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 uptodate,
 233                 int num_sectors)
 234 {
 235         if (end_that_request_first(req, uptodate, num_sectors))
 236                 return;
 237         add_disk_randomness(req->rq_disk);
 238         end_that_request_last(req, uptodate);
 239 }
 240
 241 /*
 242  * Send an actual I/O request to OS/400
 243  */
 244 static int send_request(struct request *req)
 245 {
 246         u64 start;
 247         int direction;
 248         int nsg;
 249         u16 viocmd;
 250         HvLpEvent_Rc hvrc;
 251         struct vioblocklpevent *bevent;
 252         struct HvLpEvent *hev;
 253         struct scatterlist sg[VIOMAXBLOCKDMA];
 254         int sgindex;
 255         int statindex;
 256         struct viodasd_device *d;
 257         unsigned long flags;
 258
 259         start = (u64)req->sector << 9;
 260
 261         if (rq_data_dir(req) == READ) {
 262                 direction = DMA_FROM_DEVICE;
 263                 viocmd = viomajorsubtype_blockio | vioblockread;
 264                 statindex = 0;
 265         } else {
 266                 direction = DMA_TO_DEVICE;
 267                 viocmd = viomajorsubtype_blockio | vioblockwrite;
 268                 statindex = 1;
 269         }
 270
 271         d = req->rq_disk->private_data;
 272
 273         /* Now build the scatter-gather list */
 274         sg_init_table(sg, VIOMAXBLOCKDMA);
 275         nsg = blk_rq_map_sg(req->q, req, sg);
 276         nsg = dma_map_sg(d->dev, sg, nsg, direction);
 277
 278         spin_lock_irqsave(&viodasd_spinlock, flags);
 279         num_req_outstanding++;
 280
 281         /* This optimization handles a single DMA block */
 282         if (nsg == 1)
 283                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 284                                 HvLpEvent_Type_VirtualIo, viocmd,
 285                                 HvLpEvent_AckInd_DoAck,
 286                                 HvLpEvent_AckType_ImmediateAck,
 287                                 viopath_sourceinst(viopath_hostLp),
 288                                 viopath_targetinst(viopath_hostLp),
 289                                 (u64)(unsigned long)req, VIOVERSION << 16,
 290                                 ((u64)DEVICE_NO(d) << 48), start,
 291                                 ((u64)sg_dma_address(&sg[0])) << 32,
 292                                 sg_dma_len(&sg[0]));
 293         else {
 294                 bevent = (struct vioblocklpevent *)
 295                         vio_get_event_buffer(viomajorsubtype_blockio);
 296                 if (bevent == NULL) {
 297                         printk(VIOD_KERN_WARNING
 298                                "error allocating disk event buffer\n");
 299                         goto error_ret;
 300                 }
 301
 302                 /*
 303                  * Now build up the actual request.  Note that we store
 304                  * the pointer to the request in the correlation
 305                  * token so we can match the response up later
 306                  */
 307                 memset(bevent, 0, sizeof(struct vioblocklpevent));
 308                 hev = &bevent->event;
 309                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
 310                         HV_LP_EVENT_INT;
 311                 hev->xType = HvLpEvent_Type_VirtualIo;
 312                 hev->xSubtype = viocmd;
 313                 hev->xSourceLp = HvLpConfig_getLpIndex();
 314                 hev->xTargetLp = viopath_hostLp;
 315                 hev->xSizeMinus1 =
 316                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
 317                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
 318                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
 319                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
 320                 hev->xCorrelationToken = (u64)req;
 321                 bevent->version = VIOVERSION;
 322                 bevent->disk = DEVICE_NO(d);
 323                 bevent->u.rw_data.offset = start;
 324
 325                 /*
 326                  * Copy just the dma information from the sg list
 327                  * into the request
 328                  */
 329                 for (sgindex = 0; sgindex < nsg; sgindex++) {
 330                         bevent->u.rw_data.dma_info[sgindex].token =
 331                                 sg_dma_address(&sg[sgindex]);
 332                         bevent->u.rw_data.dma_info[sgindex].len =
 333                                 sg_dma_len(&sg[sgindex]);
 334                 }
 335
 336                 /* Send the request */
 337                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
 338                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
 339         }
 340
 341         if (hvrc != HvLpEvent_Rc_Good) {
 342                 printk(VIOD_KERN_WARNING
 343                        "error sending disk event to OS/400 (rc %d)\n",
 344                        (int)hvrc);
 345                 goto error_ret;
 346         }
 347         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 348         return 0;
 349
 350 error_ret:
 351         num_req_outstanding--;
 352         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 353         dma_unmap_sg(d->dev, sg, nsg, direction);
 354         return -1;
 355 }
 356
 357 /*
 358  * This is the external request processing routine
 359  */
 360 static void do_viodasd_request(struct request_queue *q)
 361 {
 362         struct request *req;
 363
 364         /*
 365          * If we already have the maximum number of requests
 366          * outstanding to OS/400 just bail out. We'll come
 367          * back later.
