SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/infiniband/hw/ipath/ipath_user_sdma.c

   1 /*
   2  * Copyright (c) 2007, 2008 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/sched.h>
  37 #include <linux/slab.h>
  38 #include <linux/list.h>
  39 #include <linux/highmem.h>
  40 #include <linux/io.h>
  41 #include <linux/uio.h>
  42 #include <linux/rbtree.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/delay.h>
  45
  46 #include "ipath_kernel.h"
  47 #include "ipath_user_sdma.h"
  48
  49 /* minimum size of header */
  50 #define IPATH_USER_SDMA_MIN_HEADER_LENGTH       64
  51 /* expected size of headers (for dma_pool) */
  52 #define IPATH_USER_SDMA_EXP_HEADER_LENGTH       64
  53 /* length mask in PBC (lower 11 bits) */
  54 #define IPATH_PBC_LENGTH_MASK                   ((1 << 11) - 1)
  55
  56 struct ipath_user_sdma_pkt {
  57         u8 naddr;               /* dimension of addr (1..3) ... */
  58         u32 counter;            /* sdma pkts queued counter for this entry */
  59         u64 added;              /* global descq number of entries */
  60
  61         struct {
  62                 u32 offset;                     /* offset for kvaddr, addr */
  63                 u32 length;                     /* length in page */
  64                 u8  put_page;                   /* should we put_page? */
  65                 u8  dma_mapped;                 /* is page dma_mapped? */
  66                 struct page *page;              /* may be NULL (coherent mem) */
  67                 void *kvaddr;                   /* FIXME: only for pio hack */
  68                 dma_addr_t addr;
  69         } addr[4];   /* max pages, any more and we coalesce */
  70         struct list_head list;  /* list element */
  71 };
  72
  73 struct ipath_user_sdma_queue {
  74         /*
  75          * pkts sent to dma engine are queued on this
  76          * list head.  the type of the elements of this
  77          * list are struct ipath_user_sdma_pkt...
  78          */
  79         struct list_head sent;
  80
  81         /* headers with expected length are allocated from here... */
  82         char header_cache_name[64];
  83         struct dma_pool *header_cache;
  84
  85         /* packets are allocated from the slab cache... */
  86         char pkt_slab_name[64];
  87         struct kmem_cache *pkt_slab;
  88
  89         /* as packets go on the queued queue, they are counted... */
  90         u32 counter;
  91         u32 sent_counter;
  92
  93         /* dma page table */
  94         struct rb_root dma_pages_root;
  95
  96         /* protect everything above... */
  97         struct mutex lock;
  98 };
  99
 100 struct ipath_user_sdma_queue *
 101 ipath_user_sdma_queue_create(struct device *dev, int unit, int port, int sport)
 102 {
 103         struct ipath_user_sdma_queue *pq =
 104                 kmalloc(sizeof(struct ipath_user_sdma_queue), GFP_KERNEL);
 105
 106         if (!pq)
 107                 goto done;
 108
 109         pq->counter = 0;
 110         pq->sent_counter = 0;
 111         INIT_LIST_HEAD(&pq->sent);
 112
 113         mutex_init(&pq->lock);
 114
 115         snprintf(pq->pkt_slab_name, sizeof(pq->pkt_slab_name),
 116                  "ipath-user-sdma-pkts-%u-%02u.%02u", unit, port, sport);
 117         pq->pkt_slab = kmem_cache_create(pq->pkt_slab_name,
 118                                          sizeof(struct ipath_user_sdma_pkt),
 119                                          0, 0, NULL);
 120
 121         if (!pq->pkt_slab)
 122                 goto err_kfree;
 123
 124         snprintf(pq->header_cache_name, sizeof(pq->header_cache_name),
 125                  "ipath-user-sdma-headers-%u-%02u.%02u", unit, port, sport);
 126         pq->header_cache = dma_pool_create(pq->header_cache_name,
 127                                            dev,
 128                                            IPATH_USER_SDMA_EXP_HEADER_LENGTH,
 129                                            4, 0);
 130         if (!pq->header_cache)
 131                 goto err_slab;
 132
 133         pq->dma_pages_root = RB_ROOT;
 134
 135         goto done;
 136
 137 err_slab:
