drivers/infiniband/hw/hfi1/user_sdma.c

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
   2 /*
   3  * Copyright(c) 2020 - 2023 Cornelis Networks, Inc.
   4  * Copyright(c) 2015 - 2018 Intel Corporation.
   5  */
   6
   7 #include <linux/mm.h>
   8 #include <linux/types.h>
   9 #include <linux/device.h>
  10 #include <linux/dmapool.h>
  11 #include <linux/slab.h>
  12 #include <linux/list.h>
  13 #include <linux/highmem.h>
  14 #include <linux/io.h>
  15 #include <linux/uio.h>
  16 #include <linux/rbtree.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/delay.h>
  19 #include <linux/kthread.h>
  20 #include <linux/mmu_context.h>
  21 #include <linux/module.h>
  22 #include <linux/vmalloc.h>
  23 #include <linux/string.h>
  24
  25 #include "hfi.h"
  26 #include "sdma.h"
  27 #include "user_sdma.h"
  28 #include "verbs.h"  /* for the headers */
  29 #include "common.h" /* for struct hfi1_tid_info */
  30 #include "trace.h"
  31
  32 static uint hfi1_sdma_comp_ring_size = 128;
  33 module_param_named(sdma_comp_size, hfi1_sdma_comp_ring_size, uint, S_IRUGO);
  34 MODULE_PARM_DESC(sdma_comp_size, "Size of User SDMA completion ring. Default: 128");
  35
  36 static unsigned initial_pkt_count = 8;
  37
  38 static int user_sdma_send_pkts(struct user_sdma_request *req, u16 maxpkts);
  39 static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status);
  40 static inline void pq_update(struct hfi1_user_sdma_pkt_q *pq);
  41 static void user_sdma_free_request(struct user_sdma_request *req);
  42 static int check_header_template(struct user_sdma_request *req,
  43                                  struct hfi1_pkt_header *hdr, u32 lrhlen,
  44                                  u32 datalen);
  45 static int set_txreq_header(struct user_sdma_request *req,
  46                             struct user_sdma_txreq *tx, u32 datalen);
  47 static int set_txreq_header_ahg(struct user_sdma_request *req,
  48                                 struct user_sdma_txreq *tx, u32 len);
  49 static inline void set_comp_state(struct hfi1_user_sdma_pkt_q *pq,
  50                                   struct hfi1_user_sdma_comp_q *cq,
  51                                   u16 idx, enum hfi1_sdma_comp_state state,
  52                                   int ret);
  53 static inline u32 set_pkt_bth_psn(__be32 bthpsn, u8 expct, u32 frags);
  54 static inline u32 get_lrh_len(struct hfi1_pkt_header, u32 len);
  55
  56 static int defer_packet_queue(
  57         struct sdma_engine *sde,
  58         struct iowait_work *wait,
  59         struct sdma_txreq *txreq,
  60         uint seq,
  61         bool pkts_sent);
  62 static void activate_packet_queue(struct iowait *wait, int reason);
  63
  64 static int defer_packet_queue(
  65         struct sdma_engine *sde,
  66         struct iowait_work *wait,
  67         struct sdma_txreq *txreq,
  68         uint seq,
  69         bool pkts_sent)
  70 {
  71         struct hfi1_user_sdma_pkt_q *pq =
  72                 container_of(wait->iow, struct hfi1_user_sdma_pkt_q, busy);
  73
  74         write_seqlock(&sde->waitlock);
  75         trace_hfi1_usdma_defer(pq, sde, &pq->busy);
  76         if (sdma_progress(sde, seq, txreq))
  77                 goto eagain;
  78         /*
  79          * We are assuming that if the list is enqueued somewhere, it
  80          * is to the dmawait list since that is the only place where
  81          * it is supposed to be enqueued.
  82          */
  83         xchg(&pq->state, SDMA_PKT_Q_DEFERRED);
  84         if (list_empty(&pq->busy.list)) {
  85                 pq->busy.lock = &sde->waitlock;
  86                 iowait_get_priority(&pq->busy);
  87                 iowait_queue(pkts_sent, &pq->busy, &sde->dmawait);
  88         }
  89         write_sequnlock(&sde->waitlock);
  90         return -EBUSY;
  91 eagain:
  92         write_sequnlock(&sde->waitlock);
  93         return -EAGAIN;
  94 }
  95
  96 static void activate_packet_queue(struct iowait *wait, int reason)
  97 {
  98         struct hfi1_user_sdma_pkt_q *pq =
  99                 container_of(wait, struct hfi1_user_sdma_pkt_q, busy);
 100
 101         trace_hfi1_usdma_activate(pq, wait, reason);
 102         xchg(&pq->state, SDMA_PKT_Q_ACTIVE);
 103         wake_up(&wait->wait_dma);
 104 };
 105
 106 int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt,
 107                                 struct hfi1_filedata *fd)
 108 {
 109         int ret = -ENOMEM;
 110         char buf[64];
 111         struct hfi1_devdata *dd;
 112         struct hfi1_user_sdma_comp_q *cq;
 113         struct hfi1_user_sdma_pkt_q *pq;
 114
 115         if (!uctxt || !fd)
 116                 return -EBADF;
 117
 118         if (!hfi1_sdma_comp_ring_size)
 119                 return -EINVAL;
 120
 121         dd = uctxt->dd;
 122
 123         pq = kzalloc(sizeof(*pq), GFP_KERNEL);
 124         if (!pq)
 125                 return -ENOMEM;
 126         pq->dd = dd;
 127         pq->ctxt = uctxt->ctxt;
 128         pq->subctxt = fd->subctxt;
 129         pq->n_max_reqs = hfi1_sdma_comp_ring_size;
 130         atomic_set(&pq->n_reqs, 0);
 131         init_waitqueue_head(&pq->wait);
 132         atomic_set(&pq->n_locked, 0);
 133
 134         iowait_init(&pq->busy, 0, NULL, NULL, defer_packet_queue,
 135                     activate_packet_queue, NULL, NULL);
 136         pq->reqidx = 0;
 137
 138         pq->reqs = kcalloc(hfi1_sdma_comp_ring_size,
 139                            sizeof(*pq->reqs),
 140                            GFP_KERNEL);
 141         if (!pq->reqs)
 142                 goto pq_reqs_nomem;
 143
 144         pq->req_in_use = bitmap_zalloc(hfi1_sdma_comp_ring_size, GFP_KERNEL);
 145         if (!pq->req_in_use)
 146                 goto pq_reqs_no_in_use;
 147
 148         snprintf(buf, 64, "txreq-kmem-cache-%u-%u-%u", dd->unit, uctxt->ctxt,
 149                  fd->subctxt);
 150         pq->txreq_cache = kmem_cache_create(buf,
 151                                             sizeof(struct user_sdma_txreq),
 152                                             L1_CACHE_BYTES,
 153                                             SLAB_HWCACHE_ALIGN,
 154                                             NULL);
