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 "../tty/hvc/hvc_console.h"
40 * This is a global struct for storing common data for all the devices
41 * this driver handles.
43 * Mainly, it has a linked list for all the consoles in one place so
44 * that callbacks from hvc for get_chars(), put_chars() work properly
45 * across multiple devices and multiple ports per device.
47 struct ports_driver_data {
48 /* Used for registering chardevs */
51 /* Used for exporting per-port information to debugfs */
52 struct dentry *debugfs_dir;
54 /* List of all the devices we're handling */
55 struct list_head portdevs;
57 /* Number of devices this driver is handling */
61 * This is used to keep track of the number of hvc consoles
62 * spawned by this driver. This number is given as the first
63 * argument to hvc_alloc(). To correctly map an initial
64 * console spawned via hvc_instantiate to the console being
65 * hooked up via hvc_alloc, we need to pass the same vtermno.
67 * We also just assume the first console being initialised was
68 * the first one that got used as the initial console.
70 unsigned int next_vtermno;
72 /* All the console devices handled by this driver */
73 struct list_head consoles;
75 static struct ports_driver_data pdrvdata;
77 DEFINE_SPINLOCK(pdrvdata_lock);
78 DECLARE_COMPLETION(early_console_added);
80 /* This struct holds information that's relevant only for console ports */
82 /* We'll place all consoles in a list in the pdrvdata struct */
83 struct list_head list;
85 /* The hvc device associated with this console port */
86 struct hvc_struct *hvc;
88 /* The size of the console */
92 * This number identifies the number that we used to register
93 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
94 * number passed on by the hvc callbacks to us to
95 * differentiate between the other console ports handled by
104 /* size of the buffer in *buf above */
107 /* used length of the buffer */
109 /* offset in the buf from which to consume data */
114 * This is a per-device struct that stores data common to all the
115 * ports for that device (vdev->priv).
117 struct ports_device {
118 /* Next portdev in the list, head is in the pdrvdata struct */
119 struct list_head list;
122 * Workqueue handlers where we process deferred work after
125 struct work_struct control_work;
127 struct list_head ports;
129 /* To protect the list of ports */
130 spinlock_t ports_lock;
132 /* To protect the vq operations for the control channel */
135 /* The current config space is stored here */
136 struct virtio_console_config config;
138 /* The virtio device we're associated with */
139 struct virtio_device *vdev;
142 * A couple of virtqueues for the control channel: one for
143 * guest->host transfers, one for host->guest transfers
145 struct virtqueue *c_ivq, *c_ovq;
147 /* Array of per-port IO virtqueues */
148 struct virtqueue **in_vqs, **out_vqs;
150 /* Used for numbering devices for sysfs and debugfs */
151 unsigned int drv_index;
153 /* Major number for this device. Ports will be created as minors. */
158 unsigned long bytes_sent, bytes_received, bytes_discarded;
161 /* This struct holds the per-port data */
163 /* Next port in the list, head is in the ports_device */
164 struct list_head list;
166 /* Pointer to the parent virtio_console device */
167 struct ports_device *portdev;
169 /* The current buffer from which data has to be fed to readers */
170 struct port_buffer *inbuf;
173 * To protect the operations on the in_vq associated with this
174 * port. Has to be a spinlock because it can be called from
175 * interrupt context (get_char()).
177 spinlock_t inbuf_lock;
179 /* Protect the operations on the out_vq. */
180 spinlock_t outvq_lock;
182 /* The IO vqs for this port */
183 struct virtqueue *in_vq, *out_vq;
185 /* File in the debugfs directory that exposes this port's information */
186 struct dentry *debugfs_file;
189 * Keep count of the bytes sent, received and discarded for
190 * this port for accounting and debugging purposes. These
191 * counts are not reset across port open / close events.
