drivers/s390/scsi/zfcp_qdio.c

   1 /*
   2  * This file is part of the zfcp device driver for
   3  * FCP adapters for IBM System z9 and zSeries.
   4  *
   5  * (C) Copyright IBM Corp. 2002, 2006
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2, or (at your option)
  10  * any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include "zfcp_ext.h"
  23
  24 static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *, int);
  25 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_get
  26         (struct zfcp_qdio_queue *, int, int);
  27 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_resp
  28         (struct zfcp_fsf_req *, int, int);
  29 static volatile struct qdio_buffer_element *zfcp_qdio_sbal_chain
  30         (struct zfcp_fsf_req *, unsigned long);
  31 static volatile struct qdio_buffer_element *zfcp_qdio_sbale_next
  32         (struct zfcp_fsf_req *, unsigned long);
  33 static int zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *, int, int);
  34 static inline int zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *);
  35 static void zfcp_qdio_sbale_fill
  36         (struct zfcp_fsf_req *, unsigned long, void *, int);
  37 static int zfcp_qdio_sbals_from_segment
  38         (struct zfcp_fsf_req *, unsigned long, void *, unsigned long);
  39 static int zfcp_qdio_sbals_from_buffer
  40         (struct zfcp_fsf_req *, unsigned long, void *, unsigned long, int);
  41
  42 static qdio_handler_t zfcp_qdio_request_handler;
  43 static qdio_handler_t zfcp_qdio_response_handler;
  44 static int zfcp_qdio_handler_error_check(struct zfcp_adapter *,
  45         unsigned int, unsigned int, unsigned int, int, int);
  46
  47 #define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_QDIO
  48
  49 /*
  50  * Allocates BUFFER memory to each of the pointers of the qdio_buffer_t
  51  * array in the adapter struct.
  52  * Cur_buf is the pointer array and count can be any number of required
  53  * buffers, the page-fitting arithmetic is done entirely within this funciton.
  54  *
  55  * returns:     number of buffers allocated
  56  * locks:       must only be called with zfcp_data.config_sema taken
  57  */
  58 static int
  59 zfcp_qdio_buffers_enqueue(struct qdio_buffer **cur_buf, int count)
  60 {
  61         int buf_pos;
  62         int qdio_buffers_per_page;
  63         int page_pos = 0;
  64         struct qdio_buffer *first_in_page = NULL;
  65
  66         qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
  67         ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
  68
  69         for (buf_pos = 0; buf_pos < count; buf_pos++) {
  70                 if (page_pos == 0) {
  71                         cur_buf[buf_pos] = (struct qdio_buffer *)
  72                             get_zeroed_page(GFP_KERNEL);
  73                         if (cur_buf[buf_pos] == NULL) {
  74                                 ZFCP_LOG_INFO("error: allocation of "
  75                                               "QDIO buffer failed \n");
  76                                 goto out;
  77                         }
  78                         first_in_page = cur_buf[buf_pos];
  79                 } else {
  80                         cur_buf[buf_pos] = first_in_page + page_pos;
  81
  82                 }
  83                 /* was initialised to zero */
  84                 page_pos++;
  85                 page_pos %= qdio_buffers_per_page;
  86         }
  87  out:
  88         return buf_pos;
  89 }
  90
  91 /*
  92  * Frees BUFFER memory for each of the pointers of the struct qdio_buffer array
  93  * in the adapter struct cur_buf is the pointer array and count can be any
  94  * number of buffers in the array that should be freed starting from buffer 0
  95  *
  96  * locks:       must only be called with zfcp_data.config_sema taken
  97  */
  98 static void
  99 zfcp_qdio_buffers_dequeue(struct qdio_buffer **cur_buf, int count)
 100 {
 101         int buf_pos;
 102         int qdio_buffers_per_page;
 103
 104         qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
 105         ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
 106
 107         for (buf_pos = 0; buf_pos < count; buf_pos += qdio_buffers_per_page)
 108                 free_page((unsigned long) cur_buf[buf_pos]);
 109         return;
 110 }
 111
 112 /* locks:       must only be called with zfcp_data.config_sema taken */
 113 int
 114 zfcp_qdio_allocate_queues(struct zfcp_adapter *adapter)
 115 {
 116         int buffer_count;
 117         int retval = 0;
 118
 119         buffer_count =
 120             zfcp_qdio_buffers_enqueue(&(adapter->request_queue.buffer[0]),
 121                                       QDIO_MAX_BUFFERS_PER_Q);
