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 <linux/module.h>
36 #include "../tty/hvc/hvc_console.h"
39 * This is a global struct for storing common data for all the devices
40 * this driver handles.
42 * Mainly, it has a linked list for all the consoles in one place so
43 * that callbacks from hvc for get_chars(), put_chars() work properly
44 * across multiple devices and multiple ports per device.
46 struct ports_driver_data {
47 /* Used for registering chardevs */
50 /* Used for exporting per-port information to debugfs */
51 struct dentry *debugfs_dir;
53 /* List of all the devices we're handling */
54 struct list_head portdevs;
56 /* Number of devices this driver is handling */
60 * This is used to keep track of the number of hvc consoles
61 * spawned by this driver. This number is given as the first
62 * argument to hvc_alloc(). To correctly map an initial
63 * console spawned via hvc_instantiate to the console being
64 * hooked up via hvc_alloc, we need to pass the same vtermno.
66 * We also just assume the first console being initialised was
67 * the first one that got used as the initial console.
69 unsigned int next_vtermno;
71 /* All the console devices handled by this driver */
72 struct list_head consoles;
74 static struct ports_driver_data pdrvdata;
76 DEFINE_SPINLOCK(pdrvdata_lock);
78 /* This struct holds information that's relevant only for console ports */
80 /* We'll place all consoles in a list in the pdrvdata struct */
81 struct list_head list;
83 /* The hvc device associated with this console port */
84 struct hvc_struct *hvc;
86 /* The size of the console */
90 * This number identifies the number that we used to register
91 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
92 * number passed on by the hvc callbacks to us to
93 * differentiate between the other console ports handled by
102 /* size of the buffer in *buf above */
105 /* used length of the buffer */
107 /* offset in the buf from which to consume data */
112 * This is a per-device struct that stores data common to all the
113 * ports for that device (vdev->priv).
115 struct ports_device {
116 /* Next portdev in the list, head is in the pdrvdata struct */
117 struct list_head list;
120 * Workqueue handlers where we process deferred work after
123 struct work_struct control_work;
125 struct list_head ports;
127 /* To protect the list of ports */
128 spinlock_t ports_lock;
130 /* To protect the vq operations for the control channel */
133 /* The current config space is stored here */
134 struct virtio_console_config config;
136 /* The virtio device we're associated with */
137 struct virtio_device *vdev;
140 * A couple of virtqueues for the control channel: one for
141 * guest->host transfers, one for host->guest transfers
143 struct virtqueue *c_ivq, *c_ovq;
145 /* Array of per-port IO virtqueues */
146 struct virtqueue **in_vqs, **out_vqs;
148 /* Used for numbering devices for sysfs and debugfs */
149 unsigned int drv_index;
151 /* Major number for this device. Ports will be created as minors. */
155 /* This struct holds the per-port data */
157 /* Next port in the list, head is in the ports_device */
158 struct list_head list;
160 /* Pointer to the parent virtio_console device */
161 struct ports_device *portdev;
163 /* The current buffer from which data has to be fed to readers */
164 struct port_buffer *inbuf;
167 * To protect the operations on the in_vq associated with this
168 * port. Has to be a spinlock because it can be called from
169 * interrupt context (get_char()).
171 spinlock_t inbuf_lock;
173 /* Protect the operations on the out_vq. */
174 spinlock_t outvq_lock;
176 /* The IO vqs for this port */
177 struct virtqueue *in_vq, *out_vq;
179 /* File in the debugfs directory that exposes this port's information */
180 struct dentry *debugfs_file;
183 * The entries in this struct will be valid if this port is
184 * hooked up to an hvc console
188 /* Each port associates with a separate char device */
192 /* Reference-counting to handle port hot-unplugs and file operations */
195 /* A waitqueue for poll() or blocking read operations */
196 wait_queue_head_t waitqueue;
198 /* The 'name' of the port that we expose via sysfs properties */
201 /* We can notify apps of host connect / disconnect events via SIGIO */
202 struct fasync_struct *async_queue;
204 /* The 'id' to identify the port with the Host */
209 /* Is the host device open */
212 /* We should allow only one process to open a port */
213 bool guest_connected;
216 /* This is the very early arch-specified put chars function. */
217 static int (*early_put_chars)(u32, const char *, int);
219 static struct port *find_port_by_vtermno(u32 vtermno)
222 struct console *cons;
225 spin_lock_irqsave(&pdrvdata_lock, flags);
226 list_for_each_entry(cons, &pdrvdata.consoles, list) {
227 if (cons->vtermno == vtermno) {
228 port = container_of(cons, struct port, cons);
234 spin_unlock_irqrestore(&pdrvdata_lock, flags);
238 static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
