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 boundry.
 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 }
 386
 387 /*
 388  * copy headers, coalesce etc -- pq->lock must be held
 389  *
 390  * we queue all the packets to list, returning the
 391  * number of bytes total.  list must be empty initially,
 392  * as, if there is an error we clean it...
 393  */
 394 static int qib_user_sdma_queue_pkts(const struct qib_devdata *dd,
 395                                     struct qib_user_sdma_queue *pq,
 396                                     struct list_head *list,
 397                                     const struct iovec *iov,
 398                                     unsigned long niov,
 399                                     int maxpkts)
 400 {
 401         unsigned long idx = 0;
 402         int ret = 0;
 403         int npkts = 0;
 404         struct page *page = NULL;
 405         __le32 *pbc;
 406         dma_addr_t dma_addr;
 407         struct qib_user_sdma_pkt *pkt = NULL;
 408         size_t len;
 409         size_t nw;
 410         u32 counter = pq->counter;
 411         int dma_mapped = 0;
 412
 413         while (idx < niov && npkts < maxpkts) {
 414                 const unsigned long addr = (unsigned long) iov[idx].iov_base;
 415                 const unsigned long idx_save = idx;
 416                 unsigned pktnw;
 417                 unsigned pktnwc;
 418                 int nfrags = 0;
 419                 int npages = 0;
 420                 int cfur;
 421
 422                 dma_mapped = 0;
 423                 len = iov[idx].iov_len;
 424                 nw = len >> 2;
 425                 page = NULL;
 426
 427                 pkt = kmem_cache_alloc(pq->pkt_slab, GFP_KERNEL);
 428                 if (!pkt) {
 429                         ret = -ENOMEM;
 430                         goto free_list;
 431                 }
 432
 433                 if (len < QIB_USER_SDMA_MIN_HEADER_LENGTH ||
 434                     len > PAGE_SIZE || len & 3 || addr & 3) {
 435                         ret = -EINVAL;
 436                         goto free_pkt;
 437                 }
 438
 439                 if (len == QIB_USER_SDMA_EXP_HEADER_LENGTH)
 440                         pbc = dma_pool_alloc(pq->header_cache, GFP_KERNEL,
 441                                              &dma_addr);
 442                 else
 443                         pbc = NULL;
 444
 445                 if (!pbc) {
 446                         page = alloc_page(GFP_KERNEL);
 447                         if (!page) {
 448                                 ret = -ENOMEM;
 449                                 goto free_pkt;
 450                         }
 451                         pbc = kmap(page);
 452                 }
 453
 454                 cfur = copy_from_user(pbc, iov[idx].iov_base, len);
 455                 if (cfur) {
 456                         ret = -EFAULT;
 457                         goto free_pbc;
 458                 }
 459
 460                 /*
 461                  * This assignment is a bit strange.  it's because the
 462                  * the pbc counts the number of 32 bit words in the full
 463                  * packet _except_ the first word of the pbc itself...
 464                  */
 465                 pktnwc = nw - 1;
 466
 467                 /*
 468                  * pktnw computation yields the number of 32 bit words
 469                  * that the caller has indicated in the PBC.  note that
 470                  * this is one less than the total number of words that
 471                  * goes to the send DMA engine as the first 32 bit word
 472                  * of the PBC itself is not counted.  Armed with this count,
 473                  * we can verify that the packet is consistent with the
 474                  * iovec lengths.
