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 #include <asm/tpi.h>
  37
  38 /*
  39  * virtio related functions
  40  */
  41
  42 struct vq_config_block {
  43         __u16 index;
  44         __u16 num;
  45 } __packed;
  46
  47 #define VIRTIO_CCW_CONFIG_SIZE 0x100
  48 /* same as PCI config space size, should be enough for all drivers */
  49
  50 struct vcdev_dma_area {
  51         unsigned long indicators;
  52         unsigned long indicators2;
  53         struct vq_config_block config_block;
  54         __u8 status;
  55 };
  56
  57 struct virtio_ccw_device {
  58         struct virtio_device vdev;
  59         __u8 config[VIRTIO_CCW_CONFIG_SIZE];
  60         struct ccw_device *cdev;
  61         __u32 curr_io;
  62         int err;
  63         unsigned int revision; /* Transport revision */
  64         wait_queue_head_t wait_q;
  65         spinlock_t lock;
  66         rwlock_t irq_lock;
  67         struct mutex io_lock; /* Serializes I/O requests */
  68         struct list_head virtqueues;
  69         bool is_thinint;
  70         bool going_away;
  71         bool device_lost;
  72         unsigned int config_ready;
  73         void *airq_info;
  74         struct vcdev_dma_area *dma_area;
  75 };
  76
  77 static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
  78 {
  79         return &vcdev->dma_area->indicators;
  80 }
  81
  82 static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
  83 {
  84         return &vcdev->dma_area->indicators2;
  85 }
  86
  87 struct vq_info_block_legacy {
  88         __u64 queue;
  89         __u32 align;
  90         __u16 index;
  91         __u16 num;
  92 } __packed;
  93
  94 struct vq_info_block {
  95         __u64 desc;
  96         __u32 res0;
  97         __u16 index;
  98         __u16 num;
  99         __u64 avail;
 100         __u64 used;
 101 } __packed;
 102
 103 struct virtio_feature_desc {
 104         __le32 features;
 105         __u8 index;
 106 } __packed;
 107
 108 struct virtio_thinint_area {
 109         unsigned long summary_indicator;
 110         unsigned long indicator;
 111         u64 bit_nr;
 112         u8 isc;
 113 } __packed;
 114
 115 struct virtio_rev_info {
 116         __u16 revision;
 117         __u16 length;
 118         __u8 data[];
 119 };
 120
 121 /* the highest virtio-ccw revision we support */
 122 #define VIRTIO_CCW_REV_MAX 2
 123
 124 struct virtio_ccw_vq_info {
 125         struct virtqueue *vq;
 126         int num;
 127         union {
 128                 struct vq_info_block s;
 129                 struct vq_info_block_legacy l;
 130         } *info_block;
 131         int bit_nr;
 132         struct list_head node;
 133         long cookie;
 134 };
 135
 136 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
 137
 138 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
 139 #define MAX_AIRQ_AREAS 20
 140
 141 static int virtio_ccw_use_airq = 1;
 142
 143 struct airq_info {
 144         rwlock_t lock;
 145         u8 summary_indicator_idx;
 146         struct airq_struct airq;
 147         struct airq_iv *aiv;
 148 };
 149 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
 150 static DEFINE_MUTEX(airq_areas_lock);
 151
 152 static u8 *summary_indicators;
 153
 154 static inline u8 *get_summary_indicator(struct airq_info *info)
 155 {
 156         return summary_indicators + info->summary_indicator_idx;
 157 }
 158
 159 #define CCW_CMD_SET_VQ 0x13
 160 #define CCW_CMD_VDEV_RESET 0x33
 161 #define CCW_CMD_SET_IND 0x43
 162 #define CCW_CMD_SET_CONF_IND 0x53
 163 #define CCW_CMD_READ_FEAT 0x12
 164 #define CCW_CMD_WRITE_FEAT 0x11
 165 #define CCW_CMD_READ_CONF 0x22
 166 #define CCW_CMD_WRITE_CONF 0x21
 167 #define CCW_CMD_WRITE_STATUS 0x31
 168 #define CCW_CMD_READ_VQ_CONF 0x32
 169 #define CCW_CMD_READ_STATUS 0x72
 170 #define CCW_CMD_SET_IND_ADAPTER 0x73
 171 #define CCW_CMD_SET_VIRTIO_REV 0x83
 172
 173 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
 174 #define VIRTIO_CCW_DOING_RESET 0x00040000
 175 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
 176 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
 177 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
 178 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
 179 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
 180 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
 181 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
 182 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
 183 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
 184 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
 185 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
 186 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
 187
 188 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
 189 {
 190         return container_of(vdev, struct virtio_ccw_device, vdev);
 191 }
 192
 193 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
 194 {
 195         unsigned long i, flags;
 196
 197         write_lock_irqsave(&info->lock, flags);
 198         for (i = 0; i < airq_iv_end(info->aiv); i++) {
 199                 if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
 200                         airq_iv_free_bit(info->aiv, i);
 201                         airq_iv_set_ptr(info->aiv, i, 0);
 202                         break;
 203                 }
 204         }
 205         write_unlock_irqrestore(&info->lock, flags);
 206 }
 207
 208 static void virtio_airq_handler(struct airq_struct *airq,
 209                                 struct tpi_info *tpi_info)
 210 {
 211         struct airq_info *info = container_of(airq, struct airq_info, airq);
 212         unsigned long ai;
 213
 214         inc_irq_stat(IRQIO_VAI);
 215         read_lock(&info->lock);
 216         /* Walk through indicators field, summary indicator active. */
 217         for (ai = 0;;) {
 218                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 219                 if (ai == -1UL)
 220                         break;
 221                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 222         }
 223         *(get_summary_indicator(info)) = 0;
 224         smp_wmb();
 225         /* Walk through indicators field, summary indicator not active. */
 226         for (ai = 0;;) {
