drivers/s390/virtio/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/moduleparam.h>
  28 #include <linux/io.h>
  29 #include <linux/kvm_para.h>
  30 #include <linux/notifier.h>
  31 #include <asm/diag.h>
  32 #include <asm/setup.h>
  33 #include <asm/irq.h>
  34 #include <asm/cio.h>
  35 #include <asm/ccwdev.h>
  36 #include <asm/virtio-ccw.h>
  37 #include <asm/isc.h>
  38 #include <asm/airq.h>
  39
  40 /*
  41  * virtio related functions
  42  */
  43
  44 struct vq_config_block {
  45         __u16 index;
  46         __u16 num;
  47 } __packed;
  48
  49 #define VIRTIO_CCW_CONFIG_SIZE 0x100
  50 /* same as PCI config space size, should be enough for all drivers */
  51
  52 struct virtio_ccw_device {
  53         struct virtio_device vdev;
  54         __u8 *status;
  55         __u8 config[VIRTIO_CCW_CONFIG_SIZE];
  56         struct ccw_device *cdev;
  57         __u32 curr_io;
  58         int err;
  59         unsigned int revision; /* Transport revision */
  60         wait_queue_head_t wait_q;
  61         spinlock_t lock;
  62         struct list_head virtqueues;
  63         unsigned long indicators;
  64         unsigned long indicators2;
  65         struct vq_config_block *config_block;
  66         bool is_thinint;
  67         bool going_away;
  68         bool device_lost;
  69         unsigned int config_ready;
  70         void *airq_info;
  71 };
  72
  73 struct vq_info_block_legacy {
  74         __u64 queue;
  75         __u32 align;
  76         __u16 index;
  77         __u16 num;
  78 } __packed;
  79
  80 struct vq_info_block {
  81         __u64 desc;
  82         __u32 res0;
  83         __u16 index;
  84         __u16 num;
  85         __u64 avail;
  86         __u64 used;
  87 } __packed;
  88
  89 struct virtio_feature_desc {
  90         __le32 features;
  91         __u8 index;
  92 } __packed;
  93
  94 struct virtio_thinint_area {
  95         unsigned long summary_indicator;
  96         unsigned long indicator;
  97         u64 bit_nr;
  98         u8 isc;
  99 } __packed;
 100
 101 struct virtio_rev_info {
 102         __u16 revision;
 103         __u16 length;
 104         __u8 data[];
 105 };
 106
 107 /* the highest virtio-ccw revision we support */
 108 #define VIRTIO_CCW_REV_MAX 1
 109
 110 struct virtio_ccw_vq_info {
 111         struct virtqueue *vq;
 112         int num;
 113         void *queue;
 114         union {
 115                 struct vq_info_block s;
 116                 struct vq_info_block_legacy l;
 117         } *info_block;
 118         int bit_nr;
 119         struct list_head node;
 120         long cookie;
 121 };
 122
 123 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
 124
 125 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
 126 #define MAX_AIRQ_AREAS 20
 127
 128 static int virtio_ccw_use_airq = 1;
 129
 130 struct airq_info {
 131         rwlock_t lock;
 132         u8 summary_indicator;
 133         struct airq_struct airq;
 134         struct airq_iv *aiv;
 135 };
 136 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
 137
 138 #define CCW_CMD_SET_VQ 0x13
 139 #define CCW_CMD_VDEV_RESET 0x33
 140 #define CCW_CMD_SET_IND 0x43
 141 #define CCW_CMD_SET_CONF_IND 0x53
 142 #define CCW_CMD_READ_FEAT 0x12
 143 #define CCW_CMD_WRITE_FEAT 0x11
 144 #define CCW_CMD_READ_CONF 0x22
 145 #define CCW_CMD_WRITE_CONF 0x21
 146 #define CCW_CMD_WRITE_STATUS 0x31
 147 #define CCW_CMD_READ_VQ_CONF 0x32
 148 #define CCW_CMD_READ_STATUS 0x72
 149 #define CCW_CMD_SET_IND_ADAPTER 0x73
 150 #define CCW_CMD_SET_VIRTIO_REV 0x83
 151
 152 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
 153 #define VIRTIO_CCW_DOING_RESET 0x00040000
 154 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
 155 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
 156 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
 157 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
 158 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
 159 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
 160 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
 161 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
 162 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
 163 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
 164 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
 165 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
 166
 167 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
 168 {
 169         return container_of(vdev, struct virtio_ccw_device, vdev);
 170 }
 171
 172 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
 173 {
 174         unsigned long i, flags;
 175
 176         write_lock_irqsave(&info->lock, flags);
 177         for (i = 0; i < airq_iv_end(info->aiv); i++) {
 178                 if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
 179                         airq_iv_free_bit(info->aiv, i);
 180                         airq_iv_set_ptr(info->aiv, i, 0);
 181                         break;
 182                 }
 183         }
 184         write_unlock_irqrestore(&info->lock, flags);
 185 }
 186
 187 static void virtio_airq_handler(struct airq_struct *airq)
 188 {
 189         struct airq_info *info = container_of(airq, struct airq_info, airq);
 190         unsigned long ai;
 191
 192         inc_irq_stat(IRQIO_VAI);
 193         read_lock(&info->lock);
 194         /* Walk through indicators field, summary indicator active. */
 195         for (ai = 0;;) {
 196                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 197                 if (ai == -1UL)
 198                         break;
 199                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 200         }
 201         info->summary_indicator = 0;
 202         smp_wmb();
 203         /* Walk through indicators field, summary indicator not active. */
 204         for (ai = 0;;) {
