drivers/usb/wusbcore/wa-rpipe.c

   1 /*
   2  * WUSB Wire Adapter
   3  * rpipe management
   4  *
   5  * Copyright (C) 2005-2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301, USA.
  21  *
  22  *
  23  * FIXME: docs
  24  *
  25  * RPIPE
  26  *
  27  *   Targetted at different downstream endpoints
  28  *
  29  *   Descriptor: use to config the remote pipe.
  30  *
  31  *   The number of blocks could be dynamic (wBlocks in descriptor is
  32  *   0)--need to schedule them then.
  33  *
  34  * Each bit in wa->rpipe_bm represents if an rpipe is being used or
  35  * not. Rpipes are represented with a 'struct wa_rpipe' that is
  36  * attached to the hcpriv member of a 'struct usb_host_endpoint'.
  37  *
  38  * When you need to xfer data to an endpoint, you get an rpipe for it
  39  * with wa_ep_rpipe_get(), which gives you a reference to the rpipe
  40  * and keeps a single one (the first one) with the endpoint. When you
  41  * are done transferring, you drop that reference. At the end the
  42  * rpipe is always allocated and bound to the endpoint. There it might
  43  * be recycled when not used.
  44  *
  45  * Addresses:
  46  *
  47  *  We use a 1:1 mapping mechanism between port address (0 based
  48  *  index, actually) and the address. The USB stack knows about this.
  49  *
  50  *  USB Stack port number    4 (1 based)
  51  *  WUSB code port index     3 (0 based)
  52  *  USB Addresss             5 (2 based -- 0 is for default, 1 for root hub)
  53  *
  54  *  Now, because we don't use the concept as default address exactly
  55  *  like the (wired) USB code does, we need to kind of skip it. So we
  56  *  never take addresses from the urb->pipe, but from the
  57  *  urb->dev->devnum, to make sure that we always have the right
  58  *  destination address.
  59  */
  60 #include <linux/init.h>
  61 #include <asm/atomic.h>
  62 #include <linux/bitmap.h>
  63
  64 #include "wusbhc.h"
  65 #include "wa-hc.h"
  66
  67 static int __rpipe_get_descr(struct wahc *wa,
  68                              struct usb_rpipe_descriptor *descr, u16 index)
  69 {
  70         ssize_t result;
  71         struct device *dev = &wa->usb_iface->dev;
  72
  73         /* Get the RPIPE descriptor -- we cannot use the usb_get_descriptor()
  74          * function because the arguments are different.
  75          */
  76         result = usb_control_msg(
  77                 wa->usb_dev, usb_rcvctrlpipe(wa->usb_dev, 0),
  78                 USB_REQ_GET_DESCRIPTOR,
  79                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_RPIPE,
  80                 USB_DT_RPIPE<<8, index, descr, sizeof(*descr),
  81                 1000 /* FIXME: arbitrary */);
  82         if (result < 0) {
  83                 dev_err(dev, "rpipe %u: get descriptor failed: %d\n",
  84                         index, (int)result);
  85                 goto error;
  86         }
  87         if (result < sizeof(*descr)) {
  88                 dev_err(dev, "rpipe %u: got short descriptor "
  89                         "(%zd vs %zd bytes needed)\n",
  90                         index, result, sizeof(*descr));
  91                 result = -EINVAL;
  92                 goto error;
  93         }
  94         result = 0;
  95
  96 error:
  97         return result;
  98 }
  99
 100 /*
 101  *
 102  * The descriptor is assumed to be properly initialized (ie: you got
 103  * it through __rpipe_get_descr()).
 104  */
 105 static int __rpipe_set_descr(struct wahc *wa,
 106                              struct usb_rpipe_descriptor *descr, u16 index)
 107 {
 108         ssize_t result;
 109         struct device *dev = &wa->usb_iface->dev;
 110
 111         /* we cannot use the usb_get_descriptor() function because the
 112          * arguments are different.
