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  *   Targeted 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 Address             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 <linux/atomic.h>
  62 #include <linux/bitmap.h>
  63 #include <linux/slab.h>
  64 #include <linux/export.h>
  65
  66 #include "wusbhc.h"
  67 #include "wa-hc.h"
  68
  69 static int __rpipe_get_descr(struct wahc *wa,
  70                              struct usb_rpipe_descriptor *descr, u16 index)
  71 {
  72         ssize_t result;
  73         struct device *dev = &wa->usb_iface->dev;
  74
  75         /* Get the RPIPE descriptor -- we cannot use the usb_get_descriptor()
  76          * function because the arguments are different.
  77          */
  78         result = usb_control_msg(
  79                 wa->usb_dev, usb_rcvctrlpipe(wa->usb_dev, 0),
  80                 USB_REQ_GET_DESCRIPTOR,
  81                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_RPIPE,
  82                 USB_DT_RPIPE<<8, index, descr, sizeof(*descr),
  83                 1000 /* FIXME: arbitrary */);
  84         if (result < 0) {
  85                 dev_err(dev, "rpipe %u: get descriptor failed: %d\n",
  86                         index, (int)result);
  87                 goto error;
  88         }
  89         if (result < sizeof(*descr)) {
  90                 dev_err(dev, "rpipe %u: got short descriptor "
  91                         "(%zd vs %zd bytes needed)\n",
  92                         index, result, sizeof(*descr));
  93                 result = -EINVAL;
  94                 goto error;
  95         }
  96         result = 0;
  97
  98 error:
  99         return result;
 100 }
 101
 102 /*
 103  *
 104  * The descriptor is assumed to be properly initialized (ie: you got
 105  * it through __rpipe_get_descr()).
 106  */
 107 static int __rpipe_set_descr(struct wahc *wa,
 108                              struct usb_rpipe_descriptor *descr, u16 index)
 109 {
 110         ssize_t result;
 111         struct device *dev = &wa->usb_iface->dev;
 112
 113         /* we cannot use the usb_get_descriptor() function because the
 114          * arguments are different.
 115          */
 116         result = usb_control_msg(
 117                 wa->usb_dev, usb_sndctrlpipe(wa->usb_dev, 0),
 118                 USB_REQ_SET_DESCRIPTOR,
 119                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_RPIPE,
 120                 USB_DT_RPIPE<<8, index, descr, sizeof(*descr),
 121                 HZ / 10);
 122         if (result < 0) {
 123                 dev_err(dev, "rpipe %u: set descriptor failed: %d\n",
 124                         index, (int)result);
 125                 goto error;
 126         }
 127         if (result < sizeof(*descr)) {
 128                 dev_err(dev, "rpipe %u: sent short descriptor "
 129                         "(%zd vs %zd bytes required)\n",
 130                         index, result, sizeof(*descr));
 131                 result = -EINVAL;
 132                 goto error;
 133         }
 134         result = 0;
 135
 136 error:
 137         return result;
 138
 139 }
 140
 141 static void rpipe_init(struct wa_rpipe *rpipe)
 142 {
 143         kref_init(&rpipe->refcnt);
 144         spin_lock_init(&rpipe->seg_lock);
 145         INIT_LIST_HEAD(&rpipe->seg_list);
 146 }
 147
 148 static unsigned rpipe_get_idx(struct wahc *wa, unsigned rpipe_idx)
 149 {
 150         unsigned long flags;
 151
 152         spin_lock_irqsave(&wa->rpipe_bm_lock, flags);
 153         rpipe_idx = find_next_zero_bit(wa->rpipe_bm, wa->rpipes, rpipe_idx);
 154         if (rpipe_idx < wa->rpipes)
 155                 set_bit(rpipe_idx, wa->rpipe_bm);
 156         spin_unlock_irqrestore(&wa->rpipe_bm_lock, flags);
 157
 158         return rpipe_idx;
 159 }
 160
 161 static void rpipe_put_idx(struct wahc *wa, unsigned rpipe_idx)
 162 {
 163         unsigned long flags;
 164
 165         spin_lock_irqsave(&wa->rpipe_bm_lock, flags);
 166         clear_bit(rpipe_idx, wa->rpipe_bm);
 167         spin_unlock_irqrestore(&wa->rpipe_bm_lock, flags);
 168 }
 169
 170 void rpipe_destroy(struct kref *_rpipe)
 171 {
 172         struct wa_rpipe *rpipe = container_of(_rpipe, struct wa_rpipe, refcnt);
 173         u8 index = le16_to_cpu(rpipe->descr.wRPipeIndex);
 174
 175         if (rpipe->ep)
 176                 rpipe->ep->hcpriv = NULL;
 177         rpipe_put_idx(rpipe->wa, index);
 178         wa_put(rpipe->wa);
 179         kfree(rpipe);
 180 }
 181 EXPORT_SYMBOL_GPL(rpipe_destroy);
 182
 183 /*
 184  * Locate an idle rpipe, create an structure for it and return it
 185  *
 186  * @wa    is referenced and unlocked
 187  * @crs   enum rpipe_attr, required endpoint characteristics
 188  *
 189  * The rpipe can be used only sequentially (not in parallel).
