2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
4 * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 #include <linux/cdev.h>
21 #include <linux/debugfs.h>
22 #include <linux/device.h>
23 #include <linux/err.h>
24 #include <linux/freezer.h>
26 #include <linux/init.h>
27 #include <linux/list.h>
28 #include <linux/poll.h>
29 #include <linux/sched.h>
30 #include <linux/slab.h>
31 #include <linux/spinlock.h>
32 #include <linux/virtio.h>
33 #include <linux/virtio_console.h>
34 #include <linux/wait.h>
35 #include <linux/workqueue.h>
36 #include "../tty/hvc/hvc_console.h"
39 * This is a global struct for storing common data for all the devices
40 * this driver handles.
42 * Mainly, it has a linked list for all the consoles in one place so
43 * that callbacks from hvc for get_chars(), put_chars() work properly
44 * across multiple devices and multiple ports per device.
46 struct ports_driver_data {
47 /* Used for registering chardevs */
50 /* Used for exporting per-port information to debugfs */
51 struct dentry *debugfs_dir;
53 /* List of all the devices we're handling */
54 struct list_head portdevs;
56 /* Number of devices this driver is handling */
60 * This is used to keep track of the number of hvc consoles
61 * spawned by this driver. This number is given as the first
62 * argument to hvc_alloc(). To correctly map an initial
63 * console spawned via hvc_instantiate to the console being
64 * hooked up via hvc_alloc, we need to pass the same vtermno.
66 * We also just assume the first console being initialised was
67 * the first one that got used as the initial console.
69 unsigned int next_vtermno;
71 /* All the console devices handled by this driver */
72 struct list_head consoles;
74 static struct ports_driver_data pdrvdata;
76 DEFINE_SPINLOCK(pdrvdata_lock);
78 /* This struct holds information that's relevant only for console ports */
80 /* We'll place all consoles in a list in the pdrvdata struct */
81 struct list_head list;
83 /* The hvc device associated with this console port */
84 struct hvc_struct *hvc;
86 /* The size of the console */
90 * This number identifies the number that we used to register
91 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
92 * number passed on by the hvc callbacks to us to
93 * differentiate between the other console ports handled by
102 /* size of the buffer in *buf above */
105 /* used length of the buffer */
107 /* offset in the buf from which to consume data */
112 * This is a per-device struct that stores data common to all the
113 * ports for that device (vdev->priv).
115 struct ports_device {
116 /* Next portdev in the list, head is in the pdrvdata struct */
117 struct list_head list;
120 * Workqueue handlers where we process deferred work after
123 struct work_struct control_work;
125 struct list_head ports;
127 /* To protect the list of ports */
128 spinlock_t ports_lock;
130 /* To protect the vq operations for the control channel */
133 /* The current config space is stored here */
134 struct virtio_console_config config;
136 /* The virtio device we're associated with */
137 struct virtio_device *vdev;
140 * A couple of virtqueues for the control channel: one for
141 * guest->host transfers, one for host->guest transfers
143 struct virtqueue *c_ivq, *c_ovq;
145 /* Array of per-port IO virtqueues */
146 struct virtqueue **in_vqs, **out_vqs;
148 /* Used for numbering devices for sysfs and debugfs */
149 unsigned int drv_index;
151 /* Major number for this device. Ports will be created as minors. */
156 unsigned long bytes_sent, bytes_received, bytes_discarded;
159 /* This struct holds the per-port data */
161 /* Next port in the list, head is in the ports_device */
162 struct list_head list;
164 /* Pointer to the parent virtio_console device */
165 struct ports_device *portdev;
167 /* The current buffer from which data has to be fed to readers */
168 struct port_buffer *inbuf;
171 * To protect the operations on the in_vq associated with this
172 * port. Has to be a spinlock because it can be called from
173 * interrupt context (get_char()).
175 spinlock_t inbuf_lock;
177 /* Protect the operations on the out_vq. */
178 spinlock_t outvq_lock;
180 /* The IO vqs for this port */
181 struct virtqueue *in_vq, *out_vq;
183 /* File in the debugfs directory that exposes this port's information */
184 struct dentry *debugfs_file;
187 * Keep count of the bytes sent, received and discarded for
188 * this port for accounting and debugging purposes. These
189 * counts are not reset across port open / close events.