 113          */
 114         result = usb_control_msg(
 115                 wa->usb_dev, usb_sndctrlpipe(wa->usb_dev, 0),
 116                 USB_REQ_SET_DESCRIPTOR,
 117                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_RPIPE,
 118                 USB_DT_RPIPE<<8, index, descr, sizeof(*descr),
 119                 HZ / 10);
 120         if (result < 0) {
 121                 dev_err(dev, "rpipe %u: set descriptor failed: %d\n",
 122                         index, (int)result);
 123                 goto error;
 124         }
 125         if (result < sizeof(*descr)) {
 126                 dev_err(dev, "rpipe %u: sent short descriptor "
 127                         "(%zd vs %zd bytes required)\n",
 128                         index, result, sizeof(*descr));
 129                 result = -EINVAL;
 130                 goto error;
 131         }
 132         result = 0;
 133
 134 error:
 135         return result;
 136
 137 }
 138
 139 static void rpipe_init(struct wa_rpipe *rpipe)
 140 {
 141         kref_init(&rpipe->refcnt);
 142         spin_lock_init(&rpipe->seg_lock);
 143         INIT_LIST_HEAD(&rpipe->seg_list);
 144 }
 145
 146 static unsigned rpipe_get_idx(struct wahc *wa, unsigned rpipe_idx)
 147 {
 148         unsigned long flags;
 149
 150         spin_lock_irqsave(&wa->rpipe_bm_lock, flags);
 151         rpipe_idx = find_next_zero_bit(wa->rpipe_bm, wa->rpipes, rpipe_idx);
 152         if (rpipe_idx < wa->rpipes)
 153                 set_bit(rpipe_idx, wa->rpipe_bm);
 154         spin_unlock_irqrestore(&wa->rpipe_bm_lock, flags);
 155
 156         return rpipe_idx;
 157 }
 158
 159 static void rpipe_put_idx(struct wahc *wa, unsigned rpipe_idx)
 160 {
 161         unsigned long flags;
 162
 163         spin_lock_irqsave(&wa->rpipe_bm_lock, flags);
 164         clear_bit(rpipe_idx, wa->rpipe_bm);
 165         spin_unlock_irqrestore(&wa->rpipe_bm_lock, flags);
 166 }
 167
 168 void rpipe_destroy(struct kref *_rpipe)
 169 {
 170         struct wa_rpipe *rpipe = container_of(_rpipe, struct wa_rpipe, refcnt);
 171         u8 index = le16_to_cpu(rpipe->descr.wRPipeIndex);
 172
 173         if (rpipe->ep)
 174                 rpipe->ep->hcpriv = NULL;
 175         rpipe_put_idx(rpipe->wa, index);
 176         wa_put(rpipe->wa);
 177         kfree(rpipe);
 178 }
 179 EXPORT_SYMBOL_GPL(rpipe_destroy);
 180
 181 /*
 182  * Locate an idle rpipe, create an structure for it and return it
 183  *
 184  * @wa    is referenced and unlocked
 185  * @crs   enum rpipe_attr, required endpoint characteristics
 186  *
 187  * The rpipe can be used only sequentially (not in parallel).
 188  *
 189  * The rpipe is moved into the "ready" state.
