usb_atm.c

h内核

	memcpy(target, ctrl->aal5_trailer, ATM_AAL5_TRAILER);
	target += ATM_AAL5_TRAILER;
	/* set pti bit in last cell */
	*(target + 3 - ATM_CELL_SIZE) |= 0x2;
	if (instance->snd_padding) {
		memset(target, 0, instance->snd_padding);
		target += instance->snd_padding;
	}
 out:
	*target_p = target;
	return nc - ctrl->num_cells;
}

/**************
**  receive  **
**************/

static void udsl_complete_receive(struct urb *urb, struct pt_regs *regs)
{
	struct udsl_receive_buffer *buf;
	struct udsl_instance_data *instance;
	struct udsl_receiver *rcv;
	unsigned long flags;

	if (!urb || !(rcv = urb->context)) {
		dbg("udsl_complete_receive: bad urb!");
		return;
	}

	instance = rcv->instance;
	buf = rcv->buffer;

	buf->filled_cells = urb->actual_length / (ATM_CELL_SIZE + instance->rcv_padding);

	vdbg("udsl_complete_receive: urb 0x%p, status %d, actual_length %d, filled_cells %u, rcv 0x%p, buf 0x%p", urb, urb->status, urb->actual_length, buf->filled_cells, rcv, buf);

	UDSL_ASSERT(buf->filled_cells <= rcv_buf_size);

	/* may not be in_interrupt() */
	spin_lock_irqsave(&instance->receive_lock, flags);
	list_add(&rcv->list, &instance->spare_receivers);
	list_add_tail(&buf->list, &instance->filled_receive_buffers);
	if (likely(!urb->status))
		tasklet_schedule(&instance->receive_tasklet);
	spin_unlock_irqrestore(&instance->receive_lock, flags);
}

static void udsl_process_receive(unsigned long data)
{
	struct udsl_receive_buffer *buf;
	struct udsl_instance_data *instance = (struct udsl_instance_data *)data;
	struct udsl_receiver *rcv;
	int err;

 made_progress:
	while (!list_empty(&instance->spare_receive_buffers)) {
		spin_lock_irq(&instance->receive_lock);
		if (list_empty(&instance->spare_receivers)) {
			spin_unlock_irq(&instance->receive_lock);
			break;
		}
		rcv = list_entry(instance->spare_receivers.next,
				 struct udsl_receiver, list);
		list_del(&rcv->list);
		spin_unlock_irq(&instance->receive_lock);

		buf = list_entry(instance->spare_receive_buffers.next,
				 struct udsl_receive_buffer, list);
		list_del(&buf->list);

		rcv->buffer = buf;

		usb_fill_bulk_urb(rcv->urb, instance->usb_dev,
				  usb_rcvbulkpipe(instance->usb_dev, instance->data_endpoint),
				  buf->base,
				  rcv_buf_size * (ATM_CELL_SIZE + instance->rcv_padding),
				  udsl_complete_receive, rcv);

		vdbg("udsl_process_receive: sending urb 0x%p, rcv 0x%p, buf 0x%p",
		     rcv->urb, rcv, buf);

		if ((err = usb_submit_urb(rcv->urb, GFP_ATOMIC)) < 0) {
			dbg("udsl_process_receive: urb submission failed (%d)!", err);
			list_add(&buf->list, &instance->spare_receive_buffers);
			spin_lock_irq(&instance->receive_lock);
			list_add(&rcv->list, &instance->spare_receivers);
			spin_unlock_irq(&instance->receive_lock);
			break;
		}
	}

	spin_lock_irq(&instance->receive_lock);
	if (list_empty(&instance->filled_receive_buffers)) {
		spin_unlock_irq(&instance->receive_lock);
		return;		/* done - no more buffers */
	}
	buf = list_entry(instance->filled_receive_buffers.next,
			 struct udsl_receive_buffer, list);
	list_del(&buf->list);
	spin_unlock_irq(&instance->receive_lock);

	vdbg("udsl_process_receive: processing buf 0x%p", buf);
	udsl_extract_cells(instance, buf->base, buf->filled_cells);
	list_add(&buf->list, &instance->spare_receive_buffers);
	goto made_progress;
}

/***********
**  send  **
***********/

static void udsl_complete_send(struct urb *urb, struct pt_regs *regs)
{
	struct udsl_instance_data *instance;
	struct udsl_sender *snd;
	unsigned long flags;

	if (!urb || !(snd = urb->context) || !(instance = snd->instance)) {
		dbg("udsl_complete_send: bad urb!");
		return;
	}

	vdbg("udsl_complete_send: urb 0x%p, status %d, snd 0x%p, buf 0x%p", urb,
	     urb->status, snd, snd->buffer);

