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
;
82 * This number identifies the number that we used to register
83 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
84 * number passed on by the hvc callbacks to us to
85 * differentiate between the other console ports handled by
94 /* size of the buffer in *buf above */
97 /* used length of the buffer */
99 /* offset in the buf from which to consume data */
104 * This is a per-device struct that stores data common to all the
105 * ports for that device (vdev->priv).
107 struct ports_device
{
109 * Workqueue handlers where we process deferred work after
112 struct work_struct control_work
;
113 struct work_struct config_work
;
115 struct list_head ports
;
117 /* To protect the list of ports */
118 spinlock_t ports_lock
;
120 /* To protect the vq operations for the control channel */
123 /* The current config space is stored here */
124 struct virtio_console_config config
;
126 /* The virtio device we're associated with */
127 struct virtio_device
*vdev
;
130 * A couple of virtqueues for the control channel: one for
131 * guest->host transfers, one for host->guest transfers
133 struct virtqueue
*c_ivq
, *c_ovq
;
135 /* Array of per-port IO virtqueues */
136 struct virtqueue
**in_vqs
, **out_vqs
;
138 /* Used for numbering devices for sysfs and debugfs */
139 unsigned int drv_index
;
141 /* Major number for this device. Ports will be created as minors. */
145 /* This struct holds the per-port data */
147 /* Next port in the list, head is in the ports_device */
148 struct list_head list
;
150 /* Pointer to the parent virtio_console device */
151 struct ports_device
*portdev
;
153 /* The current buffer from which data has to be fed to readers */
154 struct port_buffer
*inbuf
;
157 * To protect the operations on the in_vq associated with this
158 * port. Has to be a spinlock because it can be called from
159 * interrupt context (get_char()).
161 spinlock_t inbuf_lock
;
163 /* The IO vqs for this port */
164 struct virtqueue
*in_vq
, *out_vq
;
166 /* File in the debugfs directory that exposes this port's information */
167 struct dentry
*debugfs_file
;
170 * The entries in this struct will be valid if this port is
171 * hooked up to an hvc console
175 /* Each port associates with a separate char device */
179 /* A waitqueue for poll() or blocking read operations */
180 wait_queue_head_t waitqueue
;
182 /* The 'name' of the port that we expose via sysfs properties */
185 /* The 'id' to identify the port with the Host */
188 /* Is the host device open */
191 /* We should allow only one process to open a port */
192 bool guest_connected
;
195 /* This is the very early arch-specified put chars function. */
196 static int (*early_put_chars
)(u32
, const char *, int);
198 static struct port
*find_port_by_vtermno(u32 vtermno
)
201 struct console
*cons
;
204 spin_lock_irqsave(&pdrvdata_lock
, flags
);
205 list_for_each_entry(cons
, &pdrvdata
.consoles
, list
) {
206 if (cons
->vtermno
== vtermno
) {
207 port
= container_of(cons
, struct port
, cons
);
213 spin_unlock_irqrestore(&pdrvdata_lock
, flags
);
217 static struct port
*find_port_by_id(struct ports_device
*portdev
, u32 id
)
222 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
223 list_for_each_entry(port
, &portdev
->ports
, list
)
228 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
233 static struct port
*find_port_by_vq(struct ports_device
*portdev
,
234 struct virtqueue
*vq
)
239 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
240 list_for_each_entry(port
, &portdev
->ports
, list
)
241 if (port
->in_vq
== vq
|| port
->out_vq
== vq
)
245 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
249 static bool is_console_port(struct port
*port
)
256 static inline bool use_multiport(struct ports_device
*portdev
)
259 * This condition can be true when put_chars is called from
264 return portdev
->vdev
->features
[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT
);
267 static void free_buf(struct port_buffer
*buf
)
273 static struct port_buffer
*alloc_buf(size_t buf_size
)
275 struct port_buffer
*buf
;
277 buf
= kmalloc(sizeof(*buf
), GFP_KERNEL
);
280 buf
->buf
= kzalloc(buf_size
, GFP_KERNEL
);
285 buf
->size
= buf_size
;
294 /* Callers should take appropriate locks */
295 static void *get_inbuf(struct port
*port
)
297 struct port_buffer
*buf
;
298 struct virtqueue
*vq
;
302 buf
= vq
->vq_ops
->get_buf(vq
, &len
);
311 * Create a scatter-gather list representing our input buffer and put
314 * Callers should take appropriate locks.
