drivers/staging/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 "usbip_common.h"
  21 #include "stub.h"
  22
  23
  24 static void stub_free_priv_and_urb(struct stub_priv *priv)
  25 {
  26         struct urb *urb = priv->urb;
  27
  28         kfree(urb->setup_packet);
  29         kfree(urb->transfer_buffer);
  30         list_del(&priv->list);
  31         kmem_cache_free(stub_priv_cache, priv);
  32         usb_free_urb(urb);
  33 }
  34
  35 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
  36 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
  37                              __u32 status)
  38 {
  39         struct stub_unlink *unlink;
  40
  41         unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
  42         if (!unlink) {
  43                 dev_err(&sdev->interface->dev, "alloc stub_unlink\n");
  44                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  45                 return;
  46         }
  47
  48         unlink->seqnum = seqnum;
  49         unlink->status = status;
  50
  51         list_add_tail(&unlink->list, &sdev->unlink_tx);
  52 }
  53
  54 /**
  55  * stub_complete - completion handler of a usbip urb
  56  * @urb: pointer to the urb completed
  57  *
  58  * When a urb has completed, the USB core driver calls this function mostly in
  59  * the interrupt context. To return the result of a urb, the completed urb is
  60  * linked to the pending list of returning.
  61  *
  62  */
  63 void stub_complete(struct urb *urb)
  64 {
  65         struct stub_priv *priv = (struct stub_priv *) urb->context;
  66         struct stub_device *sdev = priv->sdev;
  67         unsigned long flags;
  68
  69         usbip_dbg_stub_tx("complete! status %d\n", urb->status);
  70
  71
  72         switch (urb->status) {
  73         case 0:
  74                 /* OK */
  75                 break;
  76         case -ENOENT:
  77                 usbip_uinfo("stopped by a call of usb_kill_urb() because of"
  78                                         "cleaning up a virtual connection\n");
  79                 return;
  80         case -ECONNRESET:
  81                 usbip_uinfo("unlinked by a call of usb_unlink_urb()\n");
  82                 break;
  83         case -EPIPE:
  84                 usbip_uinfo("endpoint %d is stalled\n",
  85                                                 usb_pipeendpoint(urb->pipe));
  86                 break;
  87         case -ESHUTDOWN:
  88                 usbip_uinfo("device removed?\n");
  89                 break;
  90         default:
  91                 usbip_uinfo("urb completion with non-zero status %d\n",
  92                                                         urb->status);
  93         }
  94
  95         /* link a urb to the queue of tx. */
  96         spin_lock_irqsave(&sdev->priv_lock, flags);
  97
  98         if (priv->unlinking) {
  99                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
 100                 stub_free_priv_and_urb(priv);
 101         } else
 102                 list_move_tail(&priv->list, &sdev->priv_tx);
 103
 104
 105         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 106
 107         /* wake up tx_thread */
 108         wake_up(&sdev->tx_waitq);
 109 }
 110
 111
 112 /*-------------------------------------------------------------------------*/
 113 /* fill PDU */
 114
 115 static inline void setup_base_pdu(struct usbip_header_basic *base,
 116                 __u32 command, __u32 seqnum)
 117 {
 118         base->command = command;
 119         base->seqnum  = seqnum;
 120         base->devid   = 0;
 121         base->ep      = 0;
 122         base->direction   = 0;
 123 }
 124
 125 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 126 {
 127         struct stub_priv *priv = (struct stub_priv *) urb->context;
 128
 129         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 130
 131         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 132 }
 133
 134 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 135                 struct stub_unlink *unlink)
 136 {
 137         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 138
 139         rpdu->u.ret_unlink.status = unlink->status;
 140 }
 141
 142
 143 /*-------------------------------------------------------------------------*/
 144 /* send RET_SUBMIT */
 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                 int ret;
 176                 struct urb *urb = priv->urb;
 177                 struct usbip_header pdu_header;
 178                 void *iso_buffer = NULL;
 179                 struct kvec *iov = NULL;
 180                 int iovnum = 0;
 181
 182                 txsize = 0;
 183                 memset(&pdu_header, 0, sizeof(pdu_header));
 184                 memset(&msg, 0, sizeof(msg));
 185
 186                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 187                         iovnum = 2 + urb->number_of_packets;
