/drivers/char/virtio_console.c
C | 1683 lines | 1090 code | 278 blank | 315 comment | 127 complexity | f246dda0cd3d73d86a409fe13a0425ed MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
1/*
2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010 Red Hat, Inc.
4 *
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.
9 *
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.
14 *
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
18 */
19#include <linux/cdev.h>
20#include <linux/debugfs.h>
21#include <linux/device.h>
22#include <linux/err.h>
23#include <linux/fs.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"
35
36/*
37 * This is a global struct for storing common data for all the devices
38 * this driver handles.
39 *
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.
43 */
44struct ports_driver_data {
45 /* Used for registering chardevs */
46 struct class *class;
47
48 /* Used for exporting per-port information to debugfs */
49 struct dentry *debugfs_dir;
50
51 /* Number of devices this driver is handling */
52 unsigned int index;
53
54 /*
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.
60 *
61 * We also just assume the first console being initialised was
62 * the first one that got used as the initial console.
63 */
64 unsigned int next_vtermno;
65
66 /* All the console devices handled by this driver */
67 struct list_head consoles;
68};
69static struct ports_driver_data pdrvdata;
70
71DEFINE_SPINLOCK(pdrvdata_lock);
72
73/* This struct holds information that's relevant only for console ports */
74struct console {
75 /* We'll place all consoles in a list in the pdrvdata struct */
76 struct list_head list;
77
78 /* The hvc device associated with this console port */
79 struct hvc_struct *hvc;
80
81 /* The size of the console */
82 struct winsize ws;
83
84 /*
85 * This number identifies the number that we used to register
86 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
87 * number passed on by the hvc callbacks to us to
88 * differentiate between the other console ports handled by
89 * this driver
90 */
91 u32 vtermno;
92};
93
94struct port_buffer {
95 char *buf;
96
97 /* size of the buffer in *buf above */
98 size_t size;
99
100 /* used length of the buffer */
101 size_t len;
102 /* offset in the buf from which to consume data */
103 size_t offset;
104};
105
106/*
107 * This is a per-device struct that stores data common to all the
108 * ports for that device (vdev->priv).
109 */
110struct ports_device {
111 /*
112 * Workqueue handlers where we process deferred work after
113 * notification
114 */
115 struct work_struct control_work;
116
117 struct list_head ports;
118
119 /* To protect the list of ports */
120 spinlock_t ports_lock;
121
122 /* To protect the vq operations for the control channel */
123 spinlock_t cvq_lock;
124
125 /* The current config space is stored here */
126 struct virtio_console_config config;
127
128 /* The virtio device we're associated with */
129 struct virtio_device *vdev;
130
131 /*
132 * A couple of virtqueues for the control channel: one for
133 * guest->host transfers, one for host->guest transfers
134 */
135 struct virtqueue *c_ivq, *c_ovq;
136
137 /* Array of per-port IO virtqueues */
138 struct virtqueue **in_vqs, **out_vqs;
139
140 /* Used for numbering devices for sysfs and debugfs */
141 unsigned int drv_index;
142
143 /* Major number for this device. Ports will be created as minors. */
144 int chr_major;
145};
146
147/* This struct holds the per-port data */
148struct port {
149 /* Next port in the list, head is in the ports_device */
150 struct list_head list;
151
152 /* Pointer to the parent virtio_console device */
153 struct ports_device *portdev;
154
155 /* The current buffer from which data has to be fed to readers */
156 struct port_buffer *inbuf;
157
158 /*
159 * To protect the operations on the in_vq associated with this
160 * port. Has to be a spinlock because it can be called from
161 * interrupt context (get_char()).
162 */
163 spinlock_t inbuf_lock;
164
165 /* Protect the operations on the out_vq. */
166 spinlock_t outvq_lock;
167
168 /* The IO vqs for this port */
169 struct virtqueue *in_vq, *out_vq;
170
171 /* File in the debugfs directory that exposes this port's information */
172 struct dentry *debugfs_file;
173
174 /*
175 * The entries in this struct will be valid if this port is
176 * hooked up to an hvc console
177 */
178 struct console cons;
179
180 /* Each port associates with a separate char device */
181 struct cdev cdev;
182 struct device *dev;
183
184 /* A waitqueue for poll() or blocking read operations */
185 wait_queue_head_t waitqueue;
186
187 /* The 'name' of the port that we expose via sysfs properties */
188 char *name;
189
190 /* The 'id' to identify the port with the Host */
191 u32 id;
192
193 bool outvq_full;
194
195 /* Is the host device open */
196 bool host_connected;
197
198 /* We should allow only one process to open a port */
199 bool guest_connected;
200};
201
202/* This is the very early arch-specified put chars function. */
203static int (*early_put_chars)(u32, const char *, int);
204
205static struct port *find_port_by_vtermno(u32 vtermno)
206{
207 struct port *port;
208 struct console *cons;
209 unsigned long flags;
210
211 spin_lock_irqsave(&pdrvdata_lock, flags);
212 list_for_each_entry(cons, &pdrvdata.consoles, list) {
213 if (cons->vtermno == vtermno) {
214 port = container_of(cons, struct port, cons);
215 goto out;
216 }
217 }
218 port = NULL;
219out:
220 spin_unlock_irqrestore(&pdrvdata_lock, flags);
221 return port;
222}
223
224static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
225{
226 struct port *port;
227 unsigned long flags;
228
229 spin_lock_irqsave(&portdev->ports_lock, flags);