193 struct port_stats stats;
196 * The entries in this struct will be valid if this port is
197 * hooked up to an hvc console
201 /* Each port associates with a separate char device */
205 /* Reference-counting to handle port hot-unplugs and file operations */
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 /* We can notify apps of host connect / disconnect events via SIGIO */
215 struct fasync_struct *async_queue;
217 /* The 'id' to identify the port with the Host */
222 /* Is the host device open */
225 /* We should allow only one process to open a port */
226 bool guest_connected;
229 /* This is the very early arch-specified put chars function. */
230 static int (*early_put_chars)(u32, const char *, int);
232 static struct port *find_port_by_vtermno(u32 vtermno)
235 struct console *cons;
238 spin_lock_irqsave(&pdrvdata_lock, flags);
239 list_for_each_entry(cons, &pdrvdata.consoles, list) {
240 if (cons->vtermno == vtermno) {
241 port = container_of(cons, struct port, cons);
247 spin_unlock_irqrestore(&pdrvdata_lock, flags);
251 static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
257 spin_lock_irqsave(&portdev->ports_lock, flags);
258 list_for_each_entry(port, &portdev->ports, list)
259 if (port->cdev->dev == dev)
263 spin_unlock_irqrestore(&portdev->ports_lock, flags);
268 static struct port *find_port_by_devt(dev_t dev)
270 struct ports_device *portdev;
274 spin_lock_irqsave(&pdrvdata_lock, flags);
275 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
276 port = find_port_by_devt_in_portdev(portdev, dev);
282 spin_unlock_irqrestore(&pdrvdata_lock, flags);
286 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
291 spin_lock_irqsave(&portdev->ports_lock, flags);
292 list_for_each_entry(port, &portdev->ports, list)
297 spin_unlock_irqrestore(&portdev->ports_lock, flags);
302 static struct port *find_port_by_vq(struct ports_device *portdev,
303 struct virtqueue *vq)
308 spin_lock_irqsave(&portdev->ports_lock, flags);
309 list_for_each_entry(port, &portdev->ports, list)
310 if (port->in_vq == vq || port->out_vq == vq)
314 spin_unlock_irqrestore(&portdev->ports_lock, flags);
318 static bool is_console_port(struct port *port)
325 static inline bool use_multiport(struct ports_device *portdev)
328 * This condition can be true when put_chars is called from
333 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
336 static void free_buf(struct port_buffer *buf)
342 static struct port_buffer *alloc_buf(size_t buf_size)
344 struct port_buffer *buf;
346 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
349 buf->buf = kzalloc(buf_size, GFP_KERNEL);
354 buf->size = buf_size;
363 /* Callers should take appropriate locks */
364 static struct port_buffer *get_inbuf(struct port *port)
366 struct port_buffer *buf;
372 buf = virtqueue_get_buf(port->in_vq, &len);
376 port->stats.bytes_received += len;
382 * Create a scatter-gather list representing our input buffer and put
385 * Callers should take appropriate locks.
387 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
389 struct scatterlist sg[1];
392 sg_init_one(sg, buf->buf, buf->size);
394 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
399 /* Discard any unread data this port has. Callers lockers. */
400 static void discard_port_data(struct port *port)
402 struct port_buffer *buf;
405 if (!port->portdev) {
406 /* Device has been unplugged. vqs are already gone. */
409 buf = get_inbuf(port);
413 port->stats.bytes_discarded += buf->len - buf->offset;
414 if (add_inbuf(port->in_vq, buf) < 0) {
419 buf = get_inbuf(port);
422 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
426 static bool port_has_data(struct port *port)
432 spin_lock_irqsave(&port->inbuf_lock, flags);
433 port->inbuf = get_inbuf(port);
437 spin_unlock_irqrestore(&port->inbuf_lock, flags);
441 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
442 unsigned int event, unsigned int value)
444 struct scatterlist sg[1];
445 struct virtio_console_control cpkt;
446 struct virtqueue *vq;
449 if (!use_multiport(portdev))
458 sg_init_one(sg, &cpkt, sizeof(cpkt));
459 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
461 while (!virtqueue_get_buf(vq, &len))
467 static ssize_t send_control_msg(struct port *port, unsigned int event,
470 /* Did the port get unplugged before userspace closed it? */
472 return __send_control_msg(port->portdev, port->id, event, value);
476 /* Callers must take the port->outvq_lock */
477 static void reclaim_consumed_buffers(struct port *port)
482 if (!port->portdev) {
483 /* Device has been unplugged. vqs are already gone. */
486 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
488 port->outvq_full = false;
492 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
495 struct scatterlist sg[1];
496 struct virtqueue *out_vq;
501 out_vq = port->out_vq;
503 spin_lock_irqsave(&port->outvq_lock, flags);
505 reclaim_consumed_buffers(port);
507 sg_init_one(sg, in_buf, in_count);
508 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
510 /* Tell Host to go! */
511 virtqueue_kick(out_vq);
519 port->outvq_full = true;
525 * Wait till the host acknowledges it pushed out the data we
526 * sent. This is done for data from the hvc_console; the tty
527 * operations are performed with spinlocks held so we can't
528 * sleep here. An alternative would be to copy the data to a
529 * buffer and relax the spinning requirement. The downside is
530 * we need to kmalloc a GFP_ATOMIC buffer each time the
531 * console driver writes something out.
533 while (!virtqueue_get_buf(out_vq, &len))
536 spin_unlock_irqrestore(&port->outvq_lock, flags);
538 port->stats.bytes_sent += in_count;
540 * We're expected to return the amount of data we wrote -- all
547 * Give out the data that's requested from the buffer that we have
550 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
553 struct port_buffer *buf;
556 if (!out_count || !port_has_data(port))
560 out_count = min(out_count, buf->len - buf->offset);
565 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
569 memcpy(out_buf, buf->buf + buf->offset, out_count);
572 buf->offset += out_count;
574 if (buf->offset == buf->len) {
576 * We're done using all the data in this buffer.
