source: src/linux/universal/linux-4.4/drivers/char/virtio_console.c @ 31885

Last change on this file since 31885 was 31885, checked in by brainslayer, 3 months ago

update

File size: 56.5 KB
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1/*
2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
4 * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19 */
20#include <linux/cdev.h>
21#include <linux/debugfs.h>
22#include <linux/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 */
54struct 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};
79static struct ports_driver_data pdrvdata;
80
81static DEFINE_SPINLOCK(pdrvdata_lock);
82static DECLARE_COMPLETION(early_console_added);
83
84/* This struct holds information that's relevant only for console ports */
85struct 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
105struct 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 */
136struct 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
175struct port_stats {
176        unsigned long bytes_sent, bytes_received, bytes_discarded;
177};
178
179/* This struct holds the per-port data */
180struct 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. */
248static int (*early_put_chars)(u32, const char *, int);
249
250static 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;
264out:
265        spin_unlock_irqrestore(&pdrvdata_lock, flags);
266        return port;
267}
268
269static 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;
283out:
284        spin_unlock_irqrestore(&portdev->ports_lock, flags);
285
286        return port;
287}
288
289static 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;
302out:
303        spin_unlock_irqrestore(&pdrvdata_lock, flags);
304        return port;
305}
306
307static 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;
317out:
318        spin_unlock_irqrestore(&portdev->ports_lock, flags);
319
320        return port;
321}
322
323static 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;
334out:
335        spin_unlock_irqrestore(&portdev->ports_lock, flags);
336        return port;
337}
338
339static bool is_console_port(struct port *port)
340{
341        if (port->cons.hvc)
342                return true;
343        return false;
344}
345
346static bool is_rproc_serial(const struct virtio_device *vdev)
347{
348        return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
349}
350
351static 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
362static DEFINE_SPINLOCK(dma_bufs_lock);
363static LIST_HEAD(pending_free_dma_bufs);
364
365static 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
398static 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
420static 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
473free_buf:
474        kfree(buf);
475fail:
476        return NULL;
477}
478
479/* Callers should take appropriate locks */
480static 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 */
503static 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. */
518static 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
544static 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
559static 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
589static 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 */
600static 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
615static 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();
658done:
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 */
673static 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 */
716static 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
725static 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
748static 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
795static 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
815static 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
862free_buf:
863        free_buf(buf, true);
864out:
865        return ret;
866}
867
868struct sg_list {
869        unsigned int n;
870        unsigned int size;
871        size_t len;
872        struct scatterlist *sg;
873};
874
875static 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 */
919static 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
977error_out:
978        pipe_unlock(pipe);
979        return ret;
980}
981
982static 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
1005static void remove_port(struct kref *kref);
1006
1007static 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
1041static 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;
1090out:
1091        kref_put(&port->kref, remove_port);
1092        return ret;
1093}
1094
1095static 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 */
1109static 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 */
1129static int put_chars(u32 vtermno, const char *buf, int count)
1130{
1131        struct port *port;
1132        struct scatterlist sg[1];
1133        void *data;
1134        int ret;
1135
1136        if (unlikely(early_put_chars))
1137                return early_put_chars(vtermno, buf, count);
1138
1139        port = find_port_by_vtermno(vtermno);
1140        if (!port)
1141                return -EPIPE;
1142
1143        data = kmemdup(buf, count, GFP_ATOMIC);
1144        if (!data)
1145                return -ENOMEM;
1146
1147        sg_init_one(sg, data, count);
1148        ret = __send_to_port(port, sg, 1, count, data, false);
1149        kfree(data);
1150        return ret;
1151}
1152
1153/*
1154 * get_chars() is the callback from the hvc_console infrastructure
1155 * when an interrupt is received.
1156 *
1157 * We call out to fill_readbuf that gets us the required data from the
1158 * buffers that are queued up.
1159 */
1160static int get_chars(u32 vtermno, char *buf, int count)
1161{
1162        struct port *port;
1163
1164        /* If we've not set up the port yet, we have no input to give. */
1165        if (unlikely(early_put_chars))
1166                return 0;
1167
1168        port = find_port_by_vtermno(vtermno);
1169        if (!port)
1170                return -EPIPE;
1171
1172        /* If we don't have an input queue yet, we can't get input. */
1173        BUG_ON(!port->in_vq);
1174
1175        return fill_readbuf(port, (__force char __user *)buf, count, false);
1176}
1177
1178static void resize_console(struct port *port)
1179{
1180        struct virtio_device *vdev;
1181
1182        /* The port could have been hot-unplugged */
1183        if (!port || !is_console_port(port))
1184                return;
1185
1186        vdev = port->portdev->vdev;
1187
1188        /* Don't test F_SIZE at all if we're rproc: not a valid feature! */
1189        if (!is_rproc_serial(vdev) &&
1190            virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
1191                hvc_resize(port->cons.hvc, port->cons.ws);
1192}
1193
1194/* We set the configuration at this point, since we now have a tty */
1195static int notifier_add_vio(struct hvc_struct *hp, int data)
1196{
1197        struct port *port;
1198
1199        port = find_port_by_vtermno(hp->vtermno);
1200        if (!port)
1201                return -EINVAL;
1202
1203        hp->irq_requested = 1;
1204        resize_console(port);
1205
1206        return 0;
1207}
1208
1209static void notifier_del_vio(struct hvc_struct *hp, int data)
1210{
1211        hp->irq_requested = 0;
1212}
1213
1214/* The operations for console ports. */
1215static const struct hv_ops hv_ops = {
1216        .get_chars = get_chars,
1217        .put_chars = put_chars,
1218        .notifier_add = notifier_add_vio,
1219        .notifier_del = notifier_del_vio,
1220        .notifier_hangup = notifier_del_vio,
1221};
1222
1223/*
1224 * Console drivers are initialized very early so boot messages can go
1225 * out, so we do things slightly differently from the generic virtio
1226 * initialization of the net and block drivers.
