SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 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 or unsolicited status
 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_ismember(adapter, req_id);
 298
 299         if (!fsf_req) {
 300                 spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 301                 panic("error: unknown request id (%ld).\n", req_id);
 302         }
 303
 304         zfcp_reqlist_remove(adapter, req_id);
 305         atomic_dec(&adapter->reqs_active);
 306         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 307
 308         /* finish the FSF request */
 309         zfcp_fsf_req_complete(fsf_req);
 310 }
 311
 312 /*
 313  * function:    zfcp_qdio_response_handler
 314  *
 315  * purpose:     is called by QDIO layer for completed SBALs in response queue
 316  *
 317  * returns:     (void)
 318  */
 319 static void
 320 zfcp_qdio_response_handler(struct ccw_device *ccw_device,
 321                            unsigned int status,
 322                            unsigned int qdio_error,
 323                            unsigned int siga_error,
 324                            unsigned int queue_number,
 325                            int first_element,
 326                            int elements_processed,
 327                            unsigned long int_parm)
 328 {
 329         struct zfcp_adapter *adapter;
 330         struct zfcp_qdio_queue *queue;
 331         int buffer_index;
 332         int i;
 333         struct qdio_buffer *buffer;
 334         int retval = 0;
 335         u8 count;
 336         u8 start;
 337         volatile struct qdio_buffer_element *buffere = NULL;
 338         int buffere_index;
 339
 340         adapter = (struct zfcp_adapter *) int_parm;
 341         queue = &adapter->response_queue;
 342
 343         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
 344                                                    siga_error, first_element,
 345                                                    elements_processed)))
 346                 goto out;
 347
 348         /*
 349          * we stored address of struct zfcp_adapter  data structure
 350          * associated with irq in int_parm
 351          */
 352
 353         buffere = &(queue->buffer[first_element]->element[0]);
 354         ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
 355         /*
 356          * go through all SBALs from input queue currently
 357          * returned by QDIO layer
 358          */
 359
 360         for (i = 0; i < elements_processed; i++) {
 361
 362                 buffer_index = first_element + i;
 363                 buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
 364                 buffer = queue->buffer[buffer_index];
 365
 366                 /* go through all SBALEs of SBAL */
 367                 for (buffere_index = 0;
 368                      buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
 369                      buffere_index++) {
 370
 371                         /* look for QDIO request identifiers in SB */
 372                         buffere = &buffer->element[buffere_index];
 373                         zfcp_qdio_reqid_check(adapter,
 374                                               (unsigned long) buffere->addr);
 375
 376                         /*
 377                          * A single used SBALE per inbound SBALE has been
 378                          * implemented by QDIO so far. Hope they will
 379                          * do some optimisation. Will need to change to
 380                          * unlikely() then.
 381                          */
 382                         if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
 383                                 break;
 384                 };
 385
 386                 if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
 387                         ZFCP_LOG_NORMAL("bug: End of inbound data "
 388                                         "not marked!\n");
 389                 }
 390         }
 391
 392         /*
 393          * put range of SBALs back to response queue
 394          * (including SBALs which have already been free before)
 395          */
 396         count = atomic_read(&queue->free_count) + elements_processed;
 397         start = queue->free_index;
 398
 399         ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
 400                        "queue_no=%i, index_in_queue=%i, count=%i, "
 401                        "buffers=0x%lx\n",
 402                        zfcp_get_busid_by_adapter(adapter),
 403                        QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 404                        0, start, count, (unsigned long) &queue->buffer[start]);
 405
 406         retval = do_QDIO(ccw_device,
 407                          QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 408                          0, start, count, NULL);
 409
 410         if (unlikely(retval)) {
 411                 atomic_set(&queue->free_count, count);
 412                 ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
 413                                "queues may be down "
 414                                "(count=%d, start=%d, retval=%d)\n",
 415                                count, start, retval);
 416         } else {
 417                 queue->free_index += count;
 418                 queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
 419                 atomic_set(&queue->free_count, 0);
 420                 ZFCP_LOG_TRACE("%i buffers enqueued to response "
 421                                "queue at position %i\n", count, start);
 422         }
 423  out:
 424         return;
 425 }
 426
 427 /**
 428  * zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
 429  * @queue: queue from which SBALE should be returned
 430  * @sbal: specifies number of SBAL in queue
 431  * @sbale: specifes number of SBALE in SBAL
 432  */
 433 static inline volatile struct qdio_buffer_element *
 434 zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
 435 {
 436         return &queue->buffer[sbal]->element[sbale];
 437 }
 438
 439 /**
 440  * zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
 441  *      a struct zfcp_fsf_req
 442  */
 443 volatile struct qdio_buffer_element *
 444 zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 445 {
 446         return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
 447                                    sbal, sbale);
 448 }
 449
 450 /**
 451  * zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
 452  *      a struct zfcp_fsf_req
 453  */
 454 static inline volatile struct qdio_buffer_element *
 455 zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 456 {
 457         return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
 458                                    sbal, sbale);
 459 }
 460
 461 /**
 462  * zfcp_qdio_sbale_curr - return current SBALE on request_queue for
 463  *      a struct zfcp_fsf_req
 464  */
 465 volatile struct qdio_buffer_element *
 466 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
 467 {
 468         return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
 469                                    fsf_req->sbale_curr);
 470 }
 471
 472 /**
 473  * zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
 474  *      on the request_queue for a struct zfcp_fsf_req
 475  * @fsf_req: the number of the last SBAL that can be used is stored herein
 476  * @max_sbals: used to pass an upper limit for the number of SBALs
 477  *
 478  * Note: We can assume at least one free SBAL in the request_queue when called.
