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;
81 /* The size of the console */
85 * This number identifies the number that we used to register
86 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
87 * number passed on by the hvc callbacks to us to
88 * differentiate between the other console ports handled by
97 /* size of the buffer in *buf above */
100 /* used length of the buffer */
102 /* offset in the buf from which to consume data */
107 * This is a per-device struct that stores data common to all the
108 * ports for that device (vdev->priv).
110 struct ports_device {
112 * Workqueue handlers where we process deferred work after
115 struct work_struct control_work;
117 struct list_head ports;
119 /* To protect the list of ports */
120 spinlock_t ports_lock;
122 /* To protect the vq operations for the control channel */
125 /* The current config space is stored here */
126 struct virtio_console_config config;
128 /* The virtio device we're associated with */
129 struct virtio_device *vdev;
132 * A couple of virtqueues for the control channel: one for
133 * guest->host transfers, one for host->guest transfers
135 struct virtqueue *c_ivq, *c_ovq;
137 /* Array of per-port IO virtqueues */
138 struct virtqueue **in_vqs, **out_vqs;
140 /* Used for numbering devices for sysfs and debugfs */
141 unsigned int drv_index;
143 /* Major number for this device. Ports will be created as minors. */
147 /* This struct holds the per-port data */
149 /* Next port in the list, head is in the ports_device */
150 struct list_head list;
152 /* Pointer to the parent virtio_console device */
153 struct ports_device *portdev;
155 /* The current buffer from which data has to be fed to readers */
156 struct port_buffer *inbuf;
159 * To protect the operations on the in_vq associated with this
160 * port. Has to be a spinlock because it can be called from
161 * interrupt context (get_char()).
163 spinlock_t inbuf_lock;
165 /* Protect the operations on the out_vq. */
166 spinlock_t outvq_lock;
168 /* The IO vqs for this port */
169 struct virtqueue *in_vq, *out_vq;
171 /* File in the debugfs directory that exposes this port's information */
172 struct dentry *debugfs_file;
175 * The entries in this struct will be valid if this port is
176 * hooked up to an hvc console
180 /* Each port associates with a separate char device */
184 /* A waitqueue for poll() or blocking read operations */
185 wait_queue_head_t waitqueue;
187 /* The 'name' of the port that we expose via sysfs properties */
190 /* The 'id' to identify the port with the Host */
195 /* Is the host device open */
198 /* We should allow only one process to open a port */
199 bool guest_connected;
202 /* This is the very early arch-specified put chars function. */
203 static int (*early_put_chars)(u32, const char *, int);
205 static struct port *find_port_by_vtermno(u32 vtermno)
208 struct console *cons;
211 spin_lock_irqsave(&pdrvdata_lock, flags);
212 list_for_each_entry(cons, &pdrvdata.consoles, list) {
213 if (cons->vtermno == vtermno) {
214 port = container_of(cons, struct port, cons);
220 spin_unlock_irqrestore(&pdrvdata_lock, flags);
224 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
229 spin_lock_irqsave(&portdev->ports_lock, flags);
230 list_for_each_entry(port, &portdev->ports, list)
235 spin_unlock_irqrestore(&portdev->ports_lock, flags);
240 static struct port *find_port_by_vq(struct ports_device *portdev,
241 struct virtqueue *vq)
246 spin_lock_irqsave(&portdev->ports_lock, flags);
247 list_for_each_entry(port, &portdev->ports, list)
248 if (port->in_vq == vq || port->out_vq == vq)
252 spin_unlock_irqrestore(&portdev->ports_lock, flags);
256 static bool is_console_port(struct port *port)
263 static inline bool use_multiport(struct ports_device *portdev)
266 * This condition can be true when put_chars is called from
271 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
274 static void free_buf(struct port_buffer *buf)
280 static struct port_buffer *alloc_buf(size_t buf_size)
282 struct port_buffer *buf;
284 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
287 buf->buf = kzalloc(buf_size, GFP_KERNEL);
292 buf->size = buf_size;
301 /* Callers should take appropriate locks */
302 static void *get_inbuf(struct port *port)
304 struct port_buffer *buf;
305 struct virtqueue *vq;
309 buf = virtqueue_get_buf(vq, &len);
318 * Create a scatter-gather list representing our input buffer and put
321 * Callers should take appropriate locks.
