linux/drivers/char/virtio_console.c
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   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 */
  40struct 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};
  65static struct ports_driver_data pdrvdata = { .next_vtermno = 1};
  66
  67static DEFINE_SPINLOCK(pdrvdata_lock);
  68static DECLARE_COMPLETION(early_console_added);
  69
  70/* This struct holds information that's relevant only for console ports */
  71struct 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
  91struct 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 */
 122struct 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
 167struct port_stats {
 168        unsigned long bytes_sent, bytes_received, bytes_discarded;
 169};
 170
 171/* This struct holds the per-port data */
 172struct 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. */
 240static int (*early_put_chars)(u32, const char *, int);
 241
 242static 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;
 256out:
 257        spin_unlock_irqrestore(&pdrvdata_lock, flags);
 258        return port;
 259}
 260
 261static 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;
 275out:
 276        spin_unlock_irqrestore(&portdev->ports_lock, flags);
 277
 278        return port;
 279}
 280
 281static 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;
 294out:
 295        spin_unlock_irqrestore(&pdrvdata_lock, flags);
 296        return port;
 297}
 298
 299static 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;
 309out:
 310        spin_unlock_irqrestore(&portdev->ports_lock, flags);
 311
 312        return port;
 313}
 314
 315static 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;
 326out:
 327        spin_unlock_irqrestore(&portdev->ports_lock, flags);
 328        return port;
 329}
 330
 331static bool is_console_port(struct port *port)
 332{
 333        if (port->cons.hvc)
 334                return true;
 335        return false;
 336}
 337
 338static bool is_rproc_serial(const struct virtio_device *vdev)
 339{
 340        return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
 341}
 342
 343static 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
 354static DEFINE_SPINLOCK(dma_bufs_lock);
 355static LIST_HEAD(pending_free_dma_bufs);
 356
 357static 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
 390static 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
 412static 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 parent device:
 439                 * virtioY => remoteprocX#vdevYbuffer.
 440                 */
 441                buf->dev = vdev->dev.parent;
 442                if (!buf->dev)
 443                        goto free_buf;
 444
 445                /* Increase device refcnt to avoid freeing it */
 446                get_device(buf->dev);
 447                buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
 448                                              GFP_KERNEL);
 449        } else {
 450                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
 461free_buf:
 462        kfree(buf);
 463fail:
 464        return NULL;
 465}
 466
 467/* Callers should take appropriate locks */
 468static 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 = min_t(size_t, len, buf->size);
 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 */
 491static 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. */
 506static 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
 532static 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
 547static 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
 578static 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 */
 589static 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
 604static 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();
 647done:
 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 */
 662static 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 */
 705static 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
 714static 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
 737static 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
 784static 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
 804static 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
 851free_buf:
 852        free_buf(buf, true);
 853out:
 854        return ret;
 855}
 856
 857struct sg_list {
 858        unsigned int n;
 859        unsigned int size;
 860        size_t len;
 861        struct scatterlist *sg;
 862};
 863
 864static 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 */
 908static 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
 964error_out:
 965        pipe_unlock(pipe);
 966        return ret;
 967}
 968
 969static __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
 992static void remove_port(struct kref *kref);
 993
 994static 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
1028static 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;
1077out:
1078        kref_put(&port->kref, remove_port);
