drivers/infiniband/hw/qib/qib_sdma.c

   1 /*
   2  * Copyright (c) 2007, 2008, 2009, 2010 QLogic Corporation. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #include <linux/spinlock.h>
  34 #include <linux/netdevice.h>
  35
  36 #include "qib.h"
  37 #include "qib_common.h"
  38
  39 /* default pio off, sdma on */
  40 static ushort sdma_descq_cnt = 256;
  41 module_param_named(sdma_descq_cnt, sdma_descq_cnt, ushort, S_IRUGO);
  42 MODULE_PARM_DESC(sdma_descq_cnt, "Number of SDMA descq entries");
  43
  44 /*
  45  * Bits defined in the send DMA descriptor.
  46  */
  47 #define SDMA_DESC_LAST          (1ULL << 11)
  48 #define SDMA_DESC_FIRST         (1ULL << 12)
  49 #define SDMA_DESC_DMA_HEAD      (1ULL << 13)
  50 #define SDMA_DESC_USE_LARGE_BUF (1ULL << 14)
  51 #define SDMA_DESC_INTR          (1ULL << 15)
  52 #define SDMA_DESC_COUNT_LSB     16
  53 #define SDMA_DESC_GEN_LSB       30
  54
  55 char *qib_sdma_state_names[] = {
  56         [qib_sdma_state_s00_hw_down]          = "s00_HwDown",
  57         [qib_sdma_state_s10_hw_start_up_wait] = "s10_HwStartUpWait",
  58         [qib_sdma_state_s20_idle]             = "s20_Idle",
  59         [qib_sdma_state_s30_sw_clean_up_wait] = "s30_SwCleanUpWait",
  60         [qib_sdma_state_s40_hw_clean_up_wait] = "s40_HwCleanUpWait",
  61         [qib_sdma_state_s50_hw_halt_wait]     = "s50_HwHaltWait",
  62         [qib_sdma_state_s99_running]          = "s99_Running",
  63 };
  64
  65 char *qib_sdma_event_names[] = {
  66         [qib_sdma_event_e00_go_hw_down]   = "e00_GoHwDown",
  67         [qib_sdma_event_e10_go_hw_start]  = "e10_GoHwStart",
  68         [qib_sdma_event_e20_hw_started]   = "e20_HwStarted",
  69         [qib_sdma_event_e30_go_running]   = "e30_GoRunning",
  70         [qib_sdma_event_e40_sw_cleaned]   = "e40_SwCleaned",
  71         [qib_sdma_event_e50_hw_cleaned]   = "e50_HwCleaned",
  72         [qib_sdma_event_e60_hw_halted]    = "e60_HwHalted",
  73         [qib_sdma_event_e70_go_idle]      = "e70_GoIdle",
  74         [qib_sdma_event_e7220_err_halted] = "e7220_ErrHalted",
  75         [qib_sdma_event_e7322_err_halted] = "e7322_ErrHalted",
  76         [qib_sdma_event_e90_timer_tick]   = "e90_TimerTick",
  77 };
  78
  79 /* declare all statics here rather than keep sorting */
  80 static int alloc_sdma(struct qib_pportdata *);
  81 static void sdma_complete(struct kref *);
  82 static void sdma_finalput(struct qib_sdma_state *);
  83 static void sdma_get(struct qib_sdma_state *);
  84 static void sdma_put(struct qib_sdma_state *);
  85 static void sdma_set_state(struct qib_pportdata *, enum qib_sdma_states);
  86 static void sdma_start_sw_clean_up(struct qib_pportdata *);
  87 static void sdma_sw_clean_up_task(unsigned long);
  88 static void unmap_desc(struct qib_pportdata *, unsigned);
  89
  90 static void sdma_get(struct qib_sdma_state *ss)
  91 {
  92         kref_get(&ss->kref);
  93 }
  94
  95 static void sdma_complete(struct kref *kref)
  96 {
  97         struct qib_sdma_state *ss =
  98                 container_of(kref, struct qib_sdma_state, kref);
  99
 100         complete(&ss->comp);
 101 }
 102
 103 static void sdma_put(struct qib_sdma_state *ss)
 104 {
 105         kref_put(&ss->kref, sdma_complete);
 106 }
 107
 108 static void sdma_finalput(struct qib_sdma_state *ss)
 109 {
 110         sdma_put(ss);
 111         wait_for_completion(&ss->comp);
 112 }
 113
 114 /*
 115  * Complete all the sdma requests on the active list, in the correct
 116  * order, and with appropriate processing.   Called when cleaning up
 117  * after sdma shutdown, and when new sdma requests are submitted for
 118  * a link that is down.   This matches what is done for requests
 119  * that complete normally, it's just the full list.
