SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/block/viodasd.c

   1 /* -*- linux-c -*-
   2  * viodasd.c
   3  *  Authors: Dave Boutcher <boutcher@us.ibm.com>
   4  *           Ryan Arnold <ryanarn@us.ibm.com>
   5  *           Colin Devilbiss <devilbis@us.ibm.com>
   6  *           Stephen Rothwell
   7  *
   8  * (C) Copyright 2000-2004 IBM Corporation
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of the
  13  * License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * This routine provides access to disk space (termed "DASD" in historical
  25  * IBM terms) owned and managed by an OS/400 partition running on the
  26  * same box as this Linux partition.
  27  *
  28  * All disk operations are performed by sending messages back and forth to
  29  * the OS/400 partition.
  30  */
  31
  32 #define pr_fmt(fmt) "viod: " fmt
  33
  34 #include <linux/major.h>
  35 #include <linux/fs.h>
  36 #include <linux/module.h>
  37 #include <linux/kernel.h>
  38 #include <linux/blkdev.h>
  39 #include <linux/genhd.h>
  40 #include <linux/hdreg.h>
  41 #include <linux/errno.h>
  42 #include <linux/init.h>
  43 #include <linux/string.h>
  44 #include <linux/dma-mapping.h>
  45 #include <linux/completion.h>
  46 #include <linux/device.h>
  47 #include <linux/scatterlist.h>
  48
  49 #include <asm/uaccess.h>
  50 #include <asm/vio.h>
  51 #include <asm/iseries/hv_types.h>
  52 #include <asm/iseries/hv_lp_event.h>
  53 #include <asm/iseries/hv_lp_config.h>
  54 #include <asm/iseries/vio.h>
  55 #include <asm/firmware.h>
  56
  57 MODULE_DESCRIPTION("iSeries Virtual DASD");
  58 MODULE_AUTHOR("Dave Boutcher");
  59 MODULE_LICENSE("GPL");
  60
  61 /*
  62  * We only support 7 partitions per physical disk....so with minor
  63  * numbers 0-255 we get a maximum of 32 disks.
  64  */
  65 #define VIOD_GENHD_NAME         "iseries/vd"
  66
  67 #define VIOD_VERS               "1.64"
  68
  69 enum {
  70         PARTITION_SHIFT = 3,
  71         MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS,
  72         MAX_DISK_NAME = FIELD_SIZEOF(struct gendisk, disk_name)
  73 };
  74
  75 static DEFINE_SPINLOCK(viodasd_spinlock);
  76
  77 #define VIOMAXREQ               16
  78
  79 #define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0])
  80
  81 struct viodasd_waitevent {
  82         struct completion       com;
  83         int                     rc;
  84         u16                     sub_result;
  85         int                     max_disk;       /* open */
  86 };
  87
  88 static const struct vio_error_entry viodasd_err_table[] = {
  89         { 0x0201, EINVAL, "Invalid Range" },
  90         { 0x0202, EINVAL, "Invalid Token" },
  91         { 0x0203, EIO, "DMA Error" },
  92         { 0x0204, EIO, "Use Error" },
  93         { 0x0205, EIO, "Release Error" },
  94         { 0x0206, EINVAL, "Invalid Disk" },
  95         { 0x0207, EBUSY, "Cant Lock" },
  96         { 0x0208, EIO, "Already Locked" },
  97         { 0x0209, EIO, "Already Unlocked" },
  98         { 0x020A, EIO, "Invalid Arg" },
  99         { 0x020B, EIO, "Bad IFS File" },
 100         { 0x020C, EROFS, "Read Only Device" },
 101         { 0x02FF, EIO, "Internal Error" },
 102         { 0x0000, 0, NULL },
 103 };
 104
 105 /*
 106  * Figure out the biggest I/O request (in sectors) we can accept
 107  */
 108 #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
 109
 110 /*
 111  * Number of disk I/O requests we've sent to OS/400
 112  */
 113 static int num_req_outstanding;
 114
 115 /*
 116  * This is our internal structure for keeping track of disk devices
 117  */
 118 struct viodasd_device {
 119         u16             cylinders;
 120         u16             tracks;
 121         u16             sectors;
 122         u16             bytes_per_sector;
 123         u64             size;
 124         int             read_only;
 125         spinlock_t      q_lock;
 126         struct gendisk  *disk;
 127         struct device   *dev;
 128 } viodasd_devices[MAX_DISKNO];
 129
 130 /*
 131  * External open entry point.