1227 *
1228 * At this stage, the console is output-only.  It's too early to set
1229 * up a virtqueue, so we let the drivers do some boutique early-output
1230 * thing.
1231 */
1232int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
1233{
1234        early_put_chars = put_chars;
1235        return hvc_instantiate(0, 0, &hv_ops);
1236}
1237
1238static int init_port_console(struct port *port)
1239{
1240        int ret;
1241
1242        /*
1243         * The Host's telling us this port is a console port.  Hook it
1244         * up with an hvc console.
1245         *
1246         * To set up and manage our virtual console, we call
1247         * hvc_alloc().
1248         *
1249         * The first argument of hvc_alloc() is the virtual console
1250         * number.  The second argument is the parameter for the
1251         * notification mechanism (like irq number).  We currently
1252         * leave this as zero, virtqueues have implicit notifications.
1253         *
1254         * The third argument is a "struct hv_ops" containing the
1255         * put_chars() get_chars(), notifier_add() and notifier_del()
1256         * pointers.  The final argument is the output buffer size: we
1257         * can do any size, so we put PAGE_SIZE here.
1258         */
1259        port->cons.vtermno = pdrvdata.next_vtermno;
1260
1261        port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
1262        if (IS_ERR(port->cons.hvc)) {
1263                ret = PTR_ERR(port->cons.hvc);
1264                dev_err(port->dev,
1265                        "error %d allocating hvc for port\n", ret);
1266                port->cons.hvc = NULL;
1267                return ret;
1268        }
1269        spin_lock_irq(&pdrvdata_lock);
1270        pdrvdata.next_vtermno++;
1271        list_add_tail(&port->cons.list, &pdrvdata.consoles);
1272        spin_unlock_irq(&pdrvdata_lock);
1273        port->guest_connected = true;
1274
1275        /*
1276         * Start using the new console output if this is the first
1277         * console to come up.
1278         */
1279        if (early_put_chars)
1280                early_put_chars = NULL;
1281
1282        /* Notify host of port being opened */
1283        send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1284
1285        return 0;
1286}
1287
1288static ssize_t show_port_name(struct device *dev,
1289                              struct device_attribute *attr, char *buffer)
1290{
1291        struct port *port;
1292
1293        port = dev_get_drvdata(dev);
1294
1295        return sprintf(buffer, "%s\n", port->name);
1296}
1297
1298static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1299
1300static struct attribute *port_sysfs_entries[] = {
1301        &dev_attr_name.attr,
1302        NULL
1303};
1304
1305static struct attribute_group port_attribute_group = {
1306        .name = NULL,           /* put in device directory */
1307        .attrs = port_sysfs_entries,
1308};
1309
1310static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1311                            size_t count, loff_t *offp)
1312{
1313        struct port *port;
1314        char *buf;
1315        ssize_t ret, out_offset, out_count;
1316
1317        out_count = 1024;
1318        buf = kmalloc(out_count, GFP_KERNEL);
1319        if (!buf)
1320                return -ENOMEM;
1321
1322        port = filp->private_data;
1323        out_offset = 0;
1324        out_offset += snprintf(buf + out_offset, out_count,
1325                               "name: %s\n", port->name ? port->name : "");
1326        out_offset += snprintf(buf + out_offset, out_count - out_offset,
1327                               "guest_connected: %d\n", port->guest_connected);
1328        out_offset += snprintf(buf + out_offset, out_count - out_offset,
1329                               "host_connected: %d\n", port->host_connected);
1330        out_offset += snprintf(buf + out_offset, out_count - out_offset,
1331                               "outvq_full: %d\n", port->outvq_full);
1332        out_offset += snprintf(buf + out_offset, out_count - out_offset,
1333                               "bytes_sent: %lu\n", port->stats.bytes_sent);
1334        out_offset += snprintf(buf + out_offset, out_count - out_offset,
1335                               "bytes_received: %lu\n",
1336                               port->stats.bytes_received);
1337        out_offset += snprintf(buf + out_offset, out_count - out_offset,
1338                               "bytes_discarded: %lu\n",
1339                               port->stats.bytes_discarded);
1340        out_offset += snprintf(buf + out_offset, out_count - out_offset,
1341                               "is_console: %s\n",
1342                               is_console_port(port) ? "yes" : "no");
1343        out_offset += snprintf(buf + out_offset, out_count - out_offset,
1344                               "console_vtermno: %u\n", port->cons.vtermno);
1345
1346        ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1347        kfree(buf);
1348        return ret;
1349}
1350
