git.oblomov.eu Git - 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 <sfr@au1.ibm.com>
   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 #include <linux/major.h>
  32 #include <linux/fs.h>
  33 #include <linux/module.h>
  34 #include <linux/kernel.h>
  35 #include <linux/blkdev.h>
  36 #include <linux/genhd.h>
  37 #include <linux/hdreg.h>
  38 #include <linux/errno.h>
  39 #include <linux/init.h>
  40 #include <linux/string.h>
  41 #include <linux/dma-mapping.h>
  42 #include <linux/completion.h>
  43 #include <linux/device.h>
  44 #include <linux/scatterlist.h>
  45
  46 #include <asm/uaccess.h>
  47 #include <asm/vio.h>
  48 #include <asm/iseries/hv_types.h>
  49 #include <asm/iseries/hv_lp_event.h>
  50 #include <asm/iseries/hv_lp_config.h>
  51 #include <asm/iseries/vio.h>
  52 #include <asm/firmware.h>
  53
  54 MODULE_DESCRIPTION("iSeries Virtual DASD");
  55 MODULE_AUTHOR("Dave Boutcher");
  56 MODULE_LICENSE("GPL");
  57
  58 /*
  59  * We only support 7 partitions per physical disk....so with minor
  60  * numbers 0-255 we get a maximum of 32 disks.
  61  */
  62 #define VIOD_GENHD_NAME         "iseries/vd"
  63
  64 #define VIOD_VERS               "1.64"
  65
  66 #define VIOD_KERN_WARNING       KERN_WARNING "viod: "
  67 #define VIOD_KERN_INFO          KERN_INFO "viod: "
  68
  69 enum {
  70         PARTITION_SHIFT = 3,
  71         MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS,
  72         MAX_DISK_NAME = sizeof(((struct gendisk *)0)->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 inode *ino, struct file *fil)
 134 {
 135         struct viodasd_device *d = ino->i_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 ((fil != NULL) && (fil->f_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                 printk(VIOD_KERN_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                 printk(VIOD_KERN_WARNING
 171                                 "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 /*
 180  * External release entry point.
 181  */
 182 static int viodasd_release(struct inode *ino, struct file *fil)
 183 {
 184         struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
 185         HvLpEvent_Rc hvrc;
 186
 187         /* Send the event to OS/400.  We DON'T expect a response */
 188         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 189                         HvLpEvent_Type_VirtualIo,
 190                         viomajorsubtype_blockio | vioblockclose,
 191                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 192                         viopath_sourceinst(viopath_hostLp),
 193                         viopath_targetinst(viopath_hostLp),
 194                         0, VIOVERSION << 16,
 195                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
 196                         0, 0, 0);
 197         if (hvrc != 0)
 198                 printk(VIOD_KERN_WARNING "HV close call failed %d\n",
 199                                 (int)hvrc);
 200         return 0;
 201 }
 202
 203
 204 /* External ioctl entry point.
