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