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1/*
2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
4 * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20#include <linux/cdev.h>
21#include <linux/debugfs.h>
22#include <linux/device.h>
23#include <linux/err.h>
24#include <linux/fs.h>
25#include <linux/init.h>
26#include <linux/list.h>
27#include <linux/poll.h>
28#include <linux/sched.h>
29#include <linux/slab.h>
30#include <linux/spinlock.h>
31#include <linux/virtio.h>
32#include <linux/virtio_console.h>
33#include <linux/wait.h>
34#include <linux/workqueue.h>
35#include "../tty/hvc/hvc_console.h"
36
37/*
38 * This is a global struct for storing common data for all the devices
39 * this driver handles.
40 *
41 * Mainly, it has a linked list for all the consoles in one place so
42 * that callbacks from hvc for get_chars(), put_chars() work properly
43 * across multiple devices and multiple ports per device.
44 */
45struct ports_driver_data {
46 /* Used for registering chardevs */
47 struct class *class;
48
49 /* Used for exporting per-port information to debugfs */
50 struct dentry *debugfs_dir;
51
52 /* List of all the devices we're handling */
53 struct list_head portdevs;
54
55 /* Number of devices this driver is handling */
56 unsigned int index;
57
58 /*
59 * This is used to keep track of the number of hvc consoles
60 * spawned by this driver. This number is given as the first
61 * argument to hvc_alloc(). To correctly map an initial
62 * console spawned via hvc_instantiate to the console being
63 * hooked up via hvc_alloc, we need to pass the same vtermno.
64 *
65 * We also just assume the first console being initialised was
66 * the first one that got used as the initial console.
67 */
68 unsigned int next_vtermno;
69
70 /* All the console devices handled by this driver */
71 struct list_head consoles;
72};
73static struct ports_driver_data pdrvdata;
74
75DEFINE_SPINLOCK(pdrvdata_lock);
76
77/* This struct holds information that's relevant only for console ports */
78struct console {
79 /* We'll place all consoles in a list in the pdrvdata struct */
80 struct list_head list;
81
82 /* The hvc device associated with this console port */
83 struct hvc_struct *hvc;
84
85 /* The size of the console */
86 struct winsize ws;
87
88 /*
89 * This number identifies the number that we used to register
90 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
91 * number passed on by the hvc callbacks to us to
92 * differentiate between the other console ports handled by
93 * this driver
94 */
95 u32 vtermno;
96};
97
98struct port_buffer {
99 char *buf;
100
101 /* size of the buffer in *buf above */
102 size_t size;
103
104 /* used length of the buffer */
105 size_t len;
106 /* offset in the buf from which to consume data */
107 size_t offset;
108};
109
110/*
111 * This is a per-device struct that stores data common to all the
112 * ports for that device (vdev->priv).
113 */
114struct ports_device {
115 /* Next portdev in the list, head is in the pdrvdata struct */
116 struct list_head list;
117
118 /*
119 * Workqueue handlers where we process deferred work after
120 * notification
121 */
122 struct work_struct control_work;
123
124 struct list_head ports;
125
126 /* To protect the list of ports */
127 spinlock_t ports_lock;
128
129 /* To protect the vq operations for the control channel */
130 spinlock_t cvq_lock;
131
132 /* The current config space is stored here */
133 struct virtio_console_config config;
134
135 /* The virtio device we're associated with */
136 struct virtio_device *vdev;
137
138 /*
139 * A couple of virtqueues for the control channel: one for
140 * guest->host transfers, one for host->guest transfers
141 */
142 struct virtqueue *c_ivq, *c_ovq;
143
144 /* Array of per-port IO virtqueues */
145 struct virtqueue **in_vqs, **out_vqs;
146
147 /* Used for numbering devices for sysfs and debugfs */
148 unsigned int drv_index;
149
150 /* Major number for this device. Ports will be created as minors. */
151 int chr_major;
152};
153
154/* This struct holds the per-port data */
155struct port {
156 /* Next port in the list, head is in the ports_device */
157 struct list_head list;
158
159 /* Pointer to the parent virtio_console device */
160 struct ports_device *portdev;
161
162 /* The current buffer from which data has to be fed to readers */
163 struct port_buffer *inbuf;
164
165 /*
166 * To protect the operations on the in_vq associated with this
167 * port. Has to be a spinlock because it can be called from
168 * interrupt context (get_char()).
169 */
170 spinlock_t inbuf_lock;
171
172 /* Protect the operations on the out_vq. */
173 spinlock_t outvq_lock;
174
175 /* The IO vqs for this port */
176 struct virtqueue *in_vq, *out_vq;
177
178 /* File in the debugfs directory that exposes this port's information */
179 struct dentry *debugfs_file;
180
181 /*
182 * The entries in this struct will be valid if this port is
183 * hooked up to an hvc console
184 */
185 struct console cons;
186
187 /* Each port associates with a separate char device */
188 struct cdev *cdev;
189 struct device *dev;
190
191 /* Reference-counting to handle port hot-unplugs and file operations */
192 struct kref kref;
193
194 /* A waitqueue for poll() or blocking read operations */
195 wait_queue_head_t waitqueue;
196
197 /* The 'name' of the port that we expose via sysfs properties */
198 char *name;
199
200 /* We can notify apps of host connect / disconnect events via SIGIO */
201 struct fasync_struct *async_queue;
202
203 /* The 'id' to identify the port with the Host */
204 u32 id;
205
206 bool outvq_full;
207
208 /* Is the host device open */
209 bool host_connected;
210
211 /* We should allow only one process to open a port */
212 bool guest_connected;
213};
214
215/* This is the very early arch-specified put chars function. */
216static int (*early_put_chars)(u32, const char *, int);
217
218static struct port *find_port_by_vtermno(u32 vtermno)
219{
220 struct port *port;
221 struct console *cons;
222 unsigned long flags;
223
224 spin_lock_irqsave(&pdrvdata_lock, flags);
225 list_for_each_entry(cons, &pdrvdata.consoles, list) {
226 if (cons->vtermno == vtermno) {
227 port = container_of(cons, struct port, cons);
228 goto out;
229 }
230 }
231 port = NULL;
232out:
233 spin_unlock_irqrestore(&pdrvdata_lock, flags);
234 return port;
235}
236
237static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
238 dev_t dev)
239{
240 struct port *port;
241 unsigned long flags;
242
243 spin_lock_irqsave(&portdev->ports_lock, flags);
244 list_for_each_entry(port, &portdev->ports, list)
245 if (port->cdev->dev == dev)
246 goto out;
247 port = NULL;
248out:
249 spin_unlock_irqrestore(&portdev->ports_lock, flags);
250
251 return port;
252}
253
254static struct port *find_port_by_devt(dev_t dev)
255{
256 struct ports_device *portdev;
257 struct port *port;
258 unsigned long flags;
259
260 spin_lock_irqsave(&pdrvdata_lock, flags);
261 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
262 port = find_port_by_devt_in_portdev(portdev, dev);
263 if (port)
264 goto out;
265 }
266 port = NULL;
267out:
268 spin_unlock_irqrestore(&pdrvdata_lock, flags);
269 return port;
270}
271
272static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
273{
274 struct port *port;
275 unsigned long flags;
276
277 spin_lock_irqsave(&portdev->ports_lock, flags);
278 list_for_each_entry(port, &portdev->ports, list)
279 if (port->id == id)
280 goto out;
281 port = NULL;
282out:
283 spin_unlock_irqrestore(&portdev->ports_lock, flags);
284
285 return port;
286}
287
288static struct port *find_port_by_vq(struct ports_device *portdev,
289 struct virtqueue *vq)
290{
291 struct port *port;
292 unsigned long flags;
293
294 spin_lock_irqsave(&portdev->ports_lock, flags);
295 list_for_each_entry(port, &portdev->ports, list)
296 if (port->in_vq == vq || port->out_vq == vq)
297 goto out;
298 port = NULL;
299out:
300 spin_unlock_irqrestore(&portdev->ports_lock, flags);
301 return port;
302}
303
304static bool is_console_port(struct port *port)
305{
306 if (port->cons.hvc)
307 return true;
308 return false;
309}
310
311static inline bool use_multiport(struct ports_device *portdev)
312{
313 /*
314 * This condition can be true when put_chars is called from
315 * early_init
316 */
317 if (!portdev->vdev)
318 return 0;
319 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
320}
321
322static void free_buf(struct port_buffer *buf)
323{
324 kfree(buf->buf);
325 kfree(buf);
326}
327
328static struct port_buffer *alloc_buf(size_t buf_size)
329{
330 struct port_buffer *buf;
331
332 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
333 if (!buf)
334 goto fail;
335 buf->buf = kzalloc(buf_size, GFP_KERNEL);
336 if (!buf->buf)
337 goto free_buf;
338 buf->len = 0;
339 buf->offset = 0;
340 buf->size = buf_size;
341 return buf;
342
343free_buf:
344 kfree(buf);
345fail:
346 return NULL;
347}
348
349/* Callers should take appropriate locks */
350static void *get_inbuf(struct port *port)
351{
352 struct port_buffer *buf;
353 struct virtqueue *vq;
354 unsigned int len;
355
356 vq = port->in_vq;
357 buf = virtqueue_get_buf(vq, &len);
358 if (buf) {
359 buf->len = len;
360 buf->offset = 0;
361 }
362 return buf;
363}
364
365/*
366 * Create a scatter-gather list representing our input buffer and put
367 * it in the queue.
368 *
369 * Callers should take appropriate locks.
370 */
371static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
372{
373 struct scatterlist sg[1];
374 int ret;
375
376 sg_init_one(sg, buf->buf, buf->size);
377
378 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
379 virtqueue_kick(vq);
380 return ret;
381}
382
383/* Discard any unread data this port has. Callers lockers. */
384static void discard_port_data(struct port *port)
385{
386 struct port_buffer *buf;
387 struct virtqueue *vq;
388 unsigned int len;
389 int ret;
390
391 if (!port->portdev) {
392 /* Device has been unplugged. vqs are already gone. */
393 return;
394 }
395 vq = port->in_vq;
396 if (port->inbuf)
397 buf = port->inbuf;
398 else
399 buf = virtqueue_get_buf(vq, &len);
400
401 ret = 0;
402 while (buf) {
403 if (add_inbuf(vq, buf) < 0) {
404 ret++;
405 free_buf(buf);
406 }
407 buf = virtqueue_get_buf(vq, &len);
408 }
409 port->inbuf = NULL;
410 if (ret)
411 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
412 ret);
413}
414
415static bool port_has_data(struct port *port)
416{
417 unsigned long flags;
418 bool ret;
419
420 spin_lock_irqsave(&port->inbuf_lock, flags);
421 if (port->inbuf) {
422 ret = true;
423 goto out;
424 }
425 port->inbuf = get_inbuf(port);
426 if (port->inbuf) {
427 ret = true;
428 goto out;
429 }
430 ret = false;
431out:
432 spin_unlock_irqrestore(&port->inbuf_lock, flags);
433 return ret;
434}
435
436static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
437 unsigned int event, unsigned int value)
438{
439 struct scatterlist sg[1];
440 struct virtio_console_control cpkt;
441 struct virtqueue *vq;
442 unsigned int len;
443
444 if (!use_multiport(portdev))
445 return 0;
446
447 cpkt.id = port_id;
448 cpkt.event = event;
449 cpkt.value = value;
450
451 vq = portdev->c_ovq;
452
453 sg_init_one(sg, &cpkt, sizeof(cpkt));
454 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
455 virtqueue_kick(vq);
456 while (!virtqueue_get_buf(vq, &len))
457 cpu_relax();
458 }
459 return 0;
460}
461
462static ssize_t send_control_msg(struct port *port, unsigned int event,
463 unsigned int value)
464{
465 /* Did the port get unplugged before userspace closed it? */
466 if (port->portdev)
467 return __send_control_msg(port->portdev, port->id, event, value);
468 return 0;
469}
470
471/* Callers must take the port->outvq_lock */
472static void reclaim_consumed_buffers(struct port *port)
473{
474 void *buf;
475 unsigned int len;
476
477 if (!port->portdev) {
478 /* Device has been unplugged. vqs are already gone. */
479 return;
480 }
481 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
482 kfree(buf);
483 port->outvq_full = false;
484 }
485}
486
487static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
488 bool nonblock)
489{
490 struct scatterlist sg[1];
491 struct virtqueue *out_vq;
492 ssize_t ret;
493 unsigned long flags;
494 unsigned int len;
495
496 out_vq = port->out_vq;
497
498 spin_lock_irqsave(&port->outvq_lock, flags);
499
500 reclaim_consumed_buffers(port);
501
502 sg_init_one(sg, in_buf, in_count);
503 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
504
505 /* Tell Host to go! */
506 virtqueue_kick(out_vq);
507
508 if (ret < 0) {
509 in_count = 0;
510 goto done;
511 }
512
513 if (ret == 0)
514 port->outvq_full = true;
515
516 if (nonblock)
517 goto done;
518
519 /*
520 * Wait till the host acknowledges it pushed out the data we
521 * sent. This is done for data from the hvc_console; the tty
522 * operations are performed with spinlocks held so we can't
523 * sleep here. An alternative would be to copy the data to a
524 * buffer and relax the spinning requirement. The downside is
525 * we need to kmalloc a GFP_ATOMIC buffer each time the
526 * console driver writes something out.
527 */
528 while (!virtqueue_get_buf(out_vq, &len))
529 cpu_relax();
530done:
531 spin_unlock_irqrestore(&port->outvq_lock, flags);
532 /*
533 * We're expected to return the amount of data we wrote -- all
534 * of it
535 */
536 return in_count;
537}
538
539/*
540 * Give out the data that's requested from the buffer that we have
541 * queued up.
542 */
543static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
544 bool to_user)
545{
546 struct port_buffer *buf;
547 unsigned long flags;
548
549 if (!out_count || !port_has_data(port))
550 return 0;
551
552 buf = port->inbuf;
553 out_count = min(out_count, buf->len - buf->offset);
554
555 if (to_user) {
556 ssize_t ret;
557
558 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
559 if (ret)
560 return -EFAULT;
561 } else {
562 memcpy(out_buf, buf->buf + buf->offset, out_count);
563 }
564
565 buf->offset += out_count;
566
567 if (buf->offset == buf->len) {
568 /*
569 * We're done using all the data in this buffer.
570 * Re-queue so that the Host can send us more data.
