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/firmware.h>
  74 #include <asm/vio.h>
  75 #include <scsi/scsi.h>
  76 #include <scsi/scsi_cmnd.h>
  77 #include <scsi/scsi_host.h>
  78 #include <scsi/scsi_device.h>
  79 #include <scsi/scsi_transport_srp.h>
  80 #include "ibmvscsi.h"
  81
  82 /* The values below are somewhat arbitrary default values, but
  83  * OS/400 will use 3 busses (disks, CDs, tapes, I think.)
  84  * Note that there are 3 bits of channel value, 6 bits of id, and
  85  * 5 bits of LUN.
  86  */
  87 static int max_id = 64;
  88 static int max_channel = 3;
  89 static int init_timeout = 5;
  90 static int max_requests = IBMVSCSI_MAX_REQUESTS_DEFAULT;
  91
  92 static struct scsi_transport_template *ibmvscsi_transport_template;
  93
  94 #define IBMVSCSI_VERSION "1.5.8"
  95
  96 static struct ibmvscsi_ops *ibmvscsi_ops;
  97
  98 MODULE_DESCRIPTION("IBM Virtual SCSI");
  99 MODULE_AUTHOR("Dave Boutcher");
 100 MODULE_LICENSE("GPL");
 101 MODULE_VERSION(IBMVSCSI_VERSION);
 102
 103 module_param_named(max_id, max_id, int, S_IRUGO | S_IWUSR);
 104 MODULE_PARM_DESC(max_id, "Largest ID value for each channel");
 105 module_param_named(max_channel, max_channel, int, S_IRUGO | S_IWUSR);
 106 MODULE_PARM_DESC(max_channel, "Largest channel value");
 107 module_param_named(init_timeout, init_timeout, int, S_IRUGO | S_IWUSR);
 108 MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds");
 109 module_param_named(max_requests, max_requests, int, S_IRUGO | S_IWUSR);
 110 MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
 111
 112 /* ------------------------------------------------------------
 113  * Routines for the event pool and event structs
 114  */
 115 /**
 116  * initialize_event_pool: - Allocates and initializes the event pool for a host
 117  * @pool:       event_pool to be initialized
 118  * @size:       Number of events in pool
 119  * @hostdata:   ibmvscsi_host_data who owns the event pool
 120  *
 121  * Returns zero on success.
 122 */
 123 static int initialize_event_pool(struct event_pool *pool,
 124                                  int size, struct ibmvscsi_host_data *hostdata)
 125 {
 126         int i;
 127
 128         pool->size = size;
 129         pool->next = 0;
 130         pool->events = kcalloc(pool->size, sizeof(*pool->events), GFP_KERNEL);
 131         if (!pool->events)
 132                 return -ENOMEM;
 133
 134         pool->iu_storage =
 135             dma_alloc_coherent(hostdata->dev,
 136                                pool->size * sizeof(*pool->iu_storage),
 137                                &pool->iu_token, 0);
 138         if (!pool->iu_storage) {
 139                 kfree(pool->events);
 140                 return -ENOMEM;
 141         }
 142
 143         for (i = 0; i < pool->size; ++i) {
 144                 struct srp_event_struct *evt = &pool->events[i];
 145                 memset(&evt->crq, 0x00, sizeof(evt->crq));
 146                 atomic_set(&evt->free, 1);
 147                 evt->crq.valid = 0x80;
 148                 evt->crq.IU_length = sizeof(*evt->xfer_iu);
 149                 evt->crq.IU_data_ptr = pool->iu_token +
 150                         sizeof(*evt->xfer_iu) * i;
 151                 evt->xfer_iu = pool->iu_storage + i;
 152                 evt->hostdata = hostdata;
 153                 evt->ext_list = NULL;
 154                 evt->ext_list_token = 0;
 155         }
 156
 157         return 0;
 158 }
 159
 160 /**
 161  * release_event_pool: - Frees memory of an event pool of a host
 162  * @pool:       event_pool to be released
 163  * @hostdata:   ibmvscsi_host_data who owns the even pool
 164  *
 165  * Returns zero on success.
 166 */
 167 static void release_event_pool(struct event_pool *pool,
 168                                struct ibmvscsi_host_data *hostdata)
 169 {
 170         int i, in_use = 0;
 171         for (i = 0; i < pool->size; ++i) {
 172                 if (atomic_read(&pool->events[i].free) != 1)
 173                         ++in_use;
 174                 if (pool->events[i].ext_list) {
 175                         dma_free_coherent(hostdata->dev,
 176                                   SG_ALL * sizeof(struct srp_direct_buf),
 177                                   pool->events[i].ext_list,
 178                                   pool->events[i].ext_list_token);
 179                 }
 180         }
 181         if (in_use)
 182                 dev_warn(hostdata->dev, "releasing event pool with %d "
 183                          "events still in use?\n", in_use);
 184         kfree(pool->events);
 185         dma_free_coherent(hostdata->dev,
 186                           pool->size * sizeof(*pool->iu_storage),
 187                           pool->iu_storage, pool->iu_token);
 188 }
 189
 190 /**
 191  * valid_event_struct: - Determines if event is valid.
 192  * @pool:       event_pool that contains the event
 193  * @evt:        srp_event_struct to be checked for validity
 194  *
 195  * Returns zero if event is invalid, one otherwise.
 196 */
 197 static int valid_event_struct(struct event_pool *pool,
 198                                 struct srp_event_struct *evt)
 199 {
 200         int index = evt - pool->events;
 201         if (index < 0 || index >= pool->size)   /* outside of bounds */
 202                 return 0;
 203         if (evt != pool->events + index)        /* unaligned */
 204                 return 0;
 205         return 1;
 206 }
 207
 208 /**
 209  * ibmvscsi_free-event_struct: - Changes status of event to "free"
 210  * @pool:       event_pool that contains the event
 211  * @evt:        srp_event_struct to be modified
 212  *
 213 */
 214 static void free_event_struct(struct event_pool *pool,
 215                                        struct srp_event_struct *evt)
 216 {
 217         if (!valid_event_struct(pool, evt)) {
 218                 dev_err(evt->hostdata->dev, "Freeing invalid event_struct %p "
 219                         "(not in pool %p)\n", evt, pool->events);
 220                 return;
 221         }
 222         if (atomic_inc_return(&evt->free) != 1) {
 223                 dev_err(evt->hostdata->dev, "Freeing event_struct %p "
 224                         "which is not in use!\n", evt);
 225                 return;
 226         }
 227 }
 228
 229 /**
 230  * get_evt_struct: - Gets the next free event in pool
 231  * @pool:       event_pool that contains the events to be searched
 232  *
 233  * Returns the next event in "free" state, and NULL if none are free.
 234  * Note that no synchronization is done here, we assume the host_lock
 235  * will syncrhonze things.
 236 */
 237 static struct srp_event_struct *get_event_struct(struct event_pool *pool)
 238 {
 239         int i;
 240         int poolsize = pool->size;
 241         int offset = pool->next;
 242
 243         for (i = 0; i < poolsize; i++) {
 244                 offset = (offset + 1) % poolsize;
 245                 if (!atomic_dec_if_positive(&pool->events[offset].free)) {
 246                         pool->next = offset;
 247                         return &pool->events[offset];
 248                 }
 249         }
 250
 251         printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
 252         return NULL;
 253 }
 254
 255 /**
 256  * init_event_struct: Initialize fields in an event struct that are always
 257  *                    required.