 120  *
 121  * Must be called with sdma_lock held
 122  */
 123 static void clear_sdma_activelist(struct qib_pportdata *ppd)
 124 {
 125         struct qib_sdma_txreq *txp, *txp_next;
 126
 127         list_for_each_entry_safe(txp, txp_next, &ppd->sdma_activelist, list) {
 128                 list_del_init(&txp->list);
 129                 if (txp->flags & QIB_SDMA_TXREQ_F_FREEDESC) {
 130                         unsigned idx;
 131
 132                         idx = txp->start_idx;
 133                         while (idx != txp->next_descq_idx) {
 134                                 unmap_desc(ppd, idx);
 135                                 if (++idx == ppd->sdma_descq_cnt)
 136                                         idx = 0;
 137                         }
 138                 }
 139                 if (txp->callback)
 140                         (*txp->callback)(txp, QIB_SDMA_TXREQ_S_ABORTED);
 141         }
 142 }
 143
 144 static void sdma_sw_clean_up_task(unsigned long opaque)
 145 {
 146         struct qib_pportdata *ppd = (struct qib_pportdata *) opaque;
 147         unsigned long flags;
 148
 149         spin_lock_irqsave(&ppd->sdma_lock, flags);
 150
 151         /*
 152          * At this point, the following should always be true:
 153          * - We are halted, so no more descriptors are getting retired.
 154          * - We are not running, so no one is submitting new work.
 155          * - Only we can send the e40_sw_cleaned, so we can't start
 156          *   running again until we say so.  So, the active list and
 157          *   descq are ours to play with.
 158          */
 159
 160         /* Process all retired requests. */
 161         qib_sdma_make_progress(ppd);
 162
 163         clear_sdma_activelist(ppd);
 164
 165         /*
 166          * Resync count of added and removed.  It is VERY important that
 167          * sdma_descq_removed NEVER decrement - user_sdma depends on it.
 168          */
 169         ppd->sdma_descq_removed = ppd->sdma_descq_added;
 170
 171         /*
 172          * Reset our notion of head and tail.
 173          * Note that the HW registers will be reset when switching states
 174          * due to calling __qib_sdma_process_event() below.
 175          */
 176         ppd->sdma_descq_tail = 0;
 177         ppd->sdma_descq_head = 0;
 178         ppd->sdma_head_dma[0] = 0;
 179         ppd->sdma_generation = 0;
 180
 181         __qib_sdma_process_event(ppd, qib_sdma_event_e40_sw_cleaned);
 182
 183         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 184 }
 185
 186 /*
 187  * This is called when changing to state qib_sdma_state_s10_hw_start_up_wait
 188  * as a result of send buffer errors or send DMA descriptor errors.
 189  * We want to disarm the buffers in these cases.
 190  */
 191 static void sdma_hw_start_up(struct qib_pportdata *ppd)
 192 {
 193         struct qib_sdma_state *ss = &ppd->sdma_state;
 194         unsigned bufno;
 195
 196         for (bufno = ss->first_sendbuf; bufno < ss->last_sendbuf; ++bufno)
 197                 ppd->dd->f_sendctrl(ppd, QIB_SENDCTRL_DISARM_BUF(bufno));
 198
 199         ppd->dd->f_sdma_hw_start_up(ppd);
 200 }
 201
 202 static void sdma_sw_tear_down(struct qib_pportdata *ppd)
 203 {
 204         struct qib_sdma_state *ss = &ppd->sdma_state;
 205
 206         /* Releasing this reference means the state machine has stopped. */
 207         sdma_put(ss);
 208 }
 209
 210 static void sdma_start_sw_clean_up(struct qib_pportdata *ppd)
 211 {
 212         tasklet_hi_schedule(&ppd->sdma_sw_clean_up_task);
 213 }
 214
 215 static void sdma_set_state(struct qib_pportdata *ppd,
 216         enum qib_sdma_states next_state)
 217 {
 218         struct qib_sdma_state *ss = &ppd->sdma_state;
 219         struct sdma_set_state_action *action = ss->set_state_action;
 220         unsigned op = 0;
 221
 222         /* debugging bookkeeping */
 223         ss->previous_state = ss->current_state;
 224         ss->previous_op = ss->current_op;
 225
 226         ss->current_state = next_state;
 227
 228         if (action[next_state].op_enable)
 229                 op |= QIB_SDMA_SENDCTRL_OP_ENABLE;
 230
 231         if (action[next_state].op_intenable)
 232                 op |= QIB_SDMA_SENDCTRL_OP_INTENABLE;
 233
 234         if (action[next_state].op_halt)
 235                 op |= QIB_SDMA_SENDCTRL_OP_HALT;
 236
 237         if (action[next_state].op_drain)
 238                 op |= QIB_SDMA_SENDCTRL_OP_DRAIN;
 239
 240         if (action[next_state].go_s99_running_tofalse)
