drivers/s390/scsi/zfcp_qdio.c

   1 /*
   2  * zfcp device driver
   3  *
   4  * Setup and helper functions to access QDIO.
   5  *
   6  * Copyright IBM Corp. 2002, 2010
   7  */
   8
   9 #define KMSG_COMPONENT "zfcp"
  10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  11
  12 #include <linux/slab.h>
  13 #include <linux/module.h>
  14 #include "zfcp_ext.h"
  15 #include "zfcp_qdio.h"
  16
  17 #define QBUFF_PER_PAGE          (PAGE_SIZE / sizeof(struct qdio_buffer))
  18
  19 static bool enable_multibuffer;
  20 module_param_named(datarouter, enable_multibuffer, bool, 0400);
  21 MODULE_PARM_DESC(datarouter, "Enable hardware data router support");
  22
  23 static int zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbal)
  24 {
  25         int pos;
  26
  27         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
  28                 sbal[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
  29                 if (!sbal[pos])
  30                         return -ENOMEM;
  31         }
  32         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
  33                 if (pos % QBUFF_PER_PAGE)
  34                         sbal[pos] = sbal[pos - 1] + 1;
  35         return 0;
  36 }
  37
  38 static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *id,
  39                                     unsigned int qdio_err)
  40 {
  41         struct zfcp_adapter *adapter = qdio->adapter;
  42
  43         dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
  44
  45         if (qdio_err & QDIO_ERROR_SLSB_STATE) {
  46                 zfcp_qdio_siosl(adapter);
  47                 zfcp_erp_adapter_shutdown(adapter, 0, id);
  48                 return;
  49         }
  50         zfcp_erp_adapter_reopen(adapter,
  51                                 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
  52                                 ZFCP_STATUS_COMMON_ERP_FAILED, id);
  53 }
  54
  55 static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
  56 {
  57         int i, sbal_idx;
  58
  59         for (i = first; i < first + cnt; i++) {
  60                 sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
  61                 memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
  62         }
  63 }
  64
  65 /* this needs to be called prior to updating the queue fill level */
  66 static inline void zfcp_qdio_account(struct zfcp_qdio *qdio)
  67 {
  68         unsigned long long now, span;
  69         int used;
  70
  71         now = get_tod_clock_monotonic();
  72         span = (now - qdio->req_q_time) >> 12;
  73         used = QDIO_MAX_BUFFERS_PER_Q - atomic_read(&qdio->req_q_free);
  74         qdio->req_q_util += used * span;
  75         qdio->req_q_time = now;
  76 }
  77
  78 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
  79                               int queue_no, int idx, int count,
  80                               unsigned long parm)
  81 {
  82         struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
  83
  84         if (unlikely(qdio_err)) {
  85                 zfcp_qdio_handler_error(qdio, "qdireq1", qdio_err);
  86                 return;
  87         }
  88
  89         /* cleanup all SBALs being program-owned now */
  90         zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
  91
  92         spin_lock_irq(&qdio->stat_lock);
  93         zfcp_qdio_account(qdio);
  94         spin_unlock_irq(&qdio->stat_lock);
  95         atomic_add(count, &qdio->req_q_free);
  96         wake_up(&qdio->req_q_wq);
  97 }
  98
  99 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
 100                                int queue_no, int idx, int count,
 101                                unsigned long parm)
 102 {
 103         struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
 104         struct zfcp_adapter *adapter = qdio->adapter;
 105         int sbal_no, sbal_idx;
 106
 107         if (unlikely(qdio_err)) {
 108                 if (zfcp_adapter_multi_buffer_active(adapter)) {
 109                         void *pl[ZFCP_QDIO_MAX_SBALS_PER_REQ + 1];
 110                         struct qdio_buffer_element *sbale;
 111                         u64 req_id;
 112                         u8 scount;
 113
 114                         memset(pl, 0,
 115                                ZFCP_QDIO_MAX_SBALS_PER_REQ * sizeof(void *));
 116                         sbale = qdio->res_q[idx]->element;
 117                         req_id = (u64) sbale->addr;
 118                         scount = min(sbale->scount + 1,
 119                                      ZFCP_QDIO_MAX_SBALS_PER_REQ + 1);
 120                                      /* incl. signaling SBAL */
 121
 122                         for (sbal_no = 0; sbal_no < scount; sbal_no++) {