 475                  */
 476                 pktnw = le32_to_cpu(*pbc) & QIB_PBC_LENGTH_MASK;
 477                 if (pktnw < pktnwc || pktnw > pktnwc + (PAGE_SIZE >> 2)) {
 478                         ret = -EINVAL;
 479                         goto free_pbc;
 480                 }
 481
 482                 idx++;
 483                 while (pktnwc < pktnw && idx < niov) {
 484                         const size_t slen = iov[idx].iov_len;
 485                         const unsigned long faddr =
 486                                 (unsigned long) iov[idx].iov_base;
 487
 488                         if (slen & 3 || faddr & 3 || !slen ||
 489                             slen > PAGE_SIZE) {
 490                                 ret = -EINVAL;
 491                                 goto free_pbc;
 492                         }
 493
 494                         npages++;
 495                         if ((faddr & PAGE_MASK) !=
 496                             ((faddr + slen - 1) & PAGE_MASK))
 497                                 npages++;
 498
 499                         pktnwc += slen >> 2;
 500                         idx++;
 501                         nfrags++;
 502                 }
 503
 504                 if (pktnwc != pktnw) {
 505                         ret = -EINVAL;
 506                         goto free_pbc;
 507                 }
 508
 509                 if (page) {
 510                         dma_addr = dma_map_page(&dd->pcidev->dev,
 511                                                 page, 0, len, DMA_TO_DEVICE);
 512                         if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
 513                                 ret = -ENOMEM;
 514                                 goto free_pbc;
 515                         }
 516
 517                         dma_mapped = 1;
 518                 }
 519
 520                 qib_user_sdma_init_header(pkt, counter, 0, len, dma_mapped,
 521                                           page, pbc, dma_addr);
 522
 523                 if (nfrags) {
 524                         ret = qib_user_sdma_init_payload(dd, pq, pkt,
 525                                                          iov + idx_save + 1,
 526                                                          nfrags, npages);
 527                         if (ret < 0)
 528                                 goto free_pbc_dma;
 529                 }
 530
 531                 counter++;
 532                 npkts++;
 533
 534                 list_add_tail(&pkt->list, list);
 535         }
 536
 537         ret = idx;
 538         goto done;
 539
 540 free_pbc_dma:
 541         if (dma_mapped)
 542                 dma_unmap_page(&dd->pcidev->dev, dma_addr, len, DMA_TO_DEVICE);
 543 free_pbc:
 544         if (page) {
 545                 kunmap(page);
 546                 __free_page(page);
 547         } else
 548                 dma_pool_free(pq->header_cache, pbc, dma_addr);
 549 free_pkt:
 550         kmem_cache_free(pq->pkt_slab, pkt);
 551 free_list:
 552         qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, list);
 553 done:
 554         return ret;
 555 }
 556
 557 static void qib_user_sdma_set_complete_counter(struct qib_user_sdma_queue *pq,
 558                                                u32 c)
 559 {
 560         pq->sent_counter = c;
 561 }
 562
 563 /* try to clean out queue -- needs pq->lock */
 564 static int qib_user_sdma_queue_clean(struct qib_pportdata *ppd,
 565                                      struct qib_user_sdma_queue *pq)
 566 {
 567         struct qib_devdata *dd = ppd->dd;
 568         struct list_head free_list;
 569         struct qib_user_sdma_pkt *pkt;
 570         struct qib_user_sdma_pkt *pkt_prev;
 571         int ret = 0;
 572
 573         INIT_LIST_HEAD(&free_list);
 574
 575         list_for_each_entry_safe(pkt, pkt_prev, &pq->sent, list) {
 576                 s64 descd = ppd->sdma_descq_removed - pkt->added;
 577
 578                 if (descd < 0)
 579                         break;
 580
 581                 list_move_tail(&pkt->list, &free_list);
 582
 583                 /* one more packet cleaned */
 584                 ret++;
 585         }
 586
 587         if (!list_empty(&free_list)) {
 588                 u32 counter;
 589
 590                 pkt = list_entry(free_list.prev,
 591                                  struct qib_user_sdma_pkt, list);
 592                 counter = pkt->counter;
 593
 594                 qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
 595                 qib_user_sdma_set_complete_counter(pq, counter);
 596         }
 597
 598         return ret;
 599 }
 600
 601 void qib_user_sdma_queue_destroy(struct qib_user_sdma_queue *pq)
 602 {
 603         if (!pq)
 604                 return;
 605
 606         kmem_cache_destroy(pq->pkt_slab);
 607         dma_pool_destroy(pq->header_cache);
 608         kfree(pq);
 609 }
 610
 611 /* clean descriptor queue, returns > 0 if some elements cleaned */
 612 static int qib_user_sdma_hwqueue_clean(struct qib_pportdata *ppd)
 613 {
 614         int ret;
 615         unsigned long flags;
 616
 617         spin_lock_irqsave(&ppd->sdma_lock, flags);
 618         ret = qib_sdma_make_progress(ppd);
 619         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 620
 621         return ret;
 622 }
 623
 624 /* we're in close, drain packets so that we can cleanup successfully... */
 625 void qib_user_sdma_queue_drain(struct qib_pportdata *ppd,
 626                                struct qib_user_sdma_queue *pq)
 627 {
