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   1 /*
   2  * linux/drivers/s390/scsi/zfcp_qdio.c
   3  *
   4  * FCP adapter driver for IBM eServer zSeries
   5  *
   6  * QDIO related routines
   7  *
   8  * (C) Copyright IBM Corp. 2002, 2004
   9  *
  10  * Authors:
  11  *      Martin Peschke <mpeschke@de.ibm.com>
  12  *      Raimund Schroeder <raimund.schroeder@de.ibm.com>
  13  *      Wolfgang Taphorn
  14  *      Heiko Carstens <heiko.carstens@de.ibm.com>
  15  *      Andreas Herrmann <aherrman@de.ibm.com>
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; either version 2, or (at your option)
  20  * any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  30  */
  31
  32 #define ZFCP_QDIO_C_REVISION "$Revision: 1.20 $"
  33
  34 #include "zfcp_ext.h"
  35
  36 static inline void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *, int);
  37 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_get
  38         (struct zfcp_qdio_queue *, int, int);
  39 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_resp
  40         (struct zfcp_fsf_req *, int, int);
  41 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbal_chain
  42         (struct zfcp_fsf_req *, unsigned long);
  43 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_next
  44         (struct zfcp_fsf_req *, unsigned long);
  45 static inline int zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *, int, int);
  46 static inline int zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *);
  47 static inline void zfcp_qdio_sbale_fill
  48         (struct zfcp_fsf_req *, unsigned long, void *, int);
  49 static inline int zfcp_qdio_sbals_from_segment
  50         (struct zfcp_fsf_req *, unsigned long, void *, unsigned long);
  51 static inline int zfcp_qdio_sbals_from_buffer
  52         (struct zfcp_fsf_req *, unsigned long, void *, unsigned long, int);
  53
  54 static qdio_handler_t zfcp_qdio_request_handler;
  55 static qdio_handler_t zfcp_qdio_response_handler;
  56 static int zfcp_qdio_handler_error_check(struct zfcp_adapter *,
  57         unsigned int, unsigned int, unsigned int, int, int);
  58
  59 #define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_QDIO
  60
  61 /*
  62  * Allocates BUFFER memory to each of the pointers of the qdio_buffer_t
  63  * array in the adapter struct.
  64  * Cur_buf is the pointer array and count can be any number of required
  65  * buffers, the page-fitting arithmetic is done entirely within this funciton.
  66  *
  67  * returns:     number of buffers allocated
  68  * locks:       must only be called with zfcp_data.config_sema taken
  69  */
  70 static int
  71 zfcp_qdio_buffers_enqueue(struct qdio_buffer **cur_buf, int count)
  72 {
  73         int buf_pos;
  74         int qdio_buffers_per_page;
  75         int page_pos = 0;
  76         struct qdio_buffer *first_in_page = NULL;
  77
  78         qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
  79         ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
  80
  81         for (buf_pos = 0; buf_pos < count; buf_pos++) {
  82                 if (page_pos == 0) {
  83                         cur_buf[buf_pos] = (struct qdio_buffer *)
  84                             get_zeroed_page(GFP_KERNEL);
  85                         if (cur_buf[buf_pos] == NULL) {
  86                                 ZFCP_LOG_INFO("error: allocation of "
  87                                               "QDIO buffer failed \n");
  88                                 goto out;
  89                         }
  90                         first_in_page = cur_buf[buf_pos];
  91                 } else {
  92                         cur_buf[buf_pos] = first_in_page + page_pos;
  93
  94                 }
  95                 /* was initialised to zero */
  96                 page_pos++;
  97                 page_pos %= qdio_buffers_per_page;
  98         }
  99  out:
 100         return buf_pos;
 101 }
 102
 103 /*
 104  * Frees BUFFER memory for each of the pointers of the struct qdio_buffer array
 105  * in the adapter struct cur_buf is the pointer array and count can be any
 106  * number of buffers in the array that should be freed starting from buffer 0
 107  *
 108  * locks:       must only be called with zfcp_data.config_sema taken
 109  */
 110 static void
 111 zfcp_qdio_buffers_dequeue(struct qdio_buffer **cur_buf, int count)
 112 {
 113         int buf_pos;
 114         int qdio_buffers_per_page;
 115
 116         qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
 117         ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
 118
 119         for (buf_pos = 0; buf_pos < count; buf_pos += qdio_buffers_per_page)
 120                 free_page((unsigned long) cur_buf[buf_pos]);
 121         return;
 122 }
 123
 124 /* locks:       must only be called with zfcp_data.config_sema taken */
