qos.c

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/*********************************************************************
 *                                
 * Filename:      qos.c
 * Version:       1.0
 * Description:   IrLAP QoS parameter negotiation
 * Status:        Stable
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Tue Sep  9 00:00:26 1997
 * Modified at:   Fri Apr 14 00:30:04 2000
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 * 
 *     Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>, 
 *     All Rights Reserved.
 *     
 *     This program is free software; you can redistribute it and/or 
 *     modify it under the terms of the GNU General Public License as 
 *     published by the Free Software Foundation; either version 2 of 
 *     the License, or (at your option) any later version.
 * 
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *     GNU General Public License for more details.
 * 
 *     You should have received a copy of the GNU General Public License 
 *     along with this program; if not, write to the Free Software 
 *     Foundation, Inc., 59 Temple Place, Suite 330, Boston, 
 *     MA 02111-1307 USA
 *     
 ********************************************************************/

#include <linux/config.h>
#include <asm/byteorder.h>

#include <net/irda/irda.h>
#include <net/irda/parameters.h>
#include <net/irda/qos.h>
#include <net/irda/irlap.h>
#ifdef CONFIG_IRDA_COMPRESSION
#include <net/irda/irlap_comp.h>
#include "../../drivers/net/zlib.h"

#define CI_BZIP2  27 /* Random pick */
#endif

static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get);
static int irlap_param_link_disconnect(void *instance, irda_param_t *parm, 
                                       int get);
static int irlap_param_max_turn_time(void *instance, irda_param_t *param, 
                                     int get);
static int irlap_param_data_size(void *instance, irda_param_t *param, int get);
static int irlap_param_window_size(void *instance, irda_param_t *param, 
                                   int get);
static int irlap_param_additional_bofs(void *instance, irda_param_t *parm, 
                                       int get);
static int irlap_param_min_turn_time(void *instance, irda_param_t *param, 
                                     int get);

__u32 min_turn_times[]  = { 10000, 5000, 1000, 500, 100, 50, 10, 0 }; /* us */
__u32 baud_rates[]      = { 2400, 9600, 19200, 38400, 57600, 115200, 576000, 
                            1152000, 4000000, 16000000 };           /* bps */
__u32 data_sizes[]      = { 64, 128, 256, 512, 1024, 2048 };        /* bytes */
__u32 add_bofs[]        = { 48, 24, 12, 5, 3, 2, 1, 0 };            /* bytes */
__u32 max_turn_times[]  = { 500, 250, 100, 50 };                    /* ms */
__u32 link_disc_times[] = { 3, 8, 12, 16, 20, 25, 30, 40 };         /* secs */

#ifdef CONFIG_IRDA_COMPRESSION
__u32 compressions[] = { CI_BZIP2, CI_DEFLATE, CI_DEFLATE_DRAFT };
#endif

__u32 max_line_capacities[10][4] = {
       /* 500 ms     250 ms  100 ms  50 ms (max turn time) */
        {    100,      0,      0,     0 }, /*     2400 bps */
        {    400,      0,      0,     0 }, /*     9600 bps */
        {    800,      0,      0,     0 }, /*    19200 bps */
        {   1600,      0,      0,     0 }, /*    38400 bps */
        {   2360,      0,      0,     0 }, /*    57600 bps */
        {   4800,   2400,    960,   480 }, /*   115200 bps */
        {  28800,  11520,   5760,  2880 }, /*   576000 bps */
        {  57600,  28800,  11520,  5760 }, /*  1152000 bps */
        { 200000, 100000,  40000, 20000 }, /*  4000000 bps */
        { 800000, 400000, 160000, 80000 }, /* 16000000 bps */
};

static pi_minor_info_t pi_minor_call_table_type_0[] = {
        { NULL, 0 },
/* 01 */{ irlap_param_baud_rate,       PV_INTEGER | PV_LITTLE_ENDIAN },
        { NULL, 0 },
        { NULL, 0 },
        { NULL, 0 },
        { NULL, 0 },
        { NULL, 0 },
        { NULL, 0 },
/* 08 */{ irlap_param_link_disconnect, PV_INT_8_BITS }
};

static pi_minor_info_t pi_minor_call_table_type_1[] = {
        { NULL, 0 },
        { NULL, 0 },
/* 82 */{ irlap_param_max_turn_time,   PV_INT_8_BITS },
/* 83 */{ irlap_param_data_size,       PV_INT_8_BITS },
/* 84 */{ irlap_param_window_size,     PV_INT_8_BITS },
/* 85 */{ irlap_param_additional_bofs, PV_INT_8_BITS },
/* 86 */{ irlap_param_min_turn_time,   PV_INT_8_BITS },
};

static pi_major_info_t pi_major_call_table[] = {
        { pi_minor_call_table_type_0, 9 },
        { pi_minor_call_table_type_1, 7 },
};

static pi_param_info_t irlap_param_info = { pi_major_call_table, 2, 0x7f, 7 };