571 */
572 spin_lock_irqsave(&port->inbuf_lock, flags);
573 port->inbuf = NULL;
574
575 if (add_inbuf(port->in_vq, buf) < 0)
576 dev_warn(port->dev, "failed add_buf\n");
577
578 spin_unlock_irqrestore(&port->inbuf_lock, flags);
579 }
580 /* Return the number of bytes actually copied */
581 return out_count;
582}
583
584/* The condition that must be true for polling to end */
585static bool will_read_block(struct port *port)
586{
587 if (!port->guest_connected) {
588 /* Port got hot-unplugged. Let's exit. */
589 return false;
590 }
591 return !port_has_data(port) && port->host_connected;
592}
593
594static bool will_write_block(struct port *port)
595{
596 bool ret;
597
598 if (!port->guest_connected) {
599 /* Port got hot-unplugged. Let's exit. */
600 return false;
601 }
602 if (!port->host_connected)
603 return true;
604
605 spin_lock_irq(&port->outvq_lock);
606 /*
607 * Check if the Host has consumed any buffers since we last
608 * sent data (this is only applicable for nonblocking ports).
609 */
610 reclaim_consumed_buffers(port);
611 ret = port->outvq_full;
612 spin_unlock_irq(&port->outvq_lock);
613
614 return ret;
615}
616
617static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
618 size_t count, loff_t *offp)
619{
620 struct port *port;
621 ssize_t ret;
622
623 port = filp->private_data;
624
625 if (!port_has_data(port)) {
626 /*
627 * If nothing's connected on the host just return 0 in
628 * case of list_empty; this tells the userspace app
629 * that there's no connection
630 */
631 if (!port->host_connected)
632 return 0;
633 if (filp->f_flags & O_NONBLOCK)
634 return -EAGAIN;
635
636 ret = wait_event_interruptible(port->waitqueue,
637 !will_read_block(port));
638 if (ret < 0)
639 return ret;
640 }
641 /* Port got hot-unplugged. */
642 if (!port->guest_connected)
643 return -ENODEV;
644 /*
645 * We could've received a disconnection message while we were
646 * waiting for more data.
647 *
648 * This check is not clubbed in the if() statement above as we
649 * might receive some data as well as the host could get
650 * disconnected after we got woken up from our wait. So we
651 * really want to give off whatever data we have and only then
652 * check for host_connected.
653 */
654 if (!port_has_data(port) && !port->host_connected)
655 return 0;
656
657 return fill_readbuf(port, ubuf, count, true);
658}
659
660static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
661 size_t count, loff_t *offp)
662{
663 struct port *port;
664 char *buf;
665 ssize_t ret;
666 bool nonblock;
667
668 /* Userspace could be out to fool us */
669 if (!count)
670 return 0;
671
672 port = filp->private_data;
673
674 nonblock = filp->f_flags & O_NONBLOCK;
675
676 if (will_write_block(port)) {
677 if (nonblock)
678 return -EAGAIN;
679
680 ret = wait_event_interruptible(port->waitqueue,
681 !will_write_block(port));
682 if (ret < 0)
683 return ret;
684 }
685 /* Port got hot-unplugged. */
686 if (!port->guest_connected)
687 return -ENODEV;
688
689 count = min((size_t)(32 * 1024), count);
690
691 buf = kmalloc(count, GFP_KERNEL);
692 if (!buf)
693 return -ENOMEM;
694
695 ret = copy_from_user(buf, ubuf, count);
696 if (ret) {
697 ret = -EFAULT;
698 goto free_buf;
699 }
700
701 /*
702 * We now ask send_buf() to not spin for generic ports -- we
703 * can re-use the same code path that non-blocking file
704 * descriptors take for blocking file descriptors since the
705 * wait is already done and we're certain the write will go
706 * through to the host.
707 */
708 nonblock = true;
709 ret = send_buf(port, buf, count, nonblock);
710
711 if (nonblock && ret > 0)
712 goto out;
713
714free_buf:
715 kfree(buf);
716out:
717 return ret;
718}
719
720static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
721{
722 struct port *port;
723 unsigned int ret;
724
725 port = filp->private_data;
726 poll_wait(filp, &port->waitqueue, wait);
727
728 if (!port->guest_connected) {
729 /* Port got unplugged */
730 return POLLHUP;
731 }
732 ret = 0;
733 if (!will_read_block(port))
734 ret |= POLLIN | POLLRDNORM;
735 if (!will_write_block(port))
736 ret |= POLLOUT;
737 if (!port->host_connected)
738 ret |= POLLHUP;
739
740 return ret;
741}
742
743static void remove_port(struct kref *kref);
744
745static int port_fops_release(struct inode *inode, struct file *filp)
746{
747 struct port *port;
748
749 port = filp->private_data;
750
751 /* Notify host of port being closed */
752 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
753
754 spin_lock_irq(&port->inbuf_lock);
755 port->guest_connected = false;
756
757 discard_port_data(port);
758
759 spin_unlock_irq(&port->inbuf_lock);
760
761 spin_lock_irq(&port->outvq_lock);
762 reclaim_consumed_buffers(port);
763 spin_unlock_irq(&port->outvq_lock);
764
765 /*
766 * Locks aren't necessary here as a port can't be opened after
767 * unplug, and if a port isn't unplugged, a kref would already
768 * exist for the port. Plus, taking ports_lock here would
769 * create a dependency on other locks taken by functions
770 * inside remove_port if we're the last holder of the port,
771 * creating many problems.
772 */
773 kref_put(&port->kref, remove_port);
774
775 return 0;
776}
777
778static int port_fops_open(struct inode *inode, struct file *filp)
779{
780 struct cdev *cdev = inode->i_cdev;
781 struct port *port;
782 int ret;
783
784 port = find_port_by_devt(cdev->dev);
785 filp->private_data = port;
786
787 /* Prevent against a port getting hot-unplugged at the same time */
788 spin_lock_irq(&port->portdev->ports_lock);
789 kref_get(&port->kref);
790 spin_unlock_irq(&port->portdev->ports_lock);
791
792 /*
793 * Don't allow opening of console port devices -- that's done
794 * via /dev/hvc
795 */
796 if (is_console_port(port)) {
797 ret = -ENXIO;
798 goto out;
799 }
800
801 /* Allow only one process to open a particular port at a time */
802 spin_lock_irq(&port->inbuf_lock);
803 if (port->guest_connected) {
804 spin_unlock_irq(&port->inbuf_lock);
805 ret = -EMFILE;
806 goto out;
807 }
808
809 port->guest_connected = true;
810 spin_unlock_irq(&port->inbuf_lock);
811
812 spin_lock_irq(&port->outvq_lock);
813 /*
814 * There might be a chance that we missed reclaiming a few
815 * buffers in the window of the port getting previously closed
816 * and opening now.
817 */
818 reclaim_consumed_buffers(port);
819 spin_unlock_irq(&port->outvq_lock);
820
821 nonseekable_open(inode, filp);
822
823 /* Notify host of port being opened */
824 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
825
826 return 0;
827out:
828 kref_put(&port->kref, remove_port);
829 return ret;
830}
831
832static int port_fops_fasync(int fd, struct file *filp, int mode)
833{
834 struct port *port;
835
836 port = filp->private_data;
837 return fasync_helper(fd, filp, mode, &port->async_queue);
838}
839
840/*
841 * The file operations that we support: programs in the guest can open
842 * a console device, read from it, write to it, poll for data and
843 * close it. The devices are at
844 * /dev/vport<device number>p<port number>
845 */
846static const struct file_operations port_fops = {
847 .owner = THIS_MODULE,
848 .open = port_fops_open,
849 .read = port_fops_read,
850 .write = port_fops_write,
851 .poll = port_fops_poll,
852 .release = port_fops_release,
853 .fasync = port_fops_fasync,
854 .llseek = no_llseek,
855};
856
857/*
858 * The put_chars() callback is pretty straightforward.
859 *
860 * We turn the characters into a scatter-gather list, add it to the
861 * output queue and then kick the Host. Then we sit here waiting for
862 * it to finish: inefficient in theory, but in practice
863 * implementations will do it immediately (lguest's Launcher does).
864 */
865static int put_chars(u32 vtermno, const char *buf, int count)
866{
867 struct port *port;
868
869 if (unlikely(early_put_chars))
870 return early_put_chars(vtermno, buf, count);
871
872 port = find_port_by_vtermno(vtermno);
873 if (!port)
874 return -EPIPE;
875
876 return send_buf(port, (void *)buf, count, false);
877}
878
879/*
880 * get_chars() is the callback from the hvc_console infrastructure
881 * when an interrupt is received.
882 *
883 * We call out to fill_readbuf that gets us the required data from the
884 * buffers that are queued up.
885 */
886static int get_chars(u32 vtermno, char *buf, int count)
887{
888 struct port *port;
889
890 /* If we've not set up the port yet, we have no input to give. */
891 if (unlikely(early_put_chars))
892 return 0;
893
894 port = find_port_by_vtermno(vtermno);
895 if (!port)
896 return -EPIPE;
897
898 /* If we don't have an input queue yet, we can't get input. */
899 BUG_ON(!port->in_vq);
900
901 return fill_readbuf(port, buf, count, false);
902}
903
904static void resize_console(struct port *port)
905{
906 struct virtio_device *vdev;
907
908 /* The port could have been hot-unplugged */
909 if (!port || !is_console_port(port))
910 return;
911
912 vdev = port->portdev->vdev;
913 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
914 hvc_resize(port->cons.hvc, port->cons.ws);
915}
916
917/* We set the configuration at this point, since we now have a tty */
918static int notifier_add_vio(struct hvc_struct *hp, int data)
919{
920 struct port *port;
921
922 port = find_port_by_vtermno(hp->vtermno);
923 if (!port)
924 return -EINVAL;
925
926 hp->irq_requested = 1;
927 resize_console(port);
928
929 return 0;
930}
931
932static void notifier_del_vio(struct hvc_struct *hp, int data)
933{
934 hp->irq_requested = 0;
935}
936
937/* The operations for console ports. */
938static const struct hv_ops hv_ops = {
939 .get_chars = get_chars,
940 .put_chars = put_chars,
941 .notifier_add = notifier_add_vio,
942 .notifier_del = notifier_del_vio,
943 .notifier_hangup = notifier_del_vio,
944};
945
946/*
947 * Console drivers are initialized very early so boot messages can go
948 * out, so we do things slightly differently from the generic virtio
949 * initialization of the net and block drivers.
950 *
951 * At this stage, the console is output-only. It's too early to set
952 * up a virtqueue, so we let the drivers do some boutique early-output
953 * thing.
954 */
955int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
956{
957 early_put_chars = put_chars;
958 return hvc_instantiate(0, 0, &hv_ops);
959}
960
961int init_port_console(struct port *port)
962{
963 int ret;
964
965 /*
966 * The Host's telling us this port is a console port. Hook it
967 * up with an hvc console.
968 *
969 * To set up and manage our virtual console, we call
970 * hvc_alloc().
971 *
972 * The first argument of hvc_alloc() is the virtual console
973 * number. The second argument is the parameter for the
974 * notification mechanism (like irq number). We currently
975 * leave this as zero, virtqueues have implicit notifications.
976 *
977 * The third argument is a "struct hv_ops" containing the
978 * put_chars() get_chars(), notifier_add() and notifier_del()
979 * pointers. The final argument is the output buffer size: we
980 * can do any size, so we put PAGE_SIZE here.
981 */
982 port->cons.vtermno = pdrvdata.next_vtermno;
983
984 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
985 if (IS_ERR(port->cons.hvc)) {
986 ret = PTR_ERR(port->cons.hvc);
987 dev_err(port->dev,
988 "error %d allocating hvc for port\n", ret);
989 port->cons.hvc = NULL;
990 return ret;
991 }
992 spin_lock_irq(&pdrvdata_lock);
993 pdrvdata.next_vtermno++;
994 list_add_tail(&port->cons.list, &pdrvdata.consoles);
995 spin_unlock_irq(&pdrvdata_lock);
996 port->guest_connected = true;
997
998 /*
999 * Start using the new console output if this is the first
1000 * console to come up.