 227                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 228                 if (ai == -1UL)
 229                         break;
 230                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 231         }
 232         read_unlock(&info->lock);
 233 }
 234
 235 static struct airq_info *new_airq_info(int index)
 236 {
 237         struct airq_info *info;
 238         int rc;
 239
 240         info = kzalloc(sizeof(*info), GFP_KERNEL);
 241         if (!info)
 242                 return NULL;
 243         rwlock_init(&info->lock);
 244         info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
 245                                    | AIRQ_IV_CACHELINE, NULL);
 246         if (!info->aiv) {
 247                 kfree(info);
 248                 return NULL;
 249         }
 250         info->airq.handler = virtio_airq_handler;
 251         info->summary_indicator_idx = index;
 252         info->airq.lsi_ptr = get_summary_indicator(info);
 253         info->airq.isc = VIRTIO_AIRQ_ISC;
 254         rc = register_adapter_interrupt(&info->airq);
 255         if (rc) {
 256                 airq_iv_release(info->aiv);
 257                 kfree(info);
 258                 return NULL;
 259         }
 260         return info;
 261 }
 262
 263 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
 264                                         u64 *first, void **airq_info)
 265 {
 266         int i, j;
 267         struct airq_info *info;
 268         unsigned long indicator_addr = 0;
 269         unsigned long bit, flags;
 270
 271         for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
 272                 mutex_lock(&airq_areas_lock);
 273                 if (!airq_areas[i])
 274                         airq_areas[i] = new_airq_info(i);
 275                 info = airq_areas[i];
 276                 mutex_unlock(&airq_areas_lock);
 277                 if (!info)
 278                         return 0;
 279                 write_lock_irqsave(&info->lock, flags);
 280                 bit = airq_iv_alloc(info->aiv, nvqs);
 281                 if (bit == -1UL) {
 282                         /* Not enough vacancies. */
 283                         write_unlock_irqrestore(&info->lock, flags);
 284                         continue;
 285                 }
 286                 *first = bit;
 287                 *airq_info = info;
 288                 indicator_addr = (unsigned long)info->aiv->vector;
 289                 for (j = 0; j < nvqs; j++) {
 290                         airq_iv_set_ptr(info->aiv, bit + j,
 291                                         (unsigned long)vqs[j]);
 292                 }
 293                 write_unlock_irqrestore(&info->lock, flags);
 294         }
 295         return indicator_addr;
 296 }
 297
 298 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
 299 {
 300         struct virtio_ccw_vq_info *info;
 301
 302         if (!vcdev->airq_info)
 303                 return;
 304         list_for_each_entry(info, &vcdev->virtqueues, node)
 305                 drop_airq_indicator(info->vq, vcdev->airq_info);
 306 }
 307
 308 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
 309 {
 310         unsigned long flags;
 311         __u32 ret;
 312
 313         spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 314         if (vcdev->err)
 315                 ret = 0;
 316         else
 317                 ret = vcdev->curr_io & flag;
 318         spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 319         return ret;
 320 }
 321
 322 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
 323                          struct ccw1 *ccw, __u32 intparm)
 324 {
 325         int ret;
 326         unsigned long flags;
 327         int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
 328
 329         mutex_lock(&vcdev->io_lock);
 330         do {
 331                 spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 332                 ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
 333                 if (!ret) {
 334                         if (!vcdev->curr_io)
 335                                 vcdev->err = 0;
 336                         vcdev->curr_io |= flag;
 337                 }
 338                 spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 339                 cpu_relax();
 340         } while (ret == -EBUSY);
 341         wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
 342         ret = ret ? ret : vcdev->err;
 343         mutex_unlock(&vcdev->io_lock);
 344         return ret;
 345 }
 346
 347 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
 348                                       struct ccw1 *ccw)
 349 {
 350         int ret;
 351         unsigned long *indicatorp = NULL;
 352         struct virtio_thinint_area *thinint_area = NULL;
 353         struct airq_info *airq_info = vcdev->airq_info;
 354
 355         if (vcdev->is_thinint) {
 356                 thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
 357                                                      sizeof(*thinint_area));
 358                 if (!thinint_area)
 359                         return;
 360                 thinint_area->summary_indicator =
 361                         (unsigned long) get_summary_indicator(airq_info);
 362                 thinint_area->isc = VIRTIO_AIRQ_ISC;
 363                 ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 364                 ccw->count = sizeof(*thinint_area);
 365                 ccw->cda = (__u32)virt_to_phys(thinint_area);
 366         } else {
 367                 /* payload is the address of the indicators */
 368                 indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
 369                                                    sizeof(indicators(vcdev)));
 370                 if (!indicatorp)
 371                         return;
 372                 *indicatorp = 0;
 373                 ccw->cmd_code = CCW_CMD_SET_IND;
 374                 ccw->count = sizeof(indicators(vcdev));
 375                 ccw->cda = (__u32)virt_to_phys(indicatorp);
 376         }
 377         /* Deregister indicators from host. */
 378         *indicators(vcdev) = 0;
 379         ccw->flags = 0;
 380         ret = ccw_io_helper(vcdev, ccw,
 381                             vcdev->is_thinint ?
