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 #define KMSG_COMPONENT "zfcp"
  10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  11
  12 #include "zfcp_ext.h"
  13
  14 /* FIXME(tune): free space should be one max. SBAL chain plus what? */
  15 #define ZFCP_QDIO_PCI_INTERVAL  (QDIO_MAX_BUFFERS_PER_Q \
  16                                 - (FSF_MAX_SBALS_PER_REQ + 4))
  17 #define QBUFF_PER_PAGE          (PAGE_SIZE / sizeof(struct qdio_buffer))
  18
  19 static int zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbal)
  20 {
  21         int pos;
  22
  23         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
  24                 sbal[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
  25                 if (!sbal[pos])
  26                         return -ENOMEM;
  27         }
  28         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
  29                 if (pos % QBUFF_PER_PAGE)
  30                         sbal[pos] = sbal[pos - 1] + 1;
  31         return 0;
  32 }
  33
  34 static struct qdio_buffer_element *
  35 zfcp_qdio_sbale(struct zfcp_qdio_queue *q, int sbal_idx, int sbale_idx)
  36 {
  37         return &q->sbal[sbal_idx]->element[sbale_idx];
  38 }
  39
  40 /**
  41  * zfcp_qdio_free - free memory used by request- and resposne queue
  42  * @adapter: pointer to the zfcp_adapter structure
  43  */
  44 void zfcp_qdio_free(struct zfcp_adapter *adapter)
  45 {
  46         struct qdio_buffer **sbal_req, **sbal_resp;
  47         int p;
  48
  49         if (adapter->ccw_device)
  50                 qdio_free(adapter->ccw_device);
  51
  52         sbal_req = adapter->req_q.sbal;
  53         sbal_resp = adapter->resp_q.sbal;
  54
  55         for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
  56                 free_page((unsigned long) sbal_req[p]);
  57                 free_page((unsigned long) sbal_resp[p]);
  58         }
  59 }
  60
  61 static void zfcp_qdio_handler_error(struct zfcp_adapter *adapter, char *id)
  62 {
  63         dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
  64
  65         zfcp_erp_adapter_reopen(adapter,
  66                                 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
  67                                 ZFCP_STATUS_COMMON_ERP_FAILED, id, NULL);
  68 }
  69
  70 static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
  71 {
  72         int i, sbal_idx;
  73
  74         for (i = first; i < first + cnt; i++) {
  75                 sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
  76                 memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
  77         }
  78 }
  79
  80 /* this needs to be called prior to updating the queue fill level */
  81 static void zfcp_qdio_account(struct zfcp_adapter *adapter)
  82 {
  83         ktime_t now;
  84         s64 span;
  85         int free, used;
  86
  87         spin_lock(&adapter->qdio_stat_lock);
  88         now = ktime_get();
  89         span = ktime_us_delta(now, adapter->req_q_time);
  90         free = max(0, atomic_read(&adapter->req_q.count));
  91         used = QDIO_MAX_BUFFERS_PER_Q - free;
  92         adapter->req_q_util += used * span;
  93         adapter->req_q_time = now;
  94         spin_unlock(&adapter->qdio_stat_lock);
  95 }
  96
  97 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
  98                               int queue_no, int first, int count,
  99                               unsigned long parm)
 100 {
 101         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
 102         struct zfcp_qdio_queue *queue = &adapter->req_q;
 103
 104         if (unlikely(qdio_err)) {
 105                 zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
 106                 zfcp_qdio_handler_error(adapter, "qdireq1");
 107                 return;
 108         }
 109
 110         /* cleanup all SBALs being program-owned now */
 111         zfcp_qdio_zero_sbals(queue->sbal, first, count);
 112
 113         zfcp_qdio_account(adapter);
 114         atomic_add(count, &queue->count);
 115         wake_up(&adapter->request_wq);
 116 }
 117
 118 static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
 119                                   unsigned long req_id, int sbal_idx)
 120 {
 121         struct zfcp_fsf_req *fsf_req;
 122         unsigned long flags;
 123
 124         spin_lock_irqsave(&adapter->req_list_lock, flags);
 125         fsf_req = zfcp_reqlist_find(adapter, req_id);
 126
 127         if (!fsf_req)
 128                 /*
 129                  * Unknown request means that we have potentially memory
 130                  * corruption and must stop the machine immediatly.
