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
   7  *
   8  * (C) Copyright 2000-2004 IBM Corporation
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of the
  13  * License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * This routine provides access to disk space (termed "DASD" in historical
  25  * IBM terms) owned and managed by an OS/400 partition running on the
  26  * same box as this Linux partition.
  27  *
  28  * All disk operations are performed by sending messages back and forth to
  29  * the OS/400 partition.
  30  */
  31 #include <linux/major.h>
  32 #include <linux/fs.h>
  33 #include <linux/module.h>
  34 #include <linux/kernel.h>
  35 #include <linux/blkdev.h>
  36 #include <linux/genhd.h>
  37 #include <linux/hdreg.h>
  38 #include <linux/errno.h>
  39 #include <linux/init.h>
  40 #include <linux/string.h>
  41 #include <linux/dma-mapping.h>
  42 #include <linux/completion.h>
  43 #include <linux/device.h>
  44 #include <linux/scatterlist.h>
  45
  46 #include <asm/uaccess.h>
  47 #include <asm/vio.h>
  48 #include <asm/iseries/hv_types.h>
  49 #include <asm/iseries/hv_lp_event.h>
  50 #include <asm/iseries/hv_lp_config.h>
  51 #include <asm/iseries/vio.h>
  52 #include <asm/firmware.h>
  53
  54 MODULE_DESCRIPTION("iSeries Virtual DASD");
  55 MODULE_AUTHOR("Dave Boutcher");
  56 MODULE_LICENSE("GPL");
  57
  58 /*
  59  * We only support 7 partitions per physical disk....so with minor
  60  * numbers 0-255 we get a maximum of 32 disks.
  61  */
  62 #define VIOD_GENHD_NAME         "iseries/vd"
  63
  64 #define VIOD_VERS               "1.64"
  65
  66 #define VIOD_KERN_WARNING       KERN_WARNING "viod: "
  67 #define VIOD_KERN_INFO          KERN_INFO "viod: "
  68
  69 enum {
  70         PARTITION_SHIFT = 3,
  71         MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS,
  72         MAX_DISK_NAME = FIELD_SIZEOF(struct gendisk, disk_name)
  73 };
  74
  75 static DEFINE_SPINLOCK(viodasd_spinlock);
  76
  77 #define VIOMAXREQ               16
  78
  79 #define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0])
  80
  81 struct viodasd_waitevent {
  82         struct completion       com;
  83         int                     rc;
  84         u16                     sub_result;
  85         int                     max_disk;       /* open */
  86 };
  87
  88 static const struct vio_error_entry viodasd_err_table[] = {
  89         { 0x0201, EINVAL, "Invalid Range" },
  90         { 0x0202, EINVAL, "Invalid Token" },
  91         { 0x0203, EIO, "DMA Error" },
  92         { 0x0204, EIO, "Use Error" },
  93         { 0x0205, EIO, "Release Error" },
  94         { 0x0206, EINVAL, "Invalid Disk" },
  95         { 0x0207, EBUSY, "Cant Lock" },
  96         { 0x0208, EIO, "Already Locked" },
  97         { 0x0209, EIO, "Already Unlocked" },
  98         { 0x020A, EIO, "Invalid Arg" },
  99         { 0x020B, EIO, "Bad IFS File" },
 100         { 0x020C, EROFS, "Read Only Device" },
 101         { 0x02FF, EIO, "Internal Error" },
 102         { 0x0000, 0, NULL },
 103 };
 104
 105 /*
 106  * Figure out the biggest I/O request (in sectors) we can accept
 107  */
 108 #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
 109
 110 /*
 111  * Number of disk I/O requests we've sent to OS/400
 112  */
 113 static int num_req_outstanding;
 114
 115 /*
 116  * This is our internal structure for keeping track of disk devices
 117  */
 118 struct viodasd_device {
 119         u16             cylinders;
 120         u16             tracks;
 121         u16             sectors;
 122         u16             bytes_per_sector;
 123         u64             size;
 124         int             read_only;
 125         spinlock_t      q_lock;
 126         struct gendisk  *disk;
 127         struct device   *dev;
 128 } viodasd_devices[MAX_DISKNO];
 129
 130 /*
 131  * External open entry point.