 155         if (!pq->txreq_cache) {
 156                 dd_dev_err(dd, "[%u] Failed to allocate TxReq cache\n",
 157                            uctxt->ctxt);
 158                 goto pq_txreq_nomem;
 159         }
 160
 161         cq = kzalloc(sizeof(*cq), GFP_KERNEL);
 162         if (!cq)
 163                 goto cq_nomem;
 164
 165         cq->comps = vmalloc_user(PAGE_ALIGN(sizeof(*cq->comps)
 166                                  * hfi1_sdma_comp_ring_size));
 167         if (!cq->comps)
 168                 goto cq_comps_nomem;
 169
 170         cq->nentries = hfi1_sdma_comp_ring_size;
 171
 172         ret = hfi1_init_system_pinning(pq);
 173         if (ret)
 174                 goto pq_mmu_fail;
 175
 176         rcu_assign_pointer(fd->pq, pq);
 177         fd->cq = cq;
 178
 179         return 0;
 180
 181 pq_mmu_fail:
 182         vfree(cq->comps);
 183 cq_comps_nomem:
 184         kfree(cq);
 185 cq_nomem:
 186         kmem_cache_destroy(pq->txreq_cache);
 187 pq_txreq_nomem:
 188         bitmap_free(pq->req_in_use);
 189 pq_reqs_no_in_use:
 190         kfree(pq->reqs);
 191 pq_reqs_nomem:
 192         kfree(pq);
 193
 194         return ret;
 195 }
 196
 197 static void flush_pq_iowait(struct hfi1_user_sdma_pkt_q *pq)
 198 {
 199         unsigned long flags;
 200         seqlock_t *lock = pq->busy.lock;
 201
 202         if (!lock)
 203                 return;
 204         write_seqlock_irqsave(lock, flags);
 205         if (!list_empty(&pq->busy.list)) {
 206                 list_del_init(&pq->busy.list);
 207                 pq->busy.lock = NULL;
 208         }
 209         write_sequnlock_irqrestore(lock, flags);
 210 }
 211
 212 int hfi1_user_sdma_free_queues(struct hfi1_filedata *fd,
 213                                struct hfi1_ctxtdata *uctxt)
 214 {
 215         struct hfi1_user_sdma_pkt_q *pq;
 216
 217         trace_hfi1_sdma_user_free_queues(uctxt->dd, uctxt->ctxt, fd->subctxt);
 218
 219         spin_lock(&fd->pq_rcu_lock);
 220         pq = srcu_dereference_check(fd->pq, &fd->pq_srcu,
 221                                     lockdep_is_held(&fd->pq_rcu_lock));
 222         if (pq) {
 223                 rcu_assign_pointer(fd->pq, NULL);
 224                 spin_unlock(&fd->pq_rcu_lock);
 225                 synchronize_srcu(&fd->pq_srcu);
 226                 /* at this point there can be no more new requests */
 227                 iowait_sdma_drain(&pq->busy);
 228                 /* Wait until all requests have been freed. */
 229                 wait_event_interruptible(
 230                         pq->wait,
 231                         !atomic_read(&pq->n_reqs));
 232                 kfree(pq->reqs);
 233                 hfi1_free_system_pinning(pq);
 234                 bitmap_free(pq->req_in_use);
 235                 kmem_cache_destroy(pq->txreq_cache);
 236                 flush_pq_iowait(pq);
 237                 kfree(pq);
 238         } else {
 239                 spin_unlock(&fd->pq_rcu_lock);
 240         }
 241         if (fd->cq) {
 242                 vfree(fd->cq->comps);
 243                 kfree(fd->cq);
 244                 fd->cq = NULL;
 245         }
 246         return 0;
 247 }
 248
 249 static u8 dlid_to_selector(u16 dlid)
 250 {
 251         static u8 mapping[256];
 252         static int initialized;
 253         static u8 next;
 254         int hash;
 255
 256         if (!initialized) {
 257                 memset(mapping, 0xFF, 256);
 258                 initialized = 1;
 259         }
 260
 261         hash = ((dlid >> 8) ^ dlid) & 0xFF;
 262         if (mapping[hash] == 0xFF) {
 263                 mapping[hash] = next;
 264                 next = (next + 1) & 0x7F;
 265         }
 266
 267         return mapping[hash];
 268 }
 269
 270 /**
 271  * hfi1_user_sdma_process_request() - Process and start a user sdma request
 272  * @fd: valid file descriptor
 273  * @iovec: array of io vectors to process
 274  * @dim: overall iovec array size
 275  * @count: number of io vector array entries processed
 276  */
 277 int hfi1_user_sdma_process_request(struct hfi1_filedata *fd,
 278                                    struct iovec *iovec, unsigned long dim,
 279                                    unsigned long *count)
 280 {
 281         int ret = 0, i;
 282         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 283         struct hfi1_user_sdma_pkt_q *pq =
 284                 srcu_dereference(fd->pq, &fd->pq_srcu);
 285         struct hfi1_user_sdma_comp_q *cq = fd->cq;
 286         struct hfi1_devdata *dd = pq->dd;
 287         unsigned long idx = 0;
 288         u8 pcount = initial_pkt_count;
 289         struct sdma_req_info info;
 290         struct user_sdma_request *req;
 291         u8 opcode, sc, vl;
 292         u16 pkey;
 293         u32 slid;
 294         u16 dlid;
 295         u32 selector;
 296
 297         if (iovec[idx].iov_len < sizeof(info) + sizeof(req->hdr)) {
 298                 hfi1_cdbg(
 299                    SDMA,
 300                    "[%u:%u:%u] First vector not big enough for header %lu/%lu",
 301                    dd->unit, uctxt->ctxt, fd->subctxt,
 302                    iovec[idx].iov_len, sizeof(info) + sizeof(req->hdr));
 303                 return -EINVAL;
 304         }
 305         ret = copy_from_user(&info, iovec[idx].iov_base, sizeof(info));
 306         if (ret) {
 307                 hfi1_cdbg(SDMA, "[%u:%u:%u] Failed to copy info QW (%d)",
 308                           dd->unit, uctxt->ctxt, fd->subctxt, ret);
 309                 return -EFAULT;
 310         }
 311
 312         trace_hfi1_sdma_user_reqinfo(dd, uctxt->ctxt, fd->subctxt,
 313                                      (u16 *)&info);
 314         if (info.comp_idx >= hfi1_sdma_comp_ring_size) {
 315                 hfi1_cdbg(SDMA,
 316                           "[%u:%u:%u:%u] Invalid comp index",
 317                           dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx);
 318                 return -EINVAL;
 319         }
 320
 321         /*
 322          * Sanity check the header io vector count.  Need at least 1 vector
 323          * (header) and cannot be larger than the actual io vector count.