 132  */
 133 static int viodasd_open(struct block_device *bdev, fmode_t mode)
 134 {
 135         struct viodasd_device *d = bdev->bd_disk->private_data;
 136         HvLpEvent_Rc hvrc;
 137         struct viodasd_waitevent we;
 138         u16 flags = 0;
 139
 140         if (d->read_only) {
 141                 if (mode & FMODE_WRITE)
 142                         return -EROFS;
 143                 flags = vioblockflags_ro;
 144         }
 145
 146         init_completion(&we.com);
 147
 148         /* Send the open event to OS/400 */
 149         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 150                         HvLpEvent_Type_VirtualIo,
 151                         viomajorsubtype_blockio | vioblockopen,
 152                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 153                         viopath_sourceinst(viopath_hostLp),
 154                         viopath_targetinst(viopath_hostLp),
 155                         (u64)(unsigned long)&we, VIOVERSION << 16,
 156                         ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
 157                         0, 0, 0);
 158         if (hvrc != 0) {
 159                 pr_warning("HV open failed %d\n", (int)hvrc);
 160                 return -EIO;
 161         }
 162
 163         wait_for_completion(&we.com);
 164
 165         /* Check the return code */
 166         if (we.rc != 0) {
 167                 const struct vio_error_entry *err =
 168                         vio_lookup_rc(viodasd_err_table, we.sub_result);
 169
 170                 pr_warning("bad rc opening disk: %d:0x%04x (%s)\n",
 171                            (int)we.rc, we.sub_result, err->msg);
 172                 return -EIO;
 173         }
 174
 175         return 0;
 176 }
 177
 178 /*
 179  * External release entry point.
 180  */
 181 static int viodasd_release(struct gendisk *disk, fmode_t mode)
 182 {
 183         struct viodasd_device *d = disk->private_data;
 184         HvLpEvent_Rc hvrc;
 185
 186         /* Send the event to OS/400.  We DON'T expect a response */
 187         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 188                         HvLpEvent_Type_VirtualIo,
 189                         viomajorsubtype_blockio | vioblockclose,
 190                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 191                         viopath_sourceinst(viopath_hostLp),
 192                         viopath_targetinst(viopath_hostLp),
 193                         0, VIOVERSION << 16,
 194                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
 195                         0, 0, 0);
 196         if (hvrc != 0)
 197                 pr_warning("HV close call failed %d\n", (int)hvrc);
 198         return 0;
 199 }
 200
 201
 202 /* External ioctl entry point.