 628         struct qib_devdata *dd = ppd->dd;
 629         int i;
 630
 631         if (!pq)
 632                 return;
 633
 634         for (i = 0; i < QIB_USER_SDMA_DRAIN_TIMEOUT; i++) {
 635                 mutex_lock(&pq->lock);
 636                 if (list_empty(&pq->sent)) {
 637                         mutex_unlock(&pq->lock);
 638                         break;
 639                 }
 640                 qib_user_sdma_hwqueue_clean(ppd);
 641                 qib_user_sdma_queue_clean(ppd, pq);
 642                 mutex_unlock(&pq->lock);
 643                 msleep(10);
 644         }
 645
 646         if (!list_empty(&pq->sent)) {
 647                 struct list_head free_list;
 648
 649                 qib_dev_err(dd, "user sdma lists not empty: forcing!\n");
 650                 INIT_LIST_HEAD(&free_list);
 651                 mutex_lock(&pq->lock);
 652                 list_splice_init(&pq->sent, &free_list);
 653                 qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
 654                 mutex_unlock(&pq->lock);
 655         }
 656 }
 657
 658 static inline __le64 qib_sdma_make_desc0(struct qib_pportdata *ppd,
 659                                          u64 addr, u64 dwlen, u64 dwoffset)
 660 {
 661         u8 tmpgen;
 662
 663         tmpgen = ppd->sdma_generation;
 664
 665         return cpu_to_le64(/* SDmaPhyAddr[31:0] */
 666                            ((addr & 0xfffffffcULL) << 32) |
 667                            /* SDmaGeneration[1:0] */
 668                            ((tmpgen & 3ULL) << 30) |
 669                            /* SDmaDwordCount[10:0] */
 670                            ((dwlen & 0x7ffULL) << 16) |
 671                            /* SDmaBufOffset[12:2] */
 672                            (dwoffset & 0x7ffULL));
 673 }
 674
 675 static inline __le64 qib_sdma_make_first_desc0(__le64 descq)
 676 {
 677         return descq | cpu_to_le64(1ULL << 12);
 678 }
 679
 680 static inline __le64 qib_sdma_make_last_desc0(__le64 descq)
 681 {
 682                                               /* last */  /* dma head */
 683         return descq | cpu_to_le64(1ULL << 11 | 1ULL << 13);
 684 }
 685
 686 static inline __le64 qib_sdma_make_desc1(u64 addr)
 687 {
 688         /* SDmaPhyAddr[47:32] */
 689         return cpu_to_le64(addr >> 32);
 690 }
 691
 692 static void qib_user_sdma_send_frag(struct qib_pportdata *ppd,
 693                                     struct qib_user_sdma_pkt *pkt, int idx,
 694                                     unsigned ofs, u16 tail)
 695 {
 696         const u64 addr = (u64) pkt->addr[idx].addr +
 697                 (u64) pkt->addr[idx].offset;
 698         const u64 dwlen = (u64) pkt->addr[idx].length / 4;
 699         __le64 *descqp;
 700         __le64 descq0;
 701
 702         descqp = &ppd->sdma_descq[tail].qw[0];
 703
 704         descq0 = qib_sdma_make_desc0(ppd, addr, dwlen, ofs);
 705         if (idx == 0)
 706                 descq0 = qib_sdma_make_first_desc0(descq0);
 707         if (idx == pkt->naddr - 1)
 708                 descq0 = qib_sdma_make_last_desc0(descq0);
 709
 710         descqp[0] = descq0;
 711         descqp[1] = qib_sdma_make_desc1(addr);
 712 }
 713
 714 /* pq->lock must be held, get packets on the wire... */
 715 static int qib_user_sdma_push_pkts(struct qib_pportdata *ppd,
 716                                    struct qib_user_sdma_queue *pq,
 717                                    struct list_head *pktlist)
 718 {
 719         struct qib_devdata *dd = ppd->dd;
 720         int ret = 0;
 721         unsigned long flags;
 722         u16 tail;
 723         u8 generation;
 724         u64 descq_added;
 725
 726         if (list_empty(pktlist))
 727                 return 0;
 728
 729         if (unlikely(!(ppd->lflags & QIBL_LINKACTIVE)))
 730                 return -ECOMM;
 731
 732         spin_lock_irqsave(&ppd->sdma_lock, flags);
 733
 734         /* keep a copy for restoring purposes in case of problems */
 735         generation = ppd->sdma_generation;
 736         descq_added = ppd->sdma_descq_added;
 737
 738         if (unlikely(!__qib_sdma_running(ppd))) {
 739                 ret = -ECOMM;
 740                 goto unlock;
 741         }
 742
 743         tail = ppd->sdma_descq_tail;
 744         while (!list_empty(pktlist)) {
 745                 struct qib_user_sdma_pkt *pkt =
 746                         list_entry(pktlist->next, struct qib_user_sdma_pkt,
 747                                    list);
 748                 int i;
 749                 unsigned ofs = 0;
 750                 u16 dtail = tail;
 751
 752                 if (pkt->naddr > qib_sdma_descq_freecnt(ppd))
 753                         goto unlock_check_tail;
 754
 755                 for (i = 0; i < pkt->naddr; i++) {
 756                         qib_user_sdma_send_frag(ppd, pkt, i, ofs, tail);
 757                         ofs += pkt->addr[i].length >> 2;
 758
 759                         if (++tail == ppd->sdma_descq_cnt) {
 760                                 tail = 0;
 761                                 ++ppd->sdma_generation;
 762                         }
 763                 }
 764
 765                 if ((ofs << 2) > ppd->ibmaxlen) {
 766                         ret = -EMSGSIZE;
 767                         goto unlock;
 768                 }
 769
 770                 /*
 771                  * If the packet is >= 2KB mtu equivalent, we have to use
 772                  * the large buffers, and have to mark each descriptor as
 773                  * part of a large buffer packet.
