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: 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 msn",
- 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 %dn",
- 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 %dn",
- qos->window_size.value);
- } else if (index > 1) {
- qos->data_size.value = data_sizes[index--];
- IRDA_DEBUG(2, __FUNCTION__
- "(), redusing data size to %dn",
- 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 bytesn",
- self->qos_tx.data_size.value);
- IRDA_DEBUG(2, "Setting WINDOW_SIZE to %dn",
- self->qos_tx.window_size.value);
- IRDA_DEBUG(2, "Setting XBOFS to %dn",
- 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%02xn",
- param->pv.i);
- } else {
- /*
- * Stations must agree on baud rate, so calculate
- * intersection
- */
- IRDA_DEBUG(2, "Requested BAUD_RATE: 0x%04xn", (__u16) param->pv.i);
- final = (__u16) param->pv.i & self->qos_rx.baud_rate.bits;
- IRDA_DEBUG(2, "Final BAUD_RATE: 0x%04xn", 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: %02xn", (__u8) param->pv.i);
- final = (__u8) param->pv.i & self->qos_rx.link_disc_time.bits;
- IRDA_DEBUG(2, "Final LINK_DISC: %02xn", 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=%dn",
- 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 bytesn",
- 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=%dn",
- 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];
- }