/*
 * Function irda_qos_compute_intersection (qos, new)
 *
 *    Compute the intersection of the old QoS capabilites with new ones
 *
 */
void irda_qos_compute_intersection(struct qos_info *qos, struct qos_info *new)
{
        ASSERT(qos != NULL, return;);
        ASSERT(new != NULL, return;);

        /* Apply */
        qos->baud_rate.bits       &= new->baud_rate.bits;
        qos->window_size.bits     &= new->window_size.bits;
        qos->min_turn_time.bits   &= new->min_turn_time.bits;
        qos->max_turn_time.bits   &= new->max_turn_time.bits;
        qos->data_size.bits       &= new->data_size.bits;
        qos->link_disc_time.bits  &= new->link_disc_time.bits;
        qos->additional_bofs.bits &= new->additional_bofs.bits;

#ifdef CONFIG_IRDA_COMPRESSION
        qos->compression.bits     &= new->compression.bits;
#endif

        irda_qos_bits_to_value(qos);
}

/*
 * Function irda_init_max_qos_capabilies (qos)
 *
 *    The purpose of this function is for layers and drivers to be able to
 *    set the maximum QoS possible and then "and in" their own limitations
 * 
 */
void irda_init_max_qos_capabilies(struct qos_info *qos)
{
        /* 
         *  These are the maximum supported values as specified on pages
         *  39-43 in IrLAP
         */

        /* LSB is first byte, MSB is second byte */
        qos->baud_rate.bits     = 0x01ff; 

        qos->window_size.bits     = 0x7f;
        qos->min_turn_time.bits   = 0xff;
        qos->max_turn_time.bits   = 0x0f;
        qos->data_size.bits       = 0x3f;
        qos->link_disc_time.bits  = 0xff;
        qos->additional_bofs.bits = 0xff;

#ifdef CONFIG_IRDA_COMPRESSION  
        qos->compression.bits     = 0x03;
#endif
}

/*
 * Function irlap_adjust_qos_settings (qos)
 *
 *     Adjust QoS settings in case some values are not possible to use because
 *     of other settings
 */
void irlap_adjust_qos_settings(struct qos_info *qos)
{
        __u32 line_capacity;
        int index;

        IRDA_DEBUG(2, __FUNCTION__ "()\n");

        /* 
         * Not allowed to use a max turn time less than 500 ms if the baudrate
         * is less than 115200
         */
        if ((qos->baud_rate.value < 115200) && 
            (qos->max_turn_time.value < 500))
        {
                IRDA_DEBUG(0, __FUNCTION__ 
                           "(), adjusting max turn time from %d to 500 ms\n",
                           qos->max_turn_time.value);
                qos->max_turn_time.value = 500;
        }
        
        /*
         * The data size must be adjusted according to the baud rate and max 
         * turn time
         */
        index = value_index(qos->data_size.value, data_sizes);
        line_capacity = irlap_max_line_capacity(qos->baud_rate.value, 
                                                qos->max_turn_time.value);

#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
        while ((qos->data_size.value > line_capacity) && (index > 0)) {
                qos->data_size.value = data_sizes[index--];
                IRDA_DEBUG(2, __FUNCTION__ 
                           "(), redusing data size to %d\n",
                           qos->data_size.value);
        }
#else /* Use method descibed in section 6.6.11 of IrLAP */
        while (irlap_requested_line_capacity(qos) > line_capacity) {
                ASSERT(index != 0, return;);

                /* Must be able to send at least one frame */
                if (qos->window_size.value > 1) {
                        qos->window_size.value--;
                        IRDA_DEBUG(2, __FUNCTION__ 
                                   "(), redusing window size to %d\n",
                                   qos->window_size.value);
                } else if (index > 1) {
                        qos->data_size.value = data_sizes[index--];
                        IRDA_DEBUG(2, __FUNCTION__ 
                                   "(), redusing data size to %d\n",
                                   qos->data_size.value);
                } else {
                        WARNING(__FUNCTION__ "(), nothing more we can do!\n");
                }
        }
#endif CONFIG_IRDA_DYNAMIC_WINDOW
}