244 spin_lock_irqsave(&portdev->ports_lock, flags);
245 list_for_each_entry(port, &portdev->ports, list)
246 if (port->cdev->dev == dev)
250 spin_unlock_irqrestore(&portdev->ports_lock, flags);
255 static struct port *find_port_by_devt(dev_t dev)
257 struct ports_device *portdev;
261 spin_lock_irqsave(&pdrvdata_lock, flags);
262 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
263 port = find_port_by_devt_in_portdev(portdev, dev);
269 spin_unlock_irqrestore(&pdrvdata_lock, flags);
273 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
278 spin_lock_irqsave(&portdev->ports_lock, flags);
279 list_for_each_entry(port, &portdev->ports, list)
284 spin_unlock_irqrestore(&portdev->ports_lock, flags);
289 static struct port *find_port_by_vq(struct ports_device *portdev,
290 struct virtqueue *vq)
295 spin_lock_irqsave(&portdev->ports_lock, flags);
296 list_for_each_entry(port, &portdev->ports, list)
297 if (port->in_vq == vq || port->out_vq == vq)
301 spin_unlock_irqrestore(&portdev->ports_lock, flags);
305 static bool is_console_port(struct port *port)
312 static inline bool use_multiport(struct ports_device *portdev)
315 * This condition can be true when put_chars is called from
320 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
323 static void free_buf(struct port_buffer *buf)
329 static struct port_buffer *alloc_buf(size_t buf_size)
331 struct port_buffer *buf;
333 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
336 buf->buf = kzalloc(buf_size, GFP_KERNEL);
341 buf->size = buf_size;
350 /* Callers should take appropriate locks */
351 static void *get_inbuf(struct port *port)
353 struct port_buffer *buf;
354 struct virtqueue *vq;
358 buf = virtqueue_get_buf(vq, &len);
367 * Create a scatter-gather list representing our input buffer and put
370 * Callers should take appropriate locks.
372 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
374 struct scatterlist sg[1];
377 sg_init_one(sg, buf->buf, buf->size);
379 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
384 /* Discard any unread data this port has. Callers lockers. */
385 static void discard_port_data(struct port *port)
387 struct port_buffer *buf;
388 struct virtqueue *vq;
392 if (!port->portdev) {
393 /* Device has been unplugged. vqs are already gone. */
400 buf = virtqueue_get_buf(vq, &len);
404 if (add_inbuf(vq, buf) < 0) {
408 buf = virtqueue_get_buf(vq, &len);
412 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
416 static bool port_has_data(struct port *port)
421 spin_lock_irqsave(&port->inbuf_lock, flags);
426 port->inbuf = get_inbuf(port);
433 spin_unlock_irqrestore(&port->inbuf_lock, flags);
437 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
438 unsigned int event, unsigned int value)
440 struct scatterlist sg[1];
441 struct virtio_console_control cpkt;
442 struct virtqueue *vq;
445 if (!use_multiport(portdev))
454 sg_init_one(sg, &cpkt, sizeof(cpkt));
455 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
457 while (!virtqueue_get_buf(vq, &len))
463 static ssize_t send_control_msg(struct port *port, unsigned int event,
466 /* Did the port get unplugged before userspace closed it? */
468 return __send_control_msg(port->portdev, port->id, event, value);
472 /* Callers must take the port->outvq_lock */
473 static void reclaim_consumed_buffers(struct port *port)
478 if (!port->portdev) {
479 /* Device has been unplugged. vqs are already gone. */
482 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
484 port->outvq_full = false;
488 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
491 struct scatterlist sg[1];
492 struct virtqueue *out_vq;
497 out_vq = port->out_vq;
499 spin_lock_irqsave(&port->outvq_lock, flags);
501 reclaim_consumed_buffers(port);
503 sg_init_one(sg, in_buf, in_count);
504 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
506 /* Tell Host to go! */
507 virtqueue_kick(out_vq);
515 port->outvq_full = true;
521 * Wait till the host acknowledges it pushed out the data we
522 * sent. This is done for data from the hvc_console; the tty
523 * operations are performed with spinlocks held so we can't
524 * sleep here. An alternative would be to copy the data to a
525 * buffer and relax the spinning requirement. The downside is
526 * we need to kmalloc a GFP_ATOMIC buffer each time the
527 * console driver writes something out.
529 while (!virtqueue_get_buf(out_vq, &len))
532 spin_unlock_irqrestore(&port->outvq_lock, flags);
534 * We're expected to return the amount of data we wrote -- all
541 * Give out the data that's requested from the buffer that we have
544 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
547 struct port_buffer *buf;
550 if (!out_count || !port_has_data(port))
554 out_count = min(out_count, buf->len - buf->offset);
559 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
563 memcpy(out_buf, buf->buf + buf->offset, out_count);
566 buf->offset += out_count;
568 if (buf->offset == buf->len) {
570 * We're done using all the data in this buffer.
