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/spinlock.h>
29 #include <linux/virtio.h>
30 #include <linux/virtio_console.h>
31 #include <linux/wait.h>
32 #include <linux/workqueue.h>
33 #include "hvc_console.h"
36 * This is a global struct for storing common data for all the devices
37 * this driver handles.
39 * Mainly, it has a linked list for all the consoles in one place so
40 * that callbacks from hvc for get_chars(), put_chars() work properly
41 * across multiple devices and multiple ports per device.
43 struct ports_driver_data
{
44 /* Used for registering chardevs */
47 /* Used for exporting per-port information to debugfs */
48 struct dentry
*debugfs_dir
;
50 /* Number of devices this driver is handling */
54 * This is used to keep track of the number of hvc consoles
55 * spawned by this driver. This number is given as the first
56 * argument to hvc_alloc(). To correctly map an initial
57 * console spawned via hvc_instantiate to the console being
58 * hooked up via hvc_alloc, we need to pass the same vtermno.
60 * We also just assume the first console being initialised was
61 * the first one that got used as the initial console.
63 unsigned int next_vtermno
;
65 /* All the console devices handled by this driver */
66 struct list_head consoles
;
68 static struct ports_driver_data pdrvdata
;
70 DEFINE_SPINLOCK(pdrvdata_lock
);
72 /* This struct holds information that's relevant only for console ports */
74 /* We'll place all consoles in a list in the pdrvdata struct */
75 struct list_head list
;
77 /* The hvc device associated with this console port */
78 struct hvc_struct
*hvc
;
81 * This number identifies the number that we used to register
82 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
83 * number passed on by the hvc callbacks to us to
84 * differentiate between the other console ports handled by
93 /* size of the buffer in *buf above */
96 /* used length of the buffer */
98 /* offset in the buf from which to consume data */
103 * This is a per-device struct that stores data common to all the
104 * ports for that device (vdev->priv).
106 struct ports_device
{
108 * Workqueue handlers where we process deferred work after
111 struct work_struct control_work
;
112 struct work_struct config_work
;
114 struct list_head ports
;
116 /* To protect the list of ports */
117 spinlock_t ports_lock
;
119 /* To protect the vq operations for the control channel */
122 /* The current config space is stored here */
123 struct virtio_console_config config
;
125 /* The virtio device we're associated with */
126 struct virtio_device
*vdev
;
129 * A couple of virtqueues for the control channel: one for
130 * guest->host transfers, one for host->guest transfers
132 struct virtqueue
*c_ivq
, *c_ovq
;
134 /* Array of per-port IO virtqueues */
135 struct virtqueue
**in_vqs
, **out_vqs
;
137 /* Used for numbering devices for sysfs and debugfs */
138 unsigned int drv_index
;
140 /* Major number for this device. Ports will be created as minors. */
144 /* This struct holds the per-port data */
146 /* Next port in the list, head is in the ports_device */
147 struct list_head list
;
149 /* Pointer to the parent virtio_console device */
150 struct ports_device
*portdev
;
152 /* The current buffer from which data has to be fed to readers */
153 struct port_buffer
*inbuf
;
156 * To protect the operations on the in_vq associated with this
157 * port. Has to be a spinlock because it can be called from
158 * interrupt context (get_char()).
160 spinlock_t inbuf_lock
;
162 /* The IO vqs for this port */
163 struct virtqueue
*in_vq
, *out_vq
;
165 /* File in the debugfs directory that exposes this port's information */
166 struct dentry
*debugfs_file
;
169 * The entries in this struct will be valid if this port is
170 * hooked up to an hvc console
174 /* Each port associates with a separate char device */
178 /* A waitqueue for poll() or blocking read operations */
179 wait_queue_head_t waitqueue
;
181 /* The 'name' of the port that we expose via sysfs properties */
184 /* The 'id' to identify the port with the Host */
187 /* Is the host device open */
190 /* We should allow only one process to open a port */
191 bool guest_connected
;
194 /* This is the very early arch-specified put chars function. */
195 static int (*early_put_chars
)(u32
, const char *, int);
197 static struct port
*find_port_by_vtermno(u32 vtermno
)
200 struct console
*cons
;
203 spin_lock_irqsave(&pdrvdata_lock
, flags
);
204 list_for_each_entry(cons
, &pdrvdata
.consoles
, list
) {
205 if (cons
->vtermno
== vtermno
) {
206 port
= container_of(cons
, struct port
, cons
);
212 spin_unlock_irqrestore(&pdrvdata_lock
, flags
);
216 static struct port
*find_port_by_id(struct ports_device
*portdev
, u32 id
)
221 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
222 list_for_each_entry(port
, &portdev
->ports
, list
)
227 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
232 static struct port
*find_port_by_vq(struct ports_device
*portdev
,
233 struct virtqueue
*vq
)
238 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
239 list_for_each_entry(port
, &portdev
->ports
, list
)
240 if (port
->in_vq
== vq
|| port
->out_vq
== vq
)
244 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
248 static bool is_console_port(struct port
*port
)
255 static inline bool use_multiport(struct ports_device
*portdev
)
258 * This condition can be true when put_chars is called from
263 return portdev
->vdev
->features
[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT
);
266 static void free_buf(struct port_buffer
*buf
)
272 static struct port_buffer
*alloc_buf(size_t buf_size
)
274 struct port_buffer
*buf
;
276 buf
= kmalloc(sizeof(*buf
), GFP_KERNEL
);
279 buf
->buf
= kzalloc(buf_size
, GFP_KERNEL
);
284 buf
->size
= buf_size
;
293 /* Callers should take appropriate locks */
294 static void *get_inbuf(struct port
*port
)
296 struct port_buffer
*buf
;
297 struct virtqueue
*vq
;
301 buf
= vq
->vq_ops
->get_buf(vq
, &len
);
310 * Create a scatter-gather list representing our input buffer and put
313 * Callers should take appropriate locks.
