drivers/uwb/est.c

   1 /*
   2  * Ultra Wide Band Radio Control
   3  * Event Size Tables 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  * Infrastructure, code and data tables for guessing the size of
  26  * events received on the notification endpoints of UWB radio
  27  * controllers.
  28  *
  29  * You define a table of events and for each, its size and how to get
  30  * the extra size.
  31  *
  32  * ENTRY POINTS:
  33  *
  34  * uwb_est_{init/destroy}(): To initialize/release the EST subsystem.
  35  *
  36  * uwb_est_[u]register(): To un/register event size tables
  37  *   uwb_est_grow()
  38  *
  39  * uwb_est_find_size(): Get the size of an event
  40  *   uwb_est_get_size()
  41  */
  42 #include <linux/spinlock.h>
  43
  44 #include "uwb-internal.h"
  45
  46 struct uwb_est {
  47         u16 type_event_high;
  48         u16 vendor, product;
  49         u8 entries;
  50         const struct uwb_est_entry *entry;
  51 };
  52
  53 static struct uwb_est *uwb_est;
  54 static u8 uwb_est_size;
  55 static u8 uwb_est_used;
  56 static DEFINE_RWLOCK(uwb_est_lock);
  57
  58 /**
  59  * WUSB Standard Event Size Table, HWA-RC interface
  60  *
  61  * Sizes for events and notifications type 0 (general), high nibble 0.
  62  */
  63 static
  64 struct uwb_est_entry uwb_est_00_00xx[] = {
  65         [UWB_RC_EVT_IE_RCV] = {
  66                 .size = sizeof(struct uwb_rc_evt_ie_rcv),
  67                 .offset = 1 + offsetof(struct uwb_rc_evt_ie_rcv, wIELength),
  68         },
  69         [UWB_RC_EVT_BEACON] = {
  70                 .size = sizeof(struct uwb_rc_evt_beacon),
  71                 .offset = 1 + offsetof(struct uwb_rc_evt_beacon, wBeaconInfoLength),
  72         },
  73         [UWB_RC_EVT_BEACON_SIZE] = {
  74                 .size = sizeof(struct uwb_rc_evt_beacon_size),
  75         },
  76         [UWB_RC_EVT_BPOIE_CHANGE] = {
  77                 .size = sizeof(struct uwb_rc_evt_bpoie_change),
  78                 .offset = 1 + offsetof(struct uwb_rc_evt_bpoie_change,
  79                                        wBPOIELength),
  80         },
  81         [UWB_RC_EVT_BP_SLOT_CHANGE] = {
  82                 .size = sizeof(struct uwb_rc_evt_bp_slot_change),
  83         },
  84         [UWB_RC_EVT_BP_SWITCH_IE_RCV] = {
  85                 .size = sizeof(struct uwb_rc_evt_bp_switch_ie_rcv),
  86                 .offset = 1 + offsetof(struct uwb_rc_evt_bp_switch_ie_rcv, wIELength),
  87         },
  88         [UWB_RC_EVT_DEV_ADDR_CONFLICT] = {
  89                 .size = sizeof(struct uwb_rc_evt_dev_addr_conflict),
  90         },
  91         [UWB_RC_EVT_DRP_AVAIL] = {
  92                 .size = sizeof(struct uwb_rc_evt_drp_avail)
  93         },
  94         [UWB_RC_EVT_DRP] = {
  95                 .size = sizeof(struct uwb_rc_evt_drp),
  96                 .offset = 1 + offsetof(struct uwb_rc_evt_drp, ie_length),
  97         },
  98         [UWB_RC_EVT_BP_SWITCH_STATUS] = {
  99                 .size = sizeof(struct uwb_rc_evt_bp_switch_status),
 100         },