571 * Re-queue so that the Host can send us more data.
573 spin_lock_irqsave(&port->inbuf_lock, flags);
576 if (add_inbuf(port->in_vq, buf) < 0)
577 dev_warn(port->dev, "failed add_buf\n");
579 spin_unlock_irqrestore(&port->inbuf_lock, flags);
581 /* Return the number of bytes actually copied */
585 /* The condition that must be true for polling to end */
586 static bool will_read_block(struct port *port)
588 if (!port->guest_connected) {
589 /* Port got hot-unplugged. Let's exit. */
592 return !port_has_data(port) && port->host_connected;
595 static bool will_write_block(struct port *port)
599 if (!port->guest_connected) {
600 /* Port got hot-unplugged. Let's exit. */
603 if (!port->host_connected)
606 spin_lock_irq(&port->outvq_lock);
608 * Check if the Host has consumed any buffers since we last
609 * sent data (this is only applicable for nonblocking ports).
611 reclaim_consumed_buffers(port);
612 ret = port->outvq_full;
613 spin_unlock_irq(&port->outvq_lock);
618 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
619 size_t count, loff_t *offp)
624 port = filp->private_data;
626 if (!port_has_data(port)) {
628 * If nothing's connected on the host just return 0 in
629 * case of list_empty; this tells the userspace app
630 * that there's no connection
632 if (!port->host_connected)
634 if (filp->f_flags & O_NONBLOCK)
637 ret = wait_event_interruptible(port->waitqueue,
638 !will_read_block(port));
642 /* Port got hot-unplugged. */
643 if (!port->guest_connected)
646 * We could've received a disconnection message while we were
647 * waiting for more data.
649 * This check is not clubbed in the if() statement above as we
650 * might receive some data as well as the host could get
651 * disconnected after we got woken up from our wait. So we
652 * really want to give off whatever data we have and only then
653 * check for host_connected.
655 if (!port_has_data(port) && !port->host_connected)
658 return fill_readbuf(port, ubuf, count, true);
661 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
662 size_t count, loff_t *offp)
669 /* Userspace could be out to fool us */
673 port = filp->private_data;
675 nonblock = filp->f_flags & O_NONBLOCK;
677 if (will_write_block(port)) {
681 ret = wait_event_interruptible(port->waitqueue,
682 !will_write_block(port));
686 /* Port got hot-unplugged. */
687 if (!port->guest_connected)
690 count = min((size_t)(32 * 1024), count);
692 buf = kmalloc(count, GFP_KERNEL);
696 ret = copy_from_user(buf, ubuf, count);
703 * We now ask send_buf() to not spin for generic ports -- we
704 * can re-use the same code path that non-blocking file
705 * descriptors take for blocking file descriptors since the
706 * wait is already done and we're certain the write will go
707 * through to the host.
710 ret = send_buf(port, buf, count, nonblock);
712 if (nonblock && ret > 0)
721 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
726 port = filp->private_data;
727 poll_wait(filp, &port->waitqueue, wait);
729 if (!port->guest_connected) {
730 /* Port got unplugged */
734 if (!will_read_block(port))
735 ret |= POLLIN | POLLRDNORM;
736 if (!will_write_block(port))
738 if (!port->host_connected)
744 static void remove_port(struct kref *kref);
746 static int port_fops_release(struct inode *inode, struct file *filp)
750 port = filp->private_data;
752 /* Notify host of port being closed */
753 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
755 spin_lock_irq(&port->inbuf_lock);
756 port->guest_connected = false;
758 discard_port_data(port);
760 spin_unlock_irq(&port->inbuf_lock);
762 spin_lock_irq(&port->outvq_lock);
763 reclaim_consumed_buffers(port);
764 spin_unlock_irq(&port->outvq_lock);
767 * Locks aren't necessary here as a port can't be opened after
768 * unplug, and if a port isn't unplugged, a kref would already
769 * exist for the port. Plus, taking ports_lock here would
770 * create a dependency on other locks taken by functions
771 * inside remove_port if we're the last holder of the port,
772 * creating many problems.