 324          */
 325         if (req_iovcnt(info.ctrl) < 1 || req_iovcnt(info.ctrl) > dim) {
 326                 hfi1_cdbg(SDMA,
 327                           "[%u:%u:%u:%u] Invalid iov count %d, dim %ld",
 328                           dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx,
 329                           req_iovcnt(info.ctrl), dim);
 330                 return -EINVAL;
 331         }
 332
 333         if (!info.fragsize) {
 334                 hfi1_cdbg(SDMA,
 335                           "[%u:%u:%u:%u] Request does not specify fragsize",
 336                           dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx);
 337                 return -EINVAL;
 338         }
 339
 340         /* Try to claim the request. */
 341         if (test_and_set_bit(info.comp_idx, pq->req_in_use)) {
 342                 hfi1_cdbg(SDMA, "[%u:%u:%u] Entry %u is in use",
 343                           dd->unit, uctxt->ctxt, fd->subctxt,
 344                           info.comp_idx);
 345                 return -EBADSLT;
 346         }
 347         /*
 348          * All safety checks have been done and this request has been claimed.
 349          */
 350         trace_hfi1_sdma_user_process_request(dd, uctxt->ctxt, fd->subctxt,
 351                                              info.comp_idx);
 352         req = pq->reqs + info.comp_idx;
 353         req->data_iovs = req_iovcnt(info.ctrl) - 1; /* subtract header vector */
 354         req->data_len  = 0;
 355         req->pq = pq;
 356         req->cq = cq;
 357         req->ahg_idx = -1;
 358         req->iov_idx = 0;
 359         req->sent = 0;
 360         req->seqnum = 0;
 361         req->seqcomp = 0;
 362         req->seqsubmitted = 0;
 363         req->tids = NULL;
 364         req->has_error = 0;
 365         INIT_LIST_HEAD(&req->txps);
 366
 367         memcpy(&req->info, &info, sizeof(info));
 368
 369         /* The request is initialized, count it */
 370         atomic_inc(&pq->n_reqs);
 371
 372         if (req_opcode(info.ctrl) == EXPECTED) {
 373                 /* expected must have a TID info and at least one data vector */
 374                 if (req->data_iovs < 2) {
 375                         SDMA_DBG(req,
 376                                  "Not enough vectors for expected request");
 377                         ret = -EINVAL;
 378                         goto free_req;
 379                 }
 380                 req->data_iovs--;
 381         }
 382
 383         if (!info.npkts || req->data_iovs > MAX_VECTORS_PER_REQ) {
 384                 SDMA_DBG(req, "Too many vectors (%u/%u)", req->data_iovs,
 385                          MAX_VECTORS_PER_REQ);
 386                 ret = -EINVAL;
 387                 goto free_req;
 388         }
 389
 390         /* Copy the header from the user buffer */
 391         ret = copy_from_user(&req->hdr, iovec[idx].iov_base + sizeof(info),
 392                              sizeof(req->hdr));
 393         if (ret) {
 394                 SDMA_DBG(req, "Failed to copy header template (%d)", ret);
 395                 ret = -EFAULT;
 396                 goto free_req;
 397         }
 398
 399         /* If Static rate control is not enabled, sanitize the header. */
 400         if (!HFI1_CAP_IS_USET(STATIC_RATE_CTRL))
 401                 req->hdr.pbc[2] = 0;
 402
 403         /* Validate the opcode. Do not trust packets from user space blindly. */
 404         opcode = (be32_to_cpu(req->hdr.bth[0]) >> 24) & 0xff;
 405         if ((opcode & USER_OPCODE_CHECK_MASK) !=
 406              USER_OPCODE_CHECK_VAL) {
 407                 SDMA_DBG(req, "Invalid opcode (%d)", opcode);
 408                 ret = -EINVAL;
 409                 goto free_req;
 410         }
 411         /*
 412          * Validate the vl. Do not trust packets from user space blindly.
 413          * VL comes from PBC, SC comes from LRH, and the VL needs to
 414          * match the SC look up.
 415          */
 416         vl = (le16_to_cpu(req->hdr.pbc[0]) >> 12) & 0xF;
 417         sc = (((be16_to_cpu(req->hdr.lrh[0]) >> 12) & 0xF) |
 418               (((le16_to_cpu(req->hdr.pbc[1]) >> 14) & 0x1) << 4));
 419         if (vl >= dd->pport->vls_operational ||
 420             vl != sc_to_vlt(dd, sc)) {
 421                 SDMA_DBG(req, "Invalid SC(%u)/VL(%u)", sc, vl);
 422                 ret = -EINVAL;
 423                 goto free_req;
 424         }
 425
 426         /* Checking P_KEY for requests from user-space */
 427         pkey = (u16)be32_to_cpu(req->hdr.bth[0]);
 428         slid = be16_to_cpu(req->hdr.lrh[3]);
 429         if (egress_pkey_check(dd->pport, slid, pkey, sc, PKEY_CHECK_INVALID)) {
 430                 ret = -EINVAL;
 431                 goto free_req;
 432         }
 433
 434         /*
 435          * Also should check the BTH.lnh. If it says the next header is GRH then
 436          * the RXE parsing will be off and will land in the middle of the KDETH
 437          * or miss it entirely.
 438          */
 439         if ((be16_to_cpu(req->hdr.lrh[0]) & 0x3) == HFI1_LRH_GRH) {
 440                 SDMA_DBG(req, "User tried to pass in a GRH");
 441                 ret = -EINVAL;
 442                 goto free_req;
 443         }
 444
 445         req->koffset = le32_to_cpu(req->hdr.kdeth.swdata[6]);
 446         /*
 447          * Calculate the initial TID offset based on the values of
 448          * KDETH.OFFSET and KDETH.OM that are passed in.
 449          */
 450         req->tidoffset = KDETH_GET(req->hdr.kdeth.ver_tid_offset, OFFSET) *
 451                 (KDETH_GET(req->hdr.kdeth.ver_tid_offset, OM) ?