 205                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 206                 if (ai == -1UL)
 207                         break;
 208                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 209         }
 210         read_unlock(&info->lock);
 211 }
 212
 213 static struct airq_info *new_airq_info(void)
 214 {
 215         struct airq_info *info;
 216         int rc;
 217
 218         info = kzalloc(sizeof(*info), GFP_KERNEL);
 219         if (!info)
 220                 return NULL;
 221         rwlock_init(&info->lock);
 222         info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
 223         if (!info->aiv) {
 224                 kfree(info);
 225                 return NULL;
 226         }
 227         info->airq.handler = virtio_airq_handler;
 228         info->airq.lsi_ptr = &info->summary_indicator;
 229         info->airq.lsi_mask = 0xff;
 230         info->airq.isc = VIRTIO_AIRQ_ISC;
 231         rc = register_adapter_interrupt(&info->airq);
 232         if (rc) {
 233                 airq_iv_release(info->aiv);
 234                 kfree(info);
 235                 return NULL;
 236         }
 237         return info;
 238 }
 239
 240 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
 241                                         u64 *first, void **airq_info)
 242 {
 243         int i, j;
 244         struct airq_info *info;
 245         unsigned long indicator_addr = 0;
 246         unsigned long bit, flags;
 247
 248         for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
 249                 if (!airq_areas[i])
 250                         airq_areas[i] = new_airq_info();
 251                 info = airq_areas[i];
 252                 if (!info)
 253                         return 0;
 254                 write_lock_irqsave(&info->lock, flags);
 255                 bit = airq_iv_alloc(info->aiv, nvqs);
 256                 if (bit == -1UL) {
 257                         /* Not enough vacancies. */
 258                         write_unlock_irqrestore(&info->lock, flags);
 259                         continue;
 260                 }
 261                 *first = bit;
 262                 *airq_info = info;
 263                 indicator_addr = (unsigned long)info->aiv->vector;
 264                 for (j = 0; j < nvqs; j++) {
 265                         airq_iv_set_ptr(info->aiv, bit + j,
 266                                         (unsigned long)vqs[j]);
 267                 }
 268                 write_unlock_irqrestore(&info->lock, flags);
 269         }
 270         return indicator_addr;
 271 }
 272
 273 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
 274 {
 275         struct virtio_ccw_vq_info *info;
 276
 277         list_for_each_entry(info, &vcdev->virtqueues, node)
 278                 drop_airq_indicator(info->vq, vcdev->airq_info);
 279 }
 280
 281 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
 282 {
 283         unsigned long flags;
 284         __u32 ret;
 285
 286         spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 287         if (vcdev->err)
 288                 ret = 0;
 289         else
 290                 ret = vcdev->curr_io & flag;
 291         spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 292         return ret;
 293 }
 294
 295 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
 296                          struct ccw1 *ccw, __u32 intparm)
 297 {
 298         int ret;
 299         unsigned long flags;
 300         int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
 301
 302         do {
 303                 spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 304                 ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
 305                 if (!ret) {
 306                         if (!vcdev->curr_io)
 307                                 vcdev->err = 0;
 308                         vcdev->curr_io |= flag;
 309                 }
 310                 spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 311                 cpu_relax();
 312         } while (ret == -EBUSY);
 313         wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
 314         return ret ? ret : vcdev->err;
 315 }
 316
 317 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
 318                                       struct ccw1 *ccw)
 319 {
 320         int ret;
 321         unsigned long *indicatorp = NULL;
 322         struct virtio_thinint_area *thinint_area = NULL;
 323         struct airq_info *airq_info = vcdev->airq_info;
 324
 325         if (vcdev->is_thinint) {
 326                 thinint_area = kzalloc(sizeof(*thinint_area),
 327                                        GFP_DMA | GFP_KERNEL);
 328                 if (!thinint_area)
 329                         return;
 330                 thinint_area->summary_indicator =
 331                         (unsigned long) &airq_info->summary_indicator;
 332                 thinint_area->isc = VIRTIO_AIRQ_ISC;
 333                 ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 334                 ccw->count = sizeof(*thinint_area);
 335                 ccw->cda = (__u32)(unsigned long) thinint_area;
 336         } else {
 337                 /* payload is the address of the indicators */
 338                 indicatorp = kmalloc(sizeof(&vcdev->indicators),
 339                                      GFP_DMA | GFP_KERNEL);
 340                 if (!indicatorp)
 341                         return;
 342                 *indicatorp = 0;
 343                 ccw->cmd_code = CCW_CMD_SET_IND;
 344                 ccw->count = sizeof(&vcdev->indicators);
 345                 ccw->cda = (__u32)(unsigned long) indicatorp;
 346         }
 347         /* Deregister indicators from host. */
 348         vcdev->indicators = 0;
 349         ccw->flags = 0;
 350         ret = ccw_io_helper(vcdev, ccw,
 351                             vcdev->is_thinint ?