 101         [UWB_RC_EVT_CMD_FRAME_RCV] = {
 102                 .size = sizeof(struct uwb_rc_evt_cmd_frame_rcv),
 103                 .offset = 1 + offsetof(struct uwb_rc_evt_cmd_frame_rcv, dataLength),
 104         },
 105         [UWB_RC_EVT_CHANNEL_CHANGE_IE_RCV] = {
 106                 .size = sizeof(struct uwb_rc_evt_channel_change_ie_rcv),
 107                 .offset = 1 + offsetof(struct uwb_rc_evt_channel_change_ie_rcv, wIELength),
 108         },
 109         [UWB_RC_CMD_CHANNEL_CHANGE] = {
 110                 .size = sizeof(struct uwb_rc_evt_confirm),
 111         },
 112         [UWB_RC_CMD_DEV_ADDR_MGMT] = {
 113                 .size = sizeof(struct uwb_rc_evt_dev_addr_mgmt) },
 114         [UWB_RC_CMD_GET_IE] = {
 115                 .size = sizeof(struct uwb_rc_evt_get_ie),
 116                 .offset = 1 + offsetof(struct uwb_rc_evt_get_ie, wIELength),
 117         },
 118         [UWB_RC_CMD_RESET] = {
 119                 .size = sizeof(struct uwb_rc_evt_confirm),
 120         },
 121         [UWB_RC_CMD_SCAN] = {
 122                 .size = sizeof(struct uwb_rc_evt_confirm),
 123         },
 124         [UWB_RC_CMD_SET_BEACON_FILTER] = {
 125                 .size = sizeof(struct uwb_rc_evt_confirm),
 126         },
 127         [UWB_RC_CMD_SET_DRP_IE] = {
 128                 .size = sizeof(struct uwb_rc_evt_set_drp_ie),
 129         },
 130         [UWB_RC_CMD_SET_IE] = {
 131                 .size = sizeof(struct uwb_rc_evt_set_ie),
 132         },
 133         [UWB_RC_CMD_SET_NOTIFICATION_FILTER] = {
 134                 .size = sizeof(struct uwb_rc_evt_confirm),
 135         },
 136         [UWB_RC_CMD_SET_TX_POWER] = {
 137                 .size = sizeof(struct uwb_rc_evt_confirm),
 138         },
 139         [UWB_RC_CMD_SLEEP] = {
 140                 .size = sizeof(struct uwb_rc_evt_confirm),
 141         },
 142         [UWB_RC_CMD_START_BEACON] = {
 143                 .size = sizeof(struct uwb_rc_evt_confirm),
 144         },
 145         [UWB_RC_CMD_STOP_BEACON] = {
 146                 .size = sizeof(struct uwb_rc_evt_confirm),
 147         },
 148         [UWB_RC_CMD_BP_MERGE] = {
 149                 .size = sizeof(struct uwb_rc_evt_confirm),
 150         },
 151         [UWB_RC_CMD_SEND_COMMAND_FRAME] = {
 152                 .size = sizeof(struct uwb_rc_evt_confirm),
 153         },
 154         [UWB_RC_CMD_SET_ASIE_NOTIF] = {
 155                 .size = sizeof(struct uwb_rc_evt_confirm),
 156         },
 157 };
 158
 159 static
 160 struct uwb_est_entry uwb_est_01_00xx[] = {
 161         [UWB_RC_DAA_ENERGY_DETECTED] = {
 162                 .size = sizeof(struct uwb_rc_evt_daa_energy_detected),
 163         },
 164         [UWB_RC_SET_DAA_ENERGY_MASK] = {
 165                 .size = sizeof(struct uwb_rc_evt_set_daa_energy_mask),
 166         },
 167         [UWB_RC_SET_NOTIFICATION_FILTER_EX] = {
 168                 .size = sizeof(struct uwb_rc_evt_set_notification_filter_ex),
 169         },
 170 };
 171
 172 /**
 173  * Initialize the EST subsystem
 174  *
 175  * Register the standard tables also.
