out_count - out_offset,
852 "console_vtermno: %u\n", port->cons.vtermno);
854 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
859 static const struct file_operations port_debugfs_ops = {
860 .owner = THIS_MODULE,
861 .open = debugfs_open,
862 .read = debugfs_read,
865 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
867 struct port_buffer *buf;
868 unsigned int nr_added_bufs;
873 buf = alloc_buf(PAGE_SIZE);
878 ret = add_inbuf(vq, buf);
880 spin_unlock_irq(lock);
885 spin_unlock_irq(lock);
888 return nr_added_bufs;
891 static int add_port(struct ports_device *portdev, u32 id)
893 char debugfs_name[16];
895 struct port_buffer *buf;
897 unsigned int nr_added_bufs;
900 port = kmalloc(sizeof(*port), GFP_KERNEL);
906 port->portdev = portdev;
911 port->cons.hvc = NULL;
913 port->host_connected = port->guest_connected = false;
915 port->in_vq = portdev->in_vqs[port->id];
916 port->out_vq = portdev->out_vqs[port->id];
918 cdev_init(&port->cdev, &port_fops);
920 devt = MKDEV(portdev->chr_major, id);
921 err = cdev_add(&port->cdev, devt, 1);
923 dev_err(&port->portdev->vdev->dev,
924 "Error %d adding cdev for port %u\n", err, id);
927 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
928 devt, port, "vport%up%u",
929 port->portdev->drv_index, id);
930 if (IS_ERR(port->dev)) {
931 err = PTR_ERR(port->dev);
932 dev_err(&port->portdev->vdev->dev,
933 "Error %d creating device for port %u\n",
938 spin_lock_init(&port->inbuf_lock);
939 init_waitqueue_head(&port->waitqueue);
941 /* Fill the in_vq with buffers so the host can send us data. */
942 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
943 if (!nr_added_bufs) {
944 dev_err(port->dev, "Error allocating inbufs\n");
950 * If we're not using multiport support, this has to be a console port
952 if (!use_multiport(port->portdev)) {
953 err = init_port_console(port);
958 spin_lock_irq(&portdev->ports_lock);
959 list_add_tail(&port->list, &port->portdev->ports);
960 spin_unlock_irq(&portdev->ports_lock);
963 * Tell the Host we're set so that it can send us various
964 * configuration parameters for this port (eg, port name,
965 * caching, whether this is a console port, etc.)
967 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
969 if (pdrvdata.debugfs_dir) {
971 * Finally, create the debugfs file that we can use to
972 * inspect a port's state at any time
974 sprintf(debugfs_name, "vport%up%u",
975 port->portdev->drv_index, id);
976 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
977 pdrvdata.debugfs_dir,
984 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
987 device_destroy(pdrvdata.class, port->dev->devt);
989 cdev_del(&port->cdev);
993 /* The host might want to notify management sw about port add failure */
994 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 0);
998 /* Remove all port-specific data. */
999 static int remove_port(struct port *port)
1001 struct port_buffer *buf;
1003 spin_lock_irq(&port->portdev->ports_lock);
1004 list_del(&port->list);
1005 spin_unlock_irq(&port->portdev->ports_lock);
1007 if (is_console_port(port)) {
1008 spin_lock_irq(&pdrvdata_lock);
1009 list_del(&port->cons.list);
1010 spin_unlock_irq(&pdrvdata_lock);
1013 * hvc_remove() not called as removing one hvc port
1014 * results in other hvc ports getting frozen.
1016 * Once this is resolved in hvc, this functionality
1017 * will be enabled. Till that is done, the -EPIPE
1018 * return from get_chars() above will help
1019 * hvc_console.c to clean up on ports we remove here.
1021 hvc_remove(port->cons.hvc);
1024 if (port->guest_connected)
1025 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
1027 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1028 device_destroy(pdrvdata.class, port->dev->devt);
1029 cdev_del(&port->cdev);
1031 /* Remove unused data this port might have received. */
1032 discard_port_data(port);
1034 /* Remove buffers we queued up for the Host to send us data in. */
1035 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1040 debugfs_remove(port->debugfs_file);
1046 /* Any private messages that the Host and Guest want to share */
1047 static void handle_control_message(struct ports_device *portdev,
1048 struct port_buffer *buf)
1050 struct virtio_console_control *cpkt;
1055 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1057 port = find_port_by_id(portdev, cpkt->id);
1058 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1059 /* No valid header at start of buffer. Drop it. */
1060 dev_dbg(&portdev->vdev->dev,
1061 "Invalid index %u in control packet\n", cpkt->id);
1065 switch (cpkt->event) {
1066 case VIRTIO_CONSOLE_PORT_ADD:
1068 dev_dbg(&portdev->vdev->dev,
1069 "Port %u already added\n", port->id);
1070 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1073 if (cpkt->id >= portdev->config.max_nr_ports) {
1074 dev_warn(&portdev->vdev->dev,
1075 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1076 cpkt->id, portdev->config.max_nr_ports - 1);
1079 add_port(portdev, cpkt->id);
1081 case VIRTIO_CONSOLE_PORT_REMOVE:
1084 case VIRTIO_CONSOLE_CONSOLE_PORT:
1087 if (is_console_port(port))
1090 init_port_console(port);
1092 * Could remove the port here in case init fails - but
1093 * have to notify the host first.
