git.oblomov.eu Git - 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 inline 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 inline volatile struct qdio_buffer_element *zfcp_qdio_sbal_chain
  30         (struct zfcp_fsf_req *, unsigned long);
  31 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_next
  32         (struct zfcp_fsf_req *, unsigned long);
  33 static inline 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 inline void zfcp_qdio_sbale_fill
  36         (struct zfcp_fsf_req *, unsigned long, void *, int);
  37 static inline int zfcp_qdio_sbals_from_segment
  38         (struct zfcp_fsf_req *, unsigned long, void *, unsigned long);
  39 static inline 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 inline 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 int 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                 ZFCP_LOG_NORMAL("error: unknown request id (%ld).\n", req_id);
 302                 zfcp_erp_adapter_reopen(adapter, 0);
 303                 return -EINVAL;
 304         }
 305
 306         zfcp_reqlist_remove(adapter, req_id);
 307         atomic_dec(&adapter->reqs_active);
 308         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 309
 310         /* finish the FSF request */
 311         zfcp_fsf_req_complete(fsf_req);
 312
 313         return 0;
 314 }
 315
 316 /*
 317  * function:    zfcp_qdio_response_handler
 318  *
 319  * purpose:     is called by QDIO layer for completed SBALs in response queue
 320  *
 321  * returns:     (void)
 322  */
 323 static void
 324 zfcp_qdio_response_handler(struct ccw_device *ccw_device,
 325                            unsigned int status,
 326                            unsigned int qdio_error,
 327                            unsigned int siga_error,
 328                            unsigned int queue_number,
 329                            int first_element,
 330                            int elements_processed,
 331                            unsigned long int_parm)
 332 {
 333         struct zfcp_adapter *adapter;
 334         struct zfcp_qdio_queue *queue;
 335         int buffer_index;
 336         int i;
 337         struct qdio_buffer *buffer;
 338         int retval = 0;
 339         u8 count;
 340         u8 start;
 341         volatile struct qdio_buffer_element *buffere = NULL;
 342         int buffere_index;
 343
 344         adapter = (struct zfcp_adapter *) int_parm;
 345         queue = &adapter->response_queue;
 346
 347         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
 348                                                    siga_error, first_element,
 349                                                    elements_processed)))
 350                 goto out;
 351
 352         /*
 353          * we stored address of struct zfcp_adapter  data structure
 354          * associated with irq in int_parm
 355          */
 356
 357         buffere = &(queue->buffer[first_element]->element[0]);
 358         ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
 359         /*
 360          * go through all SBALs from input queue currently
 361          * returned by QDIO layer
 362          */
 363
 364         for (i = 0; i < elements_processed; i++) {
 365
 366                 buffer_index = first_element + i;
 367                 buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
 368                 buffer = queue->buffer[buffer_index];
 369
 370                 /* go through all SBALEs of SBAL */
 371                 for (buffere_index = 0;
 372                      buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
 373                      buffere_index++) {
 374
 375                         /* look for QDIO request identifiers in SB */
 376                         buffere = &buffer->element[buffere_index];
 377                         retval = zfcp_qdio_reqid_check(adapter,
 378                                         (unsigned long) buffere->addr);
 379
 380                         if (retval) {
 381                                 ZFCP_LOG_NORMAL("bug: unexpected inbound "
 382                                                 "packet on adapter %s "
 383                                                 "(reqid=0x%lx, "
 384                                                 "first_element=%d, "
 385                                                 "elements_processed=%d)\n",
 386                                                 zfcp_get_busid_by_adapter(adapter),
 387                                                 (unsigned long) buffere->addr,
 388                                                 first_element,
 389                                                 elements_processed);
 390                                 ZFCP_LOG_NORMAL("hex dump of inbound buffer "
 391                                                 "at address %p "
 392                                                 "(buffer_index=%d, "
 393                                                 "buffere_index=%d)\n", buffer,
 394                                                 buffer_index, buffere_index);
 395                                 ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
 396                                               (char *) buffer, SBAL_SIZE);
 397                         }
 398                         /*
 399                          * A single used SBALE per inbound SBALE has been
 400                          * implemented by QDIO so far. Hope they will
 401                          * do some optimisation. Will need to change to
 402                          * unlikely() then.
