release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/staging/usbip/vhci_rx.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 "vhci.h"
  24
  25
  26 /* get URB from transmitted urb queue */
  27 static struct urb *pickup_urb_and_free_priv(struct vhci_device *vdev,
  28                                             __u32 seqnum)
  29 {
  30         struct vhci_priv *priv, *tmp;
  31         struct urb *urb = NULL;
  32         int status;
  33
  34         spin_lock(&vdev->priv_lock);
  35
  36         list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
  37                 if (priv->seqnum == seqnum) {
  38                         urb = priv->urb;
  39                         status = urb->status;
  40
  41                         usbip_dbg_vhci_rx("find urb %p vurb %p seqnum %u\n",
  42                                     urb, priv, seqnum);
  43
  44                         /* TODO: fix logic here to improve indent situtation */
  45                         if (status != -EINPROGRESS) {
  46                                 if (status == -ENOENT ||
  47                                      status == -ECONNRESET)
  48                                         dev_info(&urb->dev->dev,
  49                                                  "urb %p was unlinked "
  50                                                  "%ssynchronuously.\n", urb,
  51                                                  status == -ENOENT ? "" : "a");
  52                                 else
  53                                         dev_info(&urb->dev->dev,
  54                                                  "urb %p may be in a error, "
  55                                                  "status %d\n", urb, status);
  56                         }
  57
  58                         list_del(&priv->list);
  59                         kfree(priv);
  60                         urb->hcpriv = NULL;
  61
  62                         break;
  63                 }
  64         }
  65
  66         spin_unlock(&vdev->priv_lock);
  67
  68         return urb;
  69 }
  70
  71 static void vhci_recv_ret_submit(struct vhci_device *vdev,
  72                                                 struct usbip_header *pdu)
  73 {
  74         struct usbip_device *ud = &vdev->ud;
  75         struct urb *urb;
  76
  77
  78         urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
  79
  80
  81         if (!urb) {
  82                 usbip_uerr("cannot find a urb of seqnum %u\n",
  83                                                         pdu->base.seqnum);
  84                 usbip_uinfo("max seqnum %d\n",
  85                                         atomic_read(&the_controller->seqnum));
  86                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
  87                 return;
  88         }
  89
  90
  91         /* unpack the pdu to a urb */
  92         usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
  93
  94
  95         /* recv transfer buffer */
  96         if (usbip_recv_xbuff(ud, urb) < 0)
  97                 return;
  98
  99
 100         /* recv iso_packet_descriptor */
 101         if (usbip_recv_iso(ud, urb) < 0)
 102                 return;
 103
 104
 105         if (usbip_dbg_flag_vhci_rx)
 106                 usbip_dump_urb(urb);
 107
 108
 109         usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 110
 111         spin_lock(&the_controller->lock);
 112         usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 113         spin_unlock(&the_controller->lock);
 114
 115         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 116
 117
 118         usbip_dbg_vhci_rx("Leave\n");
 119
 120         return;
 121 }
 122
 123
 124 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
 125                 struct usbip_header *pdu)
 126 {
 127         struct vhci_unlink *unlink, *tmp;
 128
 129         spin_lock(&vdev->priv_lock);
 130
 131         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 132                 usbip_uinfo("unlink->seqnum %lu\n", unlink->seqnum);
 133                 if (unlink->seqnum == pdu->base.seqnum) {
 134                         usbip_dbg_vhci_rx("found pending unlink, %lu\n",
 135                                                         unlink->seqnum);
 136                         list_del(&unlink->list);
 137
 138                         spin_unlock(&vdev->priv_lock);
 139                         return unlink;
 140                 }
 141         }
 142
 143         spin_unlock(&vdev->priv_lock);
 144
 145         return NULL;
 146 }
 147
 148
 149 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 150                                                 struct usbip_header *pdu)
 151 {
 152         struct vhci_unlink *unlink;
 153         struct urb *urb;
 154
 155         usbip_dump_header(pdu);
 156
 157         unlink = dequeue_pending_unlink(vdev, pdu);
 158         if (!unlink) {
 159                 usbip_uinfo("cannot find the pending unlink %u\n",
 160                                                         pdu->base.seqnum);
 161                 return;
 162         }
 163
 164         urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 165         if (!urb) {
 166                 /*
 167                  * I get the result of a unlink request. But, it seems that I
 168                  * already received the result of its submit result and gave
 169                  * back the URB.
 170                  */
 171                 usbip_uinfo("the urb (seqnum %d) was already given backed\n",
 172                                                         pdu->base.seqnum);
 173         } else {
 174                 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 175
 176                 /* If unlink is succeed, status is -ECONNRESET */
 177                 urb->status = pdu->u.ret_unlink.status;
 178                 usbip_uinfo("%d\n", urb->status);
 179
 180                 spin_lock(&the_controller->lock);
 181                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 182                 spin_unlock(&the_controller->lock);
 183
 184                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 185                                                                 urb->status);
 186         }
 187
 188         kfree(unlink);
 189
 190         return;
 191 }
 192
 193 /* recv a pdu */
 194 static void vhci_rx_pdu(struct usbip_device *ud)
 195 {
 196         int ret;
 197         struct usbip_header pdu;
 198         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 199
 200
 201         usbip_dbg_vhci_rx("Enter\n");
 202
 203         memset(&pdu, 0, sizeof(pdu));
 204
 205
 206         /* 1. receive a pdu header */
 207         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 208         if (ret != sizeof(pdu)) {
 209                 usbip_uerr("receiving pdu failed! size is %d, should be %d\n",
 210                                         ret, (unsigned int)sizeof(pdu));
 211                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 212                 return;
 213         }
 214
 215         usbip_header_correct_endian(&pdu, 0);
 216
 217         if (usbip_dbg_flag_vhci_rx)
 218                 usbip_dump_header(&pdu);
 219
 220         switch (pdu.base.command) {
 221         case USBIP_RET_SUBMIT:
 222                 vhci_recv_ret_submit(vdev, &pdu);
 223                 break;
 224         case USBIP_RET_UNLINK:
 225                 vhci_recv_ret_unlink(vdev, &pdu);
 226                 break;
 227         default:
 228                 /* NOTREACHED */
 229                 usbip_uerr("unknown pdu %u\n", pdu.base.command);
 230                 usbip_dump_header(&pdu);
 231                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 232         }
 233 }
 234
 235
 236 /*-------------------------------------------------------------------------*/
 237
 238 void vhci_rx_loop(struct usbip_task *ut)
 239 {
 240         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);
 241
 242
 243         while (1) {
 244                 if (signal_pending(current)) {
 245                         usbip_dbg_vhci_rx("signal catched!\n");
 246                         break;
 247                 }
 248
 249
 250                 if (usbip_event_happened(ud))
 251                         break;
 252
 253                 vhci_rx_pdu(ud);
 254         }
 255 }