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 <linux/slab.h>
  13 #include "zfcp_ext.h"
  14 #include "zfcp_qdio.h"
  15
  16 #define QBUFF_PER_PAGE          (PAGE_SIZE / sizeof(struct qdio_buffer))
  17
  18 static int zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbal)
  19 {
  20         int pos;
  21
  22         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
  23                 sbal[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
  24                 if (!sbal[pos])
  25                         return -ENOMEM;
  26         }
  27         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
  28                 if (pos % QBUFF_PER_PAGE)
  29                         sbal[pos] = sbal[pos - 1] + 1;
  30         return 0;
  31 }
  32
  33 static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *id)
  34 {
  35         struct zfcp_adapter *adapter = qdio->adapter;
  36
  37         dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
  38
  39         zfcp_erp_adapter_reopen(adapter,
  40                                 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
  41                                 ZFCP_STATUS_COMMON_ERP_FAILED, id, NULL);
  42 }
  43
  44 static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
  45 {
  46         int i, sbal_idx;
  47
  48         for (i = first; i < first + cnt; i++) {
  49                 sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
  50                 memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
  51         }
  52 }
  53
  54 /* this needs to be called prior to updating the queue fill level */
  55 static inline void zfcp_qdio_account(struct zfcp_qdio *qdio)
  56 {
  57         unsigned long long now, span;
  58         int free, used;
  59
  60         spin_lock(&qdio->stat_lock);
  61         now = get_clock_monotonic();
  62         span = (now - qdio->req_q_time) >> 12;
  63         free = atomic_read(&qdio->req_q.count);
  64         used = QDIO_MAX_BUFFERS_PER_Q - free;
  65         qdio->req_q_util += used * span;
  66         qdio->req_q_time = now;
  67         spin_unlock(&qdio->stat_lock);
  68 }
  69
  70 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
  71                               int queue_no, int first, int count,
  72                               unsigned long parm)
  73 {
  74         struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
  75         struct zfcp_qdio_queue *queue = &qdio->req_q;
  76
  77         if (unlikely(qdio_err)) {
  78                 zfcp_dbf_hba_qdio(qdio->adapter->dbf, qdio_err, first,
  79                                         count);
  80                 zfcp_qdio_handler_error(qdio, "qdireq1");
  81                 return;
  82         }
  83
  84         /* cleanup all SBALs being program-owned now */
  85         zfcp_qdio_zero_sbals(queue->sbal, first, count);
  86
  87         zfcp_qdio_account(qdio);
  88         atomic_add(count, &queue->count);
  89         wake_up(&qdio->req_q_wq);
  90 }
  91
  92 static void zfcp_qdio_resp_put_back(struct zfcp_qdio *qdio, int processed)
  93 {
  94         struct zfcp_qdio_queue *queue = &qdio->resp_q;
  95         struct ccw_device *cdev = qdio->adapter->ccw_device;
  96         u8 count, start = queue->first;
  97         unsigned int retval;
  98
  99         count = atomic_read(&queue->count) + processed;
 100
 101         retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, start, count);
 102
 103         if (unlikely(retval)) {
 104                 atomic_set(&queue->count, count);
 105                 zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdrpb_1", NULL);
 106         } else {
 107                 queue->first += count;
 108                 queue->first %= QDIO_MAX_BUFFERS_PER_Q;
 109                 atomic_set(&queue->count, 0);
 110         }
 111 }
 112
 113 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
 114                                int queue_no, int first, int count,
 115                                unsigned long parm)
 116 {
 117         struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
 118         int sbal_idx, sbal_no;
 119
 120         if (unlikely(qdio_err)) {
 121                 zfcp_dbf_hba_qdio(qdio->adapter->dbf, qdio_err, first,
 122                                         count);