 241                 ss->go_s99_running = 0;
 242
 243         if (action[next_state].go_s99_running_totrue)
 244                 ss->go_s99_running = 1;
 245
 246         ss->current_op = op;
 247
 248         ppd->dd->f_sdma_sendctrl(ppd, ss->current_op);
 249 }
 250
 251 static void unmap_desc(struct qib_pportdata *ppd, unsigned head)
 252 {
 253         __le64 *descqp = &ppd->sdma_descq[head].qw[0];
 254         u64 desc[2];
 255         dma_addr_t addr;
 256         size_t len;
 257
 258         desc[0] = le64_to_cpu(descqp[0]);
 259         desc[1] = le64_to_cpu(descqp[1]);
 260
 261         addr = (desc[1] << 32) | (desc[0] >> 32);
 262         len = (desc[0] >> 14) & (0x7ffULL << 2);
 263         dma_unmap_single(&ppd->dd->pcidev->dev, addr, len, DMA_TO_DEVICE);
 264 }
 265
 266 static int alloc_sdma(struct qib_pportdata *ppd)
 267 {
 268         ppd->sdma_descq_cnt = sdma_descq_cnt;
 269         if (!ppd->sdma_descq_cnt)
 270                 ppd->sdma_descq_cnt = 256;
 271
 272         /* Allocate memory for SendDMA descriptor FIFO */
 273         ppd->sdma_descq = dma_alloc_coherent(&ppd->dd->pcidev->dev,
 274                 ppd->sdma_descq_cnt * sizeof(u64[2]), &ppd->sdma_descq_phys,
 275                 GFP_KERNEL);
 276
 277         if (!ppd->sdma_descq) {
 278                 qib_dev_err(ppd->dd, "failed to allocate SendDMA descriptor "
 279                             "FIFO memory\n");
 280                 goto bail;
 281         }
 282
 283         /* Allocate memory for DMA of head register to memory */
 284         ppd->sdma_head_dma = dma_alloc_coherent(&ppd->dd->pcidev->dev,
 285                 PAGE_SIZE, &ppd->sdma_head_phys, GFP_KERNEL);
 286         if (!ppd->sdma_head_dma) {
 287                 qib_dev_err(ppd->dd, "failed to allocate SendDMA "
 288                             "head memory\n");
 289                 goto cleanup_descq;
 290         }
 291         ppd->sdma_head_dma[0] = 0;
 292         return 0;
 293
 294 cleanup_descq:
 295         dma_free_coherent(&ppd->dd->pcidev->dev,
 296                 ppd->sdma_descq_cnt * sizeof(u64[2]), (void *)ppd->sdma_descq,
 297                 ppd->sdma_descq_phys);
 298         ppd->sdma_descq = NULL;
 299         ppd->sdma_descq_phys = 0;
 300 bail:
 301         ppd->sdma_descq_cnt = 0;
 302         return -ENOMEM;
 303 }
 304
 305 static void free_sdma(struct qib_pportdata *ppd)
 306 {
 307         struct qib_devdata *dd = ppd->dd;
 308
 309         if (ppd->sdma_head_dma) {
 310                 dma_free_coherent(&dd->pcidev->dev, PAGE_SIZE,
 311                                   (void *)ppd->sdma_head_dma,
 312                                   ppd->sdma_head_phys);
 313                 ppd->sdma_head_dma = NULL;
 314                 ppd->sdma_head_phys = 0;
 315         }
 316
 317         if (ppd->sdma_descq) {
 318                 dma_free_coherent(&dd->pcidev->dev,
 319                                   ppd->sdma_descq_cnt * sizeof(u64[2]),
 320                                   ppd->sdma_descq, ppd->sdma_descq_phys);
 321                 ppd->sdma_descq = NULL;
 322                 ppd->sdma_descq_phys = 0;
 323         }
 324 }
 325
 326 static inline void make_sdma_desc(struct qib_pportdata *ppd,
 327                                   u64 *sdmadesc, u64 addr, u64 dwlen,
 328                                   u64 dwoffset)
 329 {
 330
 331         WARN_ON(addr & 3);
 332         /* SDmaPhyAddr[47:32] */
 333         sdmadesc[1] = addr >> 32;
 334         /* SDmaPhyAddr[31:0] */
 335         sdmadesc[0] = (addr & 0xfffffffcULL) << 32;
 336         /* SDmaGeneration[1:0] */
 337         sdmadesc[0] |= (ppd->sdma_generation & 3ULL) <<
 338                 SDMA_DESC_GEN_LSB;
 339         /* SDmaDwordCount[10:0] */
 340         sdmadesc[0] |= (dwlen & 0x7ffULL) << SDMA_DESC_COUNT_LSB;
 341         /* SDmaBufOffset[12:2] */
 342         sdmadesc[0] |= dwoffset & 0x7ffULL;
 343 }
 344
 345 /* sdma_lock must be held */
 346 int qib_sdma_make_progress(struct qib_pportdata *ppd)
 347 {
 348         struct list_head *lp = NULL;
 349         struct qib_sdma_txreq *txp = NULL;
 350         struct qib_devdata *dd = ppd->dd;
 351         int progress = 0;
 352         u16 hwhead;
 353         u16 idx = 0;
 354
 355         hwhead = dd->f_sdma_gethead(ppd);
 356
 357         /* The reason for some of the complexity of this code is that
 358          * not all descriptors have corresponding txps.  So, we have to
 359          * be able to skip over descs until we wander into the range of
 360          * the next txp on the list.