1079        return ret;
1080}
1081
1082static 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 */
1096static 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 */
1116static 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 */
1147static 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
1165static 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 */
1182static 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
1196static void notifier_del_vio(struct hvc_struct *hp, int data)
1197{
1198        hp->irq_requested = 0;
1199}
1200
1201/* The operations for console ports. */
1202static 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 */
1219int __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
1225static 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
1275static 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
1285static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1286
1287static struct attribute *port_sysfs_entries[] = {
1288        &dev_attr_name.attr,
1289        NULL
1290};
1291
1292static const struct attribute_group port_attribute_group = {
1293        .name = NULL,           /* put in device directory */
1294        .attrs = port_sysfs_entries,
1295};
1296
1297static 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
1315DEFINE_SHOW_ATTRIBUTE(port_debugfs);
1316
1317static 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
1326static 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
1352static 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
1358static 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        /*
1460         * Finally, create the debugfs file that we can use to
1461         * inspect a port's state at any time
1462         */
1463        snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u",
1464                 port->portdev->vdev->index, id);
1465        port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1466                                                 pdrvdata.debugfs_dir,
1467                                                 port, &port_debugfs_fops);
1468        return 0;
1469
1470free_inbufs:
1471free_device:
1472        device_destroy(pdrvdata.class, port->dev->devt);
1473free_cdev:
1474        cdev_del(port->cdev);
1475free_port:
1476        kfree(port);
1477fail:
1478        /* The host might want to notify management sw about port add failure */
1479        __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1480        return err;
1481}
1482
1483/* No users remain, remove all port-specific data. */
1484static void remove_port(struct kref *kref)
1485{
1486        struct port *port;
1487
1488        port = container_of(kref, struct port, kref);
1489
1490        kfree(port);
1491}
1492
1493static void remove_port_data(struct port *port)
1494{
1495        spin_lock_irq(&port->inbuf_lock);
1496        /* Remove unused data this port might have received. */
1497        discard_port_data(port);
1498        spin_unlock_irq(&port->inbuf_lock);
1499
1500        spin_lock_irq(&port->outvq_lock);
1501        reclaim_consumed_buffers(port);
1502        spin_unlock_irq(&port->outvq_lock);
1503}
1504
1505/*
1506 * Port got unplugged.  Remove port from portdev's list and drop the
1507 * kref reference.  If no userspace has this port opened, it will
1508 * result in immediate removal the port.
1509 */
1510static void unplug_port(struct port *port)
1511{
1512        spin_lock_irq(&port->portdev->ports_lock);
1513        list_del(&port->list);
1514        spin_unlock_irq(&port->portdev->ports_lock);
1515
1516        spin_lock_irq(&port->inbuf_lock);
1517        if (port->guest_connected) {
1518                /* Let the app know the port is going down. */
1519                send_sigio_to_port(port);
1520
1521                /* Do this after sigio is actually sent */
1522                port->guest_connected = false;
1523                port->host_connected = false;
1524
1525                wake_up_interruptible(&port->waitqueue);
1526        }
1527        spin_unlock_irq(&port->inbuf_lock);
1528
1529        if (is_console_port(port)) {
1530                spin_lock_irq(&pdrvdata_lock);
1531                list_del(&port->cons.list);
1532                spin_unlock_irq(&pdrvdata_lock);
1533                hvc_remove(port->cons.hvc);
1534        }
1535
1536        remove_port_data(port);
1537
1538        /*
1539         * We should just assume the device itself has gone off --
1540         * else a close on an open port later will try to send out a
1541         * control message.
1542         */
1543        port->portdev = NULL;
1544
1545        sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1546        device_destroy(pdrvdata.class, port->dev->devt);
1547        cdev_del(port->cdev);
1548
1549        debugfs_remove(port->debugfs_file);
1550        kfree(port->name);
1551
1552        /*
1553         * Locks around here are not necessary - a port can't be
1554         * opened after we removed the port struct from ports_list
1555         * above.