 123                                 sbal_idx = (idx + sbal_no) %
 124                                         QDIO_MAX_BUFFERS_PER_Q;
 125                                 pl[sbal_no] = qdio->res_q[sbal_idx];
 126                         }
 127                         zfcp_dbf_hba_def_err(adapter, req_id, scount, pl);
 128                 }
 129                 zfcp_qdio_handler_error(qdio, "qdires1", qdio_err);
 130                 return;
 131         }
 132
 133         /*
 134          * go through all SBALs from input queue currently
 135          * returned by QDIO layer
 136          */
 137         for (sbal_no = 0; sbal_no < count; sbal_no++) {
 138                 sbal_idx = (idx + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
 139                 /* go through all SBALEs of SBAL */
 140                 zfcp_fsf_reqid_check(qdio, sbal_idx);
 141         }
 142
 143         /*
 144          * put SBALs back to response queue
 145          */
 146         if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, idx, count))
 147                 zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdires2");
 148 }
 149
 150 static struct qdio_buffer_element *
 151 zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 152 {
 153         struct qdio_buffer_element *sbale;
 154
 155         /* set last entry flag in current SBALE of current SBAL */
 156         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 157         sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY;
 158
 159         /* don't exceed last allowed SBAL */
 160         if (q_req->sbal_last == q_req->sbal_limit)
 161                 return NULL;
 162
 163         /* set chaining flag in first SBALE of current SBAL */
 164         sbale = zfcp_qdio_sbale_req(qdio, q_req);
 165         sbale->sflags |= SBAL_SFLAGS0_MORE_SBALS;
 166
 167         /* calculate index of next SBAL */
 168         q_req->sbal_last++;
 169         q_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 170
 171         /* keep this requests number of SBALs up-to-date */
 172         q_req->sbal_number++;
 173         BUG_ON(q_req->sbal_number > ZFCP_QDIO_MAX_SBALS_PER_REQ);
 174
 175         /* start at first SBALE of new SBAL */
 176         q_req->sbale_curr = 0;
 177
 178         /* set storage-block type for new SBAL */
 179         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 180         sbale->sflags |= q_req->sbtype;
 181
 182         return sbale;
 183 }
 184
 185 static struct qdio_buffer_element *
 186 zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 187 {
 188         if (q_req->sbale_curr == qdio->max_sbale_per_sbal - 1)
 189                 return zfcp_qdio_sbal_chain(qdio, q_req);
 190         q_req->sbale_curr++;
 191         return zfcp_qdio_sbale_curr(qdio, q_req);
 192 }
 193
 194 /**
 195  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 196  * @qdio: pointer to struct zfcp_qdio
 197  * @q_req: pointer to struct zfcp_qdio_req
 198  * @sg: scatter-gather list
 199  * @max_sbals: upper bound for number of SBALs to be used
 200  * Returns: zero or -EINVAL on error
 201  */
 202 int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 203                             struct scatterlist *sg)
 204 {
 205         struct qdio_buffer_element *sbale;
 206
 207         /* set storage-block type for this request */
 208         sbale = zfcp_qdio_sbale_req(qdio, q_req);
 209         sbale->sflags |= q_req->sbtype;
 210
 211         for (; sg; sg = sg_next(sg)) {
 212                 sbale = zfcp_qdio_sbale_next(qdio, q_req);
 213                 if (!sbale) {
 214                         atomic_inc(&qdio->req_q_full);
 215                         zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
 216                                              q_req->sbal_number);
 217                         return -EINVAL;
 218                 }
 219                 sbale->addr = sg_virt(sg);
 220                 sbale->length = sg->length;
 221         }
 222         return 0;
 223 }
 224
 225 static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
 226 {
 227         spin_lock_irq(&qdio->req_q_lock);
 228         if (atomic_read(&qdio->req_q_free) ||
 229             !(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 230                 return 1;
 231         spin_unlock_irq(&qdio->req_q_lock);
 232         return 0;
 233 }
 234
 235 /**
 236  * zfcp_qdio_sbal_get - get free sbal in request queue, wait if necessary
 237  * @qdio: pointer to struct zfcp_qdio
 238  *
 239  * The req_q_lock must be held by the caller of this function, and
 240  * this function may only be called from process context; it will
 241  * sleep when waiting for a free sbal.
 242  *
 243  * Returns: 0 on success, -EIO if there is no free sbal after waiting.