 122         if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
 123                 ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for request "
 124                                "queue\n", buffer_count);
 125                 zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
 126                                           buffer_count);
 127                 retval = -ENOMEM;
 128                 goto out;
 129         }
 130
 131         buffer_count =
 132             zfcp_qdio_buffers_enqueue(&(adapter->response_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 response "
 136                                "queue", buffer_count);
 137                 zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
 138                                           buffer_count);
 139                 ZFCP_LOG_TRACE("freeing request_queue buffers\n");
 140                 zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
 141                                           QDIO_MAX_BUFFERS_PER_Q);
 142                 retval = -ENOMEM;
 143                 goto out;
 144         }
 145  out:
 146         return retval;
 147 }
 148
 149 /* locks:       must only be called with zfcp_data.config_sema taken */
 150 void
 151 zfcp_qdio_free_queues(struct zfcp_adapter *adapter)
 152 {
 153         ZFCP_LOG_TRACE("freeing request_queue buffers\n");
 154         zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
 155                                   QDIO_MAX_BUFFERS_PER_Q);
 156
 157         ZFCP_LOG_TRACE("freeing response_queue buffers\n");
 158         zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
 159                                   QDIO_MAX_BUFFERS_PER_Q);
 160 }
 161
 162 int
 163 zfcp_qdio_allocate(struct zfcp_adapter *adapter)
 164 {
 165         struct qdio_initialize *init_data;
 166
 167         init_data = &adapter->qdio_init_data;
 168
 169         init_data->cdev = adapter->ccw_device;
 170         init_data->q_format = QDIO_SCSI_QFMT;
 171         memcpy(init_data->adapter_name, zfcp_get_busid_by_adapter(adapter), 8);
 172         ASCEBC(init_data->adapter_name, 8);
 173         init_data->qib_param_field_format = 0;
 174         init_data->qib_param_field = NULL;
 175         init_data->input_slib_elements = NULL;
 176         init_data->output_slib_elements = NULL;
 177         init_data->min_input_threshold = ZFCP_MIN_INPUT_THRESHOLD;
 178         init_data->max_input_threshold = ZFCP_MAX_INPUT_THRESHOLD;
 179         init_data->min_output_threshold = ZFCP_MIN_OUTPUT_THRESHOLD;
 180         init_data->max_output_threshold = ZFCP_MAX_OUTPUT_THRESHOLD;
 181         init_data->no_input_qs = 1;
 182         init_data->no_output_qs = 1;
 183         init_data->input_handler = zfcp_qdio_response_handler;
 184         init_data->output_handler = zfcp_qdio_request_handler;
 185         init_data->int_parm = (unsigned long) adapter;
 186         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
 187             QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
 188         init_data->input_sbal_addr_array =
 189             (void **) (adapter->response_queue.buffer);
 190         init_data->output_sbal_addr_array =
 191             (void **) (adapter->request_queue.buffer);
 192
 193         return qdio_allocate(init_data);
 194 }
 195
 196 /*
 197  * function:    zfcp_qdio_handler_error_check
 198  *
 199  * purpose:     called by the response handler to determine error condition
 200  *
 201  * returns:     error flag
 202  *
 203  */
 204 static int
 205 zfcp_qdio_handler_error_check(struct zfcp_adapter *adapter, unsigned int status,
 206                               unsigned int qdio_error, unsigned int siga_error,
 207                               int first_element, int elements_processed)
 208 {
 209         int retval = 0;
 210
 211         if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
 212                 retval = -EIO;
 213
 214                 ZFCP_LOG_INFO("QDIO problem occurred (status=0x%x, "
 215                               "qdio_error=0x%x, siga_error=0x%x)\n",
 216                               status, qdio_error, siga_error);
 217
 218                 zfcp_hba_dbf_event_qdio(adapter, status, qdio_error, siga_error,
 219                                 first_element, elements_processed);
 220                /*
 221                 * Restarting IO on the failed adapter from scratch.
 222                 * Since we have been using this adapter, it is save to assume
 223                 * that it is not failed but recoverable. The card seems to
 224                 * report link-up events by self-initiated queue shutdown.