315 static int add_inbuf(struct virtqueue
*vq
, struct port_buffer
*buf
)
317 struct scatterlist sg
[1];
320 sg_init_one(sg
, buf
->buf
, buf
->size
);
322 ret
= vq
->vq_ops
->add_buf(vq
, sg
, 0, 1, buf
);
323 vq
->vq_ops
->kick(vq
);
327 /* Discard any unread data this port has. Callers lockers. */
328 static void discard_port_data(struct port
*port
)
330 struct port_buffer
*buf
;
331 struct virtqueue
*vq
;
339 buf
= vq
->vq_ops
->get_buf(vq
, &len
);
343 if (add_inbuf(vq
, buf
) < 0) {
347 buf
= vq
->vq_ops
->get_buf(vq
, &len
);
351 dev_warn(port
->dev
, "Errors adding %d buffers back to vq\n",
355 static bool port_has_data(struct port
*port
)
360 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
365 port
->inbuf
= get_inbuf(port
);
372 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
376 static ssize_t
send_control_msg(struct port
*port
, unsigned int event
,
379 struct scatterlist sg
[1];
380 struct virtio_console_control cpkt
;
381 struct virtqueue
*vq
;
384 if (!use_multiport(port
->portdev
))
391 vq
= port
->portdev
->c_ovq
;
393 sg_init_one(sg
, &cpkt
, sizeof(cpkt
));
394 if (vq
->vq_ops
->add_buf(vq
, sg
, 1, 0, &cpkt
) >= 0) {
395 vq
->vq_ops
->kick(vq
);
396 while (!vq
->vq_ops
->get_buf(vq
, &len
))
402 static ssize_t
send_buf(struct port
*port
, void *in_buf
, size_t in_count
)
404 struct scatterlist sg
[1];
405 struct virtqueue
*out_vq
;
409 out_vq
= port
->out_vq
;
411 sg_init_one(sg
, in_buf
, in_count
);
412 ret
= out_vq
->vq_ops
->add_buf(out_vq
, sg
, 1, 0, in_buf
);
414 /* Tell Host to go! */
415 out_vq
->vq_ops
->kick(out_vq
);
423 * Wait till the host acknowledges it pushed out the data we
424 * sent. Also ensure we return to userspace the number of
425 * bytes that were successfully consumed by the host.
427 while (!out_vq
->vq_ops
->get_buf(out_vq
, &len
))
430 /* We're expected to return the amount of data we wrote */
435 * Give out the data that's requested from the buffer that we have
438 static ssize_t
fill_readbuf(struct port
*port
, char *out_buf
, size_t out_count
,
441 struct port_buffer
*buf
;
444 if (!out_count
|| !port_has_data(port
))
448 out_count
= min(out_count
, buf
->len
- buf
->offset
);
453 ret
= copy_to_user(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
457 memcpy(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
460 buf
->offset
+= out_count
;
462 if (buf
->offset
== buf
->len
) {
464 * We're done using all the data in this buffer.
465 * Re-queue so that the Host can send us more data.
467 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
470 if (add_inbuf(port
->in_vq
, buf
) < 0)
471 dev_warn(port
->dev
, "failed add_buf\n");
473 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
475 /* Return the number of bytes actually copied */
479 /* The condition that must be true for polling to end */
480 static bool wait_is_over(struct port
*port
)
482 return port_has_data(port
) || !port
->host_connected
;
485 static ssize_t
port_fops_read(struct file
*filp
, char __user
*ubuf
,
486 size_t count
, loff_t
*offp
)
491 port
= filp
->private_data
;
493 if (!port_has_data(port
)) {
495 * If nothing's connected on the host just return 0 in
496 * case of list_empty; this tells the userspace app
497 * that there's no connection
499 if (!port
->host_connected
)
501 if (filp
->f_flags
& O_NONBLOCK
)
504 ret
= wait_event_interruptible(port
->waitqueue
,
510 * We could've received a disconnection message while we were
511 * waiting for more data.
