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/memblock.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 vcdev_dma_area {
  50         unsigned long indicators;
  51         unsigned long indicators2;
  52         struct vq_config_block config_block;
  53         __u8 status;
  54 };
  55
  56 struct virtio_ccw_device {
  57         struct virtio_device vdev;
  58         __u8 config[VIRTIO_CCW_CONFIG_SIZE];
  59         struct ccw_device *cdev;
  60         __u32 curr_io;
  61         int err;
  62         unsigned int revision; /* Transport revision */
  63         wait_queue_head_t wait_q;
  64         spinlock_t lock;
  65         struct mutex io_lock; /* Serializes I/O requests */
  66         struct list_head virtqueues;
  67         bool is_thinint;
  68         bool going_away;
  69         bool device_lost;
  70         unsigned int config_ready;
  71         void *airq_info;
  72         struct vcdev_dma_area *dma_area;
  73 };
  74
  75 static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
  76 {
  77         return &vcdev->dma_area->indicators;
  78 }
  79
  80 static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
  81 {
  82         return &vcdev->dma_area->indicators2;
  83 }
  84
  85 struct vq_info_block_legacy {
  86         __u64 queue;
  87         __u32 align;
  88         __u16 index;
  89         __u16 num;
  90 } __packed;
  91
  92 struct vq_info_block {
  93         __u64 desc;
  94         __u32 res0;
  95         __u16 index;
  96         __u16 num;
  97         __u64 avail;
  98         __u64 used;
  99 } __packed;
 100
 101 struct virtio_feature_desc {
 102         __le32 features;
 103         __u8 index;
 104 } __packed;
 105
 106 struct virtio_thinint_area {
 107         unsigned long summary_indicator;
 108         unsigned long indicator;
 109         u64 bit_nr;
 110         u8 isc;
 111 } __packed;
 112
 113 struct virtio_rev_info {
 114         __u16 revision;
 115         __u16 length;
 116         __u8 data[];
 117 };
 118
 119 /* the highest virtio-ccw revision we support */
 120 #define VIRTIO_CCW_REV_MAX 1
 121
 122 struct virtio_ccw_vq_info {
 123         struct virtqueue *vq;
 124         int num;
 125         union {
 126                 struct vq_info_block s;
 127                 struct vq_info_block_legacy l;
 128         } *info_block;
 129         int bit_nr;
 130         struct list_head node;
 131         long cookie;
 132 };
 133
 134 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
 135
 136 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
 137 #define MAX_AIRQ_AREAS 20
 138
 139 static int virtio_ccw_use_airq = 1;
 140
 141 struct airq_info {
 142         rwlock_t lock;
 143         u8 summary_indicator_idx;
 144         struct airq_struct airq;
 145         struct airq_iv *aiv;
 146 };
 147 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
 148 static DEFINE_MUTEX(airq_areas_lock);
 149
 150 static u8 *summary_indicators;
 151
 152 static inline u8 *get_summary_indicator(struct airq_info *info)
 153 {
 154         return summary_indicators + info->summary_indicator_idx;
 155 }
 156
 157 #define CCW_CMD_SET_VQ 0x13
 158 #define CCW_CMD_VDEV_RESET 0x33
 159 #define CCW_CMD_SET_IND 0x43
 160 #define CCW_CMD_SET_CONF_IND 0x53
 161 #define CCW_CMD_READ_FEAT 0x12
 162 #define CCW_CMD_WRITE_FEAT 0x11
 163 #define CCW_CMD_READ_CONF 0x22
 164 #define CCW_CMD_WRITE_CONF 0x21
 165 #define CCW_CMD_WRITE_STATUS 0x31
 166 #define CCW_CMD_READ_VQ_CONF 0x32
 167 #define CCW_CMD_READ_STATUS 0x72
 168 #define CCW_CMD_SET_IND_ADAPTER 0x73
 169 #define CCW_CMD_SET_VIRTIO_REV 0x83
 170
 171 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
 172 #define VIRTIO_CCW_DOING_RESET 0x00040000
 173 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
 174 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
 175 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
 176 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
 177 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
 178 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
 179 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
 180 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
 181 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
 182 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
 183 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
 184 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
 185
 186 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
 187 {
 188         return container_of(vdev, struct virtio_ccw_device, vdev);
 189 }
 190
 191 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
 192 {
 193         unsigned long i, flags;
 194
 195         write_lock_irqsave(&info->lock, flags);
 196         for (i = 0; i < airq_iv_end(info->aiv); i++) {
 197                 if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
 198                         airq_iv_free_bit(info->aiv, i);
 199                         airq_iv_set_ptr(info->aiv, i, 0);
 200                         break;
 201                 }
 202         }
 203         write_unlock_irqrestore(&info->lock, flags);
 204 }
 205
 206 static void virtio_airq_handler(struct airq_struct *airq, bool floating)
 207 {
 208         struct airq_info *info = container_of(airq, struct airq_info, airq);
 209         unsigned long ai;
 210
 211         inc_irq_stat(IRQIO_VAI);
 212         read_lock(&info->lock);
 213         /* Walk through indicators field, summary indicator active. */
 214         for (ai = 0;;) {
 215                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 216                 if (ai == -1UL)
 217                         break;
 218                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 219         }
 220         *(get_summary_indicator(info)) = 0;
 221         smp_wmb();
 222         /* Walk through indicators field, summary indicator not active. */
 223         for (ai = 0;;) {
 224                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 225                 if (ai == -1UL)
 226                         break;
 227                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 228         }
