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  * @regs:
  58  *
  59  * When a urb has completed, the USB core driver calls this function mostly in
  60  * the interrupt context. To return the result of a urb, the completed urb is
  61  * linked to the pending list of returning.
  62  *
  63  */
  64 void stub_complete(struct urb *urb)
  65 {
  66         struct stub_priv *priv = (struct stub_priv *) urb->context;
  67         struct stub_device *sdev = priv->sdev;
  68         unsigned long flags;
  69
  70         dbg_stub_tx("complete! status %d\n", urb->status);
  71
  72
  73         switch (urb->status) {
  74         case 0:
  75                 /* OK */
  76                 break;
  77         case -ENOENT:
  78                 uinfo("stopped by a call of usb_kill_urb() because of"
  79                                         "cleaning up a virtual connection\n");
  80                 return;
  81         case -ECONNRESET:
  82                 uinfo("unlinked by a call of usb_unlink_urb()\n");
  83                 break;
  84         case -EPIPE:
  85                 uinfo("endpoint %d is stalled\n", usb_pipeendpoint(urb->pipe));
  86                 break;
  87         case -ESHUTDOWN:
  88                 uinfo("device removed?\n");
  89                 break;
  90         default:
  91                 uinfo("urb completion with non-zero status %d\n", urb->status);
  92         }
  93
  94         /* link a urb to the queue of tx. */
  95         spin_lock_irqsave(&sdev->priv_lock, flags);
  96
  97         if (priv->unlinking) {
  98                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
  99                 stub_free_priv_and_urb(priv);
 100         } else
 101                 list_move_tail(&priv->list, &sdev->priv_tx);
 102
 103
 104         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 105
 106         /* wake up tx_thread */
 107         wake_up(&sdev->tx_waitq);
 108 }
 109
 110
 111 /*-------------------------------------------------------------------------*/
 112 /* fill PDU */
 113
 114 static inline void setup_base_pdu(struct usbip_header_basic *base,
 115                 __u32 command, __u32 seqnum)
 116 {
 117         base->command = command;
 118         base->seqnum  = seqnum;
 119         base->devid   = 0;
 120         base->ep      = 0;
 121         base->direction   = 0;
 122 }
 123
 124 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 125 {
 126         struct stub_priv *priv = (struct stub_priv *) urb->context;
 127
 128         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 129
 130         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 131 }
 132
 133 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 134                 struct stub_unlink *unlink)
 135 {
 136         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 137
 138         rpdu->u.ret_unlink.status = unlink->status;
 139 }
 140
 141
 142 /*-------------------------------------------------------------------------*/
 143 /* send RET_SUBMIT */
 144
 145 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 146 {
 147         unsigned long flags;
 148         struct stub_priv *priv, *tmp;
 149
 150         spin_lock_irqsave(&sdev->priv_lock, flags);
 151
 152         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 153                 list_move_tail(&priv->list, &sdev->priv_free);
 154                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 155                 return priv;
 156         }
 157
 158         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 159
 160         return NULL;
 161 }
 162
 163 static int stub_send_ret_submit(struct stub_device *sdev)
 164 {
 165         unsigned long flags;
 166         struct stub_priv *priv, *tmp;
 167
 168         struct msghdr msg;
 169         struct kvec iov[3];
 170         size_t txsize;
 171
 172         size_t total_size = 0;
 173
 174         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 175                 int ret;
 176                 struct urb *urb = priv->urb;
 177                 struct usbip_header pdu_header;
 178                 void *iso_buffer = NULL;
 179
 180                 txsize = 0;
 181                 memset(&pdu_header, 0, sizeof(pdu_header));
 182                 memset(&msg, 0, sizeof(msg));
 183                 memset(&iov, 0, sizeof(iov));
 184
 185                 dbg_stub_tx("setup txdata urb %p\n", urb);
 186
 187
 188                 /* 1. setup usbip_header */
 189                 setup_ret_submit_pdu(&pdu_header, urb);
 190                 usbip_header_correct_endian(&pdu_header, 1);
 191
 192                 iov[0].iov_base = &pdu_header;
 193                 iov[0].iov_len  = sizeof(pdu_header);
 194                 txsize += sizeof(pdu_header);
 195
 196                 /* 2. setup transfer buffer */
 197                 if (usb_pipein(urb->pipe) && urb->actual_length > 0) {
 198                         iov[1].iov_base = urb->transfer_buffer;
 199                         iov[1].iov_len  = urb->actual_length;
 200                         txsize += urb->actual_length;
 201                 }
 202
 203                 /* 3. setup iso_packet_descriptor */
 204                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 205                         ssize_t len = 0;
 206
 207                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 208                         if (!iso_buffer) {
 209                                 usbip_event_add(&sdev->ud,
 210                                                 SDEV_EVENT_ERROR_MALLOC);
 211                                 return -1;
 212                         }
 213
 214                         iov[2].iov_base = iso_buffer;
 215                         iov[2].iov_len  = len;
 216                         txsize += len;