 131                  */
 132                 panic("error: unknown request id (%lx) on adapter %s.\n",
 133                       req_id, dev_name(&adapter->ccw_device->dev));
 134
 135         zfcp_reqlist_remove(adapter, fsf_req);
 136         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 137
 138         fsf_req->sbal_response = sbal_idx;
 139         fsf_req->qdio_inb_usage = atomic_read(&adapter->resp_q.count);
 140         zfcp_fsf_req_complete(fsf_req);
 141 }
 142
 143 static void zfcp_qdio_resp_put_back(struct zfcp_adapter *adapter, int processed)
 144 {
 145         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 146         struct ccw_device *cdev = adapter->ccw_device;
 147         u8 count, start = queue->first;
 148         unsigned int retval;
 149
 150         count = atomic_read(&queue->count) + processed;
 151
 152         retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, start, count);
 153
 154         if (unlikely(retval)) {
 155                 atomic_set(&queue->count, count);
 156                 /* FIXME: Recover this with an adapter reopen? */
 157         } else {
 158                 queue->first += count;
 159                 queue->first %= QDIO_MAX_BUFFERS_PER_Q;
 160                 atomic_set(&queue->count, 0);
 161         }
 162 }
 163
 164 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
 165                                int queue_no, int first, int count,
 166                                unsigned long parm)
 167 {
 168         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
 169         struct zfcp_qdio_queue *queue = &adapter->resp_q;
 170         struct qdio_buffer_element *sbale;
 171         int sbal_idx, sbale_idx, sbal_no;
 172
 173         if (unlikely(qdio_err)) {
 174                 zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
 175                 zfcp_qdio_handler_error(adapter, "qdires1");
 176                 return;
 177         }
 178
 179         /*
 180          * go through all SBALs from input queue currently
 181          * returned by QDIO layer
 182          */
 183         for (sbal_no = 0; sbal_no < count; sbal_no++) {
 184                 sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
 185
 186                 /* go through all SBALEs of SBAL */
 187                 for (sbale_idx = 0; sbale_idx < QDIO_MAX_ELEMENTS_PER_BUFFER;
 188                      sbale_idx++) {
 189                         sbale = zfcp_qdio_sbale(queue, sbal_idx, sbale_idx);
 190                         zfcp_qdio_reqid_check(adapter,
 191                                               (unsigned long) sbale->addr,
 192                                               sbal_idx);
 193                         if (likely(sbale->flags & SBAL_FLAGS_LAST_ENTRY))
 194                                 break;
 195                 };
 196
 197                 if (unlikely(!(sbale->flags & SBAL_FLAGS_LAST_ENTRY)))
 198                         dev_warn(&adapter->ccw_device->dev,
 199                                  "A QDIO protocol error occurred, "
 200                                  "operations continue\n");
 201         }
 202
 203         /*
 204          * put range of SBALs back to response queue
 205          * (including SBALs which have already been free before)
 206          */
 207         zfcp_qdio_resp_put_back(adapter, count);
 208 }
 209
 210 /**
 211  * zfcp_qdio_sbale_req - return ptr to SBALE of req_q for a struct zfcp_fsf_req
 212  * @fsf_req: pointer to struct fsf_req
 213  * Returns: pointer to qdio_buffer_element (SBALE) structure
 214  */
 215 struct qdio_buffer_element *zfcp_qdio_sbale_req(struct zfcp_fsf_req *req)
 216 {
 217         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last, 0);
 218 }
 219
 220 /**
 221  * zfcp_qdio_sbale_curr - return curr SBALE on req_q for a struct zfcp_fsf_req
 222  * @fsf_req: pointer to struct fsf_req
 223  * Returns: pointer to qdio_buffer_element (SBALE) structure
 224  */
 225 struct qdio_buffer_element *zfcp_qdio_sbale_curr(struct zfcp_fsf_req *req)
 226 {
 227         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last,
 228                                req->sbale_curr);
 229 }
 230
 231 static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 232 {
 233         int count = atomic_read(&fsf_req->adapter->req_q.count);
 234         count = min(count, max_sbals);
 235         fsf_req->sbal_limit = (fsf_req->sbal_first + count - 1)
 236                                         % QDIO_MAX_BUFFERS_PER_Q;
 237 }
 238
 239 static struct qdio_buffer_element *
 240 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 241 {
 242         struct qdio_buffer_element *sbale;
 243
 244         /* set last entry flag in current SBALE of current SBAL */
 245         sbale = zfcp_qdio_sbale_curr(fsf_req);
 246         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 247
 248         /* don't exceed last allowed SBAL */
 249         if (fsf_req->sbal_last == fsf_req->sbal_limit)
 250                 return NULL;
 251
 252         /* set chaining flag in first SBALE of current SBAL */
 253         sbale = zfcp_qdio_sbale_req(fsf_req);