323 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
325 struct scatterlist sg[1];
328 sg_init_one(sg, buf->buf, buf->size);
330 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
335 /* Discard any unread data this port has. Callers lockers. */
336 static void discard_port_data(struct port *port)
338 struct port_buffer *buf;
339 struct virtqueue *vq;
347 buf = virtqueue_get_buf(vq, &len);
351 if (add_inbuf(vq, buf) < 0) {
355 buf = virtqueue_get_buf(vq, &len);
359 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
363 static bool port_has_data(struct port *port)
368 spin_lock_irqsave(&port->inbuf_lock, flags);
373 port->inbuf = get_inbuf(port);
380 spin_unlock_irqrestore(&port->inbuf_lock, flags);
384 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
385 unsigned int event, unsigned int value)
387 struct scatterlist sg[1];
388 struct virtio_console_control cpkt;
389 struct virtqueue *vq;
392 if (!use_multiport(portdev))
401 sg_init_one(sg, &cpkt, sizeof(cpkt));
402 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
404 while (!virtqueue_get_buf(vq, &len))
410 static ssize_t send_control_msg(struct port *port, unsigned int event,
413 /* Did the port get unplugged before userspace closed it? */
415 return __send_control_msg(port->portdev, port->id, event, value);
419 /* Callers must take the port->outvq_lock */
420 static void reclaim_consumed_buffers(struct port *port)
425 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
427 port->outvq_full = false;
431 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
434 struct scatterlist sg[1];
435 struct virtqueue *out_vq;
440 out_vq = port->out_vq;
442 spin_lock_irqsave(&port->outvq_lock, flags);
444 reclaim_consumed_buffers(port);
446 sg_init_one(sg, in_buf, in_count);
447 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
449 /* Tell Host to go! */
450 virtqueue_kick(out_vq);
458 port->outvq_full = true;
464 * Wait till the host acknowledges it pushed out the data we
465 * sent. This is done for data from the hvc_console; the tty
466 * operations are performed with spinlocks held so we can't
467 * sleep here. An alternative would be to copy the data to a
468 * buffer and relax the spinning requirement. The downside is
469 * we need to kmalloc a GFP_ATOMIC buffer each time the
470 * console driver writes something out.
472 while (!virtqueue_get_buf(out_vq, &len))
475 spin_unlock_irqrestore(&port->outvq_lock, flags);
477 * We're expected to return the amount of data we wrote -- all
484 * Give out the data that's requested from the buffer that we have
487 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
490 struct port_buffer *buf;
493 if (!out_count || !port_has_data(port))
497 out_count = min(out_count, buf->len - buf->offset);
502 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
506 memcpy(out_buf, buf->buf + buf->offset, out_count);
509 buf->offset += out_count;
511 if (buf->offset == buf->len) {
513 * We're done using all the data in this buffer.
514 * Re-queue so that the Host can send us more data.
516 spin_lock_irqsave(&port->inbuf_lock, flags);
519 if (add_inbuf(port->in_vq, buf) < 0)
520 dev_warn(port->dev, "failed add_buf\n");
522 spin_unlock_irqrestore(&port->inbuf_lock, flags);
524 /* Return the number of bytes actually copied */
528 /* The condition that must be true for polling to end */
529 static bool will_read_block(struct port *port)
531 return !port_has_data(port) && port->host_connected;
534 static bool will_write_block(struct port *port)
538 if (!port->guest_connected) {
539 /* Port got hot-unplugged. Let's exit. */
542 if (!port->host_connected)
545 spin_lock_irq(&port->outvq_lock);
547 * Check if the Host has consumed any buffers since we last
548 * sent data (this is only applicable for nonblocking ports).
