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/smp_lock.h>
  45 #include <linux/dma-mapping.h>
  46 #include <linux/completion.h>
  47 #include <linux/device.h>
  48 #include <linux/scatterlist.h>
  49
  50 #include <asm/uaccess.h>
  51 #include <asm/vio.h>
  52 #include <asm/iseries/hv_types.h>
  53 #include <asm/iseries/hv_lp_event.h>
  54 #include <asm/iseries/hv_lp_config.h>
  55 #include <asm/iseries/vio.h>
  56 #include <asm/firmware.h>
  57
  58 MODULE_DESCRIPTION("iSeries Virtual DASD");
  59 MODULE_AUTHOR("Dave Boutcher");
  60 MODULE_LICENSE("GPL");
  61
  62 /*
  63  * We only support 7 partitions per physical disk....so with minor
  64  * numbers 0-255 we get a maximum of 32 disks.
  65  */
  66 #define VIOD_GENHD_NAME         "iseries/vd"
  67
  68 #define VIOD_VERS               "1.64"
  69
  70 enum {
  71         PARTITION_SHIFT = 3,
  72         MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS,
  73         MAX_DISK_NAME = FIELD_SIZEOF(struct gendisk, disk_name)
  74 };
  75
  76 static DEFINE_SPINLOCK(viodasd_spinlock);
  77
  78 #define VIOMAXREQ               16
  79
  80 #define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0])
  81
  82 struct viodasd_waitevent {
  83         struct completion       com;
  84         int                     rc;
  85         u16                     sub_result;
  86         int                     max_disk;       /* open */
  87 };
  88
  89 static const struct vio_error_entry viodasd_err_table[] = {
  90         { 0x0201, EINVAL, "Invalid Range" },
  91         { 0x0202, EINVAL, "Invalid Token" },
  92         { 0x0203, EIO, "DMA Error" },
  93         { 0x0204, EIO, "Use Error" },
  94         { 0x0205, EIO, "Release Error" },
  95         { 0x0206, EINVAL, "Invalid Disk" },
  96         { 0x0207, EBUSY, "Cant Lock" },
  97         { 0x0208, EIO, "Already Locked" },
  98         { 0x0209, EIO, "Already Unlocked" },
  99         { 0x020A, EIO, "Invalid Arg" },
 100         { 0x020B, EIO, "Bad IFS File" },
 101         { 0x020C, EROFS, "Read Only Device" },
 102         { 0x02FF, EIO, "Internal Error" },
 103         { 0x0000, 0, NULL },
 104 };
 105
 106 /*
 107  * Figure out the biggest I/O request (in sectors) we can accept
 108  */
 109 #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
 110
 111 /*
 112  * Number of disk I/O requests we've sent to OS/400
 113  */
 114 static int num_req_outstanding;
 115
 116 /*
 117  * This is our internal structure for keeping track of disk devices
 118  */
 119 struct viodasd_device {
 120         u16             cylinders;
 121         u16             tracks;
 122         u16             sectors;
 123         u16             bytes_per_sector;
 124         u64             size;
 125         int             read_only;
 126         spinlock_t      q_lock;
 127         struct gendisk  *disk;
 128         struct device   *dev;
 129 } viodasd_devices[MAX_DISKNO];
 130
 131 /*
 132  * External open entry point.
 133  */
 134 static int viodasd_open(struct block_device *bdev, fmode_t mode)
 135 {
 136         struct viodasd_device *d = bdev->bd_disk->private_data;
 137         HvLpEvent_Rc hvrc;
 138         struct viodasd_waitevent we;
 139         u16 flags = 0;
 140
 141         if (d->read_only) {
 142                 if (mode & FMODE_WRITE)
 143                         return -EROFS;
 144                 flags = vioblockflags_ro;
 145         }
 146
 147         init_completion(&we.com);
 148
 149         /* Send the open event to OS/400 */
 150         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 151                         HvLpEvent_Type_VirtualIo,
 152                         viomajorsubtype_blockio | vioblockopen,
 153                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 154                         viopath_sourceinst(viopath_hostLp),
 155                         viopath_targetinst(viopath_hostLp),
 156                         (u64)(unsigned long)&we, VIOVERSION << 16,
 157                         ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
 158                         0, 0, 0);
 159         if (hvrc != 0) {
 160                 pr_warning("HV open failed %d\n", (int)hvrc);
 161                 return -EIO;
 162         }
 163
 164         wait_for_completion(&we.com);
 165
 166         /* Check the return code */
 167         if (we.rc != 0) {
 168                 const struct vio_error_entry *err =
 169                         vio_lookup_rc(viodasd_err_table, we.sub_result);
 170
 171                 pr_warning("bad rc opening disk: %d:0x%04x (%s)\n",
 172                            (int)we.rc, we.sub_result, err->msg);
 173                 return -EIO;
 174         }
 175
 176         return 0;
 177 }
 178
 179 static int viodasd_unlocked_open(struct block_device *bdev, fmode_t mode)
 180 {
 181         int ret;
 182
 183         lock_kernel();
 184         ret = viodasd_open(bdev, mode);
 185         unlock_kernel();
 186
 187         return ret;
 188 }
 189
 190
 191 /*
 192  * External release entry point.
