2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
4 * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 #include <linux/cdev.h>
21 #include <linux/debugfs.h>
22 #include <linux/device.h>
23 #include <linux/err.h>
25 #include <linux/init.h>
26 #include <linux/list.h>
27 #include <linux/poll.h>
28 #include <linux/sched.h>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
31 #include <linux/virtio.h>
32 #include <linux/virtio_console.h>
33 #include <linux/wait.h>
34 #include <linux/workqueue.h>
35 #include "../tty/hvc/hvc_console.h"
38 * This is a global struct for storing common data for all the devices
39 * this driver handles.
41 * Mainly, it has a linked list for all the consoles in one place so
42 * that callbacks from hvc for get_chars(), put_chars() work properly
43 * across multiple devices and multiple ports per device.
45 struct ports_driver_data {
46 /* Used for registering chardevs */
49 /* Used for exporting per-port information to debugfs */
50 struct dentry *debugfs_dir;
52 /* List of all the devices we're handling */
53 struct list_head portdevs;
55 /* Number of devices this driver is handling */
59 * This is used to keep track of the number of hvc consoles
60 * spawned by this driver. This number is given as the first
61 * argument to hvc_alloc(). To correctly map an initial
62 * console spawned via hvc_instantiate to the console being
63 * hooked up via hvc_alloc, we need to pass the same vtermno.
65 * We also just assume the first console being initialised was
66 * the first one that got used as the initial console.
68 unsigned int next_vtermno;
70 /* All the console devices handled by this driver */
71 struct list_head consoles;
73 static struct ports_driver_data pdrvdata;
75 DEFINE_SPINLOCK(pdrvdata_lock);
77 /* This struct holds information that's relevant only for console ports */
79 /* We'll place all consoles in a list in the pdrvdata struct */
80 struct list_head list;
82 /* The hvc device associated with this console port */
83 struct hvc_struct *hvc;
85 /* The size of the console */
89 * This number identifies the number that we used to register
90 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
91 * number passed on by the hvc callbacks to us to
92 * differentiate between the other console ports handled by
101 /* size of the buffer in *buf above */
104 /* used length of the buffer */
106 /* offset in the buf from which to consume data */
111 * This is a per-device struct that stores data common to all the
112 * ports for that device (vdev->priv).
114 struct ports_device {
115 /* Next portdev in the list, head is in the pdrvdata struct */
116 struct list_head list;
119 * Workqueue handlers where we process deferred work after
122 struct work_struct control_work;
124 struct list_head ports;
126 /* To protect the list of ports */
127 spinlock_t ports_lock;
129 /* To protect the vq operations for the control channel */
132 /* The current config space is stored here */
133 struct virtio_console_config config;
135 /* The virtio device we're associated with */
136 struct virtio_device *vdev;
139 * A couple of virtqueues for the control channel: one for
140 * guest->host transfers, one for host->guest transfers
142 struct virtqueue *c_ivq, *c_ovq;
144 /* Array of per-port IO virtqueues */
145 struct virtqueue **in_vqs, **out_vqs;
147 /* Used for numbering devices for sysfs and debugfs */
148 unsigned int drv_index;
150 /* Major number for this device. Ports will be created as minors. */
154 /* This struct holds the per-port data */
156 /* Next port in the list, head is in the ports_device */
157 struct list_head list;
159 /* Pointer to the parent virtio_console device */
160 struct ports_device *portdev;
162 /* The current buffer from which data has to be fed to readers */
163 struct port_buffer *inbuf;
166 * To protect the operations on the in_vq associated with this
167 * port. Has to be a spinlock because it can be called from
168 * interrupt context (get_char()).