 403                          */
 404                         if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
 405                                 break;
 406                 };
 407
 408                 if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
 409                         ZFCP_LOG_NORMAL("bug: End of inbound data "
 410                                         "not marked!\n");
 411                 }
 412         }
 413
 414         /*
 415          * put range of SBALs back to response queue
 416          * (including SBALs which have already been free before)
 417          */
 418         count = atomic_read(&queue->free_count) + elements_processed;
 419         start = queue->free_index;
 420
 421         ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
 422                        "queue_no=%i, index_in_queue=%i, count=%i, "
 423                        "buffers=0x%lx\n",
 424                        zfcp_get_busid_by_adapter(adapter),
 425                        QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 426                        0, start, count, (unsigned long) &queue->buffer[start]);
 427
 428         retval = do_QDIO(ccw_device,
 429                          QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 430                          0, start, count, NULL);
 431
 432         if (unlikely(retval)) {
 433                 atomic_set(&queue->free_count, count);
 434                 ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
 435                                "queues may be down "
 436                                "(count=%d, start=%d, retval=%d)\n",
 437                                count, start, retval);
 438         } else {
 439                 queue->free_index += count;
 440                 queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
 441                 atomic_set(&queue->free_count, 0);
 442                 ZFCP_LOG_TRACE("%i buffers enqueued to response "
 443                                "queue at position %i\n", count, start);
 444         }
 445  out:
 446         return;
 447 }
 448
 449 /**
 450  * zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
 451  * @queue: queue from which SBALE should be returned
 452  * @sbal: specifies number of SBAL in queue
 453  * @sbale: specifes number of SBALE in SBAL
 454  */
 455 static inline volatile struct qdio_buffer_element *
 456 zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
 457 {
 458         return &queue->buffer[sbal]->element[sbale];
 459 }
 460
 461 /**
 462  * zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
 463  *      a struct zfcp_fsf_req
 464  */
 465 inline volatile struct qdio_buffer_element *
 466 zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 467 {
 468         return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
 469                                    sbal, sbale);
 470 }
 471
 472 /**
 473  * zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
 474  *      a struct zfcp_fsf_req
 475  */
 476 static inline volatile struct qdio_buffer_element *
 477 zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 478 {
 479         return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
 480                                    sbal, sbale);
 481 }
 482
 483 /**
 484  * zfcp_qdio_sbale_curr - return current SBALE on request_queue for
 485  *      a struct zfcp_fsf_req
 486  */
 487 inline volatile struct qdio_buffer_element *
 488 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
 489 {
 490         return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
 491                                    fsf_req->sbale_curr);
 492 }
 493
 494 /**
 495  * zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
 496  *      on the request_queue for a struct zfcp_fsf_req
 497  * @fsf_req: the number of the last SBAL that can be used is stored herein
 498  * @max_sbals: used to pass an upper limit for the number of SBALs
 499  *
 500  * Note: We can assume at least one free SBAL in the request_queue when called.