1556         */
1557        kref_put(&port->kref, remove_port);
1558}
1559
1560/* Any private messages that the Host and Guest want to share */
1561static void handle_control_message(struct virtio_device *vdev,
1562                                   struct ports_device *portdev,
1563                                   struct port_buffer *buf)
1564{
1565        struct virtio_console_control *cpkt;
1566        struct port *port;
1567        size_t name_size;
1568        int err;
1569
1570        cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1571
1572        port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id));
1573        if (!port &&
1574            cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
1575                /* No valid header at start of buffer.  Drop it. */
1576                dev_dbg(&portdev->vdev->dev,
1577                        "Invalid index %u in control packet\n", cpkt->id);
1578                return;
1579        }
1580
1581        switch (virtio16_to_cpu(vdev, cpkt->event)) {
1582        case VIRTIO_CONSOLE_PORT_ADD:
1583                if (port) {
1584                        dev_dbg(&portdev->vdev->dev,
1585                                "Port %u already added\n", port->id);
1586                        send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1587                        break;
1588                }
1589                if (virtio32_to_cpu(vdev, cpkt->id) >=
1590                    portdev->max_nr_ports) {
1591                        dev_warn(&portdev->vdev->dev,
1592                                "Request for adding port with "
1593                                "out-of-bound id %u, max. supported id: %u\n",
1594                                cpkt->id, portdev->max_nr_ports - 1);
1595                        break;
1596                }
1597                add_port(portdev, virtio32_to_cpu(vdev, cpkt->id));
1598                break;
1599        case VIRTIO_CONSOLE_PORT_REMOVE:
1600                unplug_port(port);
1601                break;
1602        case VIRTIO_CONSOLE_CONSOLE_PORT:
1603                if (!cpkt->value)
1604                        break;
1605                if (is_console_port(port))
1606                        break;
1607
1608                init_port_console(port);
1609                complete(&early_console_added);
1610                /*
1611                 * Could remove the port here in case init fails - but
1612                 * have to notify the host first.
1613                 */
1614                break;
1615        case VIRTIO_CONSOLE_RESIZE: {
1616                struct {
1617                        __u16 rows;
1618                        __u16 cols;
1619                } size;
1620
1621                if (!is_console_port(port))
1622                        break;
1623
1624                memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1625                       sizeof(size));
1626                set_console_size(port, size.rows, size.cols);
1627
1628                port->cons.hvc->irq_requested = 1;
1629                resize_console(port);
1630                break;
1631        }
1632        case VIRTIO_CONSOLE_PORT_OPEN:
1633                port->host_connected = virtio16_to_cpu(vdev, cpkt->value);
1634                wake_up_interruptible(&port->waitqueue);
1635                /*
1636                 * If the host port got closed and the host had any
1637                 * unconsumed buffers, we'll be able to reclaim them
1638                 * now.
1639                 */
1640                spin_lock_irq(&port->outvq_lock);
1641                reclaim_consumed_buffers(port);
1642                spin_unlock_irq(&port->outvq_lock);
1643
1644                /*
1645                 * If the guest is connected, it'll be interested in
1646                 * knowing the host connection state changed.
1647                 */
1648                spin_lock_irq(&port->inbuf_lock);
1649                send_sigio_to_port(port);
1650                spin_unlock_irq(&port->inbuf_lock);
1651                break;
1652        case VIRTIO_CONSOLE_PORT_NAME:
1653                /*
1654                 * If we woke up after hibernation, we can get this
1655                 * again.  Skip it in that case.
1656                 */
1657                if (port->name)
1658                        break;
1659
1660                /*
1661                 * Skip the size of the header and the cpkt to get the size
1662                 * of the name that was sent
1663                 */
1664                name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1665
1666                port->name = kmalloc(name_size, GFP_KERNEL);
1667                if (!port->name) {
1668                        dev_err(port->dev,
1669                                "Not enough space to store port name\n");
1670                        break;
1671                }
1672                strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1673                        name_size - 1);
1674                port->name[name_size - 1] = 0;
1675
1676                /*
1677                 * Since we only have one sysfs attribute, 'name',
1678                 * create it only if we have a name for the port.
1679                 */
1680                err = sysfs_create_group(&port->dev->kobj,
1681                                         &port_attribute_group);
1682                if (err) {
1683                        dev_err(port->dev,
1684                                "Error %d creating sysfs device attributes\n",
1685                                err);
1686                } else {
1687                        /*
1688                         * Generate a udev event so that appropriate
1689                         * symlinks can be created based on udev
1690                         * rules.
