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, 2009
   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 static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *id)
  38 {
  39         struct zfcp_adapter *adapter = qdio->adapter;
  40
  41         dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
  42
  43         zfcp_erp_adapter_reopen(adapter,
  44                                 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
  45                                 ZFCP_STATUS_COMMON_ERP_FAILED, id, NULL);
  46 }
  47
  48 static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
  49 {
  50         int i, sbal_idx;
  51
  52         for (i = first; i < first + cnt; i++) {
  53                 sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
  54                 memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
  55         }
  56 }
  57
  58 /* this needs to be called prior to updating the queue fill level */
  59 static inline void zfcp_qdio_account(struct zfcp_qdio *qdio)
  60 {
  61         unsigned long long now, span;
  62         int free, used;
  63
  64         spin_lock(&qdio->stat_lock);
  65         now = get_clock_monotonic();
  66         span = (now - qdio->req_q_time) >> 12;
  67         free = atomic_read(&qdio->req_q.count);
  68         used = QDIO_MAX_BUFFERS_PER_Q - free;
  69         qdio->req_q_util += used * span;
  70         qdio->req_q_time = now;
  71         spin_unlock(&qdio->stat_lock);
  72 }
  73
  74 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
  75                               int queue_no, int first, int count,
  76                               unsigned long parm)
  77 {
  78         struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
  79         struct zfcp_qdio_queue *queue = &qdio->req_q;
  80
  81         if (unlikely(qdio_err)) {
  82                 zfcp_dbf_hba_qdio(qdio->adapter->dbf, qdio_err, first,
  83                                         count);
  84                 zfcp_qdio_handler_error(qdio, "qdireq1");
  85                 return;
  86         }
  87
  88         /* cleanup all SBALs being program-owned now */
  89         zfcp_qdio_zero_sbals(queue->sbal, first, count);
  90
  91         zfcp_qdio_account(qdio);
  92         atomic_add(count, &queue->count);
  93         wake_up(&qdio->req_q_wq);
  94 }
  95
  96 static void zfcp_qdio_resp_put_back(struct zfcp_qdio *qdio, int processed)
  97 {
  98         struct zfcp_qdio_queue *queue = &qdio->resp_q;
  99         struct ccw_device *cdev = qdio->adapter->ccw_device;
 100         u8 count, start = queue->first;
 101         unsigned int retval;
 102
 103         count = atomic_read(&queue->count) + processed;
 104
 105         retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, start, count);
 106
 107         if (unlikely(retval)) {
 108                 atomic_set(&queue->count, count);
 109                 /* FIXME: Recover this with an adapter reopen? */
 110         } else {
 111                 queue->first += count;
 112                 queue->first %= QDIO_MAX_BUFFERS_PER_Q;
 113                 atomic_set(&queue->count, 0);
 114         }
 115 }
 116
 117 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
 118                                int queue_no, int first, int count,
 119                                unsigned long parm)
 120 {
 121         struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
 122         int sbal_idx, sbal_no;
 123
 124         if (unlikely(qdio_err)) {
 125                 zfcp_dbf_hba_qdio(qdio->adapter->dbf, qdio_err, first,
 126                                         count);
 127                 zfcp_qdio_handler_error(qdio, "qdires1");
 128                 return;
 129         }
 130
 131         /*
 132          * go through all SBALs from input queue currently
 133          * returned by QDIO layer
 134          */
 135         for (sbal_no = 0; sbal_no < count; sbal_no++) {
 136                 sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
 137                 /* go through all SBALEs of SBAL */
 138                 zfcp_fsf_reqid_check(qdio, sbal_idx);
 139         }
 140
 141         /*
 142          * put range of SBALs back to response queue
 143          * (including SBALs which have already been free before)
 144          */
 145         zfcp_qdio_resp_put_back(qdio, count);
 146 }
 147
 148 /**
 149  * zfcp_qdio_sbale_req - return ptr to SBALE of req_q for a struct zfcp_fsf_req