 352                             VIRTIO_CCW_DOING_SET_IND_ADAPTER :
 353                             VIRTIO_CCW_DOING_SET_IND);
 354         if (ret && (ret != -ENODEV))
 355                 dev_info(&vcdev->cdev->dev,
 356                          "Failed to deregister indicators (%d)\n", ret);
 357         else if (vcdev->is_thinint)
 358                 virtio_ccw_drop_indicators(vcdev);
 359         kfree(indicatorp);
 360         kfree(thinint_area);
 361 }
 362
 363 static inline long __do_kvm_notify(struct subchannel_id schid,
 364                                    unsigned long queue_index,
 365                                    long cookie)
 366 {
 367         register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
 368         register struct subchannel_id __schid asm("2") = schid;
 369         register unsigned long __index asm("3") = queue_index;
 370         register long __rc asm("2");
 371         register long __cookie asm("4") = cookie;
 372
 373         asm volatile ("diag 2,4,0x500\n"
 374                       : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
 375                       "d"(__cookie)
 376                       : "memory", "cc");
 377         return __rc;
 378 }
 379
 380 static inline long do_kvm_notify(struct subchannel_id schid,
 381                                  unsigned long queue_index,
 382                                  long cookie)
 383 {
 384         diag_stat_inc(DIAG_STAT_X500);
 385         return __do_kvm_notify(schid, queue_index, cookie);
 386 }
 387
 388 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
 389 {
 390         struct virtio_ccw_vq_info *info = vq->priv;
 391         struct virtio_ccw_device *vcdev;
 392         struct subchannel_id schid;
 393
 394         vcdev = to_vc_device(info->vq->vdev);
 395         ccw_device_get_schid(vcdev->cdev, &schid);
 396         info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
 397         if (info->cookie < 0)
 398                 return false;
 399         return true;
 400 }
 401
 402 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
 403                                    struct ccw1 *ccw, int index)
 404 {
 405         int ret;
 406
 407         vcdev->config_block->index = index;
 408         ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
 409         ccw->flags = 0;
 410         ccw->count = sizeof(struct vq_config_block);
 411         ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
 412         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
 413         if (ret)
 414                 return ret;
 415         return vcdev->config_block->num;
 416 }
 417
 418 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
 419 {
 420         struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
 421         struct virtio_ccw_vq_info *info = vq->priv;
 422         unsigned long flags;
 423         unsigned long size;
 424         int ret;
 425         unsigned int index = vq->index;
 426
 427         /* Remove from our list. */
 428         spin_lock_irqsave(&vcdev->lock, flags);
 429         list_del(&info->node);
 430         spin_unlock_irqrestore(&vcdev->lock, flags);
 431
 432         /* Release from host. */
 433         if (vcdev->revision == 0) {
 434                 info->info_block->l.queue = 0;
 435                 info->info_block->l.align = 0;
 436                 info->info_block->l.index = index;
 437                 info->info_block->l.num = 0;
 438                 ccw->count = sizeof(info->info_block->l);
 439         } else {
 440                 info->info_block->s.desc = 0;
 441                 info->info_block->s.index = index;
 442                 info->info_block->s.num = 0;
 443                 info->info_block->s.avail = 0;
 444                 info->info_block->s.used = 0;
 445                 ccw->count = sizeof(info->info_block->s);
 446         }
 447         ccw->cmd_code = CCW_CMD_SET_VQ;
 448         ccw->flags = 0;
 449         ccw->cda = (__u32)(unsigned long)(info->info_block);
 450         ret = ccw_io_helper(vcdev, ccw,
 451                             VIRTIO_CCW_DOING_SET_VQ | index);
 452         /*
 453          * -ENODEV isn't considered an error: The device is gone anyway.
 454          * This may happen on device detach.
 455          */
 456         if (ret && (ret != -ENODEV))
 457                 dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
 458                          ret, index);
 459
 460         vring_del_virtqueue(vq);
 461         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
 462         free_pages_exact(info->queue, size);
 463         kfree(info->info_block);
 464         kfree(info);
 465 }
 466
 467 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
 468 {
 469         struct virtqueue *vq, *n;
 470         struct ccw1 *ccw;
 471         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 472
 473         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 474         if (!ccw)
 475                 return;
 476
 477         virtio_ccw_drop_indicator(vcdev, ccw);
 478
 479         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 480                 virtio_ccw_del_vq(vq, ccw);
 481
 482         kfree(ccw);
 483 }
 484
 485 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
 486                                              int i, vq_callback_t *callback,
 487                                              const char *name, bool ctx,
 488                                              struct ccw1 *ccw)
 489 {
 490         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 491         int err;
 492         struct virtqueue *vq = NULL;
 493         struct virtio_ccw_vq_info *info;
 494         unsigned long size = 0; /* silence the compiler */
 495         unsigned long flags;
 496
 497         /* Allocate queue. */
 498         info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
 499         if (!info) {
 500                 dev_warn(&vcdev->cdev->dev, "no info\n");
 501                 err = -ENOMEM;
 502                 goto out_err;
 503         }
 504         info->info_block = kzalloc(sizeof(*info->info_block),
 505                                    GFP_DMA | GFP_KERNEL);
 506         if (!info->info_block) {
 507                 dev_warn(&vcdev->cdev->dev, "no info block\n");
