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/slab.h>
  21 #include <linux/kthread.h>
  22
  23 #include "usbip_common.h"
  24 #include "stub.h"
  25
  26
  27 static void stub_free_priv_and_urb(struct stub_priv *priv)
  28 {
  29         struct urb *urb = priv->urb;
  30
  31         kfree(urb->setup_packet);
  32         kfree(urb->transfer_buffer);
  33         list_del(&priv->list);
  34         kmem_cache_free(stub_priv_cache, priv);
  35         usb_free_urb(urb);
  36 }
  37
  38 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
  39 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
  40                              __u32 status)
  41 {
  42         struct stub_unlink *unlink;
  43
  44         unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
  45         if (!unlink) {
  46                 dev_err(&sdev->interface->dev, "alloc stub_unlink\n");
  47                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  48                 return;
  49         }
  50
  51         unlink->seqnum = seqnum;
  52         unlink->status = status;
  53
  54         list_add_tail(&unlink->list, &sdev->unlink_tx);
  55 }
  56
  57 /**
  58  * stub_complete - completion handler of a usbip urb
  59  * @urb: pointer to the urb completed
  60  *
  61  * When a urb has completed, the USB core driver calls this function mostly in
  62  * the interrupt context. To return the result of a urb, the completed urb is
  63  * linked to the pending list of returning.
  64  *
  65  */
  66 void stub_complete(struct urb *urb)
  67 {
  68         struct stub_priv *priv = (struct stub_priv *) urb->context;
  69         struct stub_device *sdev = priv->sdev;
  70         unsigned long flags;
  71
  72         usbip_dbg_stub_tx("complete! status %d\n", urb->status);
  73
  74
  75         switch (urb->status) {
  76         case 0:
  77                 /* OK */
  78                 break;
  79         case -ENOENT:
  80                 usbip_uinfo("stopped by a call of usb_kill_urb() because of"
  81                                         "cleaning up a virtual connection\n");
  82                 return;
  83         case -ECONNRESET:
  84                 usbip_uinfo("unlinked by a call of usb_unlink_urb()\n");
  85                 break;
  86         case -EPIPE:
  87                 usbip_uinfo("endpoint %d is stalled\n",
  88                                                 usb_pipeendpoint(urb->pipe));
  89                 break;
  90         case -ESHUTDOWN:
  91                 usbip_uinfo("device removed?\n");
  92                 break;
  93         default:
  94                 usbip_uinfo("urb completion with non-zero status %d\n",
  95                                                         urb->status);
  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
 108         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 109
 110         /* wake up tx_thread */
 111         wake_up(&sdev->tx_waitq);
 112 }
 113
 114
 115 /*-------------------------------------------------------------------------*/
 116 /* fill PDU */
 117
 118 static inline void setup_base_pdu(struct usbip_header_basic *base,
 119                 __u32 command, __u32 seqnum)
 120 {
 121         base->command = command;
 122         base->seqnum  = seqnum;
 123         base->devid   = 0;
 124         base->ep      = 0;
 125         base->direction   = 0;
 126 }
 127
 128 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 129 {
 130         struct stub_priv *priv = (struct stub_priv *) urb->context;
 131
 132         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 133
 134         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 135 }
 136
 137 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 138                 struct stub_unlink *unlink)
 139 {
 140         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 141
 142         rpdu->u.ret_unlink.status = unlink->status;
 143 }
 144
 145
 146 /*-------------------------------------------------------------------------*/
 147 /* send RET_SUBMIT */
 148
 149 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 150 {
 151         unsigned long flags;
 152         struct stub_priv *priv, *tmp;
 153
 154         spin_lock_irqsave(&sdev->priv_lock, flags);
 155
 156         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 157                 list_move_tail(&priv->list, &sdev->priv_free);
 158                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 159                 return priv;
 160         }
 161
 162         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 163
 164         return NULL;
 165 }
 166
 167 static int stub_send_ret_submit(struct stub_device *sdev)
 168 {
 169         unsigned long flags;
 170         struct stub_priv *priv, *tmp;
 171
 172         struct msghdr msg;
 173         size_t txsize;
 174
 175         size_t total_size = 0;
 176
 177         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 178                 int ret;
 179                 struct urb *urb = priv->urb;
 180                 struct usbip_header pdu_header;
