Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1

Linux/drivers/char/virtio_console.c

  1 /*
  2  * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
  3  * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
  4  * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
  5  *
  6  * This program is free software; you can redistribute it and/or modify
  7  * it under the terms of the GNU General Public License as published by
  8  * the Free Software Foundation; either version 2 of the License, or
  9  * (at your option) any later version.
 10  *
 11  * This program is distributed in the hope that it will be useful,
 12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14  * GNU General Public License for more details.
 15  *
 16  * You should have received a copy of the GNU General Public License
 17  * along with this program; if not, write to the Free Software
 18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 19  */
 20 #include <linux/cdev.h>
 21 #include <linux/debugfs.h>
 22 #include <linux/completion.h>
 23 #include <linux/device.h>
 24 #include <linux/err.h>
 25 #include <linux/freezer.h>
 26 #include <linux/fs.h>
 27 #include <linux/splice.h>
 28 #include <linux/pagemap.h>
 29 #include <linux/init.h>
 30 #include <linux/list.h>
 31 #include <linux/poll.h>
 32 #include <linux/sched.h>
 33 #include <linux/slab.h>
 34 #include <linux/spinlock.h>
 35 #include <linux/virtio.h>
 36 #include <linux/virtio_console.h>
 37 #include <linux/wait.h>
 38 #include <linux/workqueue.h>
 39 #include <linux/module.h>
 40 #include <linux/dma-mapping.h>
 41 #include <linux/kconfig.h>
 42 #include "../tty/hvc/hvc_console.h"
 43 
 44 #define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
 45 
 46 /*
 47  * This is a global struct for storing common data for all the devices
 48  * this driver handles.
 49  *
 50  * Mainly, it has a linked list for all the consoles in one place so
 51  * that callbacks from hvc for get_chars(), put_chars() work properly
 52  * across multiple devices and multiple ports per device.
 53  */
 54 struct ports_driver_data {
 55         /* Used for registering chardevs */
 56         struct class *class;
 57 
 58         /* Used for exporting per-port information to debugfs */
 59         struct dentry *debugfs_dir;
 60 
 61         /* List of all the devices we're handling */
 62         struct list_head portdevs;
 63 
 64         /*
 65          * This is used to keep track of the number of hvc consoles
 66          * spawned by this driver.  This number is given as the first
 67          * argument to hvc_alloc().  To correctly map an initial
 68          * console spawned via hvc_instantiate to the console being
 69          * hooked up via hvc_alloc, we need to pass the same vtermno.
 70          *
 71          * We also just assume the first console being initialised was
 72          * the first one that got used as the initial console.
 73          */
 74         unsigned int next_vtermno;
 75 
 76         /* All the console devices handled by this driver */
 77         struct list_head consoles;
 78 };
 79 static struct ports_driver_data pdrvdata;
 80 
 81 static DEFINE_SPINLOCK(pdrvdata_lock);
 82 static DECLARE_COMPLETION(early_console_added);
 83 
 84 /* This struct holds information that's relevant only for console ports */
 85 struct console {
 86         /* We'll place all consoles in a list in the pdrvdata struct */
 87         struct list_head list;
 88 
 89         /* The hvc device associated with this console port */
 90         struct hvc_struct *hvc;
 91 
 92         /* The size of the console */
 93         struct winsize ws;
 94 
 95         /*
 96          * This number identifies the number that we used to register
 97          * with hvc in hvc_instantiate() and hvc_alloc(); this is the
 98          * number passed on by the hvc callbacks to us to
 99          * differentiate between the other console ports handled by
100          * this driver
101          */
102         u32 vtermno;
103 };
104 
105 struct port_buffer {
106         char *buf;
107 
108         /* size of the buffer in *buf above */
109         size_t size;
110 
111         /* used length of the buffer */
112         size_t len;
113         /* offset in the buf from which to consume data */
114         size_t offset;
115 
116         /* DMA address of buffer */
117         dma_addr_t dma;
118 
119         /* Device we got DMA memory from */
120         struct device *dev;
121 
122         /* List of pending dma buffers to free */
123         struct list_head list;
124 
125         /* If sgpages == 0 then buf is used */
126         unsigned int sgpages;
127 
128         /* sg is used if spages > 0. sg must be the last in is struct */
129         struct scatterlist sg[0];
130 };
131 
132 /*
133  * This is a per-device struct that stores data common to all the
134  * ports for that device (vdev->priv).
135  */
136 struct ports_device {
137         /* Next portdev in the list, head is in the pdrvdata struct */
138         struct list_head list;
139 
140         /*
141          * Workqueue handlers where we process deferred work after
142          * notification
143          */
144         struct work_struct control_work;
145         struct work_struct config_work;
146 
147         struct list_head ports;
148 
149         /* To protect the list of ports */
150         spinlock_t ports_lock;
151 
152         /* To protect the vq operations for the control channel */
153         spinlock_t c_ivq_lock;
154         spinlock_t c_ovq_lock;
155 
156         /* The current config space is stored here */
157         struct virtio_console_config config;
158 
159         /* The virtio device we're associated with */
160         struct virtio_device *vdev;
161 
162         /*
163          * A couple of virtqueues for the control channel: one for
164          * guest->host transfers, one for host->guest transfers
165          */
166         struct virtqueue *c_ivq, *c_ovq;
167 
168         /* Array of per-port IO virtqueues */
169         struct virtqueue **in_vqs, **out_vqs;
170 
171         /* Major number for this device.  Ports will be created as minors. */
172         int chr_major;
173 };
174 
175 struct port_stats {
176         unsigned long bytes_sent, bytes_received, bytes_discarded;
177 };
178 
179 /* This struct holds the per-port data */
180 struct port {
181         /* Next port in the list, head is in the ports_device */
182         struct list_head list;
183 
184         /* Pointer to the parent virtio_console device */
185         struct ports_device *portdev;
186 
187         /* The current buffer from which data has to be fed to readers */
188         struct port_buffer *inbuf;
189 
190         /*
191          * To protect the operations on the in_vq associated with this
192          * port.  Has to be a spinlock because it can be called from
193          * interrupt context (get_char()).
194          */
195         spinlock_t inbuf_lock;
196 
197         /* Protect the operations on the out_vq. */
198         spinlock_t outvq_lock;
199 
200         /* The IO vqs for this port */
201         struct virtqueue *in_vq, *out_vq;
202 
203         /* File in the debugfs directory that exposes this port's information */
204         struct dentry *debugfs_file;
205 
206         /*
207          * Keep count of the bytes sent, received and discarded for
208          * this port for accounting and debugging purposes.  These
209          * counts are not reset across port open / close events.