 188                 else
 189                         iovnum = 2;
 190
 191                 iov = kzalloc(iovnum * sizeof(struct kvec), GFP_KERNEL);
 192
 193                 if (!iov) {
 194                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
 195                         return -1;
 196                 }
 197
 198                 iovnum = 0;
 199
 200                 /* 1. setup usbip_header */
 201                 setup_ret_submit_pdu(&pdu_header, urb);
 202                 usbip_dbg_stub_tx("setup txdata seqnum: %d urb: %p\n",
 203                                                 pdu_header.base.seqnum, urb);
 204                 /*usbip_dump_header(pdu_header);*/
 205                 usbip_header_correct_endian(&pdu_header, 1);
 206
 207                 iov[iovnum].iov_base = &pdu_header;
 208                 iov[iovnum].iov_len  = sizeof(pdu_header);
 209                 iovnum++;
 210                 txsize += sizeof(pdu_header);
 211
 212                 /* 2. setup transfer buffer */
 213                 if (usb_pipein(urb->pipe) &&
 214                                 usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 215                                         urb->actual_length > 0) {
 216                         iov[iovnum].iov_base = urb->transfer_buffer;
 217                         iov[iovnum].iov_len  = urb->actual_length;
 218                         iovnum++;
 219                         txsize += urb->actual_length;
 220                 } else if (usb_pipein(urb->pipe) &&
 221                                 usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 222                         /*
 223                          * For isochronous packets: actual length is the sum of
 224                          * the actual length of the individual, packets, but as
 225                          * the packet offsets are not changed there will be
 226                          * padding between the packets. To optimally use the
 227                          * bandwidth the padding is not transmitted.
 228                          */
 229
 230                         int i;
 231                         for (i = 0; i < urb->number_of_packets; i++) {
 232                                 iov[iovnum].iov_base = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 233                                 iov[iovnum].iov_len = urb->iso_frame_desc[i].actual_length;
 234                                 iovnum++;
 235                                 txsize += urb->iso_frame_desc[i].actual_length;
 236                         }
 237
 238                         if (txsize != sizeof(pdu_header) + urb->actual_length) {
 239                                 dev_err(&sdev->interface->dev,
 240                                         "actual length of urb (%d) does not match iso packet sizes (%d)\n",
 241                                         urb->actual_length, txsize-sizeof(pdu_header));
 242                                 kfree(iov);
 243                                 usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 244                            return -1;
 245                         }
 246                 }
 247
 248                 /* 3. setup iso_packet_descriptor */
 249                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 250                         ssize_t len = 0;
 251
 252                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 253                         if (!iso_buffer) {
 254                                 usbip_event_add(&sdev->ud,
 255                                                 SDEV_EVENT_ERROR_MALLOC);
 256                                 kfree(iov);
 257                                 return -1;
 258                         }
 259
 260                         iov[iovnum].iov_base = iso_buffer;
 261                         iov[iovnum].iov_len  = len;
 262                         txsize += len;
 263                         iovnum++;
 264                 }
 265
 266                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
 267                                                 iov,  iovnum, txsize);
 268                 if (ret != txsize) {
 269                         dev_err(&sdev->interface->dev,
 270                                 "sendmsg failed!, retval %d for %zd\n",
 271                                 ret, txsize);
 272                         kfree(iov);
 273                         kfree(iso_buffer);
 274                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 275                         return -1;
 276                 }
 277
 278                 kfree(iov);
 279                 kfree(iso_buffer);
 280
 281                 total_size += txsize;
 282         }
 283
 284         spin_lock_irqsave(&sdev->priv_lock, flags);
 285
 286         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 287                 stub_free_priv_and_urb(priv);