 132  */
 133 static int viodasd_open(struct block_device *bdev, fmode_t mode)
 134 {
 135         struct viodasd_device *d = bdev->bd_disk->private_data;
 136         HvLpEvent_Rc hvrc;
 137         struct viodasd_waitevent we;
 138         u16 flags = 0;
 139
 140         if (d->read_only) {
 141                 if (mode & FMODE_WRITE)
 142                         return -EROFS;
 143                 flags = vioblockflags_ro;
 144         }
 145
 146         init_completion(&we.com);
 147
 148         /* Send the open event to OS/400 */
 149         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 150                         HvLpEvent_Type_VirtualIo,
 151                         viomajorsubtype_blockio | vioblockopen,
 152                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 153                         viopath_sourceinst(viopath_hostLp),
 154                         viopath_targetinst(viopath_hostLp),
 155                         (u64)(unsigned long)&we, VIOVERSION << 16,
 156                         ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
 157                         0, 0, 0);
 158         if (hvrc != 0) {
 159                 printk(VIOD_KERN_WARNING "HV open failed %d\n", (int)hvrc);
 160                 return -EIO;
 161         }
 162
 163         wait_for_completion(&we.com);
 164
 165         /* Check the return code */
 166         if (we.rc != 0) {
 167                 const struct vio_error_entry *err =
 168                         vio_lookup_rc(viodasd_err_table, we.sub_result);
 169
 170                 printk(VIOD_KERN_WARNING
 171                                 "bad rc opening disk: %d:0x%04x (%s)\n",
 172                                 (int)we.rc, we.sub_result, err->msg);
 173                 return -EIO;
 174         }
 175
 176         return 0;
 177 }
 178
 179 /*
 180  * External release entry point.
 181  */
 182 static int viodasd_release(struct gendisk *disk, fmode_t mode)
 183 {
 184         struct viodasd_device *d = disk->private_data;
 185         HvLpEvent_Rc hvrc;
 186
 187         /* Send the event to OS/400.  We DON'T expect a response */
 188         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 189                         HvLpEvent_Type_VirtualIo,
 190                         viomajorsubtype_blockio | vioblockclose,
 191                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 192                         viopath_sourceinst(viopath_hostLp),
 193                         viopath_targetinst(viopath_hostLp),
 194                         0, VIOVERSION << 16,
 195                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
 196                         0, 0, 0);
 197         if (hvrc != 0)
 198                 printk(VIOD_KERN_WARNING "HV close call failed %d\n",
 199                                 (int)hvrc);
 200         return 0;
 201 }
 202
 203
 204 /* External ioctl entry point.