 125 int
 126 zfcp_qdio_allocate_queues(struct zfcp_adapter *adapter)
 127 {
 128         int buffer_count;
 129         int retval = 0;
 130
 131         buffer_count =
 132             zfcp_qdio_buffers_enqueue(&(adapter->request_queue.buffer[0]),
 133                                       QDIO_MAX_BUFFERS_PER_Q);
 134         if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
 135                 ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for request "
 136                                "queue\n", buffer_count);
 137                 zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
 138                                           buffer_count);
 139                 retval = -ENOMEM;
 140                 goto out;
 141         }
 142
 143         buffer_count =
 144             zfcp_qdio_buffers_enqueue(&(adapter->response_queue.buffer[0]),
 145                                       QDIO_MAX_BUFFERS_PER_Q);
 146         if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
 147                 ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for response "
 148                                "queue", buffer_count);
 149                 zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
 150                                           buffer_count);
 151                 ZFCP_LOG_TRACE("freeing request_queue buffers\n");
 152                 zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
 153                                           QDIO_MAX_BUFFERS_PER_Q);
 154                 retval = -ENOMEM;
 155                 goto out;
 156         }
 157  out:
 158         return retval;
 159 }
 160
 161 /* locks:       must only be called with zfcp_data.config_sema taken */
 162 void
 163 zfcp_qdio_free_queues(struct zfcp_adapter *adapter)
 164 {
 165         ZFCP_LOG_TRACE("freeing request_queue buffers\n");
 166         zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
 167                                   QDIO_MAX_BUFFERS_PER_Q);
 168
 169         ZFCP_LOG_TRACE("freeing response_queue buffers\n");
 170         zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
 171                                   QDIO_MAX_BUFFERS_PER_Q);
 172 }
 173
 174 int
 175 zfcp_qdio_allocate(struct zfcp_adapter *adapter)
 176 {
 177         struct qdio_initialize *init_data;
 178
 179         init_data = &adapter->qdio_init_data;
 180
 181         init_data->cdev = adapter->ccw_device;
 182         init_data->q_format = QDIO_SCSI_QFMT;
 183         memcpy(init_data->adapter_name, &adapter->name, 8);
 184         init_data->qib_param_field_format = 0;
 185         init_data->qib_param_field = NULL;
 186         init_data->input_slib_elements = NULL;
 187         init_data->output_slib_elements = NULL;
 188         init_data->min_input_threshold = ZFCP_MIN_INPUT_THRESHOLD;
 189         init_data->max_input_threshold = ZFCP_MAX_INPUT_THRESHOLD;
 190         init_data->min_output_threshold = ZFCP_MIN_OUTPUT_THRESHOLD;
 191         init_data->max_output_threshold = ZFCP_MAX_OUTPUT_THRESHOLD;
 192         init_data->no_input_qs = 1;
 193         init_data->no_output_qs = 1;
 194         init_data->input_handler = zfcp_qdio_response_handler;
 195         init_data->output_handler = zfcp_qdio_request_handler;
 196         init_data->int_parm = (unsigned long) adapter;
 197         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
 198             QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
 199         init_data->input_sbal_addr_array =
 200             (void **) (adapter->response_queue.buffer);
 201         init_data->output_sbal_addr_array =
 202             (void **) (adapter->request_queue.buffer);
 203
 204         return qdio_allocate(init_data);
 205 }
 206
 207 /*
 208  * function:    zfcp_qdio_handler_error_check
 209  *
 210  * purpose:     called by the response handler to determine error condition
 211  *
 212  * returns:     error flag
 213  *
 214  */
 215 static inline int
 216 zfcp_qdio_handler_error_check(struct zfcp_adapter *adapter, unsigned int status,
 217                               unsigned int qdio_error, unsigned int siga_error,
 218                               int first_element, int elements_processed)
 219 {
 220         int retval = 0;
 221
 222         if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
 223                 retval = -EIO;
 224
 225                 ZFCP_LOG_INFO("QDIO problem occurred (status=0x%x, "
 226                               "qdio_error=0x%x, siga_error=0x%x)\n",
 227                               status, qdio_error, siga_error);
 228
 229                 zfcp_hba_dbf_event_qdio(adapter, status, qdio_error, siga_error,
 230                                 first_element, elements_processed);
 231                /*
 232                 * Restarting IO on the failed adapter from scratch.