 203  */
 204 static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 205 {
 206         struct gendisk *disk = bdev->bd_disk;
 207         struct viodasd_device *d = disk->private_data;
 208
 209         geo->sectors = d->sectors ? d->sectors : 32;
 210         geo->heads = d->tracks ? d->tracks  : 64;
 211         geo->cylinders = d->cylinders ? d->cylinders :
 212                 get_capacity(disk) / (geo->sectors * geo->heads);
 213
 214         return 0;
 215 }
 216
 217 /*
 218  * Our file operations table
 219  */
 220 static const struct block_device_operations viodasd_fops = {
 221         .owner = THIS_MODULE,
 222         .open = viodasd_open,
 223         .release = viodasd_release,
 224         .getgeo = viodasd_getgeo,
 225 };
 226
 227 /*
 228  * End a request
 229  */
 230 static void viodasd_end_request(struct request *req, int error,
 231                 int num_sectors)
 232 {
 233         __blk_end_request(req, error, num_sectors << 9);
 234 }
 235
 236 /*
 237  * Send an actual I/O request to OS/400
 238  */
 239 static int send_request(struct request *req)
 240 {
 241         u64 start;
 242         int direction;
 243         int nsg;
 244         u16 viocmd;
 245         HvLpEvent_Rc hvrc;
 246         struct vioblocklpevent *bevent;
 247         struct HvLpEvent *hev;
 248         struct scatterlist sg[VIOMAXBLOCKDMA];
 249         int sgindex;
 250         struct viodasd_device *d;
 251         unsigned long flags;
 252
 253         start = (u64)blk_rq_pos(req) << 9;
 254
 255         if (rq_data_dir(req) == READ) {
 256                 direction = DMA_FROM_DEVICE;
 257                 viocmd = viomajorsubtype_blockio | vioblockread;
 258         } else {
 259                 direction = DMA_TO_DEVICE;
 260                 viocmd = viomajorsubtype_blockio | vioblockwrite;
 261         }
 262
 263         d = req->rq_disk->private_data;
 264
 265         /* Now build the scatter-gather list */
 266         sg_init_table(sg, VIOMAXBLOCKDMA);
 267         nsg = blk_rq_map_sg(req->q, req, sg);
 268         nsg = dma_map_sg(d->dev, sg, nsg, direction);
 269
 270         spin_lock_irqsave(&viodasd_spinlock, flags);
 271         num_req_outstanding++;
 272
 273         /* This optimization handles a single DMA block */
 274         if (nsg == 1)
 275                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 276                                 HvLpEvent_Type_VirtualIo, viocmd,
 277                                 HvLpEvent_AckInd_DoAck,
 278                                 HvLpEvent_AckType_ImmediateAck,
 279                                 viopath_sourceinst(viopath_hostLp),
 280                                 viopath_targetinst(viopath_hostLp),
 281                                 (u64)(unsigned long)req, VIOVERSION << 16,
 282                                 ((u64)DEVICE_NO(d) << 48), start,
 283                                 ((u64)sg_dma_address(&sg[0])) << 32,
 284                                 sg_dma_len(&sg[0]));
 285         else {
 286                 bevent = (struct vioblocklpevent *)
 287                         vio_get_event_buffer(viomajorsubtype_blockio);
 288                 if (bevent == NULL) {
 289                         pr_warning("error allocating disk event buffer\n");
 290                         goto error_ret;
 291                 }
 292
 293                 /*
 294                  * Now build up the actual request.  Note that we store
 295                  * the pointer to the request in the correlation
 296                  * token so we can match the response up later
 297                  */
 298                 memset(bevent, 0, sizeof(struct vioblocklpevent));
 299                 hev = &bevent->event;
 300                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
 301                         HV_LP_EVENT_INT;
 302                 hev->xType = HvLpEvent_Type_VirtualIo;
 303                 hev->xSubtype = viocmd;
 304                 hev->xSourceLp = HvLpConfig_getLpIndex();
 305                 hev->xTargetLp = viopath_hostLp;
 306                 hev->xSizeMinus1 =
 307                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
 308                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
 309                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
 310                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
 311                 hev->xCorrelationToken = (u64)req;
 312                 bevent->version = VIOVERSION;
 313                 bevent->disk = DEVICE_NO(d);
 314                 bevent->u.rw_data.offset = start;
 315
 316                 /*
 317                  * Copy just the dma information from the sg list
 318                  * into the request
 319                  */
 320                 for (sgindex = 0; sgindex < nsg; sgindex++) {
 321                         bevent->u.rw_data.dma_info[sgindex].token =
 322                                 sg_dma_address(&sg[sgindex]);
 323                         bevent->u.rw_data.dma_info[sgindex].len =
 324                                 sg_dma_len(&sg[sgindex]);
 325                 }
 326
 327                 /* Send the request */
 328                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
 329                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
 330         }
 331
 332         if (hvrc != HvLpEvent_Rc_Good) {
 333                 pr_warning("error sending disk event to OS/400 (rc %d)\n",
 334                            (int)hvrc);
 335                 goto error_ret;
 336         }
 337         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 338         return 0;
 339
 340 error_ret:
 341         num_req_outstanding--;
 342         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 343         dma_unmap_sg(d->dev, sg, nsg, direction);
 344         return -1;
 345 }
 346
 347 /*
 348  * This is the external request processing routine
 349  */
 350 static void do_viodasd_request(struct request_queue *q)
 351 {
 352         struct request *req;
 353
 354         /*
 355          * If we already have the maximum number of requests
 356          * outstanding to OS/400 just bail out. We'll come
 357          * back later.
