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 "1.5.7"
  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                 evt->ext_list = NULL;
 149                 evt->ext_list_token = 0;
 150         }
 151
 152         return 0;
 153 }
 154
 155 /**
 156  * release_event_pool: - Frees memory of an event pool of a host
 157  * @pool:       event_pool to be released
 158  * @hostdata:   ibmvscsi_host_data who owns the even pool
 159  *
 160  * Returns zero on success.
 161 */
 162 static void release_event_pool(struct event_pool *pool,
 163                                struct ibmvscsi_host_data *hostdata)
 164 {
 165         int i, in_use = 0;
 166         for (i = 0; i < pool->size; ++i) {
 167                 if (atomic_read(&pool->events[i].free) != 1)
 168                         ++in_use;
 169                 if (pool->events[i].ext_list) {
 170                         dma_free_coherent(hostdata->dev,
 171                                   SG_ALL * sizeof(struct memory_descriptor),
 172                                   pool->events[i].ext_list,
 173                                   pool->events[i].ext_list_token);
 174                 }
 175         }
 176         if (in_use)
 177                 printk(KERN_WARNING
 178                        "ibmvscsi: releasing event pool with %d "
 179                        "events still in use?\n", in_use);
 180         kfree(pool->events);
 181         dma_free_coherent(hostdata->dev,
 182                           pool->size * sizeof(*pool->iu_storage),
 183                           pool->iu_storage, pool->iu_token);
 184 }
 185
 186 /**
 187  * valid_event_struct: - Determines if event is valid.
 188  * @pool:       event_pool that contains the event
 189  * @evt:        srp_event_struct to be checked for validity
 190  *
 191  * Returns zero if event is invalid, one otherwise.
 192 */
 193 static int valid_event_struct(struct event_pool *pool,
 194                                 struct srp_event_struct *evt)
 195 {
 196         int index = evt - pool->events;
 197         if (index < 0 || index >= pool->size)   /* outside of bounds */
 198                 return 0;
 199         if (evt != pool->events + index)        /* unaligned */
 200                 return 0;
 201         return 1;
 202 }
 203
 204 /**
 205  * ibmvscsi_free-event_struct: - Changes status of event to "free"
 206  * @pool:       event_pool that contains the event
 207  * @evt:        srp_event_struct to be modified
 208  *
 209 */
 210 static void free_event_struct(struct event_pool *pool,
 211                                        struct srp_event_struct *evt)
 212 {
 213         if (!valid_event_struct(pool, evt)) {
 214                 printk(KERN_ERR
 215                        "ibmvscsi: Freeing invalid event_struct %p "
 216                        "(not in pool %p)\n", evt, pool->events);
 217                 return;
 218         }
 219         if (atomic_inc_return(&evt->free) != 1) {
 220                 printk(KERN_ERR
 221                        "ibmvscsi: Freeing event_struct %p "
 222                        "which is not in use!\n", evt);
 223                 return;
 224         }
 225 }
 226
 227 /**
 228  * get_evt_struct: - Gets the next free event in pool
 229  * @pool:       event_pool that contains the events to be searched
 230  *
 231  * Returns the next event in "free" state, and NULL if none are free.
 232  * Note that no synchronization is done here, we assume the host_lock
 233  * will syncrhonze things.
 234 */
 235 static struct srp_event_struct *get_event_struct(struct event_pool *pool)
 236 {
 237         int i;
 238         int poolsize = pool->size;
 239         int offset = pool->next;
 240
 241         for (i = 0; i < poolsize; i++) {
 242                 offset = (offset + 1) % poolsize;
 243                 if (!atomic_dec_if_positive(&pool->events[offset].free)) {
 244                         pool->next = offset;
 245                         return &pool->events[offset];
 246                 }
 247         }
 248
 249         printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
 250         return NULL;
 251 }
 252
 253 /**
 254  * init_event_struct: Initialize fields in an event struct that are always
 255  *                    required.
 256  * @evt:        The event
 257  * @done:       Routine to call when the event is responded to
 258  * @format:     SRP or MAD format
 259  * @timeout:    timeout value set in the CRQ
 260  */
 261 static void init_event_struct(struct srp_event_struct *evt_struct,
 262                               void (*done) (struct srp_event_struct *),
 263                               u8 format,
 264                               int timeout)
 265 {
 266         evt_struct->cmnd = NULL;
 267         evt_struct->cmnd_done = NULL;
 268         evt_struct->sync_srp = NULL;
 269         evt_struct->crq.format = format;
 270         evt_struct->crq.timeout = timeout;
 271         evt_struct->done = done;
 272 }
 273
 274 /* ------------------------------------------------------------
 275  * Routines for receiving SCSI responses from the hosting partition
 276  */
 277
 278 /**
 279  * set_srp_direction: Set the fields in the srp related to data
 280  *     direction and number of buffers based on the direction in
 281  *     the scsi_cmnd and the number of buffers
 282  */
 283 static void set_srp_direction(struct scsi_cmnd *cmd,
 284                               struct srp_cmd *srp_cmd,
 285                               int numbuf)
 286 {
 287         if (numbuf == 0)
 288                 return;
 289
 290         if (numbuf == 1) {
 291                 if (cmd->sc_data_direction == DMA_TO_DEVICE)
 292                         srp_cmd->data_out_format = SRP_DIRECT_BUFFER;
 293                 else
 294                         srp_cmd->data_in_format = SRP_DIRECT_BUFFER;
 295         } else {
 296                 if (cmd->sc_data_direction == DMA_TO_DEVICE) {
 297                         srp_cmd->data_out_format = SRP_INDIRECT_BUFFER;
 298                         srp_cmd->data_out_count =
 299                                 numbuf < MAX_INDIRECT_BUFS ?
 300                                         numbuf: MAX_INDIRECT_BUFS;
 301                 } else {
 302                         srp_cmd->data_in_format = SRP_INDIRECT_BUFFER;
 303                         srp_cmd->data_in_count =
 304                                 numbuf < MAX_INDIRECT_BUFS ?
