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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/init.h>
17#include <linux/list.h>
18#include <linux/poll.h>
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include <linux/spinlock.h>
22#include <linux/virtio.h>
23#include <linux/virtio_console.h>
24#include <linux/wait.h>
25#include <linux/workqueue.h>
26#include <linux/module.h>
27#include <linux/dma-mapping.h>
28#include "../tty/hvc/hvc_console.h"
29
30#define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
31
32/*
33 * This is a global struct for storing common data for all the devices
34 * this driver handles.
35 *
36 * Mainly, it has a linked list for all the consoles in one place so
37 * that callbacks from hvc for get_chars(), put_chars() work properly
38 * across multiple devices and multiple ports per device.
39 */
40struct ports_driver_data {
41 /* Used for registering chardevs */
42 struct class *class;
43
44 /* Used for exporting per-port information to debugfs */
45 struct dentry *debugfs_dir;
46
47 /* List of all the devices we're handling */
48 struct list_head portdevs;
49
50 /*
51 * This is used to keep track of the number of hvc consoles
52 * spawned by this driver. This number is given as the first
53 * argument to hvc_alloc(). To correctly map an initial
54 * console spawned via hvc_instantiate to the console being
55 * hooked up via hvc_alloc, we need to pass the same vtermno.
56 *
57 * We also just assume the first console being initialised was
58 * the first one that got used as the initial console.
59 */
60 unsigned int next_vtermno;
61
62 /* All the console devices handled by this driver */
63 struct list_head consoles;
64};
65static struct ports_driver_data pdrvdata = { .next_vtermno = 1};
66
67static DEFINE_SPINLOCK(pdrvdata_lock);
68static DECLARE_COMPLETION(early_console_added);
69
70/* This struct holds information that's relevant only for console ports */
71struct console {
72 /* We'll place all consoles in a list in the pdrvdata struct */
73 struct list_head list;
74
75 /* The hvc device associated with this console port */
76 struct hvc_struct *hvc;
77
78 /* The size of the console */
79 struct winsize ws;
80
81 /*
82 * This number identifies the number that we used to register
83 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
84 * number passed on by the hvc callbacks to us to
85 * differentiate between the other console ports handled by
86 * this driver
87 */
88 u32 vtermno;
89};
90
91struct port_buffer {
92 char *buf;
93
94 /* size of the buffer in *buf above */
95 size_t size;
96
97 /* used length of the buffer */
98 size_t len;
99 /* offset in the buf from which to consume data */
100 size_t offset;
101
102 /* DMA address of buffer */
103 dma_addr_t dma;
104
105 /* Device we got DMA memory from */
106 struct device *dev;
107
108 /* List of pending dma buffers to free */
109 struct list_head list;
110
111 /* If sgpages == 0 then buf is used */
112 unsigned int sgpages;
113
114 /* sg is used if spages > 0. sg must be the last in is struct */
115 struct scatterlist sg[0];
116};
117
118/*
119 * This is a per-device struct that stores data common to all the
120 * ports for that device (vdev->priv).
121 */
122struct ports_device {
123 /* Next portdev in the list, head is in the pdrvdata struct */
124 struct list_head list;
125
126 /*
127 * Workqueue handlers where we process deferred work after
128 * notification
129 */
130 struct work_struct control_work;
131 struct work_struct config_work;
132
133 struct list_head ports;
134
135 /* To protect the list of ports */
136 spinlock_t ports_lock;
137
138 /* To protect the vq operations for the control channel */
139 spinlock_t c_ivq_lock;
140 spinlock_t c_ovq_lock;
141
142 /* max. number of ports this device can hold */
143 u32 max_nr_ports;
144
145 /* The virtio device we're associated with */
146 struct virtio_device *vdev;
147
148 /*
149 * A couple of virtqueues for the control channel: one for
150 * guest->host transfers, one for host->guest transfers
151 */
152 struct virtqueue *c_ivq, *c_ovq;
153
154 /*
155 * A control packet buffer for guest->host requests, protected
156 * by c_ovq_lock.
157 */
158 struct virtio_console_control cpkt;
159
160 /* Array of per-port IO virtqueues */
161 struct virtqueue **in_vqs, **out_vqs;
162
163 /* Major number for this device. Ports will be created as minors. */
164 int chr_major;
165};
166
167struct port_stats {
168 unsigned long bytes_sent, bytes_received, bytes_discarded;
169};
170
171/* This struct holds the per-port data */
172struct port {
173 /* Next port in the list, head is in the ports_device */
174 struct list_head list;
175
176 /* Pointer to the parent virtio_console device */
177 struct ports_device *portdev;
178
179 /* The current buffer from which data has to be fed to readers */
180 struct port_buffer *inbuf;
181
182 /*
183 * To protect the operations on the in_vq associated with this
184 * port. Has to be a spinlock because it can be called from
185 * interrupt context (get_char()).
186 */
187 spinlock_t inbuf_lock;
188
189 /* Protect the operations on the out_vq. */
190 spinlock_t outvq_lock;
191
192 /* The IO vqs for this port */
193 struct virtqueue *in_vq, *out_vq;
194
195 /* File in the debugfs directory that exposes this port's information */
196 struct dentry *debugfs_file;
197
198 /*
199 * Keep count of the bytes sent, received and discarded for
200 * this port for accounting and debugging purposes. These
201 * counts are not reset across port open / close events.
202 */
203 struct port_stats stats;
204
205 /*
206 * The entries in this struct will be valid if this port is
207 * hooked up to an hvc console
208 */
209 struct console cons;
210
211 /* Each port associates with a separate char device */
212 struct cdev *cdev;
213 struct device *dev;
214
215 /* Reference-counting to handle port hot-unplugs and file operations */
216 struct kref kref;
217
218 /* A waitqueue for poll() or blocking read operations */
219 wait_queue_head_t waitqueue;
220
221 /* The 'name' of the port that we expose via sysfs properties */
222 char *name;
223
224 /* We can notify apps of host connect / disconnect events via SIGIO */
225 struct fasync_struct *async_queue;
226
227 /* The 'id' to identify the port with the Host */
228 u32 id;
229
230 bool outvq_full;
231
232 /* Is the host device open */
233 bool host_connected;
234
235 /* We should allow only one process to open a port */
236 bool guest_connected;
237};
238
239/* This is the very early arch-specified put chars function. */
240static int (*early_put_chars)(u32, const char *, int);
241
242static struct port *find_port_by_vtermno(u32 vtermno)
243{
244 struct port *port;
245 struct console *cons;
246 unsigned long flags;
247
248 spin_lock_irqsave(&pdrvdata_lock, flags);
249 list_for_each_entry(cons, &pdrvdata.consoles, list) {
250 if (cons->vtermno == vtermno) {
251 port = container_of(cons, struct port, cons);
252 goto out;
253 }
254 }
255 port = NULL;
256out:
257 spin_unlock_irqrestore(&pdrvdata_lock, flags);
258 return port;
259}
260
261static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
262 dev_t dev)
263{
264 struct port *port;
265 unsigned long flags;
266
267 spin_lock_irqsave(&portdev->ports_lock, flags);
268 list_for_each_entry(port, &portdev->ports, list) {
269 if (port->cdev->dev == dev) {
270 kref_get(&port->kref);
271 goto out;
272 }
273 }
274 port = NULL;
275out:
276 spin_unlock_irqrestore(&portdev->ports_lock, flags);
277
278 return port;
279}
280
281static struct port *find_port_by_devt(dev_t dev)
282{
283 struct ports_device *portdev;
284 struct port *port;
285 unsigned long flags;
286
287 spin_lock_irqsave(&pdrvdata_lock, flags);
288 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
289 port = find_port_by_devt_in_portdev(portdev, dev);
290 if (port)
291 goto out;
292 }
293 port = NULL;
294out:
295 spin_unlock_irqrestore(&pdrvdata_lock, flags);
296 return port;
297}
298
299static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
300{
301 struct port *port;
302 unsigned long flags;
303
304 spin_lock_irqsave(&portdev->ports_lock, flags);
305 list_for_each_entry(port, &portdev->ports, list)
306 if (port->id == id)
307 goto out;
308 port = NULL;
309out:
310 spin_unlock_irqrestore(&portdev->ports_lock, flags);
