drivers/usb/usbip/stub_tx.c

   1 /*
   2  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   3  *
   4  * This is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17  * USA.
  18  */
  19
  20 #include <linux/kthread.h>
  21 #include <linux/socket.h>
  22 #include <linux/scatterlist.h>
  23
  24 #include "usbip_common.h"
  25 #include "stub.h"
  26
  27 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
  28 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
  29                              __u32 status)
  30 {
  31         struct stub_unlink *unlink;
  32
  33         unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
  34         if (!unlink) {
  35                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  36                 return;
  37         }
  38
  39         unlink->seqnum = seqnum;
  40         unlink->status = status;
  41
  42         list_add_tail(&unlink->list, &sdev->unlink_tx);
  43 }
  44
  45 /**
  46  * stub_complete - completion handler of a usbip urb
  47  * @urb: pointer to the urb completed
  48  *
  49  * When a urb has completed, the USB core driver calls this function mostly in
  50  * the interrupt context. To return the result of a urb, the completed urb is
  51  * linked to the pending list of returning.
  52  *
  53  */
  54 void stub_complete(struct urb *urb)
  55 {
  56         struct stub_priv *priv = (struct stub_priv *) urb->context;
  57         struct stub_device *sdev = priv->sdev;
  58         unsigned long flags;
  59
  60         usbip_dbg_stub_tx("complete! status %d\n", urb->status);
  61
  62         switch (urb->status) {
  63         case 0:
  64                 /* OK */
  65                 break;
  66         case -ENOENT:
  67                 dev_info(&urb->dev->dev,
  68                          "stopped by a call to usb_kill_urb() because of cleaning up a virtual connection\n");
  69                 return;
  70         case -ECONNRESET:
  71                 dev_info(&urb->dev->dev,
  72                          "unlinked by a call to usb_unlink_urb()\n");
  73                 break;
  74         case -EPIPE:
  75                 dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
  76                          usb_pipeendpoint(urb->pipe));
  77                 break;
  78         case -ESHUTDOWN:
  79                 dev_info(&urb->dev->dev, "device removed?\n");
  80                 break;
  81         default:
  82                 dev_info(&urb->dev->dev,
  83                          "urb completion with non-zero status %d\n",
  84                          urb->status);
  85                 break;
  86         }
  87
  88         /*
  89          * If the server breaks single SG request into the several URBs, the
  90          * URBs must be reassembled before sending completed URB to the vhci.
  91          * Don't wake up the tx thread until all the URBs are completed.
  92          */
  93         if (priv->sgl) {
  94                 priv->completed_urbs++;
  95
  96                 /* Only save the first error status */
  97                 if (urb->status && !priv->urb_status)
  98                         priv->urb_status = urb->status;
  99
 100                 if (priv->completed_urbs < priv->num_urbs)
 101                         return;
 102         }
 103
 104         /* link a urb to the queue of tx. */
 105         spin_lock_irqsave(&sdev->priv_lock, flags);
 106         if (sdev->ud.tcp_socket == NULL) {
 107                 usbip_dbg_stub_tx("ignore urb for closed connection\n");
 108                 /* It will be freed in stub_device_cleanup_urbs(). */
 109         } else if (priv->unlinking) {
 110                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
 111                 stub_free_priv_and_urb(priv);
 112         } else {
 113                 list_move_tail(&priv->list, &sdev->priv_tx);
 114         }
 115         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 116
 117         /* wake up tx_thread */
 118         wake_up(&sdev->tx_waitq);
 119 }
 120
 121 static inline void setup_base_pdu(struct usbip_header_basic *base,
 122                                   __u32 command, __u32 seqnum)
 123 {
 124         base->command   = command;
 125         base->seqnum    = seqnum;
 126         base->devid     = 0;
 127         base->ep        = 0;
 128         base->direction = 0;
 129 }
 130
 131 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 132 {
 133         struct stub_priv *priv = (struct stub_priv *) urb->context;
 134
 135         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 136         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 137 }
 138
 139 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 140                                  struct stub_unlink *unlink)
 141 {
 142         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 143         rpdu->u.ret_unlink.status = unlink->status;
 144 }
 145
 146 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 147 {
 148         unsigned long flags;
 149         struct stub_priv *priv, *tmp;
 150
 151         spin_lock_irqsave(&sdev->priv_lock, flags);
 152
 153         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 154                 list_move_tail(&priv->list, &sdev->priv_free);
 155                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 156                 return priv;
 157         }
 158
 159         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 160
 161         return NULL;
 162 }
 163
 164 static int stub_send_ret_submit(struct stub_device *sdev)
 165 {
 166         unsigned long flags;
 167         struct stub_priv *priv, *tmp;
 168
 169         struct msghdr msg;
 170         size_t txsize;
 171