577 * Re-queue so that the Host can send us more data.
579 spin_lock_irqsave(&port->inbuf_lock, flags);
582 if (add_inbuf(port->in_vq, buf) < 0)
583 dev_warn(port->dev, "failed add_buf\n");
585 spin_unlock_irqrestore(&port->inbuf_lock, flags);
587 /* Return the number of bytes actually copied */
591 /* The condition that must be true for polling to end */
592 static bool will_read_block(struct port *port)
594 if (!port->guest_connected) {
595 /* Port got hot-unplugged. Let's exit. */
598 return !port_has_data(port) && port->host_connected;
601 static bool will_write_block(struct port *port)
605 if (!port->guest_connected) {
606 /* Port got hot-unplugged. Let's exit. */
609 if (!port->host_connected)
612 spin_lock_irq(&port->outvq_lock);
614 * Check if the Host has consumed any buffers since we last
615 * sent data (this is only applicable for nonblocking ports).
617 reclaim_consumed_buffers(port);
618 ret = port->outvq_full;
619 spin_unlock_irq(&port->outvq_lock);
624 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
625 size_t count, loff_t *offp)
630 port = filp->private_data;
632 if (!port_has_data(port)) {
634 * If nothing's connected on the host just return 0 in
635 * case of list_empty; this tells the userspace app
636 * that there's no connection
638 if (!port->host_connected)
640 if (filp->f_flags & O_NONBLOCK)
643 ret = wait_event_freezable(port->waitqueue,
644 !will_read_block(port));
648 /* Port got hot-unplugged. */
649 if (!port->guest_connected)
652 * We could've received a disconnection message while we were
653 * waiting for more data.
655 * This check is not clubbed in the if() statement above as we
656 * might receive some data as well as the host could get
657 * disconnected after we got woken up from our wait. So we
658 * really want to give off whatever data we have and only then
659 * check for host_connected.
661 if (!port_has_data(port) && !port->host_connected)
664 return fill_readbuf(port, ubuf, count, true);
667 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
668 size_t count, loff_t *offp)
675 /* Userspace could be out to fool us */
679 port = filp->private_data;
681 nonblock = filp->f_flags & O_NONBLOCK;
683 if (will_write_block(port)) {
687 ret = wait_event_freezable(port->waitqueue,
688 !will_write_block(port));
692 /* Port got hot-unplugged. */
693 if (!port->guest_connected)
696 count = min((size_t)(32 * 1024), count);
698 buf = kmalloc(count, GFP_KERNEL);
702 ret = copy_from_user(buf, ubuf, count);
709 * We now ask send_buf() to not spin for generic ports -- we
710 * can re-use the same code path that non-blocking file
711 * descriptors take for blocking file descriptors since the
712 * wait is already done and we're certain the write will go
713 * through to the host.
716 ret = send_buf(port, buf, count, nonblock);
718 if (nonblock && ret > 0)
727 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
732 port = filp->private_data;
733 poll_wait(filp, &port->waitqueue, wait);
735 if (!port->guest_connected) {
736 /* Port got unplugged */
740 if (!will_read_block(port))
741 ret |= POLLIN | POLLRDNORM;
742 if (!will_write_block(port))
744 if (!port->host_connected)
750 static void remove_port(struct kref *kref);
752 static int port_fops_release(struct inode *inode, struct file *filp)
756 port = filp->private_data;
758 /* Notify host of port being closed */
759 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
761 spin_lock_irq(&port->inbuf_lock);
762 port->guest_connected = false;
764 discard_port_data(port);
766 spin_unlock_irq(&port->inbuf_lock);
768 spin_lock_irq(&port->outvq_lock);
769 reclaim_consumed_buffers(port);
770 spin_unlock_irq(&port->outvq_lock);
773 * Locks aren't necessary here as a port can't be opened after
774 * unplug, and if a port isn't unplugged, a kref would already
775 * exist for the port. Plus, taking ports_lock here would
776 * create a dependency on other locks taken by functions
777 * inside remove_port if we're the last holder of the port,
778 * creating many problems.