 138         kmem_cache_destroy(pq->pkt_slab);
 139 err_kfree:
 140         kfree(pq);
 141         pq = NULL;
 142
 143 done:
 144         return pq;
 145 }
 146
 147 static void ipath_user_sdma_init_frag(struct ipath_user_sdma_pkt *pkt,
 148                                       int i, size_t offset, size_t len,
 149                                       int put_page, int dma_mapped,
 150                                       struct page *page,
 151                                       void *kvaddr, dma_addr_t dma_addr)
 152 {
 153         pkt->addr[i].offset = offset;
 154         pkt->addr[i].length = len;
 155         pkt->addr[i].put_page = put_page;
 156         pkt->addr[i].dma_mapped = dma_mapped;
 157         pkt->addr[i].page = page;
 158         pkt->addr[i].kvaddr = kvaddr;
 159         pkt->addr[i].addr = dma_addr;
 160 }
 161
 162 static void ipath_user_sdma_init_header(struct ipath_user_sdma_pkt *pkt,
 163                                         u32 counter, size_t offset,
 164                                         size_t len, int dma_mapped,
 165                                         struct page *page,
 166                                         void *kvaddr, dma_addr_t dma_addr)
 167 {
 168         pkt->naddr = 1;
 169         pkt->counter = counter;
 170         ipath_user_sdma_init_frag(pkt, 0, offset, len, 0, dma_mapped, page,
 171                                   kvaddr, dma_addr);
 172 }
 173
 174 /* we've too many pages in the iovec, coalesce to a single page */
 175 static int ipath_user_sdma_coalesce(const struct ipath_devdata *dd,
 176                                     struct ipath_user_sdma_pkt *pkt,
 177                                     const struct iovec *iov,
 178                                     unsigned long niov) {
 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         ipath_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 /* how many pages in this iovec element? */
 229 static int ipath_user_sdma_num_pages(const struct iovec *iov)
 230 {
 231         const unsigned long addr  = (unsigned long) iov->iov_base;
 232         const unsigned long  len  = iov->iov_len;
 233         const unsigned long spage = addr & PAGE_MASK;
 234         const unsigned long epage = (addr + len - 1) & PAGE_MASK;
 235
 236         return 1 + ((epage - spage) >> PAGE_SHIFT);
 237 }
 238
 239 /* truncate length to page boundry */
 240 static int ipath_user_sdma_page_length(unsigned long addr, unsigned long len)
 241 {
 242         const unsigned long offset = addr & ~PAGE_MASK;
 243
 244         return ((offset + len) > PAGE_SIZE) ? (PAGE_SIZE - offset) : len;
 245 }
 246
 247 static void ipath_user_sdma_free_pkt_frag(struct device *dev,
 248                                           struct ipath_user_sdma_queue *pq,
 249                                           struct ipath_user_sdma_pkt *pkt,
 250                                           int frag)
 251 {
 252         const int i = frag;
 253
 254         if (pkt->addr[i].page) {
 255                 if (pkt->addr[i].dma_mapped)
 256                         dma_unmap_page(dev,
 257                                        pkt->addr[i].addr,
 258                                        pkt->addr[i].length,
 259                                        DMA_TO_DEVICE);
 260
 261                 if (pkt->addr[i].kvaddr)
 262                         kunmap(pkt->addr[i].page);
 263
 264                 if (pkt->addr[i].put_page)
 265                         put_page(pkt->addr[i].page);
 266                 else
 267                         __free_page(pkt->addr[i].page);
 268         } else if (pkt->addr[i].kvaddr)
 269                 /* free coherent mem from cache... */
 270                 dma_pool_free(pq->header_cache,
 271                               pkt->addr[i].kvaddr, pkt->addr[i].addr);
 272 }
 273
 274 /* return number of pages pinned... */
 275 static int ipath_user_sdma_pin_pages(const struct ipath_devdata *dd,
 276                                      struct ipath_user_sdma_pkt *pkt,
 277                                      unsigned long addr, int tlen, int npages)
 278 {
 279         struct page *pages[2];
 280         int j;
