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         fsf_req->qdio_inb_usage = atomic_read(&adapter->resp_q.count);
 119         zfcp_fsf_req_complete(fsf_req);
 120 }
 121
 122 static void zfcp_qdio_resp_put_back(struct zfcp_adapter *adapter, int processed)
 123 {
 124         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 125         struct ccw_device *cdev = adapter->ccw_device;
 126         u8 count, start = queue->first;
 127         unsigned int retval;
 128
 129         count = atomic_read(&queue->count) + processed;
 130
 131         retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, start, count);
 132
 133         if (unlikely(retval)) {
 134                 atomic_set(&queue->count, count);
 135                 /* FIXME: Recover this with an adapter reopen? */
 136         } else {
 137                 queue->first += count;
 138                 queue->first %= QDIO_MAX_BUFFERS_PER_Q;
 139                 atomic_set(&queue->count, 0);
 140         }
 141 }
 142
 143 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
 144                                int queue_no, int first, int count,
 145                                unsigned long parm)
 146 {
 147         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
 148         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 149         struct qdio_buffer_element *sbale;
 150         int sbal_idx, sbale_idx, sbal_no;
 151
 152         if (unlikely(qdio_err)) {
 153                 zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
 154                 zfcp_qdio_handler_error(adapter, 147);
 155                 return;
 156         }
 157
 158         /*
 159          * go through all SBALs from input queue currently
 160          * returned by QDIO layer
 161          */
 162         for (sbal_no = 0; sbal_no < count; sbal_no++) {
 163                 sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
 164
 165                 /* go through all SBALEs of SBAL */
 166                 for (sbale_idx = 0; sbale_idx < QDIO_MAX_ELEMENTS_PER_BUFFER;
 167                      sbale_idx++) {
 168                         sbale = zfcp_qdio_sbale(queue, sbal_idx, sbale_idx);
 169                         zfcp_qdio_reqid_check(adapter,
 170                                               (unsigned long) sbale->addr,
 171                                               sbal_idx);
 172                         if (likely(sbale->flags & SBAL_FLAGS_LAST_ENTRY))
 173                                 break;
 174                 };
 175
 176                 if (unlikely(!(sbale->flags & SBAL_FLAGS_LAST_ENTRY)))
 177                         dev_warn(&adapter->ccw_device->dev,
 178                                  "A QDIO protocol error occurred, "
 179                                  "operations continue\n");
 180         }
 181
 182         /*
 183          * put range of SBALs back to response queue
 184          * (including SBALs which have already been free before)
 185          */
 186         zfcp_qdio_resp_put_back(adapter, count);
 187 }
 188
 189 /**
 190  * zfcp_qdio_sbale_req - return ptr to SBALE of req_q for a struct zfcp_fsf_req
 191  * @fsf_req: pointer to struct fsf_req
 192  * Returns: pointer to qdio_buffer_element (SBALE) structure
 193  */
 194 struct qdio_buffer_element *zfcp_qdio_sbale_req(struct zfcp_fsf_req *req)
 195 {
 196         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last, 0);
 197 }
 198
 199 /**
 200  * zfcp_qdio_sbale_curr - return curr SBALE on req_q for a struct zfcp_fsf_req
 201  * @fsf_req: pointer to struct fsf_req
 202  * Returns: pointer to qdio_buffer_element (SBALE) structure
 203  */
 204 struct qdio_buffer_element *zfcp_qdio_sbale_curr(struct zfcp_fsf_req *req)
 205 {
 206         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last,
 207                                req->sbale_curr);
 208 }
 209
 210 static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 211 {
 212         int count = atomic_read(&fsf_req->adapter->req_q.count);
 213         count = min(count, max_sbals);
 214         fsf_req->sbal_limit = (fsf_req->sbal_first + count - 1)
 215                                         % QDIO_MAX_BUFFERS_PER_Q;
 216 }
 217
 218 static struct qdio_buffer_element *
 219 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 220 {
 221         struct qdio_buffer_element *sbale;
 222
 223         /* set last entry flag in current SBALE of current SBAL */
 224         sbale = zfcp_qdio_sbale_curr(fsf_req);
 225         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 226
 227         /* don't exceed last allowed SBAL */
 228         if (fsf_req->sbal_last == fsf_req->sbal_limit)
 229                 return NULL;
 230
 231         /* set chaining flag in first SBALE of current SBAL */
 232         sbale = zfcp_qdio_sbale_req(fsf_req);
 233         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 234
 235         /* calculate index of next SBAL */
 236         fsf_req->sbal_last++;
