net/irda/qos.c

   1 /*********************************************************************
   2  *
   3  * Filename:      qos.c
   4  * Version:       1.0
   5  * Description:   IrLAP QoS parameter negotiation
   6  * Status:        Stable
   7  * Author:        Dag Brattli <dagb@cs.uit.no>
   8  * Created at:    Tue Sep  9 00:00:26 1997
   9  * Modified at:   Sun Jan 30 14:29:16 2000
  10  * Modified by:   Dag Brattli <dagb@cs.uit.no>
  11  *
  12  *     Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
  13  *     All Rights Reserved.
  14  *     Copyright (c) 2000-2001 Jean Tourrilhes <jt@hpl.hp.com>
  15  *
  16  *     This program is free software; you can redistribute it and/or
  17  *     modify it under the terms of the GNU General Public License as
  18  *     published by the Free Software Foundation; either version 2 of
  19  *     the License, or (at your option) any later version.
  20  *
  21  *     This program is distributed in the hope that it will be useful,
  22  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  24  *     GNU General Public License for more details.
  25  *
  26  *     You should have received a copy of the GNU General Public License
  27  *     along with this program; if not, write to the Free Software
  28  *     Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  29  *     MA 02111-1307 USA
  30  *
  31  ********************************************************************/
  32
  33 #include <linux/config.h>
  34 #include <asm/byteorder.h>
  35
  36 #include <net/irda/irda.h>
  37 #include <net/irda/parameters.h>
  38 #include <net/irda/qos.h>
  39 #include <net/irda/irlap.h>
  40
  41 /*
  42  * Maximum values of the baud rate we negociate with the other end.
  43  * Most often, you don't have to change that, because Linux-IrDA will
  44  * use the maximum offered by the link layer, which usually works fine.
  45  * In some very rare cases, you may want to limit it to lower speeds...
  46  */
  47 int sysctl_max_baud_rate = 16000000;
  48 /*
  49  * Maximum value of the lap disconnect timer we negociate with the other end.
  50  * Most often, the value below represent the best compromise, but some user
  51  * may want to keep the LAP alive longuer or shorter in case of link failure.
  52  * Remember that the threshold time (early warning) is fixed to 3s...
  53  */
  54 int sysctl_max_noreply_time = 12;
  55 /*
  56  * Minimum turn time to be applied before transmitting to the peer.
  57  * Nonzero values (usec) are used as lower limit to the per-connection
  58  * mtt value which was announced by the other end during negotiation.
  59  * Might be helpful if the peer device provides too short mtt.
  60  * Default is 10 which means using the unmodified value given by the peer
  61  * except if it's 0 (0 is likely a bug in the other stack).
  62  */
  63 unsigned sysctl_min_tx_turn_time = 10;
  64
  65 static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get);
  66 static int irlap_param_link_disconnect(void *instance, irda_param_t *parm,
  67                                        int get);
  68 static int irlap_param_max_turn_time(void *instance, irda_param_t *param,
  69                                      int get);
  70 static int irlap_param_data_size(void *instance, irda_param_t *param, int get);
  71 static int irlap_param_window_size(void *instance, irda_param_t *param,
  72                                    int get);
  73 static int irlap_param_additional_bofs(void *instance, irda_param_t *parm,
  74                                        int get);
  75 static int irlap_param_min_turn_time(void *instance, irda_param_t *param,
  76                                      int get);
  77
  78 __u32 min_turn_times[]  = { 10000, 5000, 1000, 500, 100, 50, 10, 0 }; /* us */
  79 __u32 baud_rates[]      = { 2400, 9600, 19200, 38400, 57600, 115200, 576000,
  80                             1152000, 4000000, 16000000 };           /* bps */