316 static int add_inbuf(struct virtqueue
*vq
, struct port_buffer
*buf
)
318 struct scatterlist sg
[1];
321 sg_init_one(sg
, buf
->buf
, buf
->size
);
323 ret
= vq
->vq_ops
->add_buf(vq
, sg
, 0, 1, buf
);
324 vq
->vq_ops
->kick(vq
);
328 /* Discard any unread data this port has. Callers lockers. */
329 static void discard_port_data(struct port
*port
)
331 struct port_buffer
*buf
;
332 struct virtqueue
*vq
;
340 buf
= vq
->vq_ops
->get_buf(vq
, &len
);
344 if (add_inbuf(vq
, buf
) < 0) {
348 buf
= vq
->vq_ops
->get_buf(vq
, &len
);
352 dev_warn(port
->dev
, "Errors adding %d buffers back to vq\n",
356 static bool port_has_data(struct port
*port
)
361 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
366 port
->inbuf
= get_inbuf(port
);
373 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
377 static ssize_t
send_control_msg(struct port
*port
, unsigned int event
,
380 struct scatterlist sg
[1];
381 struct virtio_console_control cpkt
;
382 struct virtqueue
*vq
;
385 if (!use_multiport(port
->portdev
))
392 vq
= port
->portdev
->c_ovq
;
394 sg_init_one(sg
, &cpkt
, sizeof(cpkt
));
395 if (vq
->vq_ops
->add_buf(vq
, sg
, 1, 0, &cpkt
) >= 0) {
396 vq
->vq_ops
->kick(vq
);
397 while (!vq
->vq_ops
->get_buf(vq
, &len
))
403 static ssize_t
send_buf(struct port
*port
, void *in_buf
, size_t in_count
)
405 struct scatterlist sg
[1];
406 struct virtqueue
*out_vq
;
410 out_vq
= port
->out_vq
;
412 sg_init_one(sg
, in_buf
, in_count
);
413 ret
= out_vq
->vq_ops
->add_buf(out_vq
, sg
, 1, 0, in_buf
);
415 /* Tell Host to go! */
416 out_vq
->vq_ops
->kick(out_vq
);
424 * Wait till the host acknowledges it pushed out the data we
425 * sent. Also ensure we return to userspace the number of
426 * bytes that were successfully consumed by the host.
428 while (!out_vq
->vq_ops
->get_buf(out_vq
, &len
))
431 /* We're expected to return the amount of data we wrote */
436 * Give out the data that's requested from the buffer that we have
439 static ssize_t
fill_readbuf(struct port
*port
, char *out_buf
, size_t out_count
,
442 struct port_buffer
*buf
;
445 if (!out_count
|| !port_has_data(port
))
449 out_count
= min(out_count
, buf
->len
- buf
->offset
);
454 ret
= copy_to_user(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
458 memcpy(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
461 buf
->offset
+= out_count
;
463 if (buf
->offset
== buf
->len
) {
465 * We're done using all the data in this buffer.
466 * Re-queue so that the Host can send us more data.
468 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
471 if (add_inbuf(port
->in_vq
, buf
) < 0)
472 dev_warn(port
->dev
, "failed add_buf\n");
474 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
476 /* Return the number of bytes actually copied */
480 /* The condition that must be true for polling to end */
481 static bool wait_is_over(struct port
*port
)
483 return port_has_data(port
) || !port
->host_connected
;
486 static ssize_t
port_fops_read(struct file
*filp
, char __user
*ubuf
,
487 size_t count
, loff_t
*offp
)
492 port
= filp
->private_data
;
494 if (!port_has_data(port
)) {
496 * If nothing's connected on the host just return 0 in
497 * case of list_empty; this tells the userspace app
498 * that there's no connection
500 if (!port
->host_connected
)
502 if (filp
->f_flags
& O_NONBLOCK
)
505 ret
= wait_event_interruptible(port
->waitqueue
,
511 * We could've received a disconnection message while we were
512 * waiting for more data.
514 * This check is not clubbed in the if() statement above as we
515 * might receive some data as well as the host could get
516 * disconnected after we got woken up from our wait. So we
517 * really want to give off whatever data we have and only then
518 * check for host_connected.