 358          */
 359         while (num_req_outstanding < VIOMAXREQ) {
 360                 req = blk_fetch_request(q);
 361                 if (req == NULL)
 362                         return;
 363                 /* check that request contains a valid command */
 364                 if (!blk_fs_request(req)) {
 365                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
 366                         continue;
 367                 }
 368                 /* Try sending the request */
 369                 if (send_request(req) != 0)
 370                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
 371         }
 372 }
 373
 374 /*
 375  * Probe a single disk and fill in the viodasd_device structure
 376  * for it.
 377  */
 378 static int probe_disk(struct viodasd_device *d)
 379 {
 380         HvLpEvent_Rc hvrc;
 381         struct viodasd_waitevent we;
 382         int dev_no = DEVICE_NO(d);
 383         struct gendisk *g;
 384         struct request_queue *q;
 385         u16 flags = 0;
 386
 387 retry:
 388         init_completion(&we.com);
 389
 390         /* Send the open event to OS/400 */
 391         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 392                         HvLpEvent_Type_VirtualIo,
 393                         viomajorsubtype_blockio | vioblockopen,
 394                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 395                         viopath_sourceinst(viopath_hostLp),
 396                         viopath_targetinst(viopath_hostLp),
 397                         (u64)(unsigned long)&we, VIOVERSION << 16,
 398                         ((u64)dev_no << 48) | ((u64)flags<< 32),
 399                         0, 0, 0);
 400         if (hvrc != 0) {
 401                 pr_warning("bad rc on HV open %d\n", (int)hvrc);
 402                 return 0;
 403         }
 404
 405         wait_for_completion(&we.com);
 406
 407         if (we.rc != 0) {
 408                 if (flags != 0)
 409                         return 0;
 410                 /* try again with read only flag set */
 411                 flags = vioblockflags_ro;
 412                 goto retry;
 413         }
 414         if (we.max_disk > (MAX_DISKNO - 1)) {
 415                 printk_once(KERN_INFO pr_fmt("Only examining the first %d of %d disks connected\n"),
 416                             MAX_DISKNO, we.max_disk + 1);
 417         }
 418
 419         /* Send the close event to OS/400.  We DON'T expect a response */
 420         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 421                         HvLpEvent_Type_VirtualIo,
 422                         viomajorsubtype_blockio | vioblockclose,
 423                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 424                         viopath_sourceinst(viopath_hostLp),
 425                         viopath_targetinst(viopath_hostLp),
 426                         0, VIOVERSION << 16,
 427                         ((u64)dev_no << 48) | ((u64)flags << 32),
 428                         0, 0, 0);
 429         if (hvrc != 0) {
 430                 pr_warning("bad rc sending event to OS/400 %d\n", (int)hvrc);
 431                 return 0;
 432         }
 433
 434         if (d->dev == NULL) {
 435                 /* this is when we reprobe for new disks */
 436                 if (vio_create_viodasd(dev_no) == NULL) {
 437                         pr_warning("cannot allocate virtual device for disk %d\n",
 438                                    dev_no);
 439                         return 0;
 440                 }
 441                 /*
 442                  * The vio_create_viodasd will have recursed into this
 443                  * routine with d->dev set to the new vio device and
 444                  * will finish the setup of the disk below.