513 * This check is not clubbed in the if() statement above as we
514 * might receive some data as well as the host could get
515 * disconnected after we got woken up from our wait. So we
516 * really want to give off whatever data we have and only then
517 * check for host_connected.
519 if (!port_has_data(port
) && !port
->host_connected
)
522 return fill_readbuf(port
, ubuf
, count
, true);
525 static ssize_t
port_fops_write(struct file
*filp
, const char __user
*ubuf
,
526 size_t count
, loff_t
*offp
)
532 port
= filp
->private_data
;
534 count
= min((size_t)(32 * 1024), count
);
536 buf
= kmalloc(count
, GFP_KERNEL
);
540 ret
= copy_from_user(buf
, ubuf
, count
);
546 ret
= send_buf(port
, buf
, count
);
552 static unsigned int port_fops_poll(struct file
*filp
, poll_table
*wait
)
557 port
= filp
->private_data
;
558 poll_wait(filp
, &port
->waitqueue
, wait
);
562 ret
|= POLLIN
| POLLRDNORM
;
563 if (port
->host_connected
)
565 if (!port
->host_connected
)
571 static int port_fops_release(struct inode
*inode
, struct file
*filp
)
575 port
= filp
->private_data
;
577 /* Notify host of port being closed */
578 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
580 spin_lock_irq(&port
->inbuf_lock
);
581 port
->guest_connected
= false;
583 discard_port_data(port
);
585 spin_unlock_irq(&port
->inbuf_lock
);
590 static int port_fops_open(struct inode
*inode
, struct file
*filp
)
592 struct cdev
*cdev
= inode
->i_cdev
;
595 port
= container_of(cdev
, struct port
, cdev
);
596 filp
->private_data
= port
;
599 * Don't allow opening of console port devices -- that's done
602 if (is_console_port(port
))
605 /* Allow only one process to open a particular port at a time */
606 spin_lock_irq(&port
->inbuf_lock
);
607 if (port
->guest_connected
) {
608 spin_unlock_irq(&port
->inbuf_lock
);
612 port
->guest_connected
= true;
613 spin_unlock_irq(&port
->inbuf_lock
);
615 /* Notify host of port being opened */
616 send_control_msg(filp
->private_data
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
622 * The file operations that we support: programs in the guest can open
623 * a console device, read from it, write to it, poll for data and
624 * close it. The devices are at
625 * /dev/vport<device number>p<port number>
627 static const struct file_operations port_fops
= {
628 .owner
= THIS_MODULE
,
629 .open
= port_fops_open
,
630 .read
= port_fops_read
,
631 .write
= port_fops_write
,
632 .poll
= port_fops_poll
,
633 .release
= port_fops_release
,
637 * The put_chars() callback is pretty straightforward.
639 * We turn the characters into a scatter-gather list, add it to the
640 * output queue and then kick the Host. Then we sit here waiting for
641 * it to finish: inefficient in theory, but in practice
642 * implementations will do it immediately (lguest's Launcher does).
644 static int put_chars(u32 vtermno
, const char *buf
, int count
)
648 port
= find_port_by_vtermno(vtermno
);
652 if (unlikely(early_put_chars
))
653 return early_put_chars(vtermno
, buf
, count
);
655 return send_buf(port
, (void *)buf
, count
);
659 * get_chars() is the callback from the hvc_console infrastructure
660 * when an interrupt is received.
662 * We call out to fill_readbuf that gets us the required data from the
663 * buffers that are queued up.
665 static int get_chars(u32 vtermno
, char *buf
, int count
)
669 port
= find_port_by_vtermno(vtermno
);
673 /* If we don't have an input queue yet, we can't get input. */
674 BUG_ON(!port
->in_vq
);
676 return fill_readbuf(port
, buf
, count
, false);
679 static void resize_console(struct port
*port
)
681 struct virtio_device
*vdev
;
684 vdev
= port
->portdev
->vdev
;
685 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_SIZE
)) {
686 vdev
->config
->get(vdev
,
687 offsetof(struct virtio_console_config
, cols
),
688 &ws
.ws_col
, sizeof(u16
));
689 vdev
->config
->get(vdev
,
690 offsetof(struct virtio_console_config
, rows
),
691 &ws
.ws_row
, sizeof(u16
));
692 hvc_resize(port
->cons
.hvc
, ws
);
696 /* We set the configuration at this point, since we now have a tty */
697 static int notifier_add_vio(struct hvc_struct
*hp
, int data
)
701 port
= find_port_by_vtermno(hp
->vtermno
);
705 hp
->irq_requested
= 1;
706 resize_console(port
);
711 static void notifier_del_vio(struct hvc_struct
*hp
, int data
)
713 hp
->irq_requested
= 0;
716 /* The operations for console ports. */
717 static const struct hv_ops hv_ops
= {
718 .get_chars
= get_chars
,
719 .put_chars
= put_chars
,
720 .notifier_add
= notifier_add_vio
,
721 .notifier_del
= notifier_del_vio
,
722 .notifier_hangup
= notifier_del_vio
,
726 * Console drivers are initialized very early so boot messages can go
727 * out, so we do things slightly differently from the generic virtio
728 * initialization of the net and block drivers.