 150  * @qdio: pointer to struct zfcp_qdio
 151  * @q_rec: pointer to struct zfcp_queue_rec
 152  * Returns: pointer to qdio_buffer_element (SBALE) structure
 153  */
 154 struct qdio_buffer_element *zfcp_qdio_sbale_req(struct zfcp_qdio *qdio,
 155                                                 struct zfcp_queue_req *q_req)
 156 {
 157         return zfcp_qdio_sbale(&qdio->req_q, q_req->sbal_last, 0);
 158 }
 159
 160 /**
 161  * zfcp_qdio_sbale_curr - return curr SBALE on req_q for a struct zfcp_fsf_req
 162  * @fsf_req: pointer to struct fsf_req
 163  * Returns: pointer to qdio_buffer_element (SBALE) structure
 164  */
 165 struct qdio_buffer_element *zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio,
 166                                                  struct zfcp_queue_req *q_req)
 167 {
 168         return zfcp_qdio_sbale(&qdio->req_q, q_req->sbal_last,
 169                                q_req->sbale_curr);
 170 }
 171
 172 static void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
 173                                  struct zfcp_queue_req *q_req, int max_sbals)
 174 {
 175         int count = atomic_read(&qdio->req_q.count);
 176         count = min(count, max_sbals);
 177         q_req->sbal_limit = (q_req->sbal_first + count - 1)
 178                                         % QDIO_MAX_BUFFERS_PER_Q;
 179 }
 180
 181 static struct qdio_buffer_element *
 182 zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_queue_req *q_req,
 183                      unsigned long sbtype)
 184 {
 185         struct qdio_buffer_element *sbale;
 186
 187         /* set last entry flag in current SBALE of current SBAL */
 188         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 189         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 190
 191         /* don't exceed last allowed SBAL */
 192         if (q_req->sbal_last == q_req->sbal_limit)
 193                 return NULL;
 194
 195         /* set chaining flag in first SBALE of current SBAL */
 196         sbale = zfcp_qdio_sbale_req(qdio, q_req);
 197         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 198
 199         /* calculate index of next SBAL */
 200         q_req->sbal_last++;
 201         q_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 202
 203         /* keep this requests number of SBALs up-to-date */
 204         q_req->sbal_number++;
 205
 206         /* start at first SBALE of new SBAL */
 207         q_req->sbale_curr = 0;
 208
 209         /* set storage-block type for new SBAL */
 210         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 211         sbale->flags |= sbtype;
 212
 213         return sbale;
 214 }
 215
 216 static struct qdio_buffer_element *
 217 zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_queue_req *q_req,
 218                      unsigned int sbtype)
 219 {
 220         if (q_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 221                 return zfcp_qdio_sbal_chain(qdio, q_req, sbtype);
 222         q_req->sbale_curr++;
 223         return zfcp_qdio_sbale_curr(qdio, q_req);
 224 }
 225
 226 static void zfcp_qdio_undo_sbals(struct zfcp_qdio *qdio,
 227                                  struct zfcp_queue_req *q_req)
 228 {
 229         struct qdio_buffer **sbal = qdio->req_q.sbal;
 230         int first = q_req->sbal_first;
 231         int last = q_req->sbal_last;
 232         int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
 233                 QDIO_MAX_BUFFERS_PER_Q + 1;
 234         zfcp_qdio_zero_sbals(sbal, first, count);
 235 }
 236
 237 static int zfcp_qdio_fill_sbals(struct zfcp_qdio *qdio,
 238                                 struct zfcp_queue_req *q_req,
 239                                 unsigned int sbtype, void *start_addr,
 240                                 unsigned int total_length)
 241 {
 242         struct qdio_buffer_element *sbale;
 243         unsigned long remaining, length;
 244         void *addr;
 245
 246         /* split segment up */
 247         for (addr = start_addr, remaining = total_length; remaining > 0;
 248              addr += length, remaining -= length) {
 249                 sbale = zfcp_qdio_sbale_next(qdio, q_req, sbtype);
 250                 if (!sbale) {
 251                         atomic_inc(&qdio->req_q_full);
 252                         zfcp_qdio_undo_sbals(qdio, q_req);
 253                         return -EINVAL;
 254                 }
 255
