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