230 list_for_each_entry(port, &portdev->ports, list)
231 if (port->id == id)
232 goto out;
233 port = NULL;
234out:
235 spin_unlock_irqrestore(&portdev->ports_lock, flags);
236
237 return port;
238}
239
240static struct port *find_port_by_vq(struct ports_device *portdev,
241 struct virtqueue *vq)
242{
243 struct port *port;
244 unsigned long flags;
245
246 spin_lock_irqsave(&portdev->ports_lock, flags);
247 list_for_each_entry(port, &portdev->ports, list)
248 if (port->in_vq == vq || port->out_vq == vq)
249 goto out;
250 port = NULL;
251out:
252 spin_unlock_irqrestore(&portdev->ports_lock, flags);
253 return port;
254}
255
256static bool is_console_port(struct port *port)
257{
258 if (port->cons.hvc)
259 return true;
260 return false;
261}
262
263static inline bool use_multiport(struct ports_device *portdev)
264{
265 /*
266 * This condition can be true when put_chars is called from
267 * early_init
268 */
269 if (!portdev->vdev)
270 return 0;
271 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
272}
273
274static void free_buf(struct port_buffer *buf)
275{
276 kfree(buf->buf);
277 kfree(buf);
278}
279
280static struct port_buffer *alloc_buf(size_t buf_size)
281{
282 struct port_buffer *buf;
283
284 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
285 if (!buf)
286 goto fail;
287 buf->buf = kzalloc(buf_size, GFP_KERNEL);
288 if (!buf->buf)
289 goto free_buf;
290 buf->len = 0;
291 buf->offset = 0;
292 buf->size = buf_size;
293 return buf;
294
295free_buf:
296 kfree(buf);
297fail:
298 return NULL;
299}
300
301/* Callers should take appropriate locks */
302static void *get_inbuf(struct port *port)
303{
304 struct port_buffer *buf;
305 struct virtqueue *vq;
306 unsigned int len;
307
308 vq = port->in_vq;
309 buf = virtqueue_get_buf(vq, &len);
310 if (buf) {
311 buf->len = len;
312 buf->offset = 0;
313 }
314 return buf;
315}
316
317/*
318 * Create a scatter-gather list representing our input buffer and put
319 * it in the queue.
320 *
321 * Callers should take appropriate locks.
322 */
323static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
324{
325 struct scatterlist sg[1];
326 int ret;
327
328 sg_init_one(sg, buf->buf, buf->size);
329
330 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
331 virtqueue_kick(vq);
332 return ret;
333}
334
335/* Discard any unread data this port has. Callers lockers. */
336static void discard_port_data(struct port *port)
337{
338 struct port_buffer *buf;
339 struct virtqueue *vq;
340 unsigned int len;
341 int ret;
342
343 vq = port->in_vq;
344 if (port->inbuf)
345 buf = port->inbuf;
346 else
347 buf = virtqueue_get_buf(vq, &len);
348
349 ret = 0;
350 while (buf) {
351 if (add_inbuf(vq, buf) < 0) {
352 ret++;
353 free_buf(buf);
354 }
355 buf = virtqueue_get_buf(vq, &len);
356 }
357 port->inbuf = NULL;
358 if (ret)
359 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
360 ret);
361}
362
363static bool port_has_data(struct port *port)
364{
365 unsigned long flags;
366 bool ret;
367
368 spin_lock_irqsave(&port->inbuf_lock, flags);
369 if (port->inbuf) {
370 ret = true;
371 goto out;
372 }
373 port->inbuf = get_inbuf(port);
374 if (port->inbuf) {
375 ret = true;
376 goto out;
377 }
378 ret = false;
379out:
380 spin_unlock_irqrestore(&port->inbuf_lock, flags);
381 return ret;
382}
383
384static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
385 unsigned int event, unsigned int value)
386{
387 struct scatterlist sg[1];
388 struct virtio_console_control cpkt;
389 struct virtqueue *vq;
390 unsigned int len;
391
392 if (!use_multiport(portdev))
393 return 0;
394
395 cpkt.id = port_id;
396 cpkt.event = event;
397 cpkt.value = value;
398
399 vq = portdev->c_ovq;
400
401 sg_init_one(sg, &cpkt, sizeof(cpkt));
402 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
403 virtqueue_kick(vq);
404 while (!virtqueue_get_buf(vq, &len))
405 cpu_relax();
406 }
407 return 0;
408}
409
410static ssize_t send_control_msg(struct port *port, unsigned int event,
411 unsigned int value)
412{
413 return __send_control_msg(port->portdev, port->id, event, value);
414}
415
416/* Callers must take the port->outvq_lock */
417static void reclaim_consumed_buffers(struct port *port)
418{
419 void *buf;
420 unsigned int len;
421
422 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
423 kfree(buf);
424 port->outvq_full = false;
425 }
426}
427
428static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
429 bool nonblock)
430{
431 struct scatterlist sg[1];
432 struct virtqueue *out_vq;
433 ssize_t ret;
434 unsigned long flags;
435 unsigned int len;
436
437 out_vq = port->out_vq;
438
439 spin_lock_irqsave(&port->outvq_lock, flags);
440
441 reclaim_consumed_buffers(port);
442
443 sg_init_one(sg, in_buf, in_count);
444 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
445
446 /* Tell Host to go! */
447 virtqueue_kick(out_vq);
448
449 if (ret < 0) {
450 in_count = 0;
451 goto done;
452 }
453
454 if (ret == 0)
455 port->outvq_full = true;
456
457 if (nonblock)
458 goto done;
459
460 /*
461 * Wait till the host acknowledges it pushed out the data we
462 * sent. This is done for data from the hvc_console; the tty
463 * operations are performed with spinlocks held so we can't
464 * sleep here. An alternative would be to copy the data to a
465 * buffer and relax the spinning requirement. The downside is
466 * we need to kmalloc a GFP_ATOMIC buffer each time the
467 * console driver writes something out.
468 */
469 while (!virtqueue_get_buf(out_vq, &len))
470 cpu_relax();
471done:
472 spin_unlock_irqrestore(&port->outvq_lock, flags);
473 /*
474 * We're expected to return the amount of data we wrote -- all
475 * of it
476 */
477 return in_count;
478}
479
480/*
481 * Give out the data that's requested from the buffer that we have
482 * queued up.