1001 */
1002 if (early_put_chars)
1003 early_put_chars = NULL;
1004
1005 /* Notify host of port being opened */
1006 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1007
1008 return 0;
1009}
1010
1011static ssize_t show_port_name(struct device *dev,
1012 struct device_attribute *attr, char *buffer)
1013{
1014 struct port *port;
1015
1016 port = dev_get_drvdata(dev);
1017
1018 return sprintf(buffer, "%s\n", port->name);
1019}
1020
1021static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1022
1023static struct attribute *port_sysfs_entries[] = {
1024 &dev_attr_name.attr,
1025 NULL
1026};
1027
1028static struct attribute_group port_attribute_group = {
1029 .name = NULL, /* put in device directory */
1030 .attrs = port_sysfs_entries,
1031};
1032
1033static int debugfs_open(struct inode *inode, struct file *filp)
1034{
1035 filp->private_data = inode->i_private;
1036 return 0;
1037}
1038
1039static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1040 size_t count, loff_t *offp)
1041{
1042 struct port *port;
1043 char *buf;
1044 ssize_t ret, out_offset, out_count;
1045
1046 out_count = 1024;
1047 buf = kmalloc(out_count, GFP_KERNEL);
1048 if (!buf)
1049 return -ENOMEM;
1050
1051 port = filp->private_data;
1052 out_offset = 0;
1053 out_offset += snprintf(buf + out_offset, out_count,
1054 "name: %s\n", port->name ? port->name : "");
1055 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1056 "guest_connected: %d\n", port->guest_connected);
1057 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1058 "host_connected: %d\n", port->host_connected);
1059 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1060 "outvq_full: %d\n", port->outvq_full);
1061 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1062 "is_console: %s\n",
1063 is_console_port(port) ? "yes" : "no");
1064 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1065 "console_vtermno: %u\n", port->cons.vtermno);
1066
1067 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1068 kfree(buf);
1069 return ret;
1070}
1071
1072static const struct file_operations port_debugfs_ops = {
1073 .owner = THIS_MODULE,
1074 .open = debugfs_open,
1075 .read = debugfs_read,
1076};
1077
1078static void set_console_size(struct port *port, u16 rows, u16 cols)
1079{
1080 if (!port || !is_console_port(port))
1081 return;
1082
1083 port->cons.ws.ws_row = rows;
1084 port->cons.ws.ws_col = cols;
1085}
1086
1087static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1088{
1089 struct port_buffer *buf;
1090 unsigned int nr_added_bufs;
1091 int ret;
1092
1093 nr_added_bufs = 0;
1094 do {
1095 buf = alloc_buf(PAGE_SIZE);
1096 if (!buf)
1097 break;
1098
1099 spin_lock_irq(lock);
1100 ret = add_inbuf(vq, buf);
1101 if (ret < 0) {
1102 spin_unlock_irq(lock);
1103 free_buf(buf);
1104 break;
1105 }
1106 nr_added_bufs++;
1107 spin_unlock_irq(lock);
1108 } while (ret > 0);
1109
1110 return nr_added_bufs;
1111}
1112
1113static void send_sigio_to_port(struct port *port)
1114{
1115 if (port->async_queue && port->guest_connected)
1116 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1117}
1118
1119static int add_port(struct ports_device *portdev, u32 id)
1120{
1121 char debugfs_name[16];
1122 struct port *port;
1123 struct port_buffer *buf;
1124 dev_t devt;
1125 unsigned int nr_added_bufs;
1126 int err;
1127
1128 port = kmalloc(sizeof(*port), GFP_KERNEL);
1129 if (!port) {
1130 err = -ENOMEM;
1131 goto fail;
1132 }
1133 kref_init(&port->kref);
1134
1135 port->portdev = portdev;
1136 port->id = id;
1137
1138 port->name = NULL;
1139 port->inbuf = NULL;
1140 port->cons.hvc = NULL;
1141 port->async_queue = NULL;
1142
1143 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1144
1145 port->host_connected = port->guest_connected = false;
1146
1147 port->outvq_full = false;
1148
1149 port->in_vq = portdev->in_vqs[port->id];
1150 port->out_vq = portdev->out_vqs[port->id];
1151
1152 port->cdev = cdev_alloc();
1153 if (!port->cdev) {
1154 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1155 err = -ENOMEM;
1156 goto free_port;
1157 }
1158 port->cdev->ops = &port_fops;
1159
1160 devt = MKDEV(portdev->chr_major, id);
1161 err = cdev_add(port->cdev, devt, 1);
1162 if (err < 0) {
1163 dev_err(&port->portdev->vdev->dev,
1164 "Error %d adding cdev for port %u\n", err, id);
1165 goto free_cdev;
1166 }
1167 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1168 devt, port, "vport%up%u",
1169 port->portdev->drv_index, id);
1170 if (IS_ERR(port->dev)) {
1171 err = PTR_ERR(port->dev);
1172 dev_err(&port->portdev->vdev->dev,
1173 "Error %d creating device for port %u\n",
1174 err, id);
1175 goto free_cdev;
1176 }
1177
1178 spin_lock_init(&port->inbuf_lock);
1179 spin_lock_init(&port->outvq_lock);
1180 init_waitqueue_head(&port->waitqueue);
1181
1182 /* Fill the in_vq with buffers so the host can send us data. */
1183 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1184 if (!nr_added_bufs) {
1185 dev_err(port->dev, "Error allocating inbufs\n");
1186 err = -ENOMEM;
1187 goto free_device;
1188 }
1189
1190 /*
1191 * If we're not using multiport support, this has to be a console port
1192 */
1193 if (!use_multiport(port->portdev)) {
1194 err = init_port_console(port);
1195 if (err)
1196 goto free_inbufs;
1197 }
1198
1199 spin_lock_irq(&portdev->ports_lock);
1200 list_add_tail(&port->list, &port->portdev->ports);
1201 spin_unlock_irq(&portdev->ports_lock);
1202
1203 /*
1204 * Tell the Host we're set so that it can send us various
1205 * configuration parameters for this port (eg, port name,
1206 * caching, whether this is a console port, etc.)
1207 */
1208 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1209
1210 if (pdrvdata.debugfs_dir) {
1211 /*
1212 * Finally, create the debugfs file that we can use to
1213 * inspect a port's state at any time
1214 */
1215 sprintf(debugfs_name, "vport%up%u",
1216 port->portdev->drv_index, id);
1217 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1218 pdrvdata.debugfs_dir,
1219 port,
1220 &port_debugfs_ops);
1221 }
1222 return 0;
1223
1224free_inbufs:
1225 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1226 free_buf(buf);
1227free_device:
1228 device_destroy(pdrvdata.class, port->dev->devt);
1229free_cdev:
1230 cdev_del(port->cdev);
1231free_port:
1232 kfree(port);
1233fail:
1234 /* The host might want to notify management sw about port add failure */
1235 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1236 return err;
1237}
1238
1239/* No users remain, remove all port-specific data. */
1240static void remove_port(struct kref *kref)
1241{
1242 struct port *port;
1243
1244 port = container_of(kref, struct port, kref);
1245
1246 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1247 device_destroy(pdrvdata.class, port->dev->devt);
1248 cdev_del(port->cdev);
1249
1250 kfree(port->name);
1251
1252 debugfs_remove(port->debugfs_file);
1253
1254 kfree(port);
1255}
1256
1257/*
1258 * Port got unplugged. Remove port from portdev's list and drop the
1259 * kref reference. If no userspace has this port opened, it will
1260 * result in immediate removal the port.
1261 */
1262static void unplug_port(struct port *port)
1263{
1264 struct port_buffer *buf;
1265
1266 spin_lock_irq(&port->portdev->ports_lock);
1267 list_del(&port->list);
1268 spin_unlock_irq(&port->portdev->ports_lock);
1269
1270 if (port->guest_connected) {
1271 port->guest_connected = false;
1272 port->host_connected = false;
1273 wake_up_interruptible(&port->waitqueue);
1274
1275 /* Let the app know the port is going down. */
1276 send_sigio_to_port(port);
1277 }
1278
1279 if (is_console_port(port)) {
1280 spin_lock_irq(&pdrvdata_lock);
1281 list_del(&port->cons.list);
1282 spin_unlock_irq(&pdrvdata_lock);
1283 hvc_remove(port->cons.hvc);
1284 }
1285
1286 /* Remove unused data this port might have received. */
1287 discard_port_data(port);
1288
1289 reclaim_consumed_buffers(port);
1290
1291 /* Remove buffers we queued up for the Host to send us data in. */
1292 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1293 free_buf(buf);
1294
1295 /*
1296 * We should just assume the device itself has gone off --
1297 * else a close on an open port later will try to send out a
1298 * control message.
1299 */
1300 port->portdev = NULL;
1301
1302 /*
1303 * Locks around here are not necessary - a port can't be
1304 * opened after we removed the port struct from ports_list
1305 * above.
1306 */
1307 kref_put(&port->kref, remove_port);
1308}
1309
1310/* Any private messages that the Host and Guest want to share */
1311static void handle_control_message(struct ports_device *portdev,
1312 struct port_buffer *buf)
1313{
1314 struct virtio_console_control *cpkt;
1315 struct port *port;
1316 size_t name_size;
1317 int err;
1318
1319 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1320
1321 port = find_port_by_id(portdev, cpkt->id);
1322 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1323 /* No valid header at start of buffer. Drop it. */
1324 dev_dbg(&portdev->vdev->dev,
1325 "Invalid index %u in control packet\n", cpkt->id);
1326 return;
1327 }
1328
1329 switch (cpkt->event) {
1330 case VIRTIO_CONSOLE_PORT_ADD:
1331 if (port) {
1332 dev_dbg(&portdev->vdev->dev,
1333 "Port %u already added\n", port->id);
1334 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1335 break;
1336 }
1337 if (cpkt->id >= portdev->config.max_nr_ports) {
1338 dev_warn(&portdev->vdev->dev,
1339 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1340 cpkt->id, portdev->config.max_nr_ports - 1);
1341 break;
1342 }
1343 add_port(portdev, cpkt->id);
1344 break;
1345 case VIRTIO_CONSOLE_PORT_REMOVE:
1346 unplug_port(port);
1347 break;
1348 case VIRTIO_CONSOLE_CONSOLE_PORT:
1349 if (!cpkt->value)
1350 break;
1351 if (is_console_port(port))
1352 break;
1353
1354 init_port_console(port);
1355 /*
1356 * Could remove the port here in case init fails - but
1357 * have to notify the host first.
1358 */
1359 break;
1360 case VIRTIO_CONSOLE_RESIZE: {
1361 struct {
1362 __u16 rows;
1363 __u16 cols;
1364 } size;
1365
1366 if (!is_console_port(port))
1367 break;
1368
1369 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1370 sizeof(size));
1371 set_console_size(port, size.rows, size.cols);
1372
1373 port->cons.hvc->irq_requested = 1;
1374 resize_console(port);
1375 break;
1376 }
1377 case VIRTIO_CONSOLE_PORT_OPEN:
1378 port->host_connected = cpkt->value;
1379 wake_up_interruptible(&port->waitqueue);
1380 /*
1381 * If the host port got closed and the host had any
1382 * unconsumed buffers, we'll be able to reclaim them
1383 * now.
1384 */
1385 spin_lock_irq(&port->outvq_lock);
1386 reclaim_consumed_buffers(port);
1387 spin_unlock_irq(&port->outvq_lock);
1388
1389 /*
1390 * If the guest is connected, it'll be interested in
1391 * knowing the host connection state changed.
1392 */
1393 send_sigio_to_port(port);
1394 break;
1395 case VIRTIO_CONSOLE_PORT_NAME:
1396 /*
1397 * Skip the size of the header and the cpkt to get the size
1398 * of the name that was sent
1399 */
1400 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1401
1402 port->name = kmalloc(name_size, GFP_KERNEL);
1403 if (!port->name) {
1404 dev_err(port->dev,
1405 "Not enough space to store port name\n");
1406 break;
1407 }
1408 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1409 name_size - 1);
1410 port->name[name_size - 1] = 0;
1411
1412 /*
1413 * Since we only have one sysfs attribute, 'name',
1414 * create it only if we have a name for the port.
1415 */
1416 err = sysfs_create_group(&port->dev->kobj,
1417 &port_attribute_group);
1418 if (err) {
1419 dev_err(port->dev,
1420 "Error %d creating sysfs device attributes\n",
1421 err);
1422 } else {
1423 /*
1424 * Generate a udev event so that appropriate
1425 * symlinks can be created based on udev
1426 * rules.
1427 */
1428 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1429 }
1430 break;
1431 }
1432}
1433
1434static void control_work_handler(struct work_struct *work)
1435{
1436 struct ports_device *portdev;
1437 struct virtqueue *vq;
1438 struct port_buffer *buf;
1439 unsigned int len;
1440
1441 portdev = container_of(work, struct ports_device, control_work);
1442 vq = portdev->c_ivq;
1443
1444 spin_lock(&portdev->cvq_lock);
1445 while ((buf = virtqueue_get_buf(vq, &len))) {
1446 spin_unlock(&portdev->cvq_lock);
1447
1448 buf->len = len;
1449 buf->offset = 0;
1450
1451 handle_control_message(portdev, buf);
1452
1453 spin_lock(&portdev->cvq_lock);
1454 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1455 dev_warn(&portdev->vdev->dev,
1456 "Error adding buffer to queue\n");
1457 free_buf(buf);
1458 }
1459 }
1460 spin_unlock(&portdev->cvq_lock);
1461}
1462
1463static void out_intr(struct virtqueue *vq)
1464{
1465 struct port *port;
1466
1467 port = find_port_by_vq(vq->vdev->priv, vq);
1468 if (!port)
1469 return;
1470
1471 wake_up_interruptible(&port->waitqueue);
1472}
1473
1474static void in_intr(struct virtqueue *vq)
1475{
1476 struct port *port;
1477 unsigned long flags;
1478
1479 port = find_port_by_vq(vq->vdev->priv, vq);
1480 if (!port)
1481 return;
1482
1483 spin_lock_irqsave(&port->inbuf_lock, flags);
1484 if (!port->inbuf)
1485 port->inbuf = get_inbuf(port);
1486
1487 /*
1488 * Don't queue up data when port is closed. This condition
1489 * can be reached when a console port is not yet connected (no
1490 * tty is spawned) and the host sends out data to console
1491 * ports. For generic serial ports, the host won't
1492 * (shouldn't) send data till the guest is connected.
1493 */
1494 if (!port->guest_connected)
1495 discard_port_data(port);
1496
1497 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1498
1499 wake_up_interruptible(&port->waitqueue);
1500
1501 /* Send a SIGIO indicating new data in case the process asked for it */
1502 send_sigio_to_port(port);
1503
1504 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1505 hvc_kick();
1506}
1507
1508static void control_intr(struct virtqueue *vq)
1509{
1510 struct ports_device *portdev;
1511
1512 portdev = vq->vdev->priv;
1513 schedule_work(&portdev->control_work);
1514}
1515
1516static void config_intr(struct virtio_device *vdev)
1517{
1518 struct ports_device *portdev;
1519
1520 portdev = vdev->priv;
1521
1522 if (!use_multiport(portdev)) {
1523 struct port *port;
1524 u16 rows, cols;
1525
1526 vdev->config->get(vdev,
1527 offsetof(struct virtio_console_config, cols),
1528 &cols, sizeof(u16));
1529 vdev->config->get(vdev,
1530 offsetof(struct virtio_console_config, rows),
1531 &rows, sizeof(u16));
1532
1533 port = find_port_by_id(portdev, 0);
1534 set_console_size(port, rows, cols);
1535
1536 /*
1537 * We'll use this way of resizing only for legacy
1538 * support. For newer userspace
1539 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1540 * to indicate console size changes so that it can be
1541 * done per-port.
1542 */
1543 resize_console(port);
1544 }
1545}
1546
1547static int init_vqs(struct ports_device *portdev)
1548{
1549 vq_callback_t **io_callbacks;
1550 char **io_names;
1551 struct virtqueue **vqs;
1552 u32 i, j, nr_ports, nr_queues;
1553 int err;
1554
1555 nr_ports = portdev->config.max_nr_ports;
1556 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1557
1558 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1559 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1560 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1561 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1562 GFP_KERNEL);
1563 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1564 GFP_KERNEL);
1565 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1566 !portdev->out_vqs) {
1567 err = -ENOMEM;
1568 goto free;
1569 }
1570
1571 /*
1572 * For backward compat (newer host but older guest), the host
1573 * spawns a console port first and also inits the vqs for port
1574 * 0 before others.