 205  */
 206 static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 207 {
 208         struct gendisk *disk = bdev->bd_disk;
 209         struct viodasd_device *d = disk->private_data;
 210
 211         geo->sectors = d->sectors ? d->sectors : 32;
 212         geo->heads = d->tracks ? d->tracks  : 64;
 213         geo->cylinders = d->cylinders ? d->cylinders :
 214                 get_capacity(disk) / (geo->sectors * geo->heads);
 215
 216         return 0;
 217 }
 218
 219 /*
 220  * Our file operations table
 221  */
 222 static const struct block_device_operations viodasd_fops = {
 223         .owner = THIS_MODULE,
 224         .open = viodasd_open,
 225         .release = viodasd_release,
 226         .getgeo = viodasd_getgeo,
 227 };
 228
 229 /*
 230  * End a request
 231  */
 232 static void viodasd_end_request(struct request *req, int error,
 233                 int num_sectors)
 234 {
 235         __blk_end_request(req, error, num_sectors << 9);
 236 }
 237
 238 /*
 239  * Send an actual I/O request to OS/400
 240  */
 241 static int send_request(struct request *req)
 242 {
 243         u64 start;
 244         int direction;
 245         int nsg;
 246         u16 viocmd;
 247         HvLpEvent_Rc hvrc;
 248         struct vioblocklpevent *bevent;
 249         struct HvLpEvent *hev;
 250         struct scatterlist sg[VIOMAXBLOCKDMA];
 251         int sgindex;
 252         struct viodasd_device *d;
 253         unsigned long flags;
 254
 255         start = (u64)blk_rq_pos(req) << 9;
 256
 257         if (rq_data_dir(req) == READ) {
 258                 direction = DMA_FROM_DEVICE;
 259                 viocmd = viomajorsubtype_blockio | vioblockread;
 260         } else {
 261                 direction = DMA_TO_DEVICE;
 262                 viocmd = viomajorsubtype_blockio | vioblockwrite;
 263         }
 264
 265         d = req->rq_disk->private_data;
 266
 267         /* Now build the scatter-gather list */
 268         sg_init_table(sg, VIOMAXBLOCKDMA);
 269         nsg = blk_rq_map_sg(req->q, req, sg);
 270         nsg = dma_map_sg(d->dev, sg, nsg, direction);
 271
 272         spin_lock_irqsave(&viodasd_spinlock, flags);
 273         num_req_outstanding++;
 274
 275         /* This optimization handles a single DMA block */
 276         if (nsg == 1)
 277                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 278                                 HvLpEvent_Type_VirtualIo, viocmd,
 279                                 HvLpEvent_AckInd_DoAck,
 280                                 HvLpEvent_AckType_ImmediateAck,
 281                                 viopath_sourceinst(viopath_hostLp),
 282                                 viopath_targetinst(viopath_hostLp),
 283                                 (u64)(unsigned long)req, VIOVERSION << 16,
 284                                 ((u64)DEVICE_NO(d) << 48), start,
 285                                 ((u64)sg_dma_address(&sg[0])) << 32,
 286                                 sg_dma_len(&sg[0]));
 287         else {
 288                 bevent = (struct vioblocklpevent *)
 289                         vio_get_event_buffer(viomajorsubtype_blockio);
 290                 if (bevent == NULL) {
 291                         printk(VIOD_KERN_WARNING
 292                                "error allocating disk event buffer\n");
 293                         goto error_ret;
 294                 }
 295
 296                 /*
 297                  * Now build up the actual request.  Note that we store
 298                  * the pointer to the request in the correlation
 299                  * token so we can match the response up later
 300                  */
 301                 memset(bevent, 0, sizeof(struct vioblocklpevent));
 302                 hev = &bevent->event;
 303                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
 304                         HV_LP_EVENT_INT;
 305                 hev->xType = HvLpEvent_Type_VirtualIo;
 306                 hev->xSubtype = viocmd;
 307                 hev->xSourceLp = HvLpConfig_getLpIndex();
 308                 hev->xTargetLp = viopath_hostLp;
 309                 hev->xSizeMinus1 =
 310                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
 311                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
 312                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
 313                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
 314                 hev->xCorrelationToken = (u64)req;
 315                 bevent->version = VIOVERSION;
 316                 bevent->disk = DEVICE_NO(d);
 317                 bevent->u.rw_data.offset = start;
 318
 319                 /*
 320                  * Copy just the dma information from the sg list
 321                  * into the request
 322                  */
 323                 for (sgindex = 0; sgindex < nsg; sgindex++) {
 324                         bevent->u.rw_data.dma_info[sgindex].token =
 325                                 sg_dma_address(&sg[sgindex]);
 326                         bevent->u.rw_data.dma_info[sgindex].len =
 327                                 sg_dma_len(&sg[sgindex]);
 328                 }
 329
 330                 /* Send the request */
 331                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
 332                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
 333         }
 334
 335         if (hvrc != HvLpEvent_Rc_Good) {
 336                 printk(VIOD_KERN_WARNING
 337                        "error sending disk event to OS/400 (rc %d)\n",
 338                        (int)hvrc);
 339                 goto error_ret;
 340         }
 341         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 342         return 0;
 343
 344 error_ret:
 345         num_req_outstanding--;
 346         spin_unlock_irqrestore(&viodasd_spinlock, flags);
 347         dma_unmap_sg(d->dev, sg, nsg, direction);
 348         return -1;
 349 }
 350
 351 /*
 352  * This is the external request processing routine
 353  */
 354 static void do_viodasd_request(struct request_queue *q)
 355 {
 356         struct request *req;
 357
 358         /*
 359          * If we already have the maximum number of requests
 360          * outstanding to OS/400 just bail out. We'll come
 361          * back later.