210          */
211         struct port_stats stats;
212 
213         /*
214          * The entries in this struct will be valid if this port is
215          * hooked up to an hvc console
216          */
217         struct console cons;
218 
219         /* Each port associates with a separate char device */
220         struct cdev *cdev;
221         struct device *dev;
222 
223         /* Reference-counting to handle port hot-unplugs and file operations */
224         struct kref kref;
225 
226         /* A waitqueue for poll() or blocking read operations */
227         wait_queue_head_t waitqueue;
228 
229         /* The 'name' of the port that we expose via sysfs properties */
230         char *name;
231 
232         /* We can notify apps of host connect / disconnect events via SIGIO */
233         struct fasync_struct *async_queue;
234 
235         /* The 'id' to identify the port with the Host */
236         u32 id;
237 
238         bool outvq_full;
239 
240         /* Is the host device open */
241         bool host_connected;
242 
243         /* We should allow only one process to open a port */
244         bool guest_connected;
245 };
246 
247 /* This is the very early arch-specified put chars function. */
248 static int (*early_put_chars)(u32, const char *, int);
249 
250 static struct port *find_port_by_vtermno(u32 vtermno)
251 {
252         struct port *port;
253         struct console *cons;
254         unsigned long flags;
255 
256         spin_lock_irqsave(&pdrvdata_lock, flags);
257         list_for_each_entry(cons, &pdrvdata.consoles, list) {
258                 if (cons->vtermno == vtermno) {
259                         port = container_of(cons, struct port, cons);
260                         goto out;
261                 }
262         }
263         port = NULL;
264 out:
265         spin_unlock_irqrestore(&pdrvdata_lock, flags);
266         return port;
267 }
268 
269 static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
270                                                  dev_t dev)
271 {
272         struct port *port;
273         unsigned long flags;
274 
275         spin_lock_irqsave(&portdev->ports_lock, flags);
276         list_for_each_entry(port, &portdev->ports, list) {
277                 if (port->cdev->dev == dev) {
278                         kref_get(&port->kref);
279                         goto out;
280                 }
281         }
282         port = NULL;
283 out:
284         spin_unlock_irqrestore(&portdev->ports_lock, flags);
285 
286         return port;
287 }
288 
289 static struct port *find_port_by_devt(dev_t dev)
290 {
291         struct ports_device *portdev;
292         struct port *port;
293         unsigned long flags;
294 
295         spin_lock_irqsave(&pdrvdata_lock, flags);
296         list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
297                 port = find_port_by_devt_in_portdev(portdev, dev);
298                 if (port)
299                         goto out;
300         }
301         port = NULL;
302 out:
303         spin_unlock_irqrestore(&pdrvdata_lock, flags);
304         return port;
305 }
306 
307 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
308 {
309         struct port *port;
310         unsigned long flags;
311 
312         spin_lock_irqsave(&portdev->ports_lock, flags);
313         list_for_each_entry(port, &portdev->ports, list)
314                 if (port->id == id)
315                         goto out;
316         port = NULL;
317 out:
318         spin_unlock_irqrestore(&portdev->ports_lock, flags);
319 
320         return port;
321 }
322 
323 static struct port *find_port_by_vq(struct ports_device *portdev,
324                                     struct virtqueue *vq)
325 {
326         struct port *port;
327         unsigned long flags;
328 
329         spin_lock_irqsave(&portdev->ports_lock, flags);
330         list_for_each_entry(port, &portdev->ports, list)
331                 if (port->in_vq == vq || port->out_vq == vq)
332                         goto out;
333         port = NULL;
334 out:
335         spin_unlock_irqrestore(&portdev->ports_lock, flags);
336         return port;
337 }
338 
339 static bool is_console_port(struct port *port)
340 {
341         if (port->cons.hvc)
342                 return true;
343         return false;
344 }
345 
346 static bool is_rproc_serial(const struct virtio_device *vdev)
347 {
348         return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
349 }
350 
351 static inline bool use_multiport(struct ports_device *portdev)
352 {
353         /*
354          * This condition can be true when put_chars is called from
355          * early_init
356          */
357         if (!portdev->vdev)
358                 return false;
359         return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
360 }
361 
362 static DEFINE_SPINLOCK(dma_bufs_lock);
363 static LIST_HEAD(pending_free_dma_bufs);
364 
365 static void free_buf(struct port_buffer *buf, bool can_sleep)
366 {
367         unsigned int i;
368 
369         for (i = 0; i < buf->sgpages; i++) {
370                 struct page *page = sg_page(&buf->sg[i]);
371                 if (!page)
372                         break;
373                 put_page(page);
374         }
375 
376         if (!buf->dev) {
377                 kfree(buf->buf);
378         } else if (is_rproc_enabled) {
379                 unsigned long flags;
380 
381                 /* dma_free_coherent requires interrupts to be enabled. */
382                 if (!can_sleep) {
383                         /* queue up dma-buffers to be freed later */
384                         spin_lock_irqsave(&dma_bufs_lock, flags);
385                         list_add_tail(&buf->list, &pending_free_dma_bufs);
386                         spin_unlock_irqrestore(&dma_bufs_lock, flags);
387                         return;
388                 }
389                 dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma);
390 
391                 /* Release device refcnt and allow it to be freed */
392                 put_device(buf->dev);
393         }
394 
395         kfree(buf);
396 }
397 
398 static void reclaim_dma_bufs(void)
399 {
400         unsigned long flags;
401         struct port_buffer *buf, *tmp;
402         LIST_HEAD(tmp_list);
403 
404         if (list_empty(&pending_free_dma_bufs))
405                 return;
406 
407         /* Create a copy of the pending_free_dma_bufs while holding the lock */
408         spin_lock_irqsave(&dma_bufs_lock, flags);
409         list_cut_position(&tmp_list, &pending_free_dma_bufs,
410                           pending_free_dma_bufs.prev);
411         spin_unlock_irqrestore(&dma_bufs_lock, flags);
412 
413         /* Release the dma buffers, without irqs enabled */
414         list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
415                 list_del(&buf->list);
416                 free_buf(buf, true);
417         }
418 }
419 
420 static struct port_buffer *alloc_buf(struct virtqueue *vq, size_t buf_size,
421                                      int pages)
422 {
423         struct port_buffer *buf;
424 
425         reclaim_dma_bufs();
426 
427         /*
428          * Allocate buffer and the sg list. The sg list array is allocated
429          * directly after the port_buffer struct.
430          */
431         buf = kmalloc(sizeof(*buf) + sizeof(struct scatterlist) * pages,
432                       GFP_KERNEL);
433         if (!buf)
434                 goto fail;
435 
436         buf->sgpages = pages;
437         if (pages > 0) {
438                 buf->dev = NULL;
439                 buf->buf = NULL;
440                 return buf;
441         }
442 
443         if (is_rproc_serial(vq->vdev)) {
444                 /*
445                  * Allocate DMA memory from ancestor. When a virtio
446                  * device is created by remoteproc, the DMA memory is
447                  * associated with the grandparent device:
448                  * vdev => rproc => platform-dev.
449                  * The code here would have been less quirky if
450                  * DMA_MEMORY_INCLUDES_CHILDREN had been supported
451                  * in dma-coherent.c
452                  */
453                 if (!vq->vdev->dev.parent || !vq->vdev->dev.parent->parent)
454                         goto free_buf;
455                 buf->dev = vq->vdev->dev.parent->parent;
456 
457                 /* Increase device refcnt to avoid freeing it */
458                 get_device(buf->dev);
459                 buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
460                                               GFP_KERNEL);
461         } else {
462                 buf->dev = NULL;
463                 buf->buf = kmalloc(buf_size, GFP_KERNEL);
464         }
465 
466         if (!buf->buf)
467                 goto free_buf;
468         buf->len = 0;
469         buf->offset = 0;
470         buf->size = buf_size;
471         return buf;
472 
473 free_buf:
474         kfree(buf);
475 fail:
476         return NULL;
477 }
478 
479 /* Callers should take appropriate locks */
480 static struct port_buffer *get_inbuf(struct port *port)
481 {
482         struct port_buffer *buf;
483         unsigned int len;
484 
485         if (port->inbuf)
486                 return port->inbuf;
487 
488         buf = virtqueue_get_buf(port->in_vq, &len);
489         if (buf) {
490                 buf->len = len;
491                 buf->offset = 0;
492                 port->stats.bytes_received += len;
493         }
494         return buf;
495 }
496 
497 /*
498  * Create a scatter-gather list representing our input buffer and put
499  * it in the queue.
500  *
501  * Callers should take appropriate locks.
502  */
503 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
504 {
505         struct scatterlist sg[1];
506         int ret;
507 
508         sg_init_one(sg, buf->buf, buf->size);
509 
510         ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC);
511         virtqueue_kick(vq);
512         if (!ret)
513                 ret = vq->num_free;
514         return ret;
515 }
516 
517 /* Discard any unread data this port has. Callers lockers. */
518 static void discard_port_data(struct port *port)
519 {
520         struct port_buffer *buf;
521         unsigned int err;
522 
523         if (!port->portdev) {
524                 /* Device has been unplugged.  vqs are already gone. */
525                 return;
526         }
527         buf = get_inbuf(port);
528 
529         err = 0;
530         while (buf) {
531                 port->stats.bytes_discarded += buf->len - buf->offset;
532                 if (add_inbuf(port->in_vq, buf) < 0) {
533                         err++;
534                         free_buf(buf, false);
535                 }
536                 port->inbuf = NULL;
537                 buf = get_inbuf(port);
538         }
539         if (err)
540                 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
541                          err);
542 }
543 
544 static bool port_has_data(struct port *port)
545 {
546         unsigned long flags;
547         bool ret;
548 
549         ret = false;
550         spin_lock_irqsave(&port->inbuf_lock, flags);
551         port->inbuf = get_inbuf(port);
552         if (port->inbuf)
553                 ret = true;
554 
555         spin_unlock_irqrestore(&port->inbuf_lock, flags);
556         return ret;
557 }
558 
559 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
560                                   unsigned int event, unsigned int value)
561 {
562         struct scatterlist sg[1];
563         struct virtio_console_control cpkt;
564         struct virtqueue *vq;
565         unsigned int len;
566 
567         if (!use_multiport(portdev))
568                 return 0;
569 
570         cpkt.id = cpu_to_virtio32(portdev->vdev, port_id);
571         cpkt.event = cpu_to_virtio16(portdev->vdev, event);
572         cpkt.value = cpu_to_virtio16(portdev->vdev, value);
573 
574         vq = portdev->c_ovq;
575 
576         sg_init_one(sg, &cpkt, sizeof(cpkt));
577 
578         spin_lock(&portdev->c_ovq_lock);
579         if (virtqueue_add_outbuf(vq, sg, 1, &cpkt, GFP_ATOMIC) == 0) {
580                 virtqueue_kick(vq);
581                 while (!virtqueue_get_buf(vq, &len)
582                         && !virtqueue_is_broken(vq))
583                         cpu_relax();
584         }
585         spin_unlock(&portdev->c_ovq_lock);
586         return 0;
587 }
588 
589 static ssize_t send_control_msg(struct port *port, unsigned int event,
590                                 unsigned int value)
591 {
592         /* Did the port get unplugged before userspace closed it? */
593         if (port->portdev)
594                 return __send_control_msg(port->portdev, port->id, event, value);
595         return 0;
596 }
597 
598 
599 /* Callers must take the port->outvq_lock */
600 static void reclaim_consumed_buffers(struct port *port)
601 {
602         struct port_buffer *buf;
603         unsigned int len;
604 
605         if (!port->portdev) {
606                 /* Device has been unplugged.  vqs are already gone. */
607                 return;
608         }
609         while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
610                 free_buf(buf, false);
611                 port->outvq_full = false;
612         }
613 }
614 
615 static ssize_t __send_to_port(struct port *port, struct scatterlist *sg,
616                               int nents, size_t in_count,
617                               void *data, bool nonblock)
618 {
619         struct virtqueue *out_vq;
620         int err;
621         unsigned long flags;
622         unsigned int len;
623 
624         out_vq = port->out_vq;
625 
626         spin_lock_irqsave(&port->outvq_lock, flags);
627 
628         reclaim_consumed_buffers(port);
629 
630         err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC);
631 
632         /* Tell Host to go! */
633         virtqueue_kick(out_vq);
634 
635         if (err) {
636                 in_count = 0;
637                 goto done;
638         }
639 
640         if (out_vq->num_free == 0)
641                 port->outvq_full = true;
642 
643         if (nonblock)
644                 goto done;
645 
646         /*
647          * Wait till the host acknowledges it pushed out the data we
648          * sent.  This is done for data from the hvc_console; the tty
649          * operations are performed with spinlocks held so we can't
650          * sleep here.  An alternative would be to copy the data to a
651          * buffer and relax the spinning requirement.  The downside is
652          * we need to kmalloc a GFP_ATOMIC buffer each time the
653          * console driver writes something out.