 190  */
 191 static int rpipe_get_idle(struct wa_rpipe **prpipe, struct wahc *wa, u8 crs,
 192                           gfp_t gfp)
 193 {
 194         int result;
 195         unsigned rpipe_idx;
 196         struct wa_rpipe *rpipe;
 197         struct device *dev = &wa->usb_iface->dev;
 198
 199         rpipe = kzalloc(sizeof(*rpipe), gfp);
 200         if (rpipe == NULL)
 201                 return -ENOMEM;
 202         rpipe_init(rpipe);
 203
 204         /* Look for an idle pipe */
 205         for (rpipe_idx = 0; rpipe_idx < wa->rpipes; rpipe_idx++) {
 206                 rpipe_idx = rpipe_get_idx(wa, rpipe_idx);
 207                 if (rpipe_idx >= wa->rpipes)    /* no more pipes :( */
 208                         break;
 209                 result =  __rpipe_get_descr(wa, &rpipe->descr, rpipe_idx);
 210                 if (result < 0)
 211                         dev_err(dev, "Can't get descriptor for rpipe %u: %d\n",
 212                                 rpipe_idx, result);
 213                 else if ((rpipe->descr.bmCharacteristics & crs) != 0)
 214                         goto found;
 215                 rpipe_put_idx(wa, rpipe_idx);
 216         }
 217         *prpipe = NULL;
 218         kfree(rpipe);
 219         return -ENXIO;
 220
 221 found:
 222         set_bit(rpipe_idx, wa->rpipe_bm);
 223         rpipe->wa = wa_get(wa);
 224         *prpipe = rpipe;
 225         return 0;
 226 }
 227
 228 static int __rpipe_reset(struct wahc *wa, unsigned index)
 229 {
 230         int result;
 231         struct device *dev = &wa->usb_iface->dev;
 232
 233         result = usb_control_msg(
 234                 wa->usb_dev, usb_sndctrlpipe(wa->usb_dev, 0),
 235                 USB_REQ_RPIPE_RESET,
 236                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_RPIPE,
 237                 0, index, NULL, 0, 1000 /* FIXME: arbitrary */);
 238         if (result < 0)
 239                 dev_err(dev, "rpipe %u: reset failed: %d\n",
 240                         index, result);
 241         return result;
 242 }
 243
 244 /*
 245  * Fake companion descriptor for ep0
 246  *
 247  * See WUSB1.0[7.4.4], most of this is zero for bulk/int/ctl
 248  */
 249 static struct usb_wireless_ep_comp_descriptor epc0 = {
 250         .bLength = sizeof(epc0),
 251         .bDescriptorType = USB_DT_WIRELESS_ENDPOINT_COMP,
 252 /*      .bMaxBurst = 1, */
 253         .bMaxSequence = 31,
 254 };
 255
 256 /*
 257  * Look for EP companion descriptor
 258  *
 259  * Get there, look for Inara in the endpoint's extra descriptors
 260  */
 261 static struct usb_wireless_ep_comp_descriptor *rpipe_epc_find(
 262                 struct device *dev, struct usb_host_endpoint *ep)
 263 {
 264         void *itr;
 265         size_t itr_size;
 266         struct usb_descriptor_header *hdr;
 267         struct usb_wireless_ep_comp_descriptor *epcd;
 268
 269         if (ep->desc.bEndpointAddress == 0) {
 270                 epcd = &epc0;
 271                 goto out;
 272         }
 273         itr = ep->extra;
 274         itr_size = ep->extralen;
 275         epcd = NULL;
 276         while (itr_size > 0) {
 277                 if (itr_size < sizeof(*hdr)) {
 278                         dev_err(dev, "HW Bug? ep 0x%02x: extra descriptors "
 279                                 "at offset %zu: only %zu bytes left\n",
 280                                 ep->desc.bEndpointAddress,
 281                                 itr - (void *) ep->extra, itr_size);
 282                         break;
 283                 }
 284                 hdr = itr;
 285                 if (hdr->bDescriptorType == USB_DT_WIRELESS_ENDPOINT_COMP) {
 286                         epcd = itr;
 287                         break;
 288                 }
 289                 if (hdr->bLength > itr_size) {
 290                         dev_err(dev, "HW Bug? ep 0x%02x: extra descriptor "
 291                                 "at offset %zu (type 0x%02x) "
 292                                 "length %d but only %zu bytes left\n",
 293                                 ep->desc.bEndpointAddress,
 294                                 itr - (void *) ep->extra, hdr->bDescriptorType,
 295                                 hdr->bLength, itr_size);
 296                         break;
 297                 }
 298                 itr += hdr->bLength;
 299                 itr_size -= hdr->bDescriptorType;
 300         }
 301 out:
 302         return epcd;
 303 }
 304
 305 /*
 306  * Aim an rpipe to its device & endpoint destination
 307  *
 308  * Make sure we change the address to unauthenticathed if the device
 309  * is WUSB and it is not authenticated.