730 * At this stage, the console is output-only. It's too early to set
731 * up a virtqueue, so we let the drivers do some boutique early-output
734 int __init
virtio_cons_early_init(int (*put_chars
)(u32
, const char *, int))
736 early_put_chars
= put_chars
;
737 return hvc_instantiate(0, 0, &hv_ops
);
740 int init_port_console(struct port
*port
)
745 * The Host's telling us this port is a console port. Hook it
746 * up with an hvc console.
748 * To set up and manage our virtual console, we call
751 * The first argument of hvc_alloc() is the virtual console
752 * number. The second argument is the parameter for the
753 * notification mechanism (like irq number). We currently
754 * leave this as zero, virtqueues have implicit notifications.
756 * The third argument is a "struct hv_ops" containing the
757 * put_chars() get_chars(), notifier_add() and notifier_del()
758 * pointers. The final argument is the output buffer size: we
759 * can do any size, so we put PAGE_SIZE here.
761 port
->cons
.vtermno
= pdrvdata
.next_vtermno
;
763 port
->cons
.hvc
= hvc_alloc(port
->cons
.vtermno
, 0, &hv_ops
, PAGE_SIZE
);
764 if (IS_ERR(port
->cons
.hvc
)) {
765 ret
= PTR_ERR(port
->cons
.hvc
);
767 "error %d allocating hvc for port\n", ret
);
768 port
->cons
.hvc
= NULL
;
771 spin_lock_irq(&pdrvdata_lock
);
772 pdrvdata
.next_vtermno
++;
773 list_add_tail(&port
->cons
.list
, &pdrvdata
.consoles
);
774 spin_unlock_irq(&pdrvdata_lock
);
775 port
->guest_connected
= true;
777 /* Notify host of port being opened */
778 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
783 static ssize_t
show_port_name(struct device
*dev
,
784 struct device_attribute
*attr
, char *buffer
)
788 port
= dev_get_drvdata(dev
);
790 return sprintf(buffer
, "%s\n", port
->name
);
793 static DEVICE_ATTR(name
, S_IRUGO
, show_port_name
, NULL
);
795 static struct attribute
*port_sysfs_entries
[] = {
800 static struct attribute_group port_attribute_group
= {
801 .name
= NULL
, /* put in device directory */
802 .attrs
= port_sysfs_entries
,
805 static int debugfs_open(struct inode
*inode
, struct file
*filp
)
807 filp
->private_data
= inode
->i_private
;
811 static ssize_t
debugfs_read(struct file
*filp
, char __user
*ubuf
,
812 size_t count
, loff_t
*offp
)
816 ssize_t ret
, out_offset
, out_count
;
819 buf
= kmalloc(out_count
, GFP_KERNEL
);
823 port
= filp
->private_data
;
825 out_offset
+= snprintf(buf
+ out_offset
, out_count
,
826 "name: %s\n", port
->name
? port
->name
: "");
827 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
828 "guest_connected: %d\n", port
->guest_connected
);
829 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
830 "host_connected: %d\n", port
->host_connected
);
831 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
833 is_console_port(port
) ? "yes" : "no");
834 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
835 "console_vtermno: %u\n", port
->cons
.vtermno
);
837 ret
= simple_read_from_buffer(ubuf
, count
, offp
, buf
, out_offset
);
842 static const struct file_operations port_debugfs_ops
= {
843 .owner
= THIS_MODULE
,
844 .open
= debugfs_open
,
845 .read
= debugfs_read
,
848 /* Remove all port-specific data. */
849 static int remove_port(struct port
*port
)
851 struct port_buffer
*buf
;
853 spin_lock_irq(&port
->portdev
->ports_lock
);
854 list_del(&port
->list
);
855 spin_unlock_irq(&port
->portdev
->ports_lock
);
857 if (is_console_port(port
)) {
858 spin_lock_irq(&pdrvdata_lock
);
859 list_del(&port
->cons
.list
);
860 spin_unlock_irq(&pdrvdata_lock
);
861 hvc_remove(port
->cons
.hvc
);
863 if (port
->guest_connected
)
864 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
866 sysfs_remove_group(&port
->dev
->kobj
, &port_attribute_group
);
867 device_destroy(pdrvdata
.class, port
->dev
->devt
);
868 cdev_del(&port
->cdev
);
870 /* Remove unused data this port might have received. */
871 discard_port_data(port
);
873 /* Remove buffers we queued up for the Host to send us data in. */
874 while ((buf
= port
->in_vq
->vq_ops
->detach_unused_buf(port
->in_vq
)))
879 debugfs_remove(port
->debugfs_file
);
885 /* Any private messages that the Host and Guest want to share */
886 static void handle_control_message(struct ports_device
*portdev
,
887 struct port_buffer
*buf
)
889 struct virtio_console_control
*cpkt
;
894 cpkt
= (struct virtio_console_control
*)(buf
->buf
+ buf
->offset
);
896 port
= find_port_by_id(portdev
, cpkt
->id
);
898 /* No valid header at start of buffer. Drop it. */
899 dev_dbg(&portdev
->vdev
->dev
,
900 "Invalid index %u in control packet\n", cpkt
->id
);
904 switch (cpkt
->event
) {
905 case VIRTIO_CONSOLE_CONSOLE_PORT
:
908 if (is_console_port(port
))
911 init_port_console(port
);
913 * Could remove the port here in case init fails - but
914 * have to notify the host first.
