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/completion.h>
23 #include <linux/device.h>
24 #include <linux/err.h>
25 #include <linux/freezer.h>
27 #include <linux/init.h>
28 #include <linux/list.h>
29 #include <linux/poll.h>
30 #include <linux/sched.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <linux/virtio.h>
34 #include <linux/virtio_console.h>
35 #include <linux/wait.h>
36 #include <linux/workqueue.h>
37 #include <linux/module.h>
38 #include "../tty/hvc/hvc_console.h"
41 * This is a global struct for storing common data for all the devices
42 * this driver handles.
44 * Mainly, it has a linked list for all the consoles in one place so
45 * that callbacks from hvc for get_chars(), put_chars() work properly
46 * across multiple devices and multiple ports per device.
48 struct ports_driver_data {
49 /* Used for registering chardevs */
52 /* Used for exporting per-port information to debugfs */
53 struct dentry *debugfs_dir;
55 /* List of all the devices we're handling */
56 struct list_head portdevs;
58 /* Number of devices this driver is handling */
62 * This is used to keep track of the number of hvc consoles
63 * spawned by this driver. This number is given as the first
64 * argument to hvc_alloc(). To correctly map an initial
65 * console spawned via hvc_instantiate to the console being
66 * hooked up via hvc_alloc, we need to pass the same vtermno.
68 * We also just assume the first console being initialised was
69 * the first one that got used as the initial console.
71 unsigned int next_vtermno;
73 /* All the console devices handled by this driver */
74 struct list_head consoles;
76 static struct ports_driver_data pdrvdata;
78 DEFINE_SPINLOCK(pdrvdata_lock);
79 DECLARE_COMPLETION(early_console_added);
81 /* This struct holds information that's relevant only for console ports */
83 /* We'll place all consoles in a list in the pdrvdata struct */
84 struct list_head list;
86 /* The hvc device associated with this console port */
87 struct hvc_struct *hvc;
89 /* The size of the console */
93 * This number identifies the number that we used to register
94 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
95 * number passed on by the hvc callbacks to us to
96 * differentiate between the other console ports handled by
105 /* size of the buffer in *buf above */
108 /* used length of the buffer */
110 /* offset in the buf from which to consume data */
115 * This is a per-device struct that stores data common to all the
116 * ports for that device (vdev->priv).
118 struct ports_device {
119 /* Next portdev in the list, head is in the pdrvdata struct */
120 struct list_head list;
123 * Workqueue handlers where we process deferred work after
126 struct work_struct control_work;
127 struct work_struct config_work;
129 struct list_head ports;
131 /* To protect the list of ports */
132 spinlock_t ports_lock;
134 /* To protect the vq operations for the control channel */
135 spinlock_t c_ivq_lock;
136 spinlock_t c_ovq_lock;
138 /* The current config space is stored here */
139 struct virtio_console_config config;
141 /* The virtio device we're associated with */
142 struct virtio_device *vdev;
145 * A couple of virtqueues for the control channel: one for
146 * guest->host transfers, one for host->guest transfers
148 struct virtqueue *c_ivq, *c_ovq;
150 /* Array of per-port IO virtqueues */
151 struct virtqueue **in_vqs, **out_vqs;
153 /* Used for numbering devices for sysfs and debugfs */
154 unsigned int drv_index;
156 /* Major number for this device. Ports will be created as minors. */
161 unsigned long bytes_sent, bytes_received, bytes_discarded;
164 /* This struct holds the per-port data */
166 /* Next port in the list, head is in the ports_device */
167 struct list_head list;
169 /* Pointer to the parent virtio_console device */
170 struct ports_device *portdev;
172 /* The current buffer from which data has to be fed to readers */
173 struct port_buffer *inbuf;
176 * To protect the operations on the in_vq associated with this
177 * port. Has to be a spinlock because it can be called from
178 * interrupt context (get_char()).
180 spinlock_t inbuf_lock;
182 /* Protect the operations on the out_vq. */
183 spinlock_t outvq_lock;
185 /* The IO vqs for this port */
186 struct virtqueue *in_vq, *out_vq;
188 /* File in the debugfs directory that exposes this port's information */
189 struct dentry *debugfs_file;
192 * Keep count of the bytes sent, received and discarded for
193 * this port for accounting and debugging purposes. These
194 * counts are not reset across port open / close events.
