git.oblomov.eu Git - linux-2.6/blob - 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 #define QBUFF_PER_PAGE          (PAGE_SIZE / sizeof(struct qdio_buffer))
  15
  16 static int zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbal)
  17 {
  18         int pos;
  19
  20         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
  21                 sbal[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
  22                 if (!sbal[pos])
  23                         return -ENOMEM;
  24         }
  25         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
  26                 if (pos % QBUFF_PER_PAGE)
  27                         sbal[pos] = sbal[pos - 1] + 1;
  28         return 0;
  29 }
  30
  31 static volatile struct qdio_buffer_element *
  32 zfcp_qdio_sbale(struct zfcp_qdio_queue *q, int sbal_idx, int sbale_idx)
  33 {
  34         return &q->sbal[sbal_idx]->element[sbale_idx];
  35 }
  36
  37 /**
  38  * zfcp_qdio_free - free memory used by request- and resposne queue
  39  * @adapter: pointer to the zfcp_adapter structure
  40  */
  41 void zfcp_qdio_free(struct zfcp_adapter *adapter)
  42 {
  43         struct qdio_buffer **sbal_req, **sbal_resp;
  44         int p;
  45
  46         if (adapter->ccw_device)
  47                 qdio_free(adapter->ccw_device);
  48
  49         sbal_req = adapter->req_q.sbal;
  50         sbal_resp = adapter->resp_q.sbal;
  51
  52         for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
  53                 free_page((unsigned long) sbal_req[p]);
  54                 free_page((unsigned long) sbal_resp[p]);
  55         }
  56 }
  57
  58 static void zfcp_qdio_handler_error(struct zfcp_adapter *adapter, u8 id)
  59 {
  60         dev_warn(&adapter->ccw_device->dev, "QDIO problem occurred.\n");
  61
  62         zfcp_erp_adapter_reopen(adapter,
  63                                 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
  64                                 ZFCP_STATUS_COMMON_ERP_FAILED, id, NULL);
  65 }
  66
  67 static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
  68 {
  69         int i, sbal_idx;
  70
  71         for (i = first; i < first + cnt; i++) {
  72                 sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
  73                 memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
  74         }
  75 }
  76
  77 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int status,
  78                               unsigned int qdio_err, unsigned int siga_err,
  79                               unsigned int queue_no, int first, int count,
  80                               unsigned long parm)
  81 {
  82         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
  83         struct zfcp_qdio_queue *queue = &adapter->req_q;
  84
  85         if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
  86                 zfcp_hba_dbf_event_qdio(adapter, status, qdio_err, siga_err,
  87                                         first, count);
  88                 zfcp_qdio_handler_error(adapter, 140);
  89                 return;
  90         }
  91
  92         /* cleanup all SBALs being program-owned now */
  93         zfcp_qdio_zero_sbals(queue->sbal, first, count);
  94
  95         atomic_add(count, &queue->count);
  96         wake_up(&adapter->request_wq);
  97 }
  98
  99 static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
 100                                   unsigned long req_id, int sbal_idx)
 101 {
 102         struct zfcp_fsf_req *fsf_req;
 103         unsigned long flags;
 104
 105         spin_lock_irqsave(&adapter->req_list_lock, flags);
 106         fsf_req = zfcp_reqlist_find(adapter, req_id);
 107
 108         if (!fsf_req)
 109                 /*
 110                  * Unknown request means that we have potentially memory
 111                  * corruption and must stop the machine immediatly.