 181                 void *iso_buffer = NULL;
 182                 struct kvec *iov = NULL;
 183                 int iovnum = 0;
 184
 185                 txsize = 0;
 186                 memset(&pdu_header, 0, sizeof(pdu_header));
 187                 memset(&msg, 0, sizeof(msg));
 188
 189                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 190                         iovnum = 2 + urb->number_of_packets;
 191                 else
 192                         iovnum = 2;
 193
 194                 iov = kzalloc(iovnum * sizeof(struct kvec), GFP_KERNEL);
 195
 196                 if (!iov) {
 197                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
 198                         return -1;
 199                 }
 200
 201                 iovnum = 0;
 202
 203                 /* 1. setup usbip_header */
 204                 setup_ret_submit_pdu(&pdu_header, urb);
 205                 usbip_dbg_stub_tx("setup txdata seqnum: %d urb: %p\n",
 206                                                 pdu_header.base.seqnum, urb);
 207                 /*usbip_dump_header(pdu_header);*/
 208                 usbip_header_correct_endian(&pdu_header, 1);
 209
 210                 iov[iovnum].iov_base = &pdu_header;
 211                 iov[iovnum].iov_len  = sizeof(pdu_header);
 212                 iovnum++;
 213                 txsize += sizeof(pdu_header);
 214
 215                 /* 2. setup transfer buffer */
 216                 if (usb_pipein(urb->pipe) &&
 217                                 usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 218                                         urb->actual_length > 0) {
 219                         iov[iovnum].iov_base = urb->transfer_buffer;
 220                         iov[iovnum].iov_len  = urb->actual_length;
 221                         iovnum++;
 222                         txsize += urb->actual_length;
 223                 } else if (usb_pipein(urb->pipe) &&
 224                                 usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 225                         /*
 226                          * For isochronous packets: actual length is the sum of
 227                          * the actual length of the individual, packets, but as
 228                          * the packet offsets are not changed there will be
 229                          * padding between the packets. To optimally use the
 230                          * bandwidth the padding is not transmitted.
 231                          */
 232
 233                         int i;
 234                         for (i = 0; i < urb->number_of_packets; i++) {
 235                                 iov[iovnum].iov_base = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 236                                 iov[iovnum].iov_len = urb->iso_frame_desc[i].actual_length;
 237                                 iovnum++;
 238                                 txsize += urb->iso_frame_desc[i].actual_length;
 239                         }
 240
 241                         if (txsize != sizeof(pdu_header) + urb->actual_length) {
 242                                 dev_err(&sdev->interface->dev,
 243                                         "actual length of urb (%d) does not match iso packet sizes (%d)\n",
 244                                         urb->actual_length, txsize-sizeof(pdu_header));
 245                                 kfree(iov);
 246                                 usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 247                            return -1;
 248                         }
 249                 }
 250
 251                 /* 3. setup iso_packet_descriptor */
 252                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 253                         ssize_t len = 0;
 254
 255                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 256                         if (!iso_buffer) {
 257                                 usbip_event_add(&sdev->ud,
 258                                                 SDEV_EVENT_ERROR_MALLOC);
 259                                 kfree(iov);
 260                                 return -1;
 261                         }
 262
 263                         iov[iovnum].iov_base = iso_buffer;
 264                         iov[iovnum].iov_len  = len;
 265                         txsize += len;
 266                         iovnum++;
 267                 }
 268
 269                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
 270                                                 iov,  iovnum, txsize);
 271                 if (ret != txsize) {
 272                         dev_err(&sdev->interface->dev,
 273                                 "sendmsg failed!, retval %d for %zd\n",
 274                                 ret, txsize);
 275                         kfree(iov);
 276                         kfree(iso_buffer);
 277                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 278                         return -1;
 279                 }
 280
 281                 kfree(iov);