 305                                         numbuf: MAX_INDIRECT_BUFS;
 306                 }
 307         }
 308 }
 309
 310 static void unmap_sg_list(int num_entries,
 311                 struct device *dev,
 312                 struct memory_descriptor *md)
 313 {
 314         int i;
 315
 316         for (i = 0; i < num_entries; ++i) {
 317                 dma_unmap_single(dev,
 318                         md[i].virtual_address,
 319                         md[i].length, DMA_BIDIRECTIONAL);
 320         }
 321 }
 322
 323 /**
 324  * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
 325  * @cmd:        srp_cmd whose additional_data member will be unmapped
 326  * @dev:        device for which the memory is mapped
 327  *
 328 */
 329 static void unmap_cmd_data(struct srp_cmd *cmd,
 330                            struct srp_event_struct *evt_struct,
 331                            struct device *dev)
 332 {
 333         if ((cmd->data_out_format == SRP_NO_BUFFER) &&
 334             (cmd->data_in_format == SRP_NO_BUFFER))
 335                 return;
 336         else if ((cmd->data_out_format == SRP_DIRECT_BUFFER) ||
 337                  (cmd->data_in_format == SRP_DIRECT_BUFFER)) {
 338                 struct memory_descriptor *data =
 339                         (struct memory_descriptor *)cmd->additional_data;
 340                 dma_unmap_single(dev, data->virtual_address, data->length,
 341                                  DMA_BIDIRECTIONAL);
 342         } else {
 343                 struct indirect_descriptor *indirect =
 344                         (struct indirect_descriptor *)cmd->additional_data;
 345                 int num_mapped = indirect->head.length /
 346                         sizeof(indirect->list[0]);
 347
 348                 if (num_mapped <= MAX_INDIRECT_BUFS) {
 349                         unmap_sg_list(num_mapped, dev, &indirect->list[0]);
 350                         return;
 351                 }
 352
 353                 unmap_sg_list(num_mapped, dev, evt_struct->ext_list);
 354         }
 355 }
 356
 357 static int map_sg_list(int num_entries,
 358                        struct scatterlist *sg,
 359                        struct memory_descriptor *md)
 360 {
 361         int i;
 362         u64 total_length = 0;
 363
 364         for (i = 0; i < num_entries; ++i) {
 365                 struct memory_descriptor *descr = md + i;
 366                 struct scatterlist *sg_entry = &sg[i];
 367                 descr->virtual_address = sg_dma_address(sg_entry);
 368                 descr->length = sg_dma_len(sg_entry);
 369                 descr->memory_handle = 0;
 370                 total_length += sg_dma_len(sg_entry);
 371         }
 372         return total_length;
 373 }
 374
 375 /**
 376  * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
 377  * @cmd:        Scsi_Cmnd with the scatterlist
 378  * @srp_cmd:    srp_cmd that contains the memory descriptor
 379  * @dev:        device for which to map dma memory
 380  *
 381  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
 382  * Returns 1 on success.
 383 */
 384 static int map_sg_data(struct scsi_cmnd *cmd,
 385                        struct srp_event_struct *evt_struct,
 386                        struct srp_cmd *srp_cmd, struct device *dev)
 387 {
 388
 389         int sg_mapped;
 390         u64 total_length = 0;
 391         struct scatterlist *sg = cmd->request_buffer;
 392         struct memory_descriptor *data =
 393             (struct memory_descriptor *)srp_cmd->additional_data;
 394         struct indirect_descriptor *indirect =
 395             (struct indirect_descriptor *)data;
 396
 397         sg_mapped = dma_map_sg(dev, sg, cmd->use_sg, DMA_BIDIRECTIONAL);
 398
 399         if (sg_mapped == 0)
 400                 return 0;
 401
 402         set_srp_direction(cmd, srp_cmd, sg_mapped);
 403
 404         /* special case; we can use a single direct descriptor */
 405         if (sg_mapped == 1) {
 406                 data->virtual_address = sg_dma_address(&sg[0]);
 407                 data->length = sg_dma_len(&sg[0]);
 408                 data->memory_handle = 0;
 409                 return 1;
 410         }
 411
 412         if (sg_mapped > SG_ALL) {
 413                 printk(KERN_ERR
 414                        "ibmvscsi: More than %d mapped sg entries, got %d\n",
 415                        SG_ALL, sg_mapped);
 416                 return 0;
 417         }
 418
 419         indirect->head.virtual_address = 0;
 420         indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
 421         indirect->head.memory_handle = 0;
 422
 423         if (sg_mapped <= MAX_INDIRECT_BUFS) {
 424                 total_length = map_sg_list(sg_mapped, sg, &indirect->list[0]);
 425                 indirect->total_length = total_length;
 426                 return 1;
 427         }
 428
 429         /* get indirect table */
 430         if (!evt_struct->ext_list) {
 431                 evt_struct->ext_list =(struct memory_descriptor*)
 432                         dma_alloc_coherent(dev,
 433                                 SG_ALL * sizeof(struct memory_descriptor),
 434                                 &evt_struct->ext_list_token, 0);
 435                 if (!evt_struct->ext_list) {
 436                     printk(KERN_ERR
 437                         "ibmvscsi: Can't allocate memory for indirect table\n");
 438                         return 0;
 439
 440                 }
 441         }
 442
 443         total_length = map_sg_list(sg_mapped, sg, evt_struct->ext_list);
 444
 445         indirect->total_length = total_length;
 446         indirect->head.virtual_address = evt_struct->ext_list_token;
 447         indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
 448         memcpy(indirect->list, evt_struct->ext_list,
 449                 MAX_INDIRECT_BUFS * sizeof(struct memory_descriptor));
 450
 451         return 1;
 452 }
 453
 454 /**
 455  * map_single_data: - Maps memory and initializes memory decriptor fields
 456  * @cmd:        struct scsi_cmnd with the memory to be mapped
 457  * @srp_cmd:    srp_cmd that contains the memory descriptor
 458  * @dev:        device for which to map dma memory
 459  *
 460  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
 461  * Returns 1 on success.
 462 */
 463 static int map_single_data(struct scsi_cmnd *cmd,
 464                            struct srp_cmd *srp_cmd, struct device *dev)
 465 {
 466         struct memory_descriptor *data =
 467             (struct memory_descriptor *)srp_cmd->additional_data;
 468
 469         data->virtual_address =
 470                 dma_map_single(dev, cmd->request_buffer,
 471                                cmd->request_bufflen,
 472                                DMA_BIDIRECTIONAL);
 473         if (dma_mapping_error(data->virtual_address)) {
 474                 printk(KERN_ERR
 475                        "ibmvscsi: Unable to map request_buffer for command!\n");
 476                 return 0;
 477         }
 478         data->length = cmd->request_bufflen;
 479         data->memory_handle = 0;
 480
 481         set_srp_direction(cmd, srp_cmd, 1);
 482
 483         return 1;
 484 }
 485
 486 /**
 487  * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
 488  * @cmd:        struct scsi_cmnd with the memory to be mapped
 489  * @srp_cmd:    srp_cmd that contains the memory descriptor
 490  * @dev:        dma device for which to map dma memory
 491  *
 492  * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds
 493  * Returns 1 on success.