196 struct port_stats stats;
199 * The entries in this struct will be valid if this port is
200 * hooked up to an hvc console
204 /* Each port associates with a separate char device */
208 /* Reference-counting to handle port hot-unplugs and file operations */
211 /* A waitqueue for poll() or blocking read operations */
212 wait_queue_head_t waitqueue;
214 /* The 'name' of the port that we expose via sysfs properties */
217 /* We can notify apps of host connect / disconnect events via SIGIO */
218 struct fasync_struct *async_queue;
220 /* The 'id' to identify the port with the Host */
225 /* Is the host device open */
228 /* We should allow only one process to open a port */
229 bool guest_connected;
232 /* This is the very early arch-specified put chars function. */
233 static int (*early_put_chars)(u32, const char *, int);
235 static struct port *find_port_by_vtermno(u32 vtermno)
238 struct console *cons;
241 spin_lock_irqsave(&pdrvdata_lock, flags);
242 list_for_each_entry(cons, &pdrvdata.consoles, list) {
243 if (cons->vtermno == vtermno) {
244 port = container_of(cons, struct port, cons);
250 spin_unlock_irqrestore(&pdrvdata_lock, flags);
254 static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
260 spin_lock_irqsave(&portdev->ports_lock, flags);
261 list_for_each_entry(port, &portdev->ports, list) {
262 if (port->cdev->dev == dev) {
263 kref_get(&port->kref);
269 spin_unlock_irqrestore(&portdev->ports_lock, flags);
274 static struct port *find_port_by_devt(dev_t dev)
276 struct ports_device *portdev;
280 spin_lock_irqsave(&pdrvdata_lock, flags);
281 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
282 port = find_port_by_devt_in_portdev(portdev, dev);
288 spin_unlock_irqrestore(&pdrvdata_lock, flags);
292 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
297 spin_lock_irqsave(&portdev->ports_lock, flags);
298 list_for_each_entry(port, &portdev->ports, list)
303 spin_unlock_irqrestore(&portdev->ports_lock, flags);
308 static struct port *find_port_by_vq(struct ports_device *portdev,
309 struct virtqueue *vq)
314 spin_lock_irqsave(&portdev->ports_lock, flags);
315 list_for_each_entry(port, &portdev->ports, list)
316 if (port->in_vq == vq || port->out_vq == vq)
320 spin_unlock_irqrestore(&portdev->ports_lock, flags);
324 static bool is_console_port(struct port *port)
331 static inline bool use_multiport(struct ports_device *portdev)
334 * This condition can be true when put_chars is called from
339 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
342 static void free_buf(struct port_buffer *buf)
348 static struct port_buffer *alloc_buf(size_t buf_size)
350 struct port_buffer *buf;
352 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
355 buf->buf = kzalloc(buf_size, GFP_KERNEL);
360 buf->size = buf_size;
369 /* Callers should take appropriate locks */
370 static struct port_buffer *get_inbuf(struct port *port)
372 struct port_buffer *buf;
378 buf = virtqueue_get_buf(port->in_vq, &len);
382 port->stats.bytes_received += len;
388 * Create a scatter-gather list representing our input buffer and put
391 * Callers should take appropriate locks.
393 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
395 struct scatterlist sg[1];
398 sg_init_one(sg, buf->buf, buf->size);
400 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
405 /* Discard any unread data this port has. Callers lockers. */
406 static void discard_port_data(struct port *port)
408 struct port_buffer *buf;
411 if (!port->portdev) {
412 /* Device has been unplugged. vqs are already gone. */
415 buf = get_inbuf(port);
419 port->stats.bytes_discarded += buf->len - buf->offset;
420 if (add_inbuf(port->in_vq, buf) < 0) {
425 buf = get_inbuf(port);
428 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
432 static bool port_has_data(struct port *port)
438 spin_lock_irqsave(&port->inbuf_lock, flags);
439 port->inbuf = get_inbuf(port);
443 spin_unlock_irqrestore(&port->inbuf_lock, flags);
447 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
448 unsigned int event, unsigned int value)
450 struct scatterlist sg[1];
451 struct virtio_console_control cpkt;
452 struct virtqueue *vq;
455 if (!use_multiport(portdev))
464 sg_init_one(sg, &cpkt, sizeof(cpkt));
466 spin_lock(&portdev->c_ovq_lock);
467 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
469 while (!virtqueue_get_buf(vq, &len))
472 spin_unlock(&portdev->c_ovq_lock);
476 static ssize_t send_control_msg(struct port *port, unsigned int event,
479 /* Did the port get unplugged before userspace closed it? */
481 return __send_control_msg(port->portdev, port->id, event, value);
485 /* Callers must take the port->outvq_lock */
486 static void reclaim_consumed_buffers(struct port *port)
491 if (!port->portdev) {
492 /* Device has been unplugged. vqs are already gone. */
495 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
497 port->outvq_full = false;
501 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
504 struct scatterlist sg[1];
505 struct virtqueue *out_vq;
510 out_vq = port->out_vq;
512 spin_lock_irqsave(&port->outvq_lock, flags);
514 reclaim_consumed_buffers(port);
516 sg_init_one(sg, in_buf, in_count);
517 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
519 /* Tell Host to go! */
520 virtqueue_kick(out_vq);
528 port->outvq_full = true;
534 * Wait till the host acknowledges it pushed out the data we
535 * sent. This is done for data from the hvc_console; the tty
536 * operations are performed with spinlocks held so we can't
537 * sleep here. An alternative would be to copy the data to a
538 * buffer and relax the spinning requirement. The downside is
539 * we need to kmalloc a GFP_ATOMIC buffer each time the
540 * console driver writes something out.