/*
 * Function irlap_negotiate (qos_device, qos_session, skb)
 *
 *    Negotiate QoS values, not really that much negotiation :-)
 *    We just set the QoS capabilities for the peer station
 *
 */
int irlap_qos_negotiate(struct irlap_cb *self, struct sk_buff *skb) 
{
        int ret;
#ifdef CONFIG_IRDA_COMPRESSION
        int comp_seen = FALSE;
#endif
        ret = irda_param_extract_all(self, skb->data, skb->len, 
                                     &irlap_param_info);
        
#ifdef CONFIG_IRDA_COMPRESSION
        if (!comp_seen) {
                IRDA_DEBUG( 4, __FUNCTION__ "(), Compression not seen!\n");
                self->qos_tx.compression.bits = 0x00;
                self->qos_rx.compression.bits = 0x00;
        }
#endif

        /* Convert the negotiated bits to values */
        irda_qos_bits_to_value(&self->qos_tx);
        irda_qos_bits_to_value(&self->qos_rx);

        irlap_adjust_qos_settings(&self->qos_tx);

        IRDA_DEBUG(2, "Setting BAUD_RATE to %d bps.\n", 
                   self->qos_tx.baud_rate.value);
        IRDA_DEBUG(2, "Setting DATA_SIZE to %d bytes\n",
                   self->qos_tx.data_size.value);
        IRDA_DEBUG(2, "Setting WINDOW_SIZE to %d\n", 
                   self->qos_tx.window_size.value);
        IRDA_DEBUG(2, "Setting XBOFS to %d\n", 
                   self->qos_tx.additional_bofs.value);
        IRDA_DEBUG(2, "Setting MAX_TURN_TIME to %d ms.\n",
                   self->qos_tx.max_turn_time.value);
        IRDA_DEBUG(2, "Setting MIN_TURN_TIME to %d usecs.\n",
                   self->qos_tx.min_turn_time.value);
        IRDA_DEBUG(2, "Setting LINK_DISC to %d secs.\n", 
                   self->qos_tx.link_disc_time.value);
#ifdef CONFIG_IRDA_COMPRESSION
        IRDA_DEBUG(2, "Setting COMPRESSION to %d\n", 
                   self->qos_tx.compression.value);
#endif  
        return ret;
}

/*
 * Function irlap_insert_negotiation_params (qos, fp)
 *
 *    Insert QoS negotiaion pararameters into frame
 *
 */
int irlap_insert_qos_negotiation_params(struct irlap_cb *self, 
                                        struct sk_buff *skb)
{
        int ret;

        /* Insert data rate */
        ret = irda_param_insert(self, PI_BAUD_RATE, skb->tail, 
                                skb_tailroom(skb), &irlap_param_info);
        if (ret < 0)
                return ret;
        skb_put(skb, ret);

        /* Insert max turnaround time */
        ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb->tail, 
                                skb_tailroom(skb), &irlap_param_info);
        if (ret < 0)
                return ret;
        skb_put(skb, ret);

        /* Insert data size */
        ret = irda_param_insert(self, PI_DATA_SIZE, skb->tail, 
                                skb_tailroom(skb), &irlap_param_info);
        if (ret < 0)
                return ret;
        skb_put(skb, ret);

        /* Insert window size */
        ret = irda_param_insert(self, PI_WINDOW_SIZE, skb->tail, 
                                skb_tailroom(skb), &irlap_param_info);
        if (ret < 0)
                return ret;
        skb_put(skb, ret);

        /* Insert additional BOFs */
        ret = irda_param_insert(self, PI_ADD_BOFS, skb->tail, 
                                skb_tailroom(skb), &irlap_param_info);
        if (ret < 0)
                return ret;
        skb_put(skb, ret);

        /* Insert minimum turnaround time */
        ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb->tail, 
                                skb_tailroom(skb), &irlap_param_info);
        if (ret < 0)
                return ret;
        skb_put(skb, ret);

        /* Insert link disconnect/threshold time */
        ret = irda_param_insert(self, PI_LINK_DISC, skb->tail, 
                                skb_tailroom(skb), &irlap_param_info);
        if (ret < 0)
                return ret;
        skb_put(skb, ret);

        return 0;
}

/*
 * Function irlap_param_baud_rate (instance, param, get)
 *
 *    Negotiate data-rate
 *
 */
static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get)
{
        __u16 final;

        struct irlap_cb *self = (struct irlap_cb *) instance;