 254         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 255
 256         /* calculate index of next SBAL */
 257         fsf_req->sbal_last++;
 258         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 259
 260         /* keep this requests number of SBALs up-to-date */
 261         fsf_req->sbal_number++;
 262
 263         /* start at first SBALE of new SBAL */
 264         fsf_req->sbale_curr = 0;
 265
 266         /* set storage-block type for new SBAL */
 267         sbale = zfcp_qdio_sbale_curr(fsf_req);
 268         sbale->flags |= sbtype;
 269
 270         return sbale;
 271 }
 272
 273 static struct qdio_buffer_element *
 274 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 275 {
 276         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 277                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 278         fsf_req->sbale_curr++;
 279         return zfcp_qdio_sbale_curr(fsf_req);
 280 }
 281
 282 static void zfcp_qdio_undo_sbals(struct zfcp_fsf_req *fsf_req)
 283 {
 284         struct qdio_buffer **sbal = fsf_req->adapter->req_q.sbal;
 285         int first = fsf_req->sbal_first;
 286         int last = fsf_req->sbal_last;
 287         int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
 288                 QDIO_MAX_BUFFERS_PER_Q + 1;
 289         zfcp_qdio_zero_sbals(sbal, first, count);
 290 }
 291
 292 static int zfcp_qdio_fill_sbals(struct zfcp_fsf_req *fsf_req,
 293                                 unsigned int sbtype, void *start_addr,
 294                                 unsigned int total_length)
 295 {
 296         struct qdio_buffer_element *sbale;
 297         unsigned long remaining, length;
 298         void *addr;
 299
 300         /* split segment up */
 301         for (addr = start_addr, remaining = total_length; remaining > 0;
 302              addr += length, remaining -= length) {
 303                 sbale = zfcp_qdio_sbale_next(fsf_req, sbtype);
 304                 if (!sbale) {
 305                         atomic_inc(&fsf_req->adapter->qdio_outb_full);
 306                         zfcp_qdio_undo_sbals(fsf_req);
 307                         return -EINVAL;
 308                 }
 309
 310                 /* new piece must not exceed next page boundary */
 311                 length = min(remaining,
 312                              (PAGE_SIZE - ((unsigned long)addr &
 313                                            (PAGE_SIZE - 1))));
 314                 sbale->addr = addr;
 315                 sbale->length = length;
 316         }
 317         return 0;
 318 }
 319
 320 /**
 321  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 322  * @fsf_req: request to be processed
 323  * @sbtype: SBALE flags
 324  * @sg: scatter-gather list
 325  * @max_sbals: upper bound for number of SBALs to be used
 326  * Returns: number of bytes, or error (negativ)
 327  */
 328 int zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 329                             struct scatterlist *sg, int max_sbals)
 330 {
 331         struct qdio_buffer_element *sbale;
 332         int retval, bytes = 0;
 333
 334         /* figure out last allowed SBAL */
 335         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 336
 337         /* set storage-block type for this request */
 338         sbale = zfcp_qdio_sbale_req(fsf_req);
 339         sbale->flags |= sbtype;
 340
 341         for (; sg; sg = sg_next(sg)) {
 342                 retval = zfcp_qdio_fill_sbals(fsf_req, sbtype, sg_virt(sg),
 343                                               sg->length);
 344                 if (retval < 0)
 345                         return retval;
 346                 bytes += sg->length;
 347         }
 348
 349         /* assume that no other SBALEs are to follow in the same SBAL */
 350         sbale = zfcp_qdio_sbale_curr(fsf_req);
 351         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 352
 353         return bytes;
 354 }
 355
 356 /**
 357  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 358  * @fsf_req: pointer to struct zfcp_fsf_req
 359  * Returns: 0 on success, error otherwise
 360  */
 361 int zfcp_qdio_send(struct zfcp_fsf_req *fsf_req)
 362 {
 363         struct zfcp_adapter *adapter = fsf_req->adapter;
 364         struct zfcp_qdio_queue *req_q = &adapter->req_q;
 365         int first = fsf_req->sbal_first;
 366         int count = fsf_req->sbal_number;
 367         int retval, pci, pci_batch;
 368         struct qdio_buffer_element *sbale;
 369
 370         /* acknowledgements for transferred buffers */
 371         pci_batch = adapter->req_q_pci_batch + count;
 372         if (unlikely(pci_batch >= ZFCP_QDIO_PCI_INTERVAL)) {
 373                 pci_batch %= ZFCP_QDIO_PCI_INTERVAL;
 374                 pci = first + count - (pci_batch + 1);
 375                 pci %= QDIO_MAX_BUFFERS_PER_Q;
 376                 sbale = zfcp_qdio_sbale(req_q, pci, 0);
 377                 sbale->flags |= SBAL_FLAGS0_PCI;
 378         }
 379
 380         zfcp_qdio_account(adapter);
 381
 382         retval = do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0, first,
