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/kernel.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
  53 MODULE_DESCRIPTION("iSeries Virtual DASD");
  54 MODULE_AUTHOR("Dave Boutcher");
  55 MODULE_LICENSE("GPL");
  56
  57 /*
  58  * We only support 7 partitions per physical disk....so with minor
  59  * numbers 0-255 we get a maximum of 32 disks.
  60  */
  61 #define VIOD_GENHD_NAME         "iseries/vd"
  62
  63 #define VIOD_VERS               "1.64"
  64
  65 #define VIOD_KERN_WARNING       KERN_WARNING "viod: "
  66 #define VIOD_KERN_INFO          KERN_INFO "viod: "
  67
  68 enum {
  69         PARTITION_SHIFT = 3,
  70         MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS,
  71         MAX_DISK_NAME = sizeof(((struct gendisk *)0)->disk_name)
  72 };
  73
  74 static DEFINE_SPINLOCK(viodasd_spinlock);
  75
  76 #define VIOMAXREQ               16
  77 #define VIOMAXBLOCKDMA          12
  78
  79 #define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0])
  80
  81 struct open_data {
  82         u64     disk_size;
  83         u16     max_disk;
  84         u16     cylinders;
  85         u16     tracks;
  86         u16     sectors;
  87         u16     bytes_per_sector;
  88 };
  89
  90 struct rw_data {
  91         u64     offset;
  92         struct {
  93                 u32     token;
  94                 u32     reserved;
  95                 u64     len;
  96         } dma_info[VIOMAXBLOCKDMA];
  97 };
  98
  99 struct vioblocklpevent {
 100         struct HvLpEvent        event;
 101         u32                     reserved;
 102         u16                     version;
 103         u16                     sub_result;
 104         u16                     disk;
 105         u16                     flags;
 106         union {
 107                 struct open_data        open_data;
 108                 struct rw_data          rw_data;
 109                 u64                     changed;
 110         } u;
 111 };
 112
 113 #define vioblockflags_ro   0x0001
 114
 115 enum vioblocksubtype {
 116         vioblockopen = 0x0001,
 117         vioblockclose = 0x0002,
 118         vioblockread = 0x0003,
 119         vioblockwrite = 0x0004,
 120         vioblockflush = 0x0005,
 121         vioblockcheck = 0x0007
 122 };
 123
 124 struct viodasd_waitevent {
 125         struct completion       com;
 126         int                     rc;
 127         u16                     sub_result;
 128         int                     max_disk;       /* open */
 129 };
 130
 131 static const struct vio_error_entry viodasd_err_table[] = {
 132         { 0x0201, EINVAL, "Invalid Range" },
 133         { 0x0202, EINVAL, "Invalid Token" },
 134         { 0x0203, EIO, "DMA Error" },
 135         { 0x0204, EIO, "Use Error" },
 136         { 0x0205, EIO, "Release Error" },
 137         { 0x0206, EINVAL, "Invalid Disk" },
 138         { 0x0207, EBUSY, "Cant Lock" },
 139         { 0x0208, EIO, "Already Locked" },
 140         { 0x0209, EIO, "Already Unlocked" },
 141         { 0x020A, EIO, "Invalid Arg" },
 142         { 0x020B, EIO, "Bad IFS File" },
 143         { 0x020C, EROFS, "Read Only Device" },
 144         { 0x02FF, EIO, "Internal Error" },
 145         { 0x0000, 0, NULL },
 146 };
 147
 148 /*
 149  * Figure out the biggest I/O request (in sectors) we can accept
 150  */
 151 #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
 152
 153 /*
 154  * Number of disk I/O requests we've sent to OS/400
 155  */
 156 static int num_req_outstanding;
 157
 158 /*
 159  * This is our internal structure for keeping track of disk devices
 160  */
 161 struct viodasd_device {
 162         u16             cylinders;
 163         u16             tracks;
 164         u16             sectors;
 165         u16             bytes_per_sector;
 166         u64             size;
 167         int             read_only;
 168         spinlock_t      q_lock;
 169         struct gendisk  *disk;
 170         struct device   *dev;
 171 } viodasd_devices[MAX_DISKNO];
 172
 173 /*
 174  * External open entry point.