  81 __u32 data_sizes[]      = { 64, 128, 256, 512, 1024, 2048 };        /* bytes */
  82 __u32 add_bofs[]        = { 48, 24, 12, 5, 3, 2, 1, 0 };            /* bytes */
  83 __u32 max_turn_times[]  = { 500, 250, 100, 50 };                    /* ms */
  84 __u32 link_disc_times[] = { 3, 8, 12, 16, 20, 25, 30, 40 };         /* secs */
  85
  86 __u32 max_line_capacities[10][4] = {
  87        /* 500 ms     250 ms  100 ms  50 ms (max turn time) */
  88         {    100,      0,      0,     0 }, /*     2400 bps */
  89         {    400,      0,      0,     0 }, /*     9600 bps */
  90         {    800,      0,      0,     0 }, /*    19200 bps */
  91         {   1600,      0,      0,     0 }, /*    38400 bps */
  92         {   2360,      0,      0,     0 }, /*    57600 bps */
  93         {   4800,   2400,    960,   480 }, /*   115200 bps */
  94         {  28800,  11520,   5760,  2880 }, /*   576000 bps */
  95         {  57600,  28800,  11520,  5760 }, /*  1152000 bps */
  96         { 200000, 100000,  40000, 20000 }, /*  4000000 bps */
  97         { 800000, 400000, 160000, 80000 }, /* 16000000 bps */
  98 };
  99
 100 static pi_minor_info_t pi_minor_call_table_type_0[] = {
 101         { NULL, 0 },
 102 /* 01 */{ irlap_param_baud_rate,       PV_INTEGER | PV_LITTLE_ENDIAN },
 103         { NULL, 0 },
 104         { NULL, 0 },
 105         { NULL, 0 },
 106         { NULL, 0 },
 107         { NULL, 0 },
 108         { NULL, 0 },
 109 /* 08 */{ irlap_param_link_disconnect, PV_INT_8_BITS }
 110 };
 111
 112 static pi_minor_info_t pi_minor_call_table_type_1[] = {
 113         { NULL, 0 },
 114         { NULL, 0 },
 115 /* 82 */{ irlap_param_max_turn_time,   PV_INT_8_BITS },
 116 /* 83 */{ irlap_param_data_size,       PV_INT_8_BITS },
 117 /* 84 */{ irlap_param_window_size,     PV_INT_8_BITS },
 118 /* 85 */{ irlap_param_additional_bofs, PV_INT_8_BITS },
 119 /* 86 */{ irlap_param_min_turn_time,   PV_INT_8_BITS },
 120 };
 121
 122 static pi_major_info_t pi_major_call_table[] = {
 123         { pi_minor_call_table_type_0, 9 },
 124         { pi_minor_call_table_type_1, 7 },
 125 };
 126
 127 static pi_param_info_t irlap_param_info = { pi_major_call_table, 2, 0x7f, 7 };
 128
 129 /* ---------------------- LOCAL SUBROUTINES ---------------------- */
 130 /* Note : we start with a bunch of local subroutines.
 131  * As the compiler is "one pass", this is the only way to get them to
 132  * inline properly...
 133  * Jean II
 134  */
 135 /*
 136  * Function value_index (value, array, size)
 137  *
 138  *    Returns the index to the value in the specified array
 139  */
 140 static inline int value_index(__u32 value, __u32 *array, int size)
 141 {
 142         int i;
 143
 144         for (i=0; i < size; i++)
 145                 if (array[i] == value)
 146                         break;
 147         return i;
 148 }
 149
 150 /*
 151  * Function index_value (index, array)
 152  *
 153  *    Returns value to index in array, easy!
 154  *
 155  */
 156 static inline __u32 index_value(int index, __u32 *array)
 157 {
 158         return array[index];
 159 }
 160
 161 /*
 162  * Function msb_index (word)
 163  *
 164  *    Returns index to most significant bit (MSB) in word
 165  *
 166  */
 167 int msb_index (__u16 word)
 168 {
 169         __u16 msb = 0x8000;
 170         int index = 15;   /* Current MSB */
 171
 172         while (msb) {
 173                 if (word & msb)
 174                         break;   /* Found it! */
 175                 msb >>=1;
 176                 index--;
 177         }
 178         return index;
 179 }
 180
 181 static inline __u32 byte_value(__u8 byte, __u32 *array)
 182 {
 183         int index;
 184
 185         ASSERT(array != NULL, return -1;);
 186
 187         index = msb_index(byte);
 188
 189         return index_value(index, array);
 190 }
 191
 192 /*
 193  * Function value_lower_bits (value, array)
 194  *
 195  *    Returns a bit field marking all possibility lower than value.