 176  *
 177  * FIXME: tag init
 178  */
 179 int uwb_est_create(void)
 180 {
 181         int result;
 182
 183         uwb_est_size = 2;
 184         uwb_est_used = 0;
 185         uwb_est = kzalloc(uwb_est_size * sizeof(uwb_est[0]), GFP_KERNEL);
 186         if (uwb_est == NULL)
 187                 return -ENOMEM;
 188
 189         result = uwb_est_register(UWB_RC_CET_GENERAL, 0, 0xffff, 0xffff,
 190                                   uwb_est_00_00xx, ARRAY_SIZE(uwb_est_00_00xx));
 191         if (result < 0)
 192                 goto out;
 193         result = uwb_est_register(UWB_RC_CET_EX_TYPE_1, 0, 0xffff, 0xffff,
 194                                   uwb_est_01_00xx, ARRAY_SIZE(uwb_est_01_00xx));
 195 out:
 196         return result;
 197 }
 198
 199
 200 /** Clean it up */
 201 void uwb_est_destroy(void)
 202 {
 203         kfree(uwb_est);
 204         uwb_est = NULL;
 205         uwb_est_size = uwb_est_used = 0;
 206 }
 207
 208
 209 /**
 210  * Double the capacity of the EST table
 211  *
 212  * @returns 0 if ok, < 0 errno no error.
 213  */
 214 static
 215 int uwb_est_grow(void)
 216 {
 217         size_t actual_size = uwb_est_size * sizeof(uwb_est[0]);
 218         void *new = kmalloc(2 * actual_size, GFP_ATOMIC);
 219         if (new == NULL)
 220                 return -ENOMEM;
 221         memcpy(new, uwb_est, actual_size);
 222         memset(new + actual_size, 0, actual_size);
 223         kfree(uwb_est);
 224         uwb_est = new;
 225         uwb_est_size *= 2;
 226         return 0;
 227 }
 228
 229
 230 /**
 231  * Register an event size table
 232  *
 233  * Makes room for it if the table is full, and then inserts  it in the
 234  * right position (entries are sorted by type, event_high, vendor and
 235  * then product).
 236  *
 237  * @vendor:  vendor code for matching against the device (0x0000 and
 238  *           0xffff mean any); use 0x0000 to force all to match without
 239  *           checking possible vendor specific ones, 0xfffff to match
 240  *           after checking vendor specific ones.
 241  *
 242  * @product: product code from that vendor; same matching rules, use
 243  *           0x0000 for not allowing vendor specific matches, 0xffff
 244  *           for allowing.
 245  *
 246  * This arragement just makes the tables sort differenty. Because the
 247  * table is sorted by growing type-event_high-vendor-product, a zero
 248  * vendor will match before than a 0x456a vendor, that will match
 249  * before a 0xfffff vendor.
 250  *
 251  * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
 252  */
 253 /* FIXME: add bus type to vendor/product code */
 254 int uwb_est_register(u8 type, u8 event_high, u16 vendor, u16 product,
 255                      const struct uwb_est_entry *entry, size_t entries)
 256 {
 257         unsigned long flags;
 258         unsigned itr;
 259         u16 type_event_high;
 260         int result = 0;
 261
 262         write_lock_irqsave(&uwb_est_lock, flags);
 263         if (uwb_est_used == uwb_est_size) {
 264                 result = uwb_est_grow();
 265                 if (result < 0)
 266                         goto out;
 267         }
 268         /* Find the right spot to insert it in */
 269         type_event_high = type << 8 | event_high;
 270         for (itr = 0; itr < uwb_est_used; itr++)
 271                 if (uwb_est[itr].type_event_high < type
 272                     && uwb_est[itr].vendor < vendor
 273                     && uwb_est[itr].product < product)
 274                         break;
 275
 276         /* Shift others to make room for the new one? */
 277         if (itr < uwb_est_used)
 278                 memmove(&uwb_est[itr+1], &uwb_est[itr], uwb_est_used - itr);
 279         uwb_est[itr].type_event_high = type << 8 | event_high;
 280         uwb_est[itr].vendor = vendor;
 281         uwb_est[itr].product = product;
 282         uwb_est[itr].entry = entry;
 283         uwb_est[itr].entries = entries;
 284         uwb_est_used++;
 285 out:
 286         write_unlock_irqrestore(&uwb_est_lock, flags);
 287         return result;
 288 }
 289 EXPORT_SYMBOL_GPL(uwb_est_register);
 290
 291
 292 /**
 293  * Unregister an event size table
 294  *
 295  * This just removes the specified entry and moves the ones after it
 296  * to fill in the gap. This is needed to keep the list sorted; no
 297  * reallocation is done to reduce the size of the table.