 382                             VIRTIO_CCW_DOING_SET_IND_ADAPTER :
 383                             VIRTIO_CCW_DOING_SET_IND);
 384         if (ret && (ret != -ENODEV))
 385                 dev_info(&vcdev->cdev->dev,
 386                          "Failed to deregister indicators (%d)\n", ret);
 387         else if (vcdev->is_thinint)
 388                 virtio_ccw_drop_indicators(vcdev);
 389         ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(indicators(vcdev)));
 390         ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
 391 }
 392
 393 static inline bool virtio_ccw_do_kvm_notify(struct virtqueue *vq, u32 data)
 394 {
 395         struct virtio_ccw_vq_info *info = vq->priv;
 396         struct virtio_ccw_device *vcdev;
 397         struct subchannel_id schid;
 398
 399         vcdev = to_vc_device(info->vq->vdev);
 400         ccw_device_get_schid(vcdev->cdev, &schid);
 401         BUILD_BUG_ON(sizeof(struct subchannel_id) != sizeof(unsigned int));
 402         info->cookie = kvm_hypercall3(KVM_S390_VIRTIO_CCW_NOTIFY,
 403                                       *((unsigned int *)&schid),
 404                                       data, info->cookie);
 405         if (info->cookie < 0)
 406                 return false;
 407         return true;
 408 }
 409
 410 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
 411 {
 412         return virtio_ccw_do_kvm_notify(vq, vq->index);
 413 }
 414
 415 static bool virtio_ccw_kvm_notify_with_data(struct virtqueue *vq)
 416 {
 417         return virtio_ccw_do_kvm_notify(vq, vring_notification_data(vq));
 418 }
 419
 420 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
 421                                    struct ccw1 *ccw, int index)
 422 {
 423         int ret;
 424
 425         vcdev->dma_area->config_block.index = index;
 426         ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
 427         ccw->flags = 0;
 428         ccw->count = sizeof(struct vq_config_block);
 429         ccw->cda = (__u32)virt_to_phys(&vcdev->dma_area->config_block);
 430         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
 431         if (ret)
 432                 return ret;
 433         return vcdev->dma_area->config_block.num ?: -ENOENT;
 434 }
 435
 436 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
 437 {
 438         struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
 439         struct virtio_ccw_vq_info *info = vq->priv;
 440         unsigned long flags;
 441         int ret;
 442         unsigned int index = vq->index;
 443
 444         /* Remove from our list. */
 445         spin_lock_irqsave(&vcdev->lock, flags);
 446         list_del(&info->node);
 447         spin_unlock_irqrestore(&vcdev->lock, flags);
 448
 449         /* Release from host. */
 450         if (vcdev->revision == 0) {
 451                 info->info_block->l.queue = 0;
 452                 info->info_block->l.align = 0;
 453                 info->info_block->l.index = index;
 454                 info->info_block->l.num = 0;
 455                 ccw->count = sizeof(info->info_block->l);
 456         } else {
 457                 info->info_block->s.desc = 0;
 458                 info->info_block->s.index = index;
 459                 info->info_block->s.num = 0;
 460                 info->info_block->s.avail = 0;
 461                 info->info_block->s.used = 0;
 462                 ccw->count = sizeof(info->info_block->s);
 463         }
 464         ccw->cmd_code = CCW_CMD_SET_VQ;
 465         ccw->flags = 0;
 466         ccw->cda = (__u32)virt_to_phys(info->info_block);
 467         ret = ccw_io_helper(vcdev, ccw,
 468                             VIRTIO_CCW_DOING_SET_VQ | index);
 469         /*
 470          * -ENODEV isn't considered an error: The device is gone anyway.
 471          * This may happen on device detach.
 472          */
 473         if (ret && (ret != -ENODEV))
 474                 dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
 475                          ret, index);
 476
 477         vring_del_virtqueue(vq);
 478         ccw_device_dma_free(vcdev->cdev, info->info_block,
 479                             sizeof(*info->info_block));
 480         kfree(info);
 481 }
 482
 483 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
 484 {
 485         struct virtqueue *vq, *n;
 486         struct ccw1 *ccw;
 487         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 488
 489         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 490         if (!ccw)
 491                 return;
 492
 493         virtio_ccw_drop_indicator(vcdev, ccw);
 494
 495         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 496                 virtio_ccw_del_vq(vq, ccw);
 497
 498         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 499 }
 500
 501 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
 502                                              int i, vq_callback_t *callback,
 503                                              const char *name, bool ctx,
 504                                              struct ccw1 *ccw)
 505 {
 506         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 507         bool (*notify)(struct virtqueue *vq);
 508         int err;
 509         struct virtqueue *vq = NULL;
 510         struct virtio_ccw_vq_info *info;
 511         u64 queue;
 512         unsigned long flags;
 513         bool may_reduce;
 514
 515         if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))
 516                 notify = virtio_ccw_kvm_notify_with_data;
 517         else
 518                 notify = virtio_ccw_kvm_notify;
 519
 520         /* Allocate queue. */
 521         info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
 522         if (!info) {
 523                 dev_warn(&vcdev->cdev->dev, "no info\n");
 524                 err = -ENOMEM;
 525                 goto out_err;
 526         }
 527         info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
 528                                                  sizeof(*info->info_block));
 529         if (!info->info_block) {
 530                 dev_warn(&vcdev->cdev->dev, "no info block\n");
 531                 err = -ENOMEM;
 532                 goto out_err;
 533         }
 534         info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
 535         if (info->num < 0) {
 536                 err = info->num;
 537                 goto out_err;
 538         }
 539         may_reduce = vcdev->revision > 0;
 540         vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
 541                                     vdev, true, may_reduce, ctx,
 542                                     notify, callback, name);
 543
 544         if (!vq) {
 545                 /* For now, we fail if we can't get the requested size. */
 546                 dev_warn(&vcdev->cdev->dev, "no vq\n");
 547                 err = -ENOMEM;
 548                 goto out_err;
 549         }
 550
 551         vq->num_max = info->num;
 552
 553         /* it may have been reduced */
 554         info->num = virtqueue_get_vring_size(vq);
 555
 556         /* Register it with the host. */
 557         queue = virtqueue_get_desc_addr(vq);
 558         if (vcdev->revision == 0) {
 559                 info->info_block->l.queue = queue;
 560                 info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
 561                 info->info_block->l.index = i;
 562                 info->info_block->l.num = info->num;
 563                 ccw->count = sizeof(info->info_block->l);
 564         } else {
 565                 info->info_block->s.desc = queue;
 566                 info->info_block->s.index = i;
 567                 info->info_block->s.num = info->num;
 568                 info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
 569                 info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
 570                 ccw->count = sizeof(info->info_block->s);
 571         }
 572         ccw->cmd_code = CCW_CMD_SET_VQ;
 573         ccw->flags = 0;
 574         ccw->cda = (__u32)virt_to_phys(info->info_block);
 575         err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
 576         if (err) {
 577                 dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
 578                 goto out_err;
 579         }
 580
 581         info->vq = vq;
 582         vq->priv = info;
 583
 584         /* Save it to our list. */
 585         spin_lock_irqsave(&vcdev->lock, flags);
 586         list_add(&info->node, &vcdev->virtqueues);
 587         spin_unlock_irqrestore(&vcdev->lock, flags);
 588