311
312 return port;
313}
314
315static struct port *find_port_by_vq(struct ports_device *portdev,
316 struct virtqueue *vq)
317{
318 struct port *port;
319 unsigned long flags;
320
321 spin_lock_irqsave(&portdev->ports_lock, flags);
322 list_for_each_entry(port, &portdev->ports, list)
323 if (port->in_vq == vq || port->out_vq == vq)
324 goto out;
325 port = NULL;
326out:
327 spin_unlock_irqrestore(&portdev->ports_lock, flags);
328 return port;
329}
330
331static bool is_console_port(struct port *port)
332{
333 if (port->cons.hvc)
334 return true;
335 return false;
336}
337
338static bool is_rproc_serial(const struct virtio_device *vdev)
339{
340 return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
341}
342
343static inline bool use_multiport(struct ports_device *portdev)
344{
345 /*
346 * This condition can be true when put_chars is called from
347 * early_init
348 */
349 if (!portdev->vdev)
350 return false;
351 return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
352}
353
354static DEFINE_SPINLOCK(dma_bufs_lock);
355static LIST_HEAD(pending_free_dma_bufs);
356
357static void free_buf(struct port_buffer *buf, bool can_sleep)
358{
359 unsigned int i;
360
361 for (i = 0; i < buf->sgpages; i++) {
362 struct page *page = sg_page(&buf->sg[i]);
363 if (!page)
364 break;
365 put_page(page);
366 }
367
368 if (!buf->dev) {
369 kfree(buf->buf);
370 } else if (is_rproc_enabled) {
371 unsigned long flags;
372
373 /* dma_free_coherent requires interrupts to be enabled. */
374 if (!can_sleep) {
375 /* queue up dma-buffers to be freed later */
376 spin_lock_irqsave(&dma_bufs_lock, flags);
377 list_add_tail(&buf->list, &pending_free_dma_bufs);
378 spin_unlock_irqrestore(&dma_bufs_lock, flags);
379 return;
380 }
381 dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma);
382
383 /* Release device refcnt and allow it to be freed */
384 put_device(buf->dev);
385 }
386
387 kfree(buf);
388}
389
390static void reclaim_dma_bufs(void)
391{
392 unsigned long flags;
393 struct port_buffer *buf, *tmp;
394 LIST_HEAD(tmp_list);
395
396 if (list_empty(&pending_free_dma_bufs))
397 return;
398
399 /* Create a copy of the pending_free_dma_bufs while holding the lock */
400 spin_lock_irqsave(&dma_bufs_lock, flags);
401 list_cut_position(&tmp_list, &pending_free_dma_bufs,
402 pending_free_dma_bufs.prev);
403 spin_unlock_irqrestore(&dma_bufs_lock, flags);
404
405 /* Release the dma buffers, without irqs enabled */
406 list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
407 list_del(&buf->list);
408 free_buf(buf, true);
409 }
410}
411
412static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size,
413 int pages)
414{
415 struct port_buffer *buf;
416
417 reclaim_dma_bufs();
418
419 /*
420 * Allocate buffer and the sg list. The sg list array is allocated
421 * directly after the port_buffer struct.
422 */
423 buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL);
424 if (!buf)
425 goto fail;
426
427 buf->sgpages = pages;
428 if (pages > 0) {
429 buf->dev = NULL;
430 buf->buf = NULL;
431 return buf;
432 }
433
434 if (is_rproc_serial(vdev)) {
435 /*
436 * Allocate DMA memory from ancestor. When a virtio
437 * device is created by remoteproc, the DMA memory is
438 * associated with the grandparent device:
439 * vdev => rproc => platform-dev.
440 */
441 if (!vdev->dev.parent || !vdev->dev.parent->parent)
442 goto free_buf;
443 buf->dev = vdev->dev.parent->parent;
444
445 /* Increase device refcnt to avoid freeing it */
446 get_device(buf->dev);
447 buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
448 GFP_KERNEL);
449 } else {
450 buf->dev = NULL;
451 buf->buf = kmalloc(buf_size, GFP_KERNEL);
452 }
453
454 if (!buf->buf)
455 goto free_buf;
456 buf->len = 0;
457 buf->offset = 0;
458 buf->size = buf_size;
459 return buf;
460
461free_buf:
462 kfree(buf);
463fail:
464 return NULL;
465}
466
467/* Callers should take appropriate locks */
468static struct port_buffer *get_inbuf(struct port *port)
469{
470 struct port_buffer *buf;
471 unsigned int len;
472
473 if (port->inbuf)
474 return port->inbuf;
475
476 buf = virtqueue_get_buf(port->in_vq, &len);
477 if (buf) {
478 buf->len = len;
479 buf->offset = 0;
480 port->stats.bytes_received += len;
481 }
482 return buf;
483}
484
485/*
486 * Create a scatter-gather list representing our input buffer and put
487 * it in the queue.
488 *
489 * Callers should take appropriate locks.
490 */
491static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
492{
493 struct scatterlist sg[1];
494 int ret;
495
496 sg_init_one(sg, buf->buf, buf->size);
497
498 ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC);
499 virtqueue_kick(vq);
500 if (!ret)
501 ret = vq->num_free;
502 return ret;
503}
504
505/* Discard any unread data this port has. Callers lockers. */
506static void discard_port_data(struct port *port)
507{
508 struct port_buffer *buf;
509 unsigned int err;
510
511 if (!port->portdev) {
512 /* Device has been unplugged. vqs are already gone. */
513 return;
514 }
515 buf = get_inbuf(port);
516
517 err = 0;
518 while (buf) {
519 port->stats.bytes_discarded += buf->len - buf->offset;
520 if (add_inbuf(port->in_vq, buf) < 0) {
521 err++;
522 free_buf(buf, false);
523 }
524 port->inbuf = NULL;
525 buf = get_inbuf(port);
526 }
527 if (err)
528 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
529 err);
530}
531
532static bool port_has_data(struct port *port)
533{
534 unsigned long flags;
535 bool ret;
536
537 ret = false;
538 spin_lock_irqsave(&port->inbuf_lock, flags);
539 port->inbuf = get_inbuf(port);
540 if (port->inbuf)
541 ret = true;
542
543 spin_unlock_irqrestore(&port->inbuf_lock, flags);
544 return ret;
545}
546
547static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
548 unsigned int event, unsigned int value)
549{
550 struct scatterlist sg[1];
551 struct virtqueue *vq;
552 unsigned int len;
553
554 if (!use_multiport(portdev))
555 return 0;
556
557 vq = portdev->c_ovq;
558
559 spin_lock(&portdev->c_ovq_lock);
560
561 portdev->cpkt.id = cpu_to_virtio32(portdev->vdev, port_id);
562 portdev->cpkt.event = cpu_to_virtio16(portdev->vdev, event);
563 portdev->cpkt.value = cpu_to_virtio16(portdev->vdev, value);
564
565 sg_init_one(sg, &portdev->cpkt, sizeof(struct virtio_console_control));
566
567 if (virtqueue_add_outbuf(vq, sg, 1, &portdev->cpkt, GFP_ATOMIC) == 0) {
568 virtqueue_kick(vq);
569 while (!virtqueue_get_buf(vq, &len)
570 && !virtqueue_is_broken(vq))
571 cpu_relax();
572 }
573
574 spin_unlock(&portdev->c_ovq_lock);
575 return 0;
576}
577
578static ssize_t send_control_msg(struct port *port, unsigned int event,
579 unsigned int value)
580{
581 /* Did the port get unplugged before userspace closed it? */
582 if (port->portdev)
583 return __send_control_msg(port->portdev, port->id, event, value);
584 return 0;
585}
586
587
588/* Callers must take the port->outvq_lock */
589static void reclaim_consumed_buffers(struct port *port)
590{
591 struct port_buffer *buf;
592 unsigned int len;
593
594 if (!port->portdev) {
595 /* Device has been unplugged. vqs are already gone. */
596 return;
597 }
598 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
599 free_buf(buf, false);
600 port->outvq_full = false;
601 }
602}
603
604static ssize_t __send_to_port(struct port *port, struct scatterlist *sg,
605 int nents, size_t in_count,
606 void *data, bool nonblock)
607{
608 struct virtqueue *out_vq;
609 int err;
610 unsigned long flags;
611 unsigned int len;
612
613 out_vq = port->out_vq;
614
615 spin_lock_irqsave(&port->outvq_lock, flags);
616
617 reclaim_consumed_buffers(port);
618
619 err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC);
620
621 /* Tell Host to go! */
622 virtqueue_kick(out_vq);
623
624 if (err) {
625 in_count = 0;
626 goto done;
627 }
628
629 if (out_vq->num_free == 0)
630 port->outvq_full = true;
631
632 if (nonblock)
633 goto done;
634
635 /*
636 * Wait till the host acknowledges it pushed out the data we
637 * sent. This is done for data from the hvc_console; the tty
638 * operations are performed with spinlocks held so we can't
639 * sleep here. An alternative would be to copy the data to a
640 * buffer and relax the spinning requirement. The downside is
641 * we need to kmalloc a GFP_ATOMIC buffer each time the
642 * console driver writes something out.
