drivers/infiniband/hw/qib/qib_user_sdma.c

   1 /*
   2  * Copyright (c) 2007, 2008, 2009 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 #include <linux/mm.h>
  33 #include <linux/types.h>
  34 #include <linux/device.h>
  35 #include <linux/dmapool.h>
  36 #include <linux/slab.h>
  37 #include <linux/list.h>
  38 #include <linux/highmem.h>
  39 #include <linux/io.h>
  40 #include <linux/uio.h>
  41 #include <linux/rbtree.h>
  42 #include <linux/spinlock.h>
  43 #include <linux/delay.h>
  44
  45 #include "qib.h"
  46 #include "qib_user_sdma.h"
  47
  48 /* minimum size of header */
  49 #define QIB_USER_SDMA_MIN_HEADER_LENGTH 64
  50 /* expected size of headers (for dma_pool) */
  51 #define QIB_USER_SDMA_EXP_HEADER_LENGTH 64
  52 /* attempt to drain the queue for 5secs */
  53 #define QIB_USER_SDMA_DRAIN_TIMEOUT 500
  54
  55 struct qib_user_sdma_pkt {
  56         u8 naddr;               /* dimension of addr (1..3) ... */
  57         u32 counter;            /* sdma pkts queued counter for this entry */
  58         u64 added;              /* global descq number of entries */
  59
  60         struct {
  61                 u32 offset;                     /* offset for kvaddr, addr */
  62                 u32 length;                     /* length in page */
  63                 u8  put_page;                   /* should we put_page? */
  64                 u8  dma_mapped;                 /* is page dma_mapped? */
  65                 struct page *page;              /* may be NULL (coherent mem) */
  66                 void *kvaddr;                   /* FIXME: only for pio hack */
  67                 dma_addr_t addr;
  68         } addr[4];   /* max pages, any more and we coalesce */
  69         struct list_head list;  /* list element */
  70 };
  71
  72 struct qib_user_sdma_queue {
  73         /*
  74          * pkts sent to dma engine are queued on this
  75          * list head.  the type of the elements of this
  76          * list are struct qib_user_sdma_pkt...
  77          */
  78         struct list_head sent;
  79
  80         /* headers with expected length are allocated from here... */
  81         char header_cache_name[64];
  82         struct dma_pool *header_cache;
  83
  84         /* packets are allocated from the slab cache... */
  85         char pkt_slab_name[64];
  86         struct kmem_cache *pkt_slab;
  87
  88         /* as packets go on the queued queue, they are counted... */
  89         u32 counter;
  90         u32 sent_counter;
  91
  92         /* dma page table */
  93         struct rb_root dma_pages_root;
  94
  95         /* protect everything above... */
  96         struct mutex lock;
  97 };
  98
  99 struct qib_user_sdma_queue *
 100 qib_user_sdma_queue_create(struct device *dev, int unit, int ctxt, int sctxt)
 101 {
 102         struct qib_user_sdma_queue *pq =
 103                 kmalloc(sizeof(struct qib_user_sdma_queue), GFP_KERNEL);
 104
 105         if (!pq)
 106                 goto done;
 107
 108         pq->counter = 0;
 109         pq->sent_counter = 0;
 110         INIT_LIST_HEAD(&pq->sent);
 111
 112         mutex_init(&pq->lock);
 113
 114         snprintf(pq->pkt_slab_name, sizeof(pq->pkt_slab_name),
 115                  "qib-user-sdma-pkts-%u-%02u.%02u", unit, ctxt, sctxt);
 116         pq->pkt_slab = kmem_cache_create(pq->pkt_slab_name,
 117                                          sizeof(struct qib_user_sdma_pkt),
 118                                          0, 0, NULL);
 119
 120         if (!pq->pkt_slab)
 121                 goto err_kfree;
 122
 123         snprintf(pq->header_cache_name, sizeof(pq->header_cache_name),
 124                  "qib-user-sdma-headers-%u-%02u.%02u", unit, ctxt, sctxt);
 125         pq->header_cache = dma_pool_create(pq->header_cache_name,
 126                                            dev,
 127                                            QIB_USER_SDMA_EXP_HEADER_LENGTH,