 205  */
 206 static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 207 {
 208         struct gendisk *disk = bdev->bd_disk;
 209         struct viodasd_device *d = disk->private_data;
 210
 211         geo->sectors = d->sectors ? d->sectors : 32;
 212         geo->heads = d->tracks ? d->tracks  : 64;
 213         geo->cylinders = d->cylinders ? d->cylinders :
 214                 get_capacity(disk) / (geo->sectors * geo->heads);
 215
 216         return 0;
 217 }
 218
 219 /*
 220  * Our file operations table
 221  */
 222 static struct block_device_operations viodasd_fops = {
 223         .owner = THIS_MODULE,
 224         .open = viodasd_open,
 225         .release = viodasd_release,
 226         .getgeo = viodasd_getgeo,
 227 };
 228
 229 /*
 230  * End a request
 231  */
 232 static void viodasd_end_request(struct request *req, int error,
 233                 int num_sectors)
 234 {
 235         __blk_end_request(req, error, num_sectors << 9);
 236 }
 237
 238 /*
 239  * Send an actual I/O request to OS/400
 240  */
 241 static int send_request(struct request *req)
 242 {
 243         u64 start;
 244         int direction;
 245         int nsg;
 246         u16 viocmd;
 247         HvLpEvent_Rc hvrc;
 248         struct vioblocklpevent *bevent;
 249         struct HvLpEvent *hev;
 250         struct scatterlist sg[VIOMAXBLOCKDMA];
 251         int sgindex;
 252         int statindex;
 253         struct viodasd_device *d;
 254         unsigned long flags;
 255
 256         start = (u64)req->sector << 9;
 257
 258         if (rq_data_dir(req) == READ) {
 259                 direction = DMA_FROM_DEVICE;
 260                 viocmd = viomajorsubtype_blockio | vioblockread;
 261                 statindex = 0;
 262         } else {
 263                 direction = DMA_TO_DEVICE;
 264                 viocmd = viomajorsubtype_blockio | vioblockwrite;
 265                 statindex = 1;
 266         }
 267
 268         d = req->rq_disk->private_data;
 269
 270         /* Now build the scatter-gather list */
 271         sg_init_table(sg, VIOMAXBLOCKDMA);
 272         nsg = blk_rq_map_sg(req->q, req, sg);
 273         nsg = dma_map_sg(d->dev, sg, nsg, direction);
 274
 275         spin_lock_irqsave(&viodasd_spinlock, flags);
 276         num_req_outstanding++;
 277
 278         /* This optimization handles a single DMA block */
 279         if (nsg == 1)
 280                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 281                                 HvLpEvent_Type_VirtualIo, viocmd,
 282                                 HvLpEvent_AckInd_DoAck,
 283                                 HvLpEvent_AckType_ImmediateAck,
 284                                 viopath_sourceinst(viopath_hostLp),
 285                                 viopath_targetinst(viopath_hostLp),
 286                                 (u64)(unsigned long)req, VIOVERSION << 16,
 287                                 ((u64)DEVICE_NO(d) << 48), start,
 288                                 ((u64)sg_dma_address(&sg[0])) << 32,
 289                                 sg_dma_len(&sg[0]));
 290         else {
 291                 bevent = (struct vioblocklpevent *)
 292                         vio_get_event_buffer(viomajorsubtype_blockio);
 293                 if (bevent == NULL) {
 294                         printk(VIOD_KERN_WARNING
 295                                "error allocating disk event buffer\n");
 296                         goto error_ret;
 297                 }
 298
 299                 /*
 300                  * Now build up the actual request.  Note that we store
 301                  * the pointer to the request in the correlation
 302                  * token so we can match the response up later
 303                  */
 304                 memset(bevent, 0, sizeof(struct vioblocklpevent));
 305                 hev = &bevent->event;
 306                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
 307                         HV_LP_EVENT_INT;
 308                 hev->xType = HvLpEvent_Type_VirtualIo;
 309                 hev->xSubtype = viocmd;
 310                 hev->xSourceLp = HvLpConfig_getLpIndex();
 311                 hev->xTargetLp = viopath_hostLp;
 312                 hev->xSizeMinus1 =
 313                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
 314                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
 315                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
 316                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
 317                 hev->xCorrelationToken = (u64)req;
 318                 bevent->version = VIOVERSION;
 319                 bevent->disk = DEVICE_NO(d);
 320                 bevent->u.rw_data.offset = start;
 321
 322                 /*
 323                  * Copy just the dma information from the sg list
 324                  * into the request
 325                  */
 326                 for (sgindex = 0; sgindex < nsg; sgindex++) {
 327                         bevent->u.rw_data.dma_info[sgindex].token =
 328                                 sg_dma_address(&sg[sgindex]);
 329                         bevent->u.rw_data.dma_info[sgindex].len =
 330                                 sg_dma_len(&sg[sgindex]);
 331                 }
 332
 333                 /* Send the request */
 334                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
 335                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
 336         }
 337
 338         if (hvrc != HvLpEvent_Rc_Good) {
 339                 printk(VIOD_KERN_WARNING
 340                        "error sending disk event to OS/400 (rc %d)\n",
 341                        (int)hvrc);
 342                 goto error_ret;
 343         }
 344         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 345         return 0;
 346
 347 error_ret:
 348         num_req_outstanding--;
 349         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 350         dma_unmap_sg(d->dev, sg, nsg, direction);
 351         return -1;
 352 }
 353
 354 /*
 355  * This is the external request processing routine
 356  */
 357 static void do_viodasd_request(struct request_queue *q)
 358 {
 359         struct request *req;
 360
 361         /*
 362          * If we already have the maximum number of requests
 363          * outstanding to OS/400 just bail out. We'll come
 364          * back later.