643 */
644 while (!virtqueue_get_buf(out_vq, &len)
645 && !virtqueue_is_broken(out_vq))
646 cpu_relax();
647done:
648 spin_unlock_irqrestore(&port->outvq_lock, flags);
649
650 port->stats.bytes_sent += in_count;
651 /*
652 * We're expected to return the amount of data we wrote -- all
653 * of it
654 */
655 return in_count;
656}
657
658/*
659 * Give out the data that's requested from the buffer that we have
660 * queued up.
661 */
662static ssize_t fill_readbuf(struct port *port, char __user *out_buf,
663 size_t out_count, bool to_user)
664{
665 struct port_buffer *buf;
666 unsigned long flags;
667
668 if (!out_count || !port_has_data(port))
669 return 0;
670
671 buf = port->inbuf;
672 out_count = min(out_count, buf->len - buf->offset);
673
674 if (to_user) {
675 ssize_t ret;
676
677 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
678 if (ret)
679 return -EFAULT;
680 } else {
681 memcpy((__force char *)out_buf, buf->buf + buf->offset,
682 out_count);
683 }
684
685 buf->offset += out_count;
686
687 if (buf->offset == buf->len) {
688 /*
689 * We're done using all the data in this buffer.
690 * Re-queue so that the Host can send us more data.
691 */
692 spin_lock_irqsave(&port->inbuf_lock, flags);
693 port->inbuf = NULL;
694
695 if (add_inbuf(port->in_vq, buf) < 0)
696 dev_warn(port->dev, "failed add_buf\n");
697
698 spin_unlock_irqrestore(&port->inbuf_lock, flags);
699 }
700 /* Return the number of bytes actually copied */
701 return out_count;
702}
703
704/* The condition that must be true for polling to end */
705static bool will_read_block(struct port *port)
706{
707 if (!port->guest_connected) {
708 /* Port got hot-unplugged. Let's exit. */
709 return false;
710 }
711 return !port_has_data(port) && port->host_connected;
712}
713
714static bool will_write_block(struct port *port)
715{
716 bool ret;
717
718 if (!port->guest_connected) {
719 /* Port got hot-unplugged. Let's exit. */
720 return false;
721 }
722 if (!port->host_connected)
723 return true;
724
725 spin_lock_irq(&port->outvq_lock);
726 /*
727 * Check if the Host has consumed any buffers since we last
728 * sent data (this is only applicable for nonblocking ports).
729 */
730 reclaim_consumed_buffers(port);
731 ret = port->outvq_full;
732 spin_unlock_irq(&port->outvq_lock);
733
734 return ret;
735}
736
737static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
738 size_t count, loff_t *offp)
739{
740 struct port *port;
741 ssize_t ret;
742
743 port = filp->private_data;
744
745 /* Port is hot-unplugged. */
746 if (!port->guest_connected)
747 return -ENODEV;
748
749 if (!port_has_data(port)) {
750 /*
751 * If nothing's connected on the host just return 0 in
752 * case of list_empty; this tells the userspace app
753 * that there's no connection
754 */
755 if (!port->host_connected)
756 return 0;
757 if (filp->f_flags & O_NONBLOCK)
758 return -EAGAIN;
759
760 ret = wait_event_freezable(port->waitqueue,
761 !will_read_block(port));
762 if (ret < 0)
763 return ret;
764 }
765 /* Port got hot-unplugged while we were waiting above. */
766 if (!port->guest_connected)
767 return -ENODEV;
768 /*
769 * We could've received a disconnection message while we were
770 * waiting for more data.
771 *
772 * This check is not clubbed in the if() statement above as we
773 * might receive some data as well as the host could get
774 * disconnected after we got woken up from our wait. So we
775 * really want to give off whatever data we have and only then
776 * check for host_connected.
777 */
778 if (!port_has_data(port) && !port->host_connected)
779 return 0;
780
781 return fill_readbuf(port, ubuf, count, true);
782}
783
784static int wait_port_writable(struct port *port, bool nonblock)
785{
786 int ret;
787
788 if (will_write_block(port)) {
789 if (nonblock)
790 return -EAGAIN;
791
792 ret = wait_event_freezable(port->waitqueue,
793 !will_write_block(port));
794 if (ret < 0)
795 return ret;
796 }
797 /* Port got hot-unplugged. */
798 if (!port->guest_connected)
799 return -ENODEV;
800
801 return 0;
802}
803
804static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
805 size_t count, loff_t *offp)
806{
807 struct port *port;
808 struct port_buffer *buf;
809 ssize_t ret;
810 bool nonblock;
811 struct scatterlist sg[1];
812
813 /* Userspace could be out to fool us */
814 if (!count)
815 return 0;
816
817 port = filp->private_data;
818
819 nonblock = filp->f_flags & O_NONBLOCK;
820
821 ret = wait_port_writable(port, nonblock);
822 if (ret < 0)
823 return ret;
824
825 count = min((size_t)(32 * 1024), count);
826
827 buf = alloc_buf(port->portdev->vdev, count, 0);
828 if (!buf)
829 return -ENOMEM;
830
831 ret = copy_from_user(buf->buf, ubuf, count);
832 if (ret) {
833 ret = -EFAULT;
834 goto free_buf;
835 }
836
837 /*
838 * We now ask send_buf() to not spin for generic ports -- we
839 * can re-use the same code path that non-blocking file
840 * descriptors take for blocking file descriptors since the
841 * wait is already done and we're certain the write will go
842 * through to the host.
843 */
844 nonblock = true;
845 sg_init_one(sg, buf->buf, count);
846 ret = __send_to_port(port, sg, 1, count, buf, nonblock);
847
848 if (nonblock && ret > 0)
849 goto out;
850
851free_buf:
852 free_buf(buf, true);
853out:
854 return ret;
855}
856
857struct sg_list {
858 unsigned int n;
859 unsigned int size;
860 size_t len;
861 struct scatterlist *sg;
862};
863
864static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
865 struct splice_desc *sd)
866{
867 struct sg_list *sgl = sd->u.data;
868 unsigned int offset, len;
869
870 if (sgl->n == sgl->size)
871 return 0;
872
873 /* Try lock this page */
874 if (pipe_buf_steal(pipe, buf) == 0) {
875 /* Get reference and unlock page for moving */
876 get_page(buf->page);
877 unlock_page(buf->page);
878
879 len = min(buf->len, sd->len);
880 sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset);
881 } else {
882 /* Failback to copying a page */
883 struct page *page = alloc_page(GFP_KERNEL);
884 char *src;
885
886 if (!page)
887 return -ENOMEM;
888
889 offset = sd->pos & ~PAGE_MASK;
890
891 len = sd->len;
892 if (len + offset > PAGE_SIZE)
893 len = PAGE_SIZE - offset;
894
895 src = kmap_atomic(buf->page);
896 memcpy(page_address(page) + offset, src + buf->offset, len);
897 kunmap_atomic(src);
898
899 sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
900 }
901 sgl->n++;
902 sgl->len += len;
903
904 return len;
905}
906
907/* Faster zero-copy write by splicing */
908static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
909 struct file *filp, loff_t *ppos,
910 size_t len, unsigned int flags)
911{
912 struct port *port = filp->private_data;
913 struct sg_list sgl;
914 ssize_t ret;
915 struct port_buffer *buf;
916 struct splice_desc sd = {
917 .total_len = len,
918 .flags = flags,
919 .pos = *ppos,
920 .u.data = &sgl,
921 };
922
923 /*
924 * Rproc_serial does not yet support splice. To support splice
925 * pipe_to_sg() must allocate dma-buffers and copy content from
926 * regular pages to dma pages. And alloc_buf and free_buf must
927 * support allocating and freeing such a list of dma-buffers.
928 */
929 if (is_rproc_serial(port->out_vq->vdev))
930 return -EINVAL;
931
932 /*
933 * pipe->nrbufs == 0 means there are no data to transfer,
934 * so this returns just 0 for no data.