191 struct port_stats stats;
194 * The entries in this struct will be valid if this port is
195 * hooked up to an hvc console
199 /* Each port associates with a separate char device */
203 /* Reference-counting to handle port hot-unplugs and file operations */
206 /* A waitqueue for poll() or blocking read operations */
207 wait_queue_head_t waitqueue;
209 /* The 'name' of the port that we expose via sysfs properties */
212 /* We can notify apps of host connect / disconnect events via SIGIO */
213 struct fasync_struct *async_queue;
215 /* The 'id' to identify the port with the Host */
220 /* Is the host device open */
223 /* We should allow only one process to open a port */
224 bool guest_connected;
227 /* This is the very early arch-specified put chars function. */
228 static int (*early_put_chars)(u32, const char *, int);
230 static struct port *find_port_by_vtermno(u32 vtermno)
233 struct console *cons;
236 spin_lock_irqsave(&pdrvdata_lock, flags);
237 list_for_each_entry(cons, &pdrvdata.consoles, list) {
238 if (cons->vtermno == vtermno) {
239 port = container_of(cons, struct port, cons);
245 spin_unlock_irqrestore(&pdrvdata_lock, flags);
249 static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
255 spin_lock_irqsave(&portdev->ports_lock, flags);
256 list_for_each_entry(port, &portdev->ports, list)
257 if (port->cdev->dev == dev)
261 spin_unlock_irqrestore(&portdev->ports_lock, flags);
266 static struct port *find_port_by_devt(dev_t dev)
268 struct ports_device *portdev;
272 spin_lock_irqsave(&pdrvdata_lock, flags);
273 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
274 port = find_port_by_devt_in_portdev(portdev, dev);
280 spin_unlock_irqrestore(&pdrvdata_lock, flags);
284 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
289 spin_lock_irqsave(&portdev->ports_lock, flags);
290 list_for_each_entry(port, &portdev->ports, list)
295 spin_unlock_irqrestore(&portdev->ports_lock, flags);
300 static struct port *find_port_by_vq(struct ports_device *portdev,
301 struct virtqueue *vq)
306 spin_lock_irqsave(&portdev->ports_lock, flags);
307 list_for_each_entry(port, &portdev->ports, list)
308 if (port->in_vq == vq || port->out_vq == vq)
312 spin_unlock_irqrestore(&portdev->ports_lock, flags);
316 static bool is_console_port(struct port *port)
323 static inline bool use_multiport(struct ports_device *portdev)
326 * This condition can be true when put_chars is called from
331 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
334 static void free_buf(struct port_buffer *buf)
340 static struct port_buffer *alloc_buf(size_t buf_size)
342 struct port_buffer *buf;
344 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
347 buf->buf = kzalloc(buf_size, GFP_KERNEL);
352 buf->size = buf_size;
361 /* Callers should take appropriate locks */
362 static struct port_buffer *get_inbuf(struct port *port)
364 struct port_buffer *buf;
370 buf = virtqueue_get_buf(port->in_vq, &len);
374 port->stats.bytes_received += len;
380 * Create a scatter-gather list representing our input buffer and put
383 * Callers should take appropriate locks.
385 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
387 struct scatterlist sg[1];
390 sg_init_one(sg, buf->buf, buf->size);
392 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
397 /* Discard any unread data this port has. Callers lockers. */
398 static void discard_port_data(struct port *port)
400 struct port_buffer *buf;
403 if (!port->portdev) {
404 /* Device has been unplugged. vqs are already gone. */
407 buf = get_inbuf(port);
411 port->stats.bytes_discarded += buf->len - buf->offset;
412 if (add_inbuf(port->in_vq, buf) < 0) {
417 buf = get_inbuf(port);
420 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
424 static bool port_has_data(struct port *port)
430 spin_lock_irqsave(&port->inbuf_lock, flags);
431 port->inbuf = get_inbuf(port);
435 spin_unlock_irqrestore(&port->inbuf_lock, flags);
439 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
440 unsigned int event, unsigned int value)
442 struct scatterlist sg[1];
443 struct virtio_console_control cpkt;
444 struct virtqueue *vq;
447 if (!use_multiport(portdev))
456 sg_init_one(sg, &cpkt, sizeof(cpkt));
457 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
459 while (!virtqueue_get_buf(vq, &len))
465 static ssize_t send_control_msg(struct port *port, unsigned int event,
468 /* Did the port get unplugged before userspace closed it? */
470 return __send_control_msg(port->portdev, port->id, event, value);
474 /* Callers must take the port->outvq_lock */
475 static void reclaim_consumed_buffers(struct port *port)
480 if (!port->portdev) {
481 /* Device has been unplugged. vqs are already gone. */
484 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
486 port->outvq_full = false;
490 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
493 struct scatterlist sg[1];
494 struct virtqueue *out_vq;
499 out_vq = port->out_vq;
501 spin_lock_irqsave(&port->outvq_lock, flags);
503 reclaim_consumed_buffers(port);
505 sg_init_one(sg, in_buf, in_count);
506 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
508 /* Tell Host to go! */
509 virtqueue_kick(out_vq);
517 port->outvq_full = true;
523 * Wait till the host acknowledges it pushed out the data we
524 * sent. This is done for data from the hvc_console; the tty
525 * operations are performed with spinlocks held so we can't
526 * sleep here. An alternative would be to copy the data to a
527 * buffer and relax the spinning requirement. The downside is
528 * we need to kmalloc a GFP_ATOMIC buffer each time the
529 * console driver writes something out.
