drivers/scsi/ibmvscsi/ibmvscsi.c

   1 /* ------------------------------------------------------------
   2  * ibmvscsi.c
   3  * (C) Copyright IBM Corporation 1994, 2004
   4  * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
   5  *          Santiago Leon (santil@us.ibm.com)
   6  *          Dave Boutcher (sleddog@us.ibm.com)
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
  21  * USA
  22  *
  23  * ------------------------------------------------------------
  24  * Emulation of a SCSI host adapter for Virtual I/O devices
  25  *
  26  * This driver supports the SCSI adapter implemented by the IBM
  27  * Power5 firmware.  That SCSI adapter is not a physical adapter,
  28  * but allows Linux SCSI peripheral drivers to directly
  29  * access devices in another logical partition on the physical system.
  30  *
  31  * The virtual adapter(s) are present in the open firmware device
  32  * tree just like real adapters.
  33  *
  34  * One of the capabilities provided on these systems is the ability
  35  * to DMA between partitions.  The architecture states that for VSCSI,
  36  * the server side is allowed to DMA to and from the client.  The client
  37  * is never trusted to DMA to or from the server directly.
  38  *
  39  * Messages are sent between partitions on a "Command/Response Queue"
  40  * (CRQ), which is just a buffer of 16 byte entries in the receiver's
  41  * Senders cannot access the buffer directly, but send messages by
  42  * making a hypervisor call and passing in the 16 bytes.  The hypervisor
  43  * puts the message in the next 16 byte space in round-robbin fashion,
  44  * turns on the high order bit of the message (the valid bit), and
  45  * generates an interrupt to the receiver (if interrupts are turned on.)
  46  * The receiver just turns off the valid bit when they have copied out
  47  * the message.
  48  *
  49  * The VSCSI client builds a SCSI Remote Protocol (SRP) Information Unit
  50  * (IU) (as defined in the T10 standard available at www.t10.org), gets
  51  * a DMA address for the message, and sends it to the server as the
  52  * payload of a CRQ message.  The server DMAs the SRP IU and processes it,
  53  * including doing any additional data transfers.  When it is done, it
  54  * DMAs the SRP response back to the same address as the request came from,
  55  * and sends a CRQ message back to inform the client that the request has
  56  * completed.
  57  *
  58  * Note that some of the underlying infrastructure is different between
  59  * machines conforming to the "RS/6000 Platform Architecture" (RPA) and
  60  * the older iSeries hypervisor models.  To support both, some low level
  61  * routines have been broken out into rpa_vscsi.c and iseries_vscsi.c.
  62  * The Makefile should pick one, not two, not zero, of these.
  63  *
  64  * TODO: This is currently pretty tied to the IBM i/pSeries hypervisor
  65  * interfaces.  It would be really nice to abstract this above an RDMA
  66  * layer.
  67  */
  68
  69 #include <linux/module.h>
  70 #include <linux/moduleparam.h>
  71 #include <linux/dma-mapping.h>
  72 #include <linux/delay.h>
  73 #include <asm/vio.h>
  74 #include <scsi/scsi.h>
  75 #include <scsi/scsi_cmnd.h>
  76 #include <scsi/scsi_host.h>
  77 #include <scsi/scsi_device.h>
  78 #include "ibmvscsi.h"
  79
  80 /* The values below are somewhat arbitrary default values, but
  81  * OS/400 will use 3 busses (disks, CDs, tapes, I think.)
  82  * Note that there are 3 bits of channel value, 6 bits of id, and
  83  * 5 bits of LUN.
  84  */
  85 static int max_id = 64;
  86 static int max_channel = 3;
  87 static int init_timeout = 5;
  88 static int max_requests = 50;
  89
  90 #define IBMVSCSI_VERSION "1.5.6"
  91
  92 MODULE_DESCRIPTION("IBM Virtual SCSI");
  93 MODULE_AUTHOR("Dave Boutcher");
  94 MODULE_LICENSE("GPL");
  95 MODULE_VERSION(IBMVSCSI_VERSION);
  96
  97 module_param_named(max_id, max_id, int, S_IRUGO | S_IWUSR);
  98 MODULE_PARM_DESC(max_id, "Largest ID value for each channel");
  99 module_param_named(max_channel, max_channel, int, S_IRUGO | S_IWUSR);
 100 MODULE_PARM_DESC(max_channel, "Largest channel value");
 101 module_param_named(init_timeout, init_timeout, int, S_IRUGO | S_IWUSR);
 102 MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds");
 103 module_param_named(max_requests, max_requests, int, S_IRUGO | S_IWUSR);
 104 MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
 105
 106 /* ------------------------------------------------------------
 107  * Routines for the event pool and event structs
 108  */
 109 /**
 110  * initialize_event_pool: - Allocates and initializes the event pool for a host
 111  * @pool:       event_pool to be initialized
 112  * @size:       Number of events in pool
 113  * @hostdata:   ibmvscsi_host_data who owns the event pool
 114  *
 115  * Returns zero on success.
 116 */
 117 static int initialize_event_pool(struct event_pool *pool,
 118                                  int size, struct ibmvscsi_host_data *hostdata)
 119 {
 120         int i;
 121
 122         pool->size = size;
 123         pool->next = 0;
 124         pool->events = kmalloc(pool->size * sizeof(*pool->events), GFP_KERNEL);
 125         if (!pool->events)
 126                 return -ENOMEM;
 127         memset(pool->events, 0x00, pool->size * sizeof(*pool->events));
 128
 129         pool->iu_storage =
 130             dma_alloc_coherent(hostdata->dev,
 131                                pool->size * sizeof(*pool->iu_storage),
 132                                &pool->iu_token, 0);
 133         if (!pool->iu_storage) {
 134                 kfree(pool->events);
 135                 return -ENOMEM;
 136         }
 137
 138         for (i = 0; i < pool->size; ++i) {
 139                 struct srp_event_struct *evt = &pool->events[i];
 140                 memset(&evt->crq, 0x00, sizeof(evt->crq));
 141                 atomic_set(&evt->free, 1);
 142                 evt->crq.valid = 0x80;
 143                 evt->crq.IU_length = sizeof(*evt->xfer_iu);
 144                 evt->crq.IU_data_ptr = pool->iu_token +
 145                         sizeof(*evt->xfer_iu) * i;
 146                 evt->xfer_iu = pool->iu_storage + i;
 147                 evt->hostdata = hostdata;
 148         }
 149
 150         return 0;
 151 }
 152
 153 /**
 154  * release_event_pool: - Frees memory of an event pool of a host
 155  * @pool:       event_pool to be released
 156  * @hostdata:   ibmvscsi_host_data who owns the even pool
 157  *
 158  * Returns zero on success.