1096 case VIRTIO_CONSOLE_RESIZE:
1097 if (!is_console_port(port))
1099 port->cons.hvc->irq_requested = 1;
1100 resize_console(port);
1102 case VIRTIO_CONSOLE_PORT_OPEN:
1103 port->host_connected = cpkt->value;
1104 wake_up_interruptible(&port->waitqueue);
1106 case VIRTIO_CONSOLE_PORT_NAME:
1108 * Skip the size of the header and the cpkt to get the size
1109 * of the name that was sent
1111 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1113 port->name = kmalloc(name_size, GFP_KERNEL);
1116 "Not enough space to store port name\n");
1119 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1121 port->name[name_size - 1] = 0;
1124 * Since we only have one sysfs attribute, 'name',
1125 * create it only if we have a name for the port.
1127 err = sysfs_create_group(&port->dev->kobj,
1128 &port_attribute_group);
1131 "Error %d creating sysfs device attributes\n",
1135 * Generate a udev event so that appropriate
1136 * symlinks can be created based on udev
1139 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1145 static void control_work_handler(struct work_struct *work)
1147 struct ports_device *portdev;
1148 struct virtqueue *vq;
1149 struct port_buffer *buf;
1152 portdev = container_of(work, struct ports_device, control_work);
1153 vq = portdev->c_ivq;
1155 spin_lock(&portdev->cvq_lock);
1156 while ((buf = virtqueue_get_buf(vq, &len))) {
1157 spin_unlock(&portdev->cvq_lock);
1162 handle_control_message(portdev, buf);
1164 spin_lock(&portdev->cvq_lock);
1165 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1166 dev_warn(&portdev->vdev->dev,
1167 "Error adding buffer to queue\n");
1171 spin_unlock(&portdev->cvq_lock);
1174 static void in_intr(struct virtqueue *vq)
1177 unsigned long flags;
1179 port = find_port_by_vq(vq->vdev->priv, vq);
1183 spin_lock_irqsave(&port->inbuf_lock, flags);
1185 port->inbuf = get_inbuf(port);
1188 * Don't queue up data when port is closed. This condition
1189 * can be reached when a console port is not yet connected (no
1190 * tty is spawned) and the host sends out data to console
1191 * ports. For generic serial ports, the host won't
1192 * (shouldn't) send data till the guest is connected.
1194 if (!port->guest_connected)
1195 discard_port_data(port);
1197 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1199 wake_up_interruptible(&port->waitqueue);
1201 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1205 static void control_intr(struct virtqueue *vq)
1207 struct ports_device *portdev;
1209 portdev = vq->vdev->priv;
1210 schedule_work(&portdev->control_work);
1213 static void config_intr(struct virtio_device *vdev)
1215 struct ports_device *portdev;
1217 portdev = vdev->priv;
1220 * We'll use this way of resizing only for legacy support.
1221 * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
1222 * control messages to indicate console size changes so that
1223 * it can be done per-port
1225 resize_console(find_port_by_id(portdev, 0));
1228 static int init_vqs(struct ports_device *portdev)
1230 vq_callback_t **io_callbacks;
1232 struct virtqueue **vqs;
1233 u32 i, j, nr_ports, nr_queues;
1236 nr_ports = portdev->config.max_nr_ports;
1237 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1239 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1244 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1245 if (!io_callbacks) {
1249 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1252 goto free_callbacks;
1254 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1256 if (!portdev->in_vqs) {
1260 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1262 if (!portdev->out_vqs) {
1268 * For backward compat (newer host but older guest), the host
1269 * spawns a console port first and also inits the vqs for port
1273 io_callbacks[j] = in_intr;
1274 io_callbacks[j + 1] = NULL;
1275 io_names[j] = "input";
1276 io_names[j + 1] = "output";
1279 if (use_multiport(portdev)) {
1280 io_callbacks[j] = control_intr;
1281 io_callbacks[j + 1] = NULL;
1282 io_names[j] = "control-i";
1283 io_names[j + 1] = "control-o";
1285 for (i = 1; i < nr_ports; i++) {
1287 io_callbacks[j] = in_intr;
1288 io_callbacks[j + 1] = NULL;
1289 io_names[j] = "input";
1290 io_names[j + 1] = "output";
1293 /* Find the queues. */
1294 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1296 (const char **)io_names);
1301 portdev->in_vqs[0] = vqs[0];
1302 portdev->out_vqs[0] = vqs[1];
1304 if (use_multiport(portdev)) {
1305 portdev->c_ivq = vqs[j];
1306 portdev->c_ovq = vqs[j + 1];
1308 for (i = 1; i < nr_ports; i++) {
1310 portdev->in_vqs[i] = vqs[j];
1311 portdev->out_vqs[i] = vqs[j + 1];
1314 kfree(io_callbacks);
1323 kfree(io_callbacks);
1325 kfree(portdev->out_vqs);
1327 kfree(portdev->in_vqs);
1334 static const struct file_operations portdev_fops = {
1335 .owner = THIS_MODULE,
1339 * Once we're further in boot, we get probed like any other virtio
1342 * If the host also supports multiple console ports, we check the
1343 * config space to see how many ports the host has spawned. We
1344 * initialize each port found.