 196  */
 197 static inline int value_lower_bits(__u32 value, __u32 *array, int size, __u16 *field)
 198 {
 199         int     i;
 200         __u16   mask = 0x1;
 201         __u16   result = 0x0;
 202
 203         for (i=0; i < size; i++) {
 204                 /* Add the current value to the bit field, shift mask */
 205                 result |= mask;
 206                 mask <<= 1;
 207                 /* Finished ? */
 208                 if (array[i] >= value)
 209                         break;
 210         }
 211         /* Send back a valid index */
 212         if(i >= size)
 213           i = size - 1; /* Last item */
 214         *field = result;
 215         return i;
 216 }
 217
 218 /*
 219  * Function value_highest_bit (value, array)
 220  *
 221  *    Returns a bit field marking the highest possibility lower than value.
 222  */
 223 static inline int value_highest_bit(__u32 value, __u32 *array, int size, __u16 *field)
 224 {
 225         int     i;
 226         __u16   mask = 0x1;
 227         __u16   result = 0x0;
 228
 229         for (i=0; i < size; i++) {
 230                 /* Finished ? */
 231                 if (array[i] <= value)
 232                         break;
 233                 /* Shift mask */
 234                 mask <<= 1;
 235         }
 236         /* Set the current value to the bit field */
 237         result |= mask;
 238         /* Send back a valid index */
 239         if(i >= size)
 240           i = size - 1; /* Last item */
 241         *field = result;
 242         return i;
 243 }
 244
 245 /* -------------------------- MAIN CALLS -------------------------- */
 246
 247 /*
 248  * Function irda_qos_compute_intersection (qos, new)
 249  *
 250  *    Compute the intersection of the old QoS capabilites with new ones
 251  *
 252  */
 253 void irda_qos_compute_intersection(struct qos_info *qos, struct qos_info *new)
 254 {
 255         ASSERT(qos != NULL, return;);
 256         ASSERT(new != NULL, return;);
 257
 258         /* Apply */
 259         qos->baud_rate.bits       &= new->baud_rate.bits;
 260         qos->window_size.bits     &= new->window_size.bits;
 261         qos->min_turn_time.bits   &= new->min_turn_time.bits;
 262         qos->max_turn_time.bits   &= new->max_turn_time.bits;
 263         qos->data_size.bits       &= new->data_size.bits;
 264         qos->link_disc_time.bits  &= new->link_disc_time.bits;
 265         qos->additional_bofs.bits &= new->additional_bofs.bits;
 266
 267         irda_qos_bits_to_value(qos);
 268 }
 269
 270 /*
 271  * Function irda_init_max_qos_capabilies (qos)
 272  *
 273  *    The purpose of this function is for layers and drivers to be able to
 274  *    set the maximum QoS possible and then "and in" their own limitations
 275  *
 276  */
 277 void irda_init_max_qos_capabilies(struct qos_info *qos)
 278 {
 279         int i;
 280         /*
 281          *  These are the maximum supported values as specified on pages
 282          *  39-43 in IrLAP
 283          */
 284
 285         /* Use sysctl to set some configurable values... */
 286         /* Set configured max speed */
 287         i = value_lower_bits(sysctl_max_baud_rate, baud_rates, 10,
 288                              &qos->baud_rate.bits);
 289         sysctl_max_baud_rate = index_value(i, baud_rates);
 290
 291         /* Set configured max disc time */
 292         i = value_lower_bits(sysctl_max_noreply_time, link_disc_times, 8,
 293                              &qos->link_disc_time.bits);
 294         sysctl_max_noreply_time = index_value(i, link_disc_times);
 295
 296         /* LSB is first byte, MSB is second byte */
 297         qos->baud_rate.bits    &= 0x03ff;
 298
 299         qos->window_size.bits     = 0x7f;
 300         qos->min_turn_time.bits   = 0xff;
 301         qos->max_turn_time.bits   = 0x0f;
 302         qos->data_size.bits       = 0x3f;
 303         qos->link_disc_time.bits &= 0xff;
 304         qos->additional_bofs.bits = 0xff;
 305 }
 306
 307 /*
 308  * Function irlap_adjust_qos_settings (qos)
 309  *
 310  *     Adjust QoS settings in case some values are not possible to use because
 311  *     of other settings
 312  */
 313 void irlap_adjust_qos_settings(struct qos_info *qos)
 314 {
 315         __u32 line_capacity;
 316         int index;
 317
 318         IRDA_DEBUG(2, __FUNCTION__ "()\n");
 319
 320         /*
 321          * Make sure the mintt is sensible.