 159 */
 160 static void release_event_pool(struct event_pool *pool,
 161                                struct ibmvscsi_host_data *hostdata)
 162 {
 163         int i, in_use = 0;
 164         for (i = 0; i < pool->size; ++i)
 165                 if (atomic_read(&pool->events[i].free) != 1)
 166                         ++in_use;
 167         if (in_use)
 168                 printk(KERN_WARNING
 169                        "ibmvscsi: releasing event pool with %d "
 170                        "events still in use?\n", in_use);
 171         kfree(pool->events);
 172         dma_free_coherent(hostdata->dev,
 173                           pool->size * sizeof(*pool->iu_storage),
 174                           pool->iu_storage, pool->iu_token);
 175 }
 176
 177 /**
 178  * valid_event_struct: - Determines if event is valid.
 179  * @pool:       event_pool that contains the event
 180  * @evt:        srp_event_struct to be checked for validity
 181  *
 182  * Returns zero if event is invalid, one otherwise.
 183 */
 184 static int valid_event_struct(struct event_pool *pool,
 185                                 struct srp_event_struct *evt)
 186 {
 187         int index = evt - pool->events;
 188         if (index < 0 || index >= pool->size)   /* outside of bounds */
 189                 return 0;
 190         if (evt != pool->events + index)        /* unaligned */
 191                 return 0;
 192         return 1;
 193 }
 194
 195 /**
 196  * ibmvscsi_free-event_struct: - Changes status of event to "free"
 197  * @pool:       event_pool that contains the event
 198  * @evt:        srp_event_struct to be modified
 199  *
 200 */
 201 static void free_event_struct(struct event_pool *pool,
 202                                        struct srp_event_struct *evt)
 203 {
 204         if (!valid_event_struct(pool, evt)) {
 205                 printk(KERN_ERR
 206                        "ibmvscsi: Freeing invalid event_struct %p "
 207                        "(not in pool %p)\n", evt, pool->events);
 208                 return;
 209         }
 210         if (atomic_inc_return(&evt->free) != 1) {
 211                 printk(KERN_ERR
 212                        "ibmvscsi: Freeing event_struct %p "
 213                        "which is not in use!\n", evt);
 214                 return;
 215         }
 216 }
 217
 218 /**
 219  * get_evt_struct: - Gets the next free event in pool
 220  * @pool:       event_pool that contains the events to be searched
 221  *
 222  * Returns the next event in "free" state, and NULL if none are free.
 223  * Note that no synchronization is done here, we assume the host_lock
 224  * will syncrhonze things.
 225 */
 226 static struct srp_event_struct *get_event_struct(struct event_pool *pool)
 227 {
 228         int i;
 229         int poolsize = pool->size;
 230         int offset = pool->next;
 231
 232         for (i = 0; i < poolsize; i++) {
 233                 offset = (offset + 1) % poolsize;
 234                 if (!atomic_dec_if_positive(&pool->events[offset].free)) {
 235                         pool->next = offset;
 236                         return &pool->events[offset];
 237                 }
 238         }
 239
 240         printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
 241         return NULL;
 242 }
 243
 244 /**
 245  * init_event_struct: Initialize fields in an event struct that are always
 246  *                    required.
 247  * @evt:        The event
 248  * @done:       Routine to call when the event is responded to
 249  * @format:     SRP or MAD format
 250  * @timeout:    timeout value set in the CRQ
 251  */
 252 static void init_event_struct(struct srp_event_struct *evt_struct,
 253                               void (*done) (struct srp_event_struct *),
 254                               u8 format,
 255                               int timeout)
 256 {
 257         evt_struct->cmnd = NULL;
 258         evt_struct->cmnd_done = NULL;
 259         evt_struct->sync_srp = NULL;
 260         evt_struct->crq.format = format;
 261         evt_struct->crq.timeout = timeout;
 262         evt_struct->done = done;
 263 }
 264
 265 /* ------------------------------------------------------------
 266  * Routines for receiving SCSI responses from the hosting partition
 267  */
 268
 269 /**
 270  * set_srp_direction: Set the fields in the srp related to data
 271  *     direction and number of buffers based on the direction in
 272  *     the scsi_cmnd and the number of buffers
 273  */
 274 static void set_srp_direction(struct scsi_cmnd *cmd,
 275                               struct srp_cmd *srp_cmd,
 276                               int numbuf)
 277 {
 278         if (numbuf == 0)
 279                 return;
 280
 281         if (numbuf == 1) {
 282                 if (cmd->sc_data_direction == DMA_TO_DEVICE)
 283                         srp_cmd->data_out_format = SRP_DIRECT_BUFFER;
 284                 else
 285                         srp_cmd->data_in_format = SRP_DIRECT_BUFFER;
 286         } else {
 287                 if (cmd->sc_data_direction == DMA_TO_DEVICE) {
 288                         srp_cmd->data_out_format = SRP_INDIRECT_BUFFER;
 289                         srp_cmd->data_out_count = numbuf;
 290                 } else {
 291                         srp_cmd->data_in_format = SRP_INDIRECT_BUFFER;
 292                         srp_cmd->data_in_count = numbuf;
 293                 }
 294         }
 295 }
 296
 297 /**
 298  * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
 299  * @cmd:        srp_cmd whose additional_data member will be unmapped
 300  * @dev:        device for which the memory is mapped
 301  *
 302 */
 303 static void unmap_cmd_data(struct srp_cmd *cmd, struct device *dev)
 304 {
 305         int i;
 306
 307         if ((cmd->data_out_format == SRP_NO_BUFFER) &&
 308             (cmd->data_in_format == SRP_NO_BUFFER))
 309                 return;
 310         else if ((cmd->data_out_format == SRP_DIRECT_BUFFER) ||
 311                  (cmd->data_in_format == SRP_DIRECT_BUFFER)) {
 312                 struct memory_descriptor *data =
 313                         (struct memory_descriptor *)cmd->additional_data;
 314                 dma_unmap_single(dev, data->virtual_address, data->length,
 315                                  DMA_BIDIRECTIONAL);
 316         } else {
 317                 struct indirect_descriptor *indirect =
 318                         (struct indirect_descriptor *)cmd->additional_data;
 319                 int num_mapped = indirect->head.length /
 320                         sizeof(indirect->list[0]);
 321                 for (i = 0; i < num_mapped; ++i) {
 322                         struct memory_descriptor *data = &indirect->list[i];
 323                         dma_unmap_single(dev,
 324                                          data->virtual_address,
 325                                          data->length, DMA_BIDIRECTIONAL);
 326                 }
 327         }
 328 }
 329
 330 /**
 331  * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
 332  * @cmd:        Scsi_Cmnd with the scatterlist
 333  * @srp_cmd:    srp_cmd that contains the memory descriptor
 334  * @dev:        device for which to map dma memory
 335  *
 336  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
 337  * Returns 1 on success.
