drivers/s390/kvm/virtio_ccw.c

   1 /*
   2  * ccw based virtio transport
   3  *
   4  * Copyright IBM Corp. 2012
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License (version 2 only)
   8  * as published by the Free Software Foundation.
   9  *
  10  *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
  11  */
  12
  13 #include <linux/kernel_stat.h>
  14 #include <linux/init.h>
  15 #include <linux/bootmem.h>
  16 #include <linux/err.h>
  17 #include <linux/virtio.h>
  18 #include <linux/virtio_config.h>
  19 #include <linux/slab.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/virtio_ring.h>
  22 #include <linux/pfn.h>
  23 #include <linux/async.h>
  24 #include <linux/wait.h>
  25 #include <linux/list.h>
  26 #include <linux/bitops.h>
  27 #include <linux/module.h>
  28 #include <linux/io.h>
  29 #include <linux/kvm_para.h>
  30 #include <asm/setup.h>
  31 #include <asm/irq.h>
  32 #include <asm/cio.h>
  33 #include <asm/ccwdev.h>
  34
  35 /*
  36  * virtio related functions
  37  */
  38
  39 struct vq_config_block {
  40         __u16 index;
  41         __u16 num;
  42 } __packed;
  43
  44 #define VIRTIO_CCW_CONFIG_SIZE 0x100
  45 /* same as PCI config space size, should be enough for all drivers */
  46
  47 struct virtio_ccw_device {
  48         struct virtio_device vdev;
  49         __u8 *status;
  50         __u8 config[VIRTIO_CCW_CONFIG_SIZE];
  51         struct ccw_device *cdev;
  52         __u32 curr_io;
  53         int err;
  54         wait_queue_head_t wait_q;
  55         spinlock_t lock;
  56         struct list_head virtqueues;
  57         unsigned long indicators;
  58         unsigned long indicators2;
  59         struct vq_config_block *config_block;
  60 };
  61
  62 struct vq_info_block {
  63         __u64 queue;
  64         __u32 align;
  65         __u16 index;
  66         __u16 num;
  67 } __packed;
  68
  69 struct virtio_feature_desc {
  70         __u32 features;
  71         __u8 index;
  72 } __packed;
  73
  74 struct virtio_ccw_vq_info {
  75         struct virtqueue *vq;
  76         int num;
  77         void *queue;
  78         struct vq_info_block *info_block;
  79         struct list_head node;
  80 };
  81
  82 #define KVM_VIRTIO_CCW_RING_ALIGN 4096
  83
  84 #define KVM_S390_VIRTIO_CCW_NOTIFY 3
  85
  86 #define CCW_CMD_SET_VQ 0x13
  87 #define CCW_CMD_VDEV_RESET 0x33
  88 #define CCW_CMD_SET_IND 0x43
  89 #define CCW_CMD_SET_CONF_IND 0x53
  90 #define CCW_CMD_READ_FEAT 0x12
  91 #define CCW_CMD_WRITE_FEAT 0x11
  92 #define CCW_CMD_READ_CONF 0x22
  93 #define CCW_CMD_WRITE_CONF 0x21
  94 #define CCW_CMD_WRITE_STATUS 0x31
  95 #define CCW_CMD_READ_VQ_CONF 0x32
  96
  97 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
  98 #define VIRTIO_CCW_DOING_RESET 0x00040000
  99 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
 100 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
 101 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
 102 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
 103 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
 104 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
 105 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
 106 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
 107 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
 108
 109 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
 110 {
 111         return container_of(vdev, struct virtio_ccw_device, vdev);
 112 }
 113
 114 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
 115 {
 116         unsigned long flags;
 117         __u32 ret;
 118
 119         spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 120         if (vcdev->err)
 121                 ret = 0;
 122         else
 123                 ret = vcdev->curr_io & flag;
 124         spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 125         return ret;
 126 }
 127
 128 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
 129                          struct ccw1 *ccw, __u32 intparm)
 130 {
 131         int ret;
 132         unsigned long flags;
 133         int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
 134
 135         do {
 136                 spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 137                 ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
 138                 if (!ret)
 139                         vcdev->curr_io |= flag;
 140                 spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 141                 cpu_relax();
 142         } while (ret == -EBUSY);
 143         wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
 144         return ret ? ret : vcdev->err;
 145 }
 146
 147 static inline long do_kvm_notify(struct subchannel_id schid,
 148                                  unsigned long queue_index)
 149 {
 150         register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
 151         register struct subchannel_id __schid asm("2") = schid;
 152         register unsigned long __index asm("3") = queue_index;