654          */
655         while (!virtqueue_get_buf(out_vq, &len)
656                 && !virtqueue_is_broken(out_vq))
657                 cpu_relax();
658 done:
659         spin_unlock_irqrestore(&port->outvq_lock, flags);
660 
661         port->stats.bytes_sent += in_count;
662         /*
663          * We're expected to return the amount of data we wrote -- all
664          * of it
665          */
666         return in_count;
667 }
668 
669 /*
670  * Give out the data that's requested from the buffer that we have
671  * queued up.
672  */
673 static ssize_t fill_readbuf(struct port *port, char __user *out_buf,
674                             size_t out_count, bool to_user)
675 {
676         struct port_buffer *buf;
677         unsigned long flags;
678 
679         if (!out_count || !port_has_data(port))
680                 return 0;
681 
682         buf = port->inbuf;
683         out_count = min(out_count, buf->len - buf->offset);
684 
685         if (to_user) {
686                 ssize_t ret;
687 
688                 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
689                 if (ret)
690                         return -EFAULT;
691         } else {
692                 memcpy((__force char *)out_buf, buf->buf + buf->offset,
693                        out_count);
694         }
695 
696         buf->offset += out_count;
697 
698         if (buf->offset == buf->len) {
699                 /*
700                  * We're done using all the data in this buffer.
701                  * Re-queue so that the Host can send us more data.
702                  */
703                 spin_lock_irqsave(&port->inbuf_lock, flags);
704                 port->inbuf = NULL;
705 
706                 if (add_inbuf(port->in_vq, buf) < 0)
707                         dev_warn(port->dev, "failed add_buf\n");
708 
709                 spin_unlock_irqrestore(&port->inbuf_lock, flags);
710         }
711         /* Return the number of bytes actually copied */
712         return out_count;
713 }
714 
715 /* The condition that must be true for polling to end */
716 static bool will_read_block(struct port *port)
717 {
718         if (!port->guest_connected) {
719                 /* Port got hot-unplugged. Let's exit. */
720                 return false;
721         }
722         return !port_has_data(port) && port->host_connected;
723 }
724 
725 static bool will_write_block(struct port *port)
726 {
727         bool ret;
728 
729         if (!port->guest_connected) {
730                 /* Port got hot-unplugged. Let's exit. */
731                 return false;
732         }
733         if (!port->host_connected)
734                 return true;
735 
736         spin_lock_irq(&port->outvq_lock);
737         /*
738          * Check if the Host has consumed any buffers since we last
739          * sent data (this is only applicable for nonblocking ports).
740          */
741         reclaim_consumed_buffers(port);
742         ret = port->outvq_full;
743         spin_unlock_irq(&port->outvq_lock);
744 
745         return ret;
746 }
747 
748 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
749                               size_t count, loff_t *offp)
750 {
751         struct port *port;
752         ssize_t ret;
753 
754         port = filp->private_data;
755 
756         /* Port is hot-unplugged. */
757         if (!port->guest_connected)
758                 return -ENODEV;
759 
760         if (!port_has_data(port)) {
761                 /*
762                  * If nothing's connected on the host just return 0 in
763                  * case of list_empty; this tells the userspace app
764                  * that there's no connection
765                  */
766                 if (!port->host_connected)
767                         return 0;
768                 if (filp->f_flags & O_NONBLOCK)
769                         return -EAGAIN;
770 
771                 ret = wait_event_freezable(port->waitqueue,
772                                            !will_read_block(port));
773                 if (ret < 0)
774                         return ret;
775         }
776         /* Port got hot-unplugged while we were waiting above. */
777         if (!port->guest_connected)
778                 return -ENODEV;
779         /*
780          * We could've received a disconnection message while we were
781          * waiting for more data.
782          *
783          * This check is not clubbed in the if() statement above as we
784          * might receive some data as well as the host could get
785          * disconnected after we got woken up from our wait.  So we
786          * really want to give off whatever data we have and only then
787          * check for host_connected.
788          */
789         if (!port_has_data(port) && !port->host_connected)
790                 return 0;
791 
792         return fill_readbuf(port, ubuf, count, true);
793 }
794 
795 static int wait_port_writable(struct port *port, bool nonblock)
796 {
797         int ret;
798 
799         if (will_write_block(port)) {
800                 if (nonblock)
801                         return -EAGAIN;
802 
803                 ret = wait_event_freezable(port->waitqueue,
804                                            !will_write_block(port));
805                 if (ret < 0)
806                         return ret;
807         }
808         /* Port got hot-unplugged. */
809         if (!port->guest_connected)
810                 return -ENODEV;
811 
812         return 0;
813 }
814 
815 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
816                                size_t count, loff_t *offp)
817 {
818         struct port *port;
819         struct port_buffer *buf;
820         ssize_t ret;
821         bool nonblock;
822         struct scatterlist sg[1];
823 
824         /* Userspace could be out to fool us */
825         if (!count)
826                 return 0;
827 
828         port = filp->private_data;
829 
830         nonblock = filp->f_flags & O_NONBLOCK;
831 
832         ret = wait_port_writable(port, nonblock);
833         if (ret < 0)
834                 return ret;
835 
836         count = min((size_t)(32 * 1024), count);
837 
838         buf = alloc_buf(port->out_vq, count, 0);
839         if (!buf)
840                 return -ENOMEM;
841 
842         ret = copy_from_user(buf->buf, ubuf, count);
843         if (ret) {
844                 ret = -EFAULT;
845                 goto free_buf;
846         }
847 
848         /*
849          * We now ask send_buf() to not spin for generic ports -- we
850          * can re-use the same code path that non-blocking file
851          * descriptors take for blocking file descriptors since the
852          * wait is already done and we're certain the write will go
853          * through to the host.
854          */
855         nonblock = true;
856         sg_init_one(sg, buf->buf, count);
857         ret = __send_to_port(port, sg, 1, count, buf, nonblock);
858 
859         if (nonblock && ret > 0)
860                 goto out;
861 
862 free_buf:
863         free_buf(buf, true);
864 out:
865         return ret;
866 }
867 
868 struct sg_list {
869         unsigned int n;
870         unsigned int size;
871         size_t len;
872         struct scatterlist *sg;
873 };
874 
875 static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
876                         struct splice_desc *sd)
877 {
878         struct sg_list *sgl = sd->u.data;
879         unsigned int offset, len;
880 
881         if (sgl->n == sgl->size)
882                 return 0;
883 
884         /* Try lock this page */
885         if (buf->ops->steal(pipe, buf) == 0) {
886                 /* Get reference and unlock page for moving */
887                 get_page(buf->page);
888                 unlock_page(buf->page);
889 
890                 len = min(buf->len, sd->len);
891                 sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset);
892         } else {
893                 /* Failback to copying a page */
894                 struct page *page = alloc_page(GFP_KERNEL);
895                 char *src;
896 
897                 if (!page)
898                         return -ENOMEM;
899 
900                 offset = sd->pos & ~PAGE_MASK;
901 
902                 len = sd->len;
903                 if (len + offset > PAGE_SIZE)
904                         len = PAGE_SIZE - offset;
905 
906                 src = kmap_atomic(buf->page);
907                 memcpy(page_address(page) + offset, src + buf->offset, len);
908                 kunmap_atomic(src);
909 
910                 sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
911         }
912         sgl->n++;
913         sgl->len += len;
914 
915         return len;
916 }
917 
918 /* Faster zero-copy write by splicing */
919 static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
920                                       struct file *filp, loff_t *ppos,
921                                       size_t len, unsigned int flags)
922 {
923         struct port *port = filp->private_data;
924         struct sg_list sgl;
925         ssize_t ret;
926         struct port_buffer *buf;
927         struct splice_desc sd = {
928                 .total_len = len,
929                 .flags = flags,
930                 .pos = *ppos,
931                 .u.data = &sgl,
932         };
933 
934         /*
935          * Rproc_serial does not yet support splice. To support splice
936          * pipe_to_sg() must allocate dma-buffers and copy content from
937          * regular pages to dma pages. And alloc_buf and free_buf must
938          * support allocating and freeing such a list of dma-buffers.