1346 static int __devinit virtcons_probe(struct virtio_device *vdev)
1348 struct ports_device *portdev;
1352 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1358 /* Attach this portdev to this virtio_device, and vice-versa. */
1359 portdev->vdev = vdev;
1360 vdev->priv = portdev;
1362 spin_lock_irq(&pdrvdata_lock);
1363 portdev->drv_index = pdrvdata.index++;
1364 spin_unlock_irq(&pdrvdata_lock);
1366 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1368 if (portdev->chr_major < 0) {
1370 "Error %d registering chrdev for device %u\n",
1371 portdev->chr_major, portdev->drv_index);
1372 err = portdev->chr_major;
1377 portdev->config.max_nr_ports = 1;
1378 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1380 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1382 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1384 &portdev->config.max_nr_ports,
1385 sizeof(portdev->config.max_nr_ports));
1388 /* Let the Host know we support multiple ports.*/
1389 vdev->config->finalize_features(vdev);
1391 err = init_vqs(portdev);
1393 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1397 spin_lock_init(&portdev->ports_lock);
1398 INIT_LIST_HEAD(&portdev->ports);
1401 unsigned int nr_added_bufs;
1403 spin_lock_init(&portdev->cvq_lock);
1404 INIT_WORK(&portdev->control_work, &control_work_handler);
1406 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1407 if (!nr_added_bufs) {
1409 "Error allocating buffers for control queue\n");
1415 * For backward compatibility: Create a console port
1416 * if we're running on older host.
1418 add_port(portdev, 0);
1421 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1422 VIRTIO_CONSOLE_DEVICE_READY, 1);
1426 vdev->config->del_vqs(vdev);
1427 kfree(portdev->in_vqs);
1428 kfree(portdev->out_vqs);
1430 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1434 /* The host might want to notify mgmt sw about device add failure */
1435 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1436 VIRTIO_CONSOLE_DEVICE_READY, 0);
1440 static void virtcons_remove(struct virtio_device *vdev)
1442 struct ports_device *portdev;
1443 struct port *port, *port2;
1444 struct port_buffer *buf;
1447 portdev = vdev->priv;
1449 cancel_work_sync(&portdev->control_work);
1451 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1454 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1456 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1459 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1462 vdev->config->del_vqs(vdev);
1463 kfree(portdev->in_vqs);
1464 kfree(portdev->out_vqs);
1469 static struct virtio_device_id id_table[] = {
1470 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1474 static unsigned int features[] = {
1475 VIRTIO_CONSOLE_F_SIZE,
1476 VIRTIO_CONSOLE_F_MULTIPORT,
1479 static struct virtio_driver virtio_console = {
1480 .feature_table = features,
1481 .feature_table_size = ARRAY_SIZE(features),
1482 .driver.name = KBUILD_MODNAME,
1483 .driver.owner = THIS_MODULE,
1484 .id_table = id_table,
1485 .probe = virtcons_probe,
1486 .remove = virtcons_remove,
1487 .config_changed = config_intr,
1490 static int __init init(void)
1494 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1495 if (IS_ERR(pdrvdata.class)) {
1496 err = PTR_ERR(pdrvdata.class);
1497 pr_err("Error %d creating virtio-ports class\n", err);
1501 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1502 if (!pdrvdata.debugfs_dir) {
1503 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1504 PTR_ERR(pdrvdata.debugfs_dir));
1506 INIT_LIST_HEAD(&pdrvdata.consoles);
1508 return register_virtio_driver(&virtio_console);
1511 static void __exit fini(void)
1513 unregister_virtio_driver(&virtio_console);
1515 class_destroy(pdrvdata.class);
1516 if (pdrvdata.debugfs_dir)
1517 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1522 MODULE_DEVICE_TABLE(virtio, id_table);
1523 MODULE_DESCRIPTION("Virtio console driver");
1524 MODULE_LICENSE("GPL");