 452                  KDETH_OM_LARGE : KDETH_OM_SMALL);
 453         trace_hfi1_sdma_user_initial_tidoffset(dd, uctxt->ctxt, fd->subctxt,
 454                                                info.comp_idx, req->tidoffset);
 455         idx++;
 456
 457         /* Save all the IO vector structures */
 458         for (i = 0; i < req->data_iovs; i++) {
 459                 req->iovs[i].offset = 0;
 460                 INIT_LIST_HEAD(&req->iovs[i].list);
 461                 memcpy(&req->iovs[i].iov,
 462                        iovec + idx++,
 463                        sizeof(req->iovs[i].iov));
 464                 if (req->iovs[i].iov.iov_len == 0) {
 465                         ret = -EINVAL;
 466                         goto free_req;
 467                 }
 468                 req->data_len += req->iovs[i].iov.iov_len;
 469         }
 470         trace_hfi1_sdma_user_data_length(dd, uctxt->ctxt, fd->subctxt,
 471                                          info.comp_idx, req->data_len);
 472         if (pcount > req->info.npkts)
 473                 pcount = req->info.npkts;
 474         /*
 475          * Copy any TID info
 476          * User space will provide the TID info only when the
 477          * request type is EXPECTED. This is true even if there is
 478          * only one packet in the request and the header is already
 479          * setup. The reason for the singular TID case is that the
 480          * driver needs to perform safety checks.
 481          */
 482         if (req_opcode(req->info.ctrl) == EXPECTED) {
 483                 u16 ntids = iovec[idx].iov_len / sizeof(*req->tids);
 484                 u32 *tmp;
 485
 486                 if (!ntids || ntids > MAX_TID_PAIR_ENTRIES) {
 487                         ret = -EINVAL;
 488                         goto free_req;
 489                 }
 490
 491                 /*
 492                  * We have to copy all of the tids because they may vary
 493                  * in size and, therefore, the TID count might not be
 494                  * equal to the pkt count. However, there is no way to
 495                  * tell at this point.
 496                  */
 497                 tmp = memdup_array_user(iovec[idx].iov_base,
 498                                         ntids, sizeof(*req->tids));
 499                 if (IS_ERR(tmp)) {
 500                         ret = PTR_ERR(tmp);
 501                         SDMA_DBG(req, "Failed to copy %d TIDs (%d)",
 502                                  ntids, ret);
 503                         goto free_req;
 504                 }
 505                 req->tids = tmp;
 506                 req->n_tids = ntids;
 507                 req->tididx = 0;
 508                 idx++;
 509         }
 510
 511         dlid = be16_to_cpu(req->hdr.lrh[1]);
 512         selector = dlid_to_selector(dlid);
 513         selector += uctxt->ctxt + fd->subctxt;
 514         req->sde = sdma_select_user_engine(dd, selector, vl);
 515
 516         if (!req->sde || !sdma_running(req->sde)) {
 517                 ret = -ECOMM;
 518                 goto free_req;
 519         }
 520
 521         /* We don't need an AHG entry if the request contains only one packet */
 522         if (req->info.npkts > 1 && HFI1_CAP_IS_USET(SDMA_AHG))
 523                 req->ahg_idx = sdma_ahg_alloc(req->sde);
 524
 525         set_comp_state(pq, cq, info.comp_idx, QUEUED, 0);
 526         pq->state = SDMA_PKT_Q_ACTIVE;
 527
 528         /*
 529          * This is a somewhat blocking send implementation.
 530          * The driver will block the caller until all packets of the
 531          * request have been submitted to the SDMA engine. However, it
 532          * will not wait for send completions.
 533          */
 534         while (req->seqsubmitted != req->info.npkts) {
 535                 ret = user_sdma_send_pkts(req, pcount);
 536                 if (ret < 0) {
 537                         int we_ret;
 538
 539                         if (ret != -EBUSY)
 540                                 goto free_req;
 541                         we_ret = wait_event_interruptible_timeout(
 542                                 pq->busy.wait_dma,
 543                                 pq->state == SDMA_PKT_Q_ACTIVE,
 544                                 msecs_to_jiffies(
 545                                         SDMA_IOWAIT_TIMEOUT));
 546                         trace_hfi1_usdma_we(pq, we_ret);
 547                         if (we_ret <= 0)
 548                                 flush_pq_iowait(pq);
 549                 }
 550         }
 551         *count += idx;
 552         return 0;
 553 free_req:
 554         /*
 555          * If the submitted seqsubmitted == npkts, the completion routine
 556          * controls the final state.  If sequbmitted < npkts, wait for any
 557          * outstanding packets to finish before cleaning up.
 558          */
 559         if (req->seqsubmitted < req->info.npkts) {
 560                 if (req->seqsubmitted)
 561                         wait_event(pq->busy.wait_dma,
 562                                    (req->seqcomp == req->seqsubmitted - 1));
 563                 user_sdma_free_request(req);
 564                 pq_update(pq);
 565                 set_comp_state(pq, cq, info.comp_idx, ERROR, ret);
 566         }
 567         return ret;
 568 }
 569
 570 static inline u32 compute_data_length(struct user_sdma_request *req,
 571                                       struct user_sdma_txreq *tx)
 572 {
 573         /*
 574          * Determine the proper size of the packet data.
 575          * The size of the data of the first packet is in the header
 576          * template. However, it includes the header and ICRC, which need
 577          * to be subtracted.
 578          * The minimum representable packet data length in a header is 4 bytes,
 579          * therefore, when the data length request is less than 4 bytes, there's
 580          * only one packet, and the packet data length is equal to that of the
 581          * request data length.
 582          * The size of the remaining packets is the minimum of the frag
 583          * size (MTU) or remaining data in the request.
 584          */
 585         u32 len;
 586
 587         if (!req->seqnum) {
 588                 if (req->data_len < sizeof(u32))
 589                         len = req->data_len;
 590                 else
 591                         len = ((be16_to_cpu(req->hdr.lrh[2]) << 2) -
 592                                (sizeof(tx->hdr) - 4));
 593         } else if (req_opcode(req->info.ctrl) == EXPECTED) {
 594                 u32 tidlen = EXP_TID_GET(req->tids[req->tididx], LEN) *
 595                         PAGE_SIZE;
 596                 /*
 597                  * Get the data length based on the remaining space in the
 598                  * TID pair.
 599                  */
 600                 len = min(tidlen - req->tidoffset, (u32)req->info.fragsize);
 601                 /* If we've filled up the TID pair, move to the next one. */
 602                 if (unlikely(!len) && ++req->tididx < req->n_tids &&
 603                     req->tids[req->tididx]) {
 604                         tidlen = EXP_TID_GET(req->tids[req->tididx],
 605                                              LEN) * PAGE_SIZE;
 606                         req->tidoffset = 0;
 607                         len = min_t(u32, tidlen, req->info.fragsize);
 608                 }
 609                 /*
 610                  * Since the TID pairs map entire pages, make sure that we
 611                  * are not going to try to send more data that we have
 612                  * remaining.
