kernel/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 250
  54
  55 /*
  56  * track how many times a process open this driver.
  57  */
  58 static struct rb_root qib_user_sdma_rb_root = RB_ROOT;
  59
  60 struct qib_user_sdma_rb_node {
  61         struct rb_node node;
  62         int refcount;
  63         pid_t pid;
  64 };
  65
  66 struct qib_user_sdma_pkt {
  67         struct list_head list;  /* list element */
  68
  69         u8  tiddma;             /* if this is NEW tid-sdma */
  70         u8  largepkt;           /* this is large pkt from kmalloc */
  71         u16 frag_size;          /* frag size used by PSM */
  72         u16 index;              /* last header index or push index */
  73         u16 naddr;              /* dimension of addr (1..3) ... */
  74         u16 addrlimit;          /* addr array size */
  75         u16 tidsmidx;           /* current tidsm index */
  76         u16 tidsmcount;         /* tidsm array item count */
  77         u16 payload_size;       /* payload size so far for header */
  78         u32 bytes_togo;         /* bytes for processing */
  79         u32 counter;            /* sdma pkts queued counter for this entry */
  80         struct qib_tid_session_member *tidsm;   /* tid session member array */
  81         struct qib_user_sdma_queue *pq; /* which pq this pkt belongs to */
  82         u64 added;              /* global descq number of entries */
  83
  84         struct {
  85                 u16 offset;                     /* offset for kvaddr, addr */
  86                 u16 length;                     /* length in page */
  87                 u16 first_desc;                 /* first desc */
  88                 u16 last_desc;                  /* last desc */
  89                 u16 put_page;                   /* should we put_page? */
  90                 u16 dma_mapped;                 /* is page dma_mapped? */
  91                 u16 dma_length;                 /* for dma_unmap_page() */
  92                 u16 padding;
  93                 struct page *page;              /* may be NULL (coherent mem) */
  94                 void *kvaddr;                   /* FIXME: only for pio hack */
  95                 dma_addr_t addr;
  96         } addr[4];   /* max pages, any more and we coalesce */
  97 };
  98
  99 struct qib_user_sdma_queue {
 100         /*
 101          * pkts sent to dma engine are queued on this
 102          * list head.  the type of the elements of this
 103          * list are struct qib_user_sdma_pkt...
 104          */
 105         struct list_head sent;
 106
 107         /*
 108          * Because above list will be accessed by both process and
 109          * signal handler, we need a spinlock for it.
 110          */
 111         spinlock_t sent_lock ____cacheline_aligned_in_smp;
 112
 113         /* headers with expected length are allocated from here... */
 114         char header_cache_name[64];
 115         struct dma_pool *header_cache;
 116
 117         /* packets are allocated from the slab cache... */
 118         char pkt_slab_name[64];
 119         struct kmem_cache *pkt_slab;
 120
 121         /* as packets go on the queued queue, they are counted... */
 122         u32 counter;
 123         u32 sent_counter;
 124         /* pending packets, not sending yet */
 125         u32 num_pending;
 126         /* sending packets, not complete yet */
 127         u32 num_sending;
 128         /* global descq number of entry of last sending packet */
 129         u64 added;
 130
 131         /* dma page table */
 132         struct rb_root dma_pages_root;
 133
 134         struct qib_user_sdma_rb_node *sdma_rb_node;
 135
 136         /* protect everything above... */
 137         struct mutex lock;
 138 };
 139
 140 static struct qib_user_sdma_rb_node *
 141 qib_user_sdma_rb_search(struct rb_root *root, pid_t pid)
 142 {
 143         struct qib_user_sdma_rb_node *sdma_rb_node;
 144         struct rb_node *node = root->rb_node;
 145
 146         while (node) {
 147                 sdma_rb_node = container_of(node,
 148                         struct qib_user_sdma_rb_node, node);
 149                 if (pid < sdma_rb_node->pid)
 150                         node = node->rb_left;
 151                 else if (pid > sdma_rb_node->pid)
 152                         node = node->rb_right;
 153                 else
 154                         return sdma_rb_node;
 155         }
 156         return NULL;
 157 }
 158
 159 static int
 160 qib_user_sdma_rb_insert(struct rb_root *root, struct qib_user_sdma_rb_node *new)
 161 {
 162         struct rb_node **node = &(root->rb_node);
 163         struct rb_node *parent = NULL;
 164         struct qib_user_sdma_rb_node *got;
 165
 166         while (*node) {
 167                 got = container_of(*node, struct qib_user_sdma_rb_node, node);
 168                 parent = *node;
 169                 if (new->pid < got->pid)
 170                         node = &((*node)->rb_left);
 171                 else if (new->pid > got->pid)
 172                         node = &((*node)->rb_right);
 173                 else
 174                         return 0;
 175         }
 176
 177         rb_link_node(&new->node, parent, node);
 178         rb_insert_color(&new->node, root);
 179         return 1;
 180 }
 181
 182 struct qib_user_sdma_queue *
 183 qib_user_sdma_queue_create(struct device *dev, int unit, int ctxt, int sctxt)
 184 {
 185         struct qib_user_sdma_queue *pq =
 186                 kmalloc(sizeof(struct qib_user_sdma_queue), GFP_KERNEL);
 187         struct qib_user_sdma_rb_node *sdma_rb_node;
 188
 189         if (!pq)
 190                 goto done;
 191
 192         pq->counter = 0;
 193         pq->sent_counter = 0;
 194         pq->num_pending = 0;
 195         pq->num_sending = 0;
 196         pq->added = 0;
 197         pq->sdma_rb_node = NULL;
 198
 199         INIT_LIST_HEAD(&pq->sent);
 200         spin_lock_init(&pq->sent_lock);
 201         mutex_init(&pq->lock);
 202
 203         snprintf(pq->pkt_slab_name, sizeof(pq->pkt_slab_name),
 204                  "qib-user-sdma-pkts-%u-%02u.%02u", unit, ctxt, sctxt);
 205         pq->pkt_slab = kmem_cache_create(pq->pkt_slab_name,
 206                                          sizeof(struct qib_user_sdma_pkt),
 207                                          0, 0, NULL);
 208
 209         if (!pq->pkt_slab)
 210                 goto err_kfree;
 211
 212         snprintf(pq->header_cache_name, sizeof(pq->header_cache_name),
 213                  "qib-user-sdma-headers-%u-%02u.%02u", unit, ctxt, sctxt);
 214         pq->header_cache = dma_pool_create(pq->header_cache_name,
 215                                            dev,
 216                                            QIB_USER_SDMA_EXP_HEADER_LENGTH,
 217                                            4, 0);
 218         if (!pq->header_cache)
 219                 goto err_slab;
 220
 221         pq->dma_pages_root = RB_ROOT;
 222
 223         sdma_rb_node = qib_user_sdma_rb_search(&qib_user_sdma_rb_root,
 224                                         current->pid);
 225         if (sdma_rb_node) {
 226                 sdma_rb_node->refcount++;
 227         } else {
 228                 int ret;
 229
 230                 sdma_rb_node = kmalloc(sizeof(
 231                         struct qib_user_sdma_rb_node), GFP_KERNEL);
 232                 if (!sdma_rb_node)
 233                         goto err_rb;
 234