 322          */
 323         if (sysctl_min_tx_turn_time > qos->min_turn_time.value) {
 324                 int i;
 325
 326                 /* We don't really need bits, but easier this way */
 327                 i = value_highest_bit(sysctl_min_tx_turn_time, min_turn_times,
 328                                       8, &qos->min_turn_time.bits);
 329                 sysctl_min_tx_turn_time = index_value(i, min_turn_times);
 330                 qos->min_turn_time.value = sysctl_min_tx_turn_time;
 331         }
 332
 333         /*
 334          * Not allowed to use a max turn time less than 500 ms if the baudrate
 335          * is less than 115200
 336          */
 337         if ((qos->baud_rate.value < 115200) &&
 338             (qos->max_turn_time.value < 500))
 339         {
 340                 IRDA_DEBUG(0, __FUNCTION__
 341                            "(), adjusting max turn time from %d to 500 ms\n",
 342                            qos->max_turn_time.value);
 343                 qos->max_turn_time.value = 500;
 344         }
 345
 346         /*
 347          * The data size must be adjusted according to the baud rate and max
 348          * turn time
 349          */
 350         index = value_index(qos->data_size.value, data_sizes, 6);
 351         line_capacity = irlap_max_line_capacity(qos->baud_rate.value,
 352                                                 qos->max_turn_time.value);
 353
 354 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
 355         while ((qos->data_size.value > line_capacity) && (index > 0)) {
 356                 qos->data_size.value = data_sizes[index--];
 357                 IRDA_DEBUG(2, __FUNCTION__
 358                            "(), redusing data size to %d\n",
 359                            qos->data_size.value);
 360         }
 361 #else /* Use method descibed in section 6.6.11 of IrLAP */
 362         while (irlap_requested_line_capacity(qos) > line_capacity) {
 363                 ASSERT(index != 0, return;);
 364
 365                 /* Must be able to send at least one frame */
 366                 if (qos->window_size.value > 1) {
 367                         qos->window_size.value--;
 368                         IRDA_DEBUG(2, __FUNCTION__
 369                                    "(), redusing window size to %d\n",
 370                                    qos->window_size.value);
 371                 } else if (index > 1) {
 372                         qos->data_size.value = data_sizes[index--];
 373                         IRDA_DEBUG(2, __FUNCTION__
 374                                    "(), redusing data size to %d\n",
 375                                    qos->data_size.value);
 376                 } else {
 377                         WARNING(__FUNCTION__ "(), nothing more we can do!\n");
 378                 }
 379         }
 380 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
 381 }
 382
 383 /*
 384  * Function irlap_negotiate (qos_device, qos_session, skb)
 385  *
 386  *    Negotiate QoS values, not really that much negotiation :-)
 387  *    We just set the QoS capabilities for the peer station
 388  *
 389  */
 390 int irlap_qos_negotiate(struct irlap_cb *self, struct sk_buff *skb)
 391 {
 392         int ret;
 393
 394         ret = irda_param_extract_all(self, skb->data, skb->len,
 395                                      &irlap_param_info);
 396
 397         /* Convert the negotiated bits to values */
 398         irda_qos_bits_to_value(&self->qos_tx);
 399         irda_qos_bits_to_value(&self->qos_rx);
 400
 401         irlap_adjust_qos_settings(&self->qos_tx);
 402
 403         IRDA_DEBUG(2, "Setting BAUD_RATE to %d bps.\n",
 404                    self->qos_tx.baud_rate.value);
 405         IRDA_DEBUG(2, "Setting DATA_SIZE to %d bytes\n",
 406                    self->qos_tx.data_size.value);
 407         IRDA_DEBUG(2, "Setting WINDOW_SIZE to %d\n",
 408                    self->qos_tx.window_size.value);
 409         IRDA_DEBUG(2, "Setting XBOFS to %d\n",
 410                    self->qos_tx.additional_bofs.value);