 282                 kfree(iso_buffer);
 283
 284                 total_size += txsize;
 285         }
 286
 287         spin_lock_irqsave(&sdev->priv_lock, flags);
 288
 289         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 290                 stub_free_priv_and_urb(priv);
 291         }
 292
 293         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 294
 295         return total_size;
 296 }
 297
 298
 299 /*-------------------------------------------------------------------------*/
 300 /* send RET_UNLINK */
 301
 302 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 303 {
 304         unsigned long flags;
 305         struct stub_unlink *unlink, *tmp;
 306
 307         spin_lock_irqsave(&sdev->priv_lock, flags);
 308
 309         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 310                 list_move_tail(&unlink->list, &sdev->unlink_free);
 311                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 312                 return unlink;
 313         }
 314
 315         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 316
 317         return NULL;
 318 }
 319
 320
 321 static int stub_send_ret_unlink(struct stub_device *sdev)
 322 {
 323         unsigned long flags;
 324         struct stub_unlink *unlink, *tmp;
 325
 326         struct msghdr msg;
 327         struct kvec iov[1];
 328         size_t txsize;
 329
 330         size_t total_size = 0;
 331
 332         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 333                 int ret;
 334                 struct usbip_header pdu_header;
 335
 336                 txsize = 0;
 337                 memset(&pdu_header, 0, sizeof(pdu_header));
 338                 memset(&msg, 0, sizeof(msg));
 339                 memset(&iov, 0, sizeof(iov));
 340
 341                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 342
 343                 /* 1. setup usbip_header */
 344                 setup_ret_unlink_pdu(&pdu_header, unlink);
 345                 usbip_header_correct_endian(&pdu_header, 1);
 346
 347                 iov[0].iov_base = &pdu_header;
 348                 iov[0].iov_len  = sizeof(pdu_header);
 349                 txsize += sizeof(pdu_header);
 350
 351                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 352                                      1, txsize);
 353                 if (ret != txsize) {
 354                         dev_err(&sdev->interface->dev,
 355                                 "sendmsg failed!, retval %d for %zd\n",
 356                                 ret, txsize);
 357                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 358                         return -1;
 359                 }
 360
 361
 362                 usbip_dbg_stub_tx("send txdata\n");
 363
 364                 total_size += txsize;
 365         }
 366
 367
 368         spin_lock_irqsave(&sdev->priv_lock, flags);
 369
 370         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 371                 list_del(&unlink->list);
 372                 kfree(unlink);
 373         }
 374
 375         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 376
 377         return total_size;
 378 }
 379
 380
 381 /*-------------------------------------------------------------------------*/
 382
 383 int stub_tx_loop(void *data)
 384 {
 385         struct usbip_device *ud = data;
 386         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 387
 388         while (!kthread_should_stop()) {
 389                 if (usbip_event_happened(ud))
 390                         break;
 391
 392                 /*
 393                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 394                  * looks at only priv_init queue. If the completion of a URB is
 395                  * earlier than the receive of CMD_UNLINK, priv is moved to
 396                  * priv_tx queue and stub_rx does not find the target priv. In
 397                  * this case, vhci_rx receives the result of the submit request
 398                  * and then receives the result of the unlink request. The
 399                  * result of the submit is given back to the usbcore as the
 400                  * completion of the unlink request. The request of the
 401                  * unlink is ignored. This is ok because a driver who calls
 402                  * usb_unlink_urb() understands the unlink was too late by
 403                  * getting the status of the given-backed URB which has the
 404                  * status of usb_submit_urb().
 405                  */
 406                 if (stub_send_ret_submit(sdev) < 0)
 407                         break;
 408
 409                 if (stub_send_ret_unlink(sdev) < 0)
 410                         break;
 411
 412                 wait_event_interruptible(sdev->tx_waitq,
 413                                 (!list_empty(&sdev->priv_tx) ||
 414                                  !list_empty(&sdev->unlink_tx) ||
 415                                  kthread_should_stop()));
 416         }
 417
 418         return 0;
 419 }