 235                 sdma_rb_node->refcount = 1;
 236                 sdma_rb_node->pid = current->pid;
 237
 238                 ret = qib_user_sdma_rb_insert(&qib_user_sdma_rb_root,
 239                                         sdma_rb_node);
 240                 BUG_ON(ret == 0);
 241         }
 242         pq->sdma_rb_node = sdma_rb_node;
 243
 244         goto done;
 245
 246 err_rb:
 247         dma_pool_destroy(pq->header_cache);
 248 err_slab:
 249         kmem_cache_destroy(pq->pkt_slab);
 250 err_kfree:
 251         kfree(pq);
 252         pq = NULL;
 253
 254 done:
 255         return pq;
 256 }
 257
 258 static void qib_user_sdma_init_frag(struct qib_user_sdma_pkt *pkt,
 259                                     int i, u16 offset, u16 len,
 260                                     u16 first_desc, u16 last_desc,
 261                                     u16 put_page, u16 dma_mapped,
 262                                     struct page *page, void *kvaddr,
 263                                     dma_addr_t dma_addr, u16 dma_length)
 264 {
 265         pkt->addr[i].offset = offset;
 266         pkt->addr[i].length = len;
 267         pkt->addr[i].first_desc = first_desc;
 268         pkt->addr[i].last_desc = last_desc;
 269         pkt->addr[i].put_page = put_page;
 270         pkt->addr[i].dma_mapped = dma_mapped;
 271         pkt->addr[i].page = page;
 272         pkt->addr[i].kvaddr = kvaddr;
 273         pkt->addr[i].addr = dma_addr;
 274         pkt->addr[i].dma_length = dma_length;
 275 }
 276
 277 static void *qib_user_sdma_alloc_header(struct qib_user_sdma_queue *pq,
 278                                 size_t len, dma_addr_t *dma_addr)
 279 {
 280         void *hdr;
 281
 282         if (len == QIB_USER_SDMA_EXP_HEADER_LENGTH)
 283                 hdr = dma_pool_alloc(pq->header_cache, GFP_KERNEL,
 284                                              dma_addr);
 285         else
 286                 hdr = NULL;
 287
 288         if (!hdr) {
 289                 hdr = kmalloc(len, GFP_KERNEL);
 290                 if (!hdr)
 291                         return NULL;
 292
 293                 *dma_addr = 0;
 294         }
 295
 296         return hdr;
 297 }
 298
 299 static int qib_user_sdma_page_to_frags(const struct qib_devdata *dd,
 300                                        struct qib_user_sdma_queue *pq,
 301                                        struct qib_user_sdma_pkt *pkt,
 302                                        struct page *page, u16 put,
 303                                        u16 offset, u16 len, void *kvaddr)
 304 {
 305         __le16 *pbc16;
 306         void *pbcvaddr;
 307         struct qib_message_header *hdr;
 308         u16 newlen, pbclen, lastdesc, dma_mapped;
 309         u32 vcto;
 310         union qib_seqnum seqnum;
 311         dma_addr_t pbcdaddr;
 312         dma_addr_t dma_addr =
 313                 dma_map_page(&dd->pcidev->dev,
 314                         page, offset, len, DMA_TO_DEVICE);
 315         int ret = 0;
 316
 317         if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
 318                 /*
 319                  * dma mapping error, pkt has not managed
 320                  * this page yet, return the page here so
 321                  * the caller can ignore this page.
 322                  */
 323                 if (put) {
 324                         put_page(page);
 325                 } else {
 326                         /* coalesce case */
 327                         kunmap(page);
 328                         __free_page(page);
 329                 }
 330                 ret = -ENOMEM;
 331                 goto done;
 332         }
 333         offset = 0;
 334         dma_mapped = 1;
 335
 336
 337 next_fragment:
 338
 339         /*
 340          * In tid-sdma, the transfer length is restricted by
 341          * receiver side current tid page length.
 342          */
 343         if (pkt->tiddma && len > pkt->tidsm[pkt->tidsmidx].length)
 344                 newlen = pkt->tidsm[pkt->tidsmidx].length;
 345         else
 346                 newlen = len;
 347
 348         /*
 349          * Then the transfer length is restricted by MTU.
 350          * the last descriptor flag is determined by:
 351          * 1. the current packet is at frag size length.
 352          * 2. the current tid page is done if tid-sdma.
 353          * 3. there is no more byte togo if sdma.
 354          */
 355         lastdesc = 0;
 356         if ((pkt->payload_size + newlen) >= pkt->frag_size) {
 357                 newlen = pkt->frag_size - pkt->payload_size;
 358                 lastdesc = 1;
 359         } else if (pkt->tiddma) {
 360                 if (newlen == pkt->tidsm[pkt->tidsmidx].length)
 361                         lastdesc = 1;
 362         } else {
 363                 if (newlen == pkt->bytes_togo)
 364                         lastdesc = 1;
 365         }
 366
 367         /* fill the next fragment in this page */
 368         qib_user_sdma_init_frag(pkt, pkt->naddr, /* index */
 369                 offset, newlen,         /* offset, len */
 370                 0, lastdesc,            /* first last desc */
 371                 put, dma_mapped,        /* put page, dma mapped */
 372                 page, kvaddr,           /* struct page, virt addr */
 373                 dma_addr, len);         /* dma addr, dma length */
 374         pkt->bytes_togo -= newlen;
 375         pkt->payload_size += newlen;
 376         pkt->naddr++;
 377         if (pkt->naddr == pkt->addrlimit) {
 378                 ret = -EFAULT;
 379                 goto done;
 380         }
 381
 382         /* If there is no more byte togo. (lastdesc==1) */
 383         if (pkt->bytes_togo == 0) {
 384                 /* The packet is done, header is not dma mapped yet.
 385                  * it should be from kmalloc */
 386                 if (!pkt->addr[pkt->index].addr) {
 387                         pkt->addr[pkt->index].addr =
 388                                 dma_map_single(&dd->pcidev->dev,
 389                                         pkt->addr[pkt->index].kvaddr,
 390                                         pkt->addr[pkt->index].dma_length,
 391                                         DMA_TO_DEVICE);
 392                         if (dma_mapping_error(&dd->pcidev->dev,
 393                                         pkt->addr[pkt->index].addr)) {
 394                                 ret = -ENOMEM;
 395                                 goto done;
 396                         }
 397                         pkt->addr[pkt->index].dma_mapped = 1;
 398                 }
 399
 400                 goto done;
 401         }
 402
 403         /* If tid-sdma, advance tid info. */
 404         if (pkt->tiddma) {
 405                 pkt->tidsm[pkt->tidsmidx].length -= newlen;
 406                 if (pkt->tidsm[pkt->tidsmidx].length) {
 407                         pkt->tidsm[pkt->tidsmidx].offset += newlen;
 408                 } else {
 409                         pkt->tidsmidx++;
 410                         if (pkt->tidsmidx == pkt->tidsmcount) {
 411                                 ret = -EFAULT;
 412                                 goto done;
 413                         }
 414                 }
 415         }
 416
 417         /*
 418          * If this is NOT the last descriptor. (newlen==len)
 419          * the current packet is not done yet, but the current
 420          * send side page is done.