170 spinlock_t inbuf_lock;
172 /* Protect the operations on the out_vq. */
173 spinlock_t outvq_lock;
175 /* The IO vqs for this port */
176 struct virtqueue *in_vq, *out_vq;
178 /* File in the debugfs directory that exposes this port's information */
179 struct dentry *debugfs_file;
182 * The entries in this struct will be valid if this port is
183 * hooked up to an hvc console
187 /* Each port associates with a separate char device */
191 /* Reference-counting to handle port hot-unplugs and file operations */
194 /* A waitqueue for poll() or blocking read operations */
195 wait_queue_head_t waitqueue;
197 /* The 'name' of the port that we expose via sysfs properties */
200 /* We can notify apps of host connect / disconnect events via SIGIO */
201 struct fasync_struct *async_queue;
203 /* The 'id' to identify the port with the Host */
208 /* Is the host device open */
211 /* We should allow only one process to open a port */
212 bool guest_connected;
215 /* This is the very early arch-specified put chars function. */
216 static int (*early_put_chars)(u32, const char *, int);
218 static struct port *find_port_by_vtermno(u32 vtermno)
221 struct console *cons;
224 spin_lock_irqsave(&pdrvdata_lock, flags);
225 list_for_each_entry(cons, &pdrvdata.consoles, list) {
226 if (cons->vtermno == vtermno) {
227 port = container_of(cons, struct port, cons);
233 spin_unlock_irqrestore(&pdrvdata_lock, flags);
237 static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
243 spin_lock_irqsave(&portdev->ports_lock, flags);
244 list_for_each_entry(port, &portdev->ports, list)
245 if (port->cdev->dev == dev)
249 spin_unlock_irqrestore(&portdev->ports_lock, flags);
254 static struct port *find_port_by_devt(dev_t dev)
256 struct ports_device *portdev;
260 spin_lock_irqsave(&pdrvdata_lock, flags);
261 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
262 port = find_port_by_devt_in_portdev(portdev, dev);
268 spin_unlock_irqrestore(&pdrvdata_lock, flags);
272 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
277 spin_lock_irqsave(&portdev->ports_lock, flags);
278 list_for_each_entry(port, &portdev->ports, list)
283 spin_unlock_irqrestore(&portdev->ports_lock, flags);
288 static struct port *find_port_by_vq(struct ports_device *portdev,
289 struct virtqueue *vq)
294 spin_lock_irqsave(&portdev->ports_lock, flags);
295 list_for_each_entry(port, &portdev->ports, list)
296 if (port->in_vq == vq || port->out_vq == vq)
300 spin_unlock_irqrestore(&portdev->ports_lock, flags);
304 static bool is_console_port(struct port *port)
311 static inline bool use_multiport(struct ports_device *portdev)
314 * This condition can be true when put_chars is called from
319 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
322 static void free_buf(struct port_buffer *buf)
328 static struct port_buffer *alloc_buf(size_t buf_size)
330 struct port_buffer *buf;
332 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
335 buf->buf = kzalloc(buf_size, GFP_KERNEL);
340 buf->size = buf_size;
349 /* Callers should take appropriate locks */
350 static void *get_inbuf(struct port *port)
352 struct port_buffer *buf;
353 struct virtqueue *vq;
357 buf = virtqueue_get_buf(vq, &len);
366 * Create a scatter-gather list representing our input buffer and put
369 * Callers should take appropriate locks.
371 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
373 struct scatterlist sg[1];
376 sg_init_one(sg, buf->buf, buf->size);
378 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
383 /* Discard any unread data this port has. Callers lockers. */
384 static void discard_port_data(struct port *port)
386 struct port_buffer *buf;
387 struct virtqueue *vq;
391 if (!port->portdev) {
392 /* Device has been unplugged. vqs are already gone. */
399 buf = virtqueue_get_buf(vq, &len);
403 if (add_inbuf(vq, buf) < 0) {
407 buf = virtqueue_get_buf(vq, &len);
411 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
415 static bool port_has_data(struct port *port)
420 spin_lock_irqsave(&port->inbuf_lock, flags);
425 port->inbuf = get_inbuf(port);
432 spin_unlock_irqrestore(&port->inbuf_lock, flags);
436 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
437 unsigned int event, unsigned int value)
439 struct scatterlist sg[1];
440 struct virtio_console_control cpkt;
441 struct virtqueue *vq;
444 if (!use_multiport(portdev))
453 sg_init_one(sg, &cpkt, sizeof(cpkt));
454 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
456 while (!virtqueue_get_buf(vq, &len))
462 static ssize_t send_control_msg(struct port *port, unsigned int event,
465 /* Did the port get unplugged before userspace closed it? */
467 return __send_control_msg(port->portdev, port->id, event, value);
471 /* Callers must take the port->outvq_lock */
472 static void reclaim_consumed_buffers(struct port *port)
477 if (!port->portdev) {
478 /* Device has been unplugged. vqs are already gone. */
481 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
483 port->outvq_full = false;
487 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
490 struct scatterlist sg[1];
491 struct virtqueue *out_vq;
496 out_vq = port->out_vq;
498 spin_lock_irqsave(&port->outvq_lock, flags);
500 reclaim_consumed_buffers(port);
502 sg_init_one(sg, in_buf, in_count);
503 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
505 /* Tell Host to go! */
506 virtqueue_kick(out_vq);
514 port->outvq_full = true;
520 * Wait till the host acknowledges it pushed out the data we
521 * sent. This is done for data from the hvc_console; the tty
522 * operations are performed with spinlocks held so we can't
523 * sleep here. An alternative would be to copy the data to a
524 * buffer and relax the spinning requirement. The downside is
525 * we need to kmalloc a GFP_ATOMIC buffer each time the
526 * console driver writes something out.