 288         }
 289
 290         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 291
 292         return total_size;
 293 }
 294
 295
 296 /*-------------------------------------------------------------------------*/
 297 /* send RET_UNLINK */
 298
 299 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 300 {
 301         unsigned long flags;
 302         struct stub_unlink *unlink, *tmp;
 303
 304         spin_lock_irqsave(&sdev->priv_lock, flags);
 305
 306         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 307                 list_move_tail(&unlink->list, &sdev->unlink_free);
 308                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 309                 return unlink;
 310         }
 311
 312         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 313
 314         return NULL;
 315 }
 316
 317
 318 static int stub_send_ret_unlink(struct stub_device *sdev)
 319 {
 320         unsigned long flags;
 321         struct stub_unlink *unlink, *tmp;
 322
 323         struct msghdr msg;
 324         struct kvec iov[1];
 325         size_t txsize;
 326
 327         size_t total_size = 0;
 328
 329         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 330                 int ret;
 331                 struct usbip_header pdu_header;
 332
 333                 txsize = 0;
 334                 memset(&pdu_header, 0, sizeof(pdu_header));
 335                 memset(&msg, 0, sizeof(msg));
 336                 memset(&iov, 0, sizeof(iov));
 337
 338                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 339
 340                 /* 1. setup usbip_header */
 341                 setup_ret_unlink_pdu(&pdu_header, unlink);
 342                 usbip_header_correct_endian(&pdu_header, 1);
 343
 344                 iov[0].iov_base = &pdu_header;
 345                 iov[0].iov_len  = sizeof(pdu_header);
 346                 txsize += sizeof(pdu_header);
 347
 348                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 349                                      1, txsize);
 350                 if (ret != txsize) {
 351                         dev_err(&sdev->interface->dev,
 352                                 "sendmsg failed!, retval %d for %zd\n",
 353                                 ret, txsize);
 354                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 355                         return -1;
 356                 }
 357
 358
 359                 usbip_dbg_stub_tx("send txdata\n");
 360
 361                 total_size += txsize;
 362         }
 363
 364
 365         spin_lock_irqsave(&sdev->priv_lock, flags);
 366
 367         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 368                 list_del(&unlink->list);
 369                 kfree(unlink);
 370         }
 371
 372         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 373
 374         return total_size;
 375 }
 376
 377
 378 /*-------------------------------------------------------------------------*/
 379
 380 void stub_tx_loop(struct usbip_task *ut)
 381 {
 382         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
 383         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 384
 385         while (1) {
 386                 if (signal_pending(current)) {
 387                         usbip_dbg_stub_tx("signal catched\n");
 388                         break;
 389                 }
 390
 391                 if (usbip_event_happened(ud))
 392                         break;
 393
 394                 /*
 395                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 396                  * looks at only priv_init queue. If the completion of a URB is
 397                  * earlier than the receive of CMD_UNLINK, priv is moved to
 398                  * priv_tx queue and stub_rx does not find the target priv. In
 399                  * this case, vhci_rx receives the result of the submit request
 400                  * and then receives the result of the unlink request. The
 401                  * result of the submit is given back to the usbcore as the
 402                  * completion of the unlink request. The request of the
 403                  * unlink is ignored. This is ok because a driver who calls
 404                  * usb_unlink_urb() understands the unlink was too late by
 405                  * getting the status of the given-backed URB which has the
 406                  * status of usb_submit_urb().
 407                  */
 408                 if (stub_send_ret_submit(sdev) < 0)
 409                         break;
 410
 411                 if (stub_send_ret_unlink(sdev) < 0)
 412                         break;
 413
 414                 wait_event_interruptible(sdev->tx_waitq,
 415                                 (!list_empty(&sdev->priv_tx) ||
 416                                  !list_empty(&sdev->unlink_tx)));
 417         }
 418 }