drivers/char/virtio_console.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
   4  * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
   5  * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
   6  */
   7 #include <linux/cdev.h>
   8 #include <linux/debugfs.h>
   9 #include <linux/completion.h>
  10 #include <linux/device.h>
  11 #include <linux/err.h>
  12 #include <linux/freezer.h>
  13 #include <linux/fs.h>
  14 #include <linux/splice.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/init.h>
  17 #include <linux/list.h>
  18 #include <linux/poll.h>
  19 #include <linux/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/virtio.h>
  23 #include <linux/virtio_console.h>
  24 #include <linux/wait.h>
  25 #include <linux/workqueue.h>
  26 #include <linux/module.h>
  27 #include <linux/dma-mapping.h>
  28 #include "../tty/hvc/hvc_console.h"
  29
  30 #define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
  31
  32 /*
  33  * This is a global struct for storing common data for all the devices
  34  * this driver handles.
  35  *
  36  * Mainly, it has a linked list for all the consoles in one place so
  37  * that callbacks from hvc for get_chars(), put_chars() work properly
  38  * across multiple devices and multiple ports per device.
  39  */
  40 struct ports_driver_data {
  41         /* Used for registering chardevs */
  42         struct class *class;
  43
  44         /* Used for exporting per-port information to debugfs */
  45         struct dentry *debugfs_dir;
  46
  47         /* List of all the devices we're handling */
  48         struct list_head portdevs;
  49
  50         /*
  51          * This is used to keep track of the number of hvc consoles
  52          * spawned by this driver.  This number is given as the first
  53          * argument to hvc_alloc().  To correctly map an initial
  54          * console spawned via hvc_instantiate to the console being
  55          * hooked up via hvc_alloc, we need to pass the same vtermno.
  56          *
  57          * We also just assume the first console being initialised was
  58          * the first one that got used as the initial console.
  59          */
  60         unsigned int next_vtermno;
  61
  62         /* All the console devices handled by this driver */
  63         struct list_head consoles;
  64 };
  65 static struct ports_driver_data pdrvdata = { .next_vtermno = 1};
  66
  67 static DEFINE_SPINLOCK(pdrvdata_lock);
  68 static DECLARE_COMPLETION(early_console_added);
  69
  70 /* This struct holds information that's relevant only for console ports */
  71 struct console {
  72         /* We'll place all consoles in a list in the pdrvdata struct */
  73         struct list_head list;
  74
  75         /* The hvc device associated with this console port */
  76         struct hvc_struct *hvc;
  77
  78         /* The size of the console */
  79         struct winsize ws;
  80
  81         /*
  82          * This number identifies the number that we used to register
  83          * with hvc in hvc_instantiate() and hvc_alloc(); this is the
  84          * number passed on by the hvc callbacks to us to
  85          * differentiate between the other console ports handled by
  86          * this driver
  87          */
  88         u32 vtermno;
  89 };
  90
  91 struct port_buffer {
  92         char *buf;
  93
  94         /* size of the buffer in *buf above */
  95         size_t size;
  96
  97         /* used length of the buffer */
  98         size_t len;
  99         /* offset in the buf from which to consume data */
 100         size_t offset;
 101
 102         /* DMA address of buffer */
 103         dma_addr_t dma;
 104
 105         /* Device we got DMA memory from */
 106         struct device *dev;
 107
 108         /* List of pending dma buffers to free */
 109         struct list_head list;
 110
 111         /* If sgpages == 0 then buf is used */
 112         unsigned int sgpages;
 113
 114         /* sg is used if spages > 0. sg must be the last in is struct */
 115         struct scatterlist sg[];
 116 };
 117
 118 /*
 119  * This is a per-device struct that stores data common to all the
 120  * ports for that device (vdev->priv).
 121  */
 122 struct ports_device {
 123         /* Next portdev in the list, head is in the pdrvdata struct */
 124         struct list_head list;
 125
 126         /*
 127          * Workqueue handlers where we process deferred work after
 128          * notification
 129          */
 130         struct work_struct control_work;
 131         struct work_struct config_work;
 132
 133         struct list_head ports;
 134
 135         /* To protect the list of ports */
 136         spinlock_t ports_lock;
 137
 138         /* To protect the vq operations for the control channel */
 139         spinlock_t c_ivq_lock;
 140         spinlock_t c_ovq_lock;
 141
 142         /* max. number of ports this device can hold */
 143         u32 max_nr_ports;
 144
 145         /* The virtio device we're associated with */
 146         struct virtio_device *vdev;
 147
 148         /*
 149          * A couple of virtqueues for the control channel: one for
 150          * guest->host transfers, one for host->guest transfers
 151          */
 152         struct virtqueue *c_ivq, *c_ovq;
 153
 154         /*
 155          * A control packet buffer for guest->host requests, protected
 156          * by c_ovq_lock.
 157          */
 158         struct virtio_console_control cpkt;
 159
 160         /* Array of per-port IO virtqueues */
 161         struct virtqueue **in_vqs, **out_vqs;
 162
 163         /* Major number for this device.  Ports will be created as minors. */
 164         int chr_major;
 165 };
 166
 167 struct port_stats {
 168         unsigned long bytes_sent, bytes_received, bytes_discarded;
 169 };
 170
 171 /* This struct holds the per-port data */
 172 struct port {
 173         /* Next port in the list, head is in the ports_device */
 174         struct list_head list;
 175
 176         /* Pointer to the parent virtio_console device */
 177         struct ports_device *portdev;
 178
 179         /* The current buffer from which data has to be fed to readers */
 180         struct port_buffer *inbuf;
 181
 182         /*
 183          * To protect the operations on the in_vq associated with this
 184          * port.  Has to be a spinlock because it can be called from
 185          * interrupt context (get_char()).
 186          */
 187         spinlock_t inbuf_lock;
 188
 189         /* Protect the operations on the out_vq. */
 190         spinlock_t outvq_lock;
 191
 192         /* The IO vqs for this port */
 193         struct virtqueue *in_vq, *out_vq;
 194
 195         /* File in the debugfs directory that exposes this port's information */
 196         struct dentry *debugfs_file;
 197
 198         /*
 199          * Keep count of the bytes sent, received and discarded for
 200          * this port for accounting and debugging purposes.  These
 201          * counts are not reset across port open / close events.
 202          */
 203         struct port_stats stats;
 204
 205         /*
 206          * The entries in this struct will be valid if this port is
 207          * hooked up to an hvc console
 208          */
 209         struct console cons;
 210
 211         /* Each port associates with a separate char device */
 212         struct cdev *cdev;
 213         struct device *dev;
 214
 215         /* Reference-counting to handle port hot-unplugs and file operations */
 216         struct kref kref;
 217
 218         /* A waitqueue for poll() or blocking read operations */
 219         wait_queue_head_t waitqueue;
 220
 221         /* The 'name' of the port that we expose via sysfs properties */
 222         char *name;
 223
 224         /* We can notify apps of host connect / disconnect events via SIGIO */
 225         struct fasync_struct *async_queue;
 226
 227         /* The 'id' to identify the port with the Host */
 228         u32 id;
 229
 230         bool outvq_full;
 231
 232         /* Is the host device open */
 233         bool host_connected;
 234
 235         /* We should allow only one process to open a port */
 236         bool guest_connected;
 237 };
 238
 239 /* This is the very early arch-specified put chars function. */
 240 static int (*early_put_chars)(u32, const char *, int);
 241
 242 static struct port *find_port_by_vtermno(u32 vtermno)
 243 {
 244         struct port *port;
 245         struct console *cons;
 246         unsigned long flags;
 247
 248         spin_lock_irqsave(&pdrvdata_lock, flags);
 249         list_for_each_entry(cons, &pdrvdata.consoles, list) {
 250                 if (cons->vtermno == vtermno) {
 251                         port = container_of(cons, struct port, cons);
 252                         goto out;
 253                 }
 254         }
 255         port = NULL;
 256 out:
 257         spin_unlock_irqrestore(&pdrvdata_lock, flags);
 258         return port;
 259 }
 260
 261 static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
 262                                                  dev_t dev)
 263 {
 264         struct port *port;
 265         unsigned long flags;
 266
 267         spin_lock_irqsave(&portdev->ports_lock, flags);
 268         list_for_each_entry(port, &portdev->ports, list) {
 269                 if (port->cdev->dev == dev) {
 270                         kref_get(&port->kref);
 271                         goto out;
 272                 }
 273         }
 274         port = NULL;
 275 out:
 276         spin_unlock_irqrestore(&portdev->ports_lock, flags);
 277
 278         return port;
 279 }
 280
 281 static struct port *find_port_by_devt(dev_t dev)
 282 {
 283         struct ports_device *portdev;
 284         struct port *port;
 285         unsigned long flags;
 286
 287         spin_lock_irqsave(&pdrvdata_lock, flags);
 288         list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
 289                 port = find_port_by_devt_in_portdev(portdev, dev);
 290                 if (port)
 291                         goto out;
 292         }
 293         port = NULL;
 294 out:
 295         spin_unlock_irqrestore(&pdrvdata_lock, flags);
 296         return port;
 297 }
 298
 299 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
 300 {
 301         struct port *port;
 302         unsigned long flags;
 303
 304         spin_lock_irqsave(&portdev->ports_lock, flags);
 305         list_for_each_entry(port, &portdev->ports, list)
 306                 if (port->id == id)
 307                         goto out;
 308         port = NULL;
 309 out:
 310         spin_unlock_irqrestore(&portdev->ports_lock, flags);
 311
 312         return port;
 313 }
 314
 315 static struct port *find_port_by_vq(struct ports_device *portdev,
 316                                     struct virtqueue *vq)
 317 {
 318         struct port *port;
 319         unsigned long flags;
 320