 411         IRDA_DEBUG(2, "Setting MAX_TURN_TIME to %d ms.\n",
 412                    self->qos_tx.max_turn_time.value);
 413         IRDA_DEBUG(2, "Setting MIN_TURN_TIME to %d usecs.\n",
 414                    self->qos_tx.min_turn_time.value);
 415         IRDA_DEBUG(2, "Setting LINK_DISC to %d secs.\n",
 416                    self->qos_tx.link_disc_time.value);
 417         return ret;
 418 }
 419
 420 /*
 421  * Function irlap_insert_negotiation_params (qos, fp)
 422  *
 423  *    Insert QoS negotiaion pararameters into frame
 424  *
 425  */
 426 int irlap_insert_qos_negotiation_params(struct irlap_cb *self,
 427                                         struct sk_buff *skb)
 428 {
 429         int ret;
 430
 431         /* Insert data rate */
 432         ret = irda_param_insert(self, PI_BAUD_RATE, skb->tail,
 433                                 skb_tailroom(skb), &irlap_param_info);
 434         if (ret < 0)
 435                 return ret;
 436         skb_put(skb, ret);
 437
 438         /* Insert max turnaround time */
 439         ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb->tail,
 440                                 skb_tailroom(skb), &irlap_param_info);
 441         if (ret < 0)
 442                 return ret;
 443         skb_put(skb, ret);
 444
 445         /* Insert data size */
 446         ret = irda_param_insert(self, PI_DATA_SIZE, skb->tail,
 447                                 skb_tailroom(skb), &irlap_param_info);
 448         if (ret < 0)
 449                 return ret;
 450         skb_put(skb, ret);
 451
 452         /* Insert window size */
 453         ret = irda_param_insert(self, PI_WINDOW_SIZE, skb->tail,
 454                                 skb_tailroom(skb), &irlap_param_info);
 455         if (ret < 0)
 456                 return ret;
 457         skb_put(skb, ret);
 458
 459         /* Insert additional BOFs */
 460         ret = irda_param_insert(self, PI_ADD_BOFS, skb->tail,
 461                                 skb_tailroom(skb), &irlap_param_info);
 462         if (ret < 0)
 463                 return ret;
 464         skb_put(skb, ret);
 465
 466         /* Insert minimum turnaround time */
 467         ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb->tail,
 468                                 skb_tailroom(skb), &irlap_param_info);
 469         if (ret < 0)
 470                 return ret;
 471         skb_put(skb, ret);
 472
 473         /* Insert link disconnect/threshold time */
 474         ret = irda_param_insert(self, PI_LINK_DISC, skb->tail,
 475                                 skb_tailroom(skb), &irlap_param_info);
 476         if (ret < 0)
 477                 return ret;
 478         skb_put(skb, ret);
 479
 480         return 0;
 481 }
 482
 483 /*
 484  * Function irlap_param_baud_rate (instance, param, get)
 485  *
 486  *    Negotiate data-rate
 487  *
 488  */
 489 static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get)
 490 {
 491         __u16 final;
 492
 493         struct irlap_cb *self = (struct irlap_cb *) instance;
 494
 495         ASSERT(self != NULL, return -1;);
 496         ASSERT(self->magic == LAP_MAGIC, return -1;);
 497
 498         if (get) {
 499                 param->pv.i = self->qos_rx.baud_rate.bits;
 500                 IRDA_DEBUG(2, __FUNCTION__ "(), baud rate = 0x%02x\n",
 501                            param->pv.i);
 502         } else {
 503                 /*
 504                  *  Stations must agree on baud rate, so calculate
 505                  *  intersection
 506                  */
 507                 IRDA_DEBUG(2, "Requested BAUD_RATE: 0x%04x\n", (__u16) param->pv.i);
 508                 final = (__u16) param->pv.i & self->qos_rx.baud_rate.bits;
 509
 510                 IRDA_DEBUG(2, "Final BAUD_RATE: 0x%04x\n", final);
 511                 self->qos_tx.baud_rate.bits = final;
 512                 self->qos_rx.baud_rate.bits = final;
 513         }
 514
 515         return 0;
 516 }
 517
 518 /*
 519  * Function irlap_param_link_disconnect (instance, param, get)
 520  *
 521  *    Negotiate link disconnect/threshold time.