483 */
484static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
485 bool to_user)
486{
487 struct port_buffer *buf;
488 unsigned long flags;
489
490 if (!out_count || !port_has_data(port))
491 return 0;
492
493 buf = port->inbuf;
494 out_count = min(out_count, buf->len - buf->offset);
495
496 if (to_user) {
497 ssize_t ret;
498
499 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
500 if (ret)
501 return -EFAULT;
502 } else {
503 memcpy(out_buf, buf->buf + buf->offset, out_count);
504 }
505
506 buf->offset += out_count;
507
508 if (buf->offset == buf->len) {
509 /*
510 * We're done using all the data in this buffer.
511 * Re-queue so that the Host can send us more data.
512 */
513 spin_lock_irqsave(&port->inbuf_lock, flags);
514 port->inbuf = NULL;
515
516 if (add_inbuf(port->in_vq, buf) < 0)
517 dev_warn(port->dev, "failed add_buf\n");
518
519 spin_unlock_irqrestore(&port->inbuf_lock, flags);
520 }
521 /* Return the number of bytes actually copied */
522 return out_count;
523}
524
525/* The condition that must be true for polling to end */
526static bool will_read_block(struct port *port)
527{
528 return !port_has_data(port) && port->host_connected;
529}
530
531static bool will_write_block(struct port *port)
532{
533 bool ret;
534
535 if (!port->guest_connected) {
536 /* Port got hot-unplugged. Let's exit. */
537 return false;
538 }
539 if (!port->host_connected)
540 return true;
541
542 spin_lock_irq(&port->outvq_lock);
543 /*
544 * Check if the Host has consumed any buffers since we last
545 * sent data (this is only applicable for nonblocking ports).
546 */
547 reclaim_consumed_buffers(port);
548 ret = port->outvq_full;
549 spin_unlock_irq(&port->outvq_lock);
550
551 return ret;
552}
553
554static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
555 size_t count, loff_t *offp)
556{
557 struct port *port;
558 ssize_t ret;
559
560 port = filp->private_data;
561
562 if (!port_has_data(port)) {
563 /*
564 * If nothing's connected on the host just return 0 in
565 * case of list_empty; this tells the userspace app
566 * that there's no connection
567 */
568 if (!port->host_connected)
569 return 0;
570 if (filp->f_flags & O_NONBLOCK)
571 return -EAGAIN;
572
573 ret = wait_event_interruptible(port->waitqueue,
574 !will_read_block(port));
575 if (ret < 0)
576 return ret;
577 }
578 /*
579 * We could've received a disconnection message while we were
580 * waiting for more data.
581 *
582 * This check is not clubbed in the if() statement above as we
583 * might receive some data as well as the host could get
584 * disconnected after we got woken up from our wait. So we
585 * really want to give off whatever data we have and only then
586 * check for host_connected.
587 */
588 if (!port_has_data(port) && !port->host_connected)
589 return 0;
590
591 return fill_readbuf(port, ubuf, count, true);
592}
593
594static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
595 size_t count, loff_t *offp)
596{
597 struct port *port;
598 char *buf;
599 ssize_t ret;
600 bool nonblock;
601
602 /* Userspace could be out to fool us */
603 if (!count)
604 return 0;
605
606 port = filp->private_data;
607
608 nonblock = filp->f_flags & O_NONBLOCK;
609
610 if (will_write_block(port)) {
611 if (nonblock)
612 return -EAGAIN;
613
614 ret = wait_event_interruptible(port->waitqueue,
615 !will_write_block(port));
616 if (ret < 0)
617 return ret;
618 }
619
620 count = min((size_t)(32 * 1024), count);
621
622 buf = kmalloc(count, GFP_KERNEL);
623 if (!buf)
624 return -ENOMEM;
625
626 ret = copy_from_user(buf, ubuf, count);
627 if (ret) {
628 ret = -EFAULT;
629 goto free_buf;
630 }
631
632 /*
633 * We now ask send_buf() to not spin for generic ports -- we
634 * can re-use the same code path that non-blocking file
635 * descriptors take for blocking file descriptors since the
636 * wait is already done and we're certain the write will go
637 * through to the host.
638 */
639 nonblock = true;
640 ret = send_buf(port, buf, count, nonblock);
641
642 if (nonblock && ret > 0)
643 goto out;
644
645free_buf:
646 kfree(buf);
647out:
648 return ret;
649}
650
651static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
652{
653 struct port *port;
654 unsigned int ret;
655
656 port = filp->private_data;
657 poll_wait(filp, &port->waitqueue, wait);
658
659 ret = 0;
660 if (!will_read_block(port))
661 ret |= POLLIN | POLLRDNORM;
662 if (!will_write_block(port))
663 ret |= POLLOUT;
664 if (!port->host_connected)
665 ret |= POLLHUP;
666
667 return ret;
668}
669
670static int port_fops_release(struct inode *inode, struct file *filp)
671{
672 struct port *port;
673
674 port = filp->private_data;
675
676 /* Notify host of port being closed */
677 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
678
679 spin_lock_irq(&port->inbuf_lock);
680 port->guest_connected = false;
681
682 discard_port_data(port);
683
684 spin_unlock_irq(&port->inbuf_lock);
685
686 spin_lock_irq(&port->outvq_lock);
687 reclaim_consumed_buffers(port);
688 spin_unlock_irq(&port->outvq_lock);
689
690 return 0;
691}
692
693static int port_fops_open(struct inode *inode, struct file *filp)
694{
695 struct cdev *cdev = inode->i_cdev;
696 struct port *port;
697
698 port = container_of(cdev, struct port, cdev);
699 filp->private_data = port;
700
701 /*
702 * Don't allow opening of console port devices -- that's done
703 * via /dev/hvc
704 */
705 if (is_console_port(port))
706 return -ENXIO;
707
708 /* Allow only one process to open a particular port at a time */
709 spin_lock_irq(&port->inbuf_lock);
710 if (port->guest_connected) {
711 spin_unlock_irq(&port->inbuf_lock);
712 return -EMFILE;
713 }
714
715 port->guest_connected = true;
716 spin_unlock_irq(&port->inbuf_lock);
717
718 spin_lock_irq(&port->outvq_lock);
719 /*
720 * There might be a chance that we missed reclaiming a few
721 * buffers in the window of the port getting previously closed
722 * and opening now.