 421          */
 422         if (lastdesc == 0)
 423                 goto done;
 424
 425         /*
 426          * If running this driver under PSM with message size
 427          * fitting into one transfer unit, it is not possible
 428          * to pass this line. otherwise, it is a buggggg.
 429          */
 430
 431         /*
 432          * Since the current packet is done, and there are more
 433          * bytes togo, we need to create a new sdma header, copying
 434          * from previous sdma header and modify both.
 435          */
 436         pbclen = pkt->addr[pkt->index].length;
 437         pbcvaddr = qib_user_sdma_alloc_header(pq, pbclen, &pbcdaddr);
 438         if (!pbcvaddr) {
 439                 ret = -ENOMEM;
 440                 goto done;
 441         }
 442         /* Copy the previous sdma header to new sdma header */
 443         pbc16 = (__le16 *)pkt->addr[pkt->index].kvaddr;
 444         memcpy(pbcvaddr, pbc16, pbclen);
 445
 446         /* Modify the previous sdma header */
 447         hdr = (struct qib_message_header *)&pbc16[4];
 448
 449         /* New pbc length */
 450         pbc16[0] = cpu_to_le16(le16_to_cpu(pbc16[0])-(pkt->bytes_togo>>2));
 451
 452         /* New packet length */
 453         hdr->lrh[2] = cpu_to_be16(le16_to_cpu(pbc16[0]));
 454
 455         if (pkt->tiddma) {
 456                 /* turn on the header suppression */
 457                 hdr->iph.pkt_flags =
 458                         cpu_to_le16(le16_to_cpu(hdr->iph.pkt_flags)|0x2);
 459                 /* turn off ACK_REQ: 0x04 and EXPECTED_DONE: 0x20 */
 460                 hdr->flags &= ~(0x04|0x20);
 461         } else {
 462                 /* turn off extra bytes: 20-21 bits */
 463                 hdr->bth[0] = cpu_to_be32(be32_to_cpu(hdr->bth[0])&0xFFCFFFFF);
 464                 /* turn off ACK_REQ: 0x04 */
 465                 hdr->flags &= ~(0x04);
 466         }
 467
 468         /* New kdeth checksum */
 469         vcto = le32_to_cpu(hdr->iph.ver_ctxt_tid_offset);
 470         hdr->iph.chksum = cpu_to_le16(QIB_LRH_BTH +
 471                 be16_to_cpu(hdr->lrh[2]) -
 472                 ((vcto>>16)&0xFFFF) - (vcto&0xFFFF) -
 473                 le16_to_cpu(hdr->iph.pkt_flags));
 474
 475         /* The packet is done, header is not dma mapped yet.
 476          * it should be from kmalloc */
 477         if (!pkt->addr[pkt->index].addr) {
 478                 pkt->addr[pkt->index].addr =
 479                         dma_map_single(&dd->pcidev->dev,
 480                                 pkt->addr[pkt->index].kvaddr,
 481                                 pkt->addr[pkt->index].dma_length,
 482                                 DMA_TO_DEVICE);
 483                 if (dma_mapping_error(&dd->pcidev->dev,
 484                                 pkt->addr[pkt->index].addr)) {
 485                         ret = -ENOMEM;
 486                         goto done;
 487                 }
 488                 pkt->addr[pkt->index].dma_mapped = 1;
 489         }
 490
 491         /* Modify the new sdma header */
 492         pbc16 = (__le16 *)pbcvaddr;
 493         hdr = (struct qib_message_header *)&pbc16[4];
 494
 495         /* New pbc length */
 496         pbc16[0] = cpu_to_le16(le16_to_cpu(pbc16[0])-(pkt->payload_size>>2));
 497
 498         /* New packet length */
 499         hdr->lrh[2] = cpu_to_be16(le16_to_cpu(pbc16[0]));
 500
 501         if (pkt->tiddma) {
 502                 /* Set new tid and offset for new sdma header */
 503                 hdr->iph.ver_ctxt_tid_offset = cpu_to_le32(
 504                         (le32_to_cpu(hdr->iph.ver_ctxt_tid_offset)&0xFF000000) +
 505                         (pkt->tidsm[pkt->tidsmidx].tid<<QLOGIC_IB_I_TID_SHIFT) +
 506                         (pkt->tidsm[pkt->tidsmidx].offset>>2));
 507         } else {
 508                 /* Middle protocol new packet offset */
 509                 hdr->uwords[2] += pkt->payload_size;
 510         }
 511
 512         /* New kdeth checksum */
 513         vcto = le32_to_cpu(hdr->iph.ver_ctxt_tid_offset);
 514         hdr->iph.chksum = cpu_to_le16(QIB_LRH_BTH +
 515                 be16_to_cpu(hdr->lrh[2]) -
 516                 ((vcto>>16)&0xFFFF) - (vcto&0xFFFF) -
 517                 le16_to_cpu(hdr->iph.pkt_flags));
 518
 519         /* Next sequence number in new sdma header */
 520         seqnum.val = be32_to_cpu(hdr->bth[2]);
 521         if (pkt->tiddma)
 522                 seqnum.seq++;
 523         else
 524                 seqnum.pkt++;
 525         hdr->bth[2] = cpu_to_be32(seqnum.val);
 526
 527         /* Init new sdma header. */
 528         qib_user_sdma_init_frag(pkt, pkt->naddr, /* index */
 529                 0, pbclen,              /* offset, len */
 530                 1, 0,                   /* first last desc */
 531                 0, 0,                   /* put page, dma mapped */
 532                 NULL, pbcvaddr,         /* struct page, virt addr */
 533                 pbcdaddr, pbclen);      /* dma addr, dma length */
 534         pkt->index = pkt->naddr;
 535         pkt->payload_size = 0;
 536         pkt->naddr++;
 537         if (pkt->naddr == pkt->addrlimit) {
 538                 ret = -EFAULT;
 539                 goto done;
 540         }
 541
 542         /* Prepare for next fragment in this page */
 543         if (newlen != len) {
 544                 if (dma_mapped) {
 545                         put = 0;
 546                         dma_mapped = 0;
 547                         page = NULL;
 548                         kvaddr = NULL;
 549                 }
 550                 len -= newlen;
 551                 offset += newlen;
 552
 553                 goto next_fragment;
 554         }
 555
 556 done:
 557         return ret;
 558 }
 559
 560 /* we've too many pages in the iovec, coalesce to a single page */
 561 static int qib_user_sdma_coalesce(const struct qib_devdata *dd,
 562                                   struct qib_user_sdma_queue *pq,
 563                                   struct qib_user_sdma_pkt *pkt,
 564                                   const struct iovec *iov,
 565                                   unsigned long niov)
 566 {
 567         int ret = 0;
 568         struct page *page = alloc_page(GFP_KERNEL);
 569         void *mpage_save;
 570         char *mpage;
 571         int i;
 572         int len = 0;
 573
 574         if (!page) {
 575                 ret = -ENOMEM;
 576                 goto done;
 577         }
 578
 579         mpage = kmap(page);
 580         mpage_save = mpage;
 581         for (i = 0; i < niov; i++) {
 582                 int cfur;
 583
 584                 cfur = copy_from_user(mpage,
 585                                       iov[i].iov_base, iov[i].iov_len);
 586                 if (cfur) {
 587                         ret = -EFAULT;
 588                         goto free_unmap;
 589                 }
 590
 591                 mpage += iov[i].iov_len;
 592                 len += iov[i].iov_len;
 593         }
 594
 595         ret = qib_user_sdma_page_to_frags(dd, pq, pkt,
 596                         page, 0, 0, len, mpage_save);
 597         goto done;
 598
 599 free_unmap:
 600         kunmap(page);
 601         __free_page(page);
 602 done:
 603         return ret;
 604 }
 605
 606 /*
 607  * How many pages in this iovec element?
