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, 2010
   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                                     unsigned int qdio_err)
  35 {
  36         struct zfcp_adapter *adapter = qdio->adapter;
  37
  38         dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
  39
  40         if (qdio_err & QDIO_ERROR_SLSB_STATE)
  41                 zfcp_qdio_siosl(adapter);
  42         zfcp_erp_adapter_reopen(adapter,
  43                                 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
  44                                 ZFCP_STATUS_COMMON_ERP_FAILED, id);
  45 }
  46
  47 static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
  48 {
  49         int i, sbal_idx;
  50
  51         for (i = first; i < first + cnt; i++) {
  52                 sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
  53                 memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
  54         }
  55 }
  56
  57 /* this needs to be called prior to updating the queue fill level */
  58 static inline void zfcp_qdio_account(struct zfcp_qdio *qdio)
  59 {
  60         unsigned long long now, span;
  61         int used;
  62
  63         now = get_clock_monotonic();
  64         span = (now - qdio->req_q_time) >> 12;
  65         used = QDIO_MAX_BUFFERS_PER_Q - atomic_read(&qdio->req_q_free);
  66         qdio->req_q_util += used * span;
  67         qdio->req_q_time = now;
  68 }
  69
  70 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
  71                               int queue_no, int idx, int count,
  72                               unsigned long parm)
  73 {
  74         struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
  75
  76         if (unlikely(qdio_err)) {
  77                 zfcp_qdio_handler_error(qdio, "qdireq1", qdio_err);
  78                 return;
  79         }
  80
  81         /* cleanup all SBALs being program-owned now */
  82         zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
  83
  84         spin_lock_irq(&qdio->stat_lock);
  85         zfcp_qdio_account(qdio);
  86         spin_unlock_irq(&qdio->stat_lock);
  87         atomic_add(count, &qdio->req_q_free);
  88         wake_up(&qdio->req_q_wq);
  89 }
  90
  91 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
  92                                int queue_no, int idx, int count,
  93                                unsigned long parm)
  94 {
  95         struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
  96         int sbal_idx, sbal_no;
  97
  98         if (unlikely(qdio_err)) {
  99                 zfcp_qdio_handler_error(qdio, "qdires1", qdio_err);
 100                 return;
 101         }
 102
 103         /*
 104          * go through all SBALs from input queue currently
 105          * returned by QDIO layer
 106          */
 107         for (sbal_no = 0; sbal_no < count; sbal_no++) {
 108                 sbal_idx = (idx + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
 109                 /* go through all SBALEs of SBAL */
 110                 zfcp_fsf_reqid_check(qdio, sbal_idx);
 111         }
 112
 113         /*
 114          * put SBALs back to response queue
 115          */
 116         if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, idx, count))
 117                 zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdires2");
 118 }
 119
 120 static struct qdio_buffer_element *
 121 zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 122 {
 123         struct qdio_buffer_element *sbale;
 124
 125         /* set last entry flag in current SBALE of current SBAL */
 126         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 127         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 128
 129         /* don't exceed last allowed SBAL */
 130         if (q_req->sbal_last == q_req->sbal_limit)
 131                 return NULL;
 132
 133         /* set chaining flag in first SBALE of current SBAL */
 134         sbale = zfcp_qdio_sbale_req(qdio, q_req);
 135         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 136
 137         /* calculate index of next SBAL */
 138         q_req->sbal_last++;
 139         q_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 140
 141         /* keep this requests number of SBALs up-to-date */
 142         q_req->sbal_number++;
 143         BUG_ON(q_req->sbal_number > ZFCP_QDIO_MAX_SBALS_PER_REQ);
 144
 145         /* start at first SBALE of new SBAL */
 146         q_req->sbale_curr = 0;
 147
 148         /* set storage-block type for new SBAL */
 149         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 150         sbale->flags |= q_req->sbtype;
 151
 152         return sbale;
 153 }
 154
 155 static struct qdio_buffer_element *
 156 zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 157 {
 158         if (q_req->sbale_curr == ZFCP_QDIO_LAST_SBALE_PER_SBAL)
 159                 return zfcp_qdio_sbal_chain(qdio, q_req);
 160         q_req->sbale_curr++;
 161         return zfcp_qdio_sbale_curr(qdio, q_req);
 162 }
 163
 164 /**
 165  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 166  * @qdio: pointer to struct zfcp_qdio
 167  * @q_req: pointer to struct zfcp_qdio_req
 168  * @sg: scatter-gather list
 169  * @max_sbals: upper bound for number of SBALs to be used
 170  * Returns: number of bytes, or error (negativ)
 171  */
 172 int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 173                             struct scatterlist *sg)
 174 {
 175         struct qdio_buffer_element *sbale;
 176         int bytes = 0;
 177
 178         /* set storage-block type for this request */
 179         sbale = zfcp_qdio_sbale_req(qdio, q_req);
 180         sbale->flags |= q_req->sbtype;
 181
 182         for (; sg; sg = sg_next(sg)) {
 183                 sbale = zfcp_qdio_sbale_next(qdio, q_req);
 184                 if (!sbale) {
 185                         atomic_inc(&qdio->req_q_full);
 186                         zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
 187                                              q_req->sbal_number);
 188                         return -EINVAL;
 189                 }
 190
 191                 sbale->addr = sg_virt(sg);
 192                 sbale->length = sg->length;
 193
 194                 bytes += sg->length;
 195         }
 196
 197         return bytes;
 198 }
 199
 200 static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
 201 {
 202         spin_lock_irq(&qdio->req_q_lock);
 203         if (atomic_read(&qdio->req_q_free) ||
 204             !(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 205                 return 1;
 206         spin_unlock_irq(&qdio->req_q_lock);
 207         return 0;
 208 }
 209
 210 /**
 211  * zfcp_qdio_sbal_get - get free sbal in request queue, wait if necessary
 212  * @qdio: pointer to struct zfcp_qdio
 213  *
 214  * The req_q_lock must be held by the caller of this function, and
 215  * this function may only be called from process context; it will
 216  * sleep when waiting for a free sbal.
