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                                 - (FSF_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 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, "A 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 qdio_err,
  78                               int queue_no, int first, int count,
  79                               unsigned long parm)
  80 {
  81         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
  82         struct zfcp_qdio_queue *queue = &adapter->req_q;
  83
  84         if (unlikely(qdio_err)) {
  85                 zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
  86                 zfcp_qdio_handler_error(adapter, 140);
  87                 return;
  88         }
  89
  90         /* cleanup all SBALs being program-owned now */
  91         zfcp_qdio_zero_sbals(queue->sbal, first, count);
  92
  93         atomic_add(count, &queue->count);
  94         wake_up(&adapter->request_wq);
  95 }
  96
  97 static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
  98                                   unsigned long req_id, int sbal_idx)
  99 {
 100         struct zfcp_fsf_req *fsf_req;
 101         unsigned long flags;
 102
 103         spin_lock_irqsave(&adapter->req_list_lock, flags);
 104         fsf_req = zfcp_reqlist_find(adapter, req_id);
 105
 106         if (!fsf_req)
 107                 /*
 108                  * Unknown request means that we have potentially memory
 109                  * corruption and must stop the machine immediatly.
 110                  */
 111                 panic("error: unknown request id (%lx) on adapter %s.\n",
 112                       req_id, zfcp_get_busid_by_adapter(adapter));
 113
 114         zfcp_reqlist_remove(adapter, fsf_req);
 115         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 116
 117         fsf_req->sbal_response = sbal_idx;
 118         zfcp_fsf_req_complete(fsf_req);
 119 }
 120
 121 static void zfcp_qdio_resp_put_back(struct zfcp_adapter *adapter, int processed)
 122 {
 123         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 124         struct ccw_device *cdev = adapter->ccw_device;
 125         u8 count, start = queue->first;
 126         unsigned int retval;
 127
 128         count = atomic_read(&queue->count) + processed;
 129
 130         retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, start, count);
 131
 132         if (unlikely(retval)) {
 133                 atomic_set(&queue->count, count);
 134                 /* FIXME: Recover this with an adapter reopen? */
 135         } else {
 136                 queue->first += count;
 137                 queue->first %= QDIO_MAX_BUFFERS_PER_Q;
 138                 atomic_set(&queue->count, 0);
 139         }
 140 }
 141
 142 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
 143                                int queue_no, int first, int count,
 144                                unsigned long parm)
 145 {
 146         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
 147         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 148         struct qdio_buffer_element *sbale;
 149         int sbal_idx, sbale_idx, sbal_no;
 150
 151         if (unlikely(qdio_err)) {
 152                 zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
 153                 zfcp_qdio_handler_error(adapter, 147);
 154                 return;
 155         }
 156
 157         /*
 158          * go through all SBALs from input queue currently
 159          * returned by QDIO layer
 160          */
 161         for (sbal_no = 0; sbal_no < count; sbal_no++) {
 162                 sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
 163
 164                 /* go through all SBALEs of SBAL */
 165                 for (sbale_idx = 0; sbale_idx < QDIO_MAX_ELEMENTS_PER_BUFFER;
 166                      sbale_idx++) {
 167                         sbale = zfcp_qdio_sbale(queue, sbal_idx, sbale_idx);
 168                         zfcp_qdio_reqid_check(adapter,
 169                                               (unsigned long) sbale->addr,
 170                                               sbal_idx);
 171                         if (likely(sbale->flags & SBAL_FLAGS_LAST_ENTRY))
 172                                 break;
 173                 };
 174
 175                 if (unlikely(!(sbale->flags & SBAL_FLAGS_LAST_ENTRY)))
 176                         dev_warn(&adapter->ccw_device->dev,
 177                                  "A QDIO protocol error occurred, "
 178                                  "operations continue\n");
 179         }
 180
 181         /*
 182          * put range of SBALs back to response queue
 183          * (including SBALs which have already been free before)
 184          */
 185         zfcp_qdio_resp_put_back(adapter, count);
 186 }
 187
 188 /**
 189  * zfcp_qdio_sbale_req - return ptr to SBALE of req_q for a struct zfcp_fsf_req
 190  * @fsf_req: pointer to struct fsf_req
 191  * Returns: pointer to qdio_buffer_element (SBALE) structure
 192  */
 193 struct qdio_buffer_element *zfcp_qdio_sbale_req(struct zfcp_fsf_req *req)
 194 {
 195         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last, 0);
 196 }
 197
 198 /**
 199  * zfcp_qdio_sbale_curr - return curr SBALE on req_q for a struct zfcp_fsf_req
 200  * @fsf_req: pointer to struct fsf_req
 201  * Returns: pointer to qdio_buffer_element (SBALE) structure
 202  */
 203 struct qdio_buffer_element *zfcp_qdio_sbale_curr(struct zfcp_fsf_req *req)
 204 {
 205         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last,