 501  */
 502 static inline void
 503 zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 504 {
 505         int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
 506         count = min(count, max_sbals);
 507         fsf_req->sbal_last  = fsf_req->sbal_first;
 508         fsf_req->sbal_last += (count - 1);
 509         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 510 }
 511
 512 /**
 513  * zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
 514  *      request
 515  * @fsf_req: zfcp_fsf_req to be processed
 516  * @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
 517  *
 518  * This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
 519  */
 520 static inline volatile struct qdio_buffer_element *
 521 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 522 {
 523         volatile struct qdio_buffer_element *sbale;
 524
 525         /* set last entry flag in current SBALE of current SBAL */
 526         sbale = zfcp_qdio_sbale_curr(fsf_req);
 527         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 528
 529         /* don't exceed last allowed SBAL */
 530         if (fsf_req->sbal_curr == fsf_req->sbal_last)
 531                 return NULL;
 532
 533         /* set chaining flag in first SBALE of current SBAL */
 534         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 535         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 536
 537         /* calculate index of next SBAL */
 538         fsf_req->sbal_curr++;
 539         fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
 540
 541         /* keep this requests number of SBALs up-to-date */
 542         fsf_req->sbal_number++;
 543
 544         /* start at first SBALE of new SBAL */
 545         fsf_req->sbale_curr = 0;
 546
 547         /* set storage-block type for new SBAL */
 548         sbale = zfcp_qdio_sbale_curr(fsf_req);
 549         sbale->flags |= sbtype;
 550
 551         return sbale;
 552 }
 553
 554 /**
 555  * zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
 556  */
 557 static inline volatile struct qdio_buffer_element *
 558 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 559 {
 560         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 561                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 562
 563         fsf_req->sbale_curr++;
 564
 565         return zfcp_qdio_sbale_curr(fsf_req);
 566 }
 567
 568 /**
 569  * zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
 570  *      with zero from
 571  */
 572 static inline int
 573 zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
 574 {
 575         struct qdio_buffer **buf = queue->buffer;
 576         int curr = first;
 577         int count = 0;
 578
 579         for(;;) {
 580                 curr %= QDIO_MAX_BUFFERS_PER_Q;
 581                 count++;
 582                 memset(buf[curr], 0, sizeof(struct qdio_buffer));
 583                 if (curr == last)
 584                         break;
 585                 curr++;
 586         }
 587         return count;
 588 }
 589
 590
 591 /**
 592  * zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
 593  */
 594 static inline int
 595 zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
 596 {
 597         return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
 598                                     fsf_req->sbal_first, fsf_req->sbal_curr);
 599 }
 600
 601
 602 /**
 603  * zfcp_qdio_sbale_fill - set address and lenght in current SBALE
 604  *      on request_queue
 605  */
 606 static inline void
 607 zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 608                      void *addr, int length)
 609 {
 610         volatile struct qdio_buffer_element *sbale;
 611
 612         sbale = zfcp_qdio_sbale_curr(fsf_req);
 613         sbale->addr = addr;
 614         sbale->length = length;
 615 }
 616
 617 /**
 618  * zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
 619  * @fsf_req: request to be processed
 620  * @sbtype: SBALE flags
 621  * @start_addr: address of memory segment
 622  * @total_length: length of memory segment
 623  *
 624  * Alignment and length of the segment determine how many SBALEs are needed
 625  * for the memory segment.
 626  */
 627 static inline int
 628 zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 629                              void *start_addr, unsigned long total_length)
 630 {
 631         unsigned long remaining, length;
 632         void *addr;
 633
 634         /* split segment up heeding page boundaries */
 635         for (addr = start_addr, remaining = total_length; remaining > 0;
 636              addr += length, remaining -= length) {
 637                 /* get next free SBALE for new piece */
 638                 if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
 639                         /* no SBALE left, clean up and leave */
 640                         zfcp_qdio_sbals_wipe(fsf_req);
 641                         return -EINVAL;
 642                 }
 643                 /* calculate length of new piece */
 644                 length = min(remaining,
 645                              (PAGE_SIZE - ((unsigned long) addr &
 646                                            (PAGE_SIZE - 1))));
 647                 /* fill current SBALE with calculated piece */
 648                 zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
 649         }
 650         return total_length;
 651 }
 652
 653
 654 /**
 655  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 656  * @fsf_req: request to be processed