723 */
724 reclaim_consumed_buffers(port);
725 spin_unlock_irq(&port->outvq_lock);
726
727 /* Notify host of port being opened */
728 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
729
730 return 0;
731}
732
733/*
734 * The file operations that we support: programs in the guest can open
735 * a console device, read from it, write to it, poll for data and
736 * close it. The devices are at
737 * /dev/vport<device number>p<port number>
738 */
739static const struct file_operations port_fops = {
740 .owner = THIS_MODULE,
741 .open = port_fops_open,
742 .read = port_fops_read,
743 .write = port_fops_write,
744 .poll = port_fops_poll,
745 .release = port_fops_release,
746};
747
748/*
749 * The put_chars() callback is pretty straightforward.
750 *
751 * We turn the characters into a scatter-gather list, add it to the
752 * output queue and then kick the Host. Then we sit here waiting for
753 * it to finish: inefficient in theory, but in practice
754 * implementations will do it immediately (lguest's Launcher does).
755 */
756static int put_chars(u32 vtermno, const char *buf, int count)
757{
758 struct port *port;
759
760 if (unlikely(early_put_chars))
761 return early_put_chars(vtermno, buf, count);
762
763 port = find_port_by_vtermno(vtermno);
764 if (!port)
765 return -EPIPE;
766
767 return send_buf(port, (void *)buf, count, false);
768}
769
770/*
771 * get_chars() is the callback from the hvc_console infrastructure
772 * when an interrupt is received.
773 *
774 * We call out to fill_readbuf that gets us the required data from the
775 * buffers that are queued up.
776 */
777static int get_chars(u32 vtermno, char *buf, int count)
778{
779 struct port *port;
780
781 /* If we've not set up the port yet, we have no input to give. */
782 if (unlikely(early_put_chars))
783 return 0;
784
785 port = find_port_by_vtermno(vtermno);
786 if (!port)
787 return -EPIPE;
788
789 /* If we don't have an input queue yet, we can't get input. */
790 BUG_ON(!port->in_vq);
791
792 return fill_readbuf(port, buf, count, false);
793}
794
795static void resize_console(struct port *port)
796{
797 struct virtio_device *vdev;
798
799 /* The port could have been hot-unplugged */
800 if (!port || !is_console_port(port))
801 return;
802
803 vdev = port->portdev->vdev;
804 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
805 hvc_resize(port->cons.hvc, port->cons.ws);
806}
807
808/* We set the configuration at this point, since we now have a tty */
809static int notifier_add_vio(struct hvc_struct *hp, int data)
810{
811 struct port *port;
812
813 port = find_port_by_vtermno(hp->vtermno);
814 if (!port)
815 return -EINVAL;
816
817 hp->irq_requested = 1;
818 resize_console(port);
819
820 return 0;
821}
822
823static void notifier_del_vio(struct hvc_struct *hp, int data)
824{
825 hp->irq_requested = 0;
826}
827
828/* The operations for console ports. */
829static const struct hv_ops hv_ops = {
830 .get_chars = get_chars,
831 .put_chars = put_chars,
832 .notifier_add = notifier_add_vio,
833 .notifier_del = notifier_del_vio,
834 .notifier_hangup = notifier_del_vio,
835};
836
837/*
838 * Console drivers are initialized very early so boot messages can go
839 * out, so we do things slightly differently from the generic virtio
840 * initialization of the net and block drivers.
841 *
842 * At this stage, the console is output-only. It's too early to set
843 * up a virtqueue, so we let the drivers do some boutique early-output
844 * thing.
845 */
846int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
847{
848 early_put_chars = put_chars;
849 return hvc_instantiate(0, 0, &hv_ops);
850}
851
852int init_port_console(struct port *port)
853{
854 int ret;
855
856 /*
857 * The Host's telling us this port is a console port. Hook it
858 * up with an hvc console.
859 *
860 * To set up and manage our virtual console, we call
861 * hvc_alloc().
862 *
863 * The first argument of hvc_alloc() is the virtual console
864 * number. The second argument is the parameter for the
865 * notification mechanism (like irq number). We currently
866 * leave this as zero, virtqueues have implicit notifications.
867 *
868 * The third argument is a "struct hv_ops" containing the
869 * put_chars() get_chars(), notifier_add() and notifier_del()
870 * pointers. The final argument is the output buffer size: we
871 * can do any size, so we put PAGE_SIZE here.
872 */
873 port->cons.vtermno = pdrvdata.next_vtermno;
874
875 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
876 if (IS_ERR(port->cons.hvc)) {
877 ret = PTR_ERR(port->cons.hvc);
878 dev_err(port->dev,
879 "error %d allocating hvc for port\n", ret);
880 port->cons.hvc = NULL;
881 return ret;
882 }
883 spin_lock_irq(&pdrvdata_lock);
884 pdrvdata.next_vtermno++;
885 list_add_tail(&port->cons.list, &pdrvdata.consoles);
886 spin_unlock_irq(&pdrvdata_lock);
887 port->guest_connected = true;
888
889 /*
890 * Start using the new console output if this is the first
891 * console to come up.