 237         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 238
 239         /* keep this requests number of SBALs up-to-date */
 240         fsf_req->sbal_number++;
 241
 242         /* start at first SBALE of new SBAL */
 243         fsf_req->sbale_curr = 0;
 244
 245         /* set storage-block type for new SBAL */
 246         sbale = zfcp_qdio_sbale_curr(fsf_req);
 247         sbale->flags |= sbtype;
 248
 249         return sbale;
 250 }
 251
 252 static struct qdio_buffer_element *
 253 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 254 {
 255         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 256                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 257         fsf_req->sbale_curr++;
 258         return zfcp_qdio_sbale_curr(fsf_req);
 259 }
 260
 261 static void zfcp_qdio_undo_sbals(struct zfcp_fsf_req *fsf_req)
 262 {
 263         struct qdio_buffer **sbal = fsf_req->adapter->req_q.sbal;
 264         int first = fsf_req->sbal_first;
 265         int last = fsf_req->sbal_last;
 266         int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
 267                 QDIO_MAX_BUFFERS_PER_Q + 1;
 268         zfcp_qdio_zero_sbals(sbal, first, count);
 269 }
 270
 271 static int zfcp_qdio_fill_sbals(struct zfcp_fsf_req *fsf_req,
 272                                 unsigned int sbtype, void *start_addr,
 273                                 unsigned int total_length)
 274 {
 275         struct qdio_buffer_element *sbale;
 276         unsigned long remaining, length;
 277         void *addr;
 278
 279         /* split segment up */
 280         for (addr = start_addr, remaining = total_length; remaining > 0;
 281              addr += length, remaining -= length) {
 282                 sbale = zfcp_qdio_sbale_next(fsf_req, sbtype);
 283                 if (!sbale) {
 284                         atomic_inc(&fsf_req->adapter->qdio_outb_full);
 285                         zfcp_qdio_undo_sbals(fsf_req);
 286                         return -EINVAL;
 287                 }
 288
 289                 /* new piece must not exceed next page boundary */
 290                 length = min(remaining,
 291                              (PAGE_SIZE - ((unsigned long)addr &
 292                                            (PAGE_SIZE - 1))));
 293                 sbale->addr = addr;
 294                 sbale->length = length;
 295         }
 296         return 0;
 297 }
 298
 299 /**
 300  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 301  * @fsf_req: request to be processed
 302  * @sbtype: SBALE flags
 303  * @sg: scatter-gather list
 304  * @max_sbals: upper bound for number of SBALs to be used
 305  * Returns: number of bytes, or error (negativ)
 306  */
 307 int zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 308                             struct scatterlist *sg, int max_sbals)
 309 {
 310         struct qdio_buffer_element *sbale;
 311         int retval, bytes = 0;
 312
 313         /* figure out last allowed SBAL */
 314         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 315
 316         /* set storage-block type for this request */
 317         sbale = zfcp_qdio_sbale_req(fsf_req);
 318         sbale->flags |= sbtype;
 319
 320         for (; sg; sg = sg_next(sg)) {
 321                 retval = zfcp_qdio_fill_sbals(fsf_req, sbtype, sg_virt(sg),
 322                                               sg->length);
 323                 if (retval < 0)
 324                         return retval;
 325                 bytes += sg->length;
 326         }
 327
 328         /* assume that no other SBALEs are to follow in the same SBAL */
 329         sbale = zfcp_qdio_sbale_curr(fsf_req);
 330         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 331
 332         return bytes;
 333 }
 334
 335 /**
 336  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 337  * @fsf_req: pointer to struct zfcp_fsf_req
 338  * Returns: 0 on success, error otherwise
 339  */
 340 int zfcp_qdio_send(struct zfcp_fsf_req *fsf_req)
 341 {
 342         struct zfcp_adapter *adapter = fsf_req->adapter;
 343         struct zfcp_qdio_queue *req_q = &adapter->req_q;
 344         int first = fsf_req->sbal_first;
 345         int count = fsf_req->sbal_number;
 346         int retval, pci, pci_batch;
 347         struct qdio_buffer_element *sbale;
 348
 349         /* acknowledgements for transferred buffers */
 350         pci_batch = adapter->req_q_pci_batch + count;
 351         if (unlikely(pci_batch >= ZFCP_QDIO_PCI_INTERVAL)) {
 352                 pci_batch %= ZFCP_QDIO_PCI_INTERVAL;
 353                 pci = first + count - (pci_batch + 1);
 354                 pci %= QDIO_MAX_BUFFERS_PER_Q;
 355                 sbale = zfcp_qdio_sbale(req_q, pci, 0);
 356                 sbale->flags |= SBAL_FLAGS0_PCI;
 357         }
 358
 359         retval = do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0, first,
 360                          count);
 361         if (unlikely(retval)) {
 362                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 363                 return retval;