939          */
940         if (is_rproc_serial(port->out_vq->vdev))
941                 return -EINVAL;
942 
943         /*
944          * pipe->nrbufs == 0 means there are no data to transfer,
945          * so this returns just 0 for no data.
946          */
947         pipe_lock(pipe);
948         if (!pipe->nrbufs) {
949                 ret = 0;
950                 goto error_out;
951         }
952 
953         ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
954         if (ret < 0)
955                 goto error_out;
956 
957         buf = alloc_buf(port->out_vq, 0, pipe->nrbufs);
958         if (!buf) {
959                 ret = -ENOMEM;
960                 goto error_out;
961         }
962 
963         sgl.n = 0;
964         sgl.len = 0;
965         sgl.size = pipe->nrbufs;
966         sgl.sg = buf->sg;
967         sg_init_table(sgl.sg, sgl.size);
968         ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
969         pipe_unlock(pipe);
970         if (likely(ret > 0))
971                 ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
972 
973         if (unlikely(ret <= 0))
974                 free_buf(buf, true);
975         return ret;
976 
977 error_out:
978         pipe_unlock(pipe);
979         return ret;
980 }
981 
982 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
983 {
984         struct port *port;
985         unsigned int ret;
986 
987         port = filp->private_data;
988         poll_wait(filp, &port->waitqueue, wait);
989 
990         if (!port->guest_connected) {
991                 /* Port got unplugged */
992                 return POLLHUP;
993         }
994         ret = 0;
995         if (!will_read_block(port))
996                 ret |= POLLIN | POLLRDNORM;
997         if (!will_write_block(port))
998                 ret |= POLLOUT;
999         if (!port->host_connected)
1000                 ret |= POLLHUP;
1001 
1002         return ret;
1003 }
1004 
1005 static void remove_port(struct kref *kref);
1006 
1007 static int port_fops_release(struct inode *inode, struct file *filp)
1008 {
1009         struct port *port;
1010 
1011         port = filp->private_data;
1012 
1013         /* Notify host of port being closed */
1014         send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
1015 
1016         spin_lock_irq(&port->inbuf_lock);
1017         port->guest_connected = false;
1018 
1019         discard_port_data(port);
1020 
1021         spin_unlock_irq(&port->inbuf_lock);
1022 
1023         spin_lock_irq(&port->outvq_lock);
1024         reclaim_consumed_buffers(port);
1025         spin_unlock_irq(&port->outvq_lock);
1026 
1027         reclaim_dma_bufs();
1028         /*
1029          * Locks aren't necessary here as a port can't be opened after
1030          * unplug, and if a port isn't unplugged, a kref would already
1031          * exist for the port.  Plus, taking ports_lock here would
1032          * create a dependency on other locks taken by functions
1033          * inside remove_port if we're the last holder of the port,
1034          * creating many problems.
1035          */
1036         kref_put(&port->kref, remove_port);
1037 
1038         return 0;
1039 }
1040 
1041 static int port_fops_open(struct inode *inode, struct file *filp)
1042 {
1043         struct cdev *cdev = inode->i_cdev;
1044         struct port *port;
1045         int ret;
1046 
1047         /* We get the port with a kref here */
1048         port = find_port_by_devt(cdev->dev);
1049         if (!port) {
1050                 /* Port was unplugged before we could proceed */
1051                 return -ENXIO;
1052         }
1053         filp->private_data = port;
1054 
1055         /*
1056          * Don't allow opening of console port devices -- that's done
1057          * via /dev/hvc
1058          */
1059         if (is_console_port(port)) {
1060                 ret = -ENXIO;
1061                 goto out;
1062         }
1063 
1064         /* Allow only one process to open a particular port at a time */
1065         spin_lock_irq(&port->inbuf_lock);
1066         if (port->guest_connected) {
1067                 spin_unlock_irq(&port->inbuf_lock);
1068                 ret = -EBUSY;
1069                 goto out;
1070         }
1071 
1072         port->guest_connected = true;
1073         spin_unlock_irq(&port->inbuf_lock);
1074 
1075         spin_lock_irq(&port->outvq_lock);
1076         /*
1077          * There might be a chance that we missed reclaiming a few
1078          * buffers in the window of the port getting previously closed
1079          * and opening now.
1080          */
1081         reclaim_consumed_buffers(port);
1082         spin_unlock_irq(&port->outvq_lock);
1083 
1084         nonseekable_open(inode, filp);
1085 
1086         /* Notify host of port being opened */
1087         send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
1088 
1089         return 0;
1090 out:
1091         kref_put(&port->kref, remove_port);
1092         return ret;
1093 }
1094 
1095 static int port_fops_fasync(int fd, struct file *filp, int mode)
1096 {
1097         struct port *port;
1098 
1099         port = filp->private_data;
1100         return fasync_helper(fd, filp, mode, &port->async_queue);
1101 }
1102 
1103 /*
1104  * The file operations that we support: programs in the guest can open
1105  * a console device, read from it, write to it, poll for data and
1106  * close it.  The devices are at
1107  *   /dev/vport<device number>p<port number>
1108  */
1109 static const struct file_operations port_fops = {
1110         .owner = THIS_MODULE,
1111         .open  = port_fops_open,
1112         .read  = port_fops_read,
1113         .write = port_fops_write,
1114         .splice_write = port_fops_splice_write,
1115         .poll  = port_fops_poll,
1116         .release = port_fops_release,
1117         .fasync = port_fops_fasync,
1118         .llseek = no_llseek,
1119 };
1120 
1121 /*
1122  * The put_chars() callback is pretty straightforward.
1123  *
1124  * We turn the characters into a scatter-gather list, add it to the
1125  * output queue and then kick the Host.  Then we sit here waiting for
1126  * it to finish: inefficient in theory, but in practice
1127  * implementations will do it immediately (lguest's Launcher does).
1128  */
1129 static int put_chars(u32 vtermno, const char *buf, int count)
1130 {
1131         struct port *port;
1132         struct scatterlist sg[1];
1133 
1134         if (unlikely(early_put_chars))
1135                 return early_put_chars(vtermno, buf, count);
1136 
1137         port = find_port_by_vtermno(vtermno);
1138         if (!port)
1139                 return -EPIPE;
1140 
1141         sg_init_one(sg, buf, count);
1142         return __send_to_port(port, sg, 1, count, (void *)buf, false);
1143 }
1144 
1145 /*
1146  * get_chars() is the callback from the hvc_console infrastructure
1147  * when an interrupt is received.
1148  *
1149  * We call out to fill_readbuf that gets us the required data from the
1150  * buffers that are queued up.
1151  */
1152 static int get_chars(u32 vtermno, char *buf, int count)
1153 {
1154         struct port *port;
1155 
1156         /* If we've not set up the port yet, we have no input to give. */
1157         if (unlikely(early_put_chars))
1158                 return 0;
1159 
1160         port = find_port_by_vtermno(vtermno);
1161         if (!port)
1162                 return -EPIPE;
1163 
1164         /* If we don't have an input queue yet, we can't get input. */
1165         BUG_ON(!port->in_vq);
1166 
1167         return fill_readbuf(port, (__force char __user *)buf, count, false);
1168 }
1169 
1170 static void resize_console(struct port *port)
1171 {
1172         struct virtio_device *vdev;
1173 
1174         /* The port could have been hot-unplugged */
1175         if (!port || !is_console_port(port))
1176                 return;
1177 
1178         vdev = port->portdev->vdev;
1179 
1180         /* Don't test F_SIZE at all if we're rproc: not a valid feature! */
1181         if (!is_rproc_serial(vdev) &&
1182             virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
1183                 hvc_resize(port->cons.hvc, port->cons.ws);
1184 }
1185 
1186 /* We set the configuration at this point, since we now have a tty */
1187 static int notifier_add_vio(struct hvc_struct *hp, int data)
1188 {
1189         struct port *port;
1190 
1191         port = find_port_by_vtermno(hp->vtermno);
1192         if (!port)
1193                 return -EINVAL;
1194 
1195         hp->irq_requested = 1;
1196         resize_console(port);
1197 
1198         return 0;
1199 }
1200 
1201 static void notifier_del_vio(struct hvc_struct *hp, int data)
1202 {
1203         hp->irq_requested = 0;
1204 }
1205 
1206 /* The operations for console ports. */
1207 static const struct hv_ops hv_ops = {
1208         .get_chars = get_chars,
1209         .put_chars = put_chars,
1210         .notifier_add = notifier_add_vio,
1211         .notifier_del = notifier_del_vio,
1212         .notifier_hangup = notifier_del_vio,
1213 };
1214 
1215 /*
1216  * Console drivers are initialized very early so boot messages can go
1217  * out, so we do things slightly differently from the generic virtio
1218  * initialization of the net and block drivers.
1219  *
1220  * At this stage, the console is output-only.  It's too early to set
1221  * up a virtqueue, so we let the drivers do some boutique early-output
1222  * thing.