531 while (!virtqueue_get_buf(out_vq, &len))
534 spin_unlock_irqrestore(&port->outvq_lock, flags);
536 port->stats.bytes_sent += in_count;
538 * We're expected to return the amount of data we wrote -- all
545 * Give out the data that's requested from the buffer that we have
548 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
551 struct port_buffer *buf;
554 if (!out_count || !port_has_data(port))
558 out_count = min(out_count, buf->len - buf->offset);
563 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
567 memcpy(out_buf, buf->buf + buf->offset, out_count);
570 buf->offset += out_count;
572 if (buf->offset == buf->len) {
574 * We're done using all the data in this buffer.
575 * Re-queue so that the Host can send us more data.
577 spin_lock_irqsave(&port->inbuf_lock, flags);
580 if (add_inbuf(port->in_vq, buf) < 0)
581 dev_warn(port->dev, "failed add_buf\n");
583 spin_unlock_irqrestore(&port->inbuf_lock, flags);
585 /* Return the number of bytes actually copied */
589 /* The condition that must be true for polling to end */
590 static bool will_read_block(struct port *port)
592 if (!port->guest_connected) {
593 /* Port got hot-unplugged. Let's exit. */
596 return !port_has_data(port) && port->host_connected;
599 static bool will_write_block(struct port *port)
603 if (!port->guest_connected) {
604 /* Port got hot-unplugged. Let's exit. */
607 if (!port->host_connected)
610 spin_lock_irq(&port->outvq_lock);
612 * Check if the Host has consumed any buffers since we last
613 * sent data (this is only applicable for nonblocking ports).
615 reclaim_consumed_buffers(port);
616 ret = port->outvq_full;
617 spin_unlock_irq(&port->outvq_lock);
622 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
623 size_t count, loff_t *offp)
628 port = filp->private_data;
630 if (!port_has_data(port)) {
632 * If nothing's connected on the host just return 0 in
633 * case of list_empty; this tells the userspace app
634 * that there's no connection
636 if (!port->host_connected)
638 if (filp->f_flags & O_NONBLOCK)
641 ret = wait_event_freezable(port->waitqueue,
642 !will_read_block(port));
646 /* Port got hot-unplugged. */
647 if (!port->guest_connected)
650 * We could've received a disconnection message while we were
651 * waiting for more data.
653 * This check is not clubbed in the if() statement above as we
654 * might receive some data as well as the host could get
655 * disconnected after we got woken up from our wait. So we
656 * really want to give off whatever data we have and only then
657 * check for host_connected.
659 if (!port_has_data(port) && !port->host_connected)
662 return fill_readbuf(port, ubuf, count, true);
665 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
666 size_t count, loff_t *offp)
673 /* Userspace could be out to fool us */
677 port = filp->private_data;
679 nonblock = filp->f_flags & O_NONBLOCK;
681 if (will_write_block(port)) {
685 ret = wait_event_freezable(port->waitqueue,
686 !will_write_block(port));
690 /* Port got hot-unplugged. */
691 if (!port->guest_connected)
694 count = min((size_t)(32 * 1024), count);
696 buf = kmalloc(count, GFP_KERNEL);
700 ret = copy_from_user(buf, ubuf, count);
707 * We now ask send_buf() to not spin for generic ports -- we
708 * can re-use the same code path that non-blocking file
709 * descriptors take for blocking file descriptors since the
710 * wait is already done and we're certain the write will go
711 * through to the host.
714 ret = send_buf(port, buf, count, nonblock);
716 if (nonblock && ret > 0)
725 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
730 port = filp->private_data;
731 poll_wait(filp, &port->waitqueue, wait);
733 if (!port->guest_connected) {
734 /* Port got unplugged */
738 if (!will_read_block(port))
739 ret |= POLLIN | POLLRDNORM;
740 if (!will_write_block(port))
742 if (!port->host_connected)
748 static void remove_port(struct kref *kref);
750 static int port_fops_release(struct inode *inode, struct file *filp)
754 port = filp->private_data;
756 /* Notify host of port being closed */
757 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
759 spin_lock_irq(&port->inbuf_lock);
760 port->guest_connected = false;
762 discard_port_data(port);
764 spin_unlock_irq(&port->inbuf_lock);
766 spin_lock_irq(&port->outvq_lock);
767 reclaim_consumed_buffers(port);
768 spin_unlock_irq(&port->outvq_lock);
771 * Locks aren't necessary here as a port can't be opened after
772 * unplug, and if a port isn't unplugged, a kref would already
773 * exist for the port. Plus, taking ports_lock here would
774 * create a dependency on other locks taken by functions
775 * inside remove_port if we're the last holder of the port,
776 * creating many problems.