 494 */
 495 static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
 496                                 struct srp_event_struct *evt_struct,
 497                                 struct srp_cmd *srp_cmd, struct device *dev)
 498 {
 499         switch (cmd->sc_data_direction) {
 500         case DMA_FROM_DEVICE:
 501         case DMA_TO_DEVICE:
 502                 break;
 503         case DMA_NONE:
 504                 return 1;
 505         case DMA_BIDIRECTIONAL:
 506                 printk(KERN_ERR
 507                        "ibmvscsi: Can't map DMA_BIDIRECTIONAL to read/write\n");
 508                 return 0;
 509         default:
 510                 printk(KERN_ERR
 511                        "ibmvscsi: Unknown data direction 0x%02x; can't map!\n",
 512                        cmd->sc_data_direction);
 513                 return 0;
 514         }
 515
 516         if (!cmd->request_buffer)
 517                 return 1;
 518         if (cmd->use_sg)
 519                 return map_sg_data(cmd, evt_struct, srp_cmd, dev);
 520         return map_single_data(cmd, srp_cmd, dev);
 521 }
 522
 523 /* ------------------------------------------------------------
 524  * Routines for sending and receiving SRPs
 525  */
 526 /**
 527  * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
 528  * @evt_struct: evt_struct to be sent
 529  * @hostdata:   ibmvscsi_host_data of host
 530  *
 531  * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
 532  * Note that this routine assumes that host_lock is held for synchronization
 533 */
 534 static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
 535                                    struct ibmvscsi_host_data *hostdata)
 536 {
 537         struct scsi_cmnd *cmnd;
 538         u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
 539         int rc;
 540
 541         /* If we have exhausted our request limit, just fail this request.
 542          * Note that there are rare cases involving driver generated requests
 543          * (such as task management requests) that the mid layer may think we
 544          * can handle more requests (can_queue) when we actually can't
 545          */
 546         if ((evt_struct->crq.format == VIOSRP_SRP_FORMAT) &&
 547             (atomic_dec_if_positive(&hostdata->request_limit) < 0)) {
 548                 /* See if the adapter is disabled */
 549                 if (atomic_read(&hostdata->request_limit) < 0)
 550                         goto send_error;
 551
 552                 printk(KERN_WARNING
 553                        "ibmvscsi: Warning, request_limit exceeded\n");
 554                 unmap_cmd_data(&evt_struct->iu.srp.cmd,
 555                                evt_struct,
 556                                hostdata->dev);
 557                 free_event_struct(&hostdata->pool, evt_struct);
 558                 return SCSI_MLQUEUE_HOST_BUSY;
 559         }
 560
 561         /* Copy the IU into the transfer area */
 562         *evt_struct->xfer_iu = evt_struct->iu;
 563         evt_struct->xfer_iu->srp.generic.tag = (u64)evt_struct;
 564
 565         /* Add this to the sent list.  We need to do this
 566          * before we actually send
 567          * in case it comes back REALLY fast
 568          */
 569         list_add_tail(&evt_struct->list, &hostdata->sent);
 570
 571         if ((rc =
 572              ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
 573                 list_del(&evt_struct->list);
 574
 575                 printk(KERN_ERR "ibmvscsi: failed to send event struct rc %d\n",
 576                        rc);
 577                 goto send_error;
 578         }
 579
 580         return 0;
 581
 582  send_error:
 583         unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
 584
 585         if ((cmnd = evt_struct->cmnd) != NULL) {
 586                 cmnd->result = DID_ERROR << 16;
 587                 evt_struct->cmnd_done(cmnd);
 588         } else if (evt_struct->done)
 589                 evt_struct->done(evt_struct);
 590
 591         free_event_struct(&hostdata->pool, evt_struct);
 592         return 0;
 593 }
 594
 595 /**
 596  * handle_cmd_rsp: -  Handle responses from commands
 597  * @evt_struct: srp_event_struct to be handled
 598  *
 599  * Used as a callback by when sending scsi cmds.
 600  * Gets called by ibmvscsi_handle_crq()
 601 */
 602 static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
 603 {
 604         struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
 605         struct scsi_cmnd *cmnd = evt_struct->cmnd;
 606
 607         if (unlikely(rsp->type != SRP_RSP_TYPE)) {
 608                 if (printk_ratelimit())
 609                         printk(KERN_WARNING
 610                                "ibmvscsi: bad SRP RSP type %d\n",
 611                                rsp->type);
 612         }
 613
 614         if (cmnd) {
 615                 cmnd->result = rsp->status;
 616                 if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
 617                         memcpy(cmnd->sense_buffer,
 618                                rsp->sense_and_response_data,
 619                                rsp->sense_data_list_length);
 620                 unmap_cmd_data(&evt_struct->iu.srp.cmd,
 621                                evt_struct,
 622                                evt_struct->hostdata->dev);
 623
 624                 if (rsp->doover)
 625                         cmnd->resid = rsp->data_out_residual_count;
 626                 else if (rsp->diover)
 627                         cmnd->resid = rsp->data_in_residual_count;
 628         }
 629
 630         if (evt_struct->cmnd_done)
 631                 evt_struct->cmnd_done(cmnd);
 632 }
 633
 634 /**
 635  * lun_from_dev: - Returns the lun of the scsi device
 636  * @dev:        struct scsi_device
 637  *
 638 */
 639 static inline u16 lun_from_dev(struct scsi_device *dev)
 640 {
 641         return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
 642 }
 643
 644 /**
 645  * ibmvscsi_queue: - The queuecommand function of the scsi template
 646  * @cmd:        struct scsi_cmnd to be executed
 647  * @done:       Callback function to be called when cmd is completed
 648 */
 649 static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
 650                                  void (*done) (struct scsi_cmnd *))
 651 {
 652         struct srp_cmd *srp_cmd;
 653         struct srp_event_struct *evt_struct;
 654         struct indirect_descriptor *indirect;
 655         struct ibmvscsi_host_data *hostdata =
 656                 (struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
 657         u16 lun = lun_from_dev(cmnd->device);
 658
 659         evt_struct = get_event_struct(&hostdata->pool);
 660         if (!evt_struct)
 661                 return SCSI_MLQUEUE_HOST_BUSY;
 662
 663         /* Set up the actual SRP IU */
 664         srp_cmd = &evt_struct->iu.srp.cmd;
 665         memset(srp_cmd, 0x00, sizeof(*srp_cmd));
 666         srp_cmd->type = SRP_CMD_TYPE;
 667         memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
 668         srp_cmd->lun = ((u64) lun) << 48;
 669
 670         if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
 671                 printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
 672                 free_event_struct(&hostdata->pool, evt_struct);
 673                 return SCSI_MLQUEUE_HOST_BUSY;
 674         }
 675
 676         init_event_struct(evt_struct,