1223  */
1224 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
1225 {
1226         early_put_chars = put_chars;
1227         return hvc_instantiate(0, 0, &hv_ops);
1228 }
1229 
1230 static int init_port_console(struct port *port)
1231 {
1232         int ret;
1233 
1234         /*
1235          * The Host's telling us this port is a console port.  Hook it
1236          * up with an hvc console.
1237          *
1238          * To set up and manage our virtual console, we call
1239          * hvc_alloc().
1240          *
1241          * The first argument of hvc_alloc() is the virtual console
1242          * number.  The second argument is the parameter for the
1243          * notification mechanism (like irq number).  We currently
1244          * leave this as zero, virtqueues have implicit notifications.
1245          *
1246          * The third argument is a "struct hv_ops" containing the
1247          * put_chars() get_chars(), notifier_add() and notifier_del()
1248          * pointers.  The final argument is the output buffer size: we
1249          * can do any size, so we put PAGE_SIZE here.
1250          */
1251         port->cons.vtermno = pdrvdata.next_vtermno;
1252 
1253         port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
1254         if (IS_ERR(port->cons.hvc)) {
1255                 ret = PTR_ERR(port->cons.hvc);
1256                 dev_err(port->dev,
1257                         "error %d allocating hvc for port\n", ret);
1258                 port->cons.hvc = NULL;
1259                 return ret;
1260         }
1261         spin_lock_irq(&pdrvdata_lock);
1262         pdrvdata.next_vtermno++;
1263         list_add_tail(&port->cons.list, &pdrvdata.consoles);
1264         spin_unlock_irq(&pdrvdata_lock);
1265         port->guest_connected = true;
1266 
1267         /*
1268          * Start using the new console output if this is the first
1269          * console to come up.
1270          */
1271         if (early_put_chars)
1272                 early_put_chars = NULL;
1273 
1274         /* Notify host of port being opened */
1275         send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1276 
1277         return 0;
1278 }
1279 
1280 static ssize_t show_port_name(struct device *dev,
1281                               struct device_attribute *attr, char *buffer)
1282 {
1283         struct port *port;
1284 
1285         port = dev_get_drvdata(dev);
1286 
1287         return sprintf(buffer, "%s\n", port->name);
1288 }
1289 
1290 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1291 
1292 static struct attribute *port_sysfs_entries[] = {
1293         &dev_attr_name.attr,
1294         NULL
1295 };
1296 
1297 static struct attribute_group port_attribute_group = {
1298         .name = NULL,           /* put in device directory */
1299         .attrs = port_sysfs_entries,
1300 };
1301 
1302 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1303                             size_t count, loff_t *offp)
1304 {
1305         struct port *port;
1306         char *buf;
1307         ssize_t ret, out_offset, out_count;
1308 
1309         out_count = 1024;
1310         buf = kmalloc(out_count, GFP_KERNEL);
1311         if (!buf)
1312                 return -ENOMEM;
1313 
1314         port = filp->private_data;
1315         out_offset = 0;
1316         out_offset += snprintf(buf + out_offset, out_count,
1317                                "name: %s\n", port->name ? port->name : "");
1318         out_offset += snprintf(buf + out_offset, out_count - out_offset,
1319                                "guest_connected: %d\n", port->guest_connected);
1320         out_offset += snprintf(buf + out_offset, out_count - out_offset,
1321                                "host_connected: %d\n", port->host_connected);
1322         out_offset += snprintf(buf + out_offset, out_count - out_offset,
1323                                "outvq_full: %d\n", port->outvq_full);
1324         out_offset += snprintf(buf + out_offset, out_count - out_offset,
1325                                "bytes_sent: %lu\n", port->stats.bytes_sent);
1326         out_offset += snprintf(buf + out_offset, out_count - out_offset,
1327                                "bytes_received: %lu\n",
1328                                port->stats.bytes_received);
1329         out_offset += snprintf(buf + out_offset, out_count - out_offset,
1330                                "bytes_discarded: %lu\n",
1331                                port->stats.bytes_discarded);
1332         out_offset += snprintf(buf + out_offset, out_count - out_offset,
1333                                "is_console: %s\n",
1334                                is_console_port(port) ? "yes" : "no");
1335         out_offset += snprintf(buf + out_offset, out_count - out_offset,
1336                                "console_vtermno: %u\n", port->cons.vtermno);
1337 
1338         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1339         kfree(buf);
1340         return ret;
1341 }
1342 
1343 static const struct file_operations port_debugfs_ops = {
1344         .owner = THIS_MODULE,
1345         .open  = simple_open,
1346         .read  = debugfs_read,
1347 };
1348 
1349 static void set_console_size(struct port *port, u16 rows, u16 cols)
1350 {
1351         if (!port || !is_console_port(port))
1352                 return;
1353 
1354         port->cons.ws.ws_row = rows;
1355         port->cons.ws.ws_col = cols;
1356 }
1357 
1358 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1359 {
1360         struct port_buffer *buf;
1361         unsigned int nr_added_bufs;
1362         int ret;
1363 
1364         nr_added_bufs = 0;
1365         do {
1366                 buf = alloc_buf(vq, PAGE_SIZE, 0);
1367                 if (!buf)
1368                         break;
1369 
1370                 spin_lock_irq(lock);
1371                 ret = add_inbuf(vq, buf);
1372                 if (ret < 0) {
1373                         spin_unlock_irq(lock);
1374                         free_buf(buf, true);
1375                         break;
1376                 }
1377                 nr_added_bufs++;
1378                 spin_unlock_irq(lock);
1379         } while (ret > 0);
1380 
1381         return nr_added_bufs;
1382 }
1383 
1384 static void send_sigio_to_port(struct port *port)
1385 {
1386         if (port->async_queue && port->guest_connected)
1387                 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1388 }
1389 
1390 static int add_port(struct ports_device *portdev, u32 id)
1391 {
1392         char debugfs_name[16];
1393         struct port *port;
1394         struct port_buffer *buf;
1395         dev_t devt;
1396         unsigned int nr_added_bufs;
1397         int err;
1398 
1399         port = kmalloc(sizeof(*port), GFP_KERNEL);
1400         if (!port) {
1401                 err = -ENOMEM;
1402                 goto fail;
1403         }
1404         kref_init(&port->kref);
1405 
1406         port->portdev = portdev;
1407         port->id = id;
1408 
1409         port->name = NULL;
1410         port->inbuf = NULL;
1411         port->cons.hvc = NULL;
1412         port->async_queue = NULL;
1413 
1414         port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1415 
1416         port->host_connected = port->guest_connected = false;
1417         port->stats = (struct port_stats) { 0 };
1418 
1419         port->outvq_full = false;
1420 
1421         port->in_vq = portdev->in_vqs[port->id];
1422         port->out_vq = portdev->out_vqs[port->id];
1423 
1424         port->cdev = cdev_alloc();
1425         if (!port->cdev) {
1426                 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1427                 err = -ENOMEM;
1428                 goto free_port;
1429         }
1430         port->cdev->ops = &port_fops;
1431 
1432         devt = MKDEV(portdev->chr_major, id);
1433         err = cdev_add(port->cdev, devt, 1);
1434         if (err < 0) {
1435                 dev_err(&port->portdev->vdev->dev,
1436                         "Error %d adding cdev for port %u\n", err, id);
1437                 goto free_cdev;
1438         }
1439         port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1440                                   devt, port, "vport%up%u",
1441                                   port->portdev->vdev->index, id);
1442         if (IS_ERR(port->dev)) {
1443                 err = PTR_ERR(port->dev);
1444                 dev_err(&port->portdev->vdev->dev,
1445                         "Error %d creating device for port %u\n",
1446                         err, id);
1447                 goto free_cdev;
1448         }
1449 
1450         spin_lock_init(&port->inbuf_lock);
1451         spin_lock_init(&port->outvq_lock);
1452         init_waitqueue_head(&port->waitqueue);
1453 
1454         /* Fill the in_vq with buffers so the host can send us data. */
1455         nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1456         if (!nr_added_bufs) {
1457                 dev_err(port->dev, "Error allocating inbufs\n");
1458                 err = -ENOMEM;
1459                 goto free_device;
1460         }
1461 
1462         if (is_rproc_serial(port->portdev->vdev))
1463                 /*
1464                  * For rproc_serial assume remote processor is connected.
1465                  * rproc_serial does not want the console port, only
1466                  * the generic port implementation.
1467                  */
1468                 port->host_connected = true;
1469         else if (!use_multiport(port->portdev)) {
1470                 /*
1471                  * If we're not using multiport support,
1472                  * this has to be a console port.
1473                  */
1474                 err = init_port_console(port);
1475                 if (err)
1476                         goto free_inbufs;
1477         }
1478 
1479         spin_lock_irq(&portdev->ports_lock);
1480         list_add_tail(&port->list, &port->portdev->ports);
1481         spin_unlock_irq(&portdev->ports_lock);
1482 
1483         /*
1484          * Tell the Host we're set so that it can send us various
1485          * configuration parameters for this port (eg, port name,
1486          * caching, whether this is a console port, etc.)