917 case VIRTIO_CONSOLE_RESIZE
:
918 if (!is_console_port(port
))
920 port
->cons
.hvc
->irq_requested
= 1;
921 resize_console(port
);
923 case VIRTIO_CONSOLE_PORT_OPEN
:
924 port
->host_connected
= cpkt
->value
;
925 wake_up_interruptible(&port
->waitqueue
);
927 case VIRTIO_CONSOLE_PORT_NAME
:
929 * Skip the size of the header and the cpkt to get the size
930 * of the name that was sent
932 name_size
= buf
->len
- buf
->offset
- sizeof(*cpkt
) + 1;
934 port
->name
= kmalloc(name_size
, GFP_KERNEL
);
937 "Not enough space to store port name\n");
940 strncpy(port
->name
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
942 port
->name
[name_size
- 1] = 0;
945 * Since we only have one sysfs attribute, 'name',
946 * create it only if we have a name for the port.
948 err
= sysfs_create_group(&port
->dev
->kobj
,
949 &port_attribute_group
);
952 "Error %d creating sysfs device attributes\n",
956 case VIRTIO_CONSOLE_PORT_REMOVE
:
958 * Hot unplug the port. We don't decrement nr_ports
959 * since we don't want to deal with extra complexities
960 * of using the lowest-available port id: We can just
961 * pick up the nr_ports number as the id and not have
962 * userspace send it to us. This helps us in two
965 * - We don't need to have a 'port_id' field in the
966 * config space when a port is hot-added. This is a
967 * good thing as we might queue up multiple hotplug
968 * requests issued in our workqueue.
970 * - Another way to deal with this would have been to
971 * use a bitmap of the active ports and select the
972 * lowest non-active port from that map. That
973 * bloats the already tight config space and we
974 * would end up artificially limiting the
975 * max. number of ports to sizeof(bitmap). Right
976 * now we can support 2^32 ports (as the port id is
977 * stored in a u32 type).
985 static void control_work_handler(struct work_struct
*work
)
987 struct ports_device
*portdev
;
988 struct virtqueue
*vq
;
989 struct port_buffer
*buf
;
992 portdev
= container_of(work
, struct ports_device
, control_work
);
995 spin_lock(&portdev
->cvq_lock
);
996 while ((buf
= vq
->vq_ops
->get_buf(vq
, &len
))) {
997 spin_unlock(&portdev
->cvq_lock
);
1002 handle_control_message(portdev
, buf
);
1004 spin_lock(&portdev
->cvq_lock
);
1005 if (add_inbuf(portdev
->c_ivq
, buf
) < 0) {
1006 dev_warn(&portdev
->vdev
->dev
,
1007 "Error adding buffer to queue\n");
1011 spin_unlock(&portdev
->cvq_lock
);
1014 static void in_intr(struct virtqueue
*vq
)
1017 unsigned long flags
;
1019 port
= find_port_by_vq(vq
->vdev
->priv
, vq
);
1023 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
1025 port
->inbuf
= get_inbuf(port
);
1028 * Don't queue up data when port is closed. This condition
1029 * can be reached when a console port is not yet connected (no
1030 * tty is spawned) and the host sends out data to console
1031 * ports. For generic serial ports, the host won't
1032 * (shouldn't) send data till the guest is connected.