 281         int ret;
 282
 283         ret = get_user_pages(current, current->mm, addr,
 284                              npages, 0, 1, pages, NULL);
 285
 286         if (ret != npages) {
 287                 int i;
 288
 289                 for (i = 0; i < ret; i++)
 290                         put_page(pages[i]);
 291
 292                 ret = -ENOMEM;
 293                 goto done;
 294         }
 295
 296         for (j = 0; j < npages; j++) {
 297                 /* map the pages... */
 298                 const int flen =
 299                         ipath_user_sdma_page_length(addr, tlen);
 300                 dma_addr_t dma_addr =
 301                         dma_map_page(&dd->pcidev->dev,
 302                                      pages[j], 0, flen, DMA_TO_DEVICE);
 303                 unsigned long fofs = addr & ~PAGE_MASK;
 304
 305                 if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
 306                         ret = -ENOMEM;
 307                         goto done;
 308                 }
 309
 310                 ipath_user_sdma_init_frag(pkt, pkt->naddr, fofs, flen, 1, 1,
 311                                           pages[j], kmap(pages[j]),
 312                                           dma_addr);
 313
 314                 pkt->naddr++;
 315                 addr += flen;
 316                 tlen -= flen;
 317         }
 318
 319 done:
 320         return ret;
 321 }
 322
 323 static int ipath_user_sdma_pin_pkt(const struct ipath_devdata *dd,
 324                                    struct ipath_user_sdma_queue *pq,
 325                                    struct ipath_user_sdma_pkt *pkt,
 326                                    const struct iovec *iov,
 327                                    unsigned long niov)
 328 {
 329         int ret = 0;
 330         unsigned long idx;
 331
 332         for (idx = 0; idx < niov; idx++) {
 333                 const int npages = ipath_user_sdma_num_pages(iov + idx);
 334                 const unsigned long addr = (unsigned long) iov[idx].iov_base;
 335
 336                 ret = ipath_user_sdma_pin_pages(dd, pkt,
 337                                                 addr, iov[idx].iov_len,
 338                                                 npages);
 339                 if (ret < 0)
 340                         goto free_pkt;
 341         }
 342
 343         goto done;
 344
 345 free_pkt:
 346         for (idx = 0; idx < pkt->naddr; idx++)
 347                 ipath_user_sdma_free_pkt_frag(&dd->pcidev->dev, pq, pkt, idx);
 348
 349 done:
 350         return ret;
 351 }
 352
 353 static int ipath_user_sdma_init_payload(const struct ipath_devdata *dd,
 354                                         struct ipath_user_sdma_queue *pq,
 355                                         struct ipath_user_sdma_pkt *pkt,
 356                                         const struct iovec *iov,
 357                                         unsigned long niov, int npages)
 358 {
 359         int ret = 0;
 360
 361         if (npages >= ARRAY_SIZE(pkt->addr))
 362                 ret = ipath_user_sdma_coalesce(dd, pkt, iov, niov);
 363         else
 364                 ret = ipath_user_sdma_pin_pkt(dd, pq, pkt, iov, niov);
 365
 366         return ret;
 367 }
 368
 369 /* free a packet list -- return counter value of last packet */
 370 static void ipath_user_sdma_free_pkt_list(struct device *dev,
 371                                           struct ipath_user_sdma_queue *pq,
 372                                           struct list_head *list)
 373 {
 374         struct ipath_user_sdma_pkt *pkt, *pkt_next;
 375
 376         list_for_each_entry_safe(pkt, pkt_next, list, list) {
 377                 int i;
 378
 379                 for (i = 0; i < pkt->naddr; i++)
 380                         ipath_user_sdma_free_pkt_frag(dev, pq, pkt, i);
 381
 382                 kmem_cache_free(pq->pkt_slab, pkt);
 383         }
 384 }
 385
 386 /*
 387  * copy headers, coalesce etc -- pq->lock must be held
 388  *
 389  * we queue all the packets to list, returning the
 390  * number of bytes total.  list must be empty initially,
 391  * as, if there is an error we clean it...