 153         register long __rc asm("2");
 154
 155         asm volatile ("diag 2,4,0x500\n"
 156                       : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index)
 157                       : "memory", "cc");
 158         return __rc;
 159 }
 160
 161 static void virtio_ccw_kvm_notify(struct virtqueue *vq)
 162 {
 163         struct virtio_ccw_vq_info *info = vq->priv;
 164         struct virtio_ccw_device *vcdev;
 165         struct subchannel_id schid;
 166
 167         vcdev = to_vc_device(info->vq->vdev);
 168         ccw_device_get_schid(vcdev->cdev, &schid);
 169         do_kvm_notify(schid, vq->index);
 170 }
 171
 172 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
 173                                    struct ccw1 *ccw, int index)
 174 {
 175         vcdev->config_block->index = index;
 176         ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
 177         ccw->flags = 0;
 178         ccw->count = sizeof(struct vq_config_block);
 179         ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
 180         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
 181         return vcdev->config_block->num;
 182 }
 183
 184 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
 185 {
 186         struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
 187         struct virtio_ccw_vq_info *info = vq->priv;
 188         unsigned long flags;
 189         unsigned long size;
 190         int ret;
 191         unsigned int index = vq->index;
 192
 193         /* Remove from our list. */
 194         spin_lock_irqsave(&vcdev->lock, flags);
 195         list_del(&info->node);
 196         spin_unlock_irqrestore(&vcdev->lock, flags);
 197
 198         /* Release from host. */
 199         info->info_block->queue = 0;
 200         info->info_block->align = 0;
 201         info->info_block->index = index;
 202         info->info_block->num = 0;
 203         ccw->cmd_code = CCW_CMD_SET_VQ;
 204         ccw->flags = 0;
 205         ccw->count = sizeof(*info->info_block);
 206         ccw->cda = (__u32)(unsigned long)(info->info_block);
 207         ret = ccw_io_helper(vcdev, ccw,
 208                             VIRTIO_CCW_DOING_SET_VQ | index);
 209         /*
 210          * -ENODEV isn't considered an error: The device is gone anyway.
 211          * This may happen on device detach.
 212          */
 213         if (ret && (ret != -ENODEV))
 214                 dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d",
 215                          ret, index);
 216
 217         vring_del_virtqueue(vq);
 218         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
 219         free_pages_exact(info->queue, size);
 220         kfree(info->info_block);
 221         kfree(info);
 222 }
 223
 224 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
 225 {
 226         struct virtqueue *vq, *n;
 227         struct ccw1 *ccw;
 228
 229         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 230         if (!ccw)
 231                 return;
 232
 233
 234         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 235                 virtio_ccw_del_vq(vq, ccw);
 236
 237         kfree(ccw);
 238 }
 239
 240 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
 241                                              int i, vq_callback_t *callback,
 242                                              const char *name,
 243                                              struct ccw1 *ccw)
 244 {
 245         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 246         int err;
 247         struct virtqueue *vq = NULL;
 248         struct virtio_ccw_vq_info *info;
 249         unsigned long size = 0; /* silence the compiler */
 250         unsigned long flags;
 251
 252         /* Allocate queue. */
 253         info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
 254         if (!info) {
 255                 dev_warn(&vcdev->cdev->dev, "no info\n");
 256                 err = -ENOMEM;
 257                 goto out_err;
 258         }
 259         info->info_block = kzalloc(sizeof(*info->info_block),
 260                                    GFP_DMA | GFP_KERNEL);
 261         if (!info->info_block) {
 262                 dev_warn(&vcdev->cdev->dev, "no info block\n");
 263                 err = -ENOMEM;
 264                 goto out_err;
 265         }
 266         info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
 267         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
 268         info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
 269         if (info->queue == NULL) {
 270                 dev_warn(&vcdev->cdev->dev, "no queue\n");
 271                 err = -ENOMEM;
 272                 goto out_err;
 273         }
 274
 275         vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
 276                                  true, info->queue, virtio_ccw_kvm_notify,
 277                                  callback, name);
 278         if (!vq) {
