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 = 1;
  20 module_param_named(datarouter, enable_multibuffer, bool, 0400);
  21 MODULE_PARM_DESC(datarouter, "Enable hardware data router support (default on)");
  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         if (atomic_read(&qdio->req_q_free) ||
 228             !(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 229                 return 1;
 230         return 0;
 231 }
 232
 233 /**
 234  * zfcp_qdio_sbal_get - get free sbal in request queue, wait if necessary
 235  * @qdio: pointer to struct zfcp_qdio
 236  *
 237  * The req_q_lock must be held by the caller of this function, and
 238  * this function may only be called from process context; it will
 239  * sleep when waiting for a free sbal.
 240  *
 241  * Returns: 0 on success, -EIO if there is no free sbal after waiting.
 242  */
 243 int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
 244 {
 245         long ret;
 246
 247         ret = wait_event_interruptible_lock_irq_timeout(qdio->req_q_wq,
 248                        zfcp_qdio_sbal_check(qdio), qdio->req_q_lock, 5 * HZ);
 249
 250         if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 251                 return -EIO;
 252
 253         if (ret > 0)
 254                 return 0;
 255
 256         if (!ret) {
 257                 atomic_inc(&qdio->req_q_full);
 258                 /* assume hanging outbound queue, try queue recovery */
 259                 zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdsbg_1");
 260         }
 261
 262         return -EIO;
 263 }
 264
 265 /**
 266  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 267  * @qdio: pointer to struct zfcp_qdio
 268  * @q_req: pointer to struct zfcp_qdio_req
 269  * Returns: 0 on success, error otherwise
 270  */
 271 int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 272 {
 273         int retval;
 274         u8 sbal_number = q_req->sbal_number;
 275
 276         spin_lock(&qdio->stat_lock);
 277         zfcp_qdio_account(qdio);
 278         spin_unlock(&qdio->stat_lock);
 279
 280         retval = do_QDIO(qdio->adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0,
 281                          q_req->sbal_first, sbal_number);
 282
 283         if (unlikely(retval)) {
 284                 zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
 285                                      sbal_number);
 286                 return retval;
 287         }
 288
 289         /* account for transferred buffers */
 290         atomic_sub(sbal_number, &qdio->req_q_free);
 291         qdio->req_q_idx += sbal_number;
 292         qdio->req_q_idx %= QDIO_MAX_BUFFERS_PER_Q;
 293
 294         return 0;
 295 }
 296
 297
 298 static void zfcp_qdio_setup_init_data(struct qdio_initialize *id,
 299                                       struct zfcp_qdio *qdio)
 300 {
 301         memset(id, 0, sizeof(*id));
 302         id->cdev = qdio->adapter->ccw_device;
 303         id->q_format = QDIO_ZFCP_QFMT;
 304         memcpy(id->adapter_name, dev_name(&id->cdev->dev), 8);
 305         ASCEBC(id->adapter_name, 8);
 306         id->qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV;
 307         if (enable_multibuffer)
 308                 id->qdr_ac |= QDR_AC_MULTI_BUFFER_ENABLE;
 309         id->no_input_qs = 1;
 310         id->no_output_qs = 1;
 311         id->input_handler = zfcp_qdio_int_resp;
 312         id->output_handler = zfcp_qdio_int_req;
 313         id->int_parm = (unsigned long) qdio;
 314         id->input_sbal_addr_array = (void **) (qdio->res_q);
 315         id->output_sbal_addr_array = (void **) (qdio->req_q);
 316         id->scan_threshold =
 317                 QDIO_MAX_BUFFERS_PER_Q - ZFCP_QDIO_MAX_SBALS_PER_REQ * 2;
 318 }
 319
 320 /**
 321  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 322  * @adapter: pointer to struct zfcp_adapter
 323  * Returns: -ENOMEM on memory allocation error or return value from
 324  *          qdio_allocate
 325  */
 326 static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
 327 {
 328         struct qdio_initialize init_data;
 329
 330         if (zfcp_qdio_buffers_enqueue(qdio->req_q) ||
 331             zfcp_qdio_buffers_enqueue(qdio->res_q))
 332                 return -ENOMEM;
 333
 334         zfcp_qdio_setup_init_data(&init_data, qdio);
 335         init_waitqueue_head(&qdio->req_q_wq);
 336
 337         return qdio_allocate(&init_data);
 338 }
 339
 340 /**
 341  * zfcp_close_qdio - close qdio queues for an adapter
 342  * @qdio: pointer to structure zfcp_qdio
 343  */
 344 void zfcp_qdio_close(struct zfcp_qdio *qdio)
 345 {
 346         struct zfcp_adapter *adapter = qdio->adapter;
 347         int idx, count;
 348
 349         if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 350                 return;
 351
 352         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 353         spin_lock_irq(&qdio->req_q_lock);
 354         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
 355         spin_unlock_irq(&qdio->req_q_lock);
 356
 357         wake_up(&qdio->req_q_wq);
 358
 359         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
 360
 361         /* cleanup used outbound sbals */
 362         count = atomic_read(&qdio->req_q_free);
 363         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 364                 idx = (qdio->req_q_idx + count) % QDIO_MAX_BUFFERS_PER_Q;
