drivers/usb/host/whci/qset.c

   1 /*
   2  * Wireless Host Controller (WHC) qset management.
   3  *
   4  * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version
   8  * 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 #include <linux/kernel.h>
  19 #include <linux/dma-mapping.h>
  20 #include <linux/slab.h>
  21 #include <linux/uwb/umc.h>
  22 #include <linux/usb.h>
  23
  24 #include "../../wusbcore/wusbhc.h"
  25
  26 #include "whcd.h"
  27
  28 struct whc_qset *qset_alloc(struct whc *whc, gfp_t mem_flags)
  29 {
  30         struct whc_qset *qset;
  31         dma_addr_t dma;
  32
  33         qset = dma_pool_zalloc(whc->qset_pool, mem_flags, &dma);
  34         if (qset == NULL)
  35                 return NULL;
  36
  37         qset->qset_dma = dma;
  38         qset->whc = whc;
  39
  40         INIT_LIST_HEAD(&qset->list_node);
  41         INIT_LIST_HEAD(&qset->stds);
  42
  43         return qset;
  44 }
  45
  46 /**
  47  * qset_fill_qh - fill the static endpoint state in a qset's QHead
  48  * @qset: the qset whose QH needs initializing with static endpoint
  49  *        state
  50  * @urb:  an urb for a transfer to this endpoint
  51  */
  52 static void qset_fill_qh(struct whc *whc, struct whc_qset *qset, struct urb *urb)
  53 {
  54         struct usb_device *usb_dev = urb->dev;
  55         struct wusb_dev *wusb_dev = usb_dev->wusb_dev;
  56         struct usb_wireless_ep_comp_descriptor *epcd;
  57         bool is_out;
  58         uint8_t phy_rate;
  59
  60         is_out = usb_pipeout(urb->pipe);
  61
  62         qset->max_packet = le16_to_cpu(urb->ep->desc.wMaxPacketSize);
  63
  64         epcd = (struct usb_wireless_ep_comp_descriptor *)qset->ep->extra;
  65         if (epcd) {
  66                 qset->max_seq = epcd->bMaxSequence;
  67                 qset->max_burst = epcd->bMaxBurst;
  68         } else {
  69                 qset->max_seq = 2;
  70                 qset->max_burst = 1;
  71         }
  72
  73         /*
  74          * Initial PHY rate is 53.3 Mbit/s for control endpoints or
  75          * the maximum supported by the device for other endpoints
  76          * (unless limited by the user).
  77          */
  78         if (usb_pipecontrol(urb->pipe))
  79                 phy_rate = UWB_PHY_RATE_53;
  80         else {
  81                 uint16_t phy_rates;
  82
  83                 phy_rates = le16_to_cpu(wusb_dev->wusb_cap_descr->wPHYRates);
  84                 phy_rate = fls(phy_rates) - 1;
  85                 if (phy_rate > whc->wusbhc.phy_rate)
  86                         phy_rate = whc->wusbhc.phy_rate;
  87         }
  88
  89         qset->qh.info1 = cpu_to_le32(
  90                 QH_INFO1_EP(usb_pipeendpoint(urb->pipe))
  91                 | (is_out ? QH_INFO1_DIR_OUT : QH_INFO1_DIR_IN)
  92                 | usb_pipe_to_qh_type(urb->pipe)
  93                 | QH_INFO1_DEV_INFO_IDX(wusb_port_no_to_idx(usb_dev->portnum))
  94                 | QH_INFO1_MAX_PKT_LEN(qset->max_packet)
  95                 );
  96         qset->qh.info2 = cpu_to_le32(
  97                 QH_INFO2_BURST(qset->max_burst)
  98                 | QH_INFO2_DBP(0)
  99                 | QH_INFO2_MAX_COUNT(3)
 100                 | QH_INFO2_MAX_RETRY(3)
 101                 | QH_INFO2_MAX_SEQ(qset->max_seq - 1)
 102                 );
 103         /* FIXME: where can we obtain these Tx parameters from?  Why
 104          * doesn't the chip know what Tx power to use? It knows the Rx
 105          * strength and can presumably guess the Tx power required
 106          * from that? */
 107         qset->qh.info3 = cpu_to_le32(
 108                 QH_INFO3_TX_RATE(phy_rate)
 109                 | QH_INFO3_TX_PWR(0) /* 0 == max power */
 110                 );
 111
 112         qset->qh.cur_window = cpu_to_le32((1 << qset->max_burst) - 1);
 113 }
 114
 115 /**
 116  * qset_clear - clear fields in a qset so it may be reinserted into a
 117  * schedule.