 321         spin_lock_irqsave(&portdev->ports_lock, flags);
 322         list_for_each_entry(port, &portdev->ports, list)
 323                 if (port->in_vq == vq || port->out_vq == vq)
 324                         goto out;
 325         port = NULL;
 326 out:
 327         spin_unlock_irqrestore(&portdev->ports_lock, flags);
 328         return port;
 329 }
 330
 331 static bool is_console_port(struct port *port)
 332 {
 333         if (port->cons.hvc)
 334                 return true;
 335         return false;
 336 }
 337
 338 static bool is_rproc_serial(const struct virtio_device *vdev)
 339 {
 340         return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
 341 }
 342
 343 static inline bool use_multiport(struct ports_device *portdev)
 344 {
 345         /*
 346          * This condition can be true when put_chars is called from
 347          * early_init
 348          */
 349         if (!portdev->vdev)
 350                 return false;
 351         return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
 352 }
 353
 354 static DEFINE_SPINLOCK(dma_bufs_lock);
 355 static LIST_HEAD(pending_free_dma_bufs);
 356
 357 static void free_buf(struct port_buffer *buf, bool can_sleep)
 358 {
 359         unsigned int i;
 360
 361         for (i = 0; i < buf->sgpages; i++) {
 362                 struct page *page = sg_page(&buf->sg[i]);
 363                 if (!page)
 364                         break;
 365                 put_page(page);
 366         }
 367
 368         if (!buf->dev) {
 369                 kfree(buf->buf);
 370         } else if (is_rproc_enabled) {
 371                 unsigned long flags;
 372
 373                 /* dma_free_coherent requires interrupts to be enabled. */
 374                 if (!can_sleep) {
 375                         /* queue up dma-buffers to be freed later */
 376                         spin_lock_irqsave(&dma_bufs_lock, flags);
 377                         list_add_tail(&buf->list, &pending_free_dma_bufs);
 378                         spin_unlock_irqrestore(&dma_bufs_lock, flags);
 379                         return;
 380                 }
 381                 dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma);
 382
 383                 /* Release device refcnt and allow it to be freed */
 384                 put_device(buf->dev);
 385         }
 386
 387         kfree(buf);
 388 }
 389
 390 static void reclaim_dma_bufs(void)
 391 {
 392         unsigned long flags;
 393         struct port_buffer *buf, *tmp;
 394         LIST_HEAD(tmp_list);
 395
 396         if (list_empty(&pending_free_dma_bufs))
 397                 return;
 398
 399         /* Create a copy of the pending_free_dma_bufs while holding the lock */
 400         spin_lock_irqsave(&dma_bufs_lock, flags);
 401         list_cut_position(&tmp_list, &pending_free_dma_bufs,
 402                           pending_free_dma_bufs.prev);
 403         spin_unlock_irqrestore(&dma_bufs_lock, flags);
 404
 405         /* Release the dma buffers, without irqs enabled */
 406         list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
 407                 list_del(&buf->list);
 408                 free_buf(buf, true);
 409         }
 410 }
 411
 412 static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size,
 413                                      int pages)
 414 {
 415         struct port_buffer *buf;
 416
 417         reclaim_dma_bufs();
 418
 419         /*
 420          * Allocate buffer and the sg list. The sg list array is allocated
 421          * directly after the port_buffer struct.
 422          */
 423         buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL);
 424         if (!buf)
 425                 goto fail;
 426
 427         buf->sgpages = pages;
 428         if (pages > 0) {
 429                 buf->dev = NULL;
 430                 buf->buf = NULL;
 431                 return buf;
 432         }
 433
 434         if (is_rproc_serial(vdev)) {
 435                 /*
 436                  * Allocate DMA memory from ancestor. When a virtio
 437                  * device is created by remoteproc, the DMA memory is
 438                  * associated with the grandparent device:
 439                  * vdev => rproc => platform-dev.
 440                  */
 441                 if (!vdev->dev.parent || !vdev->dev.parent->parent)
 442                         goto free_buf;
 443                 buf->dev = vdev->dev.parent->parent;
 444
 445                 /* Increase device refcnt to avoid freeing it */
 446                 get_device(buf->dev);
 447                 buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
 448                                               GFP_KERNEL);
 449         } else {
 450                 buf->dev = NULL;
 451                 buf->buf = kmalloc(buf_size, GFP_KERNEL);
 452         }
 453
 454         if (!buf->buf)
 455                 goto free_buf;
 456         buf->len = 0;
 457         buf->offset = 0;
 458         buf->size = buf_size;
 459         return buf;
 460
 461 free_buf:
 462         kfree(buf);
 463 fail:
 464         return NULL;
 465 }
 466
 467 /* Callers should take appropriate locks */
 468 static struct port_buffer *get_inbuf(struct port *port)
 469 {
 470         struct port_buffer *buf;
 471         unsigned int len;
 472
 473         if (port->inbuf)
 474                 return port->inbuf;
 475
 476         buf = virtqueue_get_buf(port->in_vq, &len);
 477         if (buf) {
 478                 buf->len = len;
 479                 buf->offset = 0;
 480                 port->stats.bytes_received += len;
 481         }
 482         return buf;
 483 }
 484
 485 /*
 486  * Create a scatter-gather list representing our input buffer and put
 487  * it in the queue.
 488  *
 489  * Callers should take appropriate locks.
 490  */
 491 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
 492 {
 493         struct scatterlist sg[1];
 494         int ret;
 495
 496         sg_init_one(sg, buf->buf, buf->size);
 497
 498         ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC);
 499         virtqueue_kick(vq);
 500         if (!ret)
 501                 ret = vq->num_free;
 502         return ret;
 503 }
 504
 505 /* Discard any unread data this port has. Callers lockers. */
 506 static void discard_port_data(struct port *port)
 507 {
 508         struct port_buffer *buf;
 509         unsigned int err;
 510
 511         if (!port->portdev) {
 512                 /* Device has been unplugged.  vqs are already gone. */
 513                 return;
 514         }
 515         buf = get_inbuf(port);
 516
 517         err = 0;
 518         while (buf) {
 519                 port->stats.bytes_discarded += buf->len - buf->offset;
 520                 if (add_inbuf(port->in_vq, buf) < 0) {
 521                         err++;
 522                         free_buf(buf, false);
 523                 }
 524                 port->inbuf = NULL;
 525                 buf = get_inbuf(port);
 526         }
 527         if (err)
 528                 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
 529                          err);
 530 }
 531
 532 static bool port_has_data(struct port *port)
 533 {
 534         unsigned long flags;
 535         bool ret;
 536
 537         ret = false;
 538         spin_lock_irqsave(&port->inbuf_lock, flags);
 539         port->inbuf = get_inbuf(port);
 540         if (port->inbuf)
 541                 ret = true;
 542
 543         spin_unlock_irqrestore(&port->inbuf_lock, flags);
 544         return ret;
 545 }
 546
 547 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
 548                                   unsigned int event, unsigned int value)
 549 {
 550         struct scatterlist sg[1];
 551         struct virtqueue *vq;
 552         unsigned int len;
 553
 554         if (!use_multiport(portdev))
 555                 return 0;
 556
 557         vq = portdev->c_ovq;
 558
 559         spin_lock(&portdev->c_ovq_lock);
 560
 561         portdev->cpkt.id = cpu_to_virtio32(portdev->vdev, port_id);
 562         portdev->cpkt.event = cpu_to_virtio16(portdev->vdev, event);
 563         portdev->cpkt.value = cpu_to_virtio16(portdev->vdev, value);
 564
 565         sg_init_one(sg, &portdev->cpkt, sizeof(struct virtio_console_control));
 566
 567         if (virtqueue_add_outbuf(vq, sg, 1, &portdev->cpkt, GFP_ATOMIC) == 0) {
 568                 virtqueue_kick(vq);
 569                 while (!virtqueue_get_buf(vq, &len)
 570                         && !virtqueue_is_broken(vq))
 571                         cpu_relax();
 572         }
 573
 574         spin_unlock(&portdev->c_ovq_lock);
 575         return 0;
 576 }
 577
 578 static ssize_t send_control_msg(struct port *port, unsigned int event,
 579                                 unsigned int value)
 580 {
 581         /* Did the port get unplugged before userspace closed it? */
 582         if (port->portdev)
 583                 return __send_control_msg(port->portdev, port->id, event, value);
 584         return 0;
 585 }
 586
 587
 588 /* Callers must take the port->outvq_lock */
 589 static void reclaim_consumed_buffers(struct port *port)
 590 {
 591         struct port_buffer *buf;
 592         unsigned int len;
 593
 594         if (!port->portdev) {
 595                 /* Device has been unplugged.  vqs are already gone. */
 596                 return;
 597         }
 598         while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
 599                 free_buf(buf, false);
 600                 port->outvq_full = false;
 601         }
 602 }
 603
 604 static ssize_t __send_to_port(struct port *port, struct scatterlist *sg,
 605                               int nents, size_t in_count,
 606                               void *data, bool nonblock)
 607 {
 608         struct virtqueue *out_vq;
 609         int err;
 610         unsigned long flags;
 611         unsigned int len;
 612
 613         out_vq = port->out_vq;
 614
 615         spin_lock_irqsave(&port->outvq_lock, flags);
 616
 617         reclaim_consumed_buffers(port);
 618
 619         err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC);
 620
 621         /* Tell Host to go! */
 622         virtqueue_kick(out_vq);
 623
 624         if (err) {
 625                 in_count = 0;
 626                 goto done;
 627         }
 628
 629         if (out_vq->num_free == 0)
 630                 port->outvq_full = true;
 631
 632         if (nonblock)
 633                 goto done;
 634
 635         /*
 636          * Wait till the host acknowledges it pushed out the data we
 637          * sent.  This is done for data from the hvc_console; the tty
 638          * operations are performed with spinlocks held so we can't
 639          * sleep here.  An alternative would be to copy the data to a
 640          * buffer and relax the spinning requirement.  The downside is
 641          * we need to kmalloc a GFP_ATOMIC buffer each time the
 642          * console driver writes something out.
