drivers/s390/virtio/virtio_ccw.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * ccw based virtio transport
   4  *
   5  * Copyright IBM Corp. 2012, 2014
   6  *
   7  *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
   8  */
   9
  10 #include <linux/kernel_stat.h>
  11 #include <linux/init.h>
  12 #include <linux/bootmem.h>
  13 #include <linux/err.h>
  14 #include <linux/virtio.h>
  15 #include <linux/virtio_config.h>
  16 #include <linux/slab.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/virtio_ring.h>
  19 #include <linux/pfn.h>
  20 #include <linux/async.h>
  21 #include <linux/wait.h>
  22 #include <linux/list.h>
  23 #include <linux/bitops.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/io.h>
  26 #include <linux/kvm_para.h>
  27 #include <linux/notifier.h>
  28 #include <asm/diag.h>
  29 #include <asm/setup.h>
  30 #include <asm/irq.h>
  31 #include <asm/cio.h>
  32 #include <asm/ccwdev.h>
  33 #include <asm/virtio-ccw.h>
  34 #include <asm/isc.h>
  35 #include <asm/airq.h>
  36
  37 /*
  38  * virtio related functions
  39  */
  40
  41 struct vq_config_block {
  42         __u16 index;
  43         __u16 num;
  44 } __packed;
  45
  46 #define VIRTIO_CCW_CONFIG_SIZE 0x100
  47 /* same as PCI config space size, should be enough for all drivers */
  48
  49 struct virtio_ccw_device {
  50         struct virtio_device vdev;
  51         __u8 *status;
  52         __u8 config[VIRTIO_CCW_CONFIG_SIZE];
  53         struct ccw_device *cdev;
  54         __u32 curr_io;
  55         int err;
  56         unsigned int revision; /* Transport revision */
  57         wait_queue_head_t wait_q;
  58         spinlock_t lock;
  59         struct list_head virtqueues;
  60         unsigned long indicators;
  61         unsigned long indicators2;
  62         struct vq_config_block *config_block;
  63         bool is_thinint;
  64         bool going_away;
  65         bool device_lost;
  66         unsigned int config_ready;
  67         void *airq_info;
  68 };
  69
  70 struct vq_info_block_legacy {
  71         __u64 queue;
  72         __u32 align;
  73         __u16 index;
  74         __u16 num;
  75 } __packed;
  76
  77 struct vq_info_block {
  78         __u64 desc;
  79         __u32 res0;
  80         __u16 index;
  81         __u16 num;
  82         __u64 avail;
  83         __u64 used;
  84 } __packed;
  85
  86 struct virtio_feature_desc {
  87         __le32 features;
  88         __u8 index;
  89 } __packed;
  90
  91 struct virtio_thinint_area {
  92         unsigned long summary_indicator;
  93         unsigned long indicator;
  94         u64 bit_nr;
  95         u8 isc;
  96 } __packed;
  97
  98 struct virtio_rev_info {
  99         __u16 revision;
 100         __u16 length;
 101         __u8 data[];
 102 };
 103
 104 /* the highest virtio-ccw revision we support */
 105 #define VIRTIO_CCW_REV_MAX 1
 106
 107 struct virtio_ccw_vq_info {
 108         struct virtqueue *vq;
 109         int num;
 110         void *queue;
 111         union {
 112                 struct vq_info_block s;
 113                 struct vq_info_block_legacy l;
 114         } *info_block;
 115         int bit_nr;
 116         struct list_head node;
 117         long cookie;
 118 };
 119
 120 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
 121
 122 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
 123 #define MAX_AIRQ_AREAS 20
 124
 125 static int virtio_ccw_use_airq = 1;
 126
 127 struct airq_info {
 128         rwlock_t lock;
 129         u8 summary_indicator;
 130         struct airq_struct airq;
 131         struct airq_iv *aiv;
 132 };
 133 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
 134
 135 #define CCW_CMD_SET_VQ 0x13
 136 #define CCW_CMD_VDEV_RESET 0x33
 137 #define CCW_CMD_SET_IND 0x43
 138 #define CCW_CMD_SET_CONF_IND 0x53
 139 #define CCW_CMD_READ_FEAT 0x12
 140 #define CCW_CMD_WRITE_FEAT 0x11
 141 #define CCW_CMD_READ_CONF 0x22
 142 #define CCW_CMD_WRITE_CONF 0x21
 143 #define CCW_CMD_WRITE_STATUS 0x31
 144 #define CCW_CMD_READ_VQ_CONF 0x32
 145 #define CCW_CMD_READ_STATUS 0x72
 146 #define CCW_CMD_SET_IND_ADAPTER 0x73
 147 #define CCW_CMD_SET_VIRTIO_REV 0x83
 148
 149 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
 150 #define VIRTIO_CCW_DOING_RESET 0x00040000
 151 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
 152 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
 153 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
 154 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
 155 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
 156 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
 157 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
 158 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
 159 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
 160 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
 161 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
 162 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
 163
 164 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
 165 {
 166         return container_of(vdev, struct virtio_ccw_device, vdev);
 167 }
 168
 169 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
 170 {
 171         unsigned long i, flags;
 172
 173         write_lock_irqsave(&info->lock, flags);
 174         for (i = 0; i < airq_iv_end(info->aiv); i++) {
 175                 if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
 176                         airq_iv_free_bit(info->aiv, i);
 177                         airq_iv_set_ptr(info->aiv, i, 0);
 178                         break;
 179                 }
 180         }
 181         write_unlock_irqrestore(&info->lock, flags);
 182 }
 183
 184 static void virtio_airq_handler(struct airq_struct *airq)
 185 {
 186         struct airq_info *info = container_of(airq, struct airq_info, airq);
 187         unsigned long ai;
 188
 189         inc_irq_stat(IRQIO_VAI);
 190         read_lock(&info->lock);
 191         /* Walk through indicators field, summary indicator active. */
 192         for (ai = 0;;) {
 193                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 194                 if (ai == -1UL)