935 */
936 pipe_lock(pipe);
937 if (!pipe->nrbufs) {
938 ret = 0;
939 goto error_out;
940 }
941
942 ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
943 if (ret < 0)
944 goto error_out;
945
946 buf = alloc_buf(port->portdev->vdev, 0, pipe->nrbufs);
947 if (!buf) {
948 ret = -ENOMEM;
949 goto error_out;
950 }
951
952 sgl.n = 0;
953 sgl.len = 0;
954 sgl.size = pipe->nrbufs;
955 sgl.sg = buf->sg;
956 sg_init_table(sgl.sg, sgl.size);
957 ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
958 pipe_unlock(pipe);
959 if (likely(ret > 0))
960 ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
961
962 if (unlikely(ret <= 0))
963 free_buf(buf, true);
964 return ret;
965
966error_out:
967 pipe_unlock(pipe);
968 return ret;
969}
970
971static __poll_t port_fops_poll(struct file *filp, poll_table *wait)
972{
973 struct port *port;
974 __poll_t ret;
975
976 port = filp->private_data;
977 poll_wait(filp, &port->waitqueue, wait);
978
979 if (!port->guest_connected) {
980 /* Port got unplugged */
981 return EPOLLHUP;
982 }
983 ret = 0;
984 if (!will_read_block(port))
985 ret |= EPOLLIN | EPOLLRDNORM;
986 if (!will_write_block(port))
987 ret |= EPOLLOUT;
988 if (!port->host_connected)
989 ret |= EPOLLHUP;
990
991 return ret;
992}
993
994static void remove_port(struct kref *kref);
995
996static int port_fops_release(struct inode *inode, struct file *filp)
997{
998 struct port *port;
999
1000 port = filp->private_data;
1001
1002 /* Notify host of port being closed */
1003 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
1004
1005 spin_lock_irq(&port->inbuf_lock);
1006 port->guest_connected = false;
1007
1008 discard_port_data(port);
1009
1010 spin_unlock_irq(&port->inbuf_lock);
1011
1012 spin_lock_irq(&port->outvq_lock);
1013 reclaim_consumed_buffers(port);
1014 spin_unlock_irq(&port->outvq_lock);
1015
1016 reclaim_dma_bufs();
1017 /*
1018 * Locks aren't necessary here as a port can't be opened after
1019 * unplug, and if a port isn't unplugged, a kref would already
1020 * exist for the port. Plus, taking ports_lock here would
1021 * create a dependency on other locks taken by functions
1022 * inside remove_port if we're the last holder of the port,
1023 * creating many problems.
1024 */
1025 kref_put(&port->kref, remove_port);
1026
1027 return 0;
1028}
1029
1030static int port_fops_open(struct inode *inode, struct file *filp)
1031{
1032 struct cdev *cdev = inode->i_cdev;
1033 struct port *port;
1034 int ret;
1035
1036 /* We get the port with a kref here */
1037 port = find_port_by_devt(cdev->dev);
1038 if (!port) {
1039 /* Port was unplugged before we could proceed */
1040 return -ENXIO;
1041 }
1042 filp->private_data = port;
1043
1044 /*
1045 * Don't allow opening of console port devices -- that's done
1046 * via /dev/hvc
1047 */
1048 if (is_console_port(port)) {
1049 ret = -ENXIO;
1050 goto out;
1051 }
1052
1053 /* Allow only one process to open a particular port at a time */
1054 spin_lock_irq(&port->inbuf_lock);
1055 if (port->guest_connected) {
1056 spin_unlock_irq(&port->inbuf_lock);
1057 ret = -EBUSY;
1058 goto out;
1059 }
1060
1061 port->guest_connected = true;
1062 spin_unlock_irq(&port->inbuf_lock);
1063
1064 spin_lock_irq(&port->outvq_lock);
1065 /*
1066 * There might be a chance that we missed reclaiming a few
1067 * buffers in the window of the port getting previously closed
1068 * and opening now.
1069 */
1070 reclaim_consumed_buffers(port);
1071 spin_unlock_irq(&port->outvq_lock);
1072
1073 nonseekable_open(inode, filp);
1074
1075 /* Notify host of port being opened */
1076 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
1077
1078 return 0;
1079out:
1080 kref_put(&port->kref, remove_port);
1081 return ret;
1082}
1083
1084static int port_fops_fasync(int fd, struct file *filp, int mode)
1085{
1086 struct port *port;
1087
1088 port = filp->private_data;
1089 return fasync_helper(fd, filp, mode, &port->async_queue);
1090}
1091
1092/*
1093 * The file operations that we support: programs in the guest can open
1094 * a console device, read from it, write to it, poll for data and
1095 * close it. The devices are at
1096 * /dev/vport<device number>p<port number>
1097 */
1098static const struct file_operations port_fops = {
1099 .owner = THIS_MODULE,
1100 .open = port_fops_open,
1101 .read = port_fops_read,
1102 .write = port_fops_write,
1103 .splice_write = port_fops_splice_write,
1104 .poll = port_fops_poll,
1105 .release = port_fops_release,
1106 .fasync = port_fops_fasync,
1107 .llseek = no_llseek,
1108};
1109
1110/*
1111 * The put_chars() callback is pretty straightforward.
1112 *
1113 * We turn the characters into a scatter-gather list, add it to the
1114 * output queue and then kick the Host. Then we sit here waiting for
1115 * it to finish: inefficient in theory, but in practice
1116 * implementations will do it immediately.
1117 */
1118static int put_chars(u32 vtermno, const char *buf, int count)
1119{
1120 struct port *port;
1121 struct scatterlist sg[1];
1122 void *data;
1123 int ret;
1124
1125 if (unlikely(early_put_chars))
1126 return early_put_chars(vtermno, buf, count);
1127
1128 port = find_port_by_vtermno(vtermno);
1129 if (!port)
1130 return -EPIPE;
1131
1132 data = kmemdup(buf, count, GFP_ATOMIC);
1133 if (!data)
1134 return -ENOMEM;
1135
1136 sg_init_one(sg, data, count);
1137 ret = __send_to_port(port, sg, 1, count, data, false);
1138 kfree(data);
1139 return ret;
1140}
1141
1142/*
1143 * get_chars() is the callback from the hvc_console infrastructure
1144 * when an interrupt is received.
1145 *
1146 * We call out to fill_readbuf that gets us the required data from the
1147 * buffers that are queued up.
1148 */
1149static int get_chars(u32 vtermno, char *buf, int count)
1150{
1151 struct port *port;
1152
1153 /* If we've not set up the port yet, we have no input to give. */
1154 if (unlikely(early_put_chars))
1155 return 0;
1156
1157 port = find_port_by_vtermno(vtermno);
1158 if (!port)
1159 return -EPIPE;
1160
1161 /* If we don't have an input queue yet, we can't get input. */
1162 BUG_ON(!port->in_vq);
1163
1164 return fill_readbuf(port, (__force char __user *)buf, count, false);
1165}
1166
1167static void resize_console(struct port *port)
1168{
1169 struct virtio_device *vdev;
1170
1171 /* The port could have been hot-unplugged */
1172 if (!port || !is_console_port(port))
1173 return;
1174
1175 vdev = port->portdev->vdev;
1176
1177 /* Don't test F_SIZE at all if we're rproc: not a valid feature! */
1178 if (!is_rproc_serial(vdev) &&
1179 virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
1180 hvc_resize(port->cons.hvc, port->cons.ws);
1181}
1182
1183/* We set the configuration at this point, since we now have a tty */
1184static int notifier_add_vio(struct hvc_struct *hp, int data)
1185{
1186 struct port *port;
1187
1188 port = find_port_by_vtermno(hp->vtermno);
1189 if (!port)
1190 return -EINVAL;
1191
1192 hp->irq_requested = 1;
1193 resize_console(port);
1194
1195 return 0;
1196}
1197
1198static void notifier_del_vio(struct hvc_struct *hp, int data)
1199{
1200 hp->irq_requested = 0;
1201}
1202
1203/* The operations for console ports. */
1204static const struct hv_ops hv_ops = {
1205 .get_chars = get_chars,
1206 .put_chars = put_chars,
1207 .notifier_add = notifier_add_vio,
1208 .notifier_del = notifier_del_vio,
1209 .notifier_hangup = notifier_del_vio,
1210};
1211
1212/*
1213 * Console drivers are initialized very early so boot messages can go
1214 * out, so we do things slightly differently from the generic virtio
1215 * initialization of the net and block drivers.
1216 *
1217 * At this stage, the console is output-only. It's too early to set
1218 * up a virtqueue, so we let the drivers do some boutique early-output
1219 * thing.