 128                                            4, 0);
 129         if (!pq->header_cache)
 130                 goto err_slab;
 131
 132         pq->dma_pages_root = RB_ROOT;
 133
 134         goto done;
 135
 136 err_slab:
 137         kmem_cache_destroy(pq->pkt_slab);
 138 err_kfree:
 139         kfree(pq);
 140         pq = NULL;
 141
 142 done:
 143         return pq;
 144 }
 145
 146 static void qib_user_sdma_init_frag(struct qib_user_sdma_pkt *pkt,
 147                                     int i, size_t offset, size_t len,
 148                                     int put_page, int dma_mapped,
 149                                     struct page *page,
 150                                     void *kvaddr, dma_addr_t dma_addr)
 151 {
 152         pkt->addr[i].offset = offset;
 153         pkt->addr[i].length = len;
 154         pkt->addr[i].put_page = put_page;
 155         pkt->addr[i].dma_mapped = dma_mapped;
 156         pkt->addr[i].page = page;
 157         pkt->addr[i].kvaddr = kvaddr;
 158         pkt->addr[i].addr = dma_addr;
 159 }
 160
 161 static void qib_user_sdma_init_header(struct qib_user_sdma_pkt *pkt,
 162                                       u32 counter, size_t offset,
 163                                       size_t len, int dma_mapped,
 164                                       struct page *page,
 165                                       void *kvaddr, dma_addr_t dma_addr)
 166 {
 167         pkt->naddr = 1;
 168         pkt->counter = counter;
 169         qib_user_sdma_init_frag(pkt, 0, offset, len, 0, dma_mapped, page,
 170                                 kvaddr, dma_addr);
 171 }
 172
 173 /* we've too many pages in the iovec, coalesce to a single page */
 174 static int qib_user_sdma_coalesce(const struct qib_devdata *dd,
 175                                   struct qib_user_sdma_pkt *pkt,
 176                                   const struct iovec *iov,
 177                                   unsigned long niov)
 178 {
 179         int ret = 0;
 180         struct page *page = alloc_page(GFP_KERNEL);
 181         void *mpage_save;
 182         char *mpage;
 183         int i;
 184         int len = 0;
 185         dma_addr_t dma_addr;
 186
 187         if (!page) {
 188                 ret = -ENOMEM;
 189                 goto done;
 190         }
 191
 192         mpage = kmap(page);
 193         mpage_save = mpage;
 194         for (i = 0; i < niov; i++) {
 195                 int cfur;
 196
 197                 cfur = copy_from_user(mpage,
 198                                       iov[i].iov_base, iov[i].iov_len);
 199                 if (cfur) {
 200                         ret = -EFAULT;
 201                         goto free_unmap;
 202                 }
 203
 204                 mpage += iov[i].iov_len;
 205                 len += iov[i].iov_len;
 206         }
 207
 208         dma_addr = dma_map_page(&dd->pcidev->dev, page, 0, len,
 209                                 DMA_TO_DEVICE);
 210         if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
 211                 ret = -ENOMEM;
 212                 goto free_unmap;
 213         }
 214
 215         qib_user_sdma_init_frag(pkt, 1, 0, len, 0, 1, page, mpage_save,
 216                                 dma_addr);
 217         pkt->naddr = 2;
 218
 219         goto done;
 220
 221 free_unmap:
 222         kunmap(page);
 223         __free_page(page);
 224 done:
 225         return ret;
 226 }
 227
 228 /*
 229  * How many pages in this iovec element?
 230  */
 231 static int qib_user_sdma_num_pages(const struct iovec *iov)
 232 {
 233         const unsigned long addr  = (unsigned long) iov->iov_base;
 234         const unsigned long  len  = iov->iov_len;
 235         const unsigned long spage = addr & PAGE_MASK;
 236         const unsigned long epage = (addr + len - 1) & PAGE_MASK;
 237
 238         return 1 + ((epage - spage) >> PAGE_SHIFT);
 239 }
 240
 241 /*
 242  * Truncate length to page boundary.