 365          */
 366         while (num_req_outstanding < VIOMAXREQ) {
 367                 req = elv_next_request(q);
 368                 if (req == NULL)
 369                         return;
 370                 /* dequeue the current request from the queue */
 371                 blkdev_dequeue_request(req);
 372                 /* check that request contains a valid command */
 373                 if (!blk_fs_request(req)) {
 374                         viodasd_end_request(req, -EIO, req->hard_nr_sectors);
 375                         continue;
 376                 }
 377                 /* Try sending the request */
 378                 if (send_request(req) != 0)
 379                         viodasd_end_request(req, -EIO, req->hard_nr_sectors);
 380         }
 381 }
 382
 383 /*
 384  * Probe a single disk and fill in the viodasd_device structure
 385  * for it.
 386  */
 387 static int probe_disk(struct viodasd_device *d)
 388 {
 389         HvLpEvent_Rc hvrc;
 390         struct viodasd_waitevent we;
 391         int dev_no = DEVICE_NO(d);
 392         struct gendisk *g;
 393         struct request_queue *q;
 394         u16 flags = 0;
 395
 396 retry:
 397         init_completion(&we.com);
 398
 399         /* Send the open event to OS/400 */
 400         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 401                         HvLpEvent_Type_VirtualIo,
 402                         viomajorsubtype_blockio | vioblockopen,
 403                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 404                         viopath_sourceinst(viopath_hostLp),
 405                         viopath_targetinst(viopath_hostLp),
 406                         (u64)(unsigned long)&we, VIOVERSION << 16,
 407                         ((u64)dev_no << 48) | ((u64)flags<< 32),
 408                         0, 0, 0);
 409         if (hvrc != 0) {
 410                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
 411                 return 0;
 412         }
 413
 414         wait_for_completion(&we.com);
 415
 416         if (we.rc != 0) {
 417                 if (flags != 0)
 418                         return 0;
 419                 /* try again with read only flag set */
 420                 flags = vioblockflags_ro;
 421                 goto retry;
 422         }
 423         if (we.max_disk > (MAX_DISKNO - 1)) {
 424                 static int warned;
 425
 426                 if (warned == 0) {
 427                         warned++;
 428                         printk(VIOD_KERN_INFO
 429                                 "Only examining the first %d "
 430                                 "of %d disks connected\n",
 431                                 MAX_DISKNO, we.max_disk + 1);
 432                 }
 433         }
 434
 435         /* Send the close event to OS/400.  We DON'T expect a response */
 436         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 437                         HvLpEvent_Type_VirtualIo,
 438                         viomajorsubtype_blockio | vioblockclose,
 439                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 440                         viopath_sourceinst(viopath_hostLp),
 441                         viopath_targetinst(viopath_hostLp),
 442                         0, VIOVERSION << 16,
 443                         ((u64)dev_no << 48) | ((u64)flags << 32),
 444                         0, 0, 0);
 445         if (hvrc != 0) {
 446                 printk(VIOD_KERN_WARNING
 447                        "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                         printk(VIOD_KERN_WARNING
 455                                 "cannot allocate virtual device for disk %d\n",
 456                                 dev_no);
 457                         return 0;
 458                 }
 459                 /*
 460                  * The vio_create_viodasd will have recursed into this
 461                  * routine with d->dev set to the new vio device and
 462                  * will finish the setup of the disk below.