542 while (!virtqueue_get_buf(out_vq, &len))
545 spin_unlock_irqrestore(&port->outvq_lock, flags);
547 port->stats.bytes_sent += in_count;
549 * We're expected to return the amount of data we wrote -- all
556 * Give out the data that's requested from the buffer that we have
559 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
562 struct port_buffer *buf;
565 if (!out_count || !port_has_data(port))
569 out_count = min(out_count, buf->len - buf->offset);
574 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
578 memcpy(out_buf, buf->buf + buf->offset, out_count);
581 buf->offset += out_count;
583 if (buf->offset == buf->len) {
585 * We're done using all the data in this buffer.
586 * Re-queue so that the Host can send us more data.
588 spin_lock_irqsave(&port->inbuf_lock, flags);
591 if (add_inbuf(port->in_vq, buf) < 0)
592 dev_warn(port->dev, "failed add_buf\n");
594 spin_unlock_irqrestore(&port->inbuf_lock, flags);
596 /* Return the number of bytes actually copied */
600 /* The condition that must be true for polling to end */
601 static bool will_read_block(struct port *port)
603 if (!port->guest_connected) {
604 /* Port got hot-unplugged. Let's exit. */
607 return !port_has_data(port) && port->host_connected;
610 static bool will_write_block(struct port *port)
614 if (!port->guest_connected) {
615 /* Port got hot-unplugged. Let's exit. */
618 if (!port->host_connected)
621 spin_lock_irq(&port->outvq_lock);
623 * Check if the Host has consumed any buffers since we last
624 * sent data (this is only applicable for nonblocking ports).
626 reclaim_consumed_buffers(port);
627 ret = port->outvq_full;
628 spin_unlock_irq(&port->outvq_lock);
633 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
634 size_t count, loff_t *offp)
639 port = filp->private_data;
641 /* Port is hot-unplugged. */
642 if (!port->guest_connected)
645 if (!port_has_data(port)) {
647 * If nothing's connected on the host just return 0 in
648 * case of list_empty; this tells the userspace app
649 * that there's no connection
651 if (!port->host_connected)
653 if (filp->f_flags & O_NONBLOCK)
656 ret = wait_event_freezable(port->waitqueue,
657 !will_read_block(port));
661 /* Port got hot-unplugged while we were waiting above. */
662 if (!port->guest_connected)
665 * We could've received a disconnection message while we were
666 * waiting for more data.
668 * This check is not clubbed in the if() statement above as we
669 * might receive some data as well as the host could get
670 * disconnected after we got woken up from our wait. So we
671 * really want to give off whatever data we have and only then
672 * check for host_connected.
674 if (!port_has_data(port) && !port->host_connected)
677 return fill_readbuf(port, ubuf, count, true);
680 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
681 size_t count, loff_t *offp)
688 /* Userspace could be out to fool us */
692 port = filp->private_data;
694 nonblock = filp->f_flags & O_NONBLOCK;
696 if (will_write_block(port)) {
700 ret = wait_event_freezable(port->waitqueue,
701 !will_write_block(port));
705 /* Port got hot-unplugged. */
706 if (!port->guest_connected)
709 count = min((size_t)(32 * 1024), count);
711 buf = kmalloc(count, GFP_KERNEL);
715 ret = copy_from_user(buf, ubuf, count);
722 * We now ask send_buf() to not spin for generic ports -- we
723 * can re-use the same code path that non-blocking file
724 * descriptors take for blocking file descriptors since the
725 * wait is already done and we're certain the write will go
726 * through to the host.
729 ret = send_buf(port, buf, count, nonblock);
731 if (nonblock && ret > 0)
740 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
745 port = filp->private_data;
746 poll_wait(filp, &port->waitqueue, wait);
748 if (!port->guest_connected) {
749 /* Port got unplugged */
753 if (!will_read_block(port))
754 ret |= POLLIN | POLLRDNORM;
755 if (!will_write_block(port))
757 if (!port->host_connected)
763 static void remove_port(struct kref *kref);
765 static int port_fops_release(struct inode *inode, struct file *filp)
769 port = filp->private_data;
771 /* Notify host of port being closed */
772 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
774 spin_lock_irq(&port->inbuf_lock);
775 port->guest_connected = false;
777 discard_port_data(port);
779 spin_unlock_irq(&port->inbuf_lock);
781 spin_lock_irq(&port->outvq_lock);
782 reclaim_consumed_buffers(port);
783 spin_unlock_irq(&port->outvq_lock);
786 * Locks aren't necessary here as a port can't be opened after
787 * unplug, and if a port isn't unplugged, a kref would already
788 * exist for the port. Plus, taking ports_lock here would
789 * create a dependency on other locks taken by functions
790 * inside remove_port if we're the last holder of the port,
791 * creating many problems.
