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                 dev_err(&sdev->interface->dev, "alloc stub_unlink\n");
  46                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  47                 return;
  48         }
  49
  50         unlink->seqnum = seqnum;
  51         unlink->status = status;
  52
  53         list_add_tail(&unlink->list, &sdev->unlink_tx);
  54 }
  55
  56 /**
  57  * stub_complete - completion handler of a usbip urb
  58  * @urb: pointer to the urb completed
  59  *
  60  * When a urb has completed, the USB core driver calls this function mostly in
  61  * the interrupt context. To return the result of a urb, the completed urb is
  62  * linked to the pending list of returning.
  63  *
  64  */
  65 void stub_complete(struct urb *urb)
  66 {
  67         struct stub_priv *priv = (struct stub_priv *) urb->context;
  68         struct stub_device *sdev = priv->sdev;
  69         unsigned long flags;
  70
  71         usbip_dbg_stub_tx("complete! status %d\n", urb->status);
  72
  73         switch (urb->status) {
  74         case 0:
  75                 /* OK */
  76                 break;
  77         case -ENOENT:
  78                 dev_info(&urb->dev->dev, "stopped by a call to usb_kill_urb() "
  79                          "because of cleaning up a virtual connection\n");
  80                 return;
  81         case -ECONNRESET:
  82                 dev_info(&urb->dev->dev, "unlinked by a call to "
  83                          "usb_unlink_urb()\n");
  84                 break;
  85         case -EPIPE:
  86                 dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
  87                          usb_pipeendpoint(urb->pipe));
  88                 break;
  89         case -ESHUTDOWN:
  90                 dev_info(&urb->dev->dev, "device removed?\n");
  91                 break;
  92         default:
  93                 dev_info(&urb->dev->dev, "urb completion with non-zero status "
  94                          "%d\n", urb->status);
  95                 break;
  96         }
  97
  98         /* link a urb to the queue of tx. */
  99         spin_lock_irqsave(&sdev->priv_lock, flags);
 100
 101         if (priv->unlinking) {
 102                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
 103                 stub_free_priv_and_urb(priv);
 104         } else
 105                 list_move_tail(&priv->list, &sdev->priv_tx);
 106
 107         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 108
 109         /* wake up tx_thread */
 110         wake_up(&sdev->tx_waitq);
 111 }
 112
 113 static inline void setup_base_pdu(struct usbip_header_basic *base,
 114                                   __u32 command, __u32 seqnum)
 115 {
 116         base->command = command;
 117         base->seqnum  = seqnum;
 118         base->devid   = 0;
 119         base->ep      = 0;
 120         base->direction = 0;
 121 }
 122
 123 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 124 {
 125         struct stub_priv *priv = (struct stub_priv *) urb->context;
 126
 127         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 128         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 129 }
 130
 131 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 132                                  struct stub_unlink *unlink)
 133 {
 134         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 135         rpdu->u.ret_unlink.status = unlink->status;
 136 }
 137
 138 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 139 {
 140         unsigned long flags;
 141         struct stub_priv *priv, *tmp;
 142
 143         spin_lock_irqsave(&sdev->priv_lock, flags);
 144
 145         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 146                 list_move_tail(&priv->list, &sdev->priv_free);
 147                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 148                 return priv;
 149         }
 150
 151         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 152
 153         return NULL;
 154 }
 155
 156 static int stub_send_ret_submit(struct stub_device *sdev)
 157 {
 158         unsigned long flags;
 159         struct stub_priv *priv, *tmp;
 160
 161         struct msghdr msg;
 162         size_t txsize;
 163
 164         size_t total_size = 0;
 165
 166         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 167                 int ret;
 168                 struct urb *urb = priv->urb;
 169                 struct usbip_header pdu_header;
 170                 void *iso_buffer = NULL;
 171                 struct kvec *iov = NULL;
 172                 int iovnum = 0;
 173
 174                 txsize = 0;
 175                 memset(&pdu_header, 0, sizeof(pdu_header));
 176                 memset(&msg, 0, sizeof(msg));
 177
 178                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 179                         iovnum = 2 + urb->number_of_packets;
 180                 else
 181                         iovnum = 2;
 182
 183                 iov = kzalloc(iovnum * sizeof(struct kvec), GFP_KERNEL);
 184
 185                 if (!iov) {
 186                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
 187                         return -1;
 188                 }
 189
 190                 iovnum = 0;
 191
 192                 /* 1. setup usbip_header */
 193                 setup_ret_submit_pdu(&pdu_header, urb);
 194                 usbip_dbg_stub_tx("setup txdata seqnum: %d urb: %p\n",
 195                                   pdu_header.base.seqnum, urb);
 196                 /*usbip_dump_header(pdu_header);*/
 197                 usbip_header_correct_endian(&pdu_header, 1);
 198
 199                 iov[iovnum].iov_base = &pdu_header;
 200                 iov[iovnum].iov_len  = sizeof(pdu_header);
 201                 iovnum++;
 202                 txsize += sizeof(pdu_header);
 203
 204                 /* 2. setup transfer buffer */
 205                 if (usb_pipein(urb->pipe) &&
 206                     usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 207                     urb->actual_length > 0) {
 208                         iov[iovnum].iov_base = urb->transfer_buffer;
 209                         iov[iovnum].iov_len  = urb->actual_length;
 210                         iovnum++;
 211                         txsize += urb->actual_length;
 212                 } else if (usb_pipein(urb->pipe) &&
 213                            usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 214                         /*
 215                          * For isochronous packets: actual length is the sum of
 216                          * the actual length of the individual, packets, but as
 217                          * the packet offsets are not changed there will be
 218                          * padding between the packets. To optimally use the
 219                          * bandwidth the padding is not transmitted.