774 kref_put(&port->kref, remove_port);
779 static int port_fops_open(struct inode *inode, struct file *filp)
781 struct cdev *cdev = inode->i_cdev;
785 port = find_port_by_devt(cdev->dev);
786 filp->private_data = port;
788 /* Prevent against a port getting hot-unplugged at the same time */
789 spin_lock_irq(&port->portdev->ports_lock);
790 kref_get(&port->kref);
791 spin_unlock_irq(&port->portdev->ports_lock);
794 * Don't allow opening of console port devices -- that's done
797 if (is_console_port(port)) {
802 /* Allow only one process to open a particular port at a time */
803 spin_lock_irq(&port->inbuf_lock);
804 if (port->guest_connected) {
805 spin_unlock_irq(&port->inbuf_lock);
810 port->guest_connected = true;
811 spin_unlock_irq(&port->inbuf_lock);
813 spin_lock_irq(&port->outvq_lock);
815 * There might be a chance that we missed reclaiming a few
816 * buffers in the window of the port getting previously closed
819 reclaim_consumed_buffers(port);
820 spin_unlock_irq(&port->outvq_lock);
822 nonseekable_open(inode, filp);
824 /* Notify host of port being opened */
825 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
829 kref_put(&port->kref, remove_port);
833 static int port_fops_fasync(int fd, struct file *filp, int mode)
837 port = filp->private_data;
838 return fasync_helper(fd, filp, mode, &port->async_queue);
842 * The file operations that we support: programs in the guest can open
843 * a console device, read from it, write to it, poll for data and
844 * close it. The devices are at
845 * /dev/vport<device number>p<port number>
847 static const struct file_operations port_fops = {
848 .owner = THIS_MODULE,
849 .open = port_fops_open,
850 .read = port_fops_read,
851 .write = port_fops_write,
852 .poll = port_fops_poll,
853 .release = port_fops_release,
854 .fasync = port_fops_fasync,
859 * The put_chars() callback is pretty straightforward.
861 * We turn the characters into a scatter-gather list, add it to the
862 * output queue and then kick the Host. Then we sit here waiting for
863 * it to finish: inefficient in theory, but in practice
864 * implementations will do it immediately (lguest's Launcher does).
866 static int put_chars(u32 vtermno, const char *buf, int count)
870 if (unlikely(early_put_chars))
871 return early_put_chars(vtermno, buf, count);
873 port = find_port_by_vtermno(vtermno);
877 return send_buf(port, (void *)buf, count, false);
881 * get_chars() is the callback from the hvc_console infrastructure
882 * when an interrupt is received.
884 * We call out to fill_readbuf that gets us the required data from the
885 * buffers that are queued up.
887 static int get_chars(u32 vtermno, char *buf, int count)
891 /* If we've not set up the port yet, we have no input to give. */
892 if (unlikely(early_put_chars))
895 port = find_port_by_vtermno(vtermno);
899 /* If we don't have an input queue yet, we can't get input. */
900 BUG_ON(!port->in_vq);
902 return fill_readbuf(port, buf, count, false);
905 static void resize_console(struct port *port)
907 struct virtio_device *vdev;
909 /* The port could have been hot-unplugged */
910 if (!port || !is_console_port(port))
913 vdev = port->portdev->vdev;
914 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
915 hvc_resize(port->cons.hvc, port->cons.ws);
918 /* We set the configuration at this point, since we now have a tty */
919 static int notifier_add_vio(struct hvc_struct *hp, int data)
923 port = find_port_by_vtermno(hp->vtermno);
927 hp->irq_requested = 1;
928 resize_console(port);
933 static void notifier_del_vio(struct hvc_struct *hp, int data)
935 hp->irq_requested = 0;
938 /* The operations for console ports. */
939 static const struct hv_ops hv_ops = {
940 .get_chars = get_chars,
941 .put_chars = put_chars,
942 .notifier_add = notifier_add_vio,
943 .notifier_del = notifier_del_vio,
944 .notifier_hangup = notifier_del_vio,
948 * Console drivers are initialized very early so boot messages can go
949 * out, so we do things slightly differently from the generic virtio
950 * initialization of the net and block drivers.
952 * At this stage, the console is output-only. It's too early to set
953 * up a virtqueue, so we let the drivers do some boutique early-output
956 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
958 early_put_chars = put_chars;
959 return hvc_instantiate(0, 0, &hv_ops);
962 int init_port_console(struct port *port)
967 * The Host's telling us this port is a console port. Hook it
968 * up with an hvc console.
970 * To set up and manage our virtual console, we call
973 * The first argument of hvc_alloc() is the virtual console
974 * number. The second argument is the parameter for the
975 * notification mechanism (like irq number). We currently
976 * leave this as zero, virtqueues have implicit notifications.
978 * The third argument is a "struct hv_ops" containing the
979 * put_chars() get_chars(), notifier_add() and notifier_del()
980 * pointers. The final argument is the output buffer size: we
981 * can do any size, so we put PAGE_SIZE here.
983 port->cons.vtermno = pdrvdata.next_vtermno;
985 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
986 if (IS_ERR(port->cons.hvc)) {
987 ret = PTR_ERR(port->cons.hvc);
989 "error %d allocating hvc for port\n", ret);
990 port->cons.hvc = NULL;
993 spin_lock_irq(&pdrvdata_lock);
994 pdrvdata.next_vtermno++;
995 list_add_tail(&port->cons.list, &pdrvdata.consoles);
996 spin_unlock_irq(&pdrvdata_lock);
997 port->guest_connected = true;
1000 * Start using the new console output if this is the first
1001 * console to come up.