793 kref_put(&port->kref, remove_port);
798 static int port_fops_open(struct inode *inode, struct file *filp)
800 struct cdev *cdev = inode->i_cdev;
804 /* We get the port with a kref here */
805 port = find_port_by_devt(cdev->dev);
807 /* Port was unplugged before we could proceed */
810 filp->private_data = port;
813 * Don't allow opening of console port devices -- that's done
816 if (is_console_port(port)) {
821 /* Allow only one process to open a particular port at a time */
822 spin_lock_irq(&port->inbuf_lock);
823 if (port->guest_connected) {
824 spin_unlock_irq(&port->inbuf_lock);
829 port->guest_connected = true;
830 spin_unlock_irq(&port->inbuf_lock);
832 spin_lock_irq(&port->outvq_lock);
834 * There might be a chance that we missed reclaiming a few
835 * buffers in the window of the port getting previously closed
838 reclaim_consumed_buffers(port);
839 spin_unlock_irq(&port->outvq_lock);
841 nonseekable_open(inode, filp);
843 /* Notify host of port being opened */
844 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
848 kref_put(&port->kref, remove_port);
852 static int port_fops_fasync(int fd, struct file *filp, int mode)
856 port = filp->private_data;
857 return fasync_helper(fd, filp, mode, &port->async_queue);
861 * The file operations that we support: programs in the guest can open
862 * a console device, read from it, write to it, poll for data and
863 * close it. The devices are at
864 * /dev/vport<device number>p<port number>
866 static const struct file_operations port_fops = {
867 .owner = THIS_MODULE,
868 .open = port_fops_open,
869 .read = port_fops_read,
870 .write = port_fops_write,
871 .poll = port_fops_poll,
872 .release = port_fops_release,
873 .fasync = port_fops_fasync,
878 * The put_chars() callback is pretty straightforward.
880 * We turn the characters into a scatter-gather list, add it to the
881 * output queue and then kick the Host. Then we sit here waiting for
882 * it to finish: inefficient in theory, but in practice
883 * implementations will do it immediately (lguest's Launcher does).
885 static int put_chars(u32 vtermno, const char *buf, int count)
889 if (unlikely(early_put_chars))
890 return early_put_chars(vtermno, buf, count);
892 port = find_port_by_vtermno(vtermno);
896 return send_buf(port, (void *)buf, count, false);
900 * get_chars() is the callback from the hvc_console infrastructure
901 * when an interrupt is received.
903 * We call out to fill_readbuf that gets us the required data from the
904 * buffers that are queued up.
906 static int get_chars(u32 vtermno, char *buf, int count)
910 /* If we've not set up the port yet, we have no input to give. */
911 if (unlikely(early_put_chars))
914 port = find_port_by_vtermno(vtermno);
918 /* If we don't have an input queue yet, we can't get input. */
919 BUG_ON(!port->in_vq);
921 return fill_readbuf(port, buf, count, false);
924 static void resize_console(struct port *port)
926 struct virtio_device *vdev;
928 /* The port could have been hot-unplugged */
929 if (!port || !is_console_port(port))
932 vdev = port->portdev->vdev;
933 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
934 hvc_resize(port->cons.hvc, port->cons.ws);
937 /* We set the configuration at this point, since we now have a tty */
938 static int notifier_add_vio(struct hvc_struct *hp, int data)
942 port = find_port_by_vtermno(hp->vtermno);
946 hp->irq_requested = 1;
947 resize_console(port);
952 static void notifier_del_vio(struct hvc_struct *hp, int data)
954 hp->irq_requested = 0;
957 /* The operations for console ports. */
958 static const struct hv_ops hv_ops = {
959 .get_chars = get_chars,
960 .put_chars = put_chars,
961 .notifier_add = notifier_add_vio,
962 .notifier_del = notifier_del_vio,
963 .notifier_hangup = notifier_del_vio,
967 * Console drivers are initialized very early so boot messages can go
968 * out, so we do things slightly differently from the generic virtio
969 * initialization of the net and block drivers.
971 * At this stage, the console is output-only. It's too early to set
972 * up a virtqueue, so we let the drivers do some boutique early-output
975 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
977 early_put_chars = put_chars;
978 return hvc_instantiate(0, 0, &hv_ops);
981 int init_port_console(struct port *port)
986 * The Host's telling us this port is a console port. Hook it
987 * up with an hvc console.
989 * To set up and manage our virtual console, we call
992 * The first argument of hvc_alloc() is the virtual console
993 * number. The second argument is the parameter for the
994 * notification mechanism (like irq number). We currently
995 * leave this as zero, virtqueues have implicit notifications.
997 * The third argument is a "struct hv_ops" containing the
998 * put_chars() get_chars(), notifier_add() and notifier_del()
999 * pointers. The final argument is the output buffer size: we
1000 * can do any size, so we put PAGE_SIZE here.
1002 port->cons.vtermno = pdrvdata.next_vtermno;
1004 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
1005 if (IS_ERR(port->cons.hvc)) {
1006 ret = PTR_ERR(port->cons.hvc);
1008 "error %d allocating hvc for port\n", ret);
1009 port->cons.hvc = NULL;
1012 spin_lock_irq(&pdrvdata_lock);
1013 pdrvdata.next_vtermno++;
1014 list_add_tail(&port->cons.list, &pdrvdata.consoles);
1015 spin_unlock_irq(&pdrvdata_lock);
1016 port->guest_connected = true;
1019 * Start using the new console output if this is the first
1020 * console to come up.
