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 <linux/kthread.h>
  21 #include <linux/socket.h>
  22
  23 #include "usbip_common.h"
  24 #include "stub.h"
  25
  26 static void stub_free_priv_and_urb(struct stub_priv *priv)
  27 {
  28         struct urb *urb = priv->urb;
  29
  30         kfree(urb->setup_packet);
  31         kfree(urb->transfer_buffer);
  32         list_del(&priv->list);
  33         kmem_cache_free(stub_priv_cache, priv);
  34         usb_free_urb(urb);
  35 }
  36
  37 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
  38 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
  39                              __u32 status)
  40 {
  41         struct stub_unlink *unlink;
  42
  43         unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
  44         if (!unlink) {
  45                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  46                 return;
  47         }
  48
  49         unlink->seqnum = seqnum;
  50         unlink->status = status;
  51
  52         list_add_tail(&unlink->list, &sdev->unlink_tx);
  53 }
  54
  55 /**
  56  * stub_complete - completion handler of a usbip urb
  57  * @urb: pointer to the urb completed
  58  *
  59  * When a urb has completed, the USB core driver calls this function mostly in
  60  * the interrupt context. To return the result of a urb, the completed urb is
  61  * linked to the pending list of returning.
  62  *
  63  */
  64 void stub_complete(struct urb *urb)
  65 {
  66         struct stub_priv *priv = (struct stub_priv *) urb->context;
  67         struct stub_device *sdev = priv->sdev;
  68         unsigned long flags;
  69
  70         usbip_dbg_stub_tx("complete! status %d\n", urb->status);
  71
  72         switch (urb->status) {
  73         case 0:
  74                 /* OK */
  75                 break;
  76         case -ENOENT:
  77                 dev_info(&urb->dev->dev, "stopped by a call to usb_kill_urb() "
  78                          "because of cleaning up a virtual connection\n");
  79                 return;
  80         case -ECONNRESET:
  81                 dev_info(&urb->dev->dev, "unlinked by a call to "
  82                          "usb_unlink_urb()\n");
  83                 break;
  84         case -EPIPE:
  85                 dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
  86                          usb_pipeendpoint(urb->pipe));
  87                 break;
  88         case -ESHUTDOWN:
  89                 dev_info(&urb->dev->dev, "device removed?\n");
  90                 break;
  91         default:
  92                 dev_info(&urb->dev->dev, "urb completion with non-zero status "
  93                          "%d\n", urb->status);
  94                 break;
  95         }
  96
  97         /* link a urb to the queue of tx. */
  98         spin_lock_irqsave(&sdev->priv_lock, flags);
  99         if (priv->unlinking) {
 100                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
 101                 stub_free_priv_and_urb(priv);
 102         } else {
 103                 list_move_tail(&priv->list, &sdev->priv_tx);
 104         }
 105         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 106
 107         /* wake up tx_thread */
 108         wake_up(&sdev->tx_waitq);
 109 }
 110
 111 static inline void setup_base_pdu(struct usbip_header_basic *base,
 112                                   __u32 command, __u32 seqnum)
 113 {
 114         base->command   = command;
 115         base->seqnum    = seqnum;
 116         base->devid     = 0;
 117         base->ep        = 0;
 118         base->direction = 0;
 119 }
 120
 121 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 122 {
 123         struct stub_priv *priv = (struct stub_priv *) urb->context;
 124
 125         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 126         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 127 }
 128
 129 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 130                                  struct stub_unlink *unlink)
 131 {
 132         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 133         rpdu->u.ret_unlink.status = unlink->status;
 134 }
 135
 136 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 137 {
 138         unsigned long flags;
 139         struct stub_priv *priv, *tmp;
 140
 141         spin_lock_irqsave(&sdev->priv_lock, flags);
 142
 143         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 144                 list_move_tail(&priv->list, &sdev->priv_free);
 145                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 146                 return priv;
 147         }
 148
 149         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 150
 151         return NULL;
 152 }
 153
 154 static int stub_send_ret_submit(struct stub_device *sdev)
 155 {
 156         unsigned long flags;
 157         struct stub_priv *priv, *tmp;
 158
 159         struct msghdr msg;
 160         size_t txsize;
 161
 162         size_t total_size = 0;
 163
 164         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 165                 int ret;