 190  *
 191  * The rpipe is moved into the "ready" state.
 192  */
 193 static int rpipe_get_idle(struct wa_rpipe **prpipe, struct wahc *wa, u8 crs,
 194                           gfp_t gfp)
 195 {
 196         int result;
 197         unsigned rpipe_idx;
 198         struct wa_rpipe *rpipe;
 199         struct device *dev = &wa->usb_iface->dev;
 200
 201         rpipe = kzalloc(sizeof(*rpipe), gfp);
 202         if (rpipe == NULL)
 203                 return -ENOMEM;
 204         rpipe_init(rpipe);
 205
 206         /* Look for an idle pipe */
 207         for (rpipe_idx = 0; rpipe_idx < wa->rpipes; rpipe_idx++) {
 208                 rpipe_idx = rpipe_get_idx(wa, rpipe_idx);
 209                 if (rpipe_idx >= wa->rpipes)    /* no more pipes :( */
 210                         break;
 211                 result =  __rpipe_get_descr(wa, &rpipe->descr, rpipe_idx);
 212                 if (result < 0)
 213                         dev_err(dev, "Can't get descriptor for rpipe %u: %d\n",
 214                                 rpipe_idx, result);
 215                 else if ((rpipe->descr.bmCharacteristics & crs) != 0)
 216                         goto found;
 217                 rpipe_put_idx(wa, rpipe_idx);
 218         }
 219         *prpipe = NULL;
 220         kfree(rpipe);
 221         return -ENXIO;
 222
 223 found:
 224         set_bit(rpipe_idx, wa->rpipe_bm);
 225         rpipe->wa = wa_get(wa);
 226         *prpipe = rpipe;
 227         return 0;
 228 }
 229
 230 static int __rpipe_reset(struct wahc *wa, unsigned index)
 231 {
 232         int result;
 233         struct device *dev = &wa->usb_iface->dev;
 234
 235         result = usb_control_msg(
 236                 wa->usb_dev, usb_sndctrlpipe(wa->usb_dev, 0),
 237                 USB_REQ_RPIPE_RESET,
 238                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_RPIPE,
 239                 0, index, NULL, 0, 1000 /* FIXME: arbitrary */);
 240         if (result < 0)
 241                 dev_err(dev, "rpipe %u: reset failed: %d\n",
 242                         index, result);
 243         return result;
 244 }
 245
 246 /*
 247  * Fake companion descriptor for ep0
 248  *
 249  * See WUSB1.0[7.4.4], most of this is zero for bulk/int/ctl
 250  */
 251 static struct usb_wireless_ep_comp_descriptor epc0 = {
 252         .bLength = sizeof(epc0),
 253         .bDescriptorType = USB_DT_WIRELESS_ENDPOINT_COMP,
 254 /*      .bMaxBurst = 1, */
 255         .bMaxSequence = 31,
 256 };
 257
 258 /*
 259  * Look for EP companion descriptor
 260  *
 261  * Get there, look for Inara in the endpoint's extra descriptors
 262  */
 263 static struct usb_wireless_ep_comp_descriptor *rpipe_epc_find(
 264                 struct device *dev, struct usb_host_endpoint *ep)
 265 {
 266         void *itr;
 267         size_t itr_size;
 268         struct usb_descriptor_header *hdr;
 269         struct usb_wireless_ep_comp_descriptor *epcd;
 270
 271         if (ep->desc.bEndpointAddress == 0) {
 272                 epcd = &epc0;
 273                 goto out;
 274         }
 275         itr = ep->extra;
 276         itr_size = ep->extralen;
 277         epcd = NULL;