1034 if (!port
->guest_connected
)
1035 discard_port_data(port
);
1037 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
1039 wake_up_interruptible(&port
->waitqueue
);
1041 if (is_console_port(port
) && hvc_poll(port
->cons
.hvc
))
1045 static void control_intr(struct virtqueue
*vq
)
1047 struct ports_device
*portdev
;
1049 portdev
= vq
->vdev
->priv
;
1050 schedule_work(&portdev
->control_work
);
1053 static void config_intr(struct virtio_device
*vdev
)
1055 struct ports_device
*portdev
;
1057 portdev
= vdev
->priv
;
1058 if (use_multiport(portdev
)) {
1059 /* Handle port hot-add */
1060 schedule_work(&portdev
->config_work
);
1063 * We'll use this way of resizing only for legacy support.
1064 * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
1065 * control messages to indicate console size changes so that
1066 * it can be done per-port
1068 resize_console(find_port_by_id(portdev
, 0));
1071 static unsigned int fill_queue(struct virtqueue
*vq
, spinlock_t
*lock
)
1073 struct port_buffer
*buf
;
1079 buf
= alloc_buf(PAGE_SIZE
);
1083 spin_lock_irq(lock
);
1084 err
= add_inbuf(vq
, buf
);
1086 spin_unlock_irq(lock
);
1091 spin_unlock_irq(lock
);
1097 static int add_port(struct ports_device
*portdev
, u32 id
)
1099 char debugfs_name
[16];
1101 struct port_buffer
*buf
;
1105 port
= kmalloc(sizeof(*port
), GFP_KERNEL
);
1111 port
->portdev
= portdev
;
1116 port
->cons
.hvc
= NULL
;
1118 port
->host_connected
= port
->guest_connected
= false;
1120 port
->in_vq
= portdev
->in_vqs
[port
->id
];
1121 port
->out_vq
= portdev
->out_vqs
[port
->id
];
1123 cdev_init(&port
->cdev
, &port_fops
);
1125 devt
= MKDEV(portdev
->chr_major
, id
);
1126 err
= cdev_add(&port
->cdev
, devt
, 1);
1128 dev_err(&port
->portdev
->vdev
->dev
,
1129 "Error %d adding cdev for port %u\n", err
, id
);
1132 port
->dev
= device_create(pdrvdata
.class, &port
->portdev
->vdev
->dev
,
1133 devt
, port
, "vport%up%u",
1134 port
->portdev
->drv_index
, id
);
1135 if (IS_ERR(port
->dev
)) {
1136 err
= PTR_ERR(port
->dev
);
1137 dev_err(&port
->portdev
->vdev
->dev
,
1138 "Error %d creating device for port %u\n",
1143 spin_lock_init(&port
->inbuf_lock
);
1144 init_waitqueue_head(&port
->waitqueue
);
1146 /* Fill the in_vq with buffers so the host can send us data. */
1147 err
= fill_queue(port
->in_vq
, &port
->inbuf_lock
);
1149 dev_err(port
->dev
, "Error allocating inbufs\n");
1155 * If we're not using multiport support, this has to be a console port
1157 if (!use_multiport(port
->portdev
)) {
1158 err
= init_port_console(port
);
1163 spin_lock_irq(&portdev
->ports_lock
);
1164 list_add_tail(&port
->list
, &port
->portdev
->ports
);
1165 spin_unlock_irq(&portdev
->ports_lock
);
1168 * Tell the Host we're set so that it can send us various
1169 * configuration parameters for this port (eg, port name,
1170 * caching, whether this is a console port, etc.)
1172 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1174 if (pdrvdata
.debugfs_dir
) {
1176 * Finally, create the debugfs file that we can use to
1177 * inspect a port's state at any time
1179 sprintf(debugfs_name
, "vport%up%u",
1180 port
->portdev
->drv_index
, id
);
1181 port
->debugfs_file
= debugfs_create_file(debugfs_name
, 0444,
1182 pdrvdata
.debugfs_dir
,
1189 while ((buf
= port
->in_vq
->vq_ops
->detach_unused_buf(port
->in_vq
)))
1192 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1194 cdev_del(&port
->cdev
);
1202 * The workhandler for config-space updates.
1204 * This is called when ports are hot-added.
1206 static void config_work_handler(struct work_struct
*work
)
1208 struct virtio_console_config virtconconf
;
1209 struct ports_device
*portdev
;
1210 struct virtio_device
*vdev
;
1213 portdev
= container_of(work
, struct ports_device
, config_work
);
1215 vdev
= portdev
->vdev
;
1216 vdev
->config
->get(vdev
,
1217 offsetof(struct virtio_console_config
, nr_ports
),
1218 &virtconconf
.nr_ports
,
1219 sizeof(virtconconf
.nr_ports
));
1221 if (portdev
->config
.nr_ports
== virtconconf
.nr_ports
) {
1223 * Port 0 got hot-added. Since we already did all the
1224 * other initialisation for it, just tell the Host
1225 * that the port is ready if we find the port. In
1226 * case the port was hot-removed earlier, we call
1227 * add_port to add the port.
