drivers/s390/kvm/virtio_ccw.c

   1 /*
   2  * ccw based virtio transport
   3  *
   4  * Copyright IBM Corp. 2012, 2014
   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 (version 2 only)
   8  * as published by the Free Software Foundation.
   9  *
  10  *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
  11  */
  12
  13 #include <linux/kernel_stat.h>
  14 #include <linux/init.h>
  15 #include <linux/bootmem.h>
  16 #include <linux/err.h>
  17 #include <linux/virtio.h>
  18 #include <linux/virtio_config.h>
  19 #include <linux/slab.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/virtio_ring.h>
  22 #include <linux/pfn.h>
  23 #include <linux/async.h>
  24 #include <linux/wait.h>
  25 #include <linux/list.h>
  26 #include <linux/bitops.h>
  27 #include <linux/module.h>
  28 #include <linux/io.h>
  29 #include <linux/kvm_para.h>
  30 #include <linux/notifier.h>
  31 #include <asm/setup.h>
  32 #include <asm/irq.h>
  33 #include <asm/cio.h>
  34 #include <asm/ccwdev.h>
  35 #include <asm/virtio-ccw.h>
  36 #include <asm/isc.h>
  37 #include <asm/airq.h>
  38
  39 /*
  40  * virtio related functions
  41  */
  42
  43 struct vq_config_block {
  44         __u16 index;
  45         __u16 num;
  46 } __packed;
  47
  48 #define VIRTIO_CCW_CONFIG_SIZE 0x100
  49 /* same as PCI config space size, should be enough for all drivers */
  50
  51 struct virtio_ccw_device {
  52         struct virtio_device vdev;
  53         __u8 *status;
  54         __u8 config[VIRTIO_CCW_CONFIG_SIZE];
  55         struct ccw_device *cdev;
  56         __u32 curr_io;
  57         int err;
  58         wait_queue_head_t wait_q;
  59         spinlock_t lock;
  60         struct list_head virtqueues;
  61         unsigned long indicators;
  62         unsigned long indicators2;
  63         struct vq_config_block *config_block;
  64         bool is_thinint;
  65         bool going_away;
  66         bool device_lost;
  67         void *airq_info;
  68 };
  69
  70 struct vq_info_block {
  71         __u64 queue;
  72         __u32 align;
  73         __u16 index;
  74         __u16 num;
  75 } __packed;
  76
  77 struct virtio_feature_desc {
  78         __u32 features;
  79         __u8 index;
  80 } __packed;
  81
  82 struct virtio_thinint_area {
  83         unsigned long summary_indicator;
  84         unsigned long indicator;
  85         u64 bit_nr;
  86         u8 isc;
  87 } __packed;
  88
  89 struct virtio_ccw_vq_info {
  90         struct virtqueue *vq;
  91         int num;
  92         void *queue;
  93         struct vq_info_block *info_block;
  94         int bit_nr;
  95         struct list_head node;
  96         long cookie;
  97 };
  98
  99 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
 100
 101 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
 102 #define MAX_AIRQ_AREAS 20
 103
 104 static int virtio_ccw_use_airq = 1;
 105
 106 struct airq_info {
 107         rwlock_t lock;
 108         u8 summary_indicator;
 109         struct airq_struct airq;
 110         struct airq_iv *aiv;
 111 };
 112 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
 113
 114 #define CCW_CMD_SET_VQ 0x13
 115 #define CCW_CMD_VDEV_RESET 0x33
 116 #define CCW_CMD_SET_IND 0x43
 117 #define CCW_CMD_SET_CONF_IND 0x53
 118 #define CCW_CMD_READ_FEAT 0x12
 119 #define CCW_CMD_WRITE_FEAT 0x11
 120 #define CCW_CMD_READ_CONF 0x22
 121 #define CCW_CMD_WRITE_CONF 0x21
 122 #define CCW_CMD_WRITE_STATUS 0x31
 123 #define CCW_CMD_READ_VQ_CONF 0x32
 124 #define CCW_CMD_SET_IND_ADAPTER 0x73
 125
 126 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
 127 #define VIRTIO_CCW_DOING_RESET 0x00040000
 128 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
 129 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
 130 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
 131 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
 132 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
 133 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
 134 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
 135 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
 136 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
 137 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
 138
 139 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
 140 {
 141         return container_of(vdev, struct virtio_ccw_device, vdev);
 142 }
 143
 144 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
 145 {
 146         unsigned long i, flags;
 147
 148         write_lock_irqsave(&info->lock, flags);
 149         for (i = 0; i < airq_iv_end(info->aiv); i++) {
 150                 if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
 151                         airq_iv_free_bit(info->aiv, i);
 152                         airq_iv_set_ptr(info->aiv, i, 0);
 153                         break;
 154                 }
 155         }
 156         write_unlock_irqrestore(&info->lock, flags);
 157 }
 158
 159 static void virtio_airq_handler(struct airq_struct *airq)
 160 {
 161         struct airq_info *info = container_of(airq, struct airq_info, airq);
 162         unsigned long ai;
 163
 164         inc_irq_stat(IRQIO_VAI);
 165         read_lock(&info->lock);
 166         /* Walk through indicators field, summary indicator active. */
 167         for (ai = 0;;) {
 168                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 169                 if (ai == -1UL)
 170                         break;
 171                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 172         }
 173         info->summary_indicator = 0;
 174         smp_wmb();
 175         /* Walk through indicators field, summary indicator not active. */
 176         for (ai = 0;;) {
 177                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 178                 if (ai == -1UL)
 179                         break;
 180                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 181         }