 175  */
 176 static int viodasd_open(struct inode *ino, struct file *fil)
 177 {
 178         struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
 179         HvLpEvent_Rc hvrc;
 180         struct viodasd_waitevent we;
 181         u16 flags = 0;
 182
 183         if (d->read_only) {
 184                 if ((fil != NULL) && (fil->f_mode & FMODE_WRITE))
 185                         return -EROFS;
 186                 flags = vioblockflags_ro;
 187         }
 188
 189         init_completion(&we.com);
 190
 191         /* Send the open event to OS/400 */
 192         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 193                         HvLpEvent_Type_VirtualIo,
 194                         viomajorsubtype_blockio | vioblockopen,
 195                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 196                         viopath_sourceinst(viopath_hostLp),
 197                         viopath_targetinst(viopath_hostLp),
 198                         (u64)(unsigned long)&we, VIOVERSION << 16,
 199                         ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
 200                         0, 0, 0);
 201         if (hvrc != 0) {
 202                 printk(VIOD_KERN_WARNING "HV open failed %d\n", (int)hvrc);
 203                 return -EIO;
 204         }
 205
 206         wait_for_completion(&we.com);
 207
 208         /* Check the return code */
 209         if (we.rc != 0) {
 210                 const struct vio_error_entry *err =
 211                         vio_lookup_rc(viodasd_err_table, we.sub_result);
 212
 213                 printk(VIOD_KERN_WARNING
 214                                 "bad rc opening disk: %d:0x%04x (%s)\n",
 215                                 (int)we.rc, we.sub_result, err->msg);
 216                 return -EIO;
 217         }
 218
 219         return 0;
 220 }
 221
 222 /*
 223  * External release entry point.
 224  */
 225 static int viodasd_release(struct inode *ino, struct file *fil)
 226 {
 227         struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
 228         HvLpEvent_Rc hvrc;
 229
 230         /* Send the event to OS/400.  We DON'T expect a response */
 231         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 232                         HvLpEvent_Type_VirtualIo,
 233                         viomajorsubtype_blockio | vioblockclose,
 234                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 235                         viopath_sourceinst(viopath_hostLp),
 236                         viopath_targetinst(viopath_hostLp),
 237                         0, VIOVERSION << 16,
 238                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
 239                         0, 0, 0);
 240         if (hvrc != 0)
 241                 printk(VIOD_KERN_WARNING "HV close call failed %d\n",
 242                                 (int)hvrc);
 243         return 0;
 244 }
 245
 246
 247 /* External ioctl entry point.
 248  */
 249 static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 250 {
 251         struct gendisk *disk = bdev->bd_disk;
 252         struct viodasd_device *d = disk->private_data;
 253
 254         geo->sectors = d->sectors ? d->sectors : 0;
 255         geo->heads = d->tracks ? d->tracks  : 64;
 256         geo->cylinders = d->cylinders ? d->cylinders :
 257                 get_capacity(disk) / (geo->cylinders * geo->heads);
 258
 259         return 0;
 260 }
 261
 262 /*
 263  * Our file operations table
 264  */
 265 static struct block_device_operations viodasd_fops = {
 266         .owner = THIS_MODULE,
 267         .open = viodasd_open,
 268         .release = viodasd_release,
 269         .getgeo = viodasd_getgeo,
 270 };
 271
 272 /*
 273  * End a request
 274  */
 275 static void viodasd_end_request(struct request *req, int uptodate,
 276                 int num_sectors)
 277 {
 278         if (end_that_request_first(req, uptodate, num_sectors))
 279                 return;
 280         add_disk_randomness(req->rq_disk);
 281         end_that_request_last(req, uptodate);
 282 }
 283
 284 /*
 285  * Send an actual I/O request to OS/400
 286  */
 287 static int send_request(struct request *req)
 288 {
 289         u64 start;
 290         int direction;
 291         int nsg;
 292         u16 viocmd;
 293         HvLpEvent_Rc hvrc;
 294         struct vioblocklpevent *bevent;
 295         struct HvLpEvent *hev;
 296         struct scatterlist sg[VIOMAXBLOCKDMA];
 297         int sgindex;
 298         int statindex;
 299         struct viodasd_device *d;
 300         unsigned long flags;
 301
 302         start = (u64)req->sector << 9;
 303
 304         if (rq_data_dir(req) == READ) {
 305                 direction = DMA_FROM_DEVICE;
 306                 viocmd = viomajorsubtype_blockio | vioblockread;
 307                 statindex = 0;
 308         } else {
 309                 direction = DMA_TO_DEVICE;
 310                 viocmd = viomajorsubtype_blockio | vioblockwrite;
 311                 statindex = 1;
 312         }
 313
 314         d = req->rq_disk->private_data;
 315
 316         /* Now build the scatter-gather list */
 317         nsg = blk_rq_map_sg(req->q, req, sg);