 233                 * Since we have been using this adapter, it is save to assume
 234                 * that it is not failed but recoverable. The card seems to
 235                 * report link-up events by self-initiated queue shutdown.
 236                 * That is why we need to clear the the link-down flag
 237                 * which is set again in case we have missed by a mile.
 238                 */
 239                zfcp_erp_adapter_reopen(
 240                        adapter,
 241                        ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
 242                        ZFCP_STATUS_COMMON_ERP_FAILED);
 243         }
 244         return retval;
 245 }
 246
 247 /*
 248  * function:    zfcp_qdio_request_handler
 249  *
 250  * purpose:     is called by QDIO layer for completed SBALs in request queue
 251  *
 252  * returns:     (void)
 253  */
 254 static void
 255 zfcp_qdio_request_handler(struct ccw_device *ccw_device,
 256                           unsigned int status,
 257                           unsigned int qdio_error,
 258                           unsigned int siga_error,
 259                           unsigned int queue_number,
 260                           int first_element,
 261                           int elements_processed,
 262                           unsigned long int_parm)
 263 {
 264         struct zfcp_adapter *adapter;
 265         struct zfcp_qdio_queue *queue;
 266
 267         adapter = (struct zfcp_adapter *) int_parm;
 268         queue = &adapter->request_queue;
 269
 270         ZFCP_LOG_DEBUG("adapter %s, first=%d, elements_processed=%d\n",
 271                        zfcp_get_busid_by_adapter(adapter),
 272                        first_element, elements_processed);
 273
 274         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
 275                                                    siga_error, first_element,
 276                                                    elements_processed)))
 277                 goto out;
 278         /*
 279          * we stored address of struct zfcp_adapter  data structure
 280          * associated with irq in int_parm
 281          */
 282
 283         /* cleanup all SBALs being program-owned now */
 284         zfcp_qdio_zero_sbals(queue->buffer, first_element, elements_processed);
 285
 286         /* increase free space in outbound queue */
 287         atomic_add(elements_processed, &queue->free_count);
 288         ZFCP_LOG_DEBUG("free_count=%d\n", atomic_read(&queue->free_count));
 289         wake_up(&adapter->request_wq);
 290         ZFCP_LOG_DEBUG("elements_processed=%d, free count=%d\n",
 291                        elements_processed, atomic_read(&queue->free_count));
 292  out:
 293         return;
 294 }
 295
 296 /*
 297  * function:    zfcp_qdio_response_handler
 298  *
 299  * purpose:     is called by QDIO layer for completed SBALs in response queue
 300  *
 301  * returns:     (void)
 302  */
 303 static void
 304 zfcp_qdio_response_handler(struct ccw_device *ccw_device,
 305                            unsigned int status,
 306                            unsigned int qdio_error,
 307                            unsigned int siga_error,
 308                            unsigned int queue_number,
 309                            int first_element,
 310                            int elements_processed,
 311                            unsigned long int_parm)
 312 {
 313         struct zfcp_adapter *adapter;
 314         struct zfcp_qdio_queue *queue;
 315         int buffer_index;
 316         int i;
 317         struct qdio_buffer *buffer;
 318         int retval = 0;
 319         u8 count;
 320         u8 start;
 321         volatile struct qdio_buffer_element *buffere = NULL;
 322         int buffere_index;
 323
 324         adapter = (struct zfcp_adapter *) int_parm;
 325         queue = &adapter->response_queue;
 326
 327         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
 328                                                    siga_error, first_element,
 329                                                    elements_processed)))
 330                 goto out;
 331
 332         /*
 333          * we stored address of struct zfcp_adapter  data structure