1691                         */
1692                        kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1693                }
1694                break;
1695        }
1696}
1697
1698static void control_work_handler(struct work_struct *work)
1699{
1700        struct ports_device *portdev;
1701        struct virtqueue *vq;
1702        struct port_buffer *buf;
1703        unsigned int len;
1704
1705        portdev = container_of(work, struct ports_device, control_work);
1706        vq = portdev->c_ivq;
1707
1708        spin_lock(&portdev->c_ivq_lock);
1709        while ((buf = virtqueue_get_buf(vq, &len))) {
1710                spin_unlock(&portdev->c_ivq_lock);
1711
1712                buf->len = min_t(size_t, len, buf->size);
1713                buf->offset = 0;
1714
1715                handle_control_message(vq->vdev, portdev, buf);
1716
1717                spin_lock(&portdev->c_ivq_lock);
1718                if (add_inbuf(portdev->c_ivq, buf) < 0) {
1719                        dev_warn(&portdev->vdev->dev,
1720                                 "Error adding buffer to queue\n");
1721                        free_buf(buf, false);
1722                }
1723        }
1724        spin_unlock(&portdev->c_ivq_lock);
1725}
1726
1727static void flush_bufs(struct virtqueue *vq, bool can_sleep)
1728{
1729        struct port_buffer *buf;
1730        unsigned int len;
1731
1732        while ((buf = virtqueue_get_buf(vq, &len)))
1733                free_buf(buf, can_sleep);
1734}
1735
1736static void out_intr(struct virtqueue *vq)
1737{
1738        struct port *port;
1739
1740        port = find_port_by_vq(vq->vdev->priv, vq);
1741        if (!port) {
1742                flush_bufs(vq, false);
1743                return;
1744        }
1745
1746        wake_up_interruptible(&port->waitqueue);
1747}
1748
1749static void in_intr(struct virtqueue *vq)
1750{
1751        struct port *port;
1752        unsigned long flags;
1753
1754        port = find_port_by_vq(vq->vdev->priv, vq);
1755        if (!port) {
1756                flush_bufs(vq, false);
1757                return;
1758        }
1759
1760        spin_lock_irqsave(&port->inbuf_lock, flags);
1761        port->inbuf = get_inbuf(port);
1762
1763        /*
1764         * Normally the port should not accept data when the port is
1765         * closed. For generic serial ports, the host won't (shouldn't)
1766         * send data till the guest is connected. But this condition
1767         * can be reached when a console port is not yet connected (no
1768         * tty is spawned) and the other side sends out data over the
1769         * vring, or when a remote devices start sending data before
1770         * the ports are opened.
1771         *
1772         * A generic serial port will discard data if not connected,
1773         * while console ports and rproc-serial ports accepts data at
1774         * any time. rproc-serial is initiated with guest_connected to
1775         * false because port_fops_open expects this. Console ports are
1776         * hooked up with an HVC console and is initialized with
1777         * guest_connected to true.
1778         */
1779
1780        if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
1781                discard_port_data(port);
1782
1783        /* Send a SIGIO indicating new data in case the process asked for it */
1784        send_sigio_to_port(port);
1785
1786        spin_unlock_irqrestore(&port->inbuf_lock, flags);
1787
1788        wake_up_interruptible(&port->waitqueue);
1789
1790        if (is_console_port(port) && hvc_poll(port->cons.hvc))
1791                hvc_kick();
1792}
1793
1794static void control_intr(struct virtqueue *vq)
1795{
1796        struct ports_device *portdev;
1797
1798        portdev = vq->vdev->priv;
1799        schedule_work(&portdev->control_work);
1800}
1801
1802static void config_intr(struct virtio_device *vdev)
1803{
1804        struct ports_device *portdev;
1805
1806        portdev = vdev->priv;
1807
1808        if (!use_multiport(portdev))
1809                schedule_work(&portdev->config_work);
1810}
1811
1812static void config_work_handler(struct work_struct *work)
1813{
1814        struct ports_device *portdev;
1815
1816        portdev = container_of(work, struct ports_device, config_work);
1817        if (!use_multiport(portdev)) {
1818                struct virtio_device *vdev;
1819                struct port *port;
1820                u16 rows, cols;
1821
1822                vdev = portdev->vdev;
1823                virtio_cread(vdev, struct virtio_console_config, cols, &cols);
1824                virtio_cread(vdev, struct virtio_console_config, rows, &rows);
1825
1826                port = find_port_by_id(portdev, 0);
1827                set_console_size(port, rows, cols);
1828
1829                /*
1830                 * We'll use this way of resizing only for legacy
1831                 * support.  For newer userspace
1832                 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1833                 * to indicate console size changes so that it can be
1834                 * done per-port.