520 if (!port_has_data(port
) && !port
->host_connected
)
523 return fill_readbuf(port
, ubuf
, count
, true);
526 static ssize_t
port_fops_write(struct file
*filp
, const char __user
*ubuf
,
527 size_t count
, loff_t
*offp
)
533 port
= filp
->private_data
;
535 count
= min((size_t)(32 * 1024), count
);
537 buf
= kmalloc(count
, GFP_KERNEL
);
541 ret
= copy_from_user(buf
, ubuf
, count
);
547 ret
= send_buf(port
, buf
, count
);
553 static unsigned int port_fops_poll(struct file
*filp
, poll_table
*wait
)
558 port
= filp
->private_data
;
559 poll_wait(filp
, &port
->waitqueue
, wait
);
563 ret
|= POLLIN
| POLLRDNORM
;
564 if (port
->host_connected
)
566 if (!port
->host_connected
)
572 static int port_fops_release(struct inode
*inode
, struct file
*filp
)
576 port
= filp
->private_data
;
578 /* Notify host of port being closed */
579 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
581 spin_lock_irq(&port
->inbuf_lock
);
582 port
->guest_connected
= false;
584 discard_port_data(port
);
586 spin_unlock_irq(&port
->inbuf_lock
);
591 static int port_fops_open(struct inode
*inode
, struct file
*filp
)
593 struct cdev
*cdev
= inode
->i_cdev
;
596 port
= container_of(cdev
, struct port
, cdev
);
597 filp
->private_data
= port
;
600 * Don't allow opening of console port devices -- that's done
603 if (is_console_port(port
))
606 /* Allow only one process to open a particular port at a time */
607 spin_lock_irq(&port
->inbuf_lock
);
608 if (port
->guest_connected
) {
609 spin_unlock_irq(&port
->inbuf_lock
);
613 port
->guest_connected
= true;
614 spin_unlock_irq(&port
->inbuf_lock
);
616 /* Notify host of port being opened */
617 send_control_msg(filp
->private_data
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
623 * The file operations that we support: programs in the guest can open
624 * a console device, read from it, write to it, poll for data and
625 * close it. The devices are at
626 * /dev/vport<device number>p<port number>
628 static const struct file_operations port_fops
= {
629 .owner
= THIS_MODULE
,
630 .open
= port_fops_open
,
631 .read
= port_fops_read
,
632 .write
= port_fops_write
,
633 .poll
= port_fops_poll
,
634 .release
= port_fops_release
,
638 * The put_chars() callback is pretty straightforward.
640 * We turn the characters into a scatter-gather list, add it to the
641 * output queue and then kick the Host. Then we sit here waiting for
642 * it to finish: inefficient in theory, but in practice
643 * implementations will do it immediately (lguest's Launcher does).
645 static int put_chars(u32 vtermno
, const char *buf
, int count
)
649 port
= find_port_by_vtermno(vtermno
);
653 if (unlikely(early_put_chars
))
654 return early_put_chars(vtermno
, buf
, count
);
656 return send_buf(port
, (void *)buf
, count
);
660 * get_chars() is the callback from the hvc_console infrastructure
661 * when an interrupt is received.
663 * We call out to fill_readbuf that gets us the required data from the
664 * buffers that are queued up.
666 static int get_chars(u32 vtermno
, char *buf
, int count
)
670 port
= find_port_by_vtermno(vtermno
);
674 /* If we don't have an input queue yet, we can't get input. */
675 BUG_ON(!port
->in_vq
);
677 return fill_readbuf(port
, buf
, count
, false);
680 static void resize_console(struct port
*port
)
682 struct virtio_device
*vdev
;
685 /* The port could have been hot-unplugged */
689 vdev
= port
->portdev
->vdev
;
690 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_SIZE
)) {
691 vdev
->config
->get(vdev
,
692 offsetof(struct virtio_console_config
, cols
),
693 &ws
.ws_col
, sizeof(u16
));
694 vdev
->config
->get(vdev
,
695 offsetof(struct virtio_console_config
, rows
),
696 &ws
.ws_row
, sizeof(u16
));
697 hvc_resize(port
->cons
.hvc
, ws
);
701 /* We set the configuration at this point, since we now have a tty */
702 static int notifier_add_vio(struct hvc_struct
*hp
, int data
)
706 port
= find_port_by_vtermno(hp
->vtermno
);
710 hp
->irq_requested
= 1;
711 resize_console(port
);
716 static void notifier_del_vio(struct hvc_struct
*hp
, int data
)
718 hp
->irq_requested
= 0;
721 /* The operations for console ports. */
722 static const struct hv_ops hv_ops
= {
723 .get_chars
= get_chars
,
724 .put_chars
= put_chars
,
725 .notifier_add
= notifier_add_vio
,
726 .notifier_del
= notifier_del_vio
,
727 .notifier_hangup
= notifier_del_vio
,
731 * Console drivers are initialized very early so boot messages can go
732 * out, so we do things slightly differently from the generic virtio
733 * initialization of the net and block drivers.
735 * At this stage, the console is output-only. It's too early to set
736 * up a virtqueue, so we let the drivers do some boutique early-output
739 int __init
virtio_cons_early_init(int (*put_chars
)(u32
, const char *, int))
741 early_put_chars
= put_chars
;
742 return hvc_instantiate(0, 0, &hv_ops
);
745 int init_port_console(struct port
*port
)
750 * The Host's telling us this port is a console port. Hook it
751 * up with an hvc console.