 112                  */
 113                 panic("error: unknown request id (%lx) on adapter %s.\n",
 114                       req_id, zfcp_get_busid_by_adapter(adapter));
 115
 116         zfcp_reqlist_remove(adapter, fsf_req);
 117         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 118
 119         fsf_req->sbal_response = sbal_idx;
 120         zfcp_fsf_req_complete(fsf_req);
 121 }
 122
 123 static void zfcp_qdio_resp_put_back(struct zfcp_adapter *adapter, int processed)
 124 {
 125         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 126         struct ccw_device *cdev = adapter->ccw_device;
 127         u8 count, start = queue->first;
 128         unsigned int retval;
 129
 130         count = atomic_read(&queue->count) + processed;
 131
 132         retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 133                          0, start, count, NULL);
 134
 135         if (unlikely(retval)) {
 136                 atomic_set(&queue->count, count);
 137                 /* FIXME: Recover this with an adapter reopen? */
 138         } else {
 139                 queue->first += count;
 140                 queue->first %= QDIO_MAX_BUFFERS_PER_Q;
 141                 atomic_set(&queue->count, 0);
 142         }
 143 }
 144
 145 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int status,
 146                                unsigned int qdio_err, unsigned int siga_err,
 147                                unsigned int queue_no, int first, int count,
 148                                unsigned long parm)
 149 {
 150         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
 151         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 152         volatile struct qdio_buffer_element *sbale;
 153         int sbal_idx, sbale_idx, sbal_no;
 154
 155         if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
 156                 zfcp_hba_dbf_event_qdio(adapter, status, qdio_err, siga_err,
 157                                         first, count);
 158                 zfcp_qdio_handler_error(adapter, 147);
 159                 return;
 160         }
 161
 162         /*
 163          * go through all SBALs from input queue currently
 164          * returned by QDIO layer
 165          */
 166         for (sbal_no = 0; sbal_no < count; sbal_no++) {
 167                 sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
 168
 169                 /* go through all SBALEs of SBAL */
 170                 for (sbale_idx = 0; sbale_idx < QDIO_MAX_ELEMENTS_PER_BUFFER;
 171                      sbale_idx++) {
 172                         sbale = zfcp_qdio_sbale(queue, sbal_idx, sbale_idx);
 173                         zfcp_qdio_reqid_check(adapter,
 174                                               (unsigned long) sbale->addr,
 175                                               sbal_idx);
 176                         if (likely(sbale->flags & SBAL_FLAGS_LAST_ENTRY))
 177                                 break;
 178                 };
 179
 180                 if (unlikely(!(sbale->flags & SBAL_FLAGS_LAST_ENTRY)))
 181                         dev_warn(&adapter->ccw_device->dev,
 182                                  "Protocol violation by adapter. "
 183                                  "Continuing operations.\n");
 184         }
 185
 186         /*
 187          * put range of SBALs back to response queue
 188          * (including SBALs which have already been free before)
 189          */
 190         zfcp_qdio_resp_put_back(adapter, count);
 191 }
 192
 193 /**
 194  * zfcp_qdio_sbale_req - return ptr to SBALE of 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_req(struct zfcp_fsf_req *req)
 200 {
 201         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last, 0);
 202 }
 203
 204 /**
 205  * zfcp_qdio_sbale_curr - return curr SBALE on req_q for a struct zfcp_fsf_req
 206  * @fsf_req: pointer to struct fsf_req
 207  * Returns: pointer to qdio_buffer_element (SBALE) structure
 208  */
 209 volatile struct qdio_buffer_element *
 210 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *req)
 211 {
 212         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last,
 213                                req->sbale_curr);
 214 }
 215
 216 static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 217 {
 218         int count = atomic_read(&fsf_req->adapter->req_q.count);
 219         count = min(count, max_sbals);
 220         fsf_req->sbal_limit = (fsf_req->sbal_first + count - 1)
 221                                         % QDIO_MAX_BUFFERS_PER_Q;
 222 }
 223
 224 static volatile struct qdio_buffer_element *
 225 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 226 {
 227         volatile struct qdio_buffer_element *sbale;
 228
 229         /* set last entry flag in current SBALE of current SBAL */
 230         sbale = zfcp_qdio_sbale_curr(fsf_req);
 231         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 232
 233         /* don't exceed last allowed SBAL */
 234         if (fsf_req->sbal_last == fsf_req->sbal_limit)
 235                 return NULL;
 236
 237         /* set chaining flag in first SBALE of current SBAL */
 238         sbale = zfcp_qdio_sbale_req(fsf_req);
 239         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 240
 241         /* calculate index of next SBAL */
 242         fsf_req->sbal_last++;
