2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010 Red Hat, Inc.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/cdev.h>
20 #include <linux/debugfs.h>
21 #include <linux/device.h>
22 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/list.h>
26 #include <linux/poll.h>
27 #include <linux/sched.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/virtio.h>
31 #include <linux/virtio_console.h>
32 #include <linux/wait.h>
33 #include <linux/workqueue.h>
34 #include "hvc_console.h"
36 /* Moved here from .h file in order to disable MULTIPORT. */
37 #define VIRTIO_CONSOLE_F_MULTIPORT 1 /* Does host provide multiple ports? */
39 struct virtio_console_multiport_conf {
40 struct virtio_console_config config;
41 /* max. number of ports this device can hold */
43 /* number of ports added so far */
45 } __attribute__((packed));
48 * A message that's passed between the Host and the Guest for a
51 struct virtio_console_control {
52 __u32 id; /* Port number */
53 __u16 event; /* The kind of control event (see below) */
54 __u16 value; /* Extra information for the key */
57 /* Some events for control messages */
58 #define VIRTIO_CONSOLE_PORT_READY 0
59 #define VIRTIO_CONSOLE_CONSOLE_PORT 1
60 #define VIRTIO_CONSOLE_RESIZE 2
61 #define VIRTIO_CONSOLE_PORT_OPEN 3
62 #define VIRTIO_CONSOLE_PORT_NAME 4
63 #define VIRTIO_CONSOLE_PORT_REMOVE 5
66 * This is a global struct for storing common data for all the devices
67 * this driver handles.
69 * Mainly, it has a linked list for all the consoles in one place so
70 * that callbacks from hvc for get_chars(), put_chars() work properly
71 * across multiple devices and multiple ports per device.
73 struct ports_driver_data {
74 /* Used for registering chardevs */
77 /* Used for exporting per-port information to debugfs */
78 struct dentry *debugfs_dir;
80 /* Number of devices this driver is handling */
84 * This is used to keep track of the number of hvc consoles
85 * spawned by this driver. This number is given as the first
86 * argument to hvc_alloc(). To correctly map an initial
87 * console spawned via hvc_instantiate to the console being
88 * hooked up via hvc_alloc, we need to pass the same vtermno.
90 * We also just assume the first console being initialised was
91 * the first one that got used as the initial console.
93 unsigned int next_vtermno;
95 /* All the console devices handled by this driver */
96 struct list_head consoles;
98 static struct ports_driver_data pdrvdata;
100 DEFINE_SPINLOCK(pdrvdata_lock);
102 /* This struct holds information that's relevant only for console ports */
104 /* We'll place all consoles in a list in the pdrvdata struct */
105 struct list_head list;
107 /* The hvc device associated with this console port */
108 struct hvc_struct *hvc;
111 * This number identifies the number that we used to register
112 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
113 * number passed on by the hvc callbacks to us to
114 * differentiate between the other console ports handled by
123 /* size of the buffer in *buf above */
126 /* used length of the buffer */
128 /* offset in the buf from which to consume data */
133 * This is a per-device struct that stores data common to all the
134 * ports for that device (vdev->priv).
136 struct ports_device {
138 * Workqueue handlers where we process deferred work after
141 struct work_struct control_work;
142 struct work_struct config_work;
144 struct list_head ports;
146 /* To protect the list of ports */
147 spinlock_t ports_lock;
149 /* To protect the vq operations for the control channel */
152 /* The current config space is stored here */
153 struct virtio_console_multiport_conf config;
155 /* The virtio device we're associated with */
156 struct virtio_device *vdev;
159 * A couple of virtqueues for the control channel: one for
160 * guest->host transfers, one for host->guest transfers
162 struct virtqueue *c_ivq, *c_ovq;
164 /* Array of per-port IO virtqueues */
165 struct virtqueue **in_vqs, **out_vqs;
167 /* Used for numbering devices for sysfs and debugfs */
168 unsigned int drv_index;
170 /* Major number for this device. Ports will be created as minors. */
174 /* This struct holds the per-port data */
176 /* Next port in the list, head is in the ports_device */
177 struct list_head list;
179 /* Pointer to the parent virtio_console device */
180 struct ports_device *portdev;
182 /* The current buffer from which data has to be fed to readers */
183 struct port_buffer *inbuf;
186 * To protect the operations on the in_vq associated with this
187 * port. Has to be a spinlock because it can be called from
188 * interrupt context (get_char()).
