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-rw-r--r--drivers/tty/hvc/Makefile1
-rw-r--r--drivers/tty/hvc/virtio_console.c1838
2 files changed, 0 insertions, 1839 deletions
diff --git a/drivers/tty/hvc/Makefile b/drivers/tty/hvc/Makefile
index e6bed5f177ff..d79e7e9bf9d2 100644
--- a/drivers/tty/hvc/Makefile
+++ b/drivers/tty/hvc/Makefile
@@ -10,4 +10,3 @@ obj-$(CONFIG_HVC_XEN) += hvc_xen.o
10obj-$(CONFIG_HVC_IUCV) += hvc_iucv.o 10obj-$(CONFIG_HVC_IUCV) += hvc_iucv.o
11obj-$(CONFIG_HVC_UDBG) += hvc_udbg.o 11obj-$(CONFIG_HVC_UDBG) += hvc_udbg.o
12obj-$(CONFIG_HVCS) += hvcs.o 12obj-$(CONFIG_HVCS) += hvcs.o
13obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o
diff --git a/drivers/tty/hvc/virtio_console.c b/drivers/tty/hvc/virtio_console.c
deleted file mode 100644
index 896a2ced1d27..000000000000
--- a/drivers/tty/hvc/virtio_console.c
+++ /dev/null
@@ -1,1838 +0,0 @@
1/*
2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010 Red Hat, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19#include <linux/cdev.h>
20#include <linux/debugfs.h>
21#include <linux/device.h>
22#include <linux/err.h>
23#include <linux/fs.h>
24#include <linux/init.h>
25#include <linux/list.h>
26#include <linux/poll.h>
27#include <linux/sched.h>
28#include <linux/slab.h>
29#include <linux/spinlock.h>
30#include <linux/virtio.h>
31#include <linux/virtio_console.h>
32#include <linux/wait.h>
33#include <linux/workqueue.h>
34#include "hvc_console.h"
35
36/*
37 * This is a global struct for storing common data for all the devices
38 * this driver handles.
39 *
40 * Mainly, it has a linked list for all the consoles in one place so
41 * that callbacks from hvc for get_chars(), put_chars() work properly
42 * across multiple devices and multiple ports per device.
43 */
44struct ports_driver_data {
45 /* Used for registering chardevs */
46 struct class *class;
47
48 /* Used for exporting per-port information to debugfs */
49 struct dentry *debugfs_dir;
50
51 /* List of all the devices we're handling */
52 struct list_head portdevs;
53
54 /* Number of devices this driver is handling */
55 unsigned int index;
56
57 /*
58 * This is used to keep track of the number of hvc consoles
59 * spawned by this driver. This number is given as the first
60 * argument to hvc_alloc(). To correctly map an initial
61 * console spawned via hvc_instantiate to the console being
62 * hooked up via hvc_alloc, we need to pass the same vtermno.
63 *
64 * We also just assume the first console being initialised was
65 * the first one that got used as the initial console.
66 */
67 unsigned int next_vtermno;
68
69 /* All the console devices handled by this driver */
70 struct list_head consoles;
71};
72static struct ports_driver_data pdrvdata;
73
74DEFINE_SPINLOCK(pdrvdata_lock);
75
76/* This struct holds information that's relevant only for console ports */
77struct console {
78 /* We'll place all consoles in a list in the pdrvdata struct */
79 struct list_head list;
80
81 /* The hvc device associated with this console port */
82 struct hvc_struct *hvc;
83
84 /* The size of the console */
85 struct winsize ws;
86
87 /*
88 * This number identifies the number that we used to register
89 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
90 * number passed on by the hvc callbacks to us to
91 * differentiate between the other console ports handled by
92 * this driver
93 */
94 u32 vtermno;
95};
96
97struct port_buffer {
98 char *buf;
99
100 /* size of the buffer in *buf above */
101 size_t size;
102
103 /* used length of the buffer */
104 size_t len;
105 /* offset in the buf from which to consume data */
106 size_t offset;
107};
108
109/*
110 * This is a per-device struct that stores data common to all the
111 * ports for that device (vdev->priv).
112 */
113struct ports_device {
114 /* Next portdev in the list, head is in the pdrvdata struct */
115 struct list_head list;
116
117 /*
118 * Workqueue handlers where we process deferred work after
119 * notification
120 */
121 struct work_struct control_work;
122
123 struct list_head ports;
124
125 /* To protect the list of ports */
126 spinlock_t ports_lock;
127
128 /* To protect the vq operations for the control channel */
129 spinlock_t cvq_lock;
130
131 /* The current config space is stored here */
132 struct virtio_console_config config;
133
134 /* The virtio device we're associated with */
135 struct virtio_device *vdev;
136
137 /*
138 * A couple of virtqueues for the control channel: one for
139 * guest->host transfers, one for host->guest transfers
140 */
141 struct virtqueue *c_ivq, *c_ovq;
142
143 /* Array of per-port IO virtqueues */
144 struct virtqueue **in_vqs, **out_vqs;
145
146 /* Used for numbering devices for sysfs and debugfs */
147 unsigned int drv_index;
148
149 /* Major number for this device. Ports will be created as minors. */
150 int chr_major;
151};
152
153/* This struct holds the per-port data */
154struct port {
155 /* Next port in the list, head is in the ports_device */
156 struct list_head list;
157
158 /* Pointer to the parent virtio_console device */
159 struct ports_device *portdev;
160
161 /* The current buffer from which data has to be fed to readers */
162 struct port_buffer *inbuf;
163
164 /*
165 * To protect the operations on the in_vq associated with this
166 * port. Has to be a spinlock because it can be called from
167 * interrupt context (get_char()).