 258  * @evt:        The event
 259  * @done:       Routine to call when the event is responded to
 260  * @format:     SRP or MAD format
 261  * @timeout:    timeout value set in the CRQ
 262  */
 263 static void init_event_struct(struct srp_event_struct *evt_struct,
 264                               void (*done) (struct srp_event_struct *),
 265                               u8 format,
 266                               int timeout)
 267 {
 268         evt_struct->cmnd = NULL;
 269         evt_struct->cmnd_done = NULL;
 270         evt_struct->sync_srp = NULL;
 271         evt_struct->crq.format = format;
 272         evt_struct->crq.timeout = timeout;
 273         evt_struct->done = done;
 274 }
 275
 276 /* ------------------------------------------------------------
 277  * Routines for receiving SCSI responses from the hosting partition
 278  */
 279
 280 /**
 281  * set_srp_direction: Set the fields in the srp related to data
 282  *     direction and number of buffers based on the direction in
 283  *     the scsi_cmnd and the number of buffers
 284  */
 285 static void set_srp_direction(struct scsi_cmnd *cmd,
 286                               struct srp_cmd *srp_cmd,
 287                               int numbuf)
 288 {
 289         u8 fmt;
 290
 291         if (numbuf == 0)
 292                 return;
 293
 294         if (numbuf == 1)
 295                 fmt = SRP_DATA_DESC_DIRECT;
 296         else {
 297                 fmt = SRP_DATA_DESC_INDIRECT;
 298                 numbuf = min(numbuf, MAX_INDIRECT_BUFS);
 299
 300                 if (cmd->sc_data_direction == DMA_TO_DEVICE)
 301                         srp_cmd->data_out_desc_cnt = numbuf;
 302                 else
 303                         srp_cmd->data_in_desc_cnt = numbuf;
 304         }
 305
 306         if (cmd->sc_data_direction == DMA_TO_DEVICE)
 307                 srp_cmd->buf_fmt = fmt << 4;
 308         else
 309                 srp_cmd->buf_fmt = fmt;
 310 }
 311
 312 static void unmap_sg_list(int num_entries,
 313                 struct device *dev,
 314                 struct srp_direct_buf *md)
 315 {
 316         int i;
 317
 318         for (i = 0; i < num_entries; ++i)
 319                 dma_unmap_single(dev, md[i].va, md[i].len, DMA_BIDIRECTIONAL);
 320 }
 321
 322 /**
 323  * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
 324  * @cmd:        srp_cmd whose additional_data member will be unmapped
 325  * @dev:        device for which the memory is mapped
 326  *
 327 */
 328 static void unmap_cmd_data(struct srp_cmd *cmd,
 329                            struct srp_event_struct *evt_struct,
 330                            struct device *dev)
 331 {
 332         u8 out_fmt, in_fmt;
 333
 334         out_fmt = cmd->buf_fmt >> 4;
 335         in_fmt = cmd->buf_fmt & ((1U << 4) - 1);
 336
 337         if (out_fmt == SRP_NO_DATA_DESC && in_fmt == SRP_NO_DATA_DESC)
 338                 return;
 339         else if (out_fmt == SRP_DATA_DESC_DIRECT ||
 340                  in_fmt == SRP_DATA_DESC_DIRECT) {
 341                 struct srp_direct_buf *data =
 342                         (struct srp_direct_buf *) cmd->add_data;
 343                 dma_unmap_single(dev, data->va, data->len, DMA_BIDIRECTIONAL);
 344         } else {
 345                 struct srp_indirect_buf *indirect =
 346                         (struct srp_indirect_buf *) cmd->add_data;
 347                 int num_mapped = indirect->table_desc.len /
 348                         sizeof(struct srp_direct_buf);
 349
 350                 if (num_mapped <= MAX_INDIRECT_BUFS) {
 351                         unmap_sg_list(num_mapped, dev, &indirect->desc_list[0]);
 352                         return;
 353                 }
 354
 355                 unmap_sg_list(num_mapped, dev, evt_struct->ext_list);
 356         }
 357 }
 358
 359 static int map_sg_list(struct scsi_cmnd *cmd, int nseg,
 360                        struct srp_direct_buf *md)
 361 {
 362         int i;
 363         struct scatterlist *sg;
 364         u64 total_length = 0;
 365
 366         scsi_for_each_sg(cmd, sg, nseg, i) {
 367                 struct srp_direct_buf *descr = md + i;
 368                 descr->va = sg_dma_address(sg);
 369                 descr->len = sg_dma_len(sg);
 370                 descr->key = 0;
 371                 total_length += sg_dma_len(sg);
 372         }
 373         return total_length;
 374 }
 375
 376 /**
 377  * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
 378  * @cmd:        Scsi_Cmnd with the scatterlist
 379  * @srp_cmd:    srp_cmd that contains the memory descriptor
 380  * @dev:        device for which to map dma memory
 381  *
 382  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
 383  * Returns 1 on success.
 384 */
 385 static int map_sg_data(struct scsi_cmnd *cmd,
 386                        struct srp_event_struct *evt_struct,
 387                        struct srp_cmd *srp_cmd, struct device *dev)
 388 {
 389
 390         int sg_mapped;
 391         u64 total_length = 0;
 392         struct srp_direct_buf *data =
 393                 (struct srp_direct_buf *) srp_cmd->add_data;
 394         struct srp_indirect_buf *indirect =
 395                 (struct srp_indirect_buf *) data;
 396
 397         sg_mapped = scsi_dma_map(cmd);
 398         if (!sg_mapped)
 399                 return 1;
 400         else if (sg_mapped < 0)
 401                 return 0;
 402
 403         set_srp_direction(cmd, srp_cmd, sg_mapped);
 404
 405         /* special case; we can use a single direct descriptor */
 406         if (sg_mapped == 1) {
 407                 map_sg_list(cmd, sg_mapped, data);
 408                 return 1;
 409         }
 410
 411         indirect->table_desc.va = 0;
 412         indirect->table_desc.len = sg_mapped * sizeof(struct srp_direct_buf);
 413         indirect->table_desc.key = 0;
 414
 415         if (sg_mapped <= MAX_INDIRECT_BUFS) {
 416                 total_length = map_sg_list(cmd, sg_mapped,
 417                                            &indirect->desc_list[0]);
 418                 indirect->len = total_length;
 419                 return 1;
 420         }
 421
 422         /* get indirect table */
 423         if (!evt_struct->ext_list) {
 424                 evt_struct->ext_list = (struct srp_direct_buf *)
 425                         dma_alloc_coherent(dev,
 426                                            SG_ALL * sizeof(struct srp_direct_buf),
 427                                            &evt_struct->ext_list_token, 0);
 428                 if (!evt_struct->ext_list) {
 429                         sdev_printk(KERN_ERR, cmd->device,
 430                                     "Can't allocate memory for indirect table\n");
 431                         return 0;
 432                 }
 433         }
 434
 435         total_length = map_sg_list(cmd, sg_mapped, evt_struct->ext_list);
 436
 437         indirect->len = total_length;
 438         indirect->table_desc.va = evt_struct->ext_list_token;
 439         indirect->table_desc.len = sg_mapped * sizeof(indirect->desc_list[0]);
 440         memcpy(indirect->desc_list, evt_struct->ext_list,
 441                MAX_INDIRECT_BUFS * sizeof(struct srp_direct_buf));
 442         return 1;
 443 }
 444
 445 /**
 446  * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
 447  * @cmd:        struct scsi_cmnd with the memory to be mapped
 448  * @srp_cmd:    srp_cmd that contains the memory descriptor
 449  * @dev:        dma device for which to map dma memory
 450  *
 451  * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds
 452  * Returns 1 on success.