190 spinlock_t inbuf_lock;
192 /* The IO vqs for this port */
193 struct virtqueue *in_vq, *out_vq;
195 /* File in the debugfs directory that exposes this port's information */
196 struct dentry *debugfs_file;
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 /* A waitqueue for poll() or blocking read operations */
209 wait_queue_head_t waitqueue;
211 /* The 'name' of the port that we expose via sysfs properties */
214 /* The 'id' to identify the port with the Host */
217 /* Is the host device open */
220 /* We should allow only one process to open a port */
221 bool guest_connected;
224 /* This is the very early arch-specified put chars function. */
225 static int (*early_put_chars)(u32, const char *, int);
227 static struct port *find_port_by_vtermno(u32 vtermno)
230 struct console *cons;
233 spin_lock_irqsave(&pdrvdata_lock, flags);
234 list_for_each_entry(cons, &pdrvdata.consoles, list) {
235 if (cons->vtermno == vtermno) {
236 port = container_of(cons, struct port, cons);
242 spin_unlock_irqrestore(&pdrvdata_lock, flags);
246 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
251 spin_lock_irqsave(&portdev->ports_lock, flags);
252 list_for_each_entry(port, &portdev->ports, list)
257 spin_unlock_irqrestore(&portdev->ports_lock, flags);
262 static struct port *find_port_by_vq(struct ports_device *portdev,
263 struct virtqueue *vq)
268 spin_lock_irqsave(&portdev->ports_lock, flags);
269 list_for_each_entry(port, &portdev->ports, list)
270 if (port->in_vq == vq || port->out_vq == vq)
274 spin_unlock_irqrestore(&portdev->ports_lock, flags);
278 static bool is_console_port(struct port *port)
285 static inline bool use_multiport(struct ports_device *portdev)
288 * This condition can be true when put_chars is called from
293 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
296 static void free_buf(struct port_buffer *buf)
302 static struct port_buffer *alloc_buf(size_t buf_size)
304 struct port_buffer *buf;
306 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
309 buf->buf = kzalloc(buf_size, GFP_KERNEL);
314 buf->size = buf_size;
323 /* Callers should take appropriate locks */
324 static void *get_inbuf(struct port *port)
326 struct port_buffer *buf;
327 struct virtqueue *vq;
331 buf = vq->vq_ops->get_buf(vq, &len);
340 * Create a scatter-gather list representing our input buffer and put
343 * Callers should take appropriate locks.
345 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
347 struct scatterlist sg[1];
350 sg_init_one(sg, buf->buf, buf->size);
352 ret = vq->vq_ops->add_buf(vq, sg, 0, 1, buf);
353 vq->vq_ops->kick(vq);
357 /* Discard any unread data this port has. Callers lockers. */
358 static void discard_port_data(struct port *port)
360 struct port_buffer *buf;
361 struct virtqueue *vq;
369 buf = vq->vq_ops->get_buf(vq, &len);
373 if (add_inbuf(vq, buf) < 0) {
377 buf = vq->vq_ops->get_buf(vq, &len);
381 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
385 static bool port_has_data(struct port *port)
390 spin_lock_irqsave(&port->inbuf_lock, flags);
395 port->inbuf = get_inbuf(port);
402 spin_unlock_irqrestore(&port->inbuf_lock, flags);
406 static ssize_t send_control_msg(struct port *port, unsigned int event,
409 struct scatterlist sg[1];
410 struct virtio_console_control cpkt;
411 struct virtqueue *vq;
414 if (!use_multiport(port->portdev))
421 vq = port->portdev->c_ovq;
423 sg_init_one(sg, &cpkt, sizeof(cpkt));
424 if (vq->vq_ops->add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
425 vq->vq_ops->kick(vq);
426 while (!vq->vq_ops->get_buf(vq, &len))
432 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
434 struct scatterlist sg[1];
435 struct virtqueue *out_vq;
439 out_vq = port->out_vq;
441 sg_init_one(sg, in_buf, in_count);
442 ret = out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, in_buf);
444 /* Tell Host to go! */
445 out_vq->vq_ops->kick(out_vq);
452 /* Wait till the host acknowledges it pushed out the data we sent. */
453 while (!out_vq->vq_ops->get_buf(out_vq, &len))
456 /* We're expected to return the amount of data we wrote */
461 * Give out the data that's requested from the buffer that we have
464 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
467 struct port_buffer *buf;
470 if (!out_count || !port_has_data(port))
474 out_count = min(out_count, buf->len - buf->offset);
479 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
483 memcpy(out_buf, buf->buf + buf->offset, out_count);
486 buf->offset += out_count;
488 if (buf->offset == buf->len) {
490 * We're done using all the data in this buffer.