 225                 * That is why we need to clear the link-down flag
 226                 * which is set again in case we have missed by a mile.
 227                 */
 228                zfcp_erp_adapter_reopen(
 229                        adapter,
 230                        ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
 231                        ZFCP_STATUS_COMMON_ERP_FAILED);
 232         }
 233         return retval;
 234 }
 235
 236 /*
 237  * function:    zfcp_qdio_request_handler
 238  *
 239  * purpose:     is called by QDIO layer for completed SBALs in request queue
 240  *
 241  * returns:     (void)
 242  */
 243 static void
 244 zfcp_qdio_request_handler(struct ccw_device *ccw_device,
 245                           unsigned int status,
 246                           unsigned int qdio_error,
 247                           unsigned int siga_error,
 248                           unsigned int queue_number,
 249                           int first_element,
 250                           int elements_processed,
 251                           unsigned long int_parm)
 252 {
 253         struct zfcp_adapter *adapter;
 254         struct zfcp_qdio_queue *queue;
 255
 256         adapter = (struct zfcp_adapter *) int_parm;
 257         queue = &adapter->request_queue;
 258
 259         ZFCP_LOG_DEBUG("adapter %s, first=%d, elements_processed=%d\n",
 260                        zfcp_get_busid_by_adapter(adapter),
 261                        first_element, elements_processed);
 262
 263         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
 264                                                    siga_error, first_element,
 265                                                    elements_processed)))
 266                 goto out;
 267         /*
 268          * we stored address of struct zfcp_adapter  data structure
 269          * associated with irq in int_parm
 270          */
 271
 272         /* cleanup all SBALs being program-owned now */
 273         zfcp_qdio_zero_sbals(queue->buffer, first_element, elements_processed);
 274
 275         /* increase free space in outbound queue */
 276         atomic_add(elements_processed, &queue->free_count);
 277         ZFCP_LOG_DEBUG("free_count=%d\n", atomic_read(&queue->free_count));
 278         wake_up(&adapter->request_wq);
 279         ZFCP_LOG_DEBUG("elements_processed=%d, free count=%d\n",
 280                        elements_processed, atomic_read(&queue->free_count));
 281  out:
 282         return;
 283 }
 284
 285 /**
 286  * zfcp_qdio_reqid_check - checks for valid reqids.
 287  */
 288 static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
 289                                   unsigned long req_id)
 290 {
 291         struct zfcp_fsf_req *fsf_req;
 292         unsigned long flags;
 293
 294         debug_long_event(adapter->erp_dbf, 4, req_id);
 295
 296         spin_lock_irqsave(&adapter->req_list_lock, flags);
 297         fsf_req = zfcp_reqlist_find(adapter, req_id);
 298
 299         if (!fsf_req)
 300                 /*
 301                  * Unknown request means that we have potentially memory
 302                  * corruption and must stop the machine immediatly.
 303                  */
 304                 panic("error: unknown request id (%ld) on adapter %s.\n",
 305                       req_id, zfcp_get_busid_by_adapter(adapter));
 306
 307         zfcp_reqlist_remove(adapter, fsf_req);
 308         atomic_dec(&adapter->reqs_active);
 309         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 310
 311         /* finish the FSF request */
 312         zfcp_fsf_req_complete(fsf_req);
 313 }
 314
 315 /*
 316  * function:    zfcp_qdio_response_handler
 317  *
 318  * purpose:     is called by QDIO layer for completed SBALs in response queue
 319  *
 320  * returns:     (void)
 321  */
 322 static void
 323 zfcp_qdio_response_handler(struct ccw_device *ccw_device,
 324                            unsigned int status,
 325                            unsigned int qdio_error,
 326                            unsigned int siga_error,
 327                            unsigned int queue_number,
 328                            int first_element,
 329                            int elements_processed,
 330                            unsigned long int_parm)
 331 {
 332         struct zfcp_adapter *adapter;
 333         struct zfcp_qdio_queue *queue;
 334         int buffer_index;
 335         int i;
 336         struct qdio_buffer *buffer;
 337         int retval = 0;
 338         u8 count;
 339         u8 start;
 340         volatile struct qdio_buffer_element *buffere = NULL;
 341         int buffere_index;
 342
 343         adapter = (struct zfcp_adapter *) int_parm;
 344         queue = &adapter->response_queue;
 345
 346         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
 347                                                    siga_error, first_element,
 348                                                    elements_processed)))
 349                 goto out;
 350
 351         /*
 352          * we stored address of struct zfcp_adapter  data structure
 353          * associated with irq in int_parm
 354          */
 355
 356         buffere = &(queue->buffer[first_element]->element[0]);
 357         ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
 358         /*
 359          * go through all SBALs from input queue currently
 360          * returned by QDIO layer
 361          */
 362
 363         for (i = 0; i < elements_processed; i++) {
 364
 365                 buffer_index = first_element + i;
 366                 buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
 367                 buffer = queue->buffer[buffer_index];
 368
 369                 /* go through all SBALEs of SBAL */
 370                 for (buffere_index = 0;
 371                      buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
 372                      buffere_index++) {
 373
 374                         /* look for QDIO request identifiers in SB */
 375                         buffere = &buffer->element[buffere_index];
 376                         zfcp_qdio_reqid_check(adapter,
 377                                               (unsigned long) buffere->addr);
 378
 379                         /*
 380                          * A single used SBALE per inbound SBALE has been
 381                          * implemented by QDIO so far. Hope they will
 382                          * do some optimisation. Will need to change to
 383                          * unlikely() then.