1575 */
1576 j = 0;
1577 io_callbacks[j] = in_intr;
1578 io_callbacks[j + 1] = out_intr;
1579 io_names[j] = "input";
1580 io_names[j + 1] = "output";
1581 j += 2;
1582
1583 if (use_multiport(portdev)) {
1584 io_callbacks[j] = control_intr;
1585 io_callbacks[j + 1] = NULL;
1586 io_names[j] = "control-i";
1587 io_names[j + 1] = "control-o";
1588
1589 for (i = 1; i < nr_ports; i++) {
1590 j += 2;
1591 io_callbacks[j] = in_intr;
1592 io_callbacks[j + 1] = out_intr;
1593 io_names[j] = "input";
1594 io_names[j + 1] = "output";
1595 }
1596 }
1597 /* Find the queues. */
1598 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1599 io_callbacks,
1600 (const char **)io_names);
1601 if (err)
1602 goto free;
1603
1604 j = 0;
1605 portdev->in_vqs[0] = vqs[0];
1606 portdev->out_vqs[0] = vqs[1];
1607 j += 2;
1608 if (use_multiport(portdev)) {
1609 portdev->c_ivq = vqs[j];
1610 portdev->c_ovq = vqs[j + 1];
1611
1612 for (i = 1; i < nr_ports; i++) {
1613 j += 2;
1614 portdev->in_vqs[i] = vqs[j];
1615 portdev->out_vqs[i] = vqs[j + 1];
1616 }
1617 }
1618 kfree(io_names);
1619 kfree(io_callbacks);
1620 kfree(vqs);
1621
1622 return 0;
1623
1624free:
1625 kfree(portdev->out_vqs);
1626 kfree(portdev->in_vqs);
1627 kfree(io_names);
1628 kfree(io_callbacks);
1629 kfree(vqs);
1630
1631 return err;
1632}
1633
1634static const struct file_operations portdev_fops = {
1635 .owner = THIS_MODULE,
1636};
1637
1638/*
1639 * Once we're further in boot, we get probed like any other virtio
1640 * device.
1641 *
1642 * If the host also supports multiple console ports, we check the
1643 * config space to see how many ports the host has spawned. We
1644 * initialize each port found.
1645 */
1646static int __devinit virtcons_probe(struct virtio_device *vdev)
1647{
1648 struct ports_device *portdev;
1649 int err;
1650 bool multiport;
1651
1652 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1653 if (!portdev) {
1654 err = -ENOMEM;
1655 goto fail;
1656 }
1657
1658 /* Attach this portdev to this virtio_device, and vice-versa. */
1659 portdev->vdev = vdev;
1660 vdev->priv = portdev;
1661
1662 spin_lock_irq(&pdrvdata_lock);
1663 portdev->drv_index = pdrvdata.index++;
1664 spin_unlock_irq(&pdrvdata_lock);
1665
1666 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1667 &portdev_fops);
1668 if (portdev->chr_major < 0) {
1669 dev_err(&vdev->dev,
1670 "Error %d registering chrdev for device %u\n",
1671 portdev->chr_major, portdev->drv_index);
1672 err = portdev->chr_major;
1673 goto free;
1674 }
1675
1676 multiport = false;
1677 portdev->config.max_nr_ports = 1;
1678 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1679 multiport = true;
1680 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1681 max_nr_ports),
1682 &portdev->config.max_nr_ports,
1683 sizeof(portdev->config.max_nr_ports));
1684 }
1685
1686 err = init_vqs(portdev);
1687 if (err < 0) {
1688 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1689 goto free_chrdev;
1690 }
1691
1692 spin_lock_init(&portdev->ports_lock);
1693 INIT_LIST_HEAD(&portdev->ports);
1694
1695 if (multiport) {
1696 unsigned int nr_added_bufs;
1697
1698 spin_lock_init(&portdev->cvq_lock);
1699 INIT_WORK(&portdev->control_work, &control_work_handler);
1700
1701 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1702 if (!nr_added_bufs) {
1703 dev_err(&vdev->dev,
1704 "Error allocating buffers for control queue\n");
1705 err = -ENOMEM;
1706 goto free_vqs;
1707 }
1708 } else {
1709 /*
1710 * For backward compatibility: Create a console port
1711 * if we're running on older host.
1712 */
1713 add_port(portdev, 0);
1714 }
1715
1716 spin_lock_irq(&pdrvdata_lock);
1717 list_add_tail(&portdev->list, &pdrvdata.portdevs);
1718 spin_unlock_irq(&pdrvdata_lock);
1719
1720 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1721 VIRTIO_CONSOLE_DEVICE_READY, 1);
1722 return 0;
1723
1724free_vqs:
1725 /* The host might want to notify mgmt sw about device add failure */
1726 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1727 VIRTIO_CONSOLE_DEVICE_READY, 0);
1728 vdev->config->del_vqs(vdev);
1729 kfree(portdev->in_vqs);
1730 kfree(portdev->out_vqs);
1731free_chrdev:
1732 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1733free:
1734 kfree(portdev);
1735fail:
1736 return err;
1737}
1738
1739static void virtcons_remove(struct virtio_device *vdev)
1740{
1741 struct ports_device *portdev;
1742 struct port *port, *port2;
1743
1744 portdev = vdev->priv;
1745
1746 spin_lock_irq(&pdrvdata_lock);
1747 list_del(&portdev->list);
1748 spin_unlock_irq(&pdrvdata_lock);
1749
1750 /* Disable interrupts for vqs */
1751 vdev->config->reset(vdev);
1752 /* Finish up work that's lined up */
1753 cancel_work_sync(&portdev->control_work);
1754
1755 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1756 unplug_port(port);
1757
1758 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1759
1760 /*
1761 * When yanking out a device, we immediately lose the
1762 * (device-side) queues. So there's no point in keeping the
1763 * guest side around till we drop our final reference. This
1764 * also means that any ports which are in an open state will
1765 * have to just stop using the port, as the vqs are going
1766 * away.
1767 */
1768 if (use_multiport(portdev)) {
1769 struct port_buffer *buf;
1770 unsigned int len;
1771
1772 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1773 free_buf(buf);
1774
1775 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1776 free_buf(buf);
1777 }
1778
1779 vdev->config->del_vqs(vdev);
1780 kfree(portdev->in_vqs);
1781 kfree(portdev->out_vqs);
1782
1783 kfree(portdev);
1784}
1785
1786static struct virtio_device_id id_table[] = {
1787 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1788 { 0 },
1789};
1790
1791static unsigned int features[] = {
1792 VIRTIO_CONSOLE_F_SIZE,
1793 VIRTIO_CONSOLE_F_MULTIPORT,
1794};
1795
1796static struct virtio_driver virtio_console = {
1797 .feature_table = features,
1798 .feature_table_size = ARRAY_SIZE(features),
1799 .driver.name = KBUILD_MODNAME,
1800 .driver.owner = THIS_MODULE,
1801 .id_table = id_table,
1802 .probe = virtcons_probe,
1803 .remove = virtcons_remove,
1804 .config_changed = config_intr,
1805};
1806
1807static int __init init(void)
1808{
1809 int err;
1810
1811 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1812 if (IS_ERR(pdrvdata.class)) {
1813 err = PTR_ERR(pdrvdata.class);
1814 pr_err("Error %d creating virtio-ports class\n", err);
1815 return err;
1816 }
1817
1818 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1819 if (!pdrvdata.debugfs_dir) {
1820 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1821 PTR_ERR(pdrvdata.debugfs_dir));
1822 }
1823 INIT_LIST_HEAD(&pdrvdata.consoles);
1824 INIT_LIST_HEAD(&pdrvdata.portdevs);
1825
1826 return register_virtio_driver(&virtio_console);
1827}
1828
1829static void __exit fini(void)
1830{
1831 unregister_virtio_driver(&virtio_console);
1832
1833 class_destroy(pdrvdata.class);
1834 if (pdrvdata.debugfs_dir)
1835 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1836}
1837module_init(init);
1838module_exit(fini);
1839
1840MODULE_DEVICE_TABLE(virtio, id_table);
1841MODULE_DESCRIPTION("Virtio console driver");
1842MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
4 * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
5 * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
6 */
7#include <linux/cdev.h>
8#include <linux/debugfs.h>
9#include <linux/completion.h>
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/freezer.h>
13#include <linux/fs.h>
14#include <linux/splice.h>
15#include <linux/pagemap.h>
16#include <linux/idr.h>
17#include <linux/init.h>
18#include <linux/list.h>
19#include <linux/poll.h>
20#include <linux/sched.h>
21#include <linux/slab.h>
22#include <linux/spinlock.h>
23#include <linux/virtio.h>
24#include <linux/virtio_console.h>
25#include <linux/wait.h>
26#include <linux/workqueue.h>
27#include <linux/module.h>
28#include <linux/dma-mapping.h>
29#include "../tty/hvc/hvc_console.h"
30
31#define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
32#define VIRTCONS_MAX_PORTS 0x8000
33
34/*
35 * This is a global struct for storing common data for all the devices
36 * this driver handles.
37 *
38 * Mainly, it has a linked list for all the consoles in one place so
39 * that callbacks from hvc for get_chars(), put_chars() work properly
40 * across multiple devices and multiple ports per device.
41 */
42struct ports_driver_data {
43 /* Used for exporting per-port information to debugfs */
44 struct dentry *debugfs_dir;
45
46 /* List of all the devices we're handling */
47 struct list_head portdevs;
48
49 /* All the console devices handled by this driver */
50 struct list_head consoles;
51};
52
53static struct ports_driver_data pdrvdata;
54
55static const struct class port_class = {
56 .name = "virtio-ports",
57};
58
59static DEFINE_SPINLOCK(pdrvdata_lock);
60static DECLARE_COMPLETION(early_console_added);
61
62/* This struct holds information that's relevant only for console ports */
63struct console {
64 /* We'll place all consoles in a list in the pdrvdata struct */
65 struct list_head list;
66
67 /* The hvc device associated with this console port */
68 struct hvc_struct *hvc;
69
70 /* The size of the console */
71 struct winsize ws;
72
73 /*
74 * This number identifies the number that we used to register
75 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
76 * number passed on by the hvc callbacks to us to
77 * differentiate between the other console ports handled by
78 * this driver
79 */
80 u32 vtermno;
81};
82
83static DEFINE_IDA(vtermno_ida);
84
85struct port_buffer {
86 char *buf;
87
88 /* size of the buffer in *buf above */
89 size_t size;
90
91 /* used length of the buffer */
92 size_t len;
93 /* offset in the buf from which to consume data */
94 size_t offset;
95
96 /* DMA address of buffer */
97 dma_addr_t dma;
98
99 /* Device we got DMA memory from */
100 struct device *dev;
101
102 /* List of pending dma buffers to free */
103 struct list_head list;
104
105 /* If sgpages == 0 then buf is used */
106 unsigned int sgpages;
107
108 /* sg is used if spages > 0. sg must be the last in is struct */
109 struct scatterlist sg[] __counted_by(sgpages);
110};
111
112/*
113 * This is a per-device struct that stores data common to all the
114 * ports for that device (vdev->priv).
115 */
116struct ports_device {
117 /* Next portdev in the list, head is in the pdrvdata struct */
118 struct list_head list;
119
120 /*
121 * Workqueue handlers where we process deferred work after
122 * notification
123 */
124 struct work_struct control_work;
125 struct work_struct config_work;
126
127 struct list_head ports;
128
129 /* To protect the list of ports */
130 spinlock_t ports_lock;
131
132 /* To protect the vq operations for the control channel */
133 spinlock_t c_ivq_lock;
134 spinlock_t c_ovq_lock;
135
136 /* max. number of ports this device can hold */
137 u32 max_nr_ports;
138
139 /* The virtio device we're associated with */
140 struct virtio_device *vdev;
141
142 /*
143 * A couple of virtqueues for the control channel: one for
144 * guest->host transfers, one for host->guest transfers
145 */
146 struct virtqueue *c_ivq, *c_ovq;
147
148 /*
149 * A control packet buffer for guest->host requests, protected
150 * by c_ovq_lock.
151 */
152 struct virtio_console_control cpkt;
153
154 /* Array of per-port IO virtqueues */
155 struct virtqueue **in_vqs, **out_vqs;
156
157 /* Major number for this device. Ports will be created as minors. */
158 int chr_major;
159};
160
161struct port_stats {
162 unsigned long bytes_sent, bytes_received, bytes_discarded;
163};
164
165/* This struct holds the per-port data */
166struct port {
167 /* Next port in the list, head is in the ports_device */
168 struct list_head list;
169
170 /* Pointer to the parent virtio_console device */
171 struct ports_device *portdev;
172
173 /* The current buffer from which data has to be fed to readers */
174 struct port_buffer *inbuf;
175
176 /*
177 * To protect the operations on the in_vq associated with this
178 * port. Has to be a spinlock because it can be called from
179 * interrupt context (get_char()).
180 */
181 spinlock_t inbuf_lock;
182
183 /* Protect the operations on the out_vq. */
184 spinlock_t outvq_lock;
185
186 /* The IO vqs for this port */
187 struct virtqueue *in_vq, *out_vq;
188
189 /* File in the debugfs directory that exposes this port's information */
190 struct dentry *debugfs_file;
191
192 /*
193 * Keep count of the bytes sent, received and discarded for
194 * this port for accounting and debugging purposes. These
195 * counts are not reset across port open / close events.