 362          */
 363         while (num_req_outstanding < VIOMAXREQ) {
 364                 req = blk_fetch_request(q);
 365                 if (req == NULL)
 366                         return;
 367                 /* check that request contains a valid command */
 368                 if (!blk_fs_request(req)) {
 369                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
 370                         continue;
 371                 }
 372                 /* Try sending the request */
 373                 if (send_request(req) != 0)
 374                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
 375         }
 376 }
 377
 378 /*
 379  * Probe a single disk and fill in the viodasd_device structure
 380  * for it.
 381  */
 382 static int probe_disk(struct viodasd_device *d)
 383 {
 384         HvLpEvent_Rc hvrc;
 385         struct viodasd_waitevent we;
 386         int dev_no = DEVICE_NO(d);
 387         struct gendisk *g;
 388         struct request_queue *q;
 389         u16 flags = 0;
 390
 391 retry:
 392         init_completion(&we.com);
 393
 394         /* Send the open event to OS/400 */
 395         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 396                         HvLpEvent_Type_VirtualIo,
 397                         viomajorsubtype_blockio | vioblockopen,
 398                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 399                         viopath_sourceinst(viopath_hostLp),
 400                         viopath_targetinst(viopath_hostLp),
 401                         (u64)(unsigned long)&we, VIOVERSION << 16,
 402                         ((u64)dev_no << 48) | ((u64)flags<< 32),
 403                         0, 0, 0);
 404         if (hvrc != 0) {
 405                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
 406                 return 0;
 407         }
 408
 409         wait_for_completion(&we.com);
 410
 411         if (we.rc != 0) {
 412                 if (flags != 0)
 413                         return 0;
 414                 /* try again with read only flag set */
 415                 flags = vioblockflags_ro;
 416                 goto retry;
 417         }
 418         if (we.max_disk > (MAX_DISKNO - 1)) {
 419                 printk_once(VIOD_KERN_INFO
 420                         "Only examining the first %d of %d disks connected\n",
 421                         MAX_DISKNO, we.max_disk + 1);
 422         }
 423
 424         /* Send the close event to OS/400.  We DON'T expect a response */
 425         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
 426                         HvLpEvent_Type_VirtualIo,
 427                         viomajorsubtype_blockio | vioblockclose,
 428                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
 429                         viopath_sourceinst(viopath_hostLp),
 430                         viopath_targetinst(viopath_hostLp),
 431                         0, VIOVERSION << 16,
 432                         ((u64)dev_no << 48) | ((u64)flags << 32),
 433                         0, 0, 0);
 434         if (hvrc != 0) {
 435                 printk(VIOD_KERN_WARNING
 436                        "bad rc sending event to OS/400 %d\n", (int)hvrc);
 437                 return 0;
 438         }
 439
 440         if (d->dev == NULL) {
 441                 /* this is when we reprobe for new disks */
 442                 if (vio_create_viodasd(dev_no) == NULL) {
 443                         printk(VIOD_KERN_WARNING
 444                                 "cannot allocate virtual device for disk %d\n",
 445                                 dev_no);
 446                         return 0;
 447                 }
 448                 /*
 449                  * The vio_create_viodasd will have recursed into this
 450                  * routine with d->dev set to the new vio device and
 451                  * will finish the setup of the disk below.