 677                           handle_cmd_rsp,
 678                           VIOSRP_SRP_FORMAT,
 679                           cmnd->timeout_per_command/HZ);
 680
 681         evt_struct->cmnd = cmnd;
 682         evt_struct->cmnd_done = done;
 683
 684         /* Fix up dma address of the buffer itself */
 685         indirect = (struct indirect_descriptor *)srp_cmd->additional_data;
 686         if (((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
 687             (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) &&
 688             (indirect->head.virtual_address == 0)) {
 689                 indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
 690                     offsetof(struct srp_cmd, additional_data) +
 691                     offsetof(struct indirect_descriptor, list);
 692         }
 693
 694         return ibmvscsi_send_srp_event(evt_struct, hostdata);
 695 }
 696
 697 /* ------------------------------------------------------------
 698  * Routines for driver initialization
 699  */
 700 /**
 701  * adapter_info_rsp: - Handle response to MAD adapter info request
 702  * @evt_struct: srp_event_struct with the response
 703  *
 704  * Used as a "done" callback by when sending adapter_info. Gets called
 705  * by ibmvscsi_handle_crq()
 706 */
 707 static void adapter_info_rsp(struct srp_event_struct *evt_struct)
 708 {
 709         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
 710         dma_unmap_single(hostdata->dev,
 711                          evt_struct->iu.mad.adapter_info.buffer,
 712                          evt_struct->iu.mad.adapter_info.common.length,
 713                          DMA_BIDIRECTIONAL);
 714
 715         if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
 716                 printk("ibmvscsi: error %d getting adapter info\n",
 717                        evt_struct->xfer_iu->mad.adapter_info.common.status);
 718         } else {
 719                 printk("ibmvscsi: host srp version: %s, "
 720                        "host partition %s (%d), OS %d, max io %u\n",
 721                        hostdata->madapter_info.srp_version,
 722                        hostdata->madapter_info.partition_name,
 723                        hostdata->madapter_info.partition_number,
 724                        hostdata->madapter_info.os_type,
 725                        hostdata->madapter_info.port_max_txu[0]);
 726
 727                 if (hostdata->madapter_info.port_max_txu[0])
 728                         hostdata->host->max_sectors =
 729                                 hostdata->madapter_info.port_max_txu[0] >> 9;
 730
 731                 if (hostdata->madapter_info.os_type == 3 &&
 732                     strcmp(hostdata->madapter_info.srp_version, "1.6a") <= 0) {
 733                         printk("ibmvscsi: host (Ver. %s) doesn't support large"
 734                                "transfers\n",
 735                                hostdata->madapter_info.srp_version);
 736                         printk("ibmvscsi: limiting scatterlists to %d\n",
 737                                MAX_INDIRECT_BUFS);
 738                         hostdata->host->sg_tablesize = MAX_INDIRECT_BUFS;
 739                 }
 740         }
 741 }
 742
 743 /**
 744  * send_mad_adapter_info: - Sends the mad adapter info request
 745  *      and stores the result so it can be retrieved with
 746  *      sysfs.  We COULD consider causing a failure if the
 747  *      returned SRP version doesn't match ours.
 748  * @hostdata:   ibmvscsi_host_data of host
 749  *
 750  * Returns zero if successful.
 751 */
 752 static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
 753 {
 754         struct viosrp_adapter_info *req;
 755         struct srp_event_struct *evt_struct;
 756
 757         evt_struct = get_event_struct(&hostdata->pool);
 758         if (!evt_struct) {
 759                 printk(KERN_ERR "ibmvscsi: couldn't allocate an event "
 760                        "for ADAPTER_INFO_REQ!\n");
 761                 return;
 762         }
 763
 764         init_event_struct(evt_struct,
 765                           adapter_info_rsp,
 766                           VIOSRP_MAD_FORMAT,
 767                           init_timeout * HZ);
 768
 769         req = &evt_struct->iu.mad.adapter_info;
 770         memset(req, 0x00, sizeof(*req));
 771
 772         req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
 773         req->common.length = sizeof(hostdata->madapter_info);
 774         req->buffer = dma_map_single(hostdata->dev,
 775                                      &hostdata->madapter_info,
 776                                      sizeof(hostdata->madapter_info),
 777                                      DMA_BIDIRECTIONAL);
 778
 779         if (dma_mapping_error(req->buffer)) {
 780                 printk(KERN_ERR
 781                        "ibmvscsi: Unable to map request_buffer "
 782                        "for adapter_info!\n");
 783                 free_event_struct(&hostdata->pool, evt_struct);
 784                 return;
 785         }
 786
 787         if (ibmvscsi_send_srp_event(evt_struct, hostdata))
 788                 printk(KERN_ERR "ibmvscsi: couldn't send ADAPTER_INFO_REQ!\n");
 789 };
 790
 791 /**
 792  * login_rsp: - Handle response to SRP login request
 793  * @evt_struct: srp_event_struct with the response
 794  *
 795  * Used as a "done" callback by when sending srp_login. Gets called
 796  * by ibmvscsi_handle_crq()
 797 */
 798 static void login_rsp(struct srp_event_struct *evt_struct)
 799 {
 800         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
 801         switch (evt_struct->xfer_iu->srp.generic.type) {
 802         case SRP_LOGIN_RSP_TYPE:        /* it worked! */
 803                 break;
 804         case SRP_LOGIN_REJ_TYPE:        /* refused! */
 805                 printk(KERN_INFO "ibmvscsi: SRP_LOGIN_REQ rejected\n");
 806                 /* Login failed.  */
 807                 atomic_set(&hostdata->request_limit, -1);
 808                 return;
 809         default:
 810                 printk(KERN_ERR
 811                        "ibmvscsi: Invalid login response typecode 0x%02x!\n",
 812                        evt_struct->xfer_iu->srp.generic.type);
 813                 /* Login failed.  */
 814                 atomic_set(&hostdata->request_limit, -1);
 815                 return;
 816         }
 817
 818         printk(KERN_INFO "ibmvscsi: SRP_LOGIN succeeded\n");
 819
 820         if (evt_struct->xfer_iu->srp.login_rsp.request_limit_delta >
 821             (max_requests - 2))
 822                 evt_struct->xfer_iu->srp.login_rsp.request_limit_delta =
 823                     max_requests - 2;
 824
 825         /* Now we know what the real request-limit is */
 826         atomic_set(&hostdata->request_limit,
 827                    evt_struct->xfer_iu->srp.login_rsp.request_limit_delta);
 828
 829         hostdata->host->can_queue =
 830             evt_struct->xfer_iu->srp.login_rsp.request_limit_delta - 2;
 831
 832         if (hostdata->host->can_queue < 1) {
 833                 printk(KERN_ERR "ibmvscsi: Invalid request_limit_delta\n");
 834                 return;
 835         }
 836
 837         send_mad_adapter_info(hostdata);
 838         return;
 839 }
 840
 841 /**
 842  * send_srp_login: - Sends the srp login
 843  * @hostdata:   ibmvscsi_host_data of host
 844  *
 845  * Returns zero if successful.
