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