 589         return vq;
 590
 591 out_err:
 592         if (vq)
 593                 vring_del_virtqueue(vq);
 594         if (info) {
 595                 ccw_device_dma_free(vcdev->cdev, info->info_block,
 596                                     sizeof(*info->info_block));
 597         }
 598         kfree(info);
 599         return ERR_PTR(err);
 600 }
 601
 602 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
 603                                            struct virtqueue *vqs[], int nvqs,
 604                                            struct ccw1 *ccw)
 605 {
 606         int ret;
 607         struct virtio_thinint_area *thinint_area = NULL;
 608         unsigned long indicator_addr;
 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         indicator_addr = get_airq_indicator(vqs, nvqs,
 619                                             &thinint_area->bit_nr,
 620                                             &vcdev->airq_info);
 621         if (!indicator_addr) {
 622                 ret = -ENOSPC;
 623                 goto out;
 624         }
 625         thinint_area->indicator = virt_to_phys((void *)indicator_addr);
 626         info = vcdev->airq_info;
 627         thinint_area->summary_indicator =
 628                 virt_to_phys(get_summary_indicator(info));
 629         thinint_area->isc = VIRTIO_AIRQ_ISC;
 630         ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 631         ccw->flags = CCW_FLAG_SLI;
 632         ccw->count = sizeof(*thinint_area);
 633         ccw->cda = (__u32)virt_to_phys(thinint_area);
 634         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
 635         if (ret) {
 636                 if (ret == -EOPNOTSUPP) {
 637                         /*
 638                          * The host does not support adapter interrupts
 639                          * for virtio-ccw, stop trying.
 640                          */
 641                         virtio_ccw_use_airq = 0;
 642                         pr_info("Adapter interrupts unsupported on host\n");
 643                 } else
 644                         dev_warn(&vcdev->cdev->dev,
 645                                  "enabling adapter interrupts = %d\n", ret);
 646                 virtio_ccw_drop_indicators(vcdev);
 647         }
 648 out:
 649         ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
 650         return ret;
 651 }
 652
 653 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 654                                struct virtqueue *vqs[],
 655                                vq_callback_t *callbacks[],
 656                                const char * const names[],
 657                                const bool *ctx,
 658                                struct irq_affinity *desc)
 659 {
 660         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 661         unsigned long *indicatorp = NULL;
 662         int ret, i, queue_idx = 0;
 663         struct ccw1 *ccw;
 664
 665         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 666         if (!ccw)
 667                 return -ENOMEM;
 668
 669         for (i = 0; i < nvqs; ++i) {
 670                 if (!names[i]) {
 671                         vqs[i] = NULL;
 672                         continue;
 673                 }
 674
 675                 vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
 676                                              names[i], ctx ? ctx[i] : false,
 677                                              ccw);
 678                 if (IS_ERR(vqs[i])) {
 679                         ret = PTR_ERR(vqs[i]);
 680                         vqs[i] = NULL;
 681                         goto out;
 682                 }
 683         }
 684         ret = -ENOMEM;
 685         /*
 686          * We need a data area under 2G to communicate. Our payload is
 687          * the address of the indicators.
 688         */
 689         indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
 690                                            sizeof(indicators(vcdev)));
 691         if (!indicatorp)
 692                 goto out;
 693         *indicatorp = (unsigned long) indicators(vcdev);
 694         if (vcdev->is_thinint) {
 695                 ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
 696                 if (ret)
 697                         /* no error, just fall back to legacy interrupts */
 698                         vcdev->is_thinint = false;
 699         }
 700         if (!vcdev->is_thinint) {
 701                 /* Register queue indicators with host. */
 702                 *indicators(vcdev) = 0;
 703                 ccw->cmd_code = CCW_CMD_SET_IND;
 704                 ccw->flags = 0;
 705                 ccw->count = sizeof(indicators(vcdev));
 706                 ccw->cda = (__u32)virt_to_phys(indicatorp);
 707                 ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
 708                 if (ret)
 709                         goto out;
 710         }
 711         /* Register indicators2 with host for config changes */
 712         *indicatorp = (unsigned long) indicators2(vcdev);
 713         *indicators2(vcdev) = 0;
 714         ccw->cmd_code = CCW_CMD_SET_CONF_IND;
 715         ccw->flags = 0;
 716         ccw->count = sizeof(indicators2(vcdev));
 717         ccw->cda = (__u32)virt_to_phys(indicatorp);
 718         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
 719         if (ret)
 720                 goto out;
 721
 722         if (indicatorp)
 723                 ccw_device_dma_free(vcdev->cdev, indicatorp,
 724                                     sizeof(indicators(vcdev)));
 725         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 726         return 0;
 727 out:
 728         if (indicatorp)
 729                 ccw_device_dma_free(vcdev->cdev, indicatorp,
 730                                     sizeof(indicators(vcdev)));
 731         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 732         virtio_ccw_del_vqs(vdev);
 733         return ret;
 734 }
 735
 736 static void virtio_ccw_reset(struct virtio_device *vdev)
 737 {
 738         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 739         struct ccw1 *ccw;
 740
 741         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 742         if (!ccw)
 743                 return;
 744
 745         /* Zero status bits. */
 746         vcdev->dma_area->status = 0;
 747
 748         /* Send a reset ccw on device. */
 749         ccw->cmd_code = CCW_CMD_VDEV_RESET;
 750         ccw->flags = 0;
 751         ccw->count = 0;
 752         ccw->cda = 0;
 753         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
 754         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 755 }
 756
 757 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
 758 {
 759         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 760         struct virtio_feature_desc *features;
 761         int ret;
 762         u64 rc;
 763         struct ccw1 *ccw;
 764
 765         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 766         if (!ccw)
 767                 return 0;
 768
 769         features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
 770         if (!features) {
 771                 rc = 0;
 772                 goto out_free;
 773         }
 774         /* Read the feature bits from the host. */
 775         features->index = 0;
 776         ccw->cmd_code = CCW_CMD_READ_FEAT;
 777         ccw->flags = 0;
 778         ccw->count = sizeof(*features);
 779         ccw->cda = (__u32)virt_to_phys(features);
 780         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 781         if (ret) {
 782                 rc = 0;
 783                 goto out_free;
 784         }
 785
 786         rc = le32_to_cpu(features->features);
 787
 788         if (vcdev->revision == 0)
 789                 goto out_free;
 790
 791         /* Read second half of the feature bits from the host. */
 792         features->index = 1;
 793         ccw->cmd_code = CCW_CMD_READ_FEAT;
 794         ccw->flags = 0;
 795         ccw->count = sizeof(*features);
 796         ccw->cda = (__u32)virt_to_phys(features);
 797         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 798         if (ret == 0)
 799                 rc |= (u64)le32_to_cpu(features->features) << 32;
 800
 801 out_free:
 802         ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
 803         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 804         return rc;
 805 }
 806
 807 static void ccw_transport_features(struct virtio_device *vdev)
 808 {
 809         /*
 810          * Currently nothing to do here.
