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         urb->setup_packet = NULL;
  32
  33         kfree(urb->transfer_buffer);
  34         urb->transfer_buffer = NULL;
  35
  36         list_del(&priv->list);
  37         kmem_cache_free(stub_priv_cache, priv);
  38         usb_free_urb(urb);
  39 }
  40
  41 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
  42 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
  43                              __u32 status)
  44 {
  45         struct stub_unlink *unlink;
  46
  47         unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
  48         if (!unlink) {
  49                 dev_err(&sdev->interface->dev, "alloc stub_unlink\n");
  50                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  51                 return;
  52         }
  53
  54         unlink->seqnum = seqnum;
  55         unlink->status = status;
  56
  57         list_add_tail(&unlink->list, &sdev->unlink_tx);
  58 }
  59
  60 /**
  61  * stub_complete - completion handler of a usbip urb
  62  * @urb: pointer to the urb completed
  63  *
  64  * When a urb has completed, the USB core driver calls this function mostly in
  65  * the interrupt context. To return the result of a urb, the completed urb is
  66  * linked to the pending list of returning.
  67  *
  68  */
  69 void stub_complete(struct urb *urb)
  70 {
  71         struct stub_priv *priv = (struct stub_priv *) urb->context;
  72         struct stub_device *sdev = priv->sdev;
  73         unsigned long flags;
  74
  75         usbip_dbg_stub_tx("complete! status %d\n", urb->status);
  76
  77         switch (urb->status) {
  78         case 0:
  79                 /* OK */
  80                 break;
  81         case -ENOENT:
  82                 dev_info(&urb->dev->dev, "stopped by a call to usb_kill_urb() "
  83                          "because of cleaning up a virtual connection\n");
  84                 return;
  85         case -ECONNRESET:
  86                 dev_info(&urb->dev->dev, "unlinked by a call to "
  87                          "usb_unlink_urb()\n");
  88                 break;
  89         case -EPIPE:
  90                 dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
  91                          usb_pipeendpoint(urb->pipe));
  92                 break;
  93         case -ESHUTDOWN:
  94                 dev_info(&urb->dev->dev, "device removed?\n");
  95                 break;
  96         default:
  97                 dev_info(&urb->dev->dev, "urb completion with non-zero status "
  98                          "%d\n", urb->status);
  99                 break;
 100         }
 101
 102         /* link a urb to the queue of tx. */
 103         spin_lock_irqsave(&sdev->priv_lock, flags);
 104         if (priv->unlinking) {
 105                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
 106                 stub_free_priv_and_urb(priv);
 107         } else {
 108                 list_move_tail(&priv->list, &sdev->priv_tx);
 109         }
 110         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 111
 112         /* wake up tx_thread */
 113         wake_up(&sdev->tx_waitq);
 114 }
 115
 116 static inline void setup_base_pdu(struct usbip_header_basic *base,
 117                                   __u32 command, __u32 seqnum)
 118 {
 119         base->command   = command;
 120         base->seqnum    = seqnum;
 121         base->devid     = 0;
 122         base->ep        = 0;
 123         base->direction = 0;
 124 }
 125
 126 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 127 {
 128         struct stub_priv *priv = (struct stub_priv *) urb->context;
 129
 130         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 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         rpdu->u.ret_unlink.status = unlink->status;
 139 }
 140
 141 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 142 {
 143         unsigned long flags;
 144         struct stub_priv *priv, *tmp;
 145
 146         spin_lock_irqsave(&sdev->priv_lock, flags);
 147
 148         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 149                 list_move_tail(&priv->list, &sdev->priv_free);
 150                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 151                 return priv;
 152         }
 153
 154         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 155
 156         return NULL;
 157 }
 158
 159 static int stub_send_ret_submit(struct stub_device *sdev)
 160 {
 161         unsigned long flags;
 162         struct stub_priv *priv, *tmp;
 163
 164         struct msghdr msg;
 165         size_t txsize;
 166
 167         size_t total_size = 0;
 168
 169         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 170                 int ret;
 171                 struct urb *urb = priv->urb;
 172                 struct usbip_header pdu_header;
 173                 void *iso_buffer = NULL;
 174                 struct kvec *iov = NULL;
 175                 int iovnum = 0;
 176
 177                 txsize = 0;
 178                 memset(&pdu_header, 0, sizeof(pdu_header));
 179                 memset(&msg, 0, sizeof(msg));
 180
 181                 if (urb->actual_length > 0 && !urb->transfer_buffer) {
 182                         dev_err(&sdev->interface->dev,
 183                                 "urb: actual_length %d transfer_buffer null\n",
 184                                 urb->actual_length);
 185                         return -1;
 186                 }
 187
 188                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 189                         iovnum = 2 + urb->number_of_packets;
 190                 else
 191                         iovnum = 2;
 192
 193                 iov = kzalloc(iovnum * sizeof(struct kvec), GFP_KERNEL);
 194
 195                 if (!iov) {
 196                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
 197                         return -1;
 198                 }
 199
 200                 iovnum = 0;
 201
 202                 /* 1. setup usbip_header */
 203                 setup_ret_submit_pdu(&pdu_header, urb);
 204                 usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
 205                                   pdu_header.base.seqnum);
 206                 /*usbip_dump_header(pdu_header);*/
 207                 usbip_header_correct_endian(&pdu_header, 1);
 208
 209                 iov[iovnum].iov_base = &pdu_header;
 210                 iov[iovnum].iov_len  = sizeof(pdu_header);
 211                 iovnum++;
 212                 txsize += sizeof(pdu_header);
 213
 214                 /* 2. setup transfer buffer */
 215                 if (usb_pipein(urb->pipe) &&
 216                     usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 217                     urb->actual_length > 0) {
 218                         iov[iovnum].iov_base = urb->transfer_buffer;
 219                         iov[iovnum].iov_len  = urb->actual_length;
 220                         iovnum++;
 221                         txsize += urb->actual_length;
 222                 } else if (usb_pipein(urb->pipe) &&
 223                            usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 224                         /*
 225                          * For isochronous packets: actual length is the sum of
 226                          * the actual length of the individual, packets, but as
 227                          * the packet offsets are not changed there will be
 228                          * padding between the packets. To optimally use the
 229                          * bandwidth the padding is not transmitted.