 384                          */
 385                         if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
 386                                 break;
 387                 };
 388
 389                 if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
 390                         ZFCP_LOG_NORMAL("bug: End of inbound data "
 391                                         "not marked!\n");
 392                 }
 393         }
 394
 395         /*
 396          * put range of SBALs back to response queue
 397          * (including SBALs which have already been free before)
 398          */
 399         count = atomic_read(&queue->free_count) + elements_processed;
 400         start = queue->free_index;
 401
 402         ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
 403                        "queue_no=%i, index_in_queue=%i, count=%i, "
 404                        "buffers=0x%lx\n",
 405                        zfcp_get_busid_by_adapter(adapter),
 406                        QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 407                        0, start, count, (unsigned long) &queue->buffer[start]);
 408
 409         retval = do_QDIO(ccw_device,
 410                          QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 411                          0, start, count, NULL);
 412
 413         if (unlikely(retval)) {
 414                 atomic_set(&queue->free_count, count);
 415                 ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
 416                                "queues may be down "
 417                                "(count=%d, start=%d, retval=%d)\n",
 418                                count, start, retval);
 419         } else {
 420                 queue->free_index += count;
 421                 queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
 422                 atomic_set(&queue->free_count, 0);
 423                 ZFCP_LOG_TRACE("%i buffers enqueued to response "
 424                                "queue at position %i\n", count, start);
 425         }
 426  out:
 427         return;
 428 }
 429
 430 /**
 431  * zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
 432  * @queue: queue from which SBALE should be returned
 433  * @sbal: specifies number of SBAL in queue
 434  * @sbale: specifes number of SBALE in SBAL
 435  */
 436 static inline volatile struct qdio_buffer_element *
 437 zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
 438 {
 439         return &queue->buffer[sbal]->element[sbale];
 440 }
 441
 442 /**
 443  * zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
 444  *      a struct zfcp_fsf_req
 445  */
 446 volatile struct qdio_buffer_element *
 447 zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 448 {
 449         return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
 450                                    sbal, sbale);
 451 }
 452
 453 /**
 454  * zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
 455  *      a struct zfcp_fsf_req
 456  */
 457 static inline volatile struct qdio_buffer_element *
 458 zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 459 {
 460         return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
 461                                    sbal, sbale);
 462 }
 463
 464 /**
 465  * zfcp_qdio_sbale_curr - return current SBALE on request_queue for
 466  *      a struct zfcp_fsf_req
 467  */
 468 volatile struct qdio_buffer_element *
 469 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
 470 {
 471         return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
 472                                    fsf_req->sbale_curr);
 473 }
 474
 475 /**
 476  * zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
 477  *      on the request_queue for a struct zfcp_fsf_req
 478  * @fsf_req: the number of the last SBAL that can be used is stored herein
 479  * @max_sbals: used to pass an upper limit for the number of SBALs
 480  *
 481  * Note: We can assume at least one free SBAL in the request_queue when called.