 193  */
 194 static int viodasd_release(struct gendisk *disk, fmode_t mode)
 195 {
 196         struct viodasd_device *d = disk->private_data;
 197         HvLpEvent_Rc hvrc;
 198
 199         lock_kernel();
 200         /* Send the event to OS/400.  We DON'T expect a response */
 201         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 202                         HvLpEvent_Type_VirtualIo,
 203                         viomajorsubtype_blockio | vioblockclose,
 204                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 205                         viopath_sourceinst(viopath_hostLp),
 206                         viopath_targetinst(viopath_hostLp),
 207                         0, VIOVERSION << 16,
 208                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
 209                         0, 0, 0);
 210         if (hvrc != 0)
 211                 pr_warning("HV close call failed %d\n", (int)hvrc);
 212
 213         unlock_kernel();
 214
 215         return 0;
 216 }
 217
 218
 219 /* External ioctl entry point.
 220  */
 221 static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 222 {
 223         struct gendisk *disk = bdev->bd_disk;
 224         struct viodasd_device *d = disk->private_data;
 225
 226         geo->sectors = d->sectors ? d->sectors : 32;
 227         geo->heads = d->tracks ? d->tracks  : 64;
 228         geo->cylinders = d->cylinders ? d->cylinders :
 229                 get_capacity(disk) / (geo->sectors * geo->heads);
 230
 231         return 0;
 232 }
 233
 234 /*
 235  * Our file operations table
 236  */
 237 static const struct block_device_operations viodasd_fops = {
 238         .owner = THIS_MODULE,
 239         .open = viodasd_unlocked_open,
 240         .release = viodasd_release,
 241         .getgeo = viodasd_getgeo,
 242 };
 243
 244 /*
 245  * End a request
 246  */
 247 static void viodasd_end_request(struct request *req, int error,
 248                 int num_sectors)
 249 {
 250         __blk_end_request(req, error, num_sectors << 9);
 251 }
 252
 253 /*
 254  * Send an actual I/O request to OS/400
 255  */
 256 static int send_request(struct request *req)
 257 {
 258         u64 start;
 259         int direction;
 260         int nsg;
 261         u16 viocmd;
 262         HvLpEvent_Rc hvrc;
 263         struct vioblocklpevent *bevent;
 264         struct HvLpEvent *hev;
 265         struct scatterlist sg[VIOMAXBLOCKDMA];
 266         int sgindex;
 267         struct viodasd_device *d;
 268         unsigned long flags;
 269
 270         start = (u64)blk_rq_pos(req) << 9;
 271
 272         if (rq_data_dir(req) == READ) {
 273                 direction = DMA_FROM_DEVICE;
 274                 viocmd = viomajorsubtype_blockio | vioblockread;
 275         } else {
 276                 direction = DMA_TO_DEVICE;
 277                 viocmd = viomajorsubtype_blockio | vioblockwrite;
 278         }
 279
 280         d = req->rq_disk->private_data;
 281
 282         /* Now build the scatter-gather list */
 283         sg_init_table(sg, VIOMAXBLOCKDMA);
 284         nsg = blk_rq_map_sg(req->q, req, sg);
 285         nsg = dma_map_sg(d->dev, sg, nsg, direction);
 286
 287         spin_lock_irqsave(&viodasd_spinlock, flags);
 288         num_req_outstanding++;
 289
 290         /* This optimization handles a single DMA block */
 291         if (nsg == 1)
 292                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 293                                 HvLpEvent_Type_VirtualIo, viocmd,
 294                                 HvLpEvent_AckInd_DoAck,
 295                                 HvLpEvent_AckType_ImmediateAck,
 296                                 viopath_sourceinst(viopath_hostLp),
 297                                 viopath_targetinst(viopath_hostLp),
 298                                 (u64)(unsigned long)req, VIOVERSION << 16,
 299                                 ((u64)DEVICE_NO(d) << 48), start,
 300                                 ((u64)sg_dma_address(&sg[0])) << 32,