1351static const struct file_operations port_debugfs_ops = {
1352        .owner = THIS_MODULE,
1353        .open  = simple_open,
1354        .read  = debugfs_read,
1355};
1356
1357static void set_console_size(struct port *port, u16 rows, u16 cols)
1358{
1359        if (!port || !is_console_port(port))
1360                return;
1361
1362        port->cons.ws.ws_row = rows;
1363        port->cons.ws.ws_col = cols;
1364}
1365
1366static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1367{
1368        struct port_buffer *buf;
1369        unsigned int nr_added_bufs;
1370        int ret;
1371
1372        nr_added_bufs = 0;
1373        do {
1374                buf = alloc_buf(vq, PAGE_SIZE, 0);
1375                if (!buf)
1376                        break;
1377
1378                spin_lock_irq(lock);
1379                ret = add_inbuf(vq, buf);
1380                if (ret < 0) {
1381                        spin_unlock_irq(lock);
1382                        free_buf(buf, true);
1383                        break;
1384                }
1385                nr_added_bufs++;
1386                spin_unlock_irq(lock);
1387        } while (ret > 0);
1388
1389        return nr_added_bufs;
1390}
1391
1392static void send_sigio_to_port(struct port *port)
1393{
1394        if (port->async_queue && port->guest_connected)
1395                kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1396}
1397
1398static int add_port(struct ports_device *portdev, u32 id)
1399{
1400        char debugfs_name[16];
1401        struct port *port;
1402        struct port_buffer *buf;
1403        dev_t devt;
1404        unsigned int nr_added_bufs;
1405        int err;
1406
1407        port = kmalloc(sizeof(*port), GFP_KERNEL);
1408        if (!port) {
1409                err = -ENOMEM;
1410                goto fail;
1411        }
1412        kref_init(&port->kref);
1413
1414        port->portdev = portdev;
1415        port->id = id;
1416
1417        port->name = NULL;
1418        port->inbuf = NULL;
1419        port->cons.hvc = NULL;
1420        port->async_queue = NULL;
1421
1422        port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1423
1424        port->host_connected = port->guest_connected = false;
1425        port->stats = (struct port_stats) { 0 };
1426
1427        port->outvq_full = false;
1428
1429        port->in_vq = portdev->in_vqs[port->id];
1430        port->out_vq = portdev->out_vqs[port->id];
1431
1432        port->cdev = cdev_alloc();
1433        if (!port->cdev) {
1434                dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1435                err = -ENOMEM;
1436                goto free_port;
1437        }
1438        port->cdev->ops = &port_fops;
1439
1440        devt = MKDEV(portdev->chr_major, id);
1441        err = cdev_add(port->cdev, devt, 1);
1442        if (err < 0) {
1443                dev_err(&port->portdev->vdev->dev,
1444                        "Error %d adding cdev for port %u\n", err, id);
1445                goto free_cdev;
1446        }
1447        port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1448                                  devt, port, "vport%up%u",
1449                                  port->portdev->vdev->index, id);
1450        if (IS_ERR(port->dev)) {
1451                err = PTR_ERR(port->dev);
1452                dev_err(&port->portdev->vdev->dev,
1453                        "Error %d creating device for port %u\n",
1454                        err, id);
1455                goto free_cdev;
1456        }
1457
1458        spin_lock_init(&port->inbuf_lock);
1459        spin_lock_init(&port->outvq_lock);
1460        init_waitqueue_head(&port->waitqueue);
1461
1462        /* Fill the in_vq with buffers so the host can send us data. */
1463        nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1464        if (!nr_added_bufs) {
1465                dev_err(port->dev, "Error allocating inbufs\n");
1466                err = -ENOMEM;
1467                goto free_device;
1468        }
1469
1470        if (is_rproc_serial(port->portdev->vdev))
1471                /*
1472                 * For rproc_serial assume remote processor is connected.
1473                 * rproc_serial does not want the console port, only
1474                 * the generic port implementation.
1475                 */
1476                port->host_connected = true;
1477        else if (!use_multiport(port->portdev)) {
1478                /*
1479                 * If we're not using multiport support,
1480                 * this has to be a console port.
1481                 */
1482                err = init_port_console(port);
1483                if (err)
1484                        goto free_inbufs;
1485        }
1486
1487        spin_lock_irq(&portdev->ports_lock);
1488        list_add_tail(&port->list, &port->portdev->ports);
1489        spin_unlock_irq(&portdev->ports_lock);
1490
1491        /*
1492         * Tell the Host we're set so that it can send us various
1493         * configuration parameters for this port (eg, port name,
1494         * caching, whether this is a console port, etc.)