	/* may not be in_interrupt() */
	spin_lock_irqsave(&instance->send_lock, flags);
	list_add(&snd->list, &instance->spare_senders);
	list_add(&snd->buffer->list, &instance->spare_send_buffers);
	tasklet_schedule(&instance->send_tasklet);
	spin_unlock_irqrestore(&instance->send_lock, flags);
}

static void udsl_process_send(unsigned long data)
{
	struct udsl_send_buffer *buf;
	struct udsl_instance_data *instance = (struct udsl_instance_data *)data;
	struct sk_buff *skb;
	struct udsl_sender *snd;
	int err;
	unsigned int num_written;

 made_progress:
	spin_lock_irq(&instance->send_lock);
	while (!list_empty(&instance->spare_senders)) {
		if (!list_empty(&instance->filled_send_buffers)) {
			buf = list_entry(instance->filled_send_buffers.next,
					 struct udsl_send_buffer, list);
			list_del(&buf->list);
		} else if ((buf = instance->current_buffer)) {
			instance->current_buffer = NULL;
		} else		/* all buffers empty */
			break;

		snd = list_entry(instance->spare_senders.next,
				 struct udsl_sender, list);
		list_del(&snd->list);
		spin_unlock_irq(&instance->send_lock);

		snd->buffer = buf;
		usb_fill_bulk_urb(snd->urb, instance->usb_dev,
				  usb_sndbulkpipe(instance->usb_dev, instance->data_endpoint),
				  buf->base,
				  (snd_buf_size - buf->free_cells) * (ATM_CELL_SIZE + instance->snd_padding),
				  udsl_complete_send, snd);

		vdbg("udsl_process_send: submitting urb 0x%p (%d cells), snd 0x%p, buf 0x%p",
		     snd->urb, snd_buf_size - buf->free_cells, snd, buf);

		if ((err = usb_submit_urb(snd->urb, GFP_ATOMIC)) < 0) {
			dbg("udsl_process_send: urb submission failed (%d)!", err);
			spin_lock_irq(&instance->send_lock);
			list_add(&snd->list, &instance->spare_senders);
			spin_unlock_irq(&instance->send_lock);
			list_add(&buf->list, &instance->filled_send_buffers);
			return;	/* bail out */
		}

		spin_lock_irq(&instance->send_lock);
	}			/* while */
	spin_unlock_irq(&instance->send_lock);

	if (!instance->current_skb)
		instance->current_skb = skb_dequeue(&instance->sndqueue);
	if (!instance->current_skb)
		return;		/* done - no more skbs */

	skb = instance->current_skb;

	if (!(buf = instance->current_buffer)) {
		spin_lock_irq(&instance->send_lock);
		if (list_empty(&instance->spare_send_buffers)) {
			instance->current_buffer = NULL;
			spin_unlock_irq(&instance->send_lock);
			return;	/* done - no more buffers */
		}
		buf = list_entry(instance->spare_send_buffers.next,
			       struct udsl_send_buffer, list);
		list_del(&buf->list);
		spin_unlock_irq(&instance->send_lock);

		buf->free_start = buf->base;
		buf->free_cells = snd_buf_size;

		instance->current_buffer = buf;
	}

	num_written = udsl_write_cells(instance, buf->free_cells, skb, &buf->free_start);

	vdbg("udsl_process_send: wrote %u cells from skb 0x%p to buffer 0x%p",
	     num_written, skb, buf);

	if (!(buf->free_cells -= num_written)) {
		list_add_tail(&buf->list, &instance->filled_send_buffers);
		instance->current_buffer = NULL;
	}

	vdbg("udsl_process_send: buffer contains %d cells, %d left",
	     snd_buf_size - buf->free_cells, buf->free_cells);

	if (!UDSL_SKB(skb)->num_cells) {
		struct atm_vcc *vcc = UDSL_SKB(skb)->atm_data.vcc;

		udsl_pop(vcc, skb);
		instance->current_skb = NULL;

		atomic_inc(&vcc->stats->tx);
	}

	goto made_progress;
}

static void udsl_cancel_send(struct udsl_instance_data *instance,
			     struct atm_vcc *vcc)
{
	struct sk_buff *skb, *n;

	dbg("udsl_cancel_send entered");
	spin_lock_irq(&instance->sndqueue.lock);
	for (skb = instance->sndqueue.next, n = skb->next;
	     skb != (struct sk_buff *)&instance->sndqueue;
	     skb = n, n = skb->next)
		if (UDSL_SKB(skb)->atm_data.vcc == vcc) {
			dbg("udsl_cancel_send: popping skb 0x%p", skb);
			__skb_unlink(skb, &instance->sndqueue);
			udsl_pop(vcc, skb);
		}
	spin_unlock_irq(&instance->sndqueue.lock);