550 reclaim_consumed_buffers(port);
551 ret = port->outvq_full;
552 spin_unlock_irq(&port->outvq_lock);
557 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
558 size_t count, loff_t *offp)
563 port = filp->private_data;
565 if (!port_has_data(port)) {
567 * If nothing's connected on the host just return 0 in
568 * case of list_empty; this tells the userspace app
569 * that there's no connection
571 if (!port->host_connected)
573 if (filp->f_flags & O_NONBLOCK)
576 ret = wait_event_interruptible(port->waitqueue,
577 !will_read_block(port));
582 * We could've received a disconnection message while we were
583 * waiting for more data.
585 * This check is not clubbed in the if() statement above as we
586 * might receive some data as well as the host could get
587 * disconnected after we got woken up from our wait. So we
588 * really want to give off whatever data we have and only then
589 * check for host_connected.
591 if (!port_has_data(port) && !port->host_connected)
594 return fill_readbuf(port, ubuf, count, true);
597 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
598 size_t count, loff_t *offp)
605 /* Userspace could be out to fool us */
609 port = filp->private_data;
611 nonblock = filp->f_flags & O_NONBLOCK;
613 if (will_write_block(port)) {
617 ret = wait_event_interruptible(port->waitqueue,
618 !will_write_block(port));
623 count = min((size_t)(32 * 1024), count);
625 buf = kmalloc(count, GFP_KERNEL);
629 ret = copy_from_user(buf, ubuf, count);
636 * We now ask send_buf() to not spin for generic ports -- we
637 * can re-use the same code path that non-blocking file
638 * descriptors take for blocking file descriptors since the
639 * wait is already done and we're certain the write will go
640 * through to the host.
643 ret = send_buf(port, buf, count, nonblock);
645 if (nonblock && ret > 0)
654 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
659 port = filp->private_data;
660 poll_wait(filp, &port->waitqueue, wait);
663 if (!will_read_block(port))
664 ret |= POLLIN | POLLRDNORM;
665 if (!will_write_block(port))
667 if (!port->host_connected)
673 static int port_fops_release(struct inode *inode, struct file *filp)
677 port = filp->private_data;
679 /* Notify host of port being closed */
680 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
682 spin_lock_irq(&port->inbuf_lock);
683 port->guest_connected = false;
685 discard_port_data(port);
687 spin_unlock_irq(&port->inbuf_lock);
689 spin_lock_irq(&port->outvq_lock);
690 reclaim_consumed_buffers(port);
691 spin_unlock_irq(&port->outvq_lock);
696 static int port_fops_open(struct inode *inode, struct file *filp)
698 struct cdev *cdev = inode->i_cdev;
701 port = container_of(cdev, struct port, cdev);
702 filp->private_data = port;
705 * Don't allow opening of console port devices -- that's done
708 if (is_console_port(port))
711 /* Allow only one process to open a particular port at a time */
712 spin_lock_irq(&port->inbuf_lock);
713 if (port->guest_connected) {
714 spin_unlock_irq(&port->inbuf_lock);
718 port->guest_connected = true;
719 spin_unlock_irq(&port->inbuf_lock);
721 spin_lock_irq(&port->outvq_lock);
723 * There might be a chance that we missed reclaiming a few
724 * buffers in the window of the port getting previously closed
727 reclaim_consumed_buffers(port);
728 spin_unlock_irq(&port->outvq_lock);
730 /* Notify host of port being opened */
731 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
737 * The file operations that we support: programs in the guest can open
738 * a console device, read from it, write to it, poll for data and
739 * close it. The devices are at
740 * /dev/vport<device number>p<port number>
742 static const struct file_operations port_fops = {
743 .owner = THIS_MODULE,
744 .open = port_fops_open,
745 .read = port_fops_read,
746 .write = port_fops_write,
747 .poll = port_fops_poll,
748 .release = port_fops_release,
752 * The put_chars() callback is pretty straightforward.
754 * We turn the characters into a scatter-gather list, add it to the
755 * output queue and then kick the Host. Then we sit here waiting for
756 * it to finish: inefficient in theory, but in practice
757 * implementations will do it immediately (lguest's Launcher does).
759 static int put_chars(u32 vtermno, const char *buf, int count)
763 if (unlikely(early_put_chars))
764 return early_put_chars(vtermno, buf, count);
766 port = find_port_by_vtermno(vtermno);
770 return send_buf(port, (void *)buf, count, false);
774 * get_chars() is the callback from the hvc_console infrastructure
775 * when an interrupt is received.