 508                 err = -ENOMEM;
 509                 goto out_err;
 510         }
 511         info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
 512         if (info->num < 0) {
 513                 err = info->num;
 514                 goto out_err;
 515         }
 516         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
 517         info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
 518         if (info->queue == NULL) {
 519                 dev_warn(&vcdev->cdev->dev, "no queue\n");
 520                 err = -ENOMEM;
 521                 goto out_err;
 522         }
 523
 524         vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
 525                                  true, ctx, info->queue, virtio_ccw_kvm_notify,
 526                                  callback, name);
 527         if (!vq) {
 528                 /* For now, we fail if we can't get the requested size. */
 529                 dev_warn(&vcdev->cdev->dev, "no vq\n");
 530                 err = -ENOMEM;
 531                 goto out_err;
 532         }
 533
 534         /* Register it with the host. */
 535         if (vcdev->revision == 0) {
 536                 info->info_block->l.queue = (__u64)info->queue;
 537                 info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
 538                 info->info_block->l.index = i;
 539                 info->info_block->l.num = info->num;
 540                 ccw->count = sizeof(info->info_block->l);
 541         } else {
 542                 info->info_block->s.desc = (__u64)info->queue;
 543                 info->info_block->s.index = i;
 544                 info->info_block->s.num = info->num;
 545                 info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
 546                 info->info_block->s.used = (__u64)virtqueue_get_used(vq);
 547                 ccw->count = sizeof(info->info_block->s);
 548         }
 549         ccw->cmd_code = CCW_CMD_SET_VQ;
 550         ccw->flags = 0;
 551         ccw->cda = (__u32)(unsigned long)(info->info_block);
 552         err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
 553         if (err) {
 554                 dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
 555                 goto out_err;
 556         }
 557
 558         info->vq = vq;
 559         vq->priv = info;
 560
 561         /* Save it to our list. */
 562         spin_lock_irqsave(&vcdev->lock, flags);
 563         list_add(&info->node, &vcdev->virtqueues);
 564         spin_unlock_irqrestore(&vcdev->lock, flags);
 565
 566         return vq;
 567
 568 out_err:
 569         if (vq)
 570                 vring_del_virtqueue(vq);
 571         if (info) {
 572                 if (info->queue)
 573                         free_pages_exact(info->queue, size);
 574                 kfree(info->info_block);
 575         }
 576         kfree(info);
 577         return ERR_PTR(err);
 578 }
 579
 580 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
 581                                            struct virtqueue *vqs[], int nvqs,
 582                                            struct ccw1 *ccw)
 583 {
 584         int ret;
 585         struct virtio_thinint_area *thinint_area = NULL;
 586         struct airq_info *info;
 587
 588         thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
 589         if (!thinint_area) {
 590                 ret = -ENOMEM;
 591                 goto out;
 592         }
 593         /* Try to get an indicator. */
 594         thinint_area->indicator = get_airq_indicator(vqs, nvqs,
 595                                                      &thinint_area->bit_nr,
 596                                                      &vcdev->airq_info);
 597         if (!thinint_area->indicator) {
 598                 ret = -ENOSPC;
 599                 goto out;
 600         }
 601         info = vcdev->airq_info;
 602         thinint_area->summary_indicator =
 603                 (unsigned long) &info->summary_indicator;
 604         thinint_area->isc = VIRTIO_AIRQ_ISC;
 605         ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 606         ccw->flags = CCW_FLAG_SLI;
 607         ccw->count = sizeof(*thinint_area);
 608         ccw->cda = (__u32)(unsigned long)thinint_area;
 609         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
 610         if (ret) {
 611                 if (ret == -EOPNOTSUPP) {
 612                         /*
 613                          * The host does not support adapter interrupts
 614                          * for virtio-ccw, stop trying.
 615                          */
 616                         virtio_ccw_use_airq = 0;
 617                         pr_info("Adapter interrupts unsupported on host\n");
 618                 } else
 619                         dev_warn(&vcdev->cdev->dev,
 620                                  "enabling adapter interrupts = %d\n", ret);
 621                 virtio_ccw_drop_indicators(vcdev);
 622         }
 623 out:
 624         kfree(thinint_area);
 625         return ret;
 626 }
 627
 628 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 629                                struct virtqueue *vqs[],
 630                                vq_callback_t *callbacks[],
 631                                const char * const names[],
 632                                const bool *ctx,
 633                                struct irq_affinity *desc)
 634 {
 635         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 636         unsigned long *indicatorp = NULL;
 637         int ret, i;
 638         struct ccw1 *ccw;
 639
 640         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 641         if (!ccw)
 642                 return -ENOMEM;
 643
 644         for (i = 0; i < nvqs; ++i) {
 645                 vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
 646                                              ctx ? ctx[i] : false, ccw);
 647                 if (IS_ERR(vqs[i])) {
 648                         ret = PTR_ERR(vqs[i]);
 649                         vqs[i] = NULL;
 650                         goto out;
 651                 }
 652         }
 653         ret = -ENOMEM;
 654         /*
 655          * We need a data area under 2G to communicate. Our payload is
 656          * the address of the indicators.