 118  *
 119  * The sequence number and current window are not cleared (see
 120  * qset_reset()).
 121  */
 122 void qset_clear(struct whc *whc, struct whc_qset *qset)
 123 {
 124         qset->td_start = qset->td_end = qset->ntds = 0;
 125
 126         qset->qh.link = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
 127         qset->qh.status = qset->qh.status & QH_STATUS_SEQ_MASK;
 128         qset->qh.err_count = 0;
 129         qset->qh.scratch[0] = 0;
 130         qset->qh.scratch[1] = 0;
 131         qset->qh.scratch[2] = 0;
 132
 133         memset(&qset->qh.overlay, 0, sizeof(qset->qh.overlay));
 134
 135         init_completion(&qset->remove_complete);
 136 }
 137
 138 /**
 139  * qset_reset - reset endpoint state in a qset.
 140  *
 141  * Clears the sequence number and current window.  This qset must not
 142  * be in the ASL or PZL.
 143  */
 144 void qset_reset(struct whc *whc, struct whc_qset *qset)
 145 {
 146         qset->reset = 0;
 147
 148         qset->qh.status &= ~QH_STATUS_SEQ_MASK;
 149         qset->qh.cur_window = cpu_to_le32((1 << qset->max_burst) - 1);
 150 }
 151
 152 /**
 153  * get_qset - get the qset for an async endpoint
 154  *
 155  * A new qset is created if one does not already exist.
 156  */
 157 struct whc_qset *get_qset(struct whc *whc, struct urb *urb,
 158                                  gfp_t mem_flags)
 159 {
 160         struct whc_qset *qset;
 161
 162         qset = urb->ep->hcpriv;
 163         if (qset == NULL) {
 164                 qset = qset_alloc(whc, mem_flags);
 165                 if (qset == NULL)
 166                         return NULL;
 167
 168                 qset->ep = urb->ep;
 169                 urb->ep->hcpriv = qset;
 170                 qset_fill_qh(whc, qset, urb);
 171         }
 172         return qset;
 173 }
 174
 175 void qset_remove_complete(struct whc *whc, struct whc_qset *qset)
 176 {
 177         qset->remove = 0;
 178         list_del_init(&qset->list_node);
 179         complete(&qset->remove_complete);
 180 }
 181
 182 /**
 183  * qset_add_qtds - add qTDs for an URB to a qset
 184  *
 185  * Returns true if the list (ASL/PZL) must be updated because (for a
 186  * WHCI 0.95 controller) an activated qTD was pointed to be iCur.
 187  */
 188 enum whc_update qset_add_qtds(struct whc *whc, struct whc_qset *qset)
 189 {
 190         struct whc_std *std;
 191         enum whc_update update = 0;
 192
 193         list_for_each_entry(std, &qset->stds, list_node) {
 194                 struct whc_qtd *qtd;
 195                 uint32_t status;
 196
 197                 if (qset->ntds >= WHCI_QSET_TD_MAX
 198                     || (qset->pause_after_urb && std->urb != qset->pause_after_urb))
 199                         break;
 200
 201                 if (std->qtd)
 202                         continue; /* already has a qTD */
 203
 204                 qtd = std->qtd = &qset->qtd[qset->td_end];
 205
 206                 /* Fill in setup bytes for control transfers. */
 207                 if (usb_pipecontrol(std->urb->pipe))
 208                         memcpy(qtd->setup, std->urb->setup_packet, 8);
 209
 210                 status = QTD_STS_ACTIVE | QTD_STS_LEN(std->len);
 211
 212                 if (whc_std_last(std) && usb_pipeout(std->urb->pipe))
 213                         status |= QTD_STS_LAST_PKT;
 214
 215                 /*
 216                  * For an IN transfer the iAlt field should be set so
 217                  * the h/w will automatically advance to the next
 218                  * transfer. However, if there are 8 or more TDs
 219                  * remaining in this transfer then iAlt cannot be set
 220                  * as it could point to somewhere in this transfer.