168 */
169 spinlock_t inbuf_lock;
170
171 /* Protect the operations on the out_vq. */
172 spinlock_t outvq_lock;
173
174 /* The IO vqs for this port */
175 struct virtqueue *in_vq, *out_vq;
176
177 /* File in the debugfs directory that exposes this port's information */
178 struct dentry *debugfs_file;
179
180 /*
181 * The entries in this struct will be valid if this port is
182 * hooked up to an hvc console
183 */
184 struct console cons;
185
186 /* Each port associates with a separate char device */
187 struct cdev *cdev;
188 struct device *dev;
189
190 /* Reference-counting to handle port hot-unplugs and file operations */
191 struct kref kref;
192
193 /* A waitqueue for poll() or blocking read operations */
194 wait_queue_head_t waitqueue;
195
196 /* The 'name' of the port that we expose via sysfs properties */
197 char *name;
198
199 /* We can notify apps of host connect / disconnect events via SIGIO */
200 struct fasync_struct *async_queue;
201
202 /* The 'id' to identify the port with the Host */
203 u32 id;
204
205 bool outvq_full;
206
207 /* Is the host device open */
208 bool host_connected;
209
210 /* We should allow only one process to open a port */
211 bool guest_connected;
212};
213
214/* This is the very early arch-specified put chars function. */
215static int (*early_put_chars)(u32, const char *, int);
216
217static struct port *find_port_by_vtermno(u32 vtermno)
218{
219 struct port *port;
220 struct console *cons;
221 unsigned long flags;
222
223 spin_lock_irqsave(&pdrvdata_lock, flags);
224 list_for_each_entry(cons, &pdrvdata.consoles, list) {
225 if (cons->vtermno == vtermno) {
226 port = container_of(cons, struct port, cons);
227 goto out;
228 }
229 }
230 port = NULL;
231out:
232 spin_unlock_irqrestore(&pdrvdata_lock, flags);
233 return port;
234}
235
236static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
237 dev_t dev)
238{
239 struct port *port;
240 unsigned long flags;
241
242 spin_lock_irqsave(&portdev->ports_lock, flags);
243 list_for_each_entry(port, &portdev->ports, list)
244 if (port->cdev->dev == dev)
245 goto out;
246 port = NULL;
247out:
248 spin_unlock_irqrestore(&portdev->ports_lock, flags);
249
250 return port;
251}
252
253static struct port *find_port_by_devt(dev_t dev)
254{
255 struct ports_device *portdev;
256 struct port *port;
257 unsigned long flags;
258
259 spin_lock_irqsave(&pdrvdata_lock, flags);
260 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
261 port = find_port_by_devt_in_portdev(portdev, dev);
262 if (port)
263 goto out;
264 }
265 port = NULL;
266out:
267 spin_unlock_irqrestore(&pdrvdata_lock, flags);
268 return port;
269}
270
271static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
272{
273 struct port *port;
274 unsigned long flags;
275
276 spin_lock_irqsave(&portdev->ports_lock, flags);
277 list_for_each_entry(port, &portdev->ports, list)
278 if (port->id == id)
279 goto out;
280 port = NULL;
281out:
282 spin_unlock_irqrestore(&portdev->ports_lock, flags);
283
284 return port;
285}
286
287static struct port *find_port_by_vq(struct ports_device *portdev,
288 struct virtqueue *vq)
289{
290 struct port *port;
291 unsigned long flags;
292
293 spin_lock_irqsave(&portdev->ports_lock, flags);
294 list_for_each_entry(port, &portdev->ports, list)
295 if (port->in_vq == vq || port->out_vq == vq)
296 goto out;
297 port = NULL;
298out:
299 spin_unlock_irqrestore(&portdev->ports_lock, flags);
300 return port;
301}
302
303static bool is_console_port(struct port *port)
304{
305 if (port->cons.hvc)
306 return true;
307 return false;
308}
309
310static inline bool use_multiport(struct ports_device *portdev)
311{
312 /*
313 * This condition can be true when put_chars is called from
314 * early_init
315 */
316 if (!portdev->vdev)
317 return 0;
318 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
319}
320
321static void free_buf(struct port_buffer *buf)
322{
323 kfree(buf->buf);
324 kfree(buf);
325}
326
327static struct port_buffer *alloc_buf(size_t buf_size)
328{
329 struct port_buffer *buf;
330
331 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
332 if (!buf)
333 goto fail;
334 buf->buf = kzalloc(buf_size, GFP_KERNEL);
335 if (!buf->buf)
336 goto free_buf;
337 buf->len = 0;
338 buf->offset = 0;
339 buf->size = buf_size;
340 return buf;
341
342free_buf:
343 kfree(buf);
344fail:
345 return NULL;
346}
347
348/* Callers should take appropriate locks */
349static void *get_inbuf(struct port *port)
350{
351 struct port_buffer *buf;
352 struct virtqueue *vq;
353 unsigned int len;
354
355 vq = port->in_vq;
356 buf = virtqueue_get_buf(vq, &len);
357 if (buf) {
358 buf->len = len;
359 buf->offset = 0;
360 }
361 return buf;
362}
363
364/*
365 * Create a scatter-gather list representing our input buffer and put
366 * it in the queue.
367 *
368 * Callers should take appropriate locks.
369 */
370static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
371{
372 struct scatterlist sg[1];
373 int ret;
374
375 sg_init_one(sg, buf->buf, buf->size);
376
377 ret = virtqueue_add_buf(vq, sg, 0, 1, buf);
378 virtqueue_kick(vq);
379 return ret;
380}
381
382/* Discard any unread data this port has. Callers lockers. */
383static void discard_port_data(struct port *port)
384{
385 struct port_buffer *buf;
386 struct virtqueue *vq;
387 unsigned int len;
388 int ret;
389
390 vq = port->in_vq;
391 if (port->inbuf)
392 buf = port->inbuf;
393 else
394 buf = virtqueue_get_buf(vq, &len);
395
396 ret = 0;
397 while (buf) {
398 if (add_inbuf(vq, buf) < 0) {
399 ret++;
400 free_buf(buf);
401 }
402 buf = virtqueue_get_buf(vq, &len);
403 }
404 port->inbuf = NULL;
405 if (ret)
406 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
407 ret);
408}
409
410static bool port_has_data(struct port *port)
411{
412 unsigned long flags;
413 bool ret;
414
415 spin_lock_irqsave(&port->inbuf_lock, flags);
416 if (port->inbuf) {
417 ret = true;
418 goto out;
419 }
420 port->inbuf = get_inbuf(port);
421 if (port->inbuf) {
422 ret = true;
423 goto out;
424 }
425 ret = false;
426out:
427 spin_unlock_irqrestore(&port->inbuf_lock, flags);
428 return ret;
429}
430
431static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
432 unsigned int event, unsigned int value)
433{
434 struct scatterlist sg[1];
435 struct virtio_console_control cpkt;
436 struct virtqueue *vq;
437 unsigned int len;
438
439 if (!use_multiport(portdev))
440 return 0;
441
442 cpkt.id = port_id;
443 cpkt.event = event;
444 cpkt.value = value;
445
446 vq = portdev->c_ovq;
447
448 sg_init_one(sg, &cpkt, sizeof(cpkt));
449 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
450 virtqueue_kick(vq);
451 while (!virtqueue_get_buf(vq, &len))
452 cpu_relax();
453 }
454 return 0;
455}
456
457static ssize_t send_control_msg(struct port *port, unsigned int event,
458 unsigned int value)
459{
460 /* Did the port get unplugged before userspace closed it? */
461 if (port->portdev)
462 return __send_control_msg(port->portdev, port->id, event, value);
463 return 0;
464}
465
466/* Callers must take the port->outvq_lock */
467static void reclaim_consumed_buffers(struct port *port)
468{
469 void *buf;
470 unsigned int len;
471
472 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
473 kfree(buf);
474 port->outvq_full = false;
475 }
476}
477
478static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
479 bool nonblock)
480{
481 struct scatterlist sg[1];
482 struct virtqueue *out_vq;
483 ssize_t ret;
484 unsigned long flags;
485 unsigned int len;
486
487 out_vq = port->out_vq;
488
489 spin_lock_irqsave(&port->outvq_lock, flags);
490
491 reclaim_consumed_buffers(port);
492
493 sg_init_one(sg, in_buf, in_count);
494 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf);
495
496 /* Tell Host to go! */
497 virtqueue_kick(out_vq);
498
499 if (ret < 0) {
500 in_count = 0;
501 goto done;
502 }
503
504 if (ret == 0)
505 port->outvq_full = true;
506
507 if (nonblock)
508 goto done;
509
510 /*
511 * Wait till the host acknowledges it pushed out the data we
512 * sent. This is done for data from the hvc_console; the tty
513 * operations are performed with spinlocks held so we can't
514 * sleep here. An alternative would be to copy the data to a
515 * buffer and relax the spinning requirement. The downside is
516 * we need to kmalloc a GFP_ATOMIC buffer each time the
517 * console driver writes something out.