 279                 /* For now, we fail if we can't get the requested size. */
 280                 dev_warn(&vcdev->cdev->dev, "no vq\n");
 281                 err = -ENOMEM;
 282                 goto out_err;
 283         }
 284
 285         /* Register it with the host. */
 286         info->info_block->queue = (__u64)info->queue;
 287         info->info_block->align = KVM_VIRTIO_CCW_RING_ALIGN;
 288         info->info_block->index = i;
 289         info->info_block->num = info->num;
 290         ccw->cmd_code = CCW_CMD_SET_VQ;
 291         ccw->flags = 0;
 292         ccw->count = sizeof(*info->info_block);
 293         ccw->cda = (__u32)(unsigned long)(info->info_block);
 294         err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
 295         if (err) {
 296                 dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
 297                 goto out_err;
 298         }
 299
 300         info->vq = vq;
 301         vq->priv = info;
 302
 303         /* Save it to our list. */
 304         spin_lock_irqsave(&vcdev->lock, flags);
 305         list_add(&info->node, &vcdev->virtqueues);
 306         spin_unlock_irqrestore(&vcdev->lock, flags);
 307
 308         return vq;
 309
 310 out_err:
 311         if (vq)
 312                 vring_del_virtqueue(vq);
 313         if (info) {
 314                 if (info->queue)
 315                         free_pages_exact(info->queue, size);
 316                 kfree(info->info_block);
 317         }
 318         kfree(info);
 319         return ERR_PTR(err);
 320 }
 321
 322 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 323                                struct virtqueue *vqs[],
 324                                vq_callback_t *callbacks[],
 325                                const char *names[])
 326 {
 327         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 328         unsigned long *indicatorp = NULL;
 329         int ret, i;
 330         struct ccw1 *ccw;
 331
 332         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 333         if (!ccw)
 334                 return -ENOMEM;
 335
 336         for (i = 0; i < nvqs; ++i) {
 337                 vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
 338                                              ccw);
 339                 if (IS_ERR(vqs[i])) {
 340                         ret = PTR_ERR(vqs[i]);
 341                         vqs[i] = NULL;
 342                         goto out;
 343                 }
 344         }
 345         ret = -ENOMEM;
 346         /* We need a data area under 2G to communicate. */
 347         indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
 348         if (!indicatorp)
 349                 goto out;
 350         *indicatorp = (unsigned long) &vcdev->indicators;
 351         /* Register queue indicators with host. */
 352         vcdev->indicators = 0;
 353         ccw->cmd_code = CCW_CMD_SET_IND;
 354         ccw->flags = 0;
 355         ccw->count = sizeof(vcdev->indicators);
 356         ccw->cda = (__u32)(unsigned long) indicatorp;
 357         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
 358         if (ret)
 359                 goto out;
 360         /* Register indicators2 with host for config changes */
 361         *indicatorp = (unsigned long) &vcdev->indicators2;
 362         vcdev->indicators2 = 0;
 363         ccw->cmd_code = CCW_CMD_SET_CONF_IND;
 364         ccw->flags = 0;
 365         ccw->count = sizeof(vcdev->indicators2);
 366         ccw->cda = (__u32)(unsigned long) indicatorp;
 367         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
 368         if (ret)
 369                 goto out;
 370
 371         kfree(indicatorp);
 372         kfree(ccw);
 373         return 0;
 374 out:
 375         kfree(indicatorp);
 376         kfree(ccw);
 377         virtio_ccw_del_vqs(vdev);
 378         return ret;
 379 }
 380
 381 static void virtio_ccw_reset(struct virtio_device *vdev)
 382 {
 383         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 384         struct ccw1 *ccw;
 385
 386         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 387         if (!ccw)
 388                 return;
 389
 390         /* Zero status bits. */
 391         *vcdev->status = 0;
 392
 393         /* Send a reset ccw on device. */
 394         ccw->cmd_code = CCW_CMD_VDEV_RESET;
 395         ccw->flags = 0;
 396         ccw->count = 0;
 397         ccw->cda = 0;
 398         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
 399         kfree(ccw);
 400 }
 401
 402 static u32 virtio_ccw_get_features(struct virtio_device *vdev)
 403 {
 404         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 405         struct virtio_feature_desc *features;
 406         int ret, rc;
 407         struct ccw1 *ccw;
 408
 409         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 410         if (!ccw)
 411                 return 0;
 412
 413         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
 414         if (!features) {
 415                 rc = 0;