 811          */
 812 }
 813
 814 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
 815 {
 816         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 817         struct virtio_feature_desc *features;
 818         struct ccw1 *ccw;
 819         int ret;
 820
 821         if (vcdev->revision >= 1 &&
 822             !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
 823                 dev_err(&vdev->dev, "virtio: device uses revision 1 "
 824                         "but does not have VIRTIO_F_VERSION_1\n");
 825                 return -EINVAL;
 826         }
 827
 828         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 829         if (!ccw)
 830                 return -ENOMEM;
 831
 832         features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
 833         if (!features) {
 834                 ret = -ENOMEM;
 835                 goto out_free;
 836         }
 837         /* Give virtio_ring a chance to accept features. */
 838         vring_transport_features(vdev);
 839
 840         /* Give virtio_ccw a chance to accept features. */
 841         ccw_transport_features(vdev);
 842
 843         features->index = 0;
 844         features->features = cpu_to_le32((u32)vdev->features);
 845         /* Write the first half of the feature bits to the host. */
 846         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 847         ccw->flags = 0;
 848         ccw->count = sizeof(*features);
 849         ccw->cda = (__u32)virt_to_phys(features);
 850         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 851         if (ret)
 852                 goto out_free;
 853
 854         if (vcdev->revision == 0)
 855                 goto out_free;
 856
 857         features->index = 1;
 858         features->features = cpu_to_le32(vdev->features >> 32);
 859         /* Write the second half of the feature bits to the host. */
 860         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 861         ccw->flags = 0;
 862         ccw->count = sizeof(*features);
 863         ccw->cda = (__u32)virt_to_phys(features);
 864         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 865
 866 out_free:
 867         ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
 868         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 869
 870         return ret;
 871 }
 872
 873 static void virtio_ccw_get_config(struct virtio_device *vdev,
 874                                   unsigned int offset, void *buf, unsigned len)
 875 {
 876         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 877         int ret;
 878         struct ccw1 *ccw;
 879         void *config_area;
 880         unsigned long flags;
 881
 882         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 883         if (!ccw)
 884                 return;
 885
 886         config_area = ccw_device_dma_zalloc(vcdev->cdev,
 887                                             VIRTIO_CCW_CONFIG_SIZE);
 888         if (!config_area)
 889                 goto out_free;
 890
 891         /* Read the config area from the host. */
 892         ccw->cmd_code = CCW_CMD_READ_CONF;
 893         ccw->flags = 0;
 894         ccw->count = offset + len;
 895         ccw->cda = (__u32)virt_to_phys(config_area);
 896         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
 897         if (ret)
 898                 goto out_free;
 899
 900         spin_lock_irqsave(&vcdev->lock, flags);
 901         memcpy(vcdev->config, config_area, offset + len);
 902         if (vcdev->config_ready < offset + len)
 903                 vcdev->config_ready = offset + len;
 904         spin_unlock_irqrestore(&vcdev->lock, flags);
 905         if (buf)
 906                 memcpy(buf, config_area + offset, len);
 907
 908 out_free:
 909         ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
 910         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 911 }
 912
 913 static void virtio_ccw_set_config(struct virtio_device *vdev,
 914                                   unsigned int offset, const void *buf,
 915                                   unsigned len)
 916 {
 917         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 918         struct ccw1 *ccw;
 919         void *config_area;
 920         unsigned long flags;
 921
 922         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 923         if (!ccw)
 924                 return;
 925
 926         config_area = ccw_device_dma_zalloc(vcdev->cdev,
 927                                             VIRTIO_CCW_CONFIG_SIZE);
 928         if (!config_area)
 929                 goto out_free;
 930
 931         /* Make sure we don't overwrite fields. */
 932         if (vcdev->config_ready < offset)
 933                 virtio_ccw_get_config(vdev, 0, NULL, offset);
 934         spin_lock_irqsave(&vcdev->lock, flags);
 935         memcpy(&vcdev->config[offset], buf, len);
 936         /* Write the config area to the host. */
 937         memcpy(config_area, vcdev->config, sizeof(vcdev->config));
 938         spin_unlock_irqrestore(&vcdev->lock, flags);
 939         ccw->cmd_code = CCW_CMD_WRITE_CONF;
 940         ccw->flags = 0;
 941         ccw->count = offset + len;
 942         ccw->cda = (__u32)virt_to_phys(config_area);
 943         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
 944
 945 out_free:
 946         ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
 947         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 948 }
 949
 950 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
 951 {
 952         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 953         u8 old_status = vcdev->dma_area->status;
 954         struct ccw1 *ccw;
 955
 956         if (vcdev->revision < 2)
 957                 return vcdev->dma_area->status;
 958
 959         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 960         if (!ccw)
 961                 return old_status;
 962
 963         ccw->cmd_code = CCW_CMD_READ_STATUS;
 964         ccw->flags = 0;
 965         ccw->count = sizeof(vcdev->dma_area->status);
 966         ccw->cda = (__u32)virt_to_phys(&vcdev->dma_area->status);
 967         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
 968 /*
 969  * If the channel program failed (should only happen if the device
 970  * was hotunplugged, and then we clean up via the machine check
 971  * handler anyway), vcdev->dma_area->status was not overwritten and we just
 972  * return the old status, which is fine.