 452                  */
 453                 return 1;
 454         }
 455
 456         /* create the request queue for the disk */
 457         spin_lock_init(&d->q_lock);
 458         q = blk_init_queue(do_viodasd_request, &d->q_lock);
 459         if (q == NULL) {
 460                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
 461                                 dev_no);
 462                 return 0;
 463         }
 464         g = alloc_disk(1 << PARTITION_SHIFT);
 465         if (g == NULL) {
 466                 printk(VIOD_KERN_WARNING
 467                                 "cannot allocate disk structure for disk %d\n",
 468                                 dev_no);
 469                 blk_cleanup_queue(q);
 470                 return 0;
 471         }
 472
 473         d->disk = g;
 474         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
 475         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
 476         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
 477         g->major = VIODASD_MAJOR;
 478         g->first_minor = dev_no << PARTITION_SHIFT;
 479         if (dev_no >= 26)
 480                 snprintf(g->disk_name, sizeof(g->disk_name),
 481                                 VIOD_GENHD_NAME "%c%c",
 482                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
 483         else
 484                 snprintf(g->disk_name, sizeof(g->disk_name),
 485                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
 486         g->fops = &viodasd_fops;
 487         g->queue = q;
 488         g->private_data = d;
 489         g->driverfs_dev = d->dev;
 490         set_capacity(g, d->size >> 9);
 491
 492         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
 493                         "CHS=%d/%d/%d sector size %d%s\n",
 494                         dev_no, (unsigned long)(d->size >> 9),
 495                         (unsigned long)(d->size >> 20),
 496                         (int)d->cylinders, (int)d->tracks,
 497                         (int)d->sectors, (int)d->bytes_per_sector,
 498                         d->read_only ? " (RO)" : "");
 499
 500         /* register us in the global list */
 501         add_disk(g);
 502         return 1;
 503 }
 504
 505 /* returns the total number of scatterlist elements converted */
 506 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
 507                 struct scatterlist *sg, int *total_len)
 508 {
 509         int i, numsg;
 510         const struct rw_data *rw_data = &bevent->u.rw_data;
 511         static const int offset =
 512                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
 513         static const int element_size = sizeof(rw_data->dma_info[0]);
 514
 515         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
 516         if (numsg > VIOMAXBLOCKDMA)
 517                 numsg = VIOMAXBLOCKDMA;
 518
 519         *total_len = 0;
 520         sg_init_table(sg, VIOMAXBLOCKDMA);
 521         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
 522                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
 523                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
 524                 *total_len += rw_data->dma_info[i].len;
 525         }
 526         return i;
 527 }
 528
 529 /*
 530  * Restart all queues, starting with the one _after_ the disk given,
 531  * thus reducing the chance of starvation of higher numbered disks.
 532  */
 533 static void viodasd_restart_all_queues_starting_from(int first_index)
 534 {
 535         int i;
 536
 537         for (i = first_index + 1; i < MAX_DISKNO; ++i)
 538                 if (viodasd_devices[i].disk)
 539                         blk_run_queue(viodasd_devices[i].disk->queue);
 540         for (i = 0; i <= first_index; ++i)
 541                 if (viodasd_devices[i].disk)
 542                         blk_run_queue(viodasd_devices[i].disk->queue);
 543 }
 544
 545 /*
 546  * For read and write requests, decrement the number of outstanding requests,
 547  * Free the DMA buffers we allocated.