 243         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 244
 245         /* keep this requests number of SBALs up-to-date */
 246         fsf_req->sbal_number++;
 247
 248         /* start at first SBALE of new SBAL */
 249         fsf_req->sbale_curr = 0;
 250
 251         /* set storage-block type for new SBAL */
 252         sbale = zfcp_qdio_sbale_curr(fsf_req);
 253         sbale->flags |= sbtype;
 254
 255         return sbale;
 256 }
 257
 258 static volatile struct qdio_buffer_element *
 259 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 260 {
 261         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 262                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 263         fsf_req->sbale_curr++;
 264         return zfcp_qdio_sbale_curr(fsf_req);
 265 }
 266
 267 static void zfcp_qdio_undo_sbals(struct zfcp_fsf_req *fsf_req)
 268 {
 269         struct qdio_buffer **sbal = fsf_req->adapter->req_q.sbal;
 270         int first = fsf_req->sbal_first;
 271         int last = fsf_req->sbal_last;
 272         int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
 273                 QDIO_MAX_BUFFERS_PER_Q + 1;
 274         zfcp_qdio_zero_sbals(sbal, first, count);
 275 }
 276
 277 static int zfcp_qdio_fill_sbals(struct zfcp_fsf_req *fsf_req,
 278                                 unsigned int sbtype, void *start_addr,
 279                                 unsigned int total_length)
 280 {
 281         volatile struct qdio_buffer_element *sbale;
 282         unsigned long remaining, length;
 283         void *addr;
 284
 285         /* split segment up */
 286         for (addr = start_addr, remaining = total_length; remaining > 0;
 287              addr += length, remaining -= length) {
 288                 sbale = zfcp_qdio_sbale_next(fsf_req, sbtype);
 289                 if (!sbale) {
 290                         zfcp_qdio_undo_sbals(fsf_req);
 291                         return -EINVAL;
 292                 }
 293
 294                 /* new piece must not exceed next page boundary */
 295                 length = min(remaining,
 296                              (PAGE_SIZE - ((unsigned long)addr &
 297                                            (PAGE_SIZE - 1))));
 298                 sbale->addr = addr;
 299                 sbale->length = length;
 300         }
 301         return 0;
 302 }
 303
 304 /**
 305  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 306  * @fsf_req: request to be processed
 307  * @sbtype: SBALE flags
 308  * @sg: scatter-gather list
 309  * @max_sbals: upper bound for number of SBALs to be used
 310  * Returns: number of bytes, or error (negativ)
 311  */
 312 int zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 313                             struct scatterlist *sg, int max_sbals)
 314 {
 315         volatile struct qdio_buffer_element *sbale;
 316         int retval, bytes = 0;
 317
 318         /* figure out last allowed SBAL */
 319         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 320
 321         /* set storage-block type for this request */
 322         sbale = zfcp_qdio_sbale_req(fsf_req);
 323         sbale->flags |= sbtype;
 324
 325         for (; sg; sg = sg_next(sg)) {
 326                 retval = zfcp_qdio_fill_sbals(fsf_req, sbtype, sg_virt(sg),
 327                                               sg->length);
 328                 if (retval < 0)
 329                         return retval;
 330                 bytes += sg->length;
 331         }
 332
 333         /* assume that no other SBALEs are to follow in the same SBAL */
 334         sbale = zfcp_qdio_sbale_curr(fsf_req);
 335         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 336
 337         return bytes;
 338 }
 339
 340 /**
 341  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 342  * @fsf_req: pointer to struct zfcp_fsf_req
 343  * Returns: 0 on success, error otherwise
 344  */
 345 int zfcp_qdio_send(struct zfcp_fsf_req *fsf_req)
 346 {
 347         struct zfcp_adapter *adapter = fsf_req->adapter;
 348         struct zfcp_qdio_queue *req_q = &adapter->req_q;
 349         int first = fsf_req->sbal_first;
 350         int count = fsf_req->sbal_number;
 351         int retval, pci, pci_batch;
 352         volatile struct qdio_buffer_element *sbale;
 353
 354         /* acknowledgements for transferred buffers */
 355         pci_batch = req_q->pci_batch + count;
 356         if (unlikely(pci_batch >= ZFCP_QDIO_PCI_INTERVAL)) {
 357                 pci_batch %= ZFCP_QDIO_PCI_INTERVAL;
 358                 pci = first + count - (pci_batch + 1);
 359                 pci %= QDIO_MAX_BUFFERS_PER_Q;
 360                 sbale = zfcp_qdio_sbale(req_q, pci, 0);
 361                 sbale->flags |= SBAL_FLAGS0_PCI;
 362         }
 363
 364         retval = do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0, first,
 365                          count, NULL);
 366         if (unlikely(retval)) {
 367                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 368                 return retval;
 369         }
 370
 371         /* account for transferred buffers */
 372         atomic_sub(count, &req_q->count);
 373         req_q->first += count;
 374         req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
 375         req_q->pci_batch = pci_batch;
 376         return 0;