1495         */
1496        send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1497
1498        if (pdrvdata.debugfs_dir) {
1499                /*
1500                 * Finally, create the debugfs file that we can use to
1501                 * inspect a port's state at any time
1502                 */
1503                snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u",
1504                         port->portdev->vdev->index, id);
1505                port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1506                                                         pdrvdata.debugfs_dir,
1507                                                         port,
1508                                                         &port_debugfs_ops);
1509        }
1510        return 0;
1511
1512free_inbufs:
1513        while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1514                free_buf(buf, true);
1515free_device:
1516        device_destroy(pdrvdata.class, port->dev->devt);
1517free_cdev:
1518        cdev_del(port->cdev);
1519free_port:
1520        kfree(port);
1521fail:
1522        /* The host might want to notify management sw about port add failure */
1523        __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1524        return err;
1525}
1526
1527/* No users remain, remove all port-specific data. */
1528static void remove_port(struct kref *kref)
1529{
1530        struct port *port;
1531
1532        port = container_of(kref, struct port, kref);
1533
1534        kfree(port);
1535}
1536
1537static void remove_port_data(struct port *port)
1538{
1539        struct port_buffer *buf;
1540
1541        spin_lock_irq(&port->inbuf_lock);
1542        /* Remove unused data this port might have received. */
1543        discard_port_data(port);
1544        spin_unlock_irq(&port->inbuf_lock);
1545
1546        /* Remove buffers we queued up for the Host to send us data in. */
1547        do {
1548                spin_lock_irq(&port->inbuf_lock);
1549                buf = virtqueue_detach_unused_buf(port->in_vq);
1550                spin_unlock_irq(&port->inbuf_lock);
1551                if (buf)
1552                        free_buf(buf, true);
1553        } while (buf);
1554
1555        spin_lock_irq(&port->outvq_lock);
1556        reclaim_consumed_buffers(port);
1557        spin_unlock_irq(&port->outvq_lock);
1558
1559        /* Free pending buffers from the out-queue. */
1560        do {
1561                spin_lock_irq(&port->outvq_lock);
1562                buf = virtqueue_detach_unused_buf(port->out_vq);
1563                spin_unlock_irq(&port->outvq_lock);
1564                if (buf)
1565                        free_buf(buf, true);
1566        } while (buf);
1567}
1568
1569/*
1570 * Port got unplugged.  Remove port from portdev's list and drop the
1571 * kref reference.  If no userspace has this port opened, it will
1572 * result in immediate removal the port.
1573 */
1574static void unplug_port(struct port *port)
1575{
1576        spin_lock_irq(&port->portdev->ports_lock);
1577        list_del(&port->list);
1578        spin_unlock_irq(&port->portdev->ports_lock);
1579
1580        spin_lock_irq(&port->inbuf_lock);
1581        if (port->guest_connected) {
1582                /* Let the app know the port is going down. */
1583                send_sigio_to_port(port);
1584
1585                /* Do this after sigio is actually sent */
1586                port->guest_connected = false;
1587                port->host_connected = false;
1588
1589                wake_up_interruptible(&port->waitqueue);
1590        }
1591        spin_unlock_irq(&port->inbuf_lock);
1592
1593        if (is_console_port(port)) {
1594                spin_lock_irq(&pdrvdata_lock);
1595                list_del(&port->cons.list);
1596                spin_unlock_irq(&pdrvdata_lock);
1597                hvc_remove(port->cons.hvc);
1598        }
1599
1600        remove_port_data(port);
1601
1602        /*
1603         * We should just assume the device itself has gone off --
1604         * else a close on an open port later will try to send out a
1605         * control message.
1606         */
1607        port->portdev = NULL;
1608
1609        sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1610        device_destroy(pdrvdata.class, port->dev->devt);
1611        cdev_del(port->cdev);
1612
1613        debugfs_remove(port->debugfs_file);
1614        kfree(port->name);
1615
1616        /*
1617         * Locks around here are not necessary - a port can't be
1618         * opened after we removed the port struct from ports_list
1619         * above.
1620         */
1621        kref_put(&port->kref, remove_port);
1622}
1623
1624/* Any private messages that the Host and Guest want to share */
1625static void handle_control_message(struct virtio_device *vdev,
1626                                   struct ports_device *portdev,
1627                                   struct port_buffer *buf)
1628{
1629        struct virtio_console_control *cpkt;
1630        struct port *port;
1631        size_t name_size;
1632        int err;
1633
1634        cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1635
1636        port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id));
1637        if (!port &&
1638            cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
1639                /* No valid header at start of buffer.  Drop it. */
1640                dev_dbg(&portdev->vdev->dev,
1641                        "Invalid index %u in control packet\n", cpkt->id);
1642                return;
1643        }
1644
1645        switch (virtio16_to_cpu(vdev, cpkt->event)) {
1646        case VIRTIO_CONSOLE_PORT_ADD:
1647                if (port) {
1648                        dev_dbg(&portdev->vdev->dev,
1649                                "Port %u already added\n", port->id);
1650                        send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1651                        break;
1652                }
1653                if (virtio32_to_cpu(vdev, cpkt->id) >=
1654                    portdev->config.max_nr_ports) {
1655                        dev_warn(&portdev->vdev->dev,
1656                                "Request for adding port with "
1657                                "out-of-bound id %u, max. supported id: %u\n",
1658                                cpkt->id, portdev->config.max_nr_ports - 1);
1659                        break;
1660                }
1661                add_port(portdev, virtio32_to_cpu(vdev, cpkt->id));
1662                break;
1663        case VIRTIO_CONSOLE_PORT_REMOVE:
1664                unplug_port(port);
1665                break;
1666        case VIRTIO_CONSOLE_CONSOLE_PORT:
1667                if (!cpkt->value)
1668                        break;
1669                if (is_console_port(port))
1670                        break;
1671
1672                init_port_console(port);
1673                complete(&early_console_added);
1674                /*
1675                 * Could remove the port here in case init fails - but
1676                 * have to notify the host first.