778 kref_put(&port->kref, remove_port);
783 static int port_fops_open(struct inode *inode, struct file *filp)
785 struct cdev *cdev = inode->i_cdev;
789 port = find_port_by_devt(cdev->dev);
790 filp->private_data = port;
792 /* Prevent against a port getting hot-unplugged at the same time */
793 spin_lock_irq(&port->portdev->ports_lock);
794 kref_get(&port->kref);
795 spin_unlock_irq(&port->portdev->ports_lock);
798 * Don't allow opening of console port devices -- that's done
801 if (is_console_port(port)) {
806 /* Allow only one process to open a particular port at a time */
807 spin_lock_irq(&port->inbuf_lock);
808 if (port->guest_connected) {
809 spin_unlock_irq(&port->inbuf_lock);
814 port->guest_connected = true;
815 spin_unlock_irq(&port->inbuf_lock);
817 spin_lock_irq(&port->outvq_lock);
819 * There might be a chance that we missed reclaiming a few
820 * buffers in the window of the port getting previously closed
823 reclaim_consumed_buffers(port);
824 spin_unlock_irq(&port->outvq_lock);
826 nonseekable_open(inode, filp);
828 /* Notify host of port being opened */
829 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
833 kref_put(&port->kref, remove_port);
837 static int port_fops_fasync(int fd, struct file *filp, int mode)
841 port = filp->private_data;
842 return fasync_helper(fd, filp, mode, &port->async_queue);
846 * The file operations that we support: programs in the guest can open
847 * a console device, read from it, write to it, poll for data and
848 * close it. The devices are at
849 * /dev/vport<device number>p<port number>
851 static const struct file_operations port_fops = {
852 .owner = THIS_MODULE,
853 .open = port_fops_open,
854 .read = port_fops_read,
855 .write = port_fops_write,
856 .poll = port_fops_poll,
857 .release = port_fops_release,
858 .fasync = port_fops_fasync,
863 * The put_chars() callback is pretty straightforward.
865 * We turn the characters into a scatter-gather list, add it to the
866 * output queue and then kick the Host. Then we sit here waiting for
867 * it to finish: inefficient in theory, but in practice
868 * implementations will do it immediately (lguest's Launcher does).
870 static int put_chars(u32 vtermno, const char *buf, int count)
874 if (unlikely(early_put_chars))
875 return early_put_chars(vtermno, buf, count);
877 port = find_port_by_vtermno(vtermno);
881 return send_buf(port, (void *)buf, count, false);
885 * get_chars() is the callback from the hvc_console infrastructure
886 * when an interrupt is received.
888 * We call out to fill_readbuf that gets us the required data from the
889 * buffers that are queued up.
891 static int get_chars(u32 vtermno, char *buf, int count)
895 /* If we've not set up the port yet, we have no input to give. */
896 if (unlikely(early_put_chars))
899 port = find_port_by_vtermno(vtermno);
903 /* If we don't have an input queue yet, we can't get input. */
904 BUG_ON(!port->in_vq);
906 return fill_readbuf(port, buf, count, false);
909 static void resize_console(struct port *port)
911 struct virtio_device *vdev;
913 /* The port could have been hot-unplugged */
914 if (!port || !is_console_port(port))
917 vdev = port->portdev->vdev;
918 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
919 hvc_resize(port->cons.hvc, port->cons.ws);
922 /* We set the configuration at this point, since we now have a tty */
923 static int notifier_add_vio(struct hvc_struct *hp, int data)
927 port = find_port_by_vtermno(hp->vtermno);
931 hp->irq_requested = 1;
932 resize_console(port);
937 static void notifier_del_vio(struct hvc_struct *hp, int data)
939 hp->irq_requested = 0;
942 /* The operations for console ports. */
943 static const struct hv_ops hv_ops = {
944 .get_chars = get_chars,
945 .put_chars = put_chars,
946 .notifier_add = notifier_add_vio,
947 .notifier_del = notifier_del_vio,
948 .notifier_hangup = notifier_del_vio,
952 * Console drivers are initialized very early so boot messages can go
953 * out, so we do things slightly differently from the generic virtio
954 * initialization of the net and block drivers.
956 * At this stage, the console is output-only. It's too early to set
957 * up a virtqueue, so we let the drivers do some boutique early-output
960 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
962 early_put_chars = put_chars;
963 return hvc_instantiate(0, 0, &hv_ops);
966 int init_port_console(struct port *port)
971 * The Host's telling us this port is a console port. Hook it
972 * up with an hvc console.
974 * To set up and manage our virtual console, we call
977 * The first argument of hvc_alloc() is the virtual console
978 * number. The second argument is the parameter for the
979 * notification mechanism (like irq number). We currently
980 * leave this as zero, virtqueues have implicit notifications.
982 * The third argument is a "struct hv_ops" containing the
983 * put_chars() get_chars(), notifier_add() and notifier_del()
984 * pointers. The final argument is the output buffer size: we
985 * can do any size, so we put PAGE_SIZE here.