 392  */
 393 static int ipath_user_sdma_queue_pkts(const struct ipath_devdata *dd,
 394                                       struct ipath_user_sdma_queue *pq,
 395                                       struct list_head *list,
 396                                       const struct iovec *iov,
 397                                       unsigned long niov,
 398                                       int maxpkts)
 399 {
 400         unsigned long idx = 0;
 401         int ret = 0;
 402         int npkts = 0;
 403         struct page *page = NULL;
 404         __le32 *pbc;
 405         dma_addr_t dma_addr;
 406         struct ipath_user_sdma_pkt *pkt = NULL;
 407         size_t len;
 408         size_t nw;
 409         u32 counter = pq->counter;
 410         int dma_mapped = 0;
 411
 412         while (idx < niov && npkts < maxpkts) {
 413                 const unsigned long addr = (unsigned long) iov[idx].iov_base;
 414                 const unsigned long idx_save = idx;
 415                 unsigned pktnw;
 416                 unsigned pktnwc;
 417                 int nfrags = 0;
 418                 int npages = 0;
 419                 int cfur;
 420
 421                 dma_mapped = 0;
 422                 len = iov[idx].iov_len;
 423                 nw = len >> 2;
 424                 page = NULL;
 425
 426                 pkt = kmem_cache_alloc(pq->pkt_slab, GFP_KERNEL);
 427                 if (!pkt) {
 428                         ret = -ENOMEM;
 429                         goto free_list;
 430                 }
 431
 432                 if (len < IPATH_USER_SDMA_MIN_HEADER_LENGTH ||
 433                     len > PAGE_SIZE || len & 3 || addr & 3) {
 434                         ret = -EINVAL;
 435                         goto free_pkt;
 436                 }
 437
 438                 if (len == IPATH_USER_SDMA_EXP_HEADER_LENGTH)
 439                         pbc = dma_pool_alloc(pq->header_cache, GFP_KERNEL,
 440                                              &dma_addr);
 441                 else
 442                         pbc = NULL;
 443
 444                 if (!pbc) {
 445                         page = alloc_page(GFP_KERNEL);
 446                         if (!page) {
 447                                 ret = -ENOMEM;
 448                                 goto free_pkt;
 449                         }
 450                         pbc = kmap(page);
 451                 }
 452
 453                 cfur = copy_from_user(pbc, iov[idx].iov_base, len);
 454                 if (cfur) {
 455                         ret = -EFAULT;
 456                         goto free_pbc;
 457                 }
 458
 459                 /*
 460                  * this assignment is a bit strange.  it's because the
 461                  * the pbc counts the number of 32 bit words in the full
 462                  * packet _except_ the first word of the pbc itself...
 463                  */
 464                 pktnwc = nw - 1;
 465
 466                 /*
 467                  * pktnw computation yields the number of 32 bit words
 468                  * that the caller has indicated in the PBC.  note that
 469                  * this is one less than the total number of words that
 470                  * goes to the send DMA engine as the first 32 bit word
 471                  * of the PBC itself is not counted.  Armed with this count,
 472                  * we can verify that the packet is consistent with the
 473                  * iovec lengths.