 416                 goto out_free;
 417         }
 418         /* Read the feature bits from the host. */
 419         /* TODO: Features > 32 bits */
 420         features->index = 0;
 421         ccw->cmd_code = CCW_CMD_READ_FEAT;
 422         ccw->flags = 0;
 423         ccw->count = sizeof(*features);
 424         ccw->cda = (__u32)(unsigned long)features;
 425         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 426         if (ret) {
 427                 rc = 0;
 428                 goto out_free;
 429         }
 430
 431         rc = le32_to_cpu(features->features);
 432
 433 out_free:
 434         kfree(features);
 435         kfree(ccw);
 436         return rc;
 437 }
 438
 439 static void virtio_ccw_finalize_features(struct virtio_device *vdev)
 440 {
 441         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 442         struct virtio_feature_desc *features;
 443         int i;
 444         struct ccw1 *ccw;
 445
 446         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 447         if (!ccw)
 448                 return;
 449
 450         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
 451         if (!features)
 452                 goto out_free;
 453
 454         /* Give virtio_ring a chance to accept features. */
 455         vring_transport_features(vdev);
 456
 457         for (i = 0; i < sizeof(*vdev->features) / sizeof(features->features);
 458              i++) {
 459                 int highbits = i % 2 ? 32 : 0;
 460                 features->index = i;
 461                 features->features = cpu_to_le32(vdev->features[i / 2]
 462                                                  >> highbits);
 463                 /* Write the feature bits to the host. */
 464                 ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 465                 ccw->flags = 0;
 466                 ccw->count = sizeof(*features);
 467                 ccw->cda = (__u32)(unsigned long)features;
 468                 ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 469         }
 470 out_free:
 471         kfree(features);
 472         kfree(ccw);
 473 }
 474
 475 static void virtio_ccw_get_config(struct virtio_device *vdev,
 476                                   unsigned int offset, void *buf, unsigned len)
 477 {
 478         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 479         int ret;
 480         struct ccw1 *ccw;
 481         void *config_area;
 482
 483         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 484         if (!ccw)
 485                 return;
 486
 487         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
 488         if (!config_area)
 489                 goto out_free;
 490
 491         /* Read the config area from the host. */
 492         ccw->cmd_code = CCW_CMD_READ_CONF;
 493         ccw->flags = 0;
 494         ccw->count = offset + len;
 495         ccw->cda = (__u32)(unsigned long)config_area;
 496         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
 497         if (ret)
 498                 goto out_free;
 499
 500         memcpy(vcdev->config, config_area, sizeof(vcdev->config));
 501         memcpy(buf, &vcdev->config[offset], len);
 502
 503 out_free:
 504         kfree(config_area);
 505         kfree(ccw);
 506 }
 507
 508 static void virtio_ccw_set_config(struct virtio_device *vdev,
 509                                   unsigned int offset, const void *buf,
 510                                   unsigned len)
 511 {
 512         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 513         struct ccw1 *ccw;
 514         void *config_area;
 515
 516         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 517         if (!ccw)
 518                 return;
 519
 520         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
 521         if (!config_area)
 522                 goto out_free;
 523
 524         memcpy(&vcdev->config[offset], buf, len);
 525         /* Write the config area to the host. */
 526         memcpy(config_area, vcdev->config, sizeof(vcdev->config));
 527         ccw->cmd_code = CCW_CMD_WRITE_CONF;
 528         ccw->flags = 0;
 529         ccw->count = offset + len;
 530         ccw->cda = (__u32)(unsigned long)config_area;
 531         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
 532
 533 out_free:
 534         kfree(config_area);
 535         kfree(ccw);
 536 }
 537
 538 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
 539 {
 540         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 541
 542         return *vcdev->status;
 543 }
 544
 545 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 546 {
 547         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 548         struct ccw1 *ccw;
 549
 550         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 551         if (!ccw)
 552                 return;
 553
 554         /* Write the status to the host. */
 555         *vcdev->status = status;
 556         ccw->cmd_code = CCW_CMD_WRITE_STATUS;
