drivers/s390/scsi/zfcp_qdio.c

   1 /*
   2  * zfcp device driver
   3  *
   4  * Setup and helper functions to access QDIO.
   5  *
   6  * Copyright IBM Corporation 2002, 2008
   7  */
   8
   9 #include "zfcp_ext.h"
  10
  11 /* FIXME(tune): free space should be one max. SBAL chain plus what? */
  12 #define ZFCP_QDIO_PCI_INTERVAL  (QDIO_MAX_BUFFERS_PER_Q \
  13                                 - (ZFCP_MAX_SBALS_PER_REQ + 4))
  14
  15 static int zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbal)
  16 {
  17         int pos;
  18
  19         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
  20                 sbal[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
  21                 if (!sbal[pos])
  22                         return -ENOMEM;
  23         }
  24         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
  25                 if (pos % QBUFF_PER_PAGE)
  26                         sbal[pos] = sbal[pos - 1] + 1;
  27         return 0;
  28 }
  29
  30 static volatile struct qdio_buffer_element *
  31 zfcp_qdio_sbale(struct zfcp_qdio_queue *q, int sbal_idx, int sbale_idx)
  32 {
  33         return &q->sbal[sbal_idx]->element[sbale_idx];
  34 }
  35
  36 /**
  37  * zfcp_qdio_free - free memory used by request- and resposne queue
  38  * @adapter: pointer to the zfcp_adapter structure
  39  */
  40 void zfcp_qdio_free(struct zfcp_adapter *adapter)
  41 {
  42         struct qdio_buffer **sbal_req, **sbal_resp;
  43         int p;
  44
  45         if (adapter->ccw_device)
  46                 qdio_free(adapter->ccw_device);
  47
  48         sbal_req = adapter->req_q.sbal;
  49         sbal_resp = adapter->resp_q.sbal;
  50
  51         for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
  52                 free_page((unsigned long) sbal_req[p]);
  53                 free_page((unsigned long) sbal_resp[p]);
  54         }
  55 }
  56
  57 static void zfcp_qdio_handler_error(struct zfcp_adapter *adapter, u8 id)
  58 {
  59         dev_warn(&adapter->ccw_device->dev, "QDIO problem occurred.\n");
  60
  61         zfcp_erp_adapter_reopen(adapter,
  62                                 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
  63                                 ZFCP_STATUS_COMMON_ERP_FAILED, id, NULL);
  64 }
  65
  66 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int status,
  67                               unsigned int qdio_err, unsigned int siga_err,
  68                               unsigned int queue_no, int first, int count,
  69                               unsigned long parm)
  70 {
  71         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
  72         struct zfcp_qdio_queue *queue = &adapter->req_q;
  73
  74         if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
  75                 zfcp_hba_dbf_event_qdio(adapter, status, qdio_err, siga_err,
  76                                         first, count);
  77                 zfcp_qdio_handler_error(adapter, 140);
  78                 return;
  79         }
  80
  81         /* cleanup all SBALs being program-owned now */
  82         zfcp_qdio_zero_sbals(queue->sbal, first, count);
  83
  84         atomic_add(count, &queue->count);
  85         wake_up(&adapter->request_wq);
  86 }
  87
  88 static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
  89                                   unsigned long req_id, int sbal_idx)
  90 {
  91         struct zfcp_fsf_req *fsf_req;
  92         unsigned long flags;
  93
  94         spin_lock_irqsave(&adapter->req_list_lock, flags);
  95         fsf_req = zfcp_reqlist_find(adapter, req_id);
  96
  97         if (!fsf_req)
  98                 /*
  99                  * Unknown request means that we have potentially memory
 100                  * corruption and must stop the machine immediatly.
