2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010 Red Hat, Inc.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/cdev.h>
20 #include <linux/debugfs.h>
21 #include <linux/device.h>
22 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/list.h>
26 #include <linux/poll.h>
27 #include <linux/sched.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/virtio.h>
31 #include <linux/virtio_console.h>
32 #include <linux/wait.h>
33 #include <linux/workqueue.h>
34 #include "hvc_console.h"
37 * This is a global struct for storing common data for all the devices
38 * this driver handles.
40 * Mainly, it has a linked list for all the consoles in one place so
41 * that callbacks from hvc for get_chars(), put_chars() work properly
42 * across multiple devices and multiple ports per device.
44 struct ports_driver_data {
45 /* Used for registering chardevs */
48 /* Used for exporting per-port information to debugfs */
49 struct dentry *debugfs_dir;
51 /* Number of devices this driver is handling */
55 * This is used to keep track of the number of hvc consoles
56 * spawned by this driver. This number is given as the first
57 * argument to hvc_alloc(). To correctly map an initial
58 * console spawned via hvc_instantiate to the console being
59 * hooked up via hvc_alloc, we need to pass the same vtermno.
61 * We also just assume the first console being initialised was
62 * the first one that got used as the initial console.
64 unsigned int next_vtermno;
66 /* All the console devices handled by this driver */
67 struct list_head consoles;
69 static struct ports_driver_data pdrvdata;
71 DEFINE_SPINLOCK(pdrvdata_lock);
73 /* This struct holds information that's relevant only for console ports */
75 /* We'll place all consoles in a list in the pdrvdata struct */
76 struct list_head list;
78 /* The hvc device associated with this console port */
79 struct hvc_struct *hvc;
81 /* The size of the console */
85 * This number identifies the number that we used to register
86 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
87 * number passed on by the hvc callbacks to us to
88 * differentiate between the other console ports handled by
97 /* size of the buffer in *buf above */
100 /* used length of the buffer */
102 /* offset in the buf from which to consume data */
107 * This is a per-device struct that stores data common to all the
108 * ports for that device (vdev->priv).
110 struct ports_device {
112 * Workqueue handlers where we process deferred work after
115 struct work_struct control_work;
117 struct list_head ports;
119 /* To protect the list of ports */
120 spinlock_t ports_lock;
122 /* To protect the vq operations for the control channel */
125 /* The current config space is stored here */
126 struct virtio_console_config config;
128 /* The virtio device we're associated with */
129 struct virtio_device *vdev;
132 * A couple of virtqueues for the control channel: one for
133 * guest->host transfers, one for host->guest transfers
135 struct virtqueue *c_ivq, *c_ovq;
137 /* Array of per-port IO virtqueues */
138 struct virtqueue **in_vqs, **out_vqs;
140 /* Used for numbering devices for sysfs and debugfs */
141 unsigned int drv_index;
143 /* Major number for this device. Ports will be created as minors. */
147 /* This struct holds the per-port data */
149 /* Next port in the list, head is in the ports_device */
150 struct list_head list;
152 /* Pointer to the parent virtio_console device */
153 struct ports_device *portdev;
155 /* The current buffer from which data has to be fed to readers */
156 struct port_buffer *inbuf;
159 * To protect the operations on the in_vq associated with this
160 * port. Has to be a spinlock because it can be called from
161 * interrupt context (get_char()).