1003 if (early_put_chars)
1004 early_put_chars = NULL;
1006 /* Notify host of port being opened */
1007 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1012 static ssize_t show_port_name(struct device *dev,
1013 struct device_attribute *attr, char *buffer)
1017 port = dev_get_drvdata(dev);
1019 return sprintf(buffer, "%s\n", port->name);
1022 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1024 static struct attribute *port_sysfs_entries[] = {
1025 &dev_attr_name.attr,
1029 static struct attribute_group port_attribute_group = {
1030 .name = NULL, /* put in device directory */
1031 .attrs = port_sysfs_entries,
1034 static int debugfs_open(struct inode *inode, struct file *filp)
1036 filp->private_data = inode->i_private;
1040 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1041 size_t count, loff_t *offp)
1045 ssize_t ret, out_offset, out_count;
1048 buf = kmalloc(out_count, GFP_KERNEL);
1052 port = filp->private_data;
1054 out_offset += snprintf(buf + out_offset, out_count,
1055 "name: %s\n", port->name ? port->name : "");
1056 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1057 "guest_connected: %d\n", port->guest_connected);
1058 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1059 "host_connected: %d\n", port->host_connected);
1060 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1061 "outvq_full: %d\n", port->outvq_full);
1062 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1064 is_console_port(port) ? "yes" : "no");
1065 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1066 "console_vtermno: %u\n", port->cons.vtermno);
1068 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1073 static const struct file_operations port_debugfs_ops = {
1074 .owner = THIS_MODULE,
1075 .open = debugfs_open,
1076 .read = debugfs_read,
1079 static void set_console_size(struct port *port, u16 rows, u16 cols)
1081 if (!port || !is_console_port(port))
1084 port->cons.ws.ws_row = rows;
1085 port->cons.ws.ws_col = cols;
1088 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1090 struct port_buffer *buf;
1091 unsigned int nr_added_bufs;
1096 buf = alloc_buf(PAGE_SIZE);
1100 spin_lock_irq(lock);
1101 ret = add_inbuf(vq, buf);
1103 spin_unlock_irq(lock);
1108 spin_unlock_irq(lock);
1111 return nr_added_bufs;
1114 static void send_sigio_to_port(struct port *port)
1116 if (port->async_queue && port->guest_connected)
1117 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1120 static int add_port(struct ports_device *portdev, u32 id)
1122 char debugfs_name[16];
1124 struct port_buffer *buf;
1126 unsigned int nr_added_bufs;
1129 port = kmalloc(sizeof(*port), GFP_KERNEL);
1134 kref_init(&port->kref);
1136 port->portdev = portdev;
1141 port->cons.hvc = NULL;
1142 port->async_queue = NULL;
1144 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1146 port->host_connected = port->guest_connected = false;
1148 port->outvq_full = false;
1150 port->in_vq = portdev->in_vqs[port->id];
1151 port->out_vq = portdev->out_vqs[port->id];
1153 port->cdev = cdev_alloc();
1155 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1159 port->cdev->ops = &port_fops;
1161 devt = MKDEV(portdev->chr_major, id);
1162 err = cdev_add(port->cdev, devt, 1);
1164 dev_err(&port->portdev->vdev->dev,
1165 "Error %d adding cdev for port %u\n", err, id);
1168 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1169 devt, port, "vport%up%u",
1170 port->portdev->drv_index, id);
1171 if (IS_ERR(port->dev)) {
1172 err = PTR_ERR(port->dev);
1173 dev_err(&port->portdev->vdev->dev,
1174 "Error %d creating device for port %u\n",
1179 spin_lock_init(&port->inbuf_lock);
1180 spin_lock_init(&port->outvq_lock);
1181 init_waitqueue_head(&port->waitqueue);
1183 /* Fill the in_vq with buffers so the host can send us data. */
1184 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1185 if (!nr_added_bufs) {
1186 dev_err(port->dev, "Error allocating inbufs\n");
1192 * If we're not using multiport support, this has to be a console port
1194 if (!use_multiport(port->portdev)) {
1195 err = init_port_console(port);
1200 spin_lock_irq(&portdev->ports_lock);
1201 list_add_tail(&port->list, &port->portdev->ports);
1202 spin_unlock_irq(&portdev->ports_lock);
1205 * Tell the Host we're set so that it can send us various
1206 * configuration parameters for this port (eg, port name,
1207 * caching, whether this is a console port, etc.)