753 * To set up and manage our virtual console, we call
756 * The first argument of hvc_alloc() is the virtual console
757 * number. The second argument is the parameter for the
758 * notification mechanism (like irq number). We currently
759 * leave this as zero, virtqueues have implicit notifications.
761 * The third argument is a "struct hv_ops" containing the
762 * put_chars() get_chars(), notifier_add() and notifier_del()
763 * pointers. The final argument is the output buffer size: we
764 * can do any size, so we put PAGE_SIZE here.
766 port
->cons
.vtermno
= pdrvdata
.next_vtermno
;
768 port
->cons
.hvc
= hvc_alloc(port
->cons
.vtermno
, 0, &hv_ops
, PAGE_SIZE
);
769 if (IS_ERR(port
->cons
.hvc
)) {
770 ret
= PTR_ERR(port
->cons
.hvc
);
772 "error %d allocating hvc for port\n", ret
);
773 port
->cons
.hvc
= NULL
;
776 spin_lock_irq(&pdrvdata_lock
);
777 pdrvdata
.next_vtermno
++;
778 list_add_tail(&port
->cons
.list
, &pdrvdata
.consoles
);
779 spin_unlock_irq(&pdrvdata_lock
);
780 port
->guest_connected
= true;
782 /* Notify host of port being opened */
783 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
788 static ssize_t
show_port_name(struct device
*dev
,
789 struct device_attribute
*attr
, char *buffer
)
793 port
= dev_get_drvdata(dev
);
795 return sprintf(buffer
, "%s\n", port
->name
);
798 static DEVICE_ATTR(name
, S_IRUGO
, show_port_name
, NULL
);
800 static struct attribute
*port_sysfs_entries
[] = {
805 static struct attribute_group port_attribute_group
= {
806 .name
= NULL
, /* put in device directory */
807 .attrs
= port_sysfs_entries
,
810 static int debugfs_open(struct inode
*inode
, struct file
*filp
)
812 filp
->private_data
= inode
->i_private
;
816 static ssize_t
debugfs_read(struct file
*filp
, char __user
*ubuf
,
817 size_t count
, loff_t
*offp
)
821 ssize_t ret
, out_offset
, out_count
;
824 buf
= kmalloc(out_count
, GFP_KERNEL
);
828 port
= filp
->private_data
;
830 out_offset
+= snprintf(buf
+ out_offset
, out_count
,
831 "name: %s\n", port
->name
? port
->name
: "");
832 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
833 "guest_connected: %d\n", port
->guest_connected
);
834 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
835 "host_connected: %d\n", port
->host_connected
);
836 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
838 is_console_port(port
) ? "yes" : "no");
839 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
840 "console_vtermno: %u\n", port
->cons
.vtermno
);
842 ret
= simple_read_from_buffer(ubuf
, count
, offp
, buf
, out_offset
);
847 static const struct file_operations port_debugfs_ops
= {
848 .owner
= THIS_MODULE
,
849 .open
= debugfs_open
,
850 .read
= debugfs_read
,
853 /* Remove all port-specific data. */
854 static int remove_port(struct port
*port
)
856 struct port_buffer
*buf
;
858 spin_lock_irq(&port
->portdev
->ports_lock
);
859 list_del(&port
->list
);
860 spin_unlock_irq(&port
->portdev
->ports_lock
);
862 if (is_console_port(port
)) {
863 spin_lock_irq(&pdrvdata_lock
);
864 list_del(&port
->cons
.list
);
865 spin_unlock_irq(&pdrvdata_lock
);
866 hvc_remove(port
->cons
.hvc
);
868 if (port
->guest_connected
)
869 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
871 sysfs_remove_group(&port
->dev
->kobj
, &port_attribute_group
);
872 device_destroy(pdrvdata
.class, port
->dev
->devt
);
873 cdev_del(&port
->cdev
);
875 /* Remove unused data this port might have received. */
876 discard_port_data(port
);
878 /* Remove buffers we queued up for the Host to send us data in. */
879 while ((buf
= port
->in_vq
->vq_ops
->detach_unused_buf(port
->in_vq
)))
884 debugfs_remove(port
->debugfs_file
);
890 /* Any private messages that the Host and Guest want to share */
891 static void handle_control_message(struct ports_device
*portdev
,
892 struct port_buffer
*buf
)
894 struct virtio_console_control
*cpkt
;
899 cpkt
= (struct virtio_console_control
*)(buf
->buf
+ buf
->offset
);
901 port
= find_port_by_id(portdev
, cpkt
->id
);
903 /* No valid header at start of buffer. Drop it. */
904 dev_dbg(&portdev
->vdev
->dev
,
905 "Invalid index %u in control packet\n", cpkt
->id
);
909 switch (cpkt
->event
) {
910 case VIRTIO_CONSOLE_CONSOLE_PORT
:
913 if (is_console_port(port
))
916 init_port_console(port
);
918 * Could remove the port here in case init fails - but
919 * have to notify the host first.