780 kref_put(&port->kref, remove_port);
785 static int port_fops_open(struct inode *inode, struct file *filp)
787 struct cdev *cdev = inode->i_cdev;
791 port = find_port_by_devt(cdev->dev);
792 filp->private_data = port;
794 /* Prevent against a port getting hot-unplugged at the same time */
795 spin_lock_irq(&port->portdev->ports_lock);
796 kref_get(&port->kref);
797 spin_unlock_irq(&port->portdev->ports_lock);
800 * Don't allow opening of console port devices -- that's done
803 if (is_console_port(port)) {
808 /* Allow only one process to open a particular port at a time */
809 spin_lock_irq(&port->inbuf_lock);
810 if (port->guest_connected) {
811 spin_unlock_irq(&port->inbuf_lock);
816 port->guest_connected = true;
817 spin_unlock_irq(&port->inbuf_lock);
819 spin_lock_irq(&port->outvq_lock);
821 * There might be a chance that we missed reclaiming a few
822 * buffers in the window of the port getting previously closed
825 reclaim_consumed_buffers(port);
826 spin_unlock_irq(&port->outvq_lock);
828 nonseekable_open(inode, filp);
830 /* Notify host of port being opened */
831 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
835 kref_put(&port->kref, remove_port);
839 static int port_fops_fasync(int fd, struct file *filp, int mode)
843 port = filp->private_data;
844 return fasync_helper(fd, filp, mode, &port->async_queue);
848 * The file operations that we support: programs in the guest can open
849 * a console device, read from it, write to it, poll for data and
850 * close it. The devices are at
851 * /dev/vport<device number>p<port number>
853 static const struct file_operations port_fops = {
854 .owner = THIS_MODULE,
855 .open = port_fops_open,
856 .read = port_fops_read,
857 .write = port_fops_write,
858 .poll = port_fops_poll,
859 .release = port_fops_release,
860 .fasync = port_fops_fasync,
865 * The put_chars() callback is pretty straightforward.
867 * We turn the characters into a scatter-gather list, add it to the
868 * output queue and then kick the Host. Then we sit here waiting for
869 * it to finish: inefficient in theory, but in practice
870 * implementations will do it immediately (lguest's Launcher does).
872 static int put_chars(u32 vtermno, const char *buf, int count)
876 if (unlikely(early_put_chars))
877 return early_put_chars(vtermno, buf, count);
879 port = find_port_by_vtermno(vtermno);
883 return send_buf(port, (void *)buf, count, false);
887 * get_chars() is the callback from the hvc_console infrastructure
888 * when an interrupt is received.
890 * We call out to fill_readbuf that gets us the required data from the
891 * buffers that are queued up.
893 static int get_chars(u32 vtermno, char *buf, int count)
897 /* If we've not set up the port yet, we have no input to give. */
898 if (unlikely(early_put_chars))
901 port = find_port_by_vtermno(vtermno);
905 /* If we don't have an input queue yet, we can't get input. */
906 BUG_ON(!port->in_vq);
908 return fill_readbuf(port, buf, count, false);
911 static void resize_console(struct port *port)
913 struct virtio_device *vdev;
915 /* The port could have been hot-unplugged */
916 if (!port || !is_console_port(port))
919 vdev = port->portdev->vdev;
920 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
921 hvc_resize(port->cons.hvc, port->cons.ws);
924 /* We set the configuration at this point, since we now have a tty */
925 static int notifier_add_vio(struct hvc_struct *hp, int data)
929 port = find_port_by_vtermno(hp->vtermno);
933 hp->irq_requested = 1;
934 resize_console(port);
939 static void notifier_del_vio(struct hvc_struct *hp, int data)
941 hp->irq_requested = 0;
944 /* The operations for console ports. */
945 static const struct hv_ops hv_ops = {
946 .get_chars = get_chars,
947 .put_chars = put_chars,
948 .notifier_add = notifier_add_vio,
949 .notifier_del = notifier_del_vio,
950 .notifier_hangup = notifier_del_vio,
954 * Console drivers are initialized very early so boot messages can go
955 * out, so we do things slightly differently from the generic virtio
956 * initialization of the net and block drivers.
958 * At this stage, the console is output-only. It's too early to set
959 * up a virtqueue, so we let the drivers do some boutique early-output
962 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
964 early_put_chars = put_chars;
965 return hvc_instantiate(0, 0, &hv_ops);
968 int init_port_console(struct port *port)
973 * The Host's telling us this port is a console port. Hook it
974 * up with an hvc console.
976 * To set up and manage our virtual console, we call
979 * The first argument of hvc_alloc() is the virtual console
980 * number. The second argument is the parameter for the
981 * notification mechanism (like irq number). We currently
982 * leave this as zero, virtqueues have implicit notifications.
984 * The third argument is a "struct hv_ops" containing the
985 * put_chars() get_chars(), notifier_add() and notifier_del()
986 * pointers. The final argument is the output buffer size: we
987 * can do any size, so we put PAGE_SIZE here.
989 port->cons.vtermno = pdrvdata.next_vtermno;
991 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
992 if (IS_ERR(port->cons.hvc)) {
993 ret = PTR_ERR(port->cons.hvc);
995 "error %d allocating hvc for port\n", ret);
996 port->cons.hvc = NULL;
999 spin_lock_irq(&pdrvdata_lock);
1000 pdrvdata.next_vtermno++;
1001 list_add_tail(&port->cons.list, &pdrvdata.consoles);
1002 spin_unlock_irq(&pdrvdata_lock);
1003 port->guest_connected = true;
1006 * Start using the new console output if this is the first
1007 * console to come up.