1209 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1211 if (pdrvdata.debugfs_dir) {
1213 * Finally, create the debugfs file that we can use to
1214 * inspect a port's state at any time
1216 sprintf(debugfs_name, "vport%up%u",
1217 port->portdev->drv_index, id);
1218 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1219 pdrvdata.debugfs_dir,
1226 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1229 device_destroy(pdrvdata.class, port->dev->devt);
1231 cdev_del(port->cdev);
1235 /* The host might want to notify management sw about port add failure */
1236 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1240 /* No users remain, remove all port-specific data. */
1241 static void remove_port(struct kref *kref)
1245 port = container_of(kref, struct port, kref);
1247 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1248 device_destroy(pdrvdata.class, port->dev->devt);
1249 cdev_del(port->cdev);
1253 debugfs_remove(port->debugfs_file);
1259 * Port got unplugged. Remove port from portdev's list and drop the
1260 * kref reference. If no userspace has this port opened, it will
1261 * result in immediate removal the port.
1263 static void unplug_port(struct port *port)
1265 struct port_buffer *buf;
1267 spin_lock_irq(&port->portdev->ports_lock);
1268 list_del(&port->list);
1269 spin_unlock_irq(&port->portdev->ports_lock);
1271 if (port->guest_connected) {
1272 port->guest_connected = false;
1273 port->host_connected = false;
1274 wake_up_interruptible(&port->waitqueue);
1276 /* Let the app know the port is going down. */
1277 send_sigio_to_port(port);
1280 if (is_console_port(port)) {
1281 spin_lock_irq(&pdrvdata_lock);
1282 list_del(&port->cons.list);
1283 spin_unlock_irq(&pdrvdata_lock);
1284 hvc_remove(port->cons.hvc);
1287 /* Remove unused data this port might have received. */
1288 discard_port_data(port);
1290 reclaim_consumed_buffers(port);
1292 /* Remove buffers we queued up for the Host to send us data in. */
1293 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1297 * We should just assume the device itself has gone off --
1298 * else a close on an open port later will try to send out a
1301 port->portdev = NULL;
1304 * Locks around here are not necessary - a port can't be
1305 * opened after we removed the port struct from ports_list
1308 kref_put(&port->kref, remove_port);
1311 /* Any private messages that the Host and Guest want to share */
1312 static void handle_control_message(struct ports_device *portdev,
1313 struct port_buffer *buf)
1315 struct virtio_console_control *cpkt;
1320 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1322 port = find_port_by_id(portdev, cpkt->id);
1323 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1324 /* No valid header at start of buffer. Drop it. */
1325 dev_dbg(&portdev->vdev->dev,
1326 "Invalid index %u in control packet\n", cpkt->id);
1330 switch (cpkt->event) {
1331 case VIRTIO_CONSOLE_PORT_ADD:
1333 dev_dbg(&portdev->vdev->dev,
1334 "Port %u already added\n", port->id);
1335 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1338 if (cpkt->id >= portdev->config.max_nr_ports) {
1339 dev_warn(&portdev->vdev->dev,
1340 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1341 cpkt->id, portdev->config.max_nr_ports - 1);
1344 add_port(portdev, cpkt->id);
1346 case VIRTIO_CONSOLE_PORT_REMOVE:
1349 case VIRTIO_CONSOLE_CONSOLE_PORT:
1352 if (is_console_port(port))
1355 init_port_console(port);
1357 * Could remove the port here in case init fails - but
1358 * have to notify the host first.
1361 case VIRTIO_CONSOLE_RESIZE: {
1367 if (!is_console_port(port))
1370 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1372 set_console_size(port, size.rows, size.cols);
1374 port->cons.hvc->irq_requested = 1;
1375 resize_console(port);
1378 case VIRTIO_CONSOLE_PORT_OPEN:
1379 port->host_connected = cpkt->value;
1380 wake_up_interruptible(&port->waitqueue);
1382 * If the host port got closed and the host had any
1383 * unconsumed buffers, we'll be able to reclaim them
1386 spin_lock_irq(&port->outvq_lock);
1387 reclaim_consumed_buffers(port);
1388 spin_unlock_irq(&port->outvq_lock);
1391 * If the guest is connected, it'll be interested in
1392 * knowing the host connection state changed.
1394 send_sigio_to_port(port);
1396 case VIRTIO_CONSOLE_PORT_NAME:
1398 * Skip the size of the header and the cpkt to get the size
1399 * of the name that was sent
1401 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1403 port->name = kmalloc(name_size, GFP_KERNEL);
1406 "Not enough space to store port name\n");
1409 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1411 port->name[name_size - 1] = 0;
1414 * Since we only have one sysfs attribute, 'name',
1415 * create it only if we have a name for the port.