892 */
893 if (early_put_chars)
894 early_put_chars = NULL;
895
896 /* Notify host of port being opened */
897 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
898
899 return 0;
900}
901
902static ssize_t show_port_name(struct device *dev,
903 struct device_attribute *attr, char *buffer)
904{
905 struct port *port;
906
907 port = dev_get_drvdata(dev);
908
909 return sprintf(buffer, "%s\n", port->name);
910}
911
912static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
913
914static struct attribute *port_sysfs_entries[] = {
915 &dev_attr_name.attr,
916 NULL
917};
918
919static struct attribute_group port_attribute_group = {
920 .name = NULL, /* put in device directory */
921 .attrs = port_sysfs_entries,
922};
923
924static int debugfs_open(struct inode *inode, struct file *filp)
925{
926 filp->private_data = inode->i_private;
927 return 0;
928}
929
930static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
931 size_t count, loff_t *offp)
932{
933 struct port *port;
934 char *buf;
935 ssize_t ret, out_offset, out_count;
936
937 out_count = 1024;
938 buf = kmalloc(out_count, GFP_KERNEL);
939 if (!buf)
940 return -ENOMEM;
941
942 port = filp->private_data;
943 out_offset = 0;
944 out_offset += snprintf(buf + out_offset, out_count,
945 "name: %s\n", port->name ? port->name : "");
946 out_offset += snprintf(buf + out_offset, out_count - out_offset,
947 "guest_connected: %d\n", port->guest_connected);
948 out_offset += snprintf(buf + out_offset, out_count - out_offset,
949 "host_connected: %d\n", port->host_connected);
950 out_offset += snprintf(buf + out_offset, out_count - out_offset,
951 "outvq_full: %d\n", port->outvq_full);
952 out_offset += snprintf(buf + out_offset, out_count - out_offset,
953 "is_console: %s\n",
954 is_console_port(port) ? "yes" : "no");
955 out_offset += snprintf(buf + out_offset, out_count - out_offset,
956 "console_vtermno: %u\n", port->cons.vtermno);
957
958 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
959 kfree(buf);
960 return ret;
961}
962
963static const struct file_operations port_debugfs_ops = {
964 .owner = THIS_MODULE,
965 .open = debugfs_open,
966 .read = debugfs_read,
967};
968
969static void set_console_size(struct port *port, u16 rows, u16 cols)
970{
971 if (!port || !is_console_port(port))
972 return;
973
974 port->cons.ws.ws_row = rows;
975 port->cons.ws.ws_col = cols;
976}
977
978static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
979{
980 struct port_buffer *buf;
981 unsigned int nr_added_bufs;
982 int ret;
983
984 nr_added_bufs = 0;
985 do {
986 buf = alloc_buf(PAGE_SIZE);
987 if (!buf)
988 break;
989
990 spin_lock_irq(lock);
991 ret = add_inbuf(vq, buf);
992 if (ret < 0) {
993 spin_unlock_irq(lock);
994 free_buf(buf);
995 break;
996 }
997 nr_added_bufs++;
998 spin_unlock_irq(lock);
999 } while (ret > 0);
1000
1001 return nr_added_bufs;
1002}
1003
1004static int add_port(struct ports_device *portdev, u32 id)
1005{
1006 char debugfs_name[16];
1007 struct port *port;
1008 struct port_buffer *buf;
1009 dev_t devt;
1010 unsigned int nr_added_bufs;
1011 int err;
1012
1013 port = kmalloc(sizeof(*port), GFP_KERNEL);
1014 if (!port) {
1015 err = -ENOMEM;
1016 goto fail;
1017 }
1018
1019 port->portdev = portdev;
1020 port->id = id;
1021
1022 port->name = NULL;
1023 port->inbuf = NULL;
1024 port->cons.hvc = NULL;
1025
1026 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1027
1028 port->host_connected = port->guest_connected = false;
1029
1030 port->outvq_full = false;
1031
1032 port->in_vq = portdev->in_vqs[port->id];
1033 port->out_vq = portdev->out_vqs[port->id];
1034
1035 cdev_init(&port->cdev, &port_fops);
1036
1037 devt = MKDEV(portdev->chr_major, id);
1038 err = cdev_add(&port->cdev, devt, 1);
1039 if (err < 0) {
1040 dev_err(&port->portdev->vdev->dev,
1041 "Error %d adding cdev for port %u\n", err, id);
1042 goto free_port;
1043 }
1044 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1045 devt, port, "vport%up%u",
1046 port->portdev->drv_index, id);
1047 if (IS_ERR(port->dev)) {
1048 err = PTR_ERR(port->dev);
1049 dev_err(&port->portdev->vdev->dev,
1050 "Error %d creating device for port %u\n",
1051 err, id);
1052 goto free_cdev;
1053 }
1054
1055 spin_lock_init(&port->inbuf_lock);
1056 spin_lock_init(&port->outvq_lock);
1057 init_waitqueue_head(&port->waitqueue);
1058
1059 /* Fill the in_vq with buffers so the host can send us data. */
1060 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1061 if (!nr_added_bufs) {
1062 dev_err(port->dev, "Error allocating inbufs\n");
1063 err = -ENOMEM;
1064 goto free_device;
1065 }
1066
1067 /*
1068 * If we're not using multiport support, this has to be a console port
1069 */
1070 if (!use_multiport(port->portdev)) {
1071 err = init_port_console(port);
1072 if (err)
1073 goto free_inbufs;
1074 }
1075
1076 spin_lock_irq(&portdev->ports_lock);
1077 list_add_tail(&port->list, &port->portdev->ports);
1078 spin_unlock_irq(&portdev->ports_lock);
1079
1080 /*
1081 * Tell the Host we're set so that it can send us various
1082 * configuration parameters for this port (eg, port name,
1083 * caching, whether this is a console port, etc.)