 846 */
 847 static int send_srp_login(struct ibmvscsi_host_data *hostdata)
 848 {
 849         int rc;
 850         unsigned long flags;
 851         struct srp_login_req *login;
 852         struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
 853         if (!evt_struct) {
 854                 printk(KERN_ERR
 855                        "ibmvscsi: couldn't allocate an event for login req!\n");
 856                 return FAILED;
 857         }
 858
 859         init_event_struct(evt_struct,
 860                           login_rsp,
 861                           VIOSRP_SRP_FORMAT,
 862                           init_timeout * HZ);
 863
 864         login = &evt_struct->iu.srp.login_req;
 865         login->type = SRP_LOGIN_REQ_TYPE;
 866         login->max_requested_initiator_to_target_iulen = sizeof(union srp_iu);
 867         login->required_buffer_formats = 0x0006;
 868
 869         /* Start out with a request limit of 1, since this is negotiated in
 870          * the login request we are just sending
 871          */
 872         atomic_set(&hostdata->request_limit, 1);
 873
 874         spin_lock_irqsave(hostdata->host->host_lock, flags);
 875         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
 876         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 877         return rc;
 878 };
 879
 880 /**
 881  * sync_completion: Signal that a synchronous command has completed
 882  * Note that after returning from this call, the evt_struct is freed.
 883  * the caller waiting on this completion shouldn't touch the evt_struct
 884  * again.
 885  */
 886 static void sync_completion(struct srp_event_struct *evt_struct)
 887 {
 888         /* copy the response back */
 889         if (evt_struct->sync_srp)
 890                 *evt_struct->sync_srp = *evt_struct->xfer_iu;
 891
 892         complete(&evt_struct->comp);
 893 }
 894
 895 /**
 896  * ibmvscsi_abort: Abort a command...from scsi host template
 897  * send this over to the server and wait synchronously for the response
 898  */
 899 static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
 900 {
 901         struct ibmvscsi_host_data *hostdata =
 902             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
 903         struct srp_tsk_mgmt *tsk_mgmt;
 904         struct srp_event_struct *evt;
 905         struct srp_event_struct *tmp_evt, *found_evt;
 906         union viosrp_iu srp_rsp;
 907         int rsp_rc;
 908         unsigned long flags;
 909         u16 lun = lun_from_dev(cmd->device);
 910
 911         /* First, find this command in our sent list so we can figure
 912          * out the correct tag
 913          */
 914         spin_lock_irqsave(hostdata->host->host_lock, flags);
 915         found_evt = NULL;
 916         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
 917                 if (tmp_evt->cmnd == cmd) {
 918                         found_evt = tmp_evt;
 919                         break;
 920                 }
 921         }
 922
 923         if (!found_evt) {
 924                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 925                 return FAILED;
 926         }
 927
 928         evt = get_event_struct(&hostdata->pool);
 929         if (evt == NULL) {
 930                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 931                 printk(KERN_ERR "ibmvscsi: failed to allocate abort event\n");
 932                 return FAILED;
 933         }
 934
 935         init_event_struct(evt,
 936                           sync_completion,
 937                           VIOSRP_SRP_FORMAT,
 938                           init_timeout * HZ);
 939
 940         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
 941
 942         /* Set up an abort SRP command */
 943         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
 944         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
 945         tsk_mgmt->lun = ((u64) lun) << 48;
 946         tsk_mgmt->task_mgmt_flags = 0x01;       /* ABORT TASK */
 947         tsk_mgmt->managed_task_tag = (u64) found_evt;
 948
 949         printk(KERN_INFO "ibmvscsi: aborting command. lun 0x%lx, tag 0x%lx\n",
 950                tsk_mgmt->lun, tsk_mgmt->managed_task_tag);
 951
 952         evt->sync_srp = &srp_rsp;
 953         init_completion(&evt->comp);
 954         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);
 955         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 956         if (rsp_rc != 0) {
 957                 printk(KERN_ERR "ibmvscsi: failed to send abort() event\n");
 958                 return FAILED;
 959         }
 960
 961         wait_for_completion(&evt->comp);
 962
 963         /* make sure we got a good response */
 964         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
 965                 if (printk_ratelimit())
 966                         printk(KERN_WARNING
 967                                "ibmvscsi: abort bad SRP RSP type %d\n",
 968                                srp_rsp.srp.generic.type);
 969                 return FAILED;
 970         }
 971
 972         if (srp_rsp.srp.rsp.rspvalid)
 973                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
 974         else
 975                 rsp_rc = srp_rsp.srp.rsp.status;
 976
 977         if (rsp_rc) {
 978                 if (printk_ratelimit())
 979                         printk(KERN_WARNING
 980                        "ibmvscsi: abort code %d for task tag 0x%lx\n",
 981                                rsp_rc,
 982                                tsk_mgmt->managed_task_tag);
 983                 return FAILED;
 984         }
 985
 986         /* Because we dropped the spinlock above, it's possible
 987          * The event is no longer in our list.  Make sure it didn't
 988          * complete while we were aborting
 989          */
 990         spin_lock_irqsave(hostdata->host->host_lock, flags);
 991         found_evt = NULL;
 992         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
 993                 if (tmp_evt->cmnd == cmd) {
 994                         found_evt = tmp_evt;
 995                         break;
 996                 }
 997         }
 998
 999         if (found_evt == NULL) {
1000                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1001                 printk(KERN_INFO
1002                        "ibmvscsi: aborted task tag 0x%lx completed\n",
1003                        tsk_mgmt->managed_task_tag);
1004                 return SUCCESS;
1005         }
1006
1007         printk(KERN_INFO
1008                "ibmvscsi: successfully aborted task tag 0x%lx\n",
1009                tsk_mgmt->managed_task_tag);
1010
1011         cmd->result = (DID_ABORT << 16);
1012         list_del(&found_evt->list);
1013         unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
1014                        found_evt->hostdata->dev);
1015         free_event_struct(&found_evt->hostdata->pool, found_evt);
1016         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1017         atomic_inc(&hostdata->request_limit);
1018         return SUCCESS;
1019 }
1020
1021 /**
1022  * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host
1023  * template send this over to the server and wait synchronously for the
1024  * response
1025  */
1026 static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
1027 {
1028         struct ibmvscsi_host_data *hostdata =
1029             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
1030
1031         struct srp_tsk_mgmt *tsk_mgmt;
1032         struct srp_event_struct *evt;
1033         struct srp_event_struct *tmp_evt, *pos;
1034         union viosrp_iu srp_rsp;
1035         int rsp_rc;
1036         unsigned long flags;
1037         u16 lun = lun_from_dev(cmd->device);
1038
1039         spin_lock_irqsave(hostdata->host->host_lock, flags);
1040         evt = get_event_struct(&hostdata->pool);
1041         if (evt == NULL) {
1042                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1043                 printk(KERN_ERR "ibmvscsi: failed to allocate reset event\n");
1044                 return FAILED;
1045         }
1046
1047         init_event_struct(evt,
1048                           sync_completion,
1049                           VIOSRP_SRP_FORMAT,
1050                           init_timeout * HZ);
1051
1052         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1053
1054         /* Set up a lun reset SRP command */
1055         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1056         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
