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   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 #define VIOD_GENHD_DEVFS_NAME   "iseries/disc"
  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 #define VIOMAXBLOCKDMA          12
  79
  80 #define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0])
  81
  82 struct open_data {
  83         u64     disk_size;
  84         u16     max_disk;
  85         u16     cylinders;
  86         u16     tracks;
  87         u16     sectors;
  88         u16     bytes_per_sector;
  89 };
  90
  91 struct rw_data {
  92         u64     offset;
  93         struct {
  94                 u32     token;
  95                 u32     reserved;
  96                 u64     len;
  97         } dma_info[VIOMAXBLOCKDMA];
  98 };
  99
 100 struct vioblocklpevent {
 101         struct HvLpEvent        event;
 102         u32                     reserved;
 103         u16                     version;
 104         u16                     sub_result;
 105         u16                     disk;
 106         u16                     flags;
 107         union {
 108                 struct open_data        open_data;
 109                 struct rw_data          rw_data;
 110                 u64                     changed;
 111         } u;
 112 };
 113
 114 #define vioblockflags_ro   0x0001
 115
 116 enum vioblocksubtype {
 117         vioblockopen = 0x0001,
 118         vioblockclose = 0x0002,
 119         vioblockread = 0x0003,
 120         vioblockwrite = 0x0004,
 121         vioblockflush = 0x0005,
 122         vioblockcheck = 0x0007
 123 };
 124
 125 struct viodasd_waitevent {
 126         struct completion       com;
 127         int                     rc;
 128         u16                     sub_result;
 129         int                     max_disk;       /* open */
 130 };
 131
 132 static const struct vio_error_entry viodasd_err_table[] = {
 133         { 0x0201, EINVAL, "Invalid Range" },
 134         { 0x0202, EINVAL, "Invalid Token" },
 135         { 0x0203, EIO, "DMA Error" },
 136         { 0x0204, EIO, "Use Error" },
 137         { 0x0205, EIO, "Release Error" },
 138         { 0x0206, EINVAL, "Invalid Disk" },
 139         { 0x0207, EBUSY, "Cant Lock" },
 140         { 0x0208, EIO, "Already Locked" },
 141         { 0x0209, EIO, "Already Unlocked" },
 142         { 0x020A, EIO, "Invalid Arg" },
 143         { 0x020B, EIO, "Bad IFS File" },
 144         { 0x020C, EROFS, "Read Only Device" },
 145         { 0x02FF, EIO, "Internal Error" },
 146         { 0x0000, 0, NULL },
 147 };
 148
 149 /*
 150  * Figure out the biggest I/O request (in sectors) we can accept
 151  */
 152 #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
 153
 154 /*
 155  * Number of disk I/O requests we've sent to OS/400
 156  */
 157 static int num_req_outstanding;
 158
 159 /*
 160  * This is our internal structure for keeping track of disk devices
 161  */
 162 struct viodasd_device {
 163         u16             cylinders;
 164         u16             tracks;
 165         u16             sectors;
 166         u16             bytes_per_sector;
 167         u64             size;
 168         int             read_only;
 169         spinlock_t      q_lock;
 170         struct gendisk  *disk;
 171         struct device   *dev;
 172 } viodasd_devices[MAX_DISKNO];
 173
 174 /*
 175  * External open entry point.
