qos.c

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

			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];
}