 334          * associated with irq in int_parm
 335          */
 336
 337         buffere = &(queue->buffer[first_element]->element[0]);
 338         ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
 339         /*
 340          * go through all SBALs from input queue currently
 341          * returned by QDIO layer
 342          */
 343
 344         for (i = 0; i < elements_processed; i++) {
 345
 346                 buffer_index = first_element + i;
 347                 buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
 348                 buffer = queue->buffer[buffer_index];
 349
 350                 /* go through all SBALEs of SBAL */
 351                 for (buffere_index = 0;
 352                      buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
 353                      buffere_index++) {
 354
 355                         /* look for QDIO request identifiers in SB */
 356                         buffere = &buffer->element[buffere_index];
 357                         retval = zfcp_qdio_reqid_check(adapter,
 358                                                        (void *) buffere->addr);
 359
 360                         if (retval) {
 361                                 ZFCP_LOG_NORMAL("bug: unexpected inbound "
 362                                                 "packet on adapter %s "
 363                                                 "(reqid=0x%lx, "
 364                                                 "first_element=%d, "
 365                                                 "elements_processed=%d)\n",
 366                                                 zfcp_get_busid_by_adapter(adapter),
 367                                                 (unsigned long) buffere->addr,
 368                                                 first_element,
 369                                                 elements_processed);
 370                                 ZFCP_LOG_NORMAL("hex dump of inbound buffer "
 371                                                 "at address %p "
 372                                                 "(buffer_index=%d, "
 373                                                 "buffere_index=%d)\n", buffer,
 374                                                 buffer_index, buffere_index);
 375                                 ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
 376                                               (char *) buffer, SBAL_SIZE);
 377                         }
 378                         /*
 379                          * A single used SBALE per inbound SBALE has been
 380                          * implemented by QDIO so far. Hope they will
 381                          * do some optimisation. Will need to change to
 382                          * unlikely() then.
 383                          */
 384                         if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
 385                                 break;
 386                 };
 387
 388                 if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
 389                         ZFCP_LOG_NORMAL("bug: End of inbound data "
 390                                         "not marked!\n");
 391                 }
 392         }
 393
 394         /*
 395          * put range of SBALs back to response queue
 396          * (including SBALs which have already been free before)
 397          */
 398         count = atomic_read(&queue->free_count) + elements_processed;
 399         start = queue->free_index;
 400
 401         ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
 402                        "queue_no=%i, index_in_queue=%i, count=%i, "
 403                        "buffers=0x%lx\n",
 404                        zfcp_get_busid_by_adapter(adapter),
 405                        QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 406                        0, start, count, (unsigned long) &queue->buffer[start]);
 407
 408         retval = do_QDIO(ccw_device,
 409                          QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 410                          0, start, count, NULL);
 411
 412         if (unlikely(retval)) {
 413                 atomic_set(&queue->free_count, count);