 445                  */
 446                 return 1;
 447         }
 448
 449         /* create the request queue for the disk */
 450         spin_lock_init(&d->q_lock);
 451         q = blk_init_queue(do_viodasd_request, &d->q_lock);
 452         if (q == NULL) {
 453                 pr_warning("cannot allocate queue for disk %d\n", dev_no);
 454                 return 0;
 455         }
 456         g = alloc_disk(1 << PARTITION_SHIFT);
 457         if (g == NULL) {
 458                 pr_warning("cannot allocate disk structure for disk %d\n",
 459                            dev_no);
 460                 blk_cleanup_queue(q);
 461                 return 0;
 462         }
 463
 464         d->disk = g;
 465         blk_queue_max_segments(q, VIOMAXBLOCKDMA);
 466         blk_queue_max_hw_sectors(q, VIODASD_MAXSECTORS);
 467         g->major = VIODASD_MAJOR;
 468         g->first_minor = dev_no << PARTITION_SHIFT;
 469         if (dev_no >= 26)
 470                 snprintf(g->disk_name, sizeof(g->disk_name),
 471                                 VIOD_GENHD_NAME "%c%c",
 472                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
 473         else
 474                 snprintf(g->disk_name, sizeof(g->disk_name),
 475                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
 476         g->fops = &viodasd_fops;
 477         g->queue = q;
 478         g->private_data = d;
 479         g->driverfs_dev = d->dev;
 480         set_capacity(g, d->size >> 9);
 481
 482         pr_info("disk %d: %lu sectors (%lu MB) CHS=%d/%d/%d sector size %d%s\n",
 483                 dev_no, (unsigned long)(d->size >> 9),
 484                 (unsigned long)(d->size >> 20),
 485                 (int)d->cylinders, (int)d->tracks,
 486                 (int)d->sectors, (int)d->bytes_per_sector,
 487                 d->read_only ? " (RO)" : "");
 488
 489         /* register us in the global list */
 490         add_disk(g);
 491         return 1;
 492 }
 493
 494 /* returns the total number of scatterlist elements converted */
 495 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
 496                 struct scatterlist *sg, int *total_len)
 497 {
 498         int i, numsg;
 499         const struct rw_data *rw_data = &bevent->u.rw_data;
 500         static const int offset =
 501                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
 502         static const int element_size = sizeof(rw_data->dma_info[0]);
 503
 504         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
 505         if (numsg > VIOMAXBLOCKDMA)
 506                 numsg = VIOMAXBLOCKDMA;
 507
 508         *total_len = 0;
 509         sg_init_table(sg, VIOMAXBLOCKDMA);
 510         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
 511                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
 512                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
 513                 *total_len += rw_data->dma_info[i].len;
 514         }
 515         return i;
 516 }
 517
 518 /*
 519  * Restart all queues, starting with the one _after_ the disk given,
 520  * thus reducing the chance of starvation of higher numbered disks.
 521  */
 522 static void viodasd_restart_all_queues_starting_from(int first_index)
 523 {
 524         int i;
 525
 526         for (i = first_index + 1; i < MAX_DISKNO; ++i)
 527                 if (viodasd_devices[i].disk)
 528                         blk_run_queue(viodasd_devices[i].disk->queue);
 529         for (i = 0; i <= first_index; ++i)
 530                 if (viodasd_devices[i].disk)
 531                         blk_run_queue(viodasd_devices[i].disk->queue);
 532 }
 533
 534 /*
 535  * For read and write requests, decrement the number of outstanding requests,
 536  * Free the DMA buffers we allocated.