 365                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 366                 zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
 367         }
 368         qdio->req_q_idx = 0;
 369         atomic_set(&qdio->req_q_free, 0);
 370 }
 371
 372 /**
 373  * zfcp_qdio_open - prepare and initialize response queue
 374  * @qdio: pointer to struct zfcp_qdio
 375  * Returns: 0 on success, otherwise -EIO
 376  */
 377 int zfcp_qdio_open(struct zfcp_qdio *qdio)
 378 {
 379         struct qdio_buffer_element *sbale;
 380         struct qdio_initialize init_data;
 381         struct zfcp_adapter *adapter = qdio->adapter;
 382         struct ccw_device *cdev = adapter->ccw_device;
 383         struct qdio_ssqd_desc ssqd;
 384         int cc;
 385
 386         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
 387                 return -EIO;
 388
 389         atomic_clear_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
 390                           &qdio->adapter->status);
 391
 392         zfcp_qdio_setup_init_data(&init_data, qdio);
 393
 394         if (qdio_establish(&init_data))
 395                 goto failed_establish;
 396
 397         if (qdio_get_ssqd_desc(init_data.cdev, &ssqd))
 398                 goto failed_qdio;
 399
 400         if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED)
 401                 atomic_set_mask(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED,
 402                                 &qdio->adapter->status);
 403
 404         if (ssqd.qdioac2 & CHSC_AC2_MULTI_BUFFER_ENABLED) {
 405                 atomic_set_mask(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
 406                 qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER;
 407         } else {
 408                 atomic_clear_mask(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
 409                 qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER - 1;
 410         }
 411
 412         qdio->max_sbale_per_req =
 413                 ZFCP_QDIO_MAX_SBALS_PER_REQ * qdio->max_sbale_per_sbal
 414                 - 2;
 415         if (qdio_activate(cdev))
 416                 goto failed_qdio;
 417
 418         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 419                 sbale = &(qdio->res_q[cc]->element[0]);
 420                 sbale->length = 0;
 421                 sbale->eflags = SBAL_EFLAGS_LAST_ENTRY;
 422                 sbale->sflags = 0;
 423                 sbale->addr = NULL;
 424         }
 425
 426         if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0, QDIO_MAX_BUFFERS_PER_Q))
 427                 goto failed_qdio;
 428
 429         /* set index of first available SBALS / number of available SBALS */
 430         qdio->req_q_idx = 0;
 431         atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
 432         atomic_set_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
 433
 434         if (adapter->scsi_host) {
 435                 adapter->scsi_host->sg_tablesize = qdio->max_sbale_per_req;
 436                 adapter->scsi_host->max_sectors = qdio->max_sbale_per_req * 8;
 437         }
 438
 439         return 0;
 440
 441 failed_qdio:
 442         qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
 443 failed_establish:
 444         dev_err(&cdev->dev,
 445                 "Setting up the QDIO connection to the FCP adapter failed\n");
 446         return -EIO;
 447 }
 448
 449 void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
 450 {
 451         int p;
 452
 453         if (!qdio)
 454                 return;
 455
 456         if (qdio->adapter->ccw_device)
 457                 qdio_free(qdio->adapter->ccw_device);
 458
 459         for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
 460                 free_page((unsigned long) qdio->req_q[p]);
 461                 free_page((unsigned long) qdio->res_q[p]);
 462         }
 463
 464         kfree(qdio);
 465 }
 466
 467 int zfcp_qdio_setup(struct zfcp_adapter *adapter)
 468 {
 469         struct zfcp_qdio *qdio;
 470
 471         qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
 472         if (!qdio)
 473                 return -ENOMEM;
 474
 475         qdio->adapter = adapter;
 476
 477         if (zfcp_qdio_allocate(qdio)) {
 478                 zfcp_qdio_destroy(qdio);
 479                 return -ENOMEM;
 480         }
 481
 482         spin_lock_init(&qdio->req_q_lock);
 483         spin_lock_init(&qdio->stat_lock);
 484
 485         adapter->qdio = qdio;
 486         return 0;
 487 }
 488
 489 /**
 490  * zfcp_qdio_siosl - Trigger logging in FCP channel
 491  * @adapter: The zfcp_adapter where to trigger logging
 492  *
 493  * Call the cio siosl function to trigger hardware logging.  This
 494  * wrapper function sets a flag to ensure hardware logging is only
 495  * triggered once before going through qdio shutdown.
 496  *
 497  * The triggers are always run from qdio tasklet context, so no
 498  * additional synchronization is necessary.
 499  */
 500 void zfcp_qdio_siosl(struct zfcp_adapter *adapter)
 501 {
 502         int rc;
 503
 504         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED)
 505                 return;
 506
 507         rc = ccw_device_siosl(adapter->ccw_device);
 508         if (!rc)
 509                 atomic_set_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
 510                                 &adapter->status);
 511 }