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 #include <linux/slab.h>
  44 #include <linux/export.h>
  45
  46 #include "uwb-internal.h"
  47
  48 struct uwb_est {
  49         u16 type_event_high;
  50         u16 vendor, product;
  51         u8 entries;
  52         const struct uwb_est_entry *entry;
  53 };
  54
  55 static struct uwb_est *uwb_est;
  56 static u8 uwb_est_size;
  57 static u8 uwb_est_used;
  58 static DEFINE_RWLOCK(uwb_est_lock);
  59
  60 /**
  61  * WUSB Standard Event Size Table, HWA-RC interface
  62  *
  63  * Sizes for events and notifications type 0 (general), high nibble 0.
  64  */
  65 static
  66 struct uwb_est_entry uwb_est_00_00xx[] = {
  67         [UWB_RC_EVT_IE_RCV] = {
  68                 .size = sizeof(struct uwb_rc_evt_ie_rcv),
  69                 .offset = 1 + offsetof(struct uwb_rc_evt_ie_rcv, wIELength),
  70         },
  71         [UWB_RC_EVT_BEACON] = {
  72                 .size = sizeof(struct uwb_rc_evt_beacon),
  73                 .offset = 1 + offsetof(struct uwb_rc_evt_beacon, wBeaconInfoLength),
  74         },
  75         [UWB_RC_EVT_BEACON_SIZE] = {
  76                 .size = sizeof(struct uwb_rc_evt_beacon_size),
  77         },
  78         [UWB_RC_EVT_BPOIE_CHANGE] = {
  79                 .size = sizeof(struct uwb_rc_evt_bpoie_change),
  80                 .offset = 1 + offsetof(struct uwb_rc_evt_bpoie_change,
  81                                        wBPOIELength),
  82         },
  83         [UWB_RC_EVT_BP_SLOT_CHANGE] = {
  84                 .size = sizeof(struct uwb_rc_evt_bp_slot_change),
  85         },
  86         [UWB_RC_EVT_BP_SWITCH_IE_RCV] = {
  87                 .size = sizeof(struct uwb_rc_evt_bp_switch_ie_rcv),
  88                 .offset = 1 + offsetof(struct uwb_rc_evt_bp_switch_ie_rcv, wIELength),
  89         },
  90         [UWB_RC_EVT_DEV_ADDR_CONFLICT] = {
  91                 .size = sizeof(struct uwb_rc_evt_dev_addr_conflict),
  92         },
  93         [UWB_RC_EVT_DRP_AVAIL] = {
  94                 .size = sizeof(struct uwb_rc_evt_drp_avail)
  95         },
  96         [UWB_RC_EVT_DRP] = {
  97                 .size = sizeof(struct uwb_rc_evt_drp),
  98                 .offset = 1 + offsetof(struct uwb_rc_evt_drp, ie_length),
  99         },
 100         [UWB_RC_EVT_BP_SWITCH_STATUS] = {
 101                 .size = sizeof(struct uwb_rc_evt_bp_switch_status),
 102         },
 103         [UWB_RC_EVT_CMD_FRAME_RCV] = {
 104                 .size = sizeof(struct uwb_rc_evt_cmd_frame_rcv),
 105                 .offset = 1 + offsetof(struct uwb_rc_evt_cmd_frame_rcv, dataLength),
 106         },
 107         [UWB_RC_EVT_CHANNEL_CHANGE_IE_RCV] = {
 108                 .size = sizeof(struct uwb_rc_evt_channel_change_ie_rcv),
 109                 .offset = 1 + offsetof(struct uwb_rc_evt_channel_change_ie_rcv, wIELength),
 110         },
 111         [UWB_RC_CMD_CHANNEL_CHANGE] = {
 112                 .size = sizeof(struct uwb_rc_evt_confirm),
 113         },
 114         [UWB_RC_CMD_DEV_ADDR_MGMT] = {
 115                 .size = sizeof(struct uwb_rc_evt_dev_addr_mgmt) },
 116         [UWB_RC_CMD_GET_IE] = {
 117                 .size = sizeof(struct uwb_rc_evt_get_ie),
 118                 .offset = 1 + offsetof(struct uwb_rc_evt_get_ie, wIELength),
 119         },
 120         [UWB_RC_CMD_RESET] = {
 121                 .size = sizeof(struct uwb_rc_evt_confirm),
 122         },
 123         [UWB_RC_CMD_SCAN] = {
 124                 .size = sizeof(struct uwb_rc_evt_confirm),
 125         },
 126         [UWB_RC_CMD_SET_BEACON_FILTER] = {
 127                 .size = sizeof(struct uwb_rc_evt_confirm),
 128         },
 129         [UWB_RC_CMD_SET_DRP_IE] = {
 130                 .size = sizeof(struct uwb_rc_evt_set_drp_ie),