1677                 */
1678                break;
1679        case VIRTIO_CONSOLE_RESIZE: {
1680                struct {
1681                        __u16 rows;
1682                        __u16 cols;
1683                } size;
1684
1685                if (!is_console_port(port))
1686                        break;
1687
1688                memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1689                       sizeof(size));
1690                set_console_size(port, size.rows, size.cols);
1691
1692                port->cons.hvc->irq_requested = 1;
1693                resize_console(port);
1694                break;
1695        }
1696        case VIRTIO_CONSOLE_PORT_OPEN:
1697                port->host_connected = virtio16_to_cpu(vdev, cpkt->value);
1698                wake_up_interruptible(&port->waitqueue);
1699                /*
1700                 * If the host port got closed and the host had any
1701                 * unconsumed buffers, we'll be able to reclaim them
1702                 * now.
1703                 */
1704                spin_lock_irq(&port->outvq_lock);
1705                reclaim_consumed_buffers(port);
1706                spin_unlock_irq(&port->outvq_lock);
1707
1708                /*
1709                 * If the guest is connected, it'll be interested in
1710                 * knowing the host connection state changed.
1711                 */
1712                spin_lock_irq(&port->inbuf_lock);
1713                send_sigio_to_port(port);
1714                spin_unlock_irq(&port->inbuf_lock);
1715                break;
1716        case VIRTIO_CONSOLE_PORT_NAME:
1717                /*
1718                 * If we woke up after hibernation, we can get this
1719                 * again.  Skip it in that case.
1720                 */
1721                if (port->name)
1722                        break;
1723
1724                /*
1725                 * Skip the size of the header and the cpkt to get the size
1726                 * of the name that was sent
1727                 */
1728                name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1729
1730                port->name = kmalloc(name_size, GFP_KERNEL);
1731                if (!port->name) {
1732                        dev_err(port->dev,
1733                                "Not enough space to store port name\n");
1734                        break;
1735                }
1736                strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1737                        name_size - 1);
1738                port->name[name_size - 1] = 0;
1739
1740                /*
1741                 * Since we only have one sysfs attribute, 'name',
1742                 * create it only if we have a name for the port.
1743                 */
1744                err = sysfs_create_group(&port->dev->kobj,
1745                                         &port_attribute_group);
1746                if (err) {
1747                        dev_err(port->dev,
1748                                "Error %d creating sysfs device attributes\n",
1749                                err);
1750                } else {
1751                        /*
1752                         * Generate a udev event so that appropriate
1753                         * symlinks can be created based on udev
1754                         * rules.
1755                         */
1756                        kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1757                }
1758                break;
1759        }
1760}
1761
1762static void control_work_handler(struct work_struct *work)
1763{
1764        struct ports_device *portdev;
1765        struct virtqueue *vq;
1766        struct port_buffer *buf;
1767        unsigned int len;
1768
1769        portdev = container_of(work, struct ports_device, control_work);
1770        vq = portdev->c_ivq;
1771
1772        spin_lock(&portdev->c_ivq_lock);
1773        while ((buf = virtqueue_get_buf(vq, &len))) {
1774                spin_unlock(&portdev->c_ivq_lock);
1775
1776                buf->len = len;
1777                buf->offset = 0;
1778
1779                handle_control_message(vq->vdev, portdev, buf);
1780
1781                spin_lock(&portdev->c_ivq_lock);
1782                if (add_inbuf(portdev->c_ivq, buf) < 0) {
1783                        dev_warn(&portdev->vdev->dev,
1784                                 "Error adding buffer to queue\n");
1785                        free_buf(buf, false);
1786                }
1787        }
1788        spin_unlock(&portdev->c_ivq_lock);
1789}
1790
1791static void out_intr(struct virtqueue *vq)
1792{
1793        struct port *port;
1794
1795        port = find_port_by_vq(vq->vdev->priv, vq);
1796        if (!port)
1797                return;
1798
1799        wake_up_interruptible(&port->waitqueue);
1800}
1801
1802static void in_intr(struct virtqueue *vq)
1803{
1804        struct port *port;
1805        unsigned long flags;
1806
1807        port = find_port_by_vq(vq->vdev->priv, vq);
1808        if (!port)
1809                return;
1810
1811        spin_lock_irqsave(&port->inbuf_lock, flags);
1812        port->inbuf = get_inbuf(port);
1813
1814        /*
1815         * Normally the port should not accept data when the port is
1816         * closed. For generic serial ports, the host won't (shouldn't)
1817         * send data till the guest is connected. But this condition
1818         * can be reached when a console port is not yet connected (no
1819         * tty is spawned) and the other side sends out data over the
1820         * vring, or when a remote devices start sending data before
1821         * the ports are opened.
1822         *
1823         * A generic serial port will discard data if not connected,
1824         * while console ports and rproc-serial ports accepts data at
1825         * any time. rproc-serial is initiated with guest_connected to
1826         * false because port_fops_open expects this. Console ports are
1827         * hooked up with an HVC console and is initialized with
1828         * guest_connected to true.