1220 */
1221int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
1222{
1223 early_put_chars = put_chars;
1224 return hvc_instantiate(0, 0, &hv_ops);
1225}
1226
1227static int init_port_console(struct port *port)
1228{
1229 int ret;
1230
1231 /*
1232 * The Host's telling us this port is a console port. Hook it
1233 * up with an hvc console.
1234 *
1235 * To set up and manage our virtual console, we call
1236 * hvc_alloc().
1237 *
1238 * The first argument of hvc_alloc() is the virtual console
1239 * number. The second argument is the parameter for the
1240 * notification mechanism (like irq number). We currently
1241 * leave this as zero, virtqueues have implicit notifications.
1242 *
1243 * The third argument is a "struct hv_ops" containing the
1244 * put_chars() get_chars(), notifier_add() and notifier_del()
1245 * pointers. The final argument is the output buffer size: we
1246 * can do any size, so we put PAGE_SIZE here.
1247 */
1248 port->cons.vtermno = pdrvdata.next_vtermno;
1249
1250 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
1251 if (IS_ERR(port->cons.hvc)) {
1252 ret = PTR_ERR(port->cons.hvc);
1253 dev_err(port->dev,
1254 "error %d allocating hvc for port\n", ret);
1255 port->cons.hvc = NULL;
1256 return ret;
1257 }
1258 spin_lock_irq(&pdrvdata_lock);
1259 pdrvdata.next_vtermno++;
1260 list_add_tail(&port->cons.list, &pdrvdata.consoles);
1261 spin_unlock_irq(&pdrvdata_lock);
1262 port->guest_connected = true;
1263
1264 /*
1265 * Start using the new console output if this is the first
1266 * console to come up.
1267 */
1268 if (early_put_chars)
1269 early_put_chars = NULL;
1270
1271 /* Notify host of port being opened */
1272 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1273
1274 return 0;
1275}
1276
1277static ssize_t show_port_name(struct device *dev,
1278 struct device_attribute *attr, char *buffer)
1279{
1280 struct port *port;
1281
1282 port = dev_get_drvdata(dev);
1283
1284 return sprintf(buffer, "%s\n", port->name);
1285}
1286
1287static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1288
1289static struct attribute *port_sysfs_entries[] = {
1290 &dev_attr_name.attr,
1291 NULL
1292};
1293
1294static const struct attribute_group port_attribute_group = {
1295 .name = NULL, /* put in device directory */
1296 .attrs = port_sysfs_entries,
1297};
1298
1299static int port_debugfs_show(struct seq_file *s, void *data)
1300{
1301 struct port *port = s->private;
1302
1303 seq_printf(s, "name: %s\n", port->name ? port->name : "");
1304 seq_printf(s, "guest_connected: %d\n", port->guest_connected);
1305 seq_printf(s, "host_connected: %d\n", port->host_connected);
1306 seq_printf(s, "outvq_full: %d\n", port->outvq_full);
1307 seq_printf(s, "bytes_sent: %lu\n", port->stats.bytes_sent);
1308 seq_printf(s, "bytes_received: %lu\n", port->stats.bytes_received);
1309 seq_printf(s, "bytes_discarded: %lu\n", port->stats.bytes_discarded);
1310 seq_printf(s, "is_console: %s\n",
1311 is_console_port(port) ? "yes" : "no");
1312 seq_printf(s, "console_vtermno: %u\n", port->cons.vtermno);
1313
1314 return 0;
1315}
1316
1317DEFINE_SHOW_ATTRIBUTE(port_debugfs);
1318
1319static void set_console_size(struct port *port, u16 rows, u16 cols)
1320{
1321 if (!port || !is_console_port(port))
1322 return;
1323
1324 port->cons.ws.ws_row = rows;
1325 port->cons.ws.ws_col = cols;
1326}
1327
1328static int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1329{
1330 struct port_buffer *buf;
1331 int nr_added_bufs;
1332 int ret;
1333
1334 nr_added_bufs = 0;
1335 do {
1336 buf = alloc_buf(vq->vdev, PAGE_SIZE, 0);
1337 if (!buf)
1338 return -ENOMEM;
1339
1340 spin_lock_irq(lock);
1341 ret = add_inbuf(vq, buf);
1342 if (ret < 0) {
1343 spin_unlock_irq(lock);
1344 free_buf(buf, true);
1345 return ret;
1346 }
1347 nr_added_bufs++;
1348 spin_unlock_irq(lock);
1349 } while (ret > 0);
1350
1351 return nr_added_bufs;
1352}
1353
1354static void send_sigio_to_port(struct port *port)
1355{
1356 if (port->async_queue && port->guest_connected)
1357 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1358}
1359
1360static int add_port(struct ports_device *portdev, u32 id)
1361{
1362 char debugfs_name[16];
1363 struct port *port;
1364 dev_t devt;
1365 int err;
1366
1367 port = kmalloc(sizeof(*port), GFP_KERNEL);
1368 if (!port) {
1369 err = -ENOMEM;
1370 goto fail;
1371 }
1372 kref_init(&port->kref);
1373
1374 port->portdev = portdev;
1375 port->id = id;
1376
1377 port->name = NULL;
1378 port->inbuf = NULL;
1379 port->cons.hvc = NULL;
1380 port->async_queue = NULL;
1381
1382 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1383 port->cons.vtermno = 0;
1384
1385 port->host_connected = port->guest_connected = false;
1386 port->stats = (struct port_stats) { 0 };
1387
1388 port->outvq_full = false;
1389
1390 port->in_vq = portdev->in_vqs[port->id];
1391 port->out_vq = portdev->out_vqs[port->id];
1392
1393 port->cdev = cdev_alloc();
1394 if (!port->cdev) {
1395 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1396 err = -ENOMEM;
1397 goto free_port;
1398 }
1399 port->cdev->ops = &port_fops;
1400
1401 devt = MKDEV(portdev->chr_major, id);
1402 err = cdev_add(port->cdev, devt, 1);
1403 if (err < 0) {
1404 dev_err(&port->portdev->vdev->dev,
1405 "Error %d adding cdev for port %u\n", err, id);
1406 goto free_cdev;
1407 }
1408 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1409 devt, port, "vport%up%u",
1410 port->portdev->vdev->index, id);
1411 if (IS_ERR(port->dev)) {
1412 err = PTR_ERR(port->dev);
1413 dev_err(&port->portdev->vdev->dev,
1414 "Error %d creating device for port %u\n",
1415 err, id);
1416 goto free_cdev;
1417 }
1418
1419 spin_lock_init(&port->inbuf_lock);
1420 spin_lock_init(&port->outvq_lock);
1421 init_waitqueue_head(&port->waitqueue);
1422
1423 /* We can safely ignore ENOSPC because it means
1424 * the queue already has buffers. Buffers are removed
1425 * only by virtcons_remove(), not by unplug_port()
1426 */
1427 err = fill_queue(port->in_vq, &port->inbuf_lock);
1428 if (err < 0 && err != -ENOSPC) {
1429 dev_err(port->dev, "Error allocating inbufs\n");
1430 goto free_device;
1431 }
1432
1433 if (is_rproc_serial(port->portdev->vdev))
1434 /*
1435 * For rproc_serial assume remote processor is connected.
1436 * rproc_serial does not want the console port, only
1437 * the generic port implementation.
1438 */
1439 port->host_connected = true;
1440 else if (!use_multiport(port->portdev)) {
1441 /*
1442 * If we're not using multiport support,
1443 * this has to be a console port.
1444 */
1445 err = init_port_console(port);
1446 if (err)
1447 goto free_inbufs;
1448 }
1449
1450 spin_lock_irq(&portdev->ports_lock);
1451 list_add_tail(&port->list, &port->portdev->ports);
1452 spin_unlock_irq(&portdev->ports_lock);
1453
1454 /*
1455 * Tell the Host we're set so that it can send us various
1456 * configuration parameters for this port (eg, port name,
1457 * caching, whether this is a console port, etc.)