1835                 */
1836                resize_console(port);
1837        }
1838}
1839
1840static int init_vqs(struct ports_device *portdev)
1841{
1842        vq_callback_t **io_callbacks;
1843        char **io_names;
1844        struct virtqueue **vqs;
1845        u32 i, j, nr_ports, nr_queues;
1846        int err;
1847
1848        nr_ports = portdev->max_nr_ports;
1849        nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1850
1851        vqs = kmalloc_array(nr_queues, sizeof(struct virtqueue *), GFP_KERNEL);
1852        io_callbacks = kmalloc_array(nr_queues, sizeof(vq_callback_t *),
1853                                     GFP_KERNEL);
1854        io_names = kmalloc_array(nr_queues, sizeof(char *), GFP_KERNEL);
1855        portdev->in_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1856                                        GFP_KERNEL);
1857        portdev->out_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1858                                         GFP_KERNEL);
1859        if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1860            !portdev->out_vqs) {
1861                err = -ENOMEM;
1862                goto free;
1863        }
1864
1865        /*
1866         * For backward compat (newer host but older guest), the host
1867         * spawns a console port first and also inits the vqs for port
1868         * 0 before others.
1869         */
1870        j = 0;
1871        io_callbacks[j] = in_intr;
1872        io_callbacks[j + 1] = out_intr;
1873        io_names[j] = "input";
1874        io_names[j + 1] = "output";
1875        j += 2;
1876
1877        if (use_multiport(portdev)) {
1878                io_callbacks[j] = control_intr;
1879                io_callbacks[j + 1] = NULL;
1880                io_names[j] = "control-i";
1881                io_names[j + 1] = "control-o";
1882
1883                for (i = 1; i < nr_ports; i++) {
1884                        j += 2;
1885                        io_callbacks[j] = in_intr;
1886                        io_callbacks[j + 1] = out_intr;
1887                        io_names[j] = "input";
1888                        io_names[j + 1] = "output";
1889                }
1890        }
1891        /* Find the queues. */
1892        err = virtio_find_vqs(portdev->vdev, nr_queues, vqs,
1893                              io_callbacks,
1894                              (const char **)io_names, NULL);
1895        if (err)
1896                goto free;
1897
1898        j = 0;
1899        portdev->in_vqs[0] = vqs[0];
1900        portdev->out_vqs[0] = vqs[1];
1901        j += 2;
1902        if (use_multiport(portdev)) {
1903                portdev->c_ivq = vqs[j];
1904                portdev->c_ovq = vqs[j + 1];
1905
1906                for (i = 1; i < nr_ports; i++) {
1907                        j += 2;
1908                        portdev->in_vqs[i] = vqs[j];
1909                        portdev->out_vqs[i] = vqs[j + 1];
1910                }
1911        }
1912        kfree(io_names);
1913        kfree(io_callbacks);
1914        kfree(vqs);
1915
1916        return 0;
1917
1918free:
1919        kfree(portdev->out_vqs);
1920        kfree(portdev->in_vqs);
1921        kfree(io_names);
1922        kfree(io_callbacks);
1923        kfree(vqs);
1924
1925        return err;
1926}
1927
1928static const struct file_operations portdev_fops = {
1929        .owner = THIS_MODULE,
1930};
1931
1932static void remove_vqs(struct ports_device *portdev)
1933{
1934        struct virtqueue *vq;
1935
1936        virtio_device_for_each_vq(portdev->vdev, vq) {
1937                struct port_buffer *buf;
1938
1939                flush_bufs(vq, true);
1940                while ((buf = virtqueue_detach_unused_buf(vq)))
1941                        free_buf(buf, true);
1942        }
1943        portdev->vdev->config->del_vqs(portdev->vdev);
1944        kfree(portdev->in_vqs);
1945        kfree(portdev->out_vqs);
1946}
1947
1948static void virtcons_remove(struct virtio_device *vdev)
1949{
1950        struct ports_device *portdev;
1951        struct port *port, *port2;
1952
1953        portdev = vdev->priv;
1954
1955        spin_lock_irq(&pdrvdata_lock);
1956        list_del(&portdev->list);
1957        spin_unlock_irq(&pdrvdata_lock);
1958
1959        /* Disable interrupts for vqs */