922 case VIRTIO_CONSOLE_RESIZE
:
923 if (!is_console_port(port
))
925 port
->cons
.hvc
->irq_requested
= 1;
926 resize_console(port
);
928 case VIRTIO_CONSOLE_PORT_OPEN
:
929 port
->host_connected
= cpkt
->value
;
930 wake_up_interruptible(&port
->waitqueue
);
932 case VIRTIO_CONSOLE_PORT_NAME
:
934 * Skip the size of the header and the cpkt to get the size
935 * of the name that was sent
937 name_size
= buf
->len
- buf
->offset
- sizeof(*cpkt
) + 1;
939 port
->name
= kmalloc(name_size
, GFP_KERNEL
);
942 "Not enough space to store port name\n");
945 strncpy(port
->name
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
947 port
->name
[name_size
- 1] = 0;
950 * Since we only have one sysfs attribute, 'name',
951 * create it only if we have a name for the port.
953 err
= sysfs_create_group(&port
->dev
->kobj
,
954 &port_attribute_group
);
957 "Error %d creating sysfs device attributes\n",
961 * Generate a udev event so that appropriate
962 * symlinks can be created based on udev
965 kobject_uevent(&port
->dev
->kobj
, KOBJ_CHANGE
);
968 case VIRTIO_CONSOLE_PORT_REMOVE
:
970 * Hot unplug the port. We don't decrement nr_ports
971 * since we don't want to deal with extra complexities
972 * of using the lowest-available port id: We can just
973 * pick up the nr_ports number as the id and not have
974 * userspace send it to us. This helps us in two
977 * - We don't need to have a 'port_id' field in the
978 * config space when a port is hot-added. This is a
979 * good thing as we might queue up multiple hotplug
980 * requests issued in our workqueue.
982 * - Another way to deal with this would have been to
983 * use a bitmap of the active ports and select the
984 * lowest non-active port from that map. That
985 * bloats the already tight config space and we
986 * would end up artificially limiting the
987 * max. number of ports to sizeof(bitmap). Right
988 * now we can support 2^32 ports (as the port id is
989 * stored in a u32 type).
997 static void control_work_handler(struct work_struct
*work
)
999 struct ports_device
*portdev
;
1000 struct virtqueue
*vq
;
1001 struct port_buffer
*buf
;
1004 portdev
= container_of(work
, struct ports_device
, control_work
);
1005 vq
= portdev
->c_ivq
;
1007 spin_lock(&portdev
->cvq_lock
);
1008 while ((buf
= vq
->vq_ops
->get_buf(vq
, &len
))) {
1009 spin_unlock(&portdev
->cvq_lock
);
1014 handle_control_message(portdev
, buf
);
1016 spin_lock(&portdev
->cvq_lock
);
1017 if (add_inbuf(portdev
->c_ivq
, buf
) < 0) {
1018 dev_warn(&portdev
->vdev
->dev
,
1019 "Error adding buffer to queue\n");
1023 spin_unlock(&portdev
->cvq_lock
);
1026 static void in_intr(struct virtqueue
*vq
)
1029 unsigned long flags
;
1031 port
= find_port_by_vq(vq
->vdev
->priv
, vq
);
1035 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
1037 port
->inbuf
= get_inbuf(port
);
1040 * Don't queue up data when port is closed. This condition
1041 * can be reached when a console port is not yet connected (no
1042 * tty is spawned) and the host sends out data to console
1043 * ports. For generic serial ports, the host won't
1044 * (shouldn't) send data till the guest is connected.
1046 if (!port
->guest_connected
)
1047 discard_port_data(port
);
1049 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
1051 wake_up_interruptible(&port
->waitqueue
);
1053 if (is_console_port(port
) && hvc_poll(port
->cons
.hvc
))
1057 static void control_intr(struct virtqueue
*vq
)
1059 struct ports_device
*portdev
;
1061 portdev
= vq
->vdev
->priv
;
1062 schedule_work(&portdev
->control_work
);
1065 static void config_intr(struct virtio_device
*vdev
)
1067 struct ports_device
*portdev
;
1069 portdev
= vdev
->priv
;
1070 if (use_multiport(portdev
)) {
1071 /* Handle port hot-add */
1072 schedule_work(&portdev
->config_work
);
1075 * We'll use this way of resizing only for legacy support.