196 */
197 struct port_stats stats;
198
199 /*
200 * The entries in this struct will be valid if this port is
201 * hooked up to an hvc console
202 */
203 struct console cons;
204
205 /* Each port associates with a separate char device */
206 struct cdev *cdev;
207 struct device *dev;
208
209 /* Reference-counting to handle port hot-unplugs and file operations */
210 struct kref kref;
211
212 /* A waitqueue for poll() or blocking read operations */
213 wait_queue_head_t waitqueue;
214
215 /* The 'name' of the port that we expose via sysfs properties */
216 char *name;
217
218 /* We can notify apps of host connect / disconnect events via SIGIO */
219 struct fasync_struct *async_queue;
220
221 /* The 'id' to identify the port with the Host */
222 u32 id;
223
224 bool outvq_full;
225
226 /* Is the host device open */
227 bool host_connected;
228
229 /* We should allow only one process to open a port */
230 bool guest_connected;
231};
232
233static struct port *find_port_by_vtermno(u32 vtermno)
234{
235 struct port *port;
236 struct console *cons;
237 unsigned long flags;
238
239 spin_lock_irqsave(&pdrvdata_lock, flags);
240 list_for_each_entry(cons, &pdrvdata.consoles, list) {
241 if (cons->vtermno == vtermno) {
242 port = container_of(cons, struct port, cons);
243 goto out;
244 }
245 }
246 port = NULL;
247out:
248 spin_unlock_irqrestore(&pdrvdata_lock, flags);
249 return port;
250}
251
252static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
253 dev_t dev)
254{
255 struct port *port;
256 unsigned long flags;
257
258 spin_lock_irqsave(&portdev->ports_lock, flags);
259 list_for_each_entry(port, &portdev->ports, list) {
260 if (port->cdev->dev == dev) {
261 kref_get(&port->kref);
262 goto out;
263 }
264 }
265 port = NULL;
266out:
267 spin_unlock_irqrestore(&portdev->ports_lock, flags);
268
269 return port;
270}
271
272static struct port *find_port_by_devt(dev_t dev)
273{
274 struct ports_device *portdev;
275 struct port *port;
276 unsigned long flags;
277
278 spin_lock_irqsave(&pdrvdata_lock, flags);
279 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
280 port = find_port_by_devt_in_portdev(portdev, dev);
281 if (port)
282 goto out;
283 }
284 port = NULL;
285out:
286 spin_unlock_irqrestore(&pdrvdata_lock, flags);
287 return port;
288}
289
290static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
291{
292 struct port *port;
293 unsigned long flags;
294
295 spin_lock_irqsave(&portdev->ports_lock, flags);
296 list_for_each_entry(port, &portdev->ports, list)
297 if (port->id == id)
298 goto out;
299 port = NULL;
300out:
301 spin_unlock_irqrestore(&portdev->ports_lock, flags);
302
303 return port;
304}
305
306static struct port *find_port_by_vq(struct ports_device *portdev,
307 struct virtqueue *vq)
308{
309 struct port *port;
310 unsigned long flags;
311
312 spin_lock_irqsave(&portdev->ports_lock, flags);
313 list_for_each_entry(port, &portdev->ports, list)
314 if (port->in_vq == vq || port->out_vq == vq)
315 goto out;
316 port = NULL;
317out:
318 spin_unlock_irqrestore(&portdev->ports_lock, flags);
319 return port;
320}
321
322static bool is_console_port(struct port *port)
323{
324 if (port->cons.hvc)
325 return true;
326 return false;
327}
328
329static bool is_rproc_serial(const struct virtio_device *vdev)
330{
331 return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
332}
333
334static inline bool use_multiport(struct ports_device *portdev)
335{
336 /*
337 * This condition can be true when put_chars is called from
338 * early_init
339 */
340 if (!portdev->vdev)
341 return false;
342 return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
343}
344
345static DEFINE_SPINLOCK(dma_bufs_lock);
346static LIST_HEAD(pending_free_dma_bufs);
347
348static void free_buf(struct port_buffer *buf, bool can_sleep)
349{
350 unsigned int i;
351
352 for (i = 0; i < buf->sgpages; i++) {
353 struct page *page = sg_page(&buf->sg[i]);
354 if (!page)
355 break;
356 put_page(page);
357 }
358
359 if (!buf->dev) {
360 kfree(buf->buf);
361 } else if (is_rproc_enabled) {
362 unsigned long flags;
363
364 /* dma_free_coherent requires interrupts to be enabled. */
365 if (!can_sleep) {
366 /* queue up dma-buffers to be freed later */
367 spin_lock_irqsave(&dma_bufs_lock, flags);
368 list_add_tail(&buf->list, &pending_free_dma_bufs);
369 spin_unlock_irqrestore(&dma_bufs_lock, flags);
370 return;
371 }
372 dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma);
373
374 /* Release device refcnt and allow it to be freed */
375 put_device(buf->dev);
376 }
377
378 kfree(buf);
379}
380
381static void reclaim_dma_bufs(void)
382{
383 unsigned long flags;
384 struct port_buffer *buf, *tmp;
385 LIST_HEAD(tmp_list);
386
387 if (list_empty(&pending_free_dma_bufs))
388 return;
389
390 /* Create a copy of the pending_free_dma_bufs while holding the lock */
391 spin_lock_irqsave(&dma_bufs_lock, flags);
392 list_cut_position(&tmp_list, &pending_free_dma_bufs,
393 pending_free_dma_bufs.prev);
394 spin_unlock_irqrestore(&dma_bufs_lock, flags);
395
396 /* Release the dma buffers, without irqs enabled */
397 list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
398 list_del(&buf->list);
399 free_buf(buf, true);
400 }
401}
402
403static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size,
404 int pages)
405{
406 struct port_buffer *buf;
407
408 reclaim_dma_bufs();
409
410 /*
411 * Allocate buffer and the sg list. The sg list array is allocated
412 * directly after the port_buffer struct.
413 */
414 buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL);
415 if (!buf)
416 goto fail;
417
418 buf->sgpages = pages;
419 if (pages > 0) {
420 buf->dev = NULL;
421 buf->buf = NULL;
422 return buf;
423 }
424
425 if (is_rproc_serial(vdev)) {
426 /*
427 * Allocate DMA memory from ancestor. When a virtio
428 * device is created by remoteproc, the DMA memory is
429 * associated with the parent device:
430 * virtioY => remoteprocX#vdevYbuffer.
431 */
432 buf->dev = vdev->dev.parent;
433 if (!buf->dev)
434 goto free_buf;
435
436 /* Increase device refcnt to avoid freeing it */
437 get_device(buf->dev);
438 buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
439 GFP_KERNEL);
440 } else {
441 buf->dev = NULL;
442 buf->buf = kmalloc(buf_size, GFP_KERNEL);
443 }
444
445 if (!buf->buf)
446 goto free_buf;
447 buf->len = 0;
448 buf->offset = 0;
449 buf->size = buf_size;
450 return buf;
451
452free_buf:
453 kfree(buf);
454fail:
455 return NULL;
456}
457
458/* Callers should take appropriate locks */
459static struct port_buffer *get_inbuf(struct port *port)
460{
461 struct port_buffer *buf;
462 unsigned int len;
463
464 if (port->inbuf)
465 return port->inbuf;
466
467 buf = virtqueue_get_buf(port->in_vq, &len);
468 if (buf) {
469 buf->len = min_t(size_t, len, buf->size);
470 buf->offset = 0;
471 port->stats.bytes_received += len;
472 }
473 return buf;
474}
475
476/*
477 * Create a scatter-gather list representing our input buffer and put
478 * it in the queue.
479 *
480 * Callers should take appropriate locks.
481 */
482static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
483{
484 struct scatterlist sg[1];
485 int ret;
486
487 sg_init_one(sg, buf->buf, buf->size);
488
489 ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC);
490 virtqueue_kick(vq);
491 if (!ret)
492 ret = vq->num_free;
493 return ret;
494}
495
496/* Discard any unread data this port has. Callers lockers. */
497static void discard_port_data(struct port *port)
498{
499 struct port_buffer *buf;
500 unsigned int err;
501
502 if (!port->portdev) {
503 /* Device has been unplugged. vqs are already gone. */
504 return;
505 }
506 buf = get_inbuf(port);
507
508 err = 0;
509 while (buf) {
510 port->stats.bytes_discarded += buf->len - buf->offset;
511 if (add_inbuf(port->in_vq, buf) < 0) {
512 err++;
513 free_buf(buf, false);
514 }
515 port->inbuf = NULL;
516 buf = get_inbuf(port);
517 }
518 if (err)
519 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
520 err);
521}
522
523static bool port_has_data(struct port *port)
524{
525 unsigned long flags;
526 bool ret;
527
528 ret = false;
529 spin_lock_irqsave(&port->inbuf_lock, flags);
530 port->inbuf = get_inbuf(port);
531 if (port->inbuf)
532 ret = true;
533
534 spin_unlock_irqrestore(&port->inbuf_lock, flags);
535 return ret;
536}
537
538static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
539 unsigned int event, unsigned int value)
540{
541 struct scatterlist sg[1];
542 struct virtqueue *vq;
543 unsigned int len;
544
545 if (!use_multiport(portdev))
546 return 0;
547
548 vq = portdev->c_ovq;
549
550 spin_lock(&portdev->c_ovq_lock);
551
552 portdev->cpkt.id = cpu_to_virtio32(portdev->vdev, port_id);
553 portdev->cpkt.event = cpu_to_virtio16(portdev->vdev, event);
554 portdev->cpkt.value = cpu_to_virtio16(portdev->vdev, value);
555
556 sg_init_one(sg, &portdev->cpkt, sizeof(struct virtio_console_control));
557
558 if (virtqueue_add_outbuf(vq, sg, 1, &portdev->cpkt, GFP_ATOMIC) == 0) {
559 virtqueue_kick(vq);
560 while (!virtqueue_get_buf(vq, &len)
561 && !virtqueue_is_broken(vq))
562 cpu_relax();
563 }
564
565 spin_unlock(&portdev->c_ovq_lock);
566 return 0;
567}
568
569static ssize_t send_control_msg(struct port *port, unsigned int event,
570 unsigned int value)
571{
572 /* Did the port get unplugged before userspace closed it? */
573 if (port->portdev)
574 return __send_control_msg(port->portdev, port->id, event, value);
575 return 0;
576}
577
578
579/* Callers must take the port->outvq_lock */
580static void reclaim_consumed_buffers(struct port *port)
581{
582 struct port_buffer *buf;
583 unsigned int len;
584
585 if (!port->portdev) {
586 /* Device has been unplugged. vqs are already gone. */
587 return;
588 }
589 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
590 free_buf(buf, false);
591 port->outvq_full = false;
592 }
593}
594
595static ssize_t __send_to_port(struct port *port, struct scatterlist *sg,
596 int nents, size_t in_count,
597 void *data, bool nonblock)
598{
599 struct virtqueue *out_vq;
600 int err;
601 unsigned long flags;
602 unsigned int len;
603
604 out_vq = port->out_vq;
605
606 spin_lock_irqsave(&port->outvq_lock, flags);
607
608 reclaim_consumed_buffers(port);
609
610 err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC);
611
612 /* Tell Host to go! */
613 virtqueue_kick(out_vq);
614
615 if (err) {
616 in_count = 0;
617 goto done;
618 }
619
620 if (out_vq->num_free == 0)
621 port->outvq_full = true;
622
623 if (nonblock)
624 goto done;
625
626 /*
627 * Wait till the host acknowledges it pushed out the data we
628 * sent. This is done for data from the hvc_console; the tty
629 * operations are performed with spinlocks held so we can't
630 * sleep here. An alternative would be to copy the data to a
631 * buffer and relax the spinning requirement. The downside is
632 * we need to kmalloc a GFP_ATOMIC buffer each time the
633 * console driver writes something out.
634 */
635 while (!virtqueue_get_buf(out_vq, &len)
636 && !virtqueue_is_broken(out_vq))
637 cpu_relax();
638done:
639 spin_unlock_irqrestore(&port->outvq_lock, flags);
640
641 port->stats.bytes_sent += in_count;
642 /*
643 * We're expected to return the amount of data we wrote -- all
644 * of it
645 */
646 return in_count;
647}
648
649/*
650 * Give out the data that's requested from the buffer that we have
651 * queued up.
652 */
653static ssize_t fill_readbuf(struct port *port, u8 __user *out_buf,
654 size_t out_count, bool to_user)
655{
656 struct port_buffer *buf;
657 unsigned long flags;
658
659 if (!out_count || !port_has_data(port))
660 return 0;
661
662 buf = port->inbuf;
663 out_count = min(out_count, buf->len - buf->offset);
664
665 if (to_user) {
666 ssize_t ret;
667
668 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
669 if (ret)
670 return -EFAULT;
671 } else {
672 memcpy((__force u8 *)out_buf, buf->buf + buf->offset,
673 out_count);
674 }
675
676 buf->offset += out_count;
677
678 if (buf->offset == buf->len) {
679 /*
680 * We're done using all the data in this buffer.
681 * Re-queue so that the Host can send us more data.
682 */
683 spin_lock_irqsave(&port->inbuf_lock, flags);
684 port->inbuf = NULL;
685
686 if (add_inbuf(port->in_vq, buf) < 0)
687 dev_warn(port->dev, "failed add_buf\n");
688
689 spin_unlock_irqrestore(&port->inbuf_lock, flags);
690 }
691 /* Return the number of bytes actually copied */
692 return out_count;
693}
694
695/* The condition that must be true for polling to end */
696static bool will_read_block(struct port *port)
697{
698 if (!port->guest_connected) {
699 /* Port got hot-unplugged. Let's exit. */
700 return false;
701 }
702 return !port_has_data(port) && port->host_connected;
703}
704
705static bool will_write_block(struct port *port)
706{
707 bool ret;
708
709 if (!port->guest_connected) {
710 /* Port got hot-unplugged. Let's exit. */
711 return false;
712 }
713 if (!port->host_connected)
714 return true;
715
716 spin_lock_irq(&port->outvq_lock);
717 /*
718 * Check if the Host has consumed any buffers since we last
719 * sent data (this is only applicable for nonblocking ports).
720 */
721 reclaim_consumed_buffers(port);
722 ret = port->outvq_full;
723 spin_unlock_irq(&port->outvq_lock);
724
725 return ret;
726}
727
728static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
729 size_t count, loff_t *offp)
730{
731 struct port *port;
732 ssize_t ret;
733
734 port = filp->private_data;
735
736 /* Port is hot-unplugged. */
737 if (!port->guest_connected)
738 return -ENODEV;
739
740 if (!port_has_data(port)) {
741 /*
742 * If nothing's connected on the host just return 0 in
743 * case of list_empty; this tells the userspace app
744 * that there's no connection
745 */
746 if (!port->host_connected)
747 return 0;
748 if (filp->f_flags & O_NONBLOCK)
749 return -EAGAIN;
750
751 ret = wait_event_freezable(port->waitqueue,
752 !will_read_block(port));
753 if (ret < 0)
754 return ret;
755 }
756 /* Port got hot-unplugged while we were waiting above. */
757 if (!port->guest_connected)
758 return -ENODEV;
759 /*
760 * We could've received a disconnection message while we were
761 * waiting for more data.
762 *
763 * This check is not clubbed in the if() statement above as we
764 * might receive some data as well as the host could get
765 * disconnected after we got woken up from our wait. So we
766 * really want to give off whatever data we have and only then
767 * check for host_connected.
768 */
769 if (!port_has_data(port) && !port->host_connected)
770 return 0;
771
772 return fill_readbuf(port, ubuf, count, true);
773}
774
775static int wait_port_writable(struct port *port, bool nonblock)
776{
777 int ret;
778
779 if (will_write_block(port)) {
780 if (nonblock)
781 return -EAGAIN;
782
783 ret = wait_event_freezable(port->waitqueue,
784 !will_write_block(port));
785 if (ret < 0)
786 return ret;
787 }
788 /* Port got hot-unplugged. */
789 if (!port->guest_connected)
790 return -ENODEV;
791
792 return 0;
793}
794
795static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
796 size_t count, loff_t *offp)
797{
798 struct port *port;
799 struct port_buffer *buf;
800 ssize_t ret;
801 bool nonblock;
802 struct scatterlist sg[1];
803
804 /* Userspace could be out to fool us */
805 if (!count)
806 return 0;
807
808 port = filp->private_data;
809
810 nonblock = filp->f_flags & O_NONBLOCK;
811
812 ret = wait_port_writable(port, nonblock);
813 if (ret < 0)
814 return ret;
815
816 count = min((size_t)(32 * 1024), count);
817
818 buf = alloc_buf(port->portdev->vdev, count, 0);
819 if (!buf)
820 return -ENOMEM;
821
822 ret = copy_from_user(buf->buf, ubuf, count);
823 if (ret) {
824 ret = -EFAULT;
825 goto free_buf;
826 }
827
828 /*
829 * We now ask send_buf() to not spin for generic ports -- we
830 * can re-use the same code path that non-blocking file
831 * descriptors take for blocking file descriptors since the
832 * wait is already done and we're certain the write will go
833 * through to the host.