 221                  */
 222                 if (std->ntds_remaining < WHCI_QSET_TD_MAX) {
 223                         int ialt;
 224                         ialt = (qset->td_end + std->ntds_remaining) % WHCI_QSET_TD_MAX;
 225                         status |= QTD_STS_IALT(ialt);
 226                 } else if (usb_pipein(std->urb->pipe))
 227                         qset->pause_after_urb = std->urb;
 228
 229                 if (std->num_pointers)
 230                         qtd->options = cpu_to_le32(QTD_OPT_IOC);
 231                 else
 232                         qtd->options = cpu_to_le32(QTD_OPT_IOC | QTD_OPT_SMALL);
 233                 qtd->page_list_ptr = cpu_to_le64(std->dma_addr);
 234
 235                 qtd->status = cpu_to_le32(status);
 236
 237                 if (QH_STATUS_TO_ICUR(qset->qh.status) == qset->td_end)
 238                         update = WHC_UPDATE_UPDATED;
 239
 240                 if (++qset->td_end >= WHCI_QSET_TD_MAX)
 241                         qset->td_end = 0;
 242                 qset->ntds++;
 243         }
 244
 245         return update;
 246 }
 247
 248 /**
 249  * qset_remove_qtd - remove the first qTD from a qset.
 250  *
 251  * The qTD might be still active (if it's part of a IN URB that
 252  * resulted in a short read) so ensure it's deactivated.
 253  */
 254 static void qset_remove_qtd(struct whc *whc, struct whc_qset *qset)
 255 {
 256         qset->qtd[qset->td_start].status = 0;
 257
 258         if (++qset->td_start >= WHCI_QSET_TD_MAX)
 259                 qset->td_start = 0;
 260         qset->ntds--;
 261 }
 262
 263 static void qset_copy_bounce_to_sg(struct whc *whc, struct whc_std *std)
 264 {
 265         struct scatterlist *sg;
 266         void *bounce;
 267         size_t remaining, offset;
 268
 269         bounce = std->bounce_buf;
 270         remaining = std->len;
 271
 272         sg = std->bounce_sg;
 273         offset = std->bounce_offset;
 274
 275         while (remaining) {
 276                 size_t len;
 277
 278                 len = min(sg->length - offset, remaining);
 279                 memcpy(sg_virt(sg) + offset, bounce, len);
 280
 281                 bounce += len;
 282                 remaining -= len;
 283
 284                 offset += len;
 285                 if (offset >= sg->length) {
 286                         sg = sg_next(sg);
 287                         offset = 0;
 288                 }
 289         }
 290
 291 }
 292
 293 /**
 294  * qset_free_std - remove an sTD and free it.
 295  * @whc: the WHCI host controller
 296  * @std: the sTD to remove and free.
 297  */
 298 void qset_free_std(struct whc *whc, struct whc_std *std)
 299 {
 300         list_del(&std->list_node);
 301         if (std->bounce_buf) {
 302                 bool is_out = usb_pipeout(std->urb->pipe);
 303                 dma_addr_t dma_addr;
 304
 305                 if (std->num_pointers)
 306                         dma_addr = le64_to_cpu(std->pl_virt[0].buf_ptr);
 307                 else
 308                         dma_addr = std->dma_addr;
 309
 310                 dma_unmap_single(whc->wusbhc.dev, dma_addr,
 311                                  std->len, is_out ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 312                 if (!is_out)
 313                         qset_copy_bounce_to_sg(whc, std);
 314                 kfree(std->bounce_buf);
 315         }
 316         if (std->pl_virt) {
 317                 if (!dma_mapping_error(whc->wusbhc.dev, std->dma_addr))
 318                         dma_unmap_single(whc->wusbhc.dev, std->dma_addr,
 319                                          std->num_pointers * sizeof(struct whc_page_list_entry),
 320                                          DMA_TO_DEVICE);
 321                 kfree(std->pl_virt);
 322                 std->pl_virt = NULL;
 323         }
 324         kfree(std);
 325 }
 326
 327 /**
 328  * qset_remove_qtds - remove an URB's qTDs (and sTDs).