 482  */
 483 static void
 484 zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 485 {
 486         int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
 487         count = min(count, max_sbals);
 488         fsf_req->sbal_last  = fsf_req->sbal_first;
 489         fsf_req->sbal_last += (count - 1);
 490         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 491 }
 492
 493 /**
 494  * zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
 495  *      request
 496  * @fsf_req: zfcp_fsf_req to be processed
 497  * @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
 498  *
 499  * This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
 500  */
 501 static volatile struct qdio_buffer_element *
 502 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 503 {
 504         volatile struct qdio_buffer_element *sbale;
 505
 506         /* set last entry flag in current SBALE of current SBAL */
 507         sbale = zfcp_qdio_sbale_curr(fsf_req);
 508         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 509
 510         /* don't exceed last allowed SBAL */
 511         if (fsf_req->sbal_curr == fsf_req->sbal_last)
 512                 return NULL;
 513
 514         /* set chaining flag in first SBALE of current SBAL */
 515         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 516         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 517
 518         /* calculate index of next SBAL */
 519         fsf_req->sbal_curr++;
 520         fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
 521
 522         /* keep this requests number of SBALs up-to-date */
 523         fsf_req->sbal_number++;
 524
 525         /* start at first SBALE of new SBAL */
 526         fsf_req->sbale_curr = 0;
 527
 528         /* set storage-block type for new SBAL */
 529         sbale = zfcp_qdio_sbale_curr(fsf_req);
 530         sbale->flags |= sbtype;
 531
 532         return sbale;
 533 }
 534
 535 /**
 536  * zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
 537  */
 538 static volatile struct qdio_buffer_element *
 539 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 540 {
 541         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 542                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 543
 544         fsf_req->sbale_curr++;
 545
 546         return zfcp_qdio_sbale_curr(fsf_req);
 547 }
 548
 549 /**
 550  * zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
 551  *      with zero from
 552  */
 553 static int
 554 zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
 555 {
 556         struct qdio_buffer **buf = queue->buffer;
 557         int curr = first;
 558         int count = 0;
 559
 560         for(;;) {
 561                 curr %= QDIO_MAX_BUFFERS_PER_Q;
 562                 count++;
 563                 memset(buf[curr], 0, sizeof(struct qdio_buffer));
 564                 if (curr == last)
 565                         break;
 566                 curr++;
 567         }
 568         return count;
 569 }
 570
 571
 572 /**
 573  * zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
 574  */
 575 static inline int
 576 zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
 577 {
 578         return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
 579                                     fsf_req->sbal_first, fsf_req->sbal_curr);
 580 }
 581
 582
 583 /**
 584  * zfcp_qdio_sbale_fill - set address and lenght in current SBALE
 585  *      on request_queue
 586  */
 587 static void
 588 zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 589                      void *addr, int length)
 590 {
 591         volatile struct qdio_buffer_element *sbale;
 592
 593         sbale = zfcp_qdio_sbale_curr(fsf_req);
 594         sbale->addr = addr;
 595         sbale->length = length;
 596 }
 597
 598 /**
 599  * zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
 600  * @fsf_req: request to be processed
 601  * @sbtype: SBALE flags
 602  * @start_addr: address of memory segment
 603  * @total_length: length of memory segment
 604  *
 605  * Alignment and length of the segment determine how many SBALEs are needed
 606  * for the memory segment.