 657  * @sbtype: SBALE flags
 658  * @sg: scatter-gather list
 659  * @sg_count: number of elements in scatter-gather list
 660  * @max_sbals: upper bound for number of SBALs to be used
 661  */
 662 inline int
 663 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 664                         struct scatterlist *sg, int sg_count, int max_sbals)
 665 {
 666         int sg_index;
 667         struct scatterlist *sg_segment;
 668         int retval;
 669         volatile struct qdio_buffer_element *sbale;
 670         int bytes = 0;
 671
 672         /* figure out last allowed SBAL */
 673         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 674
 675         /* set storage-block type for current SBAL */
 676         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 677         sbale->flags |= sbtype;
 678
 679         /* process all segements of scatter-gather list */
 680         for (sg_index = 0, sg_segment = sg, bytes = 0;
 681              sg_index < sg_count;
 682              sg_index++, sg_segment++) {
 683                 retval = zfcp_qdio_sbals_from_segment(
 684                                 fsf_req,
 685                                 sbtype,
 686                                 zfcp_sg_to_address(sg_segment),
 687                                 sg_segment->length);
 688                 if (retval < 0) {
 689                         bytes = retval;
 690                         goto out;
 691                 } else
 692                         bytes += retval;
 693         }
 694         /* assume that no other SBALEs are to follow in the same SBAL */
 695         sbale = zfcp_qdio_sbale_curr(fsf_req);
 696         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 697 out:
 698         return bytes;
 699 }
 700
 701
 702 /**
 703  * zfcp_qdio_sbals_from_buffer - fill SBALs from buffer
 704  * @fsf_req: request to be processed
 705  * @sbtype: SBALE flags
 706  * @buffer: data buffer
 707  * @length: length of buffer
 708  * @max_sbals: upper bound for number of SBALs to be used
 709  */
 710 static inline int
 711 zfcp_qdio_sbals_from_buffer(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 712                             void *buffer, unsigned long length, int max_sbals)
 713 {
 714         struct scatterlist sg_segment;
 715
 716         zfcp_address_to_sg(buffer, &sg_segment);
 717         sg_segment.length = length;
 718
 719         return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, &sg_segment, 1,
 720                                        max_sbals);
 721 }
 722
 723
 724 /**
 725  * zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
 726  * @fsf_req: request to be processed
 727  * @sbtype: SBALE flags
 728  * @scsi_cmnd: either scatter-gather list or buffer contained herein is used
 729  *      to fill SBALs
 730  */
 731 inline int
 732 zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
 733                               unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
 734 {
 735         if (scsi_cmnd->use_sg) {
 736                 return zfcp_qdio_sbals_from_sg(fsf_req, sbtype,
 737                                                (struct scatterlist *)
 738                                                scsi_cmnd->request_buffer,
 739                                                scsi_cmnd->use_sg,
 740                                                ZFCP_MAX_SBALS_PER_REQ);
 741         } else {
 742                 return zfcp_qdio_sbals_from_buffer(fsf_req, sbtype,
 743                                                    scsi_cmnd->request_buffer,
 744                                                    scsi_cmnd->request_bufflen,
 745                                                    ZFCP_MAX_SBALS_PER_REQ);
 746         }
 747 }
 748
 749 /**
 750  * zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
 751  */
 752 int
 753 zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
 754                         struct zfcp_fsf_req *fsf_req)
 755 {
 756         int new_distance_from_int;
 757         int pci_pos;
 758         volatile struct qdio_buffer_element *sbale;
 759
 760         new_distance_from_int = req_queue->distance_from_int +
 761                 fsf_req->sbal_number;
 762
 763         if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
 764                 new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
 765                 pci_pos  = fsf_req->sbal_first;
 766                 pci_pos += fsf_req->sbal_number;
 767                 pci_pos -= new_distance_from_int;
 768                 pci_pos -= 1;
 769                 pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
 770                 sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
 771                 sbale->flags |= SBAL_FLAGS0_PCI;
 772         }
 773         return new_distance_from_int;
 774 }
 775
 776 /*
 777  * function:    zfcp_zero_sbals
 778  *
 779  * purpose:     zeros specified range of SBALs
 780  *
 781  * returns:
 782  */
 783 void
 784 zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
 785 {
 786         int cur_pos;
 787         int index;
 788
 789         for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
 790                 index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
 791                 memset(buf[index], 0, sizeof (struct qdio_buffer));
 792                 ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
 793                                index, buf[index]);
 794         }
 795 }
 796
 797 #undef ZFCP_LOG_AREA