1022 if (early_put_chars)
1023 early_put_chars = NULL;
1025 /* Notify host of port being opened */
1026 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1031 static ssize_t show_port_name(struct device *dev,
1032 struct device_attribute *attr, char *buffer)
1036 port = dev_get_drvdata(dev);
1038 return sprintf(buffer, "%s\n", port->name);
1041 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1043 static struct attribute *port_sysfs_entries[] = {
1044 &dev_attr_name.attr,
1048 static struct attribute_group port_attribute_group = {
1049 .name = NULL, /* put in device directory */
1050 .attrs = port_sysfs_entries,
1053 static int debugfs_open(struct inode *inode, struct file *filp)
1055 filp->private_data = inode->i_private;
1059 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1060 size_t count, loff_t *offp)
1064 ssize_t ret, out_offset, out_count;
1067 buf = kmalloc(out_count, GFP_KERNEL);
1071 port = filp->private_data;
1073 out_offset += snprintf(buf + out_offset, out_count,
1074 "name: %s\n", port->name ? port->name : "");
1075 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1076 "guest_connected: %d\n", port->guest_connected);
1077 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1078 "host_connected: %d\n", port->host_connected);
1079 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1080 "outvq_full: %d\n", port->outvq_full);
1081 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1082 "bytes_sent: %lu\n", port->stats.bytes_sent);
1083 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1084 "bytes_received: %lu\n",
1085 port->stats.bytes_received);
1086 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1087 "bytes_discarded: %lu\n",
1088 port->stats.bytes_discarded);
1089 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1091 is_console_port(port) ? "yes" : "no");
1092 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1093 "console_vtermno: %u\n", port->cons.vtermno);
1095 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1100 static const struct file_operations port_debugfs_ops = {
1101 .owner = THIS_MODULE,
1102 .open = debugfs_open,
1103 .read = debugfs_read,
1106 static void set_console_size(struct port *port, u16 rows, u16 cols)
1108 if (!port || !is_console_port(port))
1111 port->cons.ws.ws_row = rows;
1112 port->cons.ws.ws_col = cols;
1115 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1117 struct port_buffer *buf;
1118 unsigned int nr_added_bufs;
1123 buf = alloc_buf(PAGE_SIZE);
1127 spin_lock_irq(lock);
1128 ret = add_inbuf(vq, buf);
1130 spin_unlock_irq(lock);
1135 spin_unlock_irq(lock);
1138 return nr_added_bufs;
1141 static void send_sigio_to_port(struct port *port)
1143 if (port->async_queue && port->guest_connected)
1144 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1147 static int add_port(struct ports_device *portdev, u32 id)
1149 char debugfs_name[16];
1151 struct port_buffer *buf;
1153 unsigned int nr_added_bufs;
1156 port = kmalloc(sizeof(*port), GFP_KERNEL);
1161 kref_init(&port->kref);
1163 port->portdev = portdev;
1168 port->cons.hvc = NULL;
1169 port->async_queue = NULL;
1171 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1173 port->host_connected = port->guest_connected = false;
1174 port->stats = (struct port_stats) { 0 };
1176 port->outvq_full = false;
1178 port->in_vq = portdev->in_vqs[port->id];
1179 port->out_vq = portdev->out_vqs[port->id];
1181 port->cdev = cdev_alloc();
1183 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1187 port->cdev->ops = &port_fops;
1189 devt = MKDEV(portdev->chr_major, id);
1190 err = cdev_add(port->cdev, devt, 1);
1192 dev_err(&port->portdev->vdev->dev,
1193 "Error %d adding cdev for port %u\n", err, id);
1196 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1197 devt, port, "vport%up%u",
1198 port->portdev->drv_index, id);
1199 if (IS_ERR(port->dev)) {
1200 err = PTR_ERR(port->dev);
1201 dev_err(&port->portdev->vdev->dev,
1202 "Error %d creating device for port %u\n",
1207 spin_lock_init(&port->inbuf_lock);
1208 spin_lock_init(&port->outvq_lock);
1209 init_waitqueue_head(&port->waitqueue);
1211 /* Fill the in_vq with buffers so the host can send us data. */
1212 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1213 if (!nr_added_bufs) {
1214 dev_err(port->dev, "Error allocating inbufs\n");
1220 * If we're not using multiport support, this has to be a console port
1222 if (!use_multiport(port->portdev)) {
1223 err = init_port_console(port);
1228 spin_lock_irq(&portdev->ports_lock);
1229 list_add_tail(&port->list, &port->portdev->ports);
1230 spin_unlock_irq(&portdev->ports_lock);
1233 * Tell the Host we're set so that it can send us various
1234 * configuration parameters for this port (eg, port name,
1235 * caching, whether this is a console port, etc.)
1237 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1239 if (pdrvdata.debugfs_dir) {
1241 * Finally, create the debugfs file that we can use to
1242 * inspect a port's state at any time
1244 sprintf(debugfs_name, "vport%up%u",
1245 port->portdev->drv_index, id);
1246 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1247 pdrvdata.debugfs_dir,
1254 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1257 device_destroy(pdrvdata.class, port->dev->devt);
1259 cdev_del(port->cdev);
1263 /* The host might want to notify management sw about port add failure */
1264 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1268 /* No users remain, remove all port-specific data. */
1269 static void remove_port(struct kref *kref)
1273 port = container_of(kref, struct port, kref);
1279 * Port got unplugged. Remove port from portdev's list and drop the
1280 * kref reference. If no userspace has this port opened, it will
1281 * result in immediate removal the port.