 364         }
 365
 366         /* account for transferred buffers */
 367         atomic_sub(count, &req_q->count);
 368         req_q->first += count;
 369         req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
 370         adapter->req_q_pci_batch = pci_batch;
 371         return 0;
 372 }
 373
 374 /**
 375  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 376  * @adapter: pointer to struct zfcp_adapter
 377  * Returns: -ENOMEM on memory allocation error or return value from
 378  *          qdio_allocate
 379  */
 380 int zfcp_qdio_allocate(struct zfcp_adapter *adapter)
 381 {
 382         struct qdio_initialize *init_data;
 383
 384         if (zfcp_qdio_buffers_enqueue(adapter->req_q.sbal) ||
 385                    zfcp_qdio_buffers_enqueue(adapter->resp_q.sbal))
 386                 return -ENOMEM;
 387
 388         init_data = &adapter->qdio_init_data;
 389
 390         init_data->cdev = adapter->ccw_device;
 391         init_data->q_format = QDIO_ZFCP_QFMT;
 392         memcpy(init_data->adapter_name, zfcp_get_busid_by_adapter(adapter), 8);
 393         ASCEBC(init_data->adapter_name, 8);
 394         init_data->qib_param_field_format = 0;
 395         init_data->qib_param_field = NULL;
 396         init_data->input_slib_elements = NULL;
 397         init_data->output_slib_elements = NULL;
 398         init_data->no_input_qs = 1;
 399         init_data->no_output_qs = 1;
 400         init_data->input_handler = zfcp_qdio_int_resp;
 401         init_data->output_handler = zfcp_qdio_int_req;
 402         init_data->int_parm = (unsigned long) adapter;
 403         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
 404                         QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
 405         init_data->input_sbal_addr_array =
 406                         (void **) (adapter->resp_q.sbal);
 407         init_data->output_sbal_addr_array =
 408                         (void **) (adapter->req_q.sbal);
 409
 410         return qdio_allocate(init_data);
 411 }
 412
 413 /**
 414  * zfcp_close_qdio - close qdio queues for an adapter
 415  */
 416 void zfcp_qdio_close(struct zfcp_adapter *adapter)
 417 {
 418         struct zfcp_qdio_queue *req_q;
 419         int first, count;
 420
 421         if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 422                 return;
 423
 424         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 425         req_q = &adapter->req_q;
 426         spin_lock_bh(&adapter->req_q_lock);
 427         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
 428         spin_unlock_bh(&adapter->req_q_lock);
 429
 430         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
 431
 432         /* cleanup used outbound sbals */
 433         count = atomic_read(&req_q->count);
 434         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 435                 first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
 436                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 437                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 438         }
 439         req_q->first = 0;
 440         atomic_set(&req_q->count, 0);
 441         adapter->req_q_pci_batch = 0;
 442         adapter->resp_q.first = 0;
 443         atomic_set(&adapter->resp_q.count, 0);
 444 }
 445
 446 /**
 447  * zfcp_qdio_open - prepare and initialize response queue
 448  * @adapter: pointer to struct zfcp_adapter
 449  * Returns: 0 on success, otherwise -EIO
 450  */
 451 int zfcp_qdio_open(struct zfcp_adapter *adapter)
 452 {
 453         struct qdio_buffer_element *sbale;
 454         int cc;
 455
 456         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
 457                 return -EIO;
 458
 459         if (qdio_establish(&adapter->qdio_init_data))
 460                 goto failed_establish;
 461
 462         if (qdio_activate(adapter->ccw_device))
 463                 goto failed_qdio;
 464
 465         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 466                 sbale = &(adapter->resp_q.sbal[cc]->element[0]);
 467                 sbale->length = 0;
 468                 sbale->flags = SBAL_FLAGS_LAST_ENTRY;
 469                 sbale->addr = NULL;
 470         }
 471
 472         if (do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_INPUT, 0, 0,
 473                      QDIO_MAX_BUFFERS_PER_Q))
 474                 goto failed_qdio;
 475
 476         /* set index of first avalable SBALS / number of available SBALS */
 477         adapter->req_q.first = 0;
 478         atomic_set(&adapter->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
 479         adapter->req_q_pci_batch = 0;
 480
 481         return 0;
 482
 483 failed_qdio:
 484         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
 485 failed_establish:
 486         dev_err(&adapter->ccw_device->dev,
 487                 "Setting up the QDIO connection to the FCP adapter failed\n");
 488         return -EIO;
 489 }