 368          */
 369         while (num_req_outstanding < VIOMAXREQ) {
 370                 req = elv_next_request(q);
 371                 if (req == NULL)
 372                         return;
 373                 /* dequeue the current request from the queue */
 374                 blkdev_dequeue_request(req);
 375                 /* check that request contains a valid command */
 376                 if (!blk_fs_request(req)) {
 377                         viodasd_end_request(req, 0, req->hard_nr_sectors);
 378                         continue;
 379                 }
 380                 /* Try sending the request */
 381                 if (send_request(req) != 0)
 382                         viodasd_end_request(req, 0, req->hard_nr_sectors);
 383         }
 384 }
 385
 386 /*
 387  * Probe a single disk and fill in the viodasd_device structure
 388  * for it.
 389  */
 390 static int probe_disk(struct viodasd_device *d)
 391 {
 392         HvLpEvent_Rc hvrc;
 393         struct viodasd_waitevent we;
 394         int dev_no = DEVICE_NO(d);
 395         struct gendisk *g;
 396         struct request_queue *q;
 397         u16 flags = 0;
 398
 399 retry:
 400         init_completion(&we.com);
 401
 402         /* Send the open event to OS/400 */
 403         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 404                         HvLpEvent_Type_VirtualIo,
 405                         viomajorsubtype_blockio | vioblockopen,
 406                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 407                         viopath_sourceinst(viopath_hostLp),
 408                         viopath_targetinst(viopath_hostLp),
 409                         (u64)(unsigned long)&we, VIOVERSION << 16,
 410                         ((u64)dev_no << 48) | ((u64)flags<< 32),
 411                         0, 0, 0);
 412         if (hvrc != 0) {
 413                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
 414                 return 0;
 415         }
 416
 417         wait_for_completion(&we.com);
 418
 419         if (we.rc != 0) {
 420                 if (flags != 0)
 421                         return 0;
 422                 /* try again with read only flag set */
 423                 flags = vioblockflags_ro;
 424                 goto retry;
 425         }
 426         if (we.max_disk > (MAX_DISKNO - 1)) {
 427                 static int warned;
 428
 429                 if (warned == 0) {
 430                         warned++;
 431                         printk(VIOD_KERN_INFO
 432                                 "Only examining the first %d "
 433                                 "of %d disks connected\n",
 434                                 MAX_DISKNO, we.max_disk + 1);
 435                 }
 436         }
 437
 438         /* Send the close event to OS/400.  We DON'T expect a response */
 439         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 440                         HvLpEvent_Type_VirtualIo,
 441                         viomajorsubtype_blockio | vioblockclose,
 442                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 443                         viopath_sourceinst(viopath_hostLp),
 444                         viopath_targetinst(viopath_hostLp),
 445                         0, VIOVERSION << 16,
 446                         ((u64)dev_no << 48) | ((u64)flags << 32),
 447                         0, 0, 0);
 448         if (hvrc != 0) {
 449                 printk(VIOD_KERN_WARNING
 450                        "bad rc sending event to OS/400 %d\n", (int)hvrc);
 451                 return 0;
 452         }
 453
 454         if (d->dev == NULL) {
 455                 /* this is when we reprobe for new disks */
 456                 if (vio_create_viodasd(dev_no) == NULL) {
 457                         printk(VIOD_KERN_WARNING
 458                                 "cannot allocate virtual device for disk %d\n",
 459                                 dev_no);
 460                         return 0;
 461                 }
 462                 /*
 463                  * The vio_create_viodasd will have recursed into this
 464                  * routine with d->dev set to the new vio device and
 465                  * will finish the setup of the disk below.