1057         tsk_mgmt->lun = ((u64) lun) << 48;
1058         tsk_mgmt->task_mgmt_flags = 0x08;       /* LUN RESET */
1059
1060         printk(KERN_INFO "ibmvscsi: resetting device. lun 0x%lx\n",
1061                tsk_mgmt->lun);
1062
1063         evt->sync_srp = &srp_rsp;
1064         init_completion(&evt->comp);
1065         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);
1066         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1067         if (rsp_rc != 0) {
1068                 printk(KERN_ERR "ibmvscsi: failed to send reset event\n");
1069                 return FAILED;
1070         }
1071
1072         wait_for_completion(&evt->comp);
1073
1074         /* make sure we got a good response */
1075         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
1076                 if (printk_ratelimit())
1077                         printk(KERN_WARNING
1078                                "ibmvscsi: reset bad SRP RSP type %d\n",
1079                                srp_rsp.srp.generic.type);
1080                 return FAILED;
1081         }
1082
1083         if (srp_rsp.srp.rsp.rspvalid)
1084                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
1085         else
1086                 rsp_rc = srp_rsp.srp.rsp.status;
1087
1088         if (rsp_rc) {
1089                 if (printk_ratelimit())
1090                         printk(KERN_WARNING
1091                                "ibmvscsi: reset code %d for task tag 0x%lx\n",
1092                        rsp_rc,
1093                                tsk_mgmt->managed_task_tag);
1094                 return FAILED;
1095         }
1096
1097         /* We need to find all commands for this LUN that have not yet been
1098          * responded to, and fail them with DID_RESET
1099          */
1100         spin_lock_irqsave(hostdata->host->host_lock, flags);
1101         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1102                 if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
1103                         if (tmp_evt->cmnd)
1104                                 tmp_evt->cmnd->result = (DID_RESET << 16);
1105                         list_del(&tmp_evt->list);
1106                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
1107                                        tmp_evt->hostdata->dev);
1108                         free_event_struct(&tmp_evt->hostdata->pool,
1109                                                    tmp_evt);
1110                         atomic_inc(&hostdata->request_limit);
1111                         if (tmp_evt->cmnd_done)
1112                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1113                         else if (tmp_evt->done)
1114                                 tmp_evt->done(tmp_evt);
1115                 }
1116         }
1117         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1118         return SUCCESS;
1119 }
1120
1121 /**
1122  * purge_requests: Our virtual adapter just shut down.  purge any sent requests
1123  * @hostdata:    the adapter
1124  */
1125 static void purge_requests(struct ibmvscsi_host_data *hostdata)
1126 {
1127         struct srp_event_struct *tmp_evt, *pos;
1128         unsigned long flags;
1129
1130         spin_lock_irqsave(hostdata->host->host_lock, flags);
1131         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1132                 list_del(&tmp_evt->list);
1133                 if (tmp_evt->cmnd) {
1134                         tmp_evt->cmnd->result = (DID_ERROR << 16);
1135                         unmap_cmd_data(&tmp_evt->iu.srp.cmd,
1136                                        tmp_evt,
1137                                        tmp_evt->hostdata->dev);
1138                         if (tmp_evt->cmnd_done)
1139                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1140                 } else {
1141                         if (tmp_evt->done) {
1142                                 tmp_evt->done(tmp_evt);
1143                         }
1144                 }
1145                 free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);
1146         }
1147         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1148 }
1149
1150 /**
1151  * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
1152  * @crq:        Command/Response queue
1153  * @hostdata:   ibmvscsi_host_data of host
1154  *
1155 */
1156 void ibmvscsi_handle_crq(struct viosrp_crq *crq,
1157                          struct ibmvscsi_host_data *hostdata)
1158 {
1159         unsigned long flags;
1160         struct srp_event_struct *evt_struct =
1161             (struct srp_event_struct *)crq->IU_data_ptr;
1162         switch (crq->valid) {
1163         case 0xC0:              /* initialization */
1164                 switch (crq->format) {
1165                 case 0x01:      /* Initialization message */
1166                         printk(KERN_INFO "ibmvscsi: partner initialized\n");
1167                         /* Send back a response */
1168                         if (ibmvscsi_send_crq(hostdata,
1169                                               0xC002000000000000LL, 0) == 0) {
1170                                 /* Now login */
1171                                 send_srp_login(hostdata);
1172                         } else {
1173                                 printk(KERN_ERR
1174                                        "ibmvscsi: Unable to send init rsp\n");
1175                         }
1176
1177                         break;
1178                 case 0x02:      /* Initialization response */
1179                         printk(KERN_INFO
1180                                "ibmvscsi: partner initialization complete\n");
1181
1182                         /* Now login */
1183                         send_srp_login(hostdata);
1184                         break;
1185                 default:
1186                         printk(KERN_ERR "ibmvscsi: unknown crq message type\n");
1187                 }
1188                 return;
1189         case 0xFF:              /* Hypervisor telling us the connection is closed */
1190                 printk(KERN_INFO "ibmvscsi: Virtual adapter failed!\n");
1191
1192                 atomic_set(&hostdata->request_limit, -1);
1193                 purge_requests(hostdata);
1194                 ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
1195                 return;
1196         case 0x80:              /* real payload */
1197                 break;
1198         default:
1199                 printk(KERN_ERR
1200                        "ibmvscsi: got an invalid message type 0x%02x\n",
1201                        crq->valid);
1202                 return;
1203         }
1204
1205         /* The only kind of payload CRQs we should get are responses to
1206          * things we send. Make sure this response is to something we
1207          * actually sent
1208          */
1209         if (!valid_event_struct(&hostdata->pool, evt_struct)) {
1210                 printk(KERN_ERR
1211                        "ibmvscsi: returned correlation_token 0x%p is invalid!\n",
1212                        (void *)crq->IU_data_ptr);
1213                 return;
1214         }
1215
1216         if (atomic_read(&evt_struct->free)) {
1217                 printk(KERN_ERR
1218                        "ibmvscsi: received duplicate  correlation_token 0x%p!\n",
1219                        (void *)crq->IU_data_ptr);
1220                 return;
1221         }
1222
1223         if (crq->format == VIOSRP_SRP_FORMAT)
1224                 atomic_add(evt_struct->xfer_iu->srp.rsp.request_limit_delta,
1225                            &hostdata->request_limit);
1226
1227         if (evt_struct->done)
1228                 evt_struct->done(evt_struct);
1229         else
1230                 printk(KERN_ERR
1231                        "ibmvscsi: returned done() is NULL; not running it!\n");
1232
1233         /*
1234          * Lock the host_lock before messing with these structures, since we
1235          * are running in a task context
1236          */
1237         spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
1238         list_del(&evt_struct->list);
1239         free_event_struct(&evt_struct->hostdata->pool, evt_struct);
1240         spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
1241 }
1242
1243 /**
1244  * ibmvscsi_get_host_config: Send the command to the server to get host
1245  * configuration data.  The data is opaque to us.