 608  */
 609 static int qib_user_sdma_num_pages(const struct iovec *iov)
 610 {
 611         const unsigned long addr  = (unsigned long) iov->iov_base;
 612         const unsigned long  len  = iov->iov_len;
 613         const unsigned long spage = addr & PAGE_MASK;
 614         const unsigned long epage = (addr + len - 1) & PAGE_MASK;
 615
 616         return 1 + ((epage - spage) >> PAGE_SHIFT);
 617 }
 618
 619 static void qib_user_sdma_free_pkt_frag(struct device *dev,
 620                                         struct qib_user_sdma_queue *pq,
 621                                         struct qib_user_sdma_pkt *pkt,
 622                                         int frag)
 623 {
 624         const int i = frag;
 625
 626         if (pkt->addr[i].page) {
 627                 /* only user data has page */
 628                 if (pkt->addr[i].dma_mapped)
 629                         dma_unmap_page(dev,
 630                                        pkt->addr[i].addr,
 631                                        pkt->addr[i].dma_length,
 632                                        DMA_TO_DEVICE);
 633
 634                 if (pkt->addr[i].kvaddr)
 635                         kunmap(pkt->addr[i].page);
 636
 637                 if (pkt->addr[i].put_page)
 638                         put_page(pkt->addr[i].page);
 639                 else
 640                         __free_page(pkt->addr[i].page);
 641         } else if (pkt->addr[i].kvaddr) {
 642                 /* for headers */
 643                 if (pkt->addr[i].dma_mapped) {
 644                         /* from kmalloc & dma mapped */
 645                         dma_unmap_single(dev,
 646                                        pkt->addr[i].addr,
 647                                        pkt->addr[i].dma_length,
 648                                        DMA_TO_DEVICE);
 649                         kfree(pkt->addr[i].kvaddr);
 650                 } else if (pkt->addr[i].addr) {
 651                         /* free coherent mem from cache... */
 652                         dma_pool_free(pq->header_cache,
 653                               pkt->addr[i].kvaddr, pkt->addr[i].addr);
 654                 } else {
 655                         /* from kmalloc but not dma mapped */
 656                         kfree(pkt->addr[i].kvaddr);
 657                 }
 658         }
 659 }
 660
 661 /* return number of pages pinned... */
 662 static int qib_user_sdma_pin_pages(const struct qib_devdata *dd,
 663                                    struct qib_user_sdma_queue *pq,
 664                                    struct qib_user_sdma_pkt *pkt,
 665                                    unsigned long addr, int tlen, int npages)
 666 {
 667         struct page *pages[8];
 668         int i, j;
 669         int ret = 0;
 670
 671         while (npages) {
 672                 if (npages > 8)
 673                         j = 8;
 674                 else
 675                         j = npages;
 676
 677                 ret = get_user_pages_fast(addr, j, 0, pages);
 678                 if (ret != j) {
 679                         i = 0;
 680                         j = ret;
 681                         ret = -ENOMEM;
 682                         goto free_pages;
 683                 }
 684
 685                 for (i = 0; i < j; i++) {
 686                         /* map the pages... */
 687                         unsigned long fofs = addr & ~PAGE_MASK;
 688                         int flen = ((fofs + tlen) > PAGE_SIZE) ?
 689                                 (PAGE_SIZE - fofs) : tlen;
 690
 691                         ret = qib_user_sdma_page_to_frags(dd, pq, pkt,
 692                                 pages[i], 1, fofs, flen, NULL);
 693                         if (ret < 0) {
 694                                 /* current page has beed taken
 695                                  * care of inside above call.