1960        vdev->config->reset(vdev);
1961        /* Finish up work that's lined up */
1962        if (use_multiport(portdev))
1963                cancel_work_sync(&portdev->control_work);
1964        else
1965                cancel_work_sync(&portdev->config_work);
1966
1967        list_for_each_entry_safe(port, port2, &portdev->ports, list)
1968                unplug_port(port);
1969
1970        unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1971
1972        /*
1973         * When yanking out a device, we immediately lose the
1974         * (device-side) queues.  So there's no point in keeping the
1975         * guest side around till we drop our final reference.  This
1976         * also means that any ports which are in an open state will
1977         * have to just stop using the port, as the vqs are going
1978         * away.
1979         */
1980        remove_vqs(portdev);
1981        kfree(portdev);
1982}
1983
1984/*
1985 * Once we're further in boot, we get probed like any other virtio
1986 * device.
1987 *
1988 * If the host also supports multiple console ports, we check the
1989 * config space to see how many ports the host has spawned.  We
1990 * initialize each port found.
1991 */
1992static int virtcons_probe(struct virtio_device *vdev)
1993{
1994        struct ports_device *portdev;
1995        int err;
1996        bool multiport;
1997        bool early = early_put_chars != NULL;
1998
1999        /* We only need a config space if features are offered */
2000        if (!vdev->config->get &&
2001            (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
2002             || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
2003                dev_err(&vdev->dev, "%s failure: config access disabled\n",
2004                        __func__);
2005                return -EINVAL;
2006        }
2007
2008        /* Ensure to read early_put_chars now */
2009        barrier();
2010
2011        portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
2012        if (!portdev) {
2013                err = -ENOMEM;
2014                goto fail;
2015        }
2016
2017        /* Attach this portdev to this virtio_device, and vice-versa. */
2018        portdev->vdev = vdev;
2019        vdev->priv = portdev;
2020
2021        portdev->chr_major = register_chrdev(0, "virtio-portsdev",
2022                                             &portdev_fops);
2023        if (portdev->chr_major < 0) {
2024                dev_err(&vdev->dev,
2025                        "Error %d registering chrdev for device %u\n",
2026                        portdev->chr_major, vdev->index);
2027                err = portdev->chr_major;
2028                goto free;
2029        }
2030
2031        multiport = false;
2032        portdev->max_nr_ports = 1;
2033
2034        /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
2035        if (!is_rproc_serial(vdev) &&
2036            virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
2037                                 struct virtio_console_config, max_nr_ports,
2038                                 &portdev->max_nr_ports) == 0) {
2039                multiport = true;
2040        }
2041
2042        err = init_vqs(portdev);
2043        if (err < 0) {
2044                dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2045                goto free_chrdev;
2046        }
2047
2048        spin_lock_init(&portdev->ports_lock);
2049        INIT_LIST_HEAD(&portdev->ports);
2050        INIT_LIST_HEAD(&portdev->list);
2051
2052        virtio_device_ready(portdev->vdev);
2053
2054        INIT_WORK(&portdev->config_work, &config_work_handler);
2055        INIT_WORK(&portdev->control_work, &control_work_handler);
2056
2057        if (multiport) {
2058                spin_lock_init(&portdev->c_ivq_lock);
2059                spin_lock_init(&portdev->c_ovq_lock);
2060
2061                err = fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2062                if (err < 0) {
2063                        dev_err(&vdev->dev,
2064                                "Error allocating buffers for control queue\n");
2065                        /*
2066                         * The host might want to notify mgmt sw about device
2067                         * add failure.