 318         nsg = dma_map_sg(d->dev, sg, nsg, direction);
 319
 320         spin_lock_irqsave(&viodasd_spinlock, flags);
 321         num_req_outstanding++;
 322
 323         /* This optimization handles a single DMA block */
 324         if (nsg == 1)
 325                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 326                                 HvLpEvent_Type_VirtualIo, viocmd,
 327                                 HvLpEvent_AckInd_DoAck,
 328                                 HvLpEvent_AckType_ImmediateAck,
 329                                 viopath_sourceinst(viopath_hostLp),
 330                                 viopath_targetinst(viopath_hostLp),
 331                                 (u64)(unsigned long)req, VIOVERSION << 16,
 332                                 ((u64)DEVICE_NO(d) << 48), start,
 333                                 ((u64)sg_dma_address(&sg[0])) << 32,
 334                                 sg_dma_len(&sg[0]));
 335         else {
 336                 bevent = (struct vioblocklpevent *)
 337                         vio_get_event_buffer(viomajorsubtype_blockio);
 338                 if (bevent == NULL) {
 339                         printk(VIOD_KERN_WARNING
 340                                "error allocating disk event buffer\n");
 341                         goto error_ret;
 342                 }
 343
 344                 /*
 345                  * Now build up the actual request.  Note that we store
 346                  * the pointer to the request in the correlation
 347                  * token so we can match the response up later
 348                  */
 349                 memset(bevent, 0, sizeof(struct vioblocklpevent));
 350                 hev = &bevent->event;
 351                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
 352                         HV_LP_EVENT_INT;
 353                 hev->xType = HvLpEvent_Type_VirtualIo;
 354                 hev->xSubtype = viocmd;
 355                 hev->xSourceLp = HvLpConfig_getLpIndex();
 356                 hev->xTargetLp = viopath_hostLp;
 357                 hev->xSizeMinus1 =
 358                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
 359                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
 360                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
 361                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
 362                 hev->xCorrelationToken = (u64)req;
 363                 bevent->version = VIOVERSION;
 364                 bevent->disk = DEVICE_NO(d);
 365                 bevent->u.rw_data.offset = start;
 366
 367                 /*
 368                  * Copy just the dma information from the sg list
 369                  * into the request
 370                  */
 371                 for (sgindex = 0; sgindex < nsg; sgindex++) {
 372                         bevent->u.rw_data.dma_info[sgindex].token =
 373                                 sg_dma_address(&sg[sgindex]);
 374                         bevent->u.rw_data.dma_info[sgindex].len =
 375                                 sg_dma_len(&sg[sgindex]);
 376                 }
 377
 378                 /* Send the request */
 379                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
 380                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
 381         }
 382
 383         if (hvrc != HvLpEvent_Rc_Good) {
 384                 printk(VIOD_KERN_WARNING
 385                        "error sending disk event to OS/400 (rc %d)\n",
 386                        (int)hvrc);
 387                 goto error_ret;
 388         }
 389         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 390         return 0;
 391
 392 error_ret:
 393         num_req_outstanding--;
 394         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 395         dma_unmap_sg(d->dev, sg, nsg, direction);
 396         return -1;
 397 }
 398
 399 /*
 400  * This is the external request processing routine
 401  */
 402 static void do_viodasd_request(request_queue_t *q)
 403 {
 404         struct request *req;
 405
 406         /*
 407          * If we already have the maximum number of requests
 408          * outstanding to OS/400 just bail out. We'll come
 409          * back later.
 410          */
 411         while (num_req_outstanding < VIOMAXREQ) {
 412                 req = elv_next_request(q);
 413                 if (req == NULL)
 414                         return;
 415                 /* dequeue the current request from the queue */
 416                 blkdev_dequeue_request(req);
 417                 /* check that request contains a valid command */
 418                 if (!blk_fs_request(req)) {
 419                         viodasd_end_request(req, 0, req->hard_nr_sectors);
 420                         continue;
 421                 }
 422                 /* Try sending the request */
 423                 if (send_request(req) != 0)
 424                         viodasd_end_request(req, 0, req->hard_nr_sectors);
 425         }
 426 }
 427
 428 /*
 429  * Probe a single disk and fill in the viodasd_device structure
 430  * for it.