 301                                 sg_dma_len(&sg[0]));
 302         else {
 303                 bevent = (struct vioblocklpevent *)
 304                         vio_get_event_buffer(viomajorsubtype_blockio);
 305                 if (bevent == NULL) {
 306                         pr_warning("error allocating disk event buffer\n");
 307                         goto error_ret;
 308                 }
 309
 310                 /*
 311                  * Now build up the actual request.  Note that we store
 312                  * the pointer to the request in the correlation
 313                  * token so we can match the response up later
 314                  */
 315                 memset(bevent, 0, sizeof(struct vioblocklpevent));
 316                 hev = &bevent->event;
 317                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
 318                         HV_LP_EVENT_INT;
 319                 hev->xType = HvLpEvent_Type_VirtualIo;
 320                 hev->xSubtype = viocmd;
 321                 hev->xSourceLp = HvLpConfig_getLpIndex();
 322                 hev->xTargetLp = viopath_hostLp;
 323                 hev->xSizeMinus1 =
 324                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
 325                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
 326                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
 327                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
 328                 hev->xCorrelationToken = (u64)req;
 329                 bevent->version = VIOVERSION;
 330                 bevent->disk = DEVICE_NO(d);
 331                 bevent->u.rw_data.offset = start;
 332
 333                 /*
 334                  * Copy just the dma information from the sg list
 335                  * into the request
 336                  */
 337                 for (sgindex = 0; sgindex < nsg; sgindex++) {
 338                         bevent->u.rw_data.dma_info[sgindex].token =
 339                                 sg_dma_address(&sg[sgindex]);
 340                         bevent->u.rw_data.dma_info[sgindex].len =
 341                                 sg_dma_len(&sg[sgindex]);
 342                 }
 343
 344                 /* Send the request */
 345                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
 346                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
 347         }
 348
 349         if (hvrc != HvLpEvent_Rc_Good) {
 350                 pr_warning("error sending disk event to OS/400 (rc %d)\n",
 351                            (int)hvrc);
 352                 goto error_ret;
 353         }
 354         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 355         return 0;
 356
 357 error_ret:
 358         num_req_outstanding--;
 359         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 360         dma_unmap_sg(d->dev, sg, nsg, direction);
 361         return -1;
 362 }
 363
 364 /*
 365  * This is the external request processing routine
 366  */
 367 static void do_viodasd_request(struct request_queue *q)
 368 {
 369         struct request *req;
 370
 371         /*
 372          * If we already have the maximum number of requests
 373          * outstanding to OS/400 just bail out. We'll come
 374          * back later.
 375          */
 376         while (num_req_outstanding < VIOMAXREQ) {
 377                 req = blk_fetch_request(q);
 378                 if (req == NULL)
 379                         return;
 380                 /* check that request contains a valid command */
 381                 if (req->cmd_type != REQ_TYPE_FS) {
 382                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
 383                         continue;
 384                 }
 385                 /* Try sending the request */
 386                 if (send_request(req) != 0)
 387                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
 388         }
 389 }
 390
 391 /*
 392  * Probe a single disk and fill in the viodasd_device structure
 393  * for it.