 774                  */
 775                 if (ofs > dd->piosize2kmax_dwords) {
 776                         for (i = 0; i < pkt->naddr; i++) {
 777                                 ppd->sdma_descq[dtail].qw[0] |=
 778                                         cpu_to_le64(1ULL << 14);
 779                                 if (++dtail == ppd->sdma_descq_cnt)
 780                                         dtail = 0;
 781                         }
 782                 }
 783
 784                 ppd->sdma_descq_added += pkt->naddr;
 785                 pkt->added = ppd->sdma_descq_added;
 786                 list_move_tail(&pkt->list, &pq->sent);
 787                 ret++;
 788         }
 789
 790 unlock_check_tail:
 791         /* advance the tail on the chip if necessary */
 792         if (ppd->sdma_descq_tail != tail)
 793                 dd->f_sdma_update_tail(ppd, tail);
 794
 795 unlock:
 796         if (unlikely(ret < 0)) {
 797                 ppd->sdma_generation = generation;
 798                 ppd->sdma_descq_added = descq_added;
 799         }
 800         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
 801
 802         return ret;
 803 }
 804
 805 int qib_user_sdma_writev(struct qib_ctxtdata *rcd,
 806                          struct qib_user_sdma_queue *pq,
 807                          const struct iovec *iov,
 808                          unsigned long dim)
 809 {
 810         struct qib_devdata *dd = rcd->dd;
 811         struct qib_pportdata *ppd = rcd->ppd;
 812         int ret = 0;
 813         struct list_head list;
 814         int npkts = 0;
 815
 816         INIT_LIST_HEAD(&list);
 817
 818         mutex_lock(&pq->lock);
 819
 820         /* why not -ECOMM like qib_user_sdma_push_pkts() below? */
 821         if (!qib_sdma_running(ppd))
 822                 goto done_unlock;
 823
 824         if (ppd->sdma_descq_added != ppd->sdma_descq_removed) {
 825                 qib_user_sdma_hwqueue_clean(ppd);
 826                 qib_user_sdma_queue_clean(ppd, pq);
 827         }
 828
 829         while (dim) {
 830                 const int mxp = 8;
 831
 832                 down_write(&current->mm->mmap_sem);
 833                 ret = qib_user_sdma_queue_pkts(dd, pq, &list, iov, dim, mxp);
 834                 up_write(&current->mm->mmap_sem);
 835
 836                 if (ret <= 0)
 837                         goto done_unlock;
 838                 else {
 839                         dim -= ret;
 840                         iov += ret;
 841                 }
 842
 843                 /* force packets onto the sdma hw queue... */
 844                 if (!list_empty(&list)) {
 845                         /*
 846                          * Lazily clean hw queue.  the 4 is a guess of about
 847                          * how many sdma descriptors a packet will take (it
 848                          * doesn't have to be perfect).
 849                          */
 850                         if (qib_sdma_descq_freecnt(ppd) < ret * 4) {
 851                                 qib_user_sdma_hwqueue_clean(ppd);
 852                                 qib_user_sdma_queue_clean(ppd, pq);
 853                         }
 854
 855                         ret = qib_user_sdma_push_pkts(ppd, pq, &list);
 856                         if (ret < 0)
 857                                 goto done_unlock;
 858                         else {
 859                                 npkts += ret;
 860                                 pq->counter += ret;
 861
 862                                 if (!list_empty(&list))
 863                                         goto done_unlock;
 864                         }
 865                 }
 866         }
 867
 868 done_unlock:
 869         if (!list_empty(&list))
 870                 qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &list);
 871         mutex_unlock(&pq->lock);
 872
 873         return (ret < 0) ? ret : npkts;
 874 }
 875
 876 int qib_user_sdma_make_progress(struct qib_pportdata *ppd,
 877                                 struct qib_user_sdma_queue *pq)
 878 {
 879         int ret = 0;
 880
 881         mutex_lock(&pq->lock);
 882         qib_user_sdma_hwqueue_clean(ppd);
 883         ret = qib_user_sdma_queue_clean(ppd, pq);
 884         mutex_unlock(&pq->lock);
 885
 886         return ret;
 887 }
 888
 889 u32 qib_user_sdma_complete_counter(const struct qib_user_sdma_queue *pq)
 890 {
 891         return pq ? pq->sent_counter : 0;
 892 }
 893
 894 u32 qib_user_sdma_inflight_counter(struct qib_user_sdma_queue *pq)
 895 {
 896         return pq ? pq->counter : 0;
 897 }