 414                 ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
 415                                "queues may be down "
 416                                "(count=%d, start=%d, retval=%d)\n",
 417                                count, start, retval);
 418         } else {
 419                 queue->free_index += count;
 420                 queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
 421                 atomic_set(&queue->free_count, 0);
 422                 ZFCP_LOG_TRACE("%i buffers enqueued to response "
 423                                "queue at position %i\n", count, start);
 424         }
 425  out:
 426         return;
 427 }
 428
 429 /*
 430  * function:    zfcp_qdio_reqid_check
 431  *
 432  * purpose:     checks for valid reqids or unsolicited status
 433  *
 434  * returns:     0 - valid request id or unsolicited status
 435  *              !0 - otherwise
 436  */
 437 int
 438 zfcp_qdio_reqid_check(struct zfcp_adapter *adapter, void *sbale_addr)
 439 {
 440         struct zfcp_fsf_req *fsf_req;
 441
 442         /* invalid (per convention used in this driver) */
 443         if (unlikely(!sbale_addr)) {
 444                 ZFCP_LOG_NORMAL("bug: invalid reqid\n");
 445                 return -EINVAL;
 446         }
 447
 448         /* valid request id and thus (hopefully :) valid fsf_req address */
 449         fsf_req = (struct zfcp_fsf_req *) sbale_addr;
 450
 451         /* serialize with zfcp_fsf_req_dismiss_all */
 452         spin_lock(&adapter->fsf_req_list_lock);
 453         if (list_empty(&adapter->fsf_req_list_head)) {
 454                 spin_unlock(&adapter->fsf_req_list_lock);
 455                 return 0;
 456         }
 457         list_del(&fsf_req->list);
 458         atomic_dec(&adapter->fsf_reqs_active);
 459         spin_unlock(&adapter->fsf_req_list_lock);
 460
 461         if (unlikely(adapter != fsf_req->adapter)) {
 462                 ZFCP_LOG_NORMAL("bug: invalid reqid (fsf_req=%p, "
 463                                 "fsf_req->adapter=%p, adapter=%p)\n",
 464                                 fsf_req, fsf_req->adapter, adapter);
 465                 return -EINVAL;
 466         }
 467
 468         /* finish the FSF request */
 469         zfcp_fsf_req_complete(fsf_req);
 470
 471         return 0;
 472 }
 473
 474 /**
 475  * zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
 476  * @queue: queue from which SBALE should be returned
 477  * @sbal: specifies number of SBAL in queue
 478  * @sbale: specifes number of SBALE in SBAL
 479  */
 480 static inline volatile struct qdio_buffer_element *
 481 zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
 482 {
 483         return &queue->buffer[sbal]->element[sbale];
 484 }
 485
 486 /**
 487  * zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
 488  *      a struct zfcp_fsf_req
 489  */
 490 inline volatile struct qdio_buffer_element *
 491 zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 492 {
 493         return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
 494                                    sbal, sbale);
 495 }
 496
 497 /**
 498  * zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
 499  *      a struct zfcp_fsf_req
 500  */
 501 static inline volatile struct qdio_buffer_element *
 502 zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 503 {
 504         return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
 505                                    sbal, sbale);
 506 }
 507
 508 /**
 509  * zfcp_qdio_sbale_curr - return current SBALE on request_queue for
 510  *      a struct zfcp_fsf_req
 511  */
 512 inline volatile struct qdio_buffer_element *
 513 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
 514 {
 515         return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
 516                                    fsf_req->sbale_curr);
 517 }
 518
 519 /**
 520  * zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
 521  *      on the request_queue for a struct zfcp_fsf_req
 522  * @fsf_req: the number of the last SBAL that can be used is stored herein
 523  * @max_sbals: used to pass an upper limit for the number of SBALs
 524  *
 525  * Note: We can assume at least one free SBAL in the request_queue when called.