518 */
519 while (!virtqueue_get_buf(out_vq, &len))
520 cpu_relax();
521done:
522 spin_unlock_irqrestore(&port->outvq_lock, flags);
523 /*
524 * We're expected to return the amount of data we wrote -- all
525 * of it
526 */
527 return in_count;
528}
529
530/*
531 * Give out the data that's requested from the buffer that we have
532 * queued up.
533 */
534static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
535 bool to_user)
536{
537 struct port_buffer *buf;
538 unsigned long flags;
539
540 if (!out_count || !port_has_data(port))
541 return 0;
542
543 buf = port->inbuf;
544 out_count = min(out_count, buf->len - buf->offset);
545
546 if (to_user) {
547 ssize_t ret;
548
549 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
550 if (ret)
551 return -EFAULT;
552 } else {
553 memcpy(out_buf, buf->buf + buf->offset, out_count);
554 }
555
556 buf->offset += out_count;
557
558 if (buf->offset == buf->len) {
559 /*
560 * We're done using all the data in this buffer.
561 * Re-queue so that the Host can send us more data.
562 */
563 spin_lock_irqsave(&port->inbuf_lock, flags);
564 port->inbuf = NULL;
565
566 if (add_inbuf(port->in_vq, buf) < 0)
567 dev_warn(port->dev, "failed add_buf\n");
568
569 spin_unlock_irqrestore(&port->inbuf_lock, flags);
570 }
571 /* Return the number of bytes actually copied */
572 return out_count;
573}
574
575/* The condition that must be true for polling to end */
576static bool will_read_block(struct port *port)
577{
578 if (!port->guest_connected) {
579 /* Port got hot-unplugged. Let's exit. */
580 return false;
581 }
582 return !port_has_data(port) && port->host_connected;
583}
584
585static bool will_write_block(struct port *port)
586{
587 bool ret;
588
589 if (!port->guest_connected) {
590 /* Port got hot-unplugged. Let's exit. */
591 return false;
592 }
593 if (!port->host_connected)
594 return true;
595
596 spin_lock_irq(&port->outvq_lock);
597 /*
598 * Check if the Host has consumed any buffers since we last
599 * sent data (this is only applicable for nonblocking ports).
600 */
601 reclaim_consumed_buffers(port);
602 ret = port->outvq_full;
603 spin_unlock_irq(&port->outvq_lock);
604
605 return ret;
606}
607
608static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
609 size_t count, loff_t *offp)
610{
611 struct port *port;
612 ssize_t ret;
613
614 port = filp->private_data;
615
616 if (!port_has_data(port)) {
617 /*
618 * If nothing's connected on the host just return 0 in
619 * case of list_empty; this tells the userspace app
620 * that there's no connection
621 */
622 if (!port->host_connected)
623 return 0;
624 if (filp->f_flags & O_NONBLOCK)
625 return -EAGAIN;
626
627 ret = wait_event_interruptible(port->waitqueue,
628 !will_read_block(port));
629 if (ret < 0)
630 return ret;
631 }
632 /* Port got hot-unplugged. */
633 if (!port->guest_connected)
634 return -ENODEV;
635 /*
636 * We could've received a disconnection message while we were
637 * waiting for more data.
638 *
639 * This check is not clubbed in the if() statement above as we
640 * might receive some data as well as the host could get
641 * disconnected after we got woken up from our wait. So we
642 * really want to give off whatever data we have and only then
643 * check for host_connected.
644 */
645 if (!port_has_data(port) && !port->host_connected)
646 return 0;
647
648 return fill_readbuf(port, ubuf, count, true);
649}
650
651static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
652 size_t count, loff_t *offp)
653{
654 struct port *port;
655 char *buf;
656 ssize_t ret;
657 bool nonblock;
658
659 /* Userspace could be out to fool us */
660 if (!count)
661 return 0;
662
663 port = filp->private_data;
664
665 nonblock = filp->f_flags & O_NONBLOCK;
666
667 if (will_write_block(port)) {
668 if (nonblock)
669 return -EAGAIN;
670
671 ret = wait_event_interruptible(port->waitqueue,
672 !will_write_block(port));
673 if (ret < 0)
674 return ret;
675 }
676 /* Port got hot-unplugged. */
677 if (!port->guest_connected)
678 return -ENODEV;
679
680 count = min((size_t)(32 * 1024), count);
681
682 buf = kmalloc(count, GFP_KERNEL);
683 if (!buf)
684 return -ENOMEM;
685
686 ret = copy_from_user(buf, ubuf, count);
687 if (ret) {
688 ret = -EFAULT;
689 goto free_buf;
690 }
691
692 /*
693 * We now ask send_buf() to not spin for generic ports -- we
694 * can re-use the same code path that non-blocking file
695 * descriptors take for blocking file descriptors since the
696 * wait is already done and we're certain the write will go
697 * through to the host.