 657         */
 658         indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
 659         if (!indicatorp)
 660                 goto out;
 661         *indicatorp = (unsigned long) &vcdev->indicators;
 662         if (vcdev->is_thinint) {
 663                 ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
 664                 if (ret)
 665                         /* no error, just fall back to legacy interrupts */
 666                         vcdev->is_thinint = false;
 667         }
 668         if (!vcdev->is_thinint) {
 669                 /* Register queue indicators with host. */
 670                 vcdev->indicators = 0;
 671                 ccw->cmd_code = CCW_CMD_SET_IND;
 672                 ccw->flags = 0;
 673                 ccw->count = sizeof(&vcdev->indicators);
 674                 ccw->cda = (__u32)(unsigned long) indicatorp;
 675                 ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
 676                 if (ret)
 677                         goto out;
 678         }
 679         /* Register indicators2 with host for config changes */
 680         *indicatorp = (unsigned long) &vcdev->indicators2;
 681         vcdev->indicators2 = 0;
 682         ccw->cmd_code = CCW_CMD_SET_CONF_IND;
 683         ccw->flags = 0;
 684         ccw->count = sizeof(&vcdev->indicators2);
 685         ccw->cda = (__u32)(unsigned long) indicatorp;
 686         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
 687         if (ret)
 688                 goto out;
 689
 690         kfree(indicatorp);
 691         kfree(ccw);
 692         return 0;
 693 out:
 694         kfree(indicatorp);
 695         kfree(ccw);
 696         virtio_ccw_del_vqs(vdev);
 697         return ret;
 698 }
 699
 700 static void virtio_ccw_reset(struct virtio_device *vdev)
 701 {
 702         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 703         struct ccw1 *ccw;
 704
 705         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 706         if (!ccw)
 707                 return;
 708
 709         /* Zero status bits. */
 710         *vcdev->status = 0;
 711
 712         /* Send a reset ccw on device. */
 713         ccw->cmd_code = CCW_CMD_VDEV_RESET;
 714         ccw->flags = 0;
 715         ccw->count = 0;
 716         ccw->cda = 0;
 717         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
 718         kfree(ccw);
 719 }
 720
 721 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
 722 {
 723         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 724         struct virtio_feature_desc *features;
 725         int ret;
 726         u64 rc;
 727         struct ccw1 *ccw;
 728
 729         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 730         if (!ccw)
 731                 return 0;
 732
 733         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
 734         if (!features) {
 735                 rc = 0;
 736                 goto out_free;
 737         }
 738         /* Read the feature bits from the host. */
 739         features->index = 0;
 740         ccw->cmd_code = CCW_CMD_READ_FEAT;
 741         ccw->flags = 0;
 742         ccw->count = sizeof(*features);
 743         ccw->cda = (__u32)(unsigned long)features;
 744         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 745         if (ret) {
 746                 rc = 0;
 747                 goto out_free;
 748         }
 749
 750         rc = le32_to_cpu(features->features);
 751
 752         if (vcdev->revision == 0)
 753                 goto out_free;
 754
 755         /* Read second half of the feature bits from the host. */
 756         features->index = 1;
 757         ccw->cmd_code = CCW_CMD_READ_FEAT;
 758         ccw->flags = 0;
 759         ccw->count = sizeof(*features);
 760         ccw->cda = (__u32)(unsigned long)features;
 761         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 762         if (ret == 0)
 763                 rc |= (u64)le32_to_cpu(features->features) << 32;
 764
 765 out_free:
 766         kfree(features);
 767         kfree(ccw);
 768         return rc;
 769 }
 770
 771 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
 772 {
 773         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 774         struct virtio_feature_desc *features;
 775         struct ccw1 *ccw;
 776         int ret;
 777
 778         if (vcdev->revision >= 1 &&
 779             !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
 780                 dev_err(&vdev->dev, "virtio: device uses revision 1 "
 781                         "but does not have VIRTIO_F_VERSION_1\n");
 782                 return -EINVAL;
 783         }
 784
 785         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 786         if (!ccw)
 787                 return -ENOMEM;
 788
 789         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
 790         if (!features) {
 791                 ret = -ENOMEM;
 792                 goto out_free;
 793         }
 794         /* Give virtio_ring a chance to accept features. */
 795         vring_transport_features(vdev);
 796
 797         features->index = 0;
 798         features->features = cpu_to_le32((u32)vdev->features);
 799         /* Write the first half of the feature bits to the host. */
 800         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 801         ccw->flags = 0;
 802         ccw->count = sizeof(*features);
 803         ccw->cda = (__u32)(unsigned long)features;
 804         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 805         if (ret)
 806                 goto out_free;
 807
 808         if (vcdev->revision == 0)
 809                 goto out_free;
 810
 811         features->index = 1;
 812         features->features = cpu_to_le32(vdev->features >> 32);
 813         /* Write the second half of the feature bits to the host. */
 814         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 815         ccw->flags = 0;
 816         ccw->count = sizeof(*features);
 817         ccw->cda = (__u32)(unsigned long)features;
 818         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 819
 820 out_free:
 821         kfree(features);
 822         kfree(ccw);
 823
 824         return ret;
 825 }
 826
 827 static void virtio_ccw_get_config(struct virtio_device *vdev,
 828                                   unsigned int offset, void *buf, unsigned len)
 829 {
 830         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 831         int ret;
 832         struct ccw1 *ccw;
 833         void *config_area;
 834
 835         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 836         if (!ccw)
 837                 return;
 838
 839         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
 840         if (!config_area)
 841                 goto out_free;
 842
 843         /* Read the config area from the host. */
 844         ccw->cmd_code = CCW_CMD_READ_CONF;
 845         ccw->flags = 0;
 846         ccw->count = offset + len;
 847         ccw->cda = (__u32)(unsigned long)config_area;
 848         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
 849         if (ret)
 850                 goto out_free;
 851
 852         memcpy(vcdev->config, config_area, offset + len);
 853         if (buf)
 854                 memcpy(buf, &vcdev->config[offset], len);
 855         if (vcdev->config_ready < offset + len)
 856                 vcdev->config_ready = offset + len;
 857
 858 out_free:
 859         kfree(config_area);
 860         kfree(ccw);
 861 }
 862
 863 static void virtio_ccw_set_config(struct virtio_device *vdev,
 864                                   unsigned int offset, const void *buf,
 865                                   unsigned len)
 866 {
 867         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 868         struct ccw1 *ccw;
 869         void *config_area;
 870
 871         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 872         if (!ccw)
 873                 return;
 874
 875         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
 876         if (!config_area)
 877                 goto out_free;
 878
 879         /* Make sure we don't overwrite fields. */
 880         if (vcdev->config_ready < offset)
 881                 virtio_ccw_get_config(vdev, 0, NULL, offset);
 882         memcpy(&vcdev->config[offset], buf, len);
 883         /* Write the config area to the host. */
 884         memcpy(config_area, vcdev->config, sizeof(vcdev->config));
 885         ccw->cmd_code = CCW_CMD_WRITE_CONF;
 886         ccw->flags = 0;
 887         ccw->count = offset + len;
 888         ccw->cda = (__u32)(unsigned long)config_area;
 889         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
 890
 891 out_free:
 892         kfree(config_area);
 893         kfree(ccw);
 894 }
 895
 896 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
 897 {
 898         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 899         u8 old_status = *vcdev->status;
 900         struct ccw1 *ccw;
 901
 902         if (vcdev->revision < 1)
 903                 return *vcdev->status;
 904
 905         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 906         if (!ccw)
 907                 return old_status;
 908
 909         ccw->cmd_code = CCW_CMD_READ_STATUS;
 910         ccw->flags = 0;
 911         ccw->count = sizeof(*vcdev->status);
 912         ccw->cda = (__u32)(unsigned long)vcdev->status;
 913         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
 914 /*
 915  * If the channel program failed (should only happen if the device
 916  * was hotunplugged, and then we clean up via the machine check
 917  * handler anyway), vcdev->status was not overwritten and we just
 918  * return the old status, which is fine.
