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