163 spinlock_t inbuf_lock;
165 /* Protect the operations on the out_vq. */
166 spinlock_t outvq_lock;
168 /* The IO vqs for this port */
169 struct virtqueue *in_vq, *out_vq;
171 /* File in the debugfs directory that exposes this port's information */
172 struct dentry *debugfs_file;
175 * The entries in this struct will be valid if this port is
176 * hooked up to an hvc console
180 /* Each port associates with a separate char device */
184 /* A waitqueue for poll() or blocking read operations */
185 wait_queue_head_t waitqueue;
187 /* The 'name' of the port that we expose via sysfs properties */
190 /* The 'id' to identify the port with the Host */
195 /* Is the host device open */
198 /* We should allow only one process to open a port */
199 bool guest_connected;
202 /* This is the very early arch-specified put chars function. */
203 static int (*early_put_chars)(u32, const char *, int);
205 static struct port *find_port_by_vtermno(u32 vtermno)
208 struct console *cons;
211 spin_lock_irqsave(&pdrvdata_lock, flags);
212 list_for_each_entry(cons, &pdrvdata.consoles, list) {
213 if (cons->vtermno == vtermno) {
214 port = container_of(cons, struct port, cons);
220 spin_unlock_irqrestore(&pdrvdata_lock, flags);
224 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
229 spin_lock_irqsave(&portdev->ports_lock, flags);
230 list_for_each_entry(port, &portdev->ports, list)
235 spin_unlock_irqrestore(&portdev->ports_lock, flags);
240 static struct port *find_port_by_vq(struct ports_device *portdev,
241 struct virtqueue *vq)
246 spin_lock_irqsave(&portdev->ports_lock, flags);
247 list_for_each_entry(port, &portdev->ports, list)
248 if (port->in_vq == vq || port->out_vq == vq)
252 spin_unlock_irqrestore(&portdev->ports_lock, flags);
256 static bool is_console_port(struct port *port)
263 static inline bool use_multiport(struct ports_device *portdev)
266 * This condition can be true when put_chars is called from
271 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
274 static void free_buf(struct port_buffer *buf)
280 static struct port_buffer *alloc_buf(size_t buf_size)
282 struct port_buffer *buf;
284 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
287 buf->buf = kzalloc(buf_size, GFP_KERNEL);
292 buf->size = buf_size;
301 /* Callers should take appropriate locks */
302 static void *get_inbuf(struct port *port)
304 struct port_buffer *buf;
305 struct virtqueue *vq;
309 buf = virtqueue_get_buf(vq, &len);
318 * Create a scatter-gather list representing our input buffer and put
321 * Callers should take appropriate locks.
323 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
325 struct scatterlist sg[1];
328 sg_init_one(sg, buf->buf, buf->size);
330 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
335 /* Discard any unread data this port has. Callers lockers. */
336 static void discard_port_data(struct port *port)
338 struct port_buffer *buf;
339 struct virtqueue *vq;
347 buf = virtqueue_get_buf(vq, &len);
351 if (add_inbuf(vq, buf) < 0) {
355 buf = virtqueue_get_buf(vq, &len);
359 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
363 static bool port_has_data(struct port *port)
368 spin_lock_irqsave(&port->inbuf_lock, flags);
373 port->inbuf = get_inbuf(port);
380 spin_unlock_irqrestore(&port->inbuf_lock, flags);
384 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
385 unsigned int event, unsigned int value)
387 struct scatterlist sg[1];
388 struct virtio_console_control cpkt;
389 struct virtqueue *vq;
392 if (!use_multiport(portdev))
401 sg_init_one(sg, &cpkt, sizeof(cpkt));
402 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
404 while (!virtqueue_get_buf(vq, &len))
410 static ssize_t send_control_msg(struct port *port, unsigned int event,
413 return __send_control_msg(port->portdev, port->id, event, value);
416 /* Callers must take the port->outvq_lock */
417 static void reclaim_consumed_buffers(struct port *port)
422 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
424 port->outvq_full = false;
428 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
431 struct scatterlist sg[1];
432 struct virtqueue *out_vq;
437 out_vq = port->out_vq;
439 spin_lock_irqsave(&port->outvq_lock, flags);
441 reclaim_consumed_buffers(port);
443 sg_init_one(sg, in_buf, in_count);
444 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
446 /* Tell Host to go! */
447 virtqueue_kick(out_vq);
455 port->outvq_full = true;
461 * Wait till the host acknowledges it pushed out the data we
462 * sent. This is done for ports in blocking mode or for data
463 * from the hvc_console; the tty operations are performed with
464 * spinlocks held so we can't sleep here.
466 while (!virtqueue_get_buf(out_vq, &len))
469 spin_unlock_irqrestore(&port->outvq_lock, flags);
471 * We're expected to return the amount of data we wrote -- all
478 * Give out the data that's requested from the buffer that we have
481 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
484 struct port_buffer *buf;
487 if (!out_count || !port_has_data(port))
491 out_count = min(out_count, buf->len - buf->offset);
496 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
500 memcpy(out_buf, buf->buf + buf->offset, out_count);
503 buf->offset += out_count;
505 if (buf->offset == buf->len) {
507 * We're done using all the data in this buffer.