 329  */
 330 static void qset_remove_qtds(struct whc *whc, struct whc_qset *qset,
 331                              struct urb *urb)
 332 {
 333         struct whc_std *std, *t;
 334
 335         list_for_each_entry_safe(std, t, &qset->stds, list_node) {
 336                 if (std->urb != urb)
 337                         break;
 338                 if (std->qtd != NULL)
 339                         qset_remove_qtd(whc, qset);
 340                 qset_free_std(whc, std);
 341         }
 342 }
 343
 344 /**
 345  * qset_free_stds - free any remaining sTDs for an URB.
 346  */
 347 static void qset_free_stds(struct whc_qset *qset, struct urb *urb)
 348 {
 349         struct whc_std *std, *t;
 350
 351         list_for_each_entry_safe(std, t, &qset->stds, list_node) {
 352                 if (std->urb == urb)
 353                         qset_free_std(qset->whc, std);
 354         }
 355 }
 356
 357 static int qset_fill_page_list(struct whc *whc, struct whc_std *std, gfp_t mem_flags)
 358 {
 359         dma_addr_t dma_addr = std->dma_addr;
 360         dma_addr_t sp, ep;
 361         size_t pl_len;
 362         int p;
 363
 364         /* Short buffers don't need a page list. */
 365         if (std->len <= WHCI_PAGE_SIZE) {
 366                 std->num_pointers = 0;
 367                 return 0;
 368         }
 369
 370         sp = dma_addr & ~(WHCI_PAGE_SIZE-1);
 371         ep = dma_addr + std->len;
 372         std->num_pointers = DIV_ROUND_UP(ep - sp, WHCI_PAGE_SIZE);
 373
 374         pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
 375         std->pl_virt = kmalloc(pl_len, mem_flags);
 376         if (std->pl_virt == NULL)
 377                 return -ENOMEM;
 378         std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt, pl_len, DMA_TO_DEVICE);
 379         if (dma_mapping_error(whc->wusbhc.dev, std->dma_addr)) {
 380                 kfree(std->pl_virt);
 381                 return -EFAULT;
 382         }
 383
 384         for (p = 0; p < std->num_pointers; p++) {
 385                 std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
 386                 dma_addr = (dma_addr + WHCI_PAGE_SIZE) & ~(WHCI_PAGE_SIZE-1);
 387         }
 388
 389         return 0;
 390 }
 391
 392 /**
 393  * urb_dequeue_work - executes asl/pzl update and gives back the urb to the system.