 166                 struct urb *urb = priv->urb;
 167                 struct usbip_header pdu_header;
 168                 struct usbip_iso_packet_descriptor *iso_buffer = NULL;
 169                 struct kvec *iov = NULL;
 170                 int iovnum = 0;
 171
 172                 txsize = 0;
 173                 memset(&pdu_header, 0, sizeof(pdu_header));
 174                 memset(&msg, 0, sizeof(msg));
 175
 176                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 177                         iovnum = 2 + urb->number_of_packets;
 178                 else
 179                         iovnum = 2;
 180
 181                 iov = kzalloc(iovnum * sizeof(struct kvec), GFP_KERNEL);
 182
 183                 if (!iov) {
 184                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
 185                         return -1;
 186                 }
 187
 188                 iovnum = 0;
 189
 190                 /* 1. setup usbip_header */
 191                 setup_ret_submit_pdu(&pdu_header, urb);
 192                 usbip_dbg_stub_tx("setup txdata seqnum: %d urb: %p\n",
 193                                   pdu_header.base.seqnum, urb);
 194                 usbip_header_correct_endian(&pdu_header, 1);
 195
 196                 iov[iovnum].iov_base = &pdu_header;
 197                 iov[iovnum].iov_len  = sizeof(pdu_header);
 198                 iovnum++;
 199                 txsize += sizeof(pdu_header);
 200
 201                 /* 2. setup transfer buffer */
 202                 if (usb_pipein(urb->pipe) &&
 203                     usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 204                     urb->actual_length > 0) {
 205                         iov[iovnum].iov_base = urb->transfer_buffer;
 206                         iov[iovnum].iov_len  = urb->actual_length;
 207                         iovnum++;
 208                         txsize += urb->actual_length;
 209                 } else if (usb_pipein(urb->pipe) &&
 210                            usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 211                         /*
 212                          * For isochronous packets: actual length is the sum of
 213                          * the actual length of the individual, packets, but as
 214                          * the packet offsets are not changed there will be
 215                          * padding between the packets. To optimally use the
 216                          * bandwidth the padding is not transmitted.
 217                          */
 218
 219                         int i;
 220                         for (i = 0; i < urb->number_of_packets; i++) {
 221                                 iov[iovnum].iov_base = urb->transfer_buffer +
 222                                         urb->iso_frame_desc[i].offset;
 223                                 iov[iovnum].iov_len =
 224                                         urb->iso_frame_desc[i].actual_length;
 225                                 iovnum++;
 226                                 txsize += urb->iso_frame_desc[i].actual_length;
 227                         }
 228
 229                         if (txsize != sizeof(pdu_header) + urb->actual_length) {
 230                                 dev_err(&sdev->interface->dev,
 231                                         "actual length of urb %d does not "
 232                                         "match iso packet sizes %zu\n",
 233                                         urb->actual_length,
 234                                         txsize-sizeof(pdu_header));
 235                                 kfree(iov);
 236                                 usbip_event_add(&sdev->ud,
 237                                                 SDEV_EVENT_ERROR_TCP);
 238                            return -1;
 239                         }
 240                 }
 241
 242                 /* 3. setup iso_packet_descriptor */
 243                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 244                         ssize_t len = 0;
 245
 246                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 247                         if (!iso_buffer) {
 248                                 usbip_event_add(&sdev->ud,
 249                                                 SDEV_EVENT_ERROR_MALLOC);
 250                                 kfree(iov);
 251                                 return -1;
 252                         }
 253
 254                         iov[iovnum].iov_base = iso_buffer;
 255                         iov[iovnum].iov_len  = len;
 256                         txsize += len;
 257                         iovnum++;
 258                 }
 259
 260                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
 261                                                 iov,  iovnum, txsize);
 262                 if (ret != txsize) {
 263                         dev_err(&sdev->interface->dev,
 264                                 "sendmsg failed!, retval %d for %zd\n",
 265                                 ret, txsize);
 266                         kfree(iov);