1283 static void unplug_port(struct port *port)
1285 struct port_buffer *buf;
1287 spin_lock_irq(&port->portdev->ports_lock);
1288 list_del(&port->list);
1289 spin_unlock_irq(&port->portdev->ports_lock);
1291 if (port->guest_connected) {
1292 /* Let the app know the port is going down. */
1293 send_sigio_to_port(port);
1295 /* Do this after sigio is actually sent */
1296 port->guest_connected = false;
1297 port->host_connected = false;
1299 wake_up_interruptible(&port->waitqueue);
1302 if (is_console_port(port)) {
1303 spin_lock_irq(&pdrvdata_lock);
1304 list_del(&port->cons.list);
1305 spin_unlock_irq(&pdrvdata_lock);
1306 hvc_remove(port->cons.hvc);
1309 /* Remove unused data this port might have received. */
1310 discard_port_data(port);
1312 reclaim_consumed_buffers(port);
1314 /* Remove buffers we queued up for the Host to send us data in. */
1315 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1319 * We should just assume the device itself has gone off --
1320 * else a close on an open port later will try to send out a
1323 port->portdev = NULL;
1325 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1326 device_destroy(pdrvdata.class, port->dev->devt);
1327 cdev_del(port->cdev);
1331 debugfs_remove(port->debugfs_file);
1334 * Locks around here are not necessary - a port can't be
1335 * opened after we removed the port struct from ports_list
1338 kref_put(&port->kref, remove_port);
1341 /* Any private messages that the Host and Guest want to share */
1342 static void handle_control_message(struct ports_device *portdev,
1343 struct port_buffer *buf)
1345 struct virtio_console_control *cpkt;
1350 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1352 port = find_port_by_id(portdev, cpkt->id);
1353 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1354 /* No valid header at start of buffer. Drop it. */
1355 dev_dbg(&portdev->vdev->dev,
1356 "Invalid index %u in control packet\n", cpkt->id);
1360 switch (cpkt->event) {
1361 case VIRTIO_CONSOLE_PORT_ADD:
1363 dev_dbg(&portdev->vdev->dev,
1364 "Port %u already added\n", port->id);
1365 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1368 if (cpkt->id >= portdev->config.max_nr_ports) {
1369 dev_warn(&portdev->vdev->dev,
1370 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1371 cpkt->id, portdev->config.max_nr_ports - 1);
1374 add_port(portdev, cpkt->id);
1376 case VIRTIO_CONSOLE_PORT_REMOVE:
1379 case VIRTIO_CONSOLE_CONSOLE_PORT:
1382 if (is_console_port(port))
1385 init_port_console(port);
1386 complete(&early_console_added);
1388 * Could remove the port here in case init fails - but
1389 * have to notify the host first.
1392 case VIRTIO_CONSOLE_RESIZE: {
1398 if (!is_console_port(port))
1401 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1403 set_console_size(port, size.rows, size.cols);
1405 port->cons.hvc->irq_requested = 1;
1406 resize_console(port);
1409 case VIRTIO_CONSOLE_PORT_OPEN:
1410 port->host_connected = cpkt->value;
1411 wake_up_interruptible(&port->waitqueue);
1413 * If the host port got closed and the host had any
1414 * unconsumed buffers, we'll be able to reclaim them
1417 spin_lock_irq(&port->outvq_lock);
1418 reclaim_consumed_buffers(port);
1419 spin_unlock_irq(&port->outvq_lock);
1422 * If the guest is connected, it'll be interested in
1423 * knowing the host connection state changed.
1425 send_sigio_to_port(port);
1427 case VIRTIO_CONSOLE_PORT_NAME:
1429 * If we woke up after hibernation, we can get this
1430 * again. Skip it in that case.
1436 * Skip the size of the header and the cpkt to get the size
1437 * of the name that was sent
1439 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1441 port->name = kmalloc(name_size, GFP_KERNEL);
1444 "Not enough space to store port name\n");
1447 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1449 port->name[name_size - 1] = 0;
1452 * Since we only have one sysfs attribute, 'name',
1453 * create it only if we have a name for the port.