 338 */
 339 static int map_sg_data(struct scsi_cmnd *cmd,
 340                        struct srp_cmd *srp_cmd, struct device *dev)
 341 {
 342
 343         int i, sg_mapped;
 344         u64 total_length = 0;
 345         struct scatterlist *sg = cmd->request_buffer;
 346         struct memory_descriptor *data =
 347             (struct memory_descriptor *)srp_cmd->additional_data;
 348         struct indirect_descriptor *indirect =
 349             (struct indirect_descriptor *)data;
 350
 351         sg_mapped = dma_map_sg(dev, sg, cmd->use_sg, DMA_BIDIRECTIONAL);
 352
 353         if (sg_mapped == 0)
 354                 return 0;
 355
 356         set_srp_direction(cmd, srp_cmd, sg_mapped);
 357
 358         /* special case; we can use a single direct descriptor */
 359         if (sg_mapped == 1) {
 360                 data->virtual_address = sg_dma_address(&sg[0]);
 361                 data->length = sg_dma_len(&sg[0]);
 362                 data->memory_handle = 0;
 363                 return 1;
 364         }
 365
 366         if (sg_mapped > MAX_INDIRECT_BUFS) {
 367                 printk(KERN_ERR
 368                        "ibmvscsi: More than %d mapped sg entries, got %d\n",
 369                        MAX_INDIRECT_BUFS, sg_mapped);
 370                 return 0;
 371         }
 372
 373         indirect->head.virtual_address = 0;
 374         indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
 375         indirect->head.memory_handle = 0;
 376         for (i = 0; i < sg_mapped; ++i) {
 377                 struct memory_descriptor *descr = &indirect->list[i];
 378                 struct scatterlist *sg_entry = &sg[i];
 379                 descr->virtual_address = sg_dma_address(sg_entry);
 380                 descr->length = sg_dma_len(sg_entry);
 381                 descr->memory_handle = 0;
 382                 total_length += sg_dma_len(sg_entry);
 383         }
 384         indirect->total_length = total_length;
 385
 386         return 1;
 387 }
 388
 389 /**
 390  * map_single_data: - Maps memory and initializes memory decriptor fields
 391  * @cmd:        struct scsi_cmnd with the memory to be mapped
 392  * @srp_cmd:    srp_cmd that contains the memory descriptor
 393  * @dev:        device for which to map dma memory
 394  *
 395  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
 396  * Returns 1 on success.
 397 */
 398 static int map_single_data(struct scsi_cmnd *cmd,
 399                            struct srp_cmd *srp_cmd, struct device *dev)
 400 {
 401         struct memory_descriptor *data =
 402             (struct memory_descriptor *)srp_cmd->additional_data;
 403
 404         data->virtual_address =
 405                 dma_map_single(dev, cmd->request_buffer,
 406                                cmd->request_bufflen,
 407                                DMA_BIDIRECTIONAL);
 408         if (dma_mapping_error(data->virtual_address)) {
 409                 printk(KERN_ERR
 410                        "ibmvscsi: Unable to map request_buffer for command!\n");
 411                 return 0;
 412         }
 413         data->length = cmd->request_bufflen;
 414         data->memory_handle = 0;
 415
 416         set_srp_direction(cmd, srp_cmd, 1);
 417
 418         return 1;
 419 }
 420
 421 /**
 422  * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
 423  * @cmd:        struct scsi_cmnd with the memory to be mapped
 424  * @srp_cmd:    srp_cmd that contains the memory descriptor
 425  * @dev:        dma device for which to map dma memory
 426  *
 427  * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds
 428  * Returns 1 on success.
 429 */
 430 static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
 431                                 struct srp_cmd *srp_cmd, struct device *dev)
 432 {
 433         switch (cmd->sc_data_direction) {
 434         case DMA_FROM_DEVICE:
 435         case DMA_TO_DEVICE:
 436                 break;
 437         case DMA_NONE:
 438                 return 1;
 439         case DMA_BIDIRECTIONAL:
 440                 printk(KERN_ERR
 441                        "ibmvscsi: Can't map DMA_BIDIRECTIONAL to read/write\n");
 442                 return 0;
 443         default:
 444                 printk(KERN_ERR
 445                        "ibmvscsi: Unknown data direction 0x%02x; can't map!\n",
 446                        cmd->sc_data_direction);
 447                 return 0;
 448         }
 449
 450         if (!cmd->request_buffer)
 451                 return 1;
 452         if (cmd->use_sg)
 453                 return map_sg_data(cmd, srp_cmd, dev);
 454         return map_single_data(cmd, srp_cmd, dev);
 455 }
 456
 457 /* ------------------------------------------------------------
 458  * Routines for sending and receiving SRPs
 459  */
 460 /**
 461  * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
 462  * @evt_struct: evt_struct to be sent
 463  * @hostdata:   ibmvscsi_host_data of host
 464  *
 465  * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
 466  * Note that this routine assumes that host_lock is held for synchronization
 467 */
 468 static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
 469                                    struct ibmvscsi_host_data *hostdata)
 470 {
 471         struct scsi_cmnd *cmnd;
 472         u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
 473         int rc;
 474
 475         /* If we have exhausted our request limit, just fail this request.
 476          * Note that there are rare cases involving driver generated requests
 477          * (such as task management requests) that the mid layer may think we
 478          * can handle more requests (can_queue) when we actually can't
 479          */
 480         if ((evt_struct->crq.format == VIOSRP_SRP_FORMAT) &&
 481             (atomic_dec_if_positive(&hostdata->request_limit) < 0)) {
 482                 /* See if the adapter is disabled */
 483                 if (atomic_read(&hostdata->request_limit) < 0)
 484                         goto send_error;
 485
 486                 printk(KERN_WARNING
 487                        "ibmvscsi: Warning, request_limit exceeded\n");
 488                 unmap_cmd_data(&evt_struct->iu.srp.cmd,
 489                                hostdata->dev);
 490                 free_event_struct(&hostdata->pool, evt_struct);
 491                 return SCSI_MLQUEUE_HOST_BUSY;
 492         }
 493
 494         /* Copy the IU into the transfer area */
 495         *evt_struct->xfer_iu = evt_struct->iu;
 496         evt_struct->xfer_iu->srp.generic.tag = (u64)evt_struct;
 497
 498         /* Add this to the sent list.  We need to do this
 499          * before we actually send
 500          * in case it comes back REALLY fast
 501          */
 502         list_add_tail(&evt_struct->list, &hostdata->sent);
 503
 504         if ((rc =
 505              ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
 506                 list_del(&evt_struct->list);
 507
 508                 printk(KERN_ERR "ibmvscsi: failed to send event struct rc %d\n",
 509                        rc);
 510                 goto send_error;
 511         }
 512
 513         return 0;
 514
 515  send_error:
 516         unmap_cmd_data(&evt_struct->iu.srp.cmd, hostdata->dev);
 517
 518         if ((cmnd = evt_struct->cmnd) != NULL) {
 519                 cmnd->result = DID_ERROR << 16;
 520                 evt_struct->cmnd_done(cmnd);
 521         } else if (evt_struct->done)
 522                 evt_struct->done(evt_struct);
 523
 524         free_event_struct(&hostdata->pool, evt_struct);
 525         return 0;
 526 }
 527
 528 /**
 529  * handle_cmd_rsp: -  Handle responses from commands
 530  * @evt_struct: srp_event_struct to be handled
 531  *
 532  * Used as a callback by when sending scsi cmds.