 230                          */
 231
 232                         int i;
 233                         for (i = 0; i < urb->number_of_packets; i++) {
 234                                 iov[iovnum].iov_base = urb->transfer_buffer +
 235                                         urb->iso_frame_desc[i].offset;
 236                                 iov[iovnum].iov_len =
 237                                         urb->iso_frame_desc[i].actual_length;
 238                                 iovnum++;
 239                                 txsize += urb->iso_frame_desc[i].actual_length;
 240                         }
 241
 242                         if (txsize != sizeof(pdu_header) + urb->actual_length) {
 243                                 dev_err(&sdev->interface->dev,
 244                                         "actual length of urb %d does not "
 245                                         "match iso packet sizes %zu\n",
 246                                         urb->actual_length,
 247                                         txsize-sizeof(pdu_header));
 248                                 kfree(iov);
 249                                 usbip_event_add(&sdev->ud,
 250                                                 SDEV_EVENT_ERROR_TCP);
 251                            return -1;
 252                         }
 253                 }
 254
 255                 /* 3. setup iso_packet_descriptor */
 256                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 257                         ssize_t len = 0;
 258
 259                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 260                         if (!iso_buffer) {
 261                                 usbip_event_add(&sdev->ud,
 262                                                 SDEV_EVENT_ERROR_MALLOC);
 263                                 kfree(iov);
 264                                 return -1;
 265                         }
 266
 267                         iov[iovnum].iov_base = iso_buffer;
 268                         iov[iovnum].iov_len  = len;
 269                         txsize += len;
 270                         iovnum++;
 271                 }
 272
 273                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
 274                                                 iov,  iovnum, txsize);
 275                 if (ret != txsize) {
 276                         dev_err(&sdev->interface->dev,
 277                                 "sendmsg failed!, retval %d for %zd\n",
 278                                 ret, txsize);
 279                         kfree(iov);
 280                         kfree(iso_buffer);
 281                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 282                         return -1;
 283                 }
 284
 285                 kfree(iov);
 286                 kfree(iso_buffer);
 287
 288                 total_size += txsize;
 289         }
 290
 291         spin_lock_irqsave(&sdev->priv_lock, flags);
 292         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 293                 stub_free_priv_and_urb(priv);
 294         }
 295         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 296
 297         return total_size;
 298 }
 299
 300 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 301 {
 302         unsigned long flags;
 303         struct stub_unlink *unlink, *tmp;
 304
 305         spin_lock_irqsave(&sdev->priv_lock, flags);
 306
 307         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 308                 list_move_tail(&unlink->list, &sdev->unlink_free);
 309                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 310                 return unlink;
 311         }
 312
 313         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 314
 315         return NULL;
 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                 usbip_dbg_stub_tx("send txdata\n");
 359                 total_size += txsize;
 360         }
 361
 362         spin_lock_irqsave(&sdev->priv_lock, flags);
 363
 364         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 365                 list_del(&unlink->list);
 366                 kfree(unlink);
 367         }
 368
 369         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 370
 371         return total_size;
 372 }
 373
 374 int stub_tx_loop(void *data)
 375 {
 376         struct usbip_device *ud = data;
 377         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 378
 379         while (!kthread_should_stop()) {
 380                 if (usbip_event_happened(ud))
 381                         break;
 382
 383                 /*
 384                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 385                  * looks at only priv_init queue. If the completion of a URB is
 386                  * earlier than the receive of CMD_UNLINK, priv is moved to
 387                  * priv_tx queue and stub_rx does not find the target priv. In
 388                  * this case, vhci_rx receives the result of the submit request
 389                  * and then receives the result of the unlink request. The
 390                  * result of the submit is given back to the usbcore as the
 391                  * completion of the unlink request. The request of the
 392                  * unlink is ignored. This is ok because a driver who calls
 393                  * usb_unlink_urb() understands the unlink was too late by
 394                  * getting the status of the given-backed URB which has the
 395                  * status of usb_submit_urb().
 396                  */
 397                 if (stub_send_ret_submit(sdev) < 0)
 398                         break;
 399
 400                 if (stub_send_ret_unlink(sdev) < 0)
 401                         break;
 402
 403                 wait_event_interruptible(sdev->tx_waitq,
 404                                          (!list_empty(&sdev->priv_tx) ||
 405                                           !list_empty(&sdev->unlink_tx) ||
 406                                           kthread_should_stop()));
 407         }
 408
 409         return 0;
 410 }