 431  */
 432 static void probe_disk(struct viodasd_device *d)
 433 {
 434         HvLpEvent_Rc hvrc;
 435         struct viodasd_waitevent we;
 436         int dev_no = DEVICE_NO(d);
 437         struct gendisk *g;
 438         struct request_queue *q;
 439         u16 flags = 0;
 440
 441 retry:
 442         init_completion(&we.com);
 443
 444         /* Send the open event to OS/400 */
 445         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 446                         HvLpEvent_Type_VirtualIo,
 447                         viomajorsubtype_blockio | vioblockopen,
 448                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 449                         viopath_sourceinst(viopath_hostLp),
 450                         viopath_targetinst(viopath_hostLp),
 451                         (u64)(unsigned long)&we, VIOVERSION << 16,
 452                         ((u64)dev_no << 48) | ((u64)flags<< 32),
 453                         0, 0, 0);
 454         if (hvrc != 0) {
 455                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
 456                 return;
 457         }
 458
 459         wait_for_completion(&we.com);
 460
 461         if (we.rc != 0) {
 462                 if (flags != 0)
 463                         return;
 464                 /* try again with read only flag set */
 465                 flags = vioblockflags_ro;
 466                 goto retry;
 467         }
 468         if (we.max_disk > (MAX_DISKNO - 1)) {
 469                 static int warned;
 470
 471                 if (warned == 0) {
 472                         warned++;
 473                         printk(VIOD_KERN_INFO
 474                                 "Only examining the first %d "
 475                                 "of %d disks connected\n",
 476                                 MAX_DISKNO, we.max_disk + 1);
 477                 }
 478         }
 479
 480         /* Send the close event to OS/400.  We DON'T expect a response */
 481         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 482                         HvLpEvent_Type_VirtualIo,
 483                         viomajorsubtype_blockio | vioblockclose,
 484                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 485                         viopath_sourceinst(viopath_hostLp),
 486                         viopath_targetinst(viopath_hostLp),
 487                         0, VIOVERSION << 16,
 488                         ((u64)dev_no << 48) | ((u64)flags << 32),
 489                         0, 0, 0);
 490         if (hvrc != 0) {
 491                 printk(VIOD_KERN_WARNING
 492                        "bad rc sending event to OS/400 %d\n", (int)hvrc);
 493                 return;
 494         }
 495         /* create the request queue for the disk */
 496         spin_lock_init(&d->q_lock);
 497         q = blk_init_queue(do_viodasd_request, &d->q_lock);
 498         if (q == NULL) {
 499                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
 500                                 dev_no);
 501                 return;
 502         }
 503         g = alloc_disk(1 << PARTITION_SHIFT);
 504         if (g == NULL) {
 505                 printk(VIOD_KERN_WARNING
 506                                 "cannot allocate disk structure for disk %d\n",
 507                                 dev_no);
 508                 blk_cleanup_queue(q);
 509                 return;
 510         }
 511
 512         d->disk = g;
 513         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
 514         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
 515         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
 516         g->major = VIODASD_MAJOR;
 517         g->first_minor = dev_no << PARTITION_SHIFT;
 518         if (dev_no >= 26)
 519                 snprintf(g->disk_name, sizeof(g->disk_name),
 520                                 VIOD_GENHD_NAME "%c%c",
 521                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
 522         else
 523                 snprintf(g->disk_name, sizeof(g->disk_name),
 524                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
 525         g->fops = &viodasd_fops;
 526         g->queue = q;
 527         g->private_data = d;
 528         g->driverfs_dev = d->dev;
 529         set_capacity(g, d->size >> 9);
 530
 531         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
 532                         "CHS=%d/%d/%d sector size %d%s\n",
 533                         dev_no, (unsigned long)(d->size >> 9),
 534                         (unsigned long)(d->size >> 20),
 535                         (int)d->cylinders, (int)d->tracks,
 536                         (int)d->sectors, (int)d->bytes_per_sector,
 537                         d->read_only ? " (RO)" : "");
 538
 539         /* register us in the global list */
 540         add_disk(g);
 541 }
 542
 543 /* returns the total number of scatterlist elements converted */
 544 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
 545                 struct scatterlist *sg, int *total_len)
 546 {
 547         int i, numsg;
 548         const struct rw_data *rw_data = &bevent->u.rw_data;
 549         static const int offset =
 550                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
 551         static const int element_size = sizeof(rw_data->dma_info[0]);
 552
 553         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
 554         if (numsg > VIOMAXBLOCKDMA)
 555                 numsg = VIOMAXBLOCKDMA;
 556
 557         *total_len = 0;
 558         memset(sg, 0, sizeof(sg[0]) * VIOMAXBLOCKDMA);
 559
 560         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
 561                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
 562                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
 563                 *total_len += rw_data->dma_info[i].len;
 564         }
 565         return i;
 566 }
 567
 568 /*
 569  * Restart all queues, starting with the one _after_ the disk given,
 570  * thus reducing the chance of starvation of higher numbered disks.