 533  * Gets called by ibmvscsi_handle_crq()
 534 */
 535 static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
 536 {
 537         struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
 538         struct scsi_cmnd *cmnd = evt_struct->cmnd;
 539
 540         if (unlikely(rsp->type != SRP_RSP_TYPE)) {
 541                 if (printk_ratelimit())
 542                         printk(KERN_WARNING
 543                                "ibmvscsi: bad SRP RSP type %d\n",
 544                                rsp->type);
 545         }
 546
 547         if (cmnd) {
 548                 cmnd->result = rsp->status;
 549                 if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
 550                         memcpy(cmnd->sense_buffer,
 551                                rsp->sense_and_response_data,
 552                                rsp->sense_data_list_length);
 553                 unmap_cmd_data(&evt_struct->iu.srp.cmd,
 554                                evt_struct->hostdata->dev);
 555
 556                 if (rsp->doover)
 557                         cmnd->resid = rsp->data_out_residual_count;
 558                 else if (rsp->diover)
 559                         cmnd->resid = rsp->data_in_residual_count;
 560         }
 561
 562         if (evt_struct->cmnd_done)
 563                 evt_struct->cmnd_done(cmnd);
 564 }
 565
 566 /**
 567  * lun_from_dev: - Returns the lun of the scsi device
 568  * @dev:        struct scsi_device
 569  *
 570 */
 571 static inline u16 lun_from_dev(struct scsi_device *dev)
 572 {
 573         return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
 574 }
 575
 576 /**
 577  * ibmvscsi_queue: - The queuecommand function of the scsi template
 578  * @cmd:        struct scsi_cmnd to be executed
 579  * @done:       Callback function to be called when cmd is completed
 580 */
 581 static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
 582                                  void (*done) (struct scsi_cmnd *))
 583 {
 584         struct srp_cmd *srp_cmd;
 585         struct srp_event_struct *evt_struct;
 586         struct ibmvscsi_host_data *hostdata =
 587                 (struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
 588         u16 lun = lun_from_dev(cmnd->device);
 589
 590         evt_struct = get_event_struct(&hostdata->pool);
 591         if (!evt_struct)
 592                 return SCSI_MLQUEUE_HOST_BUSY;
 593
 594         init_event_struct(evt_struct,
 595                           handle_cmd_rsp,
 596                           VIOSRP_SRP_FORMAT,
 597                           cmnd->timeout);
 598
 599         evt_struct->cmnd = cmnd;
 600         evt_struct->cmnd_done = done;
 601
 602         /* Set up the actual SRP IU */
 603         srp_cmd = &evt_struct->iu.srp.cmd;
 604         memset(srp_cmd, 0x00, sizeof(*srp_cmd));
 605         srp_cmd->type = SRP_CMD_TYPE;
 606         memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
 607         srp_cmd->lun = ((u64) lun) << 48;
 608
 609         if (!map_data_for_srp_cmd(cmnd, srp_cmd, hostdata->dev)) {
 610                 printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
 611                 free_event_struct(&hostdata->pool, evt_struct);
 612                 return SCSI_MLQUEUE_HOST_BUSY;
 613         }
 614
 615         /* Fix up dma address of the buffer itself */
 616         if ((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
 617             (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) {
 618                 struct indirect_descriptor *indirect =
 619                     (struct indirect_descriptor *)srp_cmd->additional_data;
 620                 indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
 621                     offsetof(struct srp_cmd, additional_data) +
 622                     offsetof(struct indirect_descriptor, list);
 623         }
 624
 625         return ibmvscsi_send_srp_event(evt_struct, hostdata);
 626 }
 627
 628 /* ------------------------------------------------------------
 629  * Routines for driver initialization
 630  */
 631 /**
 632  * adapter_info_rsp: - Handle response to MAD adapter info request
 633  * @evt_struct: srp_event_struct with the response
 634  *
 635  * Used as a "done" callback by when sending adapter_info. Gets called
 636  * by ibmvscsi_handle_crq()
 637 */
 638 static void adapter_info_rsp(struct srp_event_struct *evt_struct)
 639 {
 640         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
 641         dma_unmap_single(hostdata->dev,
 642                          evt_struct->iu.mad.adapter_info.buffer,
 643                          evt_struct->iu.mad.adapter_info.common.length,
 644                          DMA_BIDIRECTIONAL);
 645
 646         if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
 647                 printk("ibmvscsi: error %d getting adapter info\n",
 648                        evt_struct->xfer_iu->mad.adapter_info.common.status);
 649         } else {
 650                 printk("ibmvscsi: host srp version: %s, "
 651                        "host partition %s (%d), OS %d, max io %u\n",
 652                        hostdata->madapter_info.srp_version,
 653                        hostdata->madapter_info.partition_name,
 654                        hostdata->madapter_info.partition_number,
 655                        hostdata->madapter_info.os_type,
 656                        hostdata->madapter_info.port_max_txu[0]);
 657
 658                 if (hostdata->madapter_info.port_max_txu[0])
 659                         hostdata->host->max_sectors =
 660                                 hostdata->madapter_info.port_max_txu[0] >> 9;
 661         }
 662 }
 663
 664 /**
 665  * send_mad_adapter_info: - Sends the mad adapter info request
 666  *      and stores the result so it can be retrieved with
 667  *      sysfs.  We COULD consider causing a failure if the
 668  *      returned SRP version doesn't match ours.
 669  * @hostdata:   ibmvscsi_host_data of host
 670  *
 671  * Returns zero if successful.