 613                  */
 614                 len = min(len, req->data_len - req->sent);
 615         } else {
 616                 len = min(req->data_len - req->sent, (u32)req->info.fragsize);
 617         }
 618         trace_hfi1_sdma_user_compute_length(req->pq->dd,
 619                                             req->pq->ctxt,
 620                                             req->pq->subctxt,
 621                                             req->info.comp_idx,
 622                                             len);
 623         return len;
 624 }
 625
 626 static inline u32 pad_len(u32 len)
 627 {
 628         if (len & (sizeof(u32) - 1))
 629                 len += sizeof(u32) - (len & (sizeof(u32) - 1));
 630         return len;
 631 }
 632
 633 static inline u32 get_lrh_len(struct hfi1_pkt_header hdr, u32 len)
 634 {
 635         /* (Size of complete header - size of PBC) + 4B ICRC + data length */
 636         return ((sizeof(hdr) - sizeof(hdr.pbc)) + 4 + len);
 637 }
 638
 639 static int user_sdma_txadd_ahg(struct user_sdma_request *req,
 640                                struct user_sdma_txreq *tx,
 641                                u32 datalen)
 642 {
 643         int ret;
 644         u16 pbclen = le16_to_cpu(req->hdr.pbc[0]);
 645         u32 lrhlen = get_lrh_len(req->hdr, pad_len(datalen));
 646         struct hfi1_user_sdma_pkt_q *pq = req->pq;
 647
 648         /*
 649          * Copy the request header into the tx header
 650          * because the HW needs a cacheline-aligned
 651          * address.
 652          * This copy can be optimized out if the hdr
 653          * member of user_sdma_request were also
 654          * cacheline aligned.
 655          */
 656         memcpy(&tx->hdr, &req->hdr, sizeof(tx->hdr));
 657         if (PBC2LRH(pbclen) != lrhlen) {
 658                 pbclen = (pbclen & 0xf000) | LRH2PBC(lrhlen);
 659                 tx->hdr.pbc[0] = cpu_to_le16(pbclen);
 660         }
 661         ret = check_header_template(req, &tx->hdr, lrhlen, datalen);
 662         if (ret)
 663                 return ret;
 664         ret = sdma_txinit_ahg(&tx->txreq, SDMA_TXREQ_F_AHG_COPY,
 665                               sizeof(tx->hdr) + datalen, req->ahg_idx,
 666                               0, NULL, 0, user_sdma_txreq_cb);
 667         if (ret)
 668                 return ret;
 669         ret = sdma_txadd_kvaddr(pq->dd, &tx->txreq, &tx->hdr, sizeof(tx->hdr));
 670         if (ret)
 671                 sdma_txclean(pq->dd, &tx->txreq);
 672         return ret;
 673 }
 674
 675 static int user_sdma_send_pkts(struct user_sdma_request *req, u16 maxpkts)
 676 {
 677         int ret = 0;
 678         u16 count;
 679         unsigned npkts = 0;
 680         struct user_sdma_txreq *tx = NULL;
 681         struct hfi1_user_sdma_pkt_q *pq = NULL;
 682         struct user_sdma_iovec *iovec = NULL;
 683
 684         if (!req->pq)
 685                 return -EINVAL;
 686
 687         pq = req->pq;
 688
 689         /* If tx completion has reported an error, we are done. */
 690         if (READ_ONCE(req->has_error))
 691                 return -EFAULT;
 692
 693         /*
 694          * Check if we might have sent the entire request already
 695          */
 696         if (unlikely(req->seqnum == req->info.npkts)) {
 697                 if (!list_empty(&req->txps))
 698                         goto dosend;
 699                 return ret;
 700         }
 701
 702         if (!maxpkts || maxpkts > req->info.npkts - req->seqnum)
 703                 maxpkts = req->info.npkts - req->seqnum;
 704
 705         while (npkts < maxpkts) {
 706                 u32 datalen = 0;
 707
 708                 /*
 709                  * Check whether any of the completions have come back
 710                  * with errors. If so, we are not going to process any
 711                  * more packets from this request.
 712                  */
 713                 if (READ_ONCE(req->has_error))
 714                         return -EFAULT;
 715
 716                 tx = kmem_cache_alloc(pq->txreq_cache, GFP_KERNEL);
 717                 if (!tx)
 718                         return -ENOMEM;
 719
 720                 tx->flags = 0;
 721                 tx->req = req;
 722                 INIT_LIST_HEAD(&tx->list);
 723
 724                 /*
 725                  * For the last packet set the ACK request
 726                  * and disable header suppression.
 727                  */
 728                 if (req->seqnum == req->info.npkts - 1)
 729                         tx->flags |= (TXREQ_FLAGS_REQ_ACK |
 730                                       TXREQ_FLAGS_REQ_DISABLE_SH);
 731
 732                 /*
 733                  * Calculate the payload size - this is min of the fragment
 734                  * (MTU) size or the remaining bytes in the request but only
 735                  * if we have payload data.
 736                  */
 737                 if (req->data_len) {
 738                         iovec = &req->iovs[req->iov_idx];
 739                         if (READ_ONCE(iovec->offset) == iovec->iov.iov_len) {
 740                                 if (++req->iov_idx == req->data_iovs) {
 741                                         ret = -EFAULT;
 742                                         goto free_tx;
 743                                 }
 744                                 iovec = &req->iovs[req->iov_idx];
 745                                 WARN_ON(iovec->offset);
 746                         }
 747
 748                         datalen = compute_data_length(req, tx);
 749
 750                         /*
 751                          * Disable header suppression for the payload <= 8DWS.
 752                          * If there is an uncorrectable error in the receive
 753                          * data FIFO when the received payload size is less than
 754                          * or equal to 8DWS then the RxDmaDataFifoRdUncErr is
 755                          * not reported.There is set RHF.EccErr if the header
 756                          * is not suppressed.
 757                          */
 758                         if (!datalen) {
 759                                 SDMA_DBG(req,
 760                                          "Request has data but pkt len is 0");
 761                                 ret = -EFAULT;
 762                                 goto free_tx;
 763                         } else if (datalen <= 32) {
 764                                 tx->flags |= TXREQ_FLAGS_REQ_DISABLE_SH;
 765                         }
 766                 }
 767
 768                 if (req->ahg_idx >= 0) {
 769                         if (!req->seqnum) {
 770                                 ret = user_sdma_txadd_ahg(req, tx, datalen);
 771                                 if (ret)
 772                                         goto free_tx;
 773                         } else {
 774                                 int changes;
 775
 776                                 changes = set_txreq_header_ahg(req, tx,
 777                                                                datalen);
 778                                 if (changes < 0) {
 779                                         ret = changes;
 780                                         goto free_tx;
 781                                 }
 782                         }
 783                 } else {
 784                         ret = sdma_txinit(&tx->txreq, 0, sizeof(req->hdr) +
 785                                           datalen, user_sdma_txreq_cb);
 786                         if (ret)
 787                                 goto free_tx;
 788                         /*
 789                          * Modify the header for this packet. This only needs
 790                          * to be done if we are not going to use AHG. Otherwise,
 791                          * the HW will do it based on the changes we gave it
 792                          * during sdma_txinit_ahg().