1076 * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
1077 * control messages to indicate console size changes so that
1078 * it can be done per-port
1080 resize_console(find_port_by_id(portdev
, 0));
1083 static unsigned int fill_queue(struct virtqueue
*vq
, spinlock_t
*lock
)
1085 struct port_buffer
*buf
;
1086 unsigned int nr_added_bufs
;
1091 buf
= alloc_buf(PAGE_SIZE
);
1095 spin_lock_irq(lock
);
1096 ret
= add_inbuf(vq
, buf
);
1098 spin_unlock_irq(lock
);
1103 spin_unlock_irq(lock
);
1106 return nr_added_bufs
;
1109 static int add_port(struct ports_device
*portdev
, u32 id
)
1111 char debugfs_name
[16];
1113 struct port_buffer
*buf
;
1115 unsigned int nr_added_bufs
;
1118 port
= kmalloc(sizeof(*port
), GFP_KERNEL
);
1124 port
->portdev
= portdev
;
1129 port
->cons
.hvc
= NULL
;
1131 port
->host_connected
= port
->guest_connected
= false;
1133 port
->in_vq
= portdev
->in_vqs
[port
->id
];
1134 port
->out_vq
= portdev
->out_vqs
[port
->id
];
1136 cdev_init(&port
->cdev
, &port_fops
);
1138 devt
= MKDEV(portdev
->chr_major
, id
);
1139 err
= cdev_add(&port
->cdev
, devt
, 1);
1141 dev_err(&port
->portdev
->vdev
->dev
,
1142 "Error %d adding cdev for port %u\n", err
, id
);
1145 port
->dev
= device_create(pdrvdata
.class, &port
->portdev
->vdev
->dev
,
1146 devt
, port
, "vport%up%u",
1147 port
->portdev
->drv_index
, id
);
1148 if (IS_ERR(port
->dev
)) {
1149 err
= PTR_ERR(port
->dev
);
1150 dev_err(&port
->portdev
->vdev
->dev
,
1151 "Error %d creating device for port %u\n",
1156 spin_lock_init(&port
->inbuf_lock
);
1157 init_waitqueue_head(&port
->waitqueue
);
1159 /* Fill the in_vq with buffers so the host can send us data. */
1160 nr_added_bufs
= fill_queue(port
->in_vq
, &port
->inbuf_lock
);
1161 if (!nr_added_bufs
) {
1162 dev_err(port
->dev
, "Error allocating inbufs\n");
1168 * If we're not using multiport support, this has to be a console port
1170 if (!use_multiport(port
->portdev
)) {
1171 err
= init_port_console(port
);
1176 spin_lock_irq(&portdev
->ports_lock
);
1177 list_add_tail(&port
->list
, &port
->portdev
->ports
);
1178 spin_unlock_irq(&portdev
->ports_lock
);
1181 * Tell the Host we're set so that it can send us various
1182 * configuration parameters for this port (eg, port name,
1183 * caching, whether this is a console port, etc.)
1185 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1187 if (pdrvdata
.debugfs_dir
) {
1189 * Finally, create the debugfs file that we can use to
1190 * inspect a port's state at any time
1192 sprintf(debugfs_name
, "vport%up%u",
1193 port
->portdev
->drv_index
, id
);
1194 port
->debugfs_file
= debugfs_create_file(debugfs_name
, 0444,
1195 pdrvdata
.debugfs_dir
,
1202 while ((buf
= port
->in_vq
->vq_ops
->detach_unused_buf(port
->in_vq
)))
1205 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1207 cdev_del(&port
->cdev
);
1215 * The workhandler for config-space updates.
1217 * This is called when ports are hot-added.
1219 static void config_work_handler(struct work_struct
*work
)
1221 struct virtio_console_config virtconconf
;
1222 struct ports_device
*portdev
;
1223 struct virtio_device
*vdev
;
1226 portdev
= container_of(work
, struct ports_device
, config_work
);
1228 vdev
= portdev
->vdev
;
1229 vdev
->config
->get(vdev
,
1230 offsetof(struct virtio_console_config
, nr_ports
),
1231 &virtconconf
.nr_ports
,
1232 sizeof(virtconconf
.nr_ports
));
1234 if (portdev
->config
.nr_ports
== virtconconf
.nr_ports
) {
1236 * Port 0 got hot-added. Since we already did all the
1237 * other initialisation for it, just tell the Host
1238 * that the port is ready if we find the port. In
1239 * case the port was hot-removed earlier, we call
1240 * add_port to add the port.