 672 */
 673 static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
 674 {
 675         struct viosrp_adapter_info *req;
 676         struct srp_event_struct *evt_struct;
 677
 678         evt_struct = get_event_struct(&hostdata->pool);
 679         if (!evt_struct) {
 680                 printk(KERN_ERR "ibmvscsi: couldn't allocate an event "
 681                        "for ADAPTER_INFO_REQ!\n");
 682                 return;
 683         }
 684
 685         init_event_struct(evt_struct,
 686                           adapter_info_rsp,
 687                           VIOSRP_MAD_FORMAT,
 688                           init_timeout * HZ);
 689
 690         req = &evt_struct->iu.mad.adapter_info;
 691         memset(req, 0x00, sizeof(*req));
 692
 693         req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
 694         req->common.length = sizeof(hostdata->madapter_info);
 695         req->buffer = dma_map_single(hostdata->dev,
 696                                      &hostdata->madapter_info,
 697                                      sizeof(hostdata->madapter_info),
 698                                      DMA_BIDIRECTIONAL);
 699
 700         if (dma_mapping_error(req->buffer)) {
 701                 printk(KERN_ERR
 702                        "ibmvscsi: Unable to map request_buffer "
 703                        "for adapter_info!\n");
 704                 free_event_struct(&hostdata->pool, evt_struct);
 705                 return;
 706         }
 707
 708         if (ibmvscsi_send_srp_event(evt_struct, hostdata))
 709                 printk(KERN_ERR "ibmvscsi: couldn't send ADAPTER_INFO_REQ!\n");
 710 };
 711
 712 /**
 713  * login_rsp: - Handle response to SRP login request
 714  * @evt_struct: srp_event_struct with the response
 715  *
 716  * Used as a "done" callback by when sending srp_login. Gets called
 717  * by ibmvscsi_handle_crq()
 718 */
 719 static void login_rsp(struct srp_event_struct *evt_struct)
 720 {
 721         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
 722         switch (evt_struct->xfer_iu->srp.generic.type) {
 723         case SRP_LOGIN_RSP_TYPE:        /* it worked! */
 724                 break;
 725         case SRP_LOGIN_REJ_TYPE:        /* refused! */
 726                 printk(KERN_INFO "ibmvscsi: SRP_LOGIN_REQ rejected\n");
 727                 /* Login failed.  */
 728                 atomic_set(&hostdata->request_limit, -1);
 729                 return;
 730         default:
 731                 printk(KERN_ERR
 732                        "ibmvscsi: Invalid login response typecode 0x%02x!\n",
 733                        evt_struct->xfer_iu->srp.generic.type);
 734                 /* Login failed.  */
 735                 atomic_set(&hostdata->request_limit, -1);
 736                 return;
 737         }
 738
 739         printk(KERN_INFO "ibmvscsi: SRP_LOGIN succeeded\n");
 740
 741         if (evt_struct->xfer_iu->srp.login_rsp.request_limit_delta >
 742             (max_requests - 2))
 743                 evt_struct->xfer_iu->srp.login_rsp.request_limit_delta =
 744                     max_requests - 2;
 745
 746         /* Now we know what the real request-limit is */
 747         atomic_set(&hostdata->request_limit,
 748                    evt_struct->xfer_iu->srp.login_rsp.request_limit_delta);
 749
 750         hostdata->host->can_queue =
 751             evt_struct->xfer_iu->srp.login_rsp.request_limit_delta - 2;
 752
 753         if (hostdata->host->can_queue < 1) {
 754                 printk(KERN_ERR "ibmvscsi: Invalid request_limit_delta\n");
 755                 return;
 756         }
 757
 758         send_mad_adapter_info(hostdata);
 759         return;
 760 }
 761
 762 /**
 763  * send_srp_login: - Sends the srp login
 764  * @hostdata:   ibmvscsi_host_data of host
 765  *
 766  * Returns zero if successful.
 767 */
 768 static int send_srp_login(struct ibmvscsi_host_data *hostdata)
 769 {
 770         int rc;
 771         unsigned long flags;
 772         struct srp_login_req *login;
 773         struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
 774         if (!evt_struct) {
 775                 printk(KERN_ERR
 776                        "ibmvscsi: couldn't allocate an event for login req!\n");
 777                 return FAILED;
 778         }
 779
 780         init_event_struct(evt_struct,
 781                           login_rsp,
 782                           VIOSRP_SRP_FORMAT,
 783                           init_timeout * HZ);
 784
 785         login = &evt_struct->iu.srp.login_req;
 786         login->type = SRP_LOGIN_REQ_TYPE;
 787         login->max_requested_initiator_to_target_iulen = sizeof(union srp_iu);
 788         login->required_buffer_formats = 0x0006;
 789
 790         /* Start out with a request limit of 1, since this is negotiated in
 791          * the login request we are just sending
 792          */
 793         atomic_set(&hostdata->request_limit, 1);
 794
 795         spin_lock_irqsave(hostdata->host->host_lock, flags);
 796         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
 797         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 798         return rc;
 799 };
 800
 801 /**
 802  * sync_completion: Signal that a synchronous command has completed
 803  * Note that after returning from this call, the evt_struct is freed.
 804  * the caller waiting on this completion shouldn't touch the evt_struct
 805  * again.
 806  */
 807 static void sync_completion(struct srp_event_struct *evt_struct)
 808 {
 809         /* copy the response back */
 810         if (evt_struct->sync_srp)
 811                 *evt_struct->sync_srp = *evt_struct->xfer_iu;
 812
 813         complete(&evt_struct->comp);
 814 }
 815
 816 /**
 817  * ibmvscsi_abort: Abort a command...from scsi host template
 818  * send this over to the server and wait synchronously for the response
 819  */
 820 static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
 821 {
 822         struct ibmvscsi_host_data *hostdata =
 823             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
 824         struct srp_tsk_mgmt *tsk_mgmt;
 825         struct srp_event_struct *evt;
 826         struct srp_event_struct *tmp_evt, *found_evt;
 827         union viosrp_iu srp_rsp;
 828         int rsp_rc;
 829         u16 lun = lun_from_dev(cmd->device);
 830
 831         /* First, find this command in our sent list so we can figure
 832          * out the correct tag
 833          */
 834         found_evt = NULL;
 835         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
 836                 if (tmp_evt->cmnd == cmd) {
 837                         found_evt = tmp_evt;
 838                         break;
 839                 }
 840         }
 841
 842         if (!found_evt)
 843                 return FAILED;
 844
 845         evt = get_event_struct(&hostdata->pool);
 846         if (evt == NULL) {
 847                 printk(KERN_ERR "ibmvscsi: failed to allocate abort event\n");
 848                 return FAILED;
 849         }
 850
 851         init_event_struct(evt,
 852                           sync_completion,
 853                           VIOSRP_SRP_FORMAT,
 854                           init_timeout * HZ);
 855
 856         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
 857
 858         /* Set up an abort SRP command */
 859         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
 860         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
 861         tsk_mgmt->lun = ((u64) lun) << 48;
 862         tsk_mgmt->task_mgmt_flags = 0x01;       /* ABORT TASK */
 863         tsk_mgmt->managed_task_tag = (u64) found_evt;
 864
 865         printk(KERN_INFO "ibmvscsi: aborting command. lun 0x%lx, tag 0x%lx\n",
 866                tsk_mgmt->lun, tsk_mgmt->managed_task_tag);
 867
 868         evt->sync_srp = &srp_rsp;
 869         init_completion(&evt->comp);
 870         if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