 195                         break;
 196                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 197         }
 198         info->summary_indicator = 0;
 199         smp_wmb();
 200         /* Walk through indicators field, summary indicator not active. */
 201         for (ai = 0;;) {
 202                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 203                 if (ai == -1UL)
 204                         break;
 205                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 206         }
 207         read_unlock(&info->lock);
 208 }
 209
 210 static struct airq_info *new_airq_info(void)
 211 {
 212         struct airq_info *info;
 213         int rc;
 214
 215         info = kzalloc(sizeof(*info), GFP_KERNEL);
 216         if (!info)
 217                 return NULL;
 218         rwlock_init(&info->lock);
 219         info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
 220         if (!info->aiv) {
 221                 kfree(info);
 222                 return NULL;
 223         }
 224         info->airq.handler = virtio_airq_handler;
 225         info->airq.lsi_ptr = &info->summary_indicator;
 226         info->airq.lsi_mask = 0xff;
 227         info->airq.isc = VIRTIO_AIRQ_ISC;
 228         rc = register_adapter_interrupt(&info->airq);
 229         if (rc) {
 230                 airq_iv_release(info->aiv);
 231                 kfree(info);
 232                 return NULL;
 233         }
 234         return info;
 235 }
 236
 237 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
 238                                         u64 *first, void **airq_info)
 239 {
 240         int i, j;
 241         struct airq_info *info;
 242         unsigned long indicator_addr = 0;
 243         unsigned long bit, flags;
 244
 245         for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
 246                 if (!airq_areas[i])
 247                         airq_areas[i] = new_airq_info();
 248                 info = airq_areas[i];
 249                 if (!info)
 250                         return 0;
 251                 write_lock_irqsave(&info->lock, flags);
 252                 bit = airq_iv_alloc(info->aiv, nvqs);
 253                 if (bit == -1UL) {
 254                         /* Not enough vacancies. */
 255                         write_unlock_irqrestore(&info->lock, flags);
 256                         continue;
 257                 }
 258                 *first = bit;
 259                 *airq_info = info;
 260                 indicator_addr = (unsigned long)info->aiv->vector;
 261                 for (j = 0; j < nvqs; j++) {
 262                         airq_iv_set_ptr(info->aiv, bit + j,
 263                                         (unsigned long)vqs[j]);
 264                 }
 265                 write_unlock_irqrestore(&info->lock, flags);
 266         }
 267         return indicator_addr;
 268 }
 269
 270 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
 271 {
 272         struct virtio_ccw_vq_info *info;
 273
 274         list_for_each_entry(info, &vcdev->virtqueues, node)
 275                 drop_airq_indicator(info->vq, vcdev->airq_info);
 276 }
 277
 278 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
 279 {
 280         unsigned long flags;
 281         __u32 ret;
 282
 283         spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 284         if (vcdev->err)
 285                 ret = 0;
 286         else
 287                 ret = vcdev->curr_io & flag;
 288         spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 289         return ret;
 290 }
 291
 292 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
 293                          struct ccw1 *ccw, __u32 intparm)
 294 {
 295         int ret;
 296         unsigned long flags;
 297         int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
 298
 299         do {
 300                 spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 301                 ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
 302                 if (!ret) {
 303                         if (!vcdev->curr_io)
 304                                 vcdev->err = 0;
 305                         vcdev->curr_io |= flag;
 306                 }
 307                 spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 308                 cpu_relax();
 309         } while (ret == -EBUSY);
 310         wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
 311         return ret ? ret : vcdev->err;
 312 }
 313
 314 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
 315                                       struct ccw1 *ccw)
 316 {
 317         int ret;
 318         unsigned long *indicatorp = NULL;
 319         struct virtio_thinint_area *thinint_area = NULL;
 320         struct airq_info *airq_info = vcdev->airq_info;
 321
 322         if (vcdev->is_thinint) {
 323                 thinint_area = kzalloc(sizeof(*thinint_area),
 324                                        GFP_DMA | GFP_KERNEL);
 325                 if (!thinint_area)
 326                         return;
 327                 thinint_area->summary_indicator =
 328                         (unsigned long) &airq_info->summary_indicator;
 329                 thinint_area->isc = VIRTIO_AIRQ_ISC;
 330                 ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 331                 ccw->count = sizeof(*thinint_area);
 332                 ccw->cda = (__u32)(unsigned long) thinint_area;
 333         } else {
 334                 /* payload is the address of the indicators */
 335                 indicatorp = kmalloc(sizeof(&vcdev->indicators),
 336                                      GFP_DMA | GFP_KERNEL);
 337                 if (!indicatorp)
 338                         return;
 339                 *indicatorp = 0;
 340                 ccw->cmd_code = CCW_CMD_SET_IND;
 341                 ccw->count = sizeof(&vcdev->indicators);
 342                 ccw->cda = (__u32)(unsigned long) indicatorp;
 343         }
 344         /* Deregister indicators from host. */
 345         vcdev->indicators = 0;
 346         ccw->flags = 0;
 347         ret = ccw_io_helper(vcdev, ccw,
 348                             vcdev->is_thinint ?