 172         size_t total_size = 0;
 173
 174         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 175                 struct urb *urb = priv->urbs[0];
 176                 struct usbip_header pdu_header;
 177                 struct usbip_iso_packet_descriptor *iso_buffer = NULL;
 178                 struct kvec *iov = NULL;
 179                 struct scatterlist *sg;
 180                 u32 actual_length = 0;
 181                 int iovnum = 0;
 182                 int ret;
 183                 int i;
 184
 185                 txsize = 0;
 186                 memset(&pdu_header, 0, sizeof(pdu_header));
 187                 memset(&msg, 0, sizeof(msg));
 188
 189                 if (urb->actual_length > 0 && !urb->transfer_buffer &&
 190                    !urb->num_sgs) {
 191                         dev_err(&sdev->udev->dev,
 192                                 "urb: actual_length %d transfer_buffer null\n",
 193                                 urb->actual_length);
 194                         return -1;
 195                 }
 196
 197                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 198                         iovnum = 2 + urb->number_of_packets;
 199                 else if (usb_pipein(urb->pipe) && urb->actual_length > 0 &&
 200                         urb->num_sgs)
 201                         iovnum = 1 + urb->num_sgs;
 202                 else if (usb_pipein(urb->pipe) && priv->sgl)
 203                         iovnum = 1 + priv->num_urbs;
 204                 else
 205                         iovnum = 2;
 206
 207                 iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL);
 208
 209                 if (!iov) {
 210                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
 211                         return -1;
 212                 }
 213
 214                 iovnum = 0;
 215
 216                 /* 1. setup usbip_header */
 217                 setup_ret_submit_pdu(&pdu_header, urb);
 218                 usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
 219                                   pdu_header.base.seqnum);
 220
 221                 if (priv->sgl) {
 222                         for (i = 0; i < priv->num_urbs; i++)
 223                                 actual_length += priv->urbs[i]->actual_length;
 224
 225                         pdu_header.u.ret_submit.status = priv->urb_status;
 226                         pdu_header.u.ret_submit.actual_length = actual_length;
 227                 }
 228
 229                 usbip_header_correct_endian(&pdu_header, 1);
 230
 231                 iov[iovnum].iov_base = &pdu_header;
 232                 iov[iovnum].iov_len  = sizeof(pdu_header);
 233                 iovnum++;
 234                 txsize += sizeof(pdu_header);
 235
 236                 /* 2. setup transfer buffer */
 237                 if (usb_pipein(urb->pipe) && priv->sgl) {
 238                         /* If the server split a single SG request into several
 239                          * URBs because the server's HCD doesn't support SG,
 240                          * reassemble the split URB buffers into a single
 241                          * return command.
 242                          */
 243                         for (i = 0; i < priv->num_urbs; i++) {
 244                                 iov[iovnum].iov_base =
 245                                         priv->urbs[i]->transfer_buffer;
 246                                 iov[iovnum].iov_len =
 247                                         priv->urbs[i]->actual_length;
 248                                 iovnum++;
 249                         }
 250                         txsize += actual_length;
 251                 } else if (usb_pipein(urb->pipe) &&
 252                     usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 253                     urb->actual_length > 0) {
 254                         if (urb->num_sgs) {
 255                                 unsigned int copy = urb->actual_length;
 256                                 int size;
 257
 258                                 for_each_sg(urb->sg, sg, urb->num_sgs, i) {
 259                                         if (copy == 0)
 260                                                 break;
 261
 262                                         if (copy < sg->length)
 263                                                 size = copy;
 264                                         else
 265                                                 size = sg->length;
 266
 267                                         iov[iovnum].iov_base = sg_virt(sg);
 268                                         iov[iovnum].iov_len = size;
 269
 270                                         iovnum++;
 271                                         copy -= size;
 272                                 }
 273                         } else {
 274                                 iov[iovnum].iov_base = urb->transfer_buffer;
 275                                 iov[iovnum].iov_len  = urb->actual_length;
 276                                 iovnum++;
 277                         }
 278                         txsize += urb->actual_length;
 279                 } else if (usb_pipein(urb->pipe) &&
 280                            usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 281                         /*
 282                          * For isochronous packets: actual length is the sum of
 283                          * the actual length of the individual, packets, but as
 284                          * the packet offsets are not changed there will be
 285                          * padding between the packets. To optimally use the
 286                          * bandwidth the padding is not transmitted.