777 * We call out to fill_readbuf that gets us the required data from the
778 * buffers that are queued up.
780 static int get_chars(u32 vtermno, char *buf, int count)
784 /* If we've not set up the port yet, we have no input to give. */
785 if (unlikely(early_put_chars))
788 port = find_port_by_vtermno(vtermno);
792 /* If we don't have an input queue yet, we can't get input. */
793 BUG_ON(!port->in_vq);
795 return fill_readbuf(port, buf, count, false);
798 static void resize_console(struct port *port)
800 struct virtio_device *vdev;
802 /* The port could have been hot-unplugged */
803 if (!port || !is_console_port(port))
806 vdev = port->portdev->vdev;
807 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
808 hvc_resize(port->cons.hvc, port->cons.ws);
811 /* We set the configuration at this point, since we now have a tty */
812 static int notifier_add_vio(struct hvc_struct *hp, int data)
816 port = find_port_by_vtermno(hp->vtermno);
820 hp->irq_requested = 1;
821 resize_console(port);
826 static void notifier_del_vio(struct hvc_struct *hp, int data)
828 hp->irq_requested = 0;
831 /* The operations for console ports. */
832 static const struct hv_ops hv_ops = {
833 .get_chars = get_chars,
834 .put_chars = put_chars,
835 .notifier_add = notifier_add_vio,
836 .notifier_del = notifier_del_vio,
837 .notifier_hangup = notifier_del_vio,
841 * Console drivers are initialized very early so boot messages can go
842 * out, so we do things slightly differently from the generic virtio
843 * initialization of the net and block drivers.
845 * At this stage, the console is output-only. It's too early to set
846 * up a virtqueue, so we let the drivers do some boutique early-output
849 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
851 early_put_chars = put_chars;
852 return hvc_instantiate(0, 0, &hv_ops);
855 int init_port_console(struct port *port)
860 * The Host's telling us this port is a console port. Hook it
861 * up with an hvc console.
863 * To set up and manage our virtual console, we call
866 * The first argument of hvc_alloc() is the virtual console
867 * number. The second argument is the parameter for the
868 * notification mechanism (like irq number). We currently
869 * leave this as zero, virtqueues have implicit notifications.
871 * The third argument is a "struct hv_ops" containing the
872 * put_chars() get_chars(), notifier_add() and notifier_del()
873 * pointers. The final argument is the output buffer size: we
874 * can do any size, so we put PAGE_SIZE here.
876 port->cons.vtermno = pdrvdata.next_vtermno;
878 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
879 if (IS_ERR(port->cons.hvc)) {
880 ret = PTR_ERR(port->cons.hvc);
882 "error %d allocating hvc for port\n", ret);
883 port->cons.hvc = NULL;
886 spin_lock_irq(&pdrvdata_lock);
887 pdrvdata.next_vtermno++;
888 list_add_tail(&port->cons.list, &pdrvdata.consoles);
889 spin_unlock_irq(&pdrvdata_lock);
890 port->guest_connected = true;
893 * Start using the new console output if this is the first
894 * console to come up.