1084 */
1085 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1086
1087 if (pdrvdata.debugfs_dir) {
1088 /*
1089 * Finally, create the debugfs file that we can use to
1090 * inspect a port's state at any time
1091 */
1092 sprintf(debugfs_name, "vport%up%u",
1093 port->portdev->drv_index, id);
1094 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1095 pdrvdata.debugfs_dir,
1096 port,
1097 &port_debugfs_ops);
1098 }
1099 return 0;
1100
1101free_inbufs:
1102 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1103 free_buf(buf);
1104free_device:
1105 device_destroy(pdrvdata.class, port->dev->devt);
1106free_cdev:
1107 cdev_del(&port->cdev);
1108free_port:
1109 kfree(port);
1110fail:
1111 /* The host might want to notify management sw about port add failure */
1112 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1113 return err;
1114}
1115
1116/* Remove all port-specific data. */
1117static int remove_port(struct port *port)
1118{
1119 struct port_buffer *buf;
1120
1121 if (port->guest_connected) {
1122 port->guest_connected = false;
1123 port->host_connected = false;
1124 wake_up_interruptible(&port->waitqueue);
1125 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
1126 }
1127
1128 spin_lock_irq(&port->portdev->ports_lock);
1129 list_del(&port->list);
1130 spin_unlock_irq(&port->portdev->ports_lock);
1131
1132 if (is_console_port(port)) {
1133 spin_lock_irq(&pdrvdata_lock);
1134 list_del(&port->cons.list);
1135 spin_unlock_irq(&pdrvdata_lock);
1136#if 0
1137 /*
1138 * hvc_remove() not called as removing one hvc port
1139 * results in other hvc ports getting frozen.
1140 *
1141 * Once this is resolved in hvc, this functionality
1142 * will be enabled. Till that is done, the -EPIPE
1143 * return from get_chars() above will help
1144 * hvc_console.c to clean up on ports we remove here.
1145 */
1146 hvc_remove(port->cons.hvc);
1147#endif
1148 }
1149 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1150 device_destroy(pdrvdata.class, port->dev->devt);
1151 cdev_del(&port->cdev);
1152
1153 /* Remove unused data this port might have received. */
1154 discard_port_data(port);
1155
1156 reclaim_consumed_buffers(port);
1157
1158 /* Remove buffers we queued up for the Host to send us data in. */
1159 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1160 free_buf(buf);
1161
1162 kfree(port->name);
1163
1164 debugfs_remove(port->debugfs_file);
1165
1166 kfree(port);
1167 return 0;
1168}
1169
1170/* Any private messages that the Host and Guest want to share */
1171static void handle_control_message(struct ports_device *portdev,
1172 struct port_buffer *buf)
1173{
1174 struct virtio_console_control *cpkt;
1175 struct port *port;
1176 size_t name_size;
1177 int err;
1178
1179 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1180
1181 port = find_port_by_id(portdev, cpkt->id);
1182 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1183 /* No valid header at start of buffer. Drop it. */
1184 dev_dbg(&portdev->vdev->dev,
1185 "Invalid index %u in control packet\n", cpkt->id);
1186 return;
1187 }
1188
1189 switch (cpkt->event) {
1190 case VIRTIO_CONSOLE_PORT_ADD:
1191 if (port) {
1192 dev_dbg(&portdev->vdev->dev,
1193 "Port %u already added\n", port->id);
1194 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1195 break;
1196 }
1197 if (cpkt->id >= portdev->config.max_nr_ports) {
1198 dev_warn(&portdev->vdev->dev,
1199 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1200 cpkt->id, portdev->config.max_nr_ports - 1);
1201 break;
1202 }
1203 add_port(portdev, cpkt->id);
1204 break;
1205 case VIRTIO_CONSOLE_PORT_REMOVE:
1206 remove_port(port);
1207 break;
1208 case VIRTIO_CONSOLE_CONSOLE_PORT:
1209 if (!cpkt->value)
1210 break;
1211 if (is_console_port(port))
1212 break;
1213
1214 init_port_console(port);
1215 /*
1216 * Could remove the port here in case init fails - but
1217 * have to notify the host first.
1218 */
1219 break;
1220 case VIRTIO_CONSOLE_RESIZE: {
1221 struct {
1222 __u16 rows;
1223 __u16 cols;
1224 } size;
1225
1226 if (!is_console_port(port))
1227 break;
1228
1229 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1230 sizeof(size));
1231 set_console_size(port, size.rows, size.cols);
1232
1233 port->cons.hvc->irq_requested = 1;
1234 resize_console(port);
1235 break;
1236 }
1237 case VIRTIO_CONSOLE_PORT_OPEN:
1238 port->host_connected = cpkt->value;
1239 wake_up_interruptible(&port->waitqueue);
1240 /*
1241 * If the host port got closed and the host had any
1242 * unconsumed buffers, we'll be able to reclaim them
1243 * now.
1244 */
1245 spin_lock_irq(&port->outvq_lock);
1246 reclaim_consumed_buffers(port);
1247 spin_unlock_irq(&port->outvq_lock);
1248 break;
1249 case VIRTIO_CONSOLE_PORT_NAME:
1250 /*
1251 * Skip the size of the header and the cpkt to get the size
1252 * of the name that was sent
1253 */
1254 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1255
1256 port->name = kmalloc(name_size, GFP_KERNEL);
1257 if (!port->name) {
1258 dev_err(port->dev,
1259 "Not enough space to store port name\n");
1260 break;
1261 }
1262 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1263 name_size - 1);
1264 port->name[name_size - 1] = 0;
1265
1266 /*
1267 * Since we only have one sysfs attribute, 'name',
1268 * create it only if we have a name for the port.
1269 */
1270 err = sysfs_create_group(&port->dev->kobj,
1271 &port_attribute_group);
1272 if (err) {
1273 dev_err(port->dev,
1274 "Error %d creating sysfs device attributes\n",
1275 err);
1276 } else {
1277 /*
1278 * Generate a udev event so that appropriate
1279 * symlinks can be created based on udev
1280 * rules.