1417 err = sysfs_create_group(&port->dev->kobj,
1418 &port_attribute_group);
1421 "Error %d creating sysfs device attributes\n",
1425 * Generate a udev event so that appropriate
1426 * symlinks can be created based on udev
1429 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1435 static void control_work_handler(struct work_struct *work)
1437 struct ports_device *portdev;
1438 struct virtqueue *vq;
1439 struct port_buffer *buf;
1442 portdev = container_of(work, struct ports_device, control_work);
1443 vq = portdev->c_ivq;
1445 spin_lock(&portdev->cvq_lock);
1446 while ((buf = virtqueue_get_buf(vq, &len))) {
1447 spin_unlock(&portdev->cvq_lock);
1452 handle_control_message(portdev, buf);
1454 spin_lock(&portdev->cvq_lock);
1455 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1456 dev_warn(&portdev->vdev->dev,
1457 "Error adding buffer to queue\n");
1461 spin_unlock(&portdev->cvq_lock);
1464 static void out_intr(struct virtqueue *vq)
1468 port = find_port_by_vq(vq->vdev->priv, vq);
1472 wake_up_interruptible(&port->waitqueue);
1475 static void in_intr(struct virtqueue *vq)
1478 unsigned long flags;
1480 port = find_port_by_vq(vq->vdev->priv, vq);
1484 spin_lock_irqsave(&port->inbuf_lock, flags);
1486 port->inbuf = get_inbuf(port);
1489 * Don't queue up data when port is closed. This condition
1490 * can be reached when a console port is not yet connected (no
1491 * tty is spawned) and the host sends out data to console
1492 * ports. For generic serial ports, the host won't
1493 * (shouldn't) send data till the guest is connected.
1495 if (!port->guest_connected)
1496 discard_port_data(port);
1498 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1500 wake_up_interruptible(&port->waitqueue);
1502 /* Send a SIGIO indicating new data in case the process asked for it */
1503 send_sigio_to_port(port);
1505 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1509 static void control_intr(struct virtqueue *vq)
1511 struct ports_device *portdev;
1513 portdev = vq->vdev->priv;
1514 schedule_work(&portdev->control_work);
1517 static void config_intr(struct virtio_device *vdev)
1519 struct ports_device *portdev;
1521 portdev = vdev->priv;
1523 if (!use_multiport(portdev)) {
1527 vdev->config->get(vdev,
1528 offsetof(struct virtio_console_config, cols),
1529 &cols, sizeof(u16));
1530 vdev->config->get(vdev,
1531 offsetof(struct virtio_console_config, rows),
1532 &rows, sizeof(u16));
1534 port = find_port_by_id(portdev, 0);
1535 set_console_size(port, rows, cols);
1538 * We'll use this way of resizing only for legacy
1539 * support. For newer userspace
1540 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1541 * to indicate console size changes so that it can be
1544 resize_console(port);
1548 static int init_vqs(struct ports_device *portdev)
1550 vq_callback_t **io_callbacks;
1552 struct virtqueue **vqs;
1553 u32 i, j, nr_ports, nr_queues;
1556 nr_ports = portdev->config.max_nr_ports;
1557 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1559 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1560 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1561 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1562 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1564 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1566 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1567 !portdev->out_vqs) {
1573 * For backward compat (newer host but older guest), the host
1574 * spawns a console port first and also inits the vqs for port
1578 io_callbacks[j] = in_intr;
1579 io_callbacks[j + 1] = out_intr;
1580 io_names[j] = "input";
1581 io_names[j + 1] = "output";
1584 if (use_multiport(portdev)) {
1585 io_callbacks[j] = control_intr;
1586 io_callbacks[j + 1] = NULL;
1587 io_names[j] = "control-i";
1588 io_names[j + 1] = "control-o";
1590 for (i = 1; i < nr_ports; i++) {
1592 io_callbacks[j] = in_intr;
1593 io_callbacks[j + 1] = out_intr;
1594 io_names[j] = "input";
1595 io_names[j + 1] = "output";
1598 /* Find the queues. */
1599 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1601 (const char **)io_names);
1606 portdev->in_vqs[0] = vqs[0];
1607 portdev->out_vqs[0] = vqs[1];
1609 if (use_multiport(portdev)) {
1610 portdev->c_ivq = vqs[j];
1611 portdev->c_ovq = vqs[j + 1];
1613 for (i = 1; i < nr_ports; i++) {
1615 portdev->in_vqs[i] = vqs[j];
1616 portdev->out_vqs[i] = vqs[j + 1];
1620 kfree(io_callbacks);
1626 kfree(portdev->out_vqs);
1627 kfree(portdev->in_vqs);
1629 kfree(io_callbacks);
1635 static const struct file_operations portdev_fops = {
1636 .owner = THIS_MODULE,
1640 * Once we're further in boot, we get probed like any other virtio
1643 * If the host also supports multiple console ports, we check the
1644 * config space to see how many ports the host has spawned. We
1645 * initialize each port found.