 453 */
 454 static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
 455                                 struct srp_event_struct *evt_struct,
 456                                 struct srp_cmd *srp_cmd, struct device *dev)
 457 {
 458         switch (cmd->sc_data_direction) {
 459         case DMA_FROM_DEVICE:
 460         case DMA_TO_DEVICE:
 461                 break;
 462         case DMA_NONE:
 463                 return 1;
 464         case DMA_BIDIRECTIONAL:
 465                 sdev_printk(KERN_ERR, cmd->device,
 466                             "Can't map DMA_BIDIRECTIONAL to read/write\n");
 467                 return 0;
 468         default:
 469                 sdev_printk(KERN_ERR, cmd->device,
 470                             "Unknown data direction 0x%02x; can't map!\n",
 471                             cmd->sc_data_direction);
 472                 return 0;
 473         }
 474
 475         return map_sg_data(cmd, evt_struct, srp_cmd, dev);
 476 }
 477
 478 /**
 479  * purge_requests: Our virtual adapter just shut down.  purge any sent requests
 480  * @hostdata:    the adapter
 481  */
 482 static void purge_requests(struct ibmvscsi_host_data *hostdata, int error_code)
 483 {
 484         struct srp_event_struct *tmp_evt, *pos;
 485         unsigned long flags;
 486
 487         spin_lock_irqsave(hostdata->host->host_lock, flags);
 488         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
 489                 list_del(&tmp_evt->list);
 490                 del_timer(&tmp_evt->timer);
 491                 if (tmp_evt->cmnd) {
 492                         tmp_evt->cmnd->result = (error_code << 16);
 493                         unmap_cmd_data(&tmp_evt->iu.srp.cmd,
 494                                        tmp_evt,
 495                                        tmp_evt->hostdata->dev);
 496                         if (tmp_evt->cmnd_done)
 497                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
 498                 } else if (tmp_evt->done)
 499                         tmp_evt->done(tmp_evt);
 500                 free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);
 501         }
 502         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 503 }
 504
 505 /**
 506  * ibmvscsi_reset_host - Reset the connection to the server
 507  * @hostdata:   struct ibmvscsi_host_data to reset
 508 */
 509 static void ibmvscsi_reset_host(struct ibmvscsi_host_data *hostdata)
 510 {
 511         scsi_block_requests(hostdata->host);
 512         atomic_set(&hostdata->request_limit, 0);
 513
 514         purge_requests(hostdata, DID_ERROR);
 515         if ((ibmvscsi_ops->reset_crq_queue(&hostdata->queue, hostdata)) ||
 516             (ibmvscsi_ops->send_crq(hostdata, 0xC001000000000000LL, 0)) ||
 517             (vio_enable_interrupts(to_vio_dev(hostdata->dev)))) {
 518                 atomic_set(&hostdata->request_limit, -1);
 519                 dev_err(hostdata->dev, "error after reset\n");
 520         }
 521
 522         scsi_unblock_requests(hostdata->host);
 523 }
 524
 525 /**
 526  * ibmvscsi_timeout - Internal command timeout handler
 527  * @evt_struct: struct srp_event_struct that timed out
 528  *
 529  * Called when an internally generated command times out
 530 */
 531 static void ibmvscsi_timeout(struct srp_event_struct *evt_struct)
 532 {
 533         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
 534
 535         dev_err(hostdata->dev, "Command timed out (%x). Resetting connection\n",
 536                 evt_struct->iu.srp.cmd.opcode);
 537
 538         ibmvscsi_reset_host(hostdata);
 539 }
 540
 541
 542 /* ------------------------------------------------------------
 543  * Routines for sending and receiving SRPs
 544  */
 545 /**
 546  * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
 547  * @evt_struct: evt_struct to be sent
 548  * @hostdata:   ibmvscsi_host_data of host
 549  * @timeout:    timeout in seconds - 0 means do not time command
 550  *
 551  * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
 552  * Note that this routine assumes that host_lock is held for synchronization
 553 */
 554 static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
 555                                    struct ibmvscsi_host_data *hostdata,
 556                                    unsigned long timeout)
 557 {
 558         u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
 559         int request_status;
 560         int rc;
 561
 562         /* If we have exhausted our request limit, just fail this request,
 563          * unless it is for a reset or abort.
 564          * Note that there are rare cases involving driver generated requests
 565          * (such as task management requests) that the mid layer may think we
 566          * can handle more requests (can_queue) when we actually can't
 567          */
 568         if (evt_struct->crq.format == VIOSRP_SRP_FORMAT) {
 569                 request_status =
 570                         atomic_dec_if_positive(&hostdata->request_limit);
 571                 /* If request limit was -1 when we started, it is now even
 572                  * less than that
 573                  */
 574                 if (request_status < -1)
 575                         goto send_error;
 576                 /* Otherwise, we may have run out of requests. */
 577                 /* Abort and reset calls should make it through.
 578                  * Nothing except abort and reset should use the last two
 579                  * slots unless we had two or less to begin with.
 580                  */
 581                 else if (request_status < 2 &&
 582                          evt_struct->iu.srp.cmd.opcode != SRP_TSK_MGMT) {
 583                         /* In the case that we have less than two requests
 584                          * available, check the server limit as a combination
 585                          * of the request limit and the number of requests
 586                          * in-flight (the size of the send list).  If the
 587                          * server limit is greater than 2, return busy so
 588                          * that the last two are reserved for reset and abort.
 589                          */
 590                         int server_limit = request_status;
 591                         struct srp_event_struct *tmp_evt;
 592
 593                         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
 594                                 server_limit++;
 595                         }
 596
 597                         if (server_limit > 2)
 598                                 goto send_busy;
 599                 }
 600         }
 601
 602         /* Copy the IU into the transfer area */
 603         *evt_struct->xfer_iu = evt_struct->iu;
 604         evt_struct->xfer_iu->srp.rsp.tag = (u64)evt_struct;
 605
 606         /* Add this to the sent list.  We need to do this
 607          * before we actually send
 608          * in case it comes back REALLY fast
 609          */
 610         list_add_tail(&evt_struct->list, &hostdata->sent);
 611
 612         init_timer(&evt_struct->timer);
 613         if (timeout) {
 614                 evt_struct->timer.data = (unsigned long) evt_struct;
 615                 evt_struct->timer.expires = jiffies + (timeout * HZ);
 616                 evt_struct->timer.function = (void (*)(unsigned long))ibmvscsi_timeout;
 617                 add_timer(&evt_struct->timer);
 618         }
 619
 620         if ((rc =
 621              ibmvscsi_ops->send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
 622                 list_del(&evt_struct->list);
 623                 del_timer(&evt_struct->timer);
 624
 625                 dev_err(hostdata->dev, "send error %d\n", rc);
 626                 atomic_inc(&hostdata->request_limit);
 627                 goto send_error;
 628         }
 629
 630         return 0;
 631
 632  send_busy:
 633         unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
 634
 635         free_event_struct(&hostdata->pool, evt_struct);
 636         atomic_inc(&hostdata->request_limit);
 637         return SCSI_MLQUEUE_HOST_BUSY;
 638
 639  send_error:
 640         unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
 641
 642         if (evt_struct->cmnd != NULL) {
 643                 evt_struct->cmnd->result = DID_ERROR << 16;
 644                 evt_struct->cmnd_done(evt_struct->cmnd);
 645         } else if (evt_struct->done)
 646                 evt_struct->done(evt_struct);
 647
 648         free_event_struct(&hostdata->pool, evt_struct);
 649         return 0;
 650 }
 651
 652 /**
 653  * handle_cmd_rsp: -  Handle responses from commands
 654  * @evt_struct: srp_event_struct to be handled
 655  *
 656  * Used as a callback by when sending scsi cmds.