 349                             VIRTIO_CCW_DOING_SET_IND_ADAPTER :
 350                             VIRTIO_CCW_DOING_SET_IND);
 351         if (ret && (ret != -ENODEV))
 352                 dev_info(&vcdev->cdev->dev,
 353                          "Failed to deregister indicators (%d)\n", ret);
 354         else if (vcdev->is_thinint)
 355                 virtio_ccw_drop_indicators(vcdev);
 356         kfree(indicatorp);
 357         kfree(thinint_area);
 358 }
 359
 360 static inline long __do_kvm_notify(struct subchannel_id schid,
 361                                    unsigned long queue_index,
 362                                    long cookie)
 363 {
 364         register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
 365         register struct subchannel_id __schid asm("2") = schid;
 366         register unsigned long __index asm("3") = queue_index;
 367         register long __rc asm("2");
 368         register long __cookie asm("4") = cookie;
 369
 370         asm volatile ("diag 2,4,0x500\n"
 371                       : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
 372                       "d"(__cookie)
 373                       : "memory", "cc");
 374         return __rc;
 375 }
 376
 377 static inline long do_kvm_notify(struct subchannel_id schid,
 378                                  unsigned long queue_index,
 379                                  long cookie)
 380 {
 381         diag_stat_inc(DIAG_STAT_X500);
 382         return __do_kvm_notify(schid, queue_index, cookie);
 383 }
 384
 385 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
 386 {
 387         struct virtio_ccw_vq_info *info = vq->priv;
 388         struct virtio_ccw_device *vcdev;
 389         struct subchannel_id schid;
 390
 391         vcdev = to_vc_device(info->vq->vdev);
 392         ccw_device_get_schid(vcdev->cdev, &schid);
 393         info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
 394         if (info->cookie < 0)
 395                 return false;
 396         return true;
 397 }
 398
 399 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
 400                                    struct ccw1 *ccw, int index)
 401 {
 402         int ret;
 403
 404         vcdev->config_block->index = index;
 405         ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
 406         ccw->flags = 0;
 407         ccw->count = sizeof(struct vq_config_block);
 408         ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
 409         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
 410         if (ret)
 411                 return ret;
 412         return vcdev->config_block->num;
 413 }
 414
 415 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
 416 {
 417         struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
 418         struct virtio_ccw_vq_info *info = vq->priv;
 419         unsigned long flags;
 420         unsigned long size;
 421         int ret;
 422         unsigned int index = vq->index;
 423
 424         /* Remove from our list. */
 425         spin_lock_irqsave(&vcdev->lock, flags);
 426         list_del(&info->node);
 427         spin_unlock_irqrestore(&vcdev->lock, flags);
 428
 429         /* Release from host. */
 430         if (vcdev->revision == 0) {
 431                 info->info_block->l.queue = 0;
 432                 info->info_block->l.align = 0;
 433                 info->info_block->l.index = index;
 434                 info->info_block->l.num = 0;
 435                 ccw->count = sizeof(info->info_block->l);
 436         } else {
 437                 info->info_block->s.desc = 0;
 438                 info->info_block->s.index = index;
 439                 info->info_block->s.num = 0;
 440                 info->info_block->s.avail = 0;
 441                 info->info_block->s.used = 0;
 442                 ccw->count = sizeof(info->info_block->s);
 443         }
 444         ccw->cmd_code = CCW_CMD_SET_VQ;
 445         ccw->flags = 0;
 446         ccw->cda = (__u32)(unsigned long)(info->info_block);
 447         ret = ccw_io_helper(vcdev, ccw,
 448                             VIRTIO_CCW_DOING_SET_VQ | index);
 449         /*
 450          * -ENODEV isn't considered an error: The device is gone anyway.
 451          * This may happen on device detach.
 452          */
 453         if (ret && (ret != -ENODEV))
 454                 dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
 455                          ret, index);
 456
 457         vring_del_virtqueue(vq);
 458         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
 459         free_pages_exact(info->queue, size);
 460         kfree(info->info_block);
 461         kfree(info);
 462 }
 463
 464 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
 465 {
 466         struct virtqueue *vq, *n;
 467         struct ccw1 *ccw;
 468         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 469
 470         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 471         if (!ccw)
 472                 return;
 473
 474         virtio_ccw_drop_indicator(vcdev, ccw);
 475
 476         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 477                 virtio_ccw_del_vq(vq, ccw);
 478
 479         kfree(ccw);
 480 }
 481
 482 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
 483                                              int i, vq_callback_t *callback,
 484                                              const char *name, bool ctx,
 485                                              struct ccw1 *ccw)
 486 {
 487         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 488         int err;
 489         struct virtqueue *vq = NULL;
 490         struct virtio_ccw_vq_info *info;
 491         unsigned long size = 0; /* silence the compiler */
 492         unsigned long flags;
 493
 494         /* Allocate queue. */
 495         info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
 496         if (!info) {
 497                 dev_warn(&vcdev->cdev->dev, "no info\n");
 498                 err = -ENOMEM;
 499                 goto out_err;
 500         }
 501         info->info_block = kzalloc(sizeof(*info->info_block),
 502                                    GFP_DMA | GFP_KERNEL);
 503         if (!info->info_block) {
 504                 dev_warn(&vcdev->cdev->dev, "no info block\n");