508 * Re-queue so that the Host can send us more data.
510 spin_lock_irqsave(&port->inbuf_lock, flags);
513 if (add_inbuf(port->in_vq, buf) < 0)
514 dev_warn(port->dev, "failed add_buf\n");
516 spin_unlock_irqrestore(&port->inbuf_lock, flags);
518 /* Return the number of bytes actually copied */
522 /* The condition that must be true for polling to end */
523 static bool will_read_block(struct port *port)
525 return !port_has_data(port) && port->host_connected;
528 static bool will_write_block(struct port *port)
532 if (!port->guest_connected) {
533 /* Port got hot-unplugged. Let's exit. */
536 if (!port->host_connected)
539 spin_lock_irq(&port->outvq_lock);
541 * Check if the Host has consumed any buffers since we last
542 * sent data (this is only applicable for nonblocking ports).
544 reclaim_consumed_buffers(port);
545 ret = port->outvq_full;
546 spin_unlock_irq(&port->outvq_lock);
551 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
552 size_t count, loff_t *offp)
557 port = filp->private_data;
559 if (!port_has_data(port)) {
561 * If nothing's connected on the host just return 0 in
562 * case of list_empty; this tells the userspace app
563 * that there's no connection
565 if (!port->host_connected)
567 if (filp->f_flags & O_NONBLOCK)
570 ret = wait_event_interruptible(port->waitqueue,
571 !will_read_block(port));
576 * We could've received a disconnection message while we were
577 * waiting for more data.
579 * This check is not clubbed in the if() statement above as we
580 * might receive some data as well as the host could get
581 * disconnected after we got woken up from our wait. So we
582 * really want to give off whatever data we have and only then
583 * check for host_connected.
585 if (!port_has_data(port) && !port->host_connected)
588 return fill_readbuf(port, ubuf, count, true);
591 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
592 size_t count, loff_t *offp)
599 port = filp->private_data;
601 nonblock = filp->f_flags & O_NONBLOCK;
603 if (will_write_block(port)) {
607 ret = wait_event_interruptible(port->waitqueue,
608 !will_write_block(port));
613 count = min((size_t)(32 * 1024), count);
615 buf = kmalloc(count, GFP_KERNEL);
619 ret = copy_from_user(buf, ubuf, count);
625 ret = send_buf(port, buf, count, nonblock);
627 if (nonblock && ret > 0)
636 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
641 port = filp->private_data;
642 poll_wait(filp, &port->waitqueue, wait);
646 ret |= POLLIN | POLLRDNORM;
647 if (!will_write_block(port))
649 if (!port->host_connected)
655 static int port_fops_release(struct inode *inode, struct file *filp)
659 port = filp->private_data;
661 /* Notify host of port being closed */
662 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
664 spin_lock_irq(&port->inbuf_lock);
665 port->guest_connected = false;
667 discard_port_data(port);
669 spin_unlock_irq(&port->inbuf_lock);
671 spin_lock_irq(&port->outvq_lock);
672 reclaim_consumed_buffers(port);
673 spin_unlock_irq(&port->outvq_lock);
678 static int port_fops_open(struct inode *inode, struct file *filp)
680 struct cdev *cdev = inode->i_cdev;
683 port = container_of(cdev, struct port, cdev);
684 filp->private_data = port;
687 * Don't allow opening of console port devices -- that's done
690 if (is_console_port(port))
693 /* Allow only one process to open a particular port at a time */
694 spin_lock_irq(&port->inbuf_lock);
695 if (port->guest_connected) {
696 spin_unlock_irq(&port->inbuf_lock);
700 port->guest_connected = true;
701 spin_unlock_irq(&port->inbuf_lock);
703 spin_lock_irq(&port->outvq_lock);
705 * There might be a chance that we missed reclaiming a few
706 * buffers in the window of the port getting previously closed
709 reclaim_consumed_buffers(port);
710 spin_unlock_irq(&port->outvq_lock);
712 /* Notify host of port being opened */
713 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
719 * The file operations that we support: programs in the guest can open
720 * a console device, read from it, write to it, poll for data and
721 * close it. The devices are at
722 * /dev/vport<device number>p<port number>
724 static const struct file_operations port_fops = {
725 .owner = THIS_MODULE,
726 .open = port_fops_open,
727 .read = port_fops_read,
728 .write = port_fops_write,
729 .poll = port_fops_poll,
730 .release = port_fops_release,
734 * The put_chars() callback is pretty straightforward.