 474                  */
 475                 pktnw = le32_to_cpu(*pbc) & IPATH_PBC_LENGTH_MASK;
 476                 if (pktnw < pktnwc || pktnw > pktnwc + (PAGE_SIZE >> 2)) {
 477                         ret = -EINVAL;
 478                         goto free_pbc;
 479                 }
 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                 ipath_user_sdma_init_header(pkt, counter, 0, len, dma_mapped,
 521                                             page, pbc, dma_addr);
 522
 523                 if (nfrags) {
 524                         ret = ipath_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         ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, list);
 553 done:
 554         return ret;
 555 }
 556
 557 static void ipath_user_sdma_set_complete_counter(struct ipath_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 ipath_user_sdma_queue_clean(const struct ipath_devdata *dd,
 565                                        struct ipath_user_sdma_queue *pq)
 566 {
 567         struct list_head free_list;
 568         struct ipath_user_sdma_pkt *pkt;
 569         struct ipath_user_sdma_pkt *pkt_prev;
 570         int ret = 0;
 571
 572         INIT_LIST_HEAD(&free_list);
 573
 574         list_for_each_entry_safe(pkt, pkt_prev, &pq->sent, list) {
 575                 s64 descd = dd->ipath_sdma_descq_removed - pkt->added;
 576
 577                 if (descd < 0)
 578                         break;
 579
 580                 list_move_tail(&pkt->list, &free_list);
 581
 582                 /* one more packet cleaned */
 583                 ret++;
 584         }
 585
 586         if (!list_empty(&free_list)) {
 587                 u32 counter;
 588
 589                 pkt = list_entry(free_list.prev,
 590                                  struct ipath_user_sdma_pkt, list);
 591                 counter = pkt->counter;
 592
 593                 ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
 594                 ipath_user_sdma_set_complete_counter(pq, counter);
 595         }
 596
 597         return ret;
 598 }
 599
 600 void ipath_user_sdma_queue_destroy(struct ipath_user_sdma_queue *pq)
 601 {
 602         if (!pq)
 603                 return;
 604
 605         kmem_cache_destroy(pq->pkt_slab);
 606         dma_pool_destroy(pq->header_cache);
 607         kfree(pq);
 608 }
 609
 610 /* clean descriptor queue, returns > 0 if some elements cleaned */
 611 static int ipath_user_sdma_hwqueue_clean(struct ipath_devdata *dd)
 612 {
 613         int ret;
 614         unsigned long flags;
 615
 616         spin_lock_irqsave(&dd->ipath_sdma_lock, flags);
 617         ret = ipath_sdma_make_progress(dd);
 618         spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);
 619
 620         return ret;
 621 }
 622
 623 /* we're in close, drain packets so that we can cleanup successfully... */
 624 void ipath_user_sdma_queue_drain(struct ipath_devdata *dd,
 625                                  struct ipath_user_sdma_queue *pq)
 626 {
 627         int i;
 628
 629         if (!pq)
 630                 return;
 631
 632         for (i = 0; i < 100; i++) {
 633                 mutex_lock(&pq->lock);
 634                 if (list_empty(&pq->sent)) {
 635                         mutex_unlock(&pq->lock);
 636                         break;
 637                 }
 638                 ipath_user_sdma_hwqueue_clean(dd);
 639                 ipath_user_sdma_queue_clean(dd, pq);
 640                 mutex_unlock(&pq->lock);
 641                 msleep(10);
 642         }
 643
 644         if (!list_empty(&pq->sent)) {
 645                 struct list_head free_list;
 646
 647                 printk(KERN_INFO "drain: lists not empty: forcing!\n");
 648                 INIT_LIST_HEAD(&free_list);
 649                 mutex_lock(&pq->lock);
 650                 list_splice_init(&pq->sent, &free_list);
 651                 ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
 652                 mutex_unlock(&pq->lock);
 653         }
 654 }
 655
 656 static inline __le64 ipath_sdma_make_desc0(struct ipath_devdata *dd,
 657                                            u64 addr, u64 dwlen, u64 dwoffset)
 658 {