 871                 printk(KERN_ERR "ibmvscsi: failed to send abort() event\n");
 872                 return FAILED;
 873         }
 874
 875         wait_for_completion(&evt->comp);
 876
 877         /* make sure we got a good response */
 878         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
 879                 if (printk_ratelimit())
 880                         printk(KERN_WARNING
 881                                "ibmvscsi: abort bad SRP RSP type %d\n",
 882                                srp_rsp.srp.generic.type);
 883                 return FAILED;
 884         }
 885
 886         if (srp_rsp.srp.rsp.rspvalid)
 887                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
 888         else
 889                 rsp_rc = srp_rsp.srp.rsp.status;
 890
 891         if (rsp_rc) {
 892                 if (printk_ratelimit())
 893                         printk(KERN_WARNING
 894                        "ibmvscsi: abort code %d for task tag 0x%lx\n",
 895                                rsp_rc,
 896                                tsk_mgmt->managed_task_tag);
 897                 return FAILED;
 898         }
 899
 900         /* Because we dropped the spinlock above, it's possible
 901          * The event is no longer in our list.  Make sure it didn't
 902          * complete while we were aborting
 903          */
 904         found_evt = NULL;
 905         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
 906                 if (tmp_evt->cmnd == cmd) {
 907                         found_evt = tmp_evt;
 908                         break;
 909                 }
 910         }
 911
 912         if (found_evt == NULL) {
 913                 printk(KERN_INFO
 914                        "ibmvscsi: aborted task tag 0x%lx completed\n",
 915                        tsk_mgmt->managed_task_tag);
 916                 return SUCCESS;
 917         }
 918
 919         printk(KERN_INFO
 920                "ibmvscsi: successfully aborted task tag 0x%lx\n",
 921                tsk_mgmt->managed_task_tag);
 922
 923         cmd->result = (DID_ABORT << 16);
 924         list_del(&found_evt->list);
 925         unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt->hostdata->dev);
 926         free_event_struct(&found_evt->hostdata->pool, found_evt);
 927         atomic_inc(&hostdata->request_limit);
 928         return SUCCESS;
 929 }
 930
 931 /**
 932  * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host
 933  * template send this over to the server and wait synchronously for the
 934  * response
 935  */
 936 static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
 937 {
 938         struct ibmvscsi_host_data *hostdata =
 939             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
 940
 941         struct srp_tsk_mgmt *tsk_mgmt;
 942         struct srp_event_struct *evt;
 943         struct srp_event_struct *tmp_evt, *pos;
 944         union viosrp_iu srp_rsp;
 945         int rsp_rc;
 946         u16 lun = lun_from_dev(cmd->device);
 947
 948         evt = get_event_struct(&hostdata->pool);
 949         if (evt == NULL) {
 950                 printk(KERN_ERR "ibmvscsi: failed to allocate reset event\n");
 951                 return FAILED;
 952         }
 953
 954         init_event_struct(evt,
 955                           sync_completion,
 956                           VIOSRP_SRP_FORMAT,
 957                           init_timeout * HZ);
 958
 959         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
 960
 961         /* Set up a lun reset SRP command */
 962         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
 963         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
 964         tsk_mgmt->lun = ((u64) lun) << 48;
 965         tsk_mgmt->task_mgmt_flags = 0x08;       /* LUN RESET */
 966
 967         printk(KERN_INFO "ibmvscsi: resetting device. lun 0x%lx\n",
 968                tsk_mgmt->lun);
 969
 970         evt->sync_srp = &srp_rsp;
 971         init_completion(&evt->comp);
 972         if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
 973                 printk(KERN_ERR "ibmvscsi: failed to send reset event\n");
 974                 return FAILED;
 975         }
 976
 977         wait_for_completion(&evt->comp);
 978
 979         /* make sure we got a good response */
 980         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
 981                 if (printk_ratelimit())
 982                         printk(KERN_WARNING
 983                                "ibmvscsi: reset bad SRP RSP type %d\n",
 984                                srp_rsp.srp.generic.type);
 985                 return FAILED;
 986         }
 987
 988         if (srp_rsp.srp.rsp.rspvalid)
 989                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
 990         else
 991                 rsp_rc = srp_rsp.srp.rsp.status;
 992
 993         if (rsp_rc) {
 994                 if (printk_ratelimit())
 995                         printk(KERN_WARNING
 996                                "ibmvscsi: reset code %d for task tag 0x%lx\n",
 997                        rsp_rc,
 998                                tsk_mgmt->managed_task_tag);
 999                 return FAILED;
1000         }
1001
1002         /* We need to find all commands for this LUN that have not yet been
1003          * responded to, and fail them with DID_RESET
1004          */
1005         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1006                 if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
1007                         if (tmp_evt->cmnd)
1008                                 tmp_evt->cmnd->result = (DID_RESET << 16);
1009                         list_del(&tmp_evt->list);
1010                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt->hostdata->dev);
1011                         free_event_struct(&tmp_evt->hostdata->pool,
1012                                                    tmp_evt);
1013                         atomic_inc(&hostdata->request_limit);
1014                         if (tmp_evt->cmnd_done)
1015                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1016                         else if (tmp_evt->done)
1017                                 tmp_evt->done(tmp_evt);
1018                 }
1019         }
1020         return SUCCESS;
1021 }
1022
1023 /**
1024  * purge_requests: Our virtual adapter just shut down.  purge any sent requests
1025  * @hostdata:    the adapter
1026  */
1027 static void purge_requests(struct ibmvscsi_host_data *hostdata)
1028 {
1029         struct srp_event_struct *tmp_evt, *pos;
1030         unsigned long flags;
1031
1032         spin_lock_irqsave(hostdata->host->host_lock, flags);
1033         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1034                 list_del(&tmp_evt->list);
1035                 if (tmp_evt->cmnd) {
1036                         tmp_evt->cmnd->result = (DID_ERROR << 16);
1037                         unmap_cmd_data(&tmp_evt->iu.srp.cmd,
1038                                        tmp_evt->hostdata->dev);
1039                         if (tmp_evt->cmnd_done)
1040                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1041                 } else {
1042                         if (tmp_evt->done) {
1043                                 tmp_evt->done(tmp_evt);
1044                         }
1045                 }
1046                 free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);
1047         }
1048         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1049 }
1050
1051 /**
1052  * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
1053  * @crq:        Command/Response queue
1054  * @hostdata:   ibmvscsi_host_data of host
1055  *
1056 */
1057 void ibmvscsi_handle_crq(struct viosrp_crq *crq,
1058                          struct ibmvscsi_host_data *hostdata)
1059 {
1060         unsigned long flags;