736 * We turn the characters into a scatter-gather list, add it to the
737 * output queue and then kick the Host. Then we sit here waiting for
738 * it to finish: inefficient in theory, but in practice
739 * implementations will do it immediately (lguest's Launcher does).
741 static int put_chars(u32 vtermno, const char *buf, int count)
745 if (unlikely(early_put_chars))
746 return early_put_chars(vtermno, buf, count);
748 port = find_port_by_vtermno(vtermno);
752 return send_buf(port, (void *)buf, count, false);
756 * get_chars() is the callback from the hvc_console infrastructure
757 * when an interrupt is received.
759 * We call out to fill_readbuf that gets us the required data from the
760 * buffers that are queued up.
762 static int get_chars(u32 vtermno, char *buf, int count)
766 /* If we've not set up the port yet, we have no input to give. */
767 if (unlikely(early_put_chars))
770 port = find_port_by_vtermno(vtermno);
774 /* If we don't have an input queue yet, we can't get input. */
775 BUG_ON(!port->in_vq);
777 return fill_readbuf(port, buf, count, false);
780 static void resize_console(struct port *port)
782 struct virtio_device *vdev;
784 /* The port could have been hot-unplugged */
785 if (!port || !is_console_port(port))
788 vdev = port->portdev->vdev;
789 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
790 hvc_resize(port->cons.hvc, port->cons.ws);
793 /* We set the configuration at this point, since we now have a tty */
794 static int notifier_add_vio(struct hvc_struct *hp, int data)
798 port = find_port_by_vtermno(hp->vtermno);
802 hp->irq_requested = 1;
803 resize_console(port);
808 static void notifier_del_vio(struct hvc_struct *hp, int data)
810 hp->irq_requested = 0;
813 /* The operations for console ports. */
814 static const struct hv_ops hv_ops = {
815 .get_chars = get_chars,
816 .put_chars = put_chars,
817 .notifier_add = notifier_add_vio,
818 .notifier_del = notifier_del_vio,
819 .notifier_hangup = notifier_del_vio,
823 * Console drivers are initialized very early so boot messages can go
824 * out, so we do things slightly differently from the generic virtio
825 * initialization of the net and block drivers.
827 * At this stage, the console is output-only. It's too early to set
828 * up a virtqueue, so we let the drivers do some boutique early-output
831 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
833 early_put_chars = put_chars;
834 return hvc_instantiate(0, 0, &hv_ops);
837 int init_port_console(struct port *port)
842 * The Host's telling us this port is a console port. Hook it
843 * up with an hvc console.
845 * To set up and manage our virtual console, we call
848 * The first argument of hvc_alloc() is the virtual console
849 * number. The second argument is the parameter for the
850 * notification mechanism (like irq number). We currently
851 * leave this as zero, virtqueues have implicit notifications.
853 * The third argument is a "struct hv_ops" containing the
854 * put_chars() get_chars(), notifier_add() and notifier_del()
855 * pointers. The final argument is the output buffer size: we
856 * can do any size, so we put PAGE_SIZE here.
858 port->cons.vtermno = pdrvdata.next_vtermno;
860 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
861 if (IS_ERR(port->cons.hvc)) {
862 ret = PTR_ERR(port->cons.hvc);
864 "error %d allocating hvc for port\n", ret);
865 port->cons.hvc = NULL;
868 spin_lock_irq(&pdrvdata_lock);
869 pdrvdata.next_vtermno++;
870 list_add_tail(&port->cons.list, &pdrvdata.consoles);
871 spin_unlock_irq(&pdrvdata_lock);
872 port->guest_connected = true;
875 * Start using the new console output if this is the first
876 * console to come up.