 229         read_unlock(&info->lock);
 230 }
 231
 232 static struct airq_info *new_airq_info(int index)
 233 {
 234         struct airq_info *info;
 235         int rc;
 236
 237         info = kzalloc(sizeof(*info), GFP_KERNEL);
 238         if (!info)
 239                 return NULL;
 240         rwlock_init(&info->lock);
 241         info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
 242                                    | AIRQ_IV_CACHELINE);
 243         if (!info->aiv) {
 244                 kfree(info);
 245                 return NULL;
 246         }
 247         info->airq.handler = virtio_airq_handler;
 248         info->summary_indicator_idx = index;
 249         info->airq.lsi_ptr = get_summary_indicator(info);
 250         info->airq.lsi_mask = 0xff;
 251         info->airq.isc = VIRTIO_AIRQ_ISC;
 252         rc = register_adapter_interrupt(&info->airq);
 253         if (rc) {
 254                 airq_iv_release(info->aiv);
 255                 kfree(info);
 256                 return NULL;
 257         }
 258         return info;
 259 }
 260
 261 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
 262                                         u64 *first, void **airq_info)
 263 {
 264         int i, j;
 265         struct airq_info *info;
 266         unsigned long indicator_addr = 0;
 267         unsigned long bit, flags;
 268
 269         for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
 270                 mutex_lock(&airq_areas_lock);
 271                 if (!airq_areas[i])
 272                         airq_areas[i] = new_airq_info(i);
 273                 info = airq_areas[i];
 274                 mutex_unlock(&airq_areas_lock);
 275                 if (!info)
 276                         return 0;
 277                 write_lock_irqsave(&info->lock, flags);
 278                 bit = airq_iv_alloc(info->aiv, nvqs);
 279                 if (bit == -1UL) {
 280                         /* Not enough vacancies. */
 281                         write_unlock_irqrestore(&info->lock, flags);
 282                         continue;
 283                 }
 284                 *first = bit;
 285                 *airq_info = info;
 286                 indicator_addr = (unsigned long)info->aiv->vector;
 287                 for (j = 0; j < nvqs; j++) {
 288                         airq_iv_set_ptr(info->aiv, bit + j,
 289                                         (unsigned long)vqs[j]);
 290                 }
 291                 write_unlock_irqrestore(&info->lock, flags);
 292         }
 293         return indicator_addr;
 294 }
 295
 296 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
 297 {
 298         struct virtio_ccw_vq_info *info;
 299
 300         if (!vcdev->airq_info)
 301                 return;
 302         list_for_each_entry(info, &vcdev->virtqueues, node)
 303                 drop_airq_indicator(info->vq, vcdev->airq_info);
 304 }
 305
 306 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
 307 {
 308         unsigned long flags;
 309         __u32 ret;
 310
 311         spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 312         if (vcdev->err)
 313                 ret = 0;
 314         else
 315                 ret = vcdev->curr_io & flag;
 316         spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 317         return ret;
 318 }
 319
 320 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
 321                          struct ccw1 *ccw, __u32 intparm)
 322 {
 323         int ret;
 324         unsigned long flags;
 325         int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
 326
 327         mutex_lock(&vcdev->io_lock);
 328         do {
 329                 spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 330                 ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
 331                 if (!ret) {
 332                         if (!vcdev->curr_io)
 333                                 vcdev->err = 0;
 334                         vcdev->curr_io |= flag;
 335                 }
 336                 spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 337                 cpu_relax();
 338         } while (ret == -EBUSY);
 339         wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
 340         ret = ret ? ret : vcdev->err;
 341         mutex_unlock(&vcdev->io_lock);
 342         return ret;
 343 }
 344
 345 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
 346                                       struct ccw1 *ccw)
 347 {
 348         int ret;
 349         unsigned long *indicatorp = NULL;
 350         struct virtio_thinint_area *thinint_area = NULL;
 351         struct airq_info *airq_info = vcdev->airq_info;
 352
 353         if (vcdev->is_thinint) {
 354                 thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
 355                                                      sizeof(*thinint_area));
 356                 if (!thinint_area)
 357                         return;
 358                 thinint_area->summary_indicator =
 359                         (unsigned long) get_summary_indicator(airq_info);
 360                 thinint_area->isc = VIRTIO_AIRQ_ISC;
 361                 ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 362                 ccw->count = sizeof(*thinint_area);
 363                 ccw->cda = (__u32)(unsigned long) thinint_area;
 364         } else {
 365                 /* payload is the address of the indicators */
 366                 indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
 367                                                    sizeof(indicators(vcdev)));
 368                 if (!indicatorp)
 369                         return;
 370                 *indicatorp = 0;
 371                 ccw->cmd_code = CCW_CMD_SET_IND;
 372                 ccw->count = sizeof(indicators(vcdev));
 373                 ccw->cda = (__u32)(unsigned long) indicatorp;
 374         }
 375         /* Deregister indicators from host. */
 376         *indicators(vcdev) = 0;
 377         ccw->flags = 0;
 378         ret = ccw_io_helper(vcdev, ccw,
 379                             vcdev->is_thinint ?