 176  */
 177 static int viodasd_open(struct inode *ino, struct file *fil)
 178 {
 179         struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
 180         HvLpEvent_Rc hvrc;
 181         struct viodasd_waitevent we;
 182         u16 flags = 0;
 183
 184         if (d->read_only) {
 185                 if ((fil != NULL) && (fil->f_mode & FMODE_WRITE))
 186                         return -EROFS;
 187                 flags = vioblockflags_ro;
 188         }
 189
 190         init_completion(&we.com);
 191
 192         /* Send the open event to OS/400 */
 193         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 194                         HvLpEvent_Type_VirtualIo,
 195                         viomajorsubtype_blockio | vioblockopen,
 196                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 197                         viopath_sourceinst(viopath_hostLp),
 198                         viopath_targetinst(viopath_hostLp),
 199                         (u64)(unsigned long)&we, VIOVERSION << 16,
 200                         ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
 201                         0, 0, 0);
 202         if (hvrc != 0) {
 203                 printk(VIOD_KERN_WARNING "HV open failed %d\n", (int)hvrc);
 204                 return -EIO;
 205         }
 206
 207         wait_for_completion(&we.com);
 208
 209         /* Check the return code */
 210         if (we.rc != 0) {
 211                 const struct vio_error_entry *err =
 212                         vio_lookup_rc(viodasd_err_table, we.sub_result);
 213
 214                 printk(VIOD_KERN_WARNING
 215                                 "bad rc opening disk: %d:0x%04x (%s)\n",
 216                                 (int)we.rc, we.sub_result, err->msg);
 217                 return -EIO;
 218         }
 219
 220         return 0;
 221 }
 222
 223 /*
 224  * External release entry point.
 225  */
 226 static int viodasd_release(struct inode *ino, struct file *fil)
 227 {
 228         struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
 229         HvLpEvent_Rc hvrc;
 230
 231         /* Send the event to OS/400.  We DON'T expect a response */
 232         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 233                         HvLpEvent_Type_VirtualIo,
 234                         viomajorsubtype_blockio | vioblockclose,
 235                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 236                         viopath_sourceinst(viopath_hostLp),
 237                         viopath_targetinst(viopath_hostLp),
 238                         0, VIOVERSION << 16,
 239                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
 240                         0, 0, 0);
 241         if (hvrc != 0)
 242                 printk(VIOD_KERN_WARNING "HV close call failed %d\n",
 243                                 (int)hvrc);
 244         return 0;
 245 }
 246
 247
 248 /* External ioctl entry point.
 249  */
 250 static int viodasd_ioctl(struct inode *ino, struct file *fil,
 251                          unsigned int cmd, unsigned long arg)
 252 {
 253         unsigned char sectors;
 254         unsigned char heads;
 255         unsigned short cylinders;
 256         struct hd_geometry *geo;
 257         struct gendisk *gendisk;
 258         struct viodasd_device *d;
 259
 260         switch (cmd) {
 261         case HDIO_GETGEO:
 262                 geo = (struct hd_geometry *)arg;
 263                 if (geo == NULL)
 264                         return -EINVAL;
 265                 if (!access_ok(VERIFY_WRITE, geo, sizeof(*geo)))
 266                         return -EFAULT;
 267                 gendisk = ino->i_bdev->bd_disk;
 268                 d = gendisk->private_data;
 269                 sectors = d->sectors;
 270                 if (sectors == 0)
 271                         sectors = 32;
 272                 heads = d->tracks;
 273                 if (heads == 0)
 274                         heads = 64;
 275                 cylinders = d->cylinders;
 276                 if (cylinders == 0)
 277                         cylinders = get_capacity(gendisk) / (sectors * heads);
 278                 if (__put_user(sectors, &geo->sectors) ||
 279                     __put_user(heads, &geo->heads) ||
 280                     __put_user(cylinders, &geo->cylinders) ||
 281                     __put_user(get_start_sect(ino->i_bdev), &geo->start))
 282                         return -EFAULT;