879 early_put_chars = NULL;
881 /* Notify host of port being opened */
882 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
887 static ssize_t show_port_name(struct device *dev,
888 struct device_attribute *attr, char *buffer)
892 port = dev_get_drvdata(dev);
894 return sprintf(buffer, "%s\n", port->name);
897 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
899 static struct attribute *port_sysfs_entries[] = {
904 static struct attribute_group port_attribute_group = {
905 .name = NULL, /* put in device directory */
906 .attrs = port_sysfs_entries,
909 static int debugfs_open(struct inode *inode, struct file *filp)
911 filp->private_data = inode->i_private;
915 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
916 size_t count, loff_t *offp)
920 ssize_t ret, out_offset, out_count;
923 buf = kmalloc(out_count, GFP_KERNEL);
927 port = filp->private_data;
929 out_offset += snprintf(buf + out_offset, out_count,
930 "name: %s\n", port->name ? port->name : "");
931 out_offset += snprintf(buf + out_offset, out_count - out_offset,
932 "guest_connected: %d\n", port->guest_connected);
933 out_offset += snprintf(buf + out_offset, out_count - out_offset,
934 "host_connected: %d\n", port->host_connected);
935 out_offset += snprintf(buf + out_offset, out_count - out_offset,
936 "outvq_full: %d\n", port->outvq_full);
937 out_offset += snprintf(buf + out_offset, out_count - out_offset,
939 is_console_port(port) ? "yes" : "no");
940 out_offset += snprintf(buf + out_offset, out_count - out_offset,
941 "console_vtermno: %u\n", port->cons.vtermno);
943 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
948 static const struct file_operations port_debugfs_ops = {
949 .owner = THIS_MODULE,
950 .open = debugfs_open,
951 .read = debugfs_read,
954 static void set_console_size(struct port *port, u16 rows, u16 cols)
956 if (!port || !is_console_port(port))
959 port->cons.ws.ws_row = rows;
960 port->cons.ws.ws_col = cols;
963 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
965 struct port_buffer *buf;
966 unsigned int nr_added_bufs;
971 buf = alloc_buf(PAGE_SIZE);
976 ret = add_inbuf(vq, buf);
978 spin_unlock_irq(lock);
983 spin_unlock_irq(lock);
986 return nr_added_bufs;
989 static int add_port(struct ports_device *portdev, u32 id)
991 char debugfs_name[16];
993 struct port_buffer *buf;
995 unsigned int nr_added_bufs;
998 port = kmalloc(sizeof(*port), GFP_KERNEL);
1004 port->portdev = portdev;
1009 port->cons.hvc = NULL;
1011 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1013 port->host_connected = port->guest_connected = false;
1015 port->outvq_full = false;
1017 port->in_vq = portdev->in_vqs[port->id];
1018 port->out_vq = portdev->out_vqs[port->id];
1020 cdev_init(&port->cdev, &port_fops);
1022 devt = MKDEV(portdev->chr_major, id);
1023 err = cdev_add(&port->cdev, devt, 1);
1025 dev_err(&port->portdev->vdev->dev,
1026 "Error %d adding cdev for port %u\n", err, id);
1029 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1030 devt, port, "vport%up%u",
1031 port->portdev->drv_index, id);
1032 if (IS_ERR(port->dev)) {
1033 err = PTR_ERR(port->dev);
1034 dev_err(&port->portdev->vdev->dev,
1035 "Error %d creating device for port %u\n",
1040 spin_lock_init(&port->inbuf_lock);
1041 spin_lock_init(&port->outvq_lock);
1042 init_waitqueue_head(&port->waitqueue);
1044 /* Fill the in_vq with buffers so the host can send us data. */
1045 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1046 if (!nr_added_bufs) {
1047 dev_err(port->dev, "Error allocating inbufs\n");
1053 * If we're not using multiport support, this has to be a console port
1055 if (!use_multiport(port->portdev)) {
1056 err = init_port_console(port);
1061 spin_lock_irq(&portdev->ports_lock);
1062 list_add_tail(&port->list, &port->portdev->ports);
1063 spin_unlock_irq(&portdev->ports_lock);
1066 * Tell the Host we're set so that it can send us various
1067 * configuration parameters for this port (eg, port name,
1068 * caching, whether this is a console port, etc.)