 793                          */
 794                         ret = set_txreq_header(req, tx, datalen);
 795                         if (ret)
 796                                 goto free_txreq;
 797                 }
 798
 799                 req->koffset += datalen;
 800                 if (req_opcode(req->info.ctrl) == EXPECTED)
 801                         req->tidoffset += datalen;
 802                 req->sent += datalen;
 803                 while (datalen) {
 804                         ret = hfi1_add_pages_to_sdma_packet(req, tx, iovec,
 805                                                             &datalen);
 806                         if (ret)
 807                                 goto free_txreq;
 808                         iovec = &req->iovs[req->iov_idx];
 809                 }
 810                 list_add_tail(&tx->txreq.list, &req->txps);
 811                 /*
 812                  * It is important to increment this here as it is used to
 813                  * generate the BTH.PSN and, therefore, can't be bulk-updated
 814                  * outside of the loop.
 815                  */
 816                 tx->seqnum = req->seqnum++;
 817                 npkts++;
 818         }
 819 dosend:
 820         ret = sdma_send_txlist(req->sde,
 821                                iowait_get_ib_work(&pq->busy),
 822                                &req->txps, &count);
 823         req->seqsubmitted += count;
 824         if (req->seqsubmitted == req->info.npkts) {
 825                 /*
 826                  * The txreq has already been submitted to the HW queue
 827                  * so we can free the AHG entry now. Corruption will not
 828                  * happen due to the sequential manner in which
 829                  * descriptors are processed.
 830                  */
 831                 if (req->ahg_idx >= 0)
 832                         sdma_ahg_free(req->sde, req->ahg_idx);
 833         }
 834         return ret;
 835
 836 free_txreq:
 837         sdma_txclean(pq->dd, &tx->txreq);
 838 free_tx:
 839         kmem_cache_free(pq->txreq_cache, tx);
 840         return ret;
 841 }
 842
 843 static int check_header_template(struct user_sdma_request *req,
 844                                  struct hfi1_pkt_header *hdr, u32 lrhlen,
 845                                  u32 datalen)
 846 {
 847         /*
 848          * Perform safety checks for any type of packet:
 849          *    - transfer size is multiple of 64bytes
 850          *    - packet length is multiple of 4 bytes
 851          *    - packet length is not larger than MTU size
 852          *
 853          * These checks are only done for the first packet of the
 854          * transfer since the header is "given" to us by user space.
 855          * For the remainder of the packets we compute the values.
 856          */
 857         if (req->info.fragsize % PIO_BLOCK_SIZE || lrhlen & 0x3 ||
 858             lrhlen > get_lrh_len(*hdr, req->info.fragsize))
 859                 return -EINVAL;
 860
 861         if (req_opcode(req->info.ctrl) == EXPECTED) {
 862                 /*
 863                  * The header is checked only on the first packet. Furthermore,
 864                  * we ensure that at least one TID entry is copied when the
 865                  * request is submitted. Therefore, we don't have to verify that
 866                  * tididx points to something sane.
 867                  */
 868                 u32 tidval = req->tids[req->tididx],
 869                         tidlen = EXP_TID_GET(tidval, LEN) * PAGE_SIZE,
 870                         tididx = EXP_TID_GET(tidval, IDX),
 871                         tidctrl = EXP_TID_GET(tidval, CTRL),
 872                         tidoff;
 873                 __le32 kval = hdr->kdeth.ver_tid_offset;
 874
 875                 tidoff = KDETH_GET(kval, OFFSET) *
 876                           (KDETH_GET(req->hdr.kdeth.ver_tid_offset, OM) ?
 877                            KDETH_OM_LARGE : KDETH_OM_SMALL);
 878                 /*
 879                  * Expected receive packets have the following
 880                  * additional checks:
 881                  *     - offset is not larger than the TID size
 882                  *     - TIDCtrl values match between header and TID array
 883                  *     - TID indexes match between header and TID array
 884                  */
 885                 if ((tidoff + datalen > tidlen) ||
 886                     KDETH_GET(kval, TIDCTRL) != tidctrl ||
 887                     KDETH_GET(kval, TID) != tididx)
 888                         return -EINVAL;
 889         }
 890         return 0;
 891 }
 892
 893 /*
 894  * Correctly set the BTH.PSN field based on type of
 895  * transfer - eager packets can just increment the PSN but
 896  * expected packets encode generation and sequence in the
 897  * BTH.PSN field so just incrementing will result in errors.
 898  */
 899 static inline u32 set_pkt_bth_psn(__be32 bthpsn, u8 expct, u32 frags)
 900 {
 901         u32 val = be32_to_cpu(bthpsn),
 902                 mask = (HFI1_CAP_IS_KSET(EXTENDED_PSN) ? 0x7fffffffull :
 903                         0xffffffull),
 904                 psn = val & mask;
 905         if (expct)
 906                 psn = (psn & ~HFI1_KDETH_BTH_SEQ_MASK) |
 907                         ((psn + frags) & HFI1_KDETH_BTH_SEQ_MASK);
 908         else
 909                 psn = psn + frags;
 910         return psn & mask;
 911 }
 912
 913 static int set_txreq_header(struct user_sdma_request *req,
 914                             struct user_sdma_txreq *tx, u32 datalen)
 915 {
 916         struct hfi1_user_sdma_pkt_q *pq = req->pq;
 917         struct hfi1_pkt_header *hdr = &tx->hdr;
 918         u8 omfactor; /* KDETH.OM */
 919         u16 pbclen;
 920         int ret;
 921         u32 tidval = 0, lrhlen = get_lrh_len(*hdr, pad_len(datalen));
 922
 923         /* Copy the header template to the request before modification */
 924         memcpy(hdr, &req->hdr, sizeof(*hdr));
 925
 926         /*
 927          * Check if the PBC and LRH length are mismatched. If so
 928          * adjust both in the header.
 929          */
 930         pbclen = le16_to_cpu(hdr->pbc[0]);
 931         if (PBC2LRH(pbclen) != lrhlen) {
 932                 pbclen = (pbclen & 0xf000) | LRH2PBC(lrhlen);
 933                 hdr->pbc[0] = cpu_to_le16(pbclen);
 934                 hdr->lrh[2] = cpu_to_be16(lrhlen >> 2);
 935                 /*
 936                  * Third packet
 937                  * This is the first packet in the sequence that has
 938                  * a "static" size that can be used for the rest of
 939                  * the packets (besides the last one).