 283                 return 0;
 284         }
 285
 286         return -EINVAL;
 287 }
 288
 289 /*
 290  * Our file operations table
 291  */
 292 static struct block_device_operations viodasd_fops = {
 293         .owner = THIS_MODULE,
 294         .open = viodasd_open,
 295         .release = viodasd_release,
 296         .ioctl = viodasd_ioctl,
 297 };
 298
 299 /*
 300  * End a request
 301  */
 302 static void viodasd_end_request(struct request *req, int uptodate,
 303                 int num_sectors)
 304 {
 305         if (end_that_request_first(req, uptodate, num_sectors))
 306                 return;
 307         add_disk_randomness(req->rq_disk);
 308         end_that_request_last(req, uptodate);
 309 }
 310
 311 /*
 312  * Send an actual I/O request to OS/400
 313  */
 314 static int send_request(struct request *req)
 315 {
 316         u64 start;
 317         int direction;
 318         int nsg;
 319         u16 viocmd;
 320         HvLpEvent_Rc hvrc;
 321         struct vioblocklpevent *bevent;
 322         struct scatterlist sg[VIOMAXBLOCKDMA];
 323         int sgindex;
 324         int statindex;
 325         struct viodasd_device *d;
 326         unsigned long flags;
 327
 328         start = (u64)req->sector << 9;
 329
 330         if (rq_data_dir(req) == READ) {
 331                 direction = DMA_FROM_DEVICE;
 332                 viocmd = viomajorsubtype_blockio | vioblockread;
 333                 statindex = 0;
 334         } else {
 335                 direction = DMA_TO_DEVICE;
 336                 viocmd = viomajorsubtype_blockio | vioblockwrite;
 337                 statindex = 1;
 338         }
 339
 340         d = req->rq_disk->private_data;
 341
 342         /* Now build the scatter-gather list */
 343         nsg = blk_rq_map_sg(req->q, req, sg);
 344         nsg = dma_map_sg(d->dev, sg, nsg, direction);
 345
 346         spin_lock_irqsave(&viodasd_spinlock, flags);
 347         num_req_outstanding++;
 348
 349         /* This optimization handles a single DMA block */
 350         if (nsg == 1)
 351                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 352                                 HvLpEvent_Type_VirtualIo, viocmd,
 353                                 HvLpEvent_AckInd_DoAck,
 354                                 HvLpEvent_AckType_ImmediateAck,
 355                                 viopath_sourceinst(viopath_hostLp),
 356                                 viopath_targetinst(viopath_hostLp),
 357                                 (u64)(unsigned long)req, VIOVERSION << 16,
 358                                 ((u64)DEVICE_NO(d) << 48), start,
 359                                 ((u64)sg_dma_address(&sg[0])) << 32,
 360                                 sg_dma_len(&sg[0]));
 361         else {
 362                 bevent = (struct vioblocklpevent *)
 363                         vio_get_event_buffer(viomajorsubtype_blockio);
 364                 if (bevent == NULL) {
 365                         printk(VIOD_KERN_WARNING
 366                                "error allocating disk event buffer\n");
 367                         goto error_ret;
 368                 }
 369
 370                 /*
 371                  * Now build up the actual request.  Note that we store
 372                  * the pointer to the request in the correlation
 373                  * token so we can match the response up later
 374                  */
 375                 memset(bevent, 0, sizeof(struct vioblocklpevent));
 376                 bevent->event.xFlags.xValid = 1;
 377                 bevent->event.xFlags.xFunction = HvLpEvent_Function_Int;
 378                 bevent->event.xFlags.xAckInd = HvLpEvent_AckInd_DoAck;
 379                 bevent->event.xFlags.xAckType = HvLpEvent_AckType_ImmediateAck;
 380                 bevent->event.xType = HvLpEvent_Type_VirtualIo;
 381                 bevent->event.xSubtype = viocmd;
 382                 bevent->event.xSourceLp = HvLpConfig_getLpIndex();
 383                 bevent->event.xTargetLp = viopath_hostLp;
 384                 bevent->event.xSizeMinus1 =
 385                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
 386                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
 387                 bevent->event.xSourceInstanceId =
 388                         viopath_sourceinst(viopath_hostLp);
 389                 bevent->event.xTargetInstanceId =
 390                         viopath_targetinst(viopath_hostLp);