 243  */
 244 static int qib_user_sdma_page_length(unsigned long addr, unsigned long len)
 245 {
 246         const unsigned long offset = addr & ~PAGE_MASK;
 247
 248         return ((offset + len) > PAGE_SIZE) ? (PAGE_SIZE - offset) : len;
 249 }
 250
 251 static void qib_user_sdma_free_pkt_frag(struct device *dev,
 252                                         struct qib_user_sdma_queue *pq,
 253                                         struct qib_user_sdma_pkt *pkt,
 254                                         int frag)
 255 {
 256         const int i = frag;
 257
 258         if (pkt->addr[i].page) {
 259                 if (pkt->addr[i].dma_mapped)
 260                         dma_unmap_page(dev,
 261                                        pkt->addr[i].addr,
 262                                        pkt->addr[i].length,
 263                                        DMA_TO_DEVICE);
 264
 265                 if (pkt->addr[i].kvaddr)
 266                         kunmap(pkt->addr[i].page);
 267
 268                 if (pkt->addr[i].put_page)
 269                         put_page(pkt->addr[i].page);
 270                 else
 271                         __free_page(pkt->addr[i].page);
 272         } else if (pkt->addr[i].kvaddr)
 273                 /* free coherent mem from cache... */
 274                 dma_pool_free(pq->header_cache,
 275                               pkt->addr[i].kvaddr, pkt->addr[i].addr);
 276 }
 277
 278 /* return number of pages pinned... */
 279 static int qib_user_sdma_pin_pages(const struct qib_devdata *dd,
 280                                    struct qib_user_sdma_pkt *pkt,
 281                                    unsigned long addr, int tlen, int npages)
 282 {
 283         struct page *pages[2];
 284         int j;
 285         int ret;
 286
 287         ret = get_user_pages(current, current->mm, addr,
 288                              npages, 0, 1, pages, NULL);
 289
 290         if (ret != npages) {
 291                 int i;
 292
 293                 for (i = 0; i < ret; i++)
 294                         put_page(pages[i]);
 295
 296                 ret = -ENOMEM;
 297                 goto done;
 298         }
 299
 300         for (j = 0; j < npages; j++) {
 301                 /* map the pages... */
 302                 const int flen = qib_user_sdma_page_length(addr, tlen);
 303                 dma_addr_t dma_addr =
 304                         dma_map_page(&dd->pcidev->dev,
 305                                      pages[j], 0, flen, DMA_TO_DEVICE);
 306                 unsigned long fofs = addr & ~PAGE_MASK;
 307
 308                 if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
 309                         ret = -ENOMEM;
 310                         goto done;
 311                 }
 312
 313                 qib_user_sdma_init_frag(pkt, pkt->naddr, fofs, flen, 1, 1,
 314                                         pages[j], kmap(pages[j]), dma_addr);
 315
 316                 pkt->naddr++;
 317                 addr += flen;
 318                 tlen -= flen;
 319         }
 320
 321 done:
 322         return ret;
 323 }
 324
 325 static int qib_user_sdma_pin_pkt(const struct qib_devdata *dd,
 326                                  struct qib_user_sdma_queue *pq,
 327                                  struct qib_user_sdma_pkt *pkt,
 328                                  const struct iovec *iov,
 329                                  unsigned long niov)
 330 {
 331         int ret = 0;
 332         unsigned long idx;
 333
 334         for (idx = 0; idx < niov; idx++) {
 335                 const int npages = qib_user_sdma_num_pages(iov + idx);
 336                 const unsigned long addr = (unsigned long) iov[idx].iov_base;
 337
 338                 ret = qib_user_sdma_pin_pages(dd, pkt, addr,
 339                                               iov[idx].iov_len, npages);
 340                 if (ret < 0)
 341                         goto free_pkt;
 342         }
 343
 344         goto done;
 345
 346 free_pkt:
 347         for (idx = 0; idx < pkt->naddr; idx++)
 348                 qib_user_sdma_free_pkt_frag(&dd->pcidev->dev, pq, pkt, idx);
 349
 350 done:
 351         return ret;
 352 }
 353
 354 static int qib_user_sdma_init_payload(const struct qib_devdata *dd,
 355                                       struct qib_user_sdma_queue *pq,