 463                  */
 464                 return 1;
 465         }
 466
 467         /* create the request queue for the disk */
 468         spin_lock_init(&d->q_lock);
 469         q = blk_init_queue(do_viodasd_request, &d->q_lock);
 470         if (q == NULL) {
 471                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
 472                                 dev_no);
 473                 return 0;
 474         }
 475         g = alloc_disk(1 << PARTITION_SHIFT);
 476         if (g == NULL) {
 477                 printk(VIOD_KERN_WARNING
 478                                 "cannot allocate disk structure for disk %d\n",
 479                                 dev_no);
 480                 blk_cleanup_queue(q);
 481                 return 0;
 482         }
 483
 484         d->disk = g;
 485         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
 486         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
 487         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
 488         g->major = VIODASD_MAJOR;
 489         g->first_minor = dev_no << PARTITION_SHIFT;
 490         if (dev_no >= 26)
 491                 snprintf(g->disk_name, sizeof(g->disk_name),
 492                                 VIOD_GENHD_NAME "%c%c",
 493                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
 494         else
 495                 snprintf(g->disk_name, sizeof(g->disk_name),
 496                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
 497         g->fops = &viodasd_fops;
 498         g->queue = q;
 499         g->private_data = d;
 500         g->driverfs_dev = d->dev;
 501         set_capacity(g, d->size >> 9);
 502
 503         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
 504                         "CHS=%d/%d/%d sector size %d%s\n",
 505                         dev_no, (unsigned long)(d->size >> 9),
 506                         (unsigned long)(d->size >> 20),
 507                         (int)d->cylinders, (int)d->tracks,
 508                         (int)d->sectors, (int)d->bytes_per_sector,
 509                         d->read_only ? " (RO)" : "");
 510
 511         /* register us in the global list */
 512         add_disk(g);
 513         return 1;
 514 }
 515
 516 /* returns the total number of scatterlist elements converted */
 517 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
 518                 struct scatterlist *sg, int *total_len)
 519 {
 520         int i, numsg;
 521         const struct rw_data *rw_data = &bevent->u.rw_data;
 522         static const int offset =
 523                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
 524         static const int element_size = sizeof(rw_data->dma_info[0]);
 525
 526         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
 527         if (numsg > VIOMAXBLOCKDMA)
 528                 numsg = VIOMAXBLOCKDMA;
 529
 530         *total_len = 0;
 531         memset(sg, 0, sizeof(sg[0]) * VIOMAXBLOCKDMA);
 532
 533         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
 534                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
 535                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
 536                 *total_len += rw_data->dma_info[i].len;
 537         }
 538         return i;
 539 }
 540
 541 /*
 542  * Restart all queues, starting with the one _after_ the disk given,
 543  * thus reducing the chance of starvation of higher numbered disks.
 544  */
 545 static void viodasd_restart_all_queues_starting_from(int first_index)
 546 {
 547         int i;
 548
 549         for (i = first_index + 1; i < MAX_DISKNO; ++i)
 550                 if (viodasd_devices[i].disk)
 551                         blk_run_queue(viodasd_devices[i].disk->queue);
 552         for (i = 0; i <= first_index; ++i)
 553                 if (viodasd_devices[i].disk)
 554                         blk_run_queue(viodasd_devices[i].disk->queue);
 555 }
 556
 557 /*
 558  * For read and write requests, decrement the number of outstanding requests,
 559  * Free the DMA buffers we allocated.