491 * Re-queue so that the Host can send us more data.
493 spin_lock_irqsave(&port->inbuf_lock, flags);
496 if (add_inbuf(port->in_vq, buf) < 0)
497 dev_warn(port->dev, "failed add_buf\n");
499 spin_unlock_irqrestore(&port->inbuf_lock, flags);
501 /* Return the number of bytes actually copied */
505 /* The condition that must be true for polling to end */
506 static bool wait_is_over(struct port *port)
508 return port_has_data(port) || !port->host_connected;
511 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
512 size_t count, loff_t *offp)
517 port = filp->private_data;
519 if (!port_has_data(port)) {
521 * If nothing's connected on the host just return 0 in
522 * case of list_empty; this tells the userspace app
523 * that there's no connection
525 if (!port->host_connected)
527 if (filp->f_flags & O_NONBLOCK)
530 ret = wait_event_interruptible(port->waitqueue,
536 * We could've received a disconnection message while we were
537 * waiting for more data.
539 * This check is not clubbed in the if() statement above as we
540 * might receive some data as well as the host could get
541 * disconnected after we got woken up from our wait. So we
542 * really want to give off whatever data we have and only then
543 * check for host_connected.
545 if (!port_has_data(port) && !port->host_connected)
548 return fill_readbuf(port, ubuf, count, true);
551 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
552 size_t count, loff_t *offp)
558 port = filp->private_data;
560 count = min((size_t)(32 * 1024), count);
562 buf = kmalloc(count, GFP_KERNEL);
566 ret = copy_from_user(buf, ubuf, count);
572 ret = send_buf(port, buf, count);
578 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
583 port = filp->private_data;
584 poll_wait(filp, &port->waitqueue, wait);
588 ret |= POLLIN | POLLRDNORM;
589 if (port->host_connected)
591 if (!port->host_connected)
597 static int port_fops_release(struct inode *inode, struct file *filp)
601 port = filp->private_data;
603 /* Notify host of port being closed */
604 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
606 spin_lock_irq(&port->inbuf_lock);
607 port->guest_connected = false;
609 discard_port_data(port);
611 spin_unlock_irq(&port->inbuf_lock);
616 static int port_fops_open(struct inode *inode, struct file *filp)
618 struct cdev *cdev = inode->i_cdev;
621 port = container_of(cdev, struct port, cdev);
622 filp->private_data = port;
625 * Don't allow opening of console port devices -- that's done
628 if (is_console_port(port))
631 /* Allow only one process to open a particular port at a time */
632 spin_lock_irq(&port->inbuf_lock);
633 if (port->guest_connected) {
634 spin_unlock_irq(&port->inbuf_lock);
638 port->guest_connected = true;
639 spin_unlock_irq(&port->inbuf_lock);
641 /* Notify host of port being opened */
642 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
648 * The file operations that we support: programs in the guest can open
649 * a console device, read from it, write to it, poll for data and
650 * close it. The devices are at
651 * /dev/vport<device number>p<port number>
653 static const struct file_operations port_fops = {
654 .owner = THIS_MODULE,
655 .open = port_fops_open,
656 .read = port_fops_read,
657 .write = port_fops_write,
658 .poll = port_fops_poll,
659 .release = port_fops_release,
663 * The put_chars() callback is pretty straightforward.
665 * We turn the characters into a scatter-gather list, add it to the
666 * output queue and then kick the Host. Then we sit here waiting for
667 * it to finish: inefficient in theory, but in practice
668 * implementations will do it immediately (lguest's Launcher does).
670 static int put_chars(u32 vtermno, const char *buf, int count)
674 if (unlikely(early_put_chars))
675 return early_put_chars(vtermno, buf, count);
677 port = find_port_by_vtermno(vtermno);
681 return send_buf(port, (void *)buf, count);
685 * get_chars() is the callback from the hvc_console infrastructure
686 * when an interrupt is received.