 310  */
 311 static int rpipe_aim(struct wa_rpipe *rpipe, struct wahc *wa,
 312                      struct usb_host_endpoint *ep, struct urb *urb, gfp_t gfp)
 313 {
 314         int result = -ENOMSG;   /* better code for lack of companion? */
 315         struct device *dev = &wa->usb_iface->dev;
 316         struct usb_device *usb_dev = urb->dev;
 317         struct usb_wireless_ep_comp_descriptor *epcd;
 318         u8 unauth;
 319
 320         epcd = rpipe_epc_find(dev, ep);
 321         if (epcd == NULL) {
 322                 dev_err(dev, "ep 0x%02x: can't find companion descriptor\n",
 323                         ep->desc.bEndpointAddress);
 324                 goto error;
 325         }
 326         unauth = usb_dev->wusb && !usb_dev->authenticated ? 0x80 : 0;
 327         __rpipe_reset(wa, le16_to_cpu(rpipe->descr.wRPipeIndex));
 328         atomic_set(&rpipe->segs_available, le16_to_cpu(rpipe->descr.wRequests));
 329         /* FIXME: block allocation system; request with queuing and timeout */
 330         /* FIXME: compute so seg_size > ep->maxpktsize */
 331         rpipe->descr.wBlocks = cpu_to_le16(16);         /* given */
 332         /* ep0 maxpktsize is 0x200 (WUSB1.0[4.8.1]) */
 333         rpipe->descr.wMaxPacketSize = cpu_to_le16(ep->desc.wMaxPacketSize);
 334         rpipe->descr.bHSHubAddress = 0;                 /* reserved: zero */
 335         rpipe->descr.bHSHubPort = wusb_port_no_to_idx(urb->dev->portnum);
 336         /* FIXME: use maximum speed as supported or recommended by device */
 337         rpipe->descr.bSpeed = usb_pipeendpoint(urb->pipe) == 0 ?
 338                 UWB_PHY_RATE_53 : UWB_PHY_RATE_200;
 339
 340         dev_dbg(dev, "addr %u (0x%02x) rpipe #%u ep# %u speed %d\n",
 341                 urb->dev->devnum, urb->dev->devnum | unauth,
 342                 le16_to_cpu(rpipe->descr.wRPipeIndex),
 343                 usb_pipeendpoint(urb->pipe), rpipe->descr.bSpeed);
 344
 345         /* see security.c:wusb_update_address() */
 346         if (unlikely(urb->dev->devnum == 0x80))
 347                 rpipe->descr.bDeviceAddress = 0;
 348         else
 349                 rpipe->descr.bDeviceAddress = urb->dev->devnum | unauth;
 350         rpipe->descr.bEndpointAddress = ep->desc.bEndpointAddress;
 351         /* FIXME: bDataSequence */
 352         rpipe->descr.bDataSequence = 0;
 353         /* FIXME: dwCurrentWindow */
 354         rpipe->descr.dwCurrentWindow = cpu_to_le32(1);
 355         /* FIXME: bMaxDataSequence */
 356         rpipe->descr.bMaxDataSequence = epcd->bMaxSequence - 1;
 357         rpipe->descr.bInterval = ep->desc.bInterval;
 358         /* FIXME: bOverTheAirInterval */
 359         rpipe->descr.bOverTheAirInterval = 0;   /* 0 if not isoc */
 360         /* FIXME: xmit power & preamble blah blah */
 361         rpipe->descr.bmAttribute = ep->desc.bmAttributes & 0x03;
 362         /* rpipe->descr.bmCharacteristics RO */
 363         /* FIXME: bmRetryOptions */
 364         rpipe->descr.bmRetryOptions = 15;
 365         /* FIXME: use for assessing link quality? */
 366         rpipe->descr.wNumTransactionErrors = 0;
 367         result = __rpipe_set_descr(wa, &rpipe->descr,
 368                                    le16_to_cpu(rpipe->descr.wRPipeIndex));
 369         if (result < 0) {
 370                 dev_err(dev, "Cannot aim rpipe: %d\n", result);
 371                 goto error;
 372         }
 373         result = 0;
 374 error:
 375         return result;
 376 }
 377
 378 /*
 379  * Check an aimed rpipe to make sure it points to where we want
 380  *
 381  * We use bit 19 of the Linux USB pipe bitmap for unauth vs auth
 382  * space; when it is like that, we or 0x80 to make an unauth address.