 659         return cpu_to_le64(/* SDmaPhyAddr[31:0] */
 660                            ((addr & 0xfffffffcULL) << 32) |
 661                            /* SDmaGeneration[1:0] */
 662                            ((dd->ipath_sdma_generation & 3ULL) << 30) |
 663                            /* SDmaDwordCount[10:0] */
 664                            ((dwlen & 0x7ffULL) << 16) |
 665                            /* SDmaBufOffset[12:2] */
 666                            (dwoffset & 0x7ffULL));
 667 }
 668
 669 static inline __le64 ipath_sdma_make_first_desc0(__le64 descq)
 670 {
 671         return descq | cpu_to_le64(1ULL << 12);
 672 }
 673
 674 static inline __le64 ipath_sdma_make_last_desc0(__le64 descq)
 675 {
 676                                               /* last */  /* dma head */
 677         return descq | cpu_to_le64(1ULL << 11 | 1ULL << 13);
 678 }
 679
 680 static inline __le64 ipath_sdma_make_desc1(u64 addr)
 681 {
 682         /* SDmaPhyAddr[47:32] */
 683         return cpu_to_le64(addr >> 32);
 684 }
 685
 686 static void ipath_user_sdma_send_frag(struct ipath_devdata *dd,
 687                                       struct ipath_user_sdma_pkt *pkt, int idx,
 688                                       unsigned ofs, u16 tail)
 689 {
 690         const u64 addr = (u64) pkt->addr[idx].addr +
 691                 (u64) pkt->addr[idx].offset;
 692         const u64 dwlen = (u64) pkt->addr[idx].length / 4;
 693         __le64 *descqp;
 694         __le64 descq0;
 695
 696         descqp = &dd->ipath_sdma_descq[tail].qw[0];
 697
 698         descq0 = ipath_sdma_make_desc0(dd, addr, dwlen, ofs);
 699         if (idx == 0)
 700                 descq0 = ipath_sdma_make_first_desc0(descq0);
 701         if (idx == pkt->naddr - 1)
 702                 descq0 = ipath_sdma_make_last_desc0(descq0);
 703
 704         descqp[0] = descq0;
 705         descqp[1] = ipath_sdma_make_desc1(addr);
 706 }
 707
 708 /* pq->lock must be held, get packets on the wire... */
 709 static int ipath_user_sdma_push_pkts(struct ipath_devdata *dd,
 710                                      struct ipath_user_sdma_queue *pq,
 711                                      struct list_head *pktlist)
 712 {
 713         int ret = 0;
 714         unsigned long flags;
 715         u16 tail;
 716
 717         if (list_empty(pktlist))
 718                 return 0;
 719
 720         if (unlikely(!(dd->ipath_flags & IPATH_LINKACTIVE)))
 721                 return -ECOMM;
 722
 723         spin_lock_irqsave(&dd->ipath_sdma_lock, flags);
 724
 725         if (unlikely(dd->ipath_sdma_status & IPATH_SDMA_ABORT_MASK)) {
 726                 ret = -ECOMM;
 727                 goto unlock;
 728         }
 729
 730         tail = dd->ipath_sdma_descq_tail;
 731         while (!list_empty(pktlist)) {
 732                 struct ipath_user_sdma_pkt *pkt =
 733                         list_entry(pktlist->next, struct ipath_user_sdma_pkt,
 734                                    list);
 735                 int i;
 736                 unsigned ofs = 0;
 737                 u16 dtail = tail;
 738
 739                 if (pkt->naddr > ipath_sdma_descq_freecnt(dd))
 740                         goto unlock_check_tail;
 741
 742                 for (i = 0; i < pkt->naddr; i++) {
 743                         ipath_user_sdma_send_frag(dd, pkt, i, ofs, tail);
 744                         ofs += pkt->addr[i].length >> 2;
 745
 746                         if (++tail == dd->ipath_sdma_descq_cnt) {
 747                                 tail = 0;
 748                                 ++dd->ipath_sdma_generation;
 749                         }
 750                 }
 751
 752                 if ((ofs<<2) > dd->ipath_ibmaxlen) {
 753                         ipath_dbg("packet size %X > ibmax %X, fail\n",
 754                                 ofs<<2, dd->ipath_ibmaxlen);
 755                         ret = -EMSGSIZE;
 756                         goto unlock;
 757                 }
 758
 759                 /*
 760                  * if the packet is >= 2KB mtu equivalent, we have to use
 761                  * the large buffers, and have to mark each descriptor as
 762                  * part of a large buffer packet.