528 while (!virtqueue_get_buf(out_vq, &len))
531 spin_unlock_irqrestore(&port->outvq_lock, flags);
533 * We're expected to return the amount of data we wrote -- all
540 * Give out the data that's requested from the buffer that we have
543 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
546 struct port_buffer *buf;
549 if (!out_count || !port_has_data(port))
553 out_count = min(out_count, buf->len - buf->offset);
558 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
562 memcpy(out_buf, buf->buf + buf->offset, out_count);
565 buf->offset += out_count;
567 if (buf->offset == buf->len) {
569 * We're done using all the data in this buffer.
570 * Re-queue so that the Host can send us more data.
572 spin_lock_irqsave(&port->inbuf_lock, flags);
575 if (add_inbuf(port->in_vq, buf) < 0)
576 dev_warn(port->dev, "failed add_buf\n");
578 spin_unlock_irqrestore(&port->inbuf_lock, flags);
580 /* Return the number of bytes actually copied */
584 /* The condition that must be true for polling to end */
585 static bool will_read_block(struct port *port)
587 if (!port->guest_connected) {
588 /* Port got hot-unplugged. Let's exit. */
591 return !port_has_data(port) && port->host_connected;
594 static bool will_write_block(struct port *port)
598 if (!port->guest_connected) {
599 /* Port got hot-unplugged. Let's exit. */
602 if (!port->host_connected)
605 spin_lock_irq(&port->outvq_lock);
607 * Check if the Host has consumed any buffers since we last
608 * sent data (this is only applicable for nonblocking ports).
610 reclaim_consumed_buffers(port);
611 ret = port->outvq_full;
612 spin_unlock_irq(&port->outvq_lock);
617 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
618 size_t count, loff_t *offp)
623 port = filp->private_data;
625 if (!port_has_data(port)) {
627 * If nothing's connected on the host just return 0 in
628 * case of list_empty; this tells the userspace app
629 * that there's no connection
631 if (!port->host_connected)
633 if (filp->f_flags & O_NONBLOCK)
636 ret = wait_event_interruptible(port->waitqueue,
637 !will_read_block(port));
641 /* Port got hot-unplugged. */
642 if (!port->guest_connected)
645 * We could've received a disconnection message while we were
646 * waiting for more data.
648 * This check is not clubbed in the if() statement above as we
649 * might receive some data as well as the host could get
650 * disconnected after we got woken up from our wait. So we
651 * really want to give off whatever data we have and only then
652 * check for host_connected.
654 if (!port_has_data(port) && !port->host_connected)
657 return fill_readbuf(port, ubuf, count, true);
660 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
661 size_t count, loff_t *offp)
668 /* Userspace could be out to fool us */
672 port = filp->private_data;
674 nonblock = filp->f_flags & O_NONBLOCK;
676 if (will_write_block(port)) {
680 ret = wait_event_interruptible(port->waitqueue,
681 !will_write_block(port));
685 /* Port got hot-unplugged. */
686 if (!port->guest_connected)
689 count = min((size_t)(32 * 1024), count);
691 buf = kmalloc(count, GFP_KERNEL);
695 ret = copy_from_user(buf, ubuf, count);
702 * We now ask send_buf() to not spin for generic ports -- we
703 * can re-use the same code path that non-blocking file
704 * descriptors take for blocking file descriptors since the
705 * wait is already done and we're certain the write will go
706 * through to the host.
709 ret = send_buf(port, buf, count, nonblock);
711 if (nonblock && ret > 0)
720 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
725 port = filp->private_data;
726 poll_wait(filp, &port->waitqueue, wait);
728 if (!port->guest_connected) {
729 /* Port got unplugged */
733 if (!will_read_block(port))
734 ret |= POLLIN | POLLRDNORM;
735 if (!will_write_block(port))
737 if (!port->host_connected)
743 static void remove_port(struct kref *kref);
745 static int port_fops_release(struct inode *inode, struct file *filp)
749 port = filp->private_data;
751 /* Notify host of port being closed */
752 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
754 spin_lock_irq(&port->inbuf_lock);
755 port->guest_connected = false;
757 discard_port_data(port);
759 spin_unlock_irq(&port->inbuf_lock);
761 spin_lock_irq(&port->outvq_lock);
762 reclaim_consumed_buffers(port);
763 spin_unlock_irq(&port->outvq_lock);
766 * Locks aren't necessary here as a port can't be opened after
767 * unplug, and if a port isn't unplugged, a kref would already
768 * exist for the port. Plus, taking ports_lock here would
769 * create a dependency on other locks taken by functions
770 * inside remove_port if we're the last holder of the port,
771 * creating many problems.
