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         struct kvec iov[3];
 174         size_t txsize;
 175
 176         size_t total_size = 0;
 177
 178         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 179                 int ret;
 180                 struct urb *urb = priv->urb;
 181                 struct usbip_header pdu_header;
 182                 void *iso_buffer = NULL;
 183
 184                 txsize = 0;
 185                 memset(&pdu_header, 0, sizeof(pdu_header));
 186                 memset(&msg, 0, sizeof(msg));
 187                 memset(&iov, 0, sizeof(iov));
 188
 189                 usbip_dbg_stub_tx("setup txdata urb %p\n", urb);
 190
 191
 192                 /* 1. setup usbip_header */
 193                 setup_ret_submit_pdu(&pdu_header, urb);
 194                 usbip_header_correct_endian(&pdu_header, 1);
 195
 196                 iov[0].iov_base = &pdu_header;
 197                 iov[0].iov_len  = sizeof(pdu_header);
 198                 txsize += sizeof(pdu_header);
 199
 200                 /* 2. setup transfer buffer */
 201                 if (usb_pipein(urb->pipe) && urb->actual_length > 0) {
 202                         iov[1].iov_base = urb->transfer_buffer;
 203                         iov[1].iov_len  = urb->actual_length;
 204                         txsize += urb->actual_length;
 205                 }
 206
 207                 /* 3. setup iso_packet_descriptor */
 208                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 209                         ssize_t len = 0;
 210
 211                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 212                         if (!iso_buffer) {
 213                                 usbip_event_add(&sdev->ud,
 214                                                 SDEV_EVENT_ERROR_MALLOC);
 215                                 return -1;
 216                         }
 217
 218                         iov[2].iov_base = iso_buffer;
 219                         iov[2].iov_len  = len;
 220                         txsize += len;
 221                 }
 222
 223                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 224                                      3, txsize);
 225                 if (ret != txsize) {
 226                         dev_err(&sdev->interface->dev,
 227                                 "sendmsg failed!, retval %d for %zd\n",
 228                                 ret, txsize);
 229                         kfree(iso_buffer);
 230                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 231                         return -1;
 232                 }
 233
 234                 kfree(iso_buffer);
 235                 usbip_dbg_stub_tx("send txdata\n");
 236
 237                 total_size += txsize;
 238         }
 239
 240
 241         spin_lock_irqsave(&sdev->priv_lock, flags);
 242
 243         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 244                 stub_free_priv_and_urb(priv);
 245         }
 246
 247         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 248
 249         return total_size;
 250 }
 251
 252
 253 /*-------------------------------------------------------------------------*/
 254 /* send RET_UNLINK */
 255
 256 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 257 {
 258         unsigned long flags;
 259         struct stub_unlink *unlink, *tmp;
 260
 261         spin_lock_irqsave(&sdev->priv_lock, flags);
 262
 263         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 264                 list_move_tail(&unlink->list, &sdev->unlink_free);
 265                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 266                 return unlink;
 267         }
 268
 269         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 270
 271         return NULL;
 272 }
 273
 274
 275 static int stub_send_ret_unlink(struct stub_device *sdev)
 276 {
 277         unsigned long flags;
 278         struct stub_unlink *unlink, *tmp;
 279
 280         struct msghdr msg;
 281         struct kvec iov[1];
 282         size_t txsize;
 283
 284         size_t total_size = 0;
 285
 286         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 287                 int ret;
 288                 struct usbip_header pdu_header;
 289
 290                 txsize = 0;
 291                 memset(&pdu_header, 0, sizeof(pdu_header));
 292                 memset(&msg, 0, sizeof(msg));
 293                 memset(&iov, 0, sizeof(iov));
 294
 295                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 296
 297                 /* 1. setup usbip_header */
 298                 setup_ret_unlink_pdu(&pdu_header, unlink);
 299                 usbip_header_correct_endian(&pdu_header, 1);
 300
 301                 iov[0].iov_base = &pdu_header;
 302                 iov[0].iov_len  = sizeof(pdu_header);
 303                 txsize += sizeof(pdu_header);
 304
 305                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 306                                      1, txsize);
 307                 if (ret != txsize) {
 308                         dev_err(&sdev->interface->dev,
 309                                 "sendmsg failed!, retval %d for %zd\n",
 310                                 ret, txsize);
 311                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 312                         return -1;
 313                 }
 314
 315
 316                 usbip_dbg_stub_tx("send txdata\n");
 317
 318                 total_size += txsize;
 319         }
 320
 321
 322         spin_lock_irqsave(&sdev->priv_lock, flags);
 323
 324         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 325                 list_del(&unlink->list);
 326                 kfree(unlink);
 327         }
 328
 329         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 330
 331         return total_size;
 332 }
 333
 334
 335 /*-------------------------------------------------------------------------*/
 336
 337 int stub_tx_loop(void *data)
 338 {
 339         struct usbip_device *ud = data;
 340         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 341
 342         while (!kthread_should_stop()) {
 343                 if (usbip_event_happened(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                                  kthread_should_stop()));
 370         }
 371
 372         return 0;
 373 }