        ASSERT(self != NULL, return -1;);
        ASSERT(self->magic == LAP_MAGIC, return -1;);

        if (get) {
                param->pv.i = self->qos_rx.baud_rate.bits;
                IRDA_DEBUG(2, __FUNCTION__ "(), baud rate = 0x%02x\n", 
                           param->pv.i);                
        } else {
                /* 
                 *  Stations must agree on baud rate, so calculate
                 *  intersection 
                 */
                IRDA_DEBUG(2, "Requested BAUD_RATE: 0x%04x\n", param->pv.s);
                final = param->pv.s & self->qos_rx.baud_rate.bits;

                IRDA_DEBUG(2, "Final BAUD_RATE: 0x%04x\n", final);
                self->qos_tx.baud_rate.bits = final;
                self->qos_rx.baud_rate.bits = final;
        }
        return 0;
}

/*
 * Function irlap_param_link_disconnect (instance, param, get)
 *
 *    Negotiate link disconnect/threshold time. 
 *
 */
static int irlap_param_link_disconnect(void *instance, irda_param_t *param, 
                                       int get)
{
        __u16 final;
        
        struct irlap_cb *self = (struct irlap_cb *) instance;
        
        ASSERT(self != NULL, return -1;);
        ASSERT(self->magic == LAP_MAGIC, return -1;);
        
        if (get)
                param->pv.b = self->qos_rx.link_disc_time.bits;
        else {
                /*  
                 *  Stations must agree on link disconnect/threshold 
                 *  time.
                 */
                IRDA_DEBUG(2, "LINK_DISC: %02x\n", param->pv.b);
                final = param->pv.b & self->qos_rx.link_disc_time.bits;

                IRDA_DEBUG(2, "Final LINK_DISC: %02x\n", final);
                self->qos_tx.link_disc_time.bits = final;
                self->qos_rx.link_disc_time.bits = final;
        }
        return 0;
}

/*
 * Function irlap_param_max_turn_time (instance, param, get)
 *
 *    Negotiate the maximum turnaround time. This is a type 1 parameter and
 *    will be negotiated independently for each station
 *
 */
static int irlap_param_max_turn_time(void *instance, irda_param_t *param, 
                                     int get)
{
        struct irlap_cb *self = (struct irlap_cb *) instance;
        
        ASSERT(self != NULL, return -1;);
        ASSERT(self->magic == LAP_MAGIC, return -1;);
        
        if (get)
                param->pv.b = self->qos_rx.max_turn_time.bits;
        else
                self->qos_tx.max_turn_time.bits = param->pv.b;

        return 0;
}

/*
 * Function irlap_param_data_size (instance, param, get)
 *
 *    Negotiate the data size. This is a type 1 parameter and
 *    will be negotiated independently for each station
 *
 */
static int irlap_param_data_size(void *instance, irda_param_t *param, int get)
{
        struct irlap_cb *self = (struct irlap_cb *) instance;
        
        ASSERT(self != NULL, return -1;);
        ASSERT(self->magic == LAP_MAGIC, return -1;);
        
        if (get)
                param->pv.b = self->qos_rx.data_size.bits;
        else
                self->qos_tx.data_size.bits = param->pv.b;

        return 0;
}

/*
 * Function irlap_param_window_size (instance, param, get)
 *
 *    Negotiate the window size. This is a type 1 parameter and
 *    will be negotiated independently for each station
 *
 */
static int irlap_param_window_size(void *instance, irda_param_t *param, 
                                   int get)
{
        struct irlap_cb *self = (struct irlap_cb *) instance;
        
        ASSERT(self != NULL, return -1;);
        ASSERT(self->magic == LAP_MAGIC, return -1;);
        
        if (get)
                param->pv.b = self->qos_rx.window_size.bits;
        else
                self->qos_tx.window_size.bits = param->pv.b;

        return 0;
}

/*
 * Function irlap_param_additional_bofs (instance, param, get)
 *
 *    Negotiate additional BOF characters. This is a type 1 parameter and
 *    will be negotiated independently for each station.
 */
static int irlap_param_additional_bofs(void *instance, irda_param_t *param, int get)
{
        struct irlap_cb *self = (struct irlap_cb *) instance;
        