 380                             VIRTIO_CCW_DOING_SET_IND_ADAPTER :
 381                             VIRTIO_CCW_DOING_SET_IND);
 382         if (ret && (ret != -ENODEV))
 383                 dev_info(&vcdev->cdev->dev,
 384                          "Failed to deregister indicators (%d)\n", ret);
 385         else if (vcdev->is_thinint)
 386                 virtio_ccw_drop_indicators(vcdev);
 387         ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(indicators(vcdev)));
 388         ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
 389 }
 390
 391 static inline long __do_kvm_notify(struct subchannel_id schid,
 392                                    unsigned long queue_index,
 393                                    long cookie)
 394 {
 395         register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
 396         register struct subchannel_id __schid asm("2") = schid;
 397         register unsigned long __index asm("3") = queue_index;
 398         register long __rc asm("2");
 399         register long __cookie asm("4") = cookie;
 400
 401         asm volatile ("diag 2,4,0x500\n"
 402                       : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
 403                       "d"(__cookie)
 404                       : "memory", "cc");
 405         return __rc;
 406 }
 407
 408 static inline long do_kvm_notify(struct subchannel_id schid,
 409                                  unsigned long queue_index,
 410                                  long cookie)
 411 {
 412         diag_stat_inc(DIAG_STAT_X500);
 413         return __do_kvm_notify(schid, queue_index, cookie);
 414 }
 415
 416 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
 417 {
 418         struct virtio_ccw_vq_info *info = vq->priv;
 419         struct virtio_ccw_device *vcdev;
 420         struct subchannel_id schid;
 421
 422         vcdev = to_vc_device(info->vq->vdev);
 423         ccw_device_get_schid(vcdev->cdev, &schid);
 424         info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
 425         if (info->cookie < 0)
 426                 return false;
 427         return true;
 428 }
 429
 430 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
 431                                    struct ccw1 *ccw, int index)
 432 {
 433         int ret;
 434
 435         vcdev->dma_area->config_block.index = index;
 436         ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
 437         ccw->flags = 0;
 438         ccw->count = sizeof(struct vq_config_block);
 439         ccw->cda = (__u32)(unsigned long)(&vcdev->dma_area->config_block);
 440         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
 441         if (ret)
 442                 return ret;
 443         return vcdev->dma_area->config_block.num ?: -ENOENT;
 444 }
 445
 446 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
 447 {
 448         struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
 449         struct virtio_ccw_vq_info *info = vq->priv;
 450         unsigned long flags;
 451         int ret;
 452         unsigned int index = vq->index;
 453
 454         /* Remove from our list. */
 455         spin_lock_irqsave(&vcdev->lock, flags);
 456         list_del(&info->node);
 457         spin_unlock_irqrestore(&vcdev->lock, flags);
 458
 459         /* Release from host. */
 460         if (vcdev->revision == 0) {
 461                 info->info_block->l.queue = 0;
 462                 info->info_block->l.align = 0;
 463                 info->info_block->l.index = index;
 464                 info->info_block->l.num = 0;
 465                 ccw->count = sizeof(info->info_block->l);
 466         } else {
 467                 info->info_block->s.desc = 0;
 468                 info->info_block->s.index = index;
 469                 info->info_block->s.num = 0;
 470                 info->info_block->s.avail = 0;
 471                 info->info_block->s.used = 0;
 472                 ccw->count = sizeof(info->info_block->s);
 473         }
 474         ccw->cmd_code = CCW_CMD_SET_VQ;
 475         ccw->flags = 0;
 476         ccw->cda = (__u32)(unsigned long)(info->info_block);
 477         ret = ccw_io_helper(vcdev, ccw,
 478                             VIRTIO_CCW_DOING_SET_VQ | index);
 479         /*
 480          * -ENODEV isn't considered an error: The device is gone anyway.
 481          * This may happen on device detach.
 482          */
 483         if (ret && (ret != -ENODEV))
 484                 dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
 485                          ret, index);
 486
 487         vring_del_virtqueue(vq);
 488         ccw_device_dma_free(vcdev->cdev, info->info_block,
 489                             sizeof(*info->info_block));
 490         kfree(info);
 491 }
 492
 493 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
 494 {
 495         struct virtqueue *vq, *n;
 496         struct ccw1 *ccw;
 497         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 498
 499         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 500         if (!ccw)
 501                 return;
 502
 503         virtio_ccw_drop_indicator(vcdev, ccw);
 504
 505         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 506                 virtio_ccw_del_vq(vq, ccw);
 507
 508         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 509 }
 510
 511 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
 512                                              int i, vq_callback_t *callback,
 513                                              const char *name, bool ctx,
 514                                              struct ccw1 *ccw)
 515 {
 516         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 517         int err;
 518         struct virtqueue *vq = NULL;
 519         struct virtio_ccw_vq_info *info;
 520         u64 queue;
 521         unsigned long flags;
 522         bool may_reduce;
 523
 524         /* Allocate queue. */
 525         info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
 526         if (!info) {
 527                 dev_warn(&vcdev->cdev->dev, "no info\n");
 528                 err = -ENOMEM;
 529                 goto out_err;
 530         }
 531         info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
 532                                                  sizeof(*info->info_block));
 533         if (!info->info_block) {
 534                 dev_warn(&vcdev->cdev->dev, "no info block\n");
 535                 err = -ENOMEM;
 536                 goto out_err;
 537         }
 538         info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
 539         if (info->num < 0) {
 540                 err = info->num;
 541                 goto out_err;
 542         }
 543         may_reduce = vcdev->revision > 0;
 544         vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
 545                                     vdev, true, may_reduce, ctx,
 546                                     virtio_ccw_kvm_notify, callback, name);
 547
 548         if (!vq) {
 549                 /* For now, we fail if we can't get the requested size. */
 550                 dev_warn(&vcdev->cdev->dev, "no vq\n");
 551                 err = -ENOMEM;
 552                 goto out_err;
 553         }
 554         /* it may have been reduced */
 555         info->num = virtqueue_get_vring_size(vq);
 556
 557         /* Register it with the host. */
 558         queue = virtqueue_get_desc_addr(vq);
 559         if (vcdev->revision == 0) {
 560                 info->info_block->l.queue = queue;
 561                 info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
 562                 info->info_block->l.index = i;
 563                 info->info_block->l.num = info->num;
 564                 ccw->count = sizeof(info->info_block->l);
 565         } else {
 566                 info->info_block->s.desc = queue;
 567                 info->info_block->s.index = i;
 568                 info->info_block->s.num = info->num;
 569                 info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