897 early_put_chars = NULL;
899 /* Notify host of port being opened */
900 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
905 static ssize_t show_port_name(struct device *dev,
906 struct device_attribute *attr, char *buffer)
910 port = dev_get_drvdata(dev);
912 return sprintf(buffer, "%s\n", port->name);
915 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
917 static struct attribute *port_sysfs_entries[] = {
922 static struct attribute_group port_attribute_group = {
923 .name = NULL, /* put in device directory */
924 .attrs = port_sysfs_entries,
927 static int debugfs_open(struct inode *inode, struct file *filp)
929 filp->private_data = inode->i_private;
933 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
934 size_t count, loff_t *offp)
938 ssize_t ret, out_offset, out_count;
941 buf = kmalloc(out_count, GFP_KERNEL);
945 port = filp->private_data;
947 out_offset += snprintf(buf + out_offset, out_count,
948 "name: %s\n", port->name ? port->name : "");
949 out_offset += snprintf(buf + out_offset, out_count - out_offset,
950 "guest_connected: %d\n", port->guest_connected);
951 out_offset += snprintf(buf + out_offset, out_count - out_offset,
952 "host_connected: %d\n", port->host_connected);
953 out_offset += snprintf(buf + out_offset, out_count - out_offset,
954 "outvq_full: %d\n", port->outvq_full);
955 out_offset += snprintf(buf + out_offset, out_count - out_offset,
957 is_console_port(port) ? "yes" : "no");
958 out_offset += snprintf(buf + out_offset, out_count - out_offset,
959 "console_vtermno: %u\n", port->cons.vtermno);
961 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
966 static const struct file_operations port_debugfs_ops = {
967 .owner = THIS_MODULE,
968 .open = debugfs_open,
969 .read = debugfs_read,
972 static void set_console_size(struct port *port, u16 rows, u16 cols)
974 if (!port || !is_console_port(port))
977 port->cons.ws.ws_row = rows;
978 port->cons.ws.ws_col = cols;
981 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
983 struct port_buffer *buf;
984 unsigned int nr_added_bufs;
989 buf = alloc_buf(PAGE_SIZE);
994 ret = add_inbuf(vq, buf);
996 spin_unlock_irq(lock);
1001 spin_unlock_irq(lock);
1004 return nr_added_bufs;
1007 static int add_port(struct ports_device *portdev, u32 id)
1009 char debugfs_name[16];
1011 struct port_buffer *buf;
1013 unsigned int nr_added_bufs;
1016 port = kmalloc(sizeof(*port), GFP_KERNEL);
1022 port->portdev = portdev;
1027 port->cons.hvc = NULL;
1029 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1031 port->host_connected = port->guest_connected = false;
1033 port->outvq_full = false;
1035 port->in_vq = portdev->in_vqs[port->id];
1036 port->out_vq = portdev->out_vqs[port->id];
1038 cdev_init(&port->cdev, &port_fops);
1040 devt = MKDEV(portdev->chr_major, id);
1041 err = cdev_add(&port->cdev, devt, 1);
1043 dev_err(&port->portdev->vdev->dev,
1044 "Error %d adding cdev for port %u\n", err, id);
1047 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1048 devt, port, "vport%up%u",
1049 port->portdev->drv_index, id);
1050 if (IS_ERR(port->dev)) {
1051 err = PTR_ERR(port->dev);
1052 dev_err(&port->portdev->vdev->dev,
1053 "Error %d creating device for port %u\n",
1058 spin_lock_init(&port->inbuf_lock);
1059 spin_lock_init(&port->outvq_lock);
1060 init_waitqueue_head(&port->waitqueue);
1062 /* Fill the in_vq with buffers so the host can send us data. */
1063 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1064 if (!nr_added_bufs) {
1065 dev_err(port->dev, "Error allocating inbufs\n");
1071 * If we're not using multiport support, this has to be a console port
1073 if (!use_multiport(port->portdev)) {
1074 err = init_port_console(port);
1079 spin_lock_irq(&portdev->ports_lock);
1080 list_add_tail(&port->list, &port->portdev->ports);
1081 spin_unlock_irq(&portdev->ports_lock);
1084 * Tell the Host we're set so that it can send us various
1085 * configuration parameters for this port (eg, port name,
1086 * caching, whether this is a console port, etc.)
1088 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1090 if (pdrvdata.debugfs_dir) {
1092 * Finally, create the debugfs file that we can use to
1093 * inspect a port's state at any time
1095 sprintf(debugfs_name, "vport%up%u",
1096 port->portdev->drv_index, id);
1097 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1098 pdrvdata.debugfs_dir,
1105 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1108 device_destroy(pdrvdata.class, port->dev->devt);
1110 cdev_del(&port->cdev);
1114 /* The host might want to notify management sw about port add failure */
1115 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1119 /* Remove all port-specific data. */
1120 static int remove_port(struct port *port)
1122 struct port_buffer *buf;
1124 if (port->guest_connected) {
1125 port->guest_connected = false;
1126 port->host_connected = false;
1127 wake_up_interruptible(&port->waitqueue);
1128 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
1131 spin_lock_irq(&port->portdev->ports_lock);
1132 list_del(&port->list);
1133 spin_unlock_irq(&port->portdev->ports_lock);
1135 if (is_console_port(port)) {
1136 spin_lock_irq(&pdrvdata_lock);
1137 list_del(&port->cons.list);
1138 spin_unlock_irq(&pdrvdata_lock);
1141 * hvc_remove() not called as removing one hvc port
1142 * results in other hvc ports getting frozen.