 217  *
 218  * Returns: 0 on success, -EIO if there is no free sbal after waiting.
 219  */
 220 int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
 221 {
 222         long ret;
 223
 224         spin_unlock_irq(&qdio->req_q_lock);
 225         ret = wait_event_interruptible_timeout(qdio->req_q_wq,
 226                                zfcp_qdio_sbal_check(qdio), 5 * HZ);
 227
 228         if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 229                 return -EIO;
 230
 231         if (ret > 0)
 232                 return 0;
 233
 234         if (!ret) {
 235                 atomic_inc(&qdio->req_q_full);
 236                 /* assume hanging outbound queue, try queue recovery */
 237                 zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdsbg_1");
 238         }
 239
 240         spin_lock_irq(&qdio->req_q_lock);
 241         return -EIO;
 242 }
 243
 244 /**
 245  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 246  * @qdio: pointer to struct zfcp_qdio
 247  * @q_req: pointer to struct zfcp_qdio_req
 248  * Returns: 0 on success, error otherwise
 249  */
 250 int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 251 {
 252         int retval;
 253         u8 sbal_number = q_req->sbal_number;
 254
 255         spin_lock(&qdio->stat_lock);
 256         zfcp_qdio_account(qdio);
 257         spin_unlock(&qdio->stat_lock);
 258
 259         retval = do_QDIO(qdio->adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0,
 260                          q_req->sbal_first, sbal_number);
 261
 262         if (unlikely(retval)) {
 263                 zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
 264                                      sbal_number);
 265                 return retval;
 266         }
 267
 268         /* account for transferred buffers */
 269         atomic_sub(sbal_number, &qdio->req_q_free);
 270         qdio->req_q_idx += sbal_number;
 271         qdio->req_q_idx %= QDIO_MAX_BUFFERS_PER_Q;
 272
 273         return 0;
 274 }
 275
 276
 277 static void zfcp_qdio_setup_init_data(struct qdio_initialize *id,
 278                                       struct zfcp_qdio *qdio)
 279 {
 280         memset(id, 0, sizeof(*id));
 281         id->cdev = qdio->adapter->ccw_device;
 282         id->q_format = QDIO_ZFCP_QFMT;
 283         memcpy(id->adapter_name, dev_name(&id->cdev->dev), 8);
 284         ASCEBC(id->adapter_name, 8);
 285         id->qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV;
 286         id->no_input_qs = 1;
 287         id->no_output_qs = 1;
 288         id->input_handler = zfcp_qdio_int_resp;
 289         id->output_handler = zfcp_qdio_int_req;
 290         id->int_parm = (unsigned long) qdio;
 291         id->input_sbal_addr_array = (void **) (qdio->res_q);
 292         id->output_sbal_addr_array = (void **) (qdio->req_q);
 293         id->scan_threshold =
 294                 QDIO_MAX_BUFFERS_PER_Q - ZFCP_QDIO_MAX_SBALS_PER_REQ * 2;
 295 }
 296
 297 /**
 298  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 299  * @adapter: pointer to struct zfcp_adapter
 300  * Returns: -ENOMEM on memory allocation error or return value from
 301  *          qdio_allocate
 302  */
 303 static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
 304 {
 305         struct qdio_initialize init_data;
 306
 307         if (zfcp_qdio_buffers_enqueue(qdio->req_q) ||
 308             zfcp_qdio_buffers_enqueue(qdio->res_q))
 309                 return -ENOMEM;
 310
 311         zfcp_qdio_setup_init_data(&init_data, qdio);
 312         init_waitqueue_head(&qdio->req_q_wq);
 313
 314         return qdio_allocate(&init_data);
 315 }
 316
 317 /**
 318  * zfcp_close_qdio - close qdio queues for an adapter
 319  * @qdio: pointer to structure zfcp_qdio
 320  */
 321 void zfcp_qdio_close(struct zfcp_qdio *qdio)
 322 {
 323         struct zfcp_adapter *adapter = qdio->adapter;
 324         int idx, count;
 325
 326         if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
 327                 return;
 328
 329         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
 330         spin_lock_irq(&qdio->req_q_lock);
 331         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
 332         spin_unlock_irq(&qdio->req_q_lock);
 333
 334         wake_up(&qdio->req_q_wq);
 335
 336         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
 337
 338         /* cleanup used outbound sbals */
 339         count = atomic_read(&qdio->req_q_free);
 340         if (count < QDIO_MAX_BUFFERS_PER_Q) {
 341                 idx = (qdio->req_q_idx + count) % QDIO_MAX_BUFFERS_PER_Q;