 101                  */
 102                 panic("error: unknown request id (%lx) on adapter %s.\n",
 103                       req_id, zfcp_get_busid_by_adapter(adapter));
 104
 105         zfcp_reqlist_remove(adapter, fsf_req);
 106         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 107
 108         fsf_req->sbal_response = sbal_idx;
 109         zfcp_fsf_req_complete(fsf_req);
 110 }
 111
 112 static void zfcp_qdio_resp_put_back(struct zfcp_adapter *adapter, int processed)
 113 {
 114         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 115         struct ccw_device *cdev = adapter->ccw_device;
 116         u8 count, start = queue->first;
 117         unsigned int retval;
 118
 119         count = atomic_read(&queue->count) + processed;
 120
 121         retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 122                          0, start, count, NULL);
 123
 124         if (unlikely(retval)) {
 125                 atomic_set(&queue->count, count);
 126                 /* FIXME: Recover this with an adapter reopen? */
 127         } else {
 128                 queue->first += count;
 129                 queue->first %= QDIO_MAX_BUFFERS_PER_Q;
 130                 atomic_set(&queue->count, 0);
 131         }
 132 }
 133
 134 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int status,
 135                                unsigned int qdio_err, unsigned int siga_err,
 136                                unsigned int queue_no, int first, int count,
 137                                unsigned long parm)
 138 {
 139         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
 140         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 141         volatile struct qdio_buffer_element *sbale;
 142         int sbal_idx, sbale_idx, sbal_no;
 143
 144         if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
 145                 zfcp_hba_dbf_event_qdio(adapter, status, qdio_err, siga_err,
 146                                         first, count);
 147                 zfcp_qdio_handler_error(adapter, 147);
 148                 return;
 149         }
 150
 151         /*
 152          * go through all SBALs from input queue currently
 153          * returned by QDIO layer
 154          */
 155         for (sbal_no = 0; sbal_no < count; sbal_no++) {
 156                 sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
 157
 158                 /* go through all SBALEs of SBAL */
 159                 for (sbale_idx = 0; sbale_idx < QDIO_MAX_ELEMENTS_PER_BUFFER;
 160                      sbale_idx++) {
 161                         sbale = zfcp_qdio_sbale(queue, sbal_idx, sbale_idx);
 162                         zfcp_qdio_reqid_check(adapter,
 163                                               (unsigned long) sbale->addr,
 164                                               sbal_idx);
 165                         if (likely(sbale->flags & SBAL_FLAGS_LAST_ENTRY))
 166                                 break;
 167                 };
 168
 169                 if (unlikely(!(sbale->flags & SBAL_FLAGS_LAST_ENTRY)))
 170                         dev_warn(&adapter->ccw_device->dev,
 171                                  "Protocol violation by adapter. "
 172                                  "Continuing operations.\n");
 173         }
 174
 175         /*
 176          * put range of SBALs back to response queue
 177          * (including SBALs which have already been free before)
 178          */
 179         zfcp_qdio_resp_put_back(adapter, count);
 180 }
 181
 182 /**
 183  * zfcp_qdio_sbale_req - return ptr to SBALE of req_q for a struct zfcp_fsf_req
 184  * @fsf_req: pointer to struct fsf_req
 185  * Returns: pointer to qdio_buffer_element (SBALE) structure
 186  */
 187 volatile struct qdio_buffer_element *
 188 zfcp_qdio_sbale_req(struct zfcp_fsf_req *req)
 189 {
 190         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last, 0);
 191 }
 192
 193 /**
 194  * zfcp_qdio_sbale_curr - return curr SBALE on req_q for a struct zfcp_fsf_req
 195  * @fsf_req: pointer to struct fsf_req
 196  * Returns: pointer to qdio_buffer_element (SBALE) structure
 197  */
 198 volatile struct qdio_buffer_element *
 199 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *req)
 200 {
 201         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last,
 202                                req->sbale_curr);
 203 }
 204
 205 static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 206 {
 207         int count = atomic_read(&fsf_req->adapter->req_q.count);
 208         count = min(count, max_sbals);
 209         fsf_req->sbal_limit = (fsf_req->sbal_first + count - 1)
 210                                         % QDIO_MAX_BUFFERS_PER_Q;
 211 }
 212
 213 static volatile struct qdio_buffer_element *
 214 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 215 {
 216         volatile struct qdio_buffer_element *sbale;
 217
 218         /* set last entry flag in current SBALE of current SBAL */
 219         sbale = zfcp_qdio_sbale_curr(fsf_req);
 220         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 221
 222         /* don't exceed last allowed SBAL */
 223         if (fsf_req->sbal_last == fsf_req->sbal_limit)
 224                 return NULL;
 225
 226         /* set chaining flag in first SBALE of current SBAL */
 227         sbale = zfcp_qdio_sbale_req(fsf_req);
 228         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 229
 230         /* calculate index of next SBAL */
 231         fsf_req->sbal_last++;
 232         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 233