 394  */
 395 static int probe_disk(struct viodasd_device *d)
 396 {
 397         HvLpEvent_Rc hvrc;
 398         struct viodasd_waitevent we;
 399         int dev_no = DEVICE_NO(d);
 400         struct gendisk *g;
 401         struct request_queue *q;
 402         u16 flags = 0;
 403
 404 retry:
 405         init_completion(&we.com);
 406
 407         /* Send the open event to OS/400 */
 408         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 409                         HvLpEvent_Type_VirtualIo,
 410                         viomajorsubtype_blockio | vioblockopen,
 411                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 412                         viopath_sourceinst(viopath_hostLp),
 413                         viopath_targetinst(viopath_hostLp),
 414                         (u64)(unsigned long)&we, VIOVERSION << 16,
 415                         ((u64)dev_no << 48) | ((u64)flags<< 32),
 416                         0, 0, 0);
 417         if (hvrc != 0) {
 418                 pr_warning("bad rc on HV open %d\n", (int)hvrc);
 419                 return 0;
 420         }
 421
 422         wait_for_completion(&we.com);
 423
 424         if (we.rc != 0) {
 425                 if (flags != 0)
 426                         return 0;
 427                 /* try again with read only flag set */
 428                 flags = vioblockflags_ro;
 429                 goto retry;
 430         }
 431         if (we.max_disk > (MAX_DISKNO - 1)) {
 432                 printk_once(KERN_INFO pr_fmt("Only examining the first %d of %d disks connected\n"),
 433                             MAX_DISKNO, we.max_disk + 1);
 434         }
 435
 436         /* Send the close event to OS/400.  We DON'T expect a response */
 437         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 438                         HvLpEvent_Type_VirtualIo,
 439                         viomajorsubtype_blockio | vioblockclose,
 440                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 441                         viopath_sourceinst(viopath_hostLp),
 442                         viopath_targetinst(viopath_hostLp),
 443                         0, VIOVERSION << 16,
 444                         ((u64)dev_no << 48) | ((u64)flags << 32),
 445                         0, 0, 0);
 446         if (hvrc != 0) {
 447                 pr_warning("bad rc sending event to OS/400 %d\n", (int)hvrc);
 448                 return 0;
 449         }
 450
 451         if (d->dev == NULL) {
 452                 /* this is when we reprobe for new disks */
 453                 if (vio_create_viodasd(dev_no) == NULL) {
 454                         pr_warning("cannot allocate virtual device for disk %d\n",
 455                                    dev_no);
 456                         return 0;
 457                 }
 458                 /*
 459                  * The vio_create_viodasd will have recursed into this
 460                  * routine with d->dev set to the new vio device and
 461                  * will finish the setup of the disk below.
 462                  */
 463                 return 1;
 464         }
 465
 466         /* create the request queue for the disk */
 467         spin_lock_init(&d->q_lock);
 468         q = blk_init_queue(do_viodasd_request, &d->q_lock);
 469         if (q == NULL) {
 470                 pr_warning("cannot allocate queue for disk %d\n", dev_no);
 471                 return 0;
 472         }
 473         g = alloc_disk(1 << PARTITION_SHIFT);
 474         if (g == NULL) {
 475                 pr_warning("cannot allocate disk structure for disk %d\n",
 476                            dev_no);
 477                 blk_cleanup_queue(q);
 478                 return 0;
 479         }
 480
 481         d->disk = g;
 482         blk_queue_max_segments(q, VIOMAXBLOCKDMA);
 483         blk_queue_max_hw_sectors(q, VIODASD_MAXSECTORS);
 484         g->major = VIODASD_MAJOR;
 485         g->first_minor = dev_no << PARTITION_SHIFT;
 486         if (dev_no >= 26)
 487                 snprintf(g->disk_name, sizeof(g->disk_name),
 488                                 VIOD_GENHD_NAME "%c%c",
 489                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
 490         else
 491                 snprintf(g->disk_name, sizeof(g->disk_name),
 492                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
 493         g->fops = &viodasd_fops;
 494         g->queue = q;
 495         g->private_data = d;
 496         g->driverfs_dev = d->dev;
 497         set_capacity(g, d->size >> 9);
 498
 499         pr_info("disk %d: %lu sectors (%lu MB) CHS=%d/%d/%d sector size %d%s\n",
 500                 dev_no, (unsigned long)(d->size >> 9),
 501                 (unsigned long)(d->size >> 20),
 502                 (int)d->cylinders, (int)d->tracks,
 503                 (int)d->sectors, (int)d->bytes_per_sector,
 504                 d->read_only ? " (RO)" : "");
 505
 506         /* register us in the global list */
 507         add_disk(g);
 508         return 1;
 509 }
 510
 511 /* returns the total number of scatterlist elements converted */
 512 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
 513                 struct scatterlist *sg, int *total_len)
 514 {
 515         int i, numsg;
 516         const struct rw_data *rw_data = &bevent->u.rw_data;
 517         static const int offset =
 518                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
 519         static const int element_size = sizeof(rw_data->dma_info[0]);
 520
 521         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
 522         if (numsg > VIOMAXBLOCKDMA)
 523                 numsg = VIOMAXBLOCKDMA;
 524
 525         *total_len = 0;
 526         sg_init_table(sg, VIOMAXBLOCKDMA);
 527         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
 528                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
 529                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
 530                 *total_len += rw_data->dma_info[i].len;
 531         }
 532         return i;
 533 }
 534
 535 /*
 536  * Restart all queues, starting with the one _after_ the disk given,
 537  * thus reducing the chance of starvation of higher numbered disks.