 571  */
 572 static void viodasd_restart_all_queues_starting_from(int first_index)
 573 {
 574         int i;
 575
 576         for (i = first_index + 1; i < MAX_DISKNO; ++i)
 577                 if (viodasd_devices[i].disk)
 578                         blk_run_queue(viodasd_devices[i].disk->queue);
 579         for (i = 0; i <= first_index; ++i)
 580                 if (viodasd_devices[i].disk)
 581                         blk_run_queue(viodasd_devices[i].disk->queue);
 582 }
 583
 584 /*
 585  * For read and write requests, decrement the number of outstanding requests,
 586  * Free the DMA buffers we allocated.
 587  */
 588 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
 589 {
 590         int num_sg, num_sect, pci_direction, total_len;
 591         struct request *req;
 592         struct scatterlist sg[VIOMAXBLOCKDMA];
 593         struct HvLpEvent *event = &bevent->event;
 594         unsigned long irq_flags;
 595         struct viodasd_device *d;
 596         int error;
 597         spinlock_t *qlock;
 598
 599         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
 600         num_sect = total_len >> 9;
 601         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
 602                 pci_direction = DMA_FROM_DEVICE;
 603         else
 604                 pci_direction = DMA_TO_DEVICE;
 605         req = (struct request *)bevent->event.xCorrelationToken;
 606         d = req->rq_disk->private_data;
 607
 608         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
 609
 610         /*
 611          * Since this is running in interrupt mode, we need to make sure
 612          * we're not stepping on any global I/O operations
 613          */
 614         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
 615         num_req_outstanding--;
 616         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
 617
 618         error = event->xRc != HvLpEvent_Rc_Good;
 619         if (error) {
 620                 const struct vio_error_entry *err;
 621                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
 622                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
 623                                 event->xRc, bevent->sub_result, err->msg);
 624                 num_sect = req->hard_nr_sectors;
 625         }
 626         qlock = req->q->queue_lock;
 627         spin_lock_irqsave(qlock, irq_flags);
 628         viodasd_end_request(req, !error, num_sect);
 629         spin_unlock_irqrestore(qlock, irq_flags);
 630
 631         /* Finally, try to get more requests off of this device's queue */
 632         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
 633
 634         return 0;
 635 }
 636
 637 /* This routine handles incoming block LP events */
 638 static void handle_block_event(struct HvLpEvent *event)
 639 {
 640         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
 641         struct viodasd_waitevent *pwe;
 642
 643         if (event == NULL)
 644                 /* Notification that a partition went away! */
 645                 return;
 646         /* First, we should NEVER get an int here...only acks */
 647         if (hvlpevent_is_int(event)) {
 648                 printk(VIOD_KERN_WARNING
 649                        "Yikes! got an int in viodasd event handler!\n");
 650                 if (hvlpevent_need_ack(event)) {
 651                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 652                         HvCallEvent_ackLpEvent(event);
 653                 }
 654         }
 655
 656         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
 657         case vioblockopen:
 658                 /*
 659                  * Handle a response to an open request.  We get all the
 660                  * disk information in the response, so update it.  The
 661                  * correlation token contains a pointer to a waitevent
 662                  * structure that has a completion in it.  update the
 663                  * return code in the waitevent structure and post the
 664                  * completion to wake up the guy who sent the request
 665                  */
 666                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
 667                 pwe->rc = event->xRc;
 668                 pwe->sub_result = bevent->sub_result;
 669                 if (event->xRc == HvLpEvent_Rc_Good) {
 670                         const struct open_data *data = &bevent->u.open_data;
 671                         struct viodasd_device *device =
 672                                 &viodasd_devices[bevent->disk];
 673                         device->read_only =
 674                                 bevent->flags & vioblockflags_ro;
 675                         device->size = data->disk_size;
 676                         device->cylinders = data->cylinders;
 677                         device->tracks = data->tracks;
 678                         device->sectors = data->sectors;
 679                         device->bytes_per_sector = data->bytes_per_sector;
 680                         pwe->max_disk = data->max_disk;
 681                 }
 682                 complete(&pwe->com);
 683                 break;
 684         case vioblockclose:
 685                 break;
 686         case vioblockread:
 687         case vioblockwrite:
 688                 viodasd_handle_read_write(bevent);
 689                 break;
 690
 691         default:
 692                 printk(VIOD_KERN_WARNING "invalid subtype!");
 693                 if (hvlpevent_need_ack(event)) {
 694                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 695                         HvCallEvent_ackLpEvent(event);
 696                 }
 697         }
 698 }
 699
 700 /*
 701  * Get the driver to reprobe for more disks.