 361          */
 362
 363         if (!list_empty(&ppd->sdma_activelist)) {
 364                 lp = ppd->sdma_activelist.next;
 365                 txp = list_entry(lp, struct qib_sdma_txreq, list);
 366                 idx = txp->start_idx;
 367         }
 368
 369         while (ppd->sdma_descq_head != hwhead) {
 370                 /* if desc is part of this txp, unmap if needed */
 371                 if (txp && (txp->flags & QIB_SDMA_TXREQ_F_FREEDESC) &&
 372                     (idx == ppd->sdma_descq_head)) {
 373                         unmap_desc(ppd, ppd->sdma_descq_head);
 374                         if (++idx == ppd->sdma_descq_cnt)
 375                                 idx = 0;
 376                 }
 377
 378                 /* increment dequed desc count */
 379                 ppd->sdma_descq_removed++;
 380
 381                 /* advance head, wrap if needed */
 382                 if (++ppd->sdma_descq_head == ppd->sdma_descq_cnt)
 383                         ppd->sdma_descq_head = 0;
 384
 385                 /* if now past this txp's descs, do the callback */
 386                 if (txp && txp->next_descq_idx == ppd->sdma_descq_head) {
 387                         /* remove from active list */
 388                         list_del_init(&txp->list);
 389                         if (txp->callback)
 390                                 (*txp->callback)(txp, QIB_SDMA_TXREQ_S_OK);
 391                         /* see if there is another txp */
 392                         if (list_empty(&ppd->sdma_activelist))
 393                                 txp = NULL;
 394                         else {
 395                                 lp = ppd->sdma_activelist.next;
 396                                 txp = list_entry(lp, struct qib_sdma_txreq,
 397                                         list);
 398                                 idx = txp->start_idx;
 399                         }
 400                 }
 401                 progress = 1;
 402         }
 403         if (progress)
 404                 qib_verbs_sdma_desc_avail(ppd, qib_sdma_descq_freecnt(ppd));
 405         return progress;
 406 }
 407
 408 /*
 409  * This is called from interrupt context.
 410  */
 411 void qib_sdma_intr(struct qib_pportdata *ppd)
 412 {
 413         unsigned long flags;
 414
 415         spin_lock_irqsave(&ppd->sdma_lock, flags);
 416
 417         __qib_sdma_intr(ppd);
 418
 419         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 420 }
 421
 422 void __qib_sdma_intr(struct qib_pportdata *ppd)
 423 {
 424         if (__qib_sdma_running(ppd))
 425                 qib_sdma_make_progress(ppd);
 426 }
 427
 428 int qib_setup_sdma(struct qib_pportdata *ppd)
 429 {
 430         struct qib_devdata *dd = ppd->dd;
 431         unsigned long flags;
 432         int ret = 0;
 433
 434         ret = alloc_sdma(ppd);
 435         if (ret)
 436                 goto bail;
 437
 438         /* set consistent sdma state */
 439         ppd->dd->f_sdma_init_early(ppd);
 440         spin_lock_irqsave(&ppd->sdma_lock, flags);
 441         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
 442         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 443
 444         /* set up reference counting */
 445         kref_init(&ppd->sdma_state.kref);
 446         init_completion(&ppd->sdma_state.comp);
 447
 448         ppd->sdma_generation = 0;
 449         ppd->sdma_descq_head = 0;
 450         ppd->sdma_descq_removed = 0;
 451         ppd->sdma_descq_added = 0;
 452
 453         INIT_LIST_HEAD(&ppd->sdma_activelist);
 454
 455         tasklet_init(&ppd->sdma_sw_clean_up_task, sdma_sw_clean_up_task,
 456                 (unsigned long)ppd);
 457
 458         ret = dd->f_init_sdma_regs(ppd);
 459         if (ret)
 460                 goto bail_alloc;
 461
 462         qib_sdma_process_event(ppd, qib_sdma_event_e10_go_hw_start);
 463
 464         return 0;
 465
 466 bail_alloc:
 467         qib_teardown_sdma(ppd);
 468 bail:
 469         return ret;
 470 }
 471
 472 void qib_teardown_sdma(struct qib_pportdata *ppd)
 473 {
 474         qib_sdma_process_event(ppd, qib_sdma_event_e00_go_hw_down);
 475
 476         /*
 477          * This waits for the state machine to exit so it is not
 478          * necessary to kill the sdma_sw_clean_up_task to make sure
 479          * it is not running.
 480          */
 481         sdma_finalput(&ppd->sdma_state);
 482
 483         free_sdma(ppd);
 484 }
 485
 486 int qib_sdma_running(struct qib_pportdata *ppd)
 487 {
 488         unsigned long flags;
 489         int ret;
 490
 491         spin_lock_irqsave(&ppd->sdma_lock, flags);
 492         ret = __qib_sdma_running(ppd);
 493         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 494
 495         return ret;
 496 }
 497
 498 /*
 499  * Complete a request when sdma not running; likely only request
 500  * but to simplify the code, always queue it, then process the full
 501  * activelist.  We process the entire list to ensure that this particular
 502  * request does get it's callback, but in the correct order.