1070 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1072 if (pdrvdata.debugfs_dir) {
1074 * Finally, create the debugfs file that we can use to
1075 * inspect a port's state at any time
1077 sprintf(debugfs_name, "vport%up%u",
1078 port->portdev->drv_index, id);
1079 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1080 pdrvdata.debugfs_dir,
1087 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1090 device_destroy(pdrvdata.class, port->dev->devt);
1092 cdev_del(&port->cdev);
1096 /* The host might want to notify management sw about port add failure */
1097 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1101 /* Remove all port-specific data. */
1102 static int remove_port(struct port *port)
1104 struct port_buffer *buf;
1106 if (port->guest_connected) {
1107 port->guest_connected = false;
1108 port->host_connected = false;
1109 wake_up_interruptible(&port->waitqueue);
1110 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
1113 spin_lock_irq(&port->portdev->ports_lock);
1114 list_del(&port->list);
1115 spin_unlock_irq(&port->portdev->ports_lock);
1117 if (is_console_port(port)) {
1118 spin_lock_irq(&pdrvdata_lock);
1119 list_del(&port->cons.list);
1120 spin_unlock_irq(&pdrvdata_lock);
1123 * hvc_remove() not called as removing one hvc port
1124 * results in other hvc ports getting frozen.
1126 * Once this is resolved in hvc, this functionality
1127 * will be enabled. Till that is done, the -EPIPE
1128 * return from get_chars() above will help
1129 * hvc_console.c to clean up on ports we remove here.
1131 hvc_remove(port->cons.hvc);
1134 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1135 device_destroy(pdrvdata.class, port->dev->devt);
1136 cdev_del(&port->cdev);
1138 /* Remove unused data this port might have received. */
1139 discard_port_data(port);
1141 reclaim_consumed_buffers(port);
1143 /* Remove buffers we queued up for the Host to send us data in. */
1144 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1149 debugfs_remove(port->debugfs_file);
1155 /* Any private messages that the Host and Guest want to share */
1156 static void handle_control_message(struct ports_device *portdev,
1157 struct port_buffer *buf)
1159 struct virtio_console_control *cpkt;
1164 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1166 port = find_port_by_id(portdev, cpkt->id);
1167 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1168 /* No valid header at start of buffer. Drop it. */
1169 dev_dbg(&portdev->vdev->dev,
1170 "Invalid index %u in control packet\n", cpkt->id);
1174 switch (cpkt->event) {
1175 case VIRTIO_CONSOLE_PORT_ADD:
1177 dev_dbg(&portdev->vdev->dev,
1178 "Port %u already added\n", port->id);
1179 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1182 if (cpkt->id >= portdev->config.max_nr_ports) {
1183 dev_warn(&portdev->vdev->dev,
1184 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1185 cpkt->id, portdev->config.max_nr_ports - 1);
1188 add_port(portdev, cpkt->id);
1190 case VIRTIO_CONSOLE_PORT_REMOVE:
1193 case VIRTIO_CONSOLE_CONSOLE_PORT:
1196 if (is_console_port(port))
1199 init_port_console(port);
1201 * Could remove the port here in case init fails - but
1202 * have to notify the host first.
1205 case VIRTIO_CONSOLE_RESIZE: {
1211 if (!is_console_port(port))
1214 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1216 set_console_size(port, size.rows, size.cols);
1218 port->cons.hvc->irq_requested = 1;
1219 resize_console(port);
1222 case VIRTIO_CONSOLE_PORT_OPEN:
1223 port->host_connected = cpkt->value;
1224 wake_up_interruptible(&port->waitqueue);
1226 * If the host port got closed and the host had any
1227 * unconsumed buffers, we'll be able to reclaim them
1230 spin_lock_irq(&port->outvq_lock);
1231 reclaim_consumed_buffers(port);
1232 spin_unlock_irq(&port->outvq_lock);
1234 case VIRTIO_CONSOLE_PORT_NAME:
1236 * Skip the size of the header and the cpkt to get the size
1237 * of the name that was sent
1239 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1241 port->name = kmalloc(name_size, GFP_KERNEL);
1244 "Not enough space to store port name\n");
1247 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1249 port->name[name_size - 1] = 0;
1252 * Since we only have one sysfs attribute, 'name',
1253 * create it only if we have a name for the port.