773 kref_put(&port->kref, remove_port);
778 static int port_fops_open(struct inode *inode, struct file *filp)
780 struct cdev *cdev = inode->i_cdev;
784 port = find_port_by_devt(cdev->dev);
785 filp->private_data = port;
787 /* Prevent against a port getting hot-unplugged at the same time */
788 spin_lock_irq(&port->portdev->ports_lock);
789 kref_get(&port->kref);
790 spin_unlock_irq(&port->portdev->ports_lock);
793 * Don't allow opening of console port devices -- that's done
796 if (is_console_port(port)) {
801 /* Allow only one process to open a particular port at a time */
802 spin_lock_irq(&port->inbuf_lock);
803 if (port->guest_connected) {
804 spin_unlock_irq(&port->inbuf_lock);
809 port->guest_connected = true;
810 spin_unlock_irq(&port->inbuf_lock);
812 spin_lock_irq(&port->outvq_lock);
814 * There might be a chance that we missed reclaiming a few
815 * buffers in the window of the port getting previously closed
818 reclaim_consumed_buffers(port);
819 spin_unlock_irq(&port->outvq_lock);
821 nonseekable_open(inode, filp);
823 /* Notify host of port being opened */
824 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
828 kref_put(&port->kref, remove_port);
832 static int port_fops_fasync(int fd, struct file *filp, int mode)
836 port = filp->private_data;
837 return fasync_helper(fd, filp, mode, &port->async_queue);
841 * The file operations that we support: programs in the guest can open
842 * a console device, read from it, write to it, poll for data and
843 * close it. The devices are at
844 * /dev/vport<device number>p<port number>
846 static const struct file_operations port_fops = {
847 .owner = THIS_MODULE,
848 .open = port_fops_open,
849 .read = port_fops_read,
850 .write = port_fops_write,
851 .poll = port_fops_poll,
852 .release = port_fops_release,
853 .fasync = port_fops_fasync,
858 * The put_chars() callback is pretty straightforward.
860 * We turn the characters into a scatter-gather list, add it to the
861 * output queue and then kick the Host. Then we sit here waiting for
862 * it to finish: inefficient in theory, but in practice
863 * implementations will do it immediately (lguest's Launcher does).
865 static int put_chars(u32 vtermno, const char *buf, int count)
869 if (unlikely(early_put_chars))
870 return early_put_chars(vtermno, buf, count);
872 port = find_port_by_vtermno(vtermno);
876 return send_buf(port, (void *)buf, count, false);
880 * get_chars() is the callback from the hvc_console infrastructure
881 * when an interrupt is received.
883 * We call out to fill_readbuf that gets us the required data from the
884 * buffers that are queued up.
886 static int get_chars(u32 vtermno, char *buf, int count)
890 /* If we've not set up the port yet, we have no input to give. */
891 if (unlikely(early_put_chars))
894 port = find_port_by_vtermno(vtermno);
898 /* If we don't have an input queue yet, we can't get input. */
899 BUG_ON(!port->in_vq);
901 return fill_readbuf(port, buf, count, false);
904 static void resize_console(struct port *port)
906 struct virtio_device *vdev;
908 /* The port could have been hot-unplugged */
909 if (!port || !is_console_port(port))
912 vdev = port->portdev->vdev;
913 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
914 hvc_resize(port->cons.hvc, port->cons.ws);
917 /* We set the configuration at this point, since we now have a tty */
918 static int notifier_add_vio(struct hvc_struct *hp, int data)
922 port = find_port_by_vtermno(hp->vtermno);
926 hp->irq_requested = 1;
927 resize_console(port);
932 static void notifier_del_vio(struct hvc_struct *hp, int data)
934 hp->irq_requested = 0;
937 /* The operations for console ports. */
938 static const struct hv_ops hv_ops = {
939 .get_chars = get_chars,
940 .put_chars = put_chars,
941 .notifier_add = notifier_add_vio,
942 .notifier_del = notifier_del_vio,
943 .notifier_hangup = notifier_del_vio,
947 * Console drivers are initialized very early so boot messages can go
948 * out, so we do things slightly differently from the generic virtio
949 * initialization of the net and block drivers.
951 * At this stage, the console is output-only. It's too early to set
952 * up a virtqueue, so we let the drivers do some boutique early-output
955 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
957 early_put_chars = put_chars;
958 return hvc_instantiate(0, 0, &hv_ops);
961 int init_port_console(struct port *port)
966 * The Host's telling us this port is a console port. Hook it
967 * up with an hvc console.
969 * To set up and manage our virtual console, we call
972 * The first argument of hvc_alloc() is the virtual console
973 * number. The second argument is the parameter for the
974 * notification mechanism (like irq number). We currently
975 * leave this as zero, virtqueues have implicit notifications.
977 * The third argument is a "struct hv_ops" containing the
978 * put_chars() get_chars(), notifier_add() and notifier_del()
979 * pointers. The final argument is the output buffer size: we
980 * can do any size, so we put PAGE_SIZE here.