1281 */
1282 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1283 }
1284 break;
1285 }
1286}
1287
1288static void control_work_handler(struct work_struct *work)
1289{
1290 struct ports_device *portdev;
1291 struct virtqueue *vq;
1292 struct port_buffer *buf;
1293 unsigned int len;
1294
1295 portdev = container_of(work, struct ports_device, control_work);
1296 vq = portdev->c_ivq;
1297
1298 spin_lock(&portdev->cvq_lock);
1299 while ((buf = virtqueue_get_buf(vq, &len))) {
1300 spin_unlock(&portdev->cvq_lock);
1301
1302 buf->len = len;
1303 buf->offset = 0;
1304
1305 handle_control_message(portdev, buf);
1306
1307 spin_lock(&portdev->cvq_lock);
1308 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1309 dev_warn(&portdev->vdev->dev,
1310 "Error adding buffer to queue\n");
1311 free_buf(buf);
1312 }
1313 }
1314 spin_unlock(&portdev->cvq_lock);
1315}
1316
1317static void in_intr(struct virtqueue *vq)
1318{
1319 struct port *port;
1320 unsigned long flags;
1321
1322 port = find_port_by_vq(vq->vdev->priv, vq);
1323 if (!port)
1324 return;
1325
1326 spin_lock_irqsave(&port->inbuf_lock, flags);
1327 if (!port->inbuf)
1328 port->inbuf = get_inbuf(port);
1329
1330 /*
1331 * Don't queue up data when port is closed. This condition
1332 * can be reached when a console port is not yet connected (no
1333 * tty is spawned) and the host sends out data to console
1334 * ports. For generic serial ports, the host won't
1335 * (shouldn't) send data till the guest is connected.
1336 */
1337 if (!port->guest_connected)
1338 discard_port_data(port);
1339
1340 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1341
1342 wake_up_interruptible(&port->waitqueue);
1343
1344 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1345 hvc_kick();
1346}
1347
1348static void control_intr(struct virtqueue *vq)
1349{
1350 struct ports_device *portdev;
1351
1352 portdev = vq->vdev->priv;
1353 schedule_work(&portdev->control_work);
1354}
1355
1356static void config_intr(struct virtio_device *vdev)
1357{
1358 struct ports_device *portdev;
1359
1360 portdev = vdev->priv;
1361
1362 if (!use_multiport(portdev)) {
1363 struct port *port;
1364 u16 rows, cols;
1365
1366 vdev->config->get(vdev,
1367 offsetof(struct virtio_console_config, cols),
1368 &cols, sizeof(u16));
1369 vdev->config->get(vdev,
1370 offsetof(struct virtio_console_config, rows),
1371 &rows, sizeof(u16));
1372
1373 port = find_port_by_id(portdev, 0);
1374 set_console_size(port, rows, cols);
1375
1376 /*
1377 * We'll use this way of resizing only for legacy
1378 * support. For newer userspace
1379 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1380 * to indicate console size changes so that it can be
1381 * done per-port.
1382 */
1383 resize_console(port);
1384 }
1385}
1386
1387static int init_vqs(struct ports_device *portdev)
1388{
1389 vq_callback_t **io_callbacks;
1390 char **io_names;
1391 struct virtqueue **vqs;
1392 u32 i, j, nr_ports, nr_queues;
1393 int err;
1394
1395 nr_ports = portdev->config.max_nr_ports;
1396 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1397
1398 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1399 if (!vqs) {
1400 err = -ENOMEM;
1401 goto fail;
1402 }
1403 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1404 if (!io_callbacks) {
1405 err = -ENOMEM;
1406 goto free_vqs;
1407 }
1408 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1409 if (!io_names) {
1410 err = -ENOMEM;
1411 goto free_callbacks;
1412 }
1413 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1414 GFP_KERNEL);
1415 if (!portdev->in_vqs) {
1416 err = -ENOMEM;
1417 goto free_names;
1418 }
1419 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1420 GFP_KERNEL);
1421 if (!portdev->out_vqs) {
1422 err = -ENOMEM;
1423 goto free_invqs;
1424 }
1425
1426 /*
1427 * For backward compat (newer host but older guest), the host
1428 * spawns a console port first and also inits the vqs for port
1429 * 0 before others.
1430 */
1431 j = 0;
1432 io_callbacks[j] = in_intr;
1433 io_callbacks[j + 1] = NULL;
1434 io_names[j] = "input";
1435 io_names[j + 1] = "output";
1436 j += 2;
1437
1438 if (use_multiport(portdev)) {
1439 io_callbacks[j] = control_intr;
1440 io_callbacks[j + 1] = NULL;
1441 io_names[j] = "control-i";
1442 io_names[j + 1] = "control-o";
1443
1444 for (i = 1; i < nr_ports; i++) {
1445 j += 2;
1446 io_callbacks[j] = in_intr;
1447 io_callbacks[j + 1] = NULL;
1448 io_names[j] = "input";
1449 io_names[j + 1] = "output";
1450 }
1451 }
1452 /* Find the queues. */
1453 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1454 io_callbacks,
1455 (const char **)io_names);
1456 if (err)
1457 goto free_outvqs;
1458
1459 j = 0;
1460 portdev->in_vqs[0] = vqs[0];
1461 portdev->out_vqs[0] = vqs[1];
1462 j += 2;
1463 if (use_multiport(portdev)) {
1464 portdev->c_ivq = vqs[j];
1465 portdev->c_ovq = vqs[j + 1];
1466
1467 for (i = 1; i < nr_ports; i++) {
1468 j += 2;
1469 portdev->in_vqs[i] = vqs[j];
1470 portdev->out_vqs[i] = vqs[j + 1];
1471 }
1472 }
1473 kfree(io_callbacks);
1474 kfree(io_names);
1475 kfree(vqs);
1476
1477 return 0;
1478
1479free_names:
1480 kfree(io_names);
1481free_callbacks:
1482 kfree(io_callbacks);
1483free_outvqs:
1484 kfree(portdev->out_vqs);
1485free_invqs:
1486 kfree(portdev->in_vqs);
1487free_vqs:
1488 kfree(vqs);
1489fail:
1490 return err;
1491}
1492
1493static const struct file_operations portdev_fops = {
1494 .owner = THIS_MODULE,
1495};
1496
1497/*
1498 * Once we're further in boot, we get probed like any other virtio
1499 * device.