 643          */
 644         while (!virtqueue_get_buf(out_vq, &len)
 645                 && !virtqueue_is_broken(out_vq))
 646                 cpu_relax();
 647 done:
 648         spin_unlock_irqrestore(&port->outvq_lock, flags);
 649
 650         port->stats.bytes_sent += in_count;
 651         /*
 652          * We're expected to return the amount of data we wrote -- all
 653          * of it
 654          */
 655         return in_count;
 656 }
 657
 658 /*
 659  * Give out the data that's requested from the buffer that we have
 660  * queued up.
 661  */
 662 static ssize_t fill_readbuf(struct port *port, char __user *out_buf,
 663                             size_t out_count, bool to_user)
 664 {
 665         struct port_buffer *buf;
 666         unsigned long flags;
 667
 668         if (!out_count || !port_has_data(port))
 669                 return 0;
 670
 671         buf = port->inbuf;
 672         out_count = min(out_count, buf->len - buf->offset);
 673
 674         if (to_user) {
 675                 ssize_t ret;
 676
 677                 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
 678                 if (ret)
 679                         return -EFAULT;
 680         } else {
 681                 memcpy((__force char *)out_buf, buf->buf + buf->offset,
 682                        out_count);
 683         }
 684
 685         buf->offset += out_count;
 686
 687         if (buf->offset == buf->len) {
 688                 /*
 689                  * We're done using all the data in this buffer.
 690                  * Re-queue so that the Host can send us more data.
 691                  */
 692                 spin_lock_irqsave(&port->inbuf_lock, flags);
 693                 port->inbuf = NULL;
 694
 695                 if (add_inbuf(port->in_vq, buf) < 0)
 696                         dev_warn(port->dev, "failed add_buf\n");
 697
 698                 spin_unlock_irqrestore(&port->inbuf_lock, flags);
 699         }
 700         /* Return the number of bytes actually copied */
 701         return out_count;
 702 }
 703
 704 /* The condition that must be true for polling to end */
 705 static bool will_read_block(struct port *port)
 706 {
 707         if (!port->guest_connected) {
 708                 /* Port got hot-unplugged. Let's exit. */
 709                 return false;
 710         }
 711         return !port_has_data(port) && port->host_connected;
 712 }
 713
 714 static bool will_write_block(struct port *port)
 715 {
 716         bool ret;
 717
 718         if (!port->guest_connected) {
 719                 /* Port got hot-unplugged. Let's exit. */
 720                 return false;
 721         }
 722         if (!port->host_connected)
 723                 return true;
 724
 725         spin_lock_irq(&port->outvq_lock);
 726         /*
 727          * Check if the Host has consumed any buffers since we last
 728          * sent data (this is only applicable for nonblocking ports).
 729          */
 730         reclaim_consumed_buffers(port);
 731         ret = port->outvq_full;
 732         spin_unlock_irq(&port->outvq_lock);
 733
 734         return ret;
 735 }
 736
 737 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
 738                               size_t count, loff_t *offp)
 739 {
 740         struct port *port;
 741         ssize_t ret;
 742
 743         port = filp->private_data;
 744
 745         /* Port is hot-unplugged. */
 746         if (!port->guest_connected)
 747                 return -ENODEV;
 748
 749         if (!port_has_data(port)) {
 750                 /*
 751                  * If nothing's connected on the host just return 0 in
 752                  * case of list_empty; this tells the userspace app
 753                  * that there's no connection
 754                  */
 755                 if (!port->host_connected)
 756                         return 0;
 757                 if (filp->f_flags & O_NONBLOCK)
 758                         return -EAGAIN;
 759
 760                 ret = wait_event_freezable(port->waitqueue,
 761                                            !will_read_block(port));
 762                 if (ret < 0)
 763                         return ret;
 764         }
 765         /* Port got hot-unplugged while we were waiting above. */
 766         if (!port->guest_connected)
 767                 return -ENODEV;
 768         /*
 769          * We could've received a disconnection message while we were
 770          * waiting for more data.
 771          *
 772          * This check is not clubbed in the if() statement above as we
 773          * might receive some data as well as the host could get
 774          * disconnected after we got woken up from our wait.  So we
 775          * really want to give off whatever data we have and only then
 776          * check for host_connected.
 777          */
 778         if (!port_has_data(port) && !port->host_connected)
 779                 return 0;
 780
 781         return fill_readbuf(port, ubuf, count, true);
 782 }
 783
 784 static int wait_port_writable(struct port *port, bool nonblock)
 785 {
 786         int ret;
 787
 788         if (will_write_block(port)) {
 789                 if (nonblock)
 790                         return -EAGAIN;
 791
 792                 ret = wait_event_freezable(port->waitqueue,
 793                                            !will_write_block(port));
 794                 if (ret < 0)
 795                         return ret;
 796         }
 797         /* Port got hot-unplugged. */
 798         if (!port->guest_connected)
 799                 return -ENODEV;
 800
 801         return 0;
 802 }
 803
 804 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
 805                                size_t count, loff_t *offp)
 806 {
 807         struct port *port;
 808         struct port_buffer *buf;
 809         ssize_t ret;
 810         bool nonblock;
 811         struct scatterlist sg[1];
 812
 813         /* Userspace could be out to fool us */
 814         if (!count)
 815                 return 0;
 816
 817         port = filp->private_data;
 818
 819         nonblock = filp->f_flags & O_NONBLOCK;
 820
 821         ret = wait_port_writable(port, nonblock);
 822         if (ret < 0)
 823                 return ret;
 824
 825         count = min((size_t)(32 * 1024), count);
 826
 827         buf = alloc_buf(port->portdev->vdev, count, 0);
 828         if (!buf)
 829                 return -ENOMEM;
 830
 831         ret = copy_from_user(buf->buf, ubuf, count);
 832         if (ret) {
 833                 ret = -EFAULT;
 834                 goto free_buf;
 835         }
 836
 837         /*
 838          * We now ask send_buf() to not spin for generic ports -- we
 839          * can re-use the same code path that non-blocking file
 840          * descriptors take for blocking file descriptors since the
 841          * wait is already done and we're certain the write will go
 842          * through to the host.
 843          */
 844         nonblock = true;
 845         sg_init_one(sg, buf->buf, count);
 846         ret = __send_to_port(port, sg, 1, count, buf, nonblock);
 847
 848         if (nonblock && ret > 0)
 849                 goto out;
 850
 851 free_buf:
 852         free_buf(buf, true);
 853 out:
 854         return ret;
 855 }
 856
 857 struct sg_list {
 858         unsigned int n;
 859         unsigned int size;
 860         size_t len;
 861         struct scatterlist *sg;
 862 };
 863
 864 static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 865                         struct splice_desc *sd)
 866 {
 867         struct sg_list *sgl = sd->u.data;
 868         unsigned int offset, len;
 869
 870         if (sgl->n == sgl->size)
 871                 return 0;
 872
 873         /* Try lock this page */
 874         if (pipe_buf_try_steal(pipe, buf)) {
 875                 /* Get reference and unlock page for moving */
 876                 get_page(buf->page);
 877                 unlock_page(buf->page);
 878
 879                 len = min(buf->len, sd->len);
 880                 sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset);
 881         } else {
 882                 /* Failback to copying a page */
 883                 struct page *page = alloc_page(GFP_KERNEL);
 884                 char *src;
 885
 886                 if (!page)
 887                         return -ENOMEM;
 888
 889                 offset = sd->pos & ~PAGE_MASK;
 890
 891                 len = sd->len;
 892                 if (len + offset > PAGE_SIZE)
 893                         len = PAGE_SIZE - offset;
 894
 895                 src = kmap_atomic(buf->page);
 896                 memcpy(page_address(page) + offset, src + buf->offset, len);
 897                 kunmap_atomic(src);
 898
 899                 sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
 900         }
 901         sgl->n++;
 902         sgl->len += len;
 903
 904         return len;
 905 }
 906
 907 /* Faster zero-copy write by splicing */
 908 static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
 909                                       struct file *filp, loff_t *ppos,
 910                                       size_t len, unsigned int flags)
 911 {
 912         struct port *port = filp->private_data;
 913         struct sg_list sgl;
 914         ssize_t ret;
 915         struct port_buffer *buf;
 916         struct splice_desc sd = {
 917                 .total_len = len,
 918                 .flags = flags,
 919                 .pos = *ppos,
 920                 .u.data = &sgl,
 921         };
 922         unsigned int occupancy;
 923
 924         /*
 925          * Rproc_serial does not yet support splice. To support splice
 926          * pipe_to_sg() must allocate dma-buffers and copy content from
 927          * regular pages to dma pages. And alloc_buf and free_buf must
 928          * support allocating and freeing such a list of dma-buffers.