1144 * Once this is resolved in hvc, this functionality
1145 * will be enabled. Till that is done, the -EPIPE
1146 * return from get_chars() above will help
1147 * hvc_console.c to clean up on ports we remove here.
1149 hvc_remove(port->cons.hvc);
1152 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1153 device_destroy(pdrvdata.class, port->dev->devt);
1154 cdev_del(&port->cdev);
1156 /* Remove unused data this port might have received. */
1157 discard_port_data(port);
1159 reclaim_consumed_buffers(port);
1161 /* Remove buffers we queued up for the Host to send us data in. */
1162 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1167 debugfs_remove(port->debugfs_file);
1173 /* Any private messages that the Host and Guest want to share */
1174 static void handle_control_message(struct ports_device *portdev,
1175 struct port_buffer *buf)
1177 struct virtio_console_control *cpkt;
1182 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1184 port = find_port_by_id(portdev, cpkt->id);
1185 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1186 /* No valid header at start of buffer. Drop it. */
1187 dev_dbg(&portdev->vdev->dev,
1188 "Invalid index %u in control packet\n", cpkt->id);
1192 switch (cpkt->event) {
1193 case VIRTIO_CONSOLE_PORT_ADD:
1195 dev_dbg(&portdev->vdev->dev,
1196 "Port %u already added\n", port->id);
1197 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1200 if (cpkt->id >= portdev->config.max_nr_ports) {
1201 dev_warn(&portdev->vdev->dev,
1202 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1203 cpkt->id, portdev->config.max_nr_ports - 1);
1206 add_port(portdev, cpkt->id);
1208 case VIRTIO_CONSOLE_PORT_REMOVE:
1211 case VIRTIO_CONSOLE_CONSOLE_PORT:
1214 if (is_console_port(port))
1217 init_port_console(port);
1219 * Could remove the port here in case init fails - but
1220 * have to notify the host first.
1223 case VIRTIO_CONSOLE_RESIZE: {
1229 if (!is_console_port(port))
1232 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1234 set_console_size(port, size.rows, size.cols);
1236 port->cons.hvc->irq_requested = 1;
1237 resize_console(port);
1240 case VIRTIO_CONSOLE_PORT_OPEN:
1241 port->host_connected = cpkt->value;
1242 wake_up_interruptible(&port->waitqueue);
1244 * If the host port got closed and the host had any
1245 * unconsumed buffers, we'll be able to reclaim them
1248 spin_lock_irq(&port->outvq_lock);
1249 reclaim_consumed_buffers(port);
1250 spin_unlock_irq(&port->outvq_lock);
1252 case VIRTIO_CONSOLE_PORT_NAME:
1254 * Skip the size of the header and the cpkt to get the size
1255 * of the name that was sent
1257 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1259 port->name = kmalloc(name_size, GFP_KERNEL);
1262 "Not enough space to store port name\n");
1265 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1267 port->name[name_size - 1] = 0;
1270 * Since we only have one sysfs attribute, 'name',
1271 * create it only if we have a name for the port.