 123                 zfcp_qdio_handler_error(qdio, "qdires1");
 124                 return;
 125         }
 126
 127         /*
 128          * go through all SBALs from input queue currently
 129          * returned by QDIO layer
 130          */
 131         for (sbal_no = 0; sbal_no < count; sbal_no++) {
 132                 sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
 133                 /* go through all SBALEs of SBAL */
 134                 zfcp_fsf_reqid_check(qdio, sbal_idx);
 135         }
 136
 137         /*
 138          * put range of SBALs back to response queue
 139          * (including SBALs which have already been free before)
 140          */
 141         zfcp_qdio_resp_put_back(qdio, count);
 142 }
 143
 144 static void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
 145                                  struct zfcp_qdio_req *q_req, int max_sbals)
 146 {
 147         int count = atomic_read(&qdio->req_q.count);
 148         count = min(count, max_sbals);
 149         q_req->sbal_limit = (q_req->sbal_first + count - 1)
 150                                         % QDIO_MAX_BUFFERS_PER_Q;
 151 }
 152
 153 static struct qdio_buffer_element *
 154 zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 155                      unsigned long sbtype)
 156 {
 157         struct qdio_buffer_element *sbale;
 158
 159         /* set last entry flag in current SBALE of current SBAL */
 160         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 161         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 162
 163         /* don't exceed last allowed SBAL */
 164         if (q_req->sbal_last == q_req->sbal_limit)
 165                 return NULL;
 166
 167         /* set chaining flag in first SBALE of current SBAL */
 168         sbale = zfcp_qdio_sbale_req(qdio, q_req);
 169         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 170
 171         /* calculate index of next SBAL */
 172         q_req->sbal_last++;
 173         q_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 174
 175         /* keep this requests number of SBALs up-to-date */
 176         q_req->sbal_number++;
 177
 178         /* start at first SBALE of new SBAL */
 179         q_req->sbale_curr = 0;
 180
 181         /* set storage-block type for new SBAL */
 182         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 183         sbale->flags |= sbtype;
 184
 185         return sbale;
 186 }
 187
 188 static struct qdio_buffer_element *
 189 zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 190                      unsigned int sbtype)
 191 {
 192         if (q_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 193                 return zfcp_qdio_sbal_chain(qdio, q_req, sbtype);
 194         q_req->sbale_curr++;
 195         return zfcp_qdio_sbale_curr(qdio, q_req);
 196 }
 197
 198 static void zfcp_qdio_undo_sbals(struct zfcp_qdio *qdio,
 199                                  struct zfcp_qdio_req *q_req)
 200 {
 201         struct qdio_buffer **sbal = qdio->req_q.sbal;
 202         int first = q_req->sbal_first;
 203         int last = q_req->sbal_last;
 204         int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
 205                 QDIO_MAX_BUFFERS_PER_Q + 1;
 206         zfcp_qdio_zero_sbals(sbal, first, count);
 207 }
 208
 209 static int zfcp_qdio_fill_sbals(struct zfcp_qdio *qdio,
 210                                 struct zfcp_qdio_req *q_req,
 211                                 unsigned int sbtype, void *start_addr,
 212                                 unsigned int total_length)
 213 {
 214         struct qdio_buffer_element *sbale;
 215         unsigned long remaining, length;
 216         void *addr;
 217
 218         /* split segment up */
 219         for (addr = start_addr, remaining = total_length; remaining > 0;
 220              addr += length, remaining -= length) {
 221                 sbale = zfcp_qdio_sbale_next(qdio, q_req, sbtype);
 222                 if (!sbale) {
 223                         atomic_inc(&qdio->req_q_full);
 224                         zfcp_qdio_undo_sbals(qdio, q_req);
 225                         return -EINVAL;
 226                 }
 227
 228                 /* new piece must not exceed next page boundary */
 229                 length = min(remaining,