 929          */
 930         if (is_rproc_serial(port->out_vq->vdev))
 931                 return -EINVAL;
 932
 933         pipe_lock(pipe);
 934         ret = 0;
 935         if (pipe_empty(pipe->head, pipe->tail))
 936                 goto error_out;
 937
 938         ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
 939         if (ret < 0)
 940                 goto error_out;
 941
 942         occupancy = pipe_occupancy(pipe->head, pipe->tail);
 943         buf = alloc_buf(port->portdev->vdev, 0, occupancy);
 944
 945         if (!buf) {
 946                 ret = -ENOMEM;
 947                 goto error_out;
 948         }
 949
 950         sgl.n = 0;
 951         sgl.len = 0;
 952         sgl.size = occupancy;
 953         sgl.sg = buf->sg;
 954         sg_init_table(sgl.sg, sgl.size);
 955         ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
 956         pipe_unlock(pipe);
 957         if (likely(ret > 0))
 958                 ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
 959
 960         if (unlikely(ret <= 0))
 961                 free_buf(buf, true);
 962         return ret;
 963
 964 error_out:
 965         pipe_unlock(pipe);
 966         return ret;
 967 }
 968
 969 static __poll_t port_fops_poll(struct file *filp, poll_table *wait)
 970 {
 971         struct port *port;
 972         __poll_t ret;
 973
 974         port = filp->private_data;
 975         poll_wait(filp, &port->waitqueue, wait);
 976
 977         if (!port->guest_connected) {
 978                 /* Port got unplugged */
 979                 return EPOLLHUP;
 980         }
 981         ret = 0;
 982         if (!will_read_block(port))
 983                 ret |= EPOLLIN | EPOLLRDNORM;
 984         if (!will_write_block(port))
 985                 ret |= EPOLLOUT;
 986         if (!port->host_connected)
 987                 ret |= EPOLLHUP;
 988
 989         return ret;
 990 }
 991
 992 static void remove_port(struct kref *kref);
 993
 994 static int port_fops_release(struct inode *inode, struct file *filp)
 995 {
 996         struct port *port;
 997
 998         port = filp->private_data;
 999
1000         /* Notify host of port being closed */
1001         send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
1002
1003         spin_lock_irq(&port->inbuf_lock);
1004         port->guest_connected = false;
1005
1006         discard_port_data(port);
1007
1008         spin_unlock_irq(&port->inbuf_lock);
1009
1010         spin_lock_irq(&port->outvq_lock);
1011         reclaim_consumed_buffers(port);
1012         spin_unlock_irq(&port->outvq_lock);
1013
1014         reclaim_dma_bufs();
1015         /*
1016          * Locks aren't necessary here as a port can't be opened after
1017          * unplug, and if a port isn't unplugged, a kref would already
1018          * exist for the port.  Plus, taking ports_lock here would
1019          * create a dependency on other locks taken by functions
1020          * inside remove_port if we're the last holder of the port,
1021          * creating many problems.
1022          */
1023         kref_put(&port->kref, remove_port);
1024
1025         return 0;
1026 }
1027
1028 static int port_fops_open(struct inode *inode, struct file *filp)
1029 {
1030         struct cdev *cdev = inode->i_cdev;
1031         struct port *port;
1032         int ret;
1033
1034         /* We get the port with a kref here */
1035         port = find_port_by_devt(cdev->dev);
1036         if (!port) {
1037                 /* Port was unplugged before we could proceed */
1038                 return -ENXIO;
1039         }
1040         filp->private_data = port;
1041
1042         /*
1043          * Don't allow opening of console port devices -- that's done
1044          * via /dev/hvc
1045          */
1046         if (is_console_port(port)) {
1047                 ret = -ENXIO;
1048                 goto out;
1049         }
1050
1051         /* Allow only one process to open a particular port at a time */
1052         spin_lock_irq(&port->inbuf_lock);
1053         if (port->guest_connected) {
1054                 spin_unlock_irq(&port->inbuf_lock);
1055                 ret = -EBUSY;
1056                 goto out;
1057         }
1058
1059         port->guest_connected = true;
1060         spin_unlock_irq(&port->inbuf_lock);
1061
1062         spin_lock_irq(&port->outvq_lock);
1063         /*
1064          * There might be a chance that we missed reclaiming a few
1065          * buffers in the window of the port getting previously closed
1066          * and opening now.
1067          */
1068         reclaim_consumed_buffers(port);
1069         spin_unlock_irq(&port->outvq_lock);
1070
1071         nonseekable_open(inode, filp);
1072
1073         /* Notify host of port being opened */
1074         send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
1075
1076         return 0;
1077 out:
1078         kref_put(&port->kref, remove_port);
1079         return ret;
1080 }
1081
1082 static int port_fops_fasync(int fd, struct file *filp, int mode)
1083 {
1084         struct port *port;
1085
1086         port = filp->private_data;
1087         return fasync_helper(fd, filp, mode, &port->async_queue);
1088 }
1089
1090 /*
1091  * The file operations that we support: programs in the guest can open
1092  * a console device, read from it, write to it, poll for data and
1093  * close it.  The devices are at
1094  *   /dev/vport<device number>p<port number>
1095  */
1096 static const struct file_operations port_fops = {
1097         .owner = THIS_MODULE,
1098         .open  = port_fops_open,
1099         .read  = port_fops_read,
1100         .write = port_fops_write,
1101         .splice_write = port_fops_splice_write,
1102         .poll  = port_fops_poll,
1103         .release = port_fops_release,
1104         .fasync = port_fops_fasync,
1105         .llseek = no_llseek,
1106 };
1107
1108 /*
1109  * The put_chars() callback is pretty straightforward.
1110  *
1111  * We turn the characters into a scatter-gather list, add it to the
1112  * output queue and then kick the Host.  Then we sit here waiting for
1113  * it to finish: inefficient in theory, but in practice
1114  * implementations will do it immediately.
1115  */
1116 static int put_chars(u32 vtermno, const char *buf, int count)
1117 {
1118         struct port *port;
1119         struct scatterlist sg[1];
1120         void *data;
1121         int ret;
1122
1123         if (unlikely(early_put_chars))
1124                 return early_put_chars(vtermno, buf, count);
1125
1126         port = find_port_by_vtermno(vtermno);
1127         if (!port)
1128                 return -EPIPE;
1129
1130         data = kmemdup(buf, count, GFP_ATOMIC);
1131         if (!data)
1132                 return -ENOMEM;
1133
1134         sg_init_one(sg, data, count);
1135         ret = __send_to_port(port, sg, 1, count, data, false);
1136         kfree(data);
1137         return ret;
1138 }
1139
1140 /*
1141  * get_chars() is the callback from the hvc_console infrastructure
1142  * when an interrupt is received.
1143  *
1144  * We call out to fill_readbuf that gets us the required data from the
1145  * buffers that are queued up.
1146  */
1147 static int get_chars(u32 vtermno, char *buf, int count)
1148 {
1149         struct port *port;
1150
1151         /* If we've not set up the port yet, we have no input to give. */
1152         if (unlikely(early_put_chars))
1153                 return 0;
1154
1155         port = find_port_by_vtermno(vtermno);
1156         if (!port)
1157                 return -EPIPE;
1158
1159         /* If we don't have an input queue yet, we can't get input. */
1160         BUG_ON(!port->in_vq);
1161
1162         return fill_readbuf(port, (__force char __user *)buf, count, false);
1163 }
1164
1165 static void resize_console(struct port *port)
1166 {
1167         struct virtio_device *vdev;
1168
1169         /* The port could have been hot-unplugged */
1170         if (!port || !is_console_port(port))
1171                 return;
1172
1173         vdev = port->portdev->vdev;
1174
1175         /* Don't test F_SIZE at all if we're rproc: not a valid feature! */
1176         if (!is_rproc_serial(vdev) &&
1177             virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
1178                 hvc_resize(port->cons.hvc, port->cons.ws);
1179 }
1180
1181 /* We set the configuration at this point, since we now have a tty */
1182 static int notifier_add_vio(struct hvc_struct *hp, int data)
1183 {
1184         struct port *port;
1185
1186         port = find_port_by_vtermno(hp->vtermno);
1187         if (!port)
1188                 return -EINVAL;
1189
1190         hp->irq_requested = 1;
1191         resize_console(port);
1192
1193         return 0;
1194 }
1195
1196 static void notifier_del_vio(struct hvc_struct *hp, int data)
1197 {
1198         hp->irq_requested = 0;
1199 }
1200
1201 /* The operations for console ports. */
1202 static const struct hv_ops hv_ops = {
1203         .get_chars = get_chars,
1204         .put_chars = put_chars,
1205         .notifier_add = notifier_add_vio,
1206         .notifier_del = notifier_del_vio,
1207         .notifier_hangup = notifier_del_vio,
1208 };
1209
1210 /*
1211  * Console drivers are initialized very early so boot messages can go
1212  * out, so we do things slightly differently from the generic virtio
1213  * initialization of the net and block drivers.
