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