982 port->cons.vtermno = pdrvdata.next_vtermno;
984 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
985 if (IS_ERR(port->cons.hvc)) {
986 ret = PTR_ERR(port->cons.hvc);
988 "error %d allocating hvc for port\n", ret);
989 port->cons.hvc = NULL;
992 spin_lock_irq(&pdrvdata_lock);
993 pdrvdata.next_vtermno++;
994 list_add_tail(&port->cons.list, &pdrvdata.consoles);
995 spin_unlock_irq(&pdrvdata_lock);
996 port->guest_connected = true;
999 * Start using the new console output if this is the first
1000 * console to come up.
1002 if (early_put_chars)
1003 early_put_chars = NULL;
1005 /* Notify host of port being opened */
1006 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1011 static ssize_t show_port_name(struct device *dev,
1012 struct device_attribute *attr, char *buffer)
1016 port = dev_get_drvdata(dev);
1018 return sprintf(buffer, "%s\n", port->name);
1021 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1023 static struct attribute *port_sysfs_entries[] = {
1024 &dev_attr_name.attr,
1028 static struct attribute_group port_attribute_group = {
1029 .name = NULL, /* put in device directory */
1030 .attrs = port_sysfs_entries,
1033 static int debugfs_open(struct inode *inode, struct file *filp)
1035 filp->private_data = inode->i_private;
1039 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1040 size_t count, loff_t *offp)
1044 ssize_t ret, out_offset, out_count;
1047 buf = kmalloc(out_count, GFP_KERNEL);
1051 port = filp->private_data;
1053 out_offset += snprintf(buf + out_offset, out_count,
1054 "name: %s\n", port->name ? port->name : "");
1055 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1056 "guest_connected: %d\n", port->guest_connected);
1057 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1058 "host_connected: %d\n", port->host_connected);
1059 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1060 "outvq_full: %d\n", port->outvq_full);
1061 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1063 is_console_port(port) ? "yes" : "no");
1064 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1065 "console_vtermno: %u\n", port->cons.vtermno);
1067 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1072 static const struct file_operations port_debugfs_ops = {
1073 .owner = THIS_MODULE,
1074 .open = debugfs_open,
1075 .read = debugfs_read,
1078 static void set_console_size(struct port *port, u16 rows, u16 cols)
1080 if (!port || !is_console_port(port))
1083 port->cons.ws.ws_row = rows;
1084 port->cons.ws.ws_col = cols;
1087 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1089 struct port_buffer *buf;
1090 unsigned int nr_added_bufs;
1095 buf = alloc_buf(PAGE_SIZE);
1099 spin_lock_irq(lock);
1100 ret = add_inbuf(vq, buf);
1102 spin_unlock_irq(lock);
1107 spin_unlock_irq(lock);
1110 return nr_added_bufs;
1113 static void send_sigio_to_port(struct port *port)
1115 if (port->async_queue && port->guest_connected)
1116 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1119 static int add_port(struct ports_device *portdev, u32 id)
1121 char debugfs_name[16];
1123 struct port_buffer *buf;
1125 unsigned int nr_added_bufs;
1128 port = kmalloc(sizeof(*port), GFP_KERNEL);
1133 kref_init(&port->kref);
1135 port->portdev = portdev;
1140 port->cons.hvc = NULL;
1141 port->async_queue = NULL;
1143 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1145 port->host_connected = port->guest_connected = false;
1147 port->outvq_full = false;
1149 port->in_vq = portdev->in_vqs[port->id];
1150 port->out_vq = portdev->out_vqs[port->id];
1152 port->cdev = cdev_alloc();
1154 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1158 port->cdev->ops = &port_fops;
1160 devt = MKDEV(portdev->chr_major, id);
1161 err = cdev_add(port->cdev, devt, 1);
1163 dev_err(&port->portdev->vdev->dev,
1164 "Error %d adding cdev for port %u\n", err, id);
1167 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1168 devt, port, "vport%up%u",
1169 port->portdev->drv_index, id);
1170 if (IS_ERR(port->dev)) {
1171 err = PTR_ERR(port->dev);
1172 dev_err(&port->portdev->vdev->dev,
1173 "Error %d creating device for port %u\n",
1178 spin_lock_init(&port->inbuf_lock);
1179 spin_lock_init(&port->outvq_lock);
1180 init_waitqueue_head(&port->waitqueue);
1182 /* Fill the in_vq with buffers so the host can send us data. */
1183 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1184 if (!nr_added_bufs) {
1185 dev_err(port->dev, "Error allocating inbufs\n");
1191 * If we're not using multiport support, this has to be a console port
1193 if (!use_multiport(port->portdev)) {
1194 err = init_port_console(port);
1199 spin_lock_irq(&portdev->ports_lock);
1200 list_add_tail(&port->list, &port->portdev->ports);
1201 spin_unlock_irq(&portdev->ports_lock);
1204 * Tell the Host we're set so that it can send us various
1205 * configuration parameters for this port (eg, port name,
1206 * caching, whether this is a console port, etc.)