 537  */
 538 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
 539 {
 540         int num_sg, num_sect, pci_direction, total_len;
 541         struct request *req;
 542         struct scatterlist sg[VIOMAXBLOCKDMA];
 543         struct HvLpEvent *event = &bevent->event;
 544         unsigned long irq_flags;
 545         struct viodasd_device *d;
 546         int error;
 547         spinlock_t *qlock;
 548
 549         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
 550         num_sect = total_len >> 9;
 551         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
 552                 pci_direction = DMA_FROM_DEVICE;
 553         else
 554                 pci_direction = DMA_TO_DEVICE;
 555         req = (struct request *)bevent->event.xCorrelationToken;
 556         d = req->rq_disk->private_data;
 557
 558         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
 559
 560         /*
 561          * Since this is running in interrupt mode, we need to make sure
 562          * we're not stepping on any global I/O operations
 563          */
 564         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
 565         num_req_outstanding--;
 566         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
 567
 568         error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO;
 569         if (error) {
 570                 const struct vio_error_entry *err;
 571                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
 572                 pr_warning("read/write error %d:0x%04x (%s)\n",
 573                            event->xRc, bevent->sub_result, err->msg);
 574                 num_sect = blk_rq_sectors(req);
 575         }
 576         qlock = req->q->queue_lock;
 577         spin_lock_irqsave(qlock, irq_flags);
 578         viodasd_end_request(req, error, num_sect);
 579         spin_unlock_irqrestore(qlock, irq_flags);
 580
 581         /* Finally, try to get more requests off of this device's queue */
 582         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
 583
 584         return 0;
 585 }
 586
 587 /* This routine handles incoming block LP events */
 588 static void handle_block_event(struct HvLpEvent *event)
 589 {
 590         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
 591         struct viodasd_waitevent *pwe;
 592
 593         if (event == NULL)
 594                 /* Notification that a partition went away! */
 595                 return;
 596         /* First, we should NEVER get an int here...only acks */
 597         if (hvlpevent_is_int(event)) {
 598                 pr_warning("Yikes! got an int in viodasd event handler!\n");
 599                 if (hvlpevent_need_ack(event)) {
 600                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 601                         HvCallEvent_ackLpEvent(event);
 602                 }
 603         }
 604
 605         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
 606         case vioblockopen:
 607                 /*
 608                  * Handle a response to an open request.  We get all the
 609                  * disk information in the response, so update it.  The
 610                  * correlation token contains a pointer to a waitevent
 611                  * structure that has a completion in it.  update the
 612                  * return code in the waitevent structure and post the
 613                  * completion to wake up the guy who sent the request
 614                  */
 615                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
 616                 pwe->rc = event->xRc;
 617                 pwe->sub_result = bevent->sub_result;
 618                 if (event->xRc == HvLpEvent_Rc_Good) {
 619                         const struct open_data *data = &bevent->u.open_data;
 620                         struct viodasd_device *device =
 621                                 &viodasd_devices[bevent->disk];
 622                         device->read_only =
 623                                 bevent->flags & vioblockflags_ro;
 624                         device->size = data->disk_size;
 625                         device->cylinders = data->cylinders;
 626                         device->tracks = data->tracks;
 627                         device->sectors = data->sectors;
 628                         device->bytes_per_sector = data->bytes_per_sector;
 629                         pwe->max_disk = data->max_disk;
 630                 }
 631                 complete(&pwe->com);
 632                 break;
 633         case vioblockclose:
 634                 break;
 635         case vioblockread:
 636         case vioblockwrite:
 637                 viodasd_handle_read_write(bevent);
 638                 break;
 639
 640         default:
 641                 pr_warning("invalid subtype!");
 642                 if (hvlpevent_need_ack(event)) {
 643                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 644                         HvCallEvent_ackLpEvent(event);
 645                 }
 646         }
 647 }
 648
 649 /*
 650  * Get the driver to reprobe for more disks.