 940                  */
 941                 if (unlikely(req->seqnum == 2)) {
 942                         /*
 943                          * From this point on the lengths in both the
 944                          * PBC and LRH are the same until the last
 945                          * packet.
 946                          * Adjust the template so we don't have to update
 947                          * every packet
 948                          */
 949                         req->hdr.pbc[0] = hdr->pbc[0];
 950                         req->hdr.lrh[2] = hdr->lrh[2];
 951                 }
 952         }
 953         /*
 954          * We only have to modify the header if this is not the
 955          * first packet in the request. Otherwise, we use the
 956          * header given to us.
 957          */
 958         if (unlikely(!req->seqnum)) {
 959                 ret = check_header_template(req, hdr, lrhlen, datalen);
 960                 if (ret)
 961                         return ret;
 962                 goto done;
 963         }
 964
 965         hdr->bth[2] = cpu_to_be32(
 966                 set_pkt_bth_psn(hdr->bth[2],
 967                                 (req_opcode(req->info.ctrl) == EXPECTED),
 968                                 req->seqnum));
 969
 970         /* Set ACK request on last packet */
 971         if (unlikely(tx->flags & TXREQ_FLAGS_REQ_ACK))
 972                 hdr->bth[2] |= cpu_to_be32(1UL << 31);
 973
 974         /* Set the new offset */
 975         hdr->kdeth.swdata[6] = cpu_to_le32(req->koffset);
 976         /* Expected packets have to fill in the new TID information */
 977         if (req_opcode(req->info.ctrl) == EXPECTED) {
 978                 tidval = req->tids[req->tididx];
 979                 /*
 980                  * If the offset puts us at the end of the current TID,
 981                  * advance everything.
 982                  */
 983                 if ((req->tidoffset) == (EXP_TID_GET(tidval, LEN) *
 984                                          PAGE_SIZE)) {
 985                         req->tidoffset = 0;
 986                         /*
 987                          * Since we don't copy all the TIDs, all at once,
 988                          * we have to check again.
 989                          */
 990                         if (++req->tididx > req->n_tids - 1 ||
 991                             !req->tids[req->tididx]) {
 992                                 return -EINVAL;
 993                         }
 994                         tidval = req->tids[req->tididx];
 995                 }
 996                 omfactor = EXP_TID_GET(tidval, LEN) * PAGE_SIZE >=
 997                         KDETH_OM_MAX_SIZE ? KDETH_OM_LARGE_SHIFT :
 998                         KDETH_OM_SMALL_SHIFT;
 999                 /* Set KDETH.TIDCtrl based on value for this TID. */
1000                 KDETH_SET(hdr->kdeth.ver_tid_offset, TIDCTRL,
1001                           EXP_TID_GET(tidval, CTRL));
1002                 /* Set KDETH.TID based on value for this TID */
1003                 KDETH_SET(hdr->kdeth.ver_tid_offset, TID,
1004                           EXP_TID_GET(tidval, IDX));
1005                 /* Clear KDETH.SH when DISABLE_SH flag is set */
1006                 if (unlikely(tx->flags & TXREQ_FLAGS_REQ_DISABLE_SH))
1007                         KDETH_SET(hdr->kdeth.ver_tid_offset, SH, 0);
1008                 /*
1009                  * Set the KDETH.OFFSET and KDETH.OM based on size of
1010                  * transfer.
1011                  */
1012                 trace_hfi1_sdma_user_tid_info(
1013                         pq->dd, pq->ctxt, pq->subctxt, req->info.comp_idx,
1014                         req->tidoffset, req->tidoffset >> omfactor,
1015                         omfactor != KDETH_OM_SMALL_SHIFT);
1016                 KDETH_SET(hdr->kdeth.ver_tid_offset, OFFSET,
1017                           req->tidoffset >> omfactor);
1018                 KDETH_SET(hdr->kdeth.ver_tid_offset, OM,
1019                           omfactor != KDETH_OM_SMALL_SHIFT);
1020         }
1021 done:
1022         trace_hfi1_sdma_user_header(pq->dd, pq->ctxt, pq->subctxt,
1023                                     req->info.comp_idx, hdr, tidval);
1024         return sdma_txadd_kvaddr(pq->dd, &tx->txreq, hdr, sizeof(*hdr));
1025 }
1026
1027 static int set_txreq_header_ahg(struct user_sdma_request *req,
1028                                 struct user_sdma_txreq *tx, u32 datalen)
1029 {
1030         u32 ahg[AHG_KDETH_ARRAY_SIZE];
1031         int idx = 0;
1032         u8 omfactor; /* KDETH.OM */
1033         struct hfi1_user_sdma_pkt_q *pq = req->pq;
1034         struct hfi1_pkt_header *hdr = &req->hdr;
1035         u16 pbclen = le16_to_cpu(hdr->pbc[0]);
1036         u32 val32, tidval = 0, lrhlen = get_lrh_len(*hdr, pad_len(datalen));
1037         size_t array_size = ARRAY_SIZE(ahg);
1038
1039         if (PBC2LRH(pbclen) != lrhlen) {
1040                 /* PBC.PbcLengthDWs */
1041                 idx = ahg_header_set(ahg, idx, array_size, 0, 0, 12,
1042                                      (__force u16)cpu_to_le16(LRH2PBC(lrhlen)));
1043                 if (idx < 0)
1044                         return idx;
1045                 /* LRH.PktLen (we need the full 16 bits due to byte swap) */
1046                 idx = ahg_header_set(ahg, idx, array_size, 3, 0, 16,
1047                                      (__force u16)cpu_to_be16(lrhlen >> 2));
1048                 if (idx < 0)
1049                         return idx;
1050         }
1051
1052         /*
1053          * Do the common updates
1054          */
1055         /* BTH.PSN and BTH.A */
1056         val32 = (be32_to_cpu(hdr->bth[2]) + req->seqnum) &
1057                 (HFI1_CAP_IS_KSET(EXTENDED_PSN) ? 0x7fffffff : 0xffffff);
1058         if (unlikely(tx->flags & TXREQ_FLAGS_REQ_ACK))
1059                 val32 |= 1UL << 31;
1060         idx = ahg_header_set(ahg, idx, array_size, 6, 0, 16,
1061                              (__force u16)cpu_to_be16(val32 >> 16));
1062         if (idx < 0)
1063                 return idx;
1064         idx = ahg_header_set(ahg, idx, array_size, 6, 16, 16,
1065                              (__force u16)cpu_to_be16(val32 & 0xffff));
1066         if (idx < 0)
1067                 return idx;
1068         /* KDETH.Offset */
1069         idx = ahg_header_set(ahg, idx, array_size, 15, 0, 16,
1070                              (__force u16)cpu_to_le16(req->koffset & 0xffff));
1071         if (idx < 0)
1072                 return idx;
1073         idx = ahg_header_set(ahg, idx, array_size, 15, 16, 16,
1074                              (__force u16)cpu_to_le16(req->koffset >> 16));
1075         if (idx < 0)
1076                 return idx;
1077         if (req_opcode(req->info.ctrl) == EXPECTED) {
1078                 __le16 val;
1079
1080                 tidval = req->tids[req->tididx];
1081
1082                 /*
1083                  * If the offset puts us at the end of the current TID,
1084                  * advance everything.