 570                 info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
 571                 ccw->count = sizeof(info->info_block->s);
 572         }
 573         ccw->cmd_code = CCW_CMD_SET_VQ;
 574         ccw->flags = 0;
 575         ccw->cda = (__u32)(unsigned long)(info->info_block);
 576         err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
 577         if (err) {
 578                 dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
 579                 goto out_err;
 580         }
 581
 582         info->vq = vq;
 583         vq->priv = info;
 584
 585         /* Save it to our list. */
 586         spin_lock_irqsave(&vcdev->lock, flags);
 587         list_add(&info->node, &vcdev->virtqueues);
 588         spin_unlock_irqrestore(&vcdev->lock, flags);
 589
 590         return vq;
 591
 592 out_err:
 593         if (vq)
 594                 vring_del_virtqueue(vq);
 595         if (info) {
 596                 ccw_device_dma_free(vcdev->cdev, info->info_block,
 597                                     sizeof(*info->info_block));
 598         }
 599         kfree(info);
 600         return ERR_PTR(err);
 601 }
 602
 603 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
 604                                            struct virtqueue *vqs[], int nvqs,
 605                                            struct ccw1 *ccw)
 606 {
 607         int ret;
 608         struct virtio_thinint_area *thinint_area = NULL;
 609         struct airq_info *info;
 610
 611         thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
 612                                              sizeof(*thinint_area));
 613         if (!thinint_area) {
 614                 ret = -ENOMEM;
 615                 goto out;
 616         }
 617         /* Try to get an indicator. */
 618         thinint_area->indicator = get_airq_indicator(vqs, nvqs,
 619                                                      &thinint_area->bit_nr,
 620                                                      &vcdev->airq_info);
 621         if (!thinint_area->indicator) {
 622                 ret = -ENOSPC;
 623                 goto out;
 624         }
 625         info = vcdev->airq_info;
 626         thinint_area->summary_indicator =
 627                 (unsigned long) get_summary_indicator(info);
 628         thinint_area->isc = VIRTIO_AIRQ_ISC;
 629         ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 630         ccw->flags = CCW_FLAG_SLI;
 631         ccw->count = sizeof(*thinint_area);
 632         ccw->cda = (__u32)(unsigned long)thinint_area;
 633         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
 634         if (ret) {
 635                 if (ret == -EOPNOTSUPP) {
 636                         /*
 637                          * The host does not support adapter interrupts
 638                          * for virtio-ccw, stop trying.
 639                          */
 640                         virtio_ccw_use_airq = 0;
 641                         pr_info("Adapter interrupts unsupported on host\n");
 642                 } else
 643                         dev_warn(&vcdev->cdev->dev,
 644                                  "enabling adapter interrupts = %d\n", ret);
 645                 virtio_ccw_drop_indicators(vcdev);
 646         }
 647 out:
 648         ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
 649         return ret;
 650 }
 651
 652 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 653                                struct virtqueue *vqs[],
 654                                vq_callback_t *callbacks[],
 655                                const char * const names[],
 656                                const bool *ctx,
 657                                struct irq_affinity *desc)
 658 {
 659         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 660         unsigned long *indicatorp = NULL;
 661         int ret, i, queue_idx = 0;
 662         struct ccw1 *ccw;
 663
 664         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 665         if (!ccw)
 666                 return -ENOMEM;
 667
 668         for (i = 0; i < nvqs; ++i) {
 669                 if (!names[i]) {
 670                         vqs[i] = NULL;
 671                         continue;
 672                 }
 673
 674                 vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
 675                                              names[i], ctx ? ctx[i] : false,
 676                                              ccw);
 677                 if (IS_ERR(vqs[i])) {
 678                         ret = PTR_ERR(vqs[i]);
 679                         vqs[i] = NULL;
 680                         goto out;
 681                 }
 682         }
 683         ret = -ENOMEM;
 684         /*
 685          * We need a data area under 2G to communicate. Our payload is
 686          * the address of the indicators.
 687         */
 688         indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
 689                                            sizeof(indicators(vcdev)));
 690         if (!indicatorp)
 691                 goto out;
 692         *indicatorp = (unsigned long) indicators(vcdev);
 693         if (vcdev->is_thinint) {
 694                 ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
 695                 if (ret)
 696                         /* no error, just fall back to legacy interrupts */
 697                         vcdev->is_thinint = false;
 698         }
 699         if (!vcdev->is_thinint) {
 700                 /* Register queue indicators with host. */
 701                 *indicators(vcdev) = 0;
 702                 ccw->cmd_code = CCW_CMD_SET_IND;
 703                 ccw->flags = 0;
 704                 ccw->count = sizeof(indicators(vcdev));
 705                 ccw->cda = (__u32)(unsigned long) indicatorp;
 706                 ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
 707                 if (ret)
 708                         goto out;
 709         }
 710         /* Register indicators2 with host for config changes */
 711         *indicatorp = (unsigned long) indicators2(vcdev);
 712         *indicators2(vcdev) = 0;
 713         ccw->cmd_code = CCW_CMD_SET_CONF_IND;
 714         ccw->flags = 0;
 715         ccw->count = sizeof(indicators2(vcdev));
 716         ccw->cda = (__u32)(unsigned long) indicatorp;
 717         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
 718         if (ret)
 719                 goto out;
 720
 721         if (indicatorp)
 722                 ccw_device_dma_free(vcdev->cdev, indicatorp,
 723                                     sizeof(indicators(vcdev)));
 724         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 725         return 0;
 726 out:
 727         if (indicatorp)
 728                 ccw_device_dma_free(vcdev->cdev, indicatorp,
 729                                     sizeof(indicators(vcdev)));
 730         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 731         virtio_ccw_del_vqs(vdev);
 732         return ret;
 733 }
 734
 735 static void virtio_ccw_reset(struct virtio_device *vdev)
 736 {
 737         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 738         struct ccw1 *ccw;
 739
 740         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 741         if (!ccw)
 742                 return;
 743
 744         /* Zero status bits. */
 745         vcdev->dma_area->status = 0;
 746
 747         /* Send a reset ccw on device. */
 748         ccw->cmd_code = CCW_CMD_VDEV_RESET;
 749         ccw->flags = 0;
 750         ccw->count = 0;
 751         ccw->cda = 0;
 752         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
 753         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 754 }
 755
 756 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
 757 {
 758         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 759         struct virtio_feature_desc *features;
 760         int ret;
 761         u64 rc;
 762         struct ccw1 *ccw;
 763
 764         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 765         if (!ccw)