 391                 bevent->event.xCorrelationToken = (u64)req;
 392                 bevent->version = VIOVERSION;
 393                 bevent->disk = DEVICE_NO(d);
 394                 bevent->u.rw_data.offset = start;
 395
 396                 /*
 397                  * Copy just the dma information from the sg list
 398                  * into the request
 399                  */
 400                 for (sgindex = 0; sgindex < nsg; sgindex++) {
 401                         bevent->u.rw_data.dma_info[sgindex].token =
 402                                 sg_dma_address(&sg[sgindex]);
 403                         bevent->u.rw_data.dma_info[sgindex].len =
 404                                 sg_dma_len(&sg[sgindex]);
 405                 }
 406
 407                 /* Send the request */
 408                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
 409                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
 410         }
 411
 412         if (hvrc != HvLpEvent_Rc_Good) {
 413                 printk(VIOD_KERN_WARNING
 414                        "error sending disk event to OS/400 (rc %d)\n",
 415                        (int)hvrc);
 416                 goto error_ret;
 417         }
 418         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 419         return 0;
 420
 421 error_ret:
 422         num_req_outstanding--;
 423         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 424         dma_unmap_sg(d->dev, sg, nsg, direction);
 425         return -1;
 426 }
 427
 428 /*
 429  * This is the external request processing routine
 430  */
 431 static void do_viodasd_request(request_queue_t *q)
 432 {
 433         struct request *req;
 434
 435         /*
 436          * If we already have the maximum number of requests
 437          * outstanding to OS/400 just bail out. We'll come
 438          * back later.
 439          */
 440         while (num_req_outstanding < VIOMAXREQ) {
 441                 req = elv_next_request(q);
 442                 if (req == NULL)
 443                         return;
 444                 /* dequeue the current request from the queue */
 445                 blkdev_dequeue_request(req);
 446                 /* check that request contains a valid command */
 447                 if (!blk_fs_request(req)) {
 448                         viodasd_end_request(req, 0, req->hard_nr_sectors);
 449                         continue;
 450                 }
 451                 /* Try sending the request */
 452                 if (send_request(req) != 0)
 453                         viodasd_end_request(req, 0, req->hard_nr_sectors);
 454         }
 455 }
 456
 457 /*
 458  * Probe a single disk and fill in the viodasd_device structure
 459  * for it.
 460  */
 461 static void probe_disk(struct viodasd_device *d)
 462 {
 463         HvLpEvent_Rc hvrc;
 464         struct viodasd_waitevent we;
 465         int dev_no = DEVICE_NO(d);
 466         struct gendisk *g;
 467         struct request_queue *q;
 468         u16 flags = 0;
 469
 470 retry:
 471         init_completion(&we.com);
 472
 473         /* Send the open event to OS/400 */
 474         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 475                         HvLpEvent_Type_VirtualIo,
 476                         viomajorsubtype_blockio | vioblockopen,
 477                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 478                         viopath_sourceinst(viopath_hostLp),
 479                         viopath_targetinst(viopath_hostLp),
 480                         (u64)(unsigned long)&we, VIOVERSION << 16,
 481                         ((u64)dev_no << 48) | ((u64)flags<< 32),
 482                         0, 0, 0);
 483         if (hvrc != 0) {
 484                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
 485                 return;
 486         }
 487
 488         wait_for_completion(&we.com);
 489
 490         if (we.rc != 0) {
 491                 if (flags != 0)
 492                         return;
 493                 /* try again with read only flag set */
 494                 flags = vioblockflags_ro;
 495                 goto retry;
 496         }
 497         if (we.max_disk > (MAX_DISKNO - 1)) {
 498                 static int warned;
 499
 500                 if (warned == 0) {
 501                         warned++;
 502                         printk(VIOD_KERN_INFO
 503                                 "Only examining the first %d "