688 * We call out to fill_readbuf that gets us the required data from the
689 * buffers that are queued up.
691 static int get_chars(u32 vtermno, char *buf, int count)
695 port = find_port_by_vtermno(vtermno);
699 /* If we don't have an input queue yet, we can't get input. */
700 BUG_ON(!port->in_vq);
702 return fill_readbuf(port, buf, count, false);
705 static void resize_console(struct port *port)
707 struct virtio_device *vdev;
710 /* The port could have been hot-unplugged */
714 vdev = port->portdev->vdev;
715 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
716 vdev->config->get(vdev,
717 offsetof(struct virtio_console_config, cols),
718 &ws.ws_col, sizeof(u16));
719 vdev->config->get(vdev,
720 offsetof(struct virtio_console_config, rows),
721 &ws.ws_row, sizeof(u16));
722 hvc_resize(port->cons.hvc, ws);
726 /* We set the configuration at this point, since we now have a tty */
727 static int notifier_add_vio(struct hvc_struct *hp, int data)
731 port = find_port_by_vtermno(hp->vtermno);
735 hp->irq_requested = 1;
736 resize_console(port);
741 static void notifier_del_vio(struct hvc_struct *hp, int data)
743 hp->irq_requested = 0;
746 /* The operations for console ports. */
747 static const struct hv_ops hv_ops = {
748 .get_chars = get_chars,
749 .put_chars = put_chars,
750 .notifier_add = notifier_add_vio,
751 .notifier_del = notifier_del_vio,
752 .notifier_hangup = notifier_del_vio,
756 * Console drivers are initialized very early so boot messages can go
757 * out, so we do things slightly differently from the generic virtio
758 * initialization of the net and block drivers.
760 * At this stage, the console is output-only. It's too early to set
761 * up a virtqueue, so we let the drivers do some boutique early-output
764 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
766 early_put_chars = put_chars;
767 return hvc_instantiate(0, 0, &hv_ops);
770 int init_port_console(struct port *port)
775 * The Host's telling us this port is a console port. Hook it
776 * up with an hvc console.
778 * To set up and manage our virtual console, we call
781 * The first argument of hvc_alloc() is the virtual console
782 * number. The second argument is the parameter for the
783 * notification mechanism (like irq number). We currently
784 * leave this as zero, virtqueues have implicit notifications.
786 * The third argument is a "struct hv_ops" containing the
787 * put_chars() get_chars(), notifier_add() and notifier_del()
788 * pointers. The final argument is the output buffer size: we
789 * can do any size, so we put PAGE_SIZE here.
791 port->cons.vtermno = pdrvdata.next_vtermno;
793 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
794 if (IS_ERR(port->cons.hvc)) {
795 ret = PTR_ERR(port->cons.hvc);
797 "error %d allocating hvc for port\n", ret);
798 port->cons.hvc = NULL;
801 spin_lock_irq(&pdrvdata_lock);
802 pdrvdata.next_vtermno++;
803 list_add_tail(&port->cons.list, &pdrvdata.consoles);
804 spin_unlock_irq(&pdrvdata_lock);
805 port->guest_connected = true;
807 /* Notify host of port being opened */
808 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
813 static ssize_t show_port_name(struct device *dev,
814 struct device_attribute *attr, char *buffer)
818 port = dev_get_drvdata(dev);
820 return sprintf(buffer, "%s\n", port->name);
823 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
825 static struct attribute *port_sysfs_entries[] = {
830 static struct attribute_group port_attribute_group = {
831 .name = NULL, /* put in device directory */
832 .attrs = port_sysfs_entries,
835 static int debugfs_open(struct inode *inode, struct file *filp)
837 filp->private_data = inode->i_private;
841 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
842 size_t count, loff_t *offp)
846 ssize_t ret, out_offset, out_count;
849 buf = kmalloc(out_count, GFP_KERNEL);
853 port = filp->private_data;
855 out_offset += snprintf(buf + out_offset, out_count,
856 "name: %s\n", port->name ? port->name : "");
857 out_offset += snprintf(buf + out_offset, out_count - out_offset,
858 "guest_connected: %d\n", port->guest_connected);