1458 */
1459 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1460
1461 if (pdrvdata.debugfs_dir) {
1462 /*
1463 * Finally, create the debugfs file that we can use to
1464 * inspect a port's state at any time
1465 */
1466 snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u",
1467 port->portdev->vdev->index, id);
1468 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1469 pdrvdata.debugfs_dir,
1470 port,
1471 &port_debugfs_fops);
1472 }
1473 return 0;
1474
1475free_inbufs:
1476free_device:
1477 device_destroy(pdrvdata.class, port->dev->devt);
1478free_cdev:
1479 cdev_del(port->cdev);
1480free_port:
1481 kfree(port);
1482fail:
1483 /* The host might want to notify management sw about port add failure */
1484 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1485 return err;
1486}
1487
1488/* No users remain, remove all port-specific data. */
1489static void remove_port(struct kref *kref)
1490{
1491 struct port *port;
1492
1493 port = container_of(kref, struct port, kref);
1494
1495 kfree(port);
1496}
1497
1498static void remove_port_data(struct port *port)
1499{
1500 spin_lock_irq(&port->inbuf_lock);
1501 /* Remove unused data this port might have received. */
1502 discard_port_data(port);
1503 spin_unlock_irq(&port->inbuf_lock);
1504
1505 spin_lock_irq(&port->outvq_lock);
1506 reclaim_consumed_buffers(port);
1507 spin_unlock_irq(&port->outvq_lock);
1508}
1509
1510/*
1511 * Port got unplugged. Remove port from portdev's list and drop the
1512 * kref reference. If no userspace has this port opened, it will
1513 * result in immediate removal the port.
1514 */
1515static void unplug_port(struct port *port)
1516{
1517 spin_lock_irq(&port->portdev->ports_lock);
1518 list_del(&port->list);
1519 spin_unlock_irq(&port->portdev->ports_lock);
1520
1521 spin_lock_irq(&port->inbuf_lock);
1522 if (port->guest_connected) {
1523 /* Let the app know the port is going down. */
1524 send_sigio_to_port(port);
1525
1526 /* Do this after sigio is actually sent */
1527 port->guest_connected = false;
1528 port->host_connected = false;
1529
1530 wake_up_interruptible(&port->waitqueue);
1531 }
1532 spin_unlock_irq(&port->inbuf_lock);
1533
1534 if (is_console_port(port)) {
1535 spin_lock_irq(&pdrvdata_lock);
1536 list_del(&port->cons.list);
1537 spin_unlock_irq(&pdrvdata_lock);
1538 hvc_remove(port->cons.hvc);
1539 }
1540
1541 remove_port_data(port);
1542
1543 /*
1544 * We should just assume the device itself has gone off --
1545 * else a close on an open port later will try to send out a
1546 * control message.
1547 */
1548 port->portdev = NULL;
1549
1550 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1551 device_destroy(pdrvdata.class, port->dev->devt);
1552 cdev_del(port->cdev);
1553
1554 debugfs_remove(port->debugfs_file);
1555 kfree(port->name);
1556
1557 /*
1558 * Locks around here are not necessary - a port can't be
1559 * opened after we removed the port struct from ports_list
1560 * above.
1561 */
1562 kref_put(&port->kref, remove_port);
1563}
1564
1565/* Any private messages that the Host and Guest want to share */
1566static void handle_control_message(struct virtio_device *vdev,
1567 struct ports_device *portdev,
1568 struct port_buffer *buf)
1569{
1570 struct virtio_console_control *cpkt;
1571 struct port *port;
1572 size_t name_size;
1573 int err;
1574
1575 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1576
1577 port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id));
1578 if (!port &&
1579 cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
1580 /* No valid header at start of buffer. Drop it. */
1581 dev_dbg(&portdev->vdev->dev,
1582 "Invalid index %u in control packet\n", cpkt->id);
1583 return;
1584 }
1585
1586 switch (virtio16_to_cpu(vdev, cpkt->event)) {
1587 case VIRTIO_CONSOLE_PORT_ADD:
1588 if (port) {
1589 dev_dbg(&portdev->vdev->dev,
1590 "Port %u already added\n", port->id);
1591 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1592 break;
1593 }
1594 if (virtio32_to_cpu(vdev, cpkt->id) >=
1595 portdev->max_nr_ports) {
1596 dev_warn(&portdev->vdev->dev,
1597 "Request for adding port with "
1598 "out-of-bound id %u, max. supported id: %u\n",
1599 cpkt->id, portdev->max_nr_ports - 1);
1600 break;
1601 }
1602 add_port(portdev, virtio32_to_cpu(vdev, cpkt->id));
1603 break;
1604 case VIRTIO_CONSOLE_PORT_REMOVE:
1605 unplug_port(port);
1606 break;
1607 case VIRTIO_CONSOLE_CONSOLE_PORT:
1608 if (!cpkt->value)
1609 break;
1610 if (is_console_port(port))
1611 break;
1612
1613 init_port_console(port);
1614 complete(&early_console_added);
1615 /*
1616 * Could remove the port here in case init fails - but
1617 * have to notify the host first.
1618 */
1619 break;
1620 case VIRTIO_CONSOLE_RESIZE: {
1621 struct {
1622 __u16 rows;
1623 __u16 cols;
1624 } size;
1625
1626 if (!is_console_port(port))
1627 break;
1628
1629 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1630 sizeof(size));
1631 set_console_size(port, size.rows, size.cols);
1632
1633 port->cons.hvc->irq_requested = 1;
1634 resize_console(port);
1635 break;
1636 }
1637 case VIRTIO_CONSOLE_PORT_OPEN:
1638 port->host_connected = virtio16_to_cpu(vdev, cpkt->value);
1639 wake_up_interruptible(&port->waitqueue);
1640 /*
1641 * If the host port got closed and the host had any
1642 * unconsumed buffers, we'll be able to reclaim them
1643 * now.
1644 */
1645 spin_lock_irq(&port->outvq_lock);
1646 reclaim_consumed_buffers(port);
1647 spin_unlock_irq(&port->outvq_lock);
1648
1649 /*
1650 * If the guest is connected, it'll be interested in
1651 * knowing the host connection state changed.
1652 */
1653 spin_lock_irq(&port->inbuf_lock);
1654 send_sigio_to_port(port);
1655 spin_unlock_irq(&port->inbuf_lock);
1656 break;
1657 case VIRTIO_CONSOLE_PORT_NAME:
1658 /*
1659 * If we woke up after hibernation, we can get this
1660 * again. Skip it in that case.
1661 */
1662 if (port->name)
1663 break;
1664
1665 /*
1666 * Skip the size of the header and the cpkt to get the size
1667 * of the name that was sent
1668 */
1669 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1670
1671 port->name = kmalloc(name_size, GFP_KERNEL);
1672 if (!port->name) {
1673 dev_err(port->dev,
1674 "Not enough space to store port name\n");
1675 break;
1676 }
1677 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1678 name_size - 1);
1679 port->name[name_size - 1] = 0;
1680
1681 /*
1682 * Since we only have one sysfs attribute, 'name',
1683 * create it only if we have a name for the port.
1684 */
1685 err = sysfs_create_group(&port->dev->kobj,
1686 &port_attribute_group);
1687 if (err) {
1688 dev_err(port->dev,
1689 "Error %d creating sysfs device attributes\n",
1690 err);
1691 } else {
1692 /*
1693 * Generate a udev event so that appropriate
1694 * symlinks can be created based on udev
1695 * rules.
1696 */
1697 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1698 }
1699 break;
1700 }
1701}
1702
1703static void control_work_handler(struct work_struct *work)
1704{
1705 struct ports_device *portdev;
1706 struct virtqueue *vq;
1707 struct port_buffer *buf;
1708 unsigned int len;
1709
1710 portdev = container_of(work, struct ports_device, control_work);
1711 vq = portdev->c_ivq;
1712
1713 spin_lock(&portdev->c_ivq_lock);
1714 while ((buf = virtqueue_get_buf(vq, &len))) {
1715 spin_unlock(&portdev->c_ivq_lock);
1716
1717 buf->len = len;
1718 buf->offset = 0;
1719
1720 handle_control_message(vq->vdev, portdev, buf);
1721
1722 spin_lock(&portdev->c_ivq_lock);
1723 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1724 dev_warn(&portdev->vdev->dev,
1725 "Error adding buffer to queue\n");
1726 free_buf(buf, false);
1727 }
1728 }
1729 spin_unlock(&portdev->c_ivq_lock);
1730}
1731
1732static void flush_bufs(struct virtqueue *vq, bool can_sleep)
1733{
1734 struct port_buffer *buf;
1735 unsigned int len;
1736
1737 while ((buf = virtqueue_get_buf(vq, &len)))
1738 free_buf(buf, can_sleep);
1739}
1740
1741static void out_intr(struct virtqueue *vq)
1742{
1743 struct port *port;
1744
1745 port = find_port_by_vq(vq->vdev->priv, vq);
1746 if (!port) {
1747 flush_bufs(vq, false);
1748 return;
1749 }
1750
1751 wake_up_interruptible(&port->waitqueue);
1752}
1753
1754static void in_intr(struct virtqueue *vq)
1755{
1756 struct port *port;
1757 unsigned long flags;
1758
1759 port = find_port_by_vq(vq->vdev->priv, vq);
1760 if (!port) {
1761 flush_bufs(vq, false);
1762 return;
1763 }
1764
1765 spin_lock_irqsave(&port->inbuf_lock, flags);
1766 port->inbuf = get_inbuf(port);
1767
1768 /*
1769 * Normally the port should not accept data when the port is
1770 * closed. For generic serial ports, the host won't (shouldn't)
1771 * send data till the guest is connected. But this condition
1772 * can be reached when a console port is not yet connected (no
1773 * tty is spawned) and the other side sends out data over the
1774 * vring, or when a remote devices start sending data before
1775 * the ports are opened.
