git.oblomov.eu Git - linux-2.6/blob - 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 "usbip_common.h"
  21 #include "stub.h"
  22
  23
  24 static void stub_free_priv_and_urb(struct stub_priv *priv)
  25 {
  26         struct urb *urb = priv->urb;
  27
  28         kfree(urb->setup_packet);
  29         kfree(urb->transfer_buffer);
  30         list_del(&priv->list);
  31         kmem_cache_free(stub_priv_cache, priv);
  32         usb_free_urb(urb);
  33 }
  34
  35 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
  36 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
  37                              __u32 status)
  38 {
  39         struct stub_unlink *unlink;
  40
  41         unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
  42         if (!unlink) {
  43                 dev_err(&sdev->interface->dev, "alloc stub_unlink\n");
  44                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  45                 return;
  46         }
  47
  48         unlink->seqnum = seqnum;
  49         unlink->status = status;
  50
  51         list_add_tail(&unlink->list, &sdev->unlink_tx);
  52 }
  53
  54 /**
  55  * stub_complete - completion handler of a usbip urb
  56  * @urb: pointer to the urb completed
  57  *
  58  * When a urb has completed, the USB core driver calls this function mostly in
  59  * the interrupt context. To return the result of a urb, the completed urb is
  60  * linked to the pending list of returning.
  61  *
  62  */
  63 void stub_complete(struct urb *urb)
  64 {
  65         struct stub_priv *priv = (struct stub_priv *) urb->context;
  66         struct stub_device *sdev = priv->sdev;
  67         unsigned long flags;
  68
  69         dbg_stub_tx("complete! status %d\n", urb->status);
  70
  71
  72         switch (urb->status) {
  73         case 0:
  74                 /* OK */
  75                 break;
  76         case -ENOENT:
  77                 uinfo("stopped by a call of usb_kill_urb() because of"
  78                                         "cleaning up a virtual connection\n");
  79                 return;
  80         case -ECONNRESET:
  81                 uinfo("unlinked by a call of usb_unlink_urb()\n");
  82                 break;
  83         case -EPIPE:
  84                 uinfo("endpoint %d is stalled\n", usb_pipeendpoint(urb->pipe));
  85                 break;
  86         case -ESHUTDOWN:
  87                 uinfo("device removed?\n");
  88                 break;
  89         default:
  90                 uinfo("urb completion with non-zero status %d\n", urb->status);
  91         }
  92
  93         /* link a urb to the queue of tx. */
  94         spin_lock_irqsave(&sdev->priv_lock, flags);
  95
  96         if (priv->unlinking) {
  97                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
  98                 stub_free_priv_and_urb(priv);
  99         } else
 100                 list_move_tail(&priv->list, &sdev->priv_tx);
 101
 102
 103         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 104
 105         /* wake up tx_thread */
 106         wake_up(&sdev->tx_waitq);
 107 }
 108
 109
 110 /*-------------------------------------------------------------------------*/
 111 /* fill PDU */
 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
 129         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 130 }
 131
 132 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 133                 struct stub_unlink *unlink)
 134 {
 135         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 136
 137         rpdu->u.ret_unlink.status = unlink->status;
 138 }
 139
 140
 141 /*-------------------------------------------------------------------------*/
 142 /* send RET_SUBMIT */
 143
 144 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 145 {
 146         unsigned long flags;
 147         struct stub_priv *priv, *tmp;
 148
 149         spin_lock_irqsave(&sdev->priv_lock, flags);
 150
 151         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 152                 list_move_tail(&priv->list, &sdev->priv_free);
 153                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 154                 return priv;
 155         }
 156
 157         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 158
 159         return NULL;
 160 }
 161
 162 static int stub_send_ret_submit(struct stub_device *sdev)
 163 {
 164         unsigned long flags;
 165         struct stub_priv *priv, *tmp;
 166
 167         struct msghdr msg;
 168         struct kvec iov[3];
 169         size_t txsize;
 170
 171         size_t total_size = 0;
 172
 173         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 174                 int ret;
 175                 struct urb *urb = priv->urb;
 176                 struct usbip_header pdu_header;
 177                 void *iso_buffer = NULL;
 178
 179                 txsize = 0;
 180                 memset(&pdu_header, 0, sizeof(pdu_header));
 181                 memset(&msg, 0, sizeof(msg));
 182                 memset(&iov, 0, sizeof(iov));
 183
 184                 dbg_stub_tx("setup txdata urb %p\n", urb);
 185
 186
 187                 /* 1. setup usbip_header */
 188                 setup_ret_submit_pdu(&pdu_header, urb);
 189                 usbip_header_correct_endian(&pdu_header, 1);
 190
 191                 iov[0].iov_base = &pdu_header;
 192                 iov[0].iov_len  = sizeof(pdu_header);
 193                 txsize += sizeof(pdu_header);
 194
 195                 /* 2. setup transfer buffer */
 196                 if (usb_pipein(urb->pipe) && urb->actual_length > 0) {
 197                         iov[1].iov_base = urb->transfer_buffer;
 198                         iov[1].iov_len  = urb->actual_length;
 199                         txsize += urb->actual_length;
 200                 }
 201
 202                 /* 3. setup iso_packet_descriptor */
 203                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 204                         ssize_t len = 0;
 205
 206                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 207                         if (!iso_buffer) {