1487          */
1488         send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1489 
1490         if (pdrvdata.debugfs_dir) {
1491                 /*
1492                  * Finally, create the debugfs file that we can use to
1493                  * inspect a port's state at any time
1494                  */
1495                 sprintf(debugfs_name, "vport%up%u",
1496                         port->portdev->vdev->index, id);
1497                 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1498                                                          pdrvdata.debugfs_dir,
1499                                                          port,
1500                                                          &port_debugfs_ops);
1501         }
1502         return 0;
1503 
1504 free_inbufs:
1505         while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1506                 free_buf(buf, true);
1507 free_device:
1508         device_destroy(pdrvdata.class, port->dev->devt);
1509 free_cdev:
1510         cdev_del(port->cdev);
1511 free_port:
1512         kfree(port);
1513 fail:
1514         /* The host might want to notify management sw about port add failure */
1515         __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1516         return err;
1517 }
1518 
1519 /* No users remain, remove all port-specific data. */
1520 static void remove_port(struct kref *kref)
1521 {
1522         struct port *port;
1523 
1524         port = container_of(kref, struct port, kref);
1525 
1526         kfree(port);
1527 }
1528 
1529 static void remove_port_data(struct port *port)
1530 {
1531         struct port_buffer *buf;
1532 
1533         spin_lock_irq(&port->inbuf_lock);
1534         /* Remove unused data this port might have received. */
1535         discard_port_data(port);
1536 
1537         /* Remove buffers we queued up for the Host to send us data in. */
1538         while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1539                 free_buf(buf, true);
1540         spin_unlock_irq(&port->inbuf_lock);
1541 
1542         spin_lock_irq(&port->outvq_lock);
1543         reclaim_consumed_buffers(port);
1544 
1545         /* Free pending buffers from the out-queue. */
1546         while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
1547                 free_buf(buf, true);
1548         spin_unlock_irq(&port->outvq_lock);
1549 }
1550 
1551 /*
1552  * Port got unplugged.  Remove port from portdev's list and drop the
1553  * kref reference.  If no userspace has this port opened, it will
1554  * result in immediate removal the port.
1555  */
1556 static void unplug_port(struct port *port)
1557 {
1558         spin_lock_irq(&port->portdev->ports_lock);
1559         list_del(&port->list);
1560         spin_unlock_irq(&port->portdev->ports_lock);
1561 
1562         spin_lock_irq(&port->inbuf_lock);
1563         if (port->guest_connected) {
1564                 /* Let the app know the port is going down. */
1565                 send_sigio_to_port(port);
1566 
1567                 /* Do this after sigio is actually sent */
1568                 port->guest_connected = false;
1569                 port->host_connected = false;
1570 
1571                 wake_up_interruptible(&port->waitqueue);
1572         }
1573         spin_unlock_irq(&port->inbuf_lock);
1574 
1575         if (is_console_port(port)) {
1576                 spin_lock_irq(&pdrvdata_lock);
1577                 list_del(&port->cons.list);
1578                 spin_unlock_irq(&pdrvdata_lock);
1579                 hvc_remove(port->cons.hvc);
1580         }
1581 
1582         remove_port_data(port);
1583 
1584         /*
1585          * We should just assume the device itself has gone off --
1586          * else a close on an open port later will try to send out a
1587          * control message.
1588          */
1589         port->portdev = NULL;
1590 
1591         sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1592         device_destroy(pdrvdata.class, port->dev->devt);
1593         cdev_del(port->cdev);
1594 
1595         debugfs_remove(port->debugfs_file);
1596         kfree(port->name);
1597 
1598         /*
1599          * Locks around here are not necessary - a port can't be
1600          * opened after we removed the port struct from ports_list
1601          * above.
1602          */
1603         kref_put(&port->kref, remove_port);
1604 }
1605 
1606 /* Any private messages that the Host and Guest want to share */
1607 static void handle_control_message(struct virtio_device *vdev,
1608                                    struct ports_device *portdev,
1609                                    struct port_buffer *buf)
1610 {
1611         struct virtio_console_control *cpkt;
1612         struct port *port;
1613         size_t name_size;
1614         int err;
1615 
1616         cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1617 
1618         port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id));
1619         if (!port &&
1620             cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
1621                 /* No valid header at start of buffer.  Drop it. */
1622                 dev_dbg(&portdev->vdev->dev,
1623                         "Invalid index %u in control packet\n", cpkt->id);
1624                 return;
1625         }
1626 
1627         switch (virtio16_to_cpu(vdev, cpkt->event)) {
1628         case VIRTIO_CONSOLE_PORT_ADD:
1629                 if (port) {
1630                         dev_dbg(&portdev->vdev->dev,
1631                                 "Port %u already added\n", port->id);
1632                         send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1633                         break;
1634                 }
1635                 if (virtio32_to_cpu(vdev, cpkt->id) >=
1636                     portdev->config.max_nr_ports) {
1637                         dev_warn(&portdev->vdev->dev,
1638                                 "Request for adding port with "
1639                                 "out-of-bound id %u, max. supported id: %u\n",
1640                                 cpkt->id, portdev->config.max_nr_ports - 1);
1641                         break;
1642                 }
1643                 add_port(portdev, virtio32_to_cpu(vdev, cpkt->id));
1644                 break;
1645         case VIRTIO_CONSOLE_PORT_REMOVE:
1646                 unplug_port(port);
1647                 break;
1648         case VIRTIO_CONSOLE_CONSOLE_PORT:
1649                 if (!cpkt->value)
1650                         break;
1651                 if (is_console_port(port))
1652                         break;
1653 
1654                 init_port_console(port);
1655                 complete(&early_console_added);
1656                 /*
1657                  * Could remove the port here in case init fails - but
1658                  * have to notify the host first.
1659                  */
1660                 break;
1661         case VIRTIO_CONSOLE_RESIZE: {
1662                 struct {
1663                         __u16 rows;
1664                         __u16 cols;
1665                 } size;
1666 
1667                 if (!is_console_port(port))
1668                         break;
1669 
1670                 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1671                        sizeof(size));
1672                 set_console_size(port, size.rows, size.cols);
1673 
1674                 port->cons.hvc->irq_requested = 1;
1675                 resize_console(port);
1676                 break;
1677         }
1678         case VIRTIO_CONSOLE_PORT_OPEN:
1679                 port->host_connected = virtio16_to_cpu(vdev, cpkt->value);
1680                 wake_up_interruptible(&port->waitqueue);
1681                 /*
1682                  * If the host port got closed and the host had any
1683                  * unconsumed buffers, we'll be able to reclaim them
1684                  * now.
1685                  */
1686                 spin_lock_irq(&port->outvq_lock);
1687                 reclaim_consumed_buffers(port);
1688                 spin_unlock_irq(&port->outvq_lock);
1689 
1690                 /*
1691                  * If the guest is connected, it'll be interested in
1692                  * knowing the host connection state changed.
1693                  */
1694                 spin_lock_irq(&port->inbuf_lock);
1695                 send_sigio_to_port(port);
1696                 spin_unlock_irq(&port->inbuf_lock);
1697                 break;
1698         case VIRTIO_CONSOLE_PORT_NAME:
1699                 /*
1700                  * If we woke up after hibernation, we can get this
1701                  * again.  Skip it in that case.
1702                  */
1703                 if (port->name)
1704                         break;
1705 
1706                 /*
1707                  * Skip the size of the header and the cpkt to get the size
1708                  * of the name that was sent
1709                  */
1710                 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1711 
1712                 port->name = kmalloc(name_size, GFP_KERNEL);
1713                 if (!port->name) {
1714                         dev_err(port->dev,
1715                                 "Not enough space to store port name\n");
1716                         break;
1717                 }
1718                 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1719                         name_size - 1);
1720                 port->name[name_size - 1] = 0;
1721 
1722                 /*
1723                  * Since we only have one sysfs attribute, 'name',
1724                  * create it only if we have a name for the port.
1725                  */
1726                 err = sysfs_create_group(&port->dev->kobj,
1727                                          &port_attribute_group);
1728                 if (err) {
1729                         dev_err(port->dev,
1730                                 "Error %d creating sysfs device attributes\n",
1731                                 err);
1732                 } else {
1733                         /*
1734                          * Generate a udev event so that appropriate
1735                          * symlinks can be created based on udev
1736                          * rules.