	tasklet_disable(&instance->send_tasklet);
	if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm_data.vcc == vcc)) {
		dbg("udsl_cancel_send: popping current skb (0x%p)", skb);
		instance->current_skb = NULL;
		udsl_pop(vcc, skb);
	}
	tasklet_enable(&instance->send_tasklet);
	dbg("udsl_cancel_send done");
}

static int udsl_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
{
	struct udsl_instance_data *instance = vcc->dev->dev_data;
	int err;

	vdbg("udsl_atm_send called (skb 0x%p, len %u)", skb, skb->len);

	if (!instance) {
		dbg("udsl_atm_send: NULL data!");
		err = -ENODEV;
		goto fail;
	}

	if (vcc->qos.aal != ATM_AAL5) {
		dbg("udsl_atm_send: unsupported ATM type %d!", vcc->qos.aal);
		err = -EINVAL;
		goto fail;
	}

	if (skb->len > ATM_MAX_AAL5_PDU) {
		dbg("udsl_atm_send: packet too long (%d vs %d)!", skb->len,
		    ATM_MAX_AAL5_PDU);
		err = -EINVAL;
		goto fail;
	}

	PACKETDEBUG(skb->data, skb->len);

	udsl_groom_skb(vcc, skb);
	skb_queue_tail(&instance->sndqueue, skb);
	tasklet_schedule(&instance->send_tasklet);

	return 0;

 fail:
	udsl_pop(vcc, skb);
	return err;
}

/********************
**  bean counting  **
********************/

static void udsl_destroy_instance(struct kref *kref)
{
	struct udsl_instance_data *instance =
	    container_of(kref, struct udsl_instance_data, refcount);

	tasklet_kill(&instance->receive_tasklet);
	tasklet_kill(&instance->send_tasklet);
	usb_put_dev(instance->usb_dev);
	kfree(instance);
}

void udsl_get_instance(struct udsl_instance_data *instance)
{
	kref_get(&instance->refcount);
}

void udsl_put_instance(struct udsl_instance_data *instance)
{
	kref_put(&instance->refcount, udsl_destroy_instance);
}

/**********
**  ATM  **
**********/

static void udsl_atm_dev_close(struct atm_dev *dev)
{
	struct udsl_instance_data *instance = dev->dev_data;

	dev->dev_data = NULL;
	udsl_put_instance(instance);
}

static int udsl_atm_proc_read(struct atm_dev *atm_dev, loff_t * pos, char *page)
{
	struct udsl_instance_data *instance = atm_dev->dev_data;
	int left = *pos;

	if (!instance) {
		dbg("udsl_atm_proc_read: NULL instance!");
		return -ENODEV;
	}

	if (!left--)
		return sprintf(page, "%s\n", instance->description);

	if (!left--)
		return sprintf(page, "MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
			       atm_dev->esi[0], atm_dev->esi[1],
			       atm_dev->esi[2], atm_dev->esi[3],
			       atm_dev->esi[4], atm_dev->esi[5]);

	if (!left--)
		return sprintf(page,
			       "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
			       atomic_read(&atm_dev->stats.aal5.tx),
			       atomic_read(&atm_dev->stats.aal5.tx_err),
			       atomic_read(&atm_dev->stats.aal5.rx),
			       atomic_read(&atm_dev->stats.aal5.rx_err),
			       atomic_read(&atm_dev->stats.aal5.rx_drop));

	if (!left--) {
		switch (atm_dev->signal) {
		case ATM_PHY_SIG_FOUND:
			sprintf(page, "Line up");
			break;
		case ATM_PHY_SIG_LOST:
			sprintf(page, "Line down");
			break;
		default:
			sprintf(page, "Line state unknown");
			break;
		}

		if (instance->usb_dev->state == USB_STATE_NOTATTACHED)
			strcat(page, ", disconnected\n");
		else {
			if (instance->status == UDSL_LOADED_FIRMWARE)
				strcat(page, ", firmware loaded\n");
			else if (instance->status == UDSL_LOADING_FIRMWARE)
				strcat(page, ", firmware loading\n");
			else
				strcat(page, ", no firmware\n");
		}

		return strlen(page);
	}

	return 0;
}

static int udsl_atm_open(struct atm_vcc *vcc)
{
	struct udsl_instance_data *instance = vcc->dev->dev_data;