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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: Sun Jan 30 14:29:16 2000
* Modified by: Dag Brattli <dagb@cs.uit.no>
*
* Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
* All Rights Reserved.
* Copyright (c) 2000-2001 Jean Tourrilhes <jt@hpl.hp.com>
*
* 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>
/*
* Maximum values of the baud rate we negociate with the other end.
* Most often, you don't have to change that, because Linux-IrDA will
* use the maximum offered by the link layer, which usually works fine.
* In some very rare cases, you may want to limit it to lower speeds...
*/
int sysctl_max_baud_rate = 16000000;
/*
* Maximum value of the lap disconnect timer we negociate with the other end.
* Most often, the value below represent the best compromise, but some user
* may want to keep the LAP alive longuer or shorter in case of link failure.
* Remember that the threshold time (early warning) is fixed to 3s...
*/
int sysctl_max_noreply_time = 12;
/*
* Minimum turn time to be applied before transmitting to the peer.
* Nonzero values (usec) are used as lower limit to the per-connection
* mtt value which was announced by the other end during negotiation.
* Might be helpful if the peer device provides too short mtt.
* Default is 10 which means using the unmodified value given by the peer
* except if it's 0 (0 is likely a bug in the other stack).
*/
unsigned sysctl_min_tx_turn_time = 10;
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 */
__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 };
/* ---------------------- LOCAL SUBROUTINES ---------------------- */
/* Note : we start with a bunch of local subroutines.
* As the compiler is "one pass", this is the only way to get them to
* inline properly...
* Jean II
*/
/*
* Function value_index (value, array, size)
*
* Returns the index to the value in the specified array
*/
static inline int value_index(__u32 value, __u32 *array, int size)
{
int i;
for (i=0; i < size; i++)
if (array[i] == value)
break;
return i;
}
/*
* Function index_value (index, array)
*
* Returns value to index in array, easy!
*
*/
static inline __u32 index_value(int index, __u32 *array)
{
return array[index];
}
/*
* 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;
}
static inline __u32 byte_value(__u8 byte, __u32 *array)
{
int index;
ASSERT(array != NULL, return -1;);
index = msb_index(byte);
return index_value(index, array);
}
/*
* Function value_lower_bits (value, array)
*
* Returns a bit field marking all possibility lower than value.
*/
static inline int value_lower_bits(__u32 value, __u32 *array, int size, __u16 *field)
{
int i;
__u16 mask = 0x1;
__u16 result = 0x0;
for (i=0; i < size; i++) {
/* Add the current value to the bit field, shift mask */
result |= mask;
mask <<= 1;
/* Finished ? */
if (array[i] >= value)
break;
}
/* Send back a valid index */
if(i >= size)
i = size - 1; /* Last item */
*field = result;
return i;
}
/*
* Function value_highest_bit (value, array)
*
* Returns a bit field marking the highest possibility lower than value.
*/
static inline int value_highest_bit(__u32 value, __u32 *array, int size, __u16 *field)
{
int i;
__u16 mask = 0x1;
__u16 result = 0x0;
for (i=0; i < size; i++) {
/* Finished ? */
if (array[i] <= value)
break;
/* Shift mask */
mask <<= 1;
}
/* Set the current value to the bit field */
result |= mask;
/* Send back a valid index */
if(i >= size)
i = size - 1; /* Last item */
*field = result;
return i;
}
/* -------------------------- MAIN CALLS -------------------------- */
/*
* 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;
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)
{
int i;
/*
* These are the maximum supported values as specified on pages
* 39-43 in IrLAP
*/
/* Use sysctl to set some configurable values... */
/* Set configured max speed */
i = value_lower_bits(sysctl_max_baud_rate, baud_rates, 10,
&qos->baud_rate.bits);
sysctl_max_baud_rate = index_value(i, baud_rates);
/* Set configured max disc time */
i = value_lower_bits(sysctl_max_noreply_time, link_disc_times, 8,
&qos->link_disc_time.bits);
sysctl_max_noreply_time = index_value(i, link_disc_times);
/* LSB is first byte, MSB is second byte */
qos->baud_rate.bits &= 0x03ff;
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;
}
/*
* 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");
/*
* Make sure the mintt is sensible.
*/
if (sysctl_min_tx_turn_time > qos->min_turn_time.value) {
int i;
/* We don't really need bits, but easier this way */
i = value_highest_bit(sysctl_min_tx_turn_time, min_turn_times,
8, &qos->min_turn_time.bits);
sysctl_min_tx_turn_time = index_value(i, min_turn_times);
qos->min_turn_time.value = sysctl_min_tx_turn_time;
}
/*
* 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, 6);
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;
ret = irda_param_extract_all(self, skb->data, skb->len,
&irlap_param_info);
/* 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);
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", (__u16) param->pv.i);
final = (__u16) param->pv.i & 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.i = self->qos_rx.link_disc_time.bits;
else {
/*
* Stations must agree on link disconnect/threshold
* time.
*/
IRDA_DEBUG(2, "LINK_DISC: %02x\n", (__u8) param->pv.i);
final = (__u8) param->pv.i & 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.i = self->qos_rx.max_turn_time.bits;
else
self->qos_tx.max_turn_time.bits = (__u8) param->pv.i;
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.i = self->qos_rx.data_size.bits;
else
self->qos_tx.data_size.bits = (__u8) param->pv.i;
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.i = self->qos_rx.window_size.bits;
else
self->qos_tx.window_size.bits = (__u8) param->pv.i;
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.i = self->qos_rx.additional_bofs.bits;
else
self->qos_tx.additional_bofs.bits = (__u8) param->pv.i;
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.i = self->qos_rx.min_turn_time.bits;
else
self->qos_tx.min_turn_time.bits = (__u8) param->pv.i;
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, 10);
j = value_index(max_turn_time, max_turn_times, 4);
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;
}
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];
}
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