 919 */
 920         kfree(ccw);
 921
 922         return *vcdev->status;
 923 }
 924
 925 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 926 {
 927         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 928         u8 old_status = *vcdev->status;
 929         struct ccw1 *ccw;
 930         int ret;
 931
 932         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 933         if (!ccw)
 934                 return;
 935
 936         /* Write the status to the host. */
 937         *vcdev->status = status;
 938         ccw->cmd_code = CCW_CMD_WRITE_STATUS;
 939         ccw->flags = 0;
 940         ccw->count = sizeof(status);
 941         ccw->cda = (__u32)(unsigned long)vcdev->status;
 942         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
 943         /* Write failed? We assume status is unchanged. */
 944         if (ret)
 945                 *vcdev->status = old_status;
 946         kfree(ccw);
 947 }
 948
 949 static const struct virtio_config_ops virtio_ccw_config_ops = {
 950         .get_features = virtio_ccw_get_features,
 951         .finalize_features = virtio_ccw_finalize_features,
 952         .get = virtio_ccw_get_config,
 953         .set = virtio_ccw_set_config,
 954         .get_status = virtio_ccw_get_status,
 955         .set_status = virtio_ccw_set_status,
 956         .reset = virtio_ccw_reset,
 957         .find_vqs = virtio_ccw_find_vqs,
 958         .del_vqs = virtio_ccw_del_vqs,
 959 };
 960
 961
 962 /*
 963  * ccw bus driver related functions
 964  */
 965
 966 static void virtio_ccw_release_dev(struct device *_d)
 967 {
 968         struct virtio_device *dev = dev_to_virtio(_d);
 969         struct virtio_ccw_device *vcdev = to_vc_device(dev);
 970
 971         kfree(vcdev->status);
 972         kfree(vcdev->config_block);
 973         kfree(vcdev);
 974 }
 975
 976 static int irb_is_error(struct irb *irb)
 977 {
 978         if (scsw_cstat(&irb->scsw) != 0)
 979                 return 1;
 980         if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
 981                 return 1;
 982         if (scsw_cc(&irb->scsw) != 0)
 983                 return 1;
 984         return 0;
 985 }
 986
 987 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
 988                                               int index)
 989 {
 990         struct virtio_ccw_vq_info *info;
 991         unsigned long flags;
 992         struct virtqueue *vq;
 993
 994         vq = NULL;
 995         spin_lock_irqsave(&vcdev->lock, flags);
 996         list_for_each_entry(info, &vcdev->virtqueues, node) {
 997                 if (info->vq->index == index) {
 998                         vq = info->vq;
 999                         break;
1000                 }
1001         }
1002         spin_unlock_irqrestore(&vcdev->lock, flags);
1003         return vq;
1004 }
1005
1006 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1007                                       __u32 activity)
1008 {
1009         if (vcdev->curr_io & activity) {
1010                 switch (activity) {
1011                 case VIRTIO_CCW_DOING_READ_FEAT:
1012                 case VIRTIO_CCW_DOING_WRITE_FEAT:
1013                 case VIRTIO_CCW_DOING_READ_CONFIG:
1014                 case VIRTIO_CCW_DOING_WRITE_CONFIG:
1015                 case VIRTIO_CCW_DOING_WRITE_STATUS:
1016                 case VIRTIO_CCW_DOING_READ_STATUS:
1017                 case VIRTIO_CCW_DOING_SET_VQ:
1018                 case VIRTIO_CCW_DOING_SET_IND:
1019                 case VIRTIO_CCW_DOING_SET_CONF_IND:
1020                 case VIRTIO_CCW_DOING_RESET:
1021                 case VIRTIO_CCW_DOING_READ_VQ_CONF:
1022                 case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1023                 case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1024                         vcdev->curr_io &= ~activity;
1025                         wake_up(&vcdev->wait_q);
1026                         break;
1027                 default:
1028                         /* don't know what to do... */
1029                         dev_warn(&vcdev->cdev->dev,
1030                                  "Suspicious activity '%08x'\n", activity);
1031                         WARN_ON(1);
1032                         break;
1033                 }
1034         }
1035 }
1036
1037 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1038                                    unsigned long intparm,
1039                                    struct irb *irb)
1040 {
1041         __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1042         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1043         int i;
1044         struct virtqueue *vq;
1045
1046         if (!vcdev)
1047                 return;
1048         if (IS_ERR(irb)) {
1049                 vcdev->err = PTR_ERR(irb);
1050                 virtio_ccw_check_activity(vcdev, activity);
1051                 /* Don't poke around indicators, something's wrong. */
1052                 return;
1053         }
1054         /* Check if it's a notification from the host. */
1055         if ((intparm == 0) &&
1056             (scsw_stctl(&irb->scsw) ==
1057              (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1058                 /* OK */
1059         }
1060         if (irb_is_error(irb)) {
1061                 /* Command reject? */
1062                 if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1063                     (irb->ecw[0] & SNS0_CMD_REJECT))
1064                         vcdev->err = -EOPNOTSUPP;
1065                 else
1066                         /* Map everything else to -EIO. */
1067                         vcdev->err = -EIO;
1068         }
1069         virtio_ccw_check_activity(vcdev, activity);
1070         for_each_set_bit(i, &vcdev->indicators,
1071                          sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1072                 /* The bit clear must happen before the vring kick. */
1073                 clear_bit(i, &vcdev->indicators);
1074                 barrier();
1075                 vq = virtio_ccw_vq_by_ind(vcdev, i);
1076                 vring_interrupt(0, vq);
1077         }
1078         if (test_bit(0, &vcdev->indicators2)) {
1079                 virtio_config_changed(&vcdev->vdev);
1080                 clear_bit(0, &vcdev->indicators2);
1081         }
1082 }
1083
1084 /*
1085  * We usually want to autoonline all devices, but give the admin
1086  * a way to exempt devices from this.