 278         while (itr_size > 0) {
 279                 if (itr_size < sizeof(*hdr)) {
 280                         dev_err(dev, "HW Bug? ep 0x%02x: extra descriptors "
 281                                 "at offset %zu: only %zu bytes left\n",
 282                                 ep->desc.bEndpointAddress,
 283                                 itr - (void *) ep->extra, itr_size);
 284                         break;
 285                 }
 286                 hdr = itr;
 287                 if (hdr->bDescriptorType == USB_DT_WIRELESS_ENDPOINT_COMP) {
 288                         epcd = itr;
 289                         break;
 290                 }
 291                 if (hdr->bLength > itr_size) {
 292                         dev_err(dev, "HW Bug? ep 0x%02x: extra descriptor "
 293                                 "at offset %zu (type 0x%02x) "
 294                                 "length %d but only %zu bytes left\n",
 295                                 ep->desc.bEndpointAddress,
 296                                 itr - (void *) ep->extra, hdr->bDescriptorType,
 297                                 hdr->bLength, itr_size);
 298                         break;
 299                 }
 300                 itr += hdr->bLength;
 301                 itr_size -= hdr->bDescriptorType;
 302         }
 303 out:
 304         return epcd;
 305 }
 306
 307 /*
 308  * Aim an rpipe to its device & endpoint destination
 309  *
 310  * Make sure we change the address to unauthenticathed if the device
 311  * is WUSB and it is not authenticated.
 312  */
 313 static int rpipe_aim(struct wa_rpipe *rpipe, struct wahc *wa,
 314                      struct usb_host_endpoint *ep, struct urb *urb, gfp_t gfp)
 315 {
 316         int result = -ENOMSG;   /* better code for lack of companion? */
 317         struct device *dev = &wa->usb_iface->dev;
 318         struct usb_device *usb_dev = urb->dev;
 319         struct usb_wireless_ep_comp_descriptor *epcd;
 320         u8 unauth;
 321
 322         epcd = rpipe_epc_find(dev, ep);
 323         if (epcd == NULL) {
 324                 dev_err(dev, "ep 0x%02x: can't find companion descriptor\n",
 325                         ep->desc.bEndpointAddress);
 326                 goto error;
 327         }
 328         unauth = usb_dev->wusb && !usb_dev->authenticated ? 0x80 : 0;
 329         __rpipe_reset(wa, le16_to_cpu(rpipe->descr.wRPipeIndex));
 330         atomic_set(&rpipe->segs_available, le16_to_cpu(rpipe->descr.wRequests));
 331         /* FIXME: block allocation system; request with queuing and timeout */
 332         /* FIXME: compute so seg_size > ep->maxpktsize */
 333         rpipe->descr.wBlocks = cpu_to_le16(16);         /* given */
 334         /* ep0 maxpktsize is 0x200 (WUSB1.0[4.8.1]) */
 335         rpipe->descr.wMaxPacketSize = cpu_to_le16(ep->desc.wMaxPacketSize);
 336         rpipe->descr.bHSHubAddress = 0;                 /* reserved: zero */
 337         rpipe->descr.bHSHubPort = wusb_port_no_to_idx(urb->dev->portnum);
 338         /* FIXME: use maximum speed as supported or recommended by device */
 339         rpipe->descr.bSpeed = usb_pipeendpoint(urb->pipe) == 0 ?