 182         read_unlock(&info->lock);
 183 }
 184
 185 static struct airq_info *new_airq_info(void)
 186 {
 187         struct airq_info *info;
 188         int rc;
 189
 190         info = kzalloc(sizeof(*info), GFP_KERNEL);
 191         if (!info)
 192                 return NULL;
 193         rwlock_init(&info->lock);
 194         info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
 195         if (!info->aiv) {
 196                 kfree(info);
 197                 return NULL;
 198         }
 199         info->airq.handler = virtio_airq_handler;
 200         info->airq.lsi_ptr = &info->summary_indicator;
 201         info->airq.lsi_mask = 0xff;
 202         info->airq.isc = VIRTIO_AIRQ_ISC;
 203         rc = register_adapter_interrupt(&info->airq);
 204         if (rc) {
 205                 airq_iv_release(info->aiv);
 206                 kfree(info);
 207                 return NULL;
 208         }
 209         return info;
 210 }
 211
 212 static void destroy_airq_info(struct airq_info *info)
 213 {
 214         if (!info)
 215                 return;
 216
 217         unregister_adapter_interrupt(&info->airq);
 218         airq_iv_release(info->aiv);
 219         kfree(info);
 220 }
 221
 222 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
 223                                         u64 *first, void **airq_info)
 224 {
 225         int i, j;
 226         struct airq_info *info;
 227         unsigned long indicator_addr = 0;
 228         unsigned long bit, flags;
 229
 230         for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
 231                 if (!airq_areas[i])
 232                         airq_areas[i] = new_airq_info();
 233                 info = airq_areas[i];
 234                 if (!info)
 235                         return 0;
 236                 write_lock_irqsave(&info->lock, flags);
 237                 bit = airq_iv_alloc(info->aiv, nvqs);
 238                 if (bit == -1UL) {
 239                         /* Not enough vacancies. */
 240                         write_unlock_irqrestore(&info->lock, flags);
 241                         continue;
 242                 }
 243                 *first = bit;
 244                 *airq_info = info;
 245                 indicator_addr = (unsigned long)info->aiv->vector;
 246                 for (j = 0; j < nvqs; j++) {
 247                         airq_iv_set_ptr(info->aiv, bit + j,
 248                                         (unsigned long)vqs[j]);
 249                 }
 250                 write_unlock_irqrestore(&info->lock, flags);
 251         }
 252         return indicator_addr;
 253 }
 254
 255 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
 256 {
 257         struct virtio_ccw_vq_info *info;
 258
 259         list_for_each_entry(info, &vcdev->virtqueues, node)
 260                 drop_airq_indicator(info->vq, vcdev->airq_info);
 261 }
 262
 263 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
 264 {
 265         unsigned long flags;
 266         __u32 ret;
 267
 268         spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 269         if (vcdev->err)
 270                 ret = 0;
 271         else
 272                 ret = vcdev->curr_io & flag;
 273         spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 274         return ret;
 275 }
 276
 277 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
 278                          struct ccw1 *ccw, __u32 intparm)
 279 {
 280         int ret;
 281         unsigned long flags;
 282         int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
 283
 284         do {
 285                 spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 286                 ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
 287                 if (!ret) {
 288                         if (!vcdev->curr_io)
 289                                 vcdev->err = 0;
 290                         vcdev->curr_io |= flag;
 291                 }
 292                 spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 293                 cpu_relax();
 294         } while (ret == -EBUSY);
 295         wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
 296         return ret ? ret : vcdev->err;
 297 }
 298
 299 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
 300                                       struct ccw1 *ccw)
 301 {
 302         int ret;
 303         unsigned long *indicatorp = NULL;
 304         struct virtio_thinint_area *thinint_area = NULL;
 305         struct airq_info *airq_info = vcdev->airq_info;
 306
 307         if (vcdev->is_thinint) {
 308                 thinint_area = kzalloc(sizeof(*thinint_area),
 309                                        GFP_DMA | GFP_KERNEL);
 310                 if (!thinint_area)
 311                         return;
 312                 thinint_area->summary_indicator =
 313                         (unsigned long) &airq_info->summary_indicator;
 314                 thinint_area->isc = VIRTIO_AIRQ_ISC;
 315                 ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 316                 ccw->count = sizeof(*thinint_area);
 317                 ccw->cda = (__u32)(unsigned long) thinint_area;
 318         } else {
 319                 indicatorp = kmalloc(sizeof(&vcdev->indicators),
 320                                      GFP_DMA | GFP_KERNEL);
 321                 if (!indicatorp)
 322                         return;
 323                 *indicatorp = 0;
 324                 ccw->cmd_code = CCW_CMD_SET_IND;
 325                 ccw->count = sizeof(vcdev->indicators);
 326                 ccw->cda = (__u32)(unsigned long) indicatorp;
 327         }
 328         /* Deregister indicators from host. */
 329         vcdev->indicators = 0;
 330         ccw->flags = 0;
 331         ret = ccw_io_helper(vcdev, ccw,
 332                             vcdev->is_thinint ?