 206                                req->sbale_curr);
 207 }
 208
 209 static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 210 {
 211         int count = atomic_read(&fsf_req->adapter->req_q.count);
 212         count = min(count, max_sbals);
 213         fsf_req->sbal_limit = (fsf_req->sbal_first + count - 1)
 214                                         % QDIO_MAX_BUFFERS_PER_Q;
 215 }
 216
 217 static struct qdio_buffer_element *
 218 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 219 {
 220         struct qdio_buffer_element *sbale;
 221
 222         /* set last entry flag in current SBALE of current SBAL */
 223         sbale = zfcp_qdio_sbale_curr(fsf_req);
 224         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 225
 226         /* don't exceed last allowed SBAL */
 227         if (fsf_req->sbal_last == fsf_req->sbal_limit)
 228                 return NULL;
 229
 230         /* set chaining flag in first SBALE of current SBAL */
 231         sbale = zfcp_qdio_sbale_req(fsf_req);
 232         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 233
 234         /* calculate index of next SBAL */
 235         fsf_req->sbal_last++;
 236         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 237
 238         /* keep this requests number of SBALs up-to-date */
 239         fsf_req->sbal_number++;
 240
 241         /* start at first SBALE of new SBAL */
 242         fsf_req->sbale_curr = 0;
 243
 244         /* set storage-block type for new SBAL */
 245         sbale = zfcp_qdio_sbale_curr(fsf_req);
 246         sbale->flags |= sbtype;
 247
 248         return sbale;
 249 }
 250
 251 static struct qdio_buffer_element *
 252 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 253 {
 254         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 255                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 256         fsf_req->sbale_curr++;
 257         return zfcp_qdio_sbale_curr(fsf_req);
 258 }
 259
 260 static void zfcp_qdio_undo_sbals(struct zfcp_fsf_req *fsf_req)
 261 {
 262         struct qdio_buffer **sbal = fsf_req->adapter->req_q.sbal;
 263         int first = fsf_req->sbal_first;
 264         int last = fsf_req->sbal_last;
 265         int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
 266                 QDIO_MAX_BUFFERS_PER_Q + 1;
 267         zfcp_qdio_zero_sbals(sbal, first, count);
 268 }
 269
 270 static int zfcp_qdio_fill_sbals(struct zfcp_fsf_req *fsf_req,
 271                                 unsigned int sbtype, void *start_addr,
 272                                 unsigned int total_length)
 273 {
 274         struct qdio_buffer_element *sbale;
 275         unsigned long remaining, length;
 276         void *addr;
 277
 278         /* split segment up */
 279         for (addr = start_addr, remaining = total_length; remaining > 0;
 280              addr += length, remaining -= length) {
 281                 sbale = zfcp_qdio_sbale_next(fsf_req, sbtype);
 282                 if (!sbale) {
 283                         atomic_inc(&fsf_req->adapter->qdio_outb_full);
 284                         zfcp_qdio_undo_sbals(fsf_req);
 285                         return -EINVAL;
 286                 }
 287
 288                 /* new piece must not exceed next page boundary */
 289                 length = min(remaining,
 290                              (PAGE_SIZE - ((unsigned long)addr &
 291                                            (PAGE_SIZE - 1))));
 292                 sbale->addr = addr;
 293                 sbale->length = length;
 294         }
 295         return 0;
 296 }
 297
 298 /**
 299  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 300  * @fsf_req: request to be processed
 301  * @sbtype: SBALE flags
 302  * @sg: scatter-gather list
 303  * @max_sbals: upper bound for number of SBALs to be used
 304  * Returns: number of bytes, or error (negativ)
 305  */
 306 int zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 307                             struct scatterlist *sg, int max_sbals)
 308 {
 309         struct qdio_buffer_element *sbale;
 310         int retval, bytes = 0;
 311
 312         /* figure out last allowed SBAL */
 313         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 314
 315         /* set storage-block type for this request */
 316         sbale = zfcp_qdio_sbale_req(fsf_req);
 317         sbale->flags |= sbtype;
 318
 319         for (; sg; sg = sg_next(sg)) {
 320                 retval = zfcp_qdio_fill_sbals(fsf_req, sbtype, sg_virt(sg),
 321                                               sg->length);
 322                 if (retval < 0)
 323                         return retval;
 324                 bytes += sg->length;
 325         }
 326
 327         /* assume that no other SBALEs are to follow in the same SBAL */
 328         sbale = zfcp_qdio_sbale_curr(fsf_req);
 329         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 330
 331         return bytes;
 332 }
 333
 334 /**
 335  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 336  * @fsf_req: pointer to struct zfcp_fsf_req
 337  * Returns: 0 on success, error otherwise
 338  */
 339 int zfcp_qdio_send(struct zfcp_fsf_req *fsf_req)
 340 {
 341         struct zfcp_adapter *adapter = fsf_req->adapter;
 342         struct zfcp_qdio_queue *req_q = &adapter->req_q;
 343         int first = fsf_req->sbal_first;
 344         int count = fsf_req->sbal_number;
 345         int retval, pci, pci_batch;
 346         struct qdio_buffer_element *sbale;
 347
 348         /* acknowledgements for transferred buffers */
 349         pci_batch = adapter->req_q_pci_batch + count;