1273 err = sysfs_create_group(&port->dev->kobj,
1274 &port_attribute_group);
1277 "Error %d creating sysfs device attributes\n",
1281 * Generate a udev event so that appropriate
1282 * symlinks can be created based on udev
1285 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1291 static void control_work_handler(struct work_struct *work)
1293 struct ports_device *portdev;
1294 struct virtqueue *vq;
1295 struct port_buffer *buf;
1298 portdev = container_of(work, struct ports_device, control_work);
1299 vq = portdev->c_ivq;
1301 spin_lock(&portdev->cvq_lock);
1302 while ((buf = virtqueue_get_buf(vq, &len))) {
1303 spin_unlock(&portdev->cvq_lock);
1308 handle_control_message(portdev, buf);
1310 spin_lock(&portdev->cvq_lock);
1311 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1312 dev_warn(&portdev->vdev->dev,
1313 "Error adding buffer to queue\n");
1317 spin_unlock(&portdev->cvq_lock);
1320 static void in_intr(struct virtqueue *vq)
1323 unsigned long flags;
1325 port = find_port_by_vq(vq->vdev->priv, vq);
1329 spin_lock_irqsave(&port->inbuf_lock, flags);
1331 port->inbuf = get_inbuf(port);
1334 * Don't queue up data when port is closed. This condition
1335 * can be reached when a console port is not yet connected (no
1336 * tty is spawned) and the host sends out data to console
1337 * ports. For generic serial ports, the host won't
1338 * (shouldn't) send data till the guest is connected.
1340 if (!port->guest_connected)
1341 discard_port_data(port);
1343 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1345 wake_up_interruptible(&port->waitqueue);
1347 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1351 static void control_intr(struct virtqueue *vq)
1353 struct ports_device *portdev;
1355 portdev = vq->vdev->priv;
1356 schedule_work(&portdev->control_work);
1359 static void config_intr(struct virtio_device *vdev)
1361 struct ports_device *portdev;
1363 portdev = vdev->priv;
1365 if (!use_multiport(portdev)) {
1369 vdev->config->get(vdev,
1370 offsetof(struct virtio_console_config, cols),
1371 &cols, sizeof(u16));
1372 vdev->config->get(vdev,
1373 offsetof(struct virtio_console_config, rows),
1374 &rows, sizeof(u16));
1376 port = find_port_by_id(portdev, 0);
1377 set_console_size(port, rows, cols);
1380 * We'll use this way of resizing only for legacy
1381 * support. For newer userspace
1382 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1383 * to indicate console size changes so that it can be
1386 resize_console(port);
1390 static int init_vqs(struct ports_device *portdev)
1392 vq_callback_t **io_callbacks;
1394 struct virtqueue **vqs;
1395 u32 i, j, nr_ports, nr_queues;
1398 nr_ports = portdev->config.max_nr_ports;
1399 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1401 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1406 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1407 if (!io_callbacks) {
1411 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1414 goto free_callbacks;
1416 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1418 if (!portdev->in_vqs) {
1422 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1424 if (!portdev->out_vqs) {
1430 * For backward compat (newer host but older guest), the host
1431 * spawns a console port first and also inits the vqs for port
1435 io_callbacks[j] = in_intr;
1436 io_callbacks[j + 1] = NULL;
1437 io_names[j] = "input";
1438 io_names[j + 1] = "output";
1441 if (use_multiport(portdev)) {
1442 io_callbacks[j] = control_intr;
1443 io_callbacks[j + 1] = NULL;
1444 io_names[j] = "control-i";
1445 io_names[j + 1] = "control-o";
1447 for (i = 1; i < nr_ports; i++) {
1449 io_callbacks[j] = in_intr;
1450 io_callbacks[j + 1] = NULL;
1451 io_names[j] = "input";
1452 io_names[j + 1] = "output";
1455 /* Find the queues. */
1456 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1458 (const char **)io_names);
1463 portdev->in_vqs[0] = vqs[0];
1464 portdev->out_vqs[0] = vqs[1];
1466 if (use_multiport(portdev)) {
1467 portdev->c_ivq = vqs[j];
1468 portdev->c_ovq = vqs[j + 1];
1470 for (i = 1; i < nr_ports; i++) {
1472 portdev->in_vqs[i] = vqs[j];
1473 portdev->out_vqs[i] = vqs[j + 1];
1476 kfree(io_callbacks);
1485 kfree(io_callbacks);
1487 kfree(portdev->out_vqs);
1489 kfree(portdev->in_vqs);
1496 static const struct file_operations portdev_fops = {
1497 .owner = THIS_MODULE,
1501 * Once we're further in boot, we get probed like any other virtio
1504 * If the host also supports multiple console ports, we check the
1505 * config space to see how many ports the host has spawned. We
1506 * initialize each port found.