1214  *
1215  * At this stage, the console is output-only.  It's too early to set
1216  * up a virtqueue, so we let the drivers do some boutique early-output
1217  * thing.
1218  */
1219 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
1220 {
1221         early_put_chars = put_chars;
1222         return hvc_instantiate(0, 0, &hv_ops);
1223 }
1224
1225 static int init_port_console(struct port *port)
1226 {
1227         int ret;
1228
1229         /*
1230          * The Host's telling us this port is a console port.  Hook it
1231          * up with an hvc console.
1232          *
1233          * To set up and manage our virtual console, we call
1234          * hvc_alloc().
1235          *
1236          * The first argument of hvc_alloc() is the virtual console
1237          * number.  The second argument is the parameter for the
1238          * notification mechanism (like irq number).  We currently
1239          * leave this as zero, virtqueues have implicit notifications.
1240          *
1241          * The third argument is a "struct hv_ops" containing the
1242          * put_chars() get_chars(), notifier_add() and notifier_del()
1243          * pointers.  The final argument is the output buffer size: we
1244          * can do any size, so we put PAGE_SIZE here.
1245          */
1246         port->cons.vtermno = pdrvdata.next_vtermno;
1247
1248         port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
1249         if (IS_ERR(port->cons.hvc)) {
1250                 ret = PTR_ERR(port->cons.hvc);
1251                 dev_err(port->dev,
1252                         "error %d allocating hvc for port\n", ret);
1253                 port->cons.hvc = NULL;
1254                 return ret;
1255         }
1256         spin_lock_irq(&pdrvdata_lock);
1257         pdrvdata.next_vtermno++;
1258         list_add_tail(&port->cons.list, &pdrvdata.consoles);
1259         spin_unlock_irq(&pdrvdata_lock);
1260         port->guest_connected = true;
1261
1262         /*
1263          * Start using the new console output if this is the first
1264          * console to come up.
1265          */
1266         if (early_put_chars)
1267                 early_put_chars = NULL;
1268
1269         /* Notify host of port being opened */
1270         send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1271
1272         return 0;
1273 }
1274
1275 static ssize_t show_port_name(struct device *dev,
1276                               struct device_attribute *attr, char *buffer)
1277 {
1278         struct port *port;
1279
1280         port = dev_get_drvdata(dev);
1281
1282         return sprintf(buffer, "%s\n", port->name);
1283 }
1284
1285 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1286
1287 static struct attribute *port_sysfs_entries[] = {
1288         &dev_attr_name.attr,
1289         NULL
1290 };
1291
1292 static const struct attribute_group port_attribute_group = {
1293         .name = NULL,           /* put in device directory */
1294         .attrs = port_sysfs_entries,
1295 };
1296
1297 static int port_debugfs_show(struct seq_file *s, void *data)
1298 {
1299         struct port *port = s->private;
1300
1301         seq_printf(s, "name: %s\n", port->name ? port->name : "");
1302         seq_printf(s, "guest_connected: %d\n", port->guest_connected);
1303         seq_printf(s, "host_connected: %d\n", port->host_connected);
1304         seq_printf(s, "outvq_full: %d\n", port->outvq_full);
1305         seq_printf(s, "bytes_sent: %lu\n", port->stats.bytes_sent);
1306         seq_printf(s, "bytes_received: %lu\n", port->stats.bytes_received);
1307         seq_printf(s, "bytes_discarded: %lu\n", port->stats.bytes_discarded);
1308         seq_printf(s, "is_console: %s\n",
1309                    is_console_port(port) ? "yes" : "no");
1310         seq_printf(s, "console_vtermno: %u\n", port->cons.vtermno);
1311
1312         return 0;
1313 }
1314
1315 DEFINE_SHOW_ATTRIBUTE(port_debugfs);
1316
1317 static void set_console_size(struct port *port, u16 rows, u16 cols)
1318 {
1319         if (!port || !is_console_port(port))
1320                 return;
1321
1322         port->cons.ws.ws_row = rows;
1323         port->cons.ws.ws_col = cols;
1324 }
1325
1326 static int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1327 {
1328         struct port_buffer *buf;
1329         int nr_added_bufs;
1330         int ret;
1331
1332         nr_added_bufs = 0;
1333         do {
1334                 buf = alloc_buf(vq->vdev, PAGE_SIZE, 0);
1335                 if (!buf)
1336                         return -ENOMEM;
1337
1338                 spin_lock_irq(lock);
1339                 ret = add_inbuf(vq, buf);
1340                 if (ret < 0) {
1341                         spin_unlock_irq(lock);
1342                         free_buf(buf, true);
1343                         return ret;
1344                 }
1345                 nr_added_bufs++;
1346                 spin_unlock_irq(lock);
1347         } while (ret > 0);
1348
1349         return nr_added_bufs;
1350 }
1351
1352 static void send_sigio_to_port(struct port *port)
1353 {
1354         if (port->async_queue && port->guest_connected)
1355                 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1356 }
1357
1358 static int add_port(struct ports_device *portdev, u32 id)
1359 {
1360         char debugfs_name[16];
1361         struct port *port;
1362         dev_t devt;
1363         int err;
1364
1365         port = kmalloc(sizeof(*port), GFP_KERNEL);
1366         if (!port) {
1367                 err = -ENOMEM;
1368                 goto fail;
1369         }
1370         kref_init(&port->kref);
1371
1372         port->portdev = portdev;
1373         port->id = id;
1374
1375         port->name = NULL;
1376         port->inbuf = NULL;
1377         port->cons.hvc = NULL;
1378         port->async_queue = NULL;
1379
1380         port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1381         port->cons.vtermno = 0;
1382
1383         port->host_connected = port->guest_connected = false;
1384         port->stats = (struct port_stats) { 0 };
1385
1386         port->outvq_full = false;
1387
1388         port->in_vq = portdev->in_vqs[port->id];
1389         port->out_vq = portdev->out_vqs[port->id];
1390
1391         port->cdev = cdev_alloc();
1392         if (!port->cdev) {
1393                 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1394                 err = -ENOMEM;
1395                 goto free_port;
1396         }
1397         port->cdev->ops = &port_fops;
1398
1399         devt = MKDEV(portdev->chr_major, id);
1400         err = cdev_add(port->cdev, devt, 1);
1401         if (err < 0) {
1402                 dev_err(&port->portdev->vdev->dev,
1403                         "Error %d adding cdev for port %u\n", err, id);
1404                 goto free_cdev;
1405         }
1406         port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1407                                   devt, port, "vport%up%u",
1408                                   port->portdev->vdev->index, id);
1409         if (IS_ERR(port->dev)) {
1410                 err = PTR_ERR(port->dev);
1411                 dev_err(&port->portdev->vdev->dev,
1412                         "Error %d creating device for port %u\n",
1413                         err, id);
1414                 goto free_cdev;
1415         }
1416
1417         spin_lock_init(&port->inbuf_lock);
1418         spin_lock_init(&port->outvq_lock);
1419         init_waitqueue_head(&port->waitqueue);
1420
1421         /* We can safely ignore ENOSPC because it means
1422          * the queue already has buffers. Buffers are removed
1423          * only by virtcons_remove(), not by unplug_port()
1424          */
1425         err = fill_queue(port->in_vq, &port->inbuf_lock);
1426         if (err < 0 && err != -ENOSPC) {
1427                 dev_err(port->dev, "Error allocating inbufs\n");
1428                 goto free_device;
1429         }
1430
1431         if (is_rproc_serial(port->portdev->vdev))
1432                 /*
1433                  * For rproc_serial assume remote processor is connected.
1434                  * rproc_serial does not want the console port, only
1435                  * the generic port implementation.
1436                  */
1437                 port->host_connected = true;
1438         else if (!use_multiport(port->portdev)) {
1439                 /*
1440                  * If we're not using multiport support,
1441                  * this has to be a console port.
1442                  */
1443                 err = init_port_console(port);
1444                 if (err)
1445                         goto free_inbufs;
1446         }
1447
1448         spin_lock_irq(&portdev->ports_lock);
1449         list_add_tail(&port->list, &port->portdev->ports);
1450         spin_unlock_irq(&portdev->ports_lock);
1451
1452         /*
1453          * Tell the Host we're set so that it can send us various
1454          * configuration parameters for this port (eg, port name,
1455          * caching, whether this is a console port, etc.)