1246  */
1247 static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
1248                                    unsigned char *buffer, int length)
1249 {
1250         struct viosrp_host_config *host_config;
1251         struct srp_event_struct *evt_struct;
1252         int rc;
1253
1254         evt_struct = get_event_struct(&hostdata->pool);
1255         if (!evt_struct) {
1256                 printk(KERN_ERR
1257                        "ibmvscsi: could't allocate event for HOST_CONFIG!\n");
1258                 return -1;
1259         }
1260
1261         init_event_struct(evt_struct,
1262                           sync_completion,
1263                           VIOSRP_MAD_FORMAT,
1264                           init_timeout * HZ);
1265
1266         host_config = &evt_struct->iu.mad.host_config;
1267
1268         /* Set up a lun reset SRP command */
1269         memset(host_config, 0x00, sizeof(*host_config));
1270         host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
1271         host_config->common.length = length;
1272         host_config->buffer = dma_map_single(hostdata->dev, buffer, length,
1273                                             DMA_BIDIRECTIONAL);
1274
1275         if (dma_mapping_error(host_config->buffer)) {
1276                 printk(KERN_ERR
1277                        "ibmvscsi: dma_mapping error " "getting host config\n");
1278                 free_event_struct(&hostdata->pool, evt_struct);
1279                 return -1;
1280         }
1281
1282         init_completion(&evt_struct->comp);
1283         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
1284         if (rc == 0) {
1285                 wait_for_completion(&evt_struct->comp);
1286                 dma_unmap_single(hostdata->dev, host_config->buffer,
1287                                  length, DMA_BIDIRECTIONAL);
1288         }
1289
1290         return rc;
1291 }
1292
1293 /* ------------------------------------------------------------
1294  * sysfs attributes
1295  */
1296 static ssize_t show_host_srp_version(struct class_device *class_dev, char *buf)
1297 {
1298         struct Scsi_Host *shost = class_to_shost(class_dev);
1299         struct ibmvscsi_host_data *hostdata =
1300             (struct ibmvscsi_host_data *)shost->hostdata;
1301         int len;
1302
1303         len = snprintf(buf, PAGE_SIZE, "%s\n",
1304                        hostdata->madapter_info.srp_version);
1305         return len;
1306 }
1307
1308 static struct class_device_attribute ibmvscsi_host_srp_version = {
1309         .attr = {
1310                  .name = "srp_version",
1311                  .mode = S_IRUGO,
1312                  },
1313         .show = show_host_srp_version,
1314 };
1315
1316 static ssize_t show_host_partition_name(struct class_device *class_dev,
1317                                         char *buf)
1318 {
1319         struct Scsi_Host *shost = class_to_shost(class_dev);
1320         struct ibmvscsi_host_data *hostdata =
1321             (struct ibmvscsi_host_data *)shost->hostdata;
1322         int len;
1323
1324         len = snprintf(buf, PAGE_SIZE, "%s\n",
1325                        hostdata->madapter_info.partition_name);
1326         return len;
1327 }
1328
1329 static struct class_device_attribute ibmvscsi_host_partition_name = {
1330         .attr = {
1331                  .name = "partition_name",
1332                  .mode = S_IRUGO,
1333                  },
1334         .show = show_host_partition_name,
1335 };
1336
1337 static ssize_t show_host_partition_number(struct class_device *class_dev,
1338                                           char *buf)
1339 {
1340         struct Scsi_Host *shost = class_to_shost(class_dev);
1341         struct ibmvscsi_host_data *hostdata =
1342             (struct ibmvscsi_host_data *)shost->hostdata;
1343         int len;
1344
1345         len = snprintf(buf, PAGE_SIZE, "%d\n",
1346                        hostdata->madapter_info.partition_number);
1347         return len;
1348 }
1349
1350 static struct class_device_attribute ibmvscsi_host_partition_number = {
1351         .attr = {
1352                  .name = "partition_number",
1353                  .mode = S_IRUGO,
1354                  },
1355         .show = show_host_partition_number,
1356 };
1357
1358 static ssize_t show_host_mad_version(struct class_device *class_dev, char *buf)
1359 {
1360         struct Scsi_Host *shost = class_to_shost(class_dev);
1361         struct ibmvscsi_host_data *hostdata =
1362             (struct ibmvscsi_host_data *)shost->hostdata;
1363         int len;
1364
1365         len = snprintf(buf, PAGE_SIZE, "%d\n",
1366                        hostdata->madapter_info.mad_version);
1367         return len;
1368 }
1369
1370 static struct class_device_attribute ibmvscsi_host_mad_version = {
1371         .attr = {
1372                  .name = "mad_version",
1373                  .mode = S_IRUGO,
1374                  },
1375         .show = show_host_mad_version,
1376 };
1377
1378 static ssize_t show_host_os_type(struct class_device *class_dev, char *buf)
1379 {
1380         struct Scsi_Host *shost = class_to_shost(class_dev);
1381         struct ibmvscsi_host_data *hostdata =
1382             (struct ibmvscsi_host_data *)shost->hostdata;
1383         int len;
1384
1385         len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
1386         return len;
1387 }
1388
1389 static struct class_device_attribute ibmvscsi_host_os_type = {
1390         .attr = {
1391                  .name = "os_type",
1392                  .mode = S_IRUGO,
1393                  },
1394         .show = show_host_os_type,
1395 };
1396
1397 static ssize_t show_host_config(struct class_device *class_dev, char *buf)
1398 {
1399         struct Scsi_Host *shost = class_to_shost(class_dev);
1400         struct ibmvscsi_host_data *hostdata =
1401             (struct ibmvscsi_host_data *)shost->hostdata;
1402
1403         /* returns null-terminated host config data */