987 port->cons.vtermno = pdrvdata.next_vtermno;
989 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
990 if (IS_ERR(port->cons.hvc)) {
991 ret = PTR_ERR(port->cons.hvc);
993 "error %d allocating hvc for port\n", ret);
994 port->cons.hvc = NULL;
997 spin_lock_irq(&pdrvdata_lock);
998 pdrvdata.next_vtermno++;
999 list_add_tail(&port->cons.list, &pdrvdata.consoles);
1000 spin_unlock_irq(&pdrvdata_lock);
1001 port->guest_connected = true;
1004 * Start using the new console output if this is the first
1005 * console to come up.
1007 if (early_put_chars)
1008 early_put_chars = NULL;
1010 /* Notify host of port being opened */
1011 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1016 static ssize_t show_port_name(struct device *dev,
1017 struct device_attribute *attr, char *buffer)
1021 port = dev_get_drvdata(dev);
1023 return sprintf(buffer, "%s\n", port->name);
1026 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1028 static struct attribute *port_sysfs_entries[] = {
1029 &dev_attr_name.attr,
1033 static struct attribute_group port_attribute_group = {
1034 .name = NULL, /* put in device directory */
1035 .attrs = port_sysfs_entries,
1038 static int debugfs_open(struct inode *inode, struct file *filp)
1040 filp->private_data = inode->i_private;
1044 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1045 size_t count, loff_t *offp)
1049 ssize_t ret, out_offset, out_count;
1052 buf = kmalloc(out_count, GFP_KERNEL);
1056 port = filp->private_data;
1058 out_offset += snprintf(buf + out_offset, out_count,
1059 "name: %s\n", port->name ? port->name : "");
1060 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1061 "guest_connected: %d\n", port->guest_connected);
1062 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1063 "host_connected: %d\n", port->host_connected);
1064 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1065 "outvq_full: %d\n", port->outvq_full);
1066 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1067 "bytes_sent: %lu\n", port->stats.bytes_sent);
1068 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1069 "bytes_received: %lu\n",
1070 port->stats.bytes_received);
1071 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1072 "bytes_discarded: %lu\n",
1073 port->stats.bytes_discarded);
1074 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1076 is_console_port(port) ? "yes" : "no");
1077 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1078 "console_vtermno: %u\n", port->cons.vtermno);
1080 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1085 static const struct file_operations port_debugfs_ops = {
1086 .owner = THIS_MODULE,
1087 .open = debugfs_open,
1088 .read = debugfs_read,
1091 static void set_console_size(struct port *port, u16 rows, u16 cols)
1093 if (!port || !is_console_port(port))
1096 port->cons.ws.ws_row = rows;
1097 port->cons.ws.ws_col = cols;
1100 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1102 struct port_buffer *buf;
1103 unsigned int nr_added_bufs;
1108 buf = alloc_buf(PAGE_SIZE);
1112 spin_lock_irq(lock);
1113 ret = add_inbuf(vq, buf);
1115 spin_unlock_irq(lock);
1120 spin_unlock_irq(lock);
1123 return nr_added_bufs;
1126 static void send_sigio_to_port(struct port *port)
1128 if (port->async_queue && port->guest_connected)
1129 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1132 static int add_port(struct ports_device *portdev, u32 id)
1134 char debugfs_name[16];
1136 struct port_buffer *buf;
1138 unsigned int nr_added_bufs;
1141 port = kmalloc(sizeof(*port), GFP_KERNEL);
1146 kref_init(&port->kref);
1148 port->portdev = portdev;
1153 port->cons.hvc = NULL;
1154 port->async_queue = NULL;
1156 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1158 port->host_connected = port->guest_connected = false;
1159 port->stats = (struct port_stats) { 0 };
1161 port->outvq_full = false;
1163 port->in_vq = portdev->in_vqs[port->id];
1164 port->out_vq = portdev->out_vqs[port->id];
1166 port->cdev = cdev_alloc();
1168 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1172 port->cdev->ops = &port_fops;
1174 devt = MKDEV(portdev->chr_major, id);
1175 err = cdev_add(port->cdev, devt, 1);
1177 dev_err(&port->portdev->vdev->dev,
1178 "Error %d adding cdev for port %u\n", err, id);
1181 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1182 devt, port, "vport%up%u",
1183 port->portdev->drv_index, id);
1184 if (IS_ERR(port->dev)) {
1185 err = PTR_ERR(port->dev);
1186 dev_err(&port->portdev->vdev->dev,
1187 "Error %d creating device for port %u\n",
1192 spin_lock_init(&port->inbuf_lock);
1193 spin_lock_init(&port->outvq_lock);
1194 init_waitqueue_head(&port->waitqueue);
1196 /* Fill the in_vq with buffers so the host can send us data. */
1197 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1198 if (!nr_added_bufs) {
1199 dev_err(port->dev, "Error allocating inbufs\n");
1205 * If we're not using multiport support, this has to be a console port
1207 if (!use_multiport(port->portdev)) {
1208 err = init_port_console(port);
1213 spin_lock_irq(&portdev->ports_lock);
1214 list_add_tail(&port->list, &port->portdev->ports);
1215 spin_unlock_irq(&portdev->ports_lock);
1218 * Tell the Host we're set so that it can send us various
1219 * configuration parameters for this port (eg, port name,
1220 * caching, whether this is a console port, etc.)