1061         struct srp_event_struct *evt_struct =
1062             (struct srp_event_struct *)crq->IU_data_ptr;
1063         switch (crq->valid) {
1064         case 0xC0:              /* initialization */
1065                 switch (crq->format) {
1066                 case 0x01:      /* Initialization message */
1067                         printk(KERN_INFO "ibmvscsi: partner initialized\n");
1068                         /* Send back a response */
1069                         if (ibmvscsi_send_crq(hostdata,
1070                                               0xC002000000000000LL, 0) == 0) {
1071                                 /* Now login */
1072                                 send_srp_login(hostdata);
1073                         } else {
1074                                 printk(KERN_ERR
1075                                        "ibmvscsi: Unable to send init rsp\n");
1076                         }
1077
1078                         break;
1079                 case 0x02:      /* Initialization response */
1080                         printk(KERN_INFO
1081                                "ibmvscsi: partner initialization complete\n");
1082
1083                         /* Now login */
1084                         send_srp_login(hostdata);
1085                         break;
1086                 default:
1087                         printk(KERN_ERR "ibmvscsi: unknown crq message type\n");
1088                 }
1089                 return;
1090         case 0xFF:              /* Hypervisor telling us the connection is closed */
1091                 printk(KERN_INFO "ibmvscsi: Virtual adapter failed!\n");
1092
1093                 atomic_set(&hostdata->request_limit, -1);
1094                 purge_requests(hostdata);
1095                 ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
1096                 return;
1097         case 0x80:              /* real payload */
1098                 break;
1099         default:
1100                 printk(KERN_ERR
1101                        "ibmvscsi: got an invalid message type 0x%02x\n",
1102                        crq->valid);
1103                 return;
1104         }
1105
1106         /* The only kind of payload CRQs we should get are responses to
1107          * things we send. Make sure this response is to something we
1108          * actually sent
1109          */
1110         if (!valid_event_struct(&hostdata->pool, evt_struct)) {
1111                 printk(KERN_ERR
1112                        "ibmvscsi: returned correlation_token 0x%p is invalid!\n",
1113                        (void *)crq->IU_data_ptr);
1114                 return;
1115         }
1116
1117         if (atomic_read(&evt_struct->free)) {
1118                 printk(KERN_ERR
1119                        "ibmvscsi: received duplicate  correlation_token 0x%p!\n",
1120                        (void *)crq->IU_data_ptr);
1121                 return;
1122         }
1123
1124         if (crq->format == VIOSRP_SRP_FORMAT)
1125                 atomic_add(evt_struct->xfer_iu->srp.rsp.request_limit_delta,
1126                            &hostdata->request_limit);
1127
1128         if (evt_struct->done)
1129                 evt_struct->done(evt_struct);
1130         else
1131                 printk(KERN_ERR
1132                        "ibmvscsi: returned done() is NULL; not running it!\n");
1133
1134         /*
1135          * Lock the host_lock before messing with these structures, since we
1136          * are running in a task context
1137          */
1138         spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
1139         list_del(&evt_struct->list);
1140         free_event_struct(&evt_struct->hostdata->pool, evt_struct);
1141         spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
1142 }
1143
1144 /**
1145  * ibmvscsi_get_host_config: Send the command to the server to get host
1146  * configuration data.  The data is opaque to us.
1147  */
1148 static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
1149                                    unsigned char *buffer, int length)
1150 {
1151         struct viosrp_host_config *host_config;
1152         struct srp_event_struct *evt_struct;
1153         int rc;
1154
1155         evt_struct = get_event_struct(&hostdata->pool);
1156         if (!evt_struct) {
1157                 printk(KERN_ERR
1158                        "ibmvscsi: could't allocate event for HOST_CONFIG!\n");
1159                 return -1;
1160         }
1161
1162         init_event_struct(evt_struct,
1163                           sync_completion,
1164                           VIOSRP_MAD_FORMAT,
1165                           init_timeout * HZ);
1166
1167         host_config = &evt_struct->iu.mad.host_config;
1168
1169         /* Set up a lun reset SRP command */
1170         memset(host_config, 0x00, sizeof(*host_config));
1171         host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
1172         host_config->common.length = length;
1173         host_config->buffer = dma_map_single(hostdata->dev, buffer, length,
1174                                             DMA_BIDIRECTIONAL);
1175
1176         if (dma_mapping_error(host_config->buffer)) {
1177                 printk(KERN_ERR
1178                        "ibmvscsi: dma_mapping error " "getting host config\n");
1179                 free_event_struct(&hostdata->pool, evt_struct);
1180                 return -1;
1181         }
1182
1183         init_completion(&evt_struct->comp);
1184         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
1185         if (rc == 0) {
1186                 wait_for_completion(&evt_struct->comp);
1187                 dma_unmap_single(hostdata->dev, host_config->buffer,
1188                                  length, DMA_BIDIRECTIONAL);
1189         }
1190
1191         return rc;
1192 }
1193
1194 /* ------------------------------------------------------------
1195  * sysfs attributes
1196  */
1197 static ssize_t show_host_srp_version(struct class_device *class_dev, char *buf)
1198 {
1199         struct Scsi_Host *shost = class_to_shost(class_dev);
1200         struct ibmvscsi_host_data *hostdata =
1201             (struct ibmvscsi_host_data *)shost->hostdata;
1202         int len;
1203
1204         len = snprintf(buf, PAGE_SIZE, "%s\n",
1205                        hostdata->madapter_info.srp_version);
1206         return len;
1207 }
1208
1209 static struct class_device_attribute ibmvscsi_host_srp_version = {
1210         .attr = {
1211                  .name = "srp_version",
1212                  .mode = S_IRUGO,
1213                  },
1214         .show = show_host_srp_version,
1215 };
1216
1217 static ssize_t show_host_partition_name(struct class_device *class_dev,
1218                                         char *buf)
1219 {
1220         struct Scsi_Host *shost = class_to_shost(class_dev);
1221         struct ibmvscsi_host_data *hostdata =
1222             (struct ibmvscsi_host_data *)shost->hostdata;
1223         int len;
1224
1225         len = snprintf(buf, PAGE_SIZE, "%s\n",
1226                        hostdata->madapter_info.partition_name);
1227         return len;
1228 }
1229
1230 static struct class_device_attribute ibmvscsi_host_partition_name = {
1231         .attr = {
1232                  .name = "partition_name",
1233                  .mode = S_IRUGO,
1234                  },
1235         .show = show_host_partition_name,
1236 };
1237
1238 static ssize_t show_host_partition_number(struct class_device *class_dev,
1239                                           char *buf)
1240 {
1241         struct Scsi_Host *shost = class_to_shost(class_dev);
1242         struct ibmvscsi_host_data *hostdata =
1243             (struct ibmvscsi_host_data *)shost->hostdata;
1244         int len;
1245
1246         len = snprintf(buf, PAGE_SIZE, "%d\n",
1247                        hostdata->madapter_info.partition_number);
1248         return len;
1249 }
1250
1251 static struct class_device_attribute ibmvscsi_host_partition_number = {