1456          */
1457         send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1458
1459         if (pdrvdata.debugfs_dir) {
1460                 /*
1461                  * Finally, create the debugfs file that we can use to
1462                  * inspect a port's state at any time
1463                  */
1464                 snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u",
1465                          port->portdev->vdev->index, id);
1466                 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1467                                                          pdrvdata.debugfs_dir,
1468                                                          port,
1469                                                          &port_debugfs_fops);
1470         }
1471         return 0;
1472
1473 free_inbufs:
1474 free_device:
1475         device_destroy(pdrvdata.class, port->dev->devt);
1476 free_cdev:
1477         cdev_del(port->cdev);
1478 free_port:
1479         kfree(port);
1480 fail:
1481         /* The host might want to notify management sw about port add failure */
1482         __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1483         return err;
1484 }
1485
1486 /* No users remain, remove all port-specific data. */
1487 static void remove_port(struct kref *kref)
1488 {
1489         struct port *port;
1490
1491         port = container_of(kref, struct port, kref);
1492
1493         kfree(port);
1494 }
1495
1496 static void remove_port_data(struct port *port)
1497 {
1498         spin_lock_irq(&port->inbuf_lock);
1499         /* Remove unused data this port might have received. */
1500         discard_port_data(port);
1501         spin_unlock_irq(&port->inbuf_lock);
1502
1503         spin_lock_irq(&port->outvq_lock);
1504         reclaim_consumed_buffers(port);
1505         spin_unlock_irq(&port->outvq_lock);
1506 }
1507
1508 /*
1509  * Port got unplugged.  Remove port from portdev's list and drop the
1510  * kref reference.  If no userspace has this port opened, it will
1511  * result in immediate removal the port.
1512  */
1513 static void unplug_port(struct port *port)
1514 {
1515         spin_lock_irq(&port->portdev->ports_lock);
1516         list_del(&port->list);
1517         spin_unlock_irq(&port->portdev->ports_lock);
1518
1519         spin_lock_irq(&port->inbuf_lock);
1520         if (port->guest_connected) {
1521                 /* Let the app know the port is going down. */
1522                 send_sigio_to_port(port);
1523
1524                 /* Do this after sigio is actually sent */
1525                 port->guest_connected = false;
1526                 port->host_connected = false;
1527
1528                 wake_up_interruptible(&port->waitqueue);
1529         }
1530         spin_unlock_irq(&port->inbuf_lock);
1531
1532         if (is_console_port(port)) {
1533                 spin_lock_irq(&pdrvdata_lock);
1534                 list_del(&port->cons.list);
1535                 spin_unlock_irq(&pdrvdata_lock);
1536                 hvc_remove(port->cons.hvc);
1537         }
1538
1539         remove_port_data(port);
1540
1541         /*
1542          * We should just assume the device itself has gone off --
1543          * else a close on an open port later will try to send out a
1544          * control message.
1545          */
1546         port->portdev = NULL;
1547
1548         sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1549         device_destroy(pdrvdata.class, port->dev->devt);
1550         cdev_del(port->cdev);
1551
1552         debugfs_remove(port->debugfs_file);
1553         kfree(port->name);
1554
1555         /*
1556          * Locks around here are not necessary - a port can't be
1557          * opened after we removed the port struct from ports_list
1558          * above.
1559          */
1560         kref_put(&port->kref, remove_port);
1561 }
1562
1563 /* Any private messages that the Host and Guest want to share */
1564 static void handle_control_message(struct virtio_device *vdev,
1565                                    struct ports_device *portdev,
1566                                    struct port_buffer *buf)
1567 {
1568         struct virtio_console_control *cpkt;
1569         struct port *port;
1570         size_t name_size;
1571         int err;
1572
1573         cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1574
1575         port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id));
1576         if (!port &&
1577             cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
1578                 /* No valid header at start of buffer.  Drop it. */
1579                 dev_dbg(&portdev->vdev->dev,
1580                         "Invalid index %u in control packet\n", cpkt->id);
1581                 return;
1582         }
1583
1584         switch (virtio16_to_cpu(vdev, cpkt->event)) {
1585         case VIRTIO_CONSOLE_PORT_ADD:
1586                 if (port) {
1587                         dev_dbg(&portdev->vdev->dev,
1588                                 "Port %u already added\n", port->id);
1589                         send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1590                         break;
1591                 }
1592                 if (virtio32_to_cpu(vdev, cpkt->id) >=
1593                     portdev->max_nr_ports) {
1594                         dev_warn(&portdev->vdev->dev,
1595                                 "Request for adding port with "
1596                                 "out-of-bound id %u, max. supported id: %u\n",
1597                                 cpkt->id, portdev->max_nr_ports - 1);
1598                         break;
1599                 }
1600                 add_port(portdev, virtio32_to_cpu(vdev, cpkt->id));
1601                 break;
1602         case VIRTIO_CONSOLE_PORT_REMOVE:
1603                 unplug_port(port);
1604                 break;
1605         case VIRTIO_CONSOLE_CONSOLE_PORT:
1606                 if (!cpkt->value)
1607                         break;
1608                 if (is_console_port(port))
1609                         break;
1610
1611                 init_port_console(port);
1612                 complete(&early_console_added);
1613                 /*
1614                  * Could remove the port here in case init fails - but
1615                  * have to notify the host first.
1616                  */
1617                 break;
1618         case VIRTIO_CONSOLE_RESIZE: {
1619                 struct {
1620                         __u16 rows;
1621                         __u16 cols;
1622                 } size;
1623
1624                 if (!is_console_port(port))
1625                         break;
1626
1627                 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1628                        sizeof(size));
1629                 set_console_size(port, size.rows, size.cols);
1630
1631                 port->cons.hvc->irq_requested = 1;
1632                 resize_console(port);
1633                 break;
1634         }
1635         case VIRTIO_CONSOLE_PORT_OPEN:
1636                 port->host_connected = virtio16_to_cpu(vdev, cpkt->value);
1637                 wake_up_interruptible(&port->waitqueue);
1638                 /*
1639                  * If the host port got closed and the host had any
1640                  * unconsumed buffers, we'll be able to reclaim them
1641                  * now.
1642                  */
1643                 spin_lock_irq(&port->outvq_lock);
1644                 reclaim_consumed_buffers(port);
1645                 spin_unlock_irq(&port->outvq_lock);
1646
1647                 /*
1648                  * If the guest is connected, it'll be interested in
1649                  * knowing the host connection state changed.
1650                  */
1651                 spin_lock_irq(&port->inbuf_lock);
1652                 send_sigio_to_port(port);
1653                 spin_unlock_irq(&port->inbuf_lock);
1654                 break;
1655         case VIRTIO_CONSOLE_PORT_NAME:
1656                 /*
1657                  * If we woke up after hibernation, we can get this
1658                  * again.  Skip it in that case.
1659                  */
1660                 if (port->name)
1661                         break;
1662
1663                 /*
1664                  * Skip the size of the header and the cpkt to get the size
1665                  * of the name that was sent
1666                  */
1667                 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1668
1669                 port->name = kmalloc(name_size, GFP_KERNEL);
1670                 if (!port->name) {
1671                         dev_err(port->dev,
1672                                 "Not enough space to store port name\n");
1673                         break;
1674                 }
1675                 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1676                         name_size - 1);
1677                 port->name[name_size - 1] = 0;
1678
1679                 /*
1680                  * Since we only have one sysfs attribute, 'name',
1681                  * create it only if we have a name for the port.
1682                  */
1683                 err = sysfs_create_group(&port->dev->kobj,
1684                                          &port_attribute_group);
1685                 if (err) {
1686                         dev_err(port->dev,
1687                                 "Error %d creating sysfs device attributes\n",
1688                                 err);
1689                 } else {
1690                         /*
1691                          * Generate a udev event so that appropriate
1692                          * symlinks can be created based on udev
1693                          * rules.