 466                  */
 467                 return 1;
 468         }
 469
 470         /* create the request queue for the disk */
 471         spin_lock_init(&d->q_lock);
 472         q = blk_init_queue(do_viodasd_request, &d->q_lock);
 473         if (q == NULL) {
 474                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
 475                                 dev_no);
 476                 return 0;
 477         }
 478         g = alloc_disk(1 << PARTITION_SHIFT);
 479         if (g == NULL) {
 480                 printk(VIOD_KERN_WARNING
 481                                 "cannot allocate disk structure for disk %d\n",
 482                                 dev_no);
 483                 blk_cleanup_queue(q);
 484                 return 0;
 485         }
 486
 487         d->disk = g;
 488         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
 489         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
 490         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
 491         g->major = VIODASD_MAJOR;
 492         g->first_minor = dev_no << PARTITION_SHIFT;
 493         if (dev_no >= 26)
 494                 snprintf(g->disk_name, sizeof(g->disk_name),
 495                                 VIOD_GENHD_NAME "%c%c",
 496                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
 497         else
 498                 snprintf(g->disk_name, sizeof(g->disk_name),
 499                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
 500         g->fops = &viodasd_fops;
 501         g->queue = q;
 502         g->private_data = d;
 503         g->driverfs_dev = d->dev;
 504         set_capacity(g, d->size >> 9);
 505
 506         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
 507                         "CHS=%d/%d/%d sector size %d%s\n",
 508                         dev_no, (unsigned long)(d->size >> 9),
 509                         (unsigned long)(d->size >> 20),
 510                         (int)d->cylinders, (int)d->tracks,
 511                         (int)d->sectors, (int)d->bytes_per_sector,
 512                         d->read_only ? " (RO)" : "");
 513
 514         /* register us in the global list */
 515         add_disk(g);
 516         return 1;
 517 }
 518
 519 /* returns the total number of scatterlist elements converted */
 520 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
 521                 struct scatterlist *sg, int *total_len)
 522 {
 523         int i, numsg;
 524         const struct rw_data *rw_data = &bevent->u.rw_data;
 525         static const int offset =
 526                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
 527         static const int element_size = sizeof(rw_data->dma_info[0]);
 528
 529         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
 530         if (numsg > VIOMAXBLOCKDMA)
 531                 numsg = VIOMAXBLOCKDMA;
 532
 533         *total_len = 0;
 534         memset(sg, 0, sizeof(sg[0]) * VIOMAXBLOCKDMA);
 535
 536         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
 537                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
 538                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
 539                 *total_len += rw_data->dma_info[i].len;
 540         }
 541         return i;
 542 }
 543
 544 /*
 545  * Restart all queues, starting with the one _after_ the disk given,
 546  * thus reducing the chance of starvation of higher numbered disks.
 547  */
 548 static void viodasd_restart_all_queues_starting_from(int first_index)
 549 {
 550         int i;
 551
 552         for (i = first_index + 1; i < MAX_DISKNO; ++i)
 553                 if (viodasd_devices[i].disk)
 554                         blk_run_queue(viodasd_devices[i].disk->queue);
 555         for (i = 0; i <= first_index; ++i)
 556                 if (viodasd_devices[i].disk)
 557                         blk_run_queue(viodasd_devices[i].disk->queue);
 558 }
 559
 560 /*
 561  * For read and write requests, decrement the number of outstanding requests,
 562  * Free the DMA buffers we allocated.