 973 */
 974         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 975
 976         return vcdev->dma_area->status;
 977 }
 978
 979 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 980 {
 981         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 982         u8 old_status = vcdev->dma_area->status;
 983         struct ccw1 *ccw;
 984         int ret;
 985
 986         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 987         if (!ccw)
 988                 return;
 989
 990         /* Write the status to the host. */
 991         vcdev->dma_area->status = status;
 992         ccw->cmd_code = CCW_CMD_WRITE_STATUS;
 993         ccw->flags = 0;
 994         ccw->count = sizeof(status);
 995         ccw->cda = (__u32)virt_to_phys(&vcdev->dma_area->status);
 996         /* We use ssch for setting the status which is a serializing
 997          * instruction that guarantees the memory writes have
 998          * completed before ssch.
 999          */
1000         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
1001         /* Write failed? We assume status is unchanged. */
1002         if (ret)
1003                 vcdev->dma_area->status = old_status;
1004         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1005 }
1006
1007 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
1008 {
1009         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1010
1011         return dev_name(&vcdev->cdev->dev);
1012 }
1013
1014 static void virtio_ccw_synchronize_cbs(struct virtio_device *vdev)
1015 {
1016         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1017         struct airq_info *info = vcdev->airq_info;
1018
1019         if (info) {
1020                 /*
1021                  * This device uses adapter interrupts: synchronize with
1022                  * vring_interrupt() called by virtio_airq_handler()
1023                  * via the indicator area lock.
1024                  */
1025                 write_lock_irq(&info->lock);
1026                 write_unlock_irq(&info->lock);
1027         } else {
1028                 /* This device uses classic interrupts: synchronize
1029                  * with vring_interrupt() called by
1030                  * virtio_ccw_int_handler() via the per-device
1031                  * irq_lock
1032                  */
1033                 write_lock_irq(&vcdev->irq_lock);
1034                 write_unlock_irq(&vcdev->irq_lock);
1035         }
1036 }
1037
1038 static const struct virtio_config_ops virtio_ccw_config_ops = {
1039         .get_features = virtio_ccw_get_features,
1040         .finalize_features = virtio_ccw_finalize_features,
1041         .get = virtio_ccw_get_config,
1042         .set = virtio_ccw_set_config,
1043         .get_status = virtio_ccw_get_status,
1044         .set_status = virtio_ccw_set_status,
1045         .reset = virtio_ccw_reset,
1046         .find_vqs = virtio_ccw_find_vqs,
1047         .del_vqs = virtio_ccw_del_vqs,
1048         .bus_name = virtio_ccw_bus_name,
1049         .synchronize_cbs = virtio_ccw_synchronize_cbs,
1050 };
1051
1052
1053 /*
1054  * ccw bus driver related functions
1055  */
1056
1057 static void virtio_ccw_release_dev(struct device *_d)
1058 {
1059         struct virtio_device *dev = dev_to_virtio(_d);
1060         struct virtio_ccw_device *vcdev = to_vc_device(dev);
1061
1062         ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1063                             sizeof(*vcdev->dma_area));
1064         kfree(vcdev);
1065 }
1066
1067 static int irb_is_error(struct irb *irb)
1068 {
1069         if (scsw_cstat(&irb->scsw) != 0)
1070                 return 1;
1071         if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1072                 return 1;
1073         if (scsw_cc(&irb->scsw) != 0)
1074                 return 1;
1075         return 0;
1076 }
1077
1078 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1079                                               int index)
1080 {
1081         struct virtio_ccw_vq_info *info;
1082         unsigned long flags;
1083         struct virtqueue *vq;
1084
1085         vq = NULL;
1086         spin_lock_irqsave(&vcdev->lock, flags);
1087         list_for_each_entry(info, &vcdev->virtqueues, node) {
1088                 if (info->vq->index == index) {
1089                         vq = info->vq;
1090                         break;
1091                 }
1092         }
1093         spin_unlock_irqrestore(&vcdev->lock, flags);
1094         return vq;
1095 }
1096
1097 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1098                                       __u32 activity)
1099 {
1100         if (vcdev->curr_io & activity) {
1101                 switch (activity) {
1102                 case VIRTIO_CCW_DOING_READ_FEAT:
1103                 case VIRTIO_CCW_DOING_WRITE_FEAT:
1104                 case VIRTIO_CCW_DOING_READ_CONFIG:
1105                 case VIRTIO_CCW_DOING_WRITE_CONFIG:
1106                 case VIRTIO_CCW_DOING_WRITE_STATUS:
1107                 case VIRTIO_CCW_DOING_READ_STATUS:
1108                 case VIRTIO_CCW_DOING_SET_VQ:
1109                 case VIRTIO_CCW_DOING_SET_IND:
1110                 case VIRTIO_CCW_DOING_SET_CONF_IND:
1111                 case VIRTIO_CCW_DOING_RESET:
1112                 case VIRTIO_CCW_DOING_READ_VQ_CONF:
1113                 case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1114                 case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1115                         vcdev->curr_io &= ~activity;
1116                         wake_up(&vcdev->wait_q);
1117                         break;
1118                 default:
1119                         /* don't know what to do... */
1120                         dev_warn(&vcdev->cdev->dev,
1121                                  "Suspicious activity '%08x'\n", activity);
1122                         WARN_ON(1);
1123                         break;
1124                 }
1125         }
1126 }
1127
1128 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1129                                    unsigned long intparm,
1130                                    struct irb *irb)
1131 {
1132         __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1133         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1134         int i;
1135         struct virtqueue *vq;
1136
1137         if (!vcdev)
1138                 return;
1139         if (IS_ERR(irb)) {
1140                 vcdev->err = PTR_ERR(irb);
1141                 virtio_ccw_check_activity(vcdev, activity);
1142                 /* Don't poke around indicators, something's wrong. */
1143                 return;
1144         }
1145         /* Check if it's a notification from the host. */
1146         if ((intparm == 0) &&
1147             (scsw_stctl(&irb->scsw) ==
1148              (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1149                 /* OK */
1150         }
1151         if (irb_is_error(irb)) {
1152                 /* Command reject? */
1153                 if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1154                     (irb->ecw[0] & SNS0_CMD_REJECT))
1155                         vcdev->err = -EOPNOTSUPP;
1156                 else
1157                         /* Map everything else to -EIO. */
1158                         vcdev->err = -EIO;
1159         }
1160         virtio_ccw_check_activity(vcdev, activity);
1161 #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1162         /*
1163          * Paired with virtio_ccw_synchronize_cbs() and interrupts are
1164          * disabled here.