1829         */
1830
1831        if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
1832                discard_port_data(port);
1833
1834        /* Send a SIGIO indicating new data in case the process asked for it */
1835        send_sigio_to_port(port);
1836
1837        spin_unlock_irqrestore(&port->inbuf_lock, flags);
1838
1839        wake_up_interruptible(&port->waitqueue);
1840
1841        if (is_console_port(port) && hvc_poll(port->cons.hvc))
1842                hvc_kick();
1843}
1844
1845static void control_intr(struct virtqueue *vq)
1846{
1847        struct ports_device *portdev;
1848
1849        portdev = vq->vdev->priv;
1850        schedule_work(&portdev->control_work);
1851}
1852
1853static void config_intr(struct virtio_device *vdev)
1854{
1855        struct ports_device *portdev;
1856
1857        portdev = vdev->priv;
1858
1859        if (!use_multiport(portdev))
1860                schedule_work(&portdev->config_work);
1861}
1862
1863static void config_work_handler(struct work_struct *work)
1864{
1865        struct ports_device *portdev;
1866
1867        portdev = container_of(work, struct ports_device, control_work);
1868        if (!use_multiport(portdev)) {
1869                struct virtio_device *vdev;
1870                struct port *port;
1871                u16 rows, cols;
1872
1873                vdev = portdev->vdev;
1874                virtio_cread(vdev, struct virtio_console_config, cols, &cols);
1875                virtio_cread(vdev, struct virtio_console_config, rows, &rows);
1876
1877                port = find_port_by_id(portdev, 0);
1878                set_console_size(port, rows, cols);
1879
1880                /*
1881                 * We'll use this way of resizing only for legacy
1882                 * support.  For newer userspace
1883                 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1884                 * to indicate console size changes so that it can be
1885                 * done per-port.
1886                 */
1887                resize_console(port);
1888        }
1889}
1890
1891static int init_vqs(struct ports_device *portdev)
1892{
1893        vq_callback_t **io_callbacks;
1894        char **io_names;
1895        struct virtqueue **vqs;
1896        u32 i, j, nr_ports, nr_queues;
1897        int err;
1898
1899        nr_ports = portdev->config.max_nr_ports;
1900        nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1901
1902        vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1903        io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1904        io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1905        portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1906                                  GFP_KERNEL);
1907        portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1908                                   GFP_KERNEL);
1909        if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1910            !portdev->out_vqs) {
1911                err = -ENOMEM;
1912                goto free;
1913        }
1914
1915        /*
1916         * For backward compat (newer host but older guest), the host
1917         * spawns a console port first and also inits the vqs for port
1918         * 0 before others.
1919         */
1920        j = 0;
1921        io_callbacks[j] = in_intr;
1922        io_callbacks[j + 1] = out_intr;
1923        io_names[j] = "input";
1924        io_names[j + 1] = "output";
1925        j += 2;
1926
1927        if (use_multiport(portdev)) {
1928                io_callbacks[j] = control_intr;
1929                io_callbacks[j + 1] = NULL;
1930                io_names[j] = "control-i";
1931                io_names[j + 1] = "control-o";
1932
1933                for (i = 1; i < nr_ports; i++) {
1934                        j += 2;
1935                        io_callbacks[j] = in_intr;
1936                        io_callbacks[j + 1] = out_intr;
1937                        io_names[j] = "input";
1938                        io_names[j + 1] = "output";
1939                }
1940        }
1941        /* Find the queues. */
1942        err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1943                                              io_callbacks,
1944                                              (const char **)io_names);
1945        if (err)
1946                goto free;
1947
1948        j = 0;
1949        portdev->in_vqs[0] = vqs[0];
1950        portdev->out_vqs[0] = vqs[1];
1951        j += 2;
1952        if (use_multiport(portdev)) {
1953                portdev->c_ivq = vqs[j];
1954                portdev->c_ovq = vqs[j + 1];
1955
1956                for (i = 1; i < nr_ports; i++) {
1957                        j += 2;
1958                        portdev->in_vqs[i] = vqs[j];
1959                        portdev->out_vqs[i] = vqs[j + 1];
1960                }
1961        }
1962        kfree(io_names);
1963        kfree(io_callbacks);
1964        kfree(vqs);
1965
1966        return 0;
1967
1968free:
1969        kfree(portdev->out_vqs);
1970        kfree(portdev->in_vqs);
1971        kfree(io_names);
1972        kfree(io_callbacks);
1973        kfree(vqs);
1974
1975        return err;
1976}
1977
1978static const struct file_operations portdev_fops = {
1979        .owner = THIS_MODULE,
1980};
1981
1982static void remove_vqs(struct ports_device *portdev)
1983{
1984        portdev->vdev->config->del_vqs(portdev->vdev);
1985        kfree(portdev->in_vqs);
1986        kfree(portdev->out_vqs);
1987}
1988
1989static void remove_controlq_data(struct ports_device *portdev)
1990{
1991        struct port_buffer *buf;
1992        unsigned int len;
1993
1994        if (!use_multiport(portdev))
1995                return;
1996
1997        while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1998                free_buf(buf, true);
1999
2000        while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
2001                free_buf(buf, true);
2002}
2003
2004/*
2005 * Once we're further in boot, we get probed like any other virtio
2006 * device.
2007 *
2008 * If the host also supports multiple console ports, we check the
2009 * config space to see how many ports the host has spawned.  We
2010 * initialize each port found.