1009 if (early_put_chars)
1010 early_put_chars = NULL;
1012 /* Notify host of port being opened */
1013 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1018 static ssize_t show_port_name(struct device *dev,
1019 struct device_attribute *attr, char *buffer)
1023 port = dev_get_drvdata(dev);
1025 return sprintf(buffer, "%s\n", port->name);
1028 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1030 static struct attribute *port_sysfs_entries[] = {
1031 &dev_attr_name.attr,
1035 static struct attribute_group port_attribute_group = {
1036 .name = NULL, /* put in device directory */
1037 .attrs = port_sysfs_entries,
1040 static int debugfs_open(struct inode *inode, struct file *filp)
1042 filp->private_data = inode->i_private;
1046 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1047 size_t count, loff_t *offp)
1051 ssize_t ret, out_offset, out_count;
1054 buf = kmalloc(out_count, GFP_KERNEL);
1058 port = filp->private_data;
1060 out_offset += snprintf(buf + out_offset, out_count,
1061 "name: %s\n", port->name ? port->name : "");
1062 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1063 "guest_connected: %d\n", port->guest_connected);
1064 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1065 "host_connected: %d\n", port->host_connected);
1066 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1067 "outvq_full: %d\n", port->outvq_full);
1068 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1069 "bytes_sent: %lu\n", port->stats.bytes_sent);
1070 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1071 "bytes_received: %lu\n",
1072 port->stats.bytes_received);
1073 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1074 "bytes_discarded: %lu\n",
1075 port->stats.bytes_discarded);
1076 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1078 is_console_port(port) ? "yes" : "no");
1079 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1080 "console_vtermno: %u\n", port->cons.vtermno);
1082 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1087 static const struct file_operations port_debugfs_ops = {
1088 .owner = THIS_MODULE,
1089 .open = debugfs_open,
1090 .read = debugfs_read,
1093 static void set_console_size(struct port *port, u16 rows, u16 cols)
1095 if (!port || !is_console_port(port))
1098 port->cons.ws.ws_row = rows;
1099 port->cons.ws.ws_col = cols;
1102 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1104 struct port_buffer *buf;
1105 unsigned int nr_added_bufs;
1110 buf = alloc_buf(PAGE_SIZE);
1114 spin_lock_irq(lock);
1115 ret = add_inbuf(vq, buf);
1117 spin_unlock_irq(lock);
1122 spin_unlock_irq(lock);
1125 return nr_added_bufs;
1128 static void send_sigio_to_port(struct port *port)
1130 if (port->async_queue && port->guest_connected)
1131 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
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);
1148 kref_init(&port->kref);
1150 port->portdev = portdev;
1155 port->cons.hvc = NULL;
1156 port->async_queue = NULL;
1158 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1160 port->host_connected = port->guest_connected = false;
1161 port->stats = (struct port_stats) { 0 };
1163 port->outvq_full = false;
1165 port->in_vq = portdev->in_vqs[port->id];
1166 port->out_vq = portdev->out_vqs[port->id];
1168 port->cdev = cdev_alloc();
1170 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1174 port->cdev->ops = &port_fops;
1176 devt = MKDEV(portdev->chr_major, id);
1177 err = cdev_add(port->cdev, devt, 1);
1179 dev_err(&port->portdev->vdev->dev,
1180 "Error %d adding cdev for port %u\n", err, id);
1183 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1184 devt, port, "vport%up%u",
1185 port->portdev->drv_index, id);
1186 if (IS_ERR(port->dev)) {
1187 err = PTR_ERR(port->dev);
1188 dev_err(&port->portdev->vdev->dev,
1189 "Error %d creating device for port %u\n",
1194 spin_lock_init(&port->inbuf_lock);
1195 spin_lock_init(&port->outvq_lock);
1196 init_waitqueue_head(&port->waitqueue);
1198 /* Fill the in_vq with buffers so the host can send us data. */
1199 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1200 if (!nr_added_bufs) {
1201 dev_err(port->dev, "Error allocating inbufs\n");
1207 * If we're not using multiport support, this has to be a console port
1209 if (!use_multiport(port->portdev)) {
1210 err = init_port_console(port);
1215 spin_lock_irq(&portdev->ports_lock);
1216 list_add_tail(&port->list, &port->portdev->ports);
1217 spin_unlock_irq(&portdev->ports_lock);
1220 * Tell the Host we're set so that it can send us various
1221 * configuration parameters for this port (eg, port name,
1222 * caching, whether this is a console port, etc.)