 607  */
 608 static int
 609 zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 610                              void *start_addr, unsigned long total_length)
 611 {
 612         unsigned long remaining, length;
 613         void *addr;
 614
 615         /* split segment up heeding page boundaries */
 616         for (addr = start_addr, remaining = total_length; remaining > 0;
 617              addr += length, remaining -= length) {
 618                 /* get next free SBALE for new piece */
 619                 if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
 620                         /* no SBALE left, clean up and leave */
 621                         zfcp_qdio_sbals_wipe(fsf_req);
 622                         return -EINVAL;
 623                 }
 624                 /* calculate length of new piece */
 625                 length = min(remaining,
 626                              (PAGE_SIZE - ((unsigned long) addr &
 627                                            (PAGE_SIZE - 1))));
 628                 /* fill current SBALE with calculated piece */
 629                 zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
 630         }
 631         return total_length;
 632 }
 633
 634
 635 /**
 636  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 637  * @fsf_req: request to be processed
 638  * @sbtype: SBALE flags
 639  * @sg: scatter-gather list
 640  * @sg_count: number of elements in scatter-gather list
 641  * @max_sbals: upper bound for number of SBALs to be used
 642  */
 643 int
 644 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 645                         struct scatterlist *sg, int sg_count, int max_sbals)
 646 {
 647         int sg_index;
 648         struct scatterlist *sg_segment;
 649         int retval;
 650         volatile struct qdio_buffer_element *sbale;
 651         int bytes = 0;
 652
 653         /* figure out last allowed SBAL */
 654         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 655
 656         /* set storage-block type for current SBAL */
 657         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 658         sbale->flags |= sbtype;
 659
 660         /* process all segements of scatter-gather list */
 661         for (sg_index = 0, sg_segment = sg, bytes = 0;
 662              sg_index < sg_count;
 663              sg_index++, sg_segment++) {
 664                 retval = zfcp_qdio_sbals_from_segment(
 665                                 fsf_req,
 666                                 sbtype,
 667                                 zfcp_sg_to_address(sg_segment),
 668                                 sg_segment->length);
 669                 if (retval < 0) {
 670                         bytes = retval;
 671                         goto out;
 672                 } else
 673                         bytes += retval;
 674         }
 675         /* assume that no other SBALEs are to follow in the same SBAL */
 676         sbale = zfcp_qdio_sbale_curr(fsf_req);
 677         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 678 out:
 679         return bytes;
 680 }
 681
 682
 683 /**
 684  * zfcp_qdio_sbals_from_buffer - fill SBALs from buffer
 685  * @fsf_req: request to be processed
 686  * @sbtype: SBALE flags
 687  * @buffer: data buffer
 688  * @length: length of buffer
 689  * @max_sbals: upper bound for number of SBALs to be used
 690  */
 691 static int
 692 zfcp_qdio_sbals_from_buffer(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 693                             void *buffer, unsigned long length, int max_sbals)
 694 {
 695         struct scatterlist sg_segment;
 696
 697         zfcp_address_to_sg(buffer, &sg_segment);
 698         sg_segment.length = length;
 699
 700         return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, &sg_segment, 1,
 701                                        max_sbals);
 702 }
 703
 704
 705 /**
 706  * zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
 707  * @fsf_req: request to be processed
 708  * @sbtype: SBALE flags
 709  * @scsi_cmnd: either scatter-gather list or buffer contained herein is used
 710  *      to fill SBALs
 711  */
 712 int
 713 zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
 714                               unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
 715 {
 716         if (scsi_cmnd->use_sg) {
 717                 return zfcp_qdio_sbals_from_sg(fsf_req, sbtype,
 718                                                (struct scatterlist *)
 719                                                scsi_cmnd->request_buffer,
 720                                                scsi_cmnd->use_sg,
 721                                                ZFCP_MAX_SBALS_PER_REQ);
 722         } else {
 723                 return zfcp_qdio_sbals_from_buffer(fsf_req, sbtype,
 724                                                    scsi_cmnd->request_buffer,
 725                                                    scsi_cmnd->request_bufflen,
 726                                                    ZFCP_MAX_SBALS_PER_REQ);
 727         }
 728 }
 729
 730 /**
 731  * zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
 732  */
 733 int
 734 zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
 735                         struct zfcp_fsf_req *fsf_req)
 736 {
 737         int new_distance_from_int;
 738         int pci_pos;
 739         volatile struct qdio_buffer_element *sbale;
 740
 741         new_distance_from_int = req_queue->distance_from_int +
 742                 fsf_req->sbal_number;
 743
 744         if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
 745                 new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
 746                 pci_pos  = fsf_req->sbal_first;
 747                 pci_pos += fsf_req->sbal_number;
 748                 pci_pos -= new_distance_from_int;
 749                 pci_pos -= 1;
 750                 pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
 751                 sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
 752                 sbale->flags |= SBAL_FLAGS0_PCI;
 753         }
 754         return new_distance_from_int;
 755 }
 756
 757 /*
 758  * function:    zfcp_zero_sbals
 759  *
 760  * purpose:     zeros specified range of SBALs
 761  *
 762  * returns:
 763  */
 764 void
 765 zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
 766 {
 767         int cur_pos;
 768         int index;
 769
 770         for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
 771                 index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
 772                 memset(buf[index], 0, sizeof (struct qdio_buffer));
 773                 ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
 774                                index, buf[index]);
 775         }
 776 }
 777
 778 #undef ZFCP_LOG_AREA