1647 static int __devinit virtcons_probe(struct virtio_device *vdev)
1649 struct ports_device *portdev;
1653 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1659 /* Attach this portdev to this virtio_device, and vice-versa. */
1660 portdev->vdev = vdev;
1661 vdev->priv = portdev;
1663 spin_lock_irq(&pdrvdata_lock);
1664 portdev->drv_index = pdrvdata.index++;
1665 spin_unlock_irq(&pdrvdata_lock);
1667 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1669 if (portdev->chr_major < 0) {
1671 "Error %d registering chrdev for device %u\n",
1672 portdev->chr_major, portdev->drv_index);
1673 err = portdev->chr_major;
1678 portdev->config.max_nr_ports = 1;
1679 if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
1680 offsetof(struct virtio_console_config,
1682 &portdev->config.max_nr_ports) == 0)
1685 err = init_vqs(portdev);
1687 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1691 spin_lock_init(&portdev->ports_lock);
1692 INIT_LIST_HEAD(&portdev->ports);
1695 unsigned int nr_added_bufs;
1697 spin_lock_init(&portdev->cvq_lock);
1698 INIT_WORK(&portdev->control_work, &control_work_handler);
1700 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1701 if (!nr_added_bufs) {
1703 "Error allocating buffers for control queue\n");
1709 * For backward compatibility: Create a console port
1710 * if we're running on older host.
1712 add_port(portdev, 0);
1715 spin_lock_irq(&pdrvdata_lock);
1716 list_add_tail(&portdev->list, &pdrvdata.portdevs);
1717 spin_unlock_irq(&pdrvdata_lock);
1719 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1720 VIRTIO_CONSOLE_DEVICE_READY, 1);
1724 /* The host might want to notify mgmt sw about device add failure */
1725 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1726 VIRTIO_CONSOLE_DEVICE_READY, 0);
1727 vdev->config->del_vqs(vdev);
1728 kfree(portdev->in_vqs);
1729 kfree(portdev->out_vqs);
1731 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1738 static void virtcons_remove(struct virtio_device *vdev)
1740 struct ports_device *portdev;
1741 struct port *port, *port2;
1743 portdev = vdev->priv;
1745 spin_lock_irq(&pdrvdata_lock);
1746 list_del(&portdev->list);
1747 spin_unlock_irq(&pdrvdata_lock);
1749 /* Disable interrupts for vqs */
1750 vdev->config->reset(vdev);
1751 /* Finish up work that's lined up */
1752 cancel_work_sync(&portdev->control_work);
1754 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1757 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1760 * When yanking out a device, we immediately lose the
1761 * (device-side) queues. So there's no point in keeping the
1762 * guest side around till we drop our final reference. This
1763 * also means that any ports which are in an open state will
1764 * have to just stop using the port, as the vqs are going
1767 if (use_multiport(portdev)) {
1768 struct port_buffer *buf;
1771 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1774 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1778 vdev->config->del_vqs(vdev);
1779 kfree(portdev->in_vqs);
1780 kfree(portdev->out_vqs);
1785 static struct virtio_device_id id_table[] = {
1786 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1790 static unsigned int features[] = {
1791 VIRTIO_CONSOLE_F_SIZE,
1792 VIRTIO_CONSOLE_F_MULTIPORT,
1795 static struct virtio_driver virtio_console = {
1796 .feature_table = features,
1797 .feature_table_size = ARRAY_SIZE(features),
1798 .driver.name = KBUILD_MODNAME,
1799 .driver.owner = THIS_MODULE,
1800 .id_table = id_table,
1801 .probe = virtcons_probe,
1802 .remove = virtcons_remove,
1803 .config_changed = config_intr,
1806 static int __init init(void)
1810 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1811 if (IS_ERR(pdrvdata.class)) {
1812 err = PTR_ERR(pdrvdata.class);
1813 pr_err("Error %d creating virtio-ports class\n", err);
1817 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1818 if (!pdrvdata.debugfs_dir) {
1819 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1820 PTR_ERR(pdrvdata.debugfs_dir));
1822 INIT_LIST_HEAD(&pdrvdata.consoles);
1823 INIT_LIST_HEAD(&pdrvdata.portdevs);
1825 return register_virtio_driver(&virtio_console);
1828 static void __exit fini(void)
1830 unregister_virtio_driver(&virtio_console);
1832 class_destroy(pdrvdata.class);
1833 if (pdrvdata.debugfs_dir)
1834 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1839 MODULE_DEVICE_TABLE(virtio, id_table);
1840 MODULE_DESCRIPTION("Virtio console driver");
1841 MODULE_LICENSE("GPL");