1224 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1226 if (pdrvdata.debugfs_dir) {
1228 * Finally, create the debugfs file that we can use to
1229 * inspect a port's state at any time
1231 sprintf(debugfs_name, "vport%up%u",
1232 port->portdev->drv_index, id);
1233 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1234 pdrvdata.debugfs_dir,
1241 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1244 device_destroy(pdrvdata.class, port->dev->devt);
1246 cdev_del(port->cdev);
1250 /* The host might want to notify management sw about port add failure */
1251 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1255 /* No users remain, remove all port-specific data. */
1256 static void remove_port(struct kref *kref)
1260 port = container_of(kref, struct port, kref);
1262 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1263 device_destroy(pdrvdata.class, port->dev->devt);
1264 cdev_del(port->cdev);
1268 debugfs_remove(port->debugfs_file);
1274 * Port got unplugged. Remove port from portdev's list and drop the
1275 * kref reference. If no userspace has this port opened, it will
1276 * result in immediate removal the port.
1278 static void unplug_port(struct port *port)
1280 struct port_buffer *buf;
1282 spin_lock_irq(&port->portdev->ports_lock);
1283 list_del(&port->list);
1284 spin_unlock_irq(&port->portdev->ports_lock);
1286 if (port->guest_connected) {
1287 port->guest_connected = false;
1288 port->host_connected = false;
1289 wake_up_interruptible(&port->waitqueue);
1291 /* Let the app know the port is going down. */
1292 send_sigio_to_port(port);
1295 if (is_console_port(port)) {
1296 spin_lock_irq(&pdrvdata_lock);
1297 list_del(&port->cons.list);
1298 spin_unlock_irq(&pdrvdata_lock);
1299 hvc_remove(port->cons.hvc);
1302 /* Remove unused data this port might have received. */
1303 discard_port_data(port);
1305 reclaim_consumed_buffers(port);
1307 /* Remove buffers we queued up for the Host to send us data in. */
1308 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1312 * We should just assume the device itself has gone off --
1313 * else a close on an open port later will try to send out a
1316 port->portdev = NULL;
1319 * Locks around here are not necessary - a port can't be
1320 * opened after we removed the port struct from ports_list
1323 kref_put(&port->kref, remove_port);
1326 /* Any private messages that the Host and Guest want to share */
1327 static void handle_control_message(struct ports_device *portdev,
1328 struct port_buffer *buf)
1330 struct virtio_console_control *cpkt;
1335 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1337 port = find_port_by_id(portdev, cpkt->id);
1338 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1339 /* No valid header at start of buffer. Drop it. */
1340 dev_dbg(&portdev->vdev->dev,
1341 "Invalid index %u in control packet\n", cpkt->id);
1345 switch (cpkt->event) {
1346 case VIRTIO_CONSOLE_PORT_ADD:
1348 dev_dbg(&portdev->vdev->dev,
1349 "Port %u already added\n", port->id);
1350 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1353 if (cpkt->id >= portdev->config.max_nr_ports) {
1354 dev_warn(&portdev->vdev->dev,
1355 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1356 cpkt->id, portdev->config.max_nr_ports - 1);
1359 add_port(portdev, cpkt->id);
1361 case VIRTIO_CONSOLE_PORT_REMOVE:
1364 case VIRTIO_CONSOLE_CONSOLE_PORT:
1367 if (is_console_port(port))
1370 init_port_console(port);
1371 complete(&early_console_added);
1373 * Could remove the port here in case init fails - but
1374 * have to notify the host first.
1377 case VIRTIO_CONSOLE_RESIZE: {
1383 if (!is_console_port(port))
1386 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1388 set_console_size(port, size.rows, size.cols);
1390 port->cons.hvc->irq_requested = 1;
1391 resize_console(port);
1394 case VIRTIO_CONSOLE_PORT_OPEN:
1395 port->host_connected = cpkt->value;
1396 wake_up_interruptible(&port->waitqueue);
1398 * If the host port got closed and the host had any
1399 * unconsumed buffers, we'll be able to reclaim them
1402 spin_lock_irq(&port->outvq_lock);
1403 reclaim_consumed_buffers(port);
1404 spin_unlock_irq(&port->outvq_lock);
1407 * If the guest is connected, it'll be interested in
1408 * knowing the host connection state changed.
1410 send_sigio_to_port(port);
1412 case VIRTIO_CONSOLE_PORT_NAME:
1414 * If we woke up after hibernation, we can get this
1415 * again. Skip it in that case.
1421 * Skip the size of the header and the cpkt to get the size
1422 * of the name that was sent
1424 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1426 port->name = kmalloc(name_size, GFP_KERNEL);
1429 "Not enough space to store port name\n");
1432 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1434 port->name[name_size - 1] = 0;
1437 * Since we only have one sysfs attribute, 'name',
1438 * create it only if we have a name for the port.
