release/src-rt-6.x.4708/linux/linux-2.6.36/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
  22 #include "usbip_common.h"
  23 #include "stub.h"
  24
  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
  74         switch (urb->status) {
  75         case 0:
  76                 /* OK */
  77                 break;
  78         case -ENOENT:
  79                 usbip_uinfo("stopped by a call of usb_kill_urb() because of"
  80                                         "cleaning up a virtual connection\n");
  81                 return;
  82         case -ECONNRESET:
  83                 usbip_uinfo("unlinked by a call of usb_unlink_urb()\n");
  84                 break;
  85         case -EPIPE:
  86                 usbip_uinfo("endpoint %d is stalled\n",
  87                                                 usb_pipeendpoint(urb->pipe));
  88                 break;
  89         case -ESHUTDOWN:
  90                 usbip_uinfo("device removed?\n");
  91                 break;
  92         default:
  93                 usbip_uinfo("urb completion with non-zero status %d\n",
  94                                                         urb->status);
  95         }
  96
  97         /* link a urb to the queue of tx. */
  98         spin_lock_irqsave(&sdev->priv_lock, flags);
  99
 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
 107         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 108
 109         /* wake up tx_thread */
 110         wake_up(&sdev->tx_waitq);
 111 }
 112
 113
 114 /*-------------------------------------------------------------------------*/
 115 /* fill PDU */
 116
 117 static inline void setup_base_pdu(struct usbip_header_basic *base,
 118                 __u32 command, __u32 seqnum)
 119 {
 120         base->command = command;
 121         base->seqnum  = seqnum;
 122         base->devid   = 0;
 123         base->ep      = 0;
 124         base->direction   = 0;
 125 }
 126
 127 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 128 {
 129         struct stub_priv *priv = (struct stub_priv *) urb->context;
 130
 131         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 132
 133         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 134 }
 135
 136 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 137                 struct stub_unlink *unlink)
 138 {
 139         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 140
 141         rpdu->u.ret_unlink.status = unlink->status;
 142 }
 143
 144
 145 /*-------------------------------------------------------------------------*/
 146 /* send RET_SUBMIT */
 147
 148 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 149 {
 150         unsigned long flags;
 151         struct stub_priv *priv, *tmp;
 152
 153         spin_lock_irqsave(&sdev->priv_lock, flags);
 154
 155         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 156                 list_move_tail(&priv->list, &sdev->priv_free);
 157                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 158                 return priv;
 159         }
 160
 161         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 162
 163         return NULL;
 164 }
 165
 166 static int stub_send_ret_submit(struct stub_device *sdev)
 167 {
 168         unsigned long flags;
 169         struct stub_priv *priv, *tmp;
 170
 171         struct msghdr msg;
 172         struct kvec iov[3];
 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
 183                 txsize = 0;
 184                 memset(&pdu_header, 0, sizeof(pdu_header));
 185                 memset(&msg, 0, sizeof(msg));
 186                 memset(&iov, 0, sizeof(iov));
 187
 188                 usbip_dbg_stub_tx("setup txdata urb %p\n", urb);
 189
 190
 191                 /* 1. setup usbip_header */
 192                 setup_ret_submit_pdu(&pdu_header, urb);
 193                 usbip_header_correct_endian(&pdu_header, 1);
 194
 195                 iov[0].iov_base = &pdu_header;
 196                 iov[0].iov_len  = sizeof(pdu_header);
 197                 txsize += sizeof(pdu_header);
 198
 199                 /* 2. setup transfer buffer */
 200                 if (usb_pipein(urb->pipe) && urb->actual_length > 0) {
 201                         iov[1].iov_base = urb->transfer_buffer;
 202                         iov[1].iov_len  = urb->actual_length;
 203                         txsize += urb->actual_length;
 204                 }
 205
 206                 /* 3. setup iso_packet_descriptor */
 207                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 208                         ssize_t len = 0;
 209
 210                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 211                         if (!iso_buffer) {
 212                                 usbip_event_add(&sdev->ud,
 213                                                 SDEV_EVENT_ERROR_MALLOC);
 214                                 return -1;
 215                         }
 216
 217                         iov[2].iov_base = iso_buffer;
 218                         iov[2].iov_len  = len;
 219                         txsize += len;
 220                 }
 221
 222                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 223                                      3, txsize);
 224                 if (ret != txsize) {
 225                         dev_err(&sdev->interface->dev,
 226                                 "sendmsg failed!, retval %d for %zd\n",