1694                          */
1695                         kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1696                 }
1697                 break;
1698         }
1699 }
1700
1701 static void control_work_handler(struct work_struct *work)
1702 {
1703         struct ports_device *portdev;
1704         struct virtqueue *vq;
1705         struct port_buffer *buf;
1706         unsigned int len;
1707
1708         portdev = container_of(work, struct ports_device, control_work);
1709         vq = portdev->c_ivq;
1710
1711         spin_lock(&portdev->c_ivq_lock);
1712         while ((buf = virtqueue_get_buf(vq, &len))) {
1713                 spin_unlock(&portdev->c_ivq_lock);
1714
1715                 buf->len = len;
1716                 buf->offset = 0;
1717
1718                 handle_control_message(vq->vdev, portdev, buf);
1719
1720                 spin_lock(&portdev->c_ivq_lock);
1721                 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1722                         dev_warn(&portdev->vdev->dev,
1723                                  "Error adding buffer to queue\n");
1724                         free_buf(buf, false);
1725                 }
1726         }
1727         spin_unlock(&portdev->c_ivq_lock);
1728 }
1729
1730 static void flush_bufs(struct virtqueue *vq, bool can_sleep)
1731 {
1732         struct port_buffer *buf;
1733         unsigned int len;
1734
1735         while ((buf = virtqueue_get_buf(vq, &len)))
1736                 free_buf(buf, can_sleep);
1737 }
1738
1739 static void out_intr(struct virtqueue *vq)
1740 {
1741         struct port *port;
1742
1743         port = find_port_by_vq(vq->vdev->priv, vq);
1744         if (!port) {
1745                 flush_bufs(vq, false);
1746                 return;
1747         }
1748
1749         wake_up_interruptible(&port->waitqueue);
1750 }
1751
1752 static void in_intr(struct virtqueue *vq)
1753 {
1754         struct port *port;
1755         unsigned long flags;
1756
1757         port = find_port_by_vq(vq->vdev->priv, vq);
1758         if (!port) {
1759                 flush_bufs(vq, false);
1760                 return;
1761         }
1762
1763         spin_lock_irqsave(&port->inbuf_lock, flags);
1764         port->inbuf = get_inbuf(port);
1765
1766         /*
1767          * Normally the port should not accept data when the port is
1768          * closed. For generic serial ports, the host won't (shouldn't)
1769          * send data till the guest is connected. But this condition
1770          * can be reached when a console port is not yet connected (no
1771          * tty is spawned) and the other side sends out data over the
1772          * vring, or when a remote devices start sending data before
1773          * the ports are opened.
1774          *
1775          * A generic serial port will discard data if not connected,
1776          * while console ports and rproc-serial ports accepts data at
1777          * any time. rproc-serial is initiated with guest_connected to
1778          * false because port_fops_open expects this. Console ports are
1779          * hooked up with an HVC console and is initialized with
1780          * guest_connected to true.
1781          */
1782
1783         if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
1784                 discard_port_data(port);
1785
1786         /* Send a SIGIO indicating new data in case the process asked for it */
1787         send_sigio_to_port(port);
1788
1789         spin_unlock_irqrestore(&port->inbuf_lock, flags);
1790
1791         wake_up_interruptible(&port->waitqueue);
1792
1793         if (is_console_port(port) && hvc_poll(port->cons.hvc))
1794                 hvc_kick();
1795 }
1796
1797 static void control_intr(struct virtqueue *vq)
1798 {
1799         struct ports_device *portdev;
1800
1801         portdev = vq->vdev->priv;
1802         schedule_work(&portdev->control_work);
1803 }
1804
1805 static void config_intr(struct virtio_device *vdev)
1806 {
1807         struct ports_device *portdev;
1808
1809         portdev = vdev->priv;
1810
1811         if (!use_multiport(portdev))
1812                 schedule_work(&portdev->config_work);
1813 }
1814
1815 static void config_work_handler(struct work_struct *work)
1816 {
1817         struct ports_device *portdev;
1818
1819         portdev = container_of(work, struct ports_device, config_work);
1820         if (!use_multiport(portdev)) {
1821                 struct virtio_device *vdev;
1822                 struct port *port;
1823                 u16 rows, cols;
1824
1825                 vdev = portdev->vdev;
1826                 virtio_cread(vdev, struct virtio_console_config, cols, &cols);
1827                 virtio_cread(vdev, struct virtio_console_config, rows, &rows);
1828
1829                 port = find_port_by_id(portdev, 0);
1830                 set_console_size(port, rows, cols);
1831
1832                 /*
1833                  * We'll use this way of resizing only for legacy
1834                  * support.  For newer userspace
1835                  * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1836                  * to indicate console size changes so that it can be
1837                  * done per-port.
1838                  */
1839                 resize_console(port);
1840         }
1841 }
1842
1843 static int init_vqs(struct ports_device *portdev)
1844 {
1845         vq_callback_t **io_callbacks;
1846         char **io_names;
1847         struct virtqueue **vqs;
1848         u32 i, j, nr_ports, nr_queues;
1849         int err;
1850
1851         nr_ports = portdev->max_nr_ports;
1852         nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1853
1854         vqs = kmalloc_array(nr_queues, sizeof(struct virtqueue *), GFP_KERNEL);
1855         io_callbacks = kmalloc_array(nr_queues, sizeof(vq_callback_t *),
1856                                      GFP_KERNEL);
1857         io_names = kmalloc_array(nr_queues, sizeof(char *), GFP_KERNEL);
1858         portdev->in_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1859                                         GFP_KERNEL);
1860         portdev->out_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1861                                          GFP_KERNEL);
1862         if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1863             !portdev->out_vqs) {
1864                 err = -ENOMEM;
1865                 goto free;
1866         }
1867
1868         /*
1869          * For backward compat (newer host but older guest), the host
1870          * spawns a console port first and also inits the vqs for port
1871          * 0 before others.
1872          */
1873         j = 0;
1874         io_callbacks[j] = in_intr;
1875         io_callbacks[j + 1] = out_intr;
1876         io_names[j] = "input";
1877         io_names[j + 1] = "output";
1878         j += 2;
1879
1880         if (use_multiport(portdev)) {
1881                 io_callbacks[j] = control_intr;
1882                 io_callbacks[j + 1] = NULL;
1883                 io_names[j] = "control-i";
1884                 io_names[j + 1] = "control-o";
1885
1886                 for (i = 1; i < nr_ports; i++) {
1887                         j += 2;
1888                         io_callbacks[j] = in_intr;
1889                         io_callbacks[j + 1] = out_intr;
1890                         io_names[j] = "input";
1891                         io_names[j + 1] = "output";
1892                 }
1893         }
1894         /* Find the queues. */
1895         err = virtio_find_vqs(portdev->vdev, nr_queues, vqs,
1896                               io_callbacks,
1897                               (const char **)io_names, NULL);
1898         if (err)
1899                 goto free;
1900
1901         j = 0;
1902         portdev->in_vqs[0] = vqs[0];
1903         portdev->out_vqs[0] = vqs[1];
1904         j += 2;
1905         if (use_multiport(portdev)) {
1906                 portdev->c_ivq = vqs[j];
1907                 portdev->c_ovq = vqs[j + 1];
1908
1909                 for (i = 1; i < nr_ports; i++) {
1910                         j += 2;
1911                         portdev->in_vqs[i] = vqs[j];
1912                         portdev->out_vqs[i] = vqs[j + 1];
1913                 }
1914         }
1915         kfree(io_names);
1916         kfree(io_callbacks);
1917         kfree(vqs);
1918
1919         return 0;
1920
1921 free:
1922         kfree(portdev->out_vqs);
1923         kfree(portdev->in_vqs);
1924         kfree(io_names);
1925         kfree(io_callbacks);
1926         kfree(vqs);
1927
1928         return err;
1929 }
1930
1931 static const struct file_operations portdev_fops = {
1932         .owner = THIS_MODULE,
1933 };
1934
1935 static void remove_vqs(struct ports_device *portdev)
1936 {
1937         struct virtqueue *vq;
1938
1939         virtio_device_for_each_vq(portdev->vdev, vq) {
1940                 struct port_buffer *buf;
1941
1942                 flush_bufs(vq, true);
1943                 while ((buf = virtqueue_detach_unused_buf(vq)))
1944                         free_buf(buf, true);
1945         }
1946         portdev->vdev->config->del_vqs(portdev->vdev);
1947         kfree(portdev->in_vqs);
1948         kfree(portdev->out_vqs);
1949 }
1950
1951 static void virtcons_remove(struct virtio_device *vdev)
1952 {
1953         struct ports_device *portdev;
1954         struct port *port, *port2;
1955
1956         portdev = vdev->priv;
1957
1958         spin_lock_irq(&pdrvdata_lock);
1959         list_del(&portdev->list);
1960         spin_unlock_irq(&pdrvdata_lock);
1961
1962         /* Disable interrupts for vqs */
1963         vdev->config->reset(vdev);
1964         /* Finish up work that's lined up */
1965         if (use_multiport(portdev))
1966                 cancel_work_sync(&portdev->control_work);
1967         else
1968                 cancel_work_sync(&portdev->config_work);
1969
1970         list_for_each_entry_safe(port, port2, &portdev->ports, list)
1971                 unplug_port(port);
1972
1973         unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1974
1975         /*
1976          * When yanking out a device, we immediately lose the
1977          * (device-side) queues.  So there's no point in keeping the
1978          * guest side around till we drop our final reference.  This
1979          * also means that any ports which are in an open state will
1980          * have to just stop using the port, as the vqs are going
1981          * away.
1982          */
1983         remove_vqs(portdev);
1984         kfree(portdev);
1985 }
1986
1987 /*
1988  * Once we're further in boot, we get probed like any other virtio
1989  * device.
1990  *
1991  * If the host also supports multiple console ports, we check the
1992  * config space to see how many ports the host has spawned.  We
1993  * initialize each port found.