 340                 UWB_PHY_RATE_53 : UWB_PHY_RATE_200;
 341
 342         dev_dbg(dev, "addr %u (0x%02x) rpipe #%u ep# %u speed %d\n",
 343                 urb->dev->devnum, urb->dev->devnum | unauth,
 344                 le16_to_cpu(rpipe->descr.wRPipeIndex),
 345                 usb_pipeendpoint(urb->pipe), rpipe->descr.bSpeed);
 346
 347         /* see security.c:wusb_update_address() */
 348         if (unlikely(urb->dev->devnum == 0x80))
 349                 rpipe->descr.bDeviceAddress = 0;
 350         else
 351                 rpipe->descr.bDeviceAddress = urb->dev->devnum | unauth;
 352         rpipe->descr.bEndpointAddress = ep->desc.bEndpointAddress;
 353         /* FIXME: bDataSequence */
 354         rpipe->descr.bDataSequence = 0;
 355         /* FIXME: dwCurrentWindow */
 356         rpipe->descr.dwCurrentWindow = cpu_to_le32(1);
 357         /* FIXME: bMaxDataSequence */
 358         rpipe->descr.bMaxDataSequence = epcd->bMaxSequence - 1;
 359         rpipe->descr.bInterval = ep->desc.bInterval;
 360         /* FIXME: bOverTheAirInterval */
 361         rpipe->descr.bOverTheAirInterval = 0;   /* 0 if not isoc */
 362         /* FIXME: xmit power & preamble blah blah */
 363         rpipe->descr.bmAttribute = ep->desc.bmAttributes & 0x03;
 364         /* rpipe->descr.bmCharacteristics RO */
 365         /* FIXME: bmRetryOptions */
 366         rpipe->descr.bmRetryOptions = 15;
 367         /* FIXME: use for assessing link quality? */
 368         rpipe->descr.wNumTransactionErrors = 0;
 369         result = __rpipe_set_descr(wa, &rpipe->descr,
 370                                    le16_to_cpu(rpipe->descr.wRPipeIndex));
 371         if (result < 0) {
 372                 dev_err(dev, "Cannot aim rpipe: %d\n", result);
 373                 goto error;
 374         }
 375         result = 0;
 376 error:
 377         return result;
 378 }
 379
 380 /*
 381  * Check an aimed rpipe to make sure it points to where we want
 382  *
 383  * We use bit 19 of the Linux USB pipe bitmap for unauth vs auth
 384  * space; when it is like that, we or 0x80 to make an unauth address.
 385  */
 386 static int rpipe_check_aim(const struct wa_rpipe *rpipe, const struct wahc *wa,
 387                            const struct usb_host_endpoint *ep,
 388                            const struct urb *urb, gfp_t gfp)
 389 {
 390         int result = 0;         /* better code for lack of companion? */
 391         struct device *dev = &wa->usb_iface->dev;
 392         struct usb_device *usb_dev = urb->dev;
 393         u8 unauth = (usb_dev->wusb && !usb_dev->authenticated) ? 0x80 : 0;
 394         u8 portnum = wusb_port_no_to_idx(urb->dev->portnum);
 395
 396 #define AIM_CHECK(rdf, val, text)                                       \
 397         do {                                                            \
 398                 if (rpipe->descr.rdf != (val)) {                        \
 399                         dev_err(dev,                                    \
 400                                 "rpipe aim discrepancy: " #rdf " " text "\n", \
 401                                 rpipe->descr.rdf, (val));               \
 402                         result = -EINVAL;                               \
 403                         WARN_ON(1);                                     \
 404                 }                                                       \
 405         } while (0)
 406         AIM_CHECK(wMaxPacketSize, cpu_to_le16(ep->desc.wMaxPacketSize),
 407                   "(%u vs %u)");
 408         AIM_CHECK(bHSHubPort, portnum, "(%u vs %u)");
 409         AIM_CHECK(bSpeed, usb_pipeendpoint(urb->pipe) == 0 ?
 410                         UWB_PHY_RATE_53 : UWB_PHY_RATE_200,
 411                   "(%u vs %u)");
 412         AIM_CHECK(bDeviceAddress, urb->dev->devnum | unauth, "(%u vs %u)");
 413         AIM_CHECK(bEndpointAddress, ep->desc.bEndpointAddress, "(%u vs %u)");
 414         AIM_CHECK(bInterval, ep->desc.bInterval, "(%u vs %u)");
 415         AIM_CHECK(bmAttribute, ep->desc.bmAttributes & 0x03, "(%u vs %u)");
 416 #undef AIM_CHECK
 417         return result;
 418 }
 419
 420 #ifndef CONFIG_BUG
 421 #define CONFIG_BUG 0
 422 #endif
 423
 424 /*
 425  * Make sure there is an rpipe allocated for an endpoint
 426  *
 427  * If already allocated, we just refcount it; if not, we get an
 428  * idle one, aim it to the right location and take it.
 429  *
 430  * Attaches to ep->hcpriv and rpipe->ep to ep.