 217                 }
 218
 219                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 220                                      3, txsize);
 221                 if (ret != txsize) {
 222                         dev_err(&sdev->interface->dev,
 223                                 "sendmsg failed!, retval %d for %zd\n",
 224                                 ret, txsize);
 225                         kfree(iso_buffer);
 226                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 227                         return -1;
 228                 }
 229
 230                 kfree(iso_buffer);
 231                 dbg_stub_tx("send txdata\n");
 232
 233                 total_size += txsize;
 234         }
 235
 236
 237         spin_lock_irqsave(&sdev->priv_lock, flags);
 238
 239         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 240                 stub_free_priv_and_urb(priv);
 241         }
 242
 243         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 244
 245         return total_size;
 246 }
 247
 248
 249 /*-------------------------------------------------------------------------*/
 250 /* send RET_UNLINK */
 251
 252 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 253 {
 254         unsigned long flags;
 255         struct stub_unlink *unlink, *tmp;
 256
 257         spin_lock_irqsave(&sdev->priv_lock, flags);
 258
 259         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 260                 list_move_tail(&unlink->list, &sdev->unlink_free);
 261                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 262                 return unlink;
 263         }
 264
 265         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 266
 267         return NULL;
 268 }
 269
 270
 271 static int stub_send_ret_unlink(struct stub_device *sdev)
 272 {
 273         unsigned long flags;
 274         struct stub_unlink *unlink, *tmp;
 275
 276         struct msghdr msg;
 277         struct kvec iov[1];
 278         size_t txsize;
 279
 280         size_t total_size = 0;
 281
 282         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 283                 int ret;
 284                 struct usbip_header pdu_header;
 285
 286                 txsize = 0;
 287                 memset(&pdu_header, 0, sizeof(pdu_header));
 288                 memset(&msg, 0, sizeof(msg));
 289                 memset(&iov, 0, sizeof(iov));
 290
 291                 dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 292
 293                 /* 1. setup usbip_header */
 294                 setup_ret_unlink_pdu(&pdu_header, unlink);
 295                 usbip_header_correct_endian(&pdu_header, 1);
 296
 297                 iov[0].iov_base = &pdu_header;
 298                 iov[0].iov_len  = sizeof(pdu_header);
 299                 txsize += sizeof(pdu_header);
 300
 301                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 302                                      1, txsize);
 303                 if (ret != txsize) {
 304                         dev_err(&sdev->interface->dev,
 305                                 "sendmsg failed!, retval %d for %zd\n",
 306                                 ret, txsize);
 307                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 308                         return -1;
 309                 }
 310
 311
 312                 dbg_stub_tx("send txdata\n");
 313
 314                 total_size += txsize;
 315         }
 316
 317
 318         spin_lock_irqsave(&sdev->priv_lock, flags);
 319
 320         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 321                 list_del(&unlink->list);
 322                 kfree(unlink);
 323         }
 324
 325         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 326
 327         return total_size;
 328 }
 329
 330
 331 /*-------------------------------------------------------------------------*/
 332
 333 void stub_tx_loop(struct usbip_task *ut)
 334 {
 335         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
 336         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 337
 338         while (1) {
 339                 if (signal_pending(current)) {
 340                         dbg_stub_tx("signal catched\n");
 341                         break;
 342                 }
 343
 344                 if (usbip_event_happend(ud))
 345                         break;
 346
 347                 /*
 348                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 349                  * looks at only priv_init queue. If the completion of a URB is
 350                  * earlier than the receive of CMD_UNLINK, priv is moved to
 351                  * priv_tx queue and stub_rx does not find the target priv. In
 352                  * this case, vhci_rx receives the result of the submit request
 353                  * and then receives the result of the unlink request. The
 354                  * result of the submit is given back to the usbcore as the
 355                  * completion of the unlink request. The request of the
 356                  * unlink is ignored. This is ok because a driver who calls
 357                  * usb_unlink_urb() understands the unlink was too late by
 358                  * getting the status of the given-backed URB which has the
 359                  * status of usb_submit_urb().
 360                  */
 361                 if (stub_send_ret_submit(sdev) < 0)
 362                         break;
 363
 364                 if (stub_send_ret_unlink(sdev) < 0)
 365                         break;
 366
 367                 wait_event_interruptible(sdev->tx_waitq,
 368                                 (!list_empty(&sdev->priv_tx) ||
 369                                  !list_empty(&sdev->unlink_tx)));
 370         }
 371 }