 356                                       struct qib_user_sdma_pkt *pkt,
 357                                       const struct iovec *iov,
 358                                       unsigned long niov, int npages)
 359 {
 360         int ret = 0;
 361
 362         if (npages >= ARRAY_SIZE(pkt->addr))
 363                 ret = qib_user_sdma_coalesce(dd, pkt, iov, niov);
 364         else
 365                 ret = qib_user_sdma_pin_pkt(dd, pq, pkt, iov, niov);
 366
 367         return ret;
 368 }
 369
 370 /* free a packet list -- return counter value of last packet */
 371 static void qib_user_sdma_free_pkt_list(struct device *dev,
 372                                         struct qib_user_sdma_queue *pq,
 373                                         struct list_head *list)
 374 {
 375         struct qib_user_sdma_pkt *pkt, *pkt_next;
 376
 377         list_for_each_entry_safe(pkt, pkt_next, list, list) {
 378                 int i;
 379
 380                 for (i = 0; i < pkt->naddr; i++)
 381                         qib_user_sdma_free_pkt_frag(dev, pq, pkt, i);
 382
 383                 kmem_cache_free(pq->pkt_slab, pkt);
 384         }
 385         INIT_LIST_HEAD(list);
 386 }
 387
 388 /*
 389  * copy headers, coalesce etc -- pq->lock must be held
 390  *
 391  * we queue all the packets to list, returning the
 392  * number of bytes total.  list must be empty initially,
 393  * as, if there is an error we clean it...
 394  */
 395 static int qib_user_sdma_queue_pkts(const struct qib_devdata *dd,
 396                                     struct qib_user_sdma_queue *pq,
 397                                     struct list_head *list,
 398                                     const struct iovec *iov,
 399                                     unsigned long niov,
 400                                     int maxpkts)
 401 {
 402         unsigned long idx = 0;
 403         int ret = 0;
 404         int npkts = 0;
 405         struct page *page = NULL;
 406         __le32 *pbc;
 407         dma_addr_t dma_addr;
 408         struct qib_user_sdma_pkt *pkt = NULL;
 409         size_t len;
 410         size_t nw;
 411         u32 counter = pq->counter;
 412         int dma_mapped = 0;
 413
 414         while (idx < niov && npkts < maxpkts) {
 415                 const unsigned long addr = (unsigned long) iov[idx].iov_base;
 416                 const unsigned long idx_save = idx;
 417                 unsigned pktnw;
 418                 unsigned pktnwc;
 419                 int nfrags = 0;
 420                 int npages = 0;
 421                 int cfur;
 422
 423                 dma_mapped = 0;
 424                 len = iov[idx].iov_len;
 425                 nw = len >> 2;
 426                 page = NULL;
 427
 428                 pkt = kmem_cache_alloc(pq->pkt_slab, GFP_KERNEL);
 429                 if (!pkt) {
 430                         ret = -ENOMEM;
 431                         goto free_list;
 432                 }
 433
 434                 if (len < QIB_USER_SDMA_MIN_HEADER_LENGTH ||
 435                     len > PAGE_SIZE || len & 3 || addr & 3) {
 436                         ret = -EINVAL;
 437                         goto free_pkt;
 438                 }
 439
 440                 if (len == QIB_USER_SDMA_EXP_HEADER_LENGTH)
 441                         pbc = dma_pool_alloc(pq->header_cache, GFP_KERNEL,
 442                                              &dma_addr);
 443                 else
 444                         pbc = NULL;
 445
 446                 if (!pbc) {
 447                         page = alloc_page(GFP_KERNEL);
 448                         if (!page) {
 449                                 ret = -ENOMEM;
 450                                 goto free_pkt;
 451                         }
 452                         pbc = kmap(page);
 453                 }
 454
 455                 cfur = copy_from_user(pbc, iov[idx].iov_base, len);
 456                 if (cfur) {
 457                         ret = -EFAULT;
 458                         goto free_pbc;
 459                 }
 460
 461                 /*
 462                  * This assignment is a bit strange.  it's because the
 463                  * the pbc counts the number of 32 bit words in the full
 464                  * packet _except_ the first word of the pbc itself...