1087  */
1088 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1089                      (8*sizeof(long)))
1090 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1091
1092 static char *no_auto = "";
1093
1094 module_param(no_auto, charp, 0444);
1095 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1096
1097 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1098 {
1099         struct ccw_dev_id id;
1100
1101         ccw_device_get_id(cdev, &id);
1102         if (test_bit(id.devno, devs_no_auto[id.ssid]))
1103                 return 0;
1104         return 1;
1105 }
1106
1107 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1108 {
1109         struct ccw_device *cdev = data;
1110         int ret;
1111
1112         ret = ccw_device_set_online(cdev);
1113         if (ret)
1114                 dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1115 }
1116
1117 static int virtio_ccw_probe(struct ccw_device *cdev)
1118 {
1119         cdev->handler = virtio_ccw_int_handler;
1120
1121         if (virtio_ccw_check_autoonline(cdev))
1122                 async_schedule(virtio_ccw_auto_online, cdev);
1123         return 0;
1124 }
1125
1126 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1127 {
1128         unsigned long flags;
1129         struct virtio_ccw_device *vcdev;
1130
1131         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1132         vcdev = dev_get_drvdata(&cdev->dev);
1133         if (!vcdev || vcdev->going_away) {
1134                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1135                 return NULL;
1136         }
1137         vcdev->going_away = true;
1138         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1139         return vcdev;
1140 }
1141
1142 static void virtio_ccw_remove(struct ccw_device *cdev)
1143 {
1144         unsigned long flags;
1145         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1146
1147         if (vcdev && cdev->online) {
1148                 if (vcdev->device_lost)
1149                         virtio_break_device(&vcdev->vdev);
1150                 unregister_virtio_device(&vcdev->vdev);
1151                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1152                 dev_set_drvdata(&cdev->dev, NULL);
1153                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1154         }
1155         cdev->handler = NULL;
1156 }
1157
1158 static int virtio_ccw_offline(struct ccw_device *cdev)
1159 {
1160         unsigned long flags;
1161         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1162
1163         if (!vcdev)
1164                 return 0;
1165         if (vcdev->device_lost)
1166                 virtio_break_device(&vcdev->vdev);
1167         unregister_virtio_device(&vcdev->vdev);
1168         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1169         dev_set_drvdata(&cdev->dev, NULL);
1170         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1171         return 0;
1172 }
1173
1174 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1175 {
1176         struct virtio_rev_info *rev;
1177         struct ccw1 *ccw;
1178         int ret;
1179
1180         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1181         if (!ccw)
1182                 return -ENOMEM;
1183         rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1184         if (!rev) {
1185                 kfree(ccw);
1186                 return -ENOMEM;
1187         }
1188
1189         /* Set transport revision */
1190         ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1191         ccw->flags = 0;
1192         ccw->count = sizeof(*rev);
1193         ccw->cda = (__u32)(unsigned long)rev;
1194
1195         vcdev->revision = VIRTIO_CCW_REV_MAX;
1196         do {
1197                 rev->revision = vcdev->revision;
1198                 /* none of our supported revisions carry payload */
1199                 rev->length = 0;
1200                 ret = ccw_io_helper(vcdev, ccw,
1201                                     VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1202                 if (ret == -EOPNOTSUPP) {
1203                         if (vcdev->revision == 0)
1204                                 /*
1205                                  * The host device does not support setting
1206                                  * the revision: let's operate it in legacy
1207                                  * mode.