 208                                 usbip_event_add(&sdev->ud,
 209                                                 SDEV_EVENT_ERROR_MALLOC);
 210                                 return -1;
 211                         }
 212
 213                         iov[2].iov_base = iso_buffer;
 214                         iov[2].iov_len  = len;
 215                         txsize += len;
 216                 }
 217
 218                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 219                                      3, txsize);
 220                 if (ret != txsize) {
 221                         dev_err(&sdev->interface->dev,
 222                                 "sendmsg failed!, retval %d for %zd\n",
 223                                 ret, txsize);
 224                         kfree(iso_buffer);
 225                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 226                         return -1;
 227                 }
 228
 229                 kfree(iso_buffer);
 230                 dbg_stub_tx("send txdata\n");
 231
 232                 total_size += txsize;
 233         }
 234
 235
 236         spin_lock_irqsave(&sdev->priv_lock, flags);
 237
 238         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 239                 stub_free_priv_and_urb(priv);
 240         }
 241
 242         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 243
 244         return total_size;
 245 }
 246
 247
 248 /*-------------------------------------------------------------------------*/
 249 /* send RET_UNLINK */
 250
 251 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 252 {
 253         unsigned long flags;
 254         struct stub_unlink *unlink, *tmp;
 255
 256         spin_lock_irqsave(&sdev->priv_lock, flags);
 257
 258         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 259                 list_move_tail(&unlink->list, &sdev->unlink_free);
 260                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 261                 return unlink;
 262         }
 263
 264         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 265
 266         return NULL;
 267 }
 268
 269
 270 static int stub_send_ret_unlink(struct stub_device *sdev)
 271 {
 272         unsigned long flags;
 273         struct stub_unlink *unlink, *tmp;
 274
 275         struct msghdr msg;
 276         struct kvec iov[1];
 277         size_t txsize;
 278
 279         size_t total_size = 0;
 280
 281         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 282                 int ret;
 283                 struct usbip_header pdu_header;
 284
 285                 txsize = 0;
 286                 memset(&pdu_header, 0, sizeof(pdu_header));
 287                 memset(&msg, 0, sizeof(msg));
 288                 memset(&iov, 0, sizeof(iov));
 289
 290                 dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 291
 292                 /* 1. setup usbip_header */
 293                 setup_ret_unlink_pdu(&pdu_header, unlink);
 294                 usbip_header_correct_endian(&pdu_header, 1);
 295
 296                 iov[0].iov_base = &pdu_header;
 297                 iov[0].iov_len  = sizeof(pdu_header);
 298                 txsize += sizeof(pdu_header);
 299
 300                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 301                                      1, txsize);
 302                 if (ret != txsize) {
 303                         dev_err(&sdev->interface->dev,
 304                                 "sendmsg failed!, retval %d for %zd\n",
 305                                 ret, txsize);
 306                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 307                         return -1;
 308                 }
 309
 310
 311                 dbg_stub_tx("send txdata\n");
 312
 313                 total_size += txsize;
 314         }
 315
 316
 317         spin_lock_irqsave(&sdev->priv_lock, flags);
 318
 319         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 320                 list_del(&unlink->list);
 321                 kfree(unlink);
 322         }
 323
 324         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 325
 326         return total_size;
 327 }
 328
 329
 330 /*-------------------------------------------------------------------------*/
 331
 332 void stub_tx_loop(struct usbip_task *ut)
 333 {
 334         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
 335         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 336
 337         while (1) {
 338                 if (signal_pending(current)) {
 339                         dbg_stub_tx("signal catched\n");
 340                         break;
 341                 }
 342
 343                 if (usbip_event_happend(ud))
 344                         break;
 345
 346                 /*
 347                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 348                  * looks at only priv_init queue. If the completion of a URB is
 349                  * earlier than the receive of CMD_UNLINK, priv is moved to
 350                  * priv_tx queue and stub_rx does not find the target priv. In
 351                  * this case, vhci_rx receives the result of the submit request
 352                  * and then receives the result of the unlink request. The
 353                  * result of the submit is given back to the usbcore as the
 354                  * completion of the unlink request. The request of the
 355                  * unlink is ignored. This is ok because a driver who calls
 356                  * usb_unlink_urb() understands the unlink was too late by
 357                  * getting the status of the given-backed URB which has the
 358                  * status of usb_submit_urb().
 359                  */
 360                 if (stub_send_ret_submit(sdev) < 0)
 361                         break;
 362
 363                 if (stub_send_ret_unlink(sdev) < 0)
 364                         break;
 365
 366                 wait_event_interruptible(sdev->tx_waitq,
 367                                 (!list_empty(&sdev->priv_tx) ||
 368                                  !list_empty(&sdev->unlink_tx)));
 369         }
 370 }