1165          */
1166         read_lock(&vcdev->irq_lock);
1167 #endif
1168         for_each_set_bit(i, indicators(vcdev),
1169                          sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1170                 /* The bit clear must happen before the vring kick. */
1171                 clear_bit(i, indicators(vcdev));
1172                 barrier();
1173                 vq = virtio_ccw_vq_by_ind(vcdev, i);
1174                 vring_interrupt(0, vq);
1175         }
1176 #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1177         read_unlock(&vcdev->irq_lock);
1178 #endif
1179         if (test_bit(0, indicators2(vcdev))) {
1180                 virtio_config_changed(&vcdev->vdev);
1181                 clear_bit(0, indicators2(vcdev));
1182         }
1183 }
1184
1185 /*
1186  * We usually want to autoonline all devices, but give the admin
1187  * a way to exempt devices from this.
1188  */
1189 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1190                      (8*sizeof(long)))
1191 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1192
1193 static char *no_auto = "";
1194
1195 module_param(no_auto, charp, 0444);
1196 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1197
1198 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1199 {
1200         struct ccw_dev_id id;
1201
1202         ccw_device_get_id(cdev, &id);
1203         if (test_bit(id.devno, devs_no_auto[id.ssid]))
1204                 return 0;
1205         return 1;
1206 }
1207
1208 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1209 {
1210         struct ccw_device *cdev = data;
1211         int ret;
1212
1213         ret = ccw_device_set_online(cdev);
1214         if (ret)
1215                 dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1216 }
1217
1218 static int virtio_ccw_probe(struct ccw_device *cdev)
1219 {
1220         cdev->handler = virtio_ccw_int_handler;
1221
1222         if (virtio_ccw_check_autoonline(cdev))
1223                 async_schedule(virtio_ccw_auto_online, cdev);
1224         return 0;
1225 }
1226
1227 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1228 {
1229         unsigned long flags;
1230         struct virtio_ccw_device *vcdev;
1231
1232         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1233         vcdev = dev_get_drvdata(&cdev->dev);
1234         if (!vcdev || vcdev->going_away) {
1235                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1236                 return NULL;
1237         }
1238         vcdev->going_away = true;
1239         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1240         return vcdev;
1241 }
1242
1243 static void virtio_ccw_remove(struct ccw_device *cdev)
1244 {
1245         unsigned long flags;
1246         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1247
1248         if (vcdev && cdev->online) {
1249                 if (vcdev->device_lost)
1250                         virtio_break_device(&vcdev->vdev);
1251                 unregister_virtio_device(&vcdev->vdev);
1252                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1253                 dev_set_drvdata(&cdev->dev, NULL);
1254                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1255         }
1256         cdev->handler = NULL;
1257 }
1258
1259 static int virtio_ccw_offline(struct ccw_device *cdev)
1260 {
1261         unsigned long flags;
1262         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1263
1264         if (!vcdev)
1265                 return 0;
1266         if (vcdev->device_lost)
1267                 virtio_break_device(&vcdev->vdev);
1268         unregister_virtio_device(&vcdev->vdev);
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         return 0;
1273 }
1274
1275 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1276 {
1277         struct virtio_rev_info *rev;
1278         struct ccw1 *ccw;
1279         int ret;
1280
1281         ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
1282         if (!ccw)
1283                 return -ENOMEM;
1284         rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev));
1285         if (!rev) {
1286                 ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1287                 return -ENOMEM;
1288         }
1289
1290         /* Set transport revision */
1291         ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1292         ccw->flags = 0;
1293         ccw->count = sizeof(*rev);
1294         ccw->cda = (__u32)virt_to_phys(rev);
1295
1296         vcdev->revision = VIRTIO_CCW_REV_MAX;
1297         do {
1298                 rev->revision = vcdev->revision;
1299                 /* none of our supported revisions carry payload */
1300                 rev->length = 0;
1301                 ret = ccw_io_helper(vcdev, ccw,
1302                                     VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1303                 if (ret == -EOPNOTSUPP) {
1304                         if (vcdev->revision == 0)
1305                                 /*
1306                                  * The host device does not support setting
1307                                  * the revision: let's operate it in legacy
1308                                  * mode.