1776 *
1777 * A generic serial port will discard data if not connected,
1778 * while console ports and rproc-serial ports accepts data at
1779 * any time. rproc-serial is initiated with guest_connected to
1780 * false because port_fops_open expects this. Console ports are
1781 * hooked up with an HVC console and is initialized with
1782 * guest_connected to true.
1783 */
1784
1785 if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
1786 discard_port_data(port);
1787
1788 /* Send a SIGIO indicating new data in case the process asked for it */
1789 send_sigio_to_port(port);
1790
1791 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1792
1793 wake_up_interruptible(&port->waitqueue);
1794
1795 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1796 hvc_kick();
1797}
1798
1799static void control_intr(struct virtqueue *vq)
1800{
1801 struct ports_device *portdev;
1802
1803 portdev = vq->vdev->priv;
1804 schedule_work(&portdev->control_work);
1805}
1806
1807static void config_intr(struct virtio_device *vdev)
1808{
1809 struct ports_device *portdev;
1810
1811 portdev = vdev->priv;
1812
1813 if (!use_multiport(portdev))
1814 schedule_work(&portdev->config_work);
1815}
1816
1817static void config_work_handler(struct work_struct *work)
1818{
1819 struct ports_device *portdev;
1820
1821 portdev = container_of(work, struct ports_device, config_work);
1822 if (!use_multiport(portdev)) {
1823 struct virtio_device *vdev;
1824 struct port *port;
1825 u16 rows, cols;
1826
1827 vdev = portdev->vdev;
1828 virtio_cread(vdev, struct virtio_console_config, cols, &cols);
1829 virtio_cread(vdev, struct virtio_console_config, rows, &rows);
1830
1831 port = find_port_by_id(portdev, 0);
1832 set_console_size(port, rows, cols);
1833
1834 /*
1835 * We'll use this way of resizing only for legacy
1836 * support. For newer userspace
1837 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1838 * to indicate console size changes so that it can be
1839 * done per-port.
1840 */
1841 resize_console(port);
1842 }
1843}
1844
1845static int init_vqs(struct ports_device *portdev)
1846{
1847 vq_callback_t **io_callbacks;
1848 char **io_names;
1849 struct virtqueue **vqs;
1850 u32 i, j, nr_ports, nr_queues;
1851 int err;
1852
1853 nr_ports = portdev->max_nr_ports;
1854 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1855
1856 vqs = kmalloc_array(nr_queues, sizeof(struct virtqueue *), GFP_KERNEL);
1857 io_callbacks = kmalloc_array(nr_queues, sizeof(vq_callback_t *),
1858 GFP_KERNEL);
1859 io_names = kmalloc_array(nr_queues, sizeof(char *), GFP_KERNEL);
1860 portdev->in_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1861 GFP_KERNEL);
1862 portdev->out_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1863 GFP_KERNEL);
1864 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1865 !portdev->out_vqs) {
1866 err = -ENOMEM;
1867 goto free;
1868 }
1869
1870 /*
1871 * For backward compat (newer host but older guest), the host
1872 * spawns a console port first and also inits the vqs for port
1873 * 0 before others.
1874 */
1875 j = 0;
1876 io_callbacks[j] = in_intr;
1877 io_callbacks[j + 1] = out_intr;
1878 io_names[j] = "input";
1879 io_names[j + 1] = "output";
1880 j += 2;
1881
1882 if (use_multiport(portdev)) {
1883 io_callbacks[j] = control_intr;
1884 io_callbacks[j + 1] = NULL;
1885 io_names[j] = "control-i";
1886 io_names[j + 1] = "control-o";
1887
1888 for (i = 1; i < nr_ports; i++) {
1889 j += 2;
1890 io_callbacks[j] = in_intr;
1891 io_callbacks[j + 1] = out_intr;
1892 io_names[j] = "input";
1893 io_names[j + 1] = "output";
1894 }
1895 }
1896 /* Find the queues. */
1897 err = virtio_find_vqs(portdev->vdev, nr_queues, vqs,
1898 io_callbacks,
1899 (const char **)io_names, NULL);
1900 if (err)
1901 goto free;
1902
1903 j = 0;
1904 portdev->in_vqs[0] = vqs[0];
1905 portdev->out_vqs[0] = vqs[1];
1906 j += 2;
1907 if (use_multiport(portdev)) {
1908 portdev->c_ivq = vqs[j];
1909 portdev->c_ovq = vqs[j + 1];
1910
1911 for (i = 1; i < nr_ports; i++) {
1912 j += 2;
1913 portdev->in_vqs[i] = vqs[j];
1914 portdev->out_vqs[i] = vqs[j + 1];
1915 }
1916 }
1917 kfree(io_names);
1918 kfree(io_callbacks);
1919 kfree(vqs);
1920
1921 return 0;
1922
1923free:
1924 kfree(portdev->out_vqs);
1925 kfree(portdev->in_vqs);
1926 kfree(io_names);
1927 kfree(io_callbacks);
1928 kfree(vqs);
1929
1930 return err;
1931}
1932
1933static const struct file_operations portdev_fops = {
1934 .owner = THIS_MODULE,
1935};
1936
1937static void remove_vqs(struct ports_device *portdev)
1938{
1939 struct virtqueue *vq;
1940
1941 virtio_device_for_each_vq(portdev->vdev, vq) {
1942 struct port_buffer *buf;
1943
1944 flush_bufs(vq, true);
1945 while ((buf = virtqueue_detach_unused_buf(vq)))
1946 free_buf(buf, true);
1947 }
1948 portdev->vdev->config->del_vqs(portdev->vdev);
1949 kfree(portdev->in_vqs);
1950 kfree(portdev->out_vqs);
1951}
1952
1953static void virtcons_remove(struct virtio_device *vdev)
1954{
1955 struct ports_device *portdev;
1956 struct port *port, *port2;
1957
1958 portdev = vdev->priv;
1959
1960 spin_lock_irq(&pdrvdata_lock);
1961 list_del(&portdev->list);
1962 spin_unlock_irq(&pdrvdata_lock);
1963
1964 /* Disable interrupts for vqs */
1965 vdev->config->reset(vdev);
1966 /* Finish up work that's lined up */
1967 if (use_multiport(portdev))
1968 cancel_work_sync(&portdev->control_work);
1969 else
1970 cancel_work_sync(&portdev->config_work);
1971
1972 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1973 unplug_port(port);
1974
1975 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1976
1977 /*
1978 * When yanking out a device, we immediately lose the
1979 * (device-side) queues. So there's no point in keeping the
1980 * guest side around till we drop our final reference. This
1981 * also means that any ports which are in an open state will
1982 * have to just stop using the port, as the vqs are going
1983 * away.
1984 */
1985 remove_vqs(portdev);
1986 kfree(portdev);
1987}
1988
1989/*
1990 * Once we're further in boot, we get probed like any other virtio
1991 * device.
1992 *
1993 * If the host also supports multiple console ports, we check the
1994 * config space to see how many ports the host has spawned. We
1995 * initialize each port found.