 131         },
 132         [UWB_RC_CMD_SET_IE] = {
 133                 .size = sizeof(struct uwb_rc_evt_set_ie),
 134         },
 135         [UWB_RC_CMD_SET_NOTIFICATION_FILTER] = {
 136                 .size = sizeof(struct uwb_rc_evt_confirm),
 137         },
 138         [UWB_RC_CMD_SET_TX_POWER] = {
 139                 .size = sizeof(struct uwb_rc_evt_confirm),
 140         },
 141         [UWB_RC_CMD_SLEEP] = {
 142                 .size = sizeof(struct uwb_rc_evt_confirm),
 143         },
 144         [UWB_RC_CMD_START_BEACON] = {
 145                 .size = sizeof(struct uwb_rc_evt_confirm),
 146         },
 147         [UWB_RC_CMD_STOP_BEACON] = {
 148                 .size = sizeof(struct uwb_rc_evt_confirm),
 149         },
 150         [UWB_RC_CMD_BP_MERGE] = {
 151                 .size = sizeof(struct uwb_rc_evt_confirm),
 152         },
 153         [UWB_RC_CMD_SEND_COMMAND_FRAME] = {
 154                 .size = sizeof(struct uwb_rc_evt_confirm),
 155         },
 156         [UWB_RC_CMD_SET_ASIE_NOTIF] = {
 157                 .size = sizeof(struct uwb_rc_evt_confirm),
 158         },
 159 };
 160
 161 static
 162 struct uwb_est_entry uwb_est_01_00xx[] = {
 163         [UWB_RC_DAA_ENERGY_DETECTED] = {
 164                 .size = sizeof(struct uwb_rc_evt_daa_energy_detected),
 165         },
 166         [UWB_RC_SET_DAA_ENERGY_MASK] = {
 167                 .size = sizeof(struct uwb_rc_evt_set_daa_energy_mask),
 168         },
 169         [UWB_RC_SET_NOTIFICATION_FILTER_EX] = {
 170                 .size = sizeof(struct uwb_rc_evt_set_notification_filter_ex),
 171         },
 172 };
 173
 174 /**
 175  * Initialize the EST subsystem
 176  *
 177  * Register the standard tables also.
 178  *
 179  * FIXME: tag init
 180  */
 181 int uwb_est_create(void)
 182 {
 183         int result;
 184
 185         uwb_est_size = 2;
 186         uwb_est_used = 0;
 187         uwb_est = kcalloc(uwb_est_size, sizeof(uwb_est[0]), GFP_KERNEL);
 188         if (uwb_est == NULL)
 189                 return -ENOMEM;
 190
 191         result = uwb_est_register(UWB_RC_CET_GENERAL, 0, 0xffff, 0xffff,
 192                                   uwb_est_00_00xx, ARRAY_SIZE(uwb_est_00_00xx));
 193         if (result < 0)
 194                 goto out;
 195         result = uwb_est_register(UWB_RC_CET_EX_TYPE_1, 0, 0xffff, 0xffff,
 196                                   uwb_est_01_00xx, ARRAY_SIZE(uwb_est_01_00xx));
 197 out:
 198         return result;
 199 }
 200
 201
 202 /** Clean it up */
 203 void uwb_est_destroy(void)
 204 {
 205         kfree(uwb_est);
 206         uwb_est = NULL;
 207         uwb_est_size = uwb_est_used = 0;
 208 }
 209
 210
 211 /**
 212  * Double the capacity of the EST table
 213  *
 214  * @returns 0 if ok, < 0 errno no error.
 215  */
 216 static
 217 int uwb_est_grow(void)
 218 {
 219         size_t actual_size = uwb_est_size * sizeof(uwb_est[0]);
 220         void *new = kmalloc(2 * actual_size, GFP_ATOMIC);
 221         if (new == NULL)
 222                 return -ENOMEM;
 223         memcpy(new, uwb_est, actual_size);
 224         memset(new + actual_size, 0, actual_size);
 225         kfree(uwb_est);
 226         uwb_est = new;
 227         uwb_est_size *= 2;
 228         return 0;
 229 }
 230
 231
 232 /**
 233  * Register an event size table
 234  *
 235  * Makes room for it if the table is full, and then inserts  it in the
 236  * right position (entries are sorted by type, event_high, vendor and
 237  * then product).
 238  *
 239  * @vendor:  vendor code for matching against the device (0x0000 and
 240  *           0xffff mean any); use 0x0000 to force all to match without
 241  *           checking possible vendor specific ones, 0xfffff to match
 242  *           after checking vendor specific ones.