 479  */
 480 static void
 481 zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 482 {
 483         int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
 484         count = min(count, max_sbals);
 485         fsf_req->sbal_last  = fsf_req->sbal_first;
 486         fsf_req->sbal_last += (count - 1);
 487         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 488 }
 489
 490 /**
 491  * zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
 492  *      request
 493  * @fsf_req: zfcp_fsf_req to be processed
 494  * @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
 495  *
 496  * This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
 497  */
 498 static volatile struct qdio_buffer_element *
 499 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 500 {
 501         volatile struct qdio_buffer_element *sbale;
 502
 503         /* set last entry flag in current SBALE of current SBAL */
 504         sbale = zfcp_qdio_sbale_curr(fsf_req);
 505         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 506
 507         /* don't exceed last allowed SBAL */
 508         if (fsf_req->sbal_curr == fsf_req->sbal_last)
 509                 return NULL;
 510
 511         /* set chaining flag in first SBALE of current SBAL */
 512         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 513         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 514
 515         /* calculate index of next SBAL */
 516         fsf_req->sbal_curr++;
 517         fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
 518
 519         /* keep this requests number of SBALs up-to-date */
 520         fsf_req->sbal_number++;
 521
 522         /* start at first SBALE of new SBAL */
 523         fsf_req->sbale_curr = 0;
 524
 525         /* set storage-block type for new SBAL */
 526         sbale = zfcp_qdio_sbale_curr(fsf_req);
 527         sbale->flags |= sbtype;
 528
 529         return sbale;
 530 }
 531
 532 /**
 533  * zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
 534  */
 535 static volatile struct qdio_buffer_element *
 536 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 537 {
 538         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 539                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 540
 541         fsf_req->sbale_curr++;
 542
 543         return zfcp_qdio_sbale_curr(fsf_req);
 544 }
 545
 546 /**
 547  * zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
 548  *      with zero from
 549  */
 550 static int
 551 zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
 552 {
 553         struct qdio_buffer **buf = queue->buffer;
 554         int curr = first;
 555         int count = 0;
 556
 557         for(;;) {
 558                 curr %= QDIO_MAX_BUFFERS_PER_Q;
 559                 count++;
 560                 memset(buf[curr], 0, sizeof(struct qdio_buffer));
 561                 if (curr == last)
 562                         break;
 563                 curr++;
 564         }
 565         return count;
 566 }
 567
 568
 569 /**
 570  * zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
 571  */
 572 static inline int
 573 zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
 574 {
 575         return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
 576                                     fsf_req->sbal_first, fsf_req->sbal_curr);
 577 }
 578
 579
 580 /**
 581  * zfcp_qdio_sbale_fill - set address and lenght in current SBALE
 582  *      on request_queue
 583  */
 584 static void
 585 zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 586                      void *addr, int length)
 587 {
 588         volatile struct qdio_buffer_element *sbale;
 589
 590         sbale = zfcp_qdio_sbale_curr(fsf_req);
 591         sbale->addr = addr;
 592         sbale->length = length;
 593 }
 594
 595 /**
 596  * zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
 597  * @fsf_req: request to be processed
 598  * @sbtype: SBALE flags
 599  * @start_addr: address of memory segment
 600  * @total_length: length of memory segment
 601  *
 602  * Alignment and length of the segment determine how many SBALEs are needed
 603  * for the memory segment.