 560  */
 561 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
 562 {
 563         int num_sg, num_sect, pci_direction, total_len;
 564         struct request *req;
 565         struct scatterlist sg[VIOMAXBLOCKDMA];
 566         struct HvLpEvent *event = &bevent->event;
 567         unsigned long irq_flags;
 568         struct viodasd_device *d;
 569         int error;
 570         spinlock_t *qlock;
 571
 572         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
 573         num_sect = total_len >> 9;
 574         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
 575                 pci_direction = DMA_FROM_DEVICE;
 576         else
 577                 pci_direction = DMA_TO_DEVICE;
 578         req = (struct request *)bevent->event.xCorrelationToken;
 579         d = req->rq_disk->private_data;
 580
 581         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
 582
 583         /*
 584          * Since this is running in interrupt mode, we need to make sure
 585          * we're not stepping on any global I/O operations
 586          */
 587         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
 588         num_req_outstanding--;
 589         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
 590
 591         error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO;
 592         if (error) {
 593                 const struct vio_error_entry *err;
 594                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
 595                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
 596                                 event->xRc, bevent->sub_result, err->msg);
 597                 num_sect = req->hard_nr_sectors;
 598         }
 599         qlock = req->q->queue_lock;
 600         spin_lock_irqsave(qlock, irq_flags);
 601         viodasd_end_request(req, error, num_sect);
 602         spin_unlock_irqrestore(qlock, irq_flags);
 603
 604         /* Finally, try to get more requests off of this device's queue */
 605         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
 606
 607         return 0;
 608 }
 609
 610 /* This routine handles incoming block LP events */
 611 static void handle_block_event(struct HvLpEvent *event)
 612 {
 613         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
 614         struct viodasd_waitevent *pwe;
 615
 616         if (event == NULL)
 617                 /* Notification that a partition went away! */
 618                 return;
 619         /* First, we should NEVER get an int here...only acks */
 620         if (hvlpevent_is_int(event)) {
 621                 printk(VIOD_KERN_WARNING
 622                        "Yikes! got an int in viodasd event handler!\n");
 623                 if (hvlpevent_need_ack(event)) {
 624                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 625                         HvCallEvent_ackLpEvent(event);
 626                 }
 627         }
 628
 629         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
 630         case vioblockopen:
 631                 /*
 632                  * Handle a response to an open request.  We get all the
 633                  * disk information in the response, so update it.  The
 634                  * correlation token contains a pointer to a waitevent
 635                  * structure that has a completion in it.  update the
 636                  * return code in the waitevent structure and post the
 637                  * completion to wake up the guy who sent the request
 638                  */
 639                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
 640                 pwe->rc = event->xRc;
 641                 pwe->sub_result = bevent->sub_result;
 642                 if (event->xRc == HvLpEvent_Rc_Good) {
 643                         const struct open_data *data = &bevent->u.open_data;
 644                         struct viodasd_device *device =
 645                                 &viodasd_devices[bevent->disk];
 646                         device->read_only =
 647                                 bevent->flags & vioblockflags_ro;
 648                         device->size = data->disk_size;
 649                         device->cylinders = data->cylinders;
 650                         device->tracks = data->tracks;
 651                         device->sectors = data->sectors;
 652                         device->bytes_per_sector = data->bytes_per_sector;
 653                         pwe->max_disk = data->max_disk;
 654                 }
 655                 complete(&pwe->com);
 656                 break;
 657         case vioblockclose:
 658                 break;
 659         case vioblockread:
 660         case vioblockwrite:
 661                 viodasd_handle_read_write(bevent);
 662                 break;
 663
 664         default:
 665                 printk(VIOD_KERN_WARNING "invalid subtype!");
 666                 if (hvlpevent_need_ack(event)) {
 667                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 668                         HvCallEvent_ackLpEvent(event);
 669                 }
 670         }
 671 }
 672
 673 /*
 674  * Get the driver to reprobe for more disks.