1252         .attr = {
1253                  .name = "partition_number",
1254                  .mode = S_IRUGO,
1255                  },
1256         .show = show_host_partition_number,
1257 };
1258
1259 static ssize_t show_host_mad_version(struct class_device *class_dev, char *buf)
1260 {
1261         struct Scsi_Host *shost = class_to_shost(class_dev);
1262         struct ibmvscsi_host_data *hostdata =
1263             (struct ibmvscsi_host_data *)shost->hostdata;
1264         int len;
1265
1266         len = snprintf(buf, PAGE_SIZE, "%d\n",
1267                        hostdata->madapter_info.mad_version);
1268         return len;
1269 }
1270
1271 static struct class_device_attribute ibmvscsi_host_mad_version = {
1272         .attr = {
1273                  .name = "mad_version",
1274                  .mode = S_IRUGO,
1275                  },
1276         .show = show_host_mad_version,
1277 };
1278
1279 static ssize_t show_host_os_type(struct class_device *class_dev, char *buf)
1280 {
1281         struct Scsi_Host *shost = class_to_shost(class_dev);
1282         struct ibmvscsi_host_data *hostdata =
1283             (struct ibmvscsi_host_data *)shost->hostdata;
1284         int len;
1285
1286         len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
1287         return len;
1288 }
1289
1290 static struct class_device_attribute ibmvscsi_host_os_type = {
1291         .attr = {
1292                  .name = "os_type",
1293                  .mode = S_IRUGO,
1294                  },
1295         .show = show_host_os_type,
1296 };
1297
1298 static ssize_t show_host_config(struct class_device *class_dev, char *buf)
1299 {
1300         struct Scsi_Host *shost = class_to_shost(class_dev);
1301         struct ibmvscsi_host_data *hostdata =
1302             (struct ibmvscsi_host_data *)shost->hostdata;
1303
1304         /* returns null-terminated host config data */
1305         if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
1306                 return strlen(buf);
1307         else
1308                 return 0;
1309 }
1310
1311 static struct class_device_attribute ibmvscsi_host_config = {
1312         .attr = {
1313                  .name = "config",
1314                  .mode = S_IRUGO,
1315                  },
1316         .show = show_host_config,
1317 };
1318
1319 static struct class_device_attribute *ibmvscsi_attrs[] = {
1320         &ibmvscsi_host_srp_version,
1321         &ibmvscsi_host_partition_name,
1322         &ibmvscsi_host_partition_number,
1323         &ibmvscsi_host_mad_version,
1324         &ibmvscsi_host_os_type,
1325         &ibmvscsi_host_config,
1326         NULL
1327 };
1328
1329 /* ------------------------------------------------------------
1330  * SCSI driver registration
1331  */
1332 static struct scsi_host_template driver_template = {
1333         .module = THIS_MODULE,
1334         .name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
1335         .proc_name = "ibmvscsi",
1336         .queuecommand = ibmvscsi_queuecommand,
1337         .eh_abort_handler = ibmvscsi_eh_abort_handler,
1338         .eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
1339         .cmd_per_lun = 16,
1340         .can_queue = 1,         /* Updated after SRP_LOGIN */
1341         .this_id = -1,
1342         .sg_tablesize = MAX_INDIRECT_BUFS,
1343         .use_clustering = ENABLE_CLUSTERING,
1344         .shost_attrs = ibmvscsi_attrs,
1345 };
1346
1347 /**
1348  * Called by bus code for each adapter
1349  */
1350 static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1351 {
1352         struct ibmvscsi_host_data *hostdata;
1353         struct Scsi_Host *host;
1354         struct device *dev = &vdev->dev;
1355         unsigned long wait_switch = 0;
1356
1357         vdev->dev.driver_data = NULL;
1358
1359         host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
1360         if (!host) {
1361                 printk(KERN_ERR "ibmvscsi: couldn't allocate host data\n");
1362                 goto scsi_host_alloc_failed;
1363         }
1364
1365         hostdata = (struct ibmvscsi_host_data *)host->hostdata;
1366         memset(hostdata, 0x00, sizeof(*hostdata));
1367         INIT_LIST_HEAD(&hostdata->sent);
1368         hostdata->host = host;
1369         hostdata->dev = dev;
1370         atomic_set(&hostdata->request_limit, -1);
1371         hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
1372
1373         if (ibmvscsi_init_crq_queue(&hostdata->queue, hostdata,
1374                                     max_requests) != 0) {
1375                 printk(KERN_ERR "ibmvscsi: couldn't initialize crq\n");
1376                 goto init_crq_failed;
1377         }
1378         if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
1379                 printk(KERN_ERR "ibmvscsi: couldn't initialize event pool\n");
1380                 goto init_pool_failed;
1381         }
1382
1383         host->max_lun = 8;
1384         host->max_id = max_id;
1385         host->max_channel = max_channel;
1386
1387         if (scsi_add_host(hostdata->host, hostdata->dev))
1388                 goto add_host_failed;
1389
1390         /* Try to send an initialization message.  Note that this is allowed
1391          * to fail if the other end is not acive.  In that case we don't
1392          * want to scan
1393          */
1394         if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0) {
1395                 /*
1396                  * Wait around max init_timeout secs for the adapter to finish
1397                  * initializing. When we are done initializing, we will have a
1398                  * valid request_limit.  We don't want Linux scanning before
1399                  * we are ready.
1400                  */
1401                 for (wait_switch = jiffies + (init_timeout * HZ);
1402                      time_before(jiffies, wait_switch) &&
1403                      atomic_read(&hostdata->request_limit) < 2;) {
1404
1405                         msleep(10);
1406                 }
1407
1408                 /* if we now have a valid request_limit, initiate a scan */
1409                 if (atomic_read(&hostdata->request_limit) > 0)
1410                         scsi_scan_host(host);
1411         }
1412
1413         vdev->dev.driver_data = hostdata;
1414         return 0;
1415
1416       add_host_failed:
1417         release_event_pool(&hostdata->pool, hostdata);
1418       init_pool_failed:
1419         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_requests);
1420       init_crq_failed:
1421         scsi_host_put(host);
1422       scsi_host_alloc_failed:
1423         return -1;
1424 }
1425
1426 static int ibmvscsi_remove(struct vio_dev *vdev)
1427 {
1428         struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
1429         release_event_pool(&hostdata->pool, hostdata);
1430         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
1431                                    max_requests);
1432
1433         scsi_remove_host(hostdata->host);
1434         scsi_host_put(hostdata->host);
1435
1436         return 0;
1437 }
1438
1439 /**
1440  * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we
1441  * support.
1442  */
1443 static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
1444         {"vscsi", "IBM,v-scsi"},
1445         {0,}
1446 };
1447
1448 MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
1449 static struct vio_driver ibmvscsi_driver = {
1450         .name = "ibmvscsi",
1451         .id_table = ibmvscsi_device_table,
1452         .probe = ibmvscsi_probe,
1453         .remove = ibmvscsi_remove
1454 };
1455
1456 int __init ibmvscsi_module_init(void)
1457 {
1458         return vio_register_driver(&ibmvscsi_driver);
1459 }
1460
1461 void __exit ibmvscsi_module_exit(void)
1462 {
1463         vio_unregister_driver(&ibmvscsi_driver);
1464 }
1465
1466 module_init(ibmvscsi_module_init);
1467 module_exit(ibmvscsi_module_exit);