 505                 err = -ENOMEM;
 506                 goto out_err;
 507         }
 508         info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
 509         if (info->num < 0) {
 510                 err = info->num;
 511                 goto out_err;
 512         }
 513         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
 514         info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
 515         if (info->queue == NULL) {
 516                 dev_warn(&vcdev->cdev->dev, "no queue\n");
 517                 err = -ENOMEM;
 518                 goto out_err;
 519         }
 520
 521         vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
 522                                  true, ctx, info->queue, virtio_ccw_kvm_notify,
 523                                  callback, name);
 524         if (!vq) {
 525                 /* For now, we fail if we can't get the requested size. */
 526                 dev_warn(&vcdev->cdev->dev, "no vq\n");
 527                 err = -ENOMEM;
 528                 goto out_err;
 529         }
 530
 531         /* Register it with the host. */
 532         if (vcdev->revision == 0) {
 533                 info->info_block->l.queue = (__u64)info->queue;
 534                 info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
 535                 info->info_block->l.index = i;
 536                 info->info_block->l.num = info->num;
 537                 ccw->count = sizeof(info->info_block->l);
 538         } else {
 539                 info->info_block->s.desc = (__u64)info->queue;
 540                 info->info_block->s.index = i;
 541                 info->info_block->s.num = info->num;
 542                 info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
 543                 info->info_block->s.used = (__u64)virtqueue_get_used(vq);
 544                 ccw->count = sizeof(info->info_block->s);
 545         }
 546         ccw->cmd_code = CCW_CMD_SET_VQ;
 547         ccw->flags = 0;
 548         ccw->cda = (__u32)(unsigned long)(info->info_block);
 549         err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
 550         if (err) {
 551                 dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
 552                 goto out_err;
 553         }
 554
 555         info->vq = vq;
 556         vq->priv = info;
 557
 558         /* Save it to our list. */
 559         spin_lock_irqsave(&vcdev->lock, flags);
 560         list_add(&info->node, &vcdev->virtqueues);
 561         spin_unlock_irqrestore(&vcdev->lock, flags);
 562
 563         return vq;
 564
 565 out_err:
 566         if (vq)
 567                 vring_del_virtqueue(vq);
 568         if (info) {
 569                 if (info->queue)
 570                         free_pages_exact(info->queue, size);
 571                 kfree(info->info_block);
 572         }
 573         kfree(info);
 574         return ERR_PTR(err);
 575 }
 576
 577 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
 578                                            struct virtqueue *vqs[], int nvqs,
 579                                            struct ccw1 *ccw)
 580 {
 581         int ret;
 582         struct virtio_thinint_area *thinint_area = NULL;
 583         struct airq_info *info;
 584
 585         thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
 586         if (!thinint_area) {
 587                 ret = -ENOMEM;
 588                 goto out;
 589         }
 590         /* Try to get an indicator. */
 591         thinint_area->indicator = get_airq_indicator(vqs, nvqs,
 592                                                      &thinint_area->bit_nr,
 593                                                      &vcdev->airq_info);
 594         if (!thinint_area->indicator) {
 595                 ret = -ENOSPC;
 596                 goto out;
 597         }
 598         info = vcdev->airq_info;
 599         thinint_area->summary_indicator =
 600                 (unsigned long) &info->summary_indicator;
 601         thinint_area->isc = VIRTIO_AIRQ_ISC;
 602         ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 603         ccw->flags = CCW_FLAG_SLI;
 604         ccw->count = sizeof(*thinint_area);
 605         ccw->cda = (__u32)(unsigned long)thinint_area;
 606         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
 607         if (ret) {
 608                 if (ret == -EOPNOTSUPP) {
 609                         /*
 610                          * The host does not support adapter interrupts
 611                          * for virtio-ccw, stop trying.
 612                          */
 613                         virtio_ccw_use_airq = 0;
 614                         pr_info("Adapter interrupts unsupported on host\n");
 615                 } else
 616                         dev_warn(&vcdev->cdev->dev,
 617                                  "enabling adapter interrupts = %d\n", ret);
 618                 virtio_ccw_drop_indicators(vcdev);
 619         }
 620 out:
 621         kfree(thinint_area);
 622         return ret;
 623 }
 624
 625 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 626                                struct virtqueue *vqs[],
 627                                vq_callback_t *callbacks[],
 628                                const char * const names[],
 629                                const bool *ctx,
 630                                struct irq_affinity *desc)
 631 {
 632         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 633         unsigned long *indicatorp = NULL;
 634         int ret, i;
 635         struct ccw1 *ccw;
 636
 637         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 638         if (!ccw)
 639                 return -ENOMEM;
 640
 641         for (i = 0; i < nvqs; ++i) {
 642                 vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
 643                                              ctx ? ctx[i] : false, ccw);
 644                 if (IS_ERR(vqs[i])) {
 645                         ret = PTR_ERR(vqs[i]);
 646                         vqs[i] = NULL;
 647                         goto out;
 648                 }
 649         }
 650         ret = -ENOMEM;
 651         /*
 652          * We need a data area under 2G to communicate. Our payload is
 653          * the address of the indicators.
