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         usbip_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                 usbip_uinfo("stopped by a call of usb_kill_urb() because of"
  78                                         "cleaning up a virtual connection\n");
  79                 return;
  80         case -ECONNRESET:
  81                 usbip_uinfo("unlinked by a call of usb_unlink_urb()\n");
  82                 break;
  83         case -EPIPE:
  84                 usbip_uinfo("endpoint %d is stalled\n",
  85                                                 usb_pipeendpoint(urb->pipe));
  86                 break;
  87         case -ESHUTDOWN:
  88                 usbip_uinfo("device removed?\n");
  89                 break;
  90         default:
  91                 usbip_uinfo("urb completion with non-zero status %d\n",
  92                                                         urb->status);
  93         }
  94
  95         /* link a urb to the queue of tx. */
  96         spin_lock_irqsave(&sdev->priv_lock, flags);
  97
  98         if (priv->unlinking) {
  99                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
 100                 stub_free_priv_and_urb(priv);
 101         } else
 102                 list_move_tail(&priv->list, &sdev->priv_tx);
 103
 104
 105         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 106
 107         /* wake up tx_thread */
 108         wake_up(&sdev->tx_waitq);
 109 }
 110
 111
 112 /*-------------------------------------------------------------------------*/
 113 /* fill PDU */
 114
 115 static inline void setup_base_pdu(struct usbip_header_basic *base,
 116                 __u32 command, __u32 seqnum)
 117 {
 118         base->command = command;
 119         base->seqnum  = seqnum;
 120         base->devid   = 0;
 121         base->ep      = 0;
 122         base->direction   = 0;
 123 }
 124
 125 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 126 {
 127         struct stub_priv *priv = (struct stub_priv *) urb->context;
 128
 129         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 130
 131         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 132 }
 133
 134 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 135                 struct stub_unlink *unlink)
 136 {
 137         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 138
 139         rpdu->u.ret_unlink.status = unlink->status;
 140 }
 141
 142
 143 /*-------------------------------------------------------------------------*/
 144 /* send RET_SUBMIT */
 145
 146 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 147 {
 148         unsigned long flags;
 149         struct stub_priv *priv, *tmp;
 150
 151         spin_lock_irqsave(&sdev->priv_lock, flags);
 152
 153         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 154                 list_move_tail(&priv->list, &sdev->priv_free);
 155                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 156                 return priv;
 157         }
 158
 159         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 160
 161         return NULL;
 162 }
 163
 164 static int stub_send_ret_submit(struct stub_device *sdev)
 165 {
 166         unsigned long flags;
 167         struct stub_priv *priv, *tmp;
 168
 169         struct msghdr msg;
 170         struct kvec iov[3];
 171         size_t txsize;
 172
 173         size_t total_size = 0;
 174
 175         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 176                 int ret;
 177                 struct urb *urb = priv->urb;
 178                 struct usbip_header pdu_header;
 179                 void *iso_buffer = NULL;
 180
 181                 txsize = 0;
 182                 memset(&pdu_header, 0, sizeof(pdu_header));
 183                 memset(&msg, 0, sizeof(msg));
 184                 memset(&iov, 0, sizeof(iov));
 185
 186                 usbip_dbg_stub_tx("setup txdata urb %p\n", urb);
 187
 188
 189                 /* 1. setup usbip_header */
 190                 setup_ret_submit_pdu(&pdu_header, urb);
 191                 usbip_header_correct_endian(&pdu_header, 1);
 192
 193                 iov[0].iov_base = &pdu_header;
 194                 iov[0].iov_len  = sizeof(pdu_header);
 195                 txsize += sizeof(pdu_header);
 196
 197                 /* 2. setup transfer buffer */
 198                 if (usb_pipein(urb->pipe) && urb->actual_length > 0) {
 199                         iov[1].iov_base = urb->transfer_buffer;
 200                         iov[1].iov_len  = urb->actual_length;
 201                         txsize += urb->actual_length;
 202                 }
 203
 204                 /* 3. setup iso_packet_descriptor */
 205                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 206                         ssize_t len = 0;
 207
 208                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 209                         if (!iso_buffer) {
 210                                 usbip_event_add(&sdev->ud,
 211                                                 SDEV_EVENT_ERROR_MALLOC);
 212                                 return -1;
 213                         }
 214
 215                         iov[2].iov_base = iso_buffer;
 216                         iov[2].iov_len  = len;
 217                         txsize += len;
 218                 }
 219
 220                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 221                                      3, txsize);
 222                 if (ret != txsize) {
 223                         dev_err(&sdev->interface->dev,