 243  *
 244  * @product: product code from that vendor; same matching rules, use
 245  *           0x0000 for not allowing vendor specific matches, 0xffff
 246  *           for allowing.
 247  *
 248  * This arragement just makes the tables sort differenty. Because the
 249  * table is sorted by growing type-event_high-vendor-product, a zero
 250  * vendor will match before than a 0x456a vendor, that will match
 251  * before a 0xfffff vendor.
 252  *
 253  * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
 254  */
 255 /* FIXME: add bus type to vendor/product code */
 256 int uwb_est_register(u8 type, u8 event_high, u16 vendor, u16 product,
 257                      const struct uwb_est_entry *entry, size_t entries)
 258 {
 259         unsigned long flags;
 260         unsigned itr;
 261         u16 type_event_high;
 262         int result = 0;
 263
 264         write_lock_irqsave(&uwb_est_lock, flags);
 265         if (uwb_est_used == uwb_est_size) {
 266                 result = uwb_est_grow();
 267                 if (result < 0)
 268                         goto out;
 269         }
 270         /* Find the right spot to insert it in */
 271         type_event_high = type << 8 | event_high;
 272         for (itr = 0; itr < uwb_est_used; itr++)
 273                 if (uwb_est[itr].type_event_high < type
 274                     && uwb_est[itr].vendor < vendor
 275                     && uwb_est[itr].product < product)
 276                         break;
 277
 278         /* Shift others to make room for the new one? */
 279         if (itr < uwb_est_used)
 280                 memmove(&uwb_est[itr+1], &uwb_est[itr], uwb_est_used - itr);
 281         uwb_est[itr].type_event_high = type << 8 | event_high;
 282         uwb_est[itr].vendor = vendor;
 283         uwb_est[itr].product = product;
 284         uwb_est[itr].entry = entry;
 285         uwb_est[itr].entries = entries;
 286         uwb_est_used++;
 287 out:
 288         write_unlock_irqrestore(&uwb_est_lock, flags);
 289         return result;
 290 }
 291 EXPORT_SYMBOL_GPL(uwb_est_register);
 292
 293
 294 /**
 295  * Unregister an event size table
 296  *
 297  * This just removes the specified entry and moves the ones after it
 298  * to fill in the gap. This is needed to keep the list sorted; no
 299  * reallocation is done to reduce the size of the table.
 300  *
 301  * We unregister by all the data we used to register instead of by
 302  * pointer to the @entry array because we might have used the same
 303  * table for a bunch of IDs (for example).
 304  *
 305  * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
 306  */
 307 int uwb_est_unregister(u8 type, u8 event_high, u16 vendor, u16 product,
 308                        const struct uwb_est_entry *entry, size_t entries)
 309 {
 310         unsigned long flags;
 311         unsigned itr;
 312         struct uwb_est est_cmp = {
 313                 .type_event_high = type << 8 | event_high,
 314                 .vendor = vendor,
 315                 .product = product,
 316                 .entry = entry,
 317                 .entries = entries
 318         };
 319         write_lock_irqsave(&uwb_est_lock, flags);
 320         for (itr = 0; itr < uwb_est_used; itr++)
 321                 if (!memcmp(&uwb_est[itr], &est_cmp, sizeof(est_cmp)))
 322                         goto found;
 323         write_unlock_irqrestore(&uwb_est_lock, flags);
 324         return -ENOENT;
 325
 326 found:
 327         if (itr < uwb_est_used - 1)     /* Not last one? move ones above */
 328                 memmove(&uwb_est[itr], &uwb_est[itr+1], uwb_est_used - itr - 1);
 329         uwb_est_used--;
 330         write_unlock_irqrestore(&uwb_est_lock, flags);
 331         return 0;
 332 }
 333 EXPORT_SYMBOL_GPL(uwb_est_unregister);
 334
 335
 336 /**
 337  * Get the size of an event from a table
 338  *
 339  * @rceb: pointer to the buffer with the event
 340  * @rceb_size: size of the area pointed to by @rceb in bytes.
 341  * @returns: > 0      Size of the event
 342  *           -ENOSPC  An area big enough was not provided to look
 343  *                    ahead into the event's guts and guess the size.
 344  *           -EINVAL  Unknown event code (wEvent).
 345  *
 346  * This will look at the received RCEB and guess what is the total
 347  * size. For variable sized events, it will look further ahead into
 348  * their length field to see how much data should be read.
 349  *
 350  * Note this size is *not* final--the neh (Notification/Event Handle)
 351  * might specificy an extra size to add.