 465                  */
 466                 pktnwc = nw - 1;
 467
 468                 /*
 469                  * pktnw computation yields the number of 32 bit words
 470                  * that the caller has indicated in the PBC.  note that
 471                  * this is one less than the total number of words that
 472                  * goes to the send DMA engine as the first 32 bit word
 473                  * of the PBC itself is not counted.  Armed with this count,
 474                  * we can verify that the packet is consistent with the
 475                  * iovec lengths.
 476                  */
 477                 pktnw = le32_to_cpu(*pbc) & QIB_PBC_LENGTH_MASK;
 478                 if (pktnw < pktnwc || pktnw > pktnwc + (PAGE_SIZE >> 2)) {
 479                         ret = -EINVAL;
 480                         goto free_pbc;
 481                 }
 482
 483                 idx++;
 484                 while (pktnwc < pktnw && idx < niov) {
 485                         const size_t slen = iov[idx].iov_len;
 486                         const unsigned long faddr =
 487                                 (unsigned long) iov[idx].iov_base;
 488
 489                         if (slen & 3 || faddr & 3 || !slen ||
 490                             slen > PAGE_SIZE) {
 491                                 ret = -EINVAL;
 492                                 goto free_pbc;
 493                         }
 494
 495                         npages++;
 496                         if ((faddr & PAGE_MASK) !=
 497                             ((faddr + slen - 1) & PAGE_MASK))
 498                                 npages++;
 499
 500                         pktnwc += slen >> 2;
 501                         idx++;
 502                         nfrags++;
 503                 }
 504
 505                 if (pktnwc != pktnw) {
 506                         ret = -EINVAL;
 507                         goto free_pbc;
 508                 }
 509
 510                 if (page) {
 511                         dma_addr = dma_map_page(&dd->pcidev->dev,
 512                                                 page, 0, len, DMA_TO_DEVICE);
 513                         if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
 514                                 ret = -ENOMEM;
 515                                 goto free_pbc;
 516                         }
 517
 518                         dma_mapped = 1;
 519                 }
 520
 521                 qib_user_sdma_init_header(pkt, counter, 0, len, dma_mapped,
 522                                           page, pbc, dma_addr);
 523
 524                 if (nfrags) {
 525                         ret = qib_user_sdma_init_payload(dd, pq, pkt,
 526                                                          iov + idx_save + 1,
 527                                                          nfrags, npages);
 528                         if (ret < 0)
 529                                 goto free_pbc_dma;
 530                 }
 531
 532                 counter++;
 533                 npkts++;
 534
 535                 list_add_tail(&pkt->list, list);
 536         }
 537
 538         ret = idx;
 539         goto done;
 540
 541 free_pbc_dma:
 542         if (dma_mapped)
 543                 dma_unmap_page(&dd->pcidev->dev, dma_addr, len, DMA_TO_DEVICE);
 544 free_pbc:
 545         if (page) {
 546                 kunmap(page);
 547                 __free_page(page);
 548         } else
 549                 dma_pool_free(pq->header_cache, pbc, dma_addr);
 550 free_pkt:
 551         kmem_cache_free(pq->pkt_slab, pkt);
 552 free_list:
 553         qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, list);
 554 done:
 555         return ret;
 556 }
 557
 558 static void qib_user_sdma_set_complete_counter(struct qib_user_sdma_queue *pq,
 559                                                u32 c)
 560 {
 561         pq->sent_counter = c;