 234         /* keep this requests number of SBALs up-to-date */
 235         fsf_req->sbal_number++;
 236
 237         /* start at first SBALE of new SBAL */
 238         fsf_req->sbale_curr = 0;
 239
 240         /* set storage-block type for new SBAL */
 241         sbale = zfcp_qdio_sbale_curr(fsf_req);
 242         sbale->flags |= sbtype;
 243
 244         return sbale;
 245 }
 246
 247 static volatile struct qdio_buffer_element *
 248 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 249 {
 250         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 251                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 252         fsf_req->sbale_curr++;
 253         return zfcp_qdio_sbale_curr(fsf_req);
 254 }
 255
 256 static void zfcp_qdio_undo_sbals(struct zfcp_fsf_req *fsf_req)
 257 {
 258         struct qdio_buffer **sbal = fsf_req->adapter->req_q.sbal;
 259         int first = fsf_req->sbal_first;
 260         int last = fsf_req->sbal_last;
 261         int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
 262                 QDIO_MAX_BUFFERS_PER_Q + 1;
 263         zfcp_qdio_zero_sbals(sbal, first, count);
 264 }
 265
 266 static int zfcp_qdio_fill_sbals(struct zfcp_fsf_req *fsf_req,
 267                                 unsigned int sbtype, void *start_addr,
 268                                 unsigned int total_length)
 269 {
 270         volatile struct qdio_buffer_element *sbale;
 271         unsigned long remaining, length;
 272         void *addr;
 273
 274         /* split segment up */
 275         for (addr = start_addr, remaining = total_length; remaining > 0;
 276              addr += length, remaining -= length) {
 277                 sbale = zfcp_qdio_sbale_next(fsf_req, sbtype);
 278                 if (!sbale) {
 279                         zfcp_qdio_undo_sbals(fsf_req);
 280                         return -EINVAL;
 281                 }
 282
 283                 /* new piece must not exceed next page boundary */
 284                 length = min(remaining,
 285                              (PAGE_SIZE - ((unsigned long)addr &
 286                                            (PAGE_SIZE - 1))));
 287                 sbale->addr = addr;
 288                 sbale->length = length;
 289         }
 290         return 0;
 291 }
 292
 293 /**
 294  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 295  * @fsf_req: request to be processed
 296  * @sbtype: SBALE flags
 297  * @sg: scatter-gather list
 298  * @max_sbals: upper bound for number of SBALs to be used
 299  * Returns: number of bytes, or error (negativ)
 300  */
 301 int zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 302                             struct scatterlist *sg, int max_sbals)
 303 {
 304         volatile struct qdio_buffer_element *sbale;
 305         int retval, bytes = 0;
 306
 307         /* figure out last allowed SBAL */
 308         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 309
 310         /* set storage-block type for this request */
 311         sbale = zfcp_qdio_sbale_req(fsf_req);
 312         sbale->flags |= sbtype;
 313
 314         for (; sg; sg = sg_next(sg)) {
 315                 retval = zfcp_qdio_fill_sbals(fsf_req, sbtype, sg_virt(sg),
 316                                               sg->length);
 317                 if (retval < 0)
 318                         return retval;
 319                 bytes += sg->length;
 320         }
 321
 322         /* assume that no other SBALEs are to follow in the same SBAL */
 323         sbale = zfcp_qdio_sbale_curr(fsf_req);
 324         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 325
 326         return bytes;
 327 }
 328
 329 /**
 330  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 331  * @fsf_req: pointer to struct zfcp_fsf_req
 332  * Returns: 0 on success, error otherwise
 333  */
 334 int zfcp_qdio_send(struct zfcp_fsf_req *fsf_req)
 335 {
 336         struct zfcp_adapter *adapter = fsf_req->adapter;
 337         struct zfcp_qdio_queue *req_q = &adapter->req_q;
 338         int first = fsf_req->sbal_first;
 339         int count = fsf_req->sbal_number;
 340         int retval, pci, pci_batch;
 341         volatile struct qdio_buffer_element *sbale;
 342
 343         /* acknowledgements for transferred buffers */
 344         pci_batch = req_q->pci_batch + count;
 345         if (unlikely(pci_batch >= ZFCP_QDIO_PCI_INTERVAL)) {
 346                 pci_batch %= ZFCP_QDIO_PCI_INTERVAL;
 347                 pci = first + count - (pci_batch + 1);
 348                 pci %= QDIO_MAX_BUFFERS_PER_Q;
 349                 sbale = zfcp_qdio_sbale(req_q, pci, 0);
 350                 sbale->flags |= SBAL_FLAGS0_PCI;
 351         }
 352
 353         retval = do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0, first,
 354                          count, NULL);
 355         if (unlikely(retval)) {
 356                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 357                 return retval;
 358         }
 359
 360         /* account for transferred buffers */
 361         atomic_sub(count, &req_q->count);
 362         req_q->first += count;
 363         req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
 364         req_q->pci_batch = pci_batch;
 365         return 0;
 366 }
 367
 368 /**
 369  * zfcp_qdio_zero_sbals - zero all sbals of the specified area and queue
 370  * @buf: pointer to array of SBALS
 371  * @first: integer specifying the SBAL number to start
 372  * @count: integer specifying the number of SBALS to process
 373  */
 374 void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int count)