 522  *
 523  */
 524 static int irlap_param_link_disconnect(void *instance, irda_param_t *param,
 525                                        int get)
 526 {
 527         __u16 final;
 528
 529         struct irlap_cb *self = (struct irlap_cb *) instance;
 530
 531         ASSERT(self != NULL, return -1;);
 532         ASSERT(self->magic == LAP_MAGIC, return -1;);
 533
 534         if (get)
 535                 param->pv.i = self->qos_rx.link_disc_time.bits;
 536         else {
 537                 /*
 538                  *  Stations must agree on link disconnect/threshold
 539                  *  time.
 540                  */
 541                 IRDA_DEBUG(2, "LINK_DISC: %02x\n", (__u8) param->pv.i);
 542                 final = (__u8) param->pv.i & self->qos_rx.link_disc_time.bits;
 543
 544                 IRDA_DEBUG(2, "Final LINK_DISC: %02x\n", final);
 545                 self->qos_tx.link_disc_time.bits = final;
 546                 self->qos_rx.link_disc_time.bits = final;
 547         }
 548         return 0;
 549 }
 550
 551 /*
 552  * Function irlap_param_max_turn_time (instance, param, get)
 553  *
 554  *    Negotiate the maximum turnaround time. This is a type 1 parameter and
 555  *    will be negotiated independently for each station
 556  *
 557  */
 558 static int irlap_param_max_turn_time(void *instance, irda_param_t *param,
 559                                      int get)
 560 {
 561         struct irlap_cb *self = (struct irlap_cb *) instance;
 562
 563         ASSERT(self != NULL, return -1;);
 564         ASSERT(self->magic == LAP_MAGIC, return -1;);
 565
 566         if (get)
 567                 param->pv.i = self->qos_rx.max_turn_time.bits;
 568         else
 569                 self->qos_tx.max_turn_time.bits = (__u8) param->pv.i;
 570
 571         return 0;
 572 }
 573
 574 /*
 575  * Function irlap_param_data_size (instance, param, get)
 576  *
 577  *    Negotiate the data size. This is a type 1 parameter and
 578  *    will be negotiated independently for each station
 579  *
 580  */
 581 static int irlap_param_data_size(void *instance, irda_param_t *param, int get)
 582 {
 583         struct irlap_cb *self = (struct irlap_cb *) instance;
 584
 585         ASSERT(self != NULL, return -1;);
 586         ASSERT(self->magic == LAP_MAGIC, return -1;);
 587
 588         if (get)
 589                 param->pv.i = self->qos_rx.data_size.bits;
 590         else
 591                 self->qos_tx.data_size.bits = (__u8) param->pv.i;
 592
 593         return 0;
 594 }
 595
 596 /*
 597  * Function irlap_param_window_size (instance, param, get)
 598  *
 599  *    Negotiate the window size. This is a type 1 parameter and
 600  *    will be negotiated independently for each station
 601  *
 602  */
 603 static int irlap_param_window_size(void *instance, irda_param_t *param,
 604                                    int get)
 605 {
 606         struct irlap_cb *self = (struct irlap_cb *) instance;
 607
 608         ASSERT(self != NULL, return -1;);
 609         ASSERT(self->magic == LAP_MAGIC, return -1;);
 610
 611         if (get)
 612                 param->pv.i = self->qos_rx.window_size.bits;
 613         else
 614                 self->qos_tx.window_size.bits = (__u8) param->pv.i;
 615
 616         return 0;
 617 }
 618
 619 /*
 620  * Function irlap_param_additional_bofs (instance, param, get)
 621  *
 622  *    Negotiate additional BOF characters. This is a type 1 parameter and
 623  *    will be negotiated independently for each station.