 526  */
 527 static inline void
 528 zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 529 {
 530         int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
 531         count = min(count, max_sbals);
 532         fsf_req->sbal_last  = fsf_req->sbal_first;
 533         fsf_req->sbal_last += (count - 1);
 534         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 535 }
 536
 537 /**
 538  * zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
 539  *      request
 540  * @fsf_req: zfcp_fsf_req to be processed
 541  * @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
 542  *
 543  * This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
 544  */
 545 static inline volatile struct qdio_buffer_element *
 546 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 547 {
 548         volatile struct qdio_buffer_element *sbale;
 549
 550         /* set last entry flag in current SBALE of current SBAL */
 551         sbale = zfcp_qdio_sbale_curr(fsf_req);
 552         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 553
 554         /* don't exceed last allowed SBAL */
 555         if (fsf_req->sbal_curr == fsf_req->sbal_last)
 556                 return NULL;
 557
 558         /* set chaining flag in first SBALE of current SBAL */
 559         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 560         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 561
 562         /* calculate index of next SBAL */
 563         fsf_req->sbal_curr++;
 564         fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
 565
 566         /* keep this requests number of SBALs up-to-date */
 567         fsf_req->sbal_number++;
 568
 569         /* start at first SBALE of new SBAL */
 570         fsf_req->sbale_curr = 0;
 571
 572         /* set storage-block type for new SBAL */
 573         sbale = zfcp_qdio_sbale_curr(fsf_req);
 574         sbale->flags |= sbtype;
 575
 576         return sbale;
 577 }
 578
 579 /**
 580  * zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
 581  */
 582 static inline volatile struct qdio_buffer_element *
 583 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 584 {
 585         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 586                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 587
 588         fsf_req->sbale_curr++;
 589
 590         return zfcp_qdio_sbale_curr(fsf_req);
 591 }
 592
 593 /**
 594  * zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
 595  *      with zero from
 596  */
 597 static inline int
 598 zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
 599 {
 600         struct qdio_buffer **buf = queue->buffer;
 601         int curr = first;
 602         int count = 0;
 603
 604         for(;;) {
 605                 curr %= QDIO_MAX_BUFFERS_PER_Q;
 606                 count++;
 607                 memset(buf[curr], 0, sizeof(struct qdio_buffer));
 608                 if (curr == last)
 609                         break;
 610                 curr++;
 611         }
 612         return count;
 613 }
 614
 615
 616 /**
 617  * zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
 618  */
 619 static inline int
 620 zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
 621 {
 622         return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
 623                                     fsf_req->sbal_first, fsf_req->sbal_curr);
 624 }
 625
 626
 627 /**
 628  * zfcp_qdio_sbale_fill - set address and lenght in current SBALE
 629  *      on request_queue
 630  */
 631 static inline void
 632 zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 633                      void *addr, int length)
 634 {
 635         volatile struct qdio_buffer_element *sbale;
 636
 637         sbale = zfcp_qdio_sbale_curr(fsf_req);
 638         sbale->addr = addr;
 639         sbale->length = length;
 640 }
 641
 642 /**
 643  * zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
 644  * @fsf_req: request to be processed
 645  * @sbtype: SBALE flags
 646  * @start_addr: address of memory segment
 647  * @total_length: length of memory segment
 648  *
 649  * Alignment and length of the segment determine how many SBALEs are needed
 650  * for the memory segment.
 651  */
 652 static inline int
 653 zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 654                              void *start_addr, unsigned long total_length)
 655 {
 656         unsigned long remaining, length;
 657         void *addr;
 658
 659         /* split segment up heeding page boundaries */
 660         for (addr = start_addr, remaining = total_length; remaining > 0;
 661              addr += length, remaining -= length) {
 662                 /* get next free SBALE for new piece */
 663                 if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
 664                         /* no SBALE left, clean up and leave */
 665                         zfcp_qdio_sbals_wipe(fsf_req);
 666                         return -EINVAL;
 667                 }
 668                 /* calculate length of new piece */
 669                 length = min(remaining,
 670                              (PAGE_SIZE - ((unsigned long) addr &
 671                                            (PAGE_SIZE - 1))));
 672                 /* fill current SBALE with calculated piece */
 673                 zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
 674         }
 675         return total_length;
 676 }
 677
 678
 679 /**
 680  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 681  * @fsf_req: request to be processed