1208                                  */
1209                                 ret = 0;
1210                         else
1211                                 vcdev->revision--;
1212                 }
1213         } while (ret == -EOPNOTSUPP);
1214
1215         kfree(ccw);
1216         kfree(rev);
1217         return ret;
1218 }
1219
1220 static int virtio_ccw_online(struct ccw_device *cdev)
1221 {
1222         int ret;
1223         struct virtio_ccw_device *vcdev;
1224         unsigned long flags;
1225
1226         vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1227         if (!vcdev) {
1228                 dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1229                 ret = -ENOMEM;
1230                 goto out_free;
1231         }
1232         vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1233                                    GFP_DMA | GFP_KERNEL);
1234         if (!vcdev->config_block) {
1235                 ret = -ENOMEM;
1236                 goto out_free;
1237         }
1238         vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1239         if (!vcdev->status) {
1240                 ret = -ENOMEM;
1241                 goto out_free;
1242         }
1243
1244         vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1245
1246         vcdev->vdev.dev.parent = &cdev->dev;
1247         vcdev->vdev.dev.release = virtio_ccw_release_dev;
1248         vcdev->vdev.config = &virtio_ccw_config_ops;
1249         vcdev->cdev = cdev;
1250         init_waitqueue_head(&vcdev->wait_q);
1251         INIT_LIST_HEAD(&vcdev->virtqueues);
1252         spin_lock_init(&vcdev->lock);
1253
1254         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1255         dev_set_drvdata(&cdev->dev, vcdev);
1256         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1257         vcdev->vdev.id.vendor = cdev->id.cu_type;
1258         vcdev->vdev.id.device = cdev->id.cu_model;
1259
1260         ret = virtio_ccw_set_transport_rev(vcdev);
1261         if (ret)
1262                 goto out_free;
1263
1264         ret = register_virtio_device(&vcdev->vdev);
1265         if (ret) {
1266                 dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1267                          ret);
1268                 goto out_put;
1269         }
1270         return 0;
1271 out_put:
1272         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1273         dev_set_drvdata(&cdev->dev, NULL);
1274         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1275         put_device(&vcdev->vdev.dev);
1276         return ret;
1277 out_free:
1278         if (vcdev) {
1279                 kfree(vcdev->status);
1280                 kfree(vcdev->config_block);
1281         }
1282         kfree(vcdev);
1283         return ret;
1284 }
1285
1286 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1287 {
1288         int rc;
1289         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1290
1291         /*
1292          * Make sure vcdev is set
1293          * i.e. set_offline/remove callback not already running
1294          */
1295         if (!vcdev)
1296                 return NOTIFY_DONE;
1297
1298         switch (event) {
1299         case CIO_GONE:
1300                 vcdev->device_lost = true;
1301                 rc = NOTIFY_DONE;
1302                 break;
1303         default:
1304                 rc = NOTIFY_DONE;
1305                 break;
1306         }
1307         return rc;
1308 }
1309
1310 static struct ccw_device_id virtio_ids[] = {
1311         { CCW_DEVICE(0x3832, 0) },
1312         {},
1313 };
1314
1315 static struct ccw_driver virtio_ccw_driver = {
1316         .driver = {
1317                 .owner = THIS_MODULE,
1318                 .name = "virtio_ccw",
1319         },
1320         .ids = virtio_ids,
1321         .probe = virtio_ccw_probe,
1322         .remove = virtio_ccw_remove,
1323         .set_offline = virtio_ccw_offline,
1324         .set_online = virtio_ccw_online,
1325         .notify = virtio_ccw_cio_notify,
1326         .int_class = IRQIO_VIR,
1327 };
1328
1329 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1330                            int max_digit, int max_val)
1331 {
1332         int diff;
1333
1334         diff = 0;
1335         *val = 0;
1336
1337         while (diff <= max_digit) {
1338                 int value = hex_to_bin(**cp);
1339
1340                 if (value < 0)
1341                         break;
1342                 *val = *val * 16 + value;
1343                 (*cp)++;
1344                 diff++;
1345         }
1346
1347         if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1348                 return 1;
1349
1350         return 0;
1351 }
1352
1353 static int __init parse_busid(char *str, unsigned int *cssid,
1354                               unsigned int *ssid, unsigned int *devno)
1355 {
1356         char *str_work;
1357         int rc, ret;
1358
1359         rc = 1;
1360
1361         if (*str == '\0')
1362                 goto out;
1363
1364         str_work = str;
1365         ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1366         if (ret || (str_work[0] != '.'))
1367                 goto out;
1368         str_work++;
1369         ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1370         if (ret || (str_work[0] != '.'))
1371                 goto out;
1372         str_work++;
1373         ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1374         if (ret || (str_work[0] != '\0'))
1375                 goto out;
1376
1377         rc = 0;
1378 out:
1379         return rc;
1380 }
1381
1382 static void __init no_auto_parse(void)
1383 {
1384         unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1385         char *parm, *str;
1386         int rc;
1387
1388         str = no_auto;
1389         while ((parm = strsep(&str, ","))) {
1390                 rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1391                                  &from_ssid, &from);
1392                 if (rc)
1393                         continue;
1394                 if (parm != NULL) {
1395                         rc = parse_busid(parm, &to_cssid,
1396                                          &to_ssid, &to);
1397                         if ((from_ssid > to_ssid) ||
1398                             ((from_ssid == to_ssid) && (from > to)))
1399                                 rc = -EINVAL;
1400                 } else {
1401                         to_cssid = from_cssid;
1402                         to_ssid = from_ssid;
1403                         to = from;
1404                 }
1405                 if (rc)
1406                         continue;
1407                 while ((from_ssid < to_ssid) ||
1408                        ((from_ssid == to_ssid) && (from <= to))) {
1409                         set_bit(from, devs_no_auto[from_ssid]);
1410                         from++;
1411                         if (from > __MAX_SUBCHANNEL) {
1412                                 from_ssid++;
1413                                 from = 0;
1414                         }
1415                 }
1416         }
1417 }
1418
1419 static int __init virtio_ccw_init(void)
1420 {
1421         /* parse no_auto string before we do anything further */
1422         no_auto_parse();
1423         return ccw_driver_register(&virtio_ccw_driver);
1424 }
1425 device_initcall(virtio_ccw_init);