1085                  */
1086                 if ((req->tidoffset) == (EXP_TID_GET(tidval, LEN) *
1087                                          PAGE_SIZE)) {
1088                         req->tidoffset = 0;
1089                         /*
1090                          * Since we don't copy all the TIDs, all at once,
1091                          * we have to check again.
1092                          */
1093                         if (++req->tididx > req->n_tids - 1 ||
1094                             !req->tids[req->tididx])
1095                                 return -EINVAL;
1096                         tidval = req->tids[req->tididx];
1097                 }
1098                 omfactor = ((EXP_TID_GET(tidval, LEN) *
1099                                   PAGE_SIZE) >=
1100                                  KDETH_OM_MAX_SIZE) ? KDETH_OM_LARGE_SHIFT :
1101                                  KDETH_OM_SMALL_SHIFT;
1102                 /* KDETH.OM and KDETH.OFFSET (TID) */
1103                 idx = ahg_header_set(
1104                                 ahg, idx, array_size, 7, 0, 16,
1105                                 ((!!(omfactor - KDETH_OM_SMALL_SHIFT)) << 15 |
1106                                 ((req->tidoffset >> omfactor)
1107                                 & 0x7fff)));
1108                 if (idx < 0)
1109                         return idx;
1110                 /* KDETH.TIDCtrl, KDETH.TID, KDETH.Intr, KDETH.SH */
1111                 val = cpu_to_le16(((EXP_TID_GET(tidval, CTRL) & 0x3) << 10) |
1112                                    (EXP_TID_GET(tidval, IDX) & 0x3ff));
1113
1114                 if (unlikely(tx->flags & TXREQ_FLAGS_REQ_DISABLE_SH)) {
1115                         val |= cpu_to_le16((KDETH_GET(hdr->kdeth.ver_tid_offset,
1116                                                       INTR) <<
1117                                             AHG_KDETH_INTR_SHIFT));
1118                 } else {
1119                         val |= KDETH_GET(hdr->kdeth.ver_tid_offset, SH) ?
1120                                cpu_to_le16(0x1 << AHG_KDETH_SH_SHIFT) :
1121                                cpu_to_le16((KDETH_GET(hdr->kdeth.ver_tid_offset,
1122                                                       INTR) <<
1123                                              AHG_KDETH_INTR_SHIFT));
1124                 }
1125
1126                 idx = ahg_header_set(ahg, idx, array_size,
1127                                      7, 16, 14, (__force u16)val);
1128                 if (idx < 0)
1129                         return idx;
1130         }
1131
1132         trace_hfi1_sdma_user_header_ahg(pq->dd, pq->ctxt, pq->subctxt,
1133                                         req->info.comp_idx, req->sde->this_idx,
1134                                         req->ahg_idx, ahg, idx, tidval);
1135         sdma_txinit_ahg(&tx->txreq,
1136                         SDMA_TXREQ_F_USE_AHG,
1137                         datalen, req->ahg_idx, idx,
1138                         ahg, sizeof(req->hdr),
1139                         user_sdma_txreq_cb);
1140
1141         return idx;
1142 }
1143
1144 /**
1145  * user_sdma_txreq_cb() - SDMA tx request completion callback.
1146  * @txreq: valid sdma tx request
1147  * @status: success/failure of request
1148  *
1149  * Called when the SDMA progress state machine gets notification that
1150  * the SDMA descriptors for this tx request have been processed by the
1151  * DMA engine. Called in interrupt context.
1152  * Only do work on completed sequences.
1153  */
1154 static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status)
1155 {
1156         struct user_sdma_txreq *tx =
1157                 container_of(txreq, struct user_sdma_txreq, txreq);
1158         struct user_sdma_request *req;
1159         struct hfi1_user_sdma_pkt_q *pq;
1160         struct hfi1_user_sdma_comp_q *cq;
1161         enum hfi1_sdma_comp_state state = COMPLETE;
1162
1163         if (!tx->req)
1164                 return;
1165
1166         req = tx->req;
1167         pq = req->pq;
1168         cq = req->cq;
1169
1170         if (status != SDMA_TXREQ_S_OK) {
1171                 SDMA_DBG(req, "SDMA completion with error %d",
1172                          status);
1173                 WRITE_ONCE(req->has_error, 1);
1174                 state = ERROR;
1175         }
1176
1177         req->seqcomp = tx->seqnum;
1178         kmem_cache_free(pq->txreq_cache, tx);
1179
1180         /* sequence isn't complete?  We are done */
1181         if (req->seqcomp != req->info.npkts - 1)
1182                 return;
1183
1184         user_sdma_free_request(req);
1185         set_comp_state(pq, cq, req->info.comp_idx, state, status);
1186         pq_update(pq);
1187 }
1188
1189 static inline void pq_update(struct hfi1_user_sdma_pkt_q *pq)
1190 {
1191         if (atomic_dec_and_test(&pq->n_reqs))
1192                 wake_up(&pq->wait);
1193 }
1194
1195 static void user_sdma_free_request(struct user_sdma_request *req)
1196 {
1197         if (!list_empty(&req->txps)) {
1198                 struct sdma_txreq *t, *p;
1199
1200                 list_for_each_entry_safe(t, p, &req->txps, list) {
1201                         struct user_sdma_txreq *tx =
1202                                 container_of(t, struct user_sdma_txreq, txreq);
1203                         list_del_init(&t->list);
1204                         sdma_txclean(req->pq->dd, t);
1205                         kmem_cache_free(req->pq->txreq_cache, tx);
1206                 }
1207         }
1208
1209         kfree(req->tids);
1210         clear_bit(req->info.comp_idx, req->pq->req_in_use);
1211 }
1212
1213 static inline void set_comp_state(struct hfi1_user_sdma_pkt_q *pq,
1214                                   struct hfi1_user_sdma_comp_q *cq,
1215                                   u16 idx, enum hfi1_sdma_comp_state state,
1216                                   int ret)
1217 {
1218         if (state == ERROR)
1219                 cq->comps[idx].errcode = -ret;
1220         smp_wmb(); /* make sure errcode is visible first */
1221         cq->comps[idx].status = state;
1222         trace_hfi1_sdma_user_completion(pq->dd, pq->ctxt, pq->subctxt,
1223                                         idx, state, ret);
1224 }