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