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