 696                                  */
 697                                 i++;
 698                                 goto free_pages;
 699                         }
 700
 701                         addr += flen;
 702                         tlen -= flen;
 703                 }
 704
 705                 npages -= j;
 706         }
 707
 708         goto done;
 709
 710         /* if error, return all pages not managed by pkt */
 711 free_pages:
 712         while (i < j)
 713                 put_page(pages[i++]);
 714
 715 done:
 716         return ret;
 717 }
 718
 719 static int qib_user_sdma_pin_pkt(const struct qib_devdata *dd,
 720                                  struct qib_user_sdma_queue *pq,
 721                                  struct qib_user_sdma_pkt *pkt,
 722                                  const struct iovec *iov,
 723                                  unsigned long niov)
 724 {
 725         int ret = 0;
 726         unsigned long idx;
 727
 728         for (idx = 0; idx < niov; idx++) {
 729                 const int npages = qib_user_sdma_num_pages(iov + idx);
 730                 const unsigned long addr = (unsigned long) iov[idx].iov_base;
 731
 732                 ret = qib_user_sdma_pin_pages(dd, pq, pkt, addr,
 733                                               iov[idx].iov_len, npages);
 734                 if (ret < 0)
 735                         goto free_pkt;
 736         }
 737
 738         goto done;
 739
 740 free_pkt:
 741         /* we need to ignore the first entry here */
 742         for (idx = 1; idx < pkt->naddr; idx++)
 743                 qib_user_sdma_free_pkt_frag(&dd->pcidev->dev, pq, pkt, idx);
 744
 745         /* need to dma unmap the first entry, this is to restore to
 746          * the original state so that caller can free the memory in
 747          * error condition. Caller does not know if dma mapped or not*/
 748         if (pkt->addr[0].dma_mapped) {
 749                 dma_unmap_single(&dd->pcidev->dev,
 750                        pkt->addr[0].addr,
 751                        pkt->addr[0].dma_length,
 752                        DMA_TO_DEVICE);
 753                 pkt->addr[0].addr = 0;
 754                 pkt->addr[0].dma_mapped = 0;
 755         }
 756
 757 done:
 758         return ret;
 759 }
 760
 761 static int qib_user_sdma_init_payload(const struct qib_devdata *dd,
 762                                       struct qib_user_sdma_queue *pq,
 763                                       struct qib_user_sdma_pkt *pkt,
 764                                       const struct iovec *iov,
 765                                       unsigned long niov, int npages)
 766 {
 767         int ret = 0;
 768
 769         if (pkt->frag_size == pkt->bytes_togo &&
 770                         npages >= ARRAY_SIZE(pkt->addr))
 771                 ret = qib_user_sdma_coalesce(dd, pq, pkt, iov, niov);
 772         else
 773                 ret = qib_user_sdma_pin_pkt(dd, pq, pkt, iov, niov);
 774
 775         return ret;
 776 }
 777
 778 /* free a packet list -- return counter value of last packet */
 779 static void qib_user_sdma_free_pkt_list(struct device *dev,
 780                                         struct qib_user_sdma_queue *pq,
 781                                         struct list_head *list)
 782 {
 783         struct qib_user_sdma_pkt *pkt, *pkt_next;
 784
 785         list_for_each_entry_safe(pkt, pkt_next, list, list) {
 786                 int i;
 787
 788                 for (i = 0; i < pkt->naddr; i++)
 789                         qib_user_sdma_free_pkt_frag(dev, pq, pkt, i);
 790
 791                 if (pkt->largepkt)
 792                         kfree(pkt);
 793                 else
 794                         kmem_cache_free(pq->pkt_slab, pkt);
 795         }
 796         INIT_LIST_HEAD(list);
 797 }
 798
 799 /*
 800  * copy headers, coalesce etc -- pq->lock must be held
 801  *
 802  * we queue all the packets to list, returning the
 803  * number of bytes total.  list must be empty initially,
 804  * as, if there is an error we clean it...
 805  */
 806 static int qib_user_sdma_queue_pkts(const struct qib_devdata *dd,
 807                                     struct qib_pportdata *ppd,
 808                                     struct qib_user_sdma_queue *pq,
 809                                     const struct iovec *iov,
 810                                     unsigned long niov,
 811                                     struct list_head *list,
 812                                     int *maxpkts, int *ndesc)
 813 {
 814         unsigned long idx = 0;
 815         int ret = 0;
 816         int npkts = 0;
 817         __le32 *pbc;
 818         dma_addr_t dma_addr;
 819         struct qib_user_sdma_pkt *pkt = NULL;
 820         size_t len;
 821         size_t nw;
 822         u32 counter = pq->counter;
 823         u16 frag_size;
 824
 825         while (idx < niov && npkts < *maxpkts) {
 826                 const unsigned long addr = (unsigned long) iov[idx].iov_base;
 827                 const unsigned long idx_save = idx;
 828                 unsigned pktnw;
 829                 unsigned pktnwc;
 830                 int nfrags = 0;
 831                 int npages = 0;
 832                 int bytes_togo = 0;
 833                 int tiddma = 0;
 834                 int cfur;
 835
 836                 len = iov[idx].iov_len;
 837                 nw = len >> 2;
 838
 839                 if (len < QIB_USER_SDMA_MIN_HEADER_LENGTH ||
 840                     len > PAGE_SIZE || len & 3 || addr & 3) {
 841                         ret = -EINVAL;
 842                         goto free_list;
 843                 }
 844
 845                 pbc = qib_user_sdma_alloc_header(pq, len, &dma_addr);
 846                 if (!pbc) {
 847                         ret = -ENOMEM;
 848                         goto free_list;
 849                 }
 850
 851                 cfur = copy_from_user(pbc, iov[idx].iov_base, len);
 852                 if (cfur) {
 853                         ret = -EFAULT;
 854                         goto free_pbc;
 855                 }
 856
 857                 /*
 858                  * This assignment is a bit strange.  it's because the
 859                  * the pbc counts the number of 32 bit words in the full
 860                  * packet _except_ the first word of the pbc itself...
 861                  */
 862                 pktnwc = nw - 1;
 863
 864                 /*
 865                  * pktnw computation yields the number of 32 bit words
 866                  * that the caller has indicated in the PBC.  note that
 867                  * this is one less than the total number of words that
 868                  * goes to the send DMA engine as the first 32 bit word
 869                  * of the PBC itself is not counted.  Armed with this count,
 870                  * we can verify that the packet is consistent with the
 871                  * iovec lengths.
 872                  */
 873                 pktnw = le32_to_cpu(*pbc) & 0xFFFF;
 874                 if (pktnw < pktnwc) {
 875                         ret = -EINVAL;
 876                         goto free_pbc;
 877                 }
 878
 879                 idx++;
 880                 while (pktnwc < pktnw && idx < niov) {
 881                         const size_t slen = iov[idx].iov_len;
 882                         const unsigned long faddr =
 883                                 (unsigned long) iov[idx].iov_base;
 884
 885                         if (slen & 3 || faddr & 3 || !slen) {
 886                                 ret = -EINVAL;
 887                                 goto free_pbc;
 888                         }
 889
 890                         npages += qib_user_sdma_num_pages(&iov[idx]);
 891
 892                         bytes_togo += slen;
 893                         pktnwc += slen >> 2;
 894                         idx++;
 895                         nfrags++;
 896                 }
 897
 898                 if (pktnwc != pktnw) {
 899                         ret = -EINVAL;
 900                         goto free_pbc;
 901                 }
 902
 903                 frag_size = ((le32_to_cpu(*pbc))>>16) & 0xFFFF;
 904                 if (((frag_size ? frag_size : bytes_togo) + len) >
 905                                                 ppd->ibmaxlen) {
 906                         ret = -EINVAL;
 907                         goto free_pbc;
 908                 }
 909
 910                 if (frag_size) {
 911                         int pktsize, tidsmsize, n;
 912
 913                         n = npages*((2*PAGE_SIZE/frag_size)+1);
 914                         pktsize = sizeof(*pkt) + sizeof(pkt->addr[0])*n;
 915
 916                         /*
 917                          * Determine if this is tid-sdma or just sdma.