 604  */
 605 static int
 606 zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 607                              void *start_addr, unsigned long total_length)
 608 {
 609         unsigned long remaining, length;
 610         void *addr;
 611
 612         /* split segment up heeding page boundaries */
 613         for (addr = start_addr, remaining = total_length; remaining > 0;
 614              addr += length, remaining -= length) {
 615                 /* get next free SBALE for new piece */
 616                 if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
 617                         /* no SBALE left, clean up and leave */
 618                         zfcp_qdio_sbals_wipe(fsf_req);
 619                         return -EINVAL;
 620                 }
 621                 /* calculate length of new piece */
 622                 length = min(remaining,
 623                              (PAGE_SIZE - ((unsigned long) addr &
 624                                            (PAGE_SIZE - 1))));
 625                 /* fill current SBALE with calculated piece */
 626                 zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
 627         }
 628         return total_length;
 629 }
 630
 631
 632 /**
 633  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 634  * @fsf_req: request to be processed
 635  * @sbtype: SBALE flags
 636  * @sg: scatter-gather list
 637  * @sg_count: number of elements in scatter-gather list
 638  * @max_sbals: upper bound for number of SBALs to be used
 639  */
 640 int
 641 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 642                         struct scatterlist *sg, int sg_count, int max_sbals)
 643 {
 644         int sg_index;
 645         struct scatterlist *sg_segment;
 646         int retval;
 647         volatile struct qdio_buffer_element *sbale;
 648         int bytes = 0;
 649
 650         /* figure out last allowed SBAL */
 651         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 652
 653         /* set storage-block type for current SBAL */
 654         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 655         sbale->flags |= sbtype;
 656
 657         /* process all segements of scatter-gather list */
 658         for (sg_index = 0, sg_segment = sg, bytes = 0;
 659              sg_index < sg_count;
 660              sg_index++, sg_segment++) {
 661                 retval = zfcp_qdio_sbals_from_segment(
 662                                 fsf_req,
 663                                 sbtype,
 664                                 zfcp_sg_to_address(sg_segment),
 665                                 sg_segment->length);
 666                 if (retval < 0) {
 667                         bytes = retval;
 668                         goto out;
 669                 } else
 670                         bytes += retval;
 671         }
 672         /* assume that no other SBALEs are to follow in the same SBAL */
 673         sbale = zfcp_qdio_sbale_curr(fsf_req);
 674         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 675 out:
 676         return bytes;
 677 }
 678
 679
 680 /**
 681  * zfcp_qdio_sbals_from_buffer - fill SBALs from buffer
 682  * @fsf_req: request to be processed
 683  * @sbtype: SBALE flags
 684  * @buffer: data buffer
 685  * @length: length of buffer
 686  * @max_sbals: upper bound for number of SBALs to be used
 687  */
 688 static int
 689 zfcp_qdio_sbals_from_buffer(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 690                             void *buffer, unsigned long length, int max_sbals)
 691 {
 692         struct scatterlist sg_segment;
 693
 694         zfcp_address_to_sg(buffer, &sg_segment);
 695         sg_segment.length = length;
 696
 697         return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, &sg_segment, 1,
 698                                        max_sbals);
 699 }
 700
 701
 702 /**
 703  * zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
 704  * @fsf_req: request to be processed
 705  * @sbtype: SBALE flags
 706  * @scsi_cmnd: either scatter-gather list or buffer contained herein is used
 707  *      to fill SBALs
 708  */
 709 int
 710 zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
 711                               unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
 712 {
 713         if (scsi_cmnd->use_sg) {
 714                 return zfcp_qdio_sbals_from_sg(fsf_req, sbtype,
 715                                                (struct scatterlist *)
 716                                                scsi_cmnd->request_buffer,
 717                                                scsi_cmnd->use_sg,
 718                                                ZFCP_MAX_SBALS_PER_REQ);
 719         } else {
 720                 return zfcp_qdio_sbals_from_buffer(fsf_req, sbtype,
 721                                                    scsi_cmnd->request_buffer,
 722                                                    scsi_cmnd->request_bufflen,
 723                                                    ZFCP_MAX_SBALS_PER_REQ);
 724         }
 725 }
 726
 727 /**
 728  * zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
 729  */
 730 int
 731 zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
 732                         struct zfcp_fsf_req *fsf_req)
 733 {
 734         int new_distance_from_int;
 735         int pci_pos;
 736         volatile struct qdio_buffer_element *sbale;
 737
 738         new_distance_from_int = req_queue->distance_from_int +
 739                 fsf_req->sbal_number;
 740
 741         if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
 742                 new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
 743                 pci_pos  = fsf_req->sbal_first;
 744                 pci_pos += fsf_req->sbal_number;
 745                 pci_pos -= new_distance_from_int;
 746                 pci_pos -= 1;
 747                 pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
 748                 sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
 749                 sbale->flags |= SBAL_FLAGS0_PCI;
 750         }
 751         return new_distance_from_int;
 752 }
 753
 754 /*
 755  * function:    zfcp_zero_sbals
 756  *
 757  * purpose:     zeros specified range of SBALs
 758  *
 759  * returns:
 760  */
 761 void
 762 zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
 763 {
 764         int cur_pos;
 765         int index;
 766
 767         for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
 768                 index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
 769                 memset(buf[index], 0, sizeof (struct qdio_buffer));
 770                 ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
 771                                index, buf[index]);
 772         }
 773 }
 774
 775 #undef ZFCP_LOG_AREA