2068                         */
2069                        __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2070                                           VIRTIO_CONSOLE_DEVICE_READY, 0);
2071                        /* Device was functional: we need full cleanup. */
2072                        virtcons_remove(vdev);
2073                        return err;
2074                }
2075        } else {
2076                /*
2077                 * For backward compatibility: Create a console port
2078                 * if we're running on older host.
2079                 */
2080                add_port(portdev, 0);
2081        }
2082
2083        spin_lock_irq(&pdrvdata_lock);
2084        list_add_tail(&portdev->list, &pdrvdata.portdevs);
2085        spin_unlock_irq(&pdrvdata_lock);
2086
2087        __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2088                           VIRTIO_CONSOLE_DEVICE_READY, 1);
2089
2090        /*
2091         * If there was an early virtio console, assume that there are no
2092         * other consoles. We need to wait until the hvc_alloc matches the
2093         * hvc_instantiate, otherwise tty_open will complain, resulting in
2094         * a "Warning: unable to open an initial console" boot failure.
2095         * Without multiport this is done in add_port above. With multiport
2096         * this might take some host<->guest communication - thus we have to
2097         * wait.
2098         */
2099        if (multiport && early)
2100                wait_for_completion(&early_console_added);
2101
2102        return 0;
2103
2104free_chrdev:
2105        unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2106free:
2107        kfree(portdev);
2108fail:
2109        return err;
2110}
2111
2112static const struct virtio_device_id id_table[] = {
2113        { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2114        { 0 },
2115};
2116MODULE_DEVICE_TABLE(virtio, id_table);
2117
2118static const unsigned int features[] = {
2119        VIRTIO_CONSOLE_F_SIZE,
2120        VIRTIO_CONSOLE_F_MULTIPORT,
2121};
2122
2123static const struct virtio_device_id rproc_serial_id_table[] = {
2124#if IS_ENABLED(CONFIG_REMOTEPROC)
2125        { VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2126#endif
2127        { 0 },
2128};
2129MODULE_DEVICE_TABLE(virtio, rproc_serial_id_table);
2130
2131static const unsigned int rproc_serial_features[] = {
2132};
2133
2134#ifdef CONFIG_PM_SLEEP
2135static int virtcons_freeze(struct virtio_device *vdev)
2136{
2137        struct ports_device *portdev;
2138        struct port *port;
2139
2140        portdev = vdev->priv;
2141
2142        vdev->config->reset(vdev);
2143
2144        if (use_multiport(portdev))
2145                virtqueue_disable_cb(portdev->c_ivq);
2146        cancel_work_sync(&portdev->control_work);
2147        cancel_work_sync(&portdev->config_work);
2148        /*
2149         * Once more: if control_work_handler() was running, it would
2150         * enable the cb as the last step.
2151         */
2152        if (use_multiport(portdev))
2153                virtqueue_disable_cb(portdev->c_ivq);
2154
2155        list_for_each_entry(port, &portdev->ports, list) {
2156                virtqueue_disable_cb(port->in_vq);
2157                virtqueue_disable_cb(port->out_vq);
2158                /*
2159                 * We'll ask the host later if the new invocation has
2160                 * the port opened or closed.