 918                          */
 919                         tiddma = (((le32_to_cpu(pbc[7])>>
 920                                 QLOGIC_IB_I_TID_SHIFT)&
 921                                 QLOGIC_IB_I_TID_MASK) !=
 922                                 QLOGIC_IB_I_TID_MASK);
 923
 924                         if (tiddma)
 925                                 tidsmsize = iov[idx].iov_len;
 926                         else
 927                                 tidsmsize = 0;
 928
 929                         pkt = kmalloc(pktsize+tidsmsize, GFP_KERNEL);
 930                         if (!pkt) {
 931                                 ret = -ENOMEM;
 932                                 goto free_pbc;
 933                         }
 934                         pkt->largepkt = 1;
 935                         pkt->frag_size = frag_size;
 936                         pkt->addrlimit = n + ARRAY_SIZE(pkt->addr);
 937
 938                         if (tiddma) {
 939                                 char *tidsm = (char *)pkt + pktsize;
 940
 941                                 cfur = copy_from_user(tidsm,
 942                                         iov[idx].iov_base, tidsmsize);
 943                                 if (cfur) {
 944                                         ret = -EFAULT;
 945                                         goto free_pkt;
 946                                 }
 947                                 pkt->tidsm =
 948                                         (struct qib_tid_session_member *)tidsm;
 949                                 pkt->tidsmcount = tidsmsize/
 950                                         sizeof(struct qib_tid_session_member);
 951                                 pkt->tidsmidx = 0;
 952                                 idx++;
 953                         }
 954
 955                         /*
 956                          * pbc 'fill1' field is borrowed to pass frag size,
 957                          * we need to clear it after picking frag size, the
 958                          * hardware requires this field to be zero.
 959                          */
 960                         *pbc = cpu_to_le32(le32_to_cpu(*pbc) & 0x0000FFFF);
 961                 } else {
 962                         pkt = kmem_cache_alloc(pq->pkt_slab, GFP_KERNEL);
 963                         if (!pkt) {
 964                                 ret = -ENOMEM;
 965                                 goto free_pbc;
 966                         }
 967                         pkt->largepkt = 0;
 968                         pkt->frag_size = bytes_togo;
 969                         pkt->addrlimit = ARRAY_SIZE(pkt->addr);
 970                 }
 971                 pkt->bytes_togo = bytes_togo;
 972                 pkt->payload_size = 0;
 973                 pkt->counter = counter;
 974                 pkt->tiddma = tiddma;
 975
 976                 /* setup the first header */
 977                 qib_user_sdma_init_frag(pkt, 0, /* index */
 978                         0, len,         /* offset, len */
 979                         1, 0,           /* first last desc */
 980                         0, 0,           /* put page, dma mapped */
 981                         NULL, pbc,      /* struct page, virt addr */
 982                         dma_addr, len); /* dma addr, dma length */
 983                 pkt->index = 0;
 984                 pkt->naddr = 1;
 985
 986                 if (nfrags) {
 987                         ret = qib_user_sdma_init_payload(dd, pq, pkt,
 988                                                          iov + idx_save + 1,
 989                                                          nfrags, npages);
 990                         if (ret < 0)
 991                                 goto free_pkt;
 992                 } else {
 993                         /* since there is no payload, mark the
 994                          * header as the last desc. */
 995                         pkt->addr[0].last_desc = 1;
 996
 997                         if (dma_addr == 0) {
 998                                 /*
 999                                  * the header is not dma mapped yet.
1000                                  * it should be from kmalloc.
1001                                  */
1002                                 dma_addr = dma_map_single(&dd->pcidev->dev,
1003                                         pbc, len, DMA_TO_DEVICE);
1004                                 if (dma_mapping_error(&dd->pcidev->dev,
1005                                                                 dma_addr)) {
1006                                         ret = -ENOMEM;
1007                                         goto free_pkt;
1008                                 }
1009                                 pkt->addr[0].addr = dma_addr;
1010                                 pkt->addr[0].dma_mapped = 1;
1011                         }
1012                 }
1013
1014                 counter++;
1015                 npkts++;
1016                 pkt->pq = pq;
1017                 pkt->index = 0; /* reset index for push on hw */
1018                 *ndesc += pkt->naddr;
1019
1020                 list_add_tail(&pkt->list, list);
1021         }
1022
1023         *maxpkts = npkts;
1024         ret = idx;
1025         goto done;
1026
1027 free_pkt:
1028         if (pkt->largepkt)
1029                 kfree(pkt);
1030         else
1031                 kmem_cache_free(pq->pkt_slab, pkt);
1032 free_pbc:
1033         if (dma_addr)
1034                 dma_pool_free(pq->header_cache, pbc, dma_addr);
1035         else
1036                 kfree(pbc);
1037 free_list:
1038         qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, list);
1039 done:
1040         return ret;
1041 }
1042
1043 static void qib_user_sdma_set_complete_counter(struct qib_user_sdma_queue *pq,
1044                                                u32 c)
1045 {
1046         pq->sent_counter = c;
1047 }
1048
1049 /* try to clean out queue -- needs pq->lock */
1050 static int qib_user_sdma_queue_clean(struct qib_pportdata *ppd,
1051                                      struct qib_user_sdma_queue *pq)
1052 {
1053         struct qib_devdata *dd = ppd->dd;
1054         struct list_head free_list;
1055         struct qib_user_sdma_pkt *pkt;
1056         struct qib_user_sdma_pkt *pkt_prev;
1057         unsigned long flags;
1058         int ret = 0;
1059
1060         if (!pq->num_sending)
1061                 return 0;
1062
1063         INIT_LIST_HEAD(&free_list);
1064
1065         /*
1066          * We need this spin lock here because interrupt handler
1067          * might modify this list in qib_user_sdma_send_desc(), also
1068          * we can not get interrupted, otherwise it is a deadlock.