 256                 /* new piece must not exceed next page boundary */
 257                 length = min(remaining,
 258                              (PAGE_SIZE - ((unsigned long)addr &
 259                                            (PAGE_SIZE - 1))));
 260                 sbale->addr = addr;
 261                 sbale->length = length;
 262         }
 263         return 0;
 264 }
 265
 266 /**
 267  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 268  * @fsf_req: request to be processed
 269  * @sbtype: SBALE flags
 270  * @sg: scatter-gather list
 271  * @max_sbals: upper bound for number of SBALs to be used
 272  * Returns: number of bytes, or error (negativ)
 273  */
 274 int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio,
 275                             struct zfcp_queue_req *q_req,
 276                             unsigned long sbtype, struct scatterlist *sg,
 277                             int max_sbals)
 278 {
 279         struct qdio_buffer_element *sbale;
 280         int retval, bytes = 0;
 281
 282         /* figure out last allowed SBAL */
 283         zfcp_qdio_sbal_limit(qdio, q_req, max_sbals);
 284
 285         /* set storage-block type for this request */
 286         sbale = zfcp_qdio_sbale_req(qdio, q_req);
 287         sbale->flags |= sbtype;
 288
 289         for (; sg; sg = sg_next(sg)) {
 290                 retval = zfcp_qdio_fill_sbals(qdio, q_req, sbtype,
 291                                               sg_virt(sg), sg->length);
 292                 if (retval < 0)
 293                         return retval;
 294                 bytes += sg->length;
 295         }
 296
 297         /* assume that no other SBALEs are to follow in the same SBAL */
 298         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 299         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 300
 301         return bytes;
 302 }
 303
 304 /**
 305  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 306  * @qdio: pointer to struct zfcp_qdio
 307  * @q_req: pointer to struct zfcp_queue_req
 308  * Returns: 0 on success, error otherwise
 309  */
 310 int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_queue_req *q_req)
 311 {
 312         struct zfcp_qdio_queue *req_q = &qdio->req_q;
 313         int first = q_req->sbal_first;
 314         int count = q_req->sbal_number;
 315         int retval;
 316         unsigned int qdio_flags = QDIO_FLAG_SYNC_OUTPUT;
 317
 318         zfcp_qdio_account(qdio);
 319
 320         retval = do_QDIO(qdio->adapter->ccw_device, qdio_flags, 0, first,
 321                          count);
 322         if (unlikely(retval)) {
 323                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 324                 return retval;
 325         }
 326
 327         /* account for transferred buffers */
 328         atomic_sub(count, &req_q->count);
 329         req_q->first += count;
 330         req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
 331         return 0;
 332 }
 333
 334
 335 static void zfcp_qdio_setup_init_data(struct qdio_initialize *id,
 336                                       struct zfcp_qdio *qdio)
 337 {
 338
 339         id->cdev = qdio->adapter->ccw_device;
 340         id->q_format = QDIO_ZFCP_QFMT;
 341         memcpy(id->adapter_name, dev_name(&id->cdev->dev), 8);
 342         ASCEBC(id->adapter_name, 8);
 343         id->qib_param_field_format = 0;
 344         id->qib_param_field = NULL;
 345         id->input_slib_elements = NULL;
 346         id->output_slib_elements = NULL;
 347         id->no_input_qs = 1;
 348         id->no_output_qs = 1;
 349         id->input_handler = zfcp_qdio_int_resp;
 350         id->output_handler = zfcp_qdio_int_req;
 351         id->int_parm = (unsigned long) qdio;
 352         id->flags = QDIO_INBOUND_0COPY_SBALS |
 353                     QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
 354         id->input_sbal_addr_array = (void **) (qdio->resp_q.sbal);
 355         id->output_sbal_addr_array = (void **) (qdio->req_q.sbal);
 356
 357 }
 358 /**
 359  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 360  * @adapter: pointer to struct zfcp_adapter
 361  * Returns: -ENOMEM on memory allocation error or return value from
 362  *          qdio_allocate
 363  */
 364 static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
 365 {
 366         struct qdio_initialize init_data;
 367
 368         if (zfcp_qdio_buffers_enqueue(qdio->req_q.sbal) ||
 369             zfcp_qdio_buffers_enqueue(qdio->resp_q.sbal))