 682  * @sbtype: SBALE flags
 683  * @sg: scatter-gather list
 684  * @sg_count: number of elements in scatter-gather list
 685  * @max_sbals: upper bound for number of SBALs to be used
 686  */
 687 inline int
 688 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 689                         struct scatterlist *sg, int sg_count, int max_sbals)
 690 {
 691         int sg_index;
 692         struct scatterlist *sg_segment;
 693         int retval;
 694         volatile struct qdio_buffer_element *sbale;
 695         int bytes = 0;
 696
 697         /* figure out last allowed SBAL */
 698         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 699
 700         /* set storage-block type for current SBAL */
 701         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 702         sbale->flags |= sbtype;
 703
 704         /* process all segements of scatter-gather list */
 705         for (sg_index = 0, sg_segment = sg, bytes = 0;
 706              sg_index < sg_count;
 707              sg_index++, sg_segment++) {
 708                 retval = zfcp_qdio_sbals_from_segment(
 709                                 fsf_req,
 710                                 sbtype,
 711                                 zfcp_sg_to_address(sg_segment),
 712                                 sg_segment->length);
 713                 if (retval < 0) {
 714                         bytes = retval;
 715                         goto out;
 716                 } else
 717                         bytes += retval;
 718         }
 719         /* assume that no other SBALEs are to follow in the same SBAL */
 720         sbale = zfcp_qdio_sbale_curr(fsf_req);
 721         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 722 out:
 723         return bytes;
 724 }
 725
 726
 727 /**
 728  * zfcp_qdio_sbals_from_buffer - fill SBALs from buffer
 729  * @fsf_req: request to be processed
 730  * @sbtype: SBALE flags
 731  * @buffer: data buffer
 732  * @length: length of buffer
 733  * @max_sbals: upper bound for number of SBALs to be used
 734  */
 735 static inline int
 736 zfcp_qdio_sbals_from_buffer(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 737                             void *buffer, unsigned long length, int max_sbals)
 738 {
 739         struct scatterlist sg_segment;
 740
 741         zfcp_address_to_sg(buffer, &sg_segment);
 742         sg_segment.length = length;
 743
 744         return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, &sg_segment, 1,
 745                                        max_sbals);
 746 }
 747
 748
 749 /**
 750  * zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
 751  * @fsf_req: request to be processed
 752  * @sbtype: SBALE flags
 753  * @scsi_cmnd: either scatter-gather list or buffer contained herein is used
 754  *      to fill SBALs
 755  */
 756 inline int
 757 zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
 758                               unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
 759 {
 760         if (scsi_cmnd->use_sg) {
 761                 return zfcp_qdio_sbals_from_sg(fsf_req, sbtype,
 762                                                (struct scatterlist *)
 763                                                scsi_cmnd->request_buffer,
 764                                                scsi_cmnd->use_sg,
 765                                                ZFCP_MAX_SBALS_PER_REQ);
 766         } else {
 767                 return zfcp_qdio_sbals_from_buffer(fsf_req, sbtype,
 768                                                    scsi_cmnd->request_buffer,
 769                                                    scsi_cmnd->request_bufflen,
 770                                                    ZFCP_MAX_SBALS_PER_REQ);
 771         }
 772 }
 773
 774 /**
 775  * zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
 776  */
 777 int
 778 zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
 779                         struct zfcp_fsf_req *fsf_req)
 780 {
 781         int new_distance_from_int;
 782         int pci_pos;
 783         volatile struct qdio_buffer_element *sbale;
 784
 785         new_distance_from_int = req_queue->distance_from_int +
 786                 fsf_req->sbal_number;
 787
 788         if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
 789                 new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
 790                 pci_pos  = fsf_req->sbal_first;
 791                 pci_pos += fsf_req->sbal_number;
 792                 pci_pos -= new_distance_from_int;
 793                 pci_pos -= 1;
 794                 pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
 795                 sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
 796                 sbale->flags |= SBAL_FLAGS0_PCI;
 797         }
 798         return new_distance_from_int;
 799 }
 800
 801 /*
 802  * function:    zfcp_zero_sbals
 803  *
 804  * purpose:     zeros specified range of SBALs
 805  *
 806  * returns:
 807  */
 808 void
 809 zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
 810 {
 811         int cur_pos;
 812         int index;
 813
 814         for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
 815                 index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
 816                 memset(buf[index], 0, sizeof (struct qdio_buffer));
 817                 ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
 818                                index, buf[index]);
 819         }
 820 }
 821
 822 #undef ZFCP_LOG_AREA