 333                             VIRTIO_CCW_DOING_SET_IND_ADAPTER :
 334                             VIRTIO_CCW_DOING_SET_IND);
 335         if (ret && (ret != -ENODEV))
 336                 dev_info(&vcdev->cdev->dev,
 337                          "Failed to deregister indicators (%d)\n", ret);
 338         else if (vcdev->is_thinint)
 339                 virtio_ccw_drop_indicators(vcdev);
 340         kfree(indicatorp);
 341         kfree(thinint_area);
 342 }
 343
 344 static inline long do_kvm_notify(struct subchannel_id schid,
 345                                  unsigned long queue_index,
 346                                  long cookie)
 347 {
 348         register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
 349         register struct subchannel_id __schid asm("2") = schid;
 350         register unsigned long __index asm("3") = queue_index;
 351         register long __rc asm("2");
 352         register long __cookie asm("4") = cookie;
 353
 354         asm volatile ("diag 2,4,0x500\n"
 355                       : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
 356                       "d"(__cookie)
 357                       : "memory", "cc");
 358         return __rc;
 359 }
 360
 361 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
 362 {
 363         struct virtio_ccw_vq_info *info = vq->priv;
 364         struct virtio_ccw_device *vcdev;
 365         struct subchannel_id schid;
 366
 367         vcdev = to_vc_device(info->vq->vdev);
 368         ccw_device_get_schid(vcdev->cdev, &schid);
 369         info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
 370         if (info->cookie < 0)
 371                 return false;
 372         return true;
 373 }
 374
 375 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
 376                                    struct ccw1 *ccw, int index)
 377 {
 378         vcdev->config_block->index = index;
 379         ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
 380         ccw->flags = 0;
 381         ccw->count = sizeof(struct vq_config_block);
 382         ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
 383         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
 384         return vcdev->config_block->num;
 385 }
 386
 387 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
 388 {
 389         struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
 390         struct virtio_ccw_vq_info *info = vq->priv;
 391         unsigned long flags;
 392         unsigned long size;
 393         int ret;
 394         unsigned int index = vq->index;
 395
 396         /* Remove from our list. */
 397         spin_lock_irqsave(&vcdev->lock, flags);
 398         list_del(&info->node);
 399         spin_unlock_irqrestore(&vcdev->lock, flags);
 400
 401         /* Release from host. */
 402         info->info_block->queue = 0;
 403         info->info_block->align = 0;
 404         info->info_block->index = index;
 405         info->info_block->num = 0;
 406         ccw->cmd_code = CCW_CMD_SET_VQ;
 407         ccw->flags = 0;
 408         ccw->count = sizeof(*info->info_block);
 409         ccw->cda = (__u32)(unsigned long)(info->info_block);
 410         ret = ccw_io_helper(vcdev, ccw,
 411                             VIRTIO_CCW_DOING_SET_VQ | index);
 412         /*
 413          * -ENODEV isn't considered an error: The device is gone anyway.
 414          * This may happen on device detach.