1455 err = sysfs_create_group(&port->dev->kobj,
1456 &port_attribute_group);
1459 "Error %d creating sysfs device attributes\n",
1463 * Generate a udev event so that appropriate
1464 * symlinks can be created based on udev
1467 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1473 static void control_work_handler(struct work_struct *work)
1475 struct ports_device *portdev;
1476 struct virtqueue *vq;
1477 struct port_buffer *buf;
1480 portdev = container_of(work, struct ports_device, control_work);
1481 vq = portdev->c_ivq;
1483 spin_lock(&portdev->c_ivq_lock);
1484 while ((buf = virtqueue_get_buf(vq, &len))) {
1485 spin_unlock(&portdev->c_ivq_lock);
1490 handle_control_message(portdev, buf);
1492 spin_lock(&portdev->c_ivq_lock);
1493 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1494 dev_warn(&portdev->vdev->dev,
1495 "Error adding buffer to queue\n");
1499 spin_unlock(&portdev->c_ivq_lock);
1502 static void out_intr(struct virtqueue *vq)
1506 port = find_port_by_vq(vq->vdev->priv, vq);
1510 wake_up_interruptible(&port->waitqueue);
1513 static void in_intr(struct virtqueue *vq)
1516 unsigned long flags;
1518 port = find_port_by_vq(vq->vdev->priv, vq);
1522 spin_lock_irqsave(&port->inbuf_lock, flags);
1523 port->inbuf = get_inbuf(port);
1526 * Don't queue up data when port is closed. This condition
1527 * can be reached when a console port is not yet connected (no
1528 * tty is spawned) and the host sends out data to console
1529 * ports. For generic serial ports, the host won't
1530 * (shouldn't) send data till the guest is connected.
1532 if (!port->guest_connected)
1533 discard_port_data(port);
1535 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1537 wake_up_interruptible(&port->waitqueue);
1539 /* Send a SIGIO indicating new data in case the process asked for it */
1540 send_sigio_to_port(port);
1542 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1546 static void control_intr(struct virtqueue *vq)
1548 struct ports_device *portdev;
1550 portdev = vq->vdev->priv;
1551 schedule_work(&portdev->control_work);
1554 static void config_intr(struct virtio_device *vdev)
1556 struct ports_device *portdev;
1558 portdev = vdev->priv;
1560 if (!use_multiport(portdev))
1561 schedule_work(&portdev->config_work);
1564 static void config_work_handler(struct work_struct *work)
1566 struct ports_device *portdev;
1568 portdev = container_of(work, struct ports_device, control_work);
1569 if (!use_multiport(portdev)) {
1570 struct virtio_device *vdev;
1574 vdev = portdev->vdev;
1575 vdev->config->get(vdev,
1576 offsetof(struct virtio_console_config, cols),
1577 &cols, sizeof(u16));
1578 vdev->config->get(vdev,
1579 offsetof(struct virtio_console_config, rows),
1580 &rows, sizeof(u16));
1582 port = find_port_by_id(portdev, 0);
1583 set_console_size(port, rows, cols);
1586 * We'll use this way of resizing only for legacy
1587 * support. For newer userspace
1588 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1589 * to indicate console size changes so that it can be
1592 resize_console(port);
1596 static int init_vqs(struct ports_device *portdev)
1598 vq_callback_t **io_callbacks;
1600 struct virtqueue **vqs;
1601 u32 i, j, nr_ports, nr_queues;
1604 nr_ports = portdev->config.max_nr_ports;
1605 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1607 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1608 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1609 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1610 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1612 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1614 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1615 !portdev->out_vqs) {
1621 * For backward compat (newer host but older guest), the host
1622 * spawns a console port first and also inits the vqs for port
1626 io_callbacks[j] = in_intr;
1627 io_callbacks[j + 1] = out_intr;
1628 io_names[j] = "input";
1629 io_names[j + 1] = "output";
1632 if (use_multiport(portdev)) {
1633 io_callbacks[j] = control_intr;
1634 io_callbacks[j + 1] = NULL;
1635 io_names[j] = "control-i";
1636 io_names[j + 1] = "control-o";
1638 for (i = 1; i < nr_ports; i++) {
1640 io_callbacks[j] = in_intr;
1641 io_callbacks[j + 1] = out_intr;
1642 io_names[j] = "input";
1643 io_names[j + 1] = "output";
1646 /* Find the queues. */
1647 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1649 (const char **)io_names);
1654 portdev->in_vqs[0] = vqs[0];
1655 portdev->out_vqs[0] = vqs[1];
1657 if (use_multiport(portdev)) {
1658 portdev->c_ivq = vqs[j];
1659 portdev->c_ovq = vqs[j + 1];
1661 for (i = 1; i < nr_ports; i++) {
1663 portdev->in_vqs[i] = vqs[j];
1664 portdev->out_vqs[i] = vqs[j + 1];
1668 kfree(io_callbacks);
1674 kfree(portdev->out_vqs);
1675 kfree(portdev->in_vqs);
1677 kfree(io_callbacks);
1683 static const struct file_operations portdev_fops = {
1684 .owner = THIS_MODULE,
1688 * Once we're further in boot, we get probed like any other virtio
1691 * If the host also supports multiple console ports, we check the
1692 * config space to see how many ports the host has spawned. We
1693 * initialize each port found.