1231 port
= find_port_by_id(portdev
, 0);
1233 add_port(portdev
, 0);
1235 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1238 if (virtconconf
.nr_ports
> portdev
->config
.max_nr_ports
) {
1239 dev_warn(&vdev
->dev
,
1240 "More ports specified (%u) than allowed (%u)",
1241 portdev
->config
.nr_ports
+ 1,
1242 portdev
->config
.max_nr_ports
);
1245 if (virtconconf
.nr_ports
< portdev
->config
.nr_ports
)
1249 while (virtconconf
.nr_ports
- portdev
->config
.nr_ports
) {
1250 err
= add_port(portdev
, portdev
->config
.nr_ports
);
1253 portdev
->config
.nr_ports
++;
1257 static int init_vqs(struct ports_device
*portdev
)
1259 vq_callback_t
**io_callbacks
;
1261 struct virtqueue
**vqs
;
1262 u32 i
, j
, nr_ports
, nr_queues
;
1265 nr_ports
= portdev
->config
.max_nr_ports
;
1266 nr_queues
= use_multiport(portdev
) ? (nr_ports
+ 1) * 2 : 2;
1268 vqs
= kmalloc(nr_queues
* sizeof(struct virtqueue
*), GFP_KERNEL
);
1273 io_callbacks
= kmalloc(nr_queues
* sizeof(vq_callback_t
*), GFP_KERNEL
);
1274 if (!io_callbacks
) {
1278 io_names
= kmalloc(nr_queues
* sizeof(char *), GFP_KERNEL
);
1281 goto free_callbacks
;
1283 portdev
->in_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1285 if (!portdev
->in_vqs
) {
1289 portdev
->out_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1291 if (!portdev
->out_vqs
) {
1297 * For backward compat (newer host but older guest), the host
1298 * spawns a console port first and also inits the vqs for port
1302 io_callbacks
[j
] = in_intr
;
1303 io_callbacks
[j
+ 1] = NULL
;
1304 io_names
[j
] = "input";
1305 io_names
[j
+ 1] = "output";
1308 if (use_multiport(portdev
)) {
1309 io_callbacks
[j
] = control_intr
;
1310 io_callbacks
[j
+ 1] = NULL
;
1311 io_names
[j
] = "control-i";
1312 io_names
[j
+ 1] = "control-o";
1314 for (i
= 1; i
< nr_ports
; i
++) {
1316 io_callbacks
[j
] = in_intr
;
1317 io_callbacks
[j
+ 1] = NULL
;
1318 io_names
[j
] = "input";
1319 io_names
[j
+ 1] = "output";
1322 /* Find the queues. */
1323 err
= portdev
->vdev
->config
->find_vqs(portdev
->vdev
, nr_queues
, vqs
,
1325 (const char **)io_names
);
1330 portdev
->in_vqs
[0] = vqs
[0];
1331 portdev
->out_vqs
[0] = vqs
[1];
1333 if (use_multiport(portdev
)) {
1334 portdev
->c_ivq
= vqs
[j
];
1335 portdev
->c_ovq
= vqs
[j
+ 1];
1337 for (i
= 1; i
< nr_ports
; i
++) {
1339 portdev
->in_vqs
[i
] = vqs
[j
];
1340 portdev
->out_vqs
[i
] = vqs
[j
+ 1];
1343 kfree(io_callbacks
);
1352 kfree(io_callbacks
);
1354 kfree(portdev
->out_vqs
);
1356 kfree(portdev
->in_vqs
);
1363 static const struct file_operations portdev_fops
= {
1364 .owner
= THIS_MODULE
,
1368 * Once we're further in boot, we get probed like any other virtio
1371 * If the host also supports multiple console ports, we check the
1372 * config space to see how many ports the host has spawned. We
1373 * initialize each port found.