1737                          */
1738                         kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1739                 }
1740                 break;
1741         }
1742 }
1743 
1744 static void control_work_handler(struct work_struct *work)
1745 {
1746         struct ports_device *portdev;
1747         struct virtqueue *vq;
1748         struct port_buffer *buf;
1749         unsigned int len;
1750 
1751         portdev = container_of(work, struct ports_device, control_work);
1752         vq = portdev->c_ivq;
1753 
1754         spin_lock(&portdev->c_ivq_lock);
1755         while ((buf = virtqueue_get_buf(vq, &len))) {
1756                 spin_unlock(&portdev->c_ivq_lock);
1757 
1758                 buf->len = len;
1759                 buf->offset = 0;
1760 
1761                 handle_control_message(vq->vdev, portdev, buf);
1762 
1763                 spin_lock(&portdev->c_ivq_lock);
1764                 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1765                         dev_warn(&portdev->vdev->dev,
1766                                  "Error adding buffer to queue\n");
1767                         free_buf(buf, false);
1768                 }
1769         }
1770         spin_unlock(&portdev->c_ivq_lock);
1771 }
1772 
1773 static void out_intr(struct virtqueue *vq)
1774 {
1775         struct port *port;
1776 
1777         port = find_port_by_vq(vq->vdev->priv, vq);
1778         if (!port)
1779                 return;
1780 
1781         wake_up_interruptible(&port->waitqueue);
1782 }
1783 
1784 static void in_intr(struct virtqueue *vq)
1785 {
1786         struct port *port;
1787         unsigned long flags;
1788 
1789         port = find_port_by_vq(vq->vdev->priv, vq);
1790         if (!port)
1791                 return;
1792 
1793         spin_lock_irqsave(&port->inbuf_lock, flags);
1794         port->inbuf = get_inbuf(port);
1795 
1796         /*
1797          * Normally the port should not accept data when the port is
1798          * closed. For generic serial ports, the host won't (shouldn't)
1799          * send data till the guest is connected. But this condition
1800          * can be reached when a console port is not yet connected (no
1801          * tty is spawned) and the other side sends out data over the
1802          * vring, or when a remote devices start sending data before
1803          * the ports are opened.
1804          *
1805          * A generic serial port will discard data if not connected,
1806          * while console ports and rproc-serial ports accepts data at
1807          * any time. rproc-serial is initiated with guest_connected to
1808          * false because port_fops_open expects this. Console ports are
1809          * hooked up with an HVC console and is initialized with
1810          * guest_connected to true.
1811          */
1812 
1813         if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
1814                 discard_port_data(port);
1815 
1816         /* Send a SIGIO indicating new data in case the process asked for it */
1817         send_sigio_to_port(port);
1818 
1819         spin_unlock_irqrestore(&port->inbuf_lock, flags);
1820 
1821         wake_up_interruptible(&port->waitqueue);
1822 
1823         if (is_console_port(port) && hvc_poll(port->cons.hvc))
1824                 hvc_kick();
1825 }
1826 
1827 static void control_intr(struct virtqueue *vq)
1828 {
1829         struct ports_device *portdev;
1830 
1831         portdev = vq->vdev->priv;
1832         schedule_work(&portdev->control_work);
1833 }
1834 
1835 static void config_intr(struct virtio_device *vdev)
1836 {
1837         struct ports_device *portdev;
1838 
1839         portdev = vdev->priv;
1840 
1841         if (!use_multiport(portdev))
1842                 schedule_work(&portdev->config_work);
1843 }
1844 
1845 static void config_work_handler(struct work_struct *work)
1846 {
1847         struct ports_device *portdev;
1848 
1849         portdev = container_of(work, struct ports_device, control_work);
1850         if (!use_multiport(portdev)) {
1851                 struct virtio_device *vdev;
1852                 struct port *port;
1853                 u16 rows, cols;
1854 
1855                 vdev = portdev->vdev;
1856                 virtio_cread(vdev, struct virtio_console_config, cols, &cols);
1857                 virtio_cread(vdev, struct virtio_console_config, rows, &rows);
1858 
1859                 port = find_port_by_id(portdev, 0);
1860                 set_console_size(port, rows, cols);
1861 
1862                 /*
1863                  * We'll use this way of resizing only for legacy
1864                  * support.  For newer userspace
1865                  * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1866                  * to indicate console size changes so that it can be
1867                  * done per-port.
1868                  */
1869                 resize_console(port);
1870         }
1871 }
1872 
1873 static int init_vqs(struct ports_device *portdev)
1874 {
1875         vq_callback_t **io_callbacks;
1876         char **io_names;
1877         struct virtqueue **vqs;
1878         u32 i, j, nr_ports, nr_queues;
1879         int err;
1880 
1881         nr_ports = portdev->config.max_nr_ports;
1882         nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1883 
1884         vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1885         io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1886         io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1887         portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1888                                   GFP_KERNEL);
1889         portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1890                                    GFP_KERNEL);
1891         if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1892             !portdev->out_vqs) {
1893                 err = -ENOMEM;
1894                 goto free;
1895         }
1896 
1897         /*
1898          * For backward compat (newer host but older guest), the host
1899          * spawns a console port first and also inits the vqs for port
1900          * 0 before others.
1901          */
1902         j = 0;
1903         io_callbacks[j] = in_intr;
1904         io_callbacks[j + 1] = out_intr;
1905         io_names[j] = "input";
1906         io_names[j + 1] = "output";
1907         j += 2;
1908 
1909         if (use_multiport(portdev)) {
1910                 io_callbacks[j] = control_intr;
1911                 io_callbacks[j + 1] = NULL;
1912                 io_names[j] = "control-i";
1913                 io_names[j + 1] = "control-o";
1914 
1915                 for (i = 1; i < nr_ports; i++) {
1916                         j += 2;
1917                         io_callbacks[j] = in_intr;
1918                         io_callbacks[j + 1] = out_intr;
1919                         io_names[j] = "input";
1920                         io_names[j + 1] = "output";
1921                 }
1922         }
1923         /* Find the queues. */
1924         err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1925                                               io_callbacks,
1926                                               (const char **)io_names);
1927         if (err)
1928                 goto free;
1929 
1930         j = 0;
1931         portdev->in_vqs[0] = vqs[0];
1932         portdev->out_vqs[0] = vqs[1];
1933         j += 2;
1934         if (use_multiport(portdev)) {
1935                 portdev->c_ivq = vqs[j];
1936                 portdev->c_ovq = vqs[j + 1];
1937 
1938                 for (i = 1; i < nr_ports; i++) {
1939                         j += 2;
1940                         portdev->in_vqs[i] = vqs[j];
1941                         portdev->out_vqs[i] = vqs[j + 1];
1942                 }
1943         }
1944         kfree(io_names);
1945         kfree(io_callbacks);
1946         kfree(vqs);
1947 
1948         return 0;
1949 
1950 free:
1951         kfree(portdev->out_vqs);
1952         kfree(portdev->in_vqs);
1953         kfree(io_names);
1954         kfree(io_callbacks);
1955         kfree(vqs);
1956 
1957         return err;
1958 }
1959 
1960 static const struct file_operations portdev_fops = {
1961         .owner = THIS_MODULE,
1962 };
1963 
1964 static void remove_vqs(struct ports_device *portdev)
1965 {
1966         portdev->vdev->config->del_vqs(portdev->vdev);
1967         kfree(portdev->in_vqs);
1968         kfree(portdev->out_vqs);
1969 }
1970 
1971 static void remove_controlq_data(struct ports_device *portdev)
1972 {
1973         struct port_buffer *buf;
1974         unsigned int len;
1975 
1976         if (!use_multiport(portdev))
1977                 return;
1978 
1979         while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1980                 free_buf(buf, true);
1981 
1982         while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1983                 free_buf(buf, true);
1984 }
1985 
1986 /*
1987  * Once we're further in boot, we get probed like any other virtio
1988  * device.
1989  *
1990  * If the host also supports multiple console ports, we check the
1991  * config space to see how many ports the host has spawned.  We
1992  * initialize each port found.
1993  */
1994 static int virtcons_probe(struct virtio_device *vdev)
1995 {
1996         struct ports_device *portdev;
1997         int err;
1998         bool multiport;
1999         bool early = early_put_chars != NULL;
2000 
2001         /* We only need a config space if features are offered */
2002         if (!vdev->config->get &&
2003             (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
2004              || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
2005                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2006                         __func__);
2007                 return -EINVAL;
2008         }
2009 
2010         /* Ensure to read early_put_chars now */
2011         barrier();
2012 
2013         portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
2014         if (!portdev) {
2015                 err = -ENOMEM;
2016                 goto fail;
2017         }
2018 
2019         /* Attach this portdev to this virtio_device, and vice-versa. */
2020         portdev->vdev = vdev;
2021         vdev->priv = portdev;
2022 
2023         portdev->chr_major = register_chrdev(0, "virtio-portsdev",
2024                                              &portdev_fops);
2025         if (portdev->chr_major < 0) {
2026                 dev_err(&vdev->dev,
2027                         "Error %d registering chrdev for device %u\n",
2028                         portdev->chr_major, vdev->index);
2029                 err = portdev->chr_major;
2030                 goto free;
2031         }
2032 
2033         multiport = false;
2034         portdev->config.max_nr_ports = 1;
2035 
2036         /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
2037         if (!is_rproc_serial(vdev) &&
2038             virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
2039                                  struct virtio_console_config, max_nr_ports,
2040                                  &portdev->config.max_nr_ports) == 0) {
2041                 multiport = true;
2042         }
2043 
2044         err = init_vqs(portdev);
2045         if (err < 0) {
2046                 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2047                 goto free_chrdev;
2048         }
2049 
2050         spin_lock_init(&portdev->ports_lock);
2051         INIT_LIST_HEAD(&portdev->ports);
2052 
2053         virtio_device_ready(portdev->vdev);
2054 
2055         INIT_WORK(&portdev->config_work, &config_work_handler);
2056         INIT_WORK(&portdev->control_work, &control_work_handler);
2057 
2058         if (multiport) {
2059                 unsigned int nr_added_bufs;
2060 
2061                 spin_lock_init(&portdev->c_ivq_lock);
2062                 spin_lock_init(&portdev->c_ovq_lock);
2063 
2064                 nr_added_bufs = fill_queue(portdev->c_ivq,
2065                                            &portdev->c_ivq_lock);
2066                 if (!nr_added_bufs) {
2067                         dev_err(&vdev->dev,
2068                                 "Error allocating buffers for control queue\n");
2069                         err = -ENOMEM;
2070                         goto free_vqs;
2071                 }
2072         } else {
2073                 /*
2074                  * For backward compatibility: Create a console port
2075                  * if we're running on older host.