1222 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1224 if (pdrvdata.debugfs_dir) {
1226 * Finally, create the debugfs file that we can use to
1227 * inspect a port's state at any time
1229 sprintf(debugfs_name, "vport%up%u",
1230 port->portdev->drv_index, id);
1231 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1232 pdrvdata.debugfs_dir,
1239 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1242 device_destroy(pdrvdata.class, port->dev->devt);
1244 cdev_del(port->cdev);
1248 /* The host might want to notify management sw about port add failure */
1249 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1253 /* No users remain, remove all port-specific data. */
1254 static void remove_port(struct kref *kref)
1258 port = container_of(kref, struct port, kref);
1260 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1261 device_destroy(pdrvdata.class, port->dev->devt);
1262 cdev_del(port->cdev);
1266 debugfs_remove(port->debugfs_file);
1272 * Port got unplugged. Remove port from portdev's list and drop the
1273 * kref reference. If no userspace has this port opened, it will
1274 * result in immediate removal the port.
1276 static void unplug_port(struct port *port)
1278 struct port_buffer *buf;
1280 spin_lock_irq(&port->portdev->ports_lock);
1281 list_del(&port->list);
1282 spin_unlock_irq(&port->portdev->ports_lock);
1284 if (port->guest_connected) {
1285 port->guest_connected = false;
1286 port->host_connected = false;
1287 wake_up_interruptible(&port->waitqueue);
1289 /* Let the app know the port is going down. */
1290 send_sigio_to_port(port);
1293 if (is_console_port(port)) {
1294 spin_lock_irq(&pdrvdata_lock);
1295 list_del(&port->cons.list);
1296 spin_unlock_irq(&pdrvdata_lock);
1297 hvc_remove(port->cons.hvc);
1300 /* Remove unused data this port might have received. */
1301 discard_port_data(port);
1303 reclaim_consumed_buffers(port);
1305 /* Remove buffers we queued up for the Host to send us data in. */
1306 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1310 * We should just assume the device itself has gone off --
1311 * else a close on an open port later will try to send out a
1314 port->portdev = NULL;
1317 * Locks around here are not necessary - a port can't be
1318 * opened after we removed the port struct from ports_list
1321 kref_put(&port->kref, remove_port);
1324 /* Any private messages that the Host and Guest want to share */
1325 static void handle_control_message(struct ports_device *portdev,
1326 struct port_buffer *buf)
1328 struct virtio_console_control *cpkt;
1333 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1335 port = find_port_by_id(portdev, cpkt->id);
1336 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1337 /* No valid header at start of buffer. Drop it. */
1338 dev_dbg(&portdev->vdev->dev,
1339 "Invalid index %u in control packet\n", cpkt->id);
1343 switch (cpkt->event) {
1344 case VIRTIO_CONSOLE_PORT_ADD:
1346 dev_dbg(&portdev->vdev->dev,
1347 "Port %u already added\n", port->id);
1348 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1351 if (cpkt->id >= portdev->config.max_nr_ports) {
1352 dev_warn(&portdev->vdev->dev,
1353 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1354 cpkt->id, portdev->config.max_nr_ports - 1);
1357 add_port(portdev, cpkt->id);
1359 case VIRTIO_CONSOLE_PORT_REMOVE:
1362 case VIRTIO_CONSOLE_CONSOLE_PORT:
1365 if (is_console_port(port))
1368 init_port_console(port);
1370 * Could remove the port here in case init fails - but
1371 * have to notify the host first.
1374 case VIRTIO_CONSOLE_RESIZE: {
1380 if (!is_console_port(port))
1383 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1385 set_console_size(port, size.rows, size.cols);
1387 port->cons.hvc->irq_requested = 1;
1388 resize_console(port);
1391 case VIRTIO_CONSOLE_PORT_OPEN:
1392 port->host_connected = cpkt->value;
1393 wake_up_interruptible(&port->waitqueue);
1395 * If the host port got closed and the host had any
1396 * unconsumed buffers, we'll be able to reclaim them
1399 spin_lock_irq(&port->outvq_lock);
1400 reclaim_consumed_buffers(port);
1401 spin_unlock_irq(&port->outvq_lock);
1404 * If the guest is connected, it'll be interested in
1405 * knowing the host connection state changed.
1407 send_sigio_to_port(port);
1409 case VIRTIO_CONSOLE_PORT_NAME:
1411 * If we woke up after hibernation, we can get this
1412 * again. Skip it in that case.