 230                              (PAGE_SIZE - ((unsigned long)addr &
 231                                            (PAGE_SIZE - 1))));
 232                 sbale->addr = addr;
 233                 sbale->length = length;
 234         }
 235         return 0;
 236 }
 237
 238 /**
 239  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 240  * @fsf_req: request to be processed
 241  * @sbtype: SBALE flags
 242  * @sg: scatter-gather list
 243  * @max_sbals: upper bound for number of SBALs to be used
 244  * Returns: number of bytes, or error (negativ)
 245  */
 246 int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 247                             unsigned long sbtype, struct scatterlist *sg,
 248                             int max_sbals)
 249 {
 250         struct qdio_buffer_element *sbale;
 251         int retval, bytes = 0;
 252
 253         /* figure out last allowed SBAL */
 254         zfcp_qdio_sbal_limit(qdio, q_req, max_sbals);
 255
 256         /* set storage-block type for this request */
 257         sbale = zfcp_qdio_sbale_req(qdio, q_req);
 258         sbale->flags |= sbtype;
 259
 260         for (; sg; sg = sg_next(sg)) {
 261                 retval = zfcp_qdio_fill_sbals(qdio, q_req, sbtype,
 262                                               sg_virt(sg), sg->length);
 263                 if (retval < 0)
 264                         return retval;
 265                 bytes += sg->length;
 266         }
 267
 268         /* assume that no other SBALEs are to follow in the same SBAL */
 269         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 270         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 271
 272         return bytes;
 273 }
 274
 275 /**
 276  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 277  * @qdio: pointer to struct zfcp_qdio
 278  * @q_req: pointer to struct zfcp_qdio_req
 279  * Returns: 0 on success, error otherwise
 280  */
 281 int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 282 {
 283         struct zfcp_qdio_queue *req_q = &qdio->req_q;
 284         int first = q_req->sbal_first;
 285         int count = q_req->sbal_number;
 286         int retval;
 287         unsigned int qdio_flags = QDIO_FLAG_SYNC_OUTPUT;
 288
 289         zfcp_qdio_account(qdio);
 290
 291         retval = do_QDIO(qdio->adapter->ccw_device, qdio_flags, 0, first,
 292                          count);
 293         if (unlikely(retval)) {
 294                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 295                 return retval;
 296         }
 297
 298         /* account for transferred buffers */
 299         atomic_sub(count, &req_q->count);
 300         req_q->first += count;
 301         req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
 302         return 0;
 303 }
 304
 305
 306 static void zfcp_qdio_setup_init_data(struct qdio_initialize *id,
 307                                       struct zfcp_qdio *qdio)
 308 {
 309
 310         id->cdev = qdio->adapter->ccw_device;
 311         id->q_format = QDIO_ZFCP_QFMT;
 312         memcpy(id->adapter_name, dev_name(&id->cdev->dev), 8);
 313         ASCEBC(id->adapter_name, 8);
 314         id->qib_param_field_format = 0;
 315         id->qib_param_field = NULL;
 316         id->input_slib_elements = NULL;
 317         id->output_slib_elements = NULL;
 318         id->no_input_qs = 1;
 319         id->no_output_qs = 1;
 320         id->input_handler = zfcp_qdio_int_resp;
 321         id->output_handler = zfcp_qdio_int_req;
 322         id->int_parm = (unsigned long) qdio;
 323         id->input_sbal_addr_array = (void **) (qdio->resp_q.sbal);
 324         id->output_sbal_addr_array = (void **) (qdio->req_q.sbal);
 325
 326 }
 327 /**
 328  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 329  * @adapter: pointer to struct zfcp_adapter
 330  * Returns: -ENOMEM on memory allocation error or return value from
 331  *          qdio_allocate
 332  */
 333 static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
 334 {
 335         struct qdio_initialize init_data;
 336
 337         if (zfcp_qdio_buffers_enqueue(qdio->req_q.sbal) ||
 338             zfcp_qdio_buffers_enqueue(qdio->resp_q.sbal))
 339                 return -ENOMEM;
 340
 341         zfcp_qdio_setup_init_data(&init_data, qdio);
 342
 343         return qdio_allocate(&init_data);