 415          */
 416         if (ret && (ret != -ENODEV))
 417                 dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d",
 418                          ret, index);
 419
 420         vring_del_virtqueue(vq);
 421         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
 422         free_pages_exact(info->queue, size);
 423         kfree(info->info_block);
 424         kfree(info);
 425 }
 426
 427 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
 428 {
 429         struct virtqueue *vq, *n;
 430         struct ccw1 *ccw;
 431         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 432
 433         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 434         if (!ccw)
 435                 return;
 436
 437         virtio_ccw_drop_indicator(vcdev, ccw);
 438
 439         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 440                 virtio_ccw_del_vq(vq, ccw);
 441
 442         kfree(ccw);
 443 }
 444
 445 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
 446                                              int i, vq_callback_t *callback,
 447                                              const char *name,
 448                                              struct ccw1 *ccw)
 449 {
 450         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 451         int err;
 452         struct virtqueue *vq = NULL;
 453         struct virtio_ccw_vq_info *info;
 454         unsigned long size = 0; /* silence the compiler */
 455         unsigned long flags;
 456
 457         /* Allocate queue. */
 458         info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
 459         if (!info) {
 460                 dev_warn(&vcdev->cdev->dev, "no info\n");
 461                 err = -ENOMEM;
 462                 goto out_err;
 463         }
 464         info->info_block = kzalloc(sizeof(*info->info_block),
 465                                    GFP_DMA | GFP_KERNEL);
 466         if (!info->info_block) {
 467                 dev_warn(&vcdev->cdev->dev, "no info block\n");
 468                 err = -ENOMEM;
 469                 goto out_err;
 470         }
 471         info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
 472         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
 473         info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
 474         if (info->queue == NULL) {
 475                 dev_warn(&vcdev->cdev->dev, "no queue\n");
 476                 err = -ENOMEM;
 477                 goto out_err;
 478         }
 479
 480         vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
 481                                  true, info->queue, virtio_ccw_kvm_notify,
 482                                  callback, name);
 483         if (!vq) {
 484                 /* For now, we fail if we can't get the requested size. */
 485                 dev_warn(&vcdev->cdev->dev, "no vq\n");
 486                 err = -ENOMEM;
 487                 goto out_err;
 488         }
 489
 490         /* Register it with the host. */
 491         info->info_block->queue = (__u64)info->queue;
 492         info->info_block->align = KVM_VIRTIO_CCW_RING_ALIGN;
 493         info->info_block->index = i;
 494         info->info_block->num = info->num;
 495         ccw->cmd_code = CCW_CMD_SET_VQ;
 496         ccw->flags = 0;
 497         ccw->count = sizeof(*info->info_block);
 498         ccw->cda = (__u32)(unsigned long)(info->info_block);
 499         err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
 500         if (err) {
 501                 dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
 502                 goto out_err;
 503         }
 504
 505         info->vq = vq;
 506         vq->priv = info;
 507
 508         /* Save it to our list. */
 509         spin_lock_irqsave(&vcdev->lock, flags);
 510         list_add(&info->node, &vcdev->virtqueues);
 511         spin_unlock_irqrestore(&vcdev->lock, flags);
 512
 513         return vq;
 514
 515 out_err:
 516         if (vq)
 517                 vring_del_virtqueue(vq);
 518         if (info) {
 519                 if (info->queue)
 520                         free_pages_exact(info->queue, size);
 521                 kfree(info->info_block);
 522         }
 523         kfree(info);
 524         return ERR_PTR(err);
 525 }
 526
 527 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
 528                                            struct virtqueue *vqs[], int nvqs,
 529                                            struct ccw1 *ccw)
 530 {
 531         int ret;
 532         struct virtio_thinint_area *thinint_area = NULL;
 533         struct airq_info *info;
 534
 535         thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
 536         if (!thinint_area) {
 537                 ret = -ENOMEM;
 538                 goto out;
 539         }
 540         /* Try to get an indicator. */
 541         thinint_area->indicator = get_airq_indicator(vqs, nvqs,
 542                                                      &thinint_area->bit_nr,
 543                                                      &vcdev->airq_info);
 544         if (!thinint_area->indicator) {
 545                 ret = -ENOSPC;
 546                 goto out;
 547         }
 548         info = vcdev->airq_info;
 549         thinint_area->summary_indicator =
 550                 (unsigned long) &info->summary_indicator;
 551         thinint_area->isc = VIRTIO_AIRQ_ISC;
 552         ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 553         ccw->flags = CCW_FLAG_SLI;
 554         ccw->count = sizeof(*thinint_area);
 555         ccw->cda = (__u32)(unsigned long)thinint_area;
 556         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
 557         if (ret) {
 558                 if (ret == -EOPNOTSUPP) {
 559                         /*
 560                          * The host does not support adapter interrupts
 561                          * for virtio-ccw, stop trying.
 562                          */
 563                         virtio_ccw_use_airq = 0;
 564                         pr_info("Adapter interrupts unsupported on host\n");
 565                 } else
 566                         dev_warn(&vcdev->cdev->dev,
 567                                  "enabling adapter interrupts = %d\n", ret);
 568                 virtio_ccw_drop_indicators(vcdev);
 569         }
 570 out:
 571         kfree(thinint_area);
 572         return ret;
 573 }
 574
 575 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 576                                struct virtqueue *vqs[],
 577                                vq_callback_t *callbacks[],
 578                                const char *names[])
 579 {
 580         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 581         unsigned long *indicatorp = NULL;
 582         int ret, i;
 583         struct ccw1 *ccw;
 584
 585         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 586         if (!ccw)