859 out_offset += snprintf(buf + out_offset, out_count - out_offset,
860 "host_connected: %d\n", port->host_connected);
861 out_offset += snprintf(buf + out_offset, out_count - out_offset,
863 is_console_port(port) ? "yes" : "no");
864 out_offset += snprintf(buf + out_offset, out_count - out_offset,
865 "console_vtermno: %u\n", port->cons.vtermno);
867 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
872 static const struct file_operations port_debugfs_ops = {
873 .owner = THIS_MODULE,
874 .open = debugfs_open,
875 .read = debugfs_read,
878 /* Remove all port-specific data. */
879 static int remove_port(struct port *port)
881 struct port_buffer *buf;
883 spin_lock_irq(&port->portdev->ports_lock);
884 list_del(&port->list);
885 spin_unlock_irq(&port->portdev->ports_lock);
887 if (is_console_port(port)) {
888 spin_lock_irq(&pdrvdata_lock);
889 list_del(&port->cons.list);
890 spin_unlock_irq(&pdrvdata_lock);
891 hvc_remove(port->cons.hvc);
893 if (port->guest_connected)
894 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
896 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
897 device_destroy(pdrvdata.class, port->dev->devt);
898 cdev_del(&port->cdev);
900 /* Remove unused data this port might have received. */
901 discard_port_data(port);
903 /* Remove buffers we queued up for the Host to send us data in. */
904 while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq)))
909 debugfs_remove(port->debugfs_file);
915 /* Any private messages that the Host and Guest want to share */
916 static void handle_control_message(struct ports_device *portdev,
917 struct port_buffer *buf)
919 struct virtio_console_control *cpkt;
924 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
926 port = find_port_by_id(portdev, cpkt->id);
928 /* No valid header at start of buffer. Drop it. */
929 dev_dbg(&portdev->vdev->dev,
930 "Invalid index %u in control packet\n", cpkt->id);
934 switch (cpkt->event) {
935 case VIRTIO_CONSOLE_CONSOLE_PORT:
938 if (is_console_port(port))
941 init_port_console(port);
943 * Could remove the port here in case init fails - but
944 * have to notify the host first.
947 case VIRTIO_CONSOLE_RESIZE:
948 if (!is_console_port(port))
950 port->cons.hvc->irq_requested = 1;
951 resize_console(port);
953 case VIRTIO_CONSOLE_PORT_OPEN:
954 port->host_connected = cpkt->value;
955 wake_up_interruptible(&port->waitqueue);
957 case VIRTIO_CONSOLE_PORT_NAME:
959 * Skip the size of the header and the cpkt to get the size
960 * of the name that was sent
962 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
964 port->name = kmalloc(name_size, GFP_KERNEL);
967 "Not enough space to store port name\n");
970 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
972 port->name[name_size - 1] = 0;
975 * Since we only have one sysfs attribute, 'name',
976 * create it only if we have a name for the port.
978 err = sysfs_create_group(&port->dev->kobj,
979 &port_attribute_group);
982 "Error %d creating sysfs device attributes\n",
986 * Generate a udev event so that appropriate
987 * symlinks can be created based on udev
990 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
993 case VIRTIO_CONSOLE_PORT_REMOVE:
995 * Hot unplug the port. We don't decrement nr_ports
996 * since we don't want to deal with extra complexities
997 * of using the lowest-available port id: We can just
998 * pick up the nr_ports number as the id and not have
999 * userspace send it to us. This helps us in two
1002 * - We don't need to have a 'port_id' field in the
1003 * config space when a port is hot-added. This is a
1004 * good thing as we might queue up multiple hotplug
1005 * requests issued in our workqueue.
1007 * - Another way to deal with this would have been to
1008 * use a bitmap of the active ports and select the
1009 * lowest non-active port from that map. That
1010 * bloats the already tight config space and we
1011 * would end up artificially limiting the
1012 * max. number of ports to sizeof(bitmap). Right
1013 * now we can support 2^32 ports (as the port id is
1014 * stored in a u32 type).