1695 static int __devinit virtcons_probe(struct virtio_device *vdev)
1697 struct ports_device *portdev;
1700 bool early = early_put_chars != NULL;
1702 /* Ensure to read early_put_chars now */
1705 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1711 /* Attach this portdev to this virtio_device, and vice-versa. */
1712 portdev->vdev = vdev;
1713 vdev->priv = portdev;
1715 spin_lock_irq(&pdrvdata_lock);
1716 portdev->drv_index = pdrvdata.index++;
1717 spin_unlock_irq(&pdrvdata_lock);
1719 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1721 if (portdev->chr_major < 0) {
1723 "Error %d registering chrdev for device %u\n",
1724 portdev->chr_major, portdev->drv_index);
1725 err = portdev->chr_major;
1730 portdev->config.max_nr_ports = 1;
1731 if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
1732 offsetof(struct virtio_console_config,
1734 &portdev->config.max_nr_ports) == 0)
1737 err = init_vqs(portdev);
1739 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1743 spin_lock_init(&portdev->ports_lock);
1744 INIT_LIST_HEAD(&portdev->ports);
1746 INIT_WORK(&portdev->config_work, &config_work_handler);
1749 unsigned int nr_added_bufs;
1751 spin_lock_init(&portdev->c_ivq_lock);
1752 spin_lock_init(&portdev->c_ovq_lock);
1753 INIT_WORK(&portdev->control_work, &control_work_handler);
1755 nr_added_bufs = fill_queue(portdev->c_ivq,
1756 &portdev->c_ivq_lock);
1757 if (!nr_added_bufs) {
1759 "Error allocating buffers for control queue\n");
1765 * For backward compatibility: Create a console port
1766 * if we're running on older host.
1768 add_port(portdev, 0);
1771 spin_lock_irq(&pdrvdata_lock);
1772 list_add_tail(&portdev->list, &pdrvdata.portdevs);
1773 spin_unlock_irq(&pdrvdata_lock);
1775 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1776 VIRTIO_CONSOLE_DEVICE_READY, 1);
1779 * If there was an early virtio console, assume that there are no
1780 * other consoles. We need to wait until the hvc_alloc matches the
1781 * hvc_instantiate, otherwise tty_open will complain, resulting in
1782 * a "Warning: unable to open an initial console" boot failure.
1783 * Without multiport this is done in add_port above. With multiport
1784 * this might take some host<->guest communication - thus we have to
1787 if (multiport && early)
1788 wait_for_completion(&early_console_added);
1793 /* The host might want to notify mgmt sw about device add failure */
1794 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1795 VIRTIO_CONSOLE_DEVICE_READY, 0);
1796 vdev->config->del_vqs(vdev);
1797 kfree(portdev->in_vqs);
1798 kfree(portdev->out_vqs);
1800 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1807 static void virtcons_remove(struct virtio_device *vdev)
1809 struct ports_device *portdev;
1810 struct port *port, *port2;
1812 portdev = vdev->priv;
1814 spin_lock_irq(&pdrvdata_lock);
1815 list_del(&portdev->list);
1816 spin_unlock_irq(&pdrvdata_lock);
1818 /* Disable interrupts for vqs */
1819 vdev->config->reset(vdev);
1820 /* Finish up work that's lined up */
1821 if (use_multiport(portdev))
1822 cancel_work_sync(&portdev->control_work);
1824 cancel_work_sync(&portdev->config_work);
1826 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1829 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1832 * When yanking out a device, we immediately lose the
1833 * (device-side) queues. So there's no point in keeping the
1834 * guest side around till we drop our final reference. This
1835 * also means that any ports which are in an open state will
1836 * have to just stop using the port, as the vqs are going
1839 if (use_multiport(portdev)) {
1840 struct port_buffer *buf;
1843 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1846 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1850 vdev->config->del_vqs(vdev);
1851 kfree(portdev->in_vqs);
1852 kfree(portdev->out_vqs);
1857 static struct virtio_device_id id_table[] = {
1858 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1862 static unsigned int features[] = {
1863 VIRTIO_CONSOLE_F_SIZE,
1864 VIRTIO_CONSOLE_F_MULTIPORT,
1867 static struct virtio_driver virtio_console = {
1868 .feature_table = features,
1869 .feature_table_size = ARRAY_SIZE(features),
1870 .driver.name = KBUILD_MODNAME,
1871 .driver.owner = THIS_MODULE,
1872 .id_table = id_table,
1873 .probe = virtcons_probe,
1874 .remove = virtcons_remove,
1875 .config_changed = config_intr,
1878 static int __init init(void)
1882 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1883 if (IS_ERR(pdrvdata.class)) {
1884 err = PTR_ERR(pdrvdata.class);
1885 pr_err("Error %d creating virtio-ports class\n", err);
1889 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1890 if (!pdrvdata.debugfs_dir) {
1891 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1892 PTR_ERR(pdrvdata.debugfs_dir));
1894 INIT_LIST_HEAD(&pdrvdata.consoles);
1895 INIT_LIST_HEAD(&pdrvdata.portdevs);
1897 return register_virtio_driver(&virtio_console);
1900 static void __exit fini(void)
1902 unregister_virtio_driver(&virtio_console);
1904 class_destroy(pdrvdata.class);
1905 if (pdrvdata.debugfs_dir)
1906 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1911 MODULE_DEVICE_TABLE(virtio, id_table);
1912 MODULE_DESCRIPTION("Virtio console driver");
1913 MODULE_LICENSE("GPL");