 766                 return 0;
 767
 768         features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
 769         if (!features) {
 770                 rc = 0;
 771                 goto out_free;
 772         }
 773         /* Read the feature bits from the host. */
 774         features->index = 0;
 775         ccw->cmd_code = CCW_CMD_READ_FEAT;
 776         ccw->flags = 0;
 777         ccw->count = sizeof(*features);
 778         ccw->cda = (__u32)(unsigned long)features;
 779         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 780         if (ret) {
 781                 rc = 0;
 782                 goto out_free;
 783         }
 784
 785         rc = le32_to_cpu(features->features);
 786
 787         if (vcdev->revision == 0)
 788                 goto out_free;
 789
 790         /* Read second half of the feature bits from the host. */
 791         features->index = 1;
 792         ccw->cmd_code = CCW_CMD_READ_FEAT;
 793         ccw->flags = 0;
 794         ccw->count = sizeof(*features);
 795         ccw->cda = (__u32)(unsigned long)features;
 796         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 797         if (ret == 0)
 798                 rc |= (u64)le32_to_cpu(features->features) << 32;
 799
 800 out_free:
 801         ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
 802         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 803         return rc;
 804 }
 805
 806 static void ccw_transport_features(struct virtio_device *vdev)
 807 {
 808         /*
 809          * Currently nothing to do here.
 810          */
 811 }
 812
 813 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
 814 {
 815         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 816         struct virtio_feature_desc *features;
 817         struct ccw1 *ccw;
 818         int ret;
 819
 820         if (vcdev->revision >= 1 &&
 821             !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
 822                 dev_err(&vdev->dev, "virtio: device uses revision 1 "
 823                         "but does not have VIRTIO_F_VERSION_1\n");
 824                 return -EINVAL;
 825         }
 826
 827         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 828         if (!ccw)
 829                 return -ENOMEM;
 830
 831         features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
 832         if (!features) {
 833                 ret = -ENOMEM;
 834                 goto out_free;
 835         }
 836         /* Give virtio_ring a chance to accept features. */
 837         vring_transport_features(vdev);
 838
 839         /* Give virtio_ccw a chance to accept features. */
 840         ccw_transport_features(vdev);
 841
 842         features->index = 0;
 843         features->features = cpu_to_le32((u32)vdev->features);
 844         /* Write the first half of the feature bits to the host. */
 845         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 846         ccw->flags = 0;
 847         ccw->count = sizeof(*features);
 848         ccw->cda = (__u32)(unsigned long)features;
 849         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 850         if (ret)
 851                 goto out_free;
 852
 853         if (vcdev->revision == 0)
 854                 goto out_free;
 855
 856         features->index = 1;
 857         features->features = cpu_to_le32(vdev->features >> 32);
 858         /* Write the second half of the feature bits to the host. */
 859         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 860         ccw->flags = 0;
 861         ccw->count = sizeof(*features);
 862         ccw->cda = (__u32)(unsigned long)features;
 863         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 864
 865 out_free:
 866         ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
 867         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 868
 869         return ret;
 870 }
 871
 872 static void virtio_ccw_get_config(struct virtio_device *vdev,
 873                                   unsigned int offset, void *buf, unsigned len)
 874 {
 875         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 876         int ret;
 877         struct ccw1 *ccw;
 878         void *config_area;
 879         unsigned long flags;
 880
 881         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 882         if (!ccw)
 883                 return;
 884
 885         config_area = ccw_device_dma_zalloc(vcdev->cdev,
 886                                             VIRTIO_CCW_CONFIG_SIZE);
 887         if (!config_area)
 888                 goto out_free;
 889
 890         /* Read the config area from the host. */
 891         ccw->cmd_code = CCW_CMD_READ_CONF;
 892         ccw->flags = 0;
 893         ccw->count = offset + len;
 894         ccw->cda = (__u32)(unsigned long)config_area;
 895         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
 896         if (ret)
 897                 goto out_free;
 898
 899         spin_lock_irqsave(&vcdev->lock, flags);
 900         memcpy(vcdev->config, config_area, offset + len);
 901         if (vcdev->config_ready < offset + len)
 902                 vcdev->config_ready = offset + len;
 903         spin_unlock_irqrestore(&vcdev->lock, flags);
 904         if (buf)
 905                 memcpy(buf, config_area + offset, len);
 906
 907 out_free:
 908         ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
 909         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 910 }
 911
 912 static void virtio_ccw_set_config(struct virtio_device *vdev,
 913                                   unsigned int offset, const void *buf,
 914                                   unsigned len)
 915 {
 916         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 917         struct ccw1 *ccw;
 918         void *config_area;
 919         unsigned long flags;
 920
 921         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 922         if (!ccw)
 923                 return;
 924
 925         config_area = ccw_device_dma_zalloc(vcdev->cdev,
 926                                             VIRTIO_CCW_CONFIG_SIZE);
 927         if (!config_area)
 928                 goto out_free;
 929
 930         /* Make sure we don't overwrite fields. */
 931         if (vcdev->config_ready < offset)
 932                 virtio_ccw_get_config(vdev, 0, NULL, offset);
 933         spin_lock_irqsave(&vcdev->lock, flags);
 934         memcpy(&vcdev->config[offset], buf, len);
 935         /* Write the config area to the host. */
 936         memcpy(config_area, vcdev->config, sizeof(vcdev->config));
 937         spin_unlock_irqrestore(&vcdev->lock, flags);
 938         ccw->cmd_code = CCW_CMD_WRITE_CONF;
 939         ccw->flags = 0;
 940         ccw->count = offset + len;
 941         ccw->cda = (__u32)(unsigned long)config_area;
 942         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
 943
 944 out_free:
 945         ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
 946         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 947 }
 948
 949 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
 950 {
 951         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 952         u8 old_status = vcdev->dma_area->status;
 953         struct ccw1 *ccw;
 954
 955         if (vcdev->revision < 1)
 956                 return vcdev->dma_area->status;
 957
 958         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 959         if (!ccw)
 960                 return old_status;
 961
 962         ccw->cmd_code = CCW_CMD_READ_STATUS;
 963         ccw->flags = 0;
 964         ccw->count = sizeof(vcdev->dma_area->status);
 965         ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
 966         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
 967 /*
 968  * If the channel program failed (should only happen if the device
 969  * was hotunplugged, and then we clean up via the machine check
 970  * handler anyway), vcdev->dma_area->status was not overwritten and we just
 971  * return the old status, which is fine.
