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