 287                          */
 288
 289                         int i;
 290
 291                         for (i = 0; i < urb->number_of_packets; i++) {
 292                                 iov[iovnum].iov_base = urb->transfer_buffer +
 293                                         urb->iso_frame_desc[i].offset;
 294                                 iov[iovnum].iov_len =
 295                                         urb->iso_frame_desc[i].actual_length;
 296                                 iovnum++;
 297                                 txsize += urb->iso_frame_desc[i].actual_length;
 298                         }
 299
 300                         if (txsize != sizeof(pdu_header) + urb->actual_length) {
 301                                 dev_err(&sdev->udev->dev,
 302                                         "actual length of urb %d does not match iso packet sizes %zu\n",
 303                                         urb->actual_length,
 304                                         txsize-sizeof(pdu_header));
 305                                 kfree(iov);
 306                                 usbip_event_add(&sdev->ud,
 307                                                 SDEV_EVENT_ERROR_TCP);
 308                            return -1;
 309                         }
 310                 }
 311
 312                 /* 3. setup iso_packet_descriptor */
 313                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 314                         ssize_t len = 0;
 315
 316                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 317                         if (!iso_buffer) {
 318                                 usbip_event_add(&sdev->ud,
 319                                                 SDEV_EVENT_ERROR_MALLOC);
 320                                 kfree(iov);
 321                                 return -1;
 322                         }
 323
 324                         iov[iovnum].iov_base = iso_buffer;
 325                         iov[iovnum].iov_len  = len;
 326                         txsize += len;
 327                         iovnum++;
 328                 }
 329
 330                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
 331                                                 iov,  iovnum, txsize);
 332                 if (ret != txsize) {
 333                         dev_err(&sdev->udev->dev,
 334                                 "sendmsg failed!, retval %d for %zd\n",
 335                                 ret, txsize);
 336                         kfree(iov);
 337                         kfree(iso_buffer);
 338                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 339                         return -1;
 340                 }
 341
 342                 kfree(iov);
 343                 kfree(iso_buffer);
 344
 345                 total_size += txsize;
 346         }
 347
 348         spin_lock_irqsave(&sdev->priv_lock, flags);
 349         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 350                 stub_free_priv_and_urb(priv);
 351         }
 352         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 353
 354         return total_size;
 355 }
 356
 357 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 358 {
 359         unsigned long flags;
 360         struct stub_unlink *unlink, *tmp;
 361
 362         spin_lock_irqsave(&sdev->priv_lock, flags);
 363
 364         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 365                 list_move_tail(&unlink->list, &sdev->unlink_free);
 366                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 367                 return unlink;
 368         }
 369
 370         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 371
 372         return NULL;
 373 }
 374
 375 static int stub_send_ret_unlink(struct stub_device *sdev)
 376 {
 377         unsigned long flags;
 378         struct stub_unlink *unlink, *tmp;
 379
 380         struct msghdr msg;
 381         struct kvec iov[1];
 382         size_t txsize;
 383
 384         size_t total_size = 0;
 385
 386         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 387                 int ret;
 388                 struct usbip_header pdu_header;
 389
 390                 txsize = 0;
 391                 memset(&pdu_header, 0, sizeof(pdu_header));
 392                 memset(&msg, 0, sizeof(msg));
 393                 memset(&iov, 0, sizeof(iov));
 394
 395                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 396
 397                 /* 1. setup usbip_header */
 398                 setup_ret_unlink_pdu(&pdu_header, unlink);
 399                 usbip_header_correct_endian(&pdu_header, 1);
 400
 401                 iov[0].iov_base = &pdu_header;
 402                 iov[0].iov_len  = sizeof(pdu_header);
 403                 txsize += sizeof(pdu_header);
 404
 405                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 406                                      1, txsize);
 407                 if (ret != txsize) {
 408                         dev_err(&sdev->udev->dev,
 409                                 "sendmsg failed!, retval %d for %zd\n",
 410                                 ret, txsize);
 411                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 412                         return -1;
 413                 }
 414
 415                 usbip_dbg_stub_tx("send txdata\n");
 416                 total_size += txsize;
 417         }
 418
 419         spin_lock_irqsave(&sdev->priv_lock, flags);
 420
 421         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 422                 list_del(&unlink->list);
 423                 kfree(unlink);
 424         }
 425
 426         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 427
 428         return total_size;
 429 }
 430
 431 int stub_tx_loop(void *data)
 432 {
 433         struct usbip_device *ud = data;
 434         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 435
 436         while (!kthread_should_stop()) {
 437                 if (usbip_event_happened(ud))
 438                         break;
 439
 440                 /*
 441                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 442                  * looks at only priv_init queue. If the completion of a URB is
 443                  * earlier than the receive of CMD_UNLINK, priv is moved to
 444                  * priv_tx queue and stub_rx does not find the target priv. In
 445                  * this case, vhci_rx receives the result of the submit request
 446                  * and then receives the result of the unlink request. The
 447                  * result of the submit is given back to the usbcore as the
 448                  * completion of the unlink request. The request of the
 449                  * unlink is ignored. This is ok because a driver who calls
 450                  * usb_unlink_urb() understands the unlink was too late by
 451                  * getting the status of the given-backed URB which has the
 452                  * status of usb_submit_urb().
 453                  */
 454                 if (stub_send_ret_submit(sdev) < 0)
 455                         break;
 456
 457                 if (stub_send_ret_unlink(sdev) < 0)
 458                         break;
 459
 460                 wait_event_interruptible(sdev->tx_waitq,
 461                                          (!list_empty(&sdev->priv_tx) ||
 462                                           !list_empty(&sdev->unlink_tx) ||
 463                                           kthread_should_stop()));
 464         }
 465
 466         return 0;
 467 }