 657  * Gets called by ibmvscsi_handle_crq()
 658 */
 659 static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
 660 {
 661         struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
 662         struct scsi_cmnd *cmnd = evt_struct->cmnd;
 663
 664         if (unlikely(rsp->opcode != SRP_RSP)) {
 665                 if (printk_ratelimit())
 666                         dev_warn(evt_struct->hostdata->dev,
 667                                  "bad SRP RSP type %d\n", rsp->opcode);
 668         }
 669
 670         if (cmnd) {
 671                 cmnd->result = rsp->status;
 672                 if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
 673                         memcpy(cmnd->sense_buffer,
 674                                rsp->data,
 675                                rsp->sense_data_len);
 676                 unmap_cmd_data(&evt_struct->iu.srp.cmd,
 677                                evt_struct,
 678                                evt_struct->hostdata->dev);
 679
 680                 if (rsp->flags & SRP_RSP_FLAG_DOOVER)
 681                         scsi_set_resid(cmnd, rsp->data_out_res_cnt);
 682                 else if (rsp->flags & SRP_RSP_FLAG_DIOVER)
 683                         scsi_set_resid(cmnd, rsp->data_in_res_cnt);
 684         }
 685
 686         if (evt_struct->cmnd_done)
 687                 evt_struct->cmnd_done(cmnd);
 688 }
 689
 690 /**
 691  * lun_from_dev: - Returns the lun of the scsi device
 692  * @dev:        struct scsi_device
 693  *
 694 */
 695 static inline u16 lun_from_dev(struct scsi_device *dev)
 696 {
 697         return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
 698 }
 699
 700 /**
 701  * ibmvscsi_queue: - The queuecommand function of the scsi template
 702  * @cmd:        struct scsi_cmnd to be executed
 703  * @done:       Callback function to be called when cmd is completed
 704 */
 705 static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
 706                                  void (*done) (struct scsi_cmnd *))
 707 {
 708         struct srp_cmd *srp_cmd;
 709         struct srp_event_struct *evt_struct;
 710         struct srp_indirect_buf *indirect;
 711         struct ibmvscsi_host_data *hostdata = shost_priv(cmnd->device->host);
 712         u16 lun = lun_from_dev(cmnd->device);
 713         u8 out_fmt, in_fmt;
 714
 715         evt_struct = get_event_struct(&hostdata->pool);
 716         if (!evt_struct)
 717                 return SCSI_MLQUEUE_HOST_BUSY;
 718
 719         /* Set up the actual SRP IU */
 720         srp_cmd = &evt_struct->iu.srp.cmd;
 721         memset(srp_cmd, 0x00, SRP_MAX_IU_LEN);
 722         srp_cmd->opcode = SRP_CMD;
 723         memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
 724         srp_cmd->lun = ((u64) lun) << 48;
 725
 726         if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
 727                 sdev_printk(KERN_ERR, cmnd->device, "couldn't convert cmd to srp_cmd\n");
 728                 free_event_struct(&hostdata->pool, evt_struct);
 729                 return SCSI_MLQUEUE_HOST_BUSY;
 730         }
 731
 732         init_event_struct(evt_struct,
 733                           handle_cmd_rsp,
 734                           VIOSRP_SRP_FORMAT,
 735                           cmnd->timeout_per_command/HZ);
 736
 737         evt_struct->cmnd = cmnd;
 738         evt_struct->cmnd_done = done;
 739
 740         /* Fix up dma address of the buffer itself */
 741         indirect = (struct srp_indirect_buf *) srp_cmd->add_data;
 742         out_fmt = srp_cmd->buf_fmt >> 4;
 743         in_fmt = srp_cmd->buf_fmt & ((1U << 4) - 1);
 744         if ((in_fmt == SRP_DATA_DESC_INDIRECT ||
 745              out_fmt == SRP_DATA_DESC_INDIRECT) &&
 746             indirect->table_desc.va == 0) {
 747                 indirect->table_desc.va = evt_struct->crq.IU_data_ptr +
 748                         offsetof(struct srp_cmd, add_data) +
 749                         offsetof(struct srp_indirect_buf, desc_list);
 750         }
 751
 752         return ibmvscsi_send_srp_event(evt_struct, hostdata, 0);
 753 }
 754
 755 /* ------------------------------------------------------------
 756  * Routines for driver initialization
 757  */
 758 /**
 759  * adapter_info_rsp: - Handle response to MAD adapter info request
 760  * @evt_struct: srp_event_struct with the response
 761  *
 762  * Used as a "done" callback by when sending adapter_info. Gets called
 763  * by ibmvscsi_handle_crq()
 764 */
 765 static void adapter_info_rsp(struct srp_event_struct *evt_struct)
 766 {
 767         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
 768         dma_unmap_single(hostdata->dev,
 769                          evt_struct->iu.mad.adapter_info.buffer,
 770                          evt_struct->iu.mad.adapter_info.common.length,
 771                          DMA_BIDIRECTIONAL);
 772
 773         if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
 774                 dev_err(hostdata->dev, "error %d getting adapter info\n",
 775                         evt_struct->xfer_iu->mad.adapter_info.common.status);
 776         } else {
 777                 dev_info(hostdata->dev, "host srp version: %s, "
 778                          "host partition %s (%d), OS %d, max io %u\n",
 779                          hostdata->madapter_info.srp_version,
 780                          hostdata->madapter_info.partition_name,
 781                          hostdata->madapter_info.partition_number,
 782                          hostdata->madapter_info.os_type,
 783                          hostdata->madapter_info.port_max_txu[0]);
 784
 785                 if (hostdata->madapter_info.port_max_txu[0])
 786                         hostdata->host->max_sectors =
 787                                 hostdata->madapter_info.port_max_txu[0] >> 9;
 788
 789                 if (hostdata->madapter_info.os_type == 3 &&
 790                     strcmp(hostdata->madapter_info.srp_version, "1.6a") <= 0) {
 791                         dev_err(hostdata->dev, "host (Ver. %s) doesn't support large transfers\n",
 792                                 hostdata->madapter_info.srp_version);
 793                         dev_err(hostdata->dev, "limiting scatterlists to %d\n",
 794                                 MAX_INDIRECT_BUFS);
 795                         hostdata->host->sg_tablesize = MAX_INDIRECT_BUFS;
 796                 }
 797         }
 798 }
 799
 800 /**
 801  * send_mad_adapter_info: - Sends the mad adapter info request
 802  *      and stores the result so it can be retrieved with
 803  *      sysfs.  We COULD consider causing a failure if the
 804  *      returned SRP version doesn't match ours.
 805  * @hostdata:   ibmvscsi_host_data of host
 806  *
 807  * Returns zero if successful.
 808 */
 809 static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
 810 {
 811         struct viosrp_adapter_info *req;
 812         struct srp_event_struct *evt_struct;
 813         unsigned long flags;
 814         dma_addr_t addr;
 815
 816         evt_struct = get_event_struct(&hostdata->pool);
 817         if (!evt_struct) {
 818                 dev_err(hostdata->dev,
 819                         "couldn't allocate an event for ADAPTER_INFO_REQ!\n");
 820                 return;
 821         }
 822
 823         init_event_struct(evt_struct,
 824                           adapter_info_rsp,
 825                           VIOSRP_MAD_FORMAT,
 826                           init_timeout);
 827
 828         req = &evt_struct->iu.mad.adapter_info;
 829         memset(req, 0x00, sizeof(*req));
 830
 831         req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
 832         req->common.length = sizeof(hostdata->madapter_info);
 833         req->buffer = addr = dma_map_single(hostdata->dev,
 834                                             &hostdata->madapter_info,
 835                                             sizeof(hostdata->madapter_info),
 836                                             DMA_BIDIRECTIONAL);
 837
 838         if (dma_mapping_error(req->buffer)) {
 839                 dev_err(hostdata->dev, "Unable to map request_buffer for adapter_info!\n");
 840                 free_event_struct(&hostdata->pool, evt_struct);
 841                 return;
 842         }
 843
 844         spin_lock_irqsave(hostdata->host->host_lock, flags);
 845         if (ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2)) {
 846                 dev_err(hostdata->dev, "couldn't send ADAPTER_INFO_REQ!\n");
 847                 dma_unmap_single(hostdata->dev,
 848                                  addr,
 849                                  sizeof(hostdata->madapter_info),
 850                                  DMA_BIDIRECTIONAL);
 851         }
 852         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 853 };
 854
 855 /**
 856  * login_rsp: - Handle response to SRP login request
 857  * @evt_struct: srp_event_struct with the response
 858  *
 859  * Used as a "done" callback by when sending srp_login. Gets called
 860  * by ibmvscsi_handle_crq()
 861 */
 862 static void login_rsp(struct srp_event_struct *evt_struct)
 863 {
 864         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
 865         switch (evt_struct->xfer_iu->srp.login_rsp.opcode) {
 866         case SRP_LOGIN_RSP:     /* it worked! */
 867                 break;
 868         case SRP_LOGIN_REJ:     /* refused! */
 869                 dev_info(hostdata->dev, "SRP_LOGIN_REJ reason %u\n",
 870                          evt_struct->xfer_iu->srp.login_rej.reason);
 871                 /* Login failed.  */
 872                 atomic_set(&hostdata->request_limit, -1);
 873                 return;
 874         default:
 875                 dev_err(hostdata->dev, "Invalid login response typecode 0x%02x!\n",
 876                         evt_struct->xfer_iu->srp.login_rsp.opcode);
 877                 /* Login failed.  */
 878                 atomic_set(&hostdata->request_limit, -1);
 879                 return;
 880         }
 881
 882         dev_info(hostdata->dev, "SRP_LOGIN succeeded\n");
 883
 884         if (evt_struct->xfer_iu->srp.login_rsp.req_lim_delta < 0)
 885                 dev_err(hostdata->dev, "Invalid request_limit.\n");
 886
 887         /* Now we know what the real request-limit is.