698 */
699 nonblock = true;
700 ret = send_buf(port, buf, count, nonblock);
701
702 if (nonblock && ret > 0)
703 goto out;
704
705free_buf:
706 kfree(buf);
707out:
708 return ret;
709}
710
711static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
712{
713 struct port *port;
714 unsigned int ret;
715
716 port = filp->private_data;
717 poll_wait(filp, &port->waitqueue, wait);
718
719 if (!port->guest_connected) {
720 /* Port got unplugged */
721 return POLLHUP;
722 }
723 ret = 0;
724 if (!will_read_block(port))
725 ret |= POLLIN | POLLRDNORM;
726 if (!will_write_block(port))
727 ret |= POLLOUT;
728 if (!port->host_connected)
729 ret |= POLLHUP;
730
731 return ret;
732}
733
734static void remove_port(struct kref *kref);
735
736static int port_fops_release(struct inode *inode, struct file *filp)
737{
738 struct port *port;
739
740 port = filp->private_data;
741
742 /* Notify host of port being closed */
743 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
744
745 spin_lock_irq(&port->inbuf_lock);
746 port->guest_connected = false;
747
748 discard_port_data(port);
749
750 spin_unlock_irq(&port->inbuf_lock);
751
752 spin_lock_irq(&port->outvq_lock);
753 reclaim_consumed_buffers(port);
754 spin_unlock_irq(&port->outvq_lock);
755
756 /*
757 * Locks aren't necessary here as a port can't be opened after
758 * unplug, and if a port isn't unplugged, a kref would already
759 * exist for the port. Plus, taking ports_lock here would
760 * create a dependency on other locks taken by functions
761 * inside remove_port if we're the last holder of the port,
762 * creating many problems.
763 */
764 kref_put(&port->kref, remove_port);
765
766 return 0;
767}
768
769static int port_fops_open(struct inode *inode, struct file *filp)
770{
771 struct cdev *cdev = inode->i_cdev;
772 struct port *port;
773 int ret;
774
775 port = find_port_by_devt(cdev->dev);
776 filp->private_data = port;
777
778 /* Prevent against a port getting hot-unplugged at the same time */
779 spin_lock_irq(&port->portdev->ports_lock);
780 kref_get(&port->kref);
781 spin_unlock_irq(&port->portdev->ports_lock);
782
783 /*
784 * Don't allow opening of console port devices -- that's done
785 * via /dev/hvc
786 */
787 if (is_console_port(port)) {
788 ret = -ENXIO;
789 goto out;
790 }
791
792 /* Allow only one process to open a particular port at a time */
793 spin_lock_irq(&port->inbuf_lock);
794 if (port->guest_connected) {
795 spin_unlock_irq(&port->inbuf_lock);
796 ret = -EMFILE;
797 goto out;
798 }
799
800 port->guest_connected = true;
801 spin_unlock_irq(&port->inbuf_lock);
802
803 spin_lock_irq(&port->outvq_lock);
804 /*
805 * There might be a chance that we missed reclaiming a few
806 * buffers in the window of the port getting previously closed
807 * and opening now.
808 */
809 reclaim_consumed_buffers(port);
810 spin_unlock_irq(&port->outvq_lock);
811
812 nonseekable_open(inode, filp);
813
814 /* Notify host of port being opened */
815 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
816
817 return 0;
818out:
819 kref_put(&port->kref, remove_port);
820 return ret;
821}
822
823static int port_fops_fasync(int fd, struct file *filp, int mode)
824{
825 struct port *port;
826
827 port = filp->private_data;
828 return fasync_helper(fd, filp, mode, &port->async_queue);
829}
830
831/*
832 * The file operations that we support: programs in the guest can open
833 * a console device, read from it, write to it, poll for data and
834 * close it. The devices are at
835 * /dev/vport<device number>p<port number>
836 */
837static const struct file_operations port_fops = {
838 .owner = THIS_MODULE,
839 .open = port_fops_open,
840 .read = port_fops_read,
841 .write = port_fops_write,
842 .poll = port_fops_poll,
843 .release = port_fops_release,
844 .fasync = port_fops_fasync,
845 .llseek = no_llseek,
846};
847
848/*
849 * The put_chars() callback is pretty straightforward.
850 *
851 * We turn the characters into a scatter-gather list, add it to the
852 * output queue and then kick the Host. Then we sit here waiting for
853 * it to finish: inefficient in theory, but in practice
854 * implementations will do it immediately (lguest's Launcher does).
855 */
856static int put_chars(u32 vtermno, const char *buf, int count)
857{
858 struct port *port;
859
860 if (unlikely(early_put_chars))
861 return early_put_chars(vtermno, buf, count);
862
863 port = find_port_by_vtermno(vtermno);
864 if (!port)
865 return -EPIPE;
866
867 return send_buf(port, (void *)buf, count, false);
868}
869
870/*
871 * get_chars() is the callback from the hvc_console infrastructure
872 * when an interrupt is received.
873 *
874 * We call out to fill_readbuf that gets us the required data from the
875 * buffers that are queued up.
876 */
877static int get_chars(u32 vtermno, char *buf, int count)
878{
879 struct port *port;
880
881 /* If we've not set up the port yet, we have no input to give. */
882 if (unlikely(early_put_chars))
883 return 0;
884
885 port = find_port_by_vtermno(vtermno);
886 if (!port)
887 return -EPIPE;
888
889 /* If we don't have an input queue yet, we can't get input. */
890 BUG_ON(!port->in_vq);
891
892 return fill_readbuf(port, buf, count, false);
893}
894
895static void resize_console(struct port *port)
896{
897 struct virtio_device *vdev;
898
899 /* The port could have been hot-unplugged */
900 if (!port || !is_console_port(port))
901 return;
902
903 vdev = port->portdev->vdev;
904 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
905 hvc_resize(port->cons.hvc, port->cons.ws);
906}
907
908/* We set the configuration at this point, since we now have a tty */
909static int notifier_add_vio(struct hvc_struct *hp, int data)
910{
911 struct port *port;
912
913 port = find_port_by_vtermno(hp->vtermno);
914 if (!port)
915 return -EINVAL;
916
917 hp->irq_requested = 1;
918 resize_console(port);
919
920 return 0;
921}
922
923static void notifier_del_vio(struct hvc_struct *hp, int data)
924{
925 hp->irq_requested = 0;
926}
927
928/* The operations for console ports. */
929static const struct hv_ops hv_ops = {
930 .get_chars = get_chars,
931 .put_chars = put_chars,
932 .notifier_add = notifier_add_vio,
933 .notifier_del = notifier_del_vio,
934 .notifier_hangup = notifier_del_vio,
935};
936
937/*
938 * Console drivers are initialized very early so boot messages can go
939 * out, so we do things slightly differently from the generic virtio
940 * initialization of the net and block drivers.
941 *
942 * At this stage, the console is output-only. It's too early to set
943 * up a virtqueue, so we let the drivers do some boutique early-output
944 * thing.
945 */
946int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
947{
948 early_put_chars = put_chars;
949 return hvc_instantiate(0, 0, &hv_ops);
950}
951
952int init_port_console(struct port *port)
953{
954 int ret;
955
956 /*
957 * The Host's telling us this port is a console port. Hook it
958 * up with an hvc console.