2076                  */
2077                 add_port(portdev, 0);
2078         }
2079 
2080         spin_lock_irq(&pdrvdata_lock);
2081         list_add_tail(&portdev->list, &pdrvdata.portdevs);
2082         spin_unlock_irq(&pdrvdata_lock);
2083 
2084         __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2085                            VIRTIO_CONSOLE_DEVICE_READY, 1);
2086 
2087         /*
2088          * If there was an early virtio console, assume that there are no
2089          * other consoles. We need to wait until the hvc_alloc matches the
2090          * hvc_instantiate, otherwise tty_open will complain, resulting in
2091          * a "Warning: unable to open an initial console" boot failure.
2092          * Without multiport this is done in add_port above. With multiport
2093          * this might take some host<->guest communication - thus we have to
2094          * wait.
2095          */
2096         if (multiport && early)
2097                 wait_for_completion(&early_console_added);
2098 
2099         return 0;
2100 
2101 free_vqs:
2102         /* The host might want to notify mgmt sw about device add failure */
2103         __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2104                            VIRTIO_CONSOLE_DEVICE_READY, 0);
2105         remove_vqs(portdev);
2106 free_chrdev:
2107         unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2108 free:
2109         kfree(portdev);
2110 fail:
2111         return err;
2112 }
2113 
2114 static void virtcons_remove(struct virtio_device *vdev)
2115 {
2116         struct ports_device *portdev;
2117         struct port *port, *port2;
2118 
2119         portdev = vdev->priv;
2120 
2121         spin_lock_irq(&pdrvdata_lock);
2122         list_del(&portdev->list);
2123         spin_unlock_irq(&pdrvdata_lock);
2124 
2125         /* Disable interrupts for vqs */
2126         vdev->config->reset(vdev);
2127         /* Finish up work that's lined up */
2128         if (use_multiport(portdev))
2129                 cancel_work_sync(&portdev->control_work);
2130         else
2131                 cancel_work_sync(&portdev->config_work);
2132 
2133         list_for_each_entry_safe(port, port2, &portdev->ports, list)
2134                 unplug_port(port);
2135 
2136         unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2137 
2138         /*
2139          * When yanking out a device, we immediately lose the
2140          * (device-side) queues.  So there's no point in keeping the
2141          * guest side around till we drop our final reference.  This
2142          * also means that any ports which are in an open state will
2143          * have to just stop using the port, as the vqs are going
2144          * away.
2145          */
2146         remove_controlq_data(portdev);
2147         remove_vqs(portdev);
2148         kfree(portdev);
2149 }
2150 
2151 static struct virtio_device_id id_table[] = {
2152         { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2153         { 0 },
2154 };
2155 
2156 static unsigned int features[] = {
2157         VIRTIO_CONSOLE_F_SIZE,
2158         VIRTIO_CONSOLE_F_MULTIPORT,
2159 };
2160 
2161 static struct virtio_device_id rproc_serial_id_table[] = {
2162 #if IS_ENABLED(CONFIG_REMOTEPROC)
2163         { VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2164 #endif
2165         { 0 },
2166 };
2167 
2168 static unsigned int rproc_serial_features[] = {
2169 };
2170 
2171 #ifdef CONFIG_PM_SLEEP
2172 static int virtcons_freeze(struct virtio_device *vdev)
2173 {
2174         struct ports_device *portdev;
2175         struct port *port;
2176 
2177         portdev = vdev->priv;
2178 
2179         vdev->config->reset(vdev);
2180 
2181         virtqueue_disable_cb(portdev->c_ivq);
2182         cancel_work_sync(&portdev->control_work);
2183         cancel_work_sync(&portdev->config_work);
2184         /*
2185          * Once more: if control_work_handler() was running, it would
2186          * enable the cb as the last step.
2187          */
2188         virtqueue_disable_cb(portdev->c_ivq);
2189         remove_controlq_data(portdev);
2190 
2191         list_for_each_entry(port, &portdev->ports, list) {
2192                 virtqueue_disable_cb(port->in_vq);
2193                 virtqueue_disable_cb(port->out_vq);
2194                 /*
2195                  * We'll ask the host later if the new invocation has
2196                  * the port opened or closed.
2197                  */
2198                 port->host_connected = false;
2199                 remove_port_data(port);
2200         }
2201         remove_vqs(portdev);
2202 
2203         return 0;
2204 }
2205 
2206 static int virtcons_restore(struct virtio_device *vdev)
2207 {
2208         struct ports_device *portdev;
2209         struct port *port;
2210         int ret;
2211 
2212         portdev = vdev->priv;
2213 
2214         ret = init_vqs(portdev);
2215         if (ret)
2216                 return ret;
2217 
2218         virtio_device_ready(portdev->vdev);
2219 
2220         if (use_multiport(portdev))
2221                 fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2222 
2223         list_for_each_entry(port, &portdev->ports, list) {
2224                 port->in_vq = portdev->in_vqs[port->id];
2225                 port->out_vq = portdev->out_vqs[port->id];
2226 
2227                 fill_queue(port->in_vq, &port->inbuf_lock);
2228 
2229                 /* Get port open/close status on the host */
2230                 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
2231 
2232                 /*
2233                  * If a port was open at the time of suspending, we
2234                  * have to let the host know that it's still open.
2235                  */
2236                 if (port->guest_connected)
2237                         send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
2238         }
2239         return 0;
2240 }
2241 #endif
2242 
2243 static struct virtio_driver virtio_console = {
2244         .feature_table = features,
2245         .feature_table_size = ARRAY_SIZE(features),
2246         .driver.name =  KBUILD_MODNAME,
2247         .driver.owner = THIS_MODULE,
2248         .id_table =     id_table,
2249         .probe =        virtcons_probe,
2250         .remove =       virtcons_remove,
2251         .config_changed = config_intr,
2252 #ifdef CONFIG_PM_SLEEP
2253         .freeze =       virtcons_freeze,
2254         .restore =      virtcons_restore,
2255 #endif
2256 };
2257 
2258 static struct virtio_driver virtio_rproc_serial = {
2259         .feature_table = rproc_serial_features,
2260         .feature_table_size = ARRAY_SIZE(rproc_serial_features),
2261         .driver.name =  "virtio_rproc_serial",
2262         .driver.owner = THIS_MODULE,
2263         .id_table =     rproc_serial_id_table,
2264         .probe =        virtcons_probe,
2265         .remove =       virtcons_remove,
2266 };
2267 
2268 static int __init init(void)
2269 {
2270         int err;
2271 
2272         pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
2273         if (IS_ERR(pdrvdata.class)) {
2274                 err = PTR_ERR(pdrvdata.class);
2275                 pr_err("Error %d creating virtio-ports class\n", err);
2276                 return err;
2277         }
2278 
2279         pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
2280         if (!pdrvdata.debugfs_dir)
2281                 pr_warning("Error creating debugfs dir for virtio-ports\n");
2282         INIT_LIST_HEAD(&pdrvdata.consoles);
2283         INIT_LIST_HEAD(&pdrvdata.portdevs);
2284 
2285         err = register_virtio_driver(&virtio_console);
2286         if (err < 0) {
2287                 pr_err("Error %d registering virtio driver\n", err);
2288                 goto free;
2289         }
2290         err = register_virtio_driver(&virtio_rproc_serial);
2291         if (err < 0) {
2292                 pr_err("Error %d registering virtio rproc serial driver\n",
2293                        err);
2294                 goto unregister;
2295         }
2296         return 0;
2297 unregister:
2298         unregister_virtio_driver(&virtio_console);
2299 free:
2300         debugfs_remove_recursive(pdrvdata.debugfs_dir);
2301         class_destroy(pdrvdata.class);
2302         return err;
2303 }
2304 
2305 static void __exit fini(void)
2306 {
2307         reclaim_dma_bufs();
2308 
2309         unregister_virtio_driver(&virtio_console);
2310         unregister_virtio_driver(&virtio_rproc_serial);
2311 
2312         class_destroy(pdrvdata.class);
2313         debugfs_remove_recursive(pdrvdata.debugfs_dir);
2314 }
2315 module_init(init);
2316 module_exit(fini);
2317 
2318 MODULE_DEVICE_TABLE(virtio, id_table);
2319 MODULE_DESCRIPTION("Virtio console driver");
2320 MODULE_LICENSE("GPL");
2321 

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