 220                          */
 221
 222                         int i;
 223                         for (i = 0; i < urb->number_of_packets; i++) {
 224                                 iov[iovnum].iov_base = urb->transfer_buffer +
 225                                         urb->iso_frame_desc[i].offset;
 226                                 iov[iovnum].iov_len =
 227                                         urb->iso_frame_desc[i].actual_length;
 228                                 iovnum++;
 229                                 txsize += urb->iso_frame_desc[i].actual_length;
 230                         }
 231
 232                         if (txsize != sizeof(pdu_header) + urb->actual_length) {
 233                                 dev_err(&sdev->interface->dev,
 234                                         "actual length of urb %d does not "
 235                                         "match iso packet sizes %lu\n",
 236                                         urb->actual_length,
 237                                         txsize-sizeof(pdu_header));
 238                                 kfree(iov);
 239                                 usbip_event_add(&sdev->ud,
 240                                                 SDEV_EVENT_ERROR_TCP);
 241                            return -1;
 242                         }
 243                 }
 244
 245                 /* 3. setup iso_packet_descriptor */
 246                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 247                         ssize_t len = 0;
 248
 249                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 250                         if (!iso_buffer) {
 251                                 usbip_event_add(&sdev->ud,
 252                                                 SDEV_EVENT_ERROR_MALLOC);
 253                                 kfree(iov);
 254                                 return -1;
 255                         }
 256
 257                         iov[iovnum].iov_base = iso_buffer;
 258                         iov[iovnum].iov_len  = len;
 259                         txsize += len;
 260                         iovnum++;
 261                 }
 262
 263                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
 264                                                 iov,  iovnum, txsize);
 265                 if (ret != txsize) {
 266                         dev_err(&sdev->interface->dev,
 267                                 "sendmsg failed!, retval %d for %zd\n",
 268                                 ret, txsize);
 269                         kfree(iov);
 270                         kfree(iso_buffer);
 271                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 272                         return -1;
 273                 }
 274
 275                 kfree(iov);
 276                 kfree(iso_buffer);
 277
 278                 total_size += txsize;
 279         }
 280
 281         spin_lock_irqsave(&sdev->priv_lock, flags);
 282         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 283                 stub_free_priv_and_urb(priv);
 284         }
 285         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 286
 287         return total_size;
 288 }
 289
 290 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 291 {
 292         unsigned long flags;
 293         struct stub_unlink *unlink, *tmp;
 294
 295         spin_lock_irqsave(&sdev->priv_lock, flags);
 296
 297         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 298                 list_move_tail(&unlink->list, &sdev->unlink_free);
 299                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 300                 return unlink;
 301         }
 302
 303         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 304
 305         return NULL;
 306 }
 307
 308 static int stub_send_ret_unlink(struct stub_device *sdev)
 309 {
 310         unsigned long flags;
 311         struct stub_unlink *unlink, *tmp;
 312
 313         struct msghdr msg;
 314         struct kvec iov[1];
 315         size_t txsize;
 316
 317         size_t total_size = 0;
 318
 319         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 320                 int ret;
 321                 struct usbip_header pdu_header;
 322
 323                 txsize = 0;
 324                 memset(&pdu_header, 0, sizeof(pdu_header));
 325                 memset(&msg, 0, sizeof(msg));
 326                 memset(&iov, 0, sizeof(iov));
 327
 328                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 329
 330                 /* 1. setup usbip_header */
 331                 setup_ret_unlink_pdu(&pdu_header, unlink);
 332                 usbip_header_correct_endian(&pdu_header, 1);
 333
 334                 iov[0].iov_base = &pdu_header;
 335                 iov[0].iov_len  = sizeof(pdu_header);
 336                 txsize += sizeof(pdu_header);
 337
 338                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 339                                      1, txsize);
 340                 if (ret != txsize) {
 341                         dev_err(&sdev->interface->dev,
 342                                 "sendmsg failed!, retval %d for %zd\n",
 343                                 ret, txsize);
 344                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 345                         return -1;
 346                 }
 347
 348                 usbip_dbg_stub_tx("send txdata\n");
 349                 total_size += txsize;
 350         }
 351
 352         spin_lock_irqsave(&sdev->priv_lock, flags);
 353
 354         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 355                 list_del(&unlink->list);
 356                 kfree(unlink);
 357         }
 358
 359         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 360
 361         return total_size;
 362 }
 363
 364 int stub_tx_loop(void *data)
 365 {
 366         struct usbip_device *ud = data;
 367         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 368
 369         while (!kthread_should_stop()) {
 370                 if (usbip_event_happened(ud))
 371                         break;
 372
 373                 /*
 374                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 375                  * looks at only priv_init queue. If the completion of a URB is
 376                  * earlier than the receive of CMD_UNLINK, priv is moved to
 377                  * priv_tx queue and stub_rx does not find the target priv. In
 378                  * this case, vhci_rx receives the result of the submit request
 379                  * and then receives the result of the unlink request. The
 380                  * result of the submit is given back to the usbcore as the
 381                  * completion of the unlink request. The request of the
 382                  * unlink is ignored. This is ok because a driver who calls
 383                  * usb_unlink_urb() understands the unlink was too late by
 384                  * getting the status of the given-backed URB which has the
 385                  * status of usb_submit_urb().
 386                  */
 387                 if (stub_send_ret_submit(sdev) < 0)
 388                         break;
 389
 390                 if (stub_send_ret_unlink(sdev) < 0)
 391                         break;
 392
 393                 wait_event_interruptible(sdev->tx_waitq,
 394                                          (!list_empty(&sdev->priv_tx) ||
 395                                           !list_empty(&sdev->unlink_tx) ||
 396                                           kthread_should_stop()));
 397         }
 398
 399         return 0;
 400 }