2011 */
2012static int virtcons_probe(struct virtio_device *vdev)
2013{
2014        struct ports_device *portdev;
2015        int err;
2016        bool multiport;
2017        bool early = early_put_chars != NULL;
2018
2019        /* We only need a config space if features are offered */
2020        if (!vdev->config->get &&
2021            (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
2022             || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
2023                dev_err(&vdev->dev, "%s failure: config access disabled\n",
2024                        __func__);
2025                return -EINVAL;
2026        }
2027
2028        /* Ensure to read early_put_chars now */
2029        barrier();
2030
2031        portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
2032        if (!portdev) {
2033                err = -ENOMEM;
2034                goto fail;
2035        }
2036
2037        /* Attach this portdev to this virtio_device, and vice-versa. */
2038        portdev->vdev = vdev;
2039        vdev->priv = portdev;
2040
2041        portdev->chr_major = register_chrdev(0, "virtio-portsdev",
2042                                             &portdev_fops);
2043        if (portdev->chr_major < 0) {
2044                dev_err(&vdev->dev,
2045                        "Error %d registering chrdev for device %u\n",
2046                        portdev->chr_major, vdev->index);
2047                err = portdev->chr_major;
2048                goto free;
2049        }
2050
2051        multiport = false;
2052        portdev->config.max_nr_ports = 1;
2053
2054        /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
2055        if (!is_rproc_serial(vdev) &&
2056            virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
2057                                 struct virtio_console_config, max_nr_ports,
2058                                 &portdev->config.max_nr_ports) == 0) {
2059                multiport = true;
2060        }
2061
2062        err = init_vqs(portdev);
2063        if (err < 0) {
2064                dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2065                goto free_chrdev;
2066        }
2067
2068        spin_lock_init(&portdev->ports_lock);
2069        INIT_LIST_HEAD(&portdev->ports);
2070
2071        virtio_device_ready(portdev->vdev);
2072
2073        INIT_WORK(&portdev->config_work, &config_work_handler);
2074        INIT_WORK(&portdev->control_work, &control_work_handler);
2075
2076        if (multiport) {
2077                unsigned int nr_added_bufs;
2078
2079                spin_lock_init(&portdev->c_ivq_lock);
2080                spin_lock_init(&portdev->c_ovq_lock);
2081
2082                nr_added_bufs = fill_queue(portdev->c_ivq,
2083                                           &portdev->c_ivq_lock);
2084                if (!nr_added_bufs) {
2085                        dev_err(&vdev->dev,
2086                                "Error allocating buffers for control queue\n");
2087                        err = -ENOMEM;
2088                        goto free_vqs;
2089                }
2090        } else {
2091                /*
2092                 * For backward compatibility: Create a console port
2093                 * if we're running on older host.
2094                 */
2095                add_port(portdev, 0);
2096        }
2097
2098        spin_lock_irq(&pdrvdata_lock);
2099        list_add_tail(&portdev->list, &pdrvdata.portdevs);
2100        spin_unlock_irq(&pdrvdata_lock);
2101
2102        __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2103                           VIRTIO_CONSOLE_DEVICE_READY, 1);
2104
2105        /*
2106         * If there was an early virtio console, assume that there are no
2107         * other consoles. We need to wait until the hvc_alloc matches the
2108         * hvc_instantiate, otherwise tty_open will complain, resulting in
2109         * a "Warning: unable to open an initial console" boot failure.
2110         * Without multiport this is done in add_port above. With multiport
2111         * this might take some host<->guest communication - thus we have to
2112         * wait.
2113         */
2114        if (multiport && early)
2115                wait_for_completion(&early_console_added);
2116
2117        return 0;
2118
2119free_vqs:
2120        /* The host might want to notify mgmt sw about device add failure */
2121        __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2122                           VIRTIO_CONSOLE_DEVICE_READY, 0);
2123        remove_vqs(portdev);
2124free_chrdev:
2125        unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2126free:
2127        kfree(portdev);
2128fail:
2129        return err;
2130}
2131
2132static void virtcons_remove(struct virtio_device *vdev)
2133{
2134        struct ports_device *portdev;
2135        struct port *port, *port2;
2136
2137        portdev = vdev->priv;
2138
2139        spin_lock_irq(&pdrvdata_lock);
2140        list_del(&portdev->list);
2141        spin_unlock_irq(&pdrvdata_lock);
2142
2143        /* Disable interrupts for vqs */
2144        vdev->config->reset(vdev);
2145        /* Finish up work that's lined up */
2146        if (use_multiport(portdev))
2147                cancel_work_sync(&portdev->control_work);
2148        else
2149                cancel_work_sync(&portdev->config_work);
2150
2151        list_for_each_entry_safe(port, port2, &portdev->ports, list)
2152                unplug_port(port);
2153
2154        unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2155
2156        /*
2157         * When yanking out a device, we immediately lose the
2158         * (device-side) queues.  So there's no point in keeping the
2159         * guest side around till we drop our final reference.  This
2160         * also means that any ports which are in an open state will
2161         * have to just stop using the port, as the vqs are going
2162         * away.