834 */
835 nonblock = true;
836 sg_init_one(sg, buf->buf, count);
837 ret = __send_to_port(port, sg, 1, count, buf, nonblock);
838
839 if (nonblock && ret > 0)
840 goto out;
841
842free_buf:
843 free_buf(buf, true);
844out:
845 return ret;
846}
847
848struct sg_list {
849 unsigned int n;
850 unsigned int size;
851 size_t len;
852 struct scatterlist *sg;
853};
854
855static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
856 struct splice_desc *sd)
857{
858 struct sg_list *sgl = sd->u.data;
859 unsigned int offset, len;
860
861 if (sgl->n == sgl->size)
862 return 0;
863
864 /* Try lock this page */
865 if (pipe_buf_try_steal(pipe, buf)) {
866 /* Get reference and unlock page for moving */
867 get_page(buf->page);
868 unlock_page(buf->page);
869
870 len = min(buf->len, sd->len);
871 sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset);
872 } else {
873 /* Failback to copying a page */
874 struct page *page = alloc_page(GFP_KERNEL);
875 char *src;
876
877 if (!page)
878 return -ENOMEM;
879
880 offset = sd->pos & ~PAGE_MASK;
881
882 len = sd->len;
883 if (len + offset > PAGE_SIZE)
884 len = PAGE_SIZE - offset;
885
886 src = kmap_atomic(buf->page);
887 memcpy(page_address(page) + offset, src + buf->offset, len);
888 kunmap_atomic(src);
889
890 sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
891 }
892 sgl->n++;
893 sgl->len += len;
894
895 return len;
896}
897
898/* Faster zero-copy write by splicing */
899static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
900 struct file *filp, loff_t *ppos,
901 size_t len, unsigned int flags)
902{
903 struct port *port = filp->private_data;
904 struct sg_list sgl;
905 ssize_t ret;
906 struct port_buffer *buf;
907 struct splice_desc sd = {
908 .total_len = len,
909 .flags = flags,
910 .pos = *ppos,
911 .u.data = &sgl,
912 };
913 unsigned int occupancy;
914
915 /*
916 * Rproc_serial does not yet support splice. To support splice
917 * pipe_to_sg() must allocate dma-buffers and copy content from
918 * regular pages to dma pages. And alloc_buf and free_buf must
919 * support allocating and freeing such a list of dma-buffers.
920 */
921 if (is_rproc_serial(port->out_vq->vdev))
922 return -EINVAL;
923
924 pipe_lock(pipe);
925 ret = 0;
926 if (pipe_empty(pipe->head, pipe->tail))
927 goto error_out;
928
929 ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
930 if (ret < 0)
931 goto error_out;
932
933 occupancy = pipe_occupancy(pipe->head, pipe->tail);
934 buf = alloc_buf(port->portdev->vdev, 0, occupancy);
935
936 if (!buf) {
937 ret = -ENOMEM;
938 goto error_out;
939 }
940
941 sgl.n = 0;
942 sgl.len = 0;
943 sgl.size = occupancy;
944 sgl.sg = buf->sg;
945 sg_init_table(sgl.sg, sgl.size);
946 ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
947 pipe_unlock(pipe);
948 if (likely(ret > 0))
949 ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
950
951 if (unlikely(ret <= 0))
952 free_buf(buf, true);
953 return ret;
954
955error_out:
956 pipe_unlock(pipe);
957 return ret;
958}
959
960static __poll_t port_fops_poll(struct file *filp, poll_table *wait)
961{
962 struct port *port;
963 __poll_t ret;
964
965 port = filp->private_data;
966 poll_wait(filp, &port->waitqueue, wait);
967
968 if (!port->guest_connected) {
969 /* Port got unplugged */
970 return EPOLLHUP;
971 }
972 ret = 0;
973 if (!will_read_block(port))
974 ret |= EPOLLIN | EPOLLRDNORM;
975 if (!will_write_block(port))
976 ret |= EPOLLOUT;
977 if (!port->host_connected)
978 ret |= EPOLLHUP;
979
980 return ret;
981}
982
983static void remove_port(struct kref *kref);
984
985static int port_fops_release(struct inode *inode, struct file *filp)
986{
987 struct port *port;
988
989 port = filp->private_data;
990
991 /* Notify host of port being closed */
992 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
993
994 spin_lock_irq(&port->inbuf_lock);
995 port->guest_connected = false;
996
997 discard_port_data(port);
998
999 spin_unlock_irq(&port->inbuf_lock);
1000
1001 spin_lock_irq(&port->outvq_lock);
1002 reclaim_consumed_buffers(port);
1003 spin_unlock_irq(&port->outvq_lock);
1004
1005 reclaim_dma_bufs();
1006 /*
1007 * Locks aren't necessary here as a port can't be opened after
1008 * unplug, and if a port isn't unplugged, a kref would already
1009 * exist for the port. Plus, taking ports_lock here would
1010 * create a dependency on other locks taken by functions
1011 * inside remove_port if we're the last holder of the port,
1012 * creating many problems.
1013 */
1014 kref_put(&port->kref, remove_port);
1015
1016 return 0;
1017}
1018
1019static int port_fops_open(struct inode *inode, struct file *filp)
1020{
1021 struct cdev *cdev = inode->i_cdev;
1022 struct port *port;
1023 int ret;
1024
1025 /* We get the port with a kref here */
1026 port = find_port_by_devt(cdev->dev);
1027 if (!port) {
1028 /* Port was unplugged before we could proceed */
1029 return -ENXIO;
1030 }
1031 filp->private_data = port;
1032
1033 /*
1034 * Don't allow opening of console port devices -- that's done
1035 * via /dev/hvc
1036 */
1037 if (is_console_port(port)) {
1038 ret = -ENXIO;
1039 goto out;
1040 }
1041
1042 /* Allow only one process to open a particular port at a time */
1043 spin_lock_irq(&port->inbuf_lock);
1044 if (port->guest_connected) {
1045 spin_unlock_irq(&port->inbuf_lock);
1046 ret = -EBUSY;
1047 goto out;
1048 }
1049
1050 port->guest_connected = true;
1051 spin_unlock_irq(&port->inbuf_lock);
1052
1053 spin_lock_irq(&port->outvq_lock);
1054 /*
1055 * There might be a chance that we missed reclaiming a few
1056 * buffers in the window of the port getting previously closed
1057 * and opening now.
1058 */
1059 reclaim_consumed_buffers(port);
1060 spin_unlock_irq(&port->outvq_lock);
1061
1062 nonseekable_open(inode, filp);
1063
1064 /* Notify host of port being opened */
1065 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
1066
1067 return 0;
1068out:
1069 kref_put(&port->kref, remove_port);
1070 return ret;
1071}
1072
1073static int port_fops_fasync(int fd, struct file *filp, int mode)
1074{
1075 struct port *port;
1076
1077 port = filp->private_data;
1078 return fasync_helper(fd, filp, mode, &port->async_queue);
1079}
1080
1081/*
1082 * The file operations that we support: programs in the guest can open
1083 * a console device, read from it, write to it, poll for data and
1084 * close it. The devices are at
1085 * /dev/vport<device number>p<port number>
1086 */
1087static const struct file_operations port_fops = {
1088 .owner = THIS_MODULE,
1089 .open = port_fops_open,
1090 .read = port_fops_read,
1091 .write = port_fops_write,
1092 .splice_write = port_fops_splice_write,
1093 .poll = port_fops_poll,
1094 .release = port_fops_release,
1095 .fasync = port_fops_fasync,
1096};
1097
1098/*
1099 * The put_chars() callback is pretty straightforward.
1100 *
1101 * We turn the characters into a scatter-gather list, add it to the
1102 * output queue and then kick the Host. Then we sit here waiting for
1103 * it to finish: inefficient in theory, but in practice
1104 * implementations will do it immediately.
1105 */
1106static ssize_t put_chars(u32 vtermno, const u8 *buf, size_t count)
1107{
1108 struct port *port;
1109 struct scatterlist sg[1];
1110 void *data;
1111 int ret;
1112
1113 port = find_port_by_vtermno(vtermno);
1114 if (!port)
1115 return -EPIPE;
1116
1117 data = kmemdup(buf, count, GFP_ATOMIC);
1118 if (!data)
1119 return -ENOMEM;
1120
1121 sg_init_one(sg, data, count);
1122 ret = __send_to_port(port, sg, 1, count, data, false);
1123 kfree(data);
1124 return ret;
1125}
1126
1127/*
1128 * get_chars() is the callback from the hvc_console infrastructure
1129 * when an interrupt is received.
1130 *
1131 * We call out to fill_readbuf that gets us the required data from the
1132 * buffers that are queued up.
1133 */
1134static ssize_t get_chars(u32 vtermno, u8 *buf, size_t count)
1135{
1136 struct port *port;
1137
1138 port = find_port_by_vtermno(vtermno);
1139 if (!port)
1140 return -EPIPE;
1141
1142 /* If we don't have an input queue yet, we can't get input. */
1143 BUG_ON(!port->in_vq);
1144
1145 return fill_readbuf(port, (__force u8 __user *)buf, count, false);
1146}
1147
1148static void resize_console(struct port *port)
1149{
1150 struct virtio_device *vdev;
1151
1152 /* The port could have been hot-unplugged */
1153 if (!port || !is_console_port(port))
1154 return;
1155
1156 vdev = port->portdev->vdev;
1157
1158 /* Don't test F_SIZE at all if we're rproc: not a valid feature! */
1159 if (!is_rproc_serial(vdev) &&
1160 virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
1161 hvc_resize(port->cons.hvc, port->cons.ws);
1162}
1163
1164/* We set the configuration at this point, since we now have a tty */
1165static int notifier_add_vio(struct hvc_struct *hp, int data)
1166{
1167 struct port *port;
1168
1169 port = find_port_by_vtermno(hp->vtermno);
1170 if (!port)
1171 return -EINVAL;
1172
1173 hp->irq_requested = 1;
1174 resize_console(port);
1175
1176 return 0;
1177}
1178
1179static void notifier_del_vio(struct hvc_struct *hp, int data)
1180{
1181 hp->irq_requested = 0;
1182}
1183
1184/* The operations for console ports. */
1185static const struct hv_ops hv_ops = {
1186 .get_chars = get_chars,
1187 .put_chars = put_chars,
1188 .notifier_add = notifier_add_vio,
1189 .notifier_del = notifier_del_vio,
1190 .notifier_hangup = notifier_del_vio,
1191};
1192
1193static int init_port_console(struct port *port)
1194{
1195 int ret;
1196
1197 /*
1198 * The Host's telling us this port is a console port. Hook it
1199 * up with an hvc console.
1200 *
1201 * To set up and manage our virtual console, we call
1202 * hvc_alloc().
1203 *
1204 * The first argument of hvc_alloc() is the virtual console
1205 * number. The second argument is the parameter for the
1206 * notification mechanism (like irq number). We currently
1207 * leave this as zero, virtqueues have implicit notifications.
1208 *
1209 * The third argument is a "struct hv_ops" containing the
1210 * put_chars() get_chars(), notifier_add() and notifier_del()
1211 * pointers. The final argument is the output buffer size: we
1212 * can do any size, so we put PAGE_SIZE here.