 383  */
 384 static int rpipe_check_aim(const struct wa_rpipe *rpipe, const struct wahc *wa,
 385                            const struct usb_host_endpoint *ep,
 386                            const struct urb *urb, gfp_t gfp)
 387 {
 388         int result = 0;         /* better code for lack of companion? */
 389         struct device *dev = &wa->usb_iface->dev;
 390         struct usb_device *usb_dev = urb->dev;
 391         u8 unauth = (usb_dev->wusb && !usb_dev->authenticated) ? 0x80 : 0;
 392         u8 portnum = wusb_port_no_to_idx(urb->dev->portnum);
 393
 394 #define AIM_CHECK(rdf, val, text)                                       \
 395         do {                                                            \
 396                 if (rpipe->descr.rdf != (val)) {                        \
 397                         dev_err(dev,                                    \
 398                                 "rpipe aim discrepancy: " #rdf " " text "\n", \
 399                                 rpipe->descr.rdf, (val));               \
 400                         result = -EINVAL;                               \
 401                         WARN_ON(1);                                     \
 402                 }                                                       \
 403         } while (0)
 404         AIM_CHECK(wMaxPacketSize, cpu_to_le16(ep->desc.wMaxPacketSize),
 405                   "(%u vs %u)");
 406         AIM_CHECK(bHSHubPort, portnum, "(%u vs %u)");
 407         AIM_CHECK(bSpeed, usb_pipeendpoint(urb->pipe) == 0 ?
 408                         UWB_PHY_RATE_53 : UWB_PHY_RATE_200,
 409                   "(%u vs %u)");
 410         AIM_CHECK(bDeviceAddress, urb->dev->devnum | unauth, "(%u vs %u)");
 411         AIM_CHECK(bEndpointAddress, ep->desc.bEndpointAddress, "(%u vs %u)");
 412         AIM_CHECK(bInterval, ep->desc.bInterval, "(%u vs %u)");
 413         AIM_CHECK(bmAttribute, ep->desc.bmAttributes & 0x03, "(%u vs %u)");
 414 #undef AIM_CHECK
 415         return result;
 416 }
 417
 418 #ifndef CONFIG_BUG
 419 #define CONFIG_BUG 0
 420 #endif
 421
 422 /*
 423  * Make sure there is an rpipe allocated for an endpoint
 424  *
 425  * If already allocated, we just refcount it; if not, we get an
 426  * idle one, aim it to the right location and take it.
 427  *
 428  * Attaches to ep->hcpriv and rpipe->ep to ep.