1208 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1210 if (pdrvdata.debugfs_dir) {
1212 * Finally, create the debugfs file that we can use to
1213 * inspect a port's state at any time
1215 sprintf(debugfs_name, "vport%up%u",
1216 port->portdev->drv_index, id);
1217 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1218 pdrvdata.debugfs_dir,
1225 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1228 device_destroy(pdrvdata.class, port->dev->devt);
1230 cdev_del(port->cdev);
1234 /* The host might want to notify management sw about port add failure */
1235 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1239 /* No users remain, remove all port-specific data. */
1240 static void remove_port(struct kref *kref)
1244 port = container_of(kref, struct port, kref);
1246 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1247 device_destroy(pdrvdata.class, port->dev->devt);
1248 cdev_del(port->cdev);
1252 debugfs_remove(port->debugfs_file);
1258 * Port got unplugged. Remove port from portdev's list and drop the
1259 * kref reference. If no userspace has this port opened, it will
1260 * result in immediate removal the port.
1262 static void unplug_port(struct port *port)
1264 struct port_buffer *buf;
1266 spin_lock_irq(&port->portdev->ports_lock);
1267 list_del(&port->list);
1268 spin_unlock_irq(&port->portdev->ports_lock);
1270 if (port->guest_connected) {
1271 port->guest_connected = false;
1272 port->host_connected = false;
1273 wake_up_interruptible(&port->waitqueue);
1275 /* Let the app know the port is going down. */
1276 send_sigio_to_port(port);
1279 if (is_console_port(port)) {
1280 spin_lock_irq(&pdrvdata_lock);
1281 list_del(&port->cons.list);
1282 spin_unlock_irq(&pdrvdata_lock);
1283 hvc_remove(port->cons.hvc);
1286 /* Remove unused data this port might have received. */
1287 discard_port_data(port);
1289 reclaim_consumed_buffers(port);
1291 /* Remove buffers we queued up for the Host to send us data in. */
1292 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1296 * We should just assume the device itself has gone off --
1297 * else a close on an open port later will try to send out a
1300 port->portdev = NULL;
1303 * Locks around here are not necessary - a port can't be
1304 * opened after we removed the port struct from ports_list
1307 kref_put(&port->kref, remove_port);
1310 /* Any private messages that the Host and Guest want to share */
1311 static void handle_control_message(struct ports_device *portdev,
1312 struct port_buffer *buf)
1314 struct virtio_console_control *cpkt;
1319 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1321 port = find_port_by_id(portdev, cpkt->id);
1322 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1323 /* No valid header at start of buffer. Drop it. */
1324 dev_dbg(&portdev->vdev->dev,
1325 "Invalid index %u in control packet\n", cpkt->id);
1329 switch (cpkt->event) {
1330 case VIRTIO_CONSOLE_PORT_ADD:
1332 dev_dbg(&portdev->vdev->dev,
1333 "Port %u already added\n", port->id);
1334 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1337 if (cpkt->id >= portdev->config.max_nr_ports) {
1338 dev_warn(&portdev->vdev->dev,
1339 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1340 cpkt->id, portdev->config.max_nr_ports - 1);
1343 add_port(portdev, cpkt->id);
1345 case VIRTIO_CONSOLE_PORT_REMOVE:
1348 case VIRTIO_CONSOLE_CONSOLE_PORT:
1351 if (is_console_port(port))
1354 init_port_console(port);
1356 * Could remove the port here in case init fails - but
1357 * have to notify the host first.
1360 case VIRTIO_CONSOLE_RESIZE: {
1366 if (!is_console_port(port))
1369 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1371 set_console_size(port, size.rows, size.cols);
1373 port->cons.hvc->irq_requested = 1;
1374 resize_console(port);
1377 case VIRTIO_CONSOLE_PORT_OPEN:
1378 port->host_connected = cpkt->value;
1379 wake_up_interruptible(&port->waitqueue);
1381 * If the host port got closed and the host had any
1382 * unconsumed buffers, we'll be able to reclaim them
1385 spin_lock_irq(&port->outvq_lock);
1386 reclaim_consumed_buffers(port);
1387 spin_unlock_irq(&port->outvq_lock);
1390 * If the guest is connected, it'll be interested in
1391 * knowing the host connection state changed.
1393 send_sigio_to_port(port);
1395 case VIRTIO_CONSOLE_PORT_NAME:
1397 * Skip the size of the header and the cpkt to get the size
1398 * of the name that was sent
1400 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1402 port->name = kmalloc(name_size, GFP_KERNEL);
1405 "Not enough space to store port name\n");
1408 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1410 port->name[name_size - 1] = 0;
1413 * Since we only have one sysfs attribute, 'name',
1414 * create it only if we have a name for the port.