 972 */
 973         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 974
 975         return vcdev->dma_area->status;
 976 }
 977
 978 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 979 {
 980         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 981         u8 old_status = vcdev->dma_area->status;
 982         struct ccw1 *ccw;
 983         int ret;
 984
 985         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 986         if (!ccw)
 987                 return;
 988
 989         /* Write the status to the host. */
 990         vcdev->dma_area->status = status;
 991         ccw->cmd_code = CCW_CMD_WRITE_STATUS;
 992         ccw->flags = 0;
 993         ccw->count = sizeof(status);
 994         ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
 995         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
 996         /* Write failed? We assume status is unchanged. */
 997         if (ret)
 998                 vcdev->dma_area->status = old_status;
 999         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1000 }
1001
1002 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
1003 {
1004         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1005
1006         return dev_name(&vcdev->cdev->dev);
1007 }
1008
1009 static const struct virtio_config_ops virtio_ccw_config_ops = {
1010         .get_features = virtio_ccw_get_features,
1011         .finalize_features = virtio_ccw_finalize_features,
1012         .get = virtio_ccw_get_config,
1013         .set = virtio_ccw_set_config,
1014         .get_status = virtio_ccw_get_status,
1015         .set_status = virtio_ccw_set_status,
1016         .reset = virtio_ccw_reset,
1017         .find_vqs = virtio_ccw_find_vqs,
1018         .del_vqs = virtio_ccw_del_vqs,
1019         .bus_name = virtio_ccw_bus_name,
1020 };
1021
1022
1023 /*
1024  * ccw bus driver related functions
1025  */
1026
1027 static void virtio_ccw_release_dev(struct device *_d)
1028 {
1029         struct virtio_device *dev = dev_to_virtio(_d);
1030         struct virtio_ccw_device *vcdev = to_vc_device(dev);
1031
1032         ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1033                             sizeof(*vcdev->dma_area));
1034         kfree(vcdev);
1035 }
1036
1037 static int irb_is_error(struct irb *irb)
1038 {
1039         if (scsw_cstat(&irb->scsw) != 0)
1040                 return 1;
1041         if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1042                 return 1;
1043         if (scsw_cc(&irb->scsw) != 0)
1044                 return 1;
1045         return 0;
1046 }
1047
1048 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1049                                               int index)
1050 {
1051         struct virtio_ccw_vq_info *info;
1052         unsigned long flags;
1053         struct virtqueue *vq;
1054
1055         vq = NULL;
1056         spin_lock_irqsave(&vcdev->lock, flags);
1057         list_for_each_entry(info, &vcdev->virtqueues, node) {
1058                 if (info->vq->index == index) {
1059                         vq = info->vq;
1060                         break;
1061                 }
1062         }
1063         spin_unlock_irqrestore(&vcdev->lock, flags);
1064         return vq;
1065 }
1066
1067 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1068                                       __u32 activity)
1069 {
1070         if (vcdev->curr_io & activity) {
1071                 switch (activity) {
1072                 case VIRTIO_CCW_DOING_READ_FEAT:
1073                 case VIRTIO_CCW_DOING_WRITE_FEAT:
1074                 case VIRTIO_CCW_DOING_READ_CONFIG:
1075                 case VIRTIO_CCW_DOING_WRITE_CONFIG:
1076                 case VIRTIO_CCW_DOING_WRITE_STATUS:
1077                 case VIRTIO_CCW_DOING_READ_STATUS:
1078                 case VIRTIO_CCW_DOING_SET_VQ:
1079                 case VIRTIO_CCW_DOING_SET_IND:
1080                 case VIRTIO_CCW_DOING_SET_CONF_IND:
1081                 case VIRTIO_CCW_DOING_RESET:
1082                 case VIRTIO_CCW_DOING_READ_VQ_CONF:
1083                 case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1084                 case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1085                         vcdev->curr_io &= ~activity;
1086                         wake_up(&vcdev->wait_q);
1087                         break;
1088                 default:
1089                         /* don't know what to do... */
1090                         dev_warn(&vcdev->cdev->dev,
1091                                  "Suspicious activity '%08x'\n", activity);
1092                         WARN_ON(1);
1093                         break;
1094                 }
1095         }
1096 }
1097
1098 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1099                                    unsigned long intparm,
1100                                    struct irb *irb)
1101 {
1102         __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1103         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1104         int i;
1105         struct virtqueue *vq;
1106
1107         if (!vcdev)
1108                 return;
1109         if (IS_ERR(irb)) {
1110                 vcdev->err = PTR_ERR(irb);
1111                 virtio_ccw_check_activity(vcdev, activity);
1112                 /* Don't poke around indicators, something's wrong. */
1113                 return;
1114         }
1115         /* Check if it's a notification from the host. */
1116         if ((intparm == 0) &&
1117             (scsw_stctl(&irb->scsw) ==
1118              (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1119                 /* OK */
1120         }
1121         if (irb_is_error(irb)) {
1122                 /* Command reject? */
1123                 if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1124                     (irb->ecw[0] & SNS0_CMD_REJECT))
1125                         vcdev->err = -EOPNOTSUPP;
1126                 else
1127                         /* Map everything else to -EIO. */
1128                         vcdev->err = -EIO;
1129         }
1130         virtio_ccw_check_activity(vcdev, activity);
1131         for_each_set_bit(i, indicators(vcdev),
1132                          sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1133                 /* The bit clear must happen before the vring kick. */
1134                 clear_bit(i, indicators(vcdev));
1135                 barrier();
1136                 vq = virtio_ccw_vq_by_ind(vcdev, i);
1137                 vring_interrupt(0, vq);
1138         }
1139         if (test_bit(0, indicators2(vcdev))) {
1140                 virtio_config_changed(&vcdev->vdev);
1141                 clear_bit(0, indicators2(vcdev));
1142         }
1143 }
1144
1145 /*
1146  * We usually want to autoonline all devices, but give the admin
1147  * a way to exempt devices from this.