 344 }
 345
 346 /**
 347  * zfcp_close_qdio - close qdio queues for an adapter
 348  * @qdio: pointer to structure zfcp_qdio
 349  */
 350 void zfcp_qdio_close(struct zfcp_qdio *qdio)
 351 {
 352         struct zfcp_qdio_queue *req_q;
 353         int first, count;
 354
 355         if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 356                 return;
 357
 358         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 359         req_q = &qdio->req_q;
 360         spin_lock_bh(&qdio->req_q_lock);
 361         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
 362         spin_unlock_bh(&qdio->req_q_lock);
 363
 364         qdio_shutdown(qdio->adapter->ccw_device,
 365                       QDIO_FLAG_CLEANUP_USING_CLEAR);
 366
 367         /* cleanup used outbound sbals */
 368         count = atomic_read(&req_q->count);
 369         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 370                 first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
 371                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 372                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
 373         }
 374         req_q->first = 0;
 375         atomic_set(&req_q->count, 0);
 376         qdio->resp_q.first = 0;
 377         atomic_set(&qdio->resp_q.count, 0);
 378 }
 379
 380 /**
 381  * zfcp_qdio_open - prepare and initialize response queue
 382  * @qdio: pointer to struct zfcp_qdio
 383  * Returns: 0 on success, otherwise -EIO
 384  */
 385 int zfcp_qdio_open(struct zfcp_qdio *qdio)
 386 {
 387         struct qdio_buffer_element *sbale;
 388         struct qdio_initialize init_data;
 389         struct ccw_device *cdev = qdio->adapter->ccw_device;
 390         int cc;
 391
 392         if (atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
 393                 return -EIO;
 394
 395         zfcp_qdio_setup_init_data(&init_data, qdio);
 396
 397         if (qdio_establish(&init_data))
 398                 goto failed_establish;
 399
 400         if (qdio_activate(cdev))
 401                 goto failed_qdio;
 402
 403         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 404                 sbale = &(qdio->resp_q.sbal[cc]->element[0]);
 405                 sbale->length = 0;
 406                 sbale->flags = SBAL_FLAGS_LAST_ENTRY;
 407                 sbale->addr = NULL;
 408         }
 409
 410         if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0,
 411                      QDIO_MAX_BUFFERS_PER_Q))
 412                 goto failed_qdio;
 413
 414         /* set index of first avalable SBALS / number of available SBALS */
 415         qdio->req_q.first = 0;
 416         atomic_set(&qdio->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
 417
 418         return 0;
 419
 420 failed_qdio:
 421         qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
 422 failed_establish:
 423         dev_err(&cdev->dev,
 424                 "Setting up the QDIO connection to the FCP adapter failed\n");
 425         return -EIO;
 426 }
 427
 428 void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
 429 {
 430         struct qdio_buffer **sbal_req, **sbal_resp;
 431         int p;
 432
 433         if (!qdio)
 434                 return;
 435
 436         if (qdio->adapter->ccw_device)
 437                 qdio_free(qdio->adapter->ccw_device);
 438
 439         sbal_req = qdio->req_q.sbal;
 440         sbal_resp = qdio->resp_q.sbal;
 441
 442         for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
 443                 free_page((unsigned long) sbal_req[p]);
 444                 free_page((unsigned long) sbal_resp[p]);
 445         }
 446
 447         kfree(qdio);
 448 }
 449
 450 int zfcp_qdio_setup(struct zfcp_adapter *adapter)
 451 {
 452         struct zfcp_qdio *qdio;
 453
 454         qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
 455         if (!qdio)
 456                 return -ENOMEM;
 457
 458         qdio->adapter = adapter;
 459
 460         if (zfcp_qdio_allocate(qdio)) {
 461                 zfcp_qdio_destroy(qdio);
 462                 return -ENOMEM;
 463         }
 464
 465         spin_lock_init(&qdio->req_q_lock);
 466         spin_lock_init(&qdio->stat_lock);
 467
 468         adapter->qdio = qdio;
 469         return 0;
 470 }
 471