 394  */
 395 static void urb_dequeue_work(struct work_struct *work)
 396 {
 397         struct whc_urb *wurb = container_of(work, struct whc_urb, dequeue_work);
 398         struct whc_qset *qset = wurb->qset;
 399         struct whc *whc = qset->whc;
 400         unsigned long flags;
 401
 402         if (wurb->is_async)
 403                 asl_update(whc, WUSBCMD_ASYNC_UPDATED
 404                            | WUSBCMD_ASYNC_SYNCED_DB
 405                            | WUSBCMD_ASYNC_QSET_RM);
 406         else
 407                 pzl_update(whc, WUSBCMD_PERIODIC_UPDATED
 408                            | WUSBCMD_PERIODIC_SYNCED_DB
 409                            | WUSBCMD_PERIODIC_QSET_RM);
 410
 411         spin_lock_irqsave(&whc->lock, flags);
 412         qset_remove_urb(whc, qset, wurb->urb, wurb->status);
 413         spin_unlock_irqrestore(&whc->lock, flags);
 414 }
 415
 416 static struct whc_std *qset_new_std(struct whc *whc, struct whc_qset *qset,
 417                                     struct urb *urb, gfp_t mem_flags)
 418 {
 419         struct whc_std *std;
 420
 421         std = kzalloc(sizeof(struct whc_std), mem_flags);
 422         if (std == NULL)
 423                 return NULL;
 424
 425         std->urb = urb;
 426         std->qtd = NULL;
 427
 428         INIT_LIST_HEAD(&std->list_node);
 429         list_add_tail(&std->list_node, &qset->stds);
 430
 431         return std;
 432 }
 433
 434 static int qset_add_urb_sg(struct whc *whc, struct whc_qset *qset, struct urb *urb,
 435                            gfp_t mem_flags)
 436 {
 437         size_t remaining;
 438         struct scatterlist *sg;
 439         int i;
 440         int ntds = 0;
 441         struct whc_std *std = NULL;
 442         struct whc_page_list_entry *new_pl_virt;
 443         dma_addr_t prev_end = 0;
 444         size_t pl_len;
 445         int p = 0;
 446
 447         remaining = urb->transfer_buffer_length;
 448
 449         for_each_sg(urb->sg, sg, urb->num_mapped_sgs, i) {
 450                 dma_addr_t dma_addr;
 451                 size_t dma_remaining;
 452                 dma_addr_t sp, ep;
 453                 int num_pointers;
 454
 455                 if (remaining == 0) {
 456                         break;
 457                 }
 458
 459                 dma_addr = sg_dma_address(sg);
 460                 dma_remaining = min_t(size_t, sg_dma_len(sg), remaining);
 461
 462                 while (dma_remaining) {
 463                         size_t dma_len;
 464
 465                         /*
 466                          * We can use the previous std (if it exists) provided that:
 467                          * - the previous one ended on a page boundary.
 468                          * - the current one begins on a page boundary.
 469                          * - the previous one isn't full.
 470                          *
 471                          * If a new std is needed but the previous one
 472                          * was not a whole number of packets then this
 473                          * sg list cannot be mapped onto multiple
 474                          * qTDs.  Return an error and let the caller
 475                          * sort it out.
 476                          */
 477                         if (!std
 478                             || (prev_end & (WHCI_PAGE_SIZE-1))
 479                             || (dma_addr & (WHCI_PAGE_SIZE-1))
 480                             || std->len + WHCI_PAGE_SIZE > QTD_MAX_XFER_SIZE) {
 481                                 if (std && std->len % qset->max_packet != 0)
 482                                         return -EINVAL;
 483                                 std = qset_new_std(whc, qset, urb, mem_flags);
 484                                 if (std == NULL) {
 485                                         return -ENOMEM;
 486                                 }
 487                                 ntds++;
 488                                 p = 0;
 489                         }
 490
 491                         dma_len = dma_remaining;
 492
 493                         /*
 494                          * If the remainder of this element doesn't
 495                          * fit in a single qTD, limit the qTD to a
 496                          * whole number of packets.  This allows the
 497                          * remainder to go into the next qTD.