 548  */
 549 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
 550 {
 551         int num_sg, num_sect, pci_direction, total_len;
 552         struct request *req;
 553         struct scatterlist sg[VIOMAXBLOCKDMA];
 554         struct HvLpEvent *event = &bevent->event;
 555         unsigned long irq_flags;
 556         struct viodasd_device *d;
 557         int error;
 558         spinlock_t *qlock;
 559
 560         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
 561         num_sect = total_len >> 9;
 562         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
 563                 pci_direction = DMA_FROM_DEVICE;
 564         else
 565                 pci_direction = DMA_TO_DEVICE;
 566         req = (struct request *)bevent->event.xCorrelationToken;
 567         d = req->rq_disk->private_data;
 568
 569         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
 570
 571         /*
 572          * Since this is running in interrupt mode, we need to make sure
 573          * we're not stepping on any global I/O operations
 574          */
 575         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
 576         num_req_outstanding--;
 577         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
 578
 579         error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO;
 580         if (error) {
 581                 const struct vio_error_entry *err;
 582                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
 583                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
 584                                 event->xRc, bevent->sub_result, err->msg);
 585                 num_sect = blk_rq_sectors(req);
 586         }
 587         qlock = req->q->queue_lock;
 588         spin_lock_irqsave(qlock, irq_flags);
 589         viodasd_end_request(req, error, num_sect);
 590         spin_unlock_irqrestore(qlock, irq_flags);
 591
 592         /* Finally, try to get more requests off of this device's queue */
 593         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
 594
 595         return 0;
 596 }
 597
 598 /* This routine handles incoming block LP events */
 599 static void handle_block_event(struct HvLpEvent *event)
 600 {
 601         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
 602         struct viodasd_waitevent *pwe;
 603
 604         if (event == NULL)
 605                 /* Notification that a partition went away! */
 606                 return;
 607         /* First, we should NEVER get an int here...only acks */
 608         if (hvlpevent_is_int(event)) {
 609                 printk(VIOD_KERN_WARNING
 610                        "Yikes! got an int in viodasd event handler!\n");
 611                 if (hvlpevent_need_ack(event)) {
 612                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 613                         HvCallEvent_ackLpEvent(event);
 614                 }
 615         }
 616
 617         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
 618         case vioblockopen:
 619                 /*
 620                  * Handle a response to an open request.  We get all the
 621                  * disk information in the response, so update it.  The
 622                  * correlation token contains a pointer to a waitevent
 623                  * structure that has a completion in it.  update the
 624                  * return code in the waitevent structure and post the
 625                  * completion to wake up the guy who sent the request
 626                  */
 627                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
 628                 pwe->rc = event->xRc;
 629                 pwe->sub_result = bevent->sub_result;
 630                 if (event->xRc == HvLpEvent_Rc_Good) {
 631                         const struct open_data *data = &bevent->u.open_data;
 632                         struct viodasd_device *device =
 633                                 &viodasd_devices[bevent->disk];
 634                         device->read_only =
 635                                 bevent->flags & vioblockflags_ro;
 636                         device->size = data->disk_size;
 637                         device->cylinders = data->cylinders;
 638                         device->tracks = data->tracks;
 639                         device->sectors = data->sectors;
 640                         device->bytes_per_sector = data->bytes_per_sector;
 641                         pwe->max_disk = data->max_disk;
 642                 }
 643                 complete(&pwe->com);
 644                 break;
 645         case vioblockclose:
 646                 break;
 647         case vioblockread:
 648         case vioblockwrite:
 649                 viodasd_handle_read_write(bevent);
 650                 break;
 651
 652         default:
 653                 printk(VIOD_KERN_WARNING "invalid subtype!");
 654                 if (hvlpevent_need_ack(event)) {
 655                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 656                         HvCallEvent_ackLpEvent(event);
 657                 }
 658         }
 659 }
 660
 661 /*
 662  * Get the driver to reprobe for more disks.