 503  * Must be called with sdma_lock held
 504  */
 505 static void complete_sdma_err_req(struct qib_pportdata *ppd,
 506                                   struct qib_verbs_txreq *tx)
 507 {
 508         atomic_inc(&tx->qp->s_dma_busy);
 509         /* no sdma descriptors, so no unmap_desc */
 510         tx->txreq.start_idx = 0;
 511         tx->txreq.next_descq_idx = 0;
 512         list_add_tail(&tx->txreq.list, &ppd->sdma_activelist);
 513         clear_sdma_activelist(ppd);
 514 }
 515
 516 /*
 517  * This function queues one IB packet onto the send DMA queue per call.
 518  * The caller is responsible for checking:
 519  * 1) The number of send DMA descriptor entries is less than the size of
 520  *    the descriptor queue.
 521  * 2) The IB SGE addresses and lengths are 32-bit aligned
 522  *    (except possibly the last SGE's length)
 523  * 3) The SGE addresses are suitable for passing to dma_map_single().
 524  */
 525 int qib_sdma_verbs_send(struct qib_pportdata *ppd,
 526                         struct qib_sge_state *ss, u32 dwords,
 527                         struct qib_verbs_txreq *tx)
 528 {
 529         unsigned long flags;
 530         struct qib_sge *sge;
 531         struct qib_qp *qp;
 532         int ret = 0;
 533         u16 tail;
 534         __le64 *descqp;
 535         u64 sdmadesc[2];
 536         u32 dwoffset;
 537         dma_addr_t addr;
 538
 539         spin_lock_irqsave(&ppd->sdma_lock, flags);
 540
 541 retry:
 542         if (unlikely(!__qib_sdma_running(ppd))) {
 543                 complete_sdma_err_req(ppd, tx);
 544                 goto unlock;
 545         }
 546
 547         if (tx->txreq.sg_count > qib_sdma_descq_freecnt(ppd)) {
 548                 if (qib_sdma_make_progress(ppd))
 549                         goto retry;
 550                 if (ppd->dd->flags & QIB_HAS_SDMA_TIMEOUT)
 551                         ppd->dd->f_sdma_set_desc_cnt(ppd,
 552                                         ppd->sdma_descq_cnt / 2);
 553                 goto busy;
 554         }
 555
 556         dwoffset = tx->hdr_dwords;
 557         make_sdma_desc(ppd, sdmadesc, (u64) tx->txreq.addr, dwoffset, 0);
 558
 559         sdmadesc[0] |= SDMA_DESC_FIRST;
 560         if (tx->txreq.flags & QIB_SDMA_TXREQ_F_USELARGEBUF)
 561                 sdmadesc[0] |= SDMA_DESC_USE_LARGE_BUF;
 562
 563         /* write to the descq */
 564         tail = ppd->sdma_descq_tail;
 565         descqp = &ppd->sdma_descq[tail].qw[0];
 566         *descqp++ = cpu_to_le64(sdmadesc[0]);
 567         *descqp++ = cpu_to_le64(sdmadesc[1]);
 568
 569         /* increment the tail */
 570         if (++tail == ppd->sdma_descq_cnt) {
 571                 tail = 0;
 572                 descqp = &ppd->sdma_descq[0].qw[0];
 573                 ++ppd->sdma_generation;
 574         }
 575
 576         tx->txreq.start_idx = tail;
 577
 578         sge = &ss->sge;
 579         while (dwords) {
 580                 u32 dw;
 581                 u32 len;
 582
 583                 len = dwords << 2;
 584                 if (len > sge->length)
 585                         len = sge->length;
 586                 if (len > sge->sge_length)
 587                         len = sge->sge_length;
 588                 BUG_ON(len == 0);
 589                 dw = (len + 3) >> 2;
 590                 addr = dma_map_single(&ppd->dd->pcidev->dev, sge->vaddr,
 591                                       dw << 2, DMA_TO_DEVICE);
 592                 if (dma_mapping_error(&ppd->dd->pcidev->dev, addr))
 593                         goto unmap;
 594                 sdmadesc[0] = 0;
 595                 make_sdma_desc(ppd, sdmadesc, (u64) addr, dw, dwoffset);
 596                 /* SDmaUseLargeBuf has to be set in every descriptor */
 597                 if (tx->txreq.flags & QIB_SDMA_TXREQ_F_USELARGEBUF)
 598                         sdmadesc[0] |= SDMA_DESC_USE_LARGE_BUF;
 599                 /* write to the descq */
 600                 *descqp++ = cpu_to_le64(sdmadesc[0]);
 601                 *descqp++ = cpu_to_le64(sdmadesc[1]);
 602
 603                 /* increment the tail */
 604                 if (++tail == ppd->sdma_descq_cnt) {
 605                         tail = 0;
 606                         descqp = &ppd->sdma_descq[0].qw[0];
 607                         ++ppd->sdma_generation;
 608                 }
 609                 sge->vaddr += len;
 610                 sge->length -= len;
 611                 sge->sge_length -= len;
 612                 if (sge->sge_length == 0) {
 613                         if (--ss->num_sge)
 614                                 *sge = *ss->sg_list++;
 615                 } else if (sge->length == 0 && sge->mr->lkey) {
 616                         if (++sge->n >= QIB_SEGSZ) {
 617                                 if (++sge->m >= sge->mr->mapsz)