 498                          */
 499                         if (std->len + dma_len > QTD_MAX_XFER_SIZE) {
 500                                 dma_len = (QTD_MAX_XFER_SIZE / qset->max_packet)
 501                                         * qset->max_packet - std->len;
 502                         }
 503
 504                         std->len += dma_len;
 505                         std->ntds_remaining = -1; /* filled in later */
 506
 507                         sp = dma_addr & ~(WHCI_PAGE_SIZE-1);
 508                         ep = dma_addr + dma_len;
 509                         num_pointers = DIV_ROUND_UP(ep - sp, WHCI_PAGE_SIZE);
 510                         std->num_pointers += num_pointers;
 511
 512                         pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
 513
 514                         new_pl_virt = krealloc(std->pl_virt, pl_len, mem_flags);
 515                         if (new_pl_virt == NULL) {
 516                                 kfree(std->pl_virt);
 517                                 std->pl_virt = NULL;
 518                                 return -ENOMEM;
 519                         }
 520                         std->pl_virt = new_pl_virt;
 521
 522                         for (;p < std->num_pointers; p++) {
 523                                 std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
 524                                 dma_addr = (dma_addr + WHCI_PAGE_SIZE) & ~(WHCI_PAGE_SIZE-1);
 525                         }
 526
 527                         prev_end = dma_addr = ep;
 528                         dma_remaining -= dma_len;
 529                         remaining -= dma_len;
 530                 }
 531         }
 532
 533         /* Now the number of stds is know, go back and fill in
 534            std->ntds_remaining. */
 535         list_for_each_entry(std, &qset->stds, list_node) {
 536                 if (std->ntds_remaining == -1) {
 537                         pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
 538                         std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt,
 539                                                        pl_len, DMA_TO_DEVICE);
 540                         if (dma_mapping_error(whc->wusbhc.dev, std->dma_addr))
 541                                 return -EFAULT;
 542                         std->ntds_remaining = ntds--;
 543                 }
 544         }
 545         return 0;
 546 }
 547
 548 /**
 549  * qset_add_urb_sg_linearize - add an urb with sg list, copying the data
 550  *
 551  * If the URB contains an sg list whose elements cannot be directly
 552  * mapped to qTDs then the data must be transferred via bounce
 553  * buffers.
 554  */
 555 static int qset_add_urb_sg_linearize(struct whc *whc, struct whc_qset *qset,
 556                                      struct urb *urb, gfp_t mem_flags)
 557 {
 558         bool is_out = usb_pipeout(urb->pipe);
 559         size_t max_std_len;
 560         size_t remaining;
 561         int ntds = 0;
 562         struct whc_std *std = NULL;
 563         void *bounce = NULL;
 564         struct scatterlist *sg;
 565         int i;
 566
 567         /* limit maximum bounce buffer to 16 * 3.5 KiB ~= 28 k */
 568         max_std_len = qset->max_burst * qset->max_packet;
 569
 570         remaining = urb->transfer_buffer_length;
 571
 572         for_each_sg(urb->sg, sg, urb->num_mapped_sgs, i) {
 573                 size_t len;
 574                 size_t sg_remaining;
 575                 void *orig;
 576
 577                 if (remaining == 0) {
 578                         break;
 579                 }
 580
 581                 sg_remaining = min_t(size_t, remaining, sg->length);
 582                 orig = sg_virt(sg);
 583
 584                 while (sg_remaining) {
 585                         if (!std || std->len == max_std_len) {
 586                                 std = qset_new_std(whc, qset, urb, mem_flags);
 587                                 if (std == NULL)
 588                                         return -ENOMEM;
 589                                 std->bounce_buf = kmalloc(max_std_len, mem_flags);
 590                                 if (std->bounce_buf == NULL)
 591                                         return -ENOMEM;
 592                                 std->bounce_sg = sg;
 593                                 std->bounce_offset = orig - sg_virt(sg);
 594                                 bounce = std->bounce_buf;
 595                                 ntds++;
 596                         }
 597
 598                         len = min(sg_remaining, max_std_len - std->len);
 599
 600                         if (is_out)
 601                                 memcpy(bounce, orig, len);
 602
 603                         std->len += len;
 604                         std->ntds_remaining = -1; /* filled in later */
 605
 606                         bounce += len;
 607                         orig += len;
 608                         sg_remaining -= len;
 609                         remaining -= len;
 610                 }
 611         }
 612
 613         /*
 614          * For each of the new sTDs, map the bounce buffers, create
 615          * page lists (if necessary), and fill in std->ntds_remaining.
 616          */
 617         list_for_each_entry(std, &qset->stds, list_node) {
 618                 if (std->ntds_remaining != -1)
 619                         continue;
 620
 621                 std->dma_addr = dma_map_single(&whc->umc->dev, std->bounce_buf, std->len,
 622                                                is_out ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 623                 if (dma_mapping_error(&whc->umc->dev, std->dma_addr))
 624                         return -EFAULT;
 625
 626                 if (qset_fill_page_list(whc, std, mem_flags) < 0)
 627                         return -ENOMEM;
 628
 629                 std->ntds_remaining = ntds--;
 630         }
 631
 632         return 0;
 633 }
 634
 635 /**
 636  * qset_add_urb - add an urb to the qset's queue.