1996 */
1997static int virtcons_probe(struct virtio_device *vdev)
1998{
1999 struct ports_device *portdev;
2000 int err;
2001 bool multiport;
2002 bool early = early_put_chars != NULL;
2003
2004 /* We only need a config space if features are offered */
2005 if (!vdev->config->get &&
2006 (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
2007 || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
2008 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2009 __func__);
2010 return -EINVAL;
2011 }
2012
2013 /* Ensure to read early_put_chars now */
2014 barrier();
2015
2016 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
2017 if (!portdev) {
2018 err = -ENOMEM;
2019 goto fail;
2020 }
2021
2022 /* Attach this portdev to this virtio_device, and vice-versa. */
2023 portdev->vdev = vdev;
2024 vdev->priv = portdev;
2025
2026 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
2027 &portdev_fops);
2028 if (portdev->chr_major < 0) {
2029 dev_err(&vdev->dev,
2030 "Error %d registering chrdev for device %u\n",
2031 portdev->chr_major, vdev->index);
2032 err = portdev->chr_major;
2033 goto free;
2034 }
2035
2036 multiport = false;
2037 portdev->max_nr_ports = 1;
2038
2039 /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
2040 if (!is_rproc_serial(vdev) &&
2041 virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
2042 struct virtio_console_config, max_nr_ports,
2043 &portdev->max_nr_ports) == 0) {
2044 multiport = true;
2045 }
2046
2047 err = init_vqs(portdev);
2048 if (err < 0) {
2049 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2050 goto free_chrdev;
2051 }
2052
2053 spin_lock_init(&portdev->ports_lock);
2054 INIT_LIST_HEAD(&portdev->ports);
2055 INIT_LIST_HEAD(&portdev->list);
2056
2057 virtio_device_ready(portdev->vdev);
2058
2059 INIT_WORK(&portdev->config_work, &config_work_handler);
2060 INIT_WORK(&portdev->control_work, &control_work_handler);
2061
2062 if (multiport) {
2063 spin_lock_init(&portdev->c_ivq_lock);
2064 spin_lock_init(&portdev->c_ovq_lock);
2065
2066 err = fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2067 if (err < 0) {
2068 dev_err(&vdev->dev,
2069 "Error allocating buffers for control queue\n");
2070 /*
2071 * The host might want to notify mgmt sw about device
2072 * add failure.
2073 */
2074 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2075 VIRTIO_CONSOLE_DEVICE_READY, 0);
2076 /* Device was functional: we need full cleanup. */
2077 virtcons_remove(vdev);
2078 return err;
2079 }
2080 } else {
2081 /*
2082 * For backward compatibility: Create a console port
2083 * if we're running on older host.
2084 */
2085 add_port(portdev, 0);
2086 }
2087
2088 spin_lock_irq(&pdrvdata_lock);
2089 list_add_tail(&portdev->list, &pdrvdata.portdevs);
2090 spin_unlock_irq(&pdrvdata_lock);
2091
2092 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2093 VIRTIO_CONSOLE_DEVICE_READY, 1);
2094
2095 /*
2096 * If there was an early virtio console, assume that there are no
2097 * other consoles. We need to wait until the hvc_alloc matches the
2098 * hvc_instantiate, otherwise tty_open will complain, resulting in
2099 * a "Warning: unable to open an initial console" boot failure.
2100 * Without multiport this is done in add_port above. With multiport
2101 * this might take some host<->guest communication - thus we have to
2102 * wait.
2103 */
2104 if (multiport && early)
2105 wait_for_completion(&early_console_added);
2106
2107 return 0;
2108
2109free_chrdev:
2110 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2111free:
2112 kfree(portdev);
2113fail:
2114 return err;
2115}
2116
2117static struct virtio_device_id id_table[] = {
2118 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2119 { 0 },
2120};
2121
2122static unsigned int features[] = {
2123 VIRTIO_CONSOLE_F_SIZE,
2124 VIRTIO_CONSOLE_F_MULTIPORT,
2125};
2126
2127static struct virtio_device_id rproc_serial_id_table[] = {
2128#if IS_ENABLED(CONFIG_REMOTEPROC)
2129 { VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2130#endif
2131 { 0 },
2132};
2133
2134static unsigned int rproc_serial_features[] = {
2135};
2136
2137#ifdef CONFIG_PM_SLEEP
2138static int virtcons_freeze(struct virtio_device *vdev)
2139{
2140 struct ports_device *portdev;
2141 struct port *port;
2142
2143 portdev = vdev->priv;
2144
2145 vdev->config->reset(vdev);
2146
2147 if (use_multiport(portdev))
2148 virtqueue_disable_cb(portdev->c_ivq);
2149 cancel_work_sync(&portdev->control_work);
2150 cancel_work_sync(&portdev->config_work);
2151 /*
2152 * Once more: if control_work_handler() was running, it would
2153 * enable the cb as the last step.
2154 */
2155 if (use_multiport(portdev))
2156 virtqueue_disable_cb(portdev->c_ivq);
2157
2158 list_for_each_entry(port, &portdev->ports, list) {
2159 virtqueue_disable_cb(port->in_vq);
2160 virtqueue_disable_cb(port->out_vq);
2161 /*
2162 * We'll ask the host later if the new invocation has
2163 * the port opened or closed.
2164 */
2165 port->host_connected = false;
2166 remove_port_data(port);
2167 }
2168 remove_vqs(portdev);
2169
2170 return 0;
2171}
2172
2173static int virtcons_restore(struct virtio_device *vdev)
2174{
2175 struct ports_device *portdev;
2176 struct port *port;
2177 int ret;
2178
2179 portdev = vdev->priv;
2180
2181 ret = init_vqs(portdev);
2182 if (ret)
2183 return ret;
2184
2185 virtio_device_ready(portdev->vdev);
2186
2187 if (use_multiport(portdev))
2188 fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2189
2190 list_for_each_entry(port, &portdev->ports, list) {
2191 port->in_vq = portdev->in_vqs[port->id];
2192 port->out_vq = portdev->out_vqs[port->id];
2193
2194 fill_queue(port->in_vq, &port->inbuf_lock);
2195
2196 /* Get port open/close status on the host */
2197 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
2198
2199 /*
2200 * If a port was open at the time of suspending, we
2201 * have to let the host know that it's still open.
2202 */
2203 if (port->guest_connected)
2204 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
2205 }
2206 return 0;
2207}
2208#endif
2209
2210static struct virtio_driver virtio_console = {
2211 .feature_table = features,
2212 .feature_table_size = ARRAY_SIZE(features),
2213 .driver.name = KBUILD_MODNAME,
2214 .driver.owner = THIS_MODULE,
2215 .id_table = id_table,
2216 .probe = virtcons_probe,
2217 .remove = virtcons_remove,
2218 .config_changed = config_intr,
2219#ifdef CONFIG_PM_SLEEP
2220 .freeze = virtcons_freeze,
2221 .restore = virtcons_restore,
2222#endif
2223};
2224
2225static struct virtio_driver virtio_rproc_serial = {
2226 .feature_table = rproc_serial_features,
2227 .feature_table_size = ARRAY_SIZE(rproc_serial_features),
2228 .driver.name = "virtio_rproc_serial",
2229 .driver.owner = THIS_MODULE,
2230 .id_table = rproc_serial_id_table,
2231 .probe = virtcons_probe,
2232 .remove = virtcons_remove,
2233};
2234
2235static int __init init(void)
2236{
2237 int err;
2238
2239 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
2240 if (IS_ERR(pdrvdata.class)) {
2241 err = PTR_ERR(pdrvdata.class);
2242 pr_err("Error %d creating virtio-ports class\n", err);
2243 return err;
2244 }
2245
2246 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
2247 if (!pdrvdata.debugfs_dir)
2248 pr_warn("Error creating debugfs dir for virtio-ports\n");
2249 INIT_LIST_HEAD(&pdrvdata.consoles);
2250 INIT_LIST_HEAD(&pdrvdata.portdevs);
2251
2252 err = register_virtio_driver(&virtio_console);
2253 if (err < 0) {
2254 pr_err("Error %d registering virtio driver\n", err);
2255 goto free;
2256 }
2257 err = register_virtio_driver(&virtio_rproc_serial);
2258 if (err < 0) {
2259 pr_err("Error %d registering virtio rproc serial driver\n",
2260 err);
2261 goto unregister;
2262 }
2263 return 0;
2264unregister:
2265 unregister_virtio_driver(&virtio_console);
2266free:
2267 debugfs_remove_recursive(pdrvdata.debugfs_dir);
2268 class_destroy(pdrvdata.class);
2269 return err;
2270}
2271
2272static void __exit fini(void)
2273{
2274 reclaim_dma_bufs();
2275
2276 unregister_virtio_driver(&virtio_console);
2277 unregister_virtio_driver(&virtio_rproc_serial);
2278
2279 class_destroy(pdrvdata.class);
2280 debugfs_remove_recursive(pdrvdata.debugfs_dir);
2281}
2282module_init(init);
2283module_exit(fini);
2284
2285MODULE_DEVICE_TABLE(virtio, id_table);
2286MODULE_DESCRIPTION("Virtio console driver");
2287MODULE_LICENSE("GPL");