1416 err = sysfs_create_group(&port->dev->kobj,
1417 &port_attribute_group);
1420 "Error %d creating sysfs device attributes\n",
1424 * Generate a udev event so that appropriate
1425 * symlinks can be created based on udev
1428 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1434 static void control_work_handler(struct work_struct *work)
1436 struct ports_device *portdev;
1437 struct virtqueue *vq;
1438 struct port_buffer *buf;
1441 portdev = container_of(work, struct ports_device, control_work);
1442 vq = portdev->c_ivq;
1444 spin_lock(&portdev->cvq_lock);
1445 while ((buf = virtqueue_get_buf(vq, &len))) {
1446 spin_unlock(&portdev->cvq_lock);
1451 handle_control_message(portdev, buf);
1453 spin_lock(&portdev->cvq_lock);
1454 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1455 dev_warn(&portdev->vdev->dev,
1456 "Error adding buffer to queue\n");
1460 spin_unlock(&portdev->cvq_lock);
1463 static void out_intr(struct virtqueue *vq)
1467 port = find_port_by_vq(vq->vdev->priv, vq);
1471 wake_up_interruptible(&port->waitqueue);
1474 static void in_intr(struct virtqueue *vq)
1477 unsigned long flags;
1479 port = find_port_by_vq(vq->vdev->priv, vq);
1483 spin_lock_irqsave(&port->inbuf_lock, flags);
1485 port->inbuf = get_inbuf(port);
1488 * Don't queue up data when port is closed. This condition
1489 * can be reached when a console port is not yet connected (no
1490 * tty is spawned) and the host sends out data to console
1491 * ports. For generic serial ports, the host won't
1492 * (shouldn't) send data till the guest is connected.
1494 if (!port->guest_connected)
1495 discard_port_data(port);
1497 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1499 wake_up_interruptible(&port->waitqueue);
1501 /* Send a SIGIO indicating new data in case the process asked for it */
1502 send_sigio_to_port(port);
1504 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1508 static void control_intr(struct virtqueue *vq)
1510 struct ports_device *portdev;
1512 portdev = vq->vdev->priv;
1513 schedule_work(&portdev->control_work);
1516 static void config_intr(struct virtio_device *vdev)
1518 struct ports_device *portdev;
1520 portdev = vdev->priv;
1522 if (!use_multiport(portdev)) {
1526 vdev->config->get(vdev,
1527 offsetof(struct virtio_console_config, cols),
1528 &cols, sizeof(u16));
1529 vdev->config->get(vdev,
1530 offsetof(struct virtio_console_config, rows),
1531 &rows, sizeof(u16));
1533 port = find_port_by_id(portdev, 0);
1534 set_console_size(port, rows, cols);
1537 * We'll use this way of resizing only for legacy
1538 * support. For newer userspace
1539 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1540 * to indicate console size changes so that it can be
1543 resize_console(port);
1547 static int init_vqs(struct ports_device *portdev)
1549 vq_callback_t **io_callbacks;
1551 struct virtqueue **vqs;
1552 u32 i, j, nr_ports, nr_queues;
1555 nr_ports = portdev->config.max_nr_ports;
1556 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1558 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1559 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1560 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1561 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1563 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1565 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1566 !portdev->out_vqs) {
1572 * For backward compat (newer host but older guest), the host
1573 * spawns a console port first and also inits the vqs for port
1577 io_callbacks[j] = in_intr;
1578 io_callbacks[j + 1] = out_intr;
1579 io_names[j] = "input";
1580 io_names[j + 1] = "output";
1583 if (use_multiport(portdev)) {
1584 io_callbacks[j] = control_intr;
1585 io_callbacks[j + 1] = NULL;
1586 io_names[j] = "control-i";
1587 io_names[j + 1] = "control-o";
1589 for (i = 1; i < nr_ports; i++) {
1591 io_callbacks[j] = in_intr;
1592 io_callbacks[j + 1] = out_intr;
1593 io_names[j] = "input";
1594 io_names[j + 1] = "output";
1597 /* Find the queues. */
1598 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1600 (const char **)io_names);
1605 portdev->in_vqs[0] = vqs[0];
1606 portdev->out_vqs[0] = vqs[1];
1608 if (use_multiport(portdev)) {
1609 portdev->c_ivq = vqs[j];
1610 portdev->c_ovq = vqs[j + 1];
1612 for (i = 1; i < nr_ports; i++) {
1614 portdev->in_vqs[i] = vqs[j];
1615 portdev->out_vqs[i] = vqs[j + 1];
1619 kfree(io_callbacks);
1625 kfree(portdev->out_vqs);
1626 kfree(portdev->in_vqs);
1628 kfree(io_callbacks);
1634 static const struct file_operations portdev_fops = {
1635 .owner = THIS_MODULE,
1639 * Once we're further in boot, we get probed like any other virtio
1642 * If the host also supports multiple console ports, we check the
1643 * config space to see how many ports the host has spawned. We
1644 * initialize each port found.