 618                                         break;
 619                                 sge->n = 0;
 620                         }
 621                         sge->vaddr =
 622                                 sge->mr->map[sge->m]->segs[sge->n].vaddr;
 623                         sge->length =
 624                                 sge->mr->map[sge->m]->segs[sge->n].length;
 625                 }
 626
 627                 dwoffset += dw;
 628                 dwords -= dw;
 629         }
 630
 631         if (!tail)
 632                 descqp = &ppd->sdma_descq[ppd->sdma_descq_cnt].qw[0];
 633         descqp -= 2;
 634         descqp[0] |= cpu_to_le64(SDMA_DESC_LAST);
 635         if (tx->txreq.flags & QIB_SDMA_TXREQ_F_HEADTOHOST)
 636                 descqp[0] |= cpu_to_le64(SDMA_DESC_DMA_HEAD);
 637         if (tx->txreq.flags & QIB_SDMA_TXREQ_F_INTREQ)
 638                 descqp[0] |= cpu_to_le64(SDMA_DESC_INTR);
 639
 640         atomic_inc(&tx->qp->s_dma_busy);
 641         tx->txreq.next_descq_idx = tail;
 642         ppd->dd->f_sdma_update_tail(ppd, tail);
 643         ppd->sdma_descq_added += tx->txreq.sg_count;
 644         list_add_tail(&tx->txreq.list, &ppd->sdma_activelist);
 645         goto unlock;
 646
 647 unmap:
 648         for (;;) {
 649                 if (!tail)
 650                         tail = ppd->sdma_descq_cnt - 1;
 651                 else
 652                         tail--;
 653                 if (tail == ppd->sdma_descq_tail)
 654                         break;
 655                 unmap_desc(ppd, tail);
 656         }
 657         qp = tx->qp;
 658         qib_put_txreq(tx);
 659         spin_lock(&qp->s_lock);
 660         if (qp->ibqp.qp_type == IB_QPT_RC) {
 661                 /* XXX what about error sending RDMA read responses? */
 662                 if (ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)
 663                         qib_error_qp(qp, IB_WC_GENERAL_ERR);
 664         } else if (qp->s_wqe)
 665                 qib_send_complete(qp, qp->s_wqe, IB_WC_GENERAL_ERR);
 666         spin_unlock(&qp->s_lock);
 667         /* return zero to process the next send work request */
 668         goto unlock;
 669
 670 busy:
 671         qp = tx->qp;
 672         spin_lock(&qp->s_lock);
 673         if (ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK) {
 674                 struct qib_ibdev *dev;
 675
 676                 /*
 677                  * If we couldn't queue the DMA request, save the info
 678                  * and try again later rather than destroying the
 679                  * buffer and undoing the side effects of the copy.
 680                  */
 681                 tx->ss = ss;
 682                 tx->dwords = dwords;
 683                 qp->s_tx = tx;
 684                 dev = &ppd->dd->verbs_dev;
 685                 spin_lock(&dev->pending_lock);
 686                 if (list_empty(&qp->iowait)) {
 687                         struct qib_ibport *ibp;
 688
 689                         ibp = &ppd->ibport_data;
 690                         ibp->n_dmawait++;
 691                         qp->s_flags |= QIB_S_WAIT_DMA_DESC;
 692                         list_add_tail(&qp->iowait, &dev->dmawait);
 693                 }
 694                 spin_unlock(&dev->pending_lock);
 695                 qp->s_flags &= ~QIB_S_BUSY;
 696                 spin_unlock(&qp->s_lock);
 697                 ret = -EBUSY;
 698         } else {
 699                 spin_unlock(&qp->s_lock);
 700                 qib_put_txreq(tx);
 701         }
 702 unlock:
 703         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 704         return ret;
 705 }
 706
 707 void qib_sdma_process_event(struct qib_pportdata *ppd,
 708         enum qib_sdma_events event)
 709 {
 710         unsigned long flags;
 711
 712         spin_lock_irqsave(&ppd->sdma_lock, flags);
 713
 714         __qib_sdma_process_event(ppd, event);
 715
 716         if (ppd->sdma_state.current_state == qib_sdma_state_s99_running)
 717                 qib_verbs_sdma_desc_avail(ppd, qib_sdma_descq_freecnt(ppd));
 718
 719         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 720 }
 721
 722 void __qib_sdma_process_event(struct qib_pportdata *ppd,
 723         enum qib_sdma_events event)
 724 {
 725         struct qib_sdma_state *ss = &ppd->sdma_state;
 726
 727         switch (ss->current_state) {
 728         case qib_sdma_state_s00_hw_down:
 729                 switch (event) {
 730                 case qib_sdma_event_e00_go_hw_down:
 731                         break;
 732                 case qib_sdma_event_e30_go_running:
 733                         /*
 734                          * If down, but running requested (usually result
 735                          * of link up, then we need to start up.