959 *
960 * To set up and manage our virtual console, we call
961 * hvc_alloc().
962 *
963 * The first argument of hvc_alloc() is the virtual console
964 * number. The second argument is the parameter for the
965 * notification mechanism (like irq number). We currently
966 * leave this as zero, virtqueues have implicit notifications.
967 *
968 * The third argument is a "struct hv_ops" containing the
969 * put_chars() get_chars(), notifier_add() and notifier_del()
970 * pointers. The final argument is the output buffer size: we
971 * can do any size, so we put PAGE_SIZE here.
972 */
973 port->cons.vtermno = pdrvdata.next_vtermno;
974
975 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
976 if (IS_ERR(port->cons.hvc)) {
977 ret = PTR_ERR(port->cons.hvc);
978 dev_err(port->dev,
979 "error %d allocating hvc for port\n", ret);
980 port->cons.hvc = NULL;
981 return ret;
982 }
983 spin_lock_irq(&pdrvdata_lock);
984 pdrvdata.next_vtermno++;
985 list_add_tail(&port->cons.list, &pdrvdata.consoles);
986 spin_unlock_irq(&pdrvdata_lock);
987 port->guest_connected = true;
988
989 /*
990 * Start using the new console output if this is the first
991 * console to come up.
992 */
993 if (early_put_chars)
994 early_put_chars = NULL;
995
996 /* Notify host of port being opened */
997 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
998
999 return 0;
1000}
1001
1002static ssize_t show_port_name(struct device *dev,
1003 struct device_attribute *attr, char *buffer)
1004{
1005 struct port *port;
1006
1007 port = dev_get_drvdata(dev);
1008
1009 return sprintf(buffer, "%s\n", port->name);
1010}
1011
1012static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1013
1014static struct attribute *port_sysfs_entries[] = {
1015 &dev_attr_name.attr,
1016 NULL
1017};
1018
1019static struct attribute_group port_attribute_group = {
1020 .name = NULL, /* put in device directory */
1021 .attrs = port_sysfs_entries,
1022};
1023
1024static int debugfs_open(struct inode *inode, struct file *filp)
1025{
1026 filp->private_data = inode->i_private;
1027 return 0;
1028}
1029
1030static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1031 size_t count, loff_t *offp)
1032{
1033 struct port *port;
1034 char *buf;
1035 ssize_t ret, out_offset, out_count;
1036
1037 out_count = 1024;
1038 buf = kmalloc(out_count, GFP_KERNEL);
1039 if (!buf)
1040 return -ENOMEM;
1041
1042 port = filp->private_data;
1043 out_offset = 0;
1044 out_offset += snprintf(buf + out_offset, out_count,
1045 "name: %s\n", port->name ? port->name : "");
1046 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1047 "guest_connected: %d\n", port->guest_connected);
1048 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1049 "host_connected: %d\n", port->host_connected);
1050 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1051 "outvq_full: %d\n", port->outvq_full);
1052 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1053 "is_console: %s\n",
1054 is_console_port(port) ? "yes" : "no");
1055 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1056 "console_vtermno: %u\n", port->cons.vtermno);
1057
1058 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1059 kfree(buf);
1060 return ret;
1061}
1062
1063static const struct file_operations port_debugfs_ops = {
1064 .owner = THIS_MODULE,
1065 .open = debugfs_open,
1066 .read = debugfs_read,
1067};
1068
1069static void set_console_size(struct port *port, u16 rows, u16 cols)
1070{
1071 if (!port || !is_console_port(port))
1072 return;
1073
1074 port->cons.ws.ws_row = rows;
1075 port->cons.ws.ws_col = cols;
1076}
1077
1078static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1079{
1080 struct port_buffer *buf;
1081 unsigned int nr_added_bufs;
1082 int ret;
1083
1084 nr_added_bufs = 0;
1085 do {
1086 buf = alloc_buf(PAGE_SIZE);
1087 if (!buf)
1088 break;
1089
1090 spin_lock_irq(lock);
1091 ret = add_inbuf(vq, buf);
1092 if (ret < 0) {
1093 spin_unlock_irq(lock);
1094 free_buf(buf);
1095 break;
1096 }
1097 nr_added_bufs++;
1098 spin_unlock_irq(lock);
1099 } while (ret > 0);
1100
1101 return nr_added_bufs;
1102}
1103
1104static void send_sigio_to_port(struct port *port)
1105{
1106 if (port->async_queue && port->guest_connected)
1107 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1108}
1109
1110static int add_port(struct ports_device *portdev, u32 id)
1111{
1112 char debugfs_name[16];
1113 struct port *port;
1114 struct port_buffer *buf;
1115 dev_t devt;
1116 unsigned int nr_added_bufs;
1117 int err;
1118
1119 port = kmalloc(sizeof(*port), GFP_KERNEL);
1120 if (!port) {
1121 err = -ENOMEM;
1122 goto fail;
1123 }
1124 kref_init(&port->kref);
1125
1126 port->portdev = portdev;
1127 port->id = id;
1128
1129 port->name = NULL;
1130 port->inbuf = NULL;
1131 port->cons.hvc = NULL;
1132 port->async_queue = NULL;
1133
1134 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1135
1136 port->host_connected = port->guest_connected = false;
1137
1138 port->outvq_full = false;
1139
1140 port->in_vq = portdev->in_vqs[port->id];
1141 port->out_vq = portdev->out_vqs[port->id];
1142
1143 port->cdev = cdev_alloc();
1144 if (!port->cdev) {
1145 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1146 err = -ENOMEM;
1147 goto free_port;
1148 }
1149 port->cdev->ops = &port_fops;
1150
1151 devt = MKDEV(portdev->chr_major, id);
1152 err = cdev_add(port->cdev, devt, 1);
1153 if (err < 0) {
1154 dev_err(&port->portdev->vdev->dev,
1155 "Error %d adding cdev for port %u\n", err, id);
1156 goto free_cdev;
1157 }
1158 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1159 devt, port, "vport%up%u",
1160 port->portdev->drv_index, id);
1161 if (IS_ERR(port->dev)) {
1162 err = PTR_ERR(port->dev);
1163 dev_err(&port->portdev->vdev->dev,
1164 "Error %d creating device for port %u\n",
1165 err, id);
1166 goto free_cdev;
1167 }
1168
1169 spin_lock_init(&port->inbuf_lock);
1170 spin_lock_init(&port->outvq_lock);
1171 init_waitqueue_head(&port->waitqueue);
1172
1173 /* Fill the in_vq with buffers so the host can send us data. */
1174 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1175 if (!nr_added_bufs) {
1176 dev_err(port->dev, "Error allocating inbufs\n");
1177 err = -ENOMEM;
1178 goto free_device;
1179 }
1180
1181 /*
1182 * If we're not using multiport support, this has to be a console port
1183 */
1184 if (!use_multiport(port->portdev)) {
1185 err = init_port_console(port);
1186 if (err)
1187 goto free_inbufs;
1188 }
1189
1190 spin_lock_irq(&portdev->ports_lock);
1191 list_add_tail(&port->list, &port->portdev->ports);
1192 spin_unlock_irq(&portdev->ports_lock);
1193
1194 /*
1195 * Tell the Host we're set so that it can send us various
1196 * configuration parameters for this port (eg, port name,
1197 * caching, whether this is a console port, etc.)