 244  */
 245 int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
 246 {
 247         long ret;
 248
 249         spin_unlock_irq(&qdio->req_q_lock);
 250         ret = wait_event_interruptible_timeout(qdio->req_q_wq,
 251                                zfcp_qdio_sbal_check(qdio), 5 * HZ);
 252
 253         if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 254                 return -EIO;
 255
 256         if (ret > 0)
 257                 return 0;
 258
 259         if (!ret) {
 260                 atomic_inc(&qdio->req_q_full);
 261                 /* assume hanging outbound queue, try queue recovery */
 262                 zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdsbg_1");
 263         }
 264
 265         spin_lock_irq(&qdio->req_q_lock);
 266         return -EIO;
 267 }
 268
 269 /**
 270  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 271  * @qdio: pointer to struct zfcp_qdio
 272  * @q_req: pointer to struct zfcp_qdio_req
 273  * Returns: 0 on success, error otherwise
 274  */
 275 int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 276 {
 277         int retval;
 278         u8 sbal_number = q_req->sbal_number;
 279
 280         spin_lock(&qdio->stat_lock);
 281         zfcp_qdio_account(qdio);
 282         spin_unlock(&qdio->stat_lock);
 283
 284         retval = do_QDIO(qdio->adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0,
 285                          q_req->sbal_first, sbal_number);
 286
 287         if (unlikely(retval)) {
 288                 zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
 289                                      sbal_number);
 290                 return retval;
 291         }
 292
 293         /* account for transferred buffers */
 294         atomic_sub(sbal_number, &qdio->req_q_free);
 295         qdio->req_q_idx += sbal_number;
 296         qdio->req_q_idx %= QDIO_MAX_BUFFERS_PER_Q;
 297
 298         return 0;
 299 }
 300
 301
 302 static void zfcp_qdio_setup_init_data(struct qdio_initialize *id,
 303                                       struct zfcp_qdio *qdio)
 304 {
 305         memset(id, 0, sizeof(*id));
 306         id->cdev = qdio->adapter->ccw_device;
 307         id->q_format = QDIO_ZFCP_QFMT;
 308         memcpy(id->adapter_name, dev_name(&id->cdev->dev), 8);
 309         ASCEBC(id->adapter_name, 8);
 310         id->qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV;
 311         if (enable_multibuffer)
 312                 id->qdr_ac |= QDR_AC_MULTI_BUFFER_ENABLE;
 313         id->no_input_qs = 1;
 314         id->no_output_qs = 1;
 315         id->input_handler = zfcp_qdio_int_resp;
 316         id->output_handler = zfcp_qdio_int_req;
 317         id->int_parm = (unsigned long) qdio;
 318         id->input_sbal_addr_array = (void **) (qdio->res_q);
 319         id->output_sbal_addr_array = (void **) (qdio->req_q);
 320         id->scan_threshold =
 321                 QDIO_MAX_BUFFERS_PER_Q - ZFCP_QDIO_MAX_SBALS_PER_REQ * 2;
 322 }
 323
 324 /**
 325  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 326  * @adapter: pointer to struct zfcp_adapter
 327  * Returns: -ENOMEM on memory allocation error or return value from
 328  *          qdio_allocate
 329  */
 330 static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
 331 {
 332         struct qdio_initialize init_data;
 333
 334         if (zfcp_qdio_buffers_enqueue(qdio->req_q) ||
 335             zfcp_qdio_buffers_enqueue(qdio->res_q))
 336                 return -ENOMEM;
 337
 338         zfcp_qdio_setup_init_data(&init_data, qdio);
 339         init_waitqueue_head(&qdio->req_q_wq);
 340
 341         return qdio_allocate(&init_data);
 342 }
 343
 344 /**
 345  * zfcp_close_qdio - close qdio queues for an adapter
 346  * @qdio: pointer to structure zfcp_qdio
 347  */
 348 void zfcp_qdio_close(struct zfcp_qdio *qdio)
 349 {
 350         struct zfcp_adapter *adapter = qdio->adapter;
 351         int idx, count;
 352
 353         if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 354                 return;
 355
 356         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 357         spin_lock_irq(&qdio->req_q_lock);
 358         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
 359         spin_unlock_irq(&qdio->req_q_lock);
 360
 361         wake_up(&qdio->req_q_wq);
 362
 363         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
 364
 365         /* cleanup used outbound sbals */
 366         count = atomic_read(&qdio->req_q_free);
 367         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 368                 idx = (qdio->req_q_idx + count) % QDIO_MAX_BUFFERS_PER_Q;
 369                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 370                 zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
 371         }
 372         qdio->req_q_idx = 0;
 373         atomic_set(&qdio->req_q_free, 0);
 374 }
 375
 376 /**
 377  * zfcp_qdio_open - prepare and initialize response queue
 378  * @qdio: pointer to struct zfcp_qdio