1508 static int __devinit virtcons_probe(struct virtio_device *vdev)
1510 struct ports_device *portdev;
1514 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1520 /* Attach this portdev to this virtio_device, and vice-versa. */
1521 portdev->vdev = vdev;
1522 vdev->priv = portdev;
1524 spin_lock_irq(&pdrvdata_lock);
1525 portdev->drv_index = pdrvdata.index++;
1526 spin_unlock_irq(&pdrvdata_lock);
1528 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1530 if (portdev->chr_major < 0) {
1532 "Error %d registering chrdev for device %u\n",
1533 portdev->chr_major, portdev->drv_index);
1534 err = portdev->chr_major;
1539 portdev->config.max_nr_ports = 1;
1540 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1542 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1544 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1546 &portdev->config.max_nr_ports,
1547 sizeof(portdev->config.max_nr_ports));
1550 /* Let the Host know we support multiple ports.*/
1551 vdev->config->finalize_features(vdev);
1553 err = init_vqs(portdev);
1555 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1559 spin_lock_init(&portdev->ports_lock);
1560 INIT_LIST_HEAD(&portdev->ports);
1563 unsigned int nr_added_bufs;
1565 spin_lock_init(&portdev->cvq_lock);
1566 INIT_WORK(&portdev->control_work, &control_work_handler);
1568 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1569 if (!nr_added_bufs) {
1571 "Error allocating buffers for control queue\n");
1577 * For backward compatibility: Create a console port
1578 * if we're running on older host.
1580 add_port(portdev, 0);
1583 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1584 VIRTIO_CONSOLE_DEVICE_READY, 1);
1588 /* The host might want to notify mgmt sw about device add failure */
1589 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1590 VIRTIO_CONSOLE_DEVICE_READY, 0);
1591 vdev->config->del_vqs(vdev);
1592 kfree(portdev->in_vqs);
1593 kfree(portdev->out_vqs);
1595 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1602 static void virtcons_remove(struct virtio_device *vdev)
1604 struct ports_device *portdev;
1605 struct port *port, *port2;
1607 portdev = vdev->priv;
1609 /* Disable interrupts for vqs */
1610 vdev->config->reset(vdev);
1611 /* Finish up work that's lined up */
1612 cancel_work_sync(&portdev->control_work);
1614 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1617 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1619 if (use_multiport(portdev)) {
1620 struct port_buffer *buf;
1623 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1626 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1630 vdev->config->del_vqs(vdev);
1631 kfree(portdev->in_vqs);
1632 kfree(portdev->out_vqs);
1637 static struct virtio_device_id id_table[] = {
1638 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1642 static unsigned int features[] = {
1643 VIRTIO_CONSOLE_F_SIZE,
1644 VIRTIO_CONSOLE_F_MULTIPORT,
1647 static struct virtio_driver virtio_console = {
1648 .feature_table = features,
1649 .feature_table_size = ARRAY_SIZE(features),
1650 .driver.name = KBUILD_MODNAME,
1651 .driver.owner = THIS_MODULE,
1652 .id_table = id_table,
1653 .probe = virtcons_probe,
1654 .remove = virtcons_remove,
1655 .config_changed = config_intr,
1658 static int __init init(void)
1662 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1663 if (IS_ERR(pdrvdata.class)) {
1664 err = PTR_ERR(pdrvdata.class);
1665 pr_err("Error %d creating virtio-ports class\n", err);
1669 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1670 if (!pdrvdata.debugfs_dir) {
1671 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1672 PTR_ERR(pdrvdata.debugfs_dir));
1674 INIT_LIST_HEAD(&pdrvdata.consoles);
1676 return register_virtio_driver(&virtio_console);
1679 static void __exit fini(void)
1681 unregister_virtio_driver(&virtio_console);
1683 class_destroy(pdrvdata.class);
1684 if (pdrvdata.debugfs_dir)
1685 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1690 MODULE_DEVICE_TABLE(virtio, id_table);
1691 MODULE_DESCRIPTION("Virtio console driver");
1692 MODULE_LICENSE("GPL");