1198 */
1199 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1200
1201 if (pdrvdata.debugfs_dir) {
1202 /*
1203 * Finally, create the debugfs file that we can use to
1204 * inspect a port's state at any time
1205 */
1206 sprintf(debugfs_name, "vport%up%u",
1207 port->portdev->drv_index, id);
1208 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1209 pdrvdata.debugfs_dir,
1210 port,
1211 &port_debugfs_ops);
1212 }
1213 return 0;
1214
1215free_inbufs:
1216 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1217 free_buf(buf);
1218free_device:
1219 device_destroy(pdrvdata.class, port->dev->devt);
1220free_cdev:
1221 cdev_del(port->cdev);
1222free_port:
1223 kfree(port);
1224fail:
1225 /* The host might want to notify management sw about port add failure */
1226 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1227 return err;
1228}
1229
1230/* No users remain, remove all port-specific data. */
1231static void remove_port(struct kref *kref)
1232{
1233 struct port *port;
1234
1235 port = container_of(kref, struct port, kref);
1236
1237 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1238 device_destroy(pdrvdata.class, port->dev->devt);
1239 cdev_del(port->cdev);
1240
1241 kfree(port->name);
1242
1243 debugfs_remove(port->debugfs_file);
1244
1245 kfree(port);
1246}
1247
1248/*
1249 * Port got unplugged. Remove port from portdev's list and drop the
1250 * kref reference. If no userspace has this port opened, it will
1251 * result in immediate removal the port.
1252 */
1253static void unplug_port(struct port *port)
1254{
1255 struct port_buffer *buf;
1256
1257 spin_lock_irq(&port->portdev->ports_lock);
1258 list_del(&port->list);
1259 spin_unlock_irq(&port->portdev->ports_lock);
1260
1261 if (port->guest_connected) {
1262 port->guest_connected = false;
1263 port->host_connected = false;
1264 wake_up_interruptible(&port->waitqueue);
1265
1266 /* Let the app know the port is going down. */
1267 send_sigio_to_port(port);
1268 }
1269
1270 if (is_console_port(port)) {
1271 spin_lock_irq(&pdrvdata_lock);
1272 list_del(&port->cons.list);
1273 spin_unlock_irq(&pdrvdata_lock);
1274#if 0
1275 /*
1276 * hvc_remove() not called as removing one hvc port
1277 * results in other hvc ports getting frozen.
1278 *
1279 * Once this is resolved in hvc, this functionality
1280 * will be enabled. Till that is done, the -EPIPE
1281 * return from get_chars() above will help
1282 * hvc_console.c to clean up on ports we remove here.
1283 */
1284 hvc_remove(port->cons.hvc);
1285#endif
1286 }
1287
1288 /* Remove unused data this port might have received. */
1289 discard_port_data(port);
1290
1291 reclaim_consumed_buffers(port);
1292
1293 /* Remove buffers we queued up for the Host to send us data in. */
1294 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1295 free_buf(buf);
1296
1297 /*
1298 * We should just assume the device itself has gone off --
1299 * else a close on an open port later will try to send out a
1300 * control message.
1301 */
1302 port->portdev = NULL;
1303
1304 /*
1305 * Locks around here are not necessary - a port can't be
1306 * opened after we removed the port struct from ports_list
1307 * above.
1308 */
1309 kref_put(&port->kref, remove_port);
1310}
1311
1312/* Any private messages that the Host and Guest want to share */
1313static void handle_control_message(struct ports_device *portdev,
1314 struct port_buffer *buf)
1315{
1316 struct virtio_console_control *cpkt;
1317 struct port *port;
1318 size_t name_size;
1319 int err;
1320
1321 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1322
1323 port = find_port_by_id(portdev, cpkt->id);
1324 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1325 /* No valid header at start of buffer. Drop it. */
1326 dev_dbg(&portdev->vdev->dev,
1327 "Invalid index %u in control packet\n", cpkt->id);
1328 return;
1329 }
1330
1331 switch (cpkt->event) {
1332 case VIRTIO_CONSOLE_PORT_ADD:
1333 if (port) {
1334 dev_dbg(&portdev->vdev->dev,
1335 "Port %u already added\n", port->id);
1336 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1337 break;
1338 }
1339 if (cpkt->id >= portdev->config.max_nr_ports) {
1340 dev_warn(&portdev->vdev->dev,
1341 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1342 cpkt->id, portdev->config.max_nr_ports - 1);
1343 break;
1344 }
1345 add_port(portdev, cpkt->id);
1346 break;
1347 case VIRTIO_CONSOLE_PORT_REMOVE:
1348 unplug_port(port);
1349 break;
1350 case VIRTIO_CONSOLE_CONSOLE_PORT:
1351 if (!cpkt->value)
1352 break;
1353 if (is_console_port(port))
1354 break;
1355
1356 init_port_console(port);
1357 /*
1358 * Could remove the port here in case init fails - but
1359 * have to notify the host first.
1360 */
1361 break;
1362 case VIRTIO_CONSOLE_RESIZE: {
1363 struct {
1364 __u16 rows;
1365 __u16 cols;
1366 } size;
1367
1368 if (!is_console_port(port))
1369 break;
1370
1371 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1372 sizeof(size));
1373 set_console_size(port, size.rows, size.cols);
1374
1375 port->cons.hvc->irq_requested = 1;
1376 resize_console(port);
1377 break;
1378 }
1379 case VIRTIO_CONSOLE_PORT_OPEN:
1380 port->host_connected = cpkt->value;
1381 wake_up_interruptible(&port->waitqueue);
1382 /*
1383 * If the host port got closed and the host had any
1384 * unconsumed buffers, we'll be able to reclaim them
1385 * now.
1386 */
1387 spin_lock_irq(&port->outvq_lock);
1388 reclaim_consumed_buffers(port);
1389 spin_unlock_irq(&port->outvq_lock);
1390
1391 /*
1392 * If the guest is connected, it'll be interested in
1393 * knowing the host connection state changed.