 624  */
 625 static int irlap_param_additional_bofs(void *instance, irda_param_t *param, int get)
 626 {
 627         struct irlap_cb *self = (struct irlap_cb *) instance;
 628
 629         ASSERT(self != NULL, return -1;);
 630         ASSERT(self->magic == LAP_MAGIC, return -1;);
 631
 632         if (get)
 633                 param->pv.i = self->qos_rx.additional_bofs.bits;
 634         else
 635                 self->qos_tx.additional_bofs.bits = (__u8) param->pv.i;
 636
 637         return 0;
 638 }
 639
 640 /*
 641  * Function irlap_param_min_turn_time (instance, param, get)
 642  *
 643  *    Negotiate the minimum turn around time. This is a type 1 parameter and
 644  *    will be negotiated independently for each station
 645  */
 646 static int irlap_param_min_turn_time(void *instance, irda_param_t *param,
 647                                      int get)
 648 {
 649         struct irlap_cb *self = (struct irlap_cb *) instance;
 650
 651         ASSERT(self != NULL, return -1;);
 652         ASSERT(self->magic == LAP_MAGIC, return -1;);
 653
 654         if (get)
 655                 param->pv.i = self->qos_rx.min_turn_time.bits;
 656         else
 657                 self->qos_tx.min_turn_time.bits = (__u8) param->pv.i;
 658
 659         return 0;
 660 }
 661
 662 /*
 663  * Function irlap_max_line_capacity (speed, max_turn_time, min_turn_time)
 664  *
 665  *    Calculate the maximum line capacity
 666  *
 667  */
 668 __u32 irlap_max_line_capacity(__u32 speed, __u32 max_turn_time)
 669 {
 670         __u32 line_capacity;
 671         int i,j;
 672
 673         IRDA_DEBUG(2, __FUNCTION__ "(), speed=%d, max_turn_time=%d\n",
 674                    speed, max_turn_time);
 675
 676         i = value_index(speed, baud_rates, 10);
 677         j = value_index(max_turn_time, max_turn_times, 4);
 678
 679         ASSERT(((i >=0) && (i <=10)), return 0;);
 680         ASSERT(((j >=0) && (j <=4)), return 0;);
 681
 682         line_capacity = max_line_capacities[i][j];
 683
 684         IRDA_DEBUG(2, __FUNCTION__ "(), line capacity=%d bytes\n",
 685                    line_capacity);
 686
 687         return line_capacity;
 688 }
 689
 690 __u32 irlap_requested_line_capacity(struct qos_info *qos)
 691 {       __u32 line_capacity;
 692
 693         line_capacity = qos->window_size.value *
 694                 (qos->data_size.value + 6 + qos->additional_bofs.value) +
 695                 irlap_min_turn_time_in_bytes(qos->baud_rate.value,
 696                                              qos->min_turn_time.value);
 697
 698         IRDA_DEBUG(2, __FUNCTION__ "(), requested line capacity=%d\n",
 699                    line_capacity);
 700
 701         return line_capacity;
 702 }
 703
 704 void irda_qos_bits_to_value(struct qos_info *qos)
 705 {
 706         int index;
 707
 708         ASSERT(qos != NULL, return;);
 709
 710         index = msb_index(qos->baud_rate.bits);
 711         qos->baud_rate.value = baud_rates[index];
 712
 713         index = msb_index(qos->data_size.bits);
 714         qos->data_size.value = data_sizes[index];
 715
 716         index = msb_index(qos->window_size.bits);
 717         qos->window_size.value = index+1;
 718
 719         index = msb_index(qos->min_turn_time.bits);
 720         qos->min_turn_time.value = min_turn_times[index];
 721
 722         index = msb_index(qos->max_turn_time.bits);
 723         qos->max_turn_time.value = max_turn_times[index];
 724
 725         index = msb_index(qos->link_disc_time.bits);
 726         qos->link_disc_time.value = link_disc_times[index];
 727
 728         index = msb_index(qos->additional_bofs.bits);
 729         qos->additional_bofs.value = add_bofs[index];
 730 }