 587                 return -ENOMEM;
 588
 589         for (i = 0; i < nvqs; ++i) {
 590                 vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
 591                                              ccw);
 592                 if (IS_ERR(vqs[i])) {
 593                         ret = PTR_ERR(vqs[i]);
 594                         vqs[i] = NULL;
 595                         goto out;
 596                 }
 597         }
 598         ret = -ENOMEM;
 599         /* We need a data area under 2G to communicate. */
 600         indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
 601         if (!indicatorp)
 602                 goto out;
 603         *indicatorp = (unsigned long) &vcdev->indicators;
 604         if (vcdev->is_thinint) {
 605                 ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
 606                 if (ret)
 607                         /* no error, just fall back to legacy interrupts */
 608                         vcdev->is_thinint = 0;
 609         }
 610         if (!vcdev->is_thinint) {
 611                 /* Register queue indicators with host. */
 612                 vcdev->indicators = 0;
 613                 ccw->cmd_code = CCW_CMD_SET_IND;
 614                 ccw->flags = 0;
 615                 ccw->count = sizeof(vcdev->indicators);
 616                 ccw->cda = (__u32)(unsigned long) indicatorp;
 617                 ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
 618                 if (ret)
 619                         goto out;
 620         }
 621         /* Register indicators2 with host for config changes */
 622         *indicatorp = (unsigned long) &vcdev->indicators2;
 623         vcdev->indicators2 = 0;
 624         ccw->cmd_code = CCW_CMD_SET_CONF_IND;
 625         ccw->flags = 0;
 626         ccw->count = sizeof(vcdev->indicators2);
 627         ccw->cda = (__u32)(unsigned long) indicatorp;
 628         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
 629         if (ret)
 630                 goto out;
 631
 632         kfree(indicatorp);
 633         kfree(ccw);
 634         return 0;
 635 out:
 636         kfree(indicatorp);
 637         kfree(ccw);
 638         virtio_ccw_del_vqs(vdev);
 639         return ret;
 640 }
 641
 642 static void virtio_ccw_reset(struct virtio_device *vdev)
 643 {
 644         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 645         struct ccw1 *ccw;
 646
 647         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 648         if (!ccw)
 649                 return;
 650
 651         /* Zero status bits. */
 652         *vcdev->status = 0;
 653
 654         /* Send a reset ccw on device. */
 655         ccw->cmd_code = CCW_CMD_VDEV_RESET;
 656         ccw->flags = 0;
 657         ccw->count = 0;
 658         ccw->cda = 0;
 659         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
 660         kfree(ccw);
 661 }
 662
 663 static u32 virtio_ccw_get_features(struct virtio_device *vdev)
 664 {
 665         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 666         struct virtio_feature_desc *features;
 667         int ret, rc;
 668         struct ccw1 *ccw;
 669
 670         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 671         if (!ccw)
 672                 return 0;
 673
 674         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
 675         if (!features) {
 676                 rc = 0;
 677                 goto out_free;
 678         }
 679         /* Read the feature bits from the host. */
 680         /* TODO: Features > 32 bits */
 681         features->index = 0;
 682         ccw->cmd_code = CCW_CMD_READ_FEAT;
 683         ccw->flags = 0;
 684         ccw->count = sizeof(*features);
 685         ccw->cda = (__u32)(unsigned long)features;
 686         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 687         if (ret) {
 688                 rc = 0;
 689                 goto out_free;
 690         }
 691
 692         rc = le32_to_cpu(features->features);
 693
 694 out_free:
 695         kfree(features);
 696         kfree(ccw);
 697         return rc;
 698 }
 699
 700 static void virtio_ccw_finalize_features(struct virtio_device *vdev)
 701 {
 702         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 703         struct virtio_feature_desc *features;
 704         int i;
 705         struct ccw1 *ccw;
 706
 707         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 708         if (!ccw)
 709                 return;
 710
 711         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
 712         if (!features)
 713                 goto out_free;
 714
 715         /* Give virtio_ring a chance to accept features. */
 716         vring_transport_features(vdev);
 717
 718         for (i = 0; i < sizeof(*vdev->features) / sizeof(features->features);
 719              i++) {
 720                 int highbits = i % 2 ? 32 : 0;
 721                 features->index = i;
 722                 features->features = cpu_to_le32(vdev->features[i / 2]
 723                                                  >> highbits);
 724                 /* Write the feature bits to the host. */
 725                 ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 726                 ccw->flags = 0;
 727                 ccw->count = sizeof(*features);
 728                 ccw->cda = (__u32)(unsigned long)features;
 729                 ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 730         }
 731 out_free:
 732         kfree(features);
 733         kfree(ccw);
 734 }
 735
 736 static void virtio_ccw_get_config(struct virtio_device *vdev,
 737                                   unsigned int offset, void *buf, unsigned len)
 738 {
 739         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 740         int ret;
 741         struct ccw1 *ccw;
 742         void *config_area;
 743
 744         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 745         if (!ccw)
 746                 return;
 747
 748         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
 749         if (!config_area)
 750                 goto out_free;
 751
 752         /* Read the config area from the host. */
 753         ccw->cmd_code = CCW_CMD_READ_CONF;
 754         ccw->flags = 0;
 755         ccw->count = offset + len;
 756         ccw->cda = (__u32)(unsigned long)config_area;
 757         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
 758         if (ret)
 759                 goto out_free;
 760
 761         memcpy(vcdev->config, config_area, sizeof(vcdev->config));
 762         memcpy(buf, &vcdev->config[offset], len);
 763
 764 out_free:
 765         kfree(config_area);
 766         kfree(ccw);
 767 }
 768
 769 static void virtio_ccw_set_config(struct virtio_device *vdev,
 770                                   unsigned int offset, const void *buf,
 771                                   unsigned len)
 772 {
 773         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 774         struct ccw1 *ccw;