 342                 count = QDIO_MAX_BUFFERS_PER_Q - count;
 343                 zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
 344         }
 345         qdio->req_q_idx = 0;
 346         atomic_set(&qdio->req_q_free, 0);
 347 }
 348
 349 /**
 350  * zfcp_qdio_open - prepare and initialize response queue
 351  * @qdio: pointer to struct zfcp_qdio
 352  * Returns: 0 on success, otherwise -EIO
 353  */
 354 int zfcp_qdio_open(struct zfcp_qdio *qdio)
 355 {
 356         struct qdio_buffer_element *sbale;
 357         struct qdio_initialize init_data;
 358         struct zfcp_adapter *adapter = qdio->adapter;
 359         struct ccw_device *cdev = adapter->ccw_device;
 360         struct qdio_ssqd_desc ssqd;
 361         int cc;
 362
 363         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
 364                 return -EIO;
 365
 366         atomic_clear_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
 367                           &qdio->adapter->status);
 368
 369         zfcp_qdio_setup_init_data(&init_data, qdio);
 370
 371         if (qdio_establish(&init_data))
 372                 goto failed_establish;
 373
 374         if (qdio_get_ssqd_desc(init_data.cdev, &ssqd))
 375                 goto failed_qdio;
 376
 377         if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED)
 378                 atomic_set_mask(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED,
 379                                 &qdio->adapter->status);
 380
 381         if (qdio_activate(cdev))
 382                 goto failed_qdio;
 383
 384         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
 385                 sbale = &(qdio->res_q[cc]->element[0]);
 386                 sbale->length = 0;
 387                 sbale->flags = SBAL_FLAGS_LAST_ENTRY;
 388                 sbale->addr = NULL;
 389         }
 390
 391         if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0, QDIO_MAX_BUFFERS_PER_Q))
 392                 goto failed_qdio;
 393
 394         /* set index of first avalable SBALS / number of available SBALS */
 395         qdio->req_q_idx = 0;
 396         atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
 397         atomic_set_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
 398
 399         return 0;
 400
 401 failed_qdio:
 402         qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
 403 failed_establish:
 404         dev_err(&cdev->dev,
 405                 "Setting up the QDIO connection to the FCP adapter failed\n");
 406         return -EIO;
 407 }
 408
 409 void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
 410 {
 411         int p;
 412
 413         if (!qdio)
 414                 return;
 415
 416         if (qdio->adapter->ccw_device)
 417                 qdio_free(qdio->adapter->ccw_device);
 418
 419         for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
 420                 free_page((unsigned long) qdio->req_q[p]);
 421                 free_page((unsigned long) qdio->res_q[p]);
 422         }
 423
 424         kfree(qdio);
 425 }
 426
 427 int zfcp_qdio_setup(struct zfcp_adapter *adapter)
 428 {
 429         struct zfcp_qdio *qdio;
 430
 431         qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
 432         if (!qdio)
 433                 return -ENOMEM;
 434
 435         qdio->adapter = adapter;
 436
 437         if (zfcp_qdio_allocate(qdio)) {
 438                 zfcp_qdio_destroy(qdio);
 439                 return -ENOMEM;
 440         }
 441
 442         spin_lock_init(&qdio->req_q_lock);
 443         spin_lock_init(&qdio->stat_lock);
 444
 445         adapter->qdio = qdio;
 446         return 0;
 447 }
 448
 449 /**
 450  * zfcp_qdio_siosl - Trigger logging in FCP channel
 451  * @adapter: The zfcp_adapter where to trigger logging
 452  *
 453  * Call the cio siosl function to trigger hardware logging.  This
 454  * wrapper function sets a flag to ensure hardware logging is only
 455  * triggered once before going through qdio shutdown.
 456  *
 457  * The triggers are always run from qdio tasklet context, so no
 458  * additional synchronization is necessary.
 459  */
 460 void zfcp_qdio_siosl(struct zfcp_adapter *adapter)
 461 {
 462         int rc;
 463
 464         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED)
 465                 return;
 466
 467         rc = ccw_device_siosl(adapter->ccw_device);
 468         if (!rc)
 469                 atomic_set_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
 470                                 &adapter->status);
 471 }