1069          */
1070         spin_lock_irqsave(&pq->sent_lock, flags);
1071         list_for_each_entry_safe(pkt, pkt_prev, &pq->sent, list) {
1072                 s64 descd = ppd->sdma_descq_removed - pkt->added;
1073
1074                 if (descd < 0)
1075                         break;
1076
1077                 list_move_tail(&pkt->list, &free_list);
1078
1079                 /* one more packet cleaned */
1080                 ret++;
1081                 pq->num_sending--;
1082         }
1083         spin_unlock_irqrestore(&pq->sent_lock, flags);
1084
1085         if (!list_empty(&free_list)) {
1086                 u32 counter;
1087
1088                 pkt = list_entry(free_list.prev,
1089                                  struct qib_user_sdma_pkt, list);
1090                 counter = pkt->counter;
1091
1092                 qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
1093                 qib_user_sdma_set_complete_counter(pq, counter);
1094         }
1095
1096         return ret;
1097 }
1098
1099 void qib_user_sdma_queue_destroy(struct qib_user_sdma_queue *pq)
1100 {
1101         if (!pq)
1102                 return;
1103
1104         pq->sdma_rb_node->refcount--;
1105         if (pq->sdma_rb_node->refcount == 0) {
1106                 rb_erase(&pq->sdma_rb_node->node, &qib_user_sdma_rb_root);
1107                 kfree(pq->sdma_rb_node);
1108         }
1109         dma_pool_destroy(pq->header_cache);
1110         kmem_cache_destroy(pq->pkt_slab);
1111         kfree(pq);
1112 }
1113
1114 /* clean descriptor queue, returns > 0 if some elements cleaned */
1115 static int qib_user_sdma_hwqueue_clean(struct qib_pportdata *ppd)
1116 {
1117         int ret;
1118         unsigned long flags;
1119
1120         spin_lock_irqsave(&ppd->sdma_lock, flags);
1121         ret = qib_sdma_make_progress(ppd);
1122         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1123
1124         return ret;
1125 }
1126
1127 /* we're in close, drain packets so that we can cleanup successfully... */
1128 void qib_user_sdma_queue_drain(struct qib_pportdata *ppd,
1129                                struct qib_user_sdma_queue *pq)
1130 {
1131         struct qib_devdata *dd = ppd->dd;
1132         unsigned long flags;
1133         int i;
1134
1135         if (!pq)
1136                 return;
1137
1138         for (i = 0; i < QIB_USER_SDMA_DRAIN_TIMEOUT; i++) {
1139                 mutex_lock(&pq->lock);
1140                 if (!pq->num_pending && !pq->num_sending) {
1141                         mutex_unlock(&pq->lock);
1142                         break;
1143                 }
1144                 qib_user_sdma_hwqueue_clean(ppd);
1145                 qib_user_sdma_queue_clean(ppd, pq);
1146                 mutex_unlock(&pq->lock);
1147                 msleep(20);
1148         }
1149
1150         if (pq->num_pending || pq->num_sending) {
1151                 struct qib_user_sdma_pkt *pkt;
1152                 struct qib_user_sdma_pkt *pkt_prev;
1153                 struct list_head free_list;
1154
1155                 mutex_lock(&pq->lock);
1156                 spin_lock_irqsave(&ppd->sdma_lock, flags);
1157                 /*
1158                  * Since we hold sdma_lock, it is safe without sent_lock.
1159                  */
1160                 if (pq->num_pending) {
1161                         list_for_each_entry_safe(pkt, pkt_prev,
1162                                         &ppd->sdma_userpending, list) {
1163                                 if (pkt->pq == pq) {
1164                                         list_move_tail(&pkt->list, &pq->sent);
1165                                         pq->num_pending--;
1166                                         pq->num_sending++;
1167                                 }
1168                         }
1169                 }
1170                 spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1171
1172                 qib_dev_err(dd, "user sdma lists not empty: forcing!\n");
1173                 INIT_LIST_HEAD(&free_list);
1174                 list_splice_init(&pq->sent, &free_list);
1175                 pq->num_sending = 0;
1176                 qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
1177                 mutex_unlock(&pq->lock);
1178         }
1179 }
1180
1181 static inline __le64 qib_sdma_make_desc0(u8 gen,
1182                                          u64 addr, u64 dwlen, u64 dwoffset)
1183 {
1184         return cpu_to_le64(/* SDmaPhyAddr[31:0] */
1185                            ((addr & 0xfffffffcULL) << 32) |
1186                            /* SDmaGeneration[1:0] */
1187                            ((gen & 3ULL) << 30) |
1188                            /* SDmaDwordCount[10:0] */
1189                            ((dwlen & 0x7ffULL) << 16) |
1190                            /* SDmaBufOffset[12:2] */
1191                            (dwoffset & 0x7ffULL));
1192 }
1193
1194 static inline __le64 qib_sdma_make_first_desc0(__le64 descq)
1195 {
1196         return descq | cpu_to_le64(1ULL << 12);
1197 }
1198
1199 static inline __le64 qib_sdma_make_last_desc0(__le64 descq)
1200 {
1201                                               /* last */  /* dma head */
1202         return descq | cpu_to_le64(1ULL << 11 | 1ULL << 13);
1203 }
1204
1205 static inline __le64 qib_sdma_make_desc1(u64 addr)
1206 {
1207         /* SDmaPhyAddr[47:32] */
1208         return cpu_to_le64(addr >> 32);
1209 }
1210
1211 static void qib_user_sdma_send_frag(struct qib_pportdata *ppd,
1212                                     struct qib_user_sdma_pkt *pkt, int idx,
1213                                     unsigned ofs, u16 tail, u8 gen)
1214 {
1215         const u64 addr = (u64) pkt->addr[idx].addr +
1216                 (u64) pkt->addr[idx].offset;
1217         const u64 dwlen = (u64) pkt->addr[idx].length / 4;
1218         __le64 *descqp;
1219         __le64 descq0;
1220
1221         descqp = &ppd->sdma_descq[tail].qw[0];
1222
1223         descq0 = qib_sdma_make_desc0(gen, addr, dwlen, ofs);
1224         if (pkt->addr[idx].first_desc)
1225                 descq0 = qib_sdma_make_first_desc0(descq0);
1226         if (pkt->addr[idx].last_desc) {
1227                 descq0 = qib_sdma_make_last_desc0(descq0);
1228                 if (ppd->sdma_intrequest) {
1229                         descq0 |= cpu_to_le64(1ULL << 15);
1230                         ppd->sdma_intrequest = 0;
1231                 }
1232         }
1233
1234         descqp[0] = descq0;
1235         descqp[1] = qib_sdma_make_desc1(addr);
1236 }
1237
1238 void qib_user_sdma_send_desc(struct qib_pportdata *ppd,
1239                                 struct list_head *pktlist)
1240 {
1241         struct qib_devdata *dd = ppd->dd;
1242         u16 nfree, nsent;
1243         u16 tail, tail_c;
1244         u8 gen, gen_c;
1245
1246         nfree = qib_sdma_descq_freecnt(ppd);
1247         if (!nfree)
1248                 return;
1249
1250 retry:
1251         nsent = 0;
1252         tail_c = tail = ppd->sdma_descq_tail;
1253         gen_c = gen = ppd->sdma_generation;
1254         while (!list_empty(pktlist)) {
1255                 struct qib_user_sdma_pkt *pkt =
1256                         list_entry(pktlist->next, struct qib_user_sdma_pkt,
1257                                    list);
1258                 int i, j, c = 0;
1259                 unsigned ofs = 0;
1260                 u16 dtail = tail;
1261
1262                 for (i = pkt->index; i < pkt->naddr && nfree; i++) {
1263                         qib_user_sdma_send_frag(ppd, pkt, i, ofs, tail, gen);
1264                         ofs += pkt->addr[i].length >> 2;
1265
1266                         if (++tail == ppd->sdma_descq_cnt) {
1267                                 tail = 0;
1268                                 ++gen;
1269                                 ppd->sdma_intrequest = 1;
1270                         } else if (tail == (ppd->sdma_descq_cnt>>1)) {
1271                                 ppd->sdma_intrequest = 1;
1272                         }
1273                         nfree--;
1274                         if (pkt->addr[i].last_desc == 0)
1275                                 continue;
1276
1277                         /*
1278                          * If the packet is >= 2KB mtu equivalent, we
1279                          * have to use the large buffers, and have to
1280                          * mark each descriptor as part of a large
1281                          * buffer packet.