1440 err = sysfs_create_group(&port->dev->kobj,
1441 &port_attribute_group);
1444 "Error %d creating sysfs device attributes\n",
1448 * Generate a udev event so that appropriate
1449 * symlinks can be created based on udev
1452 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1458 static void control_work_handler(struct work_struct *work)
1460 struct ports_device *portdev;
1461 struct virtqueue *vq;
1462 struct port_buffer *buf;
1465 portdev = container_of(work, struct ports_device, control_work);
1466 vq = portdev->c_ivq;
1468 spin_lock(&portdev->cvq_lock);
1469 while ((buf = virtqueue_get_buf(vq, &len))) {
1470 spin_unlock(&portdev->cvq_lock);
1475 handle_control_message(portdev, buf);
1477 spin_lock(&portdev->cvq_lock);
1478 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1479 dev_warn(&portdev->vdev->dev,
1480 "Error adding buffer to queue\n");
1484 spin_unlock(&portdev->cvq_lock);
1487 static void out_intr(struct virtqueue *vq)
1491 port = find_port_by_vq(vq->vdev->priv, vq);
1495 wake_up_interruptible(&port->waitqueue);
1498 static void in_intr(struct virtqueue *vq)
1501 unsigned long flags;
1503 port = find_port_by_vq(vq->vdev->priv, vq);
1507 spin_lock_irqsave(&port->inbuf_lock, flags);
1508 port->inbuf = get_inbuf(port);
1511 * Don't queue up data when port is closed. This condition
1512 * can be reached when a console port is not yet connected (no
1513 * tty is spawned) and the host sends out data to console
1514 * ports. For generic serial ports, the host won't
1515 * (shouldn't) send data till the guest is connected.
1517 if (!port->guest_connected)
1518 discard_port_data(port);
1520 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1522 wake_up_interruptible(&port->waitqueue);
1524 /* Send a SIGIO indicating new data in case the process asked for it */
1525 send_sigio_to_port(port);
1527 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1531 static void control_intr(struct virtqueue *vq)
1533 struct ports_device *portdev;
1535 portdev = vq->vdev->priv;
1536 schedule_work(&portdev->control_work);
1539 static void config_intr(struct virtio_device *vdev)
1541 struct ports_device *portdev;
1543 portdev = vdev->priv;
1545 if (!use_multiport(portdev)) {
1549 vdev->config->get(vdev,
1550 offsetof(struct virtio_console_config, cols),
1551 &cols, sizeof(u16));
1552 vdev->config->get(vdev,
1553 offsetof(struct virtio_console_config, rows),
1554 &rows, sizeof(u16));
1556 port = find_port_by_id(portdev, 0);
1557 set_console_size(port, rows, cols);
1560 * We'll use this way of resizing only for legacy
1561 * support. For newer userspace
1562 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1563 * to indicate console size changes so that it can be
1566 resize_console(port);
1570 static int init_vqs(struct ports_device *portdev)
1572 vq_callback_t **io_callbacks;
1574 struct virtqueue **vqs;
1575 u32 i, j, nr_ports, nr_queues;
1578 nr_ports = portdev->config.max_nr_ports;
1579 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1581 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1582 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1583 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1584 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1586 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1588 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1589 !portdev->out_vqs) {
1595 * For backward compat (newer host but older guest), the host
1596 * spawns a console port first and also inits the vqs for port
1600 io_callbacks[j] = in_intr;
1601 io_callbacks[j + 1] = out_intr;
1602 io_names[j] = "input";
1603 io_names[j + 1] = "output";
1606 if (use_multiport(portdev)) {
1607 io_callbacks[j] = control_intr;
1608 io_callbacks[j + 1] = NULL;
1609 io_names[j] = "control-i";
1610 io_names[j + 1] = "control-o";
1612 for (i = 1; i < nr_ports; i++) {
1614 io_callbacks[j] = in_intr;
1615 io_callbacks[j + 1] = out_intr;
1616 io_names[j] = "input";
1617 io_names[j + 1] = "output";
1620 /* Find the queues. */
1621 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1623 (const char **)io_names);
1628 portdev->in_vqs[0] = vqs[0];
1629 portdev->out_vqs[0] = vqs[1];
1631 if (use_multiport(portdev)) {
1632 portdev->c_ivq = vqs[j];
1633 portdev->c_ovq = vqs[j + 1];
1635 for (i = 1; i < nr_ports; i++) {
1637 portdev->in_vqs[i] = vqs[j];
1638 portdev->out_vqs[i] = vqs[j + 1];
1642 kfree(io_callbacks);
1648 kfree(portdev->out_vqs);
1649 kfree(portdev->in_vqs);
1651 kfree(io_callbacks);
1657 static const struct file_operations portdev_fops = {
1658 .owner = THIS_MODULE,
1662 * Once we're further in boot, we get probed like any other virtio
1665 * If the host also supports multiple console ports, we check the
1666 * config space to see how many ports the host has spawned. We
1667 * initialize each port found.