1646 static int __devinit virtcons_probe(struct virtio_device *vdev)
1648 struct ports_device *portdev;
1652 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1658 /* Attach this portdev to this virtio_device, and vice-versa. */
1659 portdev->vdev = vdev;
1660 vdev->priv = portdev;
1662 spin_lock_irq(&pdrvdata_lock);
1663 portdev->drv_index = pdrvdata.index++;
1664 spin_unlock_irq(&pdrvdata_lock);
1666 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1668 if (portdev->chr_major < 0) {
1670 "Error %d registering chrdev for device %u\n",
1671 portdev->chr_major, portdev->drv_index);
1672 err = portdev->chr_major;
1677 portdev->config.max_nr_ports = 1;
1678 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1680 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1682 &portdev->config.max_nr_ports,
1683 sizeof(portdev->config.max_nr_ports));
1686 err = init_vqs(portdev);
1688 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1692 spin_lock_init(&portdev->ports_lock);
1693 INIT_LIST_HEAD(&portdev->ports);
1696 unsigned int nr_added_bufs;
1698 spin_lock_init(&portdev->cvq_lock);
1699 INIT_WORK(&portdev->control_work, &control_work_handler);
1701 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1702 if (!nr_added_bufs) {
1704 "Error allocating buffers for control queue\n");
1710 * For backward compatibility: Create a console port
1711 * if we're running on older host.
1713 add_port(portdev, 0);
1716 spin_lock_irq(&pdrvdata_lock);
1717 list_add_tail(&portdev->list, &pdrvdata.portdevs);
1718 spin_unlock_irq(&pdrvdata_lock);
1720 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1721 VIRTIO_CONSOLE_DEVICE_READY, 1);
1725 /* The host might want to notify mgmt sw about device add failure */
1726 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1727 VIRTIO_CONSOLE_DEVICE_READY, 0);
1728 vdev->config->del_vqs(vdev);
1729 kfree(portdev->in_vqs);
1730 kfree(portdev->out_vqs);
1732 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1739 static void virtcons_remove(struct virtio_device *vdev)
1741 struct ports_device *portdev;
1742 struct port *port, *port2;
1744 portdev = vdev->priv;
1746 spin_lock_irq(&pdrvdata_lock);
1747 list_del(&portdev->list);
1748 spin_unlock_irq(&pdrvdata_lock);
1750 /* Disable interrupts for vqs */
1751 vdev->config->reset(vdev);
1752 /* Finish up work that's lined up */
1753 cancel_work_sync(&portdev->control_work);
1755 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1758 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1761 * When yanking out a device, we immediately lose the
1762 * (device-side) queues. So there's no point in keeping the
1763 * guest side around till we drop our final reference. This
1764 * also means that any ports which are in an open state will
1765 * have to just stop using the port, as the vqs are going
1768 if (use_multiport(portdev)) {
1769 struct port_buffer *buf;
1772 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1775 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1779 vdev->config->del_vqs(vdev);
1780 kfree(portdev->in_vqs);
1781 kfree(portdev->out_vqs);
1786 static struct virtio_device_id id_table[] = {
1787 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1791 static unsigned int features[] = {
1792 VIRTIO_CONSOLE_F_SIZE,
1793 VIRTIO_CONSOLE_F_MULTIPORT,
1796 static struct virtio_driver virtio_console = {
1797 .feature_table = features,
1798 .feature_table_size = ARRAY_SIZE(features),
1799 .driver.name = KBUILD_MODNAME,
1800 .driver.owner = THIS_MODULE,
1801 .id_table = id_table,
1802 .probe = virtcons_probe,
1803 .remove = virtcons_remove,
1804 .config_changed = config_intr,
1807 static int __init init(void)
1811 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1812 if (IS_ERR(pdrvdata.class)) {
1813 err = PTR_ERR(pdrvdata.class);
1814 pr_err("Error %d creating virtio-ports class\n", err);
1818 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1819 if (!pdrvdata.debugfs_dir) {
1820 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1821 PTR_ERR(pdrvdata.debugfs_dir));
1823 INIT_LIST_HEAD(&pdrvdata.consoles);
1824 INIT_LIST_HEAD(&pdrvdata.portdevs);
1826 return register_virtio_driver(&virtio_console);
1829 static void __exit fini(void)
1831 unregister_virtio_driver(&virtio_console);
1833 class_destroy(pdrvdata.class);
1834 if (pdrvdata.debugfs_dir)
1835 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1840 MODULE_DEVICE_TABLE(virtio, id_table);
1841 MODULE_DESCRIPTION("Virtio console driver");
1842 MODULE_LICENSE("GPL");