1394 */
1395 send_sigio_to_port(port);
1396 break;
1397 case VIRTIO_CONSOLE_PORT_NAME:
1398 /*
1399 * Skip the size of the header and the cpkt to get the size
1400 * of the name that was sent
1401 */
1402 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1403
1404 port->name = kmalloc(name_size, GFP_KERNEL);
1405 if (!port->name) {
1406 dev_err(port->dev,
1407 "Not enough space to store port name\n");
1408 break;
1409 }
1410 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1411 name_size - 1);
1412 port->name[name_size - 1] = 0;
1413
1414 /*
1415 * Since we only have one sysfs attribute, 'name',
1416 * create it only if we have a name for the port.
1417 */
1418 err = sysfs_create_group(&port->dev->kobj,
1419 &port_attribute_group);
1420 if (err) {
1421 dev_err(port->dev,
1422 "Error %d creating sysfs device attributes\n",
1423 err);
1424 } else {
1425 /*
1426 * Generate a udev event so that appropriate
1427 * symlinks can be created based on udev
1428 * rules.
1429 */
1430 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1431 }
1432 break;
1433 }
1434}
1435
1436static void control_work_handler(struct work_struct *work)
1437{
1438 struct ports_device *portdev;
1439 struct virtqueue *vq;
1440 struct port_buffer *buf;
1441 unsigned int len;
1442
1443 portdev = container_of(work, struct ports_device, control_work);
1444 vq = portdev->c_ivq;
1445
1446 spin_lock(&portdev->cvq_lock);
1447 while ((buf = virtqueue_get_buf(vq, &len))) {
1448 spin_unlock(&portdev->cvq_lock);
1449
1450 buf->len = len;
1451 buf->offset = 0;
1452
1453 handle_control_message(portdev, buf);
1454
1455 spin_lock(&portdev->cvq_lock);
1456 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1457 dev_warn(&portdev->vdev->dev,
1458 "Error adding buffer to queue\n");
1459 free_buf(buf);
1460 }
1461 }
1462 spin_unlock(&portdev->cvq_lock);
1463}
1464
1465static void in_intr(struct virtqueue *vq)
1466{
1467 struct port *port;
1468 unsigned long flags;
1469
1470 port = find_port_by_vq(vq->vdev->priv, vq);
1471 if (!port)
1472 return;
1473
1474 spin_lock_irqsave(&port->inbuf_lock, flags);
1475 if (!port->inbuf)
1476 port->inbuf = get_inbuf(port);
1477
1478 /*
1479 * Don't queue up data when port is closed. This condition
1480 * can be reached when a console port is not yet connected (no
1481 * tty is spawned) and the host sends out data to console
1482 * ports. For generic serial ports, the host won't
1483 * (shouldn't) send data till the guest is connected.
1484 */
1485 if (!port->guest_connected)
1486 discard_port_data(port);
1487
1488 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1489
1490 wake_up_interruptible(&port->waitqueue);
1491
1492 /* Send a SIGIO indicating new data in case the process asked for it */
1493 send_sigio_to_port(port);
1494
1495 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1496 hvc_kick();
1497}
1498
1499static void control_intr(struct virtqueue *vq)
1500{
1501 struct ports_device *portdev;
1502
1503 portdev = vq->vdev->priv;
1504 schedule_work(&portdev->control_work);
1505}
1506
1507static void config_intr(struct virtio_device *vdev)
1508{
1509 struct ports_device *portdev;
1510
1511 portdev = vdev->priv;
1512
1513 if (!use_multiport(portdev)) {
1514 struct port *port;
1515 u16 rows, cols;
1516
1517 vdev->config->get(vdev,
1518 offsetof(struct virtio_console_config, cols),
1519 &cols, sizeof(u16));
1520 vdev->config->get(vdev,
1521 offsetof(struct virtio_console_config, rows),
1522 &rows, sizeof(u16));
1523
1524 port = find_port_by_id(portdev, 0);
1525 set_console_size(port, rows, cols);
1526
1527 /*
1528 * We'll use this way of resizing only for legacy
1529 * support. For newer userspace
1530 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1531 * to indicate console size changes so that it can be
1532 * done per-port.
1533 */
1534 resize_console(port);
1535 }
1536}
1537
1538static int init_vqs(struct ports_device *portdev)
1539{
1540 vq_callback_t **io_callbacks;
1541 char **io_names;
1542 struct virtqueue **vqs;
1543 u32 i, j, nr_ports, nr_queues;
1544 int err;
1545
1546 nr_ports = portdev->config.max_nr_ports;
1547 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1548
1549 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1550 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1551 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1552 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1553 GFP_KERNEL);
1554 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1555 GFP_KERNEL);
1556 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1557 !portdev->out_vqs) {
1558 err = -ENOMEM;
1559 goto free;
1560 }
1561
1562 /*
1563 * For backward compat (newer host but older guest), the host
1564 * spawns a console port first and also inits the vqs for port
1565 * 0 before others.
1566 */
1567 j = 0;
1568 io_callbacks[j] = in_intr;
1569 io_callbacks[j + 1] = NULL;
1570 io_names[j] = "input";
1571 io_names[j + 1] = "output";
1572 j += 2;
1573
1574 if (use_multiport(portdev)) {
1575 io_callbacks[j] = control_intr;
1576 io_callbacks[j + 1] = NULL;
1577 io_names[j] = "control-i";
1578 io_names[j + 1] = "control-o";
1579
1580 for (i = 1; i < nr_ports; i++) {
1581 j += 2;
1582 io_callbacks[j] = in_intr;
1583 io_callbacks[j + 1] = NULL;
1584 io_names[j] = "input";
1585 io_names[j + 1] = "output";
1586 }
1587 }
1588 /* Find the queues. */
1589 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1590 io_callbacks,
1591 (const char **)io_names);
1592 if (err)
1593 goto free;
1594
1595 j = 0;
1596 portdev->in_vqs[0] = vqs[0];
1597 portdev->out_vqs[0] = vqs[1];
1598 j += 2;
1599 if (use_multiport(portdev)) {
1600 portdev->c_ivq = vqs[j];
1601 portdev->c_ovq = vqs[j + 1];
1602
1603 for (i = 1; i < nr_ports; i++) {
1604 j += 2;
1605 portdev->in_vqs[i] = vqs[j];
1606 portdev->out_vqs[i] = vqs[j + 1];
1607 }
1608 }
1609 kfree(io_names);
1610 kfree(io_callbacks);
1611 kfree(vqs);
1612
1613 return 0;
1614
1615free:
1616 kfree(portdev->out_vqs);
1617 kfree(portdev->in_vqs);
1618 kfree(io_names);
1619 kfree(io_callbacks);
1620 kfree(vqs);
1621
1622 return err;
1623}
1624
1625static const struct file_operations portdev_fops = {
1626 .owner = THIS_MODULE,
1627};
1628
1629/*
1630 * Once we're further in boot, we get probed like any other virtio
1631 * device.