 637  *
 638  * The URB is chopped into sTDs, one for each qTD that will required.
 639  * At least one qTD (and sTD) is required even if the transfer has no
 640  * data (e.g., for some control transfers).
 641  */
 642 int qset_add_urb(struct whc *whc, struct whc_qset *qset, struct urb *urb,
 643         gfp_t mem_flags)
 644 {
 645         struct whc_urb *wurb;
 646         int remaining = urb->transfer_buffer_length;
 647         u64 transfer_dma = urb->transfer_dma;
 648         int ntds_remaining;
 649         int ret;
 650
 651         wurb = kzalloc(sizeof(struct whc_urb), mem_flags);
 652         if (wurb == NULL)
 653                 goto err_no_mem;
 654         urb->hcpriv = wurb;
 655         wurb->qset = qset;
 656         wurb->urb = urb;
 657         INIT_WORK(&wurb->dequeue_work, urb_dequeue_work);
 658
 659         if (urb->num_sgs) {
 660                 ret = qset_add_urb_sg(whc, qset, urb, mem_flags);
 661                 if (ret == -EINVAL) {
 662                         qset_free_stds(qset, urb);
 663                         ret = qset_add_urb_sg_linearize(whc, qset, urb, mem_flags);
 664                 }
 665                 if (ret < 0)
 666                         goto err_no_mem;
 667                 return 0;
 668         }
 669
 670         ntds_remaining = DIV_ROUND_UP(remaining, QTD_MAX_XFER_SIZE);
 671         if (ntds_remaining == 0)
 672                 ntds_remaining = 1;
 673
 674         while (ntds_remaining) {
 675                 struct whc_std *std;
 676                 size_t std_len;
 677
 678                 std_len = remaining;
 679                 if (std_len > QTD_MAX_XFER_SIZE)
 680                         std_len = QTD_MAX_XFER_SIZE;
 681
 682                 std = qset_new_std(whc, qset, urb, mem_flags);
 683                 if (std == NULL)
 684                         goto err_no_mem;
 685
 686                 std->dma_addr = transfer_dma;
 687                 std->len = std_len;
 688                 std->ntds_remaining = ntds_remaining;
 689
 690                 if (qset_fill_page_list(whc, std, mem_flags) < 0)
 691                         goto err_no_mem;
 692
 693                 ntds_remaining--;
 694                 remaining -= std_len;
 695                 transfer_dma += std_len;
 696         }
 697
 698         return 0;
 699
 700 err_no_mem:
 701         qset_free_stds(qset, urb);
 702         return -ENOMEM;
 703 }
 704
 705 /**
 706  * qset_remove_urb - remove an URB from the urb queue.
 707  *
 708  * The URB is returned to the USB subsystem.
 709  */
 710 void qset_remove_urb(struct whc *whc, struct whc_qset *qset,
 711                             struct urb *urb, int status)
 712 {
 713         struct wusbhc *wusbhc = &whc->wusbhc;
 714         struct whc_urb *wurb = urb->hcpriv;
 715
 716         usb_hcd_unlink_urb_from_ep(&wusbhc->usb_hcd, urb);
 717         /* Drop the lock as urb->complete() may enqueue another urb. */
 718         spin_unlock(&whc->lock);
 719         wusbhc_giveback_urb(wusbhc, urb, status);
 720         spin_lock(&whc->lock);
 721
 722         kfree(wurb);
 723 }
 724
 725 /**
 726  * get_urb_status_from_qtd - get the completed urb status from qTD status
 727  * @urb:    completed urb
 728  * @status: qTD status
 729  */
 730 static int get_urb_status_from_qtd(struct urb *urb, u32 status)
 731 {
 732         if (status & QTD_STS_HALTED) {
 733                 if (status & QTD_STS_DBE)
 734                         return usb_pipein(urb->pipe) ? -ENOSR : -ECOMM;
 735                 else if (status & QTD_STS_BABBLE)
 736                         return -EOVERFLOW;
 737                 else if (status & QTD_STS_RCE)
 738                         return -ETIME;
 739                 return -EPIPE;
 740         }
 741         if (usb_pipein(urb->pipe)
 742             && (urb->transfer_flags & URB_SHORT_NOT_OK)
 743             && urb->actual_length < urb->transfer_buffer_length)
 744                 return -EREMOTEIO;
 745         return 0;
 746 }
 747
 748 /**
 749  * process_inactive_qtd - process an inactive (but not halted) qTD.