1148  */
1149 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1150                      (8*sizeof(long)))
1151 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1152
1153 static char *no_auto = "";
1154
1155 module_param(no_auto, charp, 0444);
1156 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1157
1158 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1159 {
1160         struct ccw_dev_id id;
1161
1162         ccw_device_get_id(cdev, &id);
1163         if (test_bit(id.devno, devs_no_auto[id.ssid]))
1164                 return 0;
1165         return 1;
1166 }
1167
1168 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1169 {
1170         struct ccw_device *cdev = data;
1171         int ret;
1172
1173         ret = ccw_device_set_online(cdev);
1174         if (ret)
1175                 dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1176 }
1177
1178 static int virtio_ccw_probe(struct ccw_device *cdev)
1179 {
1180         cdev->handler = virtio_ccw_int_handler;
1181
1182         if (virtio_ccw_check_autoonline(cdev))
1183                 async_schedule(virtio_ccw_auto_online, cdev);
1184         return 0;
1185 }
1186
1187 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1188 {
1189         unsigned long flags;
1190         struct virtio_ccw_device *vcdev;
1191
1192         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1193         vcdev = dev_get_drvdata(&cdev->dev);
1194         if (!vcdev || vcdev->going_away) {
1195                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1196                 return NULL;
1197         }
1198         vcdev->going_away = true;
1199         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1200         return vcdev;
1201 }
1202
1203 static void virtio_ccw_remove(struct ccw_device *cdev)
1204 {
1205         unsigned long flags;
1206         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1207
1208         if (vcdev && cdev->online) {
1209                 if (vcdev->device_lost)
1210                         virtio_break_device(&vcdev->vdev);
1211                 unregister_virtio_device(&vcdev->vdev);
1212                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1213                 dev_set_drvdata(&cdev->dev, NULL);
1214                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1215         }
1216         cdev->handler = NULL;
1217 }
1218
1219 static int virtio_ccw_offline(struct ccw_device *cdev)
1220 {
1221         unsigned long flags;
1222         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1223
1224         if (!vcdev)
1225                 return 0;
1226         if (vcdev->device_lost)
1227                 virtio_break_device(&vcdev->vdev);
1228         unregister_virtio_device(&vcdev->vdev);
1229         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1230         dev_set_drvdata(&cdev->dev, NULL);
1231         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1232         return 0;
1233 }
1234
1235 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1236 {
1237         struct virtio_rev_info *rev;
1238         struct ccw1 *ccw;
1239         int ret;
1240
1241         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
1242         if (!ccw)
1243                 return -ENOMEM;
1244         rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev));
1245         if (!rev) {
1246                 ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1247                 return -ENOMEM;
1248         }
1249
1250         /* Set transport revision */
1251         ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1252         ccw->flags = 0;
1253         ccw->count = sizeof(*rev);
1254         ccw->cda = (__u32)(unsigned long)rev;
1255
1256         vcdev->revision = VIRTIO_CCW_REV_MAX;
1257         do {
1258                 rev->revision = vcdev->revision;
1259                 /* none of our supported revisions carry payload */
1260                 rev->length = 0;
1261                 ret = ccw_io_helper(vcdev, ccw,
1262                                     VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1263                 if (ret == -EOPNOTSUPP) {
1264                         if (vcdev->revision == 0)
1265                                 /*
1266                                  * The host device does not support setting
1267                                  * the revision: let's operate it in legacy
1268                                  * mode.