 538  */
 539 static void viodasd_restart_all_queues_starting_from(int first_index)
 540 {
 541         int i;
 542
 543         for (i = first_index + 1; i < MAX_DISKNO; ++i)
 544                 if (viodasd_devices[i].disk)
 545                         blk_run_queue(viodasd_devices[i].disk->queue);
 546         for (i = 0; i <= first_index; ++i)
 547                 if (viodasd_devices[i].disk)
 548                         blk_run_queue(viodasd_devices[i].disk->queue);
 549 }
 550
 551 /*
 552  * For read and write requests, decrement the number of outstanding requests,
 553  * Free the DMA buffers we allocated.
 554  */
 555 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
 556 {
 557         int num_sg, num_sect, pci_direction, total_len;
 558         struct request *req;
 559         struct scatterlist sg[VIOMAXBLOCKDMA];
 560         struct HvLpEvent *event = &bevent->event;
 561         unsigned long irq_flags;
 562         struct viodasd_device *d;
 563         int error;
 564         spinlock_t *qlock;
 565
 566         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
 567         num_sect = total_len >> 9;
 568         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
 569                 pci_direction = DMA_FROM_DEVICE;
 570         else
 571                 pci_direction = DMA_TO_DEVICE;
 572         req = (struct request *)bevent->event.xCorrelationToken;
 573         d = req->rq_disk->private_data;
 574
 575         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
 576
 577         /*
 578          * Since this is running in interrupt mode, we need to make sure
 579          * we're not stepping on any global I/O operations
 580          */
 581         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
 582         num_req_outstanding--;
 583         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
 584
 585         error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO;
 586         if (error) {
 587                 const struct vio_error_entry *err;
 588                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
 589                 pr_warning("read/write error %d:0x%04x (%s)\n",
 590                            event->xRc, bevent->sub_result, err->msg);
 591                 num_sect = blk_rq_sectors(req);
 592         }
 593         qlock = req->q->queue_lock;
 594         spin_lock_irqsave(qlock, irq_flags);
 595         viodasd_end_request(req, error, num_sect);
 596         spin_unlock_irqrestore(qlock, irq_flags);
 597
 598         /* Finally, try to get more requests off of this device's queue */
 599         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
 600
 601         return 0;
 602 }
 603
 604 /* This routine handles incoming block LP events */
 605 static void handle_block_event(struct HvLpEvent *event)
 606 {
 607         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
 608         struct viodasd_waitevent *pwe;
 609
 610         if (event == NULL)
 611                 /* Notification that a partition went away! */
 612                 return;
 613         /* First, we should NEVER get an int here...only acks */
 614         if (hvlpevent_is_int(event)) {
 615                 pr_warning("Yikes! got an int in viodasd event handler!\n");
 616                 if (hvlpevent_need_ack(event)) {
 617                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 618                         HvCallEvent_ackLpEvent(event);
 619                 }
 620         }
 621
 622         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
 623         case vioblockopen:
 624                 /*
 625                  * Handle a response to an open request.  We get all the
 626                  * disk information in the response, so update it.  The
 627                  * correlation token contains a pointer to a waitevent
 628                  * structure that has a completion in it.  update the
 629                  * return code in the waitevent structure and post the
 630                  * completion to wake up the guy who sent the request
 631                  */
 632                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
 633                 pwe->rc = event->xRc;
 634                 pwe->sub_result = bevent->sub_result;
 635                 if (event->xRc == HvLpEvent_Rc_Good) {
 636                         const struct open_data *data = &bevent->u.open_data;
 637                         struct viodasd_device *device =
 638                                 &viodasd_devices[bevent->disk];
 639                         device->read_only =
 640                                 bevent->flags & vioblockflags_ro;
 641                         device->size = data->disk_size;
 642                         device->cylinders = data->cylinders;
 643                         device->tracks = data->tracks;
 644                         device->sectors = data->sectors;
 645                         device->bytes_per_sector = data->bytes_per_sector;
 646                         pwe->max_disk = data->max_disk;
 647                 }
 648                 complete(&pwe->com);
 649                 break;
 650         case vioblockclose:
 651                 break;
 652         case vioblockread:
 653         case vioblockwrite:
 654                 viodasd_handle_read_write(bevent);
 655                 break;
 656
 657         default:
 658                 pr_warning("invalid subtype!");
 659                 if (hvlpevent_need_ack(event)) {
 660                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 661                         HvCallEvent_ackLpEvent(event);
 662                 }
 663         }
 664 }
 665
 666 /*
 667  * Get the driver to reprobe for more disks.