 557         ccw->flags = 0;
 558         ccw->count = sizeof(status);
 559         ccw->cda = (__u32)(unsigned long)vcdev->status;
 560         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
 561         kfree(ccw);
 562 }
 563
 564 static struct virtio_config_ops virtio_ccw_config_ops = {
 565         .get_features = virtio_ccw_get_features,
 566         .finalize_features = virtio_ccw_finalize_features,
 567         .get = virtio_ccw_get_config,
 568         .set = virtio_ccw_set_config,
 569         .get_status = virtio_ccw_get_status,
 570         .set_status = virtio_ccw_set_status,
 571         .reset = virtio_ccw_reset,
 572         .find_vqs = virtio_ccw_find_vqs,
 573         .del_vqs = virtio_ccw_del_vqs,
 574 };
 575
 576
 577 /*
 578  * ccw bus driver related functions
 579  */
 580
 581 static void virtio_ccw_release_dev(struct device *_d)
 582 {
 583         struct virtio_device *dev = container_of(_d, struct virtio_device,
 584                                                  dev);
 585         struct virtio_ccw_device *vcdev = to_vc_device(dev);
 586
 587         kfree(vcdev->status);
 588         kfree(vcdev->config_block);
 589         kfree(vcdev);
 590 }
 591
 592 static int irb_is_error(struct irb *irb)
 593 {
 594         if (scsw_cstat(&irb->scsw) != 0)
 595                 return 1;
 596         if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
 597                 return 1;
 598         if (scsw_cc(&irb->scsw) != 0)
 599                 return 1;
 600         return 0;
 601 }
 602
 603 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
 604                                               int index)
 605 {
 606         struct virtio_ccw_vq_info *info;
 607         unsigned long flags;
 608         struct virtqueue *vq;
 609
 610         vq = NULL;
 611         spin_lock_irqsave(&vcdev->lock, flags);
 612         list_for_each_entry(info, &vcdev->virtqueues, node) {
 613                 if (info->vq->index == index) {
 614                         vq = info->vq;
 615                         break;
 616                 }
 617         }
 618         spin_unlock_irqrestore(&vcdev->lock, flags);
 619         return vq;
 620 }
 621
 622 static void virtio_ccw_int_handler(struct ccw_device *cdev,
 623                                    unsigned long intparm,
 624                                    struct irb *irb)
 625 {
 626         __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
 627         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
 628         int i;
 629         struct virtqueue *vq;
 630         struct virtio_driver *drv;
 631
 632         /* Check if it's a notification from the host. */
 633         if ((intparm == 0) &&
 634             (scsw_stctl(&irb->scsw) ==
 635              (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
 636                 /* OK */
 637         }
 638         if (irb_is_error(irb))
 639                 vcdev->err = -EIO; /* XXX - use real error */
 640         if (vcdev->curr_io & activity) {
 641                 switch (activity) {
 642                 case VIRTIO_CCW_DOING_READ_FEAT:
 643                 case VIRTIO_CCW_DOING_WRITE_FEAT:
 644                 case VIRTIO_CCW_DOING_READ_CONFIG:
 645                 case VIRTIO_CCW_DOING_WRITE_CONFIG:
 646                 case VIRTIO_CCW_DOING_WRITE_STATUS:
 647                 case VIRTIO_CCW_DOING_SET_VQ:
 648                 case VIRTIO_CCW_DOING_SET_IND:
 649                 case VIRTIO_CCW_DOING_SET_CONF_IND:
 650                 case VIRTIO_CCW_DOING_RESET:
 651                 case VIRTIO_CCW_DOING_READ_VQ_CONF:
 652                         vcdev->curr_io &= ~activity;
 653                         wake_up(&vcdev->wait_q);
 654                         break;
 655                 default:
 656                         /* don't know what to do... */
 657                         dev_warn(&cdev->dev, "Suspicious activity '%08x'\n",
 658                                  activity);
 659                         WARN_ON(1);
 660                         break;
 661                 }
 662         }
 663         for_each_set_bit(i, &vcdev->indicators,
 664                          sizeof(vcdev->indicators) * BITS_PER_BYTE) {
 665                 /* The bit clear must happen before the vring kick. */
 666                 clear_bit(i, &vcdev->indicators);
 667                 barrier();
 668                 vq = virtio_ccw_vq_by_ind(vcdev, i);
 669                 vring_interrupt(0, vq);
 670         }
 671         if (test_bit(0, &vcdev->indicators2)) {
 672                 drv = container_of(vcdev->vdev.dev.driver,
 673                                    struct virtio_driver, driver);
 674
 675                 if (drv && drv->config_changed)
 676                         drv->config_changed(&vcdev->vdev);
 677                 clear_bit(0, &vcdev->indicators2);
 678         }
 679 }
 680
 681 /*
 682  * We usually want to autoonline all devices, but give the admin
 683  * a way to exempt devices from this.