 504                                 "of %d disks connected\n",
 505                                 MAX_DISKNO, we.max_disk + 1);
 506                 }
 507         }
 508
 509         /* Send the close event to OS/400.  We DON'T expect a response */
 510         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 511                         HvLpEvent_Type_VirtualIo,
 512                         viomajorsubtype_blockio | vioblockclose,
 513                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 514                         viopath_sourceinst(viopath_hostLp),
 515                         viopath_targetinst(viopath_hostLp),
 516                         0, VIOVERSION << 16,
 517                         ((u64)dev_no << 48) | ((u64)flags << 32),
 518                         0, 0, 0);
 519         if (hvrc != 0) {
 520                 printk(VIOD_KERN_WARNING
 521                        "bad rc sending event to OS/400 %d\n", (int)hvrc);
 522                 return;
 523         }
 524         /* create the request queue for the disk */
 525         spin_lock_init(&d->q_lock);
 526         q = blk_init_queue(do_viodasd_request, &d->q_lock);
 527         if (q == NULL) {
 528                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
 529                                 dev_no);
 530                 return;
 531         }
 532         g = alloc_disk(1 << PARTITION_SHIFT);
 533         if (g == NULL) {
 534                 printk(VIOD_KERN_WARNING
 535                                 "cannot allocate disk structure for disk %d\n",
 536                                 dev_no);
 537                 blk_cleanup_queue(q);
 538                 return;
 539         }
 540
 541         d->disk = g;
 542         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
 543         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
 544         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
 545         g->major = VIODASD_MAJOR;
 546         g->first_minor = dev_no << PARTITION_SHIFT;
 547         if (dev_no >= 26)
 548                 snprintf(g->disk_name, sizeof(g->disk_name),
 549                                 VIOD_GENHD_NAME "%c%c",
 550                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
 551         else
 552                 snprintf(g->disk_name, sizeof(g->disk_name),
 553                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
 554         snprintf(g->devfs_name, sizeof(g->devfs_name),
 555                         "%s%d", VIOD_GENHD_DEVFS_NAME, dev_no);
 556         g->fops = &viodasd_fops;
 557         g->queue = q;
 558         g->private_data = d;
 559         g->driverfs_dev = d->dev;
 560         set_capacity(g, d->size >> 9);
 561
 562         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
 563                         "CHS=%d/%d/%d sector size %d%s\n",
 564                         dev_no, (unsigned long)(d->size >> 9),
 565                         (unsigned long)(d->size >> 20),
 566                         (int)d->cylinders, (int)d->tracks,
 567                         (int)d->sectors, (int)d->bytes_per_sector,
 568                         d->read_only ? " (RO)" : "");
 569
 570         /* register us in the global list */
 571         add_disk(g);
 572 }
 573
 574 /* returns the total number of scatterlist elements converted */
 575 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
 576                 struct scatterlist *sg, int *total_len)
 577 {
 578         int i, numsg;
 579         const struct rw_data *rw_data = &bevent->u.rw_data;
 580         static const int offset =
 581                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
 582         static const int element_size = sizeof(rw_data->dma_info[0]);
 583
 584         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
 585         if (numsg > VIOMAXBLOCKDMA)
 586                 numsg = VIOMAXBLOCKDMA;
 587
 588         *total_len = 0;
 589         memset(sg, 0, sizeof(sg[0]) * VIOMAXBLOCKDMA);
 590
 591         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
 592                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
 593                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
 594                 *total_len += rw_data->dma_info[i].len;
 595         }
 596         return i;
 597 }
 598
 599 /*
 600  * Restart all queues, starting with the one _after_ the disk given,
 601  * thus reducing the chance of starvation of higher numbered disks.