 379  * Returns: 0 on success, otherwise -EIO
 380  */
 381 int zfcp_qdio_open(struct zfcp_qdio *qdio)
 382 {
 383         struct qdio_buffer_element *sbale;
 384         struct qdio_initialize init_data;
 385         struct zfcp_adapter *adapter = qdio->adapter;
 386         struct ccw_device *cdev = adapter->ccw_device;
 387         struct qdio_ssqd_desc ssqd;
 388         int cc;
 389
 390         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
 391                 return -EIO;
 392
 393         atomic_clear_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
 394                           &qdio->adapter->status);
 395
 396         zfcp_qdio_setup_init_data(&init_data, qdio);
 397
 398         if (qdio_establish(&init_data))
 399                 goto failed_establish;
 400
 401         if (qdio_get_ssqd_desc(init_data.cdev, &ssqd))
 402                 goto failed_qdio;
 403
 404         if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED)
 405                 atomic_set_mask(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED,
 406                                 &qdio->adapter->status);
 407
 408         if (ssqd.qdioac2 & CHSC_AC2_MULTI_BUFFER_ENABLED) {
 409                 atomic_set_mask(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
 410                 qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER;
 411         } else {
 412                 atomic_clear_mask(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
 413                 qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER - 1;
 414         }
 415
 416         qdio->max_sbale_per_req =
 417                 ZFCP_QDIO_MAX_SBALS_PER_REQ * qdio->max_sbale_per_sbal
 418                 - 2;
 419         if (qdio_activate(cdev))
 420                 goto failed_qdio;
 421
 422         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 423                 sbale = &(qdio->res_q[cc]->element[0]);
 424                 sbale->length = 0;
 425                 sbale->eflags = SBAL_EFLAGS_LAST_ENTRY;
 426                 sbale->sflags = 0;
 427                 sbale->addr = NULL;
 428         }
 429
 430         if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0, QDIO_MAX_BUFFERS_PER_Q))
 431                 goto failed_qdio;
 432
 433         /* set index of first available SBALS / number of available SBALS */
 434         qdio->req_q_idx = 0;
 435         atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
 436         atomic_set_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
 437
 438         if (adapter->scsi_host) {
 439                 adapter->scsi_host->sg_tablesize = qdio->max_sbale_per_req;
 440                 adapter->scsi_host->max_sectors = qdio->max_sbale_per_req * 8;
 441         }
 442
 443         return 0;
 444
 445 failed_qdio:
 446         qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
 447 failed_establish:
 448         dev_err(&cdev->dev,
 449                 "Setting up the QDIO connection to the FCP adapter failed\n");
 450         return -EIO;
 451 }
 452
 453 void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
 454 {
 455         int p;
 456
 457         if (!qdio)
 458                 return;
 459
 460         if (qdio->adapter->ccw_device)
 461                 qdio_free(qdio->adapter->ccw_device);
 462
 463         for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
 464                 free_page((unsigned long) qdio->req_q[p]);
 465                 free_page((unsigned long) qdio->res_q[p]);
 466         }
 467
 468         kfree(qdio);
 469 }
 470
 471 int zfcp_qdio_setup(struct zfcp_adapter *adapter)
 472 {
 473         struct zfcp_qdio *qdio;
 474
 475         qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
 476         if (!qdio)
 477                 return -ENOMEM;
 478
 479         qdio->adapter = adapter;
 480
 481         if (zfcp_qdio_allocate(qdio)) {
 482                 zfcp_qdio_destroy(qdio);
 483                 return -ENOMEM;
 484         }
 485
 486         spin_lock_init(&qdio->req_q_lock);
 487         spin_lock_init(&qdio->stat_lock);
 488
 489         adapter->qdio = qdio;
 490         return 0;
 491 }
 492
 493 /**
 494  * zfcp_qdio_siosl - Trigger logging in FCP channel
 495  * @adapter: The zfcp_adapter where to trigger logging
 496  *
 497  * Call the cio siosl function to trigger hardware logging.  This
 498  * wrapper function sets a flag to ensure hardware logging is only
 499  * triggered once before going through qdio shutdown.
 500  *
 501  * The triggers are always run from qdio tasklet context, so no
 502  * additional synchronization is necessary.
 503  */
 504 void zfcp_qdio_siosl(struct zfcp_adapter *adapter)
 505 {
 506         int rc;
 507
 508         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED)
 509                 return;
 510
 511         rc = ccw_device_siosl(adapter->ccw_device);
 512         if (!rc)
 513                 atomic_set_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
 514                                 &adapter->status);
 515 }