1418 * Skip the size of the header and the cpkt to get the size
1419 * of the name that was sent
1421 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1423 port->name = kmalloc(name_size, GFP_KERNEL);
1426 "Not enough space to store port name\n");
1429 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1431 port->name[name_size - 1] = 0;
1434 * Since we only have one sysfs attribute, 'name',
1435 * create it only if we have a name for the port.
1437 err = sysfs_create_group(&port->dev->kobj,
1438 &port_attribute_group);
1441 "Error %d creating sysfs device attributes\n",
1445 * Generate a udev event so that appropriate
1446 * symlinks can be created based on udev
1449 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1455 static void control_work_handler(struct work_struct *work)
1457 struct ports_device *portdev;
1458 struct virtqueue *vq;
1459 struct port_buffer *buf;
1462 portdev = container_of(work, struct ports_device, control_work);
1463 vq = portdev->c_ivq;
1465 spin_lock(&portdev->cvq_lock);
1466 while ((buf = virtqueue_get_buf(vq, &len))) {
1467 spin_unlock(&portdev->cvq_lock);
1472 handle_control_message(portdev, buf);
1474 spin_lock(&portdev->cvq_lock);
1475 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1476 dev_warn(&portdev->vdev->dev,
1477 "Error adding buffer to queue\n");
1481 spin_unlock(&portdev->cvq_lock);
1484 static void out_intr(struct virtqueue *vq)
1488 port = find_port_by_vq(vq->vdev->priv, vq);
1492 wake_up_interruptible(&port->waitqueue);
1495 static void in_intr(struct virtqueue *vq)
1498 unsigned long flags;
1500 port = find_port_by_vq(vq->vdev->priv, vq);
1504 spin_lock_irqsave(&port->inbuf_lock, flags);
1505 port->inbuf = get_inbuf(port);
1508 * Don't queue up data when port is closed. This condition
1509 * can be reached when a console port is not yet connected (no
1510 * tty is spawned) and the host sends out data to console
1511 * ports. For generic serial ports, the host won't
1512 * (shouldn't) send data till the guest is connected.
1514 if (!port->guest_connected)
1515 discard_port_data(port);
1517 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1519 wake_up_interruptible(&port->waitqueue);
1521 /* Send a SIGIO indicating new data in case the process asked for it */
1522 send_sigio_to_port(port);
1524 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1528 static void control_intr(struct virtqueue *vq)
1530 struct ports_device *portdev;
1532 portdev = vq->vdev->priv;
1533 schedule_work(&portdev->control_work);
1536 static void config_intr(struct virtio_device *vdev)
1538 struct ports_device *portdev;
1540 portdev = vdev->priv;
1542 if (!use_multiport(portdev)) {
1546 vdev->config->get(vdev,
1547 offsetof(struct virtio_console_config, cols),
1548 &cols, sizeof(u16));
1549 vdev->config->get(vdev,
1550 offsetof(struct virtio_console_config, rows),
1551 &rows, sizeof(u16));
1553 port = find_port_by_id(portdev, 0);
1554 set_console_size(port, rows, cols);
1557 * We'll use this way of resizing only for legacy
1558 * support. For newer userspace
1559 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1560 * to indicate console size changes so that it can be
1563 resize_console(port);
1567 static int init_vqs(struct ports_device *portdev)
1569 vq_callback_t **io_callbacks;
1571 struct virtqueue **vqs;
1572 u32 i, j, nr_ports, nr_queues;
1575 nr_ports = portdev->config.max_nr_ports;
1576 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1578 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1579 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1580 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1581 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1583 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1585 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1586 !portdev->out_vqs) {
1592 * For backward compat (newer host but older guest), the host
1593 * spawns a console port first and also inits the vqs for port
1597 io_callbacks[j] = in_intr;
1598 io_callbacks[j + 1] = out_intr;
1599 io_names[j] = "input";
1600 io_names[j + 1] = "output";
1603 if (use_multiport(portdev)) {
1604 io_callbacks[j] = control_intr;
1605 io_callbacks[j + 1] = NULL;
1606 io_names[j] = "control-i";
1607 io_names[j + 1] = "control-o";
1609 for (i = 1; i < nr_ports; i++) {
1611 io_callbacks[j] = in_intr;
1612 io_callbacks[j + 1] = out_intr;
1613 io_names[j] = "input";
1614 io_names[j + 1] = "output";
1617 /* Find the queues. */
1618 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1620 (const char **)io_names);
1625 portdev->in_vqs[0] = vqs[0];
1626 portdev->out_vqs[0] = vqs[1];
1628 if (use_multiport(portdev)) {
1629 portdev->c_ivq = vqs[j];
1630 portdev->c_ovq = vqs[j + 1];
1632 for (i = 1; i < nr_ports; i++) {
1634 portdev->in_vqs[i] = vqs[j];
1635 portdev->out_vqs[i] = vqs[j + 1];
1639 kfree(io_callbacks);
1645 kfree(portdev->out_vqs);
1646 kfree(portdev->in_vqs);
1648 kfree(io_callbacks);
1654 static const struct file_operations portdev_fops = {
1655 .owner = THIS_MODULE,
1659 * Once we're further in boot, we get probed like any other virtio
1662 * If the host also supports multiple console ports, we check the
1663 * config space to see how many ports the host has spawned. We
1664 * initialize each port found.