1022 static void control_work_handler(struct work_struct *work)
1024 struct ports_device *portdev;
1025 struct virtqueue *vq;
1026 struct port_buffer *buf;
1029 portdev = container_of(work, struct ports_device, control_work);
1030 vq = portdev->c_ivq;
1032 spin_lock(&portdev->cvq_lock);
1033 while ((buf = vq->vq_ops->get_buf(vq, &len))) {
1034 spin_unlock(&portdev->cvq_lock);
1039 handle_control_message(portdev, buf);
1041 spin_lock(&portdev->cvq_lock);
1042 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1043 dev_warn(&portdev->vdev->dev,
1044 "Error adding buffer to queue\n");
1048 spin_unlock(&portdev->cvq_lock);
1051 static void in_intr(struct virtqueue *vq)
1054 unsigned long flags;
1056 port = find_port_by_vq(vq->vdev->priv, vq);
1060 spin_lock_irqsave(&port->inbuf_lock, flags);
1062 port->inbuf = get_inbuf(port);
1065 * Don't queue up data when port is closed. This condition
1066 * can be reached when a console port is not yet connected (no
1067 * tty is spawned) and the host sends out data to console
1068 * ports. For generic serial ports, the host won't
1069 * (shouldn't) send data till the guest is connected.
1071 if (!port->guest_connected)
1072 discard_port_data(port);
1074 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1076 wake_up_interruptible(&port->waitqueue);
1078 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1082 static void control_intr(struct virtqueue *vq)
1084 struct ports_device *portdev;
1086 portdev = vq->vdev->priv;
1087 schedule_work(&portdev->control_work);
1090 static void config_intr(struct virtio_device *vdev)
1092 struct ports_device *portdev;
1094 portdev = vdev->priv;
1095 if (use_multiport(portdev)) {
1096 /* Handle port hot-add */
1097 schedule_work(&portdev->config_work);
1100 * We'll use this way of resizing only for legacy support.
1101 * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
1102 * control messages to indicate console size changes so that
1103 * it can be done per-port
1105 resize_console(find_port_by_id(portdev, 0));
1108 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1110 struct port_buffer *buf;
1111 unsigned int nr_added_bufs;
1116 buf = alloc_buf(PAGE_SIZE);
1120 spin_lock_irq(lock);
1121 ret = add_inbuf(vq, buf);
1123 spin_unlock_irq(lock);
1128 spin_unlock_irq(lock);
1131 return nr_added_bufs;
1134 static int add_port(struct ports_device *portdev, u32 id)
1136 char debugfs_name[16];
1138 struct port_buffer *buf;
1140 unsigned int nr_added_bufs;
1143 port = kmalloc(sizeof(*port), GFP_KERNEL);
1149 port->portdev = portdev;
1154 port->cons.hvc = NULL;
1156 port->host_connected = port->guest_connected = false;
1158 port->in_vq = portdev->in_vqs[port->id];
1159 port->out_vq = portdev->out_vqs[port->id];
1161 cdev_init(&port->cdev, &port_fops);
1163 devt = MKDEV(portdev->chr_major, id);
1164 err = cdev_add(&port->cdev, devt, 1);
1166 dev_err(&port->portdev->vdev->dev,
1167 "Error %d adding cdev for port %u\n", err, id);
1170 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1171 devt, port, "vport%up%u",
1172 port->portdev->drv_index, id);
1173 if (IS_ERR(port->dev)) {
1174 err = PTR_ERR(port->dev);
1175 dev_err(&port->portdev->vdev->dev,
1176 "Error %d creating device for port %u\n",
1181 spin_lock_init(&port->inbuf_lock);
1182 init_waitqueue_head(&port->waitqueue);
1184 /* Fill the in_vq with buffers so the host can send us data. */
1185 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1186 if (!nr_added_bufs) {
1187 dev_err(port->dev, "Error allocating inbufs\n");
1193 * If we're not using multiport support, this has to be a console port
1195 if (!use_multiport(port->portdev)) {
1196 err = init_port_console(port);
1201 spin_lock_irq(&portdev->ports_lock);
1202 list_add_tail(&port->list, &port->portdev->ports);
1203 spin_unlock_irq(&portdev->ports_lock);
1206 * Tell the Host we're set so that it can send us various
1207 * configuration parameters for this port (eg, port name,
1208 * caching, whether this is a console port, etc.)
1210 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1212 if (pdrvdata.debugfs_dir) {
1214 * Finally, create the debugfs file that we can use to
1215 * inspect a port's state at any time
1217 sprintf(debugfs_name, "vport%up%u",
1218 port->portdev->drv_index, id);
1219 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1220 pdrvdata.debugfs_dir,
1227 while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq)))
1230 device_destroy(pdrvdata.class, port->dev->devt);
1232 cdev_del(&port->cdev);
1240 * The workhandler for config-space updates.