 383                          count);
 384         if (unlikely(retval)) {
 385                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 386                 return retval;
 387         }
 388
 389         /* account for transferred buffers */
 390         atomic_sub(count, &req_q->count);
 391         req_q->first += count;
 392         req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
 393         adapter->req_q_pci_batch = pci_batch;
 394         return 0;
 395 }
 396
 397 /**
 398  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 399  * @adapter: pointer to struct zfcp_adapter
 400  * Returns: -ENOMEM on memory allocation error or return value from
 401  *          qdio_allocate
 402  */
 403 int zfcp_qdio_allocate(struct zfcp_adapter *adapter)
 404 {
 405         struct qdio_initialize *init_data;
 406
 407         if (zfcp_qdio_buffers_enqueue(adapter->req_q.sbal) ||
 408                    zfcp_qdio_buffers_enqueue(adapter->resp_q.sbal))
 409                 return -ENOMEM;
 410
 411         init_data = &adapter->qdio_init_data;
 412
 413         init_data->cdev = adapter->ccw_device;
 414         init_data->q_format = QDIO_ZFCP_QFMT;
 415         memcpy(init_data->adapter_name, dev_name(&adapter->ccw_device->dev), 8);
 416         ASCEBC(init_data->adapter_name, 8);
 417         init_data->qib_param_field_format = 0;
 418         init_data->qib_param_field = NULL;
 419         init_data->input_slib_elements = NULL;
 420         init_data->output_slib_elements = NULL;
 421         init_data->no_input_qs = 1;
 422         init_data->no_output_qs = 1;
 423         init_data->input_handler = zfcp_qdio_int_resp;
 424         init_data->output_handler = zfcp_qdio_int_req;
 425         init_data->int_parm = (unsigned long) adapter;
 426         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
 427                         QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
 428         init_data->input_sbal_addr_array =
 429                         (void **) (adapter->resp_q.sbal);
 430         init_data->output_sbal_addr_array =
 431                         (void **) (adapter->req_q.sbal);
 432
 433         return qdio_allocate(init_data);
 434 }
 435
 436 /**
 437  * zfcp_close_qdio - close qdio queues for an adapter
 438  */
 439 void zfcp_qdio_close(struct zfcp_adapter *adapter)
 440 {
 441         struct zfcp_qdio_queue *req_q;
 442         int first, count;
 443
 444         if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 445                 return;
 446
 447         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 448         req_q = &adapter->req_q;
 449         spin_lock_bh(&adapter->req_q_lock);
 450         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
 451         spin_unlock_bh(&adapter->req_q_lock);
 452
 453         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
 454
 455         /* cleanup used outbound sbals */
 456         count = atomic_read(&req_q->count);
 457         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 458                 first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
 459                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 460                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 461         }
 462         req_q->first = 0;
 463         atomic_set(&req_q->count, 0);
 464         adapter->req_q_pci_batch = 0;
 465         adapter->resp_q.first = 0;
 466         atomic_set(&adapter->resp_q.count, 0);
 467 }
 468
 469 /**
 470  * zfcp_qdio_open - prepare and initialize response queue
 471  * @adapter: pointer to struct zfcp_adapter
 472  * Returns: 0 on success, otherwise -EIO
 473  */
 474 int zfcp_qdio_open(struct zfcp_adapter *adapter)
 475 {
 476         struct qdio_buffer_element *sbale;
 477         int cc;
 478
 479         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
 480                 return -EIO;
 481
 482         if (qdio_establish(&adapter->qdio_init_data))
 483                 goto failed_establish;
 484
 485         if (qdio_activate(adapter->ccw_device))
 486                 goto failed_qdio;
 487
 488         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 489                 sbale = &(adapter->resp_q.sbal[cc]->element[0]);
 490                 sbale->length = 0;
 491                 sbale->flags = SBAL_FLAGS_LAST_ENTRY;
 492                 sbale->addr = NULL;
 493         }
 494
 495         if (do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_INPUT, 0, 0,
 496                      QDIO_MAX_BUFFERS_PER_Q))
 497                 goto failed_qdio;
 498
 499         /* set index of first avalable SBALS / number of available SBALS */
 500         adapter->req_q.first = 0;
 501         atomic_set(&adapter->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
 502         adapter->req_q_pci_batch = 0;
 503
 504         return 0;
 505
 506 failed_qdio:
 507         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
 508 failed_establish:
 509         dev_err(&adapter->ccw_device->dev,
 510                 "Setting up the QDIO connection to the FCP adapter failed\n");
 511         return -EIO;
 512 }