 602  */
 603 static void viodasd_restart_all_queues_starting_from(int first_index)
 604 {
 605         int i;
 606
 607         for (i = first_index + 1; i < MAX_DISKNO; ++i)
 608                 if (viodasd_devices[i].disk)
 609                         blk_run_queue(viodasd_devices[i].disk->queue);
 610         for (i = 0; i <= first_index; ++i)
 611                 if (viodasd_devices[i].disk)
 612                         blk_run_queue(viodasd_devices[i].disk->queue);
 613 }
 614
 615 /*
 616  * For read and write requests, decrement the number of outstanding requests,
 617  * Free the DMA buffers we allocated.
 618  */
 619 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
 620 {
 621         int num_sg, num_sect, pci_direction, total_len;
 622         struct request *req;
 623         struct scatterlist sg[VIOMAXBLOCKDMA];
 624         struct HvLpEvent *event = &bevent->event;
 625         unsigned long irq_flags;
 626         struct viodasd_device *d;
 627         int error;
 628         spinlock_t *qlock;
 629
 630         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
 631         num_sect = total_len >> 9;
 632         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
 633                 pci_direction = DMA_FROM_DEVICE;
 634         else
 635                 pci_direction = DMA_TO_DEVICE;
 636         req = (struct request *)bevent->event.xCorrelationToken;
 637         d = req->rq_disk->private_data;
 638
 639         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
 640
 641         /*
 642          * Since this is running in interrupt mode, we need to make sure
 643          * we're not stepping on any global I/O operations
 644          */
 645         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
 646         num_req_outstanding--;
 647         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
 648
 649         error = event->xRc != HvLpEvent_Rc_Good;
 650         if (error) {
 651                 const struct vio_error_entry *err;
 652                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
 653                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
 654                                 event->xRc, bevent->sub_result, err->msg);
 655                 num_sect = req->hard_nr_sectors;
 656         }
 657         qlock = req->q->queue_lock;
 658         spin_lock_irqsave(qlock, irq_flags);
 659         viodasd_end_request(req, !error, num_sect);
 660         spin_unlock_irqrestore(qlock, irq_flags);
 661
 662         /* Finally, try to get more requests off of this device's queue */
 663         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
 664
 665         return 0;
 666 }
 667
 668 /* This routine handles incoming block LP events */
 669 static void handle_block_event(struct HvLpEvent *event)
 670 {
 671         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
 672         struct viodasd_waitevent *pwe;
 673
 674         if (event == NULL)
 675                 /* Notification that a partition went away! */
 676                 return;
 677         /* First, we should NEVER get an int here...only acks */
 678         if (event->xFlags.xFunction == HvLpEvent_Function_Int) {
 679                 printk(VIOD_KERN_WARNING
 680                        "Yikes! got an int in viodasd event handler!\n");
 681                 if (event->xFlags.xAckInd == HvLpEvent_AckInd_DoAck) {
 682                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 683                         HvCallEvent_ackLpEvent(event);
 684                 }
 685         }
 686
 687         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
 688         case vioblockopen:
 689                 /*
 690                  * Handle a response to an open request.  We get all the
 691                  * disk information in the response, so update it.  The
 692                  * correlation token contains a pointer to a waitevent
 693                  * structure that has a completion in it.  update the
 694                  * return code in the waitevent structure and post the
 695                  * completion to wake up the guy who sent the request
 696                  */
 697                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
 698                 pwe->rc = event->xRc;
 699                 pwe->sub_result = bevent->sub_result;
 700                 if (event->xRc == HvLpEvent_Rc_Good) {
 701                         const struct open_data *data = &bevent->u.open_data;
 702                         struct viodasd_device *device =
 703                                 &viodasd_devices[bevent->disk];
 704                         device->read_only =
 705                                 bevent->flags & vioblockflags_ro;
 706                         device->size = data->disk_size;
 707                         device->cylinders = data->cylinders;
 708                         device->tracks = data->tracks;
 709                         device->sectors = data->sectors;
 710                         device->bytes_per_sector = data->bytes_per_sector;
 711                         pwe->max_disk = data->max_disk;
 712                 }
 713                 complete(&pwe->com);
 714                 break;
 715         case vioblockclose:
 716                 break;
 717         case vioblockread:
 718         case vioblockwrite:
 719                 viodasd_handle_read_write(bevent);
 720                 break;
 721
 722         default:
 723                 printk(VIOD_KERN_WARNING "invalid subtype!");
 724                 if (event->xFlags.xAckInd == HvLpEvent_AckInd_DoAck) {
 725                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 726                         HvCallEvent_ackLpEvent(event);
 727                 }
 728         }
 729 }
 730
 731 /*
 732  * Get the driver to reprobe for more disks.