1244 port
= find_port_by_id(portdev
, 0);
1246 add_port(portdev
, 0);
1248 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1251 if (virtconconf
.nr_ports
> portdev
->config
.max_nr_ports
) {
1252 dev_warn(&vdev
->dev
,
1253 "More ports specified (%u) than allowed (%u)",
1254 portdev
->config
.nr_ports
+ 1,
1255 portdev
->config
.max_nr_ports
);
1258 if (virtconconf
.nr_ports
< portdev
->config
.nr_ports
)
1262 while (virtconconf
.nr_ports
- portdev
->config
.nr_ports
) {
1263 err
= add_port(portdev
, portdev
->config
.nr_ports
);
1266 portdev
->config
.nr_ports
++;
1270 static int init_vqs(struct ports_device
*portdev
)
1272 vq_callback_t
**io_callbacks
;
1274 struct virtqueue
**vqs
;
1275 u32 i
, j
, nr_ports
, nr_queues
;
1278 nr_ports
= portdev
->config
.max_nr_ports
;
1279 nr_queues
= use_multiport(portdev
) ? (nr_ports
+ 1) * 2 : 2;
1281 vqs
= kmalloc(nr_queues
* sizeof(struct virtqueue
*), GFP_KERNEL
);
1286 io_callbacks
= kmalloc(nr_queues
* sizeof(vq_callback_t
*), GFP_KERNEL
);
1287 if (!io_callbacks
) {
1291 io_names
= kmalloc(nr_queues
* sizeof(char *), GFP_KERNEL
);
1294 goto free_callbacks
;
1296 portdev
->in_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1298 if (!portdev
->in_vqs
) {
1302 portdev
->out_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1304 if (!portdev
->out_vqs
) {
1310 * For backward compat (newer host but older guest), the host
1311 * spawns a console port first and also inits the vqs for port
1315 io_callbacks
[j
] = in_intr
;
1316 io_callbacks
[j
+ 1] = NULL
;
1317 io_names
[j
] = "input";
1318 io_names
[j
+ 1] = "output";
1321 if (use_multiport(portdev
)) {
1322 io_callbacks
[j
] = control_intr
;
1323 io_callbacks
[j
+ 1] = NULL
;
1324 io_names
[j
] = "control-i";
1325 io_names
[j
+ 1] = "control-o";
1327 for (i
= 1; i
< nr_ports
; i
++) {
1329 io_callbacks
[j
] = in_intr
;
1330 io_callbacks
[j
+ 1] = NULL
;
1331 io_names
[j
] = "input";
1332 io_names
[j
+ 1] = "output";
1335 /* Find the queues. */
1336 err
= portdev
->vdev
->config
->find_vqs(portdev
->vdev
, nr_queues
, vqs
,
1338 (const char **)io_names
);
1343 portdev
->in_vqs
[0] = vqs
[0];
1344 portdev
->out_vqs
[0] = vqs
[1];
1346 if (use_multiport(portdev
)) {
1347 portdev
->c_ivq
= vqs
[j
];
1348 portdev
->c_ovq
= vqs
[j
+ 1];
1350 for (i
= 1; i
< nr_ports
; i
++) {
1352 portdev
->in_vqs
[i
] = vqs
[j
];
1353 portdev
->out_vqs
[i
] = vqs
[j
+ 1];
1356 kfree(io_callbacks
);
1365 kfree(io_callbacks
);
1367 kfree(portdev
->out_vqs
);
1369 kfree(portdev
->in_vqs
);
1376 static const struct file_operations portdev_fops
= {
1377 .owner
= THIS_MODULE
,
1381 * Once we're further in boot, we get probed like any other virtio
1384 * If the host also supports multiple console ports, we check the
1385 * config space to see how many ports the host has spawned. We
1386 * initialize each port found.