 562 }
 563
 564 /* try to clean out queue -- needs pq->lock */
 565 static int qib_user_sdma_queue_clean(struct qib_pportdata *ppd,
 566                                      struct qib_user_sdma_queue *pq)
 567 {
 568         struct qib_devdata *dd = ppd->dd;
 569         struct list_head free_list;
 570         struct qib_user_sdma_pkt *pkt;
 571         struct qib_user_sdma_pkt *pkt_prev;
 572         int ret = 0;
 573
 574         INIT_LIST_HEAD(&free_list);
 575
 576         list_for_each_entry_safe(pkt, pkt_prev, &pq->sent, list) {
 577                 s64 descd = ppd->sdma_descq_removed - pkt->added;
 578
 579                 if (descd < 0)
 580                         break;
 581
 582                 list_move_tail(&pkt->list, &free_list);
 583
 584                 /* one more packet cleaned */
 585                 ret++;
 586         }
 587
 588         if (!list_empty(&free_list)) {
 589                 u32 counter;
 590
 591                 pkt = list_entry(free_list.prev,
 592                                  struct qib_user_sdma_pkt, list);
 593                 counter = pkt->counter;
 594
 595                 qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
 596                 qib_user_sdma_set_complete_counter(pq, counter);
 597         }
 598
 599         return ret;
 600 }
 601
 602 void qib_user_sdma_queue_destroy(struct qib_user_sdma_queue *pq)
 603 {
 604         if (!pq)
 605                 return;
 606
 607         kmem_cache_destroy(pq->pkt_slab);
 608         dma_pool_destroy(pq->header_cache);
 609         kfree(pq);
 610 }
 611
 612 /* clean descriptor queue, returns > 0 if some elements cleaned */
 613 static int qib_user_sdma_hwqueue_clean(struct qib_pportdata *ppd)
 614 {
 615         int ret;
 616         unsigned long flags;
 617
 618         spin_lock_irqsave(&ppd->sdma_lock, flags);
 619         ret = qib_sdma_make_progress(ppd);
 620         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 621
 622         return ret;
 623 }
 624
 625 /* we're in close, drain packets so that we can cleanup successfully... */
 626 void qib_user_sdma_queue_drain(struct qib_pportdata *ppd,
 627                                struct qib_user_sdma_queue *pq)
 628 {
 629         struct qib_devdata *dd = ppd->dd;
 630         int i;
 631
 632         if (!pq)
 633                 return;
 634
 635         for (i = 0; i < QIB_USER_SDMA_DRAIN_TIMEOUT; i++) {
 636                 mutex_lock(&pq->lock);
 637                 if (list_empty(&pq->sent)) {
 638                         mutex_unlock(&pq->lock);
 639                         break;
 640                 }
 641                 qib_user_sdma_hwqueue_clean(ppd);
 642                 qib_user_sdma_queue_clean(ppd, pq);
 643                 mutex_unlock(&pq->lock);
 644                 msleep(10);
 645         }
 646
 647         if (!list_empty(&pq->sent)) {
 648                 struct list_head free_list;
 649
 650                 qib_dev_err(dd, "user sdma lists not empty: forcing!\n");
 651                 INIT_LIST_HEAD(&free_list);
 652                 mutex_lock(&pq->lock);
 653                 list_splice_init(&pq->sent, &free_list);
 654                 qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
 655                 mutex_unlock(&pq->lock);
 656         }
 657 }
 658
 659 static inline __le64 qib_sdma_make_desc0(struct qib_pportdata *ppd,
 660                                          u64 addr, u64 dwlen, u64 dwoffset)
 661 {
 662         u8 tmpgen;
 663
 664         tmpgen = ppd->sdma_generation;
 665
 666         return cpu_to_le64(/* SDmaPhyAddr[31:0] */
 667                            ((addr & 0xfffffffcULL) << 32) |
 668                            /* SDmaGeneration[1:0] */
 669                            ((tmpgen & 3ULL) << 30) |
 670                            /* SDmaDwordCount[10:0] */
 671                            ((dwlen & 0x7ffULL) << 16) |