 352  */
 353 static
 354 ssize_t uwb_est_get_size(struct uwb_rc *uwb_rc, struct uwb_est *est,
 355                          u8 event_low, const struct uwb_rceb *rceb,
 356                          size_t rceb_size)
 357 {
 358         unsigned offset;
 359         ssize_t size;
 360         struct device *dev = &uwb_rc->uwb_dev.dev;
 361         const struct uwb_est_entry *entry;
 362
 363         size = -ENOENT;
 364         if (event_low >= est->entries) {        /* in range? */
 365                 dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: event %u out of range\n",
 366                         est, est->type_event_high, est->vendor, est->product,
 367                         est->entries, event_low);
 368                 goto out;
 369         }
 370         size = -ENOENT;
 371         entry = &est->entry[event_low];
 372         if (entry->size == 0 && entry->offset == 0) {   /* unknown? */
 373                 dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: event %u unknown\n",
 374                         est, est->type_event_high, est->vendor, est->product,
 375                         est->entries, event_low);
 376                 goto out;
 377         }
 378         offset = entry->offset; /* extra fries with that? */
 379         if (offset == 0)
 380                 size = entry->size;
 381         else {
 382                 /* Ops, got an extra size field at 'offset'--read it */
 383                 const void *ptr = rceb;
 384                 size_t type_size = 0;
 385                 offset--;
 386                 size = -ENOSPC;                 /* enough data for more? */
 387                 switch (entry->type) {
 388                 case UWB_EST_16:  type_size = sizeof(__le16); break;
 389                 case UWB_EST_8:   type_size = sizeof(u8);     break;
 390                 default:         BUG();
 391                 }
 392                 if (offset + type_size > rceb_size) {
 393                         dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: "
 394                                 "not enough data to read extra size\n",
 395                                 est, est->type_event_high, est->vendor,
 396                                 est->product, est->entries);
 397                         goto out;
 398                 }
 399                 size = entry->size;
 400                 ptr += offset;
 401                 switch (entry->type) {
 402                 case UWB_EST_16:  size += le16_to_cpu(*(__le16 *)ptr); break;
 403                 case UWB_EST_8:   size += *(u8 *)ptr;                  break;
 404                 default:         BUG();
 405                 }
 406         }
 407 out:
 408         return size;
 409 }
 410
 411
 412 /**
 413  * Guesses the size of a WA event
 414  *
 415  * @rceb: pointer to the buffer with the event
 416  * @rceb_size: size of the area pointed to by @rceb in bytes.
 417  * @returns: > 0      Size of the event
 418  *           -ENOSPC  An area big enough was not provided to look
 419  *                    ahead into the event's guts and guess the size.
 420  *           -EINVAL  Unknown event code (wEvent).
 421  *
 422  * This will look at the received RCEB and guess what is the total
 423  * size by checking all the tables registered with
 424  * uwb_est_register(). For variable sized events, it will look further
 425  * ahead into their length field to see how much data should be read.
 426  *
 427  * Note this size is *not* final--the neh (Notification/Event Handle)
 428  * might specificy an extra size to add or replace.
 429  */
 430 ssize_t uwb_est_find_size(struct uwb_rc *rc, const struct uwb_rceb *rceb,
 431                           size_t rceb_size)
 432 {
 433         /* FIXME: add vendor/product data */
 434         ssize_t size;
 435         struct device *dev = &rc->uwb_dev.dev;
 436         unsigned long flags;
 437         unsigned itr;
 438         u16 type_event_high, event;
 439         u8 *ptr = (u8 *) rceb;
 440
 441         read_lock_irqsave(&uwb_est_lock, flags);
 442         size = -ENOSPC;
 443         if (rceb_size < sizeof(*rceb))
 444                 goto out;
 445         event = le16_to_cpu(rceb->wEvent);
 446         type_event_high = rceb->bEventType << 8 | (event & 0xff00) >> 8;
 447         for (itr = 0; itr < uwb_est_used; itr++) {
 448                 if (uwb_est[itr].type_event_high != type_event_high)
 449                         continue;
 450                 size = uwb_est_get_size(rc, &uwb_est[itr],
 451                                         event & 0x00ff, rceb, rceb_size);
 452                 /* try more tables that might handle the same type */
 453                 if (size != -ENOENT)
 454                         goto out;
 455         }
 456         dev_dbg(dev, "event 0x%02x/%04x/%02x: no handlers available; "
 457                 "RCEB %02x %02x %02x %02x\n",
 458                 (unsigned) rceb->bEventType,
 459                 (unsigned) le16_to_cpu(rceb->wEvent),
 460                 (unsigned) rceb->bEventContext,
 461                 ptr[0], ptr[1], ptr[2], ptr[3]);
 462         size = -ENOENT;
 463 out:
 464         read_unlock_irqrestore(&uwb_est_lock, flags);
 465         return size;
 466 }
 467 EXPORT_SYMBOL_GPL(uwb_est_find_size);