1242 * This is called when ports are hot-added.
1244 static void config_work_handler(struct work_struct *work)
1246 struct virtio_console_multiport_conf virtconconf;
1247 struct ports_device *portdev;
1248 struct virtio_device *vdev;
1251 portdev = container_of(work, struct ports_device, config_work);
1253 vdev = portdev->vdev;
1254 vdev->config->get(vdev,
1255 offsetof(struct virtio_console_multiport_conf,
1257 &virtconconf.nr_ports,
1258 sizeof(virtconconf.nr_ports));
1260 if (portdev->config.nr_ports == virtconconf.nr_ports) {
1262 * Port 0 got hot-added. Since we already did all the
1263 * other initialisation for it, just tell the Host
1264 * that the port is ready if we find the port. In
1265 * case the port was hot-removed earlier, we call
1266 * add_port to add the port.
1270 port = find_port_by_id(portdev, 0);
1272 add_port(portdev, 0);
1274 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1277 if (virtconconf.nr_ports > portdev->config.max_nr_ports) {
1278 dev_warn(&vdev->dev,
1279 "More ports specified (%u) than allowed (%u)",
1280 portdev->config.nr_ports + 1,
1281 portdev->config.max_nr_ports);
1284 if (virtconconf.nr_ports < portdev->config.nr_ports)
1288 while (virtconconf.nr_ports - portdev->config.nr_ports) {
1289 err = add_port(portdev, portdev->config.nr_ports);
1292 portdev->config.nr_ports++;
1296 static int init_vqs(struct ports_device *portdev)
1298 vq_callback_t **io_callbacks;
1300 struct virtqueue **vqs;
1301 u32 i, j, nr_ports, nr_queues;
1304 nr_ports = portdev->config.max_nr_ports;
1305 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1307 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1312 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1313 if (!io_callbacks) {
1317 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1320 goto free_callbacks;
1322 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1324 if (!portdev->in_vqs) {
1328 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1330 if (!portdev->out_vqs) {
1336 * For backward compat (newer host but older guest), the host
1337 * spawns a console port first and also inits the vqs for port
1341 io_callbacks[j] = in_intr;
1342 io_callbacks[j + 1] = NULL;
1343 io_names[j] = "input";
1344 io_names[j + 1] = "output";
1347 if (use_multiport(portdev)) {
1348 io_callbacks[j] = control_intr;
1349 io_callbacks[j + 1] = NULL;
1350 io_names[j] = "control-i";
1351 io_names[j + 1] = "control-o";
1353 for (i = 1; i < nr_ports; i++) {
1355 io_callbacks[j] = in_intr;
1356 io_callbacks[j + 1] = NULL;
1357 io_names[j] = "input";
1358 io_names[j + 1] = "output";
1361 /* Find the queues. */
1362 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1364 (const char **)io_names);
1369 portdev->in_vqs[0] = vqs[0];
1370 portdev->out_vqs[0] = vqs[1];
1372 if (use_multiport(portdev)) {
1373 portdev->c_ivq = vqs[j];
1374 portdev->c_ovq = vqs[j + 1];
1376 for (i = 1; i < nr_ports; i++) {
1378 portdev->in_vqs[i] = vqs[j];
1379 portdev->out_vqs[i] = vqs[j + 1];
1382 kfree(io_callbacks);
1391 kfree(io_callbacks);
1393 kfree(portdev->out_vqs);
1395 kfree(portdev->in_vqs);
1402 static const struct file_operations portdev_fops = {
1403 .owner = THIS_MODULE,
1407 * Once we're further in boot, we get probed like any other virtio
1410 * If the host also supports multiple console ports, we check the
1411 * config space to see how many ports the host has spawned. We
1412 * initialize each port found.