 431  */
 432 int rpipe_get_by_ep(struct wahc *wa, struct usb_host_endpoint *ep,
 433                     struct urb *urb, gfp_t gfp)
 434 {
 435         int result = 0;
 436         struct device *dev = &wa->usb_iface->dev;
 437         struct wa_rpipe *rpipe;
 438         u8 eptype;
 439
 440         mutex_lock(&wa->rpipe_mutex);
 441         rpipe = ep->hcpriv;
 442         if (rpipe != NULL) {
 443                 if (CONFIG_BUG == 1) {
 444                         result = rpipe_check_aim(rpipe, wa, ep, urb, gfp);
 445                         if (result < 0)
 446                                 goto error;
 447                 }
 448                 __rpipe_get(rpipe);
 449                 dev_dbg(dev, "ep 0x%02x: reusing rpipe %u\n",
 450                         ep->desc.bEndpointAddress,
 451                         le16_to_cpu(rpipe->descr.wRPipeIndex));
 452         } else {
 453                 /* hmm, assign idle rpipe, aim it */
 454                 result = -ENOBUFS;
 455                 eptype = ep->desc.bmAttributes & 0x03;
 456                 result = rpipe_get_idle(&rpipe, wa, 1 << eptype, gfp);
 457                 if (result < 0)
 458                         goto error;
 459                 result = rpipe_aim(rpipe, wa, ep, urb, gfp);
 460                 if (result < 0) {
 461                         rpipe_put(rpipe);
 462                         goto error;
 463                 }
 464                 ep->hcpriv = rpipe;
 465                 rpipe->ep = ep;
 466                 __rpipe_get(rpipe);     /* for caching into ep->hcpriv */
 467                 dev_dbg(dev, "ep 0x%02x: using rpipe %u\n",
 468                         ep->desc.bEndpointAddress,
 469                         le16_to_cpu(rpipe->descr.wRPipeIndex));
 470         }
 471 error:
 472         mutex_unlock(&wa->rpipe_mutex);
 473         return result;
 474 }
 475
 476 /*
 477  * Allocate the bitmap for each rpipe.
 478  */
 479 int wa_rpipes_create(struct wahc *wa)
 480 {
 481         wa->rpipes = wa->wa_descr->wNumRPipes;
 482         wa->rpipe_bm = kzalloc(BITS_TO_LONGS(wa->rpipes)*sizeof(unsigned long),
 483                                GFP_KERNEL);
 484         if (wa->rpipe_bm == NULL)
 485                 return -ENOMEM;
 486         return 0;
 487 }
 488
 489 void wa_rpipes_destroy(struct wahc *wa)
 490 {
 491         struct device *dev = &wa->usb_iface->dev;
 492
 493         if (!bitmap_empty(wa->rpipe_bm, wa->rpipes)) {
 494                 char buf[256];
 495                 WARN_ON(1);
 496                 bitmap_scnprintf(buf, sizeof(buf), wa->rpipe_bm, wa->rpipes);
 497                 dev_err(dev, "BUG: pipes not released on exit: %s\n", buf);
 498         }
 499         kfree(wa->rpipe_bm);
 500 }
 501
 502 /*
 503  * Release resources allocated for an endpoint
 504  *
 505  * If there is an associated rpipe to this endpoint, Abort any pending
 506  * transfers and put it. If the rpipe ends up being destroyed,
 507  * __rpipe_destroy() will cleanup ep->hcpriv.
 508  *
 509  * This is called before calling hcd->stop(), so you don't need to do
 510  * anything else in there.
 511  */
 512 void rpipe_ep_disable(struct wahc *wa, struct usb_host_endpoint *ep)
 513 {
 514         struct wa_rpipe *rpipe;
 515
 516         mutex_lock(&wa->rpipe_mutex);
 517         rpipe = ep->hcpriv;
 518         if (rpipe != NULL) {
 519                 u16 index = le16_to_cpu(rpipe->descr.wRPipeIndex);
 520
 521                 usb_control_msg(
 522                         wa->usb_dev, usb_rcvctrlpipe(wa->usb_dev, 0),
 523                         USB_REQ_RPIPE_ABORT,
 524                         USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_RPIPE,
 525                         0, index, NULL, 0, 1000 /* FIXME: arbitrary */);
 526                 rpipe_put(rpipe);
 527         }
 528         mutex_unlock(&wa->rpipe_mutex);
 529 }
 530 EXPORT_SYMBOL_GPL(rpipe_ep_disable);