1388 static int __devinit
virtcons_probe(struct virtio_device
*vdev
)
1390 struct ports_device
*portdev
;
1395 portdev
= kmalloc(sizeof(*portdev
), GFP_KERNEL
);
1401 /* Attach this portdev to this virtio_device, and vice-versa. */
1402 portdev
->vdev
= vdev
;
1403 vdev
->priv
= portdev
;
1405 spin_lock_irq(&pdrvdata_lock
);
1406 portdev
->drv_index
= pdrvdata
.index
++;
1407 spin_unlock_irq(&pdrvdata_lock
);
1409 portdev
->chr_major
= register_chrdev(0, "virtio-portsdev",
1411 if (portdev
->chr_major
< 0) {
1413 "Error %d registering chrdev for device %u\n",
1414 portdev
->chr_major
, portdev
->drv_index
);
1415 err
= portdev
->chr_major
;
1420 portdev
->config
.nr_ports
= 1;
1421 portdev
->config
.max_nr_ports
= 1;
1422 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_MULTIPORT
)) {
1424 vdev
->features
[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT
;
1426 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1428 &portdev
->config
.nr_ports
,
1429 sizeof(portdev
->config
.nr_ports
));
1430 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1432 &portdev
->config
.max_nr_ports
,
1433 sizeof(portdev
->config
.max_nr_ports
));
1434 if (portdev
->config
.nr_ports
> portdev
->config
.max_nr_ports
) {
1435 dev_warn(&vdev
->dev
,
1436 "More ports (%u) specified than allowed (%u). Will init %u ports.",
1437 portdev
->config
.nr_ports
,
1438 portdev
->config
.max_nr_ports
,
1439 portdev
->config
.max_nr_ports
);
1441 portdev
->config
.nr_ports
= portdev
->config
.max_nr_ports
;
1445 /* Let the Host know we support multiple ports.*/
1446 vdev
->config
->finalize_features(vdev
);
1448 err
= init_vqs(portdev
);
1450 dev_err(&vdev
->dev
, "Error %d initializing vqs\n", err
);
1454 spin_lock_init(&portdev
->ports_lock
);
1455 INIT_LIST_HEAD(&portdev
->ports
);
1458 unsigned int nr_added_bufs
;
1460 spin_lock_init(&portdev
->cvq_lock
);
1461 INIT_WORK(&portdev
->control_work
, &control_work_handler
);
1462 INIT_WORK(&portdev
->config_work
, &config_work_handler
);
1464 nr_added_bufs
= fill_queue(portdev
->c_ivq
, &portdev
->cvq_lock
);
1465 if (!nr_added_bufs
) {
1467 "Error allocating buffers for control queue\n");
1473 for (i
= 0; i
< portdev
->config
.nr_ports
; i
++)
1474 add_port(portdev
, i
);
1476 /* Start using the new console output. */
1477 early_put_chars
= NULL
;
1481 vdev
->config
->del_vqs(vdev
);
1482 kfree(portdev
->in_vqs
);
1483 kfree(portdev
->out_vqs
);
1485 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1492 static void virtcons_remove(struct virtio_device
*vdev
)
1494 struct ports_device
*portdev
;
1495 struct port
*port
, *port2
;
1496 struct port_buffer
*buf
;
1499 portdev
= vdev
->priv
;
1501 cancel_work_sync(&portdev
->control_work
);
1502 cancel_work_sync(&portdev
->config_work
);
1504 list_for_each_entry_safe(port
, port2
, &portdev
->ports
, list
)
1507 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1509 while ((buf
= portdev
->c_ivq
->vq_ops
->get_buf(portdev
->c_ivq
, &len
)))
1512 while ((buf
= portdev
->c_ivq
->vq_ops
->detach_unused_buf(portdev
->c_ivq
)))
1515 vdev
->config
->del_vqs(vdev
);
1516 kfree(portdev
->in_vqs
);
1517 kfree(portdev
->out_vqs
);
1522 static struct virtio_device_id id_table
[] = {
1523 { VIRTIO_ID_CONSOLE
, VIRTIO_DEV_ANY_ID
},
1527 static unsigned int features
[] = {
1528 VIRTIO_CONSOLE_F_SIZE
,
1529 VIRTIO_CONSOLE_F_MULTIPORT
,
1532 static struct virtio_driver virtio_console
= {
1533 .feature_table
= features
,
1534 .feature_table_size
= ARRAY_SIZE(features
),
1535 .driver
.name
= KBUILD_MODNAME
,
1536 .driver
.owner
= THIS_MODULE
,
1537 .id_table
= id_table
,
1538 .probe
= virtcons_probe
,
1539 .remove
= virtcons_remove
,
1540 .config_changed
= config_intr
,
1543 static int __init
init(void)
1547 pdrvdata
.class = class_create(THIS_MODULE
, "virtio-ports");
1548 if (IS_ERR(pdrvdata
.class)) {
1549 err
= PTR_ERR(pdrvdata
.class);
1550 pr_err("Error %d creating virtio-ports class\n", err
);
1554 pdrvdata
.debugfs_dir
= debugfs_create_dir("virtio-ports", NULL
);
1555 if (!pdrvdata
.debugfs_dir
) {
1556 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1557 PTR_ERR(pdrvdata
.debugfs_dir
));
1559 INIT_LIST_HEAD(&pdrvdata
.consoles
);
1561 return register_virtio_driver(&virtio_console
);
1564 static void __exit
fini(void)
1566 unregister_virtio_driver(&virtio_console
);
1568 class_destroy(pdrvdata
.class);
1569 if (pdrvdata
.debugfs_dir
)
1570 debugfs_remove_recursive(pdrvdata
.debugfs_dir
);
1575 MODULE_DEVICE_TABLE(virtio
, id_table
);
1576 MODULE_DESCRIPTION("Virtio console driver");
1577 MODULE_LICENSE("GPL");