2161                 */
2162                port->host_connected = false;
2163                remove_port_data(port);
2164        }
2165        remove_vqs(portdev);
2166
2167        return 0;
2168}
2169
2170static int virtcons_restore(struct virtio_device *vdev)
2171{
2172        struct ports_device *portdev;
2173        struct port *port;
2174        int ret;
2175
2176        portdev = vdev->priv;
2177
2178        ret = init_vqs(portdev);
2179        if (ret)
2180                return ret;
2181
2182        virtio_device_ready(portdev->vdev);
2183
2184        if (use_multiport(portdev))
2185                fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2186
2187        list_for_each_entry(port, &portdev->ports, list) {
2188                port->in_vq = portdev->in_vqs[port->id];
2189                port->out_vq = portdev->out_vqs[port->id];
2190
2191                fill_queue(port->in_vq, &port->inbuf_lock);
2192
2193                /* Get port open/close status on the host */
2194                send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
2195
2196                /*
2197                 * If a port was open at the time of suspending, we
2198                 * have to let the host know that it's still open.
2199                 */
2200                if (port->guest_connected)
2201                        send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
2202        }
2203        return 0;
2204}
2205#endif
2206
2207static struct virtio_driver virtio_console = {
2208        .feature_table = features,
2209        .feature_table_size = ARRAY_SIZE(features),
2210        .driver.name =  KBUILD_MODNAME,
2211        .driver.owner = THIS_MODULE,
2212        .id_table =     id_table,
2213        .probe =        virtcons_probe,
2214        .remove =       virtcons_remove,
2215        .config_changed = config_intr,
2216#ifdef CONFIG_PM_SLEEP
2217        .freeze =       virtcons_freeze,
2218        .restore =      virtcons_restore,
2219#endif
2220};
2221
2222static struct virtio_driver virtio_rproc_serial = {
2223        .feature_table = rproc_serial_features,
2224        .feature_table_size = ARRAY_SIZE(rproc_serial_features),
2225        .driver.name =  "virtio_rproc_serial",
2226        .driver.owner = THIS_MODULE,
2227        .id_table =     rproc_serial_id_table,
2228        .probe =        virtcons_probe,
2229        .remove =       virtcons_remove,
2230};
2231
2232static int __init init(void)
2233{
2234        int err;
2235
2236        pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
2237        if (IS_ERR(pdrvdata.class)) {
2238                err = PTR_ERR(pdrvdata.class);
2239                pr_err("Error %d creating virtio-ports class\n", err);
2240                return err;
2241        }
2242
2243        pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
2244        INIT_LIST_HEAD(&pdrvdata.consoles);
2245        INIT_LIST_HEAD(&pdrvdata.portdevs);
2246
2247        err = register_virtio_driver(&virtio_console);
2248        if (err < 0) {
2249                pr_err("Error %d registering virtio driver\n", err);
2250                goto free;
2251        }
2252        err = register_virtio_driver(&virtio_rproc_serial);
2253        if (err < 0) {
2254                pr_err("Error %d registering virtio rproc serial driver\n",
2255                       err);
2256                goto unregister;
2257        }
2258        return 0;
2259unregister:
2260        unregister_virtio_driver(&virtio_console);
2261free:
2262        debugfs_remove_recursive(pdrvdata.debugfs_dir);
2263        class_destroy(pdrvdata.class);
2264        return err;
2265}
2266
2267static void __exit fini(void)
2268{
2269        reclaim_dma_bufs();
2270
2271        unregister_virtio_driver(&virtio_console);
2272        unregister_virtio_driver(&virtio_rproc_serial);
2273
2274        class_destroy(pdrvdata.class);
2275        debugfs_remove_recursive(pdrvdata.debugfs_dir);
2276}
2277module_init(init);
2278module_exit(fini);
2279
2280MODULE_DESCRIPTION("Virtio console driver");
2281MODULE_LICENSE("GPL");
2282