 298  *
 299  * We unregister by all the data we used to register instead of by
 300  * pointer to the @entry array because we might have used the same
 301  * table for a bunch of IDs (for example).
 302  *
 303  * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
 304  */
 305 int uwb_est_unregister(u8 type, u8 event_high, u16 vendor, u16 product,
 306                        const struct uwb_est_entry *entry, size_t entries)
 307 {
 308         unsigned long flags;
 309         unsigned itr;
 310         struct uwb_est est_cmp = {
 311                 .type_event_high = type << 8 | event_high,
 312                 .vendor = vendor,
 313                 .product = product,
 314                 .entry = entry,
 315                 .entries = entries
 316         };
 317         write_lock_irqsave(&uwb_est_lock, flags);
 318         for (itr = 0; itr < uwb_est_used; itr++)
 319                 if (!memcmp(&uwb_est[itr], &est_cmp, sizeof(est_cmp)))
 320                         goto found;
 321         write_unlock_irqrestore(&uwb_est_lock, flags);
 322         return -ENOENT;
 323
 324 found:
 325         if (itr < uwb_est_used - 1)     /* Not last one? move ones above */
 326                 memmove(&uwb_est[itr], &uwb_est[itr+1], uwb_est_used - itr - 1);
 327         uwb_est_used--;
 328         write_unlock_irqrestore(&uwb_est_lock, flags);
 329         return 0;
 330 }
 331 EXPORT_SYMBOL_GPL(uwb_est_unregister);
 332
 333
 334 /**
 335  * Get the size of an event from a table
 336  *
 337  * @rceb: pointer to the buffer with the event
 338  * @rceb_size: size of the area pointed to by @rceb in bytes.
 339  * @returns: > 0      Size of the event
 340  *           -ENOSPC  An area big enough was not provided to look
 341  *                    ahead into the event's guts and guess the size.
 342  *           -EINVAL  Unknown event code (wEvent).
 343  *
 344  * This will look at the received RCEB and guess what is the total
 345  * size. For variable sized events, it will look further ahead into
 346  * their length field to see how much data should be read.
 347  *
 348  * Note this size is *not* final--the neh (Notification/Event Handle)
 349  * might specificy an extra size to add.