 684  */
 685 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
 686                      (8*sizeof(long)))
 687 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
 688
 689 static char *no_auto = "";
 690
 691 module_param(no_auto, charp, 0444);
 692 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
 693
 694 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
 695 {
 696         struct ccw_dev_id id;
 697
 698         ccw_device_get_id(cdev, &id);
 699         if (test_bit(id.devno, devs_no_auto[id.ssid]))
 700                 return 0;
 701         return 1;
 702 }
 703
 704 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
 705 {
 706         struct ccw_device *cdev = data;
 707         int ret;
 708
 709         ret = ccw_device_set_online(cdev);
 710         if (ret)
 711                 dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
 712 }
 713
 714 static int virtio_ccw_probe(struct ccw_device *cdev)
 715 {
 716         cdev->handler = virtio_ccw_int_handler;
 717
 718         if (virtio_ccw_check_autoonline(cdev))
 719                 async_schedule(virtio_ccw_auto_online, cdev);
 720         return 0;
 721 }
 722
 723 static void virtio_ccw_remove(struct ccw_device *cdev)
 724 {
 725         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
 726
 727         if (cdev->online) {
 728                 unregister_virtio_device(&vcdev->vdev);
 729                 dev_set_drvdata(&cdev->dev, NULL);
 730         }
 731         cdev->handler = NULL;
 732 }
 733
 734 static int virtio_ccw_offline(struct ccw_device *cdev)
 735 {
 736         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
 737
 738         unregister_virtio_device(&vcdev->vdev);
 739         dev_set_drvdata(&cdev->dev, NULL);
 740         return 0;
 741 }
 742
 743
 744 static int virtio_ccw_online(struct ccw_device *cdev)
 745 {
 746         int ret;
 747         struct virtio_ccw_device *vcdev;
 748
 749         vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
 750         if (!vcdev) {
 751                 dev_warn(&cdev->dev, "Could not get memory for virtio\n");
 752                 ret = -ENOMEM;
 753                 goto out_free;
 754         }
 755         vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
 756                                    GFP_DMA | GFP_KERNEL);
 757         if (!vcdev->config_block) {
 758                 ret = -ENOMEM;
 759                 goto out_free;
 760         }
 761         vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
 762         if (!vcdev->status) {
 763                 ret = -ENOMEM;
 764                 goto out_free;
 765         }
 766
 767         vcdev->vdev.dev.parent = &cdev->dev;
 768         vcdev->vdev.dev.release = virtio_ccw_release_dev;
 769         vcdev->vdev.config = &virtio_ccw_config_ops;
 770         vcdev->cdev = cdev;
 771         init_waitqueue_head(&vcdev->wait_q);
 772         INIT_LIST_HEAD(&vcdev->virtqueues);
 773         spin_lock_init(&vcdev->lock);
 774
 775         dev_set_drvdata(&cdev->dev, vcdev);
 776         vcdev->vdev.id.vendor = cdev->id.cu_type;
 777         vcdev->vdev.id.device = cdev->id.cu_model;
 778         ret = register_virtio_device(&vcdev->vdev);
 779         if (ret) {
 780                 dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
 781                          ret);
 782                 goto out_put;
 783         }
 784         return 0;
 785 out_put:
 786         dev_set_drvdata(&cdev->dev, NULL);
 787         put_device(&vcdev->vdev.dev);
 788         return ret;
 789 out_free:
 790         if (vcdev) {
 791                 kfree(vcdev->status);
 792                 kfree(vcdev->config_block);
 793         }
 794         kfree(vcdev);
 795         return ret;
 796 }
 797
 798 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
 799 {
 800         /* TODO: Check whether we need special handling here. */
 801         return 0;
 802 }
 803
 804 static struct ccw_device_id virtio_ids[] = {
 805         { CCW_DEVICE(0x3832, 0) },