 763                  */
 764                 if (ofs >= IPATH_SMALLBUF_DWORDS) {
 765                         for (i = 0; i < pkt->naddr; i++) {
 766                                 dd->ipath_sdma_descq[dtail].qw[0] |=
 767                                         cpu_to_le64(1ULL << 14);
 768                                 if (++dtail == dd->ipath_sdma_descq_cnt)
 769                                         dtail = 0;
 770                         }
 771                 }
 772
 773                 dd->ipath_sdma_descq_added += pkt->naddr;
 774                 pkt->added = dd->ipath_sdma_descq_added;
 775                 list_move_tail(&pkt->list, &pq->sent);
 776                 ret++;
 777         }
 778
 779 unlock_check_tail:
 780         /* advance the tail on the chip if necessary */
 781         if (dd->ipath_sdma_descq_tail != tail) {
 782                 wmb();
 783                 ipath_write_kreg(dd, dd->ipath_kregs->kr_senddmatail, tail);
 784                 dd->ipath_sdma_descq_tail = tail;
 785         }
 786
 787 unlock:
 788         spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);
 789
 790         return ret;
 791 }
 792
 793 int ipath_user_sdma_writev(struct ipath_devdata *dd,
 794                            struct ipath_user_sdma_queue *pq,
 795                            const struct iovec *iov,
 796                            unsigned long dim)
 797 {
 798         int ret = 0;
 799         struct list_head list;
 800         int npkts = 0;
 801
 802         INIT_LIST_HEAD(&list);
 803
 804         mutex_lock(&pq->lock);
 805
 806         if (dd->ipath_sdma_descq_added != dd->ipath_sdma_descq_removed) {
 807                 ipath_user_sdma_hwqueue_clean(dd);
 808                 ipath_user_sdma_queue_clean(dd, pq);
 809         }
 810
 811         while (dim) {
 812                 const int mxp = 8;
 813
 814                 down_write(&current->mm->mmap_sem);
 815                 ret = ipath_user_sdma_queue_pkts(dd, pq, &list, iov, dim, mxp);
 816                 up_write(&current->mm->mmap_sem);
 817
 818                 if (ret <= 0)
 819                         goto done_unlock;
 820                 else {
 821                         dim -= ret;
 822                         iov += ret;
 823                 }
 824
 825                 /* force packets onto the sdma hw queue... */
 826                 if (!list_empty(&list)) {
 827                         /*
 828                          * lazily clean hw queue.  the 4 is a guess of about
 829                          * how many sdma descriptors a packet will take (it
 830                          * doesn't have to be perfect).
 831                          */
 832                         if (ipath_sdma_descq_freecnt(dd) < ret * 4) {
 833                                 ipath_user_sdma_hwqueue_clean(dd);
 834                                 ipath_user_sdma_queue_clean(dd, pq);
 835                         }
 836
 837                         ret = ipath_user_sdma_push_pkts(dd, pq, &list);
 838                         if (ret < 0)
 839                                 goto done_unlock;
 840                         else {
 841                                 npkts += ret;
 842                                 pq->counter += ret;
 843
 844                                 if (!list_empty(&list))
 845                                         goto done_unlock;
 846                         }
 847                 }
 848         }
 849
 850 done_unlock:
 851         if (!list_empty(&list))
 852                 ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &list);
 853         mutex_unlock(&pq->lock);
 854
 855         return (ret < 0) ? ret : npkts;
 856 }
 857
 858 int ipath_user_sdma_make_progress(struct ipath_devdata *dd,
 859                                   struct ipath_user_sdma_queue *pq)
 860 {
 861         int ret = 0;
 862
 863         mutex_lock(&pq->lock);
 864         ipath_user_sdma_hwqueue_clean(dd);
 865         ret = ipath_user_sdma_queue_clean(dd, pq);
 866         mutex_unlock(&pq->lock);
 867
 868         return ret;
 869 }
 870
 871 u32 ipath_user_sdma_complete_counter(const struct ipath_user_sdma_queue *pq)
 872 {
 873         return pq->sent_counter;
 874 }
 875
 876 u32 ipath_user_sdma_inflight_counter(struct ipath_user_sdma_queue *pq)
 877 {
 878         return pq->counter;
 879 }
 880