 733  */
 734 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
 735                 size_t count)
 736 {
 737         struct viodasd_device *d;
 738
 739         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
 740                 if (d->disk == NULL)
 741                         probe_disk(d);
 742         }
 743         return count;
 744 }
 745 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
 746
 747 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 748 {
 749         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
 750
 751         d->dev = &vdev->dev;
 752         probe_disk(d);
 753         if (d->disk == NULL)
 754                 return -ENODEV;
 755         return 0;
 756 }
 757
 758 static int viodasd_remove(struct vio_dev *vdev)
 759 {
 760         struct viodasd_device *d;
 761
 762         d = &viodasd_devices[vdev->unit_address];
 763         if (d->disk) {
 764                 del_gendisk(d->disk);
 765                 blk_cleanup_queue(d->disk->queue);
 766                 put_disk(d->disk);
 767                 d->disk = NULL;
 768         }
 769         d->dev = NULL;
 770         return 0;
 771 }
 772
 773 /**
 774  * viodasd_device_table: Used by vio.c to match devices that we
 775  * support.
 776  */
 777 static struct vio_device_id viodasd_device_table[] __devinitdata = {
 778         { "viodasd", "" },
 779         { "", "" }
 780 };
 781 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
 782
 783 static struct vio_driver viodasd_driver = {
 784         .id_table = viodasd_device_table,
 785         .probe = viodasd_probe,
 786         .remove = viodasd_remove,
 787         .driver = {
 788                 .name = "viodasd",
 789                 .owner = THIS_MODULE,
 790         }
 791 };
 792
 793 /*
 794  * Initialize the whole device driver.  Handle module and non-module
 795  * versions
 796  */
 797 static int __init viodasd_init(void)
 798 {
 799         int rc;
 800
 801         /* Try to open to our host lp */
 802         if (viopath_hostLp == HvLpIndexInvalid)
 803                 vio_set_hostlp();
 804
 805         if (viopath_hostLp == HvLpIndexInvalid) {
 806                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
 807                 return -EIO;
 808         }
 809
 810         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
 811                         viopath_hostLp);
 812
 813         /* register the block device */
 814         if (register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME)) {
 815                 printk(VIOD_KERN_WARNING
 816                                 "Unable to get major number %d for %s\n",
 817                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
 818                 return -EIO;
 819         }
 820         /* Actually open the path to the hosting partition */
 821         if (viopath_open(viopath_hostLp, viomajorsubtype_blockio,
 822                                 VIOMAXREQ + 2)) {
 823                 printk(VIOD_KERN_WARNING
 824                        "error opening path to host partition %d\n",
 825                        viopath_hostLp);
 826                 unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 827                 return -EIO;
 828         }
 829
 830         /* Initialize our request handler */
 831         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
 832
 833         rc = vio_register_driver(&viodasd_driver);
 834         if (rc == 0)
 835                 driver_create_file(&viodasd_driver.driver, &driver_attr_probe);
 836         return rc;
 837 }
 838 module_init(viodasd_init);
 839
 840 void viodasd_exit(void)
 841 {
 842         driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
 843         vio_unregister_driver(&viodasd_driver);
 844         vio_clearHandler(viomajorsubtype_blockio);
 845         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 846         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 847 }
 848
 849 module_exit(viodasd_exit);