 563  */
 564 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
 565 {
 566         int num_sg, num_sect, pci_direction, total_len;
 567         struct request *req;
 568         struct scatterlist sg[VIOMAXBLOCKDMA];
 569         struct HvLpEvent *event = &bevent->event;
 570         unsigned long irq_flags;
 571         struct viodasd_device *d;
 572         int error;
 573         spinlock_t *qlock;
 574
 575         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
 576         num_sect = total_len >> 9;
 577         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
 578                 pci_direction = DMA_FROM_DEVICE;
 579         else
 580                 pci_direction = DMA_TO_DEVICE;
 581         req = (struct request *)bevent->event.xCorrelationToken;
 582         d = req->rq_disk->private_data;
 583
 584         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
 585
 586         /*
 587          * Since this is running in interrupt mode, we need to make sure
 588          * we're not stepping on any global I/O operations
 589          */
 590         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
 591         num_req_outstanding--;
 592         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
 593
 594         error = event->xRc != HvLpEvent_Rc_Good;
 595         if (error) {
 596                 const struct vio_error_entry *err;
 597                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
 598                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
 599                                 event->xRc, bevent->sub_result, err->msg);
 600                 num_sect = req->hard_nr_sectors;
 601         }
 602         qlock = req->q->queue_lock;
 603         spin_lock_irqsave(qlock, irq_flags);
 604         viodasd_end_request(req, !error, num_sect);
 605         spin_unlock_irqrestore(qlock, irq_flags);
 606
 607         /* Finally, try to get more requests off of this device's queue */
 608         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
 609
 610         return 0;
 611 }
 612
 613 /* This routine handles incoming block LP events */
 614 static void handle_block_event(struct HvLpEvent *event)
 615 {
 616         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
 617         struct viodasd_waitevent *pwe;
 618
 619         if (event == NULL)
 620                 /* Notification that a partition went away! */
 621                 return;
 622         /* First, we should NEVER get an int here...only acks */
 623         if (hvlpevent_is_int(event)) {
 624                 printk(VIOD_KERN_WARNING
 625                        "Yikes! got an int in viodasd event handler!\n");
 626                 if (hvlpevent_need_ack(event)) {
 627                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 628                         HvCallEvent_ackLpEvent(event);
 629                 }
 630         }
 631
 632         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
 633         case vioblockopen:
 634                 /*
 635                  * Handle a response to an open request.  We get all the
 636                  * disk information in the response, so update it.  The
 637                  * correlation token contains a pointer to a waitevent
 638                  * structure that has a completion in it.  update the
 639                  * return code in the waitevent structure and post the
 640                  * completion to wake up the guy who sent the request
 641                  */
 642                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
 643                 pwe->rc = event->xRc;
 644                 pwe->sub_result = bevent->sub_result;
 645                 if (event->xRc == HvLpEvent_Rc_Good) {
 646                         const struct open_data *data = &bevent->u.open_data;
 647                         struct viodasd_device *device =
 648                                 &viodasd_devices[bevent->disk];
 649                         device->read_only =
 650                                 bevent->flags & vioblockflags_ro;
 651                         device->size = data->disk_size;
 652                         device->cylinders = data->cylinders;
 653                         device->tracks = data->tracks;
 654                         device->sectors = data->sectors;
 655                         device->bytes_per_sector = data->bytes_per_sector;
 656                         pwe->max_disk = data->max_disk;
 657                 }
 658                 complete(&pwe->com);
 659                 break;
 660         case vioblockclose:
 661                 break;
 662         case vioblockread:
 663         case vioblockwrite:
 664                 viodasd_handle_read_write(bevent);
 665                 break;
 666
 667         default:
 668                 printk(VIOD_KERN_WARNING "invalid subtype!");
 669                 if (hvlpevent_need_ack(event)) {
 670                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 671                         HvCallEvent_ackLpEvent(event);
 672                 }
 673         }
 674 }
 675
 676 /*
 677  * Get the driver to reprobe for more disks.