        ASSERT(self != NULL, return -1;);
        ASSERT(self->magic == LAP_MAGIC, return -1;);
        
        if (get)
                param->pv.b = self->qos_rx.additional_bofs.bits;
        else
                self->qos_tx.additional_bofs.bits = param->pv.b;

        return 0;
}

/*
 * Function irlap_param_min_turn_time (instance, param, get)
 *
 *    Negotiate the minimum turn around time. This is a type 1 parameter and
 *    will be negotiated independently for each station
 */
static int irlap_param_min_turn_time(void *instance, irda_param_t *param, 
                                     int get)
{
        struct irlap_cb *self = (struct irlap_cb *) instance;
        
        ASSERT(self != NULL, return -1;);
        ASSERT(self->magic == LAP_MAGIC, return -1;);
        
        if (get)
                param->pv.b = self->qos_rx.min_turn_time.bits;
        else
                self->qos_tx.min_turn_time.bits = param->pv.b;

        return 0;
}

/*
 * Function irlap_max_line_capacity (speed, max_turn_time, min_turn_time)
 *
 *    Calculate the maximum line capacity
 *
 */
__u32 irlap_max_line_capacity(__u32 speed, __u32 max_turn_time)
{
        __u32 line_capacity;
        int i,j;

        IRDA_DEBUG(2, __FUNCTION__ "(), speed=%d, max_turn_time=%d\n",
                   speed, max_turn_time);

        i = value_index(speed, baud_rates);
        j = value_index(max_turn_time, max_turn_times);

        ASSERT(((i >=0) && (i <=10)), return 0;);
        ASSERT(((j >=0) && (j <=4)), return 0;);

        line_capacity = max_line_capacities[i][j];

        IRDA_DEBUG(2, __FUNCTION__ "(), line capacity=%d bytes\n", 
                   line_capacity);
        
        return line_capacity;
}

__u32 irlap_requested_line_capacity(struct qos_info *qos)
{       __u32 line_capacity;
        
        line_capacity = qos->window_size.value * 
                (qos->data_size.value + 6 + qos->additional_bofs.value) +
                irlap_min_turn_time_in_bytes(qos->baud_rate.value, 
                                             qos->min_turn_time.value);
        
        IRDA_DEBUG(2, __FUNCTION__ "(), requested line capacity=%d\n",
                   line_capacity);
        
        return line_capacity;                                     
}

__u32 irlap_min_turn_time_in_bytes(__u32 speed, __u32 min_turn_time)
{
        __u32 bytes;
        
        bytes = speed * min_turn_time / 10000000;
        
        return bytes;
}

__u32 byte_value(__u8 byte, __u32 *array) 
{
        int index;

        ASSERT(array != NULL, return -1;);

        index = msb_index(byte);

        return index_value(index, array);
}

/*
 * Function msb_index (word)
 *
 *    Returns index to most significant bit (MSB) in word
 *
 */
int msb_index (__u16 word) 
{
        __u16 msb = 0x8000;
        int index = 15;   /* Current MSB */
        
        while (msb) {
                if (word & msb)
                        break;   /* Found it! */
                msb >>=1;
                index--;
        }
        
        return index;
}

/*
 * Function value_index (value, array)
 *
 *    Returns the index to the value in the specified array
 */
int value_index(__u32 value, __u32 *array) 
{
        int i;
        
        for (i=0;i<8;i++)
                if (array[i] == value)
                        break;
        return i;
}

/*
 * Function index_value (index, array)
 *
 *    Returns value to index in array, easy!
 *

 */
__u32 index_value(int index, __u32 *array) 
{
        return array[index];
}

void irda_qos_bits_to_value(struct qos_info *qos)
{
        int index;

        ASSERT(qos != NULL, return;);
        
        index = msb_index(qos->baud_rate.bits);
        qos->baud_rate.value = baud_rates[index];

        index = msb_index(qos->data_size.bits);
        qos->data_size.value = data_sizes[index];

        index = msb_index(qos->window_size.bits);
        qos->window_size.value = index+1;

        index = msb_index(qos->min_turn_time.bits);
        qos->min_turn_time.value = min_turn_times[index];
        
        index = msb_index(qos->max_turn_time.bits);
        qos->max_turn_time.value = max_turn_times[index];

        index = msb_index(qos->link_disc_time.bits);
        qos->link_disc_time.value = link_disc_times[index];
        
        index = msb_index(qos->additional_bofs.bits);
        qos->additional_bofs.value = add_bofs[index];

#ifdef CONFIG_IRDA_COMPRESSION
        index = msb_index(qos->compression.bits);
        if (index >= 0)
                qos->compression.value = compressions[index];
        else 
                qos->compression.value = 0;
#endif
}

---