 654         */
 655         indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
 656         if (!indicatorp)
 657                 goto out;
 658         *indicatorp = (unsigned long) &vcdev->indicators;
 659         if (vcdev->is_thinint) {
 660                 ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
 661                 if (ret)
 662                         /* no error, just fall back to legacy interrupts */
 663                         vcdev->is_thinint = false;
 664         }
 665         if (!vcdev->is_thinint) {
 666                 /* Register queue indicators with host. */
 667                 vcdev->indicators = 0;
 668                 ccw->cmd_code = CCW_CMD_SET_IND;
 669                 ccw->flags = 0;
 670                 ccw->count = sizeof(&vcdev->indicators);
 671                 ccw->cda = (__u32)(unsigned long) indicatorp;
 672                 ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
 673                 if (ret)
 674                         goto out;
 675         }
 676         /* Register indicators2 with host for config changes */
 677         *indicatorp = (unsigned long) &vcdev->indicators2;
 678         vcdev->indicators2 = 0;
 679         ccw->cmd_code = CCW_CMD_SET_CONF_IND;
 680         ccw->flags = 0;
 681         ccw->count = sizeof(&vcdev->indicators2);
 682         ccw->cda = (__u32)(unsigned long) indicatorp;
 683         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
 684         if (ret)
 685                 goto out;
 686
 687         kfree(indicatorp);
 688         kfree(ccw);
 689         return 0;
 690 out:
 691         kfree(indicatorp);
 692         kfree(ccw);
 693         virtio_ccw_del_vqs(vdev);
 694         return ret;
 695 }
 696
 697 static void virtio_ccw_reset(struct virtio_device *vdev)
 698 {
 699         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 700         struct ccw1 *ccw;
 701
 702         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 703         if (!ccw)
 704                 return;
 705
 706         /* Zero status bits. */
 707         *vcdev->status = 0;
 708
 709         /* Send a reset ccw on device. */
 710         ccw->cmd_code = CCW_CMD_VDEV_RESET;
 711         ccw->flags = 0;
 712         ccw->count = 0;
 713         ccw->cda = 0;
 714         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
 715         kfree(ccw);
 716 }
 717
 718 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
 719 {
 720         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 721         struct virtio_feature_desc *features;
 722         int ret;
 723         u64 rc;
 724         struct ccw1 *ccw;
 725
 726         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 727         if (!ccw)
 728                 return 0;
 729
 730         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
 731         if (!features) {
 732                 rc = 0;
 733                 goto out_free;
 734         }
 735         /* Read the feature bits from the host. */
 736         features->index = 0;
 737         ccw->cmd_code = CCW_CMD_READ_FEAT;
 738         ccw->flags = 0;
 739         ccw->count = sizeof(*features);
 740         ccw->cda = (__u32)(unsigned long)features;
 741         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 742         if (ret) {
 743                 rc = 0;
 744                 goto out_free;
 745         }
 746
 747         rc = le32_to_cpu(features->features);
 748
 749         if (vcdev->revision == 0)
 750                 goto out_free;
 751
 752         /* Read second half of the feature bits from the host. */
 753         features->index = 1;
 754         ccw->cmd_code = CCW_CMD_READ_FEAT;
 755         ccw->flags = 0;
 756         ccw->count = sizeof(*features);
 757         ccw->cda = (__u32)(unsigned long)features;
 758         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 759         if (ret == 0)
 760                 rc |= (u64)le32_to_cpu(features->features) << 32;
 761
 762 out_free:
 763         kfree(features);
 764         kfree(ccw);
 765         return rc;
 766 }
 767
 768 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
 769 {
 770         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 771         struct virtio_feature_desc *features;
 772         struct ccw1 *ccw;
 773         int ret;
 774
 775         if (vcdev->revision >= 1 &&
 776             !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
 777                 dev_err(&vdev->dev, "virtio: device uses revision 1 "
 778                         "but does not have VIRTIO_F_VERSION_1\n");
 779                 return -EINVAL;
 780         }
 781
 782         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 783         if (!ccw)
 784                 return -ENOMEM;
 785
 786         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
 787         if (!features) {
 788                 ret = -ENOMEM;
 789                 goto out_free;
 790         }
 791         /* Give virtio_ring a chance to accept features. */
 792         vring_transport_features(vdev);
 793
 794         features->index = 0;
 795         features->features = cpu_to_le32((u32)vdev->features);
 796         /* Write the first half of the feature bits to the host. */
 797         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 798         ccw->flags = 0;
 799         ccw->count = sizeof(*features);
 800         ccw->cda = (__u32)(unsigned long)features;
 801         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 802         if (ret)
 803                 goto out_free;
 804
 805         if (vcdev->revision == 0)
 806                 goto out_free;
 807
 808         features->index = 1;
 809         features->features = cpu_to_le32(vdev->features >> 32);
 810         /* Write the second half of the feature bits to the host. */
 811         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 812         ccw->flags = 0;
 813         ccw->count = sizeof(*features);
 814         ccw->cda = (__u32)(unsigned long)features;
 815         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 816
 817 out_free:
 818         kfree(features);
 819         kfree(ccw);
 820
 821         return ret;
 822 }
 823
 824 static void virtio_ccw_get_config(struct virtio_device *vdev,
 825                                   unsigned int offset, void *buf, unsigned len)
 826 {
 827         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 828         int ret;
 829         struct ccw1 *ccw;
 830         void *config_area;
 831
 832         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 833         if (!ccw)
 834                 return;
 835
 836         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
 837         if (!config_area)
 838                 goto out_free;
 839
 840         /* Read the config area from the host. */
 841         ccw->cmd_code = CCW_CMD_READ_CONF;
 842         ccw->flags = 0;
 843         ccw->count = offset + len;
 844         ccw->cda = (__u32)(unsigned long)config_area;
 845         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
 846         if (ret)
 847                 goto out_free;
 848
 849         memcpy(vcdev->config, config_area, offset + len);
 850         if (buf)
 851                 memcpy(buf, &vcdev->config[offset], len);
 852         if (vcdev->config_ready < offset + len)
 853                 vcdev->config_ready = offset + len;
 854
 855 out_free:
 856         kfree(config_area);
 857         kfree(ccw);
 858 }
 859
 860 static void virtio_ccw_set_config(struct virtio_device *vdev,
 861                                   unsigned int offset, const void *buf,
 862                                   unsigned len)
 863 {
 864         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 865         struct ccw1 *ccw;
 866         void *config_area;
 867
 868         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 869         if (!ccw)
 870                 return;
 871
 872         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
 873         if (!config_area)
 874                 goto out_free;
 875
 876         /* Make sure we don't overwrite fields. */
 877         if (vcdev->config_ready < offset)
 878                 virtio_ccw_get_config(vdev, 0, NULL, offset);
 879         memcpy(&vcdev->config[offset], buf, len);
 880         /* Write the config area to the host. */
 881         memcpy(config_area, vcdev->config, sizeof(vcdev->config));
 882         ccw->cmd_code = CCW_CMD_WRITE_CONF;
 883         ccw->flags = 0;
 884         ccw->count = offset + len;
 885         ccw->cda = (__u32)(unsigned long)config_area;
 886         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
 887
 888 out_free:
 889         kfree(config_area);
 890         kfree(ccw);
 891 }
 892
 893 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
 894 {
 895         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 896         u8 old_status = *vcdev->status;
 897         struct ccw1 *ccw;
 898
 899         if (vcdev->revision < 1)
 900                 return *vcdev->status;
 901
 902         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 903         if (!ccw)
 904                 return old_status;
 905
 906         ccw->cmd_code = CCW_CMD_READ_STATUS;
 907         ccw->flags = 0;
 908         ccw->count = sizeof(*vcdev->status);
 909         ccw->cda = (__u32)(unsigned long)vcdev->status;
 910         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
 911 /*
 912  * If the channel program failed (should only happen if the device
 913  * was hotunplugged, and then we clean up via the machine check
 914  * handler anyway), vcdev->status was not overwritten and we just
 915  * return the old status, which is fine.