 775         void *config_area;
 776
 777         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 778         if (!ccw)
 779                 return;
 780
 781         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
 782         if (!config_area)
 783                 goto out_free;
 784
 785         memcpy(&vcdev->config[offset], buf, len);
 786         /* Write the config area to the host. */
 787         memcpy(config_area, vcdev->config, sizeof(vcdev->config));
 788         ccw->cmd_code = CCW_CMD_WRITE_CONF;
 789         ccw->flags = 0;
 790         ccw->count = offset + len;
 791         ccw->cda = (__u32)(unsigned long)config_area;
 792         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
 793
 794 out_free:
 795         kfree(config_area);
 796         kfree(ccw);
 797 }
 798
 799 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
 800 {
 801         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 802
 803         return *vcdev->status;
 804 }
 805
 806 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 807 {
 808         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 809         struct ccw1 *ccw;
 810
 811         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 812         if (!ccw)
 813                 return;
 814
 815         /* Write the status to the host. */
 816         *vcdev->status = status;
 817         ccw->cmd_code = CCW_CMD_WRITE_STATUS;
 818         ccw->flags = 0;
 819         ccw->count = sizeof(status);
 820         ccw->cda = (__u32)(unsigned long)vcdev->status;
 821         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
 822         kfree(ccw);
 823 }
 824
 825 static struct virtio_config_ops virtio_ccw_config_ops = {
 826         .get_features = virtio_ccw_get_features,
 827         .finalize_features = virtio_ccw_finalize_features,
 828         .get = virtio_ccw_get_config,
 829         .set = virtio_ccw_set_config,
 830         .get_status = virtio_ccw_get_status,
 831         .set_status = virtio_ccw_set_status,
 832         .reset = virtio_ccw_reset,
 833         .find_vqs = virtio_ccw_find_vqs,
 834         .del_vqs = virtio_ccw_del_vqs,
 835 };
 836
 837
 838 /*
 839  * ccw bus driver related functions
 840  */
 841
 842 static void virtio_ccw_release_dev(struct device *_d)
 843 {
 844         struct virtio_device *dev = container_of(_d, struct virtio_device,
 845                                                  dev);
 846         struct virtio_ccw_device *vcdev = to_vc_device(dev);
 847
 848         kfree(vcdev->status);
 849         kfree(vcdev->config_block);
 850         kfree(vcdev);
 851 }
 852
 853 static int irb_is_error(struct irb *irb)
 854 {
 855         if (scsw_cstat(&irb->scsw) != 0)
 856                 return 1;
 857         if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
 858                 return 1;
 859         if (scsw_cc(&irb->scsw) != 0)
 860                 return 1;
 861         return 0;
 862 }
 863
 864 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
 865                                               int index)
 866 {
 867         struct virtio_ccw_vq_info *info;
 868         unsigned long flags;
 869         struct virtqueue *vq;
 870
 871         vq = NULL;
 872         spin_lock_irqsave(&vcdev->lock, flags);
 873         list_for_each_entry(info, &vcdev->virtqueues, node) {
 874                 if (info->vq->index == index) {
 875                         vq = info->vq;
 876                         break;
 877                 }
 878         }
 879         spin_unlock_irqrestore(&vcdev->lock, flags);
 880         return vq;
 881 }
 882
 883 static void virtio_ccw_int_handler(struct ccw_device *cdev,
 884                                    unsigned long intparm,
 885                                    struct irb *irb)
 886 {
 887         __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
 888         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
 889         int i;
 890         struct virtqueue *vq;
 891         struct virtio_driver *drv;
 892
 893         if (!vcdev)
 894                 return;
 895         /* Check if it's a notification from the host. */
 896         if ((intparm == 0) &&
 897             (scsw_stctl(&irb->scsw) ==
 898              (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
 899                 /* OK */
 900         }
 901         if (irb_is_error(irb)) {
 902                 /* Command reject? */
 903                 if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
 904                     (irb->ecw[0] & SNS0_CMD_REJECT))
 905                         vcdev->err = -EOPNOTSUPP;
 906                 else
 907                         /* Map everything else to -EIO. */
 908                         vcdev->err = -EIO;
 909         }
 910         if (vcdev->curr_io & activity) {
 911                 switch (activity) {
 912                 case VIRTIO_CCW_DOING_READ_FEAT:
 913                 case VIRTIO_CCW_DOING_WRITE_FEAT:
 914                 case VIRTIO_CCW_DOING_READ_CONFIG:
 915                 case VIRTIO_CCW_DOING_WRITE_CONFIG:
 916                 case VIRTIO_CCW_DOING_WRITE_STATUS:
 917                 case VIRTIO_CCW_DOING_SET_VQ:
 918                 case VIRTIO_CCW_DOING_SET_IND:
 919                 case VIRTIO_CCW_DOING_SET_CONF_IND:
 920                 case VIRTIO_CCW_DOING_RESET:
 921                 case VIRTIO_CCW_DOING_READ_VQ_CONF:
 922                 case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
 923                         vcdev->curr_io &= ~activity;
 924                         wake_up(&vcdev->wait_q);
 925                         break;
 926                 default:
 927                         /* don't know what to do... */
 928                         dev_warn(&cdev->dev, "Suspicious activity '%08x'\n",
 929                                  activity);
 930                         WARN_ON(1);
 931                         break;
 932                 }
 933         }
 934         for_each_set_bit(i, &vcdev->indicators,
 935                          sizeof(vcdev->indicators) * BITS_PER_BYTE) {
 936                 /* The bit clear must happen before the vring kick. */
 937                 clear_bit(i, &vcdev->indicators);
 938                 barrier();
 939                 vq = virtio_ccw_vq_by_ind(vcdev, i);
 940                 vring_interrupt(0, vq);
 941         }
 942         if (test_bit(0, &vcdev->indicators2)) {
 943                 drv = container_of(vcdev->vdev.dev.driver,
 944                                    struct virtio_driver, driver);
 945
 946                 if (drv && drv->config_changed)
 947                         drv->config_changed(&vcdev->vdev);
 948                 clear_bit(0, &vcdev->indicators2);
 949         }
 950 }
 951
 952 /*
 953  * We usually want to autoonline all devices, but give the admin
 954  * a way to exempt devices from this.