1282                          */
1283                         if (ofs > dd->piosize2kmax_dwords) {
1284                                 for (j = pkt->index; j <= i; j++) {
1285                                         ppd->sdma_descq[dtail].qw[0] |=
1286                                                 cpu_to_le64(1ULL << 14);
1287                                         if (++dtail == ppd->sdma_descq_cnt)
1288                                                 dtail = 0;
1289                                 }
1290                         }
1291                         c += i + 1 - pkt->index;
1292                         pkt->index = i + 1; /* index for next first */
1293                         tail_c = dtail = tail;
1294                         gen_c = gen;
1295                         ofs = 0;  /* reset for next packet */
1296                 }
1297
1298                 ppd->sdma_descq_added += c;
1299                 nsent += c;
1300                 if (pkt->index == pkt->naddr) {
1301                         pkt->added = ppd->sdma_descq_added;
1302                         pkt->pq->added = pkt->added;
1303                         pkt->pq->num_pending--;
1304                         spin_lock(&pkt->pq->sent_lock);
1305                         pkt->pq->num_sending++;
1306                         list_move_tail(&pkt->list, &pkt->pq->sent);
1307                         spin_unlock(&pkt->pq->sent_lock);
1308                 }
1309                 if (!nfree || (nsent<<2) > ppd->sdma_descq_cnt)
1310                         break;
1311         }
1312
1313         /* advance the tail on the chip if necessary */
1314         if (ppd->sdma_descq_tail != tail_c) {
1315                 ppd->sdma_generation = gen_c;
1316                 dd->f_sdma_update_tail(ppd, tail_c);
1317         }
1318
1319         if (nfree && !list_empty(pktlist))
1320                 goto retry;
1321 }
1322
1323 /* pq->lock must be held, get packets on the wire... */
1324 static int qib_user_sdma_push_pkts(struct qib_pportdata *ppd,
1325                                  struct qib_user_sdma_queue *pq,
1326                                  struct list_head *pktlist, int count)
1327 {
1328         unsigned long flags;
1329
1330         if (unlikely(!(ppd->lflags & QIBL_LINKACTIVE)))
1331                 return -ECOMM;
1332
1333         /* non-blocking mode */
1334         if (pq->sdma_rb_node->refcount > 1) {
1335                 spin_lock_irqsave(&ppd->sdma_lock, flags);
1336                 if (unlikely(!__qib_sdma_running(ppd))) {
1337                         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1338                         return -ECOMM;
1339                 }
1340                 pq->num_pending += count;
1341                 list_splice_tail_init(pktlist, &ppd->sdma_userpending);
1342                 qib_user_sdma_send_desc(ppd, &ppd->sdma_userpending);
1343                 spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1344                 return 0;
1345         }
1346
1347         /* In this case, descriptors from this process are not
1348          * linked to ppd pending queue, interrupt handler
1349          * won't update this process, it is OK to directly
1350          * modify without sdma lock.
1351          */
1352
1353
1354         pq->num_pending += count;
1355         /*
1356          * Blocking mode for single rail process, we must
1357          * release/regain sdma_lock to give other process
1358          * chance to make progress. This is important for
1359          * performance.
1360          */
1361         do {
1362                 spin_lock_irqsave(&ppd->sdma_lock, flags);
1363                 if (unlikely(!__qib_sdma_running(ppd))) {
1364                         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1365                         return -ECOMM;
1366                 }
1367                 qib_user_sdma_send_desc(ppd, pktlist);
1368                 if (!list_empty(pktlist))
1369                         qib_sdma_make_progress(ppd);
1370                 spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1371         } while (!list_empty(pktlist));
1372
1373         return 0;
1374 }
1375
1376 int qib_user_sdma_writev(struct qib_ctxtdata *rcd,
1377                          struct qib_user_sdma_queue *pq,
1378                          const struct iovec *iov,
1379                          unsigned long dim)
1380 {
1381         struct qib_devdata *dd = rcd->dd;
1382         struct qib_pportdata *ppd = rcd->ppd;
1383         int ret = 0;
1384         struct list_head list;
1385         int npkts = 0;
1386
1387         INIT_LIST_HEAD(&list);
1388
1389         mutex_lock(&pq->lock);
1390
1391         /* why not -ECOMM like qib_user_sdma_push_pkts() below? */
1392         if (!qib_sdma_running(ppd))
1393                 goto done_unlock;
1394
1395         /* if I have packets not complete yet */
1396         if (pq->added > ppd->sdma_descq_removed)
1397                 qib_user_sdma_hwqueue_clean(ppd);
1398         /* if I have complete packets to be freed */
1399         if (pq->num_sending)
1400                 qib_user_sdma_queue_clean(ppd, pq);
1401
1402         while (dim) {
1403                 int mxp = 1;
1404                 int ndesc = 0;
1405
1406                 ret = qib_user_sdma_queue_pkts(dd, ppd, pq,
1407                                 iov, dim, &list, &mxp, &ndesc);
1408                 if (ret < 0)
1409                         goto done_unlock;
1410                 else {
1411                         dim -= ret;
1412                         iov += ret;
1413                 }
1414
1415                 /* force packets onto the sdma hw queue... */
1416                 if (!list_empty(&list)) {
1417                         /*
1418                          * Lazily clean hw queue.
1419                          */
1420                         if (qib_sdma_descq_freecnt(ppd) < ndesc) {
1421                                 qib_user_sdma_hwqueue_clean(ppd);
1422                                 if (pq->num_sending)
1423                                         qib_user_sdma_queue_clean(ppd, pq);
1424                         }
1425
1426                         ret = qib_user_sdma_push_pkts(ppd, pq, &list, mxp);
1427                         if (ret < 0)
1428                                 goto done_unlock;
1429                         else {
1430                                 npkts += mxp;
1431                                 pq->counter += mxp;
1432                         }
1433                 }
1434         }
1435
1436 done_unlock:
1437         if (!list_empty(&list))
1438                 qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &list);
1439         mutex_unlock(&pq->lock);
1440
1441         return (ret < 0) ? ret : npkts;
1442 }
1443
1444 int qib_user_sdma_make_progress(struct qib_pportdata *ppd,
1445                                 struct qib_user_sdma_queue *pq)
1446 {
1447         int ret = 0;
1448
1449         mutex_lock(&pq->lock);
1450         qib_user_sdma_hwqueue_clean(ppd);
1451         ret = qib_user_sdma_queue_clean(ppd, pq);
1452         mutex_unlock(&pq->lock);
1453
1454         return ret;
1455 }
1456
1457 u32 qib_user_sdma_complete_counter(const struct qib_user_sdma_queue *pq)
1458 {
1459         return pq ? pq->sent_counter : 0;
1460 }
1461
1462 u32 qib_user_sdma_inflight_counter(struct qib_user_sdma_queue *pq)
1463 {
1464         return pq ? pq->counter : 0;
1465 }