 227                                 ret, txsize);
 228                         kfree(iso_buffer);
 229                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 230                         return -1;
 231                 }
 232
 233                 kfree(iso_buffer);
 234                 usbip_dbg_stub_tx("send txdata\n");
 235
 236                 total_size += txsize;
 237         }
 238
 239
 240         spin_lock_irqsave(&sdev->priv_lock, flags);
 241
 242         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 243                 stub_free_priv_and_urb(priv);
 244         }
 245
 246         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 247
 248         return total_size;
 249 }
 250
 251
 252 /*-------------------------------------------------------------------------*/
 253 /* send RET_UNLINK */
 254
 255 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 256 {
 257         unsigned long flags;
 258         struct stub_unlink *unlink, *tmp;
 259
 260         spin_lock_irqsave(&sdev->priv_lock, flags);
 261
 262         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 263                 list_move_tail(&unlink->list, &sdev->unlink_free);
 264                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 265                 return unlink;
 266         }
 267
 268         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 269
 270         return NULL;
 271 }
 272
 273
 274 static int stub_send_ret_unlink(struct stub_device *sdev)
 275 {
 276         unsigned long flags;
 277         struct stub_unlink *unlink, *tmp;
 278
 279         struct msghdr msg;
 280         struct kvec iov[1];
 281         size_t txsize;
 282
 283         size_t total_size = 0;
 284
 285         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 286                 int ret;
 287                 struct usbip_header pdu_header;
 288
 289                 txsize = 0;
 290                 memset(&pdu_header, 0, sizeof(pdu_header));
 291                 memset(&msg, 0, sizeof(msg));
 292                 memset(&iov, 0, sizeof(iov));
 293
 294                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 295
 296                 /* 1. setup usbip_header */
 297                 setup_ret_unlink_pdu(&pdu_header, unlink);
 298                 usbip_header_correct_endian(&pdu_header, 1);
 299
 300                 iov[0].iov_base = &pdu_header;
 301                 iov[0].iov_len  = sizeof(pdu_header);
 302                 txsize += sizeof(pdu_header);
 303
 304                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 305                                      1, txsize);
 306                 if (ret != txsize) {
 307                         dev_err(&sdev->interface->dev,
 308                                 "sendmsg failed!, retval %d for %zd\n",
 309                                 ret, txsize);
 310                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 311                         return -1;
 312                 }
 313
 314
 315                 usbip_dbg_stub_tx("send txdata\n");
 316
 317                 total_size += txsize;
 318         }
 319
 320
 321         spin_lock_irqsave(&sdev->priv_lock, flags);
 322
 323         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 324                 list_del(&unlink->list);
 325                 kfree(unlink);
 326         }
 327
 328         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 329
 330         return total_size;
 331 }
 332
 333
 334 /*-------------------------------------------------------------------------*/
 335
 336 void stub_tx_loop(struct usbip_task *ut)
 337 {
 338         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
 339         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 340
 341         while (1) {
 342                 if (signal_pending(current)) {
 343                         usbip_dbg_stub_tx("signal catched\n");
 344                         break;
 345                 }
 346
 347                 if (usbip_event_happened(ud))
 348                         break;
 349
 350                 /*
 351                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 352                  * looks at only priv_init queue. If the completion of a URB is
 353                  * earlier than the receive of CMD_UNLINK, priv is moved to
 354                  * priv_tx queue and stub_rx does not find the target priv. In
 355                  * this case, vhci_rx receives the result of the submit request
 356                  * and then receives the result of the unlink request. The
 357                  * result of the submit is given back to the usbcore as the
 358                  * completion of the unlink request. The request of the
 359                  * unlink is ignored. This is ok because a driver who calls
 360                  * usb_unlink_urb() understands the unlink was too late by
 361                  * getting the status of the given-backed URB which has the
 362                  * status of usb_submit_urb().
 363                  */
 364                 if (stub_send_ret_submit(sdev) < 0)
 365                         break;
 366
 367                 if (stub_send_ret_unlink(sdev) < 0)
 368                         break;
 369
 370                 wait_event_interruptible(sdev->tx_waitq,
 371                                 (!list_empty(&sdev->priv_tx) ||
 372                                  !list_empty(&sdev->unlink_tx)));
 373         }
 374 }