1500 *
1501 * If the host also supports multiple console ports, we check the
1502 * config space to see how many ports the host has spawned. We
1503 * initialize each port found.
1504 */
1505static int __devinit virtcons_probe(struct virtio_device *vdev)
1506{
1507 struct ports_device *portdev;
1508 int err;
1509 bool multiport;
1510
1511 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1512 if (!portdev) {
1513 err = -ENOMEM;
1514 goto fail;
1515 }
1516
1517 /* Attach this portdev to this virtio_device, and vice-versa. */
1518 portdev->vdev = vdev;
1519 vdev->priv = portdev;
1520
1521 spin_lock_irq(&pdrvdata_lock);
1522 portdev->drv_index = pdrvdata.index++;
1523 spin_unlock_irq(&pdrvdata_lock);
1524
1525 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1526 &portdev_fops);
1527 if (portdev->chr_major < 0) {
1528 dev_err(&vdev->dev,
1529 "Error %d registering chrdev for device %u\n",
1530 portdev->chr_major, portdev->drv_index);
1531 err = portdev->chr_major;
1532 goto free;
1533 }
1534
1535 multiport = false;
1536 portdev->config.max_nr_ports = 1;
1537 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1538 multiport = true;
1539 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1540
1541 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1542 max_nr_ports),
1543 &portdev->config.max_nr_ports,
1544 sizeof(portdev->config.max_nr_ports));
1545 }
1546
1547 /* Let the Host know we support multiple ports.*/
1548 vdev->config->finalize_features(vdev);
1549
1550 err = init_vqs(portdev);
1551 if (err < 0) {
1552 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1553 goto free_chrdev;
1554 }
1555
1556 spin_lock_init(&portdev->ports_lock);
1557 INIT_LIST_HEAD(&portdev->ports);
1558
1559 if (multiport) {
1560 unsigned int nr_added_bufs;
1561
1562 spin_lock_init(&portdev->cvq_lock);
1563 INIT_WORK(&portdev->control_work, &control_work_handler);
1564
1565 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1566 if (!nr_added_bufs) {
1567 dev_err(&vdev->dev,
1568 "Error allocating buffers for control queue\n");
1569 err = -ENOMEM;
1570 goto free_vqs;
1571 }
1572 } else {
1573 /*
1574 * For backward compatibility: Create a console port
1575 * if we're running on older host.
1576 */
1577 add_port(portdev, 0);
1578 }
1579
1580 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1581 VIRTIO_CONSOLE_DEVICE_READY, 1);
1582 return 0;
1583
1584free_vqs:
1585 /* The host might want to notify mgmt sw about device add failure */
1586 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1587 VIRTIO_CONSOLE_DEVICE_READY, 0);
1588 vdev->config->del_vqs(vdev);
1589 kfree(portdev->in_vqs);
1590 kfree(portdev->out_vqs);
1591free_chrdev:
1592 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1593free:
1594 kfree(portdev);
1595fail:
1596 return err;
1597}
1598
1599static void virtcons_remove(struct virtio_device *vdev)
1600{
1601 struct ports_device *portdev;
1602 struct port *port, *port2;
1603 struct port_buffer *buf;
1604 unsigned int len;
1605
1606 portdev = vdev->priv;
1607
1608 cancel_work_sync(&portdev->control_work);
1609
1610 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1611 remove_port(port);
1612
1613 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1614
1615 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1616 free_buf(buf);
1617
1618 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1619 free_buf(buf);
1620
1621 vdev->config->del_vqs(vdev);
1622 kfree(portdev->in_vqs);
1623 kfree(portdev->out_vqs);
1624
1625 kfree(portdev);
1626}
1627
1628static struct virtio_device_id id_table[] = {
1629 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1630 { 0 },
1631};
1632
1633static unsigned int features[] = {
1634 VIRTIO_CONSOLE_F_SIZE,
1635 VIRTIO_CONSOLE_F_MULTIPORT,
1636};
1637
1638static struct virtio_driver virtio_console = {
1639 .feature_table = features,
1640 .feature_table_size = ARRAY_SIZE(features),
1641 .driver.name = KBUILD_MODNAME,
1642 .driver.owner = THIS_MODULE,
1643 .id_table = id_table,
1644 .probe = virtcons_probe,
1645 .remove = virtcons_remove,
1646 .config_changed = config_intr,
1647};
1648
1649static int __init init(void)
1650{
1651 int err;
1652
1653 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1654 if (IS_ERR(pdrvdata.class)) {
1655 err = PTR_ERR(pdrvdata.class);
1656 pr_err("Error %d creating virtio-ports class\n", err);
1657 return err;
1658 }
1659
1660 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1661 if (!pdrvdata.debugfs_dir) {
1662 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1663 PTR_ERR(pdrvdata.debugfs_dir));
1664 }
1665 INIT_LIST_HEAD(&pdrvdata.consoles);
1666
1667 return register_virtio_driver(&virtio_console);
1668}
1669
1670static void __exit fini(void)
1671{
1672 unregister_virtio_driver(&virtio_console);
1673
1674 class_destroy(pdrvdata.class);
1675 if (pdrvdata.debugfs_dir)
1676 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1677}
1678module_init(init);
1679module_exit(fini);
1680
1681MODULE_DEVICE_TABLE(virtio, id_table);
1682MODULE_DESCRIPTION("Virtio console driver");
1683MODULE_LICENSE("GPL");