 672                            /* SDmaBufOffset[12:2] */
 673                            (dwoffset & 0x7ffULL));
 674 }
 675
 676 static inline __le64 qib_sdma_make_first_desc0(__le64 descq)
 677 {
 678         return descq | cpu_to_le64(1ULL << 12);
 679 }
 680
 681 static inline __le64 qib_sdma_make_last_desc0(__le64 descq)
 682 {
 683                                               /* last */  /* dma head */
 684         return descq | cpu_to_le64(1ULL << 11 | 1ULL << 13);
 685 }
 686
 687 static inline __le64 qib_sdma_make_desc1(u64 addr)
 688 {
 689         /* SDmaPhyAddr[47:32] */
 690         return cpu_to_le64(addr >> 32);
 691 }
 692
 693 static void qib_user_sdma_send_frag(struct qib_pportdata *ppd,
 694                                     struct qib_user_sdma_pkt *pkt, int idx,
 695                                     unsigned ofs, u16 tail)
 696 {
 697         const u64 addr = (u64) pkt->addr[idx].addr +
 698                 (u64) pkt->addr[idx].offset;
 699         const u64 dwlen = (u64) pkt->addr[idx].length / 4;
 700         __le64 *descqp;
 701         __le64 descq0;
 702
 703         descqp = &ppd->sdma_descq[tail].qw[0];
 704
 705         descq0 = qib_sdma_make_desc0(ppd, addr, dwlen, ofs);
 706         if (idx == 0)
 707                 descq0 = qib_sdma_make_first_desc0(descq0);
 708         if (idx == pkt->naddr - 1)
 709                 descq0 = qib_sdma_make_last_desc0(descq0);
 710
 711         descqp[0] = descq0;
 712         descqp[1] = qib_sdma_make_desc1(addr);
 713 }
 714
 715 /* pq->lock must be held, get packets on the wire... */
 716 static int qib_user_sdma_push_pkts(struct qib_pportdata *ppd,
 717                                    struct qib_user_sdma_queue *pq,
 718                                    struct list_head *pktlist)
 719 {
 720         struct qib_devdata *dd = ppd->dd;
 721         int ret = 0;
 722         unsigned long flags;
 723         u16 tail;
 724         u8 generation;
 725         u64 descq_added;
 726
 727         if (list_empty(pktlist))
 728                 return 0;
 729
 730         if (unlikely(!(ppd->lflags & QIBL_LINKACTIVE)))
 731                 return -ECOMM;
 732
 733         spin_lock_irqsave(&ppd->sdma_lock, flags);
 734
 735         /* keep a copy for restoring purposes in case of problems */
 736         generation = ppd->sdma_generation;
 737         descq_added = ppd->sdma_descq_added;
 738
 739         if (unlikely(!__qib_sdma_running(ppd))) {
 740                 ret = -ECOMM;
 741                 goto unlock;
 742         }
 743
 744         tail = ppd->sdma_descq_tail;
 745         while (!list_empty(pktlist)) {
 746                 struct qib_user_sdma_pkt *pkt =
 747                         list_entry(pktlist->next, struct qib_user_sdma_pkt,
 748                                    list);
 749                 int i;
 750                 unsigned ofs = 0;
 751                 u16 dtail = tail;
 752
 753                 if (pkt->naddr > qib_sdma_descq_freecnt(ppd))
 754                         goto unlock_check_tail;
 755
 756                 for (i = 0; i < pkt->naddr; i++) {
 757                         qib_user_sdma_send_frag(ppd, pkt, i, ofs, tail);
 758                         ofs += pkt->addr[i].length >> 2;
 759
 760                         if (++tail == ppd->sdma_descq_cnt) {
 761                                 tail = 0;
 762                                 ++ppd->sdma_generation;
 763                         }
 764                 }
 765
 766                 if ((ofs << 2) > ppd->ibmaxlen) {
 767                         ret = -EMSGSIZE;
 768                         goto unlock;
 769                 }
 770
 771                 /*
 772                  * If the packet is >= 2KB mtu equivalent, we have to use
 773                  * the large buffers, and have to mark each descriptor as
 774                  * part of a large buffer packet.