1269                                  */
1270                                 ret = 0;
1271                         else
1272                                 vcdev->revision--;
1273                 }
1274         } while (ret == -EOPNOTSUPP);
1275
1276         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1277         ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1278         return ret;
1279 }
1280
1281 static int virtio_ccw_online(struct ccw_device *cdev)
1282 {
1283         int ret;
1284         struct virtio_ccw_device *vcdev;
1285         unsigned long flags;
1286
1287         vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1288         if (!vcdev) {
1289                 dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1290                 ret = -ENOMEM;
1291                 goto out_free;
1292         }
1293         vcdev->vdev.dev.parent = &cdev->dev;
1294         vcdev->cdev = cdev;
1295         vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1296                                                 sizeof(*vcdev->dma_area));
1297         if (!vcdev->dma_area) {
1298                 ret = -ENOMEM;
1299                 goto out_free;
1300         }
1301
1302         vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1303
1304         vcdev->vdev.dev.release = virtio_ccw_release_dev;
1305         vcdev->vdev.config = &virtio_ccw_config_ops;
1306         init_waitqueue_head(&vcdev->wait_q);
1307         INIT_LIST_HEAD(&vcdev->virtqueues);
1308         spin_lock_init(&vcdev->lock);
1309         mutex_init(&vcdev->io_lock);
1310
1311         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1312         dev_set_drvdata(&cdev->dev, vcdev);
1313         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1314         vcdev->vdev.id.vendor = cdev->id.cu_type;
1315         vcdev->vdev.id.device = cdev->id.cu_model;
1316
1317         ret = virtio_ccw_set_transport_rev(vcdev);
1318         if (ret)
1319                 goto out_free;
1320
1321         ret = register_virtio_device(&vcdev->vdev);
1322         if (ret) {
1323                 dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1324                          ret);
1325                 goto out_put;
1326         }
1327         return 0;
1328 out_put:
1329         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1330         dev_set_drvdata(&cdev->dev, NULL);
1331         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1332         put_device(&vcdev->vdev.dev);
1333         return ret;
1334 out_free:
1335         if (vcdev) {
1336                 ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1337                                     sizeof(*vcdev->dma_area));
1338         }
1339         kfree(vcdev);
1340         return ret;
1341 }
1342
1343 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1344 {
1345         int rc;
1346         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1347
1348         /*
1349          * Make sure vcdev is set
1350          * i.e. set_offline/remove callback not already running
1351          */
1352         if (!vcdev)
1353                 return NOTIFY_DONE;
1354
1355         switch (event) {
1356         case CIO_GONE:
1357                 vcdev->device_lost = true;
1358                 rc = NOTIFY_DONE;
1359                 break;
1360         case CIO_OPER:
1361                 rc = NOTIFY_OK;
1362                 break;
1363         default:
1364                 rc = NOTIFY_DONE;
1365                 break;
1366         }
1367         return rc;
1368 }
1369
1370 static struct ccw_device_id virtio_ids[] = {
1371         { CCW_DEVICE(0x3832, 0) },
1372         {},
1373 };
1374
1375 static struct ccw_driver virtio_ccw_driver = {
1376         .driver = {
1377                 .owner = THIS_MODULE,
1378                 .name = "virtio_ccw",
1379         },
1380         .ids = virtio_ids,
1381         .probe = virtio_ccw_probe,
1382         .remove = virtio_ccw_remove,
1383         .set_offline = virtio_ccw_offline,
1384         .set_online = virtio_ccw_online,
1385         .notify = virtio_ccw_cio_notify,
1386         .int_class = IRQIO_VIR,
1387 };
1388
1389 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1390                            int max_digit, int max_val)
1391 {
1392         int diff;
1393
1394         diff = 0;
1395         *val = 0;
1396
1397         while (diff <= max_digit) {
1398                 int value = hex_to_bin(**cp);
1399
1400                 if (value < 0)
1401                         break;
1402                 *val = *val * 16 + value;
1403                 (*cp)++;
1404                 diff++;
1405         }
1406
1407         if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1408                 return 1;
1409
1410         return 0;
1411 }
1412
1413 static int __init parse_busid(char *str, unsigned int *cssid,
1414                               unsigned int *ssid, unsigned int *devno)
1415 {
1416         char *str_work;
1417         int rc, ret;
1418
1419         rc = 1;
1420
1421         if (*str == '\0')
1422                 goto out;
1423
1424         str_work = str;
1425         ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1426         if (ret || (str_work[0] != '.'))
1427                 goto out;
1428         str_work++;
1429         ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1430         if (ret || (str_work[0] != '.'))
1431                 goto out;
1432         str_work++;
1433         ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1434         if (ret || (str_work[0] != '\0'))
1435                 goto out;
1436
1437         rc = 0;
1438 out:
1439         return rc;
1440 }
1441
1442 static void __init no_auto_parse(void)
1443 {
1444         unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1445         char *parm, *str;
1446         int rc;
1447
1448         str = no_auto;
1449         while ((parm = strsep(&str, ","))) {
1450                 rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1451                                  &from_ssid, &from);
1452                 if (rc)
1453                         continue;
1454                 if (parm != NULL) {
1455                         rc = parse_busid(parm, &to_cssid,
1456                                          &to_ssid, &to);
1457                         if ((from_ssid > to_ssid) ||
1458                             ((from_ssid == to_ssid) && (from > to)))
1459                                 rc = -EINVAL;
1460                 } else {
1461                         to_cssid = from_cssid;
1462                         to_ssid = from_ssid;
1463                         to = from;
1464                 }
1465                 if (rc)
1466                         continue;
1467                 while ((from_ssid < to_ssid) ||
1468                        ((from_ssid == to_ssid) && (from <= to))) {
1469                         set_bit(from, devs_no_auto[from_ssid]);
1470                         from++;
1471                         if (from > __MAX_SUBCHANNEL) {
1472                                 from_ssid++;
1473                                 from = 0;
1474                         }
1475                 }
1476         }
1477 }
1478
1479 static int __init virtio_ccw_init(void)
1480 {
1481         int rc;
1482
1483         /* parse no_auto string before we do anything further */
1484         no_auto_parse();
1485
1486         summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1487         if (!summary_indicators)
1488                 return -ENOMEM;
1489         rc = ccw_driver_register(&virtio_ccw_driver);
1490         if (rc)
1491                 cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1492         return rc;
1493 }
1494 device_initcall(virtio_ccw_init);