 916 */
 917         kfree(ccw);
 918
 919         return *vcdev->status;
 920 }
 921
 922 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 923 {
 924         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 925         u8 old_status = *vcdev->status;
 926         struct ccw1 *ccw;
 927         int ret;
 928
 929         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 930         if (!ccw)
 931                 return;
 932
 933         /* Write the status to the host. */
 934         *vcdev->status = status;
 935         ccw->cmd_code = CCW_CMD_WRITE_STATUS;
 936         ccw->flags = 0;
 937         ccw->count = sizeof(status);
 938         ccw->cda = (__u32)(unsigned long)vcdev->status;
 939         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
 940         /* Write failed? We assume status is unchanged. */
 941         if (ret)
 942                 *vcdev->status = old_status;
 943         kfree(ccw);
 944 }
 945
 946 static const struct virtio_config_ops virtio_ccw_config_ops = {
 947         .get_features = virtio_ccw_get_features,
 948         .finalize_features = virtio_ccw_finalize_features,
 949         .get = virtio_ccw_get_config,
 950         .set = virtio_ccw_set_config,
 951         .get_status = virtio_ccw_get_status,
 952         .set_status = virtio_ccw_set_status,
 953         .reset = virtio_ccw_reset,
 954         .find_vqs = virtio_ccw_find_vqs,
 955         .del_vqs = virtio_ccw_del_vqs,
 956 };
 957
 958
 959 /*
 960  * ccw bus driver related functions
 961  */
 962
 963 static void virtio_ccw_release_dev(struct device *_d)
 964 {
 965         struct virtio_device *dev = dev_to_virtio(_d);
 966         struct virtio_ccw_device *vcdev = to_vc_device(dev);
 967
 968         kfree(vcdev->status);
 969         kfree(vcdev->config_block);
 970         kfree(vcdev);
 971 }
 972
 973 static int irb_is_error(struct irb *irb)
 974 {
 975         if (scsw_cstat(&irb->scsw) != 0)
 976                 return 1;
 977         if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
 978                 return 1;
 979         if (scsw_cc(&irb->scsw) != 0)
 980                 return 1;
 981         return 0;
 982 }
 983
 984 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
 985                                               int index)
 986 {
 987         struct virtio_ccw_vq_info *info;
 988         unsigned long flags;
 989         struct virtqueue *vq;
 990
 991         vq = NULL;
 992         spin_lock_irqsave(&vcdev->lock, flags);
 993         list_for_each_entry(info, &vcdev->virtqueues, node) {
 994                 if (info->vq->index == index) {
 995                         vq = info->vq;
 996                         break;
 997                 }
 998         }
 999         spin_unlock_irqrestore(&vcdev->lock, flags);
1000         return vq;
1001 }
1002
1003 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1004                                       __u32 activity)
1005 {
1006         if (vcdev->curr_io & activity) {
1007                 switch (activity) {
1008                 case VIRTIO_CCW_DOING_READ_FEAT:
1009                 case VIRTIO_CCW_DOING_WRITE_FEAT:
1010                 case VIRTIO_CCW_DOING_READ_CONFIG:
1011                 case VIRTIO_CCW_DOING_WRITE_CONFIG:
1012                 case VIRTIO_CCW_DOING_WRITE_STATUS:
1013                 case VIRTIO_CCW_DOING_READ_STATUS:
1014                 case VIRTIO_CCW_DOING_SET_VQ:
1015                 case VIRTIO_CCW_DOING_SET_IND:
1016                 case VIRTIO_CCW_DOING_SET_CONF_IND:
1017                 case VIRTIO_CCW_DOING_RESET:
1018                 case VIRTIO_CCW_DOING_READ_VQ_CONF:
1019                 case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1020                 case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1021                         vcdev->curr_io &= ~activity;
1022                         wake_up(&vcdev->wait_q);
1023                         break;
1024                 default:
1025                         /* don't know what to do... */
1026                         dev_warn(&vcdev->cdev->dev,
1027                                  "Suspicious activity '%08x'\n", activity);
1028                         WARN_ON(1);
1029                         break;
1030                 }
1031         }
1032 }
1033
1034 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1035                                    unsigned long intparm,
1036                                    struct irb *irb)
1037 {
1038         __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1039         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1040         int i;
1041         struct virtqueue *vq;
1042
1043         if (!vcdev)
1044                 return;
1045         if (IS_ERR(irb)) {
1046                 vcdev->err = PTR_ERR(irb);
1047                 virtio_ccw_check_activity(vcdev, activity);
1048                 /* Don't poke around indicators, something's wrong. */
1049                 return;
1050         }
1051         /* Check if it's a notification from the host. */
1052         if ((intparm == 0) &&
1053             (scsw_stctl(&irb->scsw) ==
1054              (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1055                 /* OK */
1056         }
1057         if (irb_is_error(irb)) {
1058                 /* Command reject? */
1059                 if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1060                     (irb->ecw[0] & SNS0_CMD_REJECT))
1061                         vcdev->err = -EOPNOTSUPP;
1062                 else
1063                         /* Map everything else to -EIO. */
1064                         vcdev->err = -EIO;
1065         }
1066         virtio_ccw_check_activity(vcdev, activity);
1067         for_each_set_bit(i, &vcdev->indicators,
1068                          sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1069                 /* The bit clear must happen before the vring kick. */
1070                 clear_bit(i, &vcdev->indicators);
1071                 barrier();
1072                 vq = virtio_ccw_vq_by_ind(vcdev, i);
1073                 vring_interrupt(0, vq);
1074         }
1075         if (test_bit(0, &vcdev->indicators2)) {
1076                 virtio_config_changed(&vcdev->vdev);
1077                 clear_bit(0, &vcdev->indicators2);
1078         }
1079 }
1080
1081 /*
1082  * We usually want to autoonline all devices, but give the admin
1083  * a way to exempt devices from this.