 736                          * This can happen when hw down is requested while
 737                          * bringing the link up with traffic active on
 738                          * 7220, e.g. */
 739                         ss->go_s99_running = 1;
 740                         /* fall through and start dma engine */
 741                 case qib_sdma_event_e10_go_hw_start:
 742                         /* This reference means the state machine is started */
 743                         sdma_get(&ppd->sdma_state);
 744                         sdma_set_state(ppd,
 745                                        qib_sdma_state_s10_hw_start_up_wait);
 746                         break;
 747                 case qib_sdma_event_e20_hw_started:
 748                         break;
 749                 case qib_sdma_event_e40_sw_cleaned:
 750                         sdma_sw_tear_down(ppd);
 751                         break;
 752                 case qib_sdma_event_e50_hw_cleaned:
 753                         break;
 754                 case qib_sdma_event_e60_hw_halted:
 755                         break;
 756                 case qib_sdma_event_e70_go_idle:
 757                         break;
 758                 case qib_sdma_event_e7220_err_halted:
 759                         break;
 760                 case qib_sdma_event_e7322_err_halted:
 761                         break;
 762                 case qib_sdma_event_e90_timer_tick:
 763                         break;
 764                 }
 765                 break;
 766
 767         case qib_sdma_state_s10_hw_start_up_wait:
 768                 switch (event) {
 769                 case qib_sdma_event_e00_go_hw_down:
 770                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
 771                         sdma_sw_tear_down(ppd);
 772                         break;
 773                 case qib_sdma_event_e10_go_hw_start:
 774                         break;
 775                 case qib_sdma_event_e20_hw_started:
 776                         sdma_set_state(ppd, ss->go_s99_running ?
 777                                        qib_sdma_state_s99_running :
 778                                        qib_sdma_state_s20_idle);
 779                         break;
 780                 case qib_sdma_event_e30_go_running:
 781                         ss->go_s99_running = 1;
 782                         break;
 783                 case qib_sdma_event_e40_sw_cleaned:
 784                         break;
 785                 case qib_sdma_event_e50_hw_cleaned:
 786                         break;
 787                 case qib_sdma_event_e60_hw_halted:
 788                         break;
 789                 case qib_sdma_event_e70_go_idle:
 790                         ss->go_s99_running = 0;
 791                         break;
 792                 case qib_sdma_event_e7220_err_halted:
 793                         break;
 794                 case qib_sdma_event_e7322_err_halted:
 795                         break;
 796                 case qib_sdma_event_e90_timer_tick:
 797                         break;
 798                 }
 799                 break;
 800
 801         case qib_sdma_state_s20_idle:
 802                 switch (event) {
 803                 case qib_sdma_event_e00_go_hw_down:
 804                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
 805                         sdma_sw_tear_down(ppd);
 806                         break;
 807                 case qib_sdma_event_e10_go_hw_start:
 808                         break;
 809                 case qib_sdma_event_e20_hw_started:
 810                         break;
 811                 case qib_sdma_event_e30_go_running:
 812                         sdma_set_state(ppd, qib_sdma_state_s99_running);
 813                         ss->go_s99_running = 1;
 814                         break;
 815                 case qib_sdma_event_e40_sw_cleaned:
 816                         break;
 817                 case qib_sdma_event_e50_hw_cleaned:
 818                         break;
 819                 case qib_sdma_event_e60_hw_halted:
 820                         break;
 821                 case qib_sdma_event_e70_go_idle:
 822                         break;
 823                 case qib_sdma_event_e7220_err_halted:
 824                         break;
 825                 case qib_sdma_event_e7322_err_halted:
 826                         break;
 827                 case qib_sdma_event_e90_timer_tick:
 828                         break;
 829                 }
 830                 break;
 831
 832         case qib_sdma_state_s30_sw_clean_up_wait:
 833                 switch (event) {
 834                 case qib_sdma_event_e00_go_hw_down:
 835                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
 836                         break;
 837                 case qib_sdma_event_e10_go_hw_start:
 838                         break;
 839                 case qib_sdma_event_e20_hw_started:
 840                         break;
 841                 case qib_sdma_event_e30_go_running:
 842                         ss->go_s99_running = 1;
 843                         break;
 844                 case qib_sdma_event_e40_sw_cleaned:
 845                         sdma_set_state(ppd,
 846                                        qib_sdma_state_s10_hw_start_up_wait);
 847                         sdma_hw_start_up(ppd);
 848                         break;
 849                 case qib_sdma_event_e50_hw_cleaned:
 850                         break;
 851                 case qib_sdma_event_e60_hw_halted:
 852                         break;