1669 static int __devinit virtcons_probe(struct virtio_device *vdev)
1671 struct ports_device *portdev;
1674 bool early = early_put_chars != NULL;
1676 /* Ensure to read early_put_chars now */
1679 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1685 /* Attach this portdev to this virtio_device, and vice-versa. */
1686 portdev->vdev = vdev;
1687 vdev->priv = portdev;
1689 spin_lock_irq(&pdrvdata_lock);
1690 portdev->drv_index = pdrvdata.index++;
1691 spin_unlock_irq(&pdrvdata_lock);
1693 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1695 if (portdev->chr_major < 0) {
1697 "Error %d registering chrdev for device %u\n",
1698 portdev->chr_major, portdev->drv_index);
1699 err = portdev->chr_major;
1704 portdev->config.max_nr_ports = 1;
1705 if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
1706 offsetof(struct virtio_console_config,
1708 &portdev->config.max_nr_ports) == 0)
1711 err = init_vqs(portdev);
1713 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1717 spin_lock_init(&portdev->ports_lock);
1718 INIT_LIST_HEAD(&portdev->ports);
1721 unsigned int nr_added_bufs;
1723 spin_lock_init(&portdev->cvq_lock);
1724 INIT_WORK(&portdev->control_work, &control_work_handler);
1726 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1727 if (!nr_added_bufs) {
1729 "Error allocating buffers for control queue\n");
1735 * For backward compatibility: Create a console port
1736 * if we're running on older host.
1738 add_port(portdev, 0);
1741 spin_lock_irq(&pdrvdata_lock);
1742 list_add_tail(&portdev->list, &pdrvdata.portdevs);
1743 spin_unlock_irq(&pdrvdata_lock);
1745 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1746 VIRTIO_CONSOLE_DEVICE_READY, 1);
1749 * If there was an early virtio console, assume that there are no
1750 * other consoles. We need to wait until the hvc_alloc matches the
1751 * hvc_instantiate, otherwise tty_open will complain, resulting in
1752 * a "Warning: unable to open an initial console" boot failure.
1753 * Without multiport this is done in add_port above. With multiport
1754 * this might take some host<->guest communication - thus we have to
1757 if (multiport && early)
1758 wait_for_completion(&early_console_added);
1763 /* The host might want to notify mgmt sw about device add failure */
1764 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1765 VIRTIO_CONSOLE_DEVICE_READY, 0);
1766 vdev->config->del_vqs(vdev);
1767 kfree(portdev->in_vqs);
1768 kfree(portdev->out_vqs);
1770 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1777 static void virtcons_remove(struct virtio_device *vdev)
1779 struct ports_device *portdev;
1780 struct port *port, *port2;
1782 portdev = vdev->priv;
1784 spin_lock_irq(&pdrvdata_lock);
1785 list_del(&portdev->list);
1786 spin_unlock_irq(&pdrvdata_lock);
1788 /* Disable interrupts for vqs */
1789 vdev->config->reset(vdev);
1790 /* Finish up work that's lined up */
1791 cancel_work_sync(&portdev->control_work);
1793 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1796 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1799 * When yanking out a device, we immediately lose the
1800 * (device-side) queues. So there's no point in keeping the
1801 * guest side around till we drop our final reference. This
1802 * also means that any ports which are in an open state will
1803 * have to just stop using the port, as the vqs are going
1806 if (use_multiport(portdev)) {
1807 struct port_buffer *buf;
1810 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1813 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1817 vdev->config->del_vqs(vdev);
1818 kfree(portdev->in_vqs);
1819 kfree(portdev->out_vqs);
1824 static struct virtio_device_id id_table[] = {
1825 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1829 static unsigned int features[] = {
1830 VIRTIO_CONSOLE_F_SIZE,
1831 VIRTIO_CONSOLE_F_MULTIPORT,
1834 static struct virtio_driver virtio_console = {
1835 .feature_table = features,
1836 .feature_table_size = ARRAY_SIZE(features),
1837 .driver.name = KBUILD_MODNAME,
1838 .driver.owner = THIS_MODULE,
1839 .id_table = id_table,
1840 .probe = virtcons_probe,
1841 .remove = virtcons_remove,
1842 .config_changed = config_intr,
1845 static int __init init(void)
1849 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1850 if (IS_ERR(pdrvdata.class)) {
1851 err = PTR_ERR(pdrvdata.class);
1852 pr_err("Error %d creating virtio-ports class\n", err);
1856 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1857 if (!pdrvdata.debugfs_dir) {
1858 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1859 PTR_ERR(pdrvdata.debugfs_dir));
1861 INIT_LIST_HEAD(&pdrvdata.consoles);
1862 INIT_LIST_HEAD(&pdrvdata.portdevs);
1864 return register_virtio_driver(&virtio_console);
1867 static void __exit fini(void)
1869 unregister_virtio_driver(&virtio_console);
1871 class_destroy(pdrvdata.class);
1872 if (pdrvdata.debugfs_dir)
1873 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1878 MODULE_DEVICE_TABLE(virtio, id_table);
1879 MODULE_DESCRIPTION("Virtio console driver");
1880 MODULE_LICENSE("GPL");