 429  */
 430 int rpipe_get_by_ep(struct wahc *wa, struct usb_host_endpoint *ep,
 431                     struct urb *urb, gfp_t gfp)
 432 {
 433         int result = 0;
 434         struct device *dev = &wa->usb_iface->dev;
 435         struct wa_rpipe *rpipe;
 436         u8 eptype;
 437
 438         mutex_lock(&wa->rpipe_mutex);
 439         rpipe = ep->hcpriv;
 440         if (rpipe != NULL) {
 441                 if (CONFIG_BUG == 1) {
 442                         result = rpipe_check_aim(rpipe, wa, ep, urb, gfp);
 443                         if (result < 0)
 444                                 goto error;
 445                 }
 446                 __rpipe_get(rpipe);
 447                 dev_dbg(dev, "ep 0x%02x: reusing rpipe %u\n",
 448                         ep->desc.bEndpointAddress,
 449                         le16_to_cpu(rpipe->descr.wRPipeIndex));
 450         } else {
 451                 /* hmm, assign idle rpipe, aim it */
 452                 result = -ENOBUFS;
 453                 eptype = ep->desc.bmAttributes & 0x03;
 454                 result = rpipe_get_idle(&rpipe, wa, 1 << eptype, gfp);
 455                 if (result < 0)
 456                         goto error;
 457                 result = rpipe_aim(rpipe, wa, ep, urb, gfp);
 458                 if (result < 0) {
 459                         rpipe_put(rpipe);
 460                         goto error;
 461                 }
 462                 ep->hcpriv = rpipe;
 463                 rpipe->ep = ep;
 464                 __rpipe_get(rpipe);     /* for caching into ep->hcpriv */
 465                 dev_dbg(dev, "ep 0x%02x: using rpipe %u\n",
 466                         ep->desc.bEndpointAddress,
 467                         le16_to_cpu(rpipe->descr.wRPipeIndex));
 468         }
 469 error:
 470         mutex_unlock(&wa->rpipe_mutex);
 471         return result;
 472 }
 473
 474 /*
 475  * Allocate the bitmap for each rpipe.
 476  */
 477 int wa_rpipes_create(struct wahc *wa)
 478 {
 479         wa->rpipes = wa->wa_descr->wNumRPipes;
 480         wa->rpipe_bm = kzalloc(BITS_TO_LONGS(wa->rpipes)*sizeof(unsigned long),
 481                                GFP_KERNEL);
 482         if (wa->rpipe_bm == NULL)
 483                 return -ENOMEM;
 484         return 0;
 485 }
 486
 487 void wa_rpipes_destroy(struct wahc *wa)
 488 {
 489         struct device *dev = &wa->usb_iface->dev;
 490
 491         if (!bitmap_empty(wa->rpipe_bm, wa->rpipes)) {
 492                 char buf[256];
 493                 WARN_ON(1);
 494                 bitmap_scnprintf(buf, sizeof(buf), wa->rpipe_bm, wa->rpipes);
 495                 dev_err(dev, "BUG: pipes not released on exit: %s\n", buf);
 496         }
 497         kfree(wa->rpipe_bm);
 498 }
 499
 500 /*
 501  * Release resources allocated for an endpoint
 502  *
 503  * If there is an associated rpipe to this endpoint, Abort any pending
 504  * transfers and put it. If the rpipe ends up being destroyed,
 505  * __rpipe_destroy() will cleanup ep->hcpriv.
 506  *
 507  * This is called before calling hcd->stop(), so you don't need to do
 508  * anything else in there.
 509  */
 510 void rpipe_ep_disable(struct wahc *wa, struct usb_host_endpoint *ep)
 511 {
 512         struct wa_rpipe *rpipe;
 513
 514         mutex_lock(&wa->rpipe_mutex);
 515         rpipe = ep->hcpriv;
 516         if (rpipe != NULL) {
 517                 u16 index = le16_to_cpu(rpipe->descr.wRPipeIndex);
 518
 519                 usb_control_msg(
 520                         wa->usb_dev, usb_rcvctrlpipe(wa->usb_dev, 0),
 521                         USB_REQ_RPIPE_ABORT,
 522                         USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_RPIPE,
 523                         0, index, NULL, 0, 1000 /* FIXME: arbitrary */);
 524                 rpipe_put(rpipe);
 525         }
 526         mutex_unlock(&wa->rpipe_mutex);
 527 }
 528 EXPORT_SYMBOL_GPL(rpipe_ep_disable);