 853                 case qib_sdma_event_e70_go_idle:
 854                         ss->go_s99_running = 0;
 855                         break;
 856                 case qib_sdma_event_e7220_err_halted:
 857                         break;
 858                 case qib_sdma_event_e7322_err_halted:
 859                         break;
 860                 case qib_sdma_event_e90_timer_tick:
 861                         break;
 862                 }
 863                 break;
 864
 865         case qib_sdma_state_s40_hw_clean_up_wait:
 866                 switch (event) {
 867                 case qib_sdma_event_e00_go_hw_down:
 868                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
 869                         sdma_start_sw_clean_up(ppd);
 870                         break;
 871                 case qib_sdma_event_e10_go_hw_start:
 872                         break;
 873                 case qib_sdma_event_e20_hw_started:
 874                         break;
 875                 case qib_sdma_event_e30_go_running:
 876                         ss->go_s99_running = 1;
 877                         break;
 878                 case qib_sdma_event_e40_sw_cleaned:
 879                         break;
 880                 case qib_sdma_event_e50_hw_cleaned:
 881                         sdma_set_state(ppd,
 882                                        qib_sdma_state_s30_sw_clean_up_wait);
 883                         sdma_start_sw_clean_up(ppd);
 884                         break;
 885                 case qib_sdma_event_e60_hw_halted:
 886                         break;
 887                 case qib_sdma_event_e70_go_idle:
 888                         ss->go_s99_running = 0;
 889                         break;
 890                 case qib_sdma_event_e7220_err_halted:
 891                         break;
 892                 case qib_sdma_event_e7322_err_halted:
 893                         break;
 894                 case qib_sdma_event_e90_timer_tick:
 895                         break;
 896                 }
 897                 break;
 898
 899         case qib_sdma_state_s50_hw_halt_wait:
 900                 switch (event) {
 901                 case qib_sdma_event_e00_go_hw_down:
 902                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
 903                         sdma_start_sw_clean_up(ppd);
 904                         break;
 905                 case qib_sdma_event_e10_go_hw_start:
 906                         break;
 907                 case qib_sdma_event_e20_hw_started:
 908                         break;
 909                 case qib_sdma_event_e30_go_running:
 910                         ss->go_s99_running = 1;
 911                         break;
 912                 case qib_sdma_event_e40_sw_cleaned:
 913                         break;
 914                 case qib_sdma_event_e50_hw_cleaned:
 915                         break;
 916                 case qib_sdma_event_e60_hw_halted:
 917                         sdma_set_state(ppd,
 918                                        qib_sdma_state_s40_hw_clean_up_wait);
 919                         ppd->dd->f_sdma_hw_clean_up(ppd);
 920                         break;
 921                 case qib_sdma_event_e70_go_idle:
 922                         ss->go_s99_running = 0;
 923                         break;
 924                 case qib_sdma_event_e7220_err_halted:
 925                         break;
 926                 case qib_sdma_event_e7322_err_halted:
 927                         break;
 928                 case qib_sdma_event_e90_timer_tick:
 929                         break;
 930                 }
 931                 break;
 932
 933         case qib_sdma_state_s99_running:
 934                 switch (event) {
 935                 case qib_sdma_event_e00_go_hw_down:
 936                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
 937                         sdma_start_sw_clean_up(ppd);
 938                         break;
 939                 case qib_sdma_event_e10_go_hw_start:
 940                         break;
 941                 case qib_sdma_event_e20_hw_started:
 942                         break;
 943                 case qib_sdma_event_e30_go_running:
 944                         break;
 945                 case qib_sdma_event_e40_sw_cleaned:
 946                         break;
 947                 case qib_sdma_event_e50_hw_cleaned:
 948                         break;
 949                 case qib_sdma_event_e60_hw_halted:
 950                         sdma_set_state(ppd,
 951                                        qib_sdma_state_s30_sw_clean_up_wait);
 952                         sdma_start_sw_clean_up(ppd);
 953                         break;
 954                 case qib_sdma_event_e70_go_idle:
 955                         sdma_set_state(ppd, qib_sdma_state_s50_hw_halt_wait);
 956                         ss->go_s99_running = 0;
 957                         break;
 958                 case qib_sdma_event_e7220_err_halted:
 959                         sdma_set_state(ppd,
 960                                        qib_sdma_state_s30_sw_clean_up_wait);
 961                         sdma_start_sw_clean_up(ppd);
 962                         break;
 963                 case qib_sdma_event_e7322_err_halted:
 964                         sdma_set_state(ppd, qib_sdma_state_s50_hw_halt_wait);
 965                         break;
 966                 case qib_sdma_event_e90_timer_tick:
 967                         break;
 968                 }
 969                 break;
 970         }
 971
 972         ss->last_event = event;
 973 }