1414 static int __devinit virtcons_probe(struct virtio_device *vdev)
1416 struct ports_device *portdev;
1421 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1427 /* Attach this portdev to this virtio_device, and vice-versa. */
1428 portdev->vdev = vdev;
1429 vdev->priv = portdev;
1431 spin_lock_irq(&pdrvdata_lock);
1432 portdev->drv_index = pdrvdata.index++;
1433 spin_unlock_irq(&pdrvdata_lock);
1435 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1437 if (portdev->chr_major < 0) {
1439 "Error %d registering chrdev for device %u\n",
1440 portdev->chr_major, portdev->drv_index);
1441 err = portdev->chr_major;
1446 portdev->config.nr_ports = 1;
1447 portdev->config.max_nr_ports = 1;
1448 #if 0 /* Multiport is not quite ready yet --RR */
1449 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1451 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1453 vdev->config->get(vdev,
1454 offsetof(struct virtio_console_multiport_conf,
1456 &portdev->config.nr_ports,
1457 sizeof(portdev->config.nr_ports));
1458 vdev->config->get(vdev,
1459 offsetof(struct virtio_console_multiport_conf,
1461 &portdev->config.max_nr_ports,
1462 sizeof(portdev->config.max_nr_ports));
1463 if (portdev->config.nr_ports > portdev->config.max_nr_ports) {
1464 dev_warn(&vdev->dev,
1465 "More ports (%u) specified than allowed (%u). Will init %u ports.",
1466 portdev->config.nr_ports,
1467 portdev->config.max_nr_ports,
1468 portdev->config.max_nr_ports);
1470 portdev->config.nr_ports = portdev->config.max_nr_ports;
1474 /* Let the Host know we support multiple ports.*/
1475 vdev->config->finalize_features(vdev);
1478 err = init_vqs(portdev);
1480 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1484 spin_lock_init(&portdev->ports_lock);
1485 INIT_LIST_HEAD(&portdev->ports);
1488 unsigned int nr_added_bufs;
1490 spin_lock_init(&portdev->cvq_lock);
1491 INIT_WORK(&portdev->control_work, &control_work_handler);
1492 INIT_WORK(&portdev->config_work, &config_work_handler);
1494 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1495 if (!nr_added_bufs) {
1497 "Error allocating buffers for control queue\n");
1503 for (i = 0; i < portdev->config.nr_ports; i++)
1504 add_port(portdev, i);
1506 /* Start using the new console output. */
1507 early_put_chars = NULL;
1511 vdev->config->del_vqs(vdev);
1512 kfree(portdev->in_vqs);
1513 kfree(portdev->out_vqs);
1515 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1522 static void virtcons_remove(struct virtio_device *vdev)
1524 struct ports_device *portdev;
1525 struct port *port, *port2;
1526 struct port_buffer *buf;
1529 portdev = vdev->priv;
1531 cancel_work_sync(&portdev->control_work);
1532 cancel_work_sync(&portdev->config_work);
1534 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1537 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1539 while ((buf = portdev->c_ivq->vq_ops->get_buf(portdev->c_ivq, &len)))
1542 while ((buf = portdev->c_ivq->vq_ops->detach_unused_buf(portdev->c_ivq)))
1545 vdev->config->del_vqs(vdev);
1546 kfree(portdev->in_vqs);
1547 kfree(portdev->out_vqs);
1552 static struct virtio_device_id id_table[] = {
1553 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1557 static unsigned int features[] = {
1558 VIRTIO_CONSOLE_F_SIZE,
1561 static struct virtio_driver virtio_console = {
1562 .feature_table = features,
1563 .feature_table_size = ARRAY_SIZE(features),
1564 .driver.name = KBUILD_MODNAME,
1565 .driver.owner = THIS_MODULE,
1566 .id_table = id_table,
1567 .probe = virtcons_probe,
1568 .remove = virtcons_remove,
1569 .config_changed = config_intr,
1572 static int __init init(void)
1576 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1577 if (IS_ERR(pdrvdata.class)) {
1578 err = PTR_ERR(pdrvdata.class);
1579 pr_err("Error %d creating virtio-ports class\n", err);
1583 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1584 if (!pdrvdata.debugfs_dir) {
1585 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1586 PTR_ERR(pdrvdata.debugfs_dir));
1588 INIT_LIST_HEAD(&pdrvdata.consoles);
1590 return register_virtio_driver(&virtio_console);
1593 static void __exit fini(void)
1595 unregister_virtio_driver(&virtio_console);
1597 class_destroy(pdrvdata.class);
1598 if (pdrvdata.debugfs_dir)
1599 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1604 MODULE_DEVICE_TABLE(virtio, id_table);
1605 MODULE_DESCRIPTION("Virtio console driver");
1606 MODULE_LICENSE("GPL");