1084  */
1085 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1086                      (8*sizeof(long)))
1087 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1088
1089 static char *no_auto = "";
1090
1091 module_param(no_auto, charp, 0444);
1092 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1093
1094 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1095 {
1096         struct ccw_dev_id id;
1097
1098         ccw_device_get_id(cdev, &id);
1099         if (test_bit(id.devno, devs_no_auto[id.ssid]))
1100                 return 0;
1101         return 1;
1102 }
1103
1104 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1105 {
1106         struct ccw_device *cdev = data;
1107         int ret;
1108
1109         ret = ccw_device_set_online(cdev);
1110         if (ret)
1111                 dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1112 }
1113
1114 static int virtio_ccw_probe(struct ccw_device *cdev)
1115 {
1116         cdev->handler = virtio_ccw_int_handler;
1117
1118         if (virtio_ccw_check_autoonline(cdev))
1119                 async_schedule(virtio_ccw_auto_online, cdev);
1120         return 0;
1121 }
1122
1123 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1124 {
1125         unsigned long flags;
1126         struct virtio_ccw_device *vcdev;
1127
1128         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1129         vcdev = dev_get_drvdata(&cdev->dev);
1130         if (!vcdev || vcdev->going_away) {
1131                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1132                 return NULL;
1133         }
1134         vcdev->going_away = true;
1135         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1136         return vcdev;
1137 }
1138
1139 static void virtio_ccw_remove(struct ccw_device *cdev)
1140 {
1141         unsigned long flags;
1142         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1143
1144         if (vcdev && cdev->online) {
1145                 if (vcdev->device_lost)
1146                         virtio_break_device(&vcdev->vdev);
1147                 unregister_virtio_device(&vcdev->vdev);
1148                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1149                 dev_set_drvdata(&cdev->dev, NULL);
1150                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1151         }
1152         cdev->handler = NULL;
1153 }
1154
1155 static int virtio_ccw_offline(struct ccw_device *cdev)
1156 {
1157         unsigned long flags;
1158         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1159
1160         if (!vcdev)
1161                 return 0;
1162         if (vcdev->device_lost)
1163                 virtio_break_device(&vcdev->vdev);
1164         unregister_virtio_device(&vcdev->vdev);
1165         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1166         dev_set_drvdata(&cdev->dev, NULL);
1167         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1168         return 0;
1169 }
1170
1171 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1172 {
1173         struct virtio_rev_info *rev;
1174         struct ccw1 *ccw;
1175         int ret;
1176
1177         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1178         if (!ccw)
1179                 return -ENOMEM;
1180         rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1181         if (!rev) {
1182                 kfree(ccw);
1183                 return -ENOMEM;
1184         }
1185
1186         /* Set transport revision */
1187         ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1188         ccw->flags = 0;
1189         ccw->count = sizeof(*rev);
1190         ccw->cda = (__u32)(unsigned long)rev;
1191
1192         vcdev->revision = VIRTIO_CCW_REV_MAX;
1193         do {
1194                 rev->revision = vcdev->revision;
1195                 /* none of our supported revisions carry payload */
1196                 rev->length = 0;
1197                 ret = ccw_io_helper(vcdev, ccw,
1198                                     VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1199                 if (ret == -EOPNOTSUPP) {
1200                         if (vcdev->revision == 0)
1201                                 /*
1202                                  * The host device does not support setting
1203                                  * the revision: let's operate it in legacy
1204                                  * mode.