 806         {},
 807 };
 808 MODULE_DEVICE_TABLE(ccw, virtio_ids);
 809
 810 static struct ccw_driver virtio_ccw_driver = {
 811         .driver = {
 812                 .owner = THIS_MODULE,
 813                 .name = "virtio_ccw",
 814         },
 815         .ids = virtio_ids,
 816         .probe = virtio_ccw_probe,
 817         .remove = virtio_ccw_remove,
 818         .set_offline = virtio_ccw_offline,
 819         .set_online = virtio_ccw_online,
 820         .notify = virtio_ccw_cio_notify,
 821         .int_class = IRQIO_VIR,
 822 };
 823
 824 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
 825                            int max_digit, int max_val)
 826 {
 827         int diff;
 828
 829         diff = 0;
 830         *val = 0;
 831
 832         while (diff <= max_digit) {
 833                 int value = hex_to_bin(**cp);
 834
 835                 if (value < 0)
 836                         break;
 837                 *val = *val * 16 + value;
 838                 (*cp)++;
 839                 diff++;
 840         }
 841
 842         if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
 843                 return 1;
 844
 845         return 0;
 846 }
 847
 848 static int __init parse_busid(char *str, unsigned int *cssid,
 849                               unsigned int *ssid, unsigned int *devno)
 850 {
 851         char *str_work;
 852         int rc, ret;
 853
 854         rc = 1;
 855
 856         if (*str == '\0')
 857                 goto out;
 858
 859         str_work = str;
 860         ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
 861         if (ret || (str_work[0] != '.'))
 862                 goto out;
 863         str_work++;
 864         ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
 865         if (ret || (str_work[0] != '.'))
 866                 goto out;
 867         str_work++;
 868         ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
 869         if (ret || (str_work[0] != '\0'))
 870                 goto out;
 871
 872         rc = 0;
 873 out:
 874         return rc;
 875 }
 876
 877 static void __init no_auto_parse(void)
 878 {
 879         unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
 880         char *parm, *str;
 881         int rc;
 882
 883         str = no_auto;
 884         while ((parm = strsep(&str, ","))) {
 885                 rc = parse_busid(strsep(&parm, "-"), &from_cssid,
 886                                  &from_ssid, &from);
 887                 if (rc)
 888                         continue;
 889                 if (parm != NULL) {
 890                         rc = parse_busid(parm, &to_cssid,
 891                                          &to_ssid, &to);
 892                         if ((from_ssid > to_ssid) ||
 893                             ((from_ssid == to_ssid) && (from > to)))
 894                                 rc = -EINVAL;
 895                 } else {
 896                         to_cssid = from_cssid;
 897                         to_ssid = from_ssid;
 898                         to = from;
 899                 }
 900                 if (rc)
 901                         continue;
 902                 while ((from_ssid < to_ssid) ||
 903                        ((from_ssid == to_ssid) && (from <= to))) {
 904                         set_bit(from, devs_no_auto[from_ssid]);
 905                         from++;
 906                         if (from > __MAX_SUBCHANNEL) {
 907                                 from_ssid++;
 908                                 from = 0;
 909                         }
 910                 }
 911         }
 912 }
 913
 914 static int __init virtio_ccw_init(void)
 915 {
 916         /* parse no_auto string before we do anything further */
 917         no_auto_parse();
 918         return ccw_driver_register(&virtio_ccw_driver);
 919 }
 920 module_init(virtio_ccw_init);
 921
 922 static void __exit virtio_ccw_exit(void)
 923 {
 924         ccw_driver_unregister(&virtio_ccw_driver);
 925 }
 926 module_exit(virtio_ccw_exit);