 668  */
 669 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
 670                 size_t count)
 671 {
 672         struct viodasd_device *d;
 673
 674         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
 675                 if (d->disk == NULL)
 676                         probe_disk(d);
 677         }
 678         return count;
 679 }
 680 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
 681
 682 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 683 {
 684         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
 685
 686         d->dev = &vdev->dev;
 687         if (!probe_disk(d))
 688                 return -ENODEV;
 689         return 0;
 690 }
 691
 692 static int viodasd_remove(struct vio_dev *vdev)
 693 {
 694         struct viodasd_device *d;
 695
 696         d = &viodasd_devices[vdev->unit_address];
 697         if (d->disk) {
 698                 del_gendisk(d->disk);
 699                 blk_cleanup_queue(d->disk->queue);
 700                 put_disk(d->disk);
 701                 d->disk = NULL;
 702         }
 703         d->dev = NULL;
 704         return 0;
 705 }
 706
 707 /**
 708  * viodasd_device_table: Used by vio.c to match devices that we
 709  * support.
 710  */
 711 static struct vio_device_id viodasd_device_table[] __devinitdata = {
 712         { "block", "IBM,iSeries-viodasd" },
 713         { "", "" }
 714 };
 715 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
 716
 717 static struct vio_driver viodasd_driver = {
 718         .id_table = viodasd_device_table,
 719         .probe = viodasd_probe,
 720         .remove = viodasd_remove,
 721         .driver = {
 722                 .name = "viodasd",
 723                 .owner = THIS_MODULE,
 724         }
 725 };
 726
 727 static int need_delete_probe;
 728
 729 /*
 730  * Initialize the whole device driver.  Handle module and non-module
 731  * versions
 732  */
 733 static int __init viodasd_init(void)
 734 {
 735         int rc;
 736
 737         if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
 738                 rc = -ENODEV;
 739                 goto early_fail;
 740         }
 741
 742         /* Try to open to our host lp */
 743         if (viopath_hostLp == HvLpIndexInvalid)
 744                 vio_set_hostlp();
 745
 746         if (viopath_hostLp == HvLpIndexInvalid) {
 747                 pr_warning("invalid hosting partition\n");
 748                 rc = -EIO;
 749                 goto early_fail;
 750         }
 751
 752         pr_info("vers " VIOD_VERS ", hosting partition %d\n", viopath_hostLp);
 753
 754         /* register the block device */
 755         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 756         if (rc) {
 757                 pr_warning("Unable to get major number %d for %s\n",
 758                            VIODASD_MAJOR, VIOD_GENHD_NAME);
 759                 goto early_fail;
 760         }
 761         /* Actually open the path to the hosting partition */
 762         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
 763                                 VIOMAXREQ + 2);
 764         if (rc) {
 765                 pr_warning("error opening path to host partition %d\n",
 766                            viopath_hostLp);
 767                 goto unregister_blk;
 768         }
 769
 770         /* Initialize our request handler */
 771         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
 772
 773         rc = vio_register_driver(&viodasd_driver);
 774         if (rc) {
 775                 pr_warning("vio_register_driver failed\n");
 776                 goto unset_handler;
 777         }
 778
 779         /*
 780          * If this call fails, it just means that we cannot dynamically
 781          * add virtual disks, but the driver will still work fine for
 782          * all existing disk, so ignore the failure.
 783          */
 784         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
 785                 need_delete_probe = 1;
 786
 787         return 0;
 788
 789 unset_handler:
 790         vio_clearHandler(viomajorsubtype_blockio);
 791         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 792 unregister_blk:
 793         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 794 early_fail:
 795         return rc;
 796 }
 797 module_init(viodasd_init);
 798
 799 void __exit viodasd_exit(void)
 800 {
 801         if (need_delete_probe)
 802                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
 803         vio_unregister_driver(&viodasd_driver);
 804         vio_clearHandler(viomajorsubtype_blockio);
 805         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 806         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 807 }
 808 module_exit(viodasd_exit);