1666 static int __devinit virtcons_probe(struct virtio_device *vdev)
1668 struct ports_device *portdev;
1672 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1678 /* Attach this portdev to this virtio_device, and vice-versa. */
1679 portdev->vdev = vdev;
1680 vdev->priv = portdev;
1682 spin_lock_irq(&pdrvdata_lock);
1683 portdev->drv_index = pdrvdata.index++;
1684 spin_unlock_irq(&pdrvdata_lock);
1686 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1688 if (portdev->chr_major < 0) {
1690 "Error %d registering chrdev for device %u\n",
1691 portdev->chr_major, portdev->drv_index);
1692 err = portdev->chr_major;
1697 portdev->config.max_nr_ports = 1;
1698 if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
1699 offsetof(struct virtio_console_config,
1701 &portdev->config.max_nr_ports) == 0)
1704 err = init_vqs(portdev);
1706 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1710 spin_lock_init(&portdev->ports_lock);
1711 INIT_LIST_HEAD(&portdev->ports);
1714 unsigned int nr_added_bufs;
1716 spin_lock_init(&portdev->cvq_lock);
1717 INIT_WORK(&portdev->control_work, &control_work_handler);
1719 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1720 if (!nr_added_bufs) {
1722 "Error allocating buffers for control queue\n");
1728 * For backward compatibility: Create a console port
1729 * if we're running on older host.
1731 add_port(portdev, 0);
1734 spin_lock_irq(&pdrvdata_lock);
1735 list_add_tail(&portdev->list, &pdrvdata.portdevs);
1736 spin_unlock_irq(&pdrvdata_lock);
1738 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1739 VIRTIO_CONSOLE_DEVICE_READY, 1);
1743 /* The host might want to notify mgmt sw about device add failure */
1744 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1745 VIRTIO_CONSOLE_DEVICE_READY, 0);
1746 vdev->config->del_vqs(vdev);
1747 kfree(portdev->in_vqs);
1748 kfree(portdev->out_vqs);
1750 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1757 static void virtcons_remove(struct virtio_device *vdev)
1759 struct ports_device *portdev;
1760 struct port *port, *port2;
1762 portdev = vdev->priv;
1764 spin_lock_irq(&pdrvdata_lock);
1765 list_del(&portdev->list);
1766 spin_unlock_irq(&pdrvdata_lock);
1768 /* Disable interrupts for vqs */
1769 vdev->config->reset(vdev);
1770 /* Finish up work that's lined up */
1771 cancel_work_sync(&portdev->control_work);
1773 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1776 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1779 * When yanking out a device, we immediately lose the
1780 * (device-side) queues. So there's no point in keeping the
1781 * guest side around till we drop our final reference. This
1782 * also means that any ports which are in an open state will
1783 * have to just stop using the port, as the vqs are going
1786 if (use_multiport(portdev)) {
1787 struct port_buffer *buf;
1790 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1793 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1797 vdev->config->del_vqs(vdev);
1798 kfree(portdev->in_vqs);
1799 kfree(portdev->out_vqs);
1804 static struct virtio_device_id id_table[] = {
1805 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1809 static unsigned int features[] = {
1810 VIRTIO_CONSOLE_F_SIZE,
1811 VIRTIO_CONSOLE_F_MULTIPORT,
1814 static struct virtio_driver virtio_console = {
1815 .feature_table = features,
1816 .feature_table_size = ARRAY_SIZE(features),
1817 .driver.name = KBUILD_MODNAME,
1818 .driver.owner = THIS_MODULE,
1819 .id_table = id_table,
1820 .probe = virtcons_probe,
1821 .remove = virtcons_remove,
1822 .config_changed = config_intr,
1825 static int __init init(void)
1829 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1830 if (IS_ERR(pdrvdata.class)) {
1831 err = PTR_ERR(pdrvdata.class);
1832 pr_err("Error %d creating virtio-ports class\n", err);
1836 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1837 if (!pdrvdata.debugfs_dir) {
1838 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1839 PTR_ERR(pdrvdata.debugfs_dir));
1841 INIT_LIST_HEAD(&pdrvdata.consoles);
1842 INIT_LIST_HEAD(&pdrvdata.portdevs);
1844 return register_virtio_driver(&virtio_console);
1847 static void __exit fini(void)
1849 unregister_virtio_driver(&virtio_console);
1851 class_destroy(pdrvdata.class);
1852 if (pdrvdata.debugfs_dir)
1853 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1858 MODULE_DEVICE_TABLE(virtio, id_table);
1859 MODULE_DESCRIPTION("Virtio console driver");
1860 MODULE_LICENSE("GPL");