 651  */
 652 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
 653                 size_t count)
 654 {
 655         struct viodasd_device *d;
 656
 657         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
 658                 if (d->disk == NULL)
 659                         probe_disk(d);
 660         }
 661         return count;
 662 }
 663 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
 664
 665 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 666 {
 667         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
 668
 669         d->dev = &vdev->dev;
 670         if (!probe_disk(d))
 671                 return -ENODEV;
 672         return 0;
 673 }
 674
 675 static int viodasd_remove(struct vio_dev *vdev)
 676 {
 677         struct viodasd_device *d;
 678
 679         d = &viodasd_devices[vdev->unit_address];
 680         if (d->disk) {
 681                 del_gendisk(d->disk);
 682                 blk_cleanup_queue(d->disk->queue);
 683                 put_disk(d->disk);
 684                 d->disk = NULL;
 685         }
 686         d->dev = NULL;
 687         return 0;
 688 }
 689
 690 /**
 691  * viodasd_device_table: Used by vio.c to match devices that we
 692  * support.
 693  */
 694 static struct vio_device_id viodasd_device_table[] __devinitdata = {
 695         { "block", "IBM,iSeries-viodasd" },
 696         { "", "" }
 697 };
 698 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
 699
 700 static struct vio_driver viodasd_driver = {
 701         .id_table = viodasd_device_table,
 702         .probe = viodasd_probe,
 703         .remove = viodasd_remove,
 704         .driver = {
 705                 .name = "viodasd",
 706                 .owner = THIS_MODULE,
 707         }
 708 };
 709
 710 static int need_delete_probe;
 711
 712 /*
 713  * Initialize the whole device driver.  Handle module and non-module
 714  * versions
 715  */
 716 static int __init viodasd_init(void)
 717 {
 718         int rc;
 719
 720         if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
 721                 rc = -ENODEV;
 722                 goto early_fail;
 723         }
 724
 725         /* Try to open to our host lp */
 726         if (viopath_hostLp == HvLpIndexInvalid)
 727                 vio_set_hostlp();
 728
 729         if (viopath_hostLp == HvLpIndexInvalid) {
 730                 pr_warning("invalid hosting partition\n");
 731                 rc = -EIO;
 732                 goto early_fail;
 733         }
 734
 735         pr_info("vers " VIOD_VERS ", hosting partition %d\n", viopath_hostLp);
 736
 737         /* register the block device */
 738         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 739         if (rc) {
 740                 pr_warning("Unable to get major number %d for %s\n",
 741                            VIODASD_MAJOR, VIOD_GENHD_NAME);
 742                 goto early_fail;
 743         }
 744         /* Actually open the path to the hosting partition */
 745         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
 746                                 VIOMAXREQ + 2);
 747         if (rc) {
 748                 pr_warning("error opening path to host partition %d\n",
 749                            viopath_hostLp);
 750                 goto unregister_blk;
 751         }
 752
 753         /* Initialize our request handler */
 754         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
 755
 756         rc = vio_register_driver(&viodasd_driver);
 757         if (rc) {
 758                 pr_warning("vio_register_driver failed\n");
 759                 goto unset_handler;
 760         }
 761
 762         /*
 763          * If this call fails, it just means that we cannot dynamically
 764          * add virtual disks, but the driver will still work fine for
 765          * all existing disk, so ignore the failure.
 766          */
 767         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
 768                 need_delete_probe = 1;
 769
 770         return 0;
 771
 772 unset_handler:
 773         vio_clearHandler(viomajorsubtype_blockio);
 774         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 775 unregister_blk:
 776         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 777 early_fail:
 778         return rc;
 779 }
 780 module_init(viodasd_init);
 781
 782 void __exit viodasd_exit(void)
 783 {
 784         if (need_delete_probe)
 785                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
 786         vio_unregister_driver(&viodasd_driver);
 787         vio_clearHandler(viomajorsubtype_blockio);
 788         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 789         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 790 }
 791 module_exit(viodasd_exit);