 370                 return -ENOMEM;
 371
 372         zfcp_qdio_setup_init_data(&init_data, qdio);
 373
 374         return qdio_allocate(&init_data);
 375 }
 376
 377 /**
 378  * zfcp_close_qdio - close qdio queues for an adapter
 379  * @qdio: pointer to structure zfcp_qdio
 380  */
 381 void zfcp_qdio_close(struct zfcp_qdio *qdio)
 382 {
 383         struct zfcp_qdio_queue *req_q;
 384         int first, count;
 385
 386         if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 387                 return;
 388
 389         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 390         req_q = &qdio->req_q;
 391         spin_lock_bh(&qdio->req_q_lock);
 392         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
 393         spin_unlock_bh(&qdio->req_q_lock);
 394
 395         qdio_shutdown(qdio->adapter->ccw_device,
 396                       QDIO_FLAG_CLEANUP_USING_CLEAR);
 397
 398         /* cleanup used outbound sbals */
 399         count = atomic_read(&req_q->count);
 400         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 401                 first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
 402                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 403                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 404         }
 405         req_q->first = 0;
 406         atomic_set(&req_q->count, 0);
 407         qdio->resp_q.first = 0;
 408         atomic_set(&qdio->resp_q.count, 0);
 409 }
 410
 411 /**
 412  * zfcp_qdio_open - prepare and initialize response queue
 413  * @qdio: pointer to struct zfcp_qdio
 414  * Returns: 0 on success, otherwise -EIO
 415  */
 416 int zfcp_qdio_open(struct zfcp_qdio *qdio)
 417 {
 418         struct qdio_buffer_element *sbale;
 419         struct qdio_initialize init_data;
 420         struct ccw_device *cdev = qdio->adapter->ccw_device;
 421         int cc;
 422
 423         if (atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
 424                 return -EIO;
 425
 426         zfcp_qdio_setup_init_data(&init_data, qdio);
 427
 428         if (qdio_establish(&init_data))
 429                 goto failed_establish;
 430
 431         if (qdio_activate(cdev))
 432                 goto failed_qdio;
 433
 434         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 435                 sbale = &(qdio->resp_q.sbal[cc]->element[0]);
 436                 sbale->length = 0;
 437                 sbale->flags = SBAL_FLAGS_LAST_ENTRY;
 438                 sbale->addr = NULL;
 439         }
 440
 441         if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0,
 442                      QDIO_MAX_BUFFERS_PER_Q))
 443                 goto failed_qdio;
 444
 445         /* set index of first avalable SBALS / number of available SBALS */
 446         qdio->req_q.first = 0;
 447         atomic_set(&qdio->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
 448
 449         return 0;
 450
 451 failed_qdio:
 452         qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
 453 failed_establish:
 454         dev_err(&cdev->dev,
 455                 "Setting up the QDIO connection to the FCP adapter failed\n");
 456         return -EIO;
 457 }
 458
 459 void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
 460 {
 461         struct qdio_buffer **sbal_req, **sbal_resp;
 462         int p;
 463
 464         if (!qdio)
 465                 return;
 466
 467         if (qdio->adapter->ccw_device)
 468                 qdio_free(qdio->adapter->ccw_device);
 469
 470         sbal_req = qdio->req_q.sbal;
 471         sbal_resp = qdio->resp_q.sbal;
 472
 473         for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
 474                 free_page((unsigned long) sbal_req[p]);
 475                 free_page((unsigned long) sbal_resp[p]);
 476         }
 477
 478         kfree(qdio);
 479 }
 480
 481 int zfcp_qdio_setup(struct zfcp_adapter *adapter)
 482 {
 483         struct zfcp_qdio *qdio;
 484
 485         qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
 486         if (!qdio)
 487                 return -ENOMEM;
 488
 489         qdio->adapter = adapter;
 490
 491         if (zfcp_qdio_allocate(qdio)) {
 492                 zfcp_qdio_destroy(qdio);
 493                 return -ENOMEM;
 494         }
 495
 496         spin_lock_init(&qdio->req_q_lock);
 497         spin_lock_init(&qdio->stat_lock);
 498
 499         adapter->qdio = qdio;
 500         return 0;
 501 }
 502