 702  */
 703 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
 704                 size_t count)
 705 {
 706         struct viodasd_device *d;
 707
 708         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
 709                 if (d->disk == NULL)
 710                         probe_disk(d);
 711         }
 712         return count;
 713 }
 714 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
 715
 716 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 717 {
 718         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
 719
 720         d->dev = &vdev->dev;
 721         probe_disk(d);
 722         if (d->disk == NULL)
 723                 return -ENODEV;
 724         return 0;
 725 }
 726
 727 static int viodasd_remove(struct vio_dev *vdev)
 728 {
 729         struct viodasd_device *d;
 730
 731         d = &viodasd_devices[vdev->unit_address];
 732         if (d->disk) {
 733                 del_gendisk(d->disk);
 734                 blk_cleanup_queue(d->disk->queue);
 735                 put_disk(d->disk);
 736                 d->disk = NULL;
 737         }
 738         d->dev = NULL;
 739         return 0;
 740 }
 741
 742 /**
 743  * viodasd_device_table: Used by vio.c to match devices that we
 744  * support.
 745  */
 746 static struct vio_device_id viodasd_device_table[] __devinitdata = {
 747         { "block", "IBM,iSeries-viodasd" },
 748         { "", "" }
 749 };
 750 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
 751
 752 static struct vio_driver viodasd_driver = {
 753         .id_table = viodasd_device_table,
 754         .probe = viodasd_probe,
 755         .remove = viodasd_remove,
 756         .driver = {
 757                 .name = "viodasd",
 758                 .owner = THIS_MODULE,
 759         }
 760 };
 761
 762 static int need_delete_probe;
 763
 764 /*
 765  * Initialize the whole device driver.  Handle module and non-module
 766  * versions
 767  */
 768 static int __init viodasd_init(void)
 769 {
 770         int rc;
 771
 772         /* Try to open to our host lp */
 773         if (viopath_hostLp == HvLpIndexInvalid)
 774                 vio_set_hostlp();
 775
 776         if (viopath_hostLp == HvLpIndexInvalid) {
 777                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
 778                 rc = -EIO;
 779                 goto early_fail;
 780         }
 781
 782         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
 783                         viopath_hostLp);
 784
 785         /* register the block device */
 786         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 787         if (rc) {
 788                 printk(VIOD_KERN_WARNING
 789                                 "Unable to get major number %d for %s\n",
 790                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
 791                 goto early_fail;
 792         }
 793         /* Actually open the path to the hosting partition */
 794         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
 795                                 VIOMAXREQ + 2);
 796         if (rc) {
 797                 printk(VIOD_KERN_WARNING
 798                        "error opening path to host partition %d\n",
 799                        viopath_hostLp);
 800                 goto unregister_blk;
 801         }
 802
 803         /* Initialize our request handler */
 804         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
 805
 806         rc = vio_register_driver(&viodasd_driver);
 807         if (rc) {
 808                 printk(VIOD_KERN_WARNING "vio_register_driver failed\n");
 809                 goto unset_handler;
 810         }
 811
 812         /*
 813          * If this call fails, it just means that we cannot dynamically
 814          * add virtual disks, but the driver will still work fine for
 815          * all existing disk, so ignore the failure.
 816          */
 817         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
 818                 need_delete_probe = 1;
 819
 820         return 0;
 821
 822 unset_handler:
 823         vio_clearHandler(viomajorsubtype_blockio);
 824         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 825 unregister_blk:
 826         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 827 early_fail:
 828         return rc;
 829 }
 830 module_init(viodasd_init);
 831
 832 void __exit viodasd_exit(void)
 833 {
 834         if (need_delete_probe)
 835                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
 836         vio_unregister_driver(&viodasd_driver);
 837         vio_clearHandler(viomajorsubtype_blockio);
 838         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 839         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 840 }
 841 module_exit(viodasd_exit);