1255 err = sysfs_create_group(&port->dev->kobj,
1256 &port_attribute_group);
1259 "Error %d creating sysfs device attributes\n",
1263 * Generate a udev event so that appropriate
1264 * symlinks can be created based on udev
1267 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1273 static void control_work_handler(struct work_struct *work)
1275 struct ports_device *portdev;
1276 struct virtqueue *vq;
1277 struct port_buffer *buf;
1280 portdev = container_of(work, struct ports_device, control_work);
1281 vq = portdev->c_ivq;
1283 spin_lock(&portdev->cvq_lock);
1284 while ((buf = virtqueue_get_buf(vq, &len))) {
1285 spin_unlock(&portdev->cvq_lock);
1290 handle_control_message(portdev, buf);
1292 spin_lock(&portdev->cvq_lock);
1293 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1294 dev_warn(&portdev->vdev->dev,
1295 "Error adding buffer to queue\n");
1299 spin_unlock(&portdev->cvq_lock);
1302 static void in_intr(struct virtqueue *vq)
1305 unsigned long flags;
1307 port = find_port_by_vq(vq->vdev->priv, vq);
1311 spin_lock_irqsave(&port->inbuf_lock, flags);
1313 port->inbuf = get_inbuf(port);
1316 * Don't queue up data when port is closed. This condition
1317 * can be reached when a console port is not yet connected (no
1318 * tty is spawned) and the host sends out data to console
1319 * ports. For generic serial ports, the host won't
1320 * (shouldn't) send data till the guest is connected.
1322 if (!port->guest_connected)
1323 discard_port_data(port);
1325 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1327 wake_up_interruptible(&port->waitqueue);
1329 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1333 static void control_intr(struct virtqueue *vq)
1335 struct ports_device *portdev;
1337 portdev = vq->vdev->priv;
1338 schedule_work(&portdev->control_work);
1341 static void config_intr(struct virtio_device *vdev)
1343 struct ports_device *portdev;
1345 portdev = vdev->priv;
1347 if (!use_multiport(portdev)) {
1351 vdev->config->get(vdev,
1352 offsetof(struct virtio_console_config, cols),
1353 &cols, sizeof(u16));
1354 vdev->config->get(vdev,
1355 offsetof(struct virtio_console_config, rows),
1356 &rows, sizeof(u16));
1358 port = find_port_by_id(portdev, 0);
1359 set_console_size(port, rows, cols);
1362 * We'll use this way of resizing only for legacy
1363 * support. For newer userspace
1364 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1365 * to indicate console size changes so that it can be
1368 resize_console(port);
1372 static int init_vqs(struct ports_device *portdev)
1374 vq_callback_t **io_callbacks;
1376 struct virtqueue **vqs;
1377 u32 i, j, nr_ports, nr_queues;
1380 nr_ports = portdev->config.max_nr_ports;
1381 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1383 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1388 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1389 if (!io_callbacks) {
1393 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1396 goto free_callbacks;
1398 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1400 if (!portdev->in_vqs) {
1404 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1406 if (!portdev->out_vqs) {
1412 * For backward compat (newer host but older guest), the host
1413 * spawns a console port first and also inits the vqs for port
1417 io_callbacks[j] = in_intr;
1418 io_callbacks[j + 1] = NULL;
1419 io_names[j] = "input";
1420 io_names[j + 1] = "output";
1423 if (use_multiport(portdev)) {
1424 io_callbacks[j] = control_intr;
1425 io_callbacks[j + 1] = NULL;
1426 io_names[j] = "control-i";
1427 io_names[j + 1] = "control-o";
1429 for (i = 1; i < nr_ports; i++) {
1431 io_callbacks[j] = in_intr;
1432 io_callbacks[j + 1] = NULL;
1433 io_names[j] = "input";
1434 io_names[j + 1] = "output";
1437 /* Find the queues. */
1438 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1440 (const char **)io_names);
1445 portdev->in_vqs[0] = vqs[0];
1446 portdev->out_vqs[0] = vqs[1];
1448 if (use_multiport(portdev)) {
1449 portdev->c_ivq = vqs[j];
1450 portdev->c_ovq = vqs[j + 1];
1452 for (i = 1; i < nr_ports; i++) {
1454 portdev->in_vqs[i] = vqs[j];
1455 portdev->out_vqs[i] = vqs[j + 1];
1458 kfree(io_callbacks);
1467 kfree(io_callbacks);
1469 kfree(portdev->out_vqs);
1471 kfree(portdev->in_vqs);
1478 static const struct file_operations portdev_fops = {
1479 .owner = THIS_MODULE,
1483 * Once we're further in boot, we get probed like any other virtio
1486 * If the host also supports multiple console ports, we check the
1487 * config space to see how many ports the host has spawned. We
1488 * initialize each port found.