 267                         kfree(iso_buffer);
 268                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 269                         return -1;
 270                 }
 271
 272                 kfree(iov);
 273                 kfree(iso_buffer);
 274
 275                 total_size += txsize;
 276         }
 277
 278         spin_lock_irqsave(&sdev->priv_lock, flags);
 279         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 280                 stub_free_priv_and_urb(priv);
 281         }
 282         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 283
 284         return total_size;
 285 }
 286
 287 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 288 {
 289         unsigned long flags;
 290         struct stub_unlink *unlink, *tmp;
 291
 292         spin_lock_irqsave(&sdev->priv_lock, flags);
 293
 294         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 295                 list_move_tail(&unlink->list, &sdev->unlink_free);
 296                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 297                 return unlink;
 298         }
 299
 300         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 301
 302         return NULL;
 303 }
 304
 305 static int stub_send_ret_unlink(struct stub_device *sdev)
 306 {
 307         unsigned long flags;
 308         struct stub_unlink *unlink, *tmp;
 309
 310         struct msghdr msg;
 311         struct kvec iov[1];
 312         size_t txsize;
 313
 314         size_t total_size = 0;
 315
 316         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 317                 int ret;
 318                 struct usbip_header pdu_header;
 319
 320                 txsize = 0;
 321                 memset(&pdu_header, 0, sizeof(pdu_header));
 322                 memset(&msg, 0, sizeof(msg));
 323                 memset(&iov, 0, sizeof(iov));
 324
 325                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 326
 327                 /* 1. setup usbip_header */
 328                 setup_ret_unlink_pdu(&pdu_header, unlink);
 329                 usbip_header_correct_endian(&pdu_header, 1);
 330
 331                 iov[0].iov_base = &pdu_header;
 332                 iov[0].iov_len  = sizeof(pdu_header);
 333                 txsize += sizeof(pdu_header);
 334
 335                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 336                                      1, txsize);
 337                 if (ret != txsize) {
 338                         dev_err(&sdev->interface->dev,
 339                                 "sendmsg failed!, retval %d for %zd\n",
 340                                 ret, txsize);
 341                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 342                         return -1;
 343                 }
 344
 345                 usbip_dbg_stub_tx("send txdata\n");
 346                 total_size += txsize;
 347         }
 348
 349         spin_lock_irqsave(&sdev->priv_lock, flags);
 350
 351         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 352                 list_del(&unlink->list);
 353                 kfree(unlink);
 354         }
 355
 356         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 357
 358         return total_size;
 359 }
 360
 361 int stub_tx_loop(void *data)
 362 {
 363         struct usbip_device *ud = data;
 364         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 365
 366         while (!kthread_should_stop()) {
 367                 if (usbip_event_happened(ud))
 368                         break;
 369
 370                 /*
 371                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 372                  * looks at only priv_init queue. If the completion of a URB is
 373                  * earlier than the receive of CMD_UNLINK, priv is moved to
 374                  * priv_tx queue and stub_rx does not find the target priv. In
 375                  * this case, vhci_rx receives the result of the submit request
 376                  * and then receives the result of the unlink request. The
 377                  * result of the submit is given back to the usbcore as the
 378                  * completion of the unlink request. The request of the
 379                  * unlink is ignored. This is ok because a driver who calls
 380                  * usb_unlink_urb() understands the unlink was too late by
 381                  * getting the status of the given-backed URB which has the
 382                  * status of usb_submit_urb().
 383                  */
 384                 if (stub_send_ret_submit(sdev) < 0)
 385                         break;
 386
 387                 if (stub_send_ret_unlink(sdev) < 0)
 388                         break;
 389
 390                 wait_event_interruptible(sdev->tx_waitq,
 391                                          (!list_empty(&sdev->priv_tx) ||
 392                                           !list_empty(&sdev->unlink_tx) ||
 393                                           kthread_should_stop()));
 394         }
 395
 396         return 0;
 397 }