1404         if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
1405                 return strlen(buf);
1406         else
1407                 return 0;
1408 }
1409
1410 static struct class_device_attribute ibmvscsi_host_config = {
1411         .attr = {
1412                  .name = "config",
1413                  .mode = S_IRUGO,
1414                  },
1415         .show = show_host_config,
1416 };
1417
1418 static struct class_device_attribute *ibmvscsi_attrs[] = {
1419         &ibmvscsi_host_srp_version,
1420         &ibmvscsi_host_partition_name,
1421         &ibmvscsi_host_partition_number,
1422         &ibmvscsi_host_mad_version,
1423         &ibmvscsi_host_os_type,
1424         &ibmvscsi_host_config,
1425         NULL
1426 };
1427
1428 /* ------------------------------------------------------------
1429  * SCSI driver registration
1430  */
1431 static struct scsi_host_template driver_template = {
1432         .module = THIS_MODULE,
1433         .name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
1434         .proc_name = "ibmvscsi",
1435         .queuecommand = ibmvscsi_queuecommand,
1436         .eh_abort_handler = ibmvscsi_eh_abort_handler,
1437         .eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
1438         .cmd_per_lun = 16,
1439         .can_queue = 1,         /* Updated after SRP_LOGIN */
1440         .this_id = -1,
1441         .sg_tablesize = SG_ALL,
1442         .use_clustering = ENABLE_CLUSTERING,
1443         .shost_attrs = ibmvscsi_attrs,
1444 };
1445
1446 /**
1447  * Called by bus code for each adapter
1448  */
1449 static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1450 {
1451         struct ibmvscsi_host_data *hostdata;
1452         struct Scsi_Host *host;
1453         struct device *dev = &vdev->dev;
1454         unsigned long wait_switch = 0;
1455
1456         vdev->dev.driver_data = NULL;
1457
1458         host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
1459         if (!host) {
1460                 printk(KERN_ERR "ibmvscsi: couldn't allocate host data\n");
1461                 goto scsi_host_alloc_failed;
1462         }
1463
1464         hostdata = (struct ibmvscsi_host_data *)host->hostdata;
1465         memset(hostdata, 0x00, sizeof(*hostdata));
1466         INIT_LIST_HEAD(&hostdata->sent);
1467         hostdata->host = host;
1468         hostdata->dev = dev;
1469         atomic_set(&hostdata->request_limit, -1);
1470         hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
1471
1472         if (ibmvscsi_init_crq_queue(&hostdata->queue, hostdata,
1473                                     max_requests) != 0) {
1474                 printk(KERN_ERR "ibmvscsi: couldn't initialize crq\n");
1475                 goto init_crq_failed;
1476         }
1477         if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
1478                 printk(KERN_ERR "ibmvscsi: couldn't initialize event pool\n");
1479                 goto init_pool_failed;
1480         }
1481
1482         host->max_lun = 8;
1483         host->max_id = max_id;
1484         host->max_channel = max_channel;
1485
1486         if (scsi_add_host(hostdata->host, hostdata->dev))
1487                 goto add_host_failed;
1488
1489         /* Try to send an initialization message.  Note that this is allowed
1490          * to fail if the other end is not acive.  In that case we don't
1491          * want to scan
1492          */
1493         if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0) {
1494                 /*
1495                  * Wait around max init_timeout secs for the adapter to finish
1496                  * initializing. When we are done initializing, we will have a
1497                  * valid request_limit.  We don't want Linux scanning before
1498                  * we are ready.
1499                  */
1500                 for (wait_switch = jiffies + (init_timeout * HZ);
1501                      time_before(jiffies, wait_switch) &&
1502                      atomic_read(&hostdata->request_limit) < 2;) {
1503
1504                         msleep(10);
1505                 }
1506
1507                 /* if we now have a valid request_limit, initiate a scan */
1508                 if (atomic_read(&hostdata->request_limit) > 0)
1509                         scsi_scan_host(host);
1510         }
1511
1512         vdev->dev.driver_data = hostdata;
1513         return 0;
1514
1515       add_host_failed:
1516         release_event_pool(&hostdata->pool, hostdata);
1517       init_pool_failed:
1518         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_requests);
1519       init_crq_failed:
1520         scsi_host_put(host);
1521       scsi_host_alloc_failed:
1522         return -1;
1523 }
1524
1525 static int ibmvscsi_remove(struct vio_dev *vdev)
1526 {
1527         struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
1528         release_event_pool(&hostdata->pool, hostdata);
1529         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
1530                                    max_requests);
1531
1532         scsi_remove_host(hostdata->host);
1533         scsi_host_put(hostdata->host);
1534
1535         return 0;
1536 }
1537
1538 /**
1539  * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we
1540  * support.
1541  */
1542 static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
1543         {"vscsi", "IBM,v-scsi"},
1544         { "", "" }
1545 };
1546
1547 MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
1548 static struct vio_driver ibmvscsi_driver = {
1549         .name = "ibmvscsi",
1550         .id_table = ibmvscsi_device_table,
1551         .probe = ibmvscsi_probe,
1552         .remove = ibmvscsi_remove
1553 };
1554
1555 int __init ibmvscsi_module_init(void)
1556 {
1557         return vio_register_driver(&ibmvscsi_driver);
1558 }
1559
1560 void __exit ibmvscsi_module_exit(void)
1561 {
1562         vio_unregister_driver(&ibmvscsi_driver);
1563 }
1564
1565 module_init(ibmvscsi_module_init);
1566 module_exit(ibmvscsi_module_exit);