 955  */
 956 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
 957                      (8*sizeof(long)))
 958 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
 959
 960 static char *no_auto = "";
 961
 962 module_param(no_auto, charp, 0444);
 963 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
 964
 965 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
 966 {
 967         struct ccw_dev_id id;
 968
 969         ccw_device_get_id(cdev, &id);
 970         if (test_bit(id.devno, devs_no_auto[id.ssid]))
 971                 return 0;
 972         return 1;
 973 }
 974
 975 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
 976 {
 977         struct ccw_device *cdev = data;
 978         int ret;
 979
 980         ret = ccw_device_set_online(cdev);
 981         if (ret)
 982                 dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
 983 }
 984
 985 static int virtio_ccw_probe(struct ccw_device *cdev)
 986 {
 987         cdev->handler = virtio_ccw_int_handler;
 988
 989         if (virtio_ccw_check_autoonline(cdev))
 990                 async_schedule(virtio_ccw_auto_online, cdev);
 991         return 0;
 992 }
 993
 994 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
 995 {
 996         unsigned long flags;
 997         struct virtio_ccw_device *vcdev;
 998
 999         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1000         vcdev = dev_get_drvdata(&cdev->dev);
1001         if (!vcdev || vcdev->going_away) {
1002                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1003                 return NULL;
1004         }
1005         vcdev->going_away = true;
1006         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1007         return vcdev;
1008 }
1009
1010 static void virtio_ccw_remove(struct ccw_device *cdev)
1011 {
1012         unsigned long flags;
1013         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1014
1015         if (vcdev && cdev->online) {
1016                 if (vcdev->device_lost)
1017                         virtio_break_device(&vcdev->vdev);
1018                 unregister_virtio_device(&vcdev->vdev);
1019                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1020                 dev_set_drvdata(&cdev->dev, NULL);
1021                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1022         }
1023         cdev->handler = NULL;
1024 }
1025
1026 static int virtio_ccw_offline(struct ccw_device *cdev)
1027 {
1028         unsigned long flags;
1029         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1030
1031         if (!vcdev)
1032                 return 0;
1033         if (vcdev->device_lost)
1034                 virtio_break_device(&vcdev->vdev);
1035         unregister_virtio_device(&vcdev->vdev);
1036         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1037         dev_set_drvdata(&cdev->dev, NULL);
1038         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1039         return 0;
1040 }
1041
1042
1043 static int virtio_ccw_online(struct ccw_device *cdev)
1044 {
1045         int ret;
1046         struct virtio_ccw_device *vcdev;
1047         unsigned long flags;
1048
1049         vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1050         if (!vcdev) {
1051                 dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1052                 ret = -ENOMEM;
1053                 goto out_free;
1054         }
1055         vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1056                                    GFP_DMA | GFP_KERNEL);
1057         if (!vcdev->config_block) {
1058                 ret = -ENOMEM;
1059                 goto out_free;
1060         }
1061         vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1062         if (!vcdev->status) {
1063                 ret = -ENOMEM;
1064                 goto out_free;
1065         }
1066
1067         vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1068
1069         vcdev->vdev.dev.parent = &cdev->dev;
1070         vcdev->vdev.dev.release = virtio_ccw_release_dev;
1071         vcdev->vdev.config = &virtio_ccw_config_ops;
1072         vcdev->cdev = cdev;
1073         init_waitqueue_head(&vcdev->wait_q);
1074         INIT_LIST_HEAD(&vcdev->virtqueues);
1075         spin_lock_init(&vcdev->lock);
1076
1077         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1078         dev_set_drvdata(&cdev->dev, vcdev);
1079         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1080         vcdev->vdev.id.vendor = cdev->id.cu_type;
1081         vcdev->vdev.id.device = cdev->id.cu_model;
1082         ret = register_virtio_device(&vcdev->vdev);
1083         if (ret) {
1084                 dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1085                          ret);
1086                 goto out_put;
1087         }
1088         return 0;
1089 out_put:
1090         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1091         dev_set_drvdata(&cdev->dev, NULL);
1092         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1093         put_device(&vcdev->vdev.dev);
1094         return ret;
1095 out_free:
1096         if (vcdev) {
1097                 kfree(vcdev->status);
1098                 kfree(vcdev->config_block);
1099         }
1100         kfree(vcdev);
1101         return ret;
1102 }
1103
1104 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1105 {
1106         int rc;
1107         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1108
1109         /*
1110          * Make sure vcdev is set
1111          * i.e. set_offline/remove callback not already running
1112          */
1113         if (!vcdev)
1114                 return NOTIFY_DONE;
1115
1116         switch (event) {
1117         case CIO_GONE:
1118                 vcdev->device_lost = true;
1119                 rc = NOTIFY_DONE;
1120                 break;
1121         default:
1122                 rc = NOTIFY_DONE;
1123                 break;
1124         }
1125         return rc;
1126 }
1127
1128 static struct ccw_device_id virtio_ids[] = {
1129         { CCW_DEVICE(0x3832, 0) },
1130         {},
1131 };
1132 MODULE_DEVICE_TABLE(ccw, virtio_ids);
1133
1134 static struct ccw_driver virtio_ccw_driver = {
1135         .driver = {
1136                 .owner = THIS_MODULE,
1137                 .name = "virtio_ccw",
1138         },
1139         .ids = virtio_ids,
1140         .probe = virtio_ccw_probe,
1141         .remove = virtio_ccw_remove,
1142         .set_offline = virtio_ccw_offline,
1143         .set_online = virtio_ccw_online,
1144         .notify = virtio_ccw_cio_notify,
1145         .int_class = IRQIO_VIR,
1146 };
1147
1148 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1149                            int max_digit, int max_val)
1150 {
1151         int diff;
1152
1153         diff = 0;
1154         *val = 0;
1155
1156         while (diff <= max_digit) {
1157                 int value = hex_to_bin(**cp);
1158
1159                 if (value < 0)
1160                         break;
1161                 *val = *val * 16 + value;
1162                 (*cp)++;
1163                 diff++;
1164         }
1165
1166         if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1167                 return 1;
1168
1169         return 0;
1170 }
1171
1172 static int __init parse_busid(char *str, unsigned int *cssid,
1173                               unsigned int *ssid, unsigned int *devno)
1174 {
1175         char *str_work;
1176         int rc, ret;
1177
1178         rc = 1;
1179
1180         if (*str == '\0')
1181                 goto out;
1182
1183         str_work = str;
1184         ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1185         if (ret || (str_work[0] != '.'))
1186                 goto out;
1187         str_work++;
1188         ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1189         if (ret || (str_work[0] != '.'))
1190                 goto out;
1191         str_work++;
1192         ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1193         if (ret || (str_work[0] != '\0'))
1194                 goto out;
1195
1196         rc = 0;
1197 out:
1198         return rc;
1199 }
1200
1201 static void __init no_auto_parse(void)
1202 {
1203         unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1204         char *parm, *str;
1205         int rc;
1206
1207         str = no_auto;
1208         while ((parm = strsep(&str, ","))) {
1209                 rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1210                                  &from_ssid, &from);
1211                 if (rc)
1212                         continue;
1213                 if (parm != NULL) {
1214                         rc = parse_busid(parm, &to_cssid,
1215                                          &to_ssid, &to);
1216                         if ((from_ssid > to_ssid) ||
1217                             ((from_ssid == to_ssid) && (from > to)))
1218                                 rc = -EINVAL;
1219                 } else {
1220                         to_cssid = from_cssid;
1221                         to_ssid = from_ssid;
1222                         to = from;
1223                 }
1224                 if (rc)
1225                         continue;
1226                 while ((from_ssid < to_ssid) ||
1227                        ((from_ssid == to_ssid) && (from <= to))) {
1228                         set_bit(from, devs_no_auto[from_ssid]);
1229                         from++;
1230                         if (from > __MAX_SUBCHANNEL) {
1231                                 from_ssid++;
1232                                 from = 0;
1233                         }
1234                 }
1235         }
1236 }
1237
1238 static int __init virtio_ccw_init(void)
1239 {
1240         /* parse no_auto string before we do anything further */
1241         no_auto_parse();
1242         return ccw_driver_register(&virtio_ccw_driver);
1243 }
1244 module_init(virtio_ccw_init);
1245
1246 static void __exit virtio_ccw_exit(void)
1247 {
1248         int i;
1249
1250         ccw_driver_unregister(&virtio_ccw_driver);
1251         for (i = 0; i < MAX_AIRQ_AREAS; i++)
1252                 destroy_airq_info(airq_areas[i]);
1253 }
1254 module_exit(virtio_ccw_exit);