 377 }
 378
 379 /**
 380  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 381  * @adapter: pointer to struct zfcp_adapter
 382  * Returns: -ENOMEM on memory allocation error or return value from
 383  *          qdio_allocate
 384  */
 385 int zfcp_qdio_allocate(struct zfcp_adapter *adapter)
 386 {
 387         struct qdio_initialize *init_data;
 388
 389         if (zfcp_qdio_buffers_enqueue(adapter->req_q.sbal) ||
 390                    zfcp_qdio_buffers_enqueue(adapter->resp_q.sbal))
 391                 return -ENOMEM;
 392
 393         init_data = &adapter->qdio_init_data;
 394
 395         init_data->cdev = adapter->ccw_device;
 396         init_data->q_format = QDIO_ZFCP_QFMT;
 397         memcpy(init_data->adapter_name, zfcp_get_busid_by_adapter(adapter), 8);
 398         ASCEBC(init_data->adapter_name, 8);
 399         init_data->qib_param_field_format = 0;
 400         init_data->qib_param_field = NULL;
 401         init_data->input_slib_elements = NULL;
 402         init_data->output_slib_elements = NULL;
 403         init_data->min_input_threshold = 1;
 404         init_data->max_input_threshold = 5000;
 405         init_data->min_output_threshold = 1;
 406         init_data->max_output_threshold = 1000;
 407         init_data->no_input_qs = 1;
 408         init_data->no_output_qs = 1;
 409         init_data->input_handler = zfcp_qdio_int_resp;
 410         init_data->output_handler = zfcp_qdio_int_req;
 411         init_data->int_parm = (unsigned long) adapter;
 412         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
 413                         QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
 414         init_data->input_sbal_addr_array =
 415                         (void **) (adapter->resp_q.sbal);
 416         init_data->output_sbal_addr_array =
 417                         (void **) (adapter->req_q.sbal);
 418
 419         return qdio_allocate(init_data);
 420 }
 421
 422 /**
 423  * zfcp_close_qdio - close qdio queues for an adapter
 424  */
 425 void zfcp_qdio_close(struct zfcp_adapter *adapter)
 426 {
 427         struct zfcp_qdio_queue *req_q;
 428         int first, count;
 429
 430         if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status))
 431                 return;
 432
 433         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 434         req_q = &adapter->req_q;
 435         write_lock_irq(&req_q->lock);
 436         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
 437         write_unlock_irq(&req_q->lock);
 438
 439         while (qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR)
 440                         == -EINPROGRESS)
 441                 ssleep(1);
 442
 443         /* cleanup used outbound sbals */
 444         count = atomic_read(&req_q->count);
 445         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 446                 first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
 447                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 448                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 449         }
 450         req_q->first = 0;
 451         atomic_set(&req_q->count, 0);
 452         req_q->pci_batch = 0;
 453         adapter->resp_q.first = 0;
 454         atomic_set(&adapter->resp_q.count, 0);
 455 }
 456
 457 /**
 458  * zfcp_qdio_open - prepare and initialize response queue
 459  * @adapter: pointer to struct zfcp_adapter
 460  * Returns: 0 on success, otherwise -EIO
 461  */
 462 int zfcp_qdio_open(struct zfcp_adapter *adapter)
 463 {
 464         volatile struct qdio_buffer_element *sbale;
 465         int cc;
 466
 467         if (atomic_test_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status))
 468                 return -EIO;
 469
 470         if (qdio_establish(&adapter->qdio_init_data)) {
 471                 dev_err(&adapter->ccw_device->dev,
 472                          "Establish of QDIO queues failed.\n");
 473                 return -EIO;
 474         }
 475
 476         if (qdio_activate(adapter->ccw_device, 0)) {
 477                 dev_err(&adapter->ccw_device->dev,
 478                          "Activate of QDIO queues failed.\n");
 479                 goto failed_qdio;
 480         }
 481
 482         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 483                 sbale = &(adapter->resp_q.sbal[cc]->element[0]);
 484                 sbale->length = 0;
 485                 sbale->flags = SBAL_FLAGS_LAST_ENTRY;
 486                 sbale->addr = NULL;
 487         }
 488
 489         if (do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_INPUT, 0, 0,
 490                      QDIO_MAX_BUFFERS_PER_Q, NULL)) {
 491                 dev_err(&adapter->ccw_device->dev,
 492                          "Init of QDIO response queue failed.\n");
 493                 goto failed_qdio;
 494         }
 495
 496         /* set index of first avalable SBALS / number of available SBALS */
 497         adapter->req_q.first = 0;
 498         atomic_set(&adapter->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
 499         adapter->req_q.pci_batch = 0;
 500
 501         return 0;
 502
 503 failed_qdio:
 504         while (qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR)
 505                         == -EINPROGRESS)
 506                 ssleep(1);
 507
 508         return -EIO;
 509 }