2163         */
2164        remove_controlq_data(portdev);
2165        remove_vqs(portdev);
2166        kfree(portdev);
2167}
2168
2169static struct virtio_device_id id_table[] = {
2170        { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2171        { 0 },
2172};
2173
2174static unsigned int features[] = {
2175        VIRTIO_CONSOLE_F_SIZE,
2176        VIRTIO_CONSOLE_F_MULTIPORT,
2177};
2178
2179static struct virtio_device_id rproc_serial_id_table[] = {
2180#if IS_ENABLED(CONFIG_REMOTEPROC)
2181        { VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2182#endif
2183        { 0 },
2184};
2185
2186static unsigned int rproc_serial_features[] = {
2187};
2188
2189#ifdef CONFIG_PM_SLEEP
2190static int virtcons_freeze(struct virtio_device *vdev)
2191{
2192        struct ports_device *portdev;
2193        struct port *port;
2194
2195        portdev = vdev->priv;
2196
2197        vdev->config->reset(vdev);
2198
2199        virtqueue_disable_cb(portdev->c_ivq);
2200        cancel_work_sync(&portdev->control_work);
2201        cancel_work_sync(&portdev->config_work);
2202        /*
2203         * Once more: if control_work_handler() was running, it would
2204         * enable the cb as the last step.
2205         */
2206        virtqueue_disable_cb(portdev->c_ivq);
2207        remove_controlq_data(portdev);
2208
2209        list_for_each_entry(port, &portdev->ports, list) {
2210                virtqueue_disable_cb(port->in_vq);
2211                virtqueue_disable_cb(port->out_vq);
2212                /*
2213                 * We'll ask the host later if the new invocation has
2214                 * the port opened or closed.
2215                 */
2216                port->host_connected = false;
2217                remove_port_data(port);
2218        }
2219        remove_vqs(portdev);
2220
2221        return 0;
2222}
2223
2224static int virtcons_restore(struct virtio_device *vdev)
2225{
2226        struct ports_device *portdev;
2227        struct port *port;
2228        int ret;
2229
2230        portdev = vdev->priv;
2231
2232        ret = init_vqs(portdev);
2233        if (ret)
2234                return ret;
2235
2236        virtio_device_ready(portdev->vdev);
2237
2238        if (use_multiport(portdev))
2239                fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2240
2241        list_for_each_entry(port, &portdev->ports, list) {
2242                port->in_vq = portdev->in_vqs[port->id];
2243                port->out_vq = portdev->out_vqs[port->id];
2244
2245                fill_queue(port->in_vq, &port->inbuf_lock);
2246
2247                /* Get port open/close status on the host */
2248                send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
2249
2250                /*
2251                 * If a port was open at the time of suspending, we
2252                 * have to let the host know that it's still open.
2253                 */
2254                if (port->guest_connected)
2255                        send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
2256        }
2257        return 0;
2258}
2259#endif
2260
2261static struct virtio_driver virtio_console = {
2262        .feature_table = features,
2263        .feature_table_size = ARRAY_SIZE(features),
2264        .driver.name =  KBUILD_MODNAME,
2265        .driver.owner = THIS_MODULE,
2266        .id_table =     id_table,
2267        .probe =        virtcons_probe,
2268        .remove =       virtcons_remove,
2269        .config_changed = config_intr,
2270#ifdef CONFIG_PM_SLEEP
2271        .freeze =       virtcons_freeze,
2272        .restore =      virtcons_restore,
2273#endif
2274};
2275
2276static struct virtio_driver virtio_rproc_serial = {
2277        .feature_table = rproc_serial_features,
2278        .feature_table_size = ARRAY_SIZE(rproc_serial_features),
2279        .driver.name =  "virtio_rproc_serial",
2280        .driver.owner = THIS_MODULE,
2281        .id_table =     rproc_serial_id_table,
2282        .probe =        virtcons_probe,
2283        .remove =       virtcons_remove,
2284};
2285
2286static int __init init(void)
2287{
2288        int err;
2289
2290        pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
2291        if (IS_ERR(pdrvdata.class)) {
2292                err = PTR_ERR(pdrvdata.class);
2293                pr_err("Error %d creating virtio-ports class\n", err);
2294                return err;
2295        }
2296
2297        pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
2298        if (!pdrvdata.debugfs_dir)
2299                pr_warning("Error creating debugfs dir for virtio-ports\n");
2300        INIT_LIST_HEAD(&pdrvdata.consoles);
2301        INIT_LIST_HEAD(&pdrvdata.portdevs);
2302
2303        err = register_virtio_driver(&virtio_console);
2304        if (err < 0) {
2305                pr_err("Error %d registering virtio driver\n", err);
2306                goto free;
2307        }
2308        err = register_virtio_driver(&virtio_rproc_serial);
2309        if (err < 0) {
2310                pr_err("Error %d registering virtio rproc serial driver\n",
2311                       err);
2312                goto unregister;
2313        }
2314        return 0;
2315unregister:
2316        unregister_virtio_driver(&virtio_console);
2317free:
2318        debugfs_remove_recursive(pdrvdata.debugfs_dir);
2319        class_destroy(pdrvdata.class);
2320        return err;
2321}
2322
2323static void __exit fini(void)
2324{
2325        reclaim_dma_bufs();
2326
2327        unregister_virtio_driver(&virtio_console);
2328        unregister_virtio_driver(&virtio_rproc_serial);
2329
2330        class_destroy(pdrvdata.class);
2331        debugfs_remove_recursive(pdrvdata.debugfs_dir);
2332}
2333module_init(init);
2334module_exit(fini);
2335
2336MODULE_DEVICE_TABLE(virtio, id_table);
2337MODULE_DESCRIPTION("Virtio console driver");
2338MODULE_LICENSE("GPL");
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