 350         if (unlikely(pci_batch >= ZFCP_QDIO_PCI_INTERVAL)) {
 351                 pci_batch %= ZFCP_QDIO_PCI_INTERVAL;
 352                 pci = first + count - (pci_batch + 1);
 353                 pci %= QDIO_MAX_BUFFERS_PER_Q;
 354                 sbale = zfcp_qdio_sbale(req_q, pci, 0);
 355                 sbale->flags |= SBAL_FLAGS0_PCI;
 356         }
 357
 358         retval = do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0, first,
 359                          count);
 360         if (unlikely(retval)) {
 361                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 362                 return retval;
 363         }
 364
 365         /* account for transferred buffers */
 366         atomic_sub(count, &req_q->count);
 367         req_q->first += count;
 368         req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
 369         adapter->req_q_pci_batch = pci_batch;
 370         return 0;
 371 }
 372
 373 /**
 374  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 375  * @adapter: pointer to struct zfcp_adapter
 376  * Returns: -ENOMEM on memory allocation error or return value from
 377  *          qdio_allocate
 378  */
 379 int zfcp_qdio_allocate(struct zfcp_adapter *adapter)
 380 {
 381         struct qdio_initialize *init_data;
 382
 383         if (zfcp_qdio_buffers_enqueue(adapter->req_q.sbal) ||
 384                    zfcp_qdio_buffers_enqueue(adapter->resp_q.sbal))
 385                 return -ENOMEM;
 386
 387         init_data = &adapter->qdio_init_data;
 388
 389         init_data->cdev = adapter->ccw_device;
 390         init_data->q_format = QDIO_ZFCP_QFMT;
 391         memcpy(init_data->adapter_name, zfcp_get_busid_by_adapter(adapter), 8);
 392         ASCEBC(init_data->adapter_name, 8);
 393         init_data->qib_param_field_format = 0;
 394         init_data->qib_param_field = NULL;
 395         init_data->input_slib_elements = NULL;
 396         init_data->output_slib_elements = NULL;
 397         init_data->no_input_qs = 1;
 398         init_data->no_output_qs = 1;
 399         init_data->input_handler = zfcp_qdio_int_resp;
 400         init_data->output_handler = zfcp_qdio_int_req;
 401         init_data->int_parm = (unsigned long) adapter;
 402         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
 403                         QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
 404         init_data->input_sbal_addr_array =
 405                         (void **) (adapter->resp_q.sbal);
 406         init_data->output_sbal_addr_array =
 407                         (void **) (adapter->req_q.sbal);
 408
 409         return qdio_allocate(init_data);
 410 }
 411
 412 /**
 413  * zfcp_close_qdio - close qdio queues for an adapter
 414  */
 415 void zfcp_qdio_close(struct zfcp_adapter *adapter)
 416 {
 417         struct zfcp_qdio_queue *req_q;
 418         int first, count;
 419
 420         if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 421                 return;
 422
 423         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 424         req_q = &adapter->req_q;
 425         spin_lock_bh(&adapter->req_q_lock);
 426         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
 427         spin_unlock_bh(&adapter->req_q_lock);
 428
 429         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
 430
 431         /* cleanup used outbound sbals */
 432         count = atomic_read(&req_q->count);
 433         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 434                 first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
 435                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 436                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 437         }
 438         req_q->first = 0;
 439         atomic_set(&req_q->count, 0);
 440         adapter->req_q_pci_batch = 0;
 441         adapter->resp_q.first = 0;
 442         atomic_set(&adapter->resp_q.count, 0);
 443 }
 444
 445 /**
 446  * zfcp_qdio_open - prepare and initialize response queue
 447  * @adapter: pointer to struct zfcp_adapter
 448  * Returns: 0 on success, otherwise -EIO
 449  */
 450 int zfcp_qdio_open(struct zfcp_adapter *adapter)
 451 {
 452         struct qdio_buffer_element *sbale;
 453         int cc;
 454
 455         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
 456                 return -EIO;
 457
 458         if (qdio_establish(&adapter->qdio_init_data))
 459                 goto failed_establish;
 460
 461         if (qdio_activate(adapter->ccw_device))
 462                 goto failed_qdio;
 463
 464         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 465                 sbale = &(adapter->resp_q.sbal[cc]->element[0]);
 466                 sbale->length = 0;
 467                 sbale->flags = SBAL_FLAGS_LAST_ENTRY;
 468                 sbale->addr = NULL;
 469         }
 470
 471         if (do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_INPUT, 0, 0,
 472                      QDIO_MAX_BUFFERS_PER_Q))
 473                 goto failed_qdio;
 474
 475         /* set index of first avalable SBALS / number of available SBALS */
 476         adapter->req_q.first = 0;
 477         atomic_set(&adapter->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
 478         adapter->req_q_pci_batch = 0;
 479
 480         return 0;
 481
 482 failed_qdio:
 483         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
 484 failed_establish:
 485         dev_err(&adapter->ccw_device->dev,
 486                 "Setting up the QDIO connection to the FCP adapter failed\n");
 487         return -EIO;
 488 }