1490 static int __devinit virtcons_probe(struct virtio_device *vdev)
1492 struct ports_device *portdev;
1496 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1502 /* Attach this portdev to this virtio_device, and vice-versa. */
1503 portdev->vdev = vdev;
1504 vdev->priv = portdev;
1506 spin_lock_irq(&pdrvdata_lock);
1507 portdev->drv_index = pdrvdata.index++;
1508 spin_unlock_irq(&pdrvdata_lock);
1510 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1512 if (portdev->chr_major < 0) {
1514 "Error %d registering chrdev for device %u\n",
1515 portdev->chr_major, portdev->drv_index);
1516 err = portdev->chr_major;
1521 portdev->config.max_nr_ports = 1;
1522 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1524 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1526 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1528 &portdev->config.max_nr_ports,
1529 sizeof(portdev->config.max_nr_ports));
1532 /* Let the Host know we support multiple ports.*/
1533 vdev->config->finalize_features(vdev);
1535 err = init_vqs(portdev);
1537 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1541 spin_lock_init(&portdev->ports_lock);
1542 INIT_LIST_HEAD(&portdev->ports);
1545 unsigned int nr_added_bufs;
1547 spin_lock_init(&portdev->cvq_lock);
1548 INIT_WORK(&portdev->control_work, &control_work_handler);
1550 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1551 if (!nr_added_bufs) {
1553 "Error allocating buffers for control queue\n");
1559 * For backward compatibility: Create a console port
1560 * if we're running on older host.
1562 add_port(portdev, 0);
1565 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1566 VIRTIO_CONSOLE_DEVICE_READY, 1);
1570 /* The host might want to notify mgmt sw about device add failure */
1571 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1572 VIRTIO_CONSOLE_DEVICE_READY, 0);
1573 vdev->config->del_vqs(vdev);
1574 kfree(portdev->in_vqs);
1575 kfree(portdev->out_vqs);
1577 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1584 static void virtcons_remove(struct virtio_device *vdev)
1586 struct ports_device *portdev;
1587 struct port *port, *port2;
1588 struct port_buffer *buf;
1591 portdev = vdev->priv;
1593 cancel_work_sync(&portdev->control_work);
1595 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1598 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1600 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1603 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1606 vdev->config->del_vqs(vdev);
1607 kfree(portdev->in_vqs);
1608 kfree(portdev->out_vqs);
1613 static struct virtio_device_id id_table[] = {
1614 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1618 static unsigned int features[] = {
1619 VIRTIO_CONSOLE_F_SIZE,
1620 VIRTIO_CONSOLE_F_MULTIPORT,
1623 static struct virtio_driver virtio_console = {
1624 .feature_table = features,
1625 .feature_table_size = ARRAY_SIZE(features),
1626 .driver.name = KBUILD_MODNAME,
1627 .driver.owner = THIS_MODULE,
1628 .id_table = id_table,
1629 .probe = virtcons_probe,
1630 .remove = virtcons_remove,
1631 .config_changed = config_intr,
1634 static int __init init(void)
1638 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1639 if (IS_ERR(pdrvdata.class)) {
1640 err = PTR_ERR(pdrvdata.class);
1641 pr_err("Error %d creating virtio-ports class\n", err);
1645 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1646 if (!pdrvdata.debugfs_dir) {
1647 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1648 PTR_ERR(pdrvdata.debugfs_dir));
1650 INIT_LIST_HEAD(&pdrvdata.consoles);
1652 return register_virtio_driver(&virtio_console);
1655 static void __exit fini(void)
1657 unregister_virtio_driver(&virtio_console);
1659 class_destroy(pdrvdata.class);
1660 if (pdrvdata.debugfs_dir)
1661 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1666 MODULE_DEVICE_TABLE(virtio, id_table);
1667 MODULE_DESCRIPTION("Virtio console driver");
1668 MODULE_LICENSE("GPL");