1213 */
1214 ret = ida_alloc_min(&vtermno_ida, 1, GFP_KERNEL);
1215 if (ret < 0)
1216 return ret;
1217
1218 port->cons.vtermno = ret;
1219 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
1220 if (IS_ERR(port->cons.hvc)) {
1221 ret = PTR_ERR(port->cons.hvc);
1222 dev_err(port->dev,
1223 "error %d allocating hvc for port\n", ret);
1224 port->cons.hvc = NULL;
1225 ida_free(&vtermno_ida, port->cons.vtermno);
1226 return ret;
1227 }
1228 spin_lock_irq(&pdrvdata_lock);
1229 list_add_tail(&port->cons.list, &pdrvdata.consoles);
1230 spin_unlock_irq(&pdrvdata_lock);
1231 port->guest_connected = true;
1232
1233 /* Notify host of port being opened */
1234 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1235
1236 return 0;
1237}
1238
1239static ssize_t show_port_name(struct device *dev,
1240 struct device_attribute *attr, char *buffer)
1241{
1242 struct port *port;
1243
1244 port = dev_get_drvdata(dev);
1245
1246 return sprintf(buffer, "%s\n", port->name);
1247}
1248
1249static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1250
1251static struct attribute *port_sysfs_entries[] = {
1252 &dev_attr_name.attr,
1253 NULL
1254};
1255
1256static const struct attribute_group port_attribute_group = {
1257 .name = NULL, /* put in device directory */
1258 .attrs = port_sysfs_entries,
1259};
1260
1261static int port_debugfs_show(struct seq_file *s, void *data)
1262{
1263 struct port *port = s->private;
1264
1265 seq_printf(s, "name: %s\n", port->name ? port->name : "");
1266 seq_printf(s, "guest_connected: %d\n", port->guest_connected);
1267 seq_printf(s, "host_connected: %d\n", port->host_connected);
1268 seq_printf(s, "outvq_full: %d\n", port->outvq_full);
1269 seq_printf(s, "bytes_sent: %lu\n", port->stats.bytes_sent);
1270 seq_printf(s, "bytes_received: %lu\n", port->stats.bytes_received);
1271 seq_printf(s, "bytes_discarded: %lu\n", port->stats.bytes_discarded);
1272 seq_printf(s, "is_console: %s\n",
1273 is_console_port(port) ? "yes" : "no");
1274 seq_printf(s, "console_vtermno: %u\n", port->cons.vtermno);
1275
1276 return 0;
1277}
1278
1279DEFINE_SHOW_ATTRIBUTE(port_debugfs);
1280
1281static void set_console_size(struct port *port, u16 rows, u16 cols)
1282{
1283 if (!port || !is_console_port(port))
1284 return;
1285
1286 port->cons.ws.ws_row = rows;
1287 port->cons.ws.ws_col = cols;
1288}
1289
1290static int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1291{
1292 struct port_buffer *buf;
1293 int nr_added_bufs;
1294 int ret;
1295
1296 nr_added_bufs = 0;
1297 do {
1298 buf = alloc_buf(vq->vdev, PAGE_SIZE, 0);
1299 if (!buf)
1300 return -ENOMEM;
1301
1302 spin_lock_irq(lock);
1303 ret = add_inbuf(vq, buf);
1304 if (ret < 0) {
1305 spin_unlock_irq(lock);
1306 free_buf(buf, true);
1307 return ret;
1308 }
1309 nr_added_bufs++;
1310 spin_unlock_irq(lock);
1311 } while (ret > 0);
1312
1313 return nr_added_bufs;
1314}
1315
1316static void send_sigio_to_port(struct port *port)
1317{
1318 if (port->async_queue && port->guest_connected)
1319 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1320}
1321
1322static int add_port(struct ports_device *portdev, u32 id)
1323{
1324 char debugfs_name[16];
1325 struct port *port;
1326 dev_t devt;
1327 int err;
1328
1329 port = kmalloc(sizeof(*port), GFP_KERNEL);
1330 if (!port) {
1331 err = -ENOMEM;
1332 goto fail;
1333 }
1334 kref_init(&port->kref);
1335
1336 port->portdev = portdev;
1337 port->id = id;
1338
1339 port->name = NULL;
1340 port->inbuf = NULL;
1341 port->cons.hvc = NULL;
1342 port->async_queue = NULL;
1343
1344 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1345 port->cons.vtermno = 0;
1346
1347 port->host_connected = port->guest_connected = false;
1348 port->stats = (struct port_stats) { 0 };
1349
1350 port->outvq_full = false;
1351
1352 port->in_vq = portdev->in_vqs[port->id];
1353 port->out_vq = portdev->out_vqs[port->id];
1354
1355 port->cdev = cdev_alloc();
1356 if (!port->cdev) {
1357 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1358 err = -ENOMEM;
1359 goto free_port;
1360 }
1361 port->cdev->ops = &port_fops;
1362
1363 devt = MKDEV(portdev->chr_major, id);
1364 err = cdev_add(port->cdev, devt, 1);
1365 if (err < 0) {
1366 dev_err(&port->portdev->vdev->dev,
1367 "Error %d adding cdev for port %u\n", err, id);
1368 goto free_cdev;
1369 }
1370 port->dev = device_create(&port_class, &port->portdev->vdev->dev,
1371 devt, port, "vport%up%u",
1372 port->portdev->vdev->index, id);
1373 if (IS_ERR(port->dev)) {
1374 err = PTR_ERR(port->dev);
1375 dev_err(&port->portdev->vdev->dev,
1376 "Error %d creating device for port %u\n",
1377 err, id);
1378 goto free_cdev;
1379 }
1380
1381 spin_lock_init(&port->inbuf_lock);
1382 spin_lock_init(&port->outvq_lock);
1383 init_waitqueue_head(&port->waitqueue);
1384
1385 /* We can safely ignore ENOSPC because it means
1386 * the queue already has buffers. Buffers are removed
1387 * only by virtcons_remove(), not by unplug_port()
1388 */
1389 err = fill_queue(port->in_vq, &port->inbuf_lock);
1390 if (err < 0 && err != -ENOSPC) {
1391 dev_err(port->dev, "Error allocating inbufs\n");
1392 goto free_device;
1393 }
1394
1395 if (is_rproc_serial(port->portdev->vdev))
1396 /*
1397 * For rproc_serial assume remote processor is connected.
1398 * rproc_serial does not want the console port, only
1399 * the generic port implementation.
1400 */
1401 port->host_connected = true;
1402 else if (!use_multiport(port->portdev)) {
1403 /*
1404 * If we're not using multiport support,
1405 * this has to be a console port.
1406 */
1407 err = init_port_console(port);
1408 if (err)
1409 goto free_inbufs;
1410 }
1411
1412 spin_lock_irq(&portdev->ports_lock);
1413 list_add_tail(&port->list, &port->portdev->ports);
1414 spin_unlock_irq(&portdev->ports_lock);
1415
1416 /*
1417 * Tell the Host we're set so that it can send us various
1418 * configuration parameters for this port (eg, port name,
1419 * caching, whether this is a console port, etc.)
1420 */
1421 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1422
1423 /*
1424 * Finally, create the debugfs file that we can use to
1425 * inspect a port's state at any time
1426 */
1427 snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u",
1428 port->portdev->vdev->index, id);
1429 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1430 pdrvdata.debugfs_dir,
1431 port, &port_debugfs_fops);
1432 return 0;
1433
1434free_inbufs:
1435free_device:
1436 device_destroy(&port_class, port->dev->devt);
1437free_cdev:
1438 cdev_del(port->cdev);
1439free_port:
1440 kfree(port);
1441fail:
1442 /* The host might want to notify management sw about port add failure */
1443 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1444 return err;
1445}
1446
1447/* No users remain, remove all port-specific data. */
1448static void remove_port(struct kref *kref)
1449{
1450 struct port *port;
1451
1452 port = container_of(kref, struct port, kref);
1453
1454 kfree(port);
1455}
1456
1457static void remove_port_data(struct port *port)
1458{
1459 spin_lock_irq(&port->inbuf_lock);
1460 /* Remove unused data this port might have received. */
1461 discard_port_data(port);
1462 spin_unlock_irq(&port->inbuf_lock);
1463
1464 spin_lock_irq(&port->outvq_lock);
1465 reclaim_consumed_buffers(port);
1466 spin_unlock_irq(&port->outvq_lock);
1467}
1468
1469/*
1470 * Port got unplugged. Remove port from portdev's list and drop the
1471 * kref reference. If no userspace has this port opened, it will
1472 * result in immediate removal the port.
1473 */
1474static void unplug_port(struct port *port)
1475{
1476 spin_lock_irq(&port->portdev->ports_lock);
1477 list_del(&port->list);
1478 spin_unlock_irq(&port->portdev->ports_lock);
1479
1480 spin_lock_irq(&port->inbuf_lock);
1481 if (port->guest_connected) {
1482 /* Let the app know the port is going down. */
1483 send_sigio_to_port(port);
1484
1485 /* Do this after sigio is actually sent */
1486 port->guest_connected = false;
1487 port->host_connected = false;
1488
1489 wake_up_interruptible(&port->waitqueue);
1490 }
1491 spin_unlock_irq(&port->inbuf_lock);
1492
1493 if (is_console_port(port)) {
1494 spin_lock_irq(&pdrvdata_lock);
1495 list_del(&port->cons.list);
1496 spin_unlock_irq(&pdrvdata_lock);
1497 hvc_remove(port->cons.hvc);
1498 ida_free(&vtermno_ida, port->cons.vtermno);
1499 }
1500
1501 remove_port_data(port);
1502
1503 /*
1504 * We should just assume the device itself has gone off --
1505 * else a close on an open port later will try to send out a
1506 * control message.
1507 */
1508 port->portdev = NULL;
1509
1510 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1511 device_destroy(&port_class, port->dev->devt);
1512 cdev_del(port->cdev);
1513
1514 debugfs_remove(port->debugfs_file);
1515 kfree(port->name);
1516
1517 /*
1518 * Locks around here are not necessary - a port can't be
1519 * opened after we removed the port struct from ports_list
1520 * above.
1521 */
1522 kref_put(&port->kref, remove_port);
1523}
1524
1525/* Any private messages that the Host and Guest want to share */
1526static void handle_control_message(struct virtio_device *vdev,
1527 struct ports_device *portdev,
1528 struct port_buffer *buf)
1529{
1530 struct virtio_console_control *cpkt;
1531 struct port *port;
1532 size_t name_size;
1533 int err;
1534
1535 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1536
1537 port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id));
1538 if (!port &&
1539 cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
1540 /* No valid header at start of buffer. Drop it. */
1541 dev_dbg(&portdev->vdev->dev,
1542 "Invalid index %u in control packet\n", cpkt->id);
1543 return;
1544 }
1545
1546 switch (virtio16_to_cpu(vdev, cpkt->event)) {
1547 case VIRTIO_CONSOLE_PORT_ADD:
1548 if (port) {
1549 dev_dbg(&portdev->vdev->dev,
1550 "Port %u already added\n", port->id);
1551 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1552 break;
1553 }
1554 if (virtio32_to_cpu(vdev, cpkt->id) >=
1555 portdev->max_nr_ports) {
1556 dev_warn(&portdev->vdev->dev,
1557 "Request for adding port with "
1558 "out-of-bound id %u, max. supported id: %u\n",
1559 cpkt->id, portdev->max_nr_ports - 1);
1560 break;
1561 }
1562 add_port(portdev, virtio32_to_cpu(vdev, cpkt->id));
1563 break;
1564 case VIRTIO_CONSOLE_PORT_REMOVE:
1565 unplug_port(port);
1566 break;
1567 case VIRTIO_CONSOLE_CONSOLE_PORT:
1568 if (!cpkt->value)
1569 break;
1570 if (is_console_port(port))
1571 break;
1572
1573 init_port_console(port);
1574 complete(&early_console_added);
1575 /*
1576 * Could remove the port here in case init fails - but
1577 * have to notify the host first.
1578 */
1579 break;
1580 case VIRTIO_CONSOLE_RESIZE: {
1581 struct {
1582 __u16 rows;
1583 __u16 cols;
1584 } size;
1585
1586 if (!is_console_port(port))
1587 break;
1588
1589 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1590 sizeof(size));
1591 set_console_size(port, size.rows, size.cols);
1592
1593 port->cons.hvc->irq_requested = 1;
1594 resize_console(port);
1595 break;
1596 }
1597 case VIRTIO_CONSOLE_PORT_OPEN:
1598 port->host_connected = virtio16_to_cpu(vdev, cpkt->value);
1599 wake_up_interruptible(&port->waitqueue);
1600 /*
1601 * If the host port got closed and the host had any
1602 * unconsumed buffers, we'll be able to reclaim them
1603 * now.
1604 */
1605 spin_lock_irq(&port->outvq_lock);
1606 reclaim_consumed_buffers(port);
1607 spin_unlock_irq(&port->outvq_lock);
1608
1609 /*
1610 * If the guest is connected, it'll be interested in
1611 * knowing the host connection state changed.
1612 */
1613 spin_lock_irq(&port->inbuf_lock);
1614 send_sigio_to_port(port);
1615 spin_unlock_irq(&port->inbuf_lock);
1616 break;
1617 case VIRTIO_CONSOLE_PORT_NAME:
1618 /*
1619 * If we woke up after hibernation, we can get this
1620 * again. Skip it in that case.
1621 */
1622 if (port->name)
1623 break;
1624
1625 /*
1626 * Skip the size of the header and the cpkt to get the size
1627 * of the name that was sent
1628 */
1629 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1630
1631 port->name = kmalloc(name_size, GFP_KERNEL);
1632 if (!port->name) {
1633 dev_err(port->dev,
1634 "Not enough space to store port name\n");
1635 break;
1636 }
1637 strscpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1638 name_size);
1639
1640 /*
1641 * Since we only have one sysfs attribute, 'name',
1642 * create it only if we have a name for the port.
1643 */
1644 err = sysfs_create_group(&port->dev->kobj,
1645 &port_attribute_group);
1646 if (err) {
1647 dev_err(port->dev,
1648 "Error %d creating sysfs device attributes\n",
1649 err);
1650 } else {
1651 /*
1652 * Generate a udev event so that appropriate
1653 * symlinks can be created based on udev
1654 * rules.
1655 */
1656 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1657 }
1658 break;
1659 }
1660}
1661
1662static void control_work_handler(struct work_struct *work)
1663{
1664 struct ports_device *portdev;
1665 struct virtqueue *vq;
1666 struct port_buffer *buf;
1667 unsigned int len;
1668
1669 portdev = container_of(work, struct ports_device, control_work);
1670 vq = portdev->c_ivq;
1671
1672 spin_lock(&portdev->c_ivq_lock);
1673 while ((buf = virtqueue_get_buf(vq, &len))) {
1674 spin_unlock(&portdev->c_ivq_lock);
1675
1676 buf->len = min_t(size_t, len, buf->size);
1677 buf->offset = 0;
1678
1679 handle_control_message(vq->vdev, portdev, buf);
1680
1681 spin_lock(&portdev->c_ivq_lock);
1682 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1683 dev_warn(&portdev->vdev->dev,
1684 "Error adding buffer to queue\n");
1685 free_buf(buf, false);
1686 }
1687 }
1688 spin_unlock(&portdev->c_ivq_lock);
1689}
1690
1691static void flush_bufs(struct virtqueue *vq, bool can_sleep)
1692{
1693 struct port_buffer *buf;
1694 unsigned int len;
1695
1696 while ((buf = virtqueue_get_buf(vq, &len)))
1697 free_buf(buf, can_sleep);
1698}
1699
1700static void out_intr(struct virtqueue *vq)
1701{
1702 struct port *port;
1703
1704 port = find_port_by_vq(vq->vdev->priv, vq);
1705 if (!port) {
1706 flush_bufs(vq, false);
1707 return;
1708 }
1709
1710 wake_up_interruptible(&port->waitqueue);
1711}
1712
1713static void in_intr(struct virtqueue *vq)
1714{
1715 struct port *port;
1716 unsigned long flags;
1717
1718 port = find_port_by_vq(vq->vdev->priv, vq);
1719 if (!port) {
1720 flush_bufs(vq, false);
1721 return;
1722 }
1723
1724 spin_lock_irqsave(&port->inbuf_lock, flags);
1725 port->inbuf = get_inbuf(port);
1726
1727 /*
1728 * Normally the port should not accept data when the port is
1729 * closed. For generic serial ports, the host won't (shouldn't)
1730 * send data till the guest is connected. But this condition
1731 * can be reached when a console port is not yet connected (no
1732 * tty is spawned) and the other side sends out data over the
1733 * vring, or when a remote devices start sending data before
1734 * the ports are opened.
1735 *
1736 * A generic serial port will discard data if not connected,
1737 * while console ports and rproc-serial ports accepts data at
1738 * any time. rproc-serial is initiated with guest_connected to
1739 * false because port_fops_open expects this. Console ports are
1740 * hooked up with an HVC console and is initialized with
1741 * guest_connected to true.