1994  */
1995 static int virtcons_probe(struct virtio_device *vdev)
1996 {
1997         struct ports_device *portdev;
1998         int err;
1999         bool multiport;
2000         bool early = early_put_chars != NULL;
2001
2002         /* We only need a config space if features are offered */
2003         if (!vdev->config->get &&
2004             (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
2005              || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
2006                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2007                         __func__);
2008                 return -EINVAL;
2009         }
2010
2011         /* Ensure to read early_put_chars now */
2012         barrier();
2013
2014         portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
2015         if (!portdev) {
2016                 err = -ENOMEM;
2017                 goto fail;
2018         }
2019
2020         /* Attach this portdev to this virtio_device, and vice-versa. */
2021         portdev->vdev = vdev;
2022         vdev->priv = portdev;
2023
2024         portdev->chr_major = register_chrdev(0, "virtio-portsdev",
2025                                              &portdev_fops);
2026         if (portdev->chr_major < 0) {
2027                 dev_err(&vdev->dev,
2028                         "Error %d registering chrdev for device %u\n",
2029                         portdev->chr_major, vdev->index);
2030                 err = portdev->chr_major;
2031                 goto free;
2032         }
2033
2034         multiport = false;
2035         portdev->max_nr_ports = 1;
2036
2037         /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
2038         if (!is_rproc_serial(vdev) &&
2039             virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
2040                                  struct virtio_console_config, max_nr_ports,
2041                                  &portdev->max_nr_ports) == 0) {
2042                 multiport = true;
2043         }
2044
2045         err = init_vqs(portdev);
2046         if (err < 0) {
2047                 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2048                 goto free_chrdev;
2049         }
2050
2051         spin_lock_init(&portdev->ports_lock);
2052         INIT_LIST_HEAD(&portdev->ports);
2053         INIT_LIST_HEAD(&portdev->list);
2054
2055         virtio_device_ready(portdev->vdev);
2056
2057         INIT_WORK(&portdev->config_work, &config_work_handler);
2058         INIT_WORK(&portdev->control_work, &control_work_handler);
2059
2060         if (multiport) {
2061                 spin_lock_init(&portdev->c_ivq_lock);
2062                 spin_lock_init(&portdev->c_ovq_lock);
2063
2064                 err = fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2065                 if (err < 0) {
2066                         dev_err(&vdev->dev,
2067                                 "Error allocating buffers for control queue\n");
2068                         /*
2069                          * The host might want to notify mgmt sw about device
2070                          * add failure.
2071                          */
2072                         __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2073                                            VIRTIO_CONSOLE_DEVICE_READY, 0);
2074                         /* Device was functional: we need full cleanup. */
2075                         virtcons_remove(vdev);
2076                         return err;
2077                 }
2078         } else {
2079                 /*
2080                  * For backward compatibility: Create a console port
2081                  * if we're running on older host.
2082                  */
2083                 add_port(portdev, 0);
2084         }
2085
2086         spin_lock_irq(&pdrvdata_lock);
2087         list_add_tail(&portdev->list, &pdrvdata.portdevs);
2088         spin_unlock_irq(&pdrvdata_lock);
2089
2090         __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2091                            VIRTIO_CONSOLE_DEVICE_READY, 1);
2092
2093         /*
2094          * If there was an early virtio console, assume that there are no
2095          * other consoles. We need to wait until the hvc_alloc matches the
2096          * hvc_instantiate, otherwise tty_open will complain, resulting in
2097          * a "Warning: unable to open an initial console" boot failure.
2098          * Without multiport this is done in add_port above. With multiport
2099          * this might take some host<->guest communication - thus we have to
2100          * wait.
2101          */
2102         if (multiport && early)
2103                 wait_for_completion(&early_console_added);
2104
2105         return 0;
2106
2107 free_chrdev:
2108         unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2109 free:
2110         kfree(portdev);
2111 fail:
2112         return err;
2113 }
2114
2115 static struct virtio_device_id id_table[] = {
2116         { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2117         { 0 },
2118 };
2119
2120 static unsigned int features[] = {
2121         VIRTIO_CONSOLE_F_SIZE,
2122         VIRTIO_CONSOLE_F_MULTIPORT,
2123 };
2124
2125 static struct virtio_device_id rproc_serial_id_table[] = {
2126 #if IS_ENABLED(CONFIG_REMOTEPROC)
2127         { VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2128 #endif
2129         { 0 },
2130 };
2131
2132 static unsigned int rproc_serial_features[] = {
2133 };
2134
2135 #ifdef CONFIG_PM_SLEEP
2136 static int virtcons_freeze(struct virtio_device *vdev)
2137 {
2138         struct ports_device *portdev;
2139         struct port *port;
2140
2141         portdev = vdev->priv;
2142
2143         vdev->config->reset(vdev);
2144
2145         if (use_multiport(portdev))
2146                 virtqueue_disable_cb(portdev->c_ivq);
2147         cancel_work_sync(&portdev->control_work);
2148         cancel_work_sync(&portdev->config_work);
2149         /*
2150          * Once more: if control_work_handler() was running, it would
2151          * enable the cb as the last step.
2152          */
2153         if (use_multiport(portdev))
2154                 virtqueue_disable_cb(portdev->c_ivq);
2155
2156         list_for_each_entry(port, &portdev->ports, list) {
2157                 virtqueue_disable_cb(port->in_vq);
2158                 virtqueue_disable_cb(port->out_vq);
2159                 /*
2160                  * We'll ask the host later if the new invocation has
2161                  * the port opened or closed.
2162                  */
2163                 port->host_connected = false;
2164                 remove_port_data(port);
2165         }
2166         remove_vqs(portdev);
2167
2168         return 0;
2169 }
2170
2171 static int virtcons_restore(struct virtio_device *vdev)
2172 {
2173         struct ports_device *portdev;
2174         struct port *port;
2175         int ret;
2176
2177         portdev = vdev->priv;
2178
2179         ret = init_vqs(portdev);
2180         if (ret)
2181                 return ret;
2182
2183         virtio_device_ready(portdev->vdev);
2184
2185         if (use_multiport(portdev))
2186                 fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2187
2188         list_for_each_entry(port, &portdev->ports, list) {
2189                 port->in_vq = portdev->in_vqs[port->id];
2190                 port->out_vq = portdev->out_vqs[port->id];
2191
2192                 fill_queue(port->in_vq, &port->inbuf_lock);
2193
2194                 /* Get port open/close status on the host */
2195                 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
2196
2197                 /*
2198                  * If a port was open at the time of suspending, we
2199                  * have to let the host know that it's still open.
2200                  */
2201                 if (port->guest_connected)
2202                         send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
2203         }
2204         return 0;
2205 }
2206 #endif
2207
2208 static struct virtio_driver virtio_console = {
2209         .feature_table = features,
2210         .feature_table_size = ARRAY_SIZE(features),
2211         .driver.name =  KBUILD_MODNAME,
2212         .driver.owner = THIS_MODULE,
2213         .id_table =     id_table,
2214         .probe =        virtcons_probe,
2215         .remove =       virtcons_remove,
2216         .config_changed = config_intr,
2217 #ifdef CONFIG_PM_SLEEP
2218         .freeze =       virtcons_freeze,
2219         .restore =      virtcons_restore,
2220 #endif
2221 };
2222
2223 static struct virtio_driver virtio_rproc_serial = {
2224         .feature_table = rproc_serial_features,
2225         .feature_table_size = ARRAY_SIZE(rproc_serial_features),
2226         .driver.name =  "virtio_rproc_serial",
2227         .driver.owner = THIS_MODULE,
2228         .id_table =     rproc_serial_id_table,
2229         .probe =        virtcons_probe,
2230         .remove =       virtcons_remove,
2231 };
2232
2233 static int __init init(void)
2234 {
2235         int err;
2236
2237         pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
2238         if (IS_ERR(pdrvdata.class)) {
2239                 err = PTR_ERR(pdrvdata.class);
2240                 pr_err("Error %d creating virtio-ports class\n", err);
2241                 return err;
2242         }
2243
2244         pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
2245         if (!pdrvdata.debugfs_dir)
2246                 pr_warn("Error creating debugfs dir for virtio-ports\n");
2247         INIT_LIST_HEAD(&pdrvdata.consoles);
2248         INIT_LIST_HEAD(&pdrvdata.portdevs);
2249
2250         err = register_virtio_driver(&virtio_console);
2251         if (err < 0) {
2252                 pr_err("Error %d registering virtio driver\n", err);
2253                 goto free;
2254         }
2255         err = register_virtio_driver(&virtio_rproc_serial);
2256         if (err < 0) {
2257                 pr_err("Error %d registering virtio rproc serial driver\n",
2258                        err);
2259                 goto unregister;
2260         }
2261         return 0;
2262 unregister:
2263         unregister_virtio_driver(&virtio_console);
2264 free:
2265         debugfs_remove_recursive(pdrvdata.debugfs_dir);
2266         class_destroy(pdrvdata.class);
2267         return err;
2268 }
2269
2270 static void __exit fini(void)
2271 {
2272         reclaim_dma_bufs();
2273
2274         unregister_virtio_driver(&virtio_console);
2275         unregister_virtio_driver(&virtio_rproc_serial);
2276
2277         class_destroy(pdrvdata.class);
2278         debugfs_remove_recursive(pdrvdata.debugfs_dir);
2279 }
2280 module_init(init);
2281 module_exit(fini);
2282
2283 MODULE_DEVICE_TABLE(virtio, id_table);
2284 MODULE_DESCRIPTION("Virtio console driver");
2285 MODULE_LICENSE("GPL");