1375 static int __devinit
virtcons_probe(struct virtio_device
*vdev
)
1377 struct ports_device
*portdev
;
1382 portdev
= kmalloc(sizeof(*portdev
), GFP_KERNEL
);
1388 /* Attach this portdev to this virtio_device, and vice-versa. */
1389 portdev
->vdev
= vdev
;
1390 vdev
->priv
= portdev
;
1392 spin_lock_irq(&pdrvdata_lock
);
1393 portdev
->drv_index
= pdrvdata
.index
++;
1394 spin_unlock_irq(&pdrvdata_lock
);
1396 portdev
->chr_major
= register_chrdev(0, "virtio-portsdev",
1398 if (portdev
->chr_major
< 0) {
1400 "Error %d registering chrdev for device %u\n",
1401 portdev
->chr_major
, portdev
->drv_index
);
1402 err
= portdev
->chr_major
;
1407 portdev
->config
.nr_ports
= 1;
1408 portdev
->config
.max_nr_ports
= 1;
1409 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_MULTIPORT
)) {
1411 vdev
->features
[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT
;
1413 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1415 &portdev
->config
.nr_ports
,
1416 sizeof(portdev
->config
.nr_ports
));
1417 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1419 &portdev
->config
.max_nr_ports
,
1420 sizeof(portdev
->config
.max_nr_ports
));
1421 if (portdev
->config
.nr_ports
> portdev
->config
.max_nr_ports
) {
1422 dev_warn(&vdev
->dev
,
1423 "More ports (%u) specified than allowed (%u). Will init %u ports.",
1424 portdev
->config
.nr_ports
,
1425 portdev
->config
.max_nr_ports
,
1426 portdev
->config
.max_nr_ports
);
1428 portdev
->config
.nr_ports
= portdev
->config
.max_nr_ports
;
1432 /* Let the Host know we support multiple ports.*/
1433 vdev
->config
->finalize_features(vdev
);
1435 err
= init_vqs(portdev
);
1437 dev_err(&vdev
->dev
, "Error %d initializing vqs\n", err
);
1441 spin_lock_init(&portdev
->ports_lock
);
1442 INIT_LIST_HEAD(&portdev
->ports
);
1445 spin_lock_init(&portdev
->cvq_lock
);
1446 INIT_WORK(&portdev
->control_work
, &control_work_handler
);
1447 INIT_WORK(&portdev
->config_work
, &config_work_handler
);
1449 err
= fill_queue(portdev
->c_ivq
, &portdev
->cvq_lock
);
1452 "Error allocating buffers for control queue\n");
1458 for (i
= 0; i
< portdev
->config
.nr_ports
; i
++)
1459 add_port(portdev
, i
);
1461 /* Start using the new console output. */
1462 early_put_chars
= NULL
;
1466 vdev
->config
->del_vqs(vdev
);
1467 kfree(portdev
->in_vqs
);
1468 kfree(portdev
->out_vqs
);
1470 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1477 static void virtcons_remove(struct virtio_device
*vdev
)
1479 struct ports_device
*portdev
;
1480 struct port
*port
, *port2
;
1481 struct port_buffer
*buf
;
1484 portdev
= vdev
->priv
;
1486 cancel_work_sync(&portdev
->control_work
);
1487 cancel_work_sync(&portdev
->config_work
);
1489 list_for_each_entry_safe(port
, port2
, &portdev
->ports
, list
)
1492 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1494 while ((buf
= portdev
->c_ivq
->vq_ops
->get_buf(portdev
->c_ivq
, &len
)))
1497 while ((buf
= portdev
->c_ivq
->vq_ops
->detach_unused_buf(portdev
->c_ivq
)))
1500 vdev
->config
->del_vqs(vdev
);
1501 kfree(portdev
->in_vqs
);
1502 kfree(portdev
->out_vqs
);
1507 static struct virtio_device_id id_table
[] = {
1508 { VIRTIO_ID_CONSOLE
, VIRTIO_DEV_ANY_ID
},
1512 static unsigned int features
[] = {
1513 VIRTIO_CONSOLE_F_SIZE
,
1514 VIRTIO_CONSOLE_F_MULTIPORT
,
1517 static struct virtio_driver virtio_console
= {
1518 .feature_table
= features
,
1519 .feature_table_size
= ARRAY_SIZE(features
),
1520 .driver
.name
= KBUILD_MODNAME
,
1521 .driver
.owner
= THIS_MODULE
,
1522 .id_table
= id_table
,
1523 .probe
= virtcons_probe
,
1524 .remove
= virtcons_remove
,
1525 .config_changed
= config_intr
,
1528 static int __init
init(void)
1532 pdrvdata
.class = class_create(THIS_MODULE
, "virtio-ports");
1533 if (IS_ERR(pdrvdata
.class)) {
1534 err
= PTR_ERR(pdrvdata
.class);
1535 pr_err("Error %d creating virtio-ports class\n", err
);
1539 pdrvdata
.debugfs_dir
= debugfs_create_dir("virtio-ports", NULL
);
1540 if (!pdrvdata
.debugfs_dir
) {
1541 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1542 PTR_ERR(pdrvdata
.debugfs_dir
));
1544 INIT_LIST_HEAD(&pdrvdata
.consoles
);
1546 return register_virtio_driver(&virtio_console
);
1549 static void __exit
fini(void)
1551 unregister_virtio_driver(&virtio_console
);
1553 class_destroy(pdrvdata
.class);
1554 if (pdrvdata
.debugfs_dir
)
1555 debugfs_remove_recursive(pdrvdata
.debugfs_dir
);
1560 MODULE_DEVICE_TABLE(virtio
, id_table
);
1561 MODULE_DESCRIPTION("Virtio console driver");
1562 MODULE_LICENSE("GPL");