 675  */
 676 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
 677                 size_t count)
 678 {
 679         struct viodasd_device *d;
 680
 681         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
 682                 if (d->disk == NULL)
 683                         probe_disk(d);
 684         }
 685         return count;
 686 }
 687 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
 688
 689 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 690 {
 691         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
 692
 693         d->dev = &vdev->dev;
 694         if (!probe_disk(d))
 695                 return -ENODEV;
 696         return 0;
 697 }
 698
 699 static int viodasd_remove(struct vio_dev *vdev)
 700 {
 701         struct viodasd_device *d;
 702
 703         d = &viodasd_devices[vdev->unit_address];
 704         if (d->disk) {
 705                 del_gendisk(d->disk);
 706                 blk_cleanup_queue(d->disk->queue);
 707                 put_disk(d->disk);
 708                 d->disk = NULL;
 709         }
 710         d->dev = NULL;
 711         return 0;
 712 }
 713
 714 /**
 715  * viodasd_device_table: Used by vio.c to match devices that we
 716  * support.
 717  */
 718 static struct vio_device_id viodasd_device_table[] __devinitdata = {
 719         { "block", "IBM,iSeries-viodasd" },
 720         { "", "" }
 721 };
 722 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
 723
 724 static struct vio_driver viodasd_driver = {
 725         .id_table = viodasd_device_table,
 726         .probe = viodasd_probe,
 727         .remove = viodasd_remove,
 728         .driver = {
 729                 .name = "viodasd",
 730                 .owner = THIS_MODULE,
 731         }
 732 };
 733
 734 static int need_delete_probe;
 735
 736 /*
 737  * Initialize the whole device driver.  Handle module and non-module
 738  * versions
 739  */
 740 static int __init viodasd_init(void)
 741 {
 742         int rc;
 743
 744         if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
 745                 rc = -ENODEV;
 746                 goto early_fail;
 747         }
 748
 749         /* Try to open to our host lp */
 750         if (viopath_hostLp == HvLpIndexInvalid)
 751                 vio_set_hostlp();
 752
 753         if (viopath_hostLp == HvLpIndexInvalid) {
 754                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
 755                 rc = -EIO;
 756                 goto early_fail;
 757         }
 758
 759         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
 760                         viopath_hostLp);
 761
 762         /* register the block device */
 763         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 764         if (rc) {
 765                 printk(VIOD_KERN_WARNING
 766                                 "Unable to get major number %d for %s\n",
 767                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
 768                 goto early_fail;
 769         }
 770         /* Actually open the path to the hosting partition */
 771         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
 772                                 VIOMAXREQ + 2);
 773         if (rc) {
 774                 printk(VIOD_KERN_WARNING
 775                        "error opening path to host partition %d\n",
 776                        viopath_hostLp);
 777                 goto unregister_blk;
 778         }
 779
 780         /* Initialize our request handler */
 781         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
 782
 783         rc = vio_register_driver(&viodasd_driver);
 784         if (rc) {
 785                 printk(VIOD_KERN_WARNING "vio_register_driver failed\n");
 786                 goto unset_handler;
 787         }
 788
 789         /*
 790          * If this call fails, it just means that we cannot dynamically
 791          * add virtual disks, but the driver will still work fine for
 792          * all existing disk, so ignore the failure.
 793          */
 794         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
 795                 need_delete_probe = 1;
 796
 797         return 0;
 798
 799 unset_handler:
 800         vio_clearHandler(viomajorsubtype_blockio);
 801         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 802 unregister_blk:
 803         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 804 early_fail:
 805         return rc;
 806 }
 807 module_init(viodasd_init);
 808
 809 void __exit viodasd_exit(void)
 810 {
 811         if (need_delete_probe)
 812                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
 813         vio_unregister_driver(&viodasd_driver);
 814         vio_clearHandler(viomajorsubtype_blockio);
 815         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 816         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 817 }
 818 module_exit(viodasd_exit);