1632 *
1633 * If the host also supports multiple console ports, we check the
1634 * config space to see how many ports the host has spawned. We
1635 * initialize each port found.
1636 */
1637static int __devinit virtcons_probe(struct virtio_device *vdev)
1638{
1639 struct ports_device *portdev;
1640 int err;
1641 bool multiport;
1642
1643 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1644 if (!portdev) {
1645 err = -ENOMEM;
1646 goto fail;
1647 }
1648
1649 /* Attach this portdev to this virtio_device, and vice-versa. */
1650 portdev->vdev = vdev;
1651 vdev->priv = portdev;
1652
1653 spin_lock_irq(&pdrvdata_lock);
1654 portdev->drv_index = pdrvdata.index++;
1655 spin_unlock_irq(&pdrvdata_lock);
1656
1657 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1658 &portdev_fops);
1659 if (portdev->chr_major < 0) {
1660 dev_err(&vdev->dev,
1661 "Error %d registering chrdev for device %u\n",
1662 portdev->chr_major, portdev->drv_index);
1663 err = portdev->chr_major;
1664 goto free;
1665 }
1666
1667 multiport = false;
1668 portdev->config.max_nr_ports = 1;
1669 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
1670 multiport = true;
1671 vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
1672
1673 vdev->config->get(vdev, offsetof(struct virtio_console_config,
1674 max_nr_ports),
1675 &portdev->config.max_nr_ports,
1676 sizeof(portdev->config.max_nr_ports));
1677 }
1678
1679 /* Let the Host know we support multiple ports.*/
1680 vdev->config->finalize_features(vdev);
1681
1682 err = init_vqs(portdev);
1683 if (err < 0) {
1684 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
1685 goto free_chrdev;
1686 }
1687
1688 spin_lock_init(&portdev->ports_lock);
1689 INIT_LIST_HEAD(&portdev->ports);
1690
1691 if (multiport) {
1692 unsigned int nr_added_bufs;
1693
1694 spin_lock_init(&portdev->cvq_lock);
1695 INIT_WORK(&portdev->control_work, &control_work_handler);
1696
1697 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1698 if (!nr_added_bufs) {
1699 dev_err(&vdev->dev,
1700 "Error allocating buffers for control queue\n");
1701 err = -ENOMEM;
1702 goto free_vqs;
1703 }
1704 } else {
1705 /*
1706 * For backward compatibility: Create a console port
1707 * if we're running on older host.
1708 */
1709 add_port(portdev, 0);
1710 }
1711
1712 spin_lock_irq(&pdrvdata_lock);
1713 list_add_tail(&portdev->list, &pdrvdata.portdevs);
1714 spin_unlock_irq(&pdrvdata_lock);
1715
1716 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1717 VIRTIO_CONSOLE_DEVICE_READY, 1);
1718 return 0;
1719
1720free_vqs:
1721 /* The host might want to notify mgmt sw about device add failure */
1722 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1723 VIRTIO_CONSOLE_DEVICE_READY, 0);
1724 vdev->config->del_vqs(vdev);
1725 kfree(portdev->in_vqs);
1726 kfree(portdev->out_vqs);
1727free_chrdev:
1728 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1729free:
1730 kfree(portdev);
1731fail:
1732 return err;
1733}
1734
1735static void virtcons_remove(struct virtio_device *vdev)
1736{
1737 struct ports_device *portdev;
1738 struct port *port, *port2;
1739
1740 portdev = vdev->priv;
1741
1742 spin_lock_irq(&pdrvdata_lock);
1743 list_del(&portdev->list);
1744 spin_unlock_irq(&pdrvdata_lock);
1745
1746 /* Disable interrupts for vqs */
1747 vdev->config->reset(vdev);
1748 /* Finish up work that's lined up */
1749 cancel_work_sync(&portdev->control_work);
1750
1751 list_for_each_entry_safe(port, port2, &portdev->ports, list)
1752 unplug_port(port);
1753
1754 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1755
1756 /*
1757 * When yanking out a device, we immediately lose the
1758 * (device-side) queues. So there's no point in keeping the
1759 * guest side around till we drop our final reference. This
1760 * also means that any ports which are in an open state will
1761 * have to just stop using the port, as the vqs are going
1762 * away.
1763 */
1764 if (use_multiport(portdev)) {
1765 struct port_buffer *buf;
1766 unsigned int len;
1767
1768 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1769 free_buf(buf);
1770
1771 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1772 free_buf(buf);
1773 }
1774
1775 vdev->config->del_vqs(vdev);
1776 kfree(portdev->in_vqs);
1777 kfree(portdev->out_vqs);
1778
1779 kfree(portdev);
1780}
1781
1782static struct virtio_device_id id_table[] = {
1783 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1784 { 0 },
1785};
1786
1787static unsigned int features[] = {
1788 VIRTIO_CONSOLE_F_SIZE,
1789 VIRTIO_CONSOLE_F_MULTIPORT,
1790};
1791
1792static struct virtio_driver virtio_console = {
1793 .feature_table = features,
1794 .feature_table_size = ARRAY_SIZE(features),
1795 .driver.name = KBUILD_MODNAME,
1796 .driver.owner = THIS_MODULE,
1797 .id_table = id_table,
1798 .probe = virtcons_probe,
1799 .remove = virtcons_remove,
1800 .config_changed = config_intr,
1801};
1802
1803static int __init init(void)
1804{
1805 int err;
1806
1807 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1808 if (IS_ERR(pdrvdata.class)) {
1809 err = PTR_ERR(pdrvdata.class);
1810 pr_err("Error %d creating virtio-ports class\n", err);
1811 return err;
1812 }
1813
1814 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1815 if (!pdrvdata.debugfs_dir) {
1816 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1817 PTR_ERR(pdrvdata.debugfs_dir));
1818 }
1819 INIT_LIST_HEAD(&pdrvdata.consoles);
1820 INIT_LIST_HEAD(&pdrvdata.portdevs);
1821
1822 return register_virtio_driver(&virtio_console);
1823}
1824
1825static void __exit fini(void)
1826{
1827 unregister_virtio_driver(&virtio_console);
1828
1829 class_destroy(pdrvdata.class);
1830 if (pdrvdata.debugfs_dir)
1831 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1832}
1833module_init(init);
1834module_exit(fini);
1835
1836MODULE_DEVICE_TABLE(virtio, id_table);
1837MODULE_DESCRIPTION("Virtio console driver");
1838MODULE_LICENSE("GPL");
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-18 16:07:11 -0500