 888          * This value is set rather than added to request_limit because
 889          * request_limit could have been set to -1 by this client.
 890          */
 891         atomic_set(&hostdata->request_limit,
 892                    evt_struct->xfer_iu->srp.login_rsp.req_lim_delta);
 893
 894         /* If we had any pending I/Os, kick them */
 895         scsi_unblock_requests(hostdata->host);
 896
 897         send_mad_adapter_info(hostdata);
 898         return;
 899 }
 900
 901 /**
 902  * send_srp_login: - Sends the srp login
 903  * @hostdata:   ibmvscsi_host_data of host
 904  *
 905  * Returns zero if successful.
 906 */
 907 static int send_srp_login(struct ibmvscsi_host_data *hostdata)
 908 {
 909         int rc;
 910         unsigned long flags;
 911         struct srp_login_req *login;
 912         struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
 913         if (!evt_struct) {
 914                 dev_err(hostdata->dev, "couldn't allocate an event for login req!\n");
 915                 return FAILED;
 916         }
 917
 918         init_event_struct(evt_struct,
 919                           login_rsp,
 920                           VIOSRP_SRP_FORMAT,
 921                           init_timeout);
 922
 923         login = &evt_struct->iu.srp.login_req;
 924         memset(login, 0x00, sizeof(struct srp_login_req));
 925         login->opcode = SRP_LOGIN_REQ;
 926         login->req_it_iu_len = sizeof(union srp_iu);
 927         login->req_buf_fmt = SRP_BUF_FORMAT_DIRECT | SRP_BUF_FORMAT_INDIRECT;
 928
 929         spin_lock_irqsave(hostdata->host->host_lock, flags);
 930         /* Start out with a request limit of 1, since this is negotiated in
 931          * the login request we are just sending
 932          */
 933         atomic_set(&hostdata->request_limit, 1);
 934
 935         rc = ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2);
 936         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 937         dev_info(hostdata->dev, "sent SRP login\n");
 938         return rc;
 939 };
 940
 941 /**
 942  * sync_completion: Signal that a synchronous command has completed
 943  * Note that after returning from this call, the evt_struct is freed.
 944  * the caller waiting on this completion shouldn't touch the evt_struct
 945  * again.
 946  */
 947 static void sync_completion(struct srp_event_struct *evt_struct)
 948 {
 949         /* copy the response back */
 950         if (evt_struct->sync_srp)
 951                 *evt_struct->sync_srp = *evt_struct->xfer_iu;
 952
 953         complete(&evt_struct->comp);
 954 }
 955
 956 /**
 957  * ibmvscsi_abort: Abort a command...from scsi host template
 958  * send this over to the server and wait synchronously for the response
 959  */
 960 static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
 961 {
 962         struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
 963         struct srp_tsk_mgmt *tsk_mgmt;
 964         struct srp_event_struct *evt;
 965         struct srp_event_struct *tmp_evt, *found_evt;
 966         union viosrp_iu srp_rsp;
 967         int rsp_rc;
 968         unsigned long flags;
 969         u16 lun = lun_from_dev(cmd->device);
 970
 971         /* First, find this command in our sent list so we can figure
 972          * out the correct tag
 973          */
 974         spin_lock_irqsave(hostdata->host->host_lock, flags);
 975         found_evt = NULL;
 976         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
 977                 if (tmp_evt->cmnd == cmd) {
 978                         found_evt = tmp_evt;
 979                         break;
 980                 }
 981         }
 982
 983         if (!found_evt) {
 984                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 985                 return SUCCESS;
 986         }
 987
 988         evt = get_event_struct(&hostdata->pool);
 989         if (evt == NULL) {
 990                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 991                 sdev_printk(KERN_ERR, cmd->device, "failed to allocate abort event\n");
 992                 return FAILED;
 993         }
 994
 995         init_event_struct(evt,
 996                           sync_completion,
 997                           VIOSRP_SRP_FORMAT,
 998                           init_timeout);
 999
1000         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1001
1002         /* Set up an abort SRP command */
1003         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1004         tsk_mgmt->opcode = SRP_TSK_MGMT;
1005         tsk_mgmt->lun = ((u64) lun) << 48;
1006         tsk_mgmt->tsk_mgmt_func = SRP_TSK_ABORT_TASK;
1007         tsk_mgmt->task_tag = (u64) found_evt;
1008
1009         sdev_printk(KERN_INFO, cmd->device, "aborting command. lun 0x%lx, tag 0x%lx\n",
1010                     tsk_mgmt->lun, tsk_mgmt->task_tag);
1011
1012         evt->sync_srp = &srp_rsp;
1013         init_completion(&evt->comp);
1014         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, init_timeout * 2);
1015         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1016         if (rsp_rc != 0) {
1017                 sdev_printk(KERN_ERR, cmd->device,
1018                             "failed to send abort() event. rc=%d\n", rsp_rc);
1019                 return FAILED;
1020         }
1021
1022         wait_for_completion(&evt->comp);
1023
1024         /* make sure we got a good response */
1025         if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
1026                 if (printk_ratelimit())
1027                         sdev_printk(KERN_WARNING, cmd->device, "abort bad SRP RSP type %d\n",
1028                                     srp_rsp.srp.rsp.opcode);
1029                 return FAILED;
1030         }
1031
1032         if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
1033                 rsp_rc = *((int *)srp_rsp.srp.rsp.data);
1034         else
1035                 rsp_rc = srp_rsp.srp.rsp.status;
1036
1037         if (rsp_rc) {
1038                 if (printk_ratelimit())
1039                         sdev_printk(KERN_WARNING, cmd->device,
1040                                     "abort code %d for task tag 0x%lx\n",
1041                                     rsp_rc, tsk_mgmt->task_tag);
1042                 return FAILED;
1043         }
1044
1045         /* Because we dropped the spinlock above, it's possible
1046          * The event is no longer in our list.  Make sure it didn't
1047          * complete while we were aborting
1048          */
1049         spin_lock_irqsave(hostdata->host->host_lock, flags);
1050         found_evt = NULL;
1051         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
1052                 if (tmp_evt->cmnd == cmd) {
1053                         found_evt = tmp_evt;
1054                         break;
1055                 }
1056         }
1057
1058         if (found_evt == NULL) {
1059                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1060                 sdev_printk(KERN_INFO, cmd->device, "aborted task tag 0x%lx completed\n",
1061                             tsk_mgmt->task_tag);
1062                 return SUCCESS;
1063         }
1064
1065         sdev_printk(KERN_INFO, cmd->device, "successfully aborted task tag 0x%lx\n",
1066                     tsk_mgmt->task_tag);
1067
1068         cmd->result = (DID_ABORT << 16);
1069         list_del(&found_evt->list);
1070         unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
1071                        found_evt->hostdata->dev);
1072         free_event_struct(&found_evt->hostdata->pool, found_evt);
1073         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1074         atomic_inc(&hostdata->request_limit);
1075         return SUCCESS;
1076 }
1077
1078 /**
1079  * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host
1080  * template send this over to the server and wait synchronously for the
1081  * response
1082  */
1083 static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
1084 {
1085         struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
1086         struct srp_tsk_mgmt *tsk_mgmt;
1087         struct srp_event_struct *evt;
1088         struct srp_event_struct *tmp_evt, *pos;
1089         union viosrp_iu srp_rsp;
1090         int rsp_rc;
1091         unsigned long flags;
1092         u16 lun = lun_from_dev(cmd->device);
1093
1094         spin_lock_irqsave(hostdata->host->host_lock, flags);
1095         evt = get_event_struct(&hostdata->pool);
1096         if (evt == NULL) {
1097                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1098                 sdev_printk(KERN_ERR, cmd->device, "failed to allocate reset event\n");
1099                 return FAILED;
1100         }
1101
1102         init_event_struct(evt,
1103                           sync_completion,
1104                           VIOSRP_SRP_FORMAT,
1105                           init_timeout);
1106
1107         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1108
1109         /* Set up a lun reset SRP command */
1110         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1111         tsk_mgmt->opcode = SRP_TSK_MGMT;
1112         tsk_mgmt->lun = ((u64) lun) << 48;
1113         tsk_mgmt->tsk_mgmt_func = SRP_TSK_LUN_RESET;
1114
1115         sdev_printk(KERN_INFO, cmd->device, "resetting device. lun 0x%lx\n",
1116                     tsk_mgmt->lun);