1309                                  */
1310                                 ret = 0;
1311                         else
1312                                 vcdev->revision--;
1313                 }
1314         } while (ret == -EOPNOTSUPP);
1315
1316         ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1317         ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1318         return ret;
1319 }
1320
1321 static int virtio_ccw_online(struct ccw_device *cdev)
1322 {
1323         int ret;
1324         struct virtio_ccw_device *vcdev;
1325         unsigned long flags;
1326
1327         vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1328         if (!vcdev) {
1329                 dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1330                 ret = -ENOMEM;
1331                 goto out_free;
1332         }
1333         vcdev->vdev.dev.parent = &cdev->dev;
1334         vcdev->cdev = cdev;
1335         vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1336                                                 sizeof(*vcdev->dma_area));
1337         if (!vcdev->dma_area) {
1338                 ret = -ENOMEM;
1339                 goto out_free;
1340         }
1341
1342         vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1343
1344         vcdev->vdev.dev.release = virtio_ccw_release_dev;
1345         vcdev->vdev.config = &virtio_ccw_config_ops;
1346         init_waitqueue_head(&vcdev->wait_q);
1347         INIT_LIST_HEAD(&vcdev->virtqueues);
1348         spin_lock_init(&vcdev->lock);
1349         rwlock_init(&vcdev->irq_lock);
1350         mutex_init(&vcdev->io_lock);
1351
1352         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1353         dev_set_drvdata(&cdev->dev, vcdev);
1354         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1355         vcdev->vdev.id.vendor = cdev->id.cu_type;
1356         vcdev->vdev.id.device = cdev->id.cu_model;
1357
1358         ret = virtio_ccw_set_transport_rev(vcdev);
1359         if (ret)
1360                 goto out_free;
1361
1362         ret = register_virtio_device(&vcdev->vdev);
1363         if (ret) {
1364                 dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1365                          ret);
1366                 goto out_put;
1367         }
1368         return 0;
1369 out_put:
1370         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1371         dev_set_drvdata(&cdev->dev, NULL);
1372         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1373         put_device(&vcdev->vdev.dev);
1374         return ret;
1375 out_free:
1376         if (vcdev) {
1377                 ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1378                                     sizeof(*vcdev->dma_area));
1379         }
1380         kfree(vcdev);
1381         return ret;
1382 }
1383
1384 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1385 {
1386         int rc;
1387         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1388
1389         /*
1390          * Make sure vcdev is set
1391          * i.e. set_offline/remove callback not already running
1392          */
1393         if (!vcdev)
1394                 return NOTIFY_DONE;
1395
1396         switch (event) {
1397         case CIO_GONE:
1398                 vcdev->device_lost = true;
1399                 rc = NOTIFY_DONE;
1400                 break;
1401         case CIO_OPER:
1402                 rc = NOTIFY_OK;
1403                 break;
1404         default:
1405                 rc = NOTIFY_DONE;
1406                 break;
1407         }
1408         return rc;
1409 }
1410
1411 static struct ccw_device_id virtio_ids[] = {
1412         { CCW_DEVICE(0x3832, 0) },
1413         {},
1414 };
1415
1416 static struct ccw_driver virtio_ccw_driver = {
1417         .driver = {
1418                 .owner = THIS_MODULE,
1419                 .name = "virtio_ccw",
1420         },
1421         .ids = virtio_ids,
1422         .probe = virtio_ccw_probe,
1423         .remove = virtio_ccw_remove,
1424         .set_offline = virtio_ccw_offline,
1425         .set_online = virtio_ccw_online,
1426         .notify = virtio_ccw_cio_notify,
1427         .int_class = IRQIO_VIR,
1428 };
1429
1430 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1431                            int max_digit, int max_val)
1432 {
1433         int diff;
1434
1435         diff = 0;
1436         *val = 0;
1437
1438         while (diff <= max_digit) {
1439                 int value = hex_to_bin(**cp);
1440
1441                 if (value < 0)
1442                         break;
1443                 *val = *val * 16 + value;
1444                 (*cp)++;
1445                 diff++;
1446         }
1447
1448         if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1449                 return 1;
1450
1451         return 0;
1452 }
1453
1454 static int __init parse_busid(char *str, unsigned int *cssid,
1455                               unsigned int *ssid, unsigned int *devno)
1456 {
1457         char *str_work;
1458         int rc, ret;
1459
1460         rc = 1;
1461
1462         if (*str == '\0')
1463                 goto out;
1464
1465         str_work = str;
1466         ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1467         if (ret || (str_work[0] != '.'))
1468                 goto out;
1469         str_work++;
1470         ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1471         if (ret || (str_work[0] != '.'))
1472                 goto out;
1473         str_work++;
1474         ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1475         if (ret || (str_work[0] != '\0'))
1476                 goto out;
1477
1478         rc = 0;
1479 out:
1480         return rc;
1481 }
1482
1483 static void __init no_auto_parse(void)
1484 {
1485         unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1486         char *parm, *str;
1487         int rc;
1488
1489         str = no_auto;
1490         while ((parm = strsep(&str, ","))) {
1491                 rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1492                                  &from_ssid, &from);
1493                 if (rc)
1494                         continue;
1495                 if (parm != NULL) {
1496                         rc = parse_busid(parm, &to_cssid,
1497                                          &to_ssid, &to);
1498                         if ((from_ssid > to_ssid) ||
1499                             ((from_ssid == to_ssid) && (from > to)))
1500                                 rc = -EINVAL;
1501                 } else {
1502                         to_cssid = from_cssid;
1503                         to_ssid = from_ssid;
1504                         to = from;
1505                 }
1506                 if (rc)
1507                         continue;
1508                 while ((from_ssid < to_ssid) ||
1509                        ((from_ssid == to_ssid) && (from <= to))) {
1510                         set_bit(from, devs_no_auto[from_ssid]);
1511                         from++;
1512                         if (from > __MAX_SUBCHANNEL) {
1513                                 from_ssid++;
1514                                 from = 0;
1515                         }
1516                 }
1517         }
1518 }
1519
1520 static int __init virtio_ccw_init(void)
1521 {
1522         int rc;
1523
1524         /* parse no_auto string before we do anything further */
1525         no_auto_parse();
1526
1527         summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1528         if (!summary_indicators)
1529                 return -ENOMEM;
1530         rc = ccw_driver_register(&virtio_ccw_driver);
1531         if (rc)
1532                 cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1533         return rc;
1534 }
1535 device_initcall(virtio_ccw_init);