 350  */
 351 static
 352 ssize_t uwb_est_get_size(struct uwb_rc *uwb_rc, struct uwb_est *est,
 353                          u8 event_low, const struct uwb_rceb *rceb,
 354                          size_t rceb_size)
 355 {
 356         unsigned offset;
 357         ssize_t size;
 358         struct device *dev = &uwb_rc->uwb_dev.dev;
 359         const struct uwb_est_entry *entry;
 360
 361         size = -ENOENT;
 362         if (event_low >= est->entries) {        /* in range? */
 363                 dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: event %u out of range\n",
 364                         est, est->type_event_high, est->vendor, est->product,
 365                         est->entries, event_low);
 366                 goto out;
 367         }
 368         size = -ENOENT;
 369         entry = &est->entry[event_low];
 370         if (entry->size == 0 && entry->offset == 0) {   /* unknown? */
 371                 dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: event %u unknown\n",
 372                         est, est->type_event_high, est->vendor, est->product,
 373                         est->entries, event_low);
 374                 goto out;
 375         }
 376         offset = entry->offset; /* extra fries with that? */
 377         if (offset == 0)
 378                 size = entry->size;
 379         else {
 380                 /* Ops, got an extra size field at 'offset'--read it */
 381                 const void *ptr = rceb;
 382                 size_t type_size = 0;
 383                 offset--;
 384                 size = -ENOSPC;                 /* enough data for more? */
 385                 switch (entry->type) {
 386                 case UWB_EST_16:  type_size = sizeof(__le16); break;
 387                 case UWB_EST_8:   type_size = sizeof(u8);     break;
 388                 default:         BUG();
 389                 }
 390                 if (offset + type_size > rceb_size) {
 391                         dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: "
 392                                 "not enough data to read extra size\n",
 393                                 est, est->type_event_high, est->vendor,
 394                                 est->product, est->entries);
 395                         goto out;
 396                 }
 397                 size = entry->size;
 398                 ptr += offset;
 399                 switch (entry->type) {
 400                 case UWB_EST_16:  size += le16_to_cpu(*(__le16 *)ptr); break;
 401                 case UWB_EST_8:   size += *(u8 *)ptr;                  break;
 402                 default:         BUG();
 403                 }
 404         }
 405 out:
 406         return size;
 407 }
 408
 409
 410 /**
 411  * Guesses the size of a WA event
 412  *
 413  * @rceb: pointer to the buffer with the event
 414  * @rceb_size: size of the area pointed to by @rceb in bytes.
 415  * @returns: > 0      Size of the event
 416  *           -ENOSPC  An area big enough was not provided to look
 417  *                    ahead into the event's guts and guess the size.
 418  *           -EINVAL  Unknown event code (wEvent).
 419  *
 420  * This will look at the received RCEB and guess what is the total
 421  * size by checking all the tables registered with
 422  * uwb_est_register(). For variable sized events, it will look further
 423  * ahead into their length field to see how much data should be read.
 424  *
 425  * Note this size is *not* final--the neh (Notification/Event Handle)
 426  * might specificy an extra size to add or replace.
 427  */
 428 ssize_t uwb_est_find_size(struct uwb_rc *rc, const struct uwb_rceb *rceb,
 429                           size_t rceb_size)
 430 {
 431         /* FIXME: add vendor/product data */
 432         ssize_t size;
 433         struct device *dev = &rc->uwb_dev.dev;
 434         unsigned long flags;
 435         unsigned itr;
 436         u16 type_event_high, event;
 437         u8 *ptr = (u8 *) rceb;
 438
 439         read_lock_irqsave(&uwb_est_lock, flags);
 440         size = -ENOSPC;
 441         if (rceb_size < sizeof(*rceb))
 442                 goto out;
 443         event = le16_to_cpu(rceb->wEvent);
 444         type_event_high = rceb->bEventType << 8 | (event & 0xff00) >> 8;
 445         for (itr = 0; itr < uwb_est_used; itr++) {
 446                 if (uwb_est[itr].type_event_high != type_event_high)
 447                         continue;
 448                 size = uwb_est_get_size(rc, &uwb_est[itr],
 449                                         event & 0x00ff, rceb, rceb_size);
 450                 /* try more tables that might handle the same type */
 451                 if (size != -ENOENT)
 452                         goto out;
 453         }
 454         dev_dbg(dev, "event 0x%02x/%04x/%02x: no handlers available; "
 455                 "RCEB %02x %02x %02x %02x\n",
 456                 (unsigned) rceb->bEventType,
 457                 (unsigned) le16_to_cpu(rceb->wEvent),
 458                 (unsigned) rceb->bEventContext,
 459                 ptr[0], ptr[1], ptr[2], ptr[3]);
 460         size = -ENOENT;
 461 out:
 462         read_unlock_irqrestore(&uwb_est_lock, flags);
 463         return size;
 464 }
 465 EXPORT_SYMBOL_GPL(uwb_est_find_size);