1742 */
1743
1744 if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
1745 discard_port_data(port);
1746
1747 /* Send a SIGIO indicating new data in case the process asked for it */
1748 send_sigio_to_port(port);
1749
1750 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1751
1752 wake_up_interruptible(&port->waitqueue);
1753
1754 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1755 hvc_kick();
1756}
1757
1758static void control_intr(struct virtqueue *vq)
1759{
1760 struct ports_device *portdev;
1761
1762 portdev = vq->vdev->priv;
1763 schedule_work(&portdev->control_work);
1764}
1765
1766static void config_intr(struct virtio_device *vdev)
1767{
1768 struct ports_device *portdev;
1769
1770 portdev = vdev->priv;
1771
1772 if (!use_multiport(portdev))
1773 schedule_work(&portdev->config_work);
1774}
1775
1776static void config_work_handler(struct work_struct *work)
1777{
1778 struct ports_device *portdev;
1779
1780 portdev = container_of(work, struct ports_device, config_work);
1781 if (!use_multiport(portdev)) {
1782 struct virtio_device *vdev;
1783 struct port *port;
1784 u16 rows, cols;
1785
1786 vdev = portdev->vdev;
1787 virtio_cread(vdev, struct virtio_console_config, cols, &cols);
1788 virtio_cread(vdev, struct virtio_console_config, rows, &rows);
1789
1790 port = find_port_by_id(portdev, 0);
1791 set_console_size(port, rows, cols);
1792
1793 /*
1794 * We'll use this way of resizing only for legacy
1795 * support. For newer userspace
1796 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1797 * to indicate console size changes so that it can be
1798 * done per-port.
1799 */
1800 resize_console(port);
1801 }
1802}
1803
1804static int init_vqs(struct ports_device *portdev)
1805{
1806 struct virtqueue_info *vqs_info;
1807 struct virtqueue **vqs;
1808 u32 i, j, nr_ports, nr_queues;
1809 int err;
1810
1811 nr_ports = portdev->max_nr_ports;
1812 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1813
1814 vqs = kmalloc_array(nr_queues, sizeof(struct virtqueue *), GFP_KERNEL);
1815 vqs_info = kcalloc(nr_queues, sizeof(*vqs_info), GFP_KERNEL);
1816 portdev->in_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1817 GFP_KERNEL);
1818 portdev->out_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1819 GFP_KERNEL);
1820 if (!vqs || !vqs_info || !portdev->in_vqs || !portdev->out_vqs) {
1821 err = -ENOMEM;
1822 goto free;
1823 }
1824
1825 /*
1826 * For backward compat (newer host but older guest), the host
1827 * spawns a console port first and also inits the vqs for port
1828 * 0 before others.
1829 */
1830 j = 0;
1831 vqs_info[j].callback = in_intr;
1832 vqs_info[j + 1].callback = out_intr;
1833 vqs_info[j].name = "input";
1834 vqs_info[j + 1].name = "output";
1835 j += 2;
1836
1837 if (use_multiport(portdev)) {
1838 vqs_info[j].callback = control_intr;
1839 vqs_info[j].name = "control-i";
1840 vqs_info[j + 1].name = "control-o";
1841
1842 for (i = 1; i < nr_ports; i++) {
1843 j += 2;
1844 vqs_info[j].callback = in_intr;
1845 vqs_info[j + 1].callback = out_intr;
1846 vqs_info[j].name = "input";
1847 vqs_info[j + 1].name = "output";
1848 }
1849 }
1850 /* Find the queues. */
1851 err = virtio_find_vqs(portdev->vdev, nr_queues, vqs, vqs_info, NULL);
1852 if (err)
1853 goto free;
1854
1855 j = 0;
1856 portdev->in_vqs[0] = vqs[0];
1857 portdev->out_vqs[0] = vqs[1];
1858 j += 2;
1859 if (use_multiport(portdev)) {
1860 portdev->c_ivq = vqs[j];
1861 portdev->c_ovq = vqs[j + 1];
1862
1863 for (i = 1; i < nr_ports; i++) {
1864 j += 2;
1865 portdev->in_vqs[i] = vqs[j];
1866 portdev->out_vqs[i] = vqs[j + 1];
1867 }
1868 }
1869 kfree(vqs_info);
1870 kfree(vqs);
1871
1872 return 0;
1873
1874free:
1875 kfree(portdev->out_vqs);
1876 kfree(portdev->in_vqs);
1877 kfree(vqs_info);
1878 kfree(vqs);
1879
1880 return err;
1881}
1882
1883static const struct file_operations portdev_fops = {
1884 .owner = THIS_MODULE,
1885};
1886
1887static void remove_vqs(struct ports_device *portdev)
1888{
1889 struct virtqueue *vq;
1890
1891 virtio_device_for_each_vq(portdev->vdev, vq) {
1892 struct port_buffer *buf;
1893
1894 flush_bufs(vq, true);
1895 while ((buf = virtqueue_detach_unused_buf(vq)))
1896 free_buf(buf, true);
1897 cond_resched();
1898 }
1899 portdev->vdev->config->del_vqs(portdev->vdev);
1900 kfree(portdev->in_vqs);
1901 kfree(portdev->out_vqs);
1902}
1903
1904static void virtcons_remove(struct virtio_device *vdev)
1905{
1906 struct ports_device *portdev;
1907 struct port *port, *port2;
1908
1909 portdev = vdev->priv;
1910
1911 spin_lock_irq(&pdrvdata_lock);
1912 list_del(&portdev->list);
1913 spin_unlock_irq(&pdrvdata_lock);
1914
1915 /* Device is going away, exit any polling for buffers */
1916 virtio_break_device(vdev);
1917 if (use_multiport(portdev))
1918 flush_work(&portdev->control_work);
1919 else
1920 flush_work(&portdev->config_work);
1921
1922 /* Disable interrupts for vqs */
1923 virtio_reset_device(vdev);
1924 /* Finish up work that's lined up */
1925 if (use_multiport(portdev))
1926 cancel_work_sync(&portdev->control_work);
1927 else
1928 cancel_work_sync(&portdev->config_work);
1929
1930 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1931 unplug_port(port);
1932
1933 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1934
1935 /*
1936 * When yanking out a device, we immediately lose the
1937 * (device-side) queues. So there's no point in keeping the
1938 * guest side around till we drop our final reference. This
1939 * also means that any ports which are in an open state will
1940 * have to just stop using the port, as the vqs are going
1941 * away.
1942 */
1943 remove_vqs(portdev);
1944 kfree(portdev);
1945}
1946
1947/*
1948 * Once we're further in boot, we get probed like any other virtio
1949 * device.
1950 *
1951 * If the host also supports multiple console ports, we check the
1952 * config space to see how many ports the host has spawned. We
1953 * initialize each port found.
1954 */
1955static int virtcons_probe(struct virtio_device *vdev)
1956{
1957 struct ports_device *portdev;
1958 int err;
1959 bool multiport;
1960
1961 /* We only need a config space if features are offered */
1962 if (!vdev->config->get &&
1963 (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
1964 || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
1965 dev_err(&vdev->dev, "%s failure: config access disabled\n",
1966 __func__);
1967 return -EINVAL;
1968 }
1969
1970 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1971 if (!portdev) {
1972 err = -ENOMEM;
1973 goto fail;
1974 }
1975
1976 /* Attach this portdev to this virtio_device, and vice-versa. */
1977 portdev->vdev = vdev;
1978 vdev->priv = portdev;
1979
1980 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1981 &portdev_fops);
1982 if (portdev->chr_major < 0) {
1983 dev_err(&vdev->dev,
1984 "Error %d registering chrdev for device %u\n",
1985 portdev->chr_major, vdev->index);
1986 err = portdev->chr_major;
1987 goto free;
1988 }
1989
1990 multiport = false;
1991 portdev->max_nr_ports = 1;
1992
1993 /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
1994 if (!is_rproc_serial(vdev) &&
1995 virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
1996 struct virtio_console_config, max_nr_ports,
1997 &portdev->max_nr_ports) == 0) {
1998 if (portdev->max_nr_ports == 0 ||
1999 portdev->max_nr_ports > VIRTCONS_MAX_PORTS) {
2000 dev_err(&vdev->dev,
2001 "Invalidate max_nr_ports %d",
2002 portdev->max_nr_ports);
2003 err = -EINVAL;
2004 goto free;
2005 }
2006 multiport = true;
2007 }
2008
2009 spin_lock_init(&portdev->ports_lock);
2010 INIT_LIST_HEAD(&portdev->ports);
2011 INIT_LIST_HEAD(&portdev->list);
2012
2013 INIT_WORK(&portdev->config_work, &config_work_handler);
2014 INIT_WORK(&portdev->control_work, &control_work_handler);
2015
2016 if (multiport) {
2017 spin_lock_init(&portdev->c_ivq_lock);
2018 spin_lock_init(&portdev->c_ovq_lock);
2019 }
2020
2021 err = init_vqs(portdev);
2022 if (err < 0) {
2023 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2024 goto free_chrdev;
2025 }
2026
2027 virtio_device_ready(portdev->vdev);
2028
2029 if (multiport) {
2030 err = fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2031 if (err < 0) {
2032 dev_err(&vdev->dev,
2033 "Error allocating buffers for control queue\n");
2034 /*
2035 * The host might want to notify mgmt sw about device
2036 * add failure.
2037 */
2038 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2039 VIRTIO_CONSOLE_DEVICE_READY, 0);
2040 /* Device was functional: we need full cleanup. */
2041 virtcons_remove(vdev);
2042 return err;
2043 }
2044 } else {
2045 /*
2046 * For backward compatibility: Create a console port
2047 * if we're running on older host.
2048 */
2049 add_port(portdev, 0);
2050 }
2051
2052 spin_lock_irq(&pdrvdata_lock);
2053 list_add_tail(&portdev->list, &pdrvdata.portdevs);
2054 spin_unlock_irq(&pdrvdata_lock);
2055
2056 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2057 VIRTIO_CONSOLE_DEVICE_READY, 1);
2058
2059 return 0;
2060
2061free_chrdev:
2062 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2063free:
2064 kfree(portdev);
2065fail:
2066 return err;
2067}
2068
2069static const struct virtio_device_id id_table[] = {
2070 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2071 { 0 },
2072};
2073MODULE_DEVICE_TABLE(virtio, id_table);
2074
2075static const unsigned int features[] = {
2076 VIRTIO_CONSOLE_F_SIZE,
2077 VIRTIO_CONSOLE_F_MULTIPORT,
2078};
2079
2080static const struct virtio_device_id rproc_serial_id_table[] = {
2081#if IS_ENABLED(CONFIG_REMOTEPROC)
2082 { VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2083#endif
2084 { 0 },
2085};
2086MODULE_DEVICE_TABLE(virtio, rproc_serial_id_table);
2087
2088static const unsigned int rproc_serial_features[] = {
2089};
2090
2091#ifdef CONFIG_PM_SLEEP
2092static int virtcons_freeze(struct virtio_device *vdev)
2093{
2094 struct ports_device *portdev;
2095 struct port *port;
2096
2097 portdev = vdev->priv;
2098
2099 virtio_reset_device(vdev);
2100
2101 if (use_multiport(portdev))
2102 virtqueue_disable_cb(portdev->c_ivq);
2103 cancel_work_sync(&portdev->control_work);
2104 cancel_work_sync(&portdev->config_work);
2105 /*
2106 * Once more: if control_work_handler() was running, it would
2107 * enable the cb as the last step.
2108 */
2109 if (use_multiport(portdev))
2110 virtqueue_disable_cb(portdev->c_ivq);
2111
2112 list_for_each_entry(port, &portdev->ports, list) {
2113 virtqueue_disable_cb(port->in_vq);
2114 virtqueue_disable_cb(port->out_vq);
2115 /*
2116 * We'll ask the host later if the new invocation has
2117 * the port opened or closed.
2118 */
2119 port->host_connected = false;
2120 remove_port_data(port);
2121 }
2122 remove_vqs(portdev);
2123
2124 return 0;
2125}
2126
2127static int virtcons_restore(struct virtio_device *vdev)
2128{
2129 struct ports_device *portdev;
2130 struct port *port;
2131 int ret;
2132
2133 portdev = vdev->priv;
2134
2135 ret = init_vqs(portdev);
2136 if (ret)
2137 return ret;
2138
2139 virtio_device_ready(portdev->vdev);
2140
2141 if (use_multiport(portdev))
2142 fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2143
2144 list_for_each_entry(port, &portdev->ports, list) {
2145 port->in_vq = portdev->in_vqs[port->id];
2146 port->out_vq = portdev->out_vqs[port->id];
2147
2148 fill_queue(port->in_vq, &port->inbuf_lock);
2149
2150 /* Get port open/close status on the host */
2151 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
2152
2153 /*
2154 * If a port was open at the time of suspending, we
2155 * have to let the host know that it's still open.
2156 */
2157 if (port->guest_connected)
2158 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
2159 }
2160 return 0;
2161}
2162#endif
2163
2164static struct virtio_driver virtio_console = {
2165 .feature_table = features,
2166 .feature_table_size = ARRAY_SIZE(features),
2167 .driver.name = KBUILD_MODNAME,
2168 .id_table = id_table,
2169 .probe = virtcons_probe,
2170 .remove = virtcons_remove,
2171 .config_changed = config_intr,
2172#ifdef CONFIG_PM_SLEEP
2173 .freeze = virtcons_freeze,
2174 .restore = virtcons_restore,
2175#endif
2176};
2177
2178static struct virtio_driver virtio_rproc_serial = {
2179 .feature_table = rproc_serial_features,
2180 .feature_table_size = ARRAY_SIZE(rproc_serial_features),
2181 .driver.name = "virtio_rproc_serial",
2182 .id_table = rproc_serial_id_table,
2183 .probe = virtcons_probe,
2184 .remove = virtcons_remove,
2185};
2186
2187static int __init virtio_console_init(void)
2188{
2189 int err;
2190
2191 err = class_register(&port_class);
2192 if (err)
2193 return err;
2194
2195 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
2196 INIT_LIST_HEAD(&pdrvdata.consoles);
2197 INIT_LIST_HEAD(&pdrvdata.portdevs);
2198
2199 err = register_virtio_driver(&virtio_console);
2200 if (err < 0) {
2201 pr_err("Error %d registering virtio driver\n", err);
2202 goto free;
2203 }
2204 err = register_virtio_driver(&virtio_rproc_serial);
2205 if (err < 0) {
2206 pr_err("Error %d registering virtio rproc serial driver\n",
2207 err);
2208 goto unregister;
2209 }
2210 return 0;
2211unregister:
2212 unregister_virtio_driver(&virtio_console);
2213free:
2214 debugfs_remove_recursive(pdrvdata.debugfs_dir);
2215 class_unregister(&port_class);
2216 return err;
2217}
2218
2219static void __exit virtio_console_fini(void)
2220{
2221 reclaim_dma_bufs();
2222
2223 unregister_virtio_driver(&virtio_console);
2224 unregister_virtio_driver(&virtio_rproc_serial);
2225
2226 class_unregister(&port_class);
2227 debugfs_remove_recursive(pdrvdata.debugfs_dir);
2228}
2229module_init(virtio_console_init);
2230module_exit(virtio_console_fini);
2231
2232MODULE_DESCRIPTION("Virtio console driver");
2233MODULE_LICENSE("GPL");