 678  */
 679 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
 680                 size_t count)
 681 {
 682         struct viodasd_device *d;
 683
 684         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
 685                 if (d->disk == NULL)
 686                         probe_disk(d);
 687         }
 688         return count;
 689 }
 690 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
 691
 692 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 693 {
 694         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
 695
 696         d->dev = &vdev->dev;
 697         if (!probe_disk(d))
 698                 return -ENODEV;
 699         return 0;
 700 }
 701
 702 static int viodasd_remove(struct vio_dev *vdev)
 703 {
 704         struct viodasd_device *d;
 705
 706         d = &viodasd_devices[vdev->unit_address];
 707         if (d->disk) {
 708                 del_gendisk(d->disk);
 709                 blk_cleanup_queue(d->disk->queue);
 710                 put_disk(d->disk);
 711                 d->disk = NULL;
 712         }
 713         d->dev = NULL;
 714         return 0;
 715 }
 716
 717 /**
 718  * viodasd_device_table: Used by vio.c to match devices that we
 719  * support.
 720  */
 721 static struct vio_device_id viodasd_device_table[] __devinitdata = {
 722         { "block", "IBM,iSeries-viodasd" },
 723         { "", "" }
 724 };
 725 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
 726
 727 static struct vio_driver viodasd_driver = {
 728         .id_table = viodasd_device_table,
 729         .probe = viodasd_probe,
 730         .remove = viodasd_remove,
 731         .driver = {
 732                 .name = "viodasd",
 733                 .owner = THIS_MODULE,
 734         }
 735 };
 736
 737 static int need_delete_probe;
 738
 739 /*
 740  * Initialize the whole device driver.  Handle module and non-module
 741  * versions
 742  */
 743 static int __init viodasd_init(void)
 744 {
 745         int rc;
 746
 747         if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
 748                 rc = -ENODEV;
 749                 goto early_fail;
 750         }
 751
 752         /* Try to open to our host lp */
 753         if (viopath_hostLp == HvLpIndexInvalid)
 754                 vio_set_hostlp();
 755
 756         if (viopath_hostLp == HvLpIndexInvalid) {
 757                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
 758                 rc = -EIO;
 759                 goto early_fail;
 760         }
 761
 762         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
 763                         viopath_hostLp);
 764
 765         /* register the block device */
 766         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 767         if (rc) {
 768                 printk(VIOD_KERN_WARNING
 769                                 "Unable to get major number %d for %s\n",
 770                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
 771                 goto early_fail;
 772         }
 773         /* Actually open the path to the hosting partition */
 774         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
 775                                 VIOMAXREQ + 2);
 776         if (rc) {
 777                 printk(VIOD_KERN_WARNING
 778                        "error opening path to host partition %d\n",
 779                        viopath_hostLp);
 780                 goto unregister_blk;
 781         }
 782
 783         /* Initialize our request handler */
 784         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
 785
 786         rc = vio_register_driver(&viodasd_driver);
 787         if (rc) {
 788                 printk(VIOD_KERN_WARNING "vio_register_driver failed\n");
 789                 goto unset_handler;
 790         }
 791
 792         /*
 793          * If this call fails, it just means that we cannot dynamically
 794          * add virtual disks, but the driver will still work fine for
 795          * all existing disk, so ignore the failure.
 796          */
 797         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
 798                 need_delete_probe = 1;
 799
 800         return 0;
 801
 802 unset_handler:
 803         vio_clearHandler(viomajorsubtype_blockio);
 804         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 805 unregister_blk:
 806         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 807 early_fail:
 808         return rc;
 809 }
 810 module_init(viodasd_init);
 811
 812 void __exit viodasd_exit(void)
 813 {
 814         if (need_delete_probe)
 815                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
 816         vio_unregister_driver(&viodasd_driver);
 817         vio_clearHandler(viomajorsubtype_blockio);
 818         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 819         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 820 }
 821 module_exit(viodasd_exit);