 224                                 "sendmsg failed!, retval %d for %zd\n",
 225                                 ret, txsize);
 226                         kfree(iso_buffer);
 227                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 228                         return -1;
 229                 }
 230
 231                 kfree(iso_buffer);
 232                 usbip_dbg_stub_tx("send txdata\n");
 233
 234                 total_size += txsize;
 235         }
 236
 237
 238         spin_lock_irqsave(&sdev->priv_lock, flags);
 239
 240         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 241                 stub_free_priv_and_urb(priv);
 242         }
 243
 244         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 245
 246         return total_size;
 247 }
 248
 249
 250 /*-------------------------------------------------------------------------*/
 251 /* send RET_UNLINK */
 252
 253 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 254 {
 255         unsigned long flags;
 256         struct stub_unlink *unlink, *tmp;
 257
 258         spin_lock_irqsave(&sdev->priv_lock, flags);
 259
 260         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 261                 list_move_tail(&unlink->list, &sdev->unlink_free);
 262                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 263                 return unlink;
 264         }
 265
 266         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 267
 268         return NULL;
 269 }
 270
 271
 272 static int stub_send_ret_unlink(struct stub_device *sdev)
 273 {
 274         unsigned long flags;
 275         struct stub_unlink *unlink, *tmp;
 276
 277         struct msghdr msg;
 278         struct kvec iov[1];
 279         size_t txsize;
 280
 281         size_t total_size = 0;
 282
 283         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 284                 int ret;
 285                 struct usbip_header pdu_header;
 286
 287                 txsize = 0;
 288                 memset(&pdu_header, 0, sizeof(pdu_header));
 289                 memset(&msg, 0, sizeof(msg));
 290                 memset(&iov, 0, sizeof(iov));
 291
 292                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 293
 294                 /* 1. setup usbip_header */
 295                 setup_ret_unlink_pdu(&pdu_header, unlink);
 296                 usbip_header_correct_endian(&pdu_header, 1);
 297
 298                 iov[0].iov_base = &pdu_header;
 299                 iov[0].iov_len  = sizeof(pdu_header);
 300                 txsize += sizeof(pdu_header);
 301
 302                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 303                                      1, txsize);
 304                 if (ret != txsize) {
 305                         dev_err(&sdev->interface->dev,
 306                                 "sendmsg failed!, retval %d for %zd\n",
 307                                 ret, txsize);
 308                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 309                         return -1;
 310                 }
 311
 312
 313                 usbip_dbg_stub_tx("send txdata\n");
 314
 315                 total_size += txsize;
 316         }
 317
 318
 319         spin_lock_irqsave(&sdev->priv_lock, flags);
 320
 321         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 322                 list_del(&unlink->list);
 323                 kfree(unlink);
 324         }
 325
 326         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 327
 328         return total_size;
 329 }
 330
 331
 332 /*-------------------------------------------------------------------------*/
 333
 334 void stub_tx_loop(struct usbip_task *ut)
 335 {
 336         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
 337         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 338
 339         while (1) {
 340                 if (signal_pending(current)) {
 341                         usbip_dbg_stub_tx("signal catched\n");
 342                         break;
 343                 }
 344
 345                 if (usbip_event_happened(ud))
 346                         break;
 347
 348                 /*
 349                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 350                  * looks at only priv_init queue. If the completion of a URB is
 351                  * earlier than the receive of CMD_UNLINK, priv is moved to
 352                  * priv_tx queue and stub_rx does not find the target priv. In
 353                  * this case, vhci_rx receives the result of the submit request
 354                  * and then receives the result of the unlink request. The
 355                  * result of the submit is given back to the usbcore as the
 356                  * completion of the unlink request. The request of the
 357                  * unlink is ignored. This is ok because a driver who calls
 358                  * usb_unlink_urb() understands the unlink was too late by
 359                  * getting the status of the given-backed URB which has the
 360                  * status of usb_submit_urb().
 361                  */
 362                 if (stub_send_ret_submit(sdev) < 0)
 363                         break;
 364
 365                 if (stub_send_ret_unlink(sdev) < 0)
 366                         break;
 367
 368                 wait_event_interruptible(sdev->tx_waitq,
 369                                 (!list_empty(&sdev->priv_tx) ||
 370                                  !list_empty(&sdev->unlink_tx)));
 371         }
 372 }