 663  */
 664 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
 665                 size_t count)
 666 {
 667         struct viodasd_device *d;
 668
 669         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
 670                 if (d->disk == NULL)
 671                         probe_disk(d);
 672         }
 673         return count;
 674 }
 675 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
 676
 677 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 678 {
 679         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
 680
 681         d->dev = &vdev->dev;
 682         if (!probe_disk(d))
 683                 return -ENODEV;
 684         return 0;
 685 }
 686
 687 static int viodasd_remove(struct vio_dev *vdev)
 688 {
 689         struct viodasd_device *d;
 690
 691         d = &viodasd_devices[vdev->unit_address];
 692         if (d->disk) {
 693                 del_gendisk(d->disk);
 694                 blk_cleanup_queue(d->disk->queue);
 695                 put_disk(d->disk);
 696                 d->disk = NULL;
 697         }
 698         d->dev = NULL;
 699         return 0;
 700 }
 701
 702 /**
 703  * viodasd_device_table: Used by vio.c to match devices that we
 704  * support.
 705  */
 706 static struct vio_device_id viodasd_device_table[] __devinitdata = {
 707         { "block", "IBM,iSeries-viodasd" },
 708         { "", "" }
 709 };
 710 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
 711
 712 static struct vio_driver viodasd_driver = {
 713         .id_table = viodasd_device_table,
 714         .probe = viodasd_probe,
 715         .remove = viodasd_remove,
 716         .driver = {
 717                 .name = "viodasd",
 718                 .owner = THIS_MODULE,
 719         }
 720 };
 721
 722 static int need_delete_probe;
 723
 724 /*
 725  * Initialize the whole device driver.  Handle module and non-module
 726  * versions
 727  */
 728 static int __init viodasd_init(void)
 729 {
 730         int rc;
 731
 732         if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
 733                 rc = -ENODEV;
 734                 goto early_fail;
 735         }
 736
 737         /* Try to open to our host lp */
 738         if (viopath_hostLp == HvLpIndexInvalid)
 739                 vio_set_hostlp();
 740
 741         if (viopath_hostLp == HvLpIndexInvalid) {
 742                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
 743                 rc = -EIO;
 744                 goto early_fail;
 745         }
 746
 747         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
 748                         viopath_hostLp);
 749
 750         /* register the block device */
 751         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 752         if (rc) {
 753                 printk(VIOD_KERN_WARNING
 754                                 "Unable to get major number %d for %s\n",
 755                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
 756                 goto early_fail;
 757         }
 758         /* Actually open the path to the hosting partition */
 759         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
 760                                 VIOMAXREQ + 2);
 761         if (rc) {
 762                 printk(VIOD_KERN_WARNING
 763                        "error opening path to host partition %d\n",
 764                        viopath_hostLp);
 765                 goto unregister_blk;
 766         }
 767
 768         /* Initialize our request handler */
 769         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
 770
 771         rc = vio_register_driver(&viodasd_driver);
 772         if (rc) {
 773                 printk(VIOD_KERN_WARNING "vio_register_driver failed\n");
 774                 goto unset_handler;
 775         }
 776
 777         /*
 778          * If this call fails, it just means that we cannot dynamically
 779          * add virtual disks, but the driver will still work fine for
 780          * all existing disk, so ignore the failure.
 781          */
 782         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
 783                 need_delete_probe = 1;
 784
 785         return 0;
 786
 787 unset_handler:
 788         vio_clearHandler(viomajorsubtype_blockio);
 789         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 790 unregister_blk:
 791         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 792 early_fail:
 793         return rc;
 794 }
 795 module_init(viodasd_init);
 796
 797 void __exit viodasd_exit(void)
 798 {
 799         if (need_delete_probe)
 800                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
 801         vio_unregister_driver(&viodasd_driver);
 802         vio_clearHandler(viomajorsubtype_blockio);
 803         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
 804         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 805 }
 806 module_exit(viodasd_exit);