1205                                  */
1206                                 ret = 0;
1207                         else
1208                                 vcdev->revision--;
1209                 }
1210         } while (ret == -EOPNOTSUPP);
1211
1212         kfree(ccw);
1213         kfree(rev);
1214         return ret;
1215 }
1216
1217 static int virtio_ccw_online(struct ccw_device *cdev)
1218 {
1219         int ret;
1220         struct virtio_ccw_device *vcdev;
1221         unsigned long flags;
1222
1223         vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1224         if (!vcdev) {
1225                 dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1226                 ret = -ENOMEM;
1227                 goto out_free;
1228         }
1229         vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1230                                    GFP_DMA | GFP_KERNEL);
1231         if (!vcdev->config_block) {
1232                 ret = -ENOMEM;
1233                 goto out_free;
1234         }
1235         vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1236         if (!vcdev->status) {
1237                 ret = -ENOMEM;
1238                 goto out_free;
1239         }
1240
1241         vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1242
1243         vcdev->vdev.dev.parent = &cdev->dev;
1244         vcdev->vdev.dev.release = virtio_ccw_release_dev;
1245         vcdev->vdev.config = &virtio_ccw_config_ops;
1246         vcdev->cdev = cdev;
1247         init_waitqueue_head(&vcdev->wait_q);
1248         INIT_LIST_HEAD(&vcdev->virtqueues);
1249         spin_lock_init(&vcdev->lock);
1250
1251         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1252         dev_set_drvdata(&cdev->dev, vcdev);
1253         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1254         vcdev->vdev.id.vendor = cdev->id.cu_type;
1255         vcdev->vdev.id.device = cdev->id.cu_model;
1256
1257         ret = virtio_ccw_set_transport_rev(vcdev);
1258         if (ret)
1259                 goto out_free;
1260
1261         ret = register_virtio_device(&vcdev->vdev);
1262         if (ret) {
1263                 dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1264                          ret);
1265                 goto out_put;
1266         }
1267         return 0;
1268 out_put:
1269         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1270         dev_set_drvdata(&cdev->dev, NULL);
1271         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1272         put_device(&vcdev->vdev.dev);
1273         return ret;
1274 out_free:
1275         if (vcdev) {
1276                 kfree(vcdev->status);
1277                 kfree(vcdev->config_block);
1278         }
1279         kfree(vcdev);
1280         return ret;
1281 }
1282
1283 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1284 {
1285         int rc;
1286         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1287
1288         /*
1289          * Make sure vcdev is set
1290          * i.e. set_offline/remove callback not already running
1291          */
1292         if (!vcdev)
1293                 return NOTIFY_DONE;
1294
1295         switch (event) {
1296         case CIO_GONE:
1297                 vcdev->device_lost = true;
1298                 rc = NOTIFY_DONE;
1299                 break;
1300         default:
1301                 rc = NOTIFY_DONE;
1302                 break;
1303         }
1304         return rc;
1305 }
1306
1307 static struct ccw_device_id virtio_ids[] = {
1308         { CCW_DEVICE(0x3832, 0) },
1309         {},
1310 };
1311
1312 static struct ccw_driver virtio_ccw_driver = {
1313         .driver = {
1314                 .owner = THIS_MODULE,
1315                 .name = "virtio_ccw",
1316         },
1317         .ids = virtio_ids,
1318         .probe = virtio_ccw_probe,
1319         .remove = virtio_ccw_remove,
1320         .set_offline = virtio_ccw_offline,
1321         .set_online = virtio_ccw_online,
1322         .notify = virtio_ccw_cio_notify,
1323         .int_class = IRQIO_VIR,
1324 };
1325
1326 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1327                            int max_digit, int max_val)
1328 {
1329         int diff;
1330
1331         diff = 0;
1332         *val = 0;
1333
1334         while (diff <= max_digit) {
1335                 int value = hex_to_bin(**cp);
1336
1337                 if (value < 0)
1338                         break;
1339                 *val = *val * 16 + value;
1340                 (*cp)++;
1341                 diff++;
1342         }
1343
1344         if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1345                 return 1;
1346
1347         return 0;
1348 }
1349
1350 static int __init parse_busid(char *str, unsigned int *cssid,
1351                               unsigned int *ssid, unsigned int *devno)
1352 {
1353         char *str_work;
1354         int rc, ret;
1355
1356         rc = 1;
1357
1358         if (*str == '\0')
1359                 goto out;
1360
1361         str_work = str;
1362         ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1363         if (ret || (str_work[0] != '.'))
1364                 goto out;
1365         str_work++;
1366         ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1367         if (ret || (str_work[0] != '.'))
1368                 goto out;
1369         str_work++;
1370         ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1371         if (ret || (str_work[0] != '\0'))
1372                 goto out;
1373
1374         rc = 0;
1375 out:
1376         return rc;
1377 }
1378
1379 static void __init no_auto_parse(void)
1380 {
1381         unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1382         char *parm, *str;
1383         int rc;
1384
1385         str = no_auto;
1386         while ((parm = strsep(&str, ","))) {
1387                 rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1388                                  &from_ssid, &from);
1389                 if (rc)
1390                         continue;
1391                 if (parm != NULL) {
1392                         rc = parse_busid(parm, &to_cssid,
1393                                          &to_ssid, &to);
1394                         if ((from_ssid > to_ssid) ||
1395                             ((from_ssid == to_ssid) && (from > to)))
1396                                 rc = -EINVAL;
1397                 } else {
1398                         to_cssid = from_cssid;
1399                         to_ssid = from_ssid;
1400                         to = from;
1401                 }
1402                 if (rc)
1403                         continue;
1404                 while ((from_ssid < to_ssid) ||
1405                        ((from_ssid == to_ssid) && (from <= to))) {
1406                         set_bit(from, devs_no_auto[from_ssid]);
1407                         from++;
1408                         if (from > __MAX_SUBCHANNEL) {
1409                                 from_ssid++;
1410                                 from = 0;
1411                         }
1412                 }
1413         }
1414 }
1415
1416 static int __init virtio_ccw_init(void)
1417 {
1418         /* parse no_auto string before we do anything further */
1419         no_auto_parse();
1420         return ccw_driver_register(&virtio_ccw_driver);
1421 }
1422 device_initcall(virtio_ccw_init);