 750  *
 751  * Update the urb with the transfer bytes from the qTD, if the urb is
 752  * completely transferred or (in the case of an IN only) the LPF is
 753  * set, then the transfer is complete and the urb should be returned
 754  * to the system.
 755  */
 756 void process_inactive_qtd(struct whc *whc, struct whc_qset *qset,
 757                                  struct whc_qtd *qtd)
 758 {
 759         struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
 760         struct urb *urb = std->urb;
 761         uint32_t status;
 762         bool complete;
 763
 764         status = le32_to_cpu(qtd->status);
 765
 766         urb->actual_length += std->len - QTD_STS_TO_LEN(status);
 767
 768         if (usb_pipein(urb->pipe) && (status & QTD_STS_LAST_PKT))
 769                 complete = true;
 770         else
 771                 complete = whc_std_last(std);
 772
 773         qset_remove_qtd(whc, qset);
 774         qset_free_std(whc, std);
 775
 776         /*
 777          * Transfers for this URB are complete?  Then return it to the
 778          * USB subsystem.
 779          */
 780         if (complete) {
 781                 qset_remove_qtds(whc, qset, urb);
 782                 qset_remove_urb(whc, qset, urb, get_urb_status_from_qtd(urb, status));
 783
 784                 /*
 785                  * If iAlt isn't valid then the hardware didn't
 786                  * advance iCur. Adjust the start and end pointers to
 787                  * match iCur.
 788                  */
 789                 if (!(status & QTD_STS_IALT_VALID))
 790                         qset->td_start = qset->td_end
 791                                 = QH_STATUS_TO_ICUR(le16_to_cpu(qset->qh.status));
 792                 qset->pause_after_urb = NULL;
 793         }
 794 }
 795
 796 /**
 797  * process_halted_qtd - process a qset with a halted qtd
 798  *
 799  * Remove all the qTDs for the failed URB and return the failed URB to
 800  * the USB subsystem.  Then remove all other qTDs so the qset can be
 801  * removed.
 802  *
 803  * FIXME: this is the point where rate adaptation can be done.  If a
 804  * transfer failed because it exceeded the maximum number of retries
 805  * then it could be reactivated with a slower rate without having to
 806  * remove the qset.
 807  */
 808 void process_halted_qtd(struct whc *whc, struct whc_qset *qset,
 809                                struct whc_qtd *qtd)
 810 {
 811         struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
 812         struct urb *urb = std->urb;
 813         int urb_status;
 814
 815         urb_status = get_urb_status_from_qtd(urb, le32_to_cpu(qtd->status));
 816
 817         qset_remove_qtds(whc, qset, urb);
 818         qset_remove_urb(whc, qset, urb, urb_status);
 819
 820         list_for_each_entry(std, &qset->stds, list_node) {
 821                 if (qset->ntds == 0)
 822                         break;
 823                 qset_remove_qtd(whc, qset);
 824                 std->qtd = NULL;
 825         }
 826
 827         qset->remove = 1;
 828 }
 829
 830 void qset_free(struct whc *whc, struct whc_qset *qset)
 831 {
 832         dma_pool_free(whc->qset_pool, qset, qset->qset_dma);
 833 }
 834
 835 /**
 836  * qset_delete - wait for a qset to be unused, then free it.
 837  */
 838 void qset_delete(struct whc *whc, struct whc_qset *qset)
 839 {
 840         wait_for_completion(&qset->remove_complete);
 841         qset_free(whc, qset);
 842 }