 775                  */
 776                 if (ofs > dd->piosize2kmax_dwords) {
 777                         for (i = 0; i < pkt->naddr; i++) {
 778                                 ppd->sdma_descq[dtail].qw[0] |=
 779                                         cpu_to_le64(1ULL << 14);
 780                                 if (++dtail == ppd->sdma_descq_cnt)
 781                                         dtail = 0;
 782                         }
 783                 }
 784
 785                 ppd->sdma_descq_added += pkt->naddr;
 786                 pkt->added = ppd->sdma_descq_added;
 787                 list_move_tail(&pkt->list, &pq->sent);
 788                 ret++;
 789         }
 790
 791 unlock_check_tail:
 792         /* advance the tail on the chip if necessary */
 793         if (ppd->sdma_descq_tail != tail)
 794                 dd->f_sdma_update_tail(ppd, tail);
 795
 796 unlock:
 797         if (unlikely(ret < 0)) {
 798                 ppd->sdma_generation = generation;
 799                 ppd->sdma_descq_added = descq_added;
 800         }
 801         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 802
 803         return ret;
 804 }
 805
 806 int qib_user_sdma_writev(struct qib_ctxtdata *rcd,
 807                          struct qib_user_sdma_queue *pq,
 808                          const struct iovec *iov,
 809                          unsigned long dim)
 810 {
 811         struct qib_devdata *dd = rcd->dd;
 812         struct qib_pportdata *ppd = rcd->ppd;
 813         int ret = 0;
 814         struct list_head list;
 815         int npkts = 0;
 816
 817         INIT_LIST_HEAD(&list);
 818
 819         mutex_lock(&pq->lock);
 820
 821         /* why not -ECOMM like qib_user_sdma_push_pkts() below? */
 822         if (!qib_sdma_running(ppd))
 823                 goto done_unlock;
 824
 825         if (ppd->sdma_descq_added != ppd->sdma_descq_removed) {
 826                 qib_user_sdma_hwqueue_clean(ppd);
 827                 qib_user_sdma_queue_clean(ppd, pq);
 828         }
 829
 830         while (dim) {
 831                 const int mxp = 8;
 832
 833                 down_write(&current->mm->mmap_sem);
 834                 ret = qib_user_sdma_queue_pkts(dd, pq, &list, iov, dim, mxp);
 835                 up_write(&current->mm->mmap_sem);
 836
 837                 if (ret <= 0)
 838                         goto done_unlock;
 839                 else {
 840                         dim -= ret;
 841                         iov += ret;
 842                 }
 843
 844                 /* force packets onto the sdma hw queue... */
 845                 if (!list_empty(&list)) {
 846                         /*
 847                          * Lazily clean hw queue.  the 4 is a guess of about
 848                          * how many sdma descriptors a packet will take (it
 849                          * doesn't have to be perfect).
 850                          */
 851                         if (qib_sdma_descq_freecnt(ppd) < ret * 4) {
 852                                 qib_user_sdma_hwqueue_clean(ppd);
 853                                 qib_user_sdma_queue_clean(ppd, pq);
 854                         }
 855
 856                         ret = qib_user_sdma_push_pkts(ppd, pq, &list);
 857                         if (ret < 0)
 858                                 goto done_unlock;
 859                         else {
 860                                 npkts += ret;
 861                                 pq->counter += ret;
 862
 863                                 if (!list_empty(&list))
 864                                         goto done_unlock;
 865                         }
 866                 }
 867         }
 868
 869 done_unlock:
 870         if (!list_empty(&list))
 871                 qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &list);
 872         mutex_unlock(&pq->lock);
 873
 874         return (ret < 0) ? ret : npkts;
 875 }
 876
 877 int qib_user_sdma_make_progress(struct qib_pportdata *ppd,
 878                                 struct qib_user_sdma_queue *pq)
 879 {
 880         int ret = 0;
 881
 882         mutex_lock(&pq->lock);
 883         qib_user_sdma_hwqueue_clean(ppd);
 884         ret = qib_user_sdma_queue_clean(ppd, pq);
 885         mutex_unlock(&pq->lock);
 886
 887         return ret;
 888 }
 889
 890 u32 qib_user_sdma_complete_counter(const struct qib_user_sdma_queue *pq)
 891 {
 892         return pq ? pq->sent_counter : 0;
 893 }
 894
 895 u32 qib_user_sdma_inflight_counter(struct qib_user_sdma_queue *pq)
 896 {
 897         return pq ? pq->counter : 0;
 898 }