 375 {
 376         int i, sbal_idx;
 377
 378         for (i = first; i < first + count; i++) {
 379                 sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
 380                 memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
 381         }
 382 }
 383
 384 /**
 385  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 386  * @adapter: pointer to struct zfcp_adapter
 387  * Returns: -ENOMEM on memory allocation error or return value from
 388  *          qdio_allocate
 389  */
 390 int zfcp_qdio_allocate(struct zfcp_adapter *adapter)
 391 {
 392         struct qdio_initialize *init_data;
 393
 394         if (zfcp_qdio_buffers_enqueue(adapter->req_q.sbal) ||
 395                    zfcp_qdio_buffers_enqueue(adapter->resp_q.sbal))
 396                 return -ENOMEM;
 397
 398         init_data = &adapter->qdio_init_data;
 399
 400         init_data->cdev = adapter->ccw_device;
 401         init_data->q_format = QDIO_ZFCP_QFMT;
 402         memcpy(init_data->adapter_name, zfcp_get_busid_by_adapter(adapter), 8);
 403         ASCEBC(init_data->adapter_name, 8);
 404         init_data->qib_param_field_format = 0;
 405         init_data->qib_param_field = NULL;
 406         init_data->input_slib_elements = NULL;
 407         init_data->output_slib_elements = NULL;
 408         init_data->min_input_threshold = 1;
 409         init_data->max_input_threshold = 5000;
 410         init_data->min_output_threshold = 1;
 411         init_data->max_output_threshold = 1000;
 412         init_data->no_input_qs = 1;
 413         init_data->no_output_qs = 1;
 414         init_data->input_handler = zfcp_qdio_int_resp;
 415         init_data->output_handler = zfcp_qdio_int_req;
 416         init_data->int_parm = (unsigned long) adapter;
 417         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
 418                         QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
 419         init_data->input_sbal_addr_array =
 420                         (void **) (adapter->resp_q.sbal);
 421         init_data->output_sbal_addr_array =
 422                         (void **) (adapter->req_q.sbal);
 423
 424         return qdio_allocate(init_data);
 425 }
 426
 427 /**
 428  * zfcp_close_qdio - close qdio queues for an adapter
 429  */
 430 void zfcp_qdio_close(struct zfcp_adapter *adapter)
 431 {
 432         struct zfcp_qdio_queue *req_q;
 433         int first, count;
 434
 435         if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status))
 436                 return;
 437
 438         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 439         req_q = &adapter->req_q;
 440         write_lock_irq(&req_q->lock);
 441         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
 442         write_unlock_irq(&req_q->lock);
 443
 444         while (qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR)
 445                         == -EINPROGRESS)
 446                 ssleep(1);
 447
 448         /* cleanup used outbound sbals */
 449         count = atomic_read(&req_q->count);
 450         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 451                 first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
 452                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 453                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 454         }
 455         req_q->first = 0;
 456         atomic_set(&req_q->count, 0);
 457         req_q->pci_batch = 0;
 458         adapter->resp_q.first = 0;
 459         atomic_set(&adapter->resp_q.count, 0);
 460 }
 461
 462 /**
 463  * zfcp_qdio_open - prepare and initialize response queue
 464  * @adapter: pointer to struct zfcp_adapter
 465  * Returns: 0 on success, otherwise -EIO
 466  */
 467 int zfcp_qdio_open(struct zfcp_adapter *adapter)
 468 {
 469         volatile struct qdio_buffer_element *sbale;
 470         int cc;
 471
 472         if (atomic_test_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status))
 473                 return -EIO;
 474
 475         if (qdio_establish(&adapter->qdio_init_data)) {
 476                 dev_err(&adapter->ccw_device->dev,
 477                          "Establish of QDIO queues failed.\n");
 478                 return -EIO;
 479         }
 480
 481         if (qdio_activate(adapter->ccw_device, 0)) {
 482                 dev_err(&adapter->ccw_device->dev,
 483                          "Activate of QDIO queues failed.\n");
 484                 goto failed_qdio;
 485         }
 486
 487         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 488                 sbale = &(adapter->resp_q.sbal[cc]->element[0]);
 489                 sbale->length = 0;
 490                 sbale->flags = SBAL_FLAGS_LAST_ENTRY;
 491                 sbale->addr = NULL;
 492         }
 493
 494         if (do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_INPUT, 0, 0,
 495                      QDIO_MAX_BUFFERS_PER_Q, NULL)) {
 496                 dev_err(&adapter->ccw_device->dev,
 497                          "Init of QDIO response queue failed.\n");
 498                 goto failed_qdio;
 499         }
 500
 501         /* set index of first avalable SBALS / number of available SBALS */
 502         adapter->req_q.first = 0;
 503         atomic_set(&adapter->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
 504         adapter->req_q.pci_batch = 0;
 505
 506         return 0;
 507
 508 failed_qdio:
 509         while (qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR)
 510                         == -EINPROGRESS)
 511                 ssleep(1);
 512
 513         return -EIO;
 514 }