1117
1118         evt->sync_srp = &srp_rsp;
1119         init_completion(&evt->comp);
1120         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, init_timeout * 2);
1121         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1122         if (rsp_rc != 0) {
1123                 sdev_printk(KERN_ERR, cmd->device,
1124                             "failed to send reset event. rc=%d\n", rsp_rc);
1125                 return FAILED;
1126         }
1127
1128         wait_for_completion(&evt->comp);
1129
1130         /* make sure we got a good response */
1131         if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
1132                 if (printk_ratelimit())
1133                         sdev_printk(KERN_WARNING, cmd->device, "reset bad SRP RSP type %d\n",
1134                                     srp_rsp.srp.rsp.opcode);
1135                 return FAILED;
1136         }
1137
1138         if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
1139                 rsp_rc = *((int *)srp_rsp.srp.rsp.data);
1140         else
1141                 rsp_rc = srp_rsp.srp.rsp.status;
1142
1143         if (rsp_rc) {
1144                 if (printk_ratelimit())
1145                         sdev_printk(KERN_WARNING, cmd->device,
1146                                     "reset code %d for task tag 0x%lx\n",
1147                                     rsp_rc, tsk_mgmt->task_tag);
1148                 return FAILED;
1149         }
1150
1151         /* We need to find all commands for this LUN that have not yet been
1152          * responded to, and fail them with DID_RESET
1153          */
1154         spin_lock_irqsave(hostdata->host->host_lock, flags);
1155         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1156                 if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
1157                         if (tmp_evt->cmnd)
1158                                 tmp_evt->cmnd->result = (DID_RESET << 16);
1159                         list_del(&tmp_evt->list);
1160                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
1161                                        tmp_evt->hostdata->dev);
1162                         free_event_struct(&tmp_evt->hostdata->pool,
1163                                                    tmp_evt);
1164                         atomic_inc(&hostdata->request_limit);
1165                         if (tmp_evt->cmnd_done)
1166                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1167                         else if (tmp_evt->done)
1168                                 tmp_evt->done(tmp_evt);
1169                 }
1170         }
1171         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1172         return SUCCESS;
1173 }
1174
1175 /**
1176  * ibmvscsi_eh_host_reset_handler - Reset the connection to the server
1177  * @cmd:        struct scsi_cmnd having problems
1178 */
1179 static int ibmvscsi_eh_host_reset_handler(struct scsi_cmnd *cmd)
1180 {
1181         unsigned long wait_switch = 0;
1182         struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
1183
1184         dev_err(hostdata->dev, "Resetting connection due to error recovery\n");
1185
1186         ibmvscsi_reset_host(hostdata);
1187
1188         for (wait_switch = jiffies + (init_timeout * HZ);
1189              time_before(jiffies, wait_switch) &&
1190                      atomic_read(&hostdata->request_limit) < 2;) {
1191
1192                 msleep(10);
1193         }
1194
1195         if (atomic_read(&hostdata->request_limit) <= 0)
1196                 return FAILED;
1197
1198         return SUCCESS;
1199 }
1200
1201 /**
1202  * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
1203  * @crq:        Command/Response queue
1204  * @hostdata:   ibmvscsi_host_data of host
1205  *
1206 */
1207 void ibmvscsi_handle_crq(struct viosrp_crq *crq,
1208                          struct ibmvscsi_host_data *hostdata)
1209 {
1210         long rc;
1211         unsigned long flags;
1212         struct srp_event_struct *evt_struct =
1213             (struct srp_event_struct *)crq->IU_data_ptr;
1214         switch (crq->valid) {
1215         case 0xC0:              /* initialization */
1216                 switch (crq->format) {
1217                 case 0x01:      /* Initialization message */
1218                         dev_info(hostdata->dev, "partner initialized\n");
1219                         /* Send back a response */
1220                         if ((rc = ibmvscsi_ops->send_crq(hostdata,
1221                                                          0xC002000000000000LL, 0)) == 0) {
1222                                 /* Now login */
1223                                 send_srp_login(hostdata);
1224                         } else {
1225                                 dev_err(hostdata->dev, "Unable to send init rsp. rc=%ld\n", rc);
1226                         }
1227
1228                         break;
1229                 case 0x02:      /* Initialization response */
1230                         dev_info(hostdata->dev, "partner initialization complete\n");
1231
1232                         /* Now login */
1233                         send_srp_login(hostdata);
1234                         break;
1235                 default:
1236                         dev_err(hostdata->dev, "unknown crq message type: %d\n", crq->format);
1237                 }
1238                 return;
1239         case 0xFF:      /* Hypervisor telling us the connection is closed */
1240                 scsi_block_requests(hostdata->host);
1241                 atomic_set(&hostdata->request_limit, 0);
1242                 if (crq->format == 0x06) {
1243                         /* We need to re-setup the interpartition connection */
1244                         dev_info(hostdata->dev, "Re-enabling adapter!\n");
1245                         purge_requests(hostdata, DID_REQUEUE);
1246                         if ((ibmvscsi_ops->reenable_crq_queue(&hostdata->queue,
1247                                                               hostdata)) ||
1248                             (ibmvscsi_ops->send_crq(hostdata,
1249                                                     0xC001000000000000LL, 0))) {
1250                                         atomic_set(&hostdata->request_limit,
1251                                                    -1);
1252                                         dev_err(hostdata->dev, "error after enable\n");
1253                         }
1254                 } else {
1255                         dev_err(hostdata->dev, "Virtual adapter failed rc %d!\n",
1256                                 crq->format);
1257
1258                         purge_requests(hostdata, DID_ERROR);
1259                         if ((ibmvscsi_ops->reset_crq_queue(&hostdata->queue,
1260                                                            hostdata)) ||
1261                             (ibmvscsi_ops->send_crq(hostdata,
1262                                                     0xC001000000000000LL, 0))) {
1263                                         atomic_set(&hostdata->request_limit,
1264                                                    -1);
1265                                         dev_err(hostdata->dev, "error after reset\n");
1266                         }
1267                 }
1268                 scsi_unblock_requests(hostdata->host);
1269                 return;
1270         case 0x80:              /* real payload */
1271                 break;
1272         default:
1273                 dev_err(hostdata->dev, "got an invalid message type 0x%02x\n",
1274                         crq->valid);
1275                 return;
1276         }
1277
1278         /* The only kind of payload CRQs we should get are responses to
1279          * things we send. Make sure this response is to something we
1280          * actually sent
1281          */
1282         if (!valid_event_struct(&hostdata->pool, evt_struct)) {
1283                 dev_err(hostdata->dev, "returned correlation_token 0x%p is invalid!\n",
1284                        (void *)crq->IU_data_ptr);
1285                 return;
1286         }
1287
1288         if (atomic_read(&evt_struct->free)) {
1289                 dev_err(hostdata->dev, "received duplicate correlation_token 0x%p!\n",
1290                         (void *)crq->IU_data_ptr);
1291                 return;
1292         }
1293
1294         if (crq->format == VIOSRP_SRP_FORMAT)
1295                 atomic_add(evt_struct->xfer_iu->srp.rsp.req_lim_delta,
1296                            &hostdata->request_limit);
1297
1298         del_timer(&evt_struct->timer);
1299
1300         if (evt_struct->done)
1301                 evt_struct->done(evt_struct);
1302         else
1303                 dev_err(hostdata->dev, "returned done() is NULL; not running it!\n");
1304
1305         /*
1306          * Lock the host_lock before messing with these structures, since we
1307          * are running in a task context
1308          */
1309         spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
1310         list_del(&evt_struct->list);
1311         free_event_struct(&evt_struct->hostdata->pool, evt_struct);
1312         spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
1313 }
1314
1315 /**
1316  * ibmvscsi_get_host_config: Send the command to the server to get host
1317  * configuration data.  The data is opaque to us.
1318  */
1319 static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
1320                                    unsigned char *buffer, int length)
1321 {
1322         struct viosrp_host_config *host_config;
1323         struct srp_event_struct *evt_struct;
1324         unsigned long flags;
1325         dma_addr_t addr;
1326         int rc;
1327
1328         evt_struct = get_event_struct(&hostdata->pool);
1329         if (!evt_struct) {
1330                 dev_err(hostdata->dev, "couldn't allocate event for HOST_CONFIG!\n");
1331                 return -1;
1332         }
1333
1334         init_event_struct(evt_struct,
1335                           sync_completion,
1336                           VIOSRP_MAD_FORMAT,
1337                           init_timeout);
1338
1339         host_config = &evt_struct->iu.mad.host_config;
1340
1341         /* Set up a lun reset SRP command */
1342         memset(host_config, 0x00, sizeof(*host_config));
1343         host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
1344         host_config->common.length = length;
1345         host_config->buffer = addr = dma_map_single(hostdata->dev, buffer,
1346                                                     length,
1347                                                     DMA_BIDIRECTIONAL);
1348
1349         if (dma_mapping_error(host_config->buffer)) {
1350                 dev_err(hostdata->dev, "dma_mapping error getting host config\n");
1351                 free_event_struct(&hostdata->pool, evt_struct);
1352                 return -1;
1353         }
1354
1355         init_completion(&evt_struct->comp);
1356         spin_lock_irqsave(hostdata->host->host_lock, flags);
1357         rc = ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2);
1358         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1359         if (rc == 0)
1360                 wait_for_completion(&evt_struct->comp);
1361         dma_unmap_single(hostdata->dev, addr, length, DMA_BIDIRECTIONAL);
1362
1363         return rc;
1364 }
1365
1366 /**
1367  * ibmvscsi_slave_configure: Set the "allow_restart" flag for each disk.
1368  * @sdev:       struct scsi_device device to configure
1369  *
1370  * Enable allow_restart for a device if it is a disk.  Adjust the
1371  * queue_depth here also as is required by the documentation for
1372  * struct scsi_host_template.
1373  */
1374 static int ibmvscsi_slave_configure(struct scsi_device *sdev)
1375 {
1376         struct Scsi_Host *shost = sdev->host;
1377         unsigned long lock_flags = 0;
1378
1379         spin_lock_irqsave(shost->host_lock, lock_flags);
1380         if (sdev->type == TYPE_DISK)
1381                 sdev->allow_restart = 1;
1382         scsi_adjust_queue_depth(sdev, 0, shost->cmd_per_lun);
1383         spin_unlock_irqrestore(shost->host_lock, lock_flags);
1384         return 0;
1385 }
1386
1387 /**
1388  * ibmvscsi_change_queue_depth - Change the device's queue depth
1389  * @sdev:       scsi device struct
1390  * @qdepth:     depth to set
1391  *
1392  * Return value:
1393  *      actual depth set
1394  **/
1395 static int ibmvscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
1396 {
1397         if (qdepth > IBMVSCSI_MAX_CMDS_PER_LUN)
1398                 qdepth = IBMVSCSI_MAX_CMDS_PER_LUN;
1399
1400         scsi_adjust_queue_depth(sdev, 0, qdepth);
1401         return sdev->queue_depth;
1402 }
1403
1404 /* ------------------------------------------------------------
1405  * sysfs attributes
1406  */
1407 static ssize_t show_host_srp_version(struct class_device *class_dev, char *buf)
1408 {
1409         struct Scsi_Host *shost = class_to_shost(class_dev);
1410         struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1411         int len;
1412
1413         len = snprintf(buf, PAGE_SIZE, "%s\n",
1414                        hostdata->madapter_info.srp_version);
1415         return len;
1416 }
1417
1418 static struct class_device_attribute ibmvscsi_host_srp_version = {
1419         .attr = {
1420                  .name = "srp_version",
1421                  .mode = S_IRUGO,
1422                  },
1423         .show = show_host_srp_version,
1424 };
1425
1426 static ssize_t show_host_partition_name(struct class_device *class_dev,
1427                                         char *buf)
1428 {
1429         struct Scsi_Host *shost = class_to_shost(class_dev);
1430         struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1431         int len;
1432
1433         len = snprintf(buf, PAGE_SIZE, "%s\n",
1434                        hostdata->madapter_info.partition_name);
1435         return len;
1436 }
1437
1438 static struct class_device_attribute ibmvscsi_host_partition_name = {
1439         .attr = {
1440                  .name = "partition_name",
1441                  .mode = S_IRUGO,
1442                  },
1443         .show = show_host_partition_name,
1444 };
1445
1446 static ssize_t show_host_partition_number(struct class_device *class_dev,
1447                                           char *buf)
1448 {
1449         struct Scsi_Host *shost = class_to_shost(class_dev);
1450         struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1451         int len;
1452
1453         len = snprintf(buf, PAGE_SIZE, "%d\n",
1454                        hostdata->madapter_info.partition_number);
1455         return len;
1456 }
1457
1458 static struct class_device_attribute ibmvscsi_host_partition_number = {
1459         .attr = {
1460                  .name = "partition_number",
1461                  .mode = S_IRUGO,
1462                  },
1463         .show = show_host_partition_number,
1464 };
1465
1466 static ssize_t show_host_mad_version(struct class_device *class_dev, char *buf)
1467 {
1468         struct Scsi_Host *shost = class_to_shost(class_dev);
1469         struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1470         int len;
1471
1472         len = snprintf(buf, PAGE_SIZE, "%d\n",
1473                        hostdata->madapter_info.mad_version);
1474         return len;
1475 }
1476
1477 static struct class_device_attribute ibmvscsi_host_mad_version = {
1478         .attr = {
1479                  .name = "mad_version",
1480                  .mode = S_IRUGO,
1481                  },
1482         .show = show_host_mad_version,
1483 };
1484
1485 static ssize_t show_host_os_type(struct class_device *class_dev, char *buf)
1486 {
1487         struct Scsi_Host *shost = class_to_shost(class_dev);
1488         struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1489         int len;
1490
1491         len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
1492         return len;
1493 }
1494
1495 static struct class_device_attribute ibmvscsi_host_os_type = {
1496         .attr = {
1497                  .name = "os_type",
1498                  .mode = S_IRUGO,
1499                  },
1500         .show = show_host_os_type,
1501 };
1502
1503 static ssize_t show_host_config(struct class_device *class_dev, char *buf)
1504 {
1505         struct Scsi_Host *shost = class_to_shost(class_dev);
1506         struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1507
1508         /* returns null-terminated host config data */
1509         if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
1510                 return strlen(buf);
1511         else
1512                 return 0;
1513 }
1514
1515 static struct class_device_attribute ibmvscsi_host_config = {
1516         .attr = {
1517                  .name = "config",
1518                  .mode = S_IRUGO,
1519                  },
1520         .show = show_host_config,
1521 };
1522
1523 static struct class_device_attribute *ibmvscsi_attrs[] = {
1524         &ibmvscsi_host_srp_version,
1525         &ibmvscsi_host_partition_name,
1526         &ibmvscsi_host_partition_number,
1527         &ibmvscsi_host_mad_version,
1528         &ibmvscsi_host_os_type,
1529         &ibmvscsi_host_config,
1530         NULL
1531 };
1532
1533 /* ------------------------------------------------------------
1534  * SCSI driver registration
1535  */
1536 static struct scsi_host_template driver_template = {
1537         .module = THIS_MODULE,
1538         .name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
1539         .proc_name = "ibmvscsi",
1540         .queuecommand = ibmvscsi_queuecommand,
1541         .eh_abort_handler = ibmvscsi_eh_abort_handler,
1542         .eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
1543         .eh_host_reset_handler = ibmvscsi_eh_host_reset_handler,
1544         .slave_configure = ibmvscsi_slave_configure,
1545         .change_queue_depth = ibmvscsi_change_queue_depth,
1546         .cmd_per_lun = 16,
1547         .can_queue = IBMVSCSI_MAX_REQUESTS_DEFAULT,
1548         .this_id = -1,
1549         .sg_tablesize = SG_ALL,
1550         .use_clustering = ENABLE_CLUSTERING,
1551         .use_sg_chaining = ENABLE_SG_CHAINING,
1552         .shost_attrs = ibmvscsi_attrs,
1553 };
1554
1555 /**
1556  * Called by bus code for each adapter
1557  */
1558 static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1559 {
1560         struct ibmvscsi_host_data *hostdata;
1561         struct Scsi_Host *host;
1562         struct device *dev = &vdev->dev;
1563         struct srp_rport_identifiers ids;
1564         struct srp_rport *rport;
1565         unsigned long wait_switch = 0;
1566         int rc;
1567
1568         vdev->dev.driver_data = NULL;
1569
1570         driver_template.can_queue = max_requests;
1571         host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
1572         if (!host) {
1573                 dev_err(&vdev->dev, "couldn't allocate host data\n");
1574                 goto scsi_host_alloc_failed;
1575         }
1576
1577         host->transportt = ibmvscsi_transport_template;
1578         hostdata = shost_priv(host);
1579         memset(hostdata, 0x00, sizeof(*hostdata));
1580         INIT_LIST_HEAD(&hostdata->sent);
1581         hostdata->host = host;
1582         hostdata->dev = dev;
1583         atomic_set(&hostdata->request_limit, -1);
1584         hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
1585
1586         rc = ibmvscsi_ops->init_crq_queue(&hostdata->queue, hostdata, max_requests);
1587         if (rc != 0 && rc != H_RESOURCE) {
1588                 dev_err(&vdev->dev, "couldn't initialize crq. rc=%d\n", rc);
1589                 goto init_crq_failed;
1590         }
1591         if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
1592                 dev_err(&vdev->dev, "couldn't initialize event pool\n");
1593                 goto init_pool_failed;
1594         }
1595
1596         host->max_lun = 8;
1597         host->max_id = max_id;
1598         host->max_channel = max_channel;
1599
1600         if (scsi_add_host(hostdata->host, hostdata->dev))
1601                 goto add_host_failed;
1602
1603         /* we don't have a proper target_port_id so let's use the fake one */
1604         memcpy(ids.port_id, hostdata->madapter_info.partition_name,
1605                sizeof(ids.port_id));
1606         ids.roles = SRP_RPORT_ROLE_TARGET;
1607         rport = srp_rport_add(host, &ids);
1608         if (IS_ERR(rport))
1609                 goto add_srp_port_failed;
1610
1611         /* Try to send an initialization message.  Note that this is allowed
1612          * to fail if the other end is not acive.  In that case we don't
1613          * want to scan
1614          */
1615         if (ibmvscsi_ops->send_crq(hostdata, 0xC001000000000000LL, 0) == 0
1616             || rc == H_RESOURCE) {
1617                 /*
1618                  * Wait around max init_timeout secs for the adapter to finish
1619                  * initializing. When we are done initializing, we will have a
1620                  * valid request_limit.  We don't want Linux scanning before
1621                  * we are ready.
1622                  */
1623                 for (wait_switch = jiffies + (init_timeout * HZ);
1624                      time_before(jiffies, wait_switch) &&
1625                      atomic_read(&hostdata->request_limit) < 2;) {
1626
1627                         msleep(10);
1628                 }
1629
1630                 /* if we now have a valid request_limit, initiate a scan */
1631                 if (atomic_read(&hostdata->request_limit) > 0)
1632                         scsi_scan_host(host);
1633         }
1634
1635         vdev->dev.driver_data = hostdata;
1636         return 0;
1637
1638       add_srp_port_failed:
1639         scsi_remove_host(hostdata->host);
1640       add_host_failed:
1641         release_event_pool(&hostdata->pool, hostdata);
1642       init_pool_failed:
1643         ibmvscsi_ops->release_crq_queue(&hostdata->queue, hostdata, max_requests);
1644       init_crq_failed:
1645         scsi_host_put(host);
1646       scsi_host_alloc_failed:
1647         return -1;
1648 }
1649
1650 static int ibmvscsi_remove(struct vio_dev *vdev)
1651 {
1652         struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
1653         release_event_pool(&hostdata->pool, hostdata);
1654         ibmvscsi_ops->release_crq_queue(&hostdata->queue, hostdata,
1655                                         max_requests);
1656
1657         srp_remove_host(hostdata->host);
1658         scsi_remove_host(hostdata->host);
1659         scsi_host_put(hostdata->host);
1660
1661         return 0;
1662 }
1663
1664 /**
1665  * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we
1666  * support.
1667  */
1668 static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
1669         {"vscsi", "IBM,v-scsi"},
1670         { "", "" }
1671 };
1672 MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
1673
1674 static struct vio_driver ibmvscsi_driver = {
1675         .id_table = ibmvscsi_device_table,
1676         .probe = ibmvscsi_probe,
1677         .remove = ibmvscsi_remove,
1678         .driver = {
1679                 .name = "ibmvscsi",
1680                 .owner = THIS_MODULE,
1681         }
1682 };
1683
1684 static struct srp_function_template ibmvscsi_transport_functions = {
1685 };
1686
1687 int __init ibmvscsi_module_init(void)
1688 {
1689         int ret;
1690
1691         if (firmware_has_feature(FW_FEATURE_ISERIES))
1692                 ibmvscsi_ops = &iseriesvscsi_ops;
1693         else if (firmware_has_feature(FW_FEATURE_VIO))
1694                 ibmvscsi_ops = &rpavscsi_ops;
1695         else
1696                 return -ENODEV;
1697
1698         ibmvscsi_transport_template =
1699                 srp_attach_transport(&ibmvscsi_transport_functions);
1700         if (!ibmvscsi_transport_template)
1701                 return -ENOMEM;
1702
1703         ret = vio_register_driver(&ibmvscsi_driver);
1704         if (ret)
1705                 srp_release_transport(ibmvscsi_transport_template);
1706         return ret;
1707 }
1708
1709 void __exit ibmvscsi_module_exit(void)
1710 {
1711         vio_unregister_driver(&ibmvscsi_